GB1441822A - Door closers - Google Patents

Abstract

1441822 Spring hinges; spring door closers H-T GRISEBACH 27 June 1973 [27 March 1972] 14739/73 Headings E2F and E2M [Also in Division F2] A damped spring door closer, which may be incorporated in the door hinge, comprises first and second relatively rotatable parts A, B for attachment to the door and frame, one of the parts including, or being associated with a housing 25 (Figs. 1 and 2) which has therein at least two intercommunicating working chambers 34, 35, the door closer including spring means 27 relatively rotationally biassing the parts A, B, deflection of the spring means during relative rotation of the parts A, B in both directions (i.e. opening and closing of the door) producing a variation in the individual volumes of the chambers. In the embodiment of Figs. 1 and 2 a spiral spring 27 is connected between a shaft 29 fixed to the part A, and the housing 25. As the door is opened, the spring 27 winds up and -the chamber defined by the gaps between its turns gets smaller. Fluid therefore flows into the chamber 35 outside the spring, the flap valve 33 lifting. When the door closes under influence of the spring 27, fluid flows from chamber 35 back between the spring turns via the gap between the housing and the top and bottom edges of the spring. An elliptical member 31 on the shaft 29 coacts with curved leaf springs 38, 39 to provide an additional spring drive. After the door has opened to a predetermined extent detents on the springs 38, 39 co-act to provide a negative door-closing force. This ensures that the maximum closing force is obtained at the beginning of the opening movement and the minimum at the beginning of the closing movement. In the embodiment of Figs. 10 and 11 the housing 101 is resilient tubing which also provides the spring force to close the door. A shaft 103 with a rigid rib 104 is fixed to the part A. On relative rotation of parts A and B the tubing and integral rib 102 twists and fluid is transferred (by deformation of the rib 102) between the chambers defined by the two ribs. The spring may be a helical spring (Fig. 5 not shown); interconnected laminated leaf springs which zig-zag between the top and bottom of the housing (Fig. 6 not shown) or torsion bars of plastics material (Figs. 8, 12, 14 not shown) which may be reinforced by leaf springs, either singly (Fig. 14) or in stacks (Fig. 12). These springs are contained in rigid housings, except in Fig. 14 where the housing is a torsion tube. The intercommunicating working chambers are defined partly by the spring, except in Fig. 5 where the helical strip spring is surrounded by a split sleeve with overlapping edges, and the chambers are inside and outside the sleeve. The fluid is a rheopectic fluid i.e. one which exhibits a high resistance to high shearing forces but a relatively low resistance 'to low shearing forces. To avoid filling the housing with the rheopectic fluid, it is formed in situ from a specified silicon fluid and a specified hardening fluid. The door closer may be incorporated in a double hinge (Fig. 12).