Patent GB-191300486-A (GB)
Title: Improvements in and relating to Traffic Controlling Apparatus.
Inventor: HOLLIDAY JOHN SALISBURY
IPC: B61L5/06
Filed: 1913-01-07
Granted: 1913-03-13
Abstract: 486. Holliday, J. S. March 6, 1912, [Convention date]. Electric operation and control. - An alternating-current motor acts first as a repulsion motor to operate the points and then as an induction machine to supply current to the indication device. The points 1 are operated by a motor 2 controlled by a hand-lever 6 through a controller 5, a circuitbreaker 8 being arranged to prevent improper operation. The motor has two field windings 9, 10 and two sets of brushes 11, 12, the pair 11 being permanently short - circuited. It is connected to a screw 14 by a clutch 15, the screw working in a nut 16 on a bar 17 having an operating cam-plate 19 for the point - rod 22. The clutch is controlled by lugs on a bar 18 contacting with the nut 16. The bar 17 carries cams 23, 24 for rocking switch arms 25, 26 to actuate switches 27 ... 34. The controller 5 consists of a pivoted member 35 carrying an armature 37 held centrally between electro - magnets 38, 39 by springs 40, 41, its return from either side after attraction being retarded by dashpots 43, 44. The member 35 carries contacts 49 ... 55; of these, contacts 49, 55 have resilient blades and stops 56 and are both normally closed. The handlever 6 has contacts 58, 59 and is controlled by an indication device 7 comprising an induction motor 60 with windings 61, 62 and a rotor 63 geared to a rack 64 on a lever 65, which raises a latch 66 out of the path of dogs 67, 68. The circuit-breaker 8 has a normally closed contact 69 operable against the action of a spring 70 by an induction motor 71 through a rack and pinion. The motor has windings 72, 73 connected on one side to the generator 4 and at the other through a resistance 79, one end of which is connected to a power bus - bar 82 through an impedance 81, while the other end is connected to an indication bus-bar 87. The bar 82 is connected to the generator 4 through the contact 69. Current supplied to the point 80 will not turn the motor in the direction to open switch 69. To reverse the points, the lever 6 is moved until the dog 68 contacts with the latch 66. The magnet 38 is then energized by a circuit passing from generator 4 over contact 69, winding 61, switches 27, 49, and intermediate connexions, to rock the member 35 to close the circuits of the motor windings at contacts 51, 53. The motor 2 moves over the points 1, the completion of the movement effecting a rocking of the arm 25 to open contacts 27, 28, 29, 30, and the opening of the clutch 15. The winding 9 is thus cut out at the switch 30 and causes the current to flow through an impedance 104 back to the generator. The switch 29 short-circuits the brushes 12, and the motor continues to be operated by the winding 10 and to generate a current in the winding 9, the electromotive force being in quadrature. This current then passes over contacts 28, 54, 31 to the winding 62 and to the point 86. The motor 60 is thus operated to raise the latch 66, whereupon the movement of the lever may be completed. The current supplied to the coils 72, 73 from a point 86 again does not open the switch 69. The motor comes to rest when the dash-pot allows the return of the member 35 to break the contacts. Should the conductors 91 become connected with the terminal 85, current is supplied to the point 86, and the torque of the motor 71 due to this current opens the contact 69 as this current predominates, owing to the impedance 81 in the normal circuit. The motor is not then operated, and before another operation can take place the contact 69 must be closed by hand. The power and indication bus-bars may serve for a number of levers, and only one generator 4 and circuitbreaker 8 is needed for each pair of bars.