Two-part automatic bolt for doors

A door and automatic bolt combination, comprising a door having a first hole having a vertical axis and being spaced from an upper or lower corner of the door remote from the door corners about which the door pivots, and an intersecting second hole having a horizontal axis and being spaced from the same upper or lower corner of the door, the corner of the door remaining intact, a vertical bolt mechanism inserted in the first hole and having a bolt head movable between extended and retracted positions, and a separate horizontal transfer mechanism inserted in the second hole, said vertical bolt mechanism and horizontal transfer mechanism adapted to lie in a vertical plane adjacent an upper or lower corner of a door, said upper or lower corners both remote from the door corners about which the door pivots,

• said horizontal transfer mechanism comprising a casing, slide means for movement between a retracted position and an extended position and engageable with a second mating door to move to retracted position, and motion transfer means mounted on said horizontal transfer mechanism operable to cause movement of the bolt head to the extended position when the slide means moves to retracted position, and
• spring means for biasing the bolt mechanism to move the bolt head to retracted position while simultaneously biasing the slide to extended position.