GB542409A - Improvements in and relating to torsion springs - Google Patents

Abstract

542,409. Torsion springs. VOIGT, C. A. Aug. 5, 1939, No. 22733. Convention date, Aug. 6, 1938. [Class 108 (iii)] A spring unit, for transmitting torque stresses comprises a metal torsion spring which is anchored at its heads to the parts whose relative angular displacement applies the load to the spring, and is embedded in rubber to damp the spring action. In the form shown in Fig. 1, the torsional spring unit comprises an outer sleeve 1 and an inner sleeve or shaft 2 connected by a spiral spring 3. A rubber member 6 is arranged between the parts 1 and 2 so as to enclose the spring 3 and is in an unstressed condition when the spring is deformed by an amount corresponding to the average load. At increased loads, the spring 3 tends to compres the rubber thus giving an increased hardness of springing with increased load. In another form, Fig. 2, a helical spring 13 attached to two relatively rotatable members 8, 11 is embedded in a rubber block 14 rigidly cemented to conical flanges 9, 12 carried by the members 8, 11. Alternatively the rubber block is left unattached to the rotatable members. Fig. 3 shows a form in which the metal spring 29 and the surrounding rubber block 30 extend between and are attached to concentric relatively rotatable members 25, 27. The block 30 is connected to inner and outer sleeves 26 which are respectively keyed to the shaft 25 and attached by screw 33 to the sleeve 27. As shown in Fig. 4, the spring 29 is replaced by a torsion bar 39 and the rubber block 38 which is cemented to the torsion bar is of conical form in order that there shall be equal stress in all cross sections of the block. The Specification in its original form as open to inspection under Sect. 91 describes also a modification in which the helical spring of Fig. 2 is replaced by a straight torsion-rod passed through the bore of the rubber block. This subject-matter does not appear in the Specification as accepted.