Patent GB-1017295-A (GB)
Title: Improvements in or relating to garage door operator mechanisms
IPC: E05D15/42
Filed: 1963-05-20
Abstract: 1,017,295. Door operating-appliances. P. CHRISTENSEN. May 20, 1963 [May 26, 1962], No. 19982/63. Heading E2M. A garage door operating mechanism comprises an accumulator of mechanical energy, preferably a spring 21, which stores energy for use in opening the door 1 and is charged by a charging element 23, 27, 28 adapted to be located on the ground and activated by pressure exerted thereon, and a trip element also adapted to be located on the ground and actuated by pressure exerted thereon to discharge the energy of the accumulator for opening the door or to initiate the closing of the door, the charging element being moved into its charging position at the end of the door opening operation by an independent return member. The invention is shown applied to an up-and-over door 1 supported at the top by rollers movable in rails 12 and at the side by a lever 2 pivoted at 4 to the door frame and at 3 to the door. The door is partially counterbalanced by a spring 9 connected between the extended end 7 of the lever 2 and the door frame. Assuming the door to be open (Fig. 2) the wheels of a car leaving the garage roll over and depress the charging element which comprises a pair of pivotally connected plates 27, 28 extending across the doorway and carried by a shaft 24 and rollers 29 respectively. This depresses a lever 23 which is secured to the shaft 24 and thereby tensions a spring 21 the other end of which is connected to a wire 20 passing over a pulley 19 rigidly secured to an angle lever 17. Rotation of the pulley is prevented by a pawl member 53 engaging the lever 17 and freely rotatable on a rod 42, and the lever 23 is retained in its depressed position by a lower bell crank 30, 32 acting as a gravity pawl engaging a step 31 on the lever. Outside the garage the wheels roll over and compress the trip element which comprises a rubber hose 58 disposed across the driveway and connected to a cylinder 48, thereby displacing a piston rod, which is connected to an arm 46, and rotating the rod 42 on which is secured an arm 43. As the arm rises a hook 56 thereon is lifted clear of a projection 57 on the lever 2 and the door closes under its own weight. The end 7 of the lever 2 is offset (Fig. 3) and is adapted, as the door reaches its fully-closed position, to engage an offset part 55 of the arm 43 to move the arm and the rod 42 axially to the left against the force of a compression spring 50 so that a further arm 45 on the rod is brought into a position beneath a shoulder 52 on the pawl member 53. When the returning car again runs over the trip element 58 the arm 45 as it rises engages the shoulder 52 and lifts the pawl member 53 clear of the lever 17. The released lever rotates under the force of the spring 21 and its arm 18 abuts the end 7 of the lever 2 and thereby turns this lever to open the door. When the door is fully opened the lever arm 18 strikes one arm 35 of an upper bell crank the other arm 34 of which is connected by a wire 33 to the upper arm 32 of the lower bell crank. This releases the lever 23, so that the charging element, the pulley 19 and the angle lever 17 can be returned to their initial charging positions (Fig. 2) by an independent return spring 37 stressed during the opening movement and connected to a wire 36 passing around a second groove in the pulley. As the car enters the garage it re-charges the spring 21. A hand lever 44 is secured to the rod 42 so that the rod can be rotated by the driver as he leaves the garage to permit the door to close under its own weight, and can again be rotated, when the driver next wishes to use his car, to open the door automatically with the aid of the spring. The garage door may be kept open, despite actuation of the trip element, by means of a locking member (not shown) adapted to prevent movement of the hand lever.