Patent GB-190703398-A (GB)
Title: Improvements in Automatic Point and Switch Operating Mechanism.
Inventor: BURKHOLDER JOHN DAVID
Filed: 1907-02-11
Granted: 1907-08-15
Abstract: 3398. Burkholder, J. D. Feb. 11. Points and switches, operating mechanically or electrically from the vehicles. A three-to-one junction, shown in plan in Fig. 6, is controlled by movable tongues 11, 12 operated and locked through bars 18, 19. These bars are reciprocated by the interaction of vertical rollers c which they carry, and horizontally movable rods 20, 21, 22, 23 operated electrically through solenoids 33 or mechanically through rods 34, 35, 36, 37. The bars 18,19 are locked by a spring-pressed bolt 26, which is operated simultaneously with the rods 20,21,22,23. The solenoids are electrically connected to contactrails 40, Fig. 1, passed between the track rails at a suitable distance from the junction, and the rods 34, 35, 36, 37 are connected up to cranks 42, Fig. 8, the pins 44 of which lie across the slots between the contact-rails 40 and a centre block 144. The rods are supported at intervals by cross-bolts 48, Fig. 10, in casings 45, which are carried by brackets 148 on suitable blocks, drainage openings .176 being provided. The vehicle, part of which is shown diagrammatically in Fig. 1, carries two levers 46, which are capable of being moved into three positions ; only one lever and its connexions is shown completely. Normally, the lever is kept in its highest or inoperative position by means of a spring. In its middle position, an electric contact 49 is able to rub on the contact-rails 40 and connect the corresponding solenoid 33 to the overhead electric conductors 1. The lever is moved into its lowest position, so as to be able to strike the pins 44, Fig. 8, by a lever 72, it being at the same time, moved clear of the contact-rails 40. In addition to the usual motor controller 7 on the car, there is a point controller, which comprises a shaft formed in two parts 80, 81, Fig. 4, normally disconnected but capable of being coupled together by an electromagnetic clutch. An electro-magnet 102 is secured to the upper shaft, and a metal casing or sleeve 99 surrounding it is compelled by a pin 100 to rotate with the lower shaft. When the solenoid is energized, the sleeve is raised so as to bring the teeth 108 into contact with teeth 107 formed on the upper shaft. The shaft 80 is connected at its lower end to the levers 72, Fig. 1, so that, on being rotated, it moves one or other of the levers 46 into the lowest position. The levers 46 are moved into their middle position by solenoids 90, the point-operating circuit being simultaneously completed by the meeting of contacts 134,136 and 171,181. Mounted on the upper end of the shaft 81 is a small auxiliary handle 117, by which the position of contact-bars 111, 133 mounted on a bar 115 can be adjusted in relation to a fixed contact 113. Each of two fixed contacts 126, 127 is connected in circuit with one of the solenoids 90 and adapted to engage with the shaft contacts 125, 133. When the bar 115 is in its highest position, as shown in Fig. 4, and the handle 83 is turned to the left or right, the solenoid 102 and the corresponding solenoid 90 are energized. The two portions of the shaft consequently become coupled together and the mechanism is ready for mechanical operation of the points by further movement of the handle 83. To operate the points electrically, the handle 117 is turned so as to move the bar 115 into its lowest position, in which the contact 133 comes under the contacts 113, 126,127 but remains clear of the contacts 109, 125. The movement of the handle 83 then connects one of the contacts 126, 127 to the contact 113, thus energizing the corresponding solenoid 90 but leaving the solenoid 102 de-energized.