Patent GB-734538-A (GB)
Title: Improvements in or relating to door construction
IPC: E05D15/40
Filed: 1953-02-04
Abstract: 734,538. Door-operating apparatus. McKEE DOOR CO. Feb. 4, 1953 [Feb. 7, 1952], No. 3148/53. Class 65(1). [Also in Groups X and XXXIV] A metal building, e.g. an aircraft hangar, having a forward extension F and formed of arch-shaped trusses H spaced lengthwise of the building to support stringers 20, 22, 24, 26, 28 to which panels 30, 32, 34, 36 are attached has an opening I which is closed by a door G having a correspondingly forwardly extending portion 38 which is connected by intermediate portions 42 to side portions 40. The door is supported on four tracks arranged in pairs 44, 46 and 48, 50 on the inside of the side portions of the opening I, the outer tracks 44, 50 being supported by members attached to the overhead portions, and the inner tracks 46, 48 being supported at each end to upright members, of the trusses H. A pair of quadrants, one pair shown at 58, 60, Fig. 3, is connected by a torque tube 56 to the back of each side panel of the door to engage the corresponding pair of tracks 44, 46, or 48, 50. To maintain the arcuate surfaces of the quadrants in rolling contact with, and prevent them from sliding along, the tracks as the door G is raised, or lowered, between a vertical closed position and a horizontal open position, adjacent the roof of the hangar as shown in Fig. 1, the track engaging surface of each quadrant is of U-cross section to receive a pair of cables 68, 70 which are connected at their one ends to the opposite ends 72, 74 of the corresponding track and at their other ends to the quadrant. An arm 76, attached to the outer end of each tube 56, pivotally carries a counterbalancing weight 78, made e.g. of concrete, and provided with a ground engaging pulley 80, rollers on the latter engaging the floor of the building, as the door approaches to fully open position, to rotate the weight 78 and reduce the counterweight action. The door is operated in conjunction with a pair of carriers, Fig. 5, located above the door opening and having rollers 90 which traverse tracks 88 suspended from the trusses H, each carrier comprising horizontal and vertical arms 92, 94 connected by a diagonal base 96, the vertical arm 94 forming a trackway for rollers 102 of a trolley 100 attached at 104 to the corresponding upper edge of the door. Each carrier is moved lengthwise of its track by a chain 106 having its ends connected at 108, 110 to the carrier and passing round sprocket wheels 112, 114 at the front and rear ends of the rail 88, the wheels 114 being driven, through the intermediary of bevel gearing, not shown, by a chain 136 to move the door, the upper edge of which follows the path of the line 116 while the rollers 100 move up and down the carrier rails 94. The chain 136 is driven by a sprocket 138,'Fig. 12, on a shaft 140 of a gear housing 142, the other shaft 148 of which is coupled by a belt 152 to the sheave 154 of a hydraulic coupling 156 which is connected to the shaft of an electric motor 158 having suitable stopping, starting, and reversing switches, not shown, for opening, or closing the door. Normal operation of the door can be effected by means of a crank 160 freely rotatable on an extension of the shaft 140 and having a dog 164 spring pressed into a retracted position, but which can be pressed to engage one of several openings 168 in a brake drum 170 attached to the shaft 140 for moving the door, the dog 164 being released from engagement with the drum when rotative effort is discontinued. A brake band 172 encircles the drum 170 and is attached to an operating lever 174 pivoted to the framework of the assembly and having releasable ratchet engagement with complimentary teeth of an arcuate member, not shown. The assembly incorporates safety and protective features. Draught excluding strips as shown at 186, 188, are arranged around the door. In a modification, Fig. 17, a door G to fit a rectangular opening is supported on two tracks such as 230 located on opposite sides of the door. A-shaped arms 234, connecting the counterweights 236 to the door, being connected to quadrants 240 which have toothed engagement with the tracks 230, adjustable plates 252 being attached to each end of the quadrants to assist the starting, and prevent over-running of the door. In a further modification pins are provided on the quadrants to engage between the links of chains on the tracks, the ends of the chains being inclined upwardly. In a further arrangement the tracks are arranged in a plane passing through the horizontal centre line of the door, the quadrants and the lever arms being made equal to a quarter and a half of the height of the door respectively.