GB1021985A - Friction coupling - Google Patents

Abstract

1,021,985. Friction clutches; electromagnetic band brakes. WARNER ELECTRIC BRAKE & CLUTCH CO. Nov. 4, 1964, No. 44953/64. Headings F2C and F2E. A clutch or brake comprises a freely floating split friction band 20, or ring of segments, radially pressed outwardly or, as shown, inwardly into engagement with opposed radially converging friction surfaces 17, 18 of spaced, relatively rotatable driving and driven members 11, 12, by a helical resilient coil 25, one end 30 of which is anchored on the driving member 11 and the other end turn 27 of which is free and electromagnetically engaged with and disengaged from a shaped flange 19 of the driven member 12, engagement of this electromagnetic pilot clutch initially expanding or, as shown, contracting the adjacent end turns 33 to clutch the peripheral surface 34 of the driving flange 19, forming an auxiliary clutch, to augment the torque applied to the coil 25 which is thereby further wound up, contracting the band 20 to clutch, or brake, the driving and driven members. The coil end turn 27 serving as the armature of the magnetic pilot clutch is attracted both radially and axially into engagement, on energization of a stationary winding 44, with the peripheral pole surface 34, and a side pole face 39 of a ring 38 integrally formed on the driven member flange 19, the pole surfaces 34, 39 being separated by an annular restriction 40 of high magnetic reluctance to form a flux path 42. The coil end turns 27, 33 are of slightly smaller diameter than the remaining turns of the coil and are telescoped closely around the surface 34 to form the auxiliary clutch readily engaged and disengaged by the magnetic pilot clutch.