US2593412A - Gun rammer - Google Patents

Description

April 22, 1952 e. A. CHADWICK ET AL 2,593,412

GUN RAMMER Filed Nov. 15, 1943 8 Sheets-Sheet l INVENTORS 0500a: A. anAow/cx i PAUL m Bun/r.

April 22, 95 G. A. CHADWICK ET AL GUN RAMMER 8 Sheets-Sheet 2 Filed Nov. 15, 1943 INVENTORS 650/705 4. am ly/0K BY PAUL/?%LL 1 April 1952 G. A. CHADWICK ET AL 2,593,412

GUN RAMMER 8 Sheets-Sheet 3 Filed Nov. 13, 1943 FIG. 3

INVENTORS 050m: A. GHADW/GK BY P401. w. a Mr. J

April 1952 ca. A. CHADWICK ET AL 2,593,412

GU RAMMER Filed Nov. 13, 1945 8 Sheets-Sheet 4 INVENTORS GEORGE A. OHADW/CK BY PAUL IV. BUR/f.

April 22, 1952 Filed Nov. 15, 1943 G. A. CHADWICK ETAL 2,593,412

GUN RAMMER 8 Sheets-Sheet 5 INVENTORS GEORGE A. OHADW/GK BY PAUL w. 80 t.

AT QORNEY G. A. CHADWICK ET AL April 22, 1952 GUN RAMMER 8 Sheets-Sheet 6 Filed Nov. 15, 1943 Kg mJ no a mmmwm m R RL mw 6P M. m

April 22, 1952 G. A. CHADWICK ET AL GUN RAMMER 8 Sheets-Sheet 7 Filed NOV. 13, 1943 N snnszgaw W/GK Sm Y R x M mmwmm M45 3 EM/I m WW7 6P V 11 lllll April 22, 1952 e. A. CHADWICK ET AL GUN RAMMER 8 Shets-Sheet s Filed Nov. 13, 1943 INVENTORS GEORGE. A. OHADW/OK PAUL n. BURK ATTORNEY Patented Apr. 22, 1952 GUN RAMMER George A. Chadwick, Detroit, Mich., and Paul W. Burk, Washington, D. 0.

Application November 13, 1943, Serial No. 510,162

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 2 Claims.

The present invention relates to hydraulically operated slides and loading machines for mounting on guns to aid in the ramming of ammunition into the breech of the guns in a most efficient manner. In the device of the present invention the rammer may be retracted either automatically in response to the recoil of the gun or as a result of manual control.

The object of this invention is to construct an hydraulic apparatus for use on gun mounts to ram the ammunition into place in the gun barrel quickly and smoothly, permitting the breech block to be closed behind it.

A further object is to provide a hydraulic apparatus adapted to be used as a slide rammer or as a loading machine, as desired, by the use of alternate controls which may be readily substituted.

A further object is to make the above apparatus fool-proof and rugged in construction, requiring noadjustments in the field.

A further object is to provide safety features on the above apparatus to prevent any harm resulting from improper use of the controls.

A further object is to provide simple controls for the hydraulic operation of the device, which may be manually actuated to stop the rammer in any position on either its ram or retract strokes Without injury to the apparatus.

Further and more specific objects will become apparent as the description of the device proceeds, having reference to the drawings in which,

Figure 1 is a perspective view of a gun having the subject device mounted thereon,

Figures 2 to 5 are diagrammatic sectional views of the tank unit of our device showing the controls and valve elements in various positions assumed in operation,

Figure 6 is a plan view partly in section of the tank unit, with a modified form of relief pilot valve and associated passages,

' Figure '7 is a sectional view thereof taken on the line ll of Figure 6,

Figure 8 shows the substitute controls included in the apparatus when used as a loading machine,

- Figure 9 is a modified form of main operating valve.

' Figures 10 to 12 are perspective views of details of the hydraulic assembly and operating ports of the present device showing the tank and motor units mounted on top of the rammer cover plate, with the hydraulically operated piston and rod mounted below the cover plate shown in Figure 10.

The slide and loading machine consists of an electric motor I, a supply tank assembly 2, a control linkage unit 3 mounted in front thereof and a cylinder unit 4 connected by tubes 5 and 6 to the tank unit. The supply tank assembly includes a hydraulic pump 8, a main operating valve 9, a relief pilot valve It, a bypass valve II and a pilot valve block [2 which is partially extruded from the tank. The main operating valve 9 controls the operation of a hydraulic motor consisting of cylinder unit 4 and piston 40'. The pilot valve block has two pilot valves, I3 and [4, operating therein. The tank unit is mounted on the rammer cover plate 2 to the under side of which the cylinder unit is attached, as may be seen in Figure 10.

The present equipment is designed for use on single gun mounts although it may be adapted for use on multiple gun units. The equipment on both the slide and the loading machine is identical and interchangeable except for minor changes in the control mechanism. The control mechanism may be changed from one type to another by simple changes of minor parts. In both cases the equipment is mounted on the rammer cover plate 2 which is bolted to the top of the right hand side of the gun mount slide. The electric motor is mounted on the rear of the tank unit with its shaft coupled by a self-aligning coupling to the shaft 8' of the hydraulic pump within the tank unit. The electric motor and supply tank assembly is mounted toward the rear of the cover plate with the control mechanism mounted directly in front of it. The control linkage unit is mounted on the left hand side of the slide. The cylinder unit is mounted directly underneath the cover plate.

In the case of the slide rammer the control linkage unit supports the control shaft l5 on which rigidly mounted are control lever l6, lever I! with a roller I8 at the end thereof, the lever l9 connected to pilot valve I4 and the doublearmed lever 20, one arm 2! of which is adapted to abut the end of rod 22 connected to the main operating valve, the other arm 23 of which abuts against the bottom of latch 24 which is pressed into notch 25 in rod 22 by compression spring 23. Loosely mounted on this shaft I5 is lever 21, having one arm 28 connected to pilot valve l3. The opposite arm 29 is connected by rod 30 to a centering device consisting of a lever 3! resiliently held by springs 32 and 33 in a central position corresponding to the position in which the pilot valve I3 cuts ofi the relief passage 34 in the hydraulic system. A third arm 35 on lever 2'! is connected to a control lever 36 which is operated automatically in response to the closing of the breech block and raising of the rammer spade 55 thereby to open the outlet of relief passage 34 by moving pilot valve I3 in one direction, as will be hereinafter more fully pointed out. The pilot valve is moved in the other direction to open this outlet in response to the retrac tion of the rammer piston at the end of its stroke. Normally this valve maintains a central position, as shown in Figure 2, in response to the centering device 3|. Its movement to the right as viewed in this figure is occasioned by turning of the lever 36 counterclockwise by latch pin 54 as shown in Figure 3. The latch pin is a part of the rammer spade 55 referred to above. Movement of valve I3 to the left is caused by an abutment 66 on the piston rod 40 striking against the abutment 69 on the rod 39 of the centering device, as may be seen in Figure 5. Lever I1 is actuated in response to the recoil of the gun by the cam 31 which is mounted on the gun barrel unit, which reciprocate in its slide during the recoil against recoil springs.

Figure 2 shows the relation of parts obtained when the control lever I6 is moved to ram position, in which the latch 24 looks the main operating valve 9 in the position shown cutting off the pressure line 3.8 from the passage 39 which leads to the retract or front end 45 of the cylinder 46 and places only the ram or rear end 41 of the cylinder under pressure for moving the piston 49 forwardly on its ram stroke. The front end of the cylinder is relieved at this time by means of the passage 39, the chamber 4|, passage 42, chamber 43 and port 44 into the reservoir of the tank unit. At the end of the ram stroke the piston 49 is buffed by reason of the port 48 being closed thereby and the fluid in the end of the cylinder is then forced through a small opening in the passage 49 regulated by the adjusting screw 56 and through the passage into passage 39 through chamber 94. The valve 52 is merely a check valve for admitting pressure fluid from passage 39 to the retract end of the cylinder on the retract stroke of the piston 40 before the latter has opened the port 45. A similar arrangement of check valve and adjustable bleed is provided at the rear or ram end of the cylinder in connection with passage 35, which passage is connected to the outlet 53 of the hydraulic pump. Thus the ramming and retracting strokes of the piston are cushioned in its operation.

In Figure 3 with the ram at the end of its ram movement the latch pin 54 which is mounted on the rammer head or spade 55 has raised the right hand side of the lever 36, as shown, thus moving the pilot valve I3 to the right, opening the passage 34 to the relief port 56 by means of the interconnecting passage 51 in the pilot valve block between the valve bores of the pilot valves, the pilot valve I4 being already in its right hand position. The spade 55 is slidably mounted and resiliently held in ramming position in a bracket 55 mounted on the end of piston rod 46. The latch pin 54 has been raised into the position shown by reason of the rammer spade 55 in which it is mounted having been raised as a result of the upward movement of the breech block 96 into its closed position (as shown in Fig. after completion of the ram stroke (see Fig. 12). The latch'release lever 97 is depressed at the beginning of the ram stroke and permits the spade 55 to drop to its ramming level. When the ramming stroke is initiated, the end of the latch pin 54 rides up on the slope 98 of the groove 99, as it is pushed against its spring pressure into the side of the spade, and slides along the face of camplate I09. At the end of the ram stroke pin 54 snaps out over the cam IBI, which carries the spade up over to the shoulder I92 of the latch release lever at the end of the retract stroke, this shoulder being normally held against the rear end of the cam IBI. The relief of pressure in the passage 34 relieves the pressure behind the bypass valve II and permits the pressure on the opposite side thereof to open the port 58 to connect the pressure side of pump 8 to the supply tank. Normally this bypass valve II is held closed by the spring 59 and by the differential of pressure on the two sides of the valve in its closed position.

The relief pilot valve I9 is normally held in the position shown, by the spring 6|, to close off the relief passage 62. In the form shown in Figures 2 to 5 it has a stem portion 63 passing through a restricted opening 64 in the passage between the opposite sides of bypass valve II. With the relief passage 34 closed the stalling of piston 40 in ram stroke builds up pressure in line 6 to close restricted passage 64 by means of the stem 63 and at the same time valve In is unseated to permit fluid at the left end of valve I I to flow out through passage 62. The pressure differential on opposite sides of by-pass valve II then causes that valve to move to the left and clear the discharge opening 58. When the valve I0 opens the relief passage 62, the pressure on the left end of valve II is relieved whereas the pressure on its shoulder at the right end is still maintained until valve II opens the port 59 to relieve the system of the excessively high pressures. These pressures are relieved in the same manner at the end of the ram stroke prior to the operation of valve I3 to relieve the pressure through the pilot valve block. On the retract stroke, relief is always obtained at the end of the stroke by reason of the abutments 68 and 69, respectively, on the piston rod and the rod 30 of the centering device opening the valve I3.

In order to retract the ram the control shaft I5 is turned either manually by means of the control lever I6 or automatically in response to the recoil of the gun by cam 31 actuating the lever I I to the position shown in Figures 4 and 5 from that in Figure 2. This turning movement of the shaft first relieves the latch 24 by means of the arm 23 acting against the spring 26 thus permitting rod 22 which is attached to abutment rod 55 to move to the left in response to the pressure of the spring 66 acting through the shoulder 61 and through the valve 9, and thus to follow the arm 2I, turning the lever 20 counterclockwise and. the end of lever 23 against the pressure of spring 26 and thus holding the control shaft in its retract position. This turning of the shaft I5 also moves the pilot valve I4 to the left thus closing off the intermediate relief passage 51 from relief port 56 while exposing the intermediate relief passage I6 thereto. The main operating lever being now in its position, as

shown in Figures 4 and 5, to connect the passages roller bearings 89, 89 in the plates.

the pilot valve I3 to return to its central position in response to the centering mechanism 3|. The piston rod 40' has an abutment 68 in a position to strike abutment 69 on the rod 30 of thecentering device at the end of the retract stroke, as previously noted. This moves the pilot valve l3 to the left of its center position as shown in Figure 5, soas to open the relief passage 34 to the relief port 56 through the intermediate-passage in the pilot valve block. As a result, the bypass valve II is caused to open port 58 for directly relieving the pressure system until the control is again operated for moving the ram on its ram stroke.

The piston may be stopped and reversed at any point in its travel by action of the manualcontrol lever [6. This is done by holding the lever in a position between ram and retract so. that the main operating valve provides communication between passage 38 and both chambers II and 43 thus relieving directly the pressure from both sides of the rammer piston. Then, by moving the lever into either the ram or the retract position, the corresponding stroke maybe resumed.

The volume of the pump, which is of the positive displacement type, is bypassed at the retract end of the piston stroke on either the slide rammer or loading machine type apparatus, and may be bypassed at the ram end on only the rammer type. Adjustments of the spring 6| on relief valve H) by means of the adjusting sleeve H such asshown in Figure 7, provides for regulating the pressure at which the pump'volume is bypassed. The rammer may be jammed at any point in its travel with no damage to the equipment resulting. The supply tank is constructed with a removable cover 95 bolted on to the top of the tank. The outside atmosphere is prevented from reaching the tank by the application of a neoprene impregnated fabric diaphragm 12 which is inserted between the tank and the tank cover. The space between the diaphragm and the cover is vented by means of a labyrinth construction around the filler cap 13. This allows for expansion and contraction during operation of the equipment. The tank is provided with a pipe plug 14 for draining. The filler cap unit consists of the filler pipe 15, filler cap 13 and a screen 16 which prevents entrance of sizable foreign articles. It is bolted directly to the top of the tank and protrudes above an opening in the tank cover. Air is effectively sealed off from the hydraulic system with a copper gasket 11 inserted between the filler pipe and filler cap.

The main operating valve plate 18 is mounted on the pump as an integral part by means of nuts 19 on stud bolts 80. The pump and the valve plate are attached to the supply tank by means of a mounting flange 8|. This flange is rabbeted in to the supply tank and'th'e whole pump unit is effectively sealed by gaskets used between the flange and the tank. The pump is composed of a cylinder -82, bearing plates 83 and 84, one at each end of the cylinder, and two shafts 85 and 86 to which are keyed the two helical gear impellers 81 and 88. The shafts ride on The extension on the drive shaft 85 is splined for direct connectionto the motor shaft by means of a selfaligning coupling (not shown). The suction side of the cylinder is open to the tank at 90. A check valve screen is providedat this opening to prevent'foreign material through the hydraulic circult. The dischargeof the pump is directed at 9| through the front bearing plate, and out through the main operating valve plate to passage 38.

In the form shownfin Figure '7, a modification of the relief valve is illustrated wherein the main operating valve platecontains the main operating valve 9, a relief pilot valve l0 and a bypass valve H. The bypass: valve II is controlled by the valve element lq'Jfor controlling the opening of relief passage 63. and for normally maintaining a restricted vopening in the bypass between the two sides ofgbypass valve I I, there being also a retsriction element 92 within this bypass. The bypass port controlled by the bypass valve II is also somewhatdiiferently arranged as regards Figures 3-5 inclusive with reference to the high and low pressure ports without affecting the operation of the,;va1ve.

The main operating'gvalve is a three position valve. Two of the ppsfitions may be seen in Figures 2 to 5. These are the extreme left and right hand positions. The'ithird position of the valve is intermediate between these two positions, in which both passages 38 and 39 are opened to the relief port 44. Thisf-lposition may be obtained by manually holdingthe control lever l 6 midway between its ram and? retract positions, and is illustrated by the modified form of main operating valve shown in Figure 9. In this position of the valve, the pressure is relieved directly from both ends of the cylinder and the ram is thus held stationary in whatever position it happens to be at the time.

So fanthe device has been described as a slide rammer. In order toii'se this device as a loading machine, as may be desired for purposes of instruction in operating the mechanism when the gun is not bein fireil, or when it is not desired to actuate the retraeting controls automatically in response to the recoil of the gun, lever I1 is replaced by lever 93 viZh-ich is rigidly fixed to shaft I5, and lever 36 is entirely omitted, as shown in Figure 8. Lever 93 actuated in this case by the latch pin, as was'lever 36 in the slide rammer controls. The control lever I6 is operated simultaneously with ilever 93, both levers being rigidly mounted on shaft l5, for retraction pur poses, since there is' jn'o recoil in this case and cam 31 does not fu w on. The operation of the system is otherwise-identical with that of the slide rammer. 1

The pilot valve block is flange mounted on the front face of the supply tank. It is hydraulically connected to the" large area side of the bypass valve. In order fr the bypass valve to operf he pilot valves to uncover the tank ports provide in the pilot valve block.

It is to be noted that in the normal retract position of the controls, as shown in Figure 5, pilot valve I4 is in neutral position wherein it releases pressure from'both of the intermediate passages 51 and 10 in-' the pilot valve block to the relief port 56. This is because spring 26 presses down on lever 23 until lever 2| abuts against the end of rod 22. If the retract stroke is to be initiated manually, it is, therefore, necessary to pull the control lever 16 up beyond its normal retract position as shown in Figure 4, sufficiently to close off the intermediate passage 51 from the relief port 56 against the pressure of sprin 26 which normally urges the shaft [5 in a clockwise direction until stopped by the greater pressure of spring 66 acting through the abutment rod 65 and rod 22. This may be seen by reference to Figures 4 and 5. In Figure 5 the spring 26 on 7. the latch pin 24 holds the-bell crank 20 so that its arm 2! rests against the end of rod'22 but is not strong enough to push the rod 22 against the pressure of spring 26 on the operating valve 9. Upon operation of thelever l5 manually in a counterclockwise direction, the arm 23 ofrbell crank 20 moves the latch pin 24 against the pressure of spring 26, and the lever l9 moves the pilot valve I4 from its neutral position, as shown in Figure 5, to close off the passage 51 from the relief port 56, as shown in Figure 4, andpressure is built up in the system for the retract stroke. As soon as the retract stroke begins, latch pin 54 is moved out from under level: 36 and lever ['6 may then be released, whereupon-it will assume its normal retract position until manually moved again. In the automatically initiated retract stroke the latch pin 54 is movedbackdue to the recoil of the gun so that the centering device moves valve l3 to close ofi relief passage 34.and the retract stroke is started immediately. The operation of the ramming device will now be described. At the time the projectileis placed on the slide, the spade55. is held-in its upper DOSi-e tion (see Fig. 11) by lever Gland lever 16 is in the upper position as shown in Fig. 5. .When lever 9'! is depressed, the spade drops behind the cartridge case into a position ready for. ramming. In order to start the ramming operation the lever i6 is swung downwardly to the, position shown in Fig. 2. The latch 24 will then look the rod 22 in a positionsuch that valve: 9 will admit fluid to the rear end only of the cylinder 4. The piston 49 will move forward on the ramming stroke and will ram the projectile and cartridge case into the gun. In Fig. 12, the spade 55 is shown at the end of the ramming stroke and at this time it will rest upon'the breech block 96. When the cartridge case strikes the ejector pins of the breech (not shown) the breech block will be elevated by springs and will, in turn, move the spade 55 to the upper position. At this time pin 54, carried by spade 55,- will contact lever 35 and position the lever 36 and valve I3 in the positions as shown in Fig. 3. During the ramming stroke the pin 54 has been moved to the retracted position in the spade 55 by groove 99 and maintained in the position by the surface of cam I85.

At the time the spade is moved upwardly by. the

breech, pin 54 is allowed to project outwardly so as to be able to contact lever 36. The round is now positioned ready for firing and, as shown in Fig. 3, the bypass valve II is in the open position. This is possiblesince valve I3 has been moved rearwardly from its blocking position to allow fluid to flow through passages 34, 51, 56 in order to relieve the pressure on the spring biased side of valve ll Until the gun is fired the valve II will bypass fluid from'pump 8 and spade will remain its upward, forward position.

Upon the firing of the gun, pin 54 and cam 31 will move rearwardly. Lever ll, riding upon cam 31, will move lever arm IE to the upper position and at the same time release latch24 to allow valve 9 to move into its forward position under the influence of its spring bias. The valve. 9 'as shown in Fig. 4 will now admit fluid to both sides of piston 40 and will start the piston on its retracting stroke. At the start of the stroke, valve I4 is positioned to block passage 51 and. to open passage It! to exhaust. Valve l3'will be positioned to block passage H) as shown in Fig. 4, but will immediately more into its centered position when pin 54 startsrearwardly because of the recoil. Bypass valve H will remain closed onv the retracted stroke since during this time passage 34 will be blocked. During the retracting stroke, the pin 54 will ride upon the upper surface of cam I and will be moved back to the latched position shown in Fig. 10. As the piston 40 approaches the end of the retracting stroke, lug 58 will contact lug 60 on rod 30 and will move valve l3 forwardly from its blocking position. The passages 34, W and 56 are now opened to exhaust since valve l4 will be in its neutral position'as shown in Fig. 5. The pressure will drop on the spring side of bypass valve II and will allow the valve to open so that the fluid pressure on the ends of piston 40 will become neutralized. ihe ramming operation has now been completed and the lever I6 is in the position to be pulled downwardly to start a new operation when a second projectile has been placed in the gun for loading.

As has been pointed out, a safety valve II] has been provided to relieve the pressure in the hydraulic system when the piston 49 becomes jammed in any position. At the time of jamming, the pressure in the system will rise and will act upon the surfaces of valve N] to move the valve against the bias of spring 61. This movement will close passage 63 and will cut off the spring side of valve H from the increasing pressure in the system so that the bypass valve will open.

In the loadin operation of the gun, when it is not intended to fire the projectile but simply to test the mechanism, the latch 91 is first released and lever it pulled in the same manner as in automatic operation. The projectile will then be rammed and the breech block and spade will be moved upwardly at the end of the ramming operation. However, since there will be no recoil, the. lever l5 must be manually moved to its upperposition as shown in Fig. 4 because cam 31 will not be effective to operate upon lever I1. At the start of the retracting motion pin 54 is efiective to displace valve [3 from the blocking position and it is therefore necessary to move lever arm 2| away from the end of arm 22 so that valve :4 will block passage 51. After pin 54 has moved out or" contact with lever 36, the lever arm 2! may be allowed to move back into contact with the end of rod 22 and place valve [4 in its neutral position: After the retracting motion starts, the spring bias on valve 13 will move it to the blocking position and it is no longer required that valve l4 block passage 57.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed is:

1. A hydraulic system for actuating a reciprocable motor comprising, a pressure source, a motor having a reciprocable member, separate conduits for conducting pressure to opposite sides of said reciprocable member, valve means in one of said conduits for controlling the application of pressure to one side of said reciprocable member, said valve means being mechanically linked to the reciprocable member so as to be tripped by arrival of the reciprocable member at one extremity of. its movement, a separate by-pass valve for venting excess pressures arising upon interruption of the reciprocable member during the portion of its travel between the limits of its movement, mechanical means for preventing opening of the bypass valve, and hydraulic means for preventing opening of the by-pass valve.

2. A hydraulic system for actuating a reciprocable motor comprising a hydraulic pressure source, a hydraulic motor having a reciprocable member, conduits for applying the hydraulic pressure -to opposite sides of said reciprocable member, a valve for controlling the application of pressure to one side of the reciprocable memher said valve being mechanically tripped upon arrival of the reciprocable member at one limit of its movement, pressure by-passing means for relieving the hydraulic pressure when it builds up to an excessive value upon interruption of the reciprocable member during its travel between limits, a mechanicallytripped valve for controlling the action of the by-pass means, and a hydraulic valve for controlling the action of the by-pass means, said mechanical and hydraulic valves being actuable independently of each other.

GEORGE A. CHADWICK. PAUL W. BURK.

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

UNITED STATES PATENTS Number Name Date 2,112,853 Lucht et a1. -1 Apr. 5, 1938 2,189,823 Vickers et al Feb. 13, 1940 2,213,401 Lindgren et al. Sept. 3, 1940 2,261,194 Vickers Nov. 4, 1941 2,379,180 Pohl June 26, 1945 FOREIGN PATENTS Number Country Date 20,119 Great Britain Aug. 29, 1910 15,064 Great Britain June 27, 1912

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