Patent GB-1179105-A (GB)
Title: Improvements in Actuators.
Inventor: STEER RONALD JOHN
IPC: F16H35/10
Filed: 1966-05-03
Abstract: 1,179,105. Clutches; toothed gearing. ENGLISH ELECTRIC CO. Ltd. 26 April, 1967 [3 May, 1966], No. 19406/66. Addition to 1,058,593. Headings F2E and F2Q. In a modification of the actuator claimed in Specification 1,058,593, the locking means comprises a stationary member 18, Fig. 1, a rotatable input member (10), Fig. 2 (not shown), and a coaxial rotatable output member 16 which is connected to the actuator drive member and defines with the stationary member a circumferentially tapering space 20 containing a roller or ball 24, the input member and output member having driving parts and the input member having also a freeing portion 36 which holds the roller at or near the middle of the space when the input member is driving the output member, the arrangement being such that, if the output member attempts to drive the input member the roller wedges between the stationary and output members and thus locks the output member. When the input member drives the output member in the clockwise direction in Fig. 1, fingers 28 and 30 engage shoulders 32 and 34 on the output member to drive it positively whilst fingers 36 and 38 hold each roller in the centre of its space to prevent it wedging. If the input drive ceases and the output member tends to over-run or back drive in a clockwise direction the output member moves to a position where it is locked by the wedging action of the rollers. If the output member tends to rotate in a counter-clockwise direction the engagement of fingers 28 and 30 with shoulders 32 and 34 initially moves the input member until the output member is locked by the roller wedging action. A flange on the stationary part may be provided to prevent the rollers from rotating with respect to the output member by frictional engagement with the flange. In a modification spring-loaded plungers (40a, 42a), Fig. 3 (not shown), move the rollers (44, 46) to cause wedging whilst only one finger (52) or (54) drives in each direction, the non- driving finger serving to free the roller. In another embodiment a stationary member 200, Fig. 6, surrounds sections 204 of the input member (202), Fig. 8 (not shown), and has curved flanks 206 in a recessed part and a partcircular spring 210 in a circumferential groove (212). The pins 216 hold the spring 210 in a stressed state so that it holds roller 208 against the stationary surface. During normal operation the engagement of edges 205 via spring ends 214 on radial pin 218 provides a positive drive whilst the tightening of the spring causes its disengagement from the roller which is held in the centre of the tapering space by the edge of a section 204. A further part-circular spring may be included to hold the roller disengaged. In further application to an epicyclic gear actuator Fig. 4 (not shown), a rotor 124, Fig. 5, is connected to an annular input member 150 driving an output member 152 which is connected to shaft 123 by radial pins 154, the stationary part being a flange 156. During manual operation the wedging of the rollers 160 prevents rotation of the shaft 123. In a further application the epicyclic gear actuator, Fig. 9 (not shown), includes a drive transmission as shown in Fig. 6.