Telephone booth door guide linkage - has levers hinged at two points on door upper edge forming four bar linkage

摘要

The telephone booth door guide linkage is attached to the door upper edge at two positions, and determines the path of the door between closed and open end position. One end of the door is guided initially outwards on opening, and subsequently the door swings into the booth to facilitate opening. The linkage consists of two levers (6, 7) pivoted on bearing lugs (4, 5) on the door (3). The other rotating ends are held in bearings on the ceiling. Alternatively two guide cams can be used, one of which is preferably circular and is held on the door. Or a combination of a lever and a cam can be used. The locus of position of the opening movement pole is a spiral contained within a square attached to the inside of the inner half of the door width.