Patent GB-818502-A (GB)
Title: Improved one-way detents and freewheel clutches
IPC: F16D41/08
Filed: 1956-02-03
Abstract: 818,502. One-way brakes. ZAHNRADFABRIK FRIEDRICHSHAFEN A.G. Feb. 3, 1956 [Feb. 4, 1955; Nov. 30, 1955], No. 3469/56. Class 103 (1). [Also in Group XXIV] A ratchet clutch or one-way detent comprises a number of pairs of rollers disposed between inner and outer cylindrical surfaces. the rollers of each pair being engageable peripherally with one another and with the adjacent cylindrical surfaces. In one form, inner and outer free-wheel members 1, 3, Fig. 1, have cylindrical surfaces 2, 4 between which are engaged pairs of rollers 5, 6 held in position by springs 9. In another form, rollers 15, 16, Fig. 2, are positioned by relatively rotatable cages 17, 18 biased by springs 19 to engage the rollers with the surrounding cylindrical surfaces. In a similar form of a one-way detent which may also be adapted for use as a free-wheel clutch, rollers 35, 36, Figs. 3, 4, are disposed between a cylindrical surface 34 on a member 33 rotatable with a shaft 29 and a cylindrical surface 32 on a ring 31 which is connected to a stationary casing 30 by turning a spindle 39 in the casing having a roller 40 engaged in a recess 41 in the ring. A lever 42 can rotate about a pivot-pin 43 fast in an inner cage 38 containing the rollers 36 and is pivotally connected to a pin 47 fast on an outer race 37 containing the rollers 35. The inner end 44 of the lever 42 lies in a socket 45 in a stationary casing part 46. Springs 48 between the inner and outer cages bias the pairs of rollers to engage each other and their associated races. The arrangement is such that when the shaft 29 &c. rotates anti-clockwise of Fig. 4, the rollers 35, 36 are free, but when the shaft 29 tries to rotate clockwise, the rollers wedge between the inner and outer cylindrical surfaces 34, 32 and such rotation is prevented. On turning the spindle 39 clockwise, the outer ring 31 turns clockwise in the stationary casing 30. The cage 38 and lever 42 move clockwise until the inner end 44 of the lever abuts the right-hand edge of the socket 45, so that the lever turns on its pin 43 and thus rotates the inner and outer cages 38, 37 relatively to each other. The rollers 35, 36 disengage from each other and their associated cylindrical surfaces, and the shaft 29 &c. is then free to turn in the clockwise direction. In one modification, Figs. 5-7 (not shown), the outer roller of each pair is formed by two parts of different radius of curvature, the part of smaller radius engaging the inner roller, and in another similar modification, Fig. 8 (also not shown), the outer roller has a flat surface lying along a chord of its generating surface and engaging the inner roller. In a one-way detent similar to that of Figs. 3, 4 above, which also may be adapted for use as a one-way clutch, the rollers used are of the latter configuration, the outer ring 31, Figs. 9, 10, having an inner cylindrical surface 32 and the ring 33 having an outer cylindrical surface 34 between which surfaces the pairs of rollers 35, 36 engage. In this form, the lever 42 is pivoted on a pin 52 in the ring 31, as well as being pivoted on the pins 43, 47 on the inner and outer cages 38, 37. When the shaft 29 tends to rotate clockwise of Fig. 9, the rollers 35, 36 wedge between the cylindrical surfaces as before, and prevent such rotation. On turning the spindle 39 clockwise the outer ring 31 is similarly turned clockwise and the end 44 of the lever 42 abuts the edge of the socket 45 on the stationary caging part 46. The lever 42 is thus turned on its pin 52 and rotates the cages 38, 37 relatively to each other, so that the rollers 35, 36 are disengaged from each other and the shaft 29 can turn freely in the clockwise direction.