Patent GB-1182607-A (GB)
Title: Improvements in and relating to a Pair of Swing Doors
Inventor: DUNCAN ROBERT
IPC: E05F5/02
Filed: 1966-04-14
Abstract: 1,182,607. Releasable fastenings. R. DUNCAN. 13 April, 1967 [14 April, 1966], No. 16348/66. Heading E2A. A pair of swing doors A, B spring biased to their closed position are provided with a controller to prevent them being blown open, the controller comprising supporting means secured to the door lintel C and a displaceable member or members supported by the supporting means, such member or members, when the doors are closed serving to prevent both doors being blown open, and which when pressure is applied to only one door permit the opening of said door while continuing to prevent the other door being blown open. In one construction, Figs. 1 and 4, the supporting means as a bracket 10 secured to the lintel centrally of the opening, the bracket having a horizontally inwardly extending arm 11 having longitudinally extending slots and supported on the under side of the arm is a frame 13 of U formation. The frame is adjustably supported by screws or studs extending through the slots. Rotatably supported by the frame 13 are two displaceable members in the form of upper and lower discs 14, 15, the discs being rotatable on a central pin 16. Each disc has a gap which at the periphery of the disc is slightly less than half the diameter of the disc. The gaps are in vertical alignment and form vertically aligned pairs of horns 17, 18 between the extremities of which are mounted rollers 19 and 20 which normally bear on the inner face of respective doors. On each side of the pivot pin 16 is a pin 21, 22 the pins extending between the discs and co-operating with a cross head 23 which is notched to receive the pins. The cross head is carried by a spindle 24 encircled by a compression spring 25 which bears on the inner end of the cross head and on the closed end of the frame 13 when the doors are subjected to wind pressure; tending to force them inwardly, similar pressure is exerted on both rollers and consequently the discs will not rotate and both doors are prevented from being blown open, each door can be independently swung inwards to its open position but they both cannot be opened at the same time; when either door is opened inwardly it applies pressure to one roller and partially rotates the discs, the free edge portion of the door first entering the gaps and then clearing the gaps. The periphery of the discs engage the other door and prevent it being opened. During the opening movement of the door one of the pins 21 or 22 forces the cross head 23 outwards against the action of the spring 25 and rocks the cross head and its spindle until the pin has passed the dead centre. In a second embodiment Fig. 6 the supporting means is a guide 31 in which a bar 30 is slidably supported, the guide being secured to the lintel and extending longitudinally of the lintel. The two end portions of the bar are doubled back to form U bends 32 and then inwardly inclined legs 33 and to each U bend is anchored one end of a helical tension spring 34, the other end of which is anchored to the adjacent guide 31. The two springs tends to hold the barin a central position with respect to the two doors. To each door is secured a bracket 35 carrying avertical arm 36 (each forming one of the displaceable members) which in turn carries a roller 37 which bears on the bar. When the two doors are closed the two rollers are positioned on the bar where it is bent over to form the legs 33; wind blowing on the outer faces of the doors will not open the doors because both rollers exert the same pressure on the bar but the latter is not displaced. If either door is swung inwardly and roller carried thereby rides over the leg 33 adjacent thereto and displaces the bar longitudinally so that the other roller is received in the U bend of the other end portion of the bar to prevent the other door being opened; the movement of the bar tensions one of the springs and when the opened door is closed the spring returns the bar to its normal position. A third embodiment is shown in Fig. 8 and comprises a housing 40 forming the supporting means secured to the lintelwithin which a frame 41 is pivotally mounted on a vertical pin 42; the frame carries two pairs of opposed rollers 43 (not shown) and 44 and between the rollers is a longitudinally slidable bar 45 forming the displaceable means; near -each end of the bar -is anchored one end of a respective tension spring 46, the other ends of the springs being anchored to the housing, the springs biassing the bar to a central position. The bar has a downward extension at each end and carried by each of said extensions is a spindle 47 which mounts a roller 48; the rollers bearing on the inner faces of the two doors. When both doors are closed wind pressure on the doors is equal and hence the bar 45 does not move relative to the frame 41. When one door is opened the roller causes the bar and frame 41 to swivel about the pivot pin 42 and also causes the bar to move longitudinally, so tensioning one of the springs; the other roller prevents the second door being opened. A fourth embodiment is shown in Fig. 14 and the purpose of this is to prevent the doors being blown outwardly as is likely to occur in building heated or ventilated by pressurized air. A supporting means in the form of a bracket 50 is secured centrally of the door lintel and carries a downwardly extending spindle 51 on which is a disc 52 forming the displaceable member. This has a gap which forms two horns 53, 54, the gap normally facing away from the doors. Secured to each door is a resilient arm 55 which extends so that its free end portion bears on the extremity of a respective horn. When the doors are subjected to internal air pressure there is the same pressure on the two horns and neither door will open outwardly. Pressure applied to one door to open it outwardly causes the free end portion of the resilient arm carried thereby to move into the gap and rotate the discs, the free end portion of the other resilient arm riding on the periphery of the discs and preventing the other door being opened. When the opened door is closed the free end portions of the arm carried thereby enters the gap and rotates the disc back to its normal position. If substantial pressure is applied to both doors which might occur in the event of panic the resilient arms will yield and both will ride on the periphery of the disc thus allowing the two doors to open outwardly.