Friction hinge assembly for openable closure member

摘要

A restricted friction hinge assembly (30) for mounting an openable closure member, such as a side hung or top hung window frame, on a fixed frame member of a fixed frame, said hinge assembly (30) having a fixed guide track (31) which is securable to said fixed frame member and a linkage (32) which is connectable to a frame element of the openable closure member, and which is capable of carrying out opening and closing movement relative to the fixed guide track (31), in which the linkage (30) comprises: a first arm (33) securable to said frame element; a second connecting arm (36) pivoted at one end (37) to an end region of the first arm (33) and pivoted at its opposite end (38) to the guide track (31) via a slidable mounting block (39) mounted for slidable movement lengthwise of the guide track (31); a third connecting arm (41) pivoted at one end (42) to the first arm (33) and pivoted at its opposite end to a fixed pivot point (not shown) on the guide track (31); and, a fourth control arm (43) pivoted at one end (44) to the guide track (31) on the same mounting block (39) on which said second arm (36) is mounted, said fourth arm (43) also being pivoted at its opposite end (45) to the third arm (41) at a position intermediate the ends of the third arm (41) so that the fourth arm (43) extends substantially parallel to the first arm (33) to form an approximate parallelogram linkage therewith, and in which: an elongate control element (46) is connected to said movable slide block (39) for movement therewith during opening and closing movement of the linkage (32); an abutment (47) is mounted on the guide track (31) and which has an operative position lying in the path of travel of the control element (46) to limit movement thereof and thereby determine a required limit to the opening movement of the linkage (32); the abutment (47) is adjustable to a disabled and inoperative position out of the path of movement of the control element (46) and thereby to allow a greater extent of opening movement of the linkage (32); and, the abutment (47) is automatically returnable to its operative position as the linkage (32) carries out closing movement whereby subsequent opening movement of the linkage (32) can again be restricted by limiting the movement of the control element (46).