Patent GB-526486-A (GB)
Title: Improvements in traffic signaling system
IPC: G08G1/08
Filed: 1939-03-17
Abstract: 526,486. Road-traffic signals. HORNI, P. P. March 17, 1939, No. 8585. [Class 118 (ii)] In a system with normally extinguished lights, a call on one street causes a "stop " followed by a " go " signal to be presented to that street. The invention is described for a system controlling a highway intersected by side streets in which vehicle actuated means are provided only in the side streets and cause a cycle of long red, green, amber, red, out for such a street and a complementary cycle of green, amber, long red, green, out, for the highway. The switches are driven by a motor having a decelerating winding brought into play by a limited number of additional calls on the side street, a subsequent additional call being stored to produce a second cycle. A lengthened green period results from operation of a pedestrian actuated device. Provision is also made for converting the system to one having a normal highway green or to one with continuous cyclic operation independent of the traffic. Normal-highway-green system. Switch 9, 37 is thrown to the right and switch 41, 52 is in the position shown. The cams 1-7 are in the normal position (see Fig. 2) with contact levers in the full line position (Fig. 1), but the lights are highway-green and cross-street red and not out as indicated in Fig. 2. When a vehicle in the cross-street operates pad 36 or a tramcar operates relay 79, relay M1 pulls up and makes a circuit for the driving windings D, PI (main and phase) motor M of the induction disc type. The cams make one revolution (one cycle) giving right-of-way to the cross street and then to the highway, relay M1 being held until relay E operates in parallel with green light G2 in the cross-street, and the motor circuit being maintained over contacts 1B of cam 1. At the end of the cycle, the reversing windings R, P11 are energized over contacts 1A of cam 1 and the cams rotate backwardly a small distance to a definite normal position determined by pawl and ratchet wheel 64, 65. Normally extinguished system. The switches 9, 37 and 41, 52 are in the position shown, the reversing windings of the motor being thus prepared for operation during a cycle to decelerate the motor for extending the cross-street right-of-way period. The cycle is initiated and proceeds to the operation of relay E in parallel with cross-street green G2 as in the preceding paragraph. During the major portion of: the G2 period, operations of relay M1 by vehicles after its release by E, connect up the reversing windings of the motor to extend the period, the holding circuit of M1 being periodically opened by cam 5. Towards the end of the G2 period, however, and at the commencement of the subsequent amber period, relay M1, if operated, is held over contacts of cam 6 and continues to be held after the relapse of E on the commencement of the amber period but the relapse of E opens the circuit of the reversing windings. When the cycle has proceeded to normal, Ml is. already operated so that a second cycle is commenced. Continuous cyclic operation independent of traffic. Switch 41, 52 is thrown to the right to disconnect the vehicle actuated devices and connect the motor permanently in circuit. Pedestrian control. Pedestrian button P operates relay TD which locks up and energizes M1 to start a cycle. The circuit of TD is opened by relay Y at the commencement of the sidestreet green.interval, but TD is slow and maintains M1 for the period equivalent to two teeth of cam 5A so that as E is operated, the decelerating windings of the motor are effective.