Patent GB-968084-A (GB)
Title: Improved automatic door gear
Inventor: BOOTH MARCUS BAXTER
IPC: E05D15/42
Filed: 1960-06-02
Abstract: 968,084. Door operating appliances; door stops; remotely controlled fastenings; latches; sliding bolts. E. C. S. (COVENTRY) Ltd. Aug. 28, 1961 [June 2, 1960], No. 19503/60. Headings E2A, E2M and E2X. Gear for operating a partly counterbalanced door of the upwardly opening kind comprises weight and/or spring loaded operating means controlled by remote control mechanism for augmenting the counterbalancing of the door so that the door becomes over counterbalanced and is thereby opened, the remote control mechanism being also operable to enable the door to close automatically under its own weight. The invention is shown applied to an up-and-over garage door 1 having weight and/or spring counterbalancing means of known type (not shown) which are adjusted so that the door when free can close gently under gravity. The operating means comprises a weight 3 connected by a cord 4 to a slider 6 slidable on a further cord 7 connected at one end to a suitable point 11 on the door and at the other end to a spring 13. The slider is held by a releasable catch means 15 attached to the lintel 17, so that the door can be moved manually between its open and closed positions independently of the weight 3, during which movement the cord 7 passes freely through the slider and is kept taut by the spring 13, but can be opened by the weight 3 upon release of the catch means, the slider engaging a collar 24 fast on the cord 7 to transmit the movement of the weight 3 to the door. After the door has been thus opened, manual closing re-loads the operating means, the slider being drawn forward by the collar 24 until it snaps into engagement with the catch. The catch means comprises a lever 21 pivoted to the lintel at 16 and having a cranked end 23 engaging the slider, the lever being biased towards the "engaged" position by a spring 26 connected to an arm 20 pivoted to the lever at 18 and abutting a stop 27 on the lever. Release of the catch is effected by a cable 19 which turns the arm 20 until the latter, after lost motion, abuts a stop 22 on the lever, the cable 19, which may be part of a Bowden cable, being connected to a road pad or a control lever situated at a suitable position in front of the door beside the driveway. During the lost motion the arm 20 depresses a push rod 37 which causes release movement of a pivoted catch 31 (Fig. 4) adapted to engage a co-operating member 32 on the door when the latter is in its open position. Release of the slider 6 except when the door is fully closed is prevented by a spring blade 39 which engages under an arm 40 of the lever 21 and is deflected to an inoperative position by a push rod 44 carried by the door. The push rod 44 which is depressed by the arm 40 when the lever 21 begins to turn, is connected to an inner handle 45 on the door which releases a bolt 47 engaging a striking plate 49 on the lintel. If desired, the weight 3 may consist of a length of chain which, as the door opens, lies to an increasing extent on the floor, thereby preventing violent opening movement. Door operating sequence. On driving up to the garage a motorist operates the control lever in the driveway thus releasing the bolt 47 and the slider 6 so that the door opens automatically under the action of the weight 3. After driving into the garage he alights, presses and turns the handle 36 to release the member 32 from the catch 31, and closes the door manually, thus raising the weight 3 and reengaging the slider 6 with the catch means 15. When he next wishes to use his car the motorist releases the bolt 47 by means of the door handle 45, 50 and opens the door manually and independently of the weight 3, the door being held open by the catch 31. On driving out of the garage he operates the control lever which releases the catch 31 so that the door closes under gravity, release of the weight 3 being prevented by the spring blade 39. The door is then ready for automatic opening when the car returns to the garage. Doorstops. One or more spring loaded buffers 51, 52 may be provided on the lintel for cushioning the closing and opening movement, respectively, of the door. The buffers may also serve to impart an initial impetus to the door movement.