GB962975A - Improvements in or relating to centrifugal friction couplings - Google Patents

Abstract

962,975. Friction clutches. TWIFLEX COUPLINGS Ltd., and K. J. FREEMAN. Aug. 2, 1962 [July 14, 1961], No. 25680/61. Heading F2C. A centrifugally-engaged friction clutch of the type comprising a driving hub 10 carrying on resilient pivots 17, e.g. rubber bushes between sleeves 15, 16, levers 12 mounting friction shoes 23 engageable with a surrounding driven drum 25, the inner ends 14 of the levers moving radially inwards in the clutch-engaged condition to abut surfaces on the driving hub, is characterized by the provision of means on the driving hub for limiting the radial movement of the levers in the neighbourhood of the pivotal connection, or for limiting the radial movement of a part of the pivotal connection itself. In the form shown, convex surfaces 32 on the levers 12 can contact and roll upon inwardly directed concave surfaces 33 provided by radial lugs 11 fast with the driving hub 10, to limit the radial movement of the levers. In a modified construction, Figs. 3, 4 (not shown), the bolts 19 at the centres of the resilient pivots have axial projections engaging holes in circular plates surrounding and journalled upon the driving hub 10, to limit the radial movement of the pivots. As shown, links 20 pivot between the ends 13 of the levers 12 and the friction shoes 23, and are formed with balance weights 22. Pins 29 in the links 20 engage oversize holes 30 in the levers 12, to limit the relative angular movement between the levers and the links. Bolts 27 pivoting the links 20 to the friction shoes 23 at their ends 35 pass through radial slots 36 in a circular plate 35 journalled upon the driving hub 10, so that circumferential movement of all the shoes 23, &c. is equalized. In the modified construction referred to above, Figs. 3, 4 (not shown), helical springs surrounding each end of the shoe pivot bolts 27 and between the associated friction shoes 23 and links 20, allow axial movement of the shoes relative to the driving hub 10. Specification 609,550 is referred to.