Bevan's patent 1908 Lock-nut, double roller type, for 1" diam. bolt

Bevan's patent 1908 Lock-nut, double roller type, for 1" diam. bolt

These are specimens of the roller clutch type of lock nut containing improvements patented by Mr. W. R. Bevan in 1908. The nut has a longitudinal slot cut inside it, deeper at one edge than the other. A grooved roller lies in this slot and is pressed towards the narrow end by a flat spring, so that when the nut is screwed on to the bolt the roller frees itself, but should the nut tend to unscrew, the roller jams itself between the bolt thread and the back of the slot, preventing further relative motion. A hardened plate is inserted in the slot behind the roller, and the nut is recessed at the top and bottom for the reception of lipped washers that hold the rollers and springs in place; the ends of the rollers are turned smaller for this purpose. In order to release the nut, a pin or wire nail is inserted in front of the roller, through a hole in the top washer. One of the specimens shown, which are for bolts of 1 in. diam., has two rollers fitted so that it cannot move in either direction until a releasing pin is placed between the rollers to hold them out of engagement with the bolt.