| 摘要 |
: "IMPROVEMENTS IN OR RELATING TO DOOR CLOSERS" The door closer is of the kind which acts, for example between a door hinge stile and a hinge jamb and has a body for mounting usually in the stile, from which body a spring-biased tension member extends correspondingly for anchoring to an anchoring point (for example in said jamb), wherein a hydraulic cylinder-piston damper is interposed between said tension member and a biasing spring therefor, said damper being adapted to allow fluid in use to flow restrictedly past said piston when said tension member (12) is moved in door-closing and door-opening directions; characterised in that the cylinder of the hydraulic cylinder piston damper is formed of a plastics material, and the cylinder is resiliently expansible in response to an increase in pressure therein such that the clearance between the piston and cylinder is increased to permit increased flow of fluid around the piston.
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