GB345322A - Improvements in or relating to friction clutches - Google Patents

Abstract

345,322. Friction clutches ; slipping couplings. BETHLEHEM STEEL CO., Bethlehem, Pennsylvania, U.S.A.-(Assignees of Nieman, H. W.; 115, East Market Street, Bethlehem, Pennsylvania, U.S.A.) Nov. 22, 1929, No. 35827. Convention date, Dec. 27, 1928. [Class 80 (ii).] A friction clutch, particularly applicable for the unloaded starting of motors, comprises a weighted flexible band under tension, the torque transmissible being increased with the speed of the driving-member due to centrifugal action on the band, which has an angle of wrap of not less than 180‹, so that the transmissible torque shall be substantially unaffected by variations in the co-efficient of friction. An arm 16, Fig. 2, on the driving-shaft 14 engages one end of the clutch band 19, which is provided externally with a facing 20 having a high minimum co-efficient of friction (say, 0-35), and internally with brass &c. weights 21, preferably uniformly-distributed. Above a certain minimum speed, the band engages centrifugally a drum 11 on the driven shaft (not shown), in which the shaft 14 is spigoted. The direction of rotation, shown by the arrow a, is such that the band is in tension. The e band may be replaced by a helix. Figs. 4 and 5 show a form suitable for bi - directional rotation, two driving-pins 31, 32 engaging respectively slots 38, 39 in the weighted band 33, so that one or other pin engages the end of its slot, according to the direction of rotation, and drives the band always in tension. A second band 34, with diametricallyopposed driving-pins 31<1>, 32<1>, is provided to improve the balance. In this form, the shafts 13, 14 are not spigoted together, the clearances allowing angular and lateral displacements thereof. The centrifugal weights may be of non- uniform mass ordistribution, and the friction facing may be thicker at the ends, particularly the free end. The Specification as open to inspection under Sect. 91 (3) (a), comprises also the following subject-matter: Fig. 6 (Cancelled) shows a slipping coupling, in which the weights are replaced by radiallyacting springs 53. The band may act externally on the drum and either member may drive, provided that an expanding-type band is subjected to tension and a contracting-type band to compression under drive. This subject-matter does not appear in the Specification as accepted.