Patent GB-918777-A (GB)
Title: Door closer
IPC: E05F3/10
Filed: 1959-06-22
Abstract: 918,777. Door checks. KAWNEER CO. June 22, 1959 [June 23, 1958], No. 21319/59. Class 65 (1). [Also in Group XXXII] A check mechanism for use in a door closer 30 suitable for swing doors comprises a piston 60 movable in a cylinder 86 and a system of valves and passageways for controlling the flow of checking fluid between the two chambers 86a, 86b, on either side of the piston. The piston, which is located midway between the ends of the cylinder when the door is in its closed position, is connected, by a rack-and-pinion assembly 61, 62 to a spindle 36, which is either the door pivot or may carry an operating arm (not shown) connected to the door, and the cylinder is formed by a bore in a support block 84, the passageways being located in a section 84b and a surface 84c of the block. A co-operating plate 85 is provided to cover the surface. When the door is opened so as to move the piston to the left, as shown in Fig. 3, fluid flows from the chamber 86a through a passageway 100 in the section 84b past a non-return valve 108 (Fig. 6) and into a passage 102 in the surface 84c from which it enters the chamber 86b through a passage 104. When the door begins to close under the action of a closing spring 58 (see below) fluid begins to leave the chamber 86b through a port 116a at a rate controlled by an adjustable needle valve 126 (Fig. 5) and reaches the chamber 86a via passages 118 and 120 (Fig. 6), the latter containing a non-return valve 117. As the door approaches its fully closed position the piston closes the port 116a and simultaneously uncovers a port 121a which is interconnected with a port 122a on the other side of the piston by passages 124, 122 containing an adjustable needle valve 130 which enables the latching speed of the door to be regulated independently of the closing speed. If the door is opened in the other direction a similar flow of fluid occurs as may be seen from Fig. 4, the flow during the closing movement being from the port 116a to the passage 138 and the flow during latching being from the port 121a to the port 122a so that the same needle valves 126, 130 control the speed of the door. The door may be hydraulically locked in the closed position by making the piston of sufficient length to cover both the outlets 104, 134 of the passage 102. The check includes a variable volume fluid reservoir 140 which communicates with the passage 118 via a passage 150, 151 to compensate for fluid leakage. The reservoir may be in the form of a cylindrical bellows, as shown, made from a metal, e.g. brass, or may comprise an elastic rubber tube. Spring closing mechanism.-The closing spring 58 is held between flanges 74, 78 on sleeves 72, 76, respectively, movable in a housing 66, and the piston-rod 56 extends into the sleeve 72 and makes screw-threaded engagement with a rod 70 having a head 70b inside the sleeve 76. When the piston moves to the left the sleeve 72 is also moved to the left by the engagement of the end of the piston-rod 56 with an internal shoulder 72a whilst the rod 70 slides through the sleeve 76, and the spring is thereby compressed. Alternatively, if the piston moves to the right, the sleeve 76 is drawn to the right by the head 70b while the rod 70 slides through the sleeve 72, and the spring is again compressed. Aligning the door closed position with the doorframe.-The closer, which is located in the transom 32, may be turned about the spindle 36 to align the door, in its closed position, with the doorframe. For this purpose there is provided a lever 158 (Fig. 3) having at one end a depending stud 164 located in an opening in the base-plate 32a of the transom and turnable by means of a wrench and at the other end an upstanding lug 166 received by a slot 168 in a plate 160 welded to the housing 66. The closer is clamped in its adjusted position by bolt assemblies 170, 171. Hold-open mechanism.-The door may be held in either of its fully open positions or in the closed position by providing on the spindle 36 a cam having notches for engagement by a spring-loaded plunger. The cam may be shaped so that the door-opening movement is resisted just before a fully open position is reached.