Patent GB-735377-A (GB)
Title: Improvements in switch frogs for the overhead conductors of electric traction systems
Inventor: FLETCHER CLAUD
IPC: B60M1/14
Filed: 1953-02-17
Abstract: 735,377. Overhead electric conductor switch frogs. BRITISH INSULATED CALLENDER'S CABLES, Ltd. Feb. 16, 1954 [Feb. 17, 1953], No. 4431/53. Class 104 (3). A switch frog for the overhead conductors of an electric traction system has its switch member moved into its two end positions by energizing one or other of two solenoids acting on a single armature which moves in a horizontal plane to actuate a rack which turns a pinion on a vertically-disposed spindle fitted with a crank linked to the switch member. The switch member 2 is pivotally mounted in a horizontal plane about a vertical pivot 7 attached to a body member 1 and between the approach end tongue 3 and the departure end tongues 4 of the frog. The switch member 2 is provided with two downwardly extending tongues 5, 6 and is moved from one operative position to the other by a link 8 pivotally attached at one end to a pin 9 on the switch member 2 and at the other end on an eccentric bush 10 attached by a bolt 13 to a crank arm bracket 11 secured to the lower end of a spindle 14 by a pin 15. The spindle 14 is rotated to move the switch member 2 to one or other of its two positions either electromagnetically by a pinion 17 on its upper end engaging with a rack 18 attached to an armature 21 or manually by an arm 60 also attached to the upper end of the spindle 14. A spring-loaded ball 73 engages recesses 74 in the rack 18 to hold the rack in one or other of the end positions. The armature 21 common to two solenoids 19, 20 is moved to set the switch member 2 to the desired setting, if not already in that setting, by the controller on the vehicle being kept in the " on " position to cause, when a contact 99, Fig. 7 (not shown), is passed, the energization of one of the solenoids 19, 20. When the vehicle leaves the switch frog a resetting contact 100, Fig. 7 (not shown), causes the energization of the other solenoid 20, 19 to return the switch member 2 to its initial position. A brass collar 31 and an insulating sleeve 32 are held in position on the end of the armature 21 by a brass bolt 28 formed with a head 30. A contact 34 or 35 engages the head 30 or the sleeve 32 to complete an electric circuit to an indicating device such as electric lamps, Fig. 7 (not shown), to indicate the position of the switch member 2 to an approaching driver. Manual operation of the rack 18 is effected by rotating the arm 60 to which is attached a plate 64 formed with projections or fingers 67 which engage a roller 68 mounted on the rack 18. A spring 70 of arcuate form and bearing against projections 72 formed on a casing 33 is compressed by and when the plate 64 is rotated and on release of the member 60 the plate 64 is returned by the spring 70 into its initial position, shown in Fig. 3, in which the projections 67 will not be engaged by the roller 68 when the rack 18 is moved to its extreme end positions by the armature 21. The spindle 14 is rotated through 180 degrees from one to another deadcentre position of the crank arm bracket 11 in each of the end positions of the switch member 2. Adjustment of the crank arm is effected by an eccentric bush 10, locked by serrations on the bush 10 and the bracket 11. Positioning of the manual operation arm 60 is effected by serrations 78 on a boss 61 of the arm 60 and a boss 62 on the plate 64. Casings 33, 36 enclosing the apparatus are mounted on the body 1 so that the longitudinal axis of the casing 36 is to one side of and parallel to the longitudinal axis of the body 1. The casing 33 is formed with a recess 84 which receives a rectangular block portion 83 of the body 1 and is held in position by screws 85. The casing 36 is attached to the body 1 by a plate 89 attached at one end to the casing 36 by bolts 93 and at the other to the pivot 7.