Patent GB-191501729-A (GB)
Title: Improvements in and relating to Fluid Pressure Brakes for Ordnance.
IPC: F41A25/02
Filed: 1915-02-03
Granted: 1915-08-12
Abstract: 1729. Krupp Akt.-Ges., F. Feb. 3, 1914, [Convention date]. [Addition to 4080/14.] Recoil apparatus. - Relates to fluid-pressure recoil brakes for ordnance having means for regulating the length of recoil and also for braking the run-out, of the kind described in the parent Specification. In the invention described in the parent Specification, the run-out braking-device is characterized by the provision of an auxiliary passage through the piston member, which comes into action to reduce the braking effect upon the run-out when the apparatus is set for short recoils. The present invention consists in arranging the auxiliary passage through elements of the piston member which, during the run-out, are pressed against each other by the pressure of the brake fluid to prevent any escape of the fluid otherwise than through the passages provided for the purpose. The piston member B, B' is provided with a rotatable ring C held in place by a screwed sleeve B<2> and having projections c<1>, engaging helical grooves a<1> in the cylinder member A. During recoil, fluid under pressure passes from one side A<1> of the piston through ports b<3> therein to the other side, the size of the ports being determined by the position of projections d<2> upon a two-part ring D rotatably mounted on the piston member B and formed with lugs d<1> engaging longitudinal grooves a<2> in the cylinder, the operation of the valve ring D and the rotary adjustment of the piston member for long or short recoil being as described in the parent Specification. During recoil, fluid passing through passages b<6> lifts a spring-pressed valve F within the hollow piston member B, and passes into the hollow end b<5> of the piston member B'. During the run-out, the fluid in the hollow end b<5> passes through longitudinal grooves e' in the throttling-rod E to the other side of the piston. The auxiliary passage, to ease the braking action on the run-out after a short recoil, is arranged so as to obviate leakage. For this purpose, a sleeve G, mounted to fit closely the rod E and carried by the piston member B<1>, is provided with a flange g<1> engaging a shoulder b<8> on the piston member B, and is connected to the valve ring D by means of two screw bolts H passing through sector-shaped slots in the piston member. The auxiliary outlet from the chamber b<5> is formed by a passage g<2> in the flange g<1> leading to a short segmental groove b<9>, from which a passage b<10> in the piston member B leads to a groove b<11> provided in the outer surface thereof and communicating with a radial passage d<3> in the valve ring D. When the piston is rotated to set the device for short recoil, as shown in Fig. 4, the passages g<2>, b<10>, d<3> are in communication, and the exit d<3> is situated close to the edge a<3> of one of the grooves a<1> in the cylinder, so that during the greater part of the run-out movement of the cylinder, the passage d<3> provides an outlet into the groove a<1> for the auxiliary passage. When, however, the device is set for normal or long recoil, the relative position of the piston is such that the passage g<2> does not communicate with the groove b<9>. In this case. the pressure of the fluid in the hollow end b<5> forces the flange g<1> against its seating b<8> and prevents any leakage or flow except through the grooves e<1>.