GB483102A - Improvements in or relating to automatic centrifugal clutches - Google Patents

Abstract

483,102. Friction clutches. NEWTON, N. B. Dec. 15, 1936, No. 34398. [Class 80 (ii)] In a centrifugal friction clutch wherein centrifugal masses act on the presser plate through or against springs, the extension of which is limited, and wherein manual disengagement may be effected, means, separate from the manual disengaging means, are provided for voluntarily allowing the springs to extend further so as to cause clutch engagement below the critical speed. The masses 14 are movable against springs in radial guides in the driving flywheel 10, and act, through bell-crank levers 24 pivoted on the flywheel, on a plate b which acts on the presser plate a through interposed springs d<1> and which is normally retracted by springs 45. One end of each lever 24 slidably engages an aperture in the corresponding mass 14, while its other end acts on the plate b through an adjustable stud 28. Fibre plugs 21 on the masses cushion the inward movement of the latter. The presser plate can be retracted by radial levers 48 controlled by a pedalcontrolled sleeve 52, the levers co-operating with studs 46 secured to the plate a and being pivoted on a back plate c which is fixed to the flywheel by studs 31 fitted with spacing sleeves 32. The plate b slides on the studs 46. Studs e fixed to the plate a are secured to one end of flat blade springs g, the other end of which is secured to the plate c, so as to provide a driving connection between the plates a and c while allowing axial movement of the plate a. Centrifugal arms h, pivotally mounted on the plate b, are urged inwards by weak springs i and are capable of engaging behind collars f secured on the studs e within clearance holes in the plates band c. Normally, the arms h, are projected centrifugally outwards to the position shown in dotted lines in Fig. 7, in which they engage behind the collars f so as to limit the extension of the springs d<1>. In these circumstances, the clutch operates automatically while being capable of manual disengagement by operation of the sleeve 52. If, however, the flywheel is stationary or rotating very slowly, the arms h being still held in the dotted position by the friction between the arms and the collars ,f, and the sleeve 52 is operated so as further to withdraw the plate a, the friction is relieved and the springs i act to move the arms inwards into the position shown in full lines in Fig. 7. On releasing the sleeve 52, the springs d<1> can now extend beyond their previous limit, causing engagement of the clutch. As soon as the speed is sufficient, the arms h again move outwards and re-engage behind the collars f.