GB191002048A - A Three-speed, Hub-contained Gear, for Bicycles and Light Motor Vehicles. - Google Patents

Abstract

2048. Browne, H. C. Jan. 27. Variable-speed epicyclic gearing.-In three-speed single-train hub gears for bicycles and light motorvehicles, of the kind wherein on the normal or direct drive the gear is disengaged from the hub and from the driving-member, friction disks s with or without guide flanges t, are applied to each side of all the wheels, the non-rotatable sun-wheel, the planet-pinions, and the internally - toothed wheel being arranged to slide together within the hub in order to effect the gear changes. To prevent possible jarring of the extreme edges of the teeth of a wheel against the edges of the disks attached to other wheels of the train, the teeth of the wheels are for a short distance from their outer edges cut down to the diameter of the disks. As shown in Figs. VI and VII, a ring 1 carries internally and externally projecting pawls 7, 8 to engage ratchet teeth 9, 10 upon the driving- sleeve and the hub, the tails of the pawls being arranged to project in openings 11 in the ring. The direct drive is transmitted through the pawls 7, 8 to the hub. To obtain the low gear, the train is moved one step to the right so that the projections 2 on the internal wheel enter the openings 11, and engage the tail of the outwardlyprojecting pawls ; the internal wheel is thus connected to the driving-member, and the hub is driven by the engagement of pawls 3 upon the carrier with ratchet teeth 4. Further motion of the train towards the right disconnects the clutch 3, 4 and causes the projections 2 to engage the inwardly-projecting pawls 7 and to release the pawls 8. The hub is then driven at high speed through the train, the carrier being rotated by the engagement of clutch dogs 5, 6 and the internal wheel connected to the hub through the pawls 8. The pawls of the clutch 3, 4 have tails or projections which bear upon springs 13 carried by the internal periphery of the channelled carrying-ring. To provide a free-engine position for motor-vehicles, the clutch pieces 4 are shortened slightly so that the inner pawls are released from engagement with the driver before the parts 5, 6 come into contact. It is not necessary that the inner pawls should be of the trigger type as they would overrun on the high gear. In a modification, the internal wheel and the planet-pinion carrier are provided with rings of ratchet teeth which in turn engage the inner ends of broad double pawls, mounted on the driver, to take up the drive and to turn the outer ends of the pawls inwards out of engagement with the hub, the low gear being transmitted through a clutch 3, 4, as before, and the high gear by the engagement of dog or ratchet clutch members on the internal wheel and the hub. By providing a plain ring upon the left-hand side of the ratchet ring on the internal wheel or upon the right-hand side of the ratchet ring on the carrier, the outer ends of the pawls may be moved out of engagement with the hub to furnish the free-engine position. The gear may be controlled by the mechanism described in Specification 5320/10.