GB743732A - Improvements in or relating to clutch means, more especially for motor vehicles and the like - Google Patents

Abstract

743,732. Friction clutches. GRASSMUCK, A. May 21, 1953, No. 14358/53. Class 80(2) In an automatic clutch, e.g. for a motor-vheicle, electric motor or Diesel engine, clutch shoes 17, movable centrifugally outwards into frictional engagement with a drum 11, fast to a driven shaft 9, are each connected at opposite ends by unequal links 21, 80 respectively to one of two radial arms on a freely-mounted boss 18 and to shoe-guiding segments 13 fast with a support-plate 3 bolted at 105 to a freely-mounted driving housing 1 secured to an engine flywheel and completely enclosing the clutch. The shoes 17 are of T- section with their radial webs guided in slots 14 in the segments 13. Tangential compression coil springs 19, between the arms of the boss 18 and the segments 13, oppose outward movement of the shoes and may be adjusted by shims 109. Rubber buffers 23 cushion return inward movement. The friction facings of the shoes are slightly crowned in the centre, on opposite sides of which they are divided into two halves each having the same radius of curvature as the surrounding drum 11, and this. together with the unequal lengths of the links 21, 80, results in frictional contact with the driven drum occurring initially (Fig. 5, not shown), on that half of the shoe nearest the longer link 21 (for direction of rotation shown by the arrow), then transferring by a rolling motion over the crown to the opposite half (Fig. 6, not shown), on which the link 80 then has a wedging action. On over-run contact transfers back to the first half, again with a wedging action, and persists to idle speed. Holes 103, 104, 106 circulate cooling air and the clutch runs dry. In Fig. 8, not shown, the friction shoes engage over their entire surface but in the release position their radii of curvature are displaced on opposite sides of the centre rotation, and the outer pivots 20, 79 of the links lie at the corners of a rectangle whilst the inner pivots 15, 20a lie on its sides. The segments 13 may be attached directly to the housing 1, eliminating the plate 3.