Patent ID: 6886217
Filing Date: 2005-05-03
Classification: E05F,E05Y,Y10T

Abstract:
1. A door closer comprising: an anchor member for mounting on a door frame, an actuator assembly for mounting within the thickness of a door which is hinged for movement between open and closed positions relative to said door frame, an operating member coupled by an articulated link to said anchor member and wherein said operating member is mounted in said actuator assembly and capable of a range of movement between a retracted position in which said anchor member is held immediately adjacent to said actuator assembly and an extended position in which said anchor member is held in spaced relation to said actuator assembly, a resilient driving means arranged to exert a driving force on said operating member in a manner such as to drive said operating member at a rate of movement towards said retracted position and thereby draw said anchor member and said actuator assembly together such that, when installed, the door closer acts to draw the door into the closed position relative to the door frame, a damper connected to said operating member, wherein the rate of movement of the operating member can be controlled in at least a direction towards said retracted position, said damper comprising a cylinder containing hydraulic fluid, said hydraulic fluid having a rate of flow, a piston rod carrying a piston which divides the cylinder into two chambers, and flow-restricting means to limit the rate of flow of hydraulic fluid from one of said chambers to the other at least in one direction of fluid flow in response to movement of said operating member towards said retracted position, a resilient thrust means arranged to exert an increased driving force on said operating member, a control means whereby said resilient thrust means applies said increased driving force to said operating member over a defined part of said range of movement as said operating member approaches said retracted position, wherein the defined part corresponds to movement of the door over a final part of its movement into the closed position and beginning at a point in the range of movement, and an adjustment member operatively connected with said control means to vary the point in the range of movement of said operating member at which said resilient thrust means applies said increased driving force, wherein the control means comprises a cam mechanism having a cam surface and a cam follower operatively associated with said thrust means, wherein movement of said cam follower along said cam surface causes a deformation of said thrust means, and wherein said cam surface comprises part of a slot provided in a control sleeve, the cam follower being moveable along a slot provided in a control member, the control member being slidably received within said control sleeve, movement of said operating member between said retracted and extended positions effecting movement of said control member within said control sleeve.