US Patent 7036854 Flush bolt

A flush bolt mechanism to be mounted into a recess at the vertical edge of an inactive door of a pair of swinging doors. The flush bolt mechanism has a manually-activated trigger, a shaft connected to the trigger by a pin, a spring clip biasing the shaft, and a bolt to be projected into a strike plate which is mounted onto the door frame or the sill. The bolt mechanism is supported and elevated at the upper end by the front base which has a foot and by a cylindrical spacer placed at the round base. This flush bolt mechanism can simply be constructed with extruded aluminum or copper, and can be mounted into a recess at the vertical edge of an inactive door with ease, accuracy, and certainty.