GEAR TO CLOSE DOOR WITH COMPRESSED-AIR PISTON BRAKE Russian patent published in 2003 - IPC

FIELD: equipment closing doors, windows, lids. SUBSTANCE: gear to close door has spring drive and compressed-air piston brake and can be used in residential, production and public buildings, predominantly on outer doors for their automatic closing. Gear includes telescopic structure and cylindrical body with cover, first spring-loaded piston sealed on one side with hollow rod where second spring-loaded piston with rod is located. Holes are made in walls of body and hollow rod in close proximity to their covers. Annular groove locating sealing ring is cut in first piston, face wall of this piston has holes. One hole communicates first space under piston with second space under piston in hollow rod, rod space of first piston communicates through second hole and annular clearance to spaces under pistons. Body of gear is fitted with limiter of piston stroke that comes in the form of two rests anchored on internal surface of wall of body. EFFECT: enhanced functional reliability at various speed modes, mode of accelerated door closing included, and easy adaptability to manufacture. 2 cl, 2 dwg