| 摘要 |
572,237. Cycle driving-mechanism. BIRMINGHAM SMALL ARMS CO., Ltd., and URRY, W. C. Aug. 17, 1943, No. 13334. [Class 136 (ii)] To enable the driving wheel of a bicycle to be removed from the frame 11 without detaching the chain froin the sprocket a separate axle unit 9 secured to the frame carries rotatably chain sprockets 3 of different sizes on a member 1. provided with clutch teeth 15, and the ratchet free-wheel mechanism on a sleeve 31 extending through the hub 21 has clutch teeth 17 adapted to engage the teeth 15, an axle member 43 being screwed to the axle unit 9 to maintain the clutch parts in engagement. The three sprockets 3 of a change-speed gear are mounted on the sleeve 1 rotatable by ball bearings 5, 7 on the short axle 9 fixed to one of the rear forks 11 of the bicycle by nuts 13, and the clutch teeth 15 are formed on the inner face of the sleeve. The driving member 19 of the free-wheel mechanism has facial clutch teeth 17 and drives the hub 21 through spring- pressed pawls 23. The hub 21 is supported on a hollow sleeve 31 through which passes the bolt 43 of which the outer end is received in the other fork 11 and the inner end is threaded to engage a central tapped hole 41 in the fixed axle unit 9. Between the end of the hub 21 and the fork 11 is a distance piece 45 of a width slightly larger than the depth of the clutch teeth 17 so that when the bolt 43 and the distance piece 45 have been removed the clutch may be disengaged and the wheel readily removed without forcing open the forks, leaving the chain sprockets 3 and the chain undisturbed. Shields 37, 39 exclude grit &c. from the mechanism. |
