Abstract: A shock pivot hinge for the upper corner of a door at its hinge side includes an upper jamb leaf and a door leaf below it having an inner side for engaging the face of the door and also having an end portion provided with a vertical opening. The jamb leaf is provided with an opening directly above the door leaf opening, and a block is mounted in each opening with a pivot pin extending vertically from one of the blocks toward the other block which has a vertical passage therein receiving the pin. The pin is offset in the same direction relative to the centers of both blocks in a vertical plane perpendicular to the inner side of the door leaf, and the blocks are adapted to be turned 180.degree. in the leaf openings to locate the pin a different distance from the inner side of the door leaf.

Abstract: A hinge is secured to the jamb of a door frame and to a door in the frame. Behind the jamb leaf of the hinge the jamb is provided with a hole that is concealed by the hinge. The back of the jamb leaf is provided with a recess facing the hole. An electric switch and its operating magnet are mounted in a housing that is held in the jamb hole and projects into the jamb leaf recess. The housing is not attached to the hinge. In case the hinge leaves are substantially parallel when the door is closed, a ferrous area of the door leaf will activate the switch. If the hinge leaves are at right angles to each other when the door is closed, a ferrous metal area of the edge of the door itself activates the switch.

Abstract: A hinge is secured to the jamb of a door frame and to the adjacent edge of a door in the frame. Behind the hinge leaves the jamb and the door are provided with aligned holes that are concealed by the hinge. The back of each hinge leaf is provided with a recess facing the adjacent hole. A magnetically operated electric switch is held in the jamb hole and projects into the jamb leaf recess, and a magnetic device is held in the door hole and projects into the door leaf recess. The switch and magnetic device are not attached to the hinge.

Abstract: A housing with an open outer end engages the inner face of a faceplate around an opening through the plate, which is designed for attachment to a door jamb. A spring in the housing normally holds a plunger in a position in which it projects from the faceplate. The projecting portion of the plunger has a laterally facing abutment for engagement by a bidirectional swinging door when the door is closed in its normal closing direction. Pivotally connected to the plunger on a vertical axis adjacent the outer end of the housing at its door side is a lever that has a latch portion projecting from the opposite side of the plunger and engaging the inner face of the faceplate.

Abstract: A lock housing is adapted to be mounted at the free vertical edge of the inactive one of a pair of hinged doors that have adjacent vertical edges when both doors are closed. Slidably mounted in the housing is an axially movable shaft that extends vertically therefrom and has a normally retracted latch bolt mounted on its outer end. Operatively connected to the opposite end of the shaft is the inner end of a rocker arm, the central part of which is pivotally connected to the housing on a horizontal axis. A cam pivotally connected on a vertical axis to the housing normally projects from it for engagement by the free vertical edge of the active door for swinging the cam into the housing to swing the rocker arm vertically in order to project the latch bolt from a horizontal edge of the inactive door. The rocker arm is so mounted in the housing that it will be moved by the cam bodily away from the free edge of the door if the shaft cannot move, whereby the mechanism will not be damaged.

Abstract: One of a pair of hinge leaves has an integral open outer loop extending along one edge and the other leaf has an integral inner loop extending along one edge and disposed inside the outer loop. The inner loop is mounted on a hinge pin extending through it and provided with longitudinally spaced exposed areas encircled and engaged by spacing members rigidly mounted in the outer loop to hold the pin in predetermined position in that loop. The opposed surfaces of the two loops are held apart by the pin and spacing members to prevent the loops from rubbing together when the hinge is opened and closed. By making the hinge pin hollow and extending a torsion rod through it, with one end of the rod attached to the inner loop and the opposite end connected to the outer loop, the rod will be twisted when the hinge is opened and will close the hinge when it is released.