Patent GB-728110-A (GB)
Title: Improvements in ram mechanism with a quick release valve for adjustment of the stroke of the ram
Inventor: WULFF ROY A
IPC: F41A9/49
Filed: 1953-06-30
Abstract: 728,110. Gun loading mechanisms. ELECTROL, Inc. June 30, 1953 [July 9, 1952], No. 18134/53. Class 92(1). In a gun loading mechanism automatically actuated by the recoil, a hydraulic plunger and cylinder member 11, 10 as shown in Figs. 1, 2 is mounted by lugs 102, 103 in the recoil carriage of the gun and on recoil, fluid is trapped in the cylinder 10 and the plunger end 37 engages a cocking member of the gun loader, a valve in the cylinder 10 then being opened to release fluid and allow retraction of the plunger 11 by a spring 32 to move it out of the path of the shell loading mechanism so that the latter is free to transfer a shell from the magazine to the breech during counter recoil of the gun. The plunger and cylinder member 11, 10 is also arranged to retract quickly to accommodate over-recoil and also to buffer the over-recoil or an over-rapid movement of the shell loader. The plunger 11 comprises a tubular piston rod 12 having at its inner end an outer sleeve 13 and an inner sleeve 16 forming a piston. The right-hand end of the sleeve 16 is tapered and forms a metering pin 20. The plunger 11 is biased towards the retracted position by the spring 32, one end of which bears against a collar 23 on the cylinder 10 while the other end bears against a plate 33 slidably mounted on the cylinder 10 and connected by rods 35, 36 to the flange member 37 at the end of the plunger 11. The end of the cylinder 10 carries a housing 50 with a pair of parallel bores 51, 52 containing respectively a quick release valve assembly 53 and a sliding piston 54. The connection between the cylinder 10 and housing 50 serves to position in the right hand end of the cylinder an orifice ring 57 having a metering port 58 therein. Ports 64, 63, 70, 71 permit passage of fluid from the cylinder 10 to the fluid reservoir in the bore 52, this passage of fluid being controlled by a valve 67 so arranged that pressure in the cylinder 10 normally tends to move it away from its seat 66 to permit passage of fluid through the valve orifice 68 but which is held against its seat by a spring 85. The valve 67 has a stem 90 with an outer end 93 for actuation of the valve by means of a cam 94. In use, during recoil movement of the gun, the valve 67 is closed and the plunger and cylinder 11, 10 thus maintained rigid and the gun loader is cocked by the plunger end 37. At about the end of the recoil stroke, the valve 67 is displaced from its seat 66 by means of the cam 94 so that liquid flows from the cylinder 10 to the reservoir 52 permitting the rapid retraction of the plunger 11 by the spring 32 to shorten the plunger and cylinder mechanism. This shortening action begins before or during the early stage of counter recoil so as to move the plunger out of the path of the shell transporting element of the shell loader, thereby permitting the latter to move rapidly to feed the shell into the gun breech during the counter recoil. During the last stage of counter recoil, the plunger end 37 abuts against a fixed stop which withdraws the plunger from the cylinder and upon closing of the valve 67 by action of the cam 94, will lock the plunger in its extended position ready for another cocking action. When the recoil of the gun is more extended due to greater powder charge, the inward stroke of the plunger is buffered by action of the metering pin 20 entering the metering port 58 to restrict the flow of liquid and thereby acts as a shock absorber. This arrangement also prevents damage if the loading mechanism strikes the plunger. If too great resistance is offered by the shell loader, e.g., by jamming, the pressure in the cylinder 10 unseats the valve 67 and the plunger can retract. A modified form of pressure responsive valve. Fig. 3 (not shown), is described.