Patent GB-326535-A (GB)
Title: Improved means for controlling the operation of movable parts
IPC: E05B65/42
Filed: 1928-12-13
Abstract: 326,535. Peters & Co., Ltd., G. D., and Arthurton, R. I. D. Dec. 13, 1928. Operating and controlling doors electrically, magnetically, pneumatically, and by starting and stopping of vehicle. - The operation of power-operated movable parts carried by a railway &c. vehicle, such as the movable doors or steps, is prevented whilst the vehicle is m motion by means actuated automatically by the movement of the vehicle. Preferably the first movement of such means, as initiated by the starting of the vehicle, causes the doors, stops, &c. to be moved to the normal or safe travelling position, while, when the vehicle is at rest, the doors, stops, &c. are preferably moved to the in-use position non-automatically, i.e. by a conscious action on the part of the operator, such as pressing a switch button &c. In the arrangement shown in Figs. 1 - - 5, the invention is applied to the control of the electrically-operated steps of a railway vehicle, the control circuit being closed to bring the steps to the in-use position and opened to restore them to the out-of-use or travelling position. The switch mechanism disposed within a casing 1, Fig. 1, comprises a sliding rod 4 adapted to bear at one end against a cam 3 mounted on a shaft 2 driven from the axle or other moving part of the vehicle and at the other end to be associated with a pivoted lever 10, the position of which is controlled by a spring 12 and by the core 15 of a solenoid 16. The rod 4 carries two pairs of insulated contacts 18, 19 adapted to cooperated with insulated contact collars or bridging pieces 24 mounted on a second slidable rod 20, which is arranged parallel to the rod 4 and is actuated with a certain amount of lost motion by stops 22 on the latter. Light springs 26 bearing against abutments 27 allow the contact collars 24 to slide or yield to pressure, while a sleeve 25 fixed to the rod 20 is disposed between the collars. The contacts 18 are associated directly with the step control circuit, while the contacts 19 are associated with the solenoid 16, the circuit through which may be broken, however, by depressing anyone of a series of spring-returned press-buttons A. Assuming the parts are initially in the position shown in Fig. 2, with the step control circuit closed and the solenoid 16 deenergized, when the vehicle commences to move. the cam 3 pushes the rod 4 to the right, breaking the step control circuit between the contacts 18 and causing the steps to be restored to their outof-use position. During the initial part of the movement of the rod 4, Fig. 3, the rod 20 is not displaced, but as soon as the circuit of the solenoid 16 is established at the contacts 19, the lever 10 is pulled over against the action of the spring 12, and the rod 4 is pushed further to the right, moving the rod 20 with it. the rod 4 finally assuming a position, Fig. 4. out of the sphere of action of the cam 3, which revolves inactively,- such being the normal or travelling position of the parts. When the vehicle comes to rest and one of the press-buttons A is momentarily depressed to de-energize the solenoid 16, the spring- 12 displaces the rod 4 to the left, independent of the position of the cam 3, so as to close the step control circuit at the contacts 18, as shown in Fig. 5. Whether the parts are in the position shown in Fig. 2 or in Fig. 5, any subsequent movement of the vehicle restores them to the normal position, Fig. 4. The contacts 18 and collars 24 may be replaced by valves for controlling a fluid-pressure operated system. In a modification, a slidable shaft carrying contact collars similar to the collars 24 is displaced in one direction by a spring plunger after the movement has been initiated by a cam coacting with a spring trigger on the shaft, and is returned by movement of a piston in a cylinder to which compressed air may be admitted. In further modifications, the shaft 2 is fitted with a pair of cams displaced 180‹ relatively to each other and actuating a pair of pivoted levers adapted to break the step control circuit when the shaft 2 rotates, and to re-establish the circuit either when a button such as A is depressed or auomatically by connecting the levers to spring-returned dash pot pistons.