| 摘要 |
421,658. Door-operating appliances. HAGGLUND, G. E., Ornsk÷ldsvik, Sweden. July 11, 1933, No. 19660. [A Specification was laid open to inspection under Sect. 91 of the Acts, April 18, 1934.] [Class 65 (i)] Hinged or folding doors, particularly of vehicles, are operated by an electrically - controlled vacuum engine by means of a rack on the piston-rod of the engine engaging a toothed sector fixed on the door coaxially with the hinge thereof. Two doors 1, 2, mounted on hinges 3, 4, are shown, with toothed sectors 5, 6 fixed thereon to engage racks 7, 8 operated by the pistons of two cylinders 11, 12. The inner ends of the cylinders are connected by a pipe 19, and the outer ends by a pipe 18, with a slide valve 26 which at any time opens one of these pipes to the atmosphere and connects the other to a vacuum reservoir 22; the vacuum may be maintained by connecting the reservoir to the engine of a motorvehicle. The slide-valve is normally held in the position shown by an electromagnet 28, thus connecting the inner ends of the cylinders to the reservoir 22 and allowing atmospheric pressure to act on the outer sides of the pistons to close the doors ; when the circuit of the electromagnet is broken, the valve is moved to the left-hand position to open the doors. In a modification, the two pistons may be arranged in a single cylinder, the pipe 18 being connected to both ends of the cylinder and 19 to the middle. |
