Abstract: A pattern change mechanism is provided for use with a lighting fixture. The mechanism includes a plurality of blocking members for blocking light directed by the reflector of the lighting fixture toward a target surface, means for moving the blocking members to achieve small, medium and large patterns of light on the target surface. The moving means includes a rotation member, drive means, actuator means linked to the blocking members and a handle for rotating the rotation member to thereby effect movement of the blocking members through the drive means and actuator means.

Abstract: A mechanism for positioning one of a plurality of lamps, each carried by a lamp socket, at a desired focal point of an optical system is comprised of a first lamp socket positioned in an operative position such that a lamp carried by that socket will be at a desired focal point of the optical system. At least one other lamp socket is positioned in an inoperative position. A mechanism for enabling movement of the first lamp socket from the operative position to an inoperative position while simultaneously moving the other lamp socket from the inoperative position to the operative position is provided. The present invention enables a failed lamp to be replaced by a backup lamp in such a manner that no degradation or change in optical performance occurs.

Abstract: A door which may undergo rotational as well as vertical and horizontal movement relative to a door frame is provided. The door is provided with a lifting means which includes a slide plate which may be vertically displaced relative to the door. A lever is pivotally mounted on the door with one end having a roller which engages a slot on the slide plate and the other end having a roller which engages a block mounted on the door frame. The vertical displacement of the slide plate causes the lever's roller to ride in the slot until the roller reaches the end of the slot at which point the slide plate causes the lever to lift the door relative to the door frame. To accommodate such door movement, the door is provided with a hinge which includes a clevis mounted on the door frame which includes a lower section having a bearing surface and an upper section having an internal cavity. The internal cavity includes an internal shoulder area and slots which communicate with the lower area of the upper clevis section.