GB683198A - Shock absorber - Google Patents

Abstract

683,198. Hydraulic shock absorbers. GABRIEL CO. June 1, 1951, No. 13040/51. Class 108 (iii). The invention relates to a hydraulic shockabsorber which comprises a piston 22 having an opening 37-48-55<1> along the side which cooperates with the cylinder wall 13 to provide a fluid passage, and an annular valve member 66 supported in the cylinder in sealing engagement with the cylinder walls and engageable by the piston 22 after a pre-determined degree of relative movement between the piston and cylinder during one of the strokes, for closing the passage. According to the invention the valve member 66 is of resilient material and has an annular surface 68 facing the piston and normal to the axis of the cylinder, and the inner and outer walls 67, 67a of the valve member converge away from the piston to form a sealing lip. The invention is described as applied to a shock absorber of the kind in which flow on the compression stroke takes place through circumferentially-spaced axial grooves 37 in a main piston-portion 35 and lifts a valve 50 so as to pass along grooves 48 in a reduced piston-portion 36, and escape around the periphery of a plate 55. On rebound, the valve 50 closes and flow takes place through a spring-loaded valve 42 which has a metering restriction 41. Flow to and from a reservoir 15 is controlled by valves 62 and 61 respectively. Beyond a predetermined degree of compression movement, the piston engages the valve 66 and this cuts off all flow except that provided by a metering orifice 49 in the wall of the piston portion 35. The valve 66 is mounted on the end-coil of a helical spring 71. An edge of an annular plate 72 engages a recess in the rubber ring, and lugs 73 engage the spring. A similar annular plate 77 secured to the other end-coil of the spring 71, has its edge clamped between a shoulder in the cylinder wall 13 and the lower cylinder head 63. A further valve 65 is similarly spring-mounted on the upper cylinder head 17 and cuts off flow around the periphery of the disc 55. A metering flow is provided by an orifice 57.