GB1284229A - Centrifugally actuated clutch - Google Patents

Abstract

1284229 Ratchet clutches; change speed gearing FICHTEL & SACHS AG 14 Nov 1969 [15 Nov 1968 (2)] 55833/69 Headings F2C and F2D A centrifugally actuated ratchet clutch which automatically effects the ratio shift in a twospeed cycle hub in response to speed comprises pawls 58 held out of engagement with a ratchet wheel 62 below a predetermined speed by centrifugal weights 70 which are pivoted on pins 66 fast with a pawl carrier 56, are biased inwardly by helical torsions springs 72 and are connected for movement in unison by a plate 78. In Fig. 3 the centrifugal weights have projections 84 which, below a predetermined speed, engage the ends of the pawls 58 to hold them disengaged from the ratchet wheel 62. When the speed exceeds the predetermined value the weights 70 pivot outwardly and the projections 84 release the pawls 58. The weights 70 carry pins 76 which engage diametrically opposed slots (82) in the plate 78. The two speed hub, Fig. 1, comprises a planet gear having input carried planet pinions 38 meshing a stationary sun gear 32 and a ring gear 40 fast with the pawl carrier 56. Below the predetermined speed a driving sprocket 16 fast with the planet carrier 36 is connected through a sleeve 44 and ratchet clutch 50, 52 with a driven drum 20 for direct-drive. Above the predetermined speed the pawls 58 are released and the driving sprocket drives the drum 20 through the planet gear and ratchet clutch 58, 62 for overdrive. In Fig. 11 the pawls 158 of the centrifugally controlled ratchet clutch are held disengaged from the ratchet wheel by a plate 178 which connects the centrifugal weights 170 for movement in unison. When the speed exceeds the predetermined value the weights 170 move outwardly and pins 176 thereon rotate the plate 178 to align apertures 188 therein with the pawls 158 which are thus permitted to engage with the ratchet wheel. In Fig. 13 three equally space centrifugal weights 270 are connected for movement in unison by a ring 278 which holds the pawls disengaged from the ratchet wheel when the speed is below the predetermined value. The centrifugal weights may be sintered mouldings or die castings.