Improvements in or relating to resilient return mechanisms

摘要

700,405. Springs. RANSOMES & RAPIER, Ltd., CAMERON, C. M., and BALICKI, F. K. July 10, 1951 [July 10, 1950], No. 17207/50. Class 108(3) Spring return mechanism comprises a resilient member 7, opposite ends of which act on two movable members 9, 10, which normally bear against stops 20 to maintain the member 7 pre-stressed, and a controlled member 24,.25 having lost-motion connections 19, 21 with the movable members 9, 10. The member 7 comprises a torsion bar or tube and is connected by dogs 13, 15 (having no lost motion) to the members 9, 10 at least one of which is also a torsion tube. The tube is journalled in a bushing 8 rigid with a fixed mounting 1. Flanged sleeves 2, 3 secured by bolts 6 to the mounting 1 carry bearings 12 in which are journalled rings 11 rigid with the ends of the tubes 9, 10. The controlled member is in the form of two arms 24, 25 which are journalled respectively on the ends of the tubes 9, 10 and are secured along a dividing line 26. Each ring 11 has two sets of dogs 18, 19 which have lost-motion connection respectively with dogs 20, 21 rigid with the mounting 1 and the corresponding arm 24 or 25 respectively. The lost-motion connections are so arranged that deflection of the member 24, 25 in either direction causes dogs 21 to pick up the dogs 19 on one or other side of the tubes 9, 10 to cause further loading of the torsion tubes 7, 9, 10. The mechanism is initially set by removing the bolts 6 and bolts (not shown) which secure the arms 24, 25. The latter are then drawn into alignment and bolted together thus prestressing the tube 7, and the bolts 6 are inserted and secured. The member 24, 25 may constitute one end of a vertical return arm connected to the foot of the walking mechanism of a drag-line excavator described in Specification 700,406, [Group XXXI].