GB373187A - Improvements in or relating to friction ratchet clutches and friction ratchet drives - Google Patents

Abstract

373,187. Friction ratchet clutches and gearing. AKTIEBOLAGET SPONTAN, 2, Norrmalmstorg, Stockholm. Feb. 13, 1931, No. 4563. Convention date, Feb. 28, 1930. [Classes 80 (ii) and 80 (iii).] In friction roller ratchet clutches or gearing, particularly in which caged rollers are spring- pressed into engagement with wedging surfaces on an outer member and thus tend to move centrifugally to the disengaged position, a centrifugal device is provided to increase the spring pressure at high speed and preferably acts on control means for reversing the direction of drive. In an automatic variable-speed gear as described in Specifications 259,975, 276,853, and 314,873, [all in Class 80 (ii), Gearing, Variable-speed &c.], wherein negative turning- moments are transmitted to a stationary part by a roller-detent arrangement V and positive turning-moments to a cylindrical inner member A by a roller clutch B, C, compensating balls S in recesses R in the part B coact with inclined surfaces P on the axially-moved control sleeve L which angularly shifts the cage D to exert forward or reverse pressure on the rollers C through springs E. The sleeve L is coupled to the cage D by studs N passing through circumferential slots (not shown) in the part B and through helical slots M in the sleeve L, and is prevented from rotating relatively to the part B by axial slots and further studs rigid in the part B, similar to the slots and studs M<1>, N<1> associated with the corresponding sleeve L<1> for controlling the detent device V. The sleeve L is axially moved through a thrust bearing J by sleeves F, G, acted on by means allowing lost motion ; as shown, this means comprises an arm H rotated about the axis of a cylindrical guide Z, the arm being free to tilt and acted on by a rod 3 responsive to changes in lubricating oil viscosity, as described in Specification 349,010. A duplicate compensating device operative for reverse drive may be provided, but is usually unnecessary on a vehicle, the balls S being thrust wholly into their recesses R when the sleeve L is in the reverse position. Escape of the balls through the slots M is then prevented, for instance by the irregular distribution thereof shown in Fig. 4.