Friction hinge for openable closure member

摘要

A friction hinge assembly (10) for mounting an openable closure member, such as a side hung window frame, on a fixed frame member of a fixed frame, said hinge assembly having a fixed guide track (11) which is securable to said fixed frame member and a linkage (12) which is connectable to a frame element of said openable closure member, in which the linkage comprises: a first arm (13) securable to the frame element; a short second connecting arm (16) pivoted at one end (17) to an end region of the first arm (13) and mounted pivotally at its opposite end (18) on the guide track (11); a longer third connecting arm (19) pivoted at one end (20) to the first arm (13) and pivoted at its opposite end to a slide block (not shown) mounted for slidable movement lengthwise of the guide track (11) during opening and closing movement of the closure member; and, a fourth control arm (21) mounted pivotally at one end (22) on the guide track (11) close to the pivot mounting (18) of the second arm (16) on the guide track (11), and pivoted at its opposite end (23) to the third arm (19) at a position intermediate the ends thereof so that the fourth arm (21) extends generally parallel to the first arm (13) to form an approximate parallelogram linkage therewith; and, in which: the second and fourth arms (16, 21) are pivotally connected to a mounting block (25) which is positioned on the guide track (11) at a mounting position close to one end (15) of the guide track (11) to determine a required position for the hinge axis of the closure member for usual opening and closing movements of the closure member relative to the fixed frame, said mounting block (25) being adjustable lengthwise of the guide track (11) from said mounting position when it is required to increase the spacing of the hinge axis from the end (15) of the guide track (11) and thereby allow easier access for cleaning purposes to the outer face of the closure member, when the latter is moved to an open position.