Patent GB-347782-A (GB)
Title: Improvements in or relating to electric road-traffic signalling systems and circuit controllers therefor
IPC: G08G1/082
Filed: 1930-02-12
Abstract: 347,782. Roadtraffic signals. BRITISH THOMSONHOUSTON CO., Ltd., Crown House, Aldwych, London.-(Assignees of Hall, C. I. ; 1429, Walnut Street, Philadelphia, U.S.A.) Feb. 12, 1930, No. 4742. Convention date, Feb. 12, 1929. [Class 118 (ii).] In an electric signalling system in which a central station synchronously steps a plurality of auxiliary controllers giving either simultaneous or progressive cycles of signals, an auxiliary controller is temporarily rendered inoperative if it falls out of synchronism. Impulse transmitter. The central station equipment comprises an induction disc motor 2, 3, 4, Fig..1, the speed of which is regulated by an arm 38a, Fig. 2, controlling the position of the motor shading coils, driving through gearing 29 .. 34, Fig. 3, and a shaft 37a, toothed wheels 38, 39, adapted alternately to make the contacts 6, 7 with the conductor 5. The shaft 37a may also be driven through gearing 36, 35, the gearing change being made by rotating the arm 36a, Fig. 2, a pin 35b on a spindle 34b integral with the arm 36a, moving a sleeve 34a connected to the arm 35a laterally. Auxiliary controllers. Controllers A and B, operating the lamp signals at different street intersections are shown in Fig. 1, and each comprises a toothed wheel 45, Fig. 4, stepped round by pins 46, 46<1> when the shaft 41 fixed to the arm 44 is rocked upon alternate energisation of the magnets 10, 11, from the central station. Rotating concentrically with the wheel 45 are main cams 47, 48, pinned by a rod 49. Cam 47 is mounted on a sleeve 47a fixed to a disc 50, Fig. 5, having a dial 51. A cam 52, auxiliary to the cam 48, is secured to a hollow shaft 52<1> and may be adjusted relatively to the cam 48 by rotating the cam 54, a dog 55 locking arm 54 in position relative to the dial 51, when the segment 53, fixed to the shaft 52<1>, and resiliently connected to arm 54 will come to rest against the latter. A second auxiliary cam 60 may be adjusted with respect to cam 52 by movement of the arm 62 over the segment 53. Similarly, a cam 56 auxiliary to the cam 47 may be adjusted relatively thereto by positioning the arm 57 over the dial 51. Cams 47, 56 and 48, 52, 60 respectively, actuate sprung levers 67 and 65 pivoted about a spindle 64, which control, through an insulated arm 68, the contacts 24, 23, 21, 22, Figs. 1 and 4, actuating the signal lamps R (red), G (green), A M (main-road amber), and A C (crossroad amber), the auxiliary cams enabling the duration of the signals to be varied. Sequence control. Auxiliary controllers actuate their corresponding signals either simultaneously or progressively according to which of the holes 50a in each disc 50 a pin 69 is inserted in. The magnet 11 is directly operated over conductor Y and contact 5, Fig. 1, but magnet 10 may be operated over contact 16 or 17 by way of leads X, 9 and contact 7. If any of the auxiliary controllers are out of step the switch 71 is opened. With the pins 69 in the position shown at A the magnets 10, 11 will still be alternately energized to step the wheel 45 and disc 50, but when the pin 69 reaches an element 70 it pushes the spring contact 15, normally against contact 17, over to make circuit with contact 16 when the magnet 10 will not energize thus stopping rotation of the wheel 45. Accordingly, all the discs 50 will eventually come to rest with their pins 69 against the elements 70, when being now in step they may be restarted by closing the switch 71. This re-timing operation may be effected automatically by opening switches 71, 71b, and closing switch 71a, when the cam 85 driven by gearing from the shaft 37a at the same speed as the disc 50 connects contacts 7 to lead 9 and contact 17, during nearly the whole of a revolution and to conductor X and contact 16 when the spring contact 80 falls on to the surface 91 until the contact 79 falls. The pins 69 are adapted to pass the elements 70 at this point, and if one is not in step it will remain in the position shown at B, until the next time the cam 85 energizes contact 16, when it will again be in synchronism.