US Patent 7849719 Locking device

The locking device contains an axle, a bolt, a positioning plate, and a cylinder. The axle is connected to a thumb-turn knob and, from a circumference of the axle, a lever is extended perpendicularly. The bolt has a vertical trough in a rear section. An end of the lever is embedded in the trough. The positioning plate has an elongated opening inside which the axle is embedded. The cylinder is positioned adjacent to and above the rear section of the bolt. The cylinder has a key hole in the center and an activation bar extended from a circumference of the cylinder. When the thumb-turn knob or a key in the key hole is turned, the positioning plate is moved towards an opposite direction. In turn, the lever of the axle pushes or pulls the bolt in the same directions as the key or the knob is turned.