GB571540A - Improvements in fluid flow damping arrangements - Google Patents

Abstract

571,540. Shock-absorbers, dashpots, &c. DOWTY EQUIPMENT, Ltd., and BURKE, P. W. June 23, 1943, No. 10157. [Class 108 (iii)] A dashpot, shock-absorber, or like device comprises a plunger 4 adapted to compress fluid resiliently in a cylinder 3, a damping head 7 on the plunger divided by a peripheral groove 8 into a clearance flange 9, having a space 14 around its periphery for substantially unrestricted flow of fluid, and a second flange 10 which partitions the cylinder into two axiallyspaced compartments, a shuttle ring 11, located in the groove, which fits the bore of the cylinder and is spaced from the base of the groove, ports 12 in the partition flange 10 for free flow of liquid and ports 13 in the clearance flange for restricted flow. The peripheral space 14 is open or sealed off by the shuttle ring according to the direction of plunger travel so that flow of fluid in one direction of movement of the plunger is confined to the ports 13. In the construction shown, the whole of the available space within the cylinder 3 is filled with liquid and on movement of the damper head 7 into the cylinder, compression of liquid is caused in accordance with the increasing volume occupied by the plunger 4. During this movement, the shuttle ring 11 abuts the lower surface of the groove 8 and liquid flows freely through the space 14 and through the ports 13, 12. On extension, the ring contacts the upper surface of the groove, closing the space 14 and liquid flows through the ports 12 and through the restricting ports 13 which damp recoil. The ring may be a split metallio piston ring heavily chamfered at 15 for sealing and assembly purposes. The invention is applicable to oleo-pneumatic and other shock-absorbers &c. where a differential damping action is required.