DOOR CLOSER: DOOR ROTATES A SPINDLE IN CLOSER HOUSING WHICH DRIVES A CAM FOLLOWER ALONG A TRACK THEREIN AGAINST A RESILIENTLY BIASED RECIPROCAL PISTON: TORQUE AT SPINDLE GREATER WHEN DOOR CLOSED THAN WHEN OPEN

摘要

PCT No. PCT/GB94/02668 Sec. 371 Date Apr. 17, 1996 Sec. 102(e) Date Apr. 17, 1996 PCT Filed Dec. 6, 1994 PCT Pub. No. WO95/16845 PCT Pub. Date Jun. 22, 1995A door closer comprises a housing (21) in which a compression spring (23) urges a piston (22) in one direction, an operating spindle (18) in the housing defining an axis (19) about which an arm mechanism (52) connected to the housing is angularly movable to effect movement of the piston in the opposite direction. Connected between said axis (19) and the piston (22) is a linkage mechanism which provides that, in use, maximum torque is exerted on the arm mechanism at the near closed position of the door. The linkage mechanism can have a pivotal connection (27) between links (25, 26) thereof constrained to follow a continuous curve by means of a cam track (30, 31) or an additional link (48).