| 摘要 |
613,547. Door-operating appliances. DE VRIES ROBBE & CO., N.V. May 6, 1946, No. 13619. Convention date, June 5, 1944. [Class 65 (i)] [Also in Group X] A device adapted to move an overhead door 3, pivoted substantially at its centre on a radially movable support 4, by exerting on the upper anc lower parts of the door a substantially horizonta and vertical force respec tively, is characterised in that a cable or chain 8 i attached by its respective ends to the top and bottom of the door, the cable passing over rollers or the like, at least one of which is displaceable horizontally away from the door. As shown, displacement of the roller 6 in the direction of the. arrow serves to open the door. In a modification, the directions of the forces exerted by the ends of the cable are reversed, i.e. displacement of the roller 6 in the direction of the arrow serves to close the door. It is stated that both the above systems can be applied to the same door. Alternatively, either one or the other may be used, the door being respectively closed or opened by means of counterweights, spring means, or the like. |
