Patent GB-398184-A (GB)
Title: Improvements in or relating to automatic traffic-control systems
IPC: G08G1/085
Filed: 1932-03-04
Abstract: 398,184. Road signals for controlling traffic. REYROLLE & CO., Ltd., A., Hebburn-on-Tyne, and WRIGHT, H., 34, Hawarden Crescent, Sunderland. March 4, 1932, No. 6555. [Class 118 (ii).] In a system of the flexible progressive type the signals at each control point are actuated by a cam shaft driven step-by-step from a timing shaft through a disc member secured to the timing shaft but angularly adjustable with respect thereto to vary the phase of the signal cycle. The timing shafts of the local controllers are driven by electric motors which come to rest twice during a signal cycle and are restarted by synchronizing signals from the master controller. Provision is made at the master controller for altering the time of a signal cycle and at each local controller for varying the relative times of the signals of a cycle. The master controller comprises an electric motor D, of the induction disc type,. the speed of which may be varied by altering the angular position of the brake magnet acting on the disc D<1>. This is effected by moving a pointer E<3> over a scale E<4> which may be graduated to read either the motor speed or the time of a signal cycle. The motor drives through gearing C<1> a main timing shaft C, cams C<2>, C<3> on which actuate contacts F<3>, F<4>, Figs. 1 and 4, through pivoted levers F, F<1> respectively. Rigid with the shaft C is a disc C<4> to which a disc G<0>, rotatable on shaft C, may be secured in a selected angular position by a screw G<2> passing through one of the holes G<1> in disc G<0>, into disc C<4>. The signalling lamps red, amber, and green at the master signalling point are controlled by contacts L, L<1> .. L<4> actuated by cams K, K<1> '.. K<4> respectively, mounted on a shaft J. The latter has four operative positions to which it is stepped when lugs J<1> .. J4 thereon are advanced by pins G<5>. G<6>, H3, H4 respectively. In the position of the shaft J shown in Fig. 4, contacts L, L<4> are closed to give a red signal on the E-W road and green on the N-S road. In the next position to which shaft J is stepped by pin G<5> both amber lamps and the E-W red are operative, in the next position the E-W green and N-S red signals are given, and in the following position the red on the N-S road is shown with both amber signals, after which the shaft J is stepped to the position shown. One signal cycle thus corresponds to one revolution of disc G<0>, and the angular displacements between pins H4 and G<5>, G<5> and G<6>, G<6> and H<3>, H<3> and H<4> give the relative times of the red, red and amber, green, and amber signals in a cycle for one of the roads. To vary these relative times, pin G<5> is fixed to disc G‹, pin G<6> may be fixed in any of the holes G<60> in disc G<0>, and pins H<3>, H<7> are mounted on an arm H which may be fixed to disc G<0> by a screw H2, in any angular position corresponding to one of the holes G<4>, the latter adjustment being limited by projections C<5>, C<6> on disc C<4> adapted to coact with a pin Hl on arm H engaging in a slot G<3>. The pin H<3> is fixed to arm H but H<4> may be fixed in any one of the holes H<40> therein. Synchronizing. The controller at each local signalling point is identical with the master controller, the master controller and one local controller being shown in Fig. 4. The master motor D rotates continuously but the field of the local control motor d is dependent on contacts F<3>, F<4>, f<3>, f<4>, As the motor d is arranged to rotate slightly faster than D, contact f<3> will be opened and f<4> closed slightly before the corresponding operation at the master controller. Motor d therefore stops and is restarted when contact F<3> -is opened and F<4> closed at the master controller. Motor d again stops when f<3> is closed and f<4> opened, being restarted by the corresponding operation of F<3>, F<4>. The local controller is thus synchronized twice during each signal cycle. The signal cycles at the two stations shown are in phase. To give progressive signals the discs G<0> at the appropriate stations are angularly displaced with respect to the discs C<4>. The projections G<5>, G<6>, Fig. 2, limit the adjustability of arm H to prevent the synchronizing stoppages of the shaft C occurring during the amber signal. At each controller is a main power switch M, a switch M<1> for switching off the motor only, and a switch M<2> for illuminating a further amber lamp to indicate whether or not the contrcller is in use and to give the usual caution signal to traffic. The apparatus is contained in a casing A<0> holed at A<1>, A<2> for the passage of cables, and at A<4> for the insertion of a handle whereby shaft J may be rotated manually to control the signals, the hole A<4> being normally plugged at A<5>. Semaphore arms may be used instead of or with the signalling lamps.