GB531099A - Improvements in or relating to telescopic shock absorbers - Google Patents

Abstract

531,099. Shock-absorbers. RIBBESFORD CO., Ltd., and THORNHILL, P. W. July 7, 1939, No. 19873. [Class 108 (iii)] In telescopic shock-absorbers, for motor vehicles and aircraft landing-gear, of the kind comprising a hollow plunger and cylinder with a resilient medium such as compressed air and oil or like damping fluid, the passage of fluid from the space between the reciprocating parts is controlled by an annular valve mounted in a groove in the piston-head of the plunger cooperating with ports connecting said space and the main working-space of the cylinder. In the form shown in Fig. 1, the plunger 11 has a piston-head 12 with packing-rings 20a, 20b fitting a cylinder 10 the lower end 15 of which is flared and fitted with packing rings 18, 19 secured by a gland-nut 16. The space 22 of the cylinder 10 and a rubber &c. bag 24 secured to the piston-head 12 are filled with oil &c., a restricted passage 21 being provided in the pistonhead. The plunger-space 27 around the bag 24 is inflated through a valve 28. The space 29 between the plunger and cylinder is connected to the cylinder-space 22 by posts 34 in the pistonhead. Fitted in a groove 31 in the latter is a rubber &c. ring 32 which closes the ports 34 in the shortening movements of the device. During the rebound stroke, excess pressure in the space 29 is avoided by the ring 32 being forced from its seat in the bottom of the groove 31. In the modification shown in Fig. 2, a packing-ring 51 in the piston-head acts as a non- return valve controlling communication between the spaces 22, 29 through ports 56. Communication between the cylinder-space 22 and the exterior of the inflated airbag 24 is controlled by an axially-adjustable valve 37 having an axial passage 42 leading to grooves 39, 40, 41 which register with cylinder-ports 44, 45, 46. Fig. 5 shows a further modification in which the plunger is arranged above the cylinder and fitted with a tubular sheath 58. The rubber bag of the previous modifications is replaced by a floating piston 60 against which oil from the space 22 is forced through a tubular stem 35 projecting from the cylinder-head 36. Restricted flow from the space 22 through a port 69 is controlled by an adjustable plug-valve 65. The cylinder 10 is shown fitted with a packing-ring 62 of the kind described in Specification 531,098, [Group XXVI].