* GB784958 (A)

Description: GB784958 (A) ? 1957-10-16

Improvements relating to gear hobbing machines

Description of GB784958 (A)

PATENT SPECIFICATION Inventor: ALFRED KURT THOMAS Date of filing Complete Specification June 13, 1956. Application Date Aug 10, 1955. ' ' Complete Specification Published Oct 16, 1957. Index at Acceptance:-Class 83 ( 3), K( 3 D: 5 A 1: 5 E: 6). International Classification: -B 23 c. COMPLETE SPECIFICATION Improvements relating to Gear Hobbing Machines 784958 No 23024/55. We, CRAVEN BROTHERS (MANCHESTER) LIMITED, a British Company, of Vauxhall Works, Reddish, Stockport, Cheshire, 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 relates to gear hobbing machines of the type in which the gears which are being hobbed are mounted on a horizontal axis and revolved at the normal slow speed requisite for hobbing and at high speeds for a gear shaving operation The running of what is termed the work spindle at high speeds for the gear shaving operation jeopardises the high degree of accuracy called for in the gear hobbing operation. The object of our present invention is to provide an improved construction of gear hobbing machine which obviates the aforesaid disadvantage of present constructions. In accordance with the present invention, we provide in a gear hobbing machine having the workpiece axis horizontal, means whereby the workpiece is driven through one headstock at the slow speed requisite for hobbing and is disconnected from the drive in said headstock and connected to a drive through the other headstock for the high speed shaving operation In this way we keep the drives for hobbing and shaving separate and distinct and avoid damage to the normal hobbing

drive which might occur if it is driven at high speed for shaving It will of course be apprecated that when shaving, the normal hob slide is replaced by a shaving head. We also provide on the machine bed, a support for a mating gear which can mesh with the newly hobbed gear in order to enable selective correction of such gear to be made by -shaving. Referring to the accompanying explanatory drawings:Figure 1 is a front elevation and Figure 2 a side elevation of a gear hobbing machine constructed in accordance with the present invention. t Price 3 s 6 d. Figure 3 shows the shaving which replaces the normal hob slide for the shaving operation. The workpiece a upon its spindle a' is driven from or through one headstock b at the slow speed requisite for hobbing and is disconnected from such drive and connected to a drive from or through the other headstock c for the high speed shaving operation In this way, the drives for hobbing and shaving are kept separate and distinct and thus we avoid damage to the normal hobbing drive which might occur if it is driven at high speed for shaving. When shaving, the hob slide d (Figure 1) is replaced by the shaving head shown mn Figure 3. We preferably provide on the machine bed, a support f for a mating gear which can mesh with the newly hobbed gear in the machine in order to test the hobbed gear for accuracy and enable selective shaving thereof to be effected. The driving means for the spindle a' are not shown and can be of any usual construction.

* Sitemap * Accessibility * Legal notice * Terms of use * Last updated: 08.04.2015 * Worldwide Database * 5.8.23.4; 93p

* GB784959 (A)

Description: GB784959 (A) ? 1957-10-23

Microtomes

Description of GB784959 (A)

COMPLETE SPECIFICATION Microtomes We, TECHNICON INTERNATIONAL LTD., a Corporation organized and existing under the laws of the State of New York, United States of America, of Chauncey, New York, United States of America, 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 relates to improvements in microtomes generally and more particularly to improvements in microtomes of the type having a knife and specimen holder, one of which rotates past the other to slice the specimen. According to the present invention there is provided a microtome comprising a knife and means for feeding a specimen to said knife, characterized in that a stationary holder is provided for said knife and the feeding means is constituted by a mechanically driven feed device which during feeding movement continuously advances the specimen with a stepless movement at a uniform rate toward the knife and which rotates the specimen relative to the knife along a path of rotation which causes the specimen to engage the stationary cutting edge of the knife, slide over the cutting edge and disengage the knife during each cycle of specimen rotation. The invention will be described, by way of example, with reference to the accompanying illustrative drawings, in which: Fig. 1 is a fragmentary longitudinal sectional veiw of a microtome made according to the present invention Fig. 2 is a sectional view taken on the line 2-2 of Fig. 1; Fig. 3 is a sectional view taken on the line 3-3 of Fig. 1; Fig. 4 is a fragmentary side elevationali view of the microtome; Fig. 5 is a sectional view taken on the line 5-5 of Fig. 1; Fig. 6 is a sectional view taken on the line 6-6 of Fig. 3; Fig. 7 is a sectional view taken on the line 7-7 of Fig. 4; Fig. 8 is a plan view of the microtome knife holder taken in the direction of arrow 8 of Fig. 1; Fig. 9 is a vertical sectional view of the knife holder shown in Fig. 8; and Fig. 10 is a sectional view taken on the line 10-10 of Fig. 9.

Fig. 11 is a top plan view with parts broken away, of a microtome according to a modified form of the present invention Fig. 12 is a sectional view taken substantially on the line 12-12 of Fig. 11; and Fig. 13 is a side elevational view looking in the direction of the arrow 13 of Fig. 12. The microtome 10, according to the present invention, comprises a knife holder A, a paraffin block holder B, means C for rotating the specimen block holder B and means D for imparting to the specimen block holder B a translatory or rectilinear movement. The knife holder A is adapted to be adjustably mounted to the frame 12 while the specimen block holder B is adapted to be rotated by the rotating means C relative to the knife holder A to slice specimen sections S (Fig. 8) of accurately predetermined thickness for histological examination. The knife holder A comprises a main frame or base 14 which is adapted to be adjustably secured to the frame 12 by means to be described, said frame 14 mounting a holder 16 in which is adjustably mounted knife 18 of any conventional construction. The knife edge 20, of blade or cutting implement 18, is adapted to cut thin specimen sections from the specimens embedded in a paraffin block 26 and carried by the specimen block holder B. The holder frame or base 14 is longitudinally adjustably mounted relative to frame 12 of the apparatus by means of the threaded shaft 300 (Fig. 10) which is adapted to coact with element 302 having a tapered aperture 304 formed com plementary to tapered portion 306 of the threaded shaft 300. The element 302 is provided with a projecting portion 308 (Fig. 9) having a collar member 310 secured thereto, the face 312 of said collar co-operating with adjacent portions of the frame 12 to secure base 14 to said frame. The frame 14 of the holder A is provided with a threaded aperture 314 which is adapted to co-operate with the threaded portion of the shaft 300. Shaft 300 is provided with a lever 316 which is readily accessible for manual actuation. From the above it will be seen that the rotation of shaft 300, by means of lever 316, will be effective to axially move said shaft whereby collar 312 may be releasably secured to adjacent portions of the underside 11 of the frame 12. When shaft 300 is rotated in a locking direction the tapered portion 306 will enter the tapered aperture 304 of element 302 to move the collar 310 closer to underside 11 of frame 12. Conversely, when the lever 316 is rotated in an unlocking direction the shaft 300 will be retracted from element 302 thereby allowing the collar 310 to gravitate away from the frame 12. The knife holder or clamp 16, which is adjustably mounted on the

holder frame or base 14, comprises a pair of generally Ushaped blocks 318, one block being mounted at each end of the shaft 320 and secured thereto by means of pins 324 (Fig. 8). The blocks 318 are secured to shaft 320 against rotation relative thereto in the same angular relationship whereby the adjustment of shaft 320 in a rotary or angular direction will be effective to correspondingly adjust blocks 318. The shaft 320 is rotatably mounted in the frame 14 of holder A whereby the blocks 318 may be adjusted in a rotary or angular direction. In order to secure shaft 320 and concomitantly the blocks 318 in adjusted angular position relative to the frame 14, there is provided a centrally positioned set screw 322, preferably having an Allen-type head, which bears on the soft metal bearing member 326 (Fig. 9) to thereby releasably clamp shaft 320 in its adjusted position. It will be un- derstood that the member 326 will be provided with an arcuate face 328 .vheleby the rotation of the screw 322 in a clamping directon will be effective to clamp said arcuate face against adjacent arcuate portions of shaft 320. Thus the set screw 322 and its associated bearing member 326 provide means visor the ready adjustment. in a rotary or angular direction, of the blocks 318 secured outboard at each end of shaft 320. In order to provide a means for indicating the rotary or angular position of the blocks 318 and consequently knife 18 there is provided an indicating member 330 (Fig. 1) fixed to the block 318' in any suitable manner, for example by press-fitting an end portion 332 in a complementary socket 334 in block 3181. The ba5e 14 is provided with a suitable graduated scale 336 which in association with the pointer 338 of the indicawing member 330 is adapted to indicate the angular position of the blocks 318 and consequently the angular position of knife 18. Thus the pointer 338, in conjunction with scale 336, provides a ready means for indicating the angularly adjusted position of knife 18 and provides a ready means for guiding the operator in altering the angle of said knife about the axis of shaft 320. The knife 18 may be adjusted laterally about an axis perpendicular to the plane of said knife by means of adjusting screws 340 associated with each of the blocks 318. The adjusting screws 340 (Fig. 8) are threadedly received in the apertures 342 of the blocks 318 and are each provided with a tapered end portion 344 which is adapted to coact with adjacent portions of the back edge 346 of the knife 18. It will be understood that each of the screws 340 is independently adjustable whereby the lateral position of knife edge 20 may be readily adjusted about an axis perpendicular to the plane of the knife. Each of the block's 318 has at one side a stationary jaw 348 (Figs. 1

and 9) adapted to bear against one side of the knife 18 and at the opposite sdie a movable jaw 350 which is pivoted to the block 318 at 352 and is adapted to bear at its free end against the knife in the region of its cutting edge 20. A set or clamping screw 354, working in the threaded aperture 356 in the movable body 350 is adapted to engage one face of the knife in the region of its back edge 346. Thus by tightening the set screws 354 one side of the knife is pressed firmly against the stationary jaw 348 and the free end of the pivoted jaw 350 is pressed forcibly against the other side of the knife adjacent its cutting edge 20. Thus the blocks 318 by means of +'he set or clamp- ing screws 354 grip end portions of the knife to hold the latter very securely, nevertThlern enabling the knife to be quickly adjuster, or removed and replaced. As previously described. the cutting angle of the knife 18 rnav be readily adjusted by means of the adjust inp screw 322 which is adapted to cramp the shaft 320 in any predetermined adjusted position. From the above, it will be underStood that the screws 340 are adapted for laterally adjusting the knife, screws 354 are adapted for clamping the knife to the blocks 318, and that screw 322 is adapted to hold the knife in the position in which it is disposed for determining the cutting angle of said knife, it being understood that said cutting angle will be indicated on the scale 336 by means of pointer 338. The specimen block holder B comprises a casing 22 (Fig. li having a socket 24 which is adapts to receive a conventional paraffin block 26 having a specimen embedded there in. The paraffin block 26 is adapted to be releasably secured in the socket 24 by means of a clamping screw 28, it being understood that a specimen block 26 is positioned in socliet 24 and clamping screw 28 is tightened sufficiently to retain said block in the socket 24 of casing 22. The specimen block holder B is adapted to be releasably secured in the socket 30 of flywheel 32, said socket being located laterally to one side of the axis of the flywheel 32. The holder B is retained in socket 30 by means of the clamping screws 34 shown in Fig. 4 which are adapted to bear against complementary peripheral portions 36 of the holder B. Thus the specimen block holder B is inserted in the socket 30 of the flywheel 32 and is retained in said position by means of the clamping screws 34 which coact with peripheral portions 36 of said holder. The flywheel 32, carrying the holder B is adapted to be rotated by rotating means or mechanism C and is adapted to be concomitantly advanced relative to the knife 18, at a predetermined rate, by the advancing means or mechanism D hereinafter to be described. It will be understood that the rotation of flywheel 32 will impart to the holder B a smooth rotary movement due to the inertia effects of said flywheel during said rotation. Thus the flywheel 32, due to its

inherent inertia characteristics, will impart to the specimen block 26 a smooth and uniform rotary movement whereby to achieve a smooth and uniform slicing or cutting action. Flywheel 32 is secured to a hollow shaft 38 (Fig. 1) in any conventional manner, as by means of screws 40 which are received in the threaded apertures 42 of shaft 38. It will be noted that flywheel 32 and shaft 38 are coaxially mounted and the rotation of shaft 38 will be effective to rotate flywheel 32. Ey- wheel 32 is centrally recessed at 44 for a purpose which will be evident from the description which follows. In order to effect the rotation of shaft 38 and concomitantly flywheel 32, there is provided rotating means C which comprises a drum 46 having a drive shaft 48 secured thereto and coaxial therewith. The drum 46 is secured to shaft 48 in any conventional manner, as by means of the key 50 which is received in a complementary recess in shaft 48. The drum 46 is in the form of a pulley having a V-groove 52 at its outer periphery which is adapted for the reception of a V-belt when it is desired to power drive the apparatus 10. For convenience in manually rotating the drum 46, there is provided an operating handle 54 having an arm 56 secured to the face 58 of drum 46 in any conventional manner, as by screws 60 which are received in threaded apertures 62 of said drum. It will be readily apparent from the above that the rotation of drum 46 by means of handle 54 will be effective to rotate the drive shaft 48 and the mechanism associated with said drive shaft. The end portion 64 of shaft 48 is mounted in a suitable bearing 66 which is in turn mounted in the bearing block S8 which is secured to the frame 12 by means of the screws 70. The end 72 of shaft 48 is provided with projecting pins 74 which are received in longitudinal slots 76 of shaft 38. From the above it will be seen that the coaxially arranged shafts 38 and 48 may be relatively longitudinally displaced but are locked against relative rotary movement due to the pins 74 being positioned in slots 76. Thus the rotation of shaft 48 will be effective to rotate shaft 38 and the rotation of the former will not effect the longitudinal movement of shaft 38 along the common axis of rotation XX (see Fig. 1). It will be further evident from the above that the thrust forces produced by the rotation of drive shaft 48 will not effect the longitudinal or axial movement or positioning of shaft 38 for the full range of axial movement of shaft 38. Shaft 38 is rotatably mounted relative to the frame 12 by means of the bearing 78 at one side of the apparatus and the bearing part 80 at the opposite side of the apparatus, said bearing 78 and said bearing part 80 being fixed to frame 12 in any desiredl manner. The flywheel 32 is adapted to be axially or longitudinally advanced from the dot and dash line position shown in Fig. 1 to the solid line position for the slicing of a section S from

the paraffin block 26. The recess 44 of the flywheel 32 is adapted to receive the bearing part 80 of frame 12, which bearing part acts as a guide for the flywheel for its range of translatory motion. From the above it will be seen that the rotation of drum 46 will be effective to rotate the flywheel 32 and that said flywheel may be translatorily moved during its rotation within a predetermined range whereby flywheel 32 may be concomitantly rotated and advanced or retracted. The means D for advancing or retracting the flywheel 32 during its rotation comprises a train of mechanism now to be described which is actuated on the rotation of drum 46. The mechanism D comprises an annular member 82 which is keyed to the shaft 38 by means of key 84. The member 82 has an annular flange 86 at one end thereof, said' flange having a gear 88 secured thereto in any conventional manner as by means of the screws 90. Gear 88 is in mesh with the gear 92 whereby the rotation of shaft 48 will be effective to rotate gear 92 which is associated with the frame 12 in a manner to be described in detail below. With reference to Fig. 5, there is shown a plate 94 which constitutes part of frame 12 and is provided with a plurality of spaced projecting legs 96, 98, 100 and 102 which are adapted to mount the mechanism about to be described. The gear 92 is secured to a shaft 104 which has its end portions mounted in suitable bearings 106 and 1(48, said bearings having their outer peripheries mounted in the legs 96 and 98, respectively, in any conventional manner. Shaft 104 has a driving plate 110 secured to one end whereby the rotation of gear 92 will be effective to rotate plate 110 as will be readily apparent. In order to urge shaft 104 and consequently plate 110 to the right, as viewed in Fig. 5, there is provided a tubular member 112 having an annular flange portion 114 which abuts the bearing 106 at one side thereof. Surrounding the tubular member 112 is a compression spring 116 which bears against flange 114at one end and has its other end seated in a complementary recess 118 of part 120 secured to the part 122 of frame 12. As shown in Fig. 5, the parts 120 and 122 are provided with complementary threads whereby the compression of spring 116 may be adjusted by the rotation of part 120 relative to the part 122. It will be understood that spring 116 will be effective to urge the tubular member 112 and concomitantly plate 110 to the right, as viewed in Fig. 5. The rotation of plate 110 is adapted to rotate the driver plate 124 through the medium of a variable speed device 126 to be described below. The plate 124 is formed integral with the gear 128 which has shaft portions 130 and 132 which are received in bearings 134 and 136, respectively, secured to the legs 100 and 102, respectively, of frame 12. Thus gear 128 is rotatably mounted relative to frame 12 by means of the bearings 134 and 136 and the rotation of plate 110 will be

effective to rotate gear 128 through the intermediation of the variable speed device 126 about to be described. With reference to Figs. 2 and 5, the variable speed device - 126 comprises a block member 138 carrying a pair of balls 140 which are in surface to surface contact relation with each other internally of said block member. Each of the balls or spheres 140 is also in surface contact with the confronting faces of plates 110 and 124 whereby the rotation of plate 110 will be effective to rotate plate 124 when the balls 140 are displaced from the axis of rotation of shaft 104. Thus the balls 140 are in surface contact with each other as well as being in surface contact with their associated plates 110 and 124 whereby the rotation of shaft 104 will be effective to rotate gear 128 when balls 140 are displaced radially from the axis of plate 124, for example to the position 1401. The transverse movement of the block member 138 and its associated balls 140 relative to the axis of rotation of plate 110 will be effective to vary the speed between the plates 110 and 124 in a manner to be described. With the balls 140 positioned in- the solid line position shown in Fig. 5, the plate 124 will be declutched from, or stationary relative to, plate 110 since balls 140 are coaxially positioned relative to plate 110. On the movement of the balls 140 of block member 138 from the solid line position to the dot and dash line position 1401 the rotation of plate 110 will be effective to rotate plate 124, the speed of plate 124 increasing as the radial distance of the block member 138 from the axis of plate 110 is increased. Similarly, as the block member 138 is moved outwardly of the axis of rotation of plate 110 the relative speed of plate 124 relative to plate 110 will increase at an increasing rate with the rate of increase being the greatest when the block member 138 is spaced at an extreme position from the axis of rotation of the plate 110. It will therefore be apparent that for a quick return of the flywheel 32 from its fully advanced position to its retracted position and for a quick advance to a cutting position, it is desired that block member 138 be displaced from the axis of rotation of plate 110 a maximum amount and for this purpose there is provided a control knob 142 which is adapted to be moved from the solid line position, shown in Fig. 2, to the broken line position indicated at 1421. In order to adjust the transverse position of block member 138 relative to the axis of rotation of plate 110 there is provided an adjusting shaft 144 which is threaded at 146, said threaded portion being adapted to co-operate with the threaded aperture 148 in block member 138. The adjusting shaft 144 is journalled for rotation in the bearings 150 and 152 secured to the projecting parts 154 and 156, respectively, which are formed integral with the leg 100 of the frame 12. It will be

apparent that the rotation of the adjusting shaft 144 will be effective to move the block member 138 longitudinally of said shaft whereby to vary the speed of rotation of plate 124 relative to plate 110. The adjusting shaft 144 is secured to the externally accessible control knob 142 m any conventional manner, a's by means of pin 158, said knob being adapted to facilitate the manual rotation and adjustment of the shaft 144 for controlling the speed of rotation of plate 124. In order to guide the block member 138 for movement axially of the shaft 144 there is provided a guide shaft 16() which has its end portions 162 and 164 positioned in the projecting parts 154 and 156, respectively of the leg 100. The block member 138 is provided with an arcuate longitudinal guideway 166 which is adapted to co-operate with peripheral portions of the guide shaft 160 to guide block member 138 for its full range of movement. Secured to the adjusting shaft 144 in any desired manner is a stop collar 168 which co-operates with end portions of the block member 138 to limit the movement of said block member in a direction to increase the speed of rotation of plate 124. Thus to increase the speed of rotation of plate 124 the control knob 142 is rotated in a direction to move the balls 140 away from the axis of rotation of plate 110 and this movement will be limited by the engagement of block member 138 against stop collar 168. It will be understood that the stop collar acts to limit the movement of block member 138 when the control knob 142 is in a full line position as shown in Fig. 2 and that said control knob will normally be in a full line or "IN" position for controlling the thickness of the specimen section S to be sliced from the specimen block 26 during the advancing movement of flywheel 32. In order to rapidly advance the flywheel -32 to the knife 18 and to provide for the quick retraction of the flywheel 32 to its initial position the control knob 142 is manually moved in an outward direction to tne position 1421 whereby the balls 140 will be moved to a position radially outwardly of their position when the control knob is in its "IN" position. Thus with the control knob in position 142l the block member 138 will be moved transversely outwardly of the axis of rotation of plate 110 to a position where the balls 140 will be adjacent the outer periphery of plate 110. It will be understood that the movement of control knob 142 to the position 1421 will result in correspondingly moving balls 140 to thereby rapidly increase the speed of rotation of plate 124 relative to plate 110. When the

shaft 144 is axially displaced due to the movement of the control knob 142 to the position 1421, the stop collar 168 will be correspondingly axially displaced whereby it will be ineffective to act as a stop means for limiting the adjustment of the block member 138. In order to limit the radial movement of the balls 140 relative to plate 110 when control knob 142 is in position 1421, there is provided a stop collar 170 which is secured to the guide shaft 160 by means of the pin 172. Thus with the con trol knob in position 1421the stop collar 170 will be effective to limit the movement of the block member 138 in a radial direction relative to the plate 110. It will be understood that the stop collars 168 and 170 aforede scribed will be effective to limit the adjust ment of member 138 whereby to prevent the balls 140 from being displaced from surface contact with the plates 110 and 124 to thus prevent said balls from being displaced from the block member 138. From the above, it will be apparent that the rotation of the con trol knob 142 will be effective to control the speed of rotation of plate 124 and its associ- ated mechanism and that said speed may be controlled within two distinct ranges as governed by the axial position of the control knob 142, the "IN" position constituting the range for adjustment of the thickness of the slice of the specimen section S to be cut and the "OUT" position 142l constituting a high speed range to provide for a fast return or retraction of flywheel 32 and to provide for a fast advance of said flywheel to a cutting position. Shaft 144 is peripherally grooved at 174 for the reception of a spring projected ball 176 which constitutes detent means for the control knob 142 in the "IN" position or low speed range position. Thus the spring driven ball 176 will be received in the peripheral groove 174 when the control knob 142 is in the "IN" position whereby a deliberate axial force will be required to move the control knob 142 to position 142'. Intermediate the ends of the adjusting shaft 144 there is secured an elongated gear 178 which is in mesh with a gear 180 having a gear 182 integral therewith. Gears 180 and 182 constitute idler gears and are adapted to transmit their motion to gear 184 which is in mesh with gear 182. It will be noted that gears 178 and 182 are of relatively small diameter whereas gears 180 and 184 are of relatively large diameter whereby for each revolution of shaft 186 of gear 184, shaft 144 of gear 178 will be rotated more than one revolution as determined by the relative diameter of the gears in the aforedescribed gear

train. Thus shaft 144 will constitute the fine adjustment for adjusting the speed of rotation of plate 124 and shaft 186 will constitute the coarse adjustment for adjusting the speed of rotation of said plate. As aforedescribed, control knob 142 is secured to the shaft 144 whereby said control knob which is accessible externally of the apparatus, as best shown in Fig. 4 constitutes the fine adjusting control for the speed of rotation of plate 124 and its associated mechanism for advancing and retracting flywheel 32. Similarly, a control knob 188 is secured to shaft 186 in any conventional manner whereby said control knob constitutes a companion speed control to the knob 142. It will be understood that suitable pointers and scales will be associated with the knobs 142 and 188 whereby the adjustment of said knobs will control the rate of advancement and retraction of flywheel 32. The aforementioned scales atssociated with the control knobs 142 and 188 will preferably be graduated in microns whereby the movement of the control knobs 142 and 188 one micron, as indicated by their associated scales, will correspondingly move the flywheel 32 one micron in an axial direction for each revolution of said flywheel. From the above, it will be apparent that the knobs 142 and 188, which are accessible externally of the apparatus, will constitute means to control the rate of axial movement of the flywheel 32 to thereby control the thickness of the specimen section S sliced from the specimen block 26. Gear 128 operatively associated with plate 124 is in mesh with gear 190 (Figs. 3 and 6) fixed to elongated gear 192 which is journalled for rotation in bearings 194 and 196 secured to the parts 198 and 200, respectively. Control shaft 202 is provided with a gear 204 secured at an intermediate portion thereof, which latter gear is in mesh with the elongated gear 192 which is driven by gear 128. Control shaft 202 has a threaded portion 206 which is adapted to be threadedly received in aperture 208 of part 198 which is threaded complementary to the threaded portion 206. At the end of the threaded portion 206 of the control shaft 202 there is provided a hardened steel ball 210 which is adapted to co-operate with annular plate 212 in a manner to be described in detail hereinafter. It will be apparent that the rotation of gear 204 will be effective to axially move shaft 202, which axial movement will be transmitted to plate 212. In order to guide shaft 202 for axial movement there is provided a guide socket 214 which is secured to the part 200 of frame 12. The end portion 216 of the control shaft 202 is adapted to be received in the central aperture 215 of the socket 214 whereby said socket and said end portion constitute guide means for the axial movement of shaft 2G2. It

therefore appear evident from the above that the rotation of plate 124 will be effective to rotate shaft 202 through the intermediation of gears 128, 190, 192 and 204, the rotation of said shaft 202 axially displacing the latter in a direction and by an amount corresponding to the direction mechanism 252 about to be described. In order to lock the flywheel 32 in fixed position, as when mounting the specimen block 26 in the specimen block holder B, there is provided a shaft 254 having a locking portion 256 at one end which is adapted to be received between a pair of adjacent teeth of gear 250 for locking the annular member 236 and its associated train of mechaniXsm. The shaft 254 is mounted in frame 12 for axial movement and is provided with a control knob 258 which is fixed to shaft 254 in any conventional manner, said knob being accessible externally of the apparatus and being adapted for manual operation to control the locking and unlocking of flywheel 32. Shaft 254 is provided with a pair of spaced peripherally extending grooves 260 and 262 which are adapted to co-operate with the spring projected balI 264 mounted in frame 12. Thus ball 264 constitutes detent means. for shaft 254, said ball being received in groove 262 in the unlocked position of flywheel 32 and said ball being received in groove 260 in the locked position of said flywheel. It will be readily apparent that when the knob 258 is in the "IN" position the annular member 236 will be locked against rotation to thereby lock the shaft 38 against rotation, which shaft has the flywheel 32 secured thereto. In order to indicate the position of flywheel 32 relative to the axis XX to thereby determine its translatory position there is provided indicating means 266 (Figs. 1 and 2) which is visible externally of the apparatus. The indicating means 266 comprises a shaft 268 having a pair of spaced projecting arms 270 and 272 which are adapted to co-operate with the faces 274 and 276, respectively, of gear 88. Thus gear 88 is positioned between the arm's 270 and 272 whereby the translatory movement of gear 88 and its associated train of mechanism will be imparted to shaft 268 (see Fig. 1). The shaft 268 is guided for longitudinal or axial movement in the bearing parts 278 and 280 of the stationary block 282 which is fixed to the frame 12 in any suitable manner. It will be noted in Fig. 2 that the stationary block 282 is slotted at 284 and arms 270 and 272 extend through said slot. The movable shaft 268 is provided; with an indicating element 286 which is visible externally of the apparatus 10 through any suitable window means 288. Thus the indicating element 286 will give a continuous reading of the translatory position of flywheel 32, it being understood that said indicating element will have associated therewith a suitable scale

which may be formed in the window 288. It will be further apparent from the above that the position indicating means 266 will be effective to indicate the position of the flywheel 32 in both the advancing and retracting directions since arms 270 and 272 straddle the gear 88. In practice, the specimen embedded in a paraffin block 26 is secured to the holder B and the latter is secured in position on the flywheel 32 in the manner aforedescribed. The flywheel 32 will be released for rotation by manipulating knob 258 to the "OUT" position, as shown in Fig 7, and said flywheel will be advanced to a cutting position adjacent the region of edge 20 of knife 18. As aforedescribed in detail, the knob 142 will be manipulated to its "OUT" position to obtain a fast advance to the aforenoted cutting position. The rotation of drum 46, by means of the handle 54, will be effective to rotate said flywheel and to axially move the latter, the rate of said axial movement being under the control of the knobs 142 and 188 which are in turn effective to control the rate of advance of shaft 202 relative to the speed of rotation of the flywheel. After the flywheel 32 is initially moved to the cutting position aforedescribed, in which the specimen block 26 is adjacent the edge 20 of knife 18, the knobs 142 and 188 are set for the thickness of the specimen section S desired and the drum 46 is rotated to concomitantly rotate the specimen block 26 and to advance the latter continuously by the amount set by the knobs 14-2 and 188. It will be understood that if, for example, the knobs 142 and 188 are set for four microns, flywheel 32 will be advanced four microns for each revolution of the latter. The thickness of the paraffin section to be cut or sliced may be adjusted at any time with the apparatus either in the operative or the inoperative condition and during said cutting or slicing, knob 142 will be in the "IN" position. It will be understood that the specimen section's S cut by the knife 18 during the rotation of flywheel 32 will be identical for identical settings of the knobs 142 and 188 and furthermore paraffin sections of any desired thickness within the design limits of the apparatus may be obtained. After the completion of the operation d cutting the specimen section's from the block 26, the flywheel 32 will be retracted to its initial position, which retraction may be effected in a rapid manner by the manipulation of the knob 142 to its "OUT" position, as aforedescribed. The knife edge 20, of the knife 18, is so arranged relative to the paraffin block 26 that said knife edge will be substantially parallel to the edge of the paraffin section which is last to be severed from the block 26 whereby when the paraffin section ribbons are formed they will be deposited along the surface 290. of the knife holder A, centrally thereof, to facilitate the further

handling of said ribbon. Thus the specimen block 26 and the knife 18 are so positioned relative to each other that the edge 292 of specimen section S is substantially parallel to knife edge 20 upon being severed from block 26 whereby a ribbon R will be formed running substantially centrally of the knife holder A, (see Fig. 8). In order to achieve the above result, the knife edge 20 of knife 18 is positioned slightly above the axis XX of rotation of flywheel 32, although it will be understood that said knife may be otherwise positioned, if desired. It will also be understood that knife holder A will be transversely displaced relative to the axis of rotation of the flywheel whereby the knife 18 will be disposed in the path of the circle of travel of the block 26. In the slicing of paraffin sections S from the paraffin block 26 said block will be continually advanced during its rotation resulting in said paraffin sections being tapered an infinitesimal amount although it will be readily apparent that for all intents and purposes said 'sections will be of uniform thickness. Thus since the block 26 is advanced in increments of microns which are 'I,,ooo of an inch and since the cutting or slicing of said block takes place for a relatively small angular distance during the rotation of the flywheel, the variance of the thickness of the sections S will be so infinitesimal that said sections may be considered as of uniform thickness as a practical matter. Thus it will be seen that the above described microtome 10 is provided with improved means or mechanism D for advancing flywheel 32 an accurately predetermined amount during its rotation. The rate of advance of the flywheel 32, during its rotation, will be identical for identical settings of the knobs 142 and 188 of the advancing feed mechanism and said rate may be accurately adjusted to produce specimens of like thickness or of any desired thickness. The means C for rotating flywheel 32 and the means D for advancing said flywheel are independent to the extent whereby the thrust forces produced by the rotation of shaft 48 will not effect the translation means D whereby specimens of accurately predetermined thickness may be obtained. The block member 138 and its associated mechanism provides an extremely efficient means for controlling the rate of advance or translation of flywheel 32 and also provides for the fast translation of said flywheel to return the latter to its initial position and to advance said flywheel to a cutting position. The indicating means 266 provides a ready means for indicating the translatory position of the flywheel 32 for its full range of translatory movement. With reference to Figs. 11 through 13, there is shown a microtome 10', according to a modified form of the present invention, which is structurally similar to microtome 10 except for the rotating means C1

for rotating shaft 38 and consequently flywheel 32. Rotating means C', of microtome 101, comprises a drum 46 which is secured to the shaft 400 in any conventional manner, as by means of key 402, said drum 46 being structurally identical with drum 46 of microtome 10. Thus the drum 46 is in the form of a pulley having a V-groove 52 at its outer periphery which is adapted for the reception of a suitable belt when it is desired to power drive the microtome. It will be readily apparent that the rotation of drum 46 by means of handle 54 will be effective to rotate the shaft 400 and the mechanism associated with said shaft. The shaft 400 is journaled for rotation in the portion 404 of the frame 121. Keyed to shaft 460, internally of frame 121, is a bevel gear 406 which is in mesh with a complementary bevel gear 408 which is fixed to the shaft 410, the latter being journaled for rotation in the portion 412 formed integral with portion 404. Secured to shaft 410 in any conventional manner is a gear 414 which is laterally spaced from the bevel gear 408, said gear 414 being in mesh with the idler gear 416 which is fixed to shaft 418 in any conventional manner, the ends of said latter shaft being journaled for rotation in the portions 420 and 422 of the frame 121. The gear 416 is in mesh with gear 88, the latter gear and its associated train of mechanism being structurally identical as in microtome 10. The gear 416 is elongated as shown in Fig. 11 in order to provide a driving means for gear 88, the latter being adapted for translatory movement in the manner aforedescribed. It will be apparent from the above that the rotation of drum 46 will be effective to rotate the associated pair of bevel gears 406 and 408, the latter gear being effective to rotate gears 414 and 416, with the gear 416 being adapted to rotate gear 88 whereby it will be seen that the rotation of drum 46 will be effective to rotate and axially move the flywheel 32. Thus flywheel 32 may be concomitantly rotated and advanced or retracted in the manner aforedescribed in detail. It will be noted that rotating means C1 dispenses with the drive shaft 48 of microtome 10 and said rotating means has the drum 46 positioned at one side ot the apparatus whereas rotating means C of microtome 10 has the drum 46 positioned at the end of the apparatus remote from the flywheeL The means 2521 for locking the flywheel 32 in fixed position is structurally identical with mechanism 252 in microtome 10, except that shaft 2541 is longer than shaft 254 of the locking mechanism 252. In all other respects, the flywheel locking mechanisms 252 are structurally identical. Any suit able gear ratio between gear 406 and gear 88 may be used. said gear ratio preferably being so designed tliat one revolution of drum 46 will he effective to rotate gear 88 one revolution. From the above, it will be seen that the rotary driving means 416 and the gear 88 which is associated with gear 416,

are re latively movable longitudinally and restrained against relative rotation whereby to inhibit transmission of endwise thrust to the gear 88. Both microtome 10 and 101 are provided with a part for rotating member 38 with respect to which shaft or member 38 is longitudinally movable during the rotation thereof, said part being the shaft 48 in microtome 10 and gear 416 in microtome 101. What we claim is: - 1. A microtome comprising a knife and means for feeding a specimen to said knife, characterized in that a stationary holder is provided for said knife and the feeding means is constituted by a mechanically driven feed device which during feeding movement continuously advances the specimen with a stepless movement at a uniform rate toward the knife and which rotates the specimen relative to the knife along a path of rotation which causes the specimen to engage the stationary cutting edge of the knife, slide over the cutting edge and disengage the knife during each cycle of specimen rotation. 2. A microtome according to Claim 1, characterized in the provision of mechanism to vary the rate at which the specimen is advanced toward the knife. 3. A microtome according to Claim 2, characterized in the provision of controls accessible externally of the microtome for adjusting the rate-varying mechanism. 4. A mcirotome according to Claim 2, characterized in that the continuous advance of the specimen is effected by a system which is driven by the drive shaft of a flywheel which mounts the specimen holder, said system including spaced driving and driven plates which rotate in parallel relation to each other and which have laterally offset axes of rotation, respectively, together with intermediate balls which engage said plates for transmitting the motion of the driving plate to the driven plate and which are movable radially of the axes of said plates for adjusting the movement of the driven plate by the driving plate. 5. A microtome according to Claim 4, further characterized in that a spring opposing the feed of the specimen acts on a flange of the drive shaft to prevent a direct transmission of the end thrust of the feed means to the flywheel carrying the specimen. 6. A microtome according to Claim 1, characterized in that the feed device includes a flywheel which mounts the specimen in a position offset from the flywheel axis, and a drive shaft for the flywheel which rotates the flywheel about said axis and which advances the flywheel in the direction of said axis toward the knife. 7. A microtome according to Claim 1. characterized in that the feed device includes a specimen holder which

is rotated relative to the knife and concomitantly advanced thereto, a rotatable and axially movable shaft mounting said specimen holder to rotate the specimen holder and to axially move the specimen holder toward the knife for successive cutting operations, a second shaft connected to the first shaft to rotate the first shaft, and mechanism connected to the first shaft independently of the second shaft to advance the specimen holder part for the cutting operations independently of the second shaft so as to inhibit transmission of endwise thrust from the second shaft to the first shaft.

* GB784960 (A)

Description: GB784960 (A) ? 1957-10-23

Improvements in and relating to shaft packings and a method to produce suchpackings

Description of GB784960 (A)

COMPLETE SPECIFICATION Improvements in and relating to Shaft Packings and -a method to Produce such Packings We, MUNDENER GUMMIWARENFABRDC, GEBR. KUNTH G.M.B.H., of Questenbergweg -4, Hann. Munden, Germany, a German Company, and FRANZ HARTMANN, of Eugen- berg, Duderstadt, Germany, a German C fri- Zen, do hereby declare the invention, for which we pray that a patent may be granted td us, and the method by which it is to be performed, to be particularly descrlbed in and by the following statement: The invention relates to shaft packings formed of diisocyanate modified polyester (at present sold comm'ercially under the Registered Trade Mark Vulkollan, and at the same time includes a method relating to their manufacture: It hasready been proposed to employ diisocyanate modified oly- ester for sealing purPoses because of its elastic properties. However, to seal rotating or reciprocating machine parts as for in stance shafts or slides, it was unsuitable. In such cases different packings and sealing elements are made use of, for instance, rubber in which particles of graphite or similar self

lubricating material can be embedded. Packings of such kind required a complicated manufacturing process, particularly a subsequent vulcanising operation. Although such packings proved efficient in many cases, diffi- culties and deficiencies appear when the packings are subjected to abrasion, since the working life of the known packings is not very long. Abrasion of the known packings was particularly great when lubrication of the moving parts from outside was interrupted, or in case of dry operation. The invention eliminates the deficiencies of the known packings in that it provides a packing for shafts comprising a base material of diisocyanate modified polyester having inclusions of materials such as carbon, graphite or like self lubricating substances embedded therein with contact faces located in the sliding contact sealing surface of the packing so that said surface is constituted by alternate areas of the base material and self lubricating substance. Preferably, the packing is designed so that a stiff or comparatively rigid layer of hard -dusocyanate modified polyester adjoins a highly resilient layer of diisocyanate modi fied -polyester which encloses the carbon or graphite pieces. The carbon or graphite faeces consist of electrolytically annealed high-grade carbon in form of solid pieces. The diisocyanate modified polyester is produced by conversion, with polydiisocy anates, of low - molecular polyesters of straight or lineage structure, and/or poly esteramides which contain free groups of hydroxyl and/or other groups with reactive hydrogen atoms, as amino and/or amido groups, the polydiisocyanates being pre dominant from the outset In the method to produce such highly re silient sealing rings or packing, highly resili ent soft diisocyanate modified polyester is used for embedding the carbon pieces on the inner side of the rings. On its outer circum ference the soft diisocyanate modified poly ester is enclosed by less resilient hard di isocyanate modified polyester. It is of particular advantage to produce the packing in a way that in the moulds car bon pieces are secured to the cores or sleeves

so that after filling the mould with diisocy anate modified polyester the carbon is se cured on the working surface. The sealing elements produced in this way are oil and gasoline proof and resist chemical attack. Due to their good slidability they are ex tremely wear-resistant and do not absorb frictional heat. Furthermore, it is possible to do away with the outer metal ring used on the known shaft packings, in that by means of soft diisocyanate modified polyester the inner portion of the shaft packing is made highly resilient, whilst the outer ring of the packing is formed of hard diisocyanate modified polyester which may have proper ties similar to metal. One embodiment of an annular packing is illustrated, by way of example, in the accom panying drawing. To produce the illustrated sealing element in a simple way, carbon rods 1 are arranged in a mould, around a core (not illustrated) so that their working surfaces rest against the core, the carbon rods consisting of, for in stance, electrolytically annealedhighest-grade carbon. Then the highly resilient softdiisocy anate modified polyester 2 is poured into the mould, the diisocyanate modified polyester enclosing the carbon rods and securing them in their position. Eventually, hard diisocy anate modified polyester 3, which gives the sealing ring 2 the rigidity required, may be applied around the ring. If the sealing ele ment is produced in the form of a cylinder, such cylinder may be divided in individual rings as illustrated, after the diisocyanate modified polyester has consolidated. It is to be understood, that the sealing ele ments may also be produced in other shapes. It is possible, for instance, to provide graphite bridges also on the outside of the ring if the outer circumference of the ring has to serve as a sealing surface, too. Fur thermore, it is possible to use highly resili

ent soft diisocyanate modified polyester only to produce the sealing elements. What we claim is : 1. A packing for shafts comprising a base material of diisocyanate modified polyester having inclusions of materials such as car bon, graphite or like self lubricating sub stances embedded therein with contact faces located in the sliding contact sealing surface of the packing so that said surface is consti tuted by alternate areas of the base material and the self-lubricating substance. 2. A packing for shafts according to Claim 1 having a hard layer of base material adja cent an elastic layer of base material in which latter layer are the said inclusions. 3. A packing for shafts according to either Claim 1 or Claim 2 wherein the said inclusions consist of an electrolytically an nealed high percentage content carbon in the form of solid lumps. 4. A method of producing packings for shafts as claimed in Claims 1 to 3, characterised in that the inclusions are placed around a core, and that the base material is cast into a mould in such manner that the pieces of carbon are located in the sliding contact seal ing surface of the finished packing. 5. A method of producing packings for shafts as claimed in Claim 4, characterised in that for producing rings the inclusions on the inside of the said rings are embedded in a highly elastic soft base material mass -whereas the outer periphery of the latter is enclosed in a mass of hard base material of low elasticity. 6. A method of producing packings for shafts as claimed in Claims 4 or 5, character ised in that pieces of carbon in the form of rods are placed around a core and that the said rods are then embedded in a cast found ation layer of base material, the resultant cylinder of carbon rods and foundation material being divided up into individual

sealing rings when the cast material has bonded and set. 7. A shaft packing substantially as de scribed and illustrated in the accompanying drawing. 8. The method of producing shaft pack ings substantially as described and illustrated herein with reference to the accompanying drawing.

* GB784961 (A)

Description: GB784961 (A) ? 1957-10-23

Apparatus for fiberizing wood fragments of chip or shredded form

Description of GB784961 (A)

PATENT SPECIFICATION Date of Application and filing Complete Specification: Sept 26, 1955. 784,961 No 27354/55. A j Application mode in United States of America on Oct 6, 1954. Complete Specification Published: Oct 23, 1957. Index at acceptance:-Class 96, A( 1:3 D). International Classification:-D 21 b. COMPLETE SPECIFICATION Apparatus for Fiberizing Wood Fragments of Chip or Shredded Form We, PANDIA, INC, a Corporation organised under the laws of the State of New York, United States of America, of 250, Park Avenue, New York, State of New York, United States of America, 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 relates to the preparation of cellulosic starting material, such as wood chips, for conditioning them preparatory to rendering them suitable for paper-making or for hard-board making More particularly this invention comprises an improvement on the fiberizing machine shown and described in British Patent Specification 678,761.

The specification shows ways and means for fiberizing the wood chips and the like into pulp by maintaining at super-pressure and super-temperature above 212 'F an enclosed conduit having at least one materialsupporting section leading to a free-fall section followed by a closed-end terminal section having an orifice in its peripheral wall for determining the size of fragments passing therethrough, supplying a stream of pressurized steam flowing through the conduit to exit from the orifice, feeding such chips into the conduit while minimizing loss of steam pressure therefrom, conveying such chips along the material-supporting section while softened by the steam, dropping the softened chips down the free-fall section, and ejecting chip fragments of predetermined size range from the orifice minimized as to shearing and degradation thereof as a result of treating them by the following steps: speeding the chips in the closed-end terminal section in the plane of the orifice by projective and centrifugal force to form them into a whirling turbulent mass of mobilized gas-suspended particles wherein the chips are generally diminuted along their lines of natural lPrice 3/6 l cleavage, maintaining the orifice in unobstructed condition by rotation of the whirling mass concentrated to wipe it clean, and forcing fragments from the whirling mass through the orifice with the stream of steam 50 exiting therethrough while reducing specifically their diameter further along their lines of cleavage and thus emitting them as woodfibre by threading them through that orifice. Thus there is a continuously flowing 55 stream of steam issuing at all times during operation of the machine through the continuously open orifice into a conduit that conducts the stream of steam and the chip fragments (or wood-fibre as it really is by 60 then) suspended therein, to a steam separator for further treatment. Considering now the entrance portion of the conduit for conducting to the steam separator, the steam suspended wood-fibre 65 issuing from the orifice, there is a tendency for the stream of steam to escape through the orifice with less than its full burden of wood-fibre In other words, it tends to leave the wood-fibre behind, at least during 70 periods of less-than-full capacity of the machine So at lower rates of production by the machine, there is a tendency for the steam consumption to be too great This seems to be due to the fact that the orifice and the 75 bore of the conduit into which it discharges are aligned, which permits the steam to escape in a straight-flow pattern So it is proposed by this invention to prevent such straight-flow of the escaping steam by de 80 vising a construction that will cause flowretarding back-pressure on the escaping steam. It has been found that the best form of flow-retardation is induced turbulence, not 85 of the eddying type but of the symmetrical bouncing

or zig-zag flow type that is in the nature of wave action, involving action and reaction, or perhaps, it is better to call it repetitive reflection In other words, the stream 90 piice Z 784,961 of steam issued from the small orifice nonalignedly into the bore of the conduit is to be caused to be forcibly projected against the wall of the conduit surrounding its bore from which it is reflected or bounced to the diametrically opposite side of the bore, and so on repetitively, until the main part of the conduit is reached The diameter of the bore of that steam-receiving and bouncing section is critical and in some degree so is its relative length, therefore, this invention proposes to interpose a particular renewable sleeve in that section so the bore thereof can be carefully made and used Also, the bore of that sleeve must be out of alignment with the axis of the orifice; the effective diameter of the orifice must be substantially less than the diameter of the bore; and the bore of the sleeve must be less than that of the conduit into which it discharges. According to the invention there is provided apparatus for fiberizing wood fragments of chip or shre-dded form including an enclosed pathway having means for introducing thereinto a mixture of steam and wood fragments to be fiberized and for conveying said mixture through a discharge orifice at the end of said pathway into a conduit, said conveying means including an impeller adapted to discharge said mixture through said orifice at high speed, wherein means is provided to control the size of said orifice and wherein said orifice is so positioned with regard to said conduit that the mixture discharging through said orifice bounces against a portion of the wall of said conduit and is reflected at least once across said conduit towards an opposite portion of said wall In order that the invention may be understood, it will now be described with reference to the accompanying drawings in which: Fig 1 shows a view of a fiberizing machine with parts broken away in order to illustrate the environment of the invention, Fig 2 is a partial vertical section view taken along line 2-2 of Fig 9; Fig 3 is a view similar to Fig 2, except taken at right angles thereto, namely, along the line 3-3 of Fig 9, Fig 4 is a composite side elevational but exploded view of certain parts forming the entrance to the arrangement of Figs 2 and 3; Fig 5 is a partial vertical sectional view of a lower section of the discharge end of Fig 1 l Fig 6 is a partial side elevational view of the discharge orifice and its shutter, taken from Fig 5, showing the shutter in open position; Fig 7 is a similar view to Fig 6, except that the shutter is full open; Fig 8 is a vertical section view, on an enlarged scale, of the same parts as shown in Fig 5; and Fig 9 is similar to Fig 7, except that the shutter is only partially open instead of being full open.

Referring to Figs 1 and 5, the apparatus 70 has a feeding-in zone A, and intermediate zone B from which depends a discharge zone C including an orifice-bearing closed-end terminal zone D (see Fig 5) of a mobilized suspension of fragmentized fibre bundles, 75 discharged therefrom through an orifice in its peripheral wall and an emission conduit leading to a cyclone More particularly, the feeding-in zone A comprises a feed hopper 11 for the wood-chips (about the size of a 80 silver dollar) or other forms of ligno-cellulose, that conducts it to a screw feeder 12. rotatably driven in tapered neck-like casing 13, wherein the screw-feeder 12 forms the chips into a compacted plug formation suffi 85 ciently dense to prevent heat and pressure loss from pipe or conduit 15 of the intermediate zone B Conduit 15 (which can be as large as 3 ft in diameter) has the plug formation fed thereto eccentrically through a 90 feed opening and the conduit is horizontally placed or at least sufficiently horizontal to support the material being treated therein. Saturated steam is supplied to the conduit through valved injector pipe 17 for main 95 taining a regulated super-atmospheric pressure and temperature in both the intermediate zone B and the discharge zone C for softening the ligneous fibre-binding incrustants. Into those zones may also be supplied a 100 chemical through valved injection pipe 18 for use in rendering the ligneous binding material water-soluble, or for other purposes. The conduit 15 is much larger in diameter than the plug formed in the neck-like casing 105 13 so that the particles expand under the influence of the moist heat in the conduit 15. A screw conveyor 19, suitably rotated, is provided in the conduit 15 for the purpose of controlling carefully the rate of progress 110 and the time of transit of the chips through and along the conduit 15 as well as the total time of their transit therethrough Near one end of the conduit 15 a down-pipe 22 depends into which wood-chips from the con 115 duit 15 freely fall through opening 23 The down-pipe merges into an impeller compartment that is closed off at its bottom by closure wall or bottom 24 through which extends a shaft 25 driven by motor 26 On 120 the upper end of the shaft 25 is an impeller 27 having blades 28 In the horizontal plane of the impeller 27, there is at least one discharge outlet orifice or port 29 (see Fig 8) opening into a discharge conduit 30 that 125 leads the pulp to further treatment The effective size of the discharge orifice 29 is controlled, such as by apparatus shown in Figs 5 and 8, the clearance between the blades 28 of the impeller 27 and the encas 130 784,961 ing walls being critical as well as the diameter of the discharge orifice. Referring now to Fig 5, the impeller 27 is held in place on shaft 25

by nut or hub 32, and each blade 28 is preferably set nonradial to the hub 32 to provide pumping action and also is preferably shaped so that the outer free end thereof is somewhat taller than the inner end thereof The lower outer edge 34 is curved to correspond with the closure bottom 24 beneath the impeller, because it is important that the clearance between this and the blades be minimized while the clearance between the blade ends 33 and their encasing wall 20 must be a critical distance Just above the top of the blades 28, the effective diameter of the down-pipe 22 is smaller than the diameter of the wall 20 encircling the impeller 27. One manner of accomplishing this relative relationship of smaller effective diameter of feed delivery pipe to larger diameter or impeller is by the interposition axially of the sleeve 35 in the down-pipe 22, so that the lower terminus of the sleeve forms an annular baffle or shoulder 36 above the outer extremities of the blades 28 The annular shoulder 36 and the bottom closure wall 24 form with the wall 20 a casing for the impeller which comprises an annular space D wherein there is a flattened vortex-shaped concentration of the chip fragments being batted around by the ends 33 of the blades 28, and reflected or deflected between the vortex flattening or limiting shoulder 36 and adjacent parts of the encasement adjacent the impeller 37 represents a removable handhole plate. The taller ends 33 of the blades tend to cause the fragments to rise or swirl upwardly against the shoulder 36 which results in a strong downward deflective action Meanwhile, the high rate of rotation of the blades rotates or whirls the mobilized suspension so rapidly that centrifugal impulses are imposed on the fragments sufficient in addition to the flow velocity to impel them through the sizecontrolled discharge orifice 29. The discharge orifice 29 discharges treated pulp into an emission conduit 30 of progressively increasing cross-section which conducts the pulp to a steam separator 38 having a gas-escape stack 39 and a water-spray for thoroughly mixing the treated pulp in a water bath in a usual stock-chest 41 This bath may be heated by steam or otherwise, to control its temperature, as desired A water suspension of the pulp overflows a usual weir 42 to pass for further treatment. Since the effective size of the orifice 29 is critical means for varying its size is provided, an example of which is the shutter type valve described hereinafter Referring to Figs 2, 3, 4 and 6, the discharge orifice 29 is elliptical and is formed in a fixed plate member Secured to the lower front portion of plate member 50 by means of bolts 51, is a fixed bottom plate 52, the upper edge of which comprises two interrupted curved portions 53 and 54, separated by a straight face 70 Rockably supported on a rockshaft 56, which passes

through the fixed plate 50, is a rockable shutter 58 having its lower edge curved at 53 ', 54 ' and 55 ' reversely to the corresponding edges 53, 54 and 55 of the 75 fixed plate member 50 The upper part of the rockable shutter 58 is curved at 59 to allow space for the rocking motion of the shutter The fixed plate 50 is held in place by means of screws 60 securing it to a flanged 80 coupling element 61 Element 61 accommodates inside the same an inner replaceable sleeve element 62, having a bore 63 therethrough provided with a tapered or funnel-like entrance 64 This inner sleeve leads 85 to a further replaceable sleeve 65, whose bore 66 is larger in diameter than the bore 63 of the sleeve 62 Bore 63 communicates with the emission conduit 30, or E, leading to the cyclone 38 67 is a flanged coupling with a 90 cylindrical portion 68, that holds the parts just described in place in the wall 20 69 is a set screw for holding the replaceable inner sleeve 62. Shaft 56 is supported in flanges 70 and 71, 95 and is operated by a handle 72, with means for clamping it in adjusted position, such as another handle 73 which functions more or less in lock-nut fashion 74 indicates a pointer co-operating with a scale 75 on flange 100 71, for showing the extent of the effective opening of the orifice 29 as a result of the portion of shutter 58. OPERATION The wood-chips are supplied to the feed 105 ing-in zone A of the digester, wherein the screw-feeder 12 forces the chips into the intermediate zone B of the digester under conditions that prevent any substantial loss of steam therefrom The quantity of wood 110 chips fed is correlated to cross-sectional area of the horizontal pipe 15 (or vice versa) so that the chips never fill that area but space is left for the particles to expand due to the heat, pressure and moisture conditions of 115 that pipe. In the discharge zone C chips freely fall from the screw conveyor 19 into vertical pipe 22 In so falling, the chips encounter in the closed-end terminal zone D what may be 120 termed a cushion of a mobilized, fluidized, whirling suspension of chip fragments, shives and fibre-bundles This suspension that is generally annular in shape is produced by intense agitation and turbulence generated in 125 the zone by means such as the impeller 27 with its blades 28. The suspension then is impelled out through orifices 29, partly due to the stream of steam flowing therethrough The maxi 130 784,961 mum particle-size in the emitted suspension is under the control of the operator, by means of the handle or lever 72 for turning rotatable shaft 56 From the orifice the disti charged gas-suspended wood-fibres are carried by the moving gas into the cyclone 38. The separation of the fibre-bundles into individual fibres is believed to be due to their forced passage threadingly through the orifice and to their impingement against the walls of the discharge pipe 30.

The stream of steam escaping or discharging through the orifice 29 carries its full burden of wood fragments through that orifice 13 into the receiving conduit whereby there is minimized the escape of steam through the orifice The effective opening of orifice 29 is controlled by the rockable shutter 58 whose straight face or edge 55 ' is movable to and fro across the face of the orifice, as shown in fully closed position in Fig 6 and in fully open position in Fig 7 Fig 9 shows it in partially open position, which is the usual position during operation In usual operation the effective opening of the orifice is rarely less than 15 sq in The orifice itself may have parallel sides connected together by semi-circular ends, the dimensions of the orifice being 3/4 " wide and 11114 ' long, so that its wide open area is approximately 0 82 sq ins Therefore, it can be operated with any effective opening between and 0 82 sq in, but 15 sq in seems to be the optimum, because the smaller the opening used, the less is the steam consumption per ton of pulp discharged The bore 63 of inner sleeve 62 has a diameter of not more than 1 in which means it has a crosssectional open area of 75 sq in The minimum diameter should be approximately 3/4 in otherwise plugging may occur The ideal relationship seems to be that the bore should have an opening of about three times the effective orifice opening The most satisfactory relationship as shown by tests is that the orifice should be open to the extent of 15 sq in while the bore is 45 sq in Since the maximum opening of the orifice 29 is 1 04 sq in, the tapered or funnel-like entrance 64 to the bore 63 must be as large at its entrance as the maximum opening of the orifice, because there should be no step or obstruction between the bore 63 in the sleeve and the orifice 29 The preferred angle of the bevel S is about 15 ' from the bore axis The bore of the further sleeve 65 should be at least twice as large in diameter as the bore 63 of the inner sleeve 62 The further sleeve is not essential but desirable to take up wear, C whereupon it can be easily replaced The length of the inner sleeve 62 should be approximately 4 to 10 inches. Referring to Fig 2, it can be seen that the rockable shutter 58 causes its edge 55 ' to 67 cover up the orifice 29 to the extent shown, to provide a restricted entrance thereto between fixed edge 55 'and the movable edge '. It is to be noted that the stream of steam with its burden of wood fragments enters the 70 bore 63 of inner sleeve 62 in a non-aligned manner, as is well shown in Fig 2 The steam first impinges with considerable force upon the bevelled wall 64 from which the steam is reflected to the opposite side of the 75 bore 63 as shown by the arrow, and this in turn causes further reflection or bounce to the opposite side of the bore This controlled reflection or bouncing of

the stream of steam is the important feature of the pre 80 sent invention with the result to prevent the quick escape of the steam without its full burden of fragments or fibres Care has to be taken not to have such turbulence of the stean as to set up disadvantageous back 85 pressure, because any significant building up of back-pressure will result in plugging up of the orifice Therefore, the turbulence must not only be controlled as to quantity but also as to its character The "turbulence" in 90 fact is a bouncing with a regular frequency. The bouncing action tends to retard the forward rate of progress of the stream of steam not enough to set up serious back-pressure but just enough to make the stream of steam 95 carry its full load of fibres It has been observed that the bounces seem to take place at the same spots of the sleeve and that at these spots the metal of the sleeve wears or washes away For this reason it is desirable 100 to have the inner sleeve 62 readily replaceable The first bounce seems to take place about 3 inches from the shutter plate 58 which determines the minimum length of the sleeve 105

* Sitemap * Accessibility * Legal notice * Terms of use * Last updated: 08.04.2015 * Worldwide Database * 5.8.23.4; 93p

* GB784962 (A)

Description: GB784962 (A) ? 1957-10-23

Improved machine for trimming ceramic appendages

Description of GB784962 (A)

PATENT SPECIFICATION 784,962 Date of filing Complete Specification: Sept 18, 1956. Application Date: Sept 29, 1955. No 27679/55.

I' t JJ| 'CE (Patent of Addition to No 727,273, dated Sept 15, 1953). %, 3 Complete Specification Published: Oct 23, 1957. Index at acceptance: Class 87 ( 1), C 6. International Classification:-CO 4 b. COMP'LETE SPECIFIOCATION Improved Machine for Trimming Ceramic Appendages I, HANS STRASSER, a Bdiitish Subject, of 94 Trent Valley Road, Penkhull, 'Stoke-onTrent, S Staffordshire, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by wvhich it is to be perfoltned, to be particularly described in and by the following statement: - This invention relates to machines for trimming ceramic appendages, such as handles for cups and similar articoles of hollowv-ware,,and is an imnprovement min or modfication of the machine described and claimed in the specification of my prior patent No 727,273. The machine according to the parent specification consists in an endless conveyor carryIng a number of handle-supporting units each comprising a cradle for holding a handle and guide means corresponding to ithe contour of the cup, the handle-supporting units being 20,carried by the conveyor successively through a cutting station where a trimming device controlled by the guide means acts upon each handle to produce on it the contour of the cup to which it is later to be attached. The,cpadles described in the parent specificatlon are made in two parts hinged Itogether, containing rubber or similar flexible members, and the guide means comprises a profile along which ride rollers forming part of the trimming device The trimming device is in,the form of a blade of the appropriate shape carried in a holder. The present improvement is concerned more particularly with the trimming device; it does not affect the general lay-out of the machine, including the handle-supporting units, guide means,and the conveyor. This invention consists in subjecting the cutting blade to an oscillatory movement of rather high frequency and small amplitude while it is making its guided cutting action, so that the blade moves rapidly to and fro across the line of cut. In order to achieve this oscillatory movement the cuttn g blade is preferably mounted in a holder which is oscillated 'about a pivot during its cutting acotion. lPrice 3 s 6 d l Provision is made for laltering preferably both the frequency and the 'amplitude of the oscillatory movement. A constructional form of the invention will now be described with reference to the accompanying drawings in which: Figure 1 is an end elevation showing one of the handle supporting devices in the cutting station.

Figure 2 is a front view thereof, partly in section. The machine,as a whole follows the lines as shown in the drawings,of the parent specification The drawings itherefore show only the cutting station and such parts as are relevant to it Reference numerals pertaining to new parts forming the subject of this invention comtmeace at 71 Reference numerals below that are used o denote parts described in the parent specification where they are identified by the same reference numerals. The handleqsupporting units each comprise a base or platform 25 'carrying guide rollers 24 and a profile 26, together with a cradle having a fixed base 27 and a movable part 31 hinged at 32 to the fixed base 27 The cradle has a ramp 45 which is engaged by a striker + 4 to 'close it against the action of a spring 36 as itr moves towards the cutting station, and it is held,closed by a clip 37 A lever 34 may be arranged to press on the rubber part of the cradle,to fadcilitate the removal of the handles. The outting unit comprises a verntical pillar supported on the urame 10 of the machine and having an arm 51 carrying the spindle 64 about which the cutting device swivels, under the control of the spring '63, as its guide rollers 55, 61 ride along the profile 26 The cutting blade 57 is mounted in 'a holder 52. This holder 52 is itself pivotally mounted for oscdlintg movement 'about a horizontal axis 71 in a further holder 172 which forms part of the vertical spindle 64 The blade holder is provided with a tailpiece 73 which is connected by a universal coupling joint 74 with a,connecting rod 75, the other end of which is attached to an eccentric 76 with provision for varying the,amount of eccentricity, actuated by a fractional horse power electric motor 77 mounted on top of the spindle 64 aforesaid, so that the oscillation mechanism including the motor and blade holder 52 follow the swivelling or turning movement of the spindle The horizontal spindle 78 of the motor 77 drive the eccentric at a speed governed by the speed of the motor, which may be of the order of some 3000 revolutions per minute The setting of the eccentric 76 governs the amplitude of the oscillation given to the connecting rod 75; the latter has a screwed adjustment 79 coupling together upper and lower parts of the rod so that its effective length can be varied Thus the amplitude of the oscillation imparted through the universal joint 74 to the blade holder 52 can be altered to suit different conditions or needs, for instance due to different shapes of handle or different clay bodies The blade 5 i 7 may be of rather stouter design than, the wafer blades hitherto used for this purpose and it may have turned-over edges 80 at top and bottom which fit round the sides of the blade holder and have screws 81 passed through them to secure the blade immovably to the holder The

arm 51 which carries the cotter assembly may have a spring 82 connected to it and to a suitable bolt or the like on the frame of the machine, and alternatively to the spring loading 63 aforesaid coil springs connecting the guide roller holder to a suitable bolt or the like. By means of this improved oscillating cutter motion the trimming machine will operate on the clay handles more smoothly and successfully, giving a smoother and cleaner cut, with a reduced resistance by the clay to the cutting action of the blade, and damaged or imperfectly trimmed handles will be largely avoided. Moreover the new stronger type of blade now described will not need to be replaced at such frequent intervals My experiments suggest that it is possible in this way to use clay handles in various conditions, from soft to hard, with equal success, which has caused difficulties hitherto. It is possible that the oscillatory movement may be contrived in other ways, besides movement about a pivot It is necessary that ithe oscillation shall be cleanly and accurately across the cut face of the clay, but subject to this requirement the invention is not restricted to 'any particular method of producing the movement.

* Sitemap * Accessibility * Legal notice * Terms of use * Last updated: 08.04.2015 * Worldwide Database * 5.8.23.4; 93p