5421 5425.output

* GB785829 (A)

Description: GB785829 (A) ? 1957-11-06

Improvements in or relating to machines for broadcasting seed, fertilizer

and other granular or powdered materials

Description of GB785829 (A)

COMPLETE SPECIFICATION

Improvements in or relating to Machines for Broadcasting Seed,

Fertilizer and other Granular or Powdered Materials

I, WILLIAM THOMAS TEAGLE, of Blackwater, Truro, Cornwall, a British

Subject, do hereby declare the invention, for which I pray that a

patent may be granted to me and the method by which it is to be

performed, to be particularly described in and by the following

statement :-

This invention relates to machines for broadcasting seed, fertilizer

and other granular or powdered materials, and has specific reference

to machines of the kind wherein the material is carried in a hopper

from which it is discharged through an outlet at the base of the

hopper onto a rotary distributor that rotates about a vertical or

substantially vertical axis and ejects the material onto the ground by

centrifugal force.

The object of the invention is to provide in a machine of the above

kind improved means for enabling the distribution of the material to

be confined to an arc of variable spread and direction, that is

direction in a radial sense relative to the distributor and for

varying the rate at which the material is discharged from the hopper

onto the distributor and therefore the rate or intensity of

distribution over a given arc. These adjustments are used to avoid

unevenness of distribution due to variations in the character of the

material being distributed, such as differences in weight or density,

and in the speed of the tractor or other vehicle by which the machine

is being towed or carried. For example, a tractor cannot travel so

quickly on ploughed land as on grassland, and if the rotary

distributor is driven from the power take-off of the tractor, as is

usually the case, this compulsory reduction in the speed'ofthe tractor

affects the operation of the distributor and therefore the

distribution of the material

Furthermore, different makes and types of tractor employ different

gear ratios in their transmission. systems and this again affects the

operation of the distributor and produces- different distribution

characteristics.

According to ifhe invention ; a machinfe of the

above kind is provided with means mounted !

at the base of the hopper above the rotary

distributor and having parts which co-operate

to form an'outlet for. the discharge of mater

ial from the hopper onto said distributor, the

outlet thus formed being offset from the axis of the distributor in a

plane substantially per-

pendicular to said axis, and shaped so as to

cause the distribution of the material to be confined to an arc, and

one of said parts being

ajustable to vary the dimension of said out-

let in a direction mu alter the spread of said arc of distribution,

and, the parts being

together angularly adjustable about the axis of

the distributor so as to vary the radial dis

position of the outlet in relation thereto and

. thereby alter the. direction of said arc of dis

tribution in relation to the machine.

Reference wiM now be made ? the accom-

panying drawings in which

Fig. 1 is a plan view of one embodiment of

. the invention,

Fig. 2 is a sectional elevation taken on the

line II-IL of, Fig. 1,

Fig. 3 is a fragmentary plan view of a moiti-

ficatioll of the embodiment shown in Figs. 1

and 2,

Fig. 4 is a similar view of another modifica

tion of this embodiment,

Fig 5. is a plan view of an alternative em

bodiment of the invention,

Fig. 5a is a plan view of one of the com

ponents of Fig. 5 shown separately, and

Fig. 6 is a sectional elevation taken on the

line VI-VI of Fig. 5.,

In the embodiment illustrated in Figs. 1

and 2 an annular plate 1 is welded to the base of the hopper, which is

shown fragmentarily . at 2, to form an external flan, thereon and

to provide a circular opening 3 in the bottom

of the hopper above the rotary distributor,

which is shown at 4. The distributor com prises a central hub 4a

formed with a pulley

4b to receive a belt drive, and a triangular plate 4c bolted to the

hub and carrying a number of ribs or vanes 4d on its upper surface.

In the embodiment of Figs. 1 and 2 the plate is formed with a central

conical portion 4e on its upper surface and a number of subsidiary

vanes 4t for guiding the material falling from the hopper in front of

the main vanes 4d to be ejected thereby onto-the ground. A plate 5,

which may be substantially rectangular in shape as shown in Fig. 1, is

clamped horizontally to the flange 1 by means of bolts 16 engaging

iirl arcuate slots 7 in the plate so that it can be adjusted angularly

about the axis of the distributor. The plate is made considerably,

larger th-an the flange so that it projects well beyond the edge

thereof. When the invention is appllled to a machine in which the

shaft of the distributor extends up into the hopper for some reason,

for example, to drive an agitator therein as described in my

application No. 31428/53 (Serial No. 747, 274) in which the

distributor has a hollow shaft rotatably mounted on a central post

which is adapted to support the hopper, the plate 5 is formed with a

central aperture 8 to fit round this shaft, vhich is shown at 9 in the

drawings. The supporting post is shown at 9a. On one side of the

plate there is mounted a sliding panel 10 which can be drawn back to

leave an elongated gap or slot 11 between the inner edge 12 of the

panel and the opposite edge 13 of the adjacent part of the plate. This

slot provides an outlet for the discharge of material from the hopper

onto the distributor.

The slot is offset from the axis of the dis. tributor and is arranged

in its elongation to extend across a sector of the circle described by

the distributor during its rotation. This causes the material to fall

onto the distributor in a manner such that it is ejected thereby over

an arc.

The rate at which the material is. discharged onto the distributor,

and. therefore the rate or intensity of distribution of said arc, is

varied by adjusting the panel inwardly or outwardly of the plate to

alter the width of the slot, as shown by the dot-dash line 121 in Fig.

1. The discharge can be cut off altogether by sliding the panel right

in to close the slot.

The edges 12. and 13 of the panel and the plate 5 can be straight to

form a straight slot, as shown in Fig. 1, or curved to form an arcuate

slot, preferably concentric with the axis of the distributor.

The panel can conveniently be formed by cutting a rectangular piece

out of the plate from the edge thereof to a point adjacent its centre

above the distributor and mounting this piece, which constitutes the

panel, for sliding movement in the space formed by cutting the piece

out of the plate. The panel, which is then ilush-wifh the plate can be

slidably supported. on pins 14 welded or otherwise nxed to the

underside of the plate so as to project horizontally beneath the side

edges of the panel. These side edges have sliding engagement with the

corresponding edges of the plate at the sides of the aforesaid space

in which the panel is mounted. The panel is held in this space by the

flange on the bottom of the hopper. To facilitate the adjustment of

the panel a hand lever 15 is provided. This lever, which can be fitted

with an extension 16, is mounted on the upper surface of the plate

externally of the hopper and is formed at one end with a slot 17 which

engages loosely over a pin 18 on the plate to allow pivotal movement

of the lever in a horizontal direction. A spring-loaded clamp 19 is

mounted on said piti to urge the lever into frictional engagement with

the upper surface of the plate and thereby assist in holding the lever

in the position to which it is adjusted. Intermediate its ends the

lever is pivotally connecte to the panel by a pin 20. An adjustable

abutment is provided for the lever to determine the adjustment of the

panel and thus the width of the slot. This abutment consists of'a

screwthreaded stem 21 mounted in a lug 22 on the edge of the plate and

arranged to ace as a stop for the lever in its outward movement, that

is, the movement which increases the width of the slot. The stem is

provided with a fingergrip 23 to facilitate its adjustment, and a

lock-nut 24 to secure it in the position to which it is adjusted.

The spread or length of the arc of distribution of the material is

varied by altering the length of the outlet provided by the slot. This

is achieved by means of a masking plate 25 adjustably mounted on the

plate 5 so as partially to cover the slot to a variable extent and

thereby determine the length of the outlet. The masking plate is of

circular form with a piece cut away to expose the slot, and is of

sufficient diameter for its masking portion 25a to extend right across

the slot when the latter is opened to its greatest width. It is

ajustable uver the slot from one end thereof and can be moved back to

a position (shown in full lines in Fig. 1) wherein it completely

uncovers the slot so that the entire length thereof is available for

the discharge of material onto the distributor. When the invention is

applied to a machine in which, as referred to earlier herein, the

shaft of the distributor extends up into the hopper, the masking plate

is apertured to fit freely round said shaft. The masking plate can.

then be angularly adjusted about the shaft so as partially to cover

the slot to the extent required. A number of positions of adjustment

can be determined for the masking plate by forming an arcuate series

of holes 26 in the main plate 5 for selective engagement by a pin 27

projecting downwardly from the undersurface of the masking plate. An

intermediate position of the masking plate is shown in dot-dash lines

in Fig. 1. The holes 26 are preferably slightly elongated ; o allow

the masking plate to be self-centering on the shaft of the

distributor. In the modification shown m Fig. 3. the masking plate

adjusted by means, of a bar 28 which is slidably and pivotally

attached to the underside of the main plate 5 by a bolt. 28iel

engaging in a slot 28b in the bar, and which is apertured to receive,

the pin 27 on the masking plate, the pin extending freely through an

arcuate slot 5a provided in the main plate to allow the necessary

angular adjustment of the masking plate. The latter is secured in its

position of adjustmen by tightening up the bolt 28a so as to leck the

bar 28.

An alternative form of masking plate is shown in Fig. 4. In. this

form. the masking plate designated by the numeral 316, is of narrow

elongated ; shape and is slidably attached to the underside of. the

main plate. 5 so as to be ajustable transversely thereof to cover the

slot

11 to the required extent. The masking plate is attached to the main

plate by a bolt 3 engaging in a slot 38 in the masking plate. The

latter is locli ed in its position of adjustment by tightening up this

bolt. If desired, two of these masking plates can be provided one at

each end of the slot.

In addition to enabling the spread of the arc of distribution to be

varied the adjustment of the length of the outlet can also be used to

maintain a constant arc of distribution, when required, in the

broadcasting of different materials whose varying characteristics,

such as differences in weight or density, might otherwise affect the

spread of the arc. For example, grass seed is considerably lighter

than granular fertilizer and would consequently be spread over a much

greater arc if discharged from the hopper onto the distributor through

the same length of outlet as the fertilizer. By means of the masking

plate 25, however, the length of the outlet can be made shorter for

the distribution of the grass'seed than for the distribution of the

fertilizer and thus the same spread can be obtained for both

materials.

The direction of the arc in, relation to the machine is varied by

adjusting the main plate 5 angularly about the axis of the distributor

so as to alter the radial disposition of the slot

11 in relation to said device. As the masking plate 25 and the sliding

panel 10 are carried by the main plate they move with it during this

adjustment. The adjustment is permitted by the arcuate slots 7 through

which pass the bolts 6 that secure the main plate to the hopper.

To enable the plate 5 to be mounted in position at the base of the

hopper without having to be passed over the end ; of the suppoing post

9a and the shaft 9 of the distributor, which would entail a curtain

amount of dismantling of the machine including the removal of the

distributor, the centra3 aperture 8 in the plate is extended into the

space in which the panel 10 is mounted so that by removing the panel

from said space the latter can be moved into position horizontally

between the distribujfor and base of the hopper. When the apparats is

assembled the masking plate 25 covers the extension of the aperture 8

as shown in Figs,. 1 and 2, and prevents any material falling through

it.

The alternative embodiment of. the inven'- tion illustrated in Figs.

5, 5a and 6 consists of two discs 2. 9 and 30 each formed with an

arcuate slot 29a and 30a respectively which can extend approximately

halfway round the respective disc and is concentric therewith.

The two discs are mounted together face to face over a circular

opening 3'1 in a plate 32 welded to the bottom of the hopper, the

discs and the opening being co-axial with the distributor'4. The discs

are clamped in position by a number of clips or lugs 33'which can be

released to free the discs for angular adjustment together or

independently of one another about the axis of the distributor. When

the discs are applied to a machine in which, as referred to earlier

herein, the shaft of the distributor extends up into the hopper, they

are each formed with a central aperture 29b and ; 30b respectively to

fit round said shaft. In order to enable the discs to be mounted in

position over the opening 31 without having to be passed over the end

of the shaft of the distributor, which would entail a certain amount

of dismantling of the machine, the central aperture in, each disc is

extended into the slot therein, as shown at 29c and 30c on

Figs. 5, and 5a, and the strip of plate between the slot and the outer

edge of the disc is sheared at a point opposite the extension of the

aperture as shown at 29d and 30d. By twisting each disc at this point

the sheared edges can be separated sufficiently to be passed over and

around the shaft of the distributor and so enable the central aperture

in the disc to be brought into engagement with said shaft.

The discs are mounted with one reversed relative to the other so that

the extension of the central aperture in each disc is covered by a

portion of the other disc, and the configuraition, of each aperture

and its extension is such that when the discs are arranged in their

mutually reverse positions the two apertures together form a circular

; opening through which the shaft of the distributor freely passes.

In use the discs are angularly adjusted one relative to the other so

that the two slots register or coincide with one another no provide an

arcuate outlet (indicated by the arrowed line A in Fig. 5) for the

discharge of material from the hopper onto the distributor.

As the outlet thus formed is of elongated shape and, being arcuate and

concentric with the distributor, extends across a sector of wu circule

described by said device during its rotation, the material is caused

by the outlet tu-fan onto the distributor in a manner such that it is

ejected thereby over an arc. The spread or length of this arc is

varied by adjusting one of the discs relative to the other so as to

vary the amount of coincidence between the two slots in the discs,

that is to say, the extent to which the slots overlap one another, or

to which the slot in one disc is masked by the other disc. This varies

the length'of the outlet provided by the slots. As with die embodiment

of the invention described earlier herein, the adjustment of the

length of the outlet can be used to maintain a constant arc of

distribution, in the broadcasting of different materials having

varying characteristics which might otherwise affect the spread of the

arc.

By adjusting the two plates together about their axis, the radial

disposition of the outlet in relation to the distributor can be varied

to alter the direction of the arc of distribution in relation to the

machine.

In this embodiment of the invention the rate of distribution of the

material is controlled by a disc 34 arranged below the opening 31 in

the base of the hopper and co-axially therewith, and which is movable

axially towards or away from said opening. The adjustment of the

spacing of the disc from the opening controls the rate at which the

material is discharged from the hopper onto the distributor through a

given : length of outlet and therefore the rate or intensity of

distribution over a given arc. The disc is engageable with an

annular seating 35 round the opening 31 in order to close the latter

and thereby cut off the discharge of material from the hopper.

The axial movement of the disc 34 can, be effected in a manner similar

to that of the conical valve member featured in my aforesaid

application No. 31428/53 (Serial No.

; 747, 2 : 74), namely through the distributor. The disc is arranged

to rest on the hub of the distributor, the hub being extended above

the top of the vanes 4d (as shown in Fig. 6)'for this purpose, and is

moved, towards or away from the opening 31 by raising or lowering the

distributor by means of a control member (not shown) such as that

described in the speciefication of my applica, tion No. 3142L8/53

(Serial No.. T'4'7, 274), the shaft 9 of the distributor being

slidable on the supporting post 9a to allow this. The disc is

centrally apertured to fit freely round the shaft 9 so that the latter

acts as a guide for the disc in its vertical movement. On its

underside the disc is formed with a pin 34a which projects downwardly

for engagement by one of the vanes of the distributor so that the

disc rotates with the distributor whilst having a limited freedom of

angular movement relative thereto. When the disc is raised into

engagement with. the annular seating 35 by. the distributor, the

turning movement of the disc in combination with its limited freedom

of movement relative to the shaft 9 and the distributor ensures that

it is tightly shut against the seating and in accurate align- ment

therewith.

What we claim is :

1. A machine of the kind referred to, wherein. there are provided

means mounted at the base of the hopper above the rotary distributor

and having parts which co-operate to form an outlet for the discharge

of material from the hopper onto said distributor, the outlet thus

formed being offset from the axis of , the distributor in a plane

substantially perpen- dicular to said. axis, and shaped so as to cause

the distribution of the material to be confine to an arc, and one of

said parts being adjustable to vary the dimension of said outlet in a

direction to alter. the spread of said arc of distribution, and the

parts being together angularly ajustable about the axis of the

distributor so as to vary the radial disposition of the outlet in

relation thereto and. thereby alter the direction of said arc of

distribution in relation to the machine.

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* GB785830 (A)

Description: GB785830 (A) ? 1957-11-06

Improvements in or relating to agricultural machines


COMPLETE SPECIFICATION.

Improvements m or relating to Agricultural Machines.

I, WILLIAM THOMAS TEAGLE, a British

Subject, of Blackwater, Truro, Cornwall, do hereby declare the

invention, for which I pray that a patent may be granted to me, and

the method by which it is to be performed, to be particularly

described in and by the following statement :-

This invention relates to agricultural machines of the kind which is

adapted to be carried on an hydraulic lift on a tractor and be movable

vertically thereby between inoperative and operative positions, and

which embodies a rotary device that is adapted to be driven by a power

take-off shaft on the tractor through a belt and pulley transmission

system. Included in machines of this kind are broadcasters in which a

rotary device is used for distributing seed, fertiliser or other

granula or powdered materials onto the ground, weed-cutting and like

machines in which a rotary cutting tool is employed, and spraying

machines.

The invention is particularly applicable to a broadcasting machine of

the above kind, which is adapted to be raised by the hydraulic lift of

a tractor from a loading position into a operating position, and which

has a belt and pulley system for transmitting drive from the tractor's

power take-off shaft to the rotary distributor of the machine.

The object of the present invention is to provide, in a machine of the

above character, an improved belt and pulley transmission system

having means whereby the drive to the rotary device of machine is

automatically disconnected when the machine is moved by the

hydraulic lift into its inoperative position, and automatically

reconnected when the machine is moved into its operative position.

According to the invention, in a machine of the kind referred to which

is adapted to be carried on an hydraulic lift on a tractor and be

moved vertically thereby between inoperative and operative positions,

and which has a belt and pulley system for transmitting drive from a

power take-off shaft on the tractor to a rotary device on the machine,

the belt and pulley system includes a driven pulley fast with said

rotary device, a belt passing round said driven pulley, and a pair of

resiliently mounted idler pulleys for guiding the belt round a driving

pulley on the power talce-off shaft, and means are provided which are

adapted to co-operate with said idler pulleys so as to form a bight in

the belt for engagement with said driving pulley when the machine is

moved into its operative position, and for causing the disengagement

of the belt from said driving pulley when the machine is moved into

its inoperative position.

Reference will now be made to the accompanying drawings which

illustrate a preferred embodiment of the invention as applied to a

broadcasting machine, and in which :-

Fig. 1 is a side view of the machine in its operative position ;

Fig. 2 is an enlarged fragmentary plan view taken on the line II-II of

Fig. ;

Fig. 3 is an enlarged fragmentary side view of the machine in its

operative position ; and

Fig. 4 is a view similar to Fig. 3, showing the machine resting on the

ground in its inoperative or loading position.

In the construction illustrated the machine has a frame on which a

hopper 1 is supported and which comprises two vertical legs 2 arranged

at the front of the hopper and to the sides thereof, and a pair of

arms 3 extending from the legs to the rear of the hopper. The legs are

adapted to be attached to the forked arms 4 of the hydraulic lift on

the rear of a tractor and are arranged to support the machine on the

ground when it is lowered by the hydraulic lift into its inoperative

or loading position, as shown in Fig. 4. For their attachment to the

arms 4 the legs 2 are each formed with a vertical series of holes 5 to

receive the horizontal pins, shown at 6, which are usually provided on

the forked arms of an hydraulic lift. The provision of a series of

holes permits vertically adjustment of the operative position of the

machine in relation to the tractor. At the base of the hopper there is

provided a controlled outlet (not shown) for the discharge of material

from the hopper onto a rotary distributor 7 which is situated

immediately below the outlet. The latter can be controlled by means

constructed in accordance with the invention which forms the subject

of my co-pending cognate Patent

Applications Nos. 1944/55 and 30517/55 (Serial No 785,829). The

distributor 7, which can be of any convenient form, is adapted to

rotate about a vertical spindle 8 mounted on the rear end of a bar 9

which extends longitudinally of the machine and is rigidly suspended

by a short vertical support 10 from a transverse frame member 11

joining the two legs 2. The support 10 can comprise a pair of parallel

bars 12 welded at their lower ends to the bar 9 and joined at their

upper ends by a transverse plate 13 which is adapted to be bolted to

the transverse frame member 11. The spindle 8 is fixed to the

longitudinal bar 9 by a pair of bolts 14 extending through a

longitudinal slot 15 in the bar and engaging in a flange 16 welded on

the lower end of the spindle.

The rotary distributor is driven by the power take-off shaft 17 of the

tractor through a belt and pulley transmission system which includes a

belt 18, pulley 19 on the distributor, and a pair of idler pulleys 20

carried on a swinging-arm assembly 21 at the forward end of the bar 9.

The idler pulleys are rotatably mounted one at each end of an axle 22

extending transversely of the machine and carried on an arm 23 which

is pivoted for angular movement in a vertical and longitudinal plane

on the forward end of a second arm 24 that extends longitudinally of

the machine beneath the bar 9 and is pivotally attached thereto at its

rear end, also for movement in a vertical plane. The second arm 24 and

the bar 9 are preferably of inverted channel section, the arm nesting

within the bar 9 so as to be guided by the side pieces thereof in its

pivotal movement and prevented from any lateral displacement.

The forward end of the arm 24 projectes beyond the forward end cf the

bar to provide clearance for the first arm 23 of the sving- ing-arm

assembly. The arm 24 is attached to the bar 9 by a bolt 25 which

engages in the slot 15 in the bar and which, together with a spacing

sleeve 25a mounted on the bolt so as to abut the undersurface of the

bar, extends freely through a hole 26 in the arm 24, the hole being

large enough to allow the necessary pivotal movement of the arm.

The swinging-arm assembly can be adjusted longitudinally ouf the

machine by loosening the bolt 25 and sliding it along the slot 15. A

coil spring 27 is provided on the bolt 25 to hold the rear end of the

arm 24 firmly against the bar 15. Intermediate its ends the arm is

pressed upwardly against the bar by a pair of coil springs 28 mounted

on bolts 29 which also engage in the slot 15 and which extend with

clearance through holes 30 in the arm. A single spring can be used in

place of the two springs 28. As will be described later herein, these

springs act to tension the driving belt 18.

The driving belt engages round the rear side of the pulley 19 on the

distributor and its two runs extend forwardly therefrom to pass one

over each or the idler pulleys 20.

Mounted above the idler pulleys is a clamping device 31 towards which

the pulleys are urged by a torsion spring 32 acting on the first arm

23 of the swinging-arm assembly to bias it relatively to the second

arm 24 in an upward and rearward direction. When the machine is

resting on the ground in its inoperative position, as shown in Fig. 4,

the pulleys are urged into engagement with said device and the two

runs of the belt are clamped between it and the idler pulleys so as to

be formed into a stiff bight projecting downwardly and forwardly from

the idler pulleys, as shown at 33 in Fig. 4. The camping device is

conveniently constructed from a short lent'lu of angle iron extending

transversely of the machine with the angle uppermost so that the

pulleys are received between the sides of the angle and clamp the belt

against the inner surfaces thereof.

The camping device is carried on a slotted arm 34 which is adjustably

secured by a bolt 35 to another slotted arm 36 welded on the forward

end of the arm 24 of the swinging-arm assembly. The arrangement of the

slotted arms enables the camping device to be adjusted vertically and

longitudinally of the machine.

The bight thus formed in the belt is held by its inherent stiffness in

a position such that when the machine is raised by the hydraulic lift

towards its operative position the bight engages beneath a driving

pulley 37 which is provided on the power take-off shaft of the

tractor. This shaft projects longitudinally from the rear of the

tractor.

Due to the engagement of the bent with the driving pulley, the idler

pulleys are held back while the remainder of the machine continues to

rise. As a result of this the belt-clamping device 31 is moved away

from the idler pulleys so as to release the belt for operative

movement by the driving pulley, and the two arms 23 and 24 of the

swinging-arm assembly are straightened out, somewhat in the manner of

a toggle joint, so as to produce a forward movement of the idler

pulleys which brings them to a position above the driving pulley such

that the belt leads vertically to and from this pulley as shown in

Fig. 3. When the arms 23 and 24 are straightened out, or nearly so, an

abutment 38 which is adjustably secured to a bracket 39 welded on the

forward end of the arm 24 engages the arm 23, so that during the final

stage of the machine's movement into its operative position the two

arms are together held down by the driving belt against the pressure

of the coil springs 28 acting on the arm 24. The longitudinal bar to

which the arm 24 is pivotally at ached is thus moved on away from said

arm to leave the idler pulleys free to tension the belt under the

upward pressure of the springs 28 acting through the two arms 23 and

24. In this tensioning action the swinging-arm assembly pivots about

the point of contact of the rear end of arm 24 with the bar 9. The

tension on the driving belt can be varied by altering the compression

on the springs 28 ; by adjusting the abutment 38 vertically on the

bracket 39; or by vertical adjustment of the operative position of the

machine relative to the power take-off shaft, which is done by

selecting a different pair of the holes 5 for engagement with the pins

6 on the arms of the hydraulic lift.

When the machine is lowered to its inoperative position the above

operations are reverse and automatically cause the disengagement of

the belt from the driving pulley on the power take-off shaft. The

rearward movement imparted to the idler pulleys during the lowering of

the machine carries them well clear of the driving pulley so that

there is no danger of them fouling it.

The position of the idler pulleys in relation to the driving pulley

when the machine is in its operative position is determined by the

longitudinal adjustment of the swinging- arm assembly 21. This

adjustment is used to ensure that the driving belt has a good lead to

and from the driving pulley.

The swinging-arm assembly 21, including the belt-clamping device 31,

can be readily applied to a machine for cutting weeds, grass, or like

vegetable ground growth, in which a rotary cutter is supported by a

frame for rotation about a vertical axis, the machine being carried on

the hydraulic lift of a tractor and being movable vertically thereby

between an inoperative position, in which it is clear of the ground,

and a cutting position adjacent the ground. In such application the

swing-arm assembly is inverted from the position shown in the drawings

and is supported on top of a fixed member, which can be the bar 9

similarly inverted. This arrangement operates in a manner similar to

that described above, except that the directions of the various

vertical movements in the different stages of the operation are

reversed. Thus, when the cutting machine is in its inoperative

position, a bight is formed in the belt for engagement with the top of

the driving pulley as the machine is lowered by the hydraulic lift

into its operative cutting position. When the machine is raised back

into its inoperative position the bight is again formed so that the

belt is disengaged from the driving pulley.

What I claim is :-

1. A machine of the kind referred to whicli is adapted to be carried

on an hydraulic lift on a tractor and be moved vertically thereby

between inoperative and operative positions, and which has a belt and

pulley system for transmitting drive from a power take-off on the

tractor to a rotary device on the machine, wherein the belt and pulley

system includes a driven pulley fast with said rotary device, a belt

passing round said driven pulley, and a pair of resiliently mounted

idler pulleys for guiding the belt round a driving pulley on the power

take-off shaft, and wherein means are provided which are adapted to

co-operate with said idler pulleys so as to form a bight in the belt

for engagement with said driving pulley when the machine is moved into

its operative position, and for causing the disengagement of the belt

from said driving pulley when the machine is moved into its

inoperative position.

2. A machine of the kind referred to which is adapted to be carried on

an hydraulic lift on a tractor and to be raised thereby into an

operative position and lowered thereby into an inoperative position,

and which has a rotary distributor and a belt and pulley system for

transmitting drive from a power take-off shaft on the tractor to a

rotary device on the machine, wherein the belt and pulley system

includes a driven pulley fast with said rotary device, a belt passing

round said driven pulley, and a pair of resiliently mounted idler

pulleys for guiding the belt round a driving pulley on the power

take-off shaft, and wherein means are provided which are adapted to

cooperate with said idler pulleys to form a bight in the belt for

engagement with said driving pulley when the machine is raised into

its operative position, and for causing the disengagement of the belt

from said driving pulley when the machine is lowered into its

inoperative position.

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* 5.8.23.4; 93p

* GB785831 (A)

Description: GB785831 (A) ? 1957-11-06

Profile grinding machine


PATENT SPECIFICATION

785,831 Date of Application and filing Complete Specification: January

26, 1955.

Application made in Switzerland on February 5, 1954 Complete

Specification Published: November 6, 1957

Index at acceptance:-Class 60, D 1 D( 3 X:4 X), D 2 A( 4:5:8:20).

International Classification:-B 24 b.


Profile Grinding Machine We, DIAMETAL A G, a limited company duly

organised under the law of Switzerland, of Gurzelenstrasse 3, Biel

Switzerland, do hereby declare the invention, for which we pray that a

patent may be granted to us, and the method by which it is to be


statement:-

The present invention relates to improvements in profile grinding

machines comprising a work holder and a tracer which is guidable along

a former plate, as described in the complete specification of our

copending application for letters Patent No 2275/55 (Serial No

785832), and the profile grinding machine as disclosed herein is

characterized by the provision of a control plate which is movable on

the stationary machine frame and to whch are secured 2 Q said former

plate and work holder.

The main objects of the present invention are to provide an

arrangement which permits to grind a prescribed profile very

accurately by relatively simple means, to make the overall height of

the machine small, and to keep the space above the grinding disc free

to permit, for example, of readily mounting an optical control means.

These and related objects are attained by the machine shown, in one

form of invention and by way of example, in the accompanying drawings,

in which:

Fig 1 is a top plan view, Fig 2 is a section through the upper machine

portion on the line II-II of Fig.

1, the parallel guiding means having been omitted, Fig 3 is a front

elevation on a smaller scale, Fig 4 is a side view also on a smaller

scale, Ftg 5 shows a top plan view of a twin pantograph, Fig 6 shows a

section on the line VI-VI lPrice 3 s 6 d l of Fig 5 on a larger scale,

Fig 7 is a top plan view of the work, and Fig 8 is a sideview, partly

in section, of the work 5 G The machine frame consists of a body 1

which at the same time serves as a column, and a cylindrical head 2

which is disposed laterally and slightly offset forwardly of the body

Within said frame, motor 4, suspen 55 ded from a horizontal shaft 3,

is adapted to impart drive to a grooved pulley 6 via a reduction gear

5 At the level of this suspended assembly, the body 1 is closed by a

removable cover la Reduction gear 5 is 60 of the continuously variable

speed type, and the degree of reduction may be adjusted by a handwheel

7 acting through belt 8 and a pulley 9 The rotation of pulley 6

transfers drive through a belt 10 to a fur 65 ther grooved pulley 11

which is journalled upon an arm 12 The pulley 11 is fast upon one end

of a spindle which extends through and is rotatable in the said arm,

and a crank 13 which is coupled to a connecting 7 G rod 14, is secured

upon the opposite spindle end The arm 12 is incorporated and forms a

part of a portion of the machine which is rotatable about stationary

centering pins and 16 and is journalled within and 75 relatively to

the frame about a main vertical axis by bearing members 17 and 18

located in the said main axis The said rotatable machine portion also

includes a U-shaped yoke 19 in one leg 19 a of which 80 the bearing

member 18 for the centreing pin 16 is accommodated The centreing pin

which is engaged by the bearing member 17 is secured in an arm 2 a

integral with head 2 whereas the said bearing member 85 17 is carried

within an ear which is integral with the arm 12.

The web 20 of the U-shaped yoke is formed in its outer face with

vertical Vways with which a vertical slide 21 engages 90 No 2274155 j

785,831 and along which the said slide is adapted to be reciprocated A

downwards extension 22 from the slide is formed with an elongated hole

23 through which a pin 24.

mounted in the connecting rod 14, projects, so that the latter and

thus slide 21 are vertically reciprocated by motor 4 The head of the

slide 21 is formed with horizontal V-ways with which a horizontal

slide 26 makes sliding engagement and is adapted for adjustment

lengthwise of the said ways by a screw 25 a The slide 26 has a head 27

and horizontal V-ways 28 which are located at right angles to the

V-ways in the head 25 are formed in the side of the head adjacent to

the main axis of the machine along which a tool holder 29 is

adjustable by a screw 30, said holder being also movable horizontally,

but at right angles to slide 26 Screws 30 a serve for clamping the

tool holder in its adjusted setting within the V-ways 28 In tool

holder 29 is rotatably mounted a spindle 31 which carries a grinding

disc 32 at the end adjacent the main axis, and a grooved pulley 33 at

the other end Grinding disc 32 may thus be moved in the horizontal

plane into any desired position by slide 26 and tool holder 29, and

vertically by slide 21, connecting rod 14 and eccenritc 13 In the

operating position, the grinding disc is set so that its vertical

tangent which is remote from tool holder 29, i e to the left in Fig 2,

coincides with the machine main axis, and the corresponding tangential

point is the point of contact (working point) with the work.

Thus, the machine portion which is rotatable about the main axis,

essentially comprises the arm 12, yoke 19, the bearing members 17 and

18, the tool holder 29; the means for producing and transferring the

vertical reciprocation to the tool holder, namely the grooved pulley

11, crank 13, connecting rod 14, slides 21 and 26, and grinding disc

32.

A second motor 35 is secured to a platform 34 of body 1, and a grooved

pulley 36 fast upon the motor shaft transfers the rotary movement of

the motor via a belt 37 on to a second grooved pulley 38 The latter

and a further grooved pulley 39 arc fixed to an axle 40 which is

rotatably mounted in a bearing 41 of body 1 A fur.

ther bearing member 42 is rotatable upon shaft 40 and comprises two

symmetrical arms 43 at the ends of which are journalled axles 44 at

right angles thereto, and each axle 44 again carries at its ends two

pulleys 45, 46 and 47, 48, respectively An endless belt 135 is trained

from pulley 39 over pulleys 46, 48, thence through an aperture of a

cover 49, over the driving pulley 33 of grinding disc 32, through said

aperture.

over pulleys 47 and 45 and back to pulley 39 Such arrangement ensures

operation of grinding disc 32 even when the latter, due to its

incorporation in the rotatable machine portion, is swung about the

machine main axis 70 The crown of the frame conssts of a fixed plate

50 of which an arm 50 a carries the centreing pin 16 A control plate

51 is set freely slidable on plate 50, and its relative sliding

movements are limited by its 75 edges 52 and 53 abutting respectively

against corresponding shoulders 54 and 55 of plate 50 On control plate

51 is provided a first V-way 56 (Figure 3) in which a slide 57 is

mounted movable by a screw 58 80 Slide 57 comprises a lug 59 on the

vertical outside face of which is provided a further V-way 60 in which

a slide 62 is mounted movable by a screw 61, said slide 62 being

movable at right angles to slide 57 Slide 85 62 carries a bracket 63

to which is secured a former-plate table 65 by means of a screw 64

Table 65 is provided with two grooves 66 (Fig 1) in which is secured a

former plate 68 by means of screws 67 9 g Opposite former-plate

profile 68 a is disposed a tracer 69 which is retained in d V-way 70

in vertically movable relation, the corresponding clamping screw being

designated by 71 The V-way 70 is pro g 5 vided with an extension 72

which points towards former plate 68 and is fixed to a lever 73 to

which, at 74 and 75, are pivoted two arms 76, 77 of a parallel guiding

means The latter further comprises, in con 100 ventional manner, rings

78 and 79 and further arms 80 to 83 The connection and disposition of

said rings and arms corresponds to the conventional arrangement of a

parallel guiding means The last arms 82 105 and 83 of the latter are

pivoted, at 84 and 85, to a plate 86 which is incorporated in and

forms the upper leg of the U-shaped yoke 19 Any and each rotary

movement of tracer 69 thus is transmitted, via the 110 lever 73 and

the parallel guiding means 76 to 83, on to the yoke 19 and, therefore,

on to the grinding disc 32 as a consequence of the rotatable portion

of the machine turning about the main axis Translatory move 115 ments

of the tracer, i e movements which do not provoke any angular movement

of ring 78, do not bias the movable machine portion, as far as the

transmission on to the parallel guiding means is concerned 120 The

arms 80 and 81 of the latter are interconnected by a strap 87 of which

the ends are pivoted to said arms at 88 and 89.

To strap 87 is rotatably secured a vertical pin 90 to the free end of

which are 125 pivoted two rollers 91 which run in a groove 92 of a

rail 93 The latter is connected to control plate 51 via a pedestal 94

and screws 95 The parallel guiding means thus is supported through

said 130 785,831 rollers on the control plate 51, without impairing

the mobility thereof.

To V-way 70 of tracer 69 is pivoted the long arm 96 of a first

individual panto.

graph which comprises, in a conventional manner, said long arm 96 and

other arms 97 to 99 which are interconnected in pivotable relation Leg

99 at 100 is rotatably mounted in a bearing 101 of control plate -0

51, whilst leg 98 is pivoted to the long arm 102 of a second

individual pantograph.

Bearing 101 is secured to control plate 51 by screws 101 a, elongated

holes 101 b being provided in the control plate so that the J 5

bearing and, thus, the point of articulation of pantograph 96 to 99 is

movable on the control plate relatively thereto and may oe

screw-locked thereto again Said second pantograph is fundamentally

constructed :20 similar to the first and comprises, besides leg 102,

two parallel legs 103, 104 and a leg 105 which is parallel to long leg

10 ?.

The two hingeably interconnected pantographs 96 to 99 and 102 to 105

together :25 form a twin pantograph Each of the legs 104, 105 (Fig 5)

has a slot 104 a and 105 a respectively, and in each of these slots is

movably mounted a sliding block 106 and 107 respectively The latter

may be fixed in their positions by screws 108 and 109 ac.

cording to the desired reduction ratio Each of the blocks 106, 107

comprises an underplate 110 which is secured in its position by screws

111, the edge of said plate securing the pivot pin 112 and 113

respectively The two pins 112, 113 stand at right angles to the plane

of the pantograph, pin 112 which is fixed to leg 105, pointing

upwardly and pin 113 which is fixed to leg -40 104, pointing

downwardly Pin 113 is rotatably held in an eye 114 of an arm 115 which

is secured to control plate 51 by means of screws 116 Pin 112 forms

the fixed point of the pantograph, is situated in the machine main

axis and is journalled in leg 19 b of the yoke 19 which as already

explained, belongs to the rotatable machine portion.

From the foregoing may be seen that -50 each single pantograph at one

point ( 100 and 113 respectively) is rotatably connectedto the control

plate 51, whilst the twin pantograph has a fixed point ( 112) situated

in the machine main axis.

Control plate 51 further comprises a bracket 118 (Fig 3) to the upper

side of which is attached a plate 119 On the latter is secured by

screws 120 a carriage 121 with respect to which the work slide 122 is

movable, at right angles to slide 57, so far laterally as is permitted

by a slot 123 of the work slide, said slot being traversed by a screw

124 for attachment to the carriage A guide pin 123 a serves for

rectilinearly guiding such displacing movement In work slide 122 is

mounted a work spindle 125 which is rotatable by meansj of a handwheel

126 The work 128 is clamped to spindle 125 by means of a screw 127 For

the sake of clarity, the 70 work slide in Fig 3 has been moved to the

right so that the work becomes visible next to grinding disc 32,

whereas in reality the latter and the work are situated in the same

vertical plane The work spindle 125 75 carries an indexing wheel 129

which coacts with two pawls 130 of which only the upper one is visible

in the drawing These pawls are pivoted at 131 (Fig 1) and are

disengageable from index wheel 129 by 80 means of a lever 132.

On the control plate 51 is provided a guide means 133 on which may be

mounted an optical control device 134 of known construction and which

is schematically 85 shown in Figs 3 and 4.

To perform a grinding operation in the machine after the work 128 has

been mounted upon the spindle 125 in the plane of the rotating and

vertically reciprocating 9 o grinding disc 32, and the former plate 68

has been clamped upon the control plate 51, the tracer is moved

linearly towards the former plate so as to take the work into contact

with the disc 95 The work is taken into contact with the disc because

the said movement of the tracer imparts a corresponding movement to

that end of the longer arm 96 of the first individual pantograph on

which the tracer 100 O is pivoted, thereby tending to impart a similar

movement to the said arm; since the arm is pivoted to the pantograph

arms 97, 99 which are also pivoted upon the control plate at 100 the

said longer arm 105 and the arm 98 are constrained to make combined

linear and swinging movements.

The combined movement of the arm 98 displaces the longer arm 102 of

the second individual pantograph in a manner which 110 tends to swing

the arm 104 of the second pantograph about the pivot pin 113 and

impart a combined longitudinal and swinging movement to the arm 105;

however since the arm 105 is pivoted about the pin 115 112 which is

held in the main axis of the machine, the said arm is prevented from

making any longitudinal movement with the result that the pivot pin

113 is moved and, since the pin is mounted on the con 120 trol plate,

the said plate is moved carrying with it the pivot 100 The arrangement

of the two individual pantographs is such that the movement imparted

therethrough from the tracer to the control plate causes the 125 plate

(and therefore the work) to move in the opposite direction to, but

through a smaller distance than, the tracer, the relative distances of

travel being determined by the location of the blocks 106 and 107 130

a' lengthwise of their respective slots 104 a and 105 a.

Having taken the work into contact with the periphery of the grinding

disc, the tracer is moved laterally relative to the former plate

whereupon the control plate and work are again displaced by the

pantographs in the opposite direction to, but through a smaller

distance than, the tracer so that the work is traversed across and in

contact with the disc periphery and is ground away until the tracer

comes into abutment with the profile 68 a of the former plate.

In the event that, in making each traversing movement across the

profile, the tracer is swung about its pivoted connection to the

longer arm 96 of the first individual pantograph, the lever 73, which

is fixed to the tracer, is swung in the same direction and through the

same angle so as to actuate the parallel guiding means 74 and 83

whereby the grinding disc is swung through an identical angle about

the main axis of the machine.

Since linear movements of the tracer into contact with and across the

profile 68 a are translated, on a reduced scale, to the work via the

twin panto-graphs and the control 3 Q plate, and angular movements of

the said tracer are translated to the grinding disc via the parallel

grinding means, the profile imparted to the work is identical but on a

reduced scale relatively to the profile of the former plate.

The progress of the grinding operation may be followed visually by the

operator of the machine since an enlarged image of the profile

imparted to the work is projected on to a screen of the optical device

134; consequently the carrying out of the grinding operation is

facilitated.

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* GB785832 (A)

Description: GB785832 (A) ? 1957-11-06

Profile grinding machine



Date of Application and filing Complete Specification: January 26,

1955.

Application made in Switzerland on February 5, 1954 Complete

Specification Published: November 6, 1957

Index at acceptance:-Class 60, D 1 D( 3 D:4 X), D 2 A( 4:5:8:20).

International Classification:-B 24 b.


Profile Grnding Machine We, DIAMETAL A G, a limited company duly

organised under the Law of Switzerland, of Gurzelenstrasse 3, Biel,

Switzerland, do hereby declare the invention, for which we pray that a

patent may be granted to us, and the method by which it is to be


statement:-

The present invention relates to improvements in profile grinding

machines comprising a work holder and a tracer which is guidable along

a former plate, and the profile grinding machine as disclosed herein

is characterized by the provision of a control plate which is movable

on the stationary machine frame and to which are secured said former

plate and work holder, as described in our co-pending application for

letters patent No 2274/55 (Serial No.

785,831).

The main objects of the present invention are to provide an

arrangement which permits to grind a prescribed profile very

accurately by relatively simple means, to make the overall height of

the machine small, and to keep the space above the grinding disc free

to permit, for example, of readily mounting an optical control means.

Those and related objects are attained by the machine shown, in one

form of invention and by way of example, in the accompanying drawings,

in which:

Fig 1 is a top plan view, Fig 2 is a section through the upper machine

portion on the line II-II of Fig 1.

the parallel guiding means having been omitted, Fig 3 is a front

elevation on a smaller scale, Fig 4 is a side view also on a smaller

scale, Fig 5 shows a top plan view of a twin pantograph, Fig 6 shows a

section on the line VI-VI of Fig 5 on a larger scale, Fig 7 is a top

plan view of the work, and lPrice 3 s 6 d I Fig 8 is a side view,

partly in section, of the work.

The machine frame consists of a body 1 which at the-same time serves

as a column, and a cylindrical head 2 which is disposed 5 (X}

laterally and slightly offset forwardly of the body Within said frame,

a motor 4, suspended from a horizontal shaft 3, is adapted to impart

drive to a grooved pulley 6, via a reduction gear 5, at the level of

this sus 55 pended assembly the body 1 is closed by a removable cover

la Reduction gear 5 is of the continuously variable speed type, and

the degree of reduction may be adjusted by a handwheel 7 acting

through a belt 8 and 60 a pulley 9 The rotation of pulley 6 transfers

drive through a belt 10 to a further grooved pulley 11 which is

journalled upon an arm 12 The pulley 11 is fast upon one end of a

spindle which extends through and 65 is rotatable in the said arm, and

a crank 13 which is coupled to a connecting rod 14, is secured upon

the opposite spindle end The arm 12 is incorporated in and forms a

part of a portion of the machine which is rotat 70 able about

stationary centreing pins 15 and 16 and is journalled within and

relatively to the frame about a main vertical axis by bearing members

17 and 18 located in the said main axis The said rotatable machine 75

portion also includes a U-shaped yoke 19 in one leg 19 a of which the

bearing member 18 for the centreing pin 16 is accommodated.

The centreing pin which is engaged by the bearing member 17, is

secured in an arm 2 a 89 integral with head 2 Whereas the said bearing

member 17 is carried within an ear which is integral with the arm 12.

The web 20 of the U-shaped yoke is formed in its outer face with

vertical V-ways 85 with which a vertical slide 21 engages and along

which the said slide is adapted to be reciprocated A downwards

extension 22 from the slide is formed with an elongated hole 23

through which a pin 24, mounted 90 785,832 No 2275/55 785,832 in the

connecting rod 14, projects so that the latter and thus slide 21 are

vertically reciprocated by motor 4 The head 25 of slide 21 is formed

with horizontal V-ways with which a horizontal slide 26 makes sliding

engagement and is adapted for adjustment lengthwise of the said ways

by a screw a The slide 26 has a head 27 and horizontal V-ways 28 which

are located at right angles to the V-ways in the head 25 are formed in

the side of the head adjacent to the main axis of the machine, along

which a tool holder 29 is adjustable by a screw 30, said holder being

also movable horizontally, J 5 but at right angles to slide 26 Screws

30 a serve for clamping the tool holder in its adjusted setting within

the V-ways 28 In tool holder 29 is rotatably mounted a spindle 31

which carries a grinding disc 32 at the end adjacent the main axis,

and a grooved roller 33 at the other end Grinding disc 32 thus may be

moved in the horizontal plane into any desired position by slide 26

and tool holder 29, and verticaly by slide 21, connecting rod 14 and

eccentric 13 In the operating position, the grinding disc is set so

that its vertical tangent which is remote from tool holder 29, i e to

the left in Fig.

2, coincides with the machine main axis, and the corresponding

tangential point is the point of contact (working point) with the

work.

Thus, the movable machine portion which is rotatable about the main

axis, essentially comprises the arm 12, yoke 19, the bearing members

17 and 18, the tool holder 29, the means for producing and

transferring the vertical reciprocation to the tool holder, namely the

grooved pulley 11, crank 13, connecting rod 14, slides 21 and 26, and

grinding disc 32.

A second motor 35 is secured to a platform 34 of body 1, and a grooved

pulley 36 fast upon the motor shaft transfers the rotary movement of

the motor via a belt 37 to a second grooved pulley 38 The latter and a

further grooved pulley 39 are fixed to an axle 40 which is rotatably

mounted in a bearing 41 of body 1 A further bearing member 42 is

rotatably held in the axis of shaft 40 and comprises two symmetrical

arms 43 at the ends of which are journalled axles 44 at right angles

thereto, and each axle 44 again carries at its ends two pulleys 45, 46

and 47, 48 respectively An endless belt 135 is trained from pulley 39

over pulleys 46 and 48, thence through an aperture of a cover 49, over

the driving pulley 33 of grinding disc 32, through said aperture, over

pulleys 47 and 45 and back to pulley 39 Such arrangement ensures

operation of grinding disc 32 even when the latter, due to its

incorporation in the rotatable machine portion, is swung about the

machine main axis.

The crown of the frame consists of a fixed plate 50 of which an arm 50

a carries the centreing pin 16 A control plate 51 is set freely

slidable on plate 50, and its relative sliding movements are limited

by its edges 52 70 and 53 abutting respectively against corresponding

shoulders 54 and 55 of plate 50 In control plate 51 is provided a

first V-way 56 (Figure 3) in which a slide 57 is mounted and is

adjustable by a screw 58 Slide 57 75 comprises a lug 59 on the

vertical outside face of which is provided a further V-w vay in which

a slide 62 is mounted and is adjustable by a screw 61, said slide 62

being movable at right angles to slide 57 Slide 62 80 carries a

bracket 63 to which is secured a former-plate table 65 by means of a

screw 64 Table 65 is provided with two grooves 66 (Fig 1) in which is

secured a former plate 68 by means of screws 67 Opposite former 85

plate profile 68 a is disposed a tracer 69 which is retained in a

V-way 70 in vertically movable relation, the corresponding clamping

screw being designated by 71 The V-way 70 is provided with an

extension 72 which 90 points towards former plate 68 and is fixed to a

lever 73 to which, at 74 and 75, are pivoted two arms 76, 77 of a

parallel guiding means The latter further comprises, in a conventional

manner, rings 78 and 79 and 95 further arms 80 to 83 The connection

and disposition of said rings and arms corresponds to the conventional

arrangement of a parallel guiding means The last arms 82 and 83 of the

latter are pivoted, at 84 and 100 85, to a plate 86 which is

incorporated in and forms the upper leg of the V-shaped yoke 19 Any

and each rotary movement of tracer 69 thus is transmitted, via the

lever 73 and the parallel guiding means 76 105 to 83, on to the yoke

19 and, therefore, on to the grinding disc 32 as a consequence of the

rotatable portion of the machine turning about the main axis

Translatory movements of the tracer, i e movements which do 110 not

provoke any angular movement of ring 78, do not bias the movable

machine portion, as far as the transmission on to the parallel guiding

means is concerned The arms 80 and 81 of the latter are inter 1 15

connected by a strap 87 of which the ends are pivoted to said arms at

88 and 89.

To strap 87 is rotatably secured a vertical pin 90 to the free end of

which are pivoted two rollers 91 which run in a groove 120 92 of a

rail 93 The latter is connected to control plate 51 via a pedestal 94

and screws The parallel guiding means thus is supported through said

rollers on the control plate 51, without impairing the mobility 125

thereof.

To V-way 70 of tracer 69 is pivoted the long arm 96 of a first

individual pantograph which comprises, in conventional manner, said

long arm 96 and other arms 97 to 99 130 785,832 which are

interconnected in pivotable relation Leg 99 at 100 is rotatably

mounted in a bearing 101 of control plate 51, whilst leg 98 is pivoted

to the long arm 102 of a second individual pantograph Bearing 101 is

secured to control plate 51 by screws 101 a, elongated holes 101 b

being provided in the control plate so that the bearing and, thus, the

point of articulation of pantograph 96 to 99 is movable on the control

plate relatively thereto and may be screw-locked thereto again Said

second pantograph is fundamentally constructed similar to the first

and comprises, besides leg 102, two parallel legs 103, 104 and a leg

105 whch is parallel to long leg 102 The two hingeably interconnected

pantographs 96 to 99 and 102 to 105 together form a twn pantograph

Each of the legs 104, 105 (Fig 5) has a slot 104 a :0 and 105 a

respectively, and in each of these dlots is movably mounted a sliding

block 106 and 107 respectively The latter may be fixed in their

positions by screws 108 and 109 according to the desired reduction

ratio.

-25 Each of the blocks 106, 107 comprises an underplate 110 which is

secured in its position by screws 111, the edge of said plate securing

the pivot pin 112 and 113 respectively The two pins 112, 113 stand at

right :30 angles to the plane of the pantograph, pin 112 which is

fixed to leg 105, pointing upwardly and pin 113 which is fixed to leg

104, pointing downwardly Pin 113 is rotatably held in an eye 114 of an

arm 115 which -35 is secured to control plate 51 by means of screws

116 Pin 112 forms the fixed point of the pantograph, is situated in

the machine main axis and is journalled in leg 19 b of yoke 19 which,

as already explained, belongs to the rotatable machine portion.

From the foregoing may be seen that each single pantograph at one

point ( 100 and 113 respectively) is rotatably connected to the

control plate 51, whilst the twin pantograph has a fixed point ( 112)

situated in the machine main axis.

Control plate 51 further comprises a bracket 118 (Fig 3) to the upper

side of which is attached a plate 119 On the latter -50 is secured by

screws 120 a carriage 121 with respect to which the work slide 122 is

movable, at right angles to slide 57, so far laterally as is permitted

by a slot 123 of the work slide, said slot being traversed by a -55

screw 124 for attachment to the carriage.

A guide pin 123 a serves for rectilinearly guiding such displacing

movement In work slide 122 is mounted a work spindle 125 which is

rotatable by means of a handwheel 126 The work 128 is clamped to

spindle by means of a screw 127 For the sake of clarity, the work

slide in Fig 3 has been moved to the right so that the work becomes

visible next to grinding disc 32, whereas in -G 5 reality the latter

and the work are situated in the same vertical plane The work spindle

carries an indexing wheel 129 which coacts with two pawls 130 of which

only the upper one is visible in the drawing These pawls are pivoted

at 131 (Fig 1) and are 70 disengageable from index wheel 129 by means

of a lever 132.

On the control plate 51 is provided a guide means 133 on which may be

mounted an optical control device 134 of known con 75 struction and

which is schematically shown in Figs 3 and 4.

To perform a grinding operation in the machine after the work 128 has

been mounted upon the spindle 125 in the plane 80 of the rotating and

vertically reciprocating grinding disc 32, and the former plate 68 has

been clamped upon the control plate 51, the tracer is moved linearly

towards the former plate so as to take the work into 85 contact with

the disc.

The work is taken into contact with the disc because the said movement

of the tracer imparts a corresponding movement to that end of the

longer arm 96 of the first indi 90 vidual pantograph on which the

tracer is pivoted, thereby tending to impart a similar movement to the

said arm; since the arm is pivoted to the pantograph arms 97, 99 which

are also pivoted upon the control plate at 95 the said longer arm and

the arm 98 are constrained to make combined linear and swinging

movements The combined movement of the arm 98 displaces the longer arm

102 of the second individual pantograph 100 in a manner which tends to

swing the arm 104 of the second pantograph about the pivot pin 113 and

impart a combined longitudinal and swinging movement to the arm 105;

however since the arm 105 is pivoted 105 about the pin 112 which is

held in the main axis of the machine, the said arm is prevented from

making any longitudinal movement with the result that the pivot pin

113 is moved and, since the pin is mounted on 110 the control plate,

the said plate is moved carrying with it the pivot 100 The arrangement

of the two individual pantographs is such that the movement imparted

therethrough from the tracer to the control plate 115 causes the plate

(and therefore the work) to move in the opposite direction to, but

through a smaller distance than, the tracer, the relative distances of

travel being determined by the location of the blocks 106 and 120 107

lengthwise of their respective slots 104 a and 105 a.

Having taken the work into contact with the periphery of the grinding

disc, the tracer is moved laterally relative to the former 125 plate

whereupon the control plate and work are again displaced by the

pantographs in the opposite direction to, but through a smaller

distance than, the tracer so that the work is traversed across and in

contact with 13 Or 785,832 the disc periphery and is ground away until

the tracer comes into abutment with the profile 68 a of the former

plate.

In the event that, in making each traversing movement across the

profile, the tracer is swung about its pivoted connection to the

longer arm 96 of the first individual pantograph, the lever 73, which

is fixed to the tracer, is swung in the same direction and through the

same angle so as to actuate the parallel guiding means 74 and 83

whereby the grinding disc is swung through an identical angle about

the main axis of the machine.

J 5 Since linear movements of the tracer into contact with and across

the profile 68 a are translated, on a reduced scale, to the work via

the twin pantographs and the control plate, and angular movements of

the said tracer are translated to the grinding disc via the parallel

grinding means, the profile imparted to the work is identical but on a

reduced scale relatively to the profile of the former plate.

The progress of the grinding operation may be followed visually by the

operator of the machine since an enlarged image of the profile

imparted to the work is projected on to a screen of the optical device

134: consequently the carrying out of the grinding operation is

facilitated.

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* GB785833 (A)

Description: GB785833 (A) ? 1957-11-06

Improvements in or relating to a method and apparatus for effecting

transmissions oftelevision images


A high quality text as facsimile in your desired language may be available

amongst the following family members:

BE526230 (A) FR1019549 (A) US2786887 (A) FR64960 (E)

BE526230 (A) FR1019549 (A) US2786887 (A) FR64960 (E) less

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The EPO does not accept any responsibility for the accuracy of data

and information originating from other authorities than the EPO; in

particular, the EPO does not guarantee that they are complete,

up-to-date or fit for specific purposes.


785,833 Date of Application and filing Complete Specification:

February 2, 1954.

Application made in France on Februarny 4 1953 Complete Specification

Published: Novemlber 6, 1957

No 3094/54 J Index at acceptance:-Class 40 ( 3), F( 2 F 3:2 X:3 A:6

K).

International Classification:-HO 4 n.


Improvements in or relating to a Method and Apparatus for Eiecting

Transmissions of Television Images We, SOCIETE NOUVELLE DE L'OUTILLAGE

R.B V ET DE LA RADIO-INDUSTRIE, 45 Avenue K 16 ber, Paris 16 eme,

France, a Body Corporate organised according to the laws of France, do

hereby declare the invention, for which we pray that a patent may be

granted to us, and the method by which it is to be performed, to be

particularly described in and by the following statement:-

This invention is ain improvement in or modification of the invention

forming the subject matter of British Patent No 694,005 which

describes an apparatus for producing a transmission of television

pictures wherein from a video-signal of normal television standard

frequency a recording is produced occupying a narrower bandwidth the

said recording being transmitted and reconverted at the receiving

station to a video-signal of the original bandwidth whereby the

reduced frequency band is required for the transmission.

According to the said prior Patent No.

694,005 one method of producing the recording was to use a light

sensitive film which was then developed and scanned thus making it

possible to scan any one or more of the pictures so produced at the

desired bandwidth for transmission purposes At the receiving end the

procedure was reversed by again producing a permanent recording on a

light sensitive film which was developed and the frames thereon

scanned the requisite number of times to reconvert the narrow

bandwidth transmission to the standard frequency video-signal In the

second method described in the above Patent No 694,005 instead of

using a light sensitive film an electro-static process was employed

whereby the video-signal was used to impose on the target of a storage

tube electrostatic charges corresponding to the image of the

video-signal Such targets were then scanned at any desired lower speed

to produce a narrow bandwidth signal for transmissions.

lPrice 3 s 6 d l At the receiving end the low frequency signal was

again imposed on a number of targets in a bank of storage tubes the

number of targets being such that they could be scanned in succession

at the scanning fre 50 G quency of the original signal.

The method used in said prior Patent to effect a lower scanning

frequency recording for transmission over a reduced frequency band,

was to omit some of the frames, by 55 scanning at a lower frequency

The picture was then restored at the receiving end by scanning some of

the frames more than once at the original frequency.

In the present invention instead of omit 60 ting some of the frames,

all the frames are in fact transmitted over the narrow bandwidth

channel, but some of the lines in each frame are omitted, by scanning

at a lower frequency, the original picture line number 65 being

restored at the receiving end by scanning some of the lines more than

once to replace the omitted lines.

In the B B C high definition television service the picture is

composed of 405 horizon 70 Q tal lines and there are 25 complete

pictures per second A system of interlaced scanning is used in which

the odd numbered lines of the picture are scanned in 1/50th second and

the even numbered lines are scanned in 75 the succeeding 1/50th second

When this picture is transmitted over the narrow bandwidth cable, each

frame still lasts 1/50th second, but the number of lines contained in

each frame is reduced to a half or a third or 80 > some other

convenient sub multiple.

The frequency band occupied by a television signal is equal to the

frame scanning frequency times the line per picture number times the

dot per line number The horizon 85, tal definition rests on the number

of dots and the vertical definition on the number of lines and the

type of scanning (interlaced or plain) Numerous tests have confirmed

that when the number of lines of a television pic 9 g / 785,833 ture

are reduced, there results an impression of loss of vertical

definition even if interlaced scanning is maintained However if the

high number of lines is preserved, but with S one or even two

repetitions of the same lines, for some of them, or each of them, the

subjective vertical definition and accurateness in details of the

picture persists, provided the horizontal definition remains constant.

Actually, during the transmission through the narrow bandwidth

channel, the line frequency of the video-signal is lowered so that.

during a frame period, only part of the lines constituting the picture

are conveyed along said transmission channel with the same frequency

band as delivered by the pick-up equipment, that is to say that each

second (or third or so on), line is transmitted with full details

while the other lines are suppressed.

During one normal frame period, only some of the lines are therefore

transmitted along the channel, the remaining lines are transmitted

during the succeeding picture since the succeeding frame does not

include the same lines owing to the fact that interlaced scanning is

used At the end of the transmission channel, the signal is displayed

at the reduced scanning rate on a long after glow picture tube which

co-operates with a pick-up tube, the scanning frequencies being chosen

according to the required values to match the receiving sets at the

point of location of the end of the transmission channel.

These will not necessarily be the same as those used at the pick-up

end of the television chain.

According to the present invention we provide a method of generating a

television signal representing television pictures formed by a given

number of lines scanned at a first frequency which consists in

deriving a signal by scanning the said television picture at a second

frequency lower than said first frequency in such a way that all the

frames are scanned and some of the lines omitted, transmitting said

signal through a narrow bandwidth transmission channel, receiving said

signal and producing therefrom a television picture signal of the

original number of lines at a frequency equal to the first frequency

by repeating the signal of adjacent lines to replace the missing

lines; and we also provide an apparatus for carrying out the above

method comprising at the transmitting end a picture tube displaying

the television picture to be transmitted and optical means to project

said picture onto a pick-up tube the scanning assembly of which is

operated at said second frequency for producing the signal to be

transmitted, and at the receiving end a picture tube on which a

television picture is displayed by scanning at said second frequency,

optical means for projecting said picture on a pick-up tube and means

for scanning said picture at the first frequency some of the lines

being scanned more than once to build up the said picture signal

containing said first given number of 70 lines.

The invention will be well understood by referring to the following

description of the embodiment of the invention using intermediate

equipments including a pick-up and a 75 picture tube, in combination,

at both ends of the transmission channel It is well understood that

other equivalent means may be used to modify the line scanning

frequency such as for instance special cathode ray tubes 80 including

a storage target and one or two electron gun assemblies such, for

instance, as the tubes shown on Figures 3 and 4 of the parent Patent.

Figure 1 and Figure 2 of the accompany 85 ing drawings show such

intermediate equipment at both ends of the transmission channel shown

as coaxial cable 4 Cathode ray tube 1 of Figure 1 gives a picture of

the incoming video-signal using interlaced scan 90 ning rates in

accordance with the standard scanning rates used at the pick-up

equipment (that is 50 frames of 2021 lines per second) The picture

displayed is focussed by means of an optical system shown as 2 95 on

the photosensitive surface of pick-up tube 3 which feeds the input of

the narrow bandwidth transmission channel such as a cable 4, by means

of video amplifiers not shown on the Figure The scanning of target of

tube 100 3 is made at a slower rate than the corresponding scanning

speed on picture tube 1.

The decrease in speed is chosen so that the narrow bandwidth of cable

4 will be able to transmit the whole of the information in 105 cluded

in each point of the picture displayed by tube 1 at a repetition

frequency less than per second.

Figure 3 shows the line scanning voltages as applied to picture tube 1

and pick-up tube 110 3 Curve A shows the line scanning voltage applied

to tube 1 and curve B the line scanning voltage of camera tube 3 In

this case the speed of the line scanning on camera tube 3 is half the

speed on picture tube 1 Under 115 these conditions, vertical

deflecting voltages are applied at half the frame frequency to the

camera tube Interlaced scanning is maintained on camera tube 3 Picture

tube 1 is of the ordinary type used in television sets The 120 output

signal from tube 3 occupies a frequency band which has half the width

necessary to the signal applied to tube 1, to obtain the same

horizontal definition.

Curve C of Figure 3 shows the line scan 125 ning signal in the case

when the reduction of the line scanning speeds are 2 to 5 between

picture tube 1 and camera tube 3 In this case only two lines out of

every five are transmitted along cable 4 130 785,833 At the terminal

of cable 4 as shown on Figure 2, the video signal is applied, by means

of a video amplifier 5, to the modulating electrode of picture tube 6

The scanning voltages applied to picture tube 6 are identical with the

scanning voltages used in camera tube 3 which in this example is half

the line scanning speed used on tube 1 During a normal picture period,

that is 1/25th second, only half of the lines constituting the whole

picture raster are scanned at the pick-up tube 3 and displayed on the

picture tube 6 at the same time, that is to say only 202 5 lines

Therefore, the whole picture comprising two interlaced frames requires

1/12 5 second to be reproduced on tube 6.

The fluorescent screen of picture tube 1 shows little attenuation in

1/25 second so that the two frames constituting a whole picture will

appear almost as brilliant on screen of cathode ray tube 6 The picture

reproduced on tube 6 is focused by means of an optical system 7 on the

photosensitive electrode of a second camera tube 8 which delivers a

signal, the frame and line frequencies of which match the

corresponding values used on the receiving sets which receive this

transmission This means that the signal delivered by the tube 8 should

have line and frame frequencies equal to the ones used at a pick-up

equipment, unless it is necessary to change the number of lines per

picture, for instance when transmitting the signal from one country to

another the two countries having different numbers of lines per

picture.

If the same standard is used at both ends of the transmission channel

4, the line scanning voltage of camera tube 8 is shown by curve A of

Figure 3 The frame frequency is equal to 25 per second.

Figures 4 A and 4 B show respectively in detail the successive lines

displayed on the screen of the picture tube 6 and camera tube 8

Horizontal line scanning is used on the tubes 6 and 8 Figures 4 A and

4 B are shown turned through 900, and in order to avoid confusion the

words "vertical" and "horizontal" have been marked on the drawing

During one scanning on picture tube 6, the target of camera tube 8 is

scanned twice It is therefore necessary that the lines pertaining to a

previous frame should still be apparent on the screen of picture tube

6.

Figure 4 A shows the whole raster ( 405 lines) on tube 6, the lines

corresponding to one frame are figured as full lines and the ones

pertaining to the following frame are shown as dotted lines The size

of the spot in the picture tube 6 may be of an elliptical cross

section instead of a round, cross section to suppress any black

interval between successive lines of the same picture due to the

reduced number of lines constituting each frame; the cross section

should be elliptical so that the horizontal size of the spot should

not be bigger than the one corresponding to the complete horizontal

definition at the pick-up end Only the vertical size should be

increased The scanning spot of tube 6 should have a horizontal size

corresponding 7 Q to the high horizontal definition of the video

signal applied to tube 1 of Figure 1 and a vertical size twice the

size corresponding to the whole number of lines of the raster ( 405

for the area of the picture), that is a vertical 75 size larger than

d' and smaller than 2 d' (distance between two successive lines of the

same frame of scansion on the target of tube 8) Thereby, information

is picked-up during each line scanning of target of tube 8 The 8 j

raster on tube 8 is shown in Fig 4 B. If desired, the display of the

picture on intermediate picture tubes 1 and 6 may be made as a

negative picture of the scene being televised, as described in our

British Patent 85 No 776,764 Also allowance may be made for an

automatic gamma and shading correction when the pick-up equipment

comprises a supericonoscope type of tube.

As was said above, it is necessary that the 90 brilliancy of the

different parts of the picture displayed on picture tube 6 at

successive frame intervals be equal, so as to provide for the high

quality output signal from camera tube 8 95 Such a condition may be

obtained by controlling the gain of the video amplifier 5 or of the

picture tube 6 as is described in our British Application No 4249/54

(Serial No.

784,856 10

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