GB328660A - Improvements in and relating to the actuation of brake bands, reaction bands for epicyclic gearing, or any lever actuation of parts - Google Patents

Abstract

328,660. Wilson, W. G. Nov. 3, 1928. Actuated by springs.-An actuating system for brakes and other devices comprises a lever p, a link l and springs a, the line of thrust of which acts through the connections k between the springs and the link whereby the connection is brought nearer to or farther away from the fulcrum p<1> of the lever according to whether the load on the springs is increased or decreased, so that the leverage moment is varied in inverse ratio to the stress on the springs. As applied to the manipulation of the various reaction bands in a mechanically operated gear box, a bar having levers p, q, lies on a knife edge p<1> at the bottom of the gear box and selectively operates the bands such as 13, Fig. 9, by a strut 11 and toggle mechanism 12. The lever p supports a link l by a knife-edge n and a socket k is supported in the other end of this link by a knife-edge m. A stop s on the lever p limits the inward movement of the link l and a stop r on the link l limits the outward movement of the socket k. A spring a, for applying the bands, is engaged between plates band c provided with extensions d, e which telescope into one another, and the plate c engages a ball f fixed to the casing g whilst the plate b is extended at h to engage in the socket k. The foot pedal engages the arm q through a strut 2, Fig. 9, and when the pedal is depressed so that the lever q, is down, the gears are free and the spring a is fully compressed, whereby the resistance to movement is least due to the proximity of the line of thrust of the spring to the knife edge p<1> When the foot-pedal is raised the lever p, q, turns on the knife-edge p<1> with the link l in contact with the stop s and a slight increase in resistance occurs up to the position in which the pivots f, n and k<1> are in alignment. When this position has been passed the link l swings rapidly away from the lever p and contacts through the socket k with the stop r, Fig. 2. The resistance to movement thus rapidly increases until a maximum is reached which corresponds to the engaged position of the brake band. Only one socket member may be used and the stops may be placed in various positions.