The size adjustment is set by a screw, and has a "locking screw" collar. The lock release is a secondary lever on the lever handle that presses on a projection extending from the toggle link. This arrangement for the lever handle and lock release facilitates one-handed operation.
Produced as the CHANNELLOCK No. 950 TOG-L-LOK Locking pliers, which is marked with this patent and 3,545,315.