GB399901A - Improvements in and relating to spanners - Google Patents

Abstract

399,901. Wrenches. BATHO, C., ROWAN, C., and BATEMAN, E. H., Civil Engineering Department, University of Birmingham, Birmingham. April 30, 1932, No. 12509. [Class 61 (iii).] A rigid-jaw wrench head is connected to the handle so as to permit relative movement, and such movement is opposed in operation by a yielding resistance to indicate the torque applied to the nut &c. In the construction shown the operative resistance of the wrench head 1 pivoted at 3 to the handle 23 is opposed by a spring 19 through the intermediary of a second order lever 10 provided with a bent end 9 terminating in a knife edge 8 bearing on a hardened plate 7 and with a second knife edge 11 engaging the end 13 of the wrench head 1, the lever 10 being retained in position for proper engagement of the knife edges by a pin 14 engaging guide slots in the walls 5 of the channel section handle portion 6. A contact screw 20 engages a plunger 21 moving through a friction washer 22, which plunger may be graduated to indicate the torque or may actuate a dial or it may operate a mechanical device to ring a bell when the required torque has been reached. Or the relative movement between wrench head and handle may be arranged to close an electrical circuit for ringing a bell or lighting a lamp.