GB929128A - Improvements in or relating to centrifugal shoe-clutches - Google Patents

Abstract

929,128. Friction-clutches; clutch combinations; ratchet clutches. ZAVODY 9 KVETNA NARODNI PODNIK. Nov. 23, 1961 [Dec. 30, 1960], No. 41998/61. Addition to 919,296. Class 80 (2). In a centrifugal friction clutch of the parent Specification wherein lined clutch shoes 4 pivoted on an axially free driving carrier 2 and having conical and auxiliary lateral friction surfaces are centrifually moved, to a limited extent, against return springs to engage two driven plates 5, 6 respectively axially fixed and movable, the driven plate 6 is axially acted on by a disengaging device comprising a release lever and plate 18, 15 by pressure springs 14 reacting on a drum 7 rotatably carrying the driven plates, and, for towed starting or engine braking, by an inertia-drag screw-and nut device in which the screw 9 is integral with an axially fixed driven shaft 10, the nut 8 has fast thereon the drum 7 and is movable on the screw between axial stops 12, 13, and the driven plate 6 rotates with the nut but has axial freedom thereon limited towards the shoes by a stop 11. When the driven shaft overruns the driving shaft the inertia of both driven plates, the drum 7 and the spring 14 effects retardation of the nut relative to the screw and axial movement of the nut to move the driven plate 6 into contact with the lateral friction surfaces of the shoes. Further nut retardation ensues due to this frictional engagement until slip ceases. In this condition the clutch may be disengaged at will by the device 18, 15. As soon as the driving shaft speed rises in respect of the driven shaft the clutch is disengaged by axial movement of the nut away from the shoes to withdraw the driven plate 6 which moves to the stop 12. With further rise in driving shaft speed the clutch is engaged centrifugally. The driven and driving shafts may be arranged following in-line (Fig. 2, not shown).