GB734097A - An improved spring suspension for telescopic forks for motor cycles - Google Patents

Abstract

734,097. Spring forks for motor-cycles. KRONPRINZ AKT.-GES. Aug. 27, 1952 [Aug. 27, 1951], No. 21566/52. Class 136(3). [Also in Group XXXII] In a telescopic fork for motor cycles in which each limb, Fig. 2, of the fork comprises two tubes 1, 2 sliding one inside the other, a spring arranged in the tubes 1, 2 is in two parts 3, 4 bearing against one another through a piston 5 slidable in the tube 1 and having a liquid throttling passage therethrough, for liquid which partly fills the tube 1. A rod 10 rigid with the tube 1 and having grooves 14, extends through the piston 5. Flow through the grooves 14 is controlled by a sleeve 13, which moves against controlling springs 11, 12 in accordance with the acceleration of the tube 1. In a modification (Fig. 1, not shown), the rod 10 and sleeve 13 are dispensed with, and an orifice adjustable by screw means, connects opposite sides of the piston 5. In a modification of the latter construction (Fig. 4, not shown), the orifice 8 opens into a closed chamber within the chamber formed by the tube 2. The liquid level in the device may be below the piston 5, or the liquid may extend partially into the closed chamber. In this construction, the orifice may be disposed in the wall of the closed chamber, instead of in the piston 5. There may be a plurality of the orifices. In Fig. 3, flow through the piston 5, via ports 18, is controlled by a spring-loaded piston valve 20, which also functions as an inertia mass. The chamber 17 in which the valve 20 is slidable, may contain air instead of liquid, or partly air and partly liquid.