GB269283A - Improvements in and relating to change-speed gears - Google Patents

Abstract

269,283. Hunt, W. Feb. 18, 1926. Variable-speed gearing; shaft couplings.-A. change-speed gear which is controllable optionally either manual v or automatically in accordance with load is combined with one or more screw yielding couplings. In the arrangement shown, the speed changes are effected by sliding the driving-shaft X longitudinally, which may be done either by a governor or by a hand-lever M. A countershaft Z carries gears A<2>, B<2>, C' meshing with gears A<1>, B' loose on the shaft X and with a gear C<2> free-wheel mounted on a driven shaft Y. The gear A<2> is free-wheel mounted. In the configuration shown, the lowest speed is operative through a clutch D and train A<1>, A', C', C<2>. If the speed increases, the governor moves the shaft X to the right when clutch E engages and the pair B<1>, B<2> replaces the pair A<1>, A<2>, the gear A<2> over-running the shaft Z. On further increase of speed, a clutch member F on the shaft X engages a clutch frame G on the shaft Y. yielding a direct drive, the toothed rims A', C' overrunning their shafts. There may be a governor for each clutch, and the clutches may be nested, one within the other. The coupling comprises a frame U fast on the shaft Y which turns loose on the screwed tail shaft W, and carries with it as it rotates a nut T screwing on the screw W. On increase of resistance, the nut T screws along compressing springs R until the increased torque is transmitted. This shock-absorbing structure forms a unit, which may be used with each clutch, or with some of them.