GB620144A - Improvements in or relating to flexible supports - Google Patents

Abstract

620,144. Resilient mountings ; dashpots. THIRY, L. F. April 15, 1946, No. 11579. [Class 108 (iii)] A flexible support comprises an annular rubber bushing 3, Fig. 4, and substantially co-axial outer and inner members 1, 2, which constitute respectively an open ended cylinder and piston which with the adjacent end of the rubber bushing provide a liquid chamber which is substantially filled with liquid and is closed except for a restricted communicating passage between it and an otherwise closed displacement chamber formed within the piston and partly filled with liquid and partly filled with gas. In the construction shown in Fig. 4 the main restriction comprises an orifice 9 formed in a plate 8 carried by the member 2, which is variable by an adjustable needle valve 38 carried by a pre-compressed rubber bush 37 in the member 2. In a further construction (Fig. 3, not shown), the needle valve 38 which is threaded directly to the member 2, is set on assembly and then secured by a ring of annealed copper hammered around the upper end. A small duct 12 may be provided to prevent the formation of a gas pocket under the edge of the bushing 3. In a further construction (Fig. 2, not shown) the plate 8 is of arched formation and the end faces of the bushing slope downwardly and outwardly to prevent the formation of air pockets. In the construction of the inner member 2, shown in Fig. 5, a rotary disc valve 49 having a scalloped edge 49<SP>1</SP> co-operates with a flange 54 on the member 2, having a scalloped inner periphery, the valve 49 being rotated thermostatically by a bi-metallic spiral 45 to allow for viscosity changes. The valve 49 is set on assembly by a screw head 43a which is then locked by hammering in a copper ring 57. Liquid and gas are introduced by a hypodermic needle inserted through a hole 15 in a rubber plug 14, precompression of the rubber closing the hole when the needle has been removed.