GB782467A - Improvements in or relating to vices and other screw-operated mechanisms - Google Patents

Abstract

782,467. Vices. TROW, A. C. June 16, 1955 No. 17414/55. Addition to 779,153. Class 61. The torque controlled locking means for locking the slow pitch thread of the screw member of the device of the parent Specification comprises a cammed collar 20 mounted on the screwed member 7 the collar having a cam surface engaging a similarly shaped cam surface 19 on the operating member 13, a spring being provided between the cammed collar and screw thread whereby relative rotation of the two slow pitch thread elements 17, 18 is prevented until the longitudinal force produced by the torque applied to the operating member is sufficient to force the cammed collar longitudinally along the screw thread. As shown a compression spring 22 is provided between the inner end of the cammed collar 20 and an annular shoulder 21 on the spindle 7. Rotation between the collar and spindle is prevented by providing a slot 23 in the spindle and an inwardly projecting peg 24 on the collar. In a modification the collar rides on longitudinal splines on the spindle. Means may be provided to ensure the resetting of the thread 18 to the normally indexed operation of the operating member 13. On initial rotation of the member 13 the spindle 7 and member 13 rotate conjointly. On resistance being encountered by the sliding jaw, the member 13 commences to rotate with respect to the spindle whereupon the slow pitch thread 18 comes into operation.