GB209770A - Improvements relating to friction driving devices - Google Patents

Abstract

209,770. Schiffers, G. E. Jan. 13, 1923, [Convention date]. Void [Published under Sect. 91 of the Act]. Clutches, friction; shaft couplings.-A slipping friction coupling or clutch comprises a driving band or helix acting internally or externally on a driven drum under the predetermined force of an elastic member, the direction of rotation being such as to tend to cause release. As applied to an invariable torque-limiting coupling, the driving-shaft 2, Fig. 1, carries a counterbalanced arm 3, to which is secured one end 6 of a band 5, the other end 7 of which is pressed by a spring 8 bearing against the arm 3. The compression of the spring 8, which has preferably a low stiffness rate, is calculated to produce sufficient friction against the driven member 1 to transmit the desired torque, allowance being made for the resilience of the. band 5. The arrow shows the direction of rotation. Fig. 3 shows a modification, wherein the compression of the spring 8 can be varied from a value insufficient to apply the band 5 up to a maximum. A link 13, connected to a sliding collar (not shown), actuates an arm 9 rigid with a screwed stem 10 engaging the arm 3. The spring 8 bears against the arm 9 and is guided by the plain portion 10<1> of the stem 10. Other forms are described in which an external band or helix and a tension spring are used, and in which the spring is replaced by a cylinder and piston subject to liquid or gaseous pressure.