US2459572A - Breech-loading mechanism for ordnance - Google Patents

Description

Jan. 18,v 1949.

Filed March 15, 1943 D. W. MOI-INS BREGH LOADING MEcHANIsM FOR OBDNANCE .'4 Sheets-Sheet 1 7i fue wrm ATTORNEY Jan. 18, 1949. D, w. MoLlNs I BREEGH LOADING MECHANISM FoR oRDNANcE- Filed March 13, 1943 4 Sheets-Sheet 2 ,qTToR/YEY fyi Jany18, 1949. D. w. MoLlNs 2y459572 BREECH LOADING MECHANISM`FOR ORDNANCE- Filed MICh 13, 1943 4 Sheets-Sheet 3 Jan. 18, 1949; D. w. MoLlNs 2,459,572

BREECH LOADING MECHANISM FOR ORDNANCE Filed March 15, 1943 4 Sheets-sheet 4 Patented Jan. 18, 1949 2,459,572 ICE BREECH-LOADING IVIE'CHANISM FOR ORDNANCE Desmond Walter Molins, Deptford, London S. E..

8, England, assigner to Molins Machine Company Limited, London, England Application March 13, 1943, Serial No. 479,119 In Great Britain August 20, 1941 Y 4 Claims.

This invention concerns improvements in or relating to breech loading mechanism for ordnance.

Various devices are already known for automatically ramming shells into the breeches of guns, some being hydraulically operated and some electrically operated. Hand ramming devices are also known in which the shell after being placed in the loading tray is carried by the moving tray when the latter is swung in front of the breech so as to be in alignment with the breech. In certain constructions a carriage, arranged to travel along a track located at the side of the semi-circular shell guide of the loading tray, is providedv with a projectionwhich engages the base of the shell and when the carriage is actuated, ramsthe shell into the breech. Ramming is executed in such a case by means of a cable running over a pulley at the breech end of the gun, so that on pulling the cable the carriage is moved up the track and rams the shell home. The carriage is returned to its original position either by a second cable or by being slid back by hand, a suitable handle being provided for the purpose. Means are known whereby this system is electrically operated. In this `case the cable is attached to the ram in both directions so that pulling on one cable eiects the ramming stroke and pulling on the other cable eiects the return. The two cables are connected to one shaft and wound round in opposite directions so that by rotating the shaft a suitable number of revolutions rst in one direction and then in the reverse direction, a cycle of ramming and return is eilected. This shaft is connected up to an electric motor and by suitable switch mechanism together with a reversing switch, automatic ramming is provided.

It is an object of the present invention to provide a power driven ramming device in ordnance of the kind having a loading tray ymovable between a loading position and a ramming position, such ordnance being referred to hereinafter as ordnance of the kind described.

According to the invention there is provided in breech loading mechanism for ordnance of the kind described, a carriage arranged to be reciprocable along a guide track on the loading tray and adapted to act as a ram to .propel a cartridge or shell into the breech on the forward stroke, a source o power (e. g. an electric motor) mounted at a positionv remote from said loading tray, and a mechanical coupling between the source of power and the carriage, said coupling including a flexible shaft.

The exible shaft may be connected to a gearwheel rotatably mounted lon the carriage and geared to a rack which is fixed relatively to the guide track. The invention is not, however, limited lto a direct connection between the flexible shaft and the carriage for, providing the flexible shaft is included in the driving devices, the advantages s et forth below are obtained. Means may be provided for arresting the carriage at the end of each movement along the guide track, comprising an arrangement for -cutitng oir the power drive to the carriage, and buiiers on said carriage.

Where an electric motor is employed, the means for arresting the carriage may comprise regenerative braking.

By such an arrangement, several important advantages are obtainable. By mounting the source of power at a point other than on the loading tray, the weight of the latter is kept down, the number of electric cables movable with the tray is kept low, both oi which features are important for e'lcient operation of the ordnance, and further, the employment of a flexible shaft provides a resilient drive and acts to reduce the shock on the motor and other parts at the beginning and end of a stroke of the carriage. Thus the present invention provides a device which is simple and reliable and easy to maintain.

One example of a breech loading mechanism made in accordance with the present invention for use with 3.7" anti-aircraft guns will now be described with reference to the accompanying drawings in which:

Figure l is an elevation oi the breech end of the gun showing the loading tray, motor and iiexible drive.

Figure 2 is a plan of the tray member. l

Figure 3 is a plan view, on a larger scale, of the carriage and associated parts, partly broken away. Y

Figui-e4 is a view of Figure in the direction of the arrow A and partly in section.

Figure 5 is a diagram of the electric circuit and certain mechanically operated parts for controlling the same, said figure indicating in solid lines the positions of the parts at the end of the ramming stroke.`

Like reference numerals refer to like parts throughout the several gures of the drawings.

Referring to the drawings: the loading tray I of the gun is arranged to swing on an axis 2 parallel to the gun barrel 3 and is movable between two angular positions, one being the loading position and the other being the ramming position. In the latter position the shell in the tray is in alignment with the barrel. The loading tray is provided with a shell guide t of semi-circular cross-section. At the side of this semi-circular shell guide there is a channel 5. A toothed rack B is provided in the channel extending along the length of the channel and a carriage `'l provided with side rollers 3 and a top roller S is arranged to run along al guide member 2li xed in the channel and to be coni-ined to movement along the channel. In Figure 3 the rack isbrok-e'n away for clearness, the vparts being connected by the pitch line. An intermediate gear wheel I is rotatably mounted on the carriage and tis adapted to mesh with the teeth of the toothed rack. This gear wheel is driven by vanother gear wheel II from an electrical motor I2 which is coupled to a shaft I3, mounted on roller bearings tted in the carriage v'I, and on "which Vthe gear wheel l I is mounted, through a flexible -ca'ble drive Ill. This drive comprises ya steel ycable -VI-5 enclosed within a thick rubber tube t6, the cable and rubber tube being coupled to the rotating and non-rotating parts respectively of Vthe car-` riage and motor as the `case may be. The actual coupling is not in itself new and anyconvenient construction can be used for 'the purpose. The carriage l is provided with a rammer -head 22, 4Figure 2, which engages the base of :the shell.

Buiers il are fitted on the carriage and furnished with a spring I8. The buiers `help Ato Aarrest the carriage at leachend of'its movements by striking against abutments suitably llocated -on the loading tray,

The electrical motor l2 may bemounted 'in any suitable position o-n the gun mounting and, as shown, is fixed on the counterpoise and fsuitable switch means, mounted on the motor, `isprovided to cause the motor, when the switch is operated, to'turn the requisite number of revolutions suilin cient to drive the carriage the necessary distance for effecting the ramr'ning and then automatically to stop the motor.

Referring to Figure 5, the electrical circuit', comprises a throw-over switch TO which is adapted to make contact alternately with terminals on one or 'the other of two paths which form parts of alternative circuits. One of these circuits is fior ythe ramming stroke and the other for the return Stroke. This throw-over Switch is'mou'ntedoh the loading tray and when the tray enters the vramming position engages a contact on the ram'ming circuit and when in the loading position engages a contact on the return circuit. Associated with each of these alternative circuits there nis also a mechanically operated limit-switch R11/L 4and RL respectively and there is also provided la switch attached to the usual 'tray release catch 23 and marked'TRS. The limit-switches Rm'L and RtL are brought into operative condition for the respective strokes by contacts which are made land broken as necessary by the movements 'ofthe arms of the switch TO though they do not lorm part of the main circuits controlled by this switch. The switch TRS is so arranged that when the tray release catch 23 is actuated 'to lock the tray in either of its two positions -the contacts are closed. The limit-switches appert'aining to lthe two alternative circuits may be of any known type and are normally held in a closed position. The contact made by these 'limit-switches is arranged to be broken when the -motorlhas 'rotated the necessary number of times to cause *the Vcarriage to complete the rarnming or return stroke as the case may be. In the example described, the parts are geared up so that'th'e motor rotates 1'0 revolutions for the ramming stroke and 10 revolutions for the return stroke. In 10 4'revoluti'oi-is of the motor a cam 24 geared to the ymotor s'haft rotates half a revolution The cam is vmounted on a worm-wheel 25 which is vdriven vby a worm 26 on the motor shaft, the reduction ratio -bein'g 20:1. This cam is arranged at the fend fof half a revolution to break the appropriate limit-switch. When vthe loading -tray -is in the lra'lriinin'g Tpos'ition the .throw-lover switch makes `4contact with the terminal in ethe rammin'g circuit. The circuit is not, however, completed until the hand opera'ted switch TRS is actuated. This is done by the operator after he has swung the tray into the ramming position and allowed the catch of the 'locking device to engage its notch. The circuit Tis then completed :and the carriage is driven by vthe motor'through the ilexible coupling and gear vwheels. When `the motor has rotated the necessary vnumber of revolutions to cause the carriage to `have rammed the shell home, the cam on the worm wheel breaks the limit-switch appertaining -to 'th'e ramming circuit and the motor and carriage are stopped. Theicircuit is so arranged that the motor 'is 'automatically braked by 'regenerating ibrakingl as 'described below. The loading tray is then manually swung outwardly to the loading position `in 'readiness to receive fthe next :shell and to allow `the -breech to be closed and this 'movefm'enit tof the loading ltray causes the throwover switch to disconnect fthe ramming circuitand .to 4'connect aipfto'the return-circuit. On "-Iockingthe 'tray in this position vthe Yhand roperated switch TRS closes the=contacts, the motor 'Irotatesin -the .reverse direction and the return stroke is `then oonfipleted. The motor is la'gain stopped 'when the cam yon the 'worm-wheel (or a separate `cam if `desired) throws out "the limit-switch apper taining vto the v.return circuit. It will be evident from the fioregoing 'that .the framming and return circuits iare lso arranged that fthe current is reyversed through the-armature fand Aso the-motor Arotates in opposite Idirections for the rammin'g and return movements. The handles and other parts for fma'nlually swinging the tray have been omitted iromthe :drawings as they do-'not concern 'theflpresentinviention As the apparatus is intended for Ause in the iield, the motor, which iis preferably compound Wound, may be driven by a battery B which, in the "example being described, is a y'24 volti'storage battery. Tofassist in 'rapidly stopping the `motor at the end of la carriage llr'no'vement, regenerative bra-mug 1me`anslis1-provid'ed, which operates as the appropriatelimit-Switch is broken. For this purpose, one linefrom theb'atteryleads to'the Aswitch IIRS and Ithrough fthe fswi-tch tolalliinlt -swtchand thenceltothe coils *of fa contactor -'C and afshunt sc'ld relay fSFR in parallel "there-with,- Ivto 'the other linie -andback to fthe battery. 'The first 'line also passes lto the motor `through lthe 'series field SF and via the switch TO 'to the armature A and to one contacta of the contacter, being tapped ybetween the fterminal jof the switch TRS and a series iielft'by 4lines leading to fa second contact b of the Acontactor and -tofone 'terminal of the shunt Held ShF @respectively The other end of the shunt field is connected 'to yone contact re of the shunt field relay and the second contact f ofsaid i'elayfiscorinected tothe other pole of the-battery, being tapped -en Aroute for the other ends -of 'the contacter 'and shunt field relay coils and for a line vleading te a third contacter lcontact c. `The fourth contacter Contact d is joined `to the rst contact. :A condenser Land resistance rare 'shunted ac'ifcsslthe s'hun'tfeldrelay contact.

When the 'switch TRS 'is turned to the on position, fe. fg. as 'the trayfis locked in itheframming position, the moving contact baro'f the contactor is 'connected vto the 'nrst and third contacted. e. the lower pair in Figure f5) and the shunt eld is 'Ienergised by fthe shunt `field relay so vthat the motor Bruns y.as La compound motor. When Ithe limit-switch RmL fis broken las Ithe carriage reaches the end of the ramming stroke, the contactor bar moves back by spring pressure to the second and fourth contacts o and d (i. e. the upper Dair in Figure and the series eld and armature are short circuited. Meanwhile the shunt ield is still energised due to the delay action incorporated in the shunt eld relay, so that the back E. M. F. of the motor flowing through the low impedance oi the armature and series field gives instant and heavy regenerative braking; after a period of say half a second the shunt eld relay opens and the shunt field ceases. A similar sequence of events takes place on the return stroke when the tray is locked in the loading position.

Figure 5 illustrates in solid lines the positions occupied by the various parts when the ramrning has just :been completed, the limit-switch RmL has just been broken by the cam 2d, and the contact bar of the contacter has sprung back to the contacts b and d.

With the exception of the hand operated switch and the throw-over switch the switch arrangements described above are housed in a casing xed to the motor itself and thus the motor and the limit switch can be located on a part of the gun mounting out of the way. With the construction described above there is only the flexible drive between the motor and the loading tray, and thus there is very little, if any, increase in the weight of the loading tray. It is found a simple matter in practice to arrange the motor at a convenient distance from the ramming carriage so that the flexible cable does not adversely airect the operation of loading or firing the gun.

While the above construction involves the use of a direct current electric motor it will be appreciated that any other suitable source of power may be used for driving the flexible shaft, for example other forms of electric motor or any suitable form of uid motor.

What I claim as my invention and desire to secure by Letters Patent is:

l. Breech loading mechanism for ordnance of the kind described comprising a loading tray movable between a loading position and a rarnming position relative to a gun, a guide track on the loading tray, a carriage arranged to reciprocate along said guide track and adapted to act as a ram to propel a cartridge or shell into the breech on the forward stroke, an electric motor for driving said carriage mounted at a position remote from said loading tray and relative to which the loading tray can move, means for energizing the motor throughout the ramming stroke of said carriage and for automatically de-energizing the motor only after the carriage has completely rammed the cartridge or shell into the breech, and a, mechanical coupling between the motor and the carriage, said coupling including a resilient torsional drive means so constructed and operatively connected to the motor and carriage as to reduce the shock on the motor and other parts when the carriage is abruptly brought to a stop at the end of a rapid ramming stroke.

2. Breech loading mechanism for ordnance of the kind described comprising a loading tray movable between a loading position and a, ramrning position relative to a gun, a guide track on the loading tray, a carriage arranged to reciprocate along said guide track and adapted to act as a ram to propel a cartridge or shell into the breech on the forward stroke, a motor for driving said carriage mounted at a position remote from said loading tray and relative to which the loading tray can move, a mechanical coupling between the motor and the carriage, said coupling including a resiliently flexible shaft driven by the motor, a rack which is fixed relatively to the guide track, and a gear wheel rotatably mounted on the carriage in geared relation to said rack and operatively connected to the flexible shaft to be driven thereby.

3. Breech loading mechanism for ordnance of the kind described comprising a loading tray movable between a loading position and a ramming position relative to a gun, a guide track on the loading tray, a carriage arranged to reciprocate along said guide track and adapted to act as a ram to propel a cartridge or shell into the breech on the forward stroke, a motor for driving said carriage mounted at a position remote from said loading tray and relative to which the loading tray can move, a mechanical coupling between the motor and the carriage, said coupling including a resiliently iiexible shaft driven by the motor, a rack which is fixed relatively to the guide track, a gear wheel rotatably mounted on the carriage in geared relation to said rack and operatively connected to the ilexible shaft to be driven thereby, and means for arresting the carriage at the end of each movement along the guide track, said means comprising means for discontinuing the operation of said motor, and buffers on said carriage.

4. Breech loading mechanism for ordnance of the described comprising a loading tray movable between a loading position and a ramming position relative to a gun, a guide track on the loading tray, a, carriage arranged to reciprocate along said guide track and adapted to act as a ram to propel a cartridge or shell into the breech on the forward stroke, an electric motor for driving said carriage mounted at a position remote from said loading tray and relative to which the loading tra-y can move, a mechanical coupling between the motor and the carriage, said coupling including a resiliently flexible shaft driven by the motor, a rack which is fixed relatively to the guide track, a gear wheel rotatably mounted on the carriage in geared relation to said rack and operatively connected to the eXible shaft to be driven thereby, and means for arresting the carriage Iat the end of each movement along the guide track, said means comprising switch means for cutting off the electric current to the motor and means associated with said motor whereby said motor is operative by regenerative braking for arresting the movement of said motor.

DESMOND WALTER MOLINS,

REFERENCES CITED The following references are of record in the die of this patent:

UNITED STATES PATENTS Number Name Date 696,087 Schoeller Mar. 25, 1902 789,885 Schneider May 16, 1905 900,755 Meigs Oct` 13, 1908 1,310,890 Schneider July 22, 1919 1,460,096 Davis June 26, 1923 1,629,683 Debrasky May 24, 1927 1,656,727 Dawson et al Jan. 17, 1928 1,682,323 Conlon Aug. 28, 1928

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