GB178346A - Improvements in or relating to shock absorbers - Google Patents

Abstract

178,346. Poindexter, F. E. May 11, 1921. Pneumatic and hydraulic springs. - Relates to vehicle shockabsorbers utilizing both air and oil, and comprises a casing with a main piston formed to provide an oil reservoir, a pump cylinder carried by the piston, a plunger connected to the casing operating therein, and an air inlet to the pump chamber, which is also connected to the oil reservoir by a restricted opening. The casing 1 is connected to the frame member 52, and the piston 3 to a spring 54. The upper end of the piston has an annular extension 7 supporting the pump cylinder 24 which is connected at its base to a valved plug 20 in a cross-member 16, below which is a vented supply chamber 15 connected with an annular channel 12 to receive oil passing outside the piston and held above the packing 17. The cylinder 24 has a restricted opening 26 connecting the oil-reservoir 19 with the pump chamber which is closed by a valved piston carried on a hollow piston-rod 27 secured to the cap 2, between which and the piston 3 is arranged a spring 36. An opening 34 connects the rod with the chamber 35, from which an oil return passage 39 leads to the reservoir 19. Road vibrations cause relative movement of pistons and cylinders, air being pumped thereby into the main chamber 35 through the valve 33 in the piston-rod 27, the pump chamber being supplied with air through the valved plug 20, while oil enters through the restricted passage 26, the oil acting as a variable base for pumping air. The cylinder 24 is slotted at 56 to restrict the pumping action. The pump cylinder mav alternatively be attached to the cap 2, and the piston-rod to the plug 20.