* GB785203 (A)

Description: GB785203 (A) ? 1957-10-23

Lubricating device for refrigeration compressors

Description of GB785203 (A)

We, H Ei Nz Trv Es AND ERNST Au GUST TEVES, both German Citizens trading as ALFRED Tnv Es i M As CH Imx N u ND A Rmii ATURENFABP IK KG, of 41-53 Rebstdcker Strasse, Frankfurt/Main, Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, anid the method by which it is to be performed, to be particularly described in and by the following statement:- The invention relates to a lubricating device for refrigeration compressors As is known, the compressors are surrounded by a closed casing through which the refrigerant vapour is aspirated from the evaporator into the compressor or compressors Situated generally at the bottom of the casing is the oil supply for lubricating the compressor, and, as is known, this is permeated by the refrigerant since the casing is continually under the suction pressure of the refrigerating agent Lubrication of the compressor can be carried out by the method of splash lubrication or by the pressure lubrication method In the latter case oil is sucked by a pump from the oil sump and fed under pressure to the individual lubrication points. Owing to the fact that the lubricating oil contains refrigerant, when the compressor and therefore the pump are started up the expansion causes foaming of the oil, which results in the pump delivering only a very small quantity of lubricant, or none at all This entails the danger that no lubricant may be supplied to the lubrication points, so that the bearings run dry. In order to obviate this disadvantage, the invention proposes a lubricating device for refrigeration compressors in which the lubrication points are connected to an oil receiving ring which surrounds the shaft, and to which oil is fed from the sump by means of a pump by way of a large-surface collector lPrice 3 s 6 d 1 and an overflow container According to the invention the oil receiving rings

are arranged on the shaft so that during opera. tion they act as a centrifugal pump and supply the lubricant under pressure to the places requiring lubrication. The arrangement of collectors of large surface area which cause substantial evaporating-out of the refrigerant-containing oil, and the arrangement of oil receiving rings acting as pumps and serving at the same time as reservoirs, has the result that both when the machine is started and also during operation an adequately large quantity of oil free from refrigerant is always supplied to the places requiring lubrication. In a further feature of the invention, in the case of multi-cylinder machines, an overflow reservoir, an oil receiving ring, and where appropriate a collector is associated with each individual cylinder or each cylinder group, but the rings are supplied by means of a common pump. One constructional form of the lubricating device according to the invention is shown by way of example in the drawing. Mounted in the closed casing 1 is the crankshaft 2, which at the same time serves as the motor shaft Mounted on the crankshaft 2 are two connecting rods 3 and 4 which act upon two pistons (not shown) of two compressor cylinders Situated at the bottom of the casing 1 is the oil sump 5 which delivers the oil required for lubrication A lubricating oil pump 6 sucks oil from the said sump through a suction filter 7 and a pipe 8 and delivers the said oil through pipes 9 and two collectors 10 which are of large surface area and are arranged in inclined fashion. Oil is conveyed from each collector to an overflow container 11 A bore 12 connected to the overflow container supplies lubricant to the crankshaft bearings Furthermore. 785,203 PATENT SPECIFICATION Date of Application and filing Complete Specification. May 17, 1956 No 15468156. Application made in Germany on June 4, 195 5. 6 Complete Specification Published: Oct 23, 1957. Index at Acceptance -Olass 12 ( 3), C( 5 A 1: 25). International Classification:-F 06 n. COMPLETE SPECIFICATION. Lubricating Device for Refrigeration Compressors. 4 j 5 785,203 oil flows from the overflow container 11 by way of an overflow 13 to the receiving ring 14 which is arranged on the crankshaft 2. Owing to the centrifugal effect during operation the lubricant is supplied under pressure through ducts 15 and 16 to the lubrication points.

During operation of the compressor, and thus of the pump, oil is aspirated from the sump and fed to the collectors Owing to the large surface area of the collectors and to the heating of the collectors during operation, the refrigerant is evaporated out. The oil, free from refrigerant to a considerable degree, then passes into the overflow container and thence into the oil receiving rings which supply the refrigerant-free lubricant, to the places requiring lubrication When the machine is stopped, the lower part of the receiving ring is filled with oil which is free of refrigerant, so that, upon starting, a quantity of oil free from refrigerant can be supplied to the places requiring lubrication. The collecting ring is of course so dimensioned that the oil which is situated in the ring at the time of stopping is sufficient to meet the requirements of the lubrication points at the time of starting until oil delivered by the pump is available.

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* GB785204 (A)

Description: GB785204 (A) ? 1957-10-23

Improvements in impact fuzes for explosive projectiles including amechanical self-destruction device

Description of GB785204 (A)

A high quality text as facsimile in your desired language may be available amongst the following family members:

BE547941 (A) CH330867 (A) DE1006317 (B) FR1153517 (A) LU33614 (A) NL93971 (C) US2871788 (A) BE547941 (A) CH330867 (A) DE1006317 (B) FR1153517 (A) LU33614 (A) NL93971 (C) US2871788 (A) 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.

PATENT SPECIFICATION 7 $ Date of Application and filing Complete Specification: Xk Dray 22, 1956 No 158 Z 1156. a) 4 | Application made in Luxembourg on Mlay 24, 1955. Complete Specification Published: Oct 23, 1957. Index at Acceptance: -Class 9 ( 1), A 5 (A 1: A 5: A 7: 04: X). International Classification:-F 07 f. COMPLETE SPECIFICATION. Improvements in Impact Fuzes for Explosive Projectiles including a Mechanical Self-Destruction Device. We, BREVETS ARRO-MECANIQUES S A, a Company organised and existing under the laws of Switzerland, of 12 Rue de Hollande, Geneva, 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 performed, to be particularly described in and by the following statement:- The present invention relates to impact fuzes for explosive projectiles, and in particular for small calibre shells (of a calibre ranging from 20 to 50 mm) for anti-aircraft automatic guns, said fuzes being intended to be mounted on projectiles having a movement of rotation about their axis and which include a self-destruction device including at least one centrifugal locking member kept in locking position as long as the speed of rotation of the projectile about its axis remains above a predetermined value, said locking member temporarily holding in waiting position an intermediate member capable, when released and under the action of a resilient system, of setting off the fuze by displacement of a movable part which is generally a firing pin Self-destruction devices comprising centrifugal locking members constituted by a ring segment or segments are described in our Patent Specification Nos 725,821, 624,811 and 605,683. It is well known to provide mechanical fuzes with a push-piece which acts directly on the firing pin. The object of our invention is to provide a fuse which is better

adapted to meet the requirements of practice than those used up to this time, and in particular which works always in the same fashion irrespective of the value of the impact shock (provided of course this shock is sufficient). lPrice For this purpose, according to our invention, we provide, in the front portion of the fuze body, a push-piece operative by an impact shock and mounted to act directly, 45 through its displacement caused by said shock, on said locking member so as to produce the retraction thereof and consequently the release of the intermediate member which then communicates to the movable part 50 (firing pin), under the sole action of the resilient system (that is to say irrespective of the violence of the impact shock), a displacement which sets off the fuze. A preferred embodiment of our invention 55 will be hereinafter described with reference to the accompanying drawings, given merely by way of example and in which:Fig 1 is an axial section view of an impact fuze made according to our invention, said 60 fuze being shown in the state of rest, that is to say such as it is before the projectile is fired. Figs 2 and 3 are half-sections showing the positions of the parts of this fuze at two 65 different times during the operation thereof. Inside an ogive-shaped fuze body 1 there is provided an axial cylindrical hole 2 in which is slidable axially a first sleeve 3 the rear part of which is surrounded by a spring 70 ring 4 the rear edge of which bears against a shoulder 5 provided in said sleeve 3, said ring 4 and shoulder 5 being located in an enlarged hole 6 in line with the hole 2 at the rear thereof 75 Sleeve 3 is provided, rearwardly of shoulder 5, with a transverse cylindrical housing 7 in which are slidably guided two cylindrical masses 8 the outer ends of which are of frusto-comncal shape So A second sleeve 9 is slidable axially in the first sleeve 3 and it is provided with radial 5,5204 _ _ 785,204 housings 10 each of which contains a centrifugal mass constituted by a ball 11 which, in its position at the maximum distance from the axis of the fuze body, is applied against a the bevel-shaped edge 3 a of sleeve 3, this front edge 3 a therefore acting as a frustoconical cam Sleeve 9 forms a housing for a spring 12 surrounding a firing pin 13 The rear end of said spring 12 is applied against a shoulder 9 a integral with sleeve 9 The front end of spring 12 is applied against a piece 18 applied frontwardly against a shoulder of the fuze body 1 and will be more explicitly referred to hereinafter. In the position of rest, the elements of this fuze occupy the positions indicated by Fig 1. Sleeve 3 is kept in its rear position by spring ring 4 and the firing pin 13 is held in fixed position because its collar or its shoulder 14

is applied against the two masses 8 which are themselves held in a housing having oblique walls 15 provided in a threaded plug 16 fixed on the rear portion of the fuze body 1. Said plug 16 is provided with another housing 17 intended to receive the detonator which may for instance be of the delay type. Before describing the essential feature of our invention it seems preferable, for the sake of clarity, to explain how the system above described will operate when the shell is fired. As soon as said shell leaves the gun and under the effect of the centrifugal forces created by the rotation of said shell, the balls 11 are applied against the bevel-shaped front edge 3 a of sleeve 3, thus temporarily preventing any possibility of rearward movement of the inner sleeve 9 with respect to sleeve 3 On the other hand, said centrifugal forces cause ring 4 to expand (thus releasing sleeve 3) and masses 8 to move radially in the outward direction Said masses, by reaction against inclined walls 15, push frontwardly the whole of sleeves 3 and 9 and firing pin 13 Finally, the external sleeve 3 is locked in its forward position by masses 8 which are at the maximum distance from each other and which then release the enlarged portion 14 of the firing pin 13, the inner sleeve 9 being held in its forward position by balls 11. The fuze is then ready to be set off, in case of impact upon an obstacle, by percussion means which will be explained hereinafter and the various parts of said fuze occupy the positions illustrated by Fig 2. If no obstacle is struck by the shell, automatic destruction thereof will take place at the time the centrifugal force acting upon the balls 11 is no longer sufficient to balance the action of spring 12 This spring will first compel balls 11 to retract in their housings 10, then it will push the inner sleeve 9 thus released and the firing pin 13 toward the primer of the detonator, thus operating the fuze and causing destruction of the shell. Up to the present time, in order to ensure operation of the fuze in case of an impact of the shell upon an obstacle, the firing pin was directly exposed to the impact shock. The drawback of such an arrangement is 70 that the percussion effect is dependent upon the violence of said shock, which does not permit of determining in advance, when the fuze is being manufactured, the optimum conditions of percussion and in particular the 75 force with which the firing pin is to strike the primer of the detonator. The object of the present invention is to obviate this drawback, that is to say to make the percussion effect, when the shell strikes SO an obstacle, practically independent of the violence of the impact shock, provided of course that this violence exceeds a predetermined minimum.

According to our invention, we provide in 85 the front portion of the body 1 of the fuze a push-piece 18 exposed to the impact shock and which acts directly upon the locking balls 11 for retracting them into sleeve 9 when there is an impact of the shell upon an go obstacle Advantageously, said push-piece is protected within certain limits by a relatively thin disc 19 capable of resisting slight shocks of a violence lower than the minimum violence under which the fuze is to operate 95 In order to enable push-piece 18 to retract the balls 11 into sleeve 9 when there is an impact of the shell upon an obstacle, it suffices to give the rear end of said pushpiece the shape of a sleeve the rear edge of 100 which 18 ac is frusto-conical so that said rear edge can, when push-piece 18 is driven rearwardly into the fuze body, compel balls 11 to retract into their respective housings 10. Fig 3 shows the positions occupied by the 1 U'S elements of the fuze just at the time impact occurs, that is to say when push-piece 18 has caused balls 11 to retract into the housing 10 and the whole of sleeve 9 and firing pin 13 is going to be driven rearwardly 110 by spring 12, as indicated by arrow F. Itwillbe seen that, withlsuch a construction, the greatness of the impact shock has no influence upon the operation of the fuze and this result is obtained merely by the addition 115 to a self-destruction mechanical device as above described of a supplementary part, namely the push-piece 18.

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* GB785205 (A)

Description: GB785205 (A) ? 1957-10-23

A new complex calcium salt of 4-aminosalicylic acid and method for preparingsame

Description of GB785205 (A)

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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.

COMPLETE SPECIFICATION A New Complex Calcium Salt of 4"Aminosalicylic Acid and method for preparing same We, GOHEI TANABE AND Co. LTD., a Body Corporate, organised under the Laws of Japan, of 21, Dosho-Machi 3-Chome Higashiku, Osaka, Japan, do hereby declane the ininvention, for vzhkh we pray that a patent may be granted X us, and the method by which it is to be performed, to be particularly describes in and by the following statement: - This invention relates to a new complex salt of Saminolsahcylic acid and the preparation thereof. 4-aminosalicylic acid has been of great importance in the treatment of tuberculosis in human b-eings. This compound has to be admiinistered in large doses and often for' a long period of time. When the free acid is used in large doses required, excessive acidity has resulted in serious gastric disturbances in a number of patients. Suggestion has been made ro make USR of the sodium salt which is readily obtainable and which, like the free acid itself, is stable in storage. However, the required large doses are liable to introduce too much sodium into human tissues, thus upsetting potassium balance and producing undesirable side-effects. The calcium salts, both neutral and basic, are unstable in storage and difficult to be orally administered because of their bitter taste. The calcium salt of alumino-4-aminosalicylic acid according to the invention is characterized in that it consists of calcium alumino4-aminosalicylate containing calcium and 4aminosalicylic acid and aluminium in the molecular ratio of 1:2: 1. According to this invention, it bas been found that, when calcium ,alumino- 4-aminosalicylate is prepared by a neutralizing or metathetical reaction of a member selected from the group consisting of free alumino-4aminosalicylic acid, its ammonium salt and its alkali metal salts, upon a member selected from the group consisting of calcium hydroxide and water-soluble calcium salts, such as calcium halide, calcium nitrate or calcium acetate, the complex salt obtained

is hardly soluble in water and suitable for oral administration. This compound, being stable for a long period of time, is the most palatable salt among the 4-aminosalicylates ever prepared. Furthermore, it has been found that, when this salt is administered orally, a prolonged 4-amino- salicylic acid blood level can be maintained. This compound may be repkesented by the following formula, in which "n" stands for 3 to 5: <img class="EMIRef" id="026581666-00010001" /> Molecular ratio of calcium:4 - aminosalicylic acid: aluminium in this compound is 1:2:1. Free alumino-4-aminosalicylic acid and its ammonium or alkali metal salts may be prepared by a similar process to that for preparing aluminosalicylic acid and its correspond- ing salts described in J.C.S. (London) 1928. Part I, pp. 222-229. Preferably, allumino-4-aminosalicylic acid, which occurs as white powder hardly soluble in water, is prepared by a metathetical reac tion of an ammonium salt or an alkali meal salt of 4-aminosalicylic aad upon a water siuble aluminium salt, such as ?.- clnlcridz, the sulfate, or potassium or ammonium alum, in the presence of an alkali, such as sodium bicarbonate. The acid contains aluminium and 4-aminosalicylic acid in the molecular ratio of 1:2 and is combined with 2-3 mols of crystallisation water The reactions may be typicaliy illustrated, as flows: <img class="EMIRef" id="026581666-00020001" /> wherein "n" stands for 2 to 3. Calcium alumino-4-aminosalicylate can be prepared by neutralizing an aqueous suspension of alumino-4-aminosalicylic acid with an aqueous suspension of equivalent calcium hydroxide, preferably at 30--40"C. An alternative process for preparing this compound involves a metathetical reaction of a member selected from the group consisting of ammonium salts and alkali metal salts of alumino-4-aminosalicylic acid, upon a water soluble calcium salt, such as the chloride, the bromide, the nitrate, the acetate or the formate. Upon drying the salt, some ofthe crystallization water effloresces, and tetrahydrate is ordinarily obtainable. Ammonium salt and alkali metal salts of alumino-4-aminosalicylic acid can be prepared by neutralizing in water alumino-4-aminosalicylic acid with equivalent ammonium hydroxide or an alkali metal hydroxide, preferably sodium hydroxide. For the - metathetical reaction, ammonium alumino-4-aminosalicylate is of the most advantageous use. Specific examples are given below to illustrate the invention. The word "part" shall be understood in terms of weight.

EXAMPLE 1 Add 118 parts of crystalline potassium alum dissolved in 500 parts of water to a solution of 105 parts of sodium 4-aminosalicylate and 10 parts of sodium bicarbonate. Warm the mixture up to 40"C and stir it for 3 hours. Whereupon, alumino-4-aminosalicylic acid is precipitated. 85 parts of alumino-4aminosalicylic acid is obtained by filtering and drying the precipitate in vacuo. A clear aqueous solution of sodium alumino4-aminosalicylate is obtained by dissolving 42 parts of alumino-4-aminosalicylic acid trihydrate in a suspension of 8 parts of sodium hydroxide and 185 parts of water. Add to this solution (pH 7.8-8.0) 15 parts of calcium chloride dihydrate dissolved in 15 parts of water. Stir the mixture at 40"C. for 2 hours, and cool it Then, 50 parts of calcium alumino-4-aminosalicylate is obtained by filtering, washing with water and drying in vacuo. This salt contains calcium and 4-aminosalicylic acid and aluminium in the molecular ratio of 1:2: 1. EXAMPLE 2 Add a suspension of calcium hydroxide freshly prepared with 14.7 parts of calcium chloride dihydrate and 8 parts of sodium hydroxide in 80 parts of water, to a suspension of 42 parts of alumino-4-aminosalicylic acid trihydrate dispersed in 160 parts of water. Stir the mixture at 40 C for 2 hours, and cool it. Then, 40 parts of calcium alumino-4-aminosalicylate is obtained by filtering, washing with water and drying in vacuo. EXAMPLE 3 Dissolve 17 parts of alumino-4-aminosalicylic acid trihydrate in 56 parts of 3.1 to aqueous ammonium solution, so as to form ammonium alumino-4-aminosalicylate. Add to the solution 7 parts of calcium chloride dihydrate dissolved in 7 parts of water. Stir the mixture at 40"C for 2 hours, and cool it. Then, 17.8 parts of calcium alumino-4-aminosalicylate is obtained by filtering, washing with water and drying in vacuo. What we claim is: - 1. A new complex calcium salt of alumino4-aminosalicylic acid characterised in that it consists of calcium alumino-4-aminosalicylate containing calcium and 4-aminosalicylic acid and aluminium- in the molecular ratio of 1:2:1. 2. Process for preparing a calcium alumino4-aminosalicylate according to claim 1, characterised in that it comprises a neutralising or metathetical reaction of a member selected from the group consisting of free alumino-4aminosalicylic acid, its ammonium salt and its alkali metal salts, upon a member selected from th- group consisting of

calcium hydroxide and water-soluble calcium salts, such as calcium halide, calcium nitrate or calcium acetate. 3. Process for preparing calcium alumino-4aminosalicylate containing calcium and 4aminosalicylic acid and aluminium in the molecular ratio of 1:2:1, which involves a metathetical reaction of sodium alumino-4aminosalicylate upon a water-soluble calcium salt. 4. Process for preparing calcium alumino-4aminosalicylate containing calcium and 4

* GB785206 (A)

Description: GB785206 (A) ? 1957-10-23

Card stacking device

Description of GB785206 (A)

PATENT SPECIFICATION Date of Application and filing Complete Specificaiion May 29, 1956 No 16625156. Application made in United States of America on May 31, 1955. (C 3 ' rplete Specification Published: Oct 23, 1957. Index at Acceptance:-Class 146 ( 1), E( 1 C: SB: 9 A:19 F 4 B 19 G). International Classification:-B 421. COMPLETE SPECIFICATION. Card Stacking Device. We, EASTMAN KODAK COMPANY, a Company organised under the Laws of the State of New Jersey, United States of America, of 343 State Street, Rochester, New York, United States of America, (assignees of JOHN ROBERT CUSHMAN), 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 particulo larly described in and by the following statement:- The present invention relates generally to card handling devices, and more particularly to a device adapted to support and transport a stack of miniature photographic films. In certain types of record keeping systems relatively small photographic films are used in lieu of conventional cards for storing

coded information For example, a rect" O angular piece of photographic film sixteen by thirty-two millimeters may be used for storing records of documents eight and onehalf by fourteen inches Photographic films of this type are handled in quantities of the order of two thousand in a stack, and it is necessary to move such stacks from storage files to and between various types of film handling and record translating or interpreting machines. The principle object of this invention is to provide a device for picking up and removing a stack of photographic films to or from a magazine without moving the magazine and without utilizing any additional retaining member to hold the stack of films on the device. In accordance with the present invention there is provided a card handling device for a plurality of cards having a slot adjacent to one end thereof, comprising an elongated member congruous in cross section with said slot and serving as a guide for a slide memlPrice p ' ber carrying at one end thereof a keeper which upon movement of the slide member relatively to the guide, is movable along a cam surface on the guide for displacement from a position in which it is in alignment with the guide to a position in which it retains the cards mounted on the device. In order that the invention may readily be understood, reference will now be made to the accompanying drawing, in which:Fig 1 is a perspective view of a card handling device constructed in accordance with one form of the invention; Fig 2 is a side elevation of the device shown in Fig 1 with a stack of cards indicated as mounted thereon; Fig 3 is an elevation, to an enlarged scale, of the lower end of the device shown in Figs 1 and 2; and Fig 4 is a plan of a card adapted to be handled by the device. As illustrated, the card handling device comprises a handle 10 within the central portion of which is fixedly mounted a guide member 11 having folded over retaining members 12 disposed in spaced relation to the rear portion 14, thereby to provide a guiding means for supporting an elongated slide 15 Slide 15 extends through the handle end of guide 11 and is provided with a handle 16 A compression spring 17 normally holds the slide 15 in a retracted position. At the lower end of the slide 15 there is provided a keeper 18 which includes a pin member 19 over which the end of the slide is folded The keeper 18 co-operates with a pair of raised camming surfaces 20 formed at the lower end of the guide 11. Thus, when the slide 15 is reciprocated within the guide 12, the keeper 18 slides off the camming surface 20 into alignment with the guide 11. 7859206 6,5 SC 785,206 The device is operated by pressing downwardly on the handle 16 to extend the slide outwardly of the cam surfaces 20,

whereby keeper 18 aligns itself with the guide 11. The lower end of the device may then be inserted through a slot 22 in each of a stack of miniature films 23 Thus, the device penetrates slot 22 of each miniature film in the stack until it extends all the way through the lowermost film therein By relieving the pressure on handle 16, the keeper 18 is drawn backwardly by means of the spring 17 acting on the slide 15 and over the camming surfaces 20, so that the keeper 18 engages the underneath surface of the lowermost film in the stack and locks the stack on the device Thereafter the stack may be handled without danger of the films becoming scattered.

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* GB785207 (A)

Description: GB785207 (A) ? 1957-10-23

Improvements in ships' stabilizing fins

Description of GB785207 (A)

PATENT SPECIFICATION Date of Application and filing Complete Specification June S 1956. air __ No 17331/56. \ 4 f 1 Complete Specification Published Oct23, 1957. Index at Acceptance: -Class 113, M. International Classification: -163 b. COMPLETE SPECIFICATION Improvements in Ships' Stabilizing Fins I, FRANZ SUBERKRUB, a German Citizen, of Chilehaus CVI, Hamburg, 1, Germany, 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: -

It is known to provide a ship with angularly-movable stabilizing fins having aero-foil section profiles, the fins being mounted externally on both sides of the ship at about the level of the bilges in order to reduce the rolling movements of the ship during forward motion in a seaway The angular movements of the fins, which movements are actuated from the inside of the ship, must take place after every period during which the ship has heeled over at the moment when the fins have reached their highest and lowest positions respectively. The fins are then turned in such a way that their profiles form a certain angle of attack, e.g 200 with respect to the general direction of the water flowing against them, whereby the induced "lift" on the fins counteracts the next heeling movement of the ship. It is also known to use fins with permanently symmetrical profiles The advantage of such fins, as compared with fins having an angular movable rear end and, therefore, not permanently symmetrical profiles, is that the hydrodynamic centre of pressure changes its longitudinal position, i e, with respect to the direction of the passing water, at various angles of attack considerably less than in the case of fins which have non-permanently symmetrical profiles On symmetrical profiles with angles of attack up to about 100 the hydro-dynamic centre of pressure hardly moves at all Only at larger angles does the centre of pressure move toward the rear while at such larger angles the total hydro-dynamic pressure on the fins increases rapidly at the same time. In order to keep the torque forces necessary for turning the fins to a minimum on a known device having symmetrical fins, it is arranged that the centre line of the turning shaft shall be in line with the hydro-dynamic centre of pressure at the maximum angle of attack. lPrce 3 s 6 d l According to the present invention, however, also by using fins having permanently symmetrical profiles, the centre of pressure of the attacking forces at the maximum angle of attack is arranged to lie behind the centre line of the turnable shaft The term " permanently symmetrical " is used herein to indicate onepiece fins which are movable as a whole but which do not include any parts between which relative movement can take place. The invention consists in fins for damping the rolling movement of ships extending below the water line at both sides beyond the ship's hull, such fins having a permanently symmetrical aerofoil section profile and being arranged to be turned angularly from the inside of the ship, characterised by such positioning of the axis of the turnable shaft of the fin with respect to the hydro-dynamic centre of pressure that, at maximum angles of attack of the fins the hydro-dynamic centre of pressure lies behind the axis of the turnable shaft.

Reversing of the angular position:of the fins must take place at the moment when the heeling movement of the ship to one side reaches a maximum and then begins to reverse, i.e when the ship starts to roll back to the other side Reversing of the fins must then be effected quickly, say within one or two seconds. The weight of the fins is considerable, e g 20 tons It is obvious, therefore, that the quick turning of these masses, especially at the start of the movement, requires a lot of energy to overcome the moment of inertia With fins designed according to the present invention, i.e with the centre of the hydro-dynamic pressure at large angular positions of attack falling behind the centre line of the turnable shaft, the external forces on the fins will materially assist the start of the angular reversing movement On the other hand, the same external forces will act as a brake to stop the turning movement when the fins reach their new maximum angular position In this way the required power of the shaft turning machinery in the inside of the ship can be reduced accordingly. The accompanying drawing shows, by way 785,207 of example, the profile of a fin constructed in accordance with the present invention. The fin 1 is shown arranged at a maximum angle of about 200 with respect to the direction 2 of the attacking water The turnable shaft 3 to which the fin is fitted has its axis somewhat forward of the hydrodynamic centre of pressure 4 At this point, the concentrated hydro-dynamic forces 5 press in a vertical direction when the ship is heeling over to one side and thus damp the rolling movement. In the position of the fin as shown on the drawing the fin is assumed to be moving downward After the fin has reached its lowest position and starts to move upward again the hydro-dynamic torque on the fin assists the torque requirements of the machinery in the ship, thus assisting the initial moment of inertia to be overcome While the fin is turning, the hydro-dynamic centre of pressure at first moves in a direction towards the forward edge of the fin and then moves rather quickly rearwardly again when the fin is nearing the limit of its new angular position, which is intended to damp the upward movement In this new position the hydrodynamic forces press the fin downward and act at the same time as a braking force to stop the angular reversing movement of the fin.

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