| 摘要 |
<p>1,023,356. Change-speed gear. FICHTEL & SACHS A.G. Aug. 13, 1963 [Aug. 18, 1962], No. 31935/63. Heading F2D. Direct drive in a two-speed planetary hub for bicycles is obtained from an input sprocket 3 connected through a planet carrier 2 and a ratchet clutch 5, 6 to a driven hub 7, increasing speed of rotation driving through a non- planetary step-up ratio reverse gear train 19, 21, 23 to centrifugal weights 25 which fly radially outwards into engagement with a sleeve 16 to turn it backwards against a light friction engagement with the hub, a screw connection 15 between the sleeve and a ring 13 sliding the latter axially so that its coned inner face 18 releases the pawls 12 of a second ratchet clutch for engagement with teeth 28 in the hub 7. A step-up drive from the input sprocket 3 and the carrier 2 is then obtained, planets 4 on the carrier meshing a fixed sun gear 10 and a ring gear 11 driving through the ratchet clutch 12, 28 to the hub 7, while the ratchet clutch 5, 6 over-rung. The sleeve 16 is provided with a friction spring 17 sliding over the inner face of the hub 7, and the ring 13 is restrained against rotation by its slotted engagement with a friction spring 14 on a fixed axle 1. The step-up ratio train comprises a ring gear 19 in the hub 7 meshing idle pinions 21 in turn meshing an inner gear 23 connected to a carrier 24 on which are pivoted the centrifugal masses 25, biased radially inwards by springs 27. The centrifugal weights 25 engage positively in slots 26 in the sleeve 16. In a modified form, the carrier 24, Fig. 3 (not shown), of the centrifugal weights is made of a synthetic plastics material, and the centrifugal weights 25 slide radially outwards, along arms on the carrier, to engage frictionally with the hub 7.</p> |
