Патент USA US2129446код для вставки
Sept. 6, 1938. ' P. B. RENsHAw 2,129,445 TRAFFIC CONTROL SIGNAL Filed June-22, 1953 4 Sheets-Sheet 1 INVENTOR ’ Piper BA/LfV Paw/MW BY édara/MM, A TTORNE Y5 Sept. 6, 1938. P. B. RENSHAW 2,129,446 TRAFFIC CONTROL SIGNAL Filed June 22, 1933 B. P 355,741 F/aQ 4 Sheets-Sheet 2 Sept. 6, 1938. P. B. RENSHAW , 2,129,446 TRAFFIC CONTROL SIGNAL Filed June 22, 1953 wmMUW wM 1193 B 4 Sheets-Sheet 3 g y, ha NQVmTWWQWWm Patented Sept. 6, 1938 2,129,446 UNITED STATES PATENT OFFICE 2,129,446 TRAFFIC CONTROL SIGNAL Percy Bailey Renshaw, Liverpool, England, as signor, by mesne assignments, to Automatic Telephone & Electric Company Limited, Lon don, England Application June 22, 1933, Serial No. 677,029 In Great Britain June 30, 1932 10 Claims. The present invention relates to traffic control signals for use at road crossings or the like and rying it into effect, reference being had to the accompanying drawings, in which Figs. 1 and 2 is more particularly concerned with a progres sive type tra?ic control system by means of which a number of controllers located at successive crossings on a main road may be regulated from a master timer in a certain phase relationship show by way of example a master timer arranged to regulate three controllers of which the circuit connections for one areshown in detail, Fig. 3 shows one form of individual traf?c actuated controller and system which may be controlled by the master controller, and illustrates in more detail the embodiment shown in brief in the rec 10 to each other, so that if the average speed of 10 the traf?c is known it is possible to time the control signals so as to ensure a substantially continuous flow of trai?c along the main road. Systems of this type have been found to give good results in use but their operation is not particularly ?exible in that they require the controllers to be individually set as regards their time periods in the cycle, and a further disad vantage is the danger that all controllers will cease to function in the event of a breakdown at 20 2 (Cl. 177-337) the master timer. ‘ From the point of view of the traf?c engineer in charge of the system, individual setting of the controller is undesirable and de?nitely pre cludes quick adjustment of the time cycle since each controller requires a personal Visit. By far the more satisfactory arrangement is for com plete control to be exercised from some master point where the necessary tra?ic data and tim ing charts for the whole system are readily avail 30 able. It is also desirable that service shall be maintained even if the master timer fails and al though this latter event is extremely improbable, the possibility of a complete stoppage of all con trollers along an important route should pref erably be eliminated. Accordingly the object of the present invention is to provide an improved system of the type described which obviates the shortcomings mentioned and provides in a par ticularly reliable manner the improvements men 40 tioned. According to one feature of the invention in a progressive system of traffic control the indi vidual controllers are operated by impulses trans mitted thereto at different times from a master timer so that their phase relationship may be altered at the master timer. According to another feature of the inven tion in a progressive system of traffic control in the event of a complete failure of the master 50 timer the individual controllers which are nor 'mally regulated thereby continue to function ow ing to the provision of independent timing ap paratus. The invention will be better understood from, the following description of one method, Q; @841.’ tangle of heavy dash lines in Figure 2; Fig. 4 illustrates another form of individual tra?'lc ac tuated controller, in which traflic actuating de vices may be employed in each road, and. illus trates an arrangement whereby certain maximum 15 periods of right of way may be controlled by the master timer. It should be explained generally that the‘ sys tem comprises a master timer from which sepa rate pairs of conductors radiate to each con troller for the purpose of regulating their time periods in relation. to each other. The control lers may be conveniently of the general type dis closed in British speci?cation No. 355,741 but for the purpose of the illustration in Figure 1 25 and Figure 2 may be arranged to operate at ?xed time periods independent of the tra?ic flow, that is to say, there is no question of extending their normal period as a result of a continuous flow of traffic passing over a road contact or the like. 30 These controllers will be set to operate at rather long periods, considerably in excess of that re quired in the progressive system, but the periods will be curtailed by the right amount upon the reception of socalled “light” and “heavy” pulses 35 over the control leads from the master timer. Referring now to the circuit shown, the sys tem is arranged for operation from A. C. mains and suitable rectifying arrangements are pro vided for obtaining direct current to operate the 40 relays and neon lamps. In the drawing the al ternating current mains designated I0 and II are shown incoming from the left hand side of Fig. 1 and for the operation of the master timer a tapping is made from these leads by way of 45 the fuses FUS and main switches MNS to the primary winding of the transformer XFR. This transformer is provided with three secondary windings, two of which connect with the ther mionic valve ampli?er VLV which supplies di 50 rect current of the order of 400 volts to the ter minals designated + and — in a circle, for the purpose of ?ashing the neon lamp N. The third winding on the secondary side of the transform d1’ XFR connects with the full wave metal rec 56 2 2,129,446 ti?er bridge MRA which supplies direct current of the order of 50 volts to the terminal points impulse relay A. The cam assembly is more over, a standard unit which may be used in dif marked + and —~ in a square, for the purpose of ferent circumstances and controls 22 spring sets with six different positions. The full number of cams is not employed in the present instance and the chart shown in Fig. 2 shows the effect of the operating the relay F and the driving magnet DSM. Essentially the master timer comprises a rotary step-by-step switch DST of the type used various cams which are used in this particular ar rangement. The cam contacts which are oper ated in each of the six positions are designated operated step by step from a neon lamp im 1.0 pulser, the speed of which may be altered, by. .irnthe ?gure by a black circle or a bar. in automatic telephone systems which may be completely immersed in .oil and. arranged to be varying the setting of the resistance switch 112 ‘ connected in series with the condenser QBQ' ». . As regards the automatic stepping. circuit, 1 "If it is assumed with regard to controller No. 2, . that thecamshaft is in its ?rst position, cam con tacts Ci, C9. and C22 will be operated, thereby should be explained that when the neon lamp N ‘ lighting the green signal lamps GNS for the north south- road, and the red signal lamps REW for 15 ?ashes as the result of the.charging. of the con denser QB to the required voltage, relay E is oper the east-west road,-while at the same time over ated in series therewith, thereby at armature ,el cam contacts Cl, a circuit is complete from the ' operating relay F, and at armature,~ e2‘ connect: valve‘ recti?er I VLV‘ by way of a tapping on the ing negative potential to the wipers "of the switch ' common resistance I3 for charging the condenser Relay F on operating, at armatureflcome ~QA. 'Afterthe initial period of for example, 10 20 pletes the circuit for the driving magnetDSM, seconds has elapsed, the condenser QA will be at armature ft supplements the connection-to the charged sufficiently to cause the'neon lamp IN to wipers of the-switch DST‘, at armature f3 shunts ?ash over, thereby operating relay A which at armature al energizes the solenoid S which ad the neon lamp N_' and‘ relay'E by way of re vances thecam shaft into its second position. In 25 25 sistance- YB, and‘at armature -,f4~flashes the master this position, as will be evident from the chart, fail alarm lamp MFA. .Relay E‘ thereupon re the signal l'am-ps already lit‘ are maintained and leases and- upon the release of relay F after its 20 DST. slow period due-to the copper slug? on its core, the driving magnet is de-energized to advance 30' the wipers on torthe next set of‘ bank contacts. over cam‘ springs C2 and‘ the adjusting switch shown a charging circuit is again completed for the condenser. Four such adjusting switches are 30 This action continues automatically so long as the system is in service; One bank-and wiper of the switch DST'is'allotte'd to each controller to shown in the drawings and it should be explained that the terminals of these switches connect with suitable tapping points on the common resistance be regulated; and the’ control leads extend from l3. To meet the requirements of the invention the resistance now connected in circuit must be very high to ensure that the condenser charges slowly, and for this reason the adjusting switch in the appropriate contacts in‘ the associated bank. Bank la connects with controller No. I- of which only the regulating relays have been ‘shown in the dotted rectangle; this controller may be located adjacent to the master timer. -Bank 20. connects 40 with controller No. 2 ‘shown in Fig. 2, and bank 3a connects with controller No. 3; whichis not shown as it is: assumed to‘ be identical with controller No. 2. In the drawings each control lead.‘ is shown as ., making‘. two connections with its associated bank, one of which is directand the other extends by way of'a resistance. Consequently as the switch rotates so-called light‘ ‘and'heavy ‘pulses are‘de livered over the control leads to the respective controllers in‘ turn. The control. leads may comprise light gauge wires, for example, telephone lines, and terminate in- the controllers ‘on a pair. of relays B and. C shown in Fig. 2 connect'edsin series one of whichv Asa result of the operation‘ ofione or both of these relays fromthe light and heavy pulses the signallights of the controller. are regu , is marginal. lated; accordingly. ‘ ' I In- this particular example the complete cycle time of‘the system is represented"by>t25 ‘steps of‘ 60 the rotary'switch DST in the‘master. tim'er. Each stepof the switch therefore rep-resents 4% of the total cycle. time ~ so’ that by. varying. the connec tion of the‘ control leads to: the banks the phase relationshipbetween the di?erentsets of control signals may-xbe- adjusted to a very ?ne degree. Each ofi't'hecontrollers, which are. all identical, comprises: essentially va battery. of cams mounted‘ on a'commonashaft" and arranged to close contact springs‘in'a-particular order. .As regards theiNo. 2 controllerfshown‘inr Fig. 2‘it shouldbe ex plained thatthe cam shaft is rotated step by'step under'the control’ of‘ a. solenoid S which is im question is preferably'turned round into its ex treme position where it will be understood that it connects with the end of the common-resistance 4:0 shown. During progressive working this particular timing circuit will have practically no effect on the operation of the controller since with the normal operation of the master timer a light pulse is de— livered over the control leads before it becomes operative. As already explained this light pulse is obtained by including a high resistance in the pulse leads at the banks of the master timer, and as a result relay B only is operated in the controller, thereupon at its armature bl in con junction with the cam contacts C1 completing low resistance charging'circuit for the condenser QA. Almost" immediately therefore the neon lamp IN flashes and‘ causes the controller to step to posi tion’ 3. Non-inductive resistances are connected across the control leads as shown in order to guard against. false operation owing to surges and inductive discharges. In accordance with the change of the cam con tacts, the green lights for the north-south road are now replaced with amber lights ANS, and over cam contacts C3 and the adjustable resist 60 ance switch a circuit is completed for the con denser QA to control the duration of the amber 65 signal. With this arrangement although the phase of the amber signal may be changed when an adjustment is made in the cycle at'the master timer, its'actual duration remains constant since it is determined by the setting of the local ad .70 justing switches and is not influenced by the re lays connected to the control leads. pulsedatpredeterminedtime.periods from aineo'n' In case it should be desired to show the amber signal simultaneously to both roads, as is the re lamp .timingdevice,‘comprising the. lamp IN ' and quirement of certain administrations, this may be 75 3 2,129,446 achieved by bridging the amber circuits by means of the strap and switch [4 shown in the drawings‘ After the duration of the amber warning period the solenoid S again operates to step the cam and at springs 'CSS3 connects potential to the common lead Hi to operate a relay CS in all con trollers, which thereupon at armatures csl dis shaft to position 4 and the control signals are connect the respective controllers from the alter nating current mains. This method of control is then completely reversed while over cam springs preferred to the alternative, whereby the relay is 04 a charging circuit is completed for the con denser QA which provides an initial timing period of 10 seconds for the east-west road. When this 10 period has elapsed, the solenoid S steps the cam shaft to position 5 and although the signals pre operated to connect up the controller since a fail ure at the master timer might then result in the viously showing are retained, the charging circuit for the condenser QA is completed by way of the very high resistance as a result of the adjusting 15 switch associated with cam contacts C5 being turned into an extreme position. Here again this second comparatively long time period has practically no effect upon the con troller during normal progressive operation since 20 a heavy pulse will be received from the master > timer meanwhile, which results in the operation of both relays B and C, and the latter at arma ture cl in conjunction with the cam contacts Cl8 steps the cam shaft into its ?nal position 6. In 25 this manner the controllers are stepped progres sively depending on the connections to'the banks ‘ of the timing switch, and providing the master timer is functioning correctly, the time periods of their “stop” and “go” signals will be directly 30 regulated therefrom. If, however, for any reason the master timer should fail in such a manner that no further im pulses are delivered over the control leads, the individual controllers will continue to function 35 satisfactorily at somewhat longer time intervals as a result of the charging circuits completed over the cam contacts C2 and C5. Moreover, in case a particular line fault on. the control conductors should maintain operated one or both of the signal 40 relays at the controller, the latter will continue to function at somewhat shorter time intervals as determined by the initial timing circuit com pleted over cam contacts Cl and C4. In addition to the normal operation of the system and the necessary safeguards against fail ure, it is also possible to provide special features such as for example causing all controllers to show a red signal to all approaches» thereby effecting a complete hold up of the traffic. This condition may be brought about instantaneously from the master timer by the operation of the 'manual switch which closes the contact marked ARS in the drawings, thereby connecting potential to a common wire [5 extending to all controllers which 55 results in the operation of a relay AR in each. Relay AR, at armature arl disconnects the oper ating circuit for the controller which is thus brought to rest in the position to which it is set, at armature arZ opens the circuit of the green and 60 amber signal lamps and at armature m3 bridges the circuit of the red signal lamps so that both sets are lighted. It will be appreciated from a consideration of the chart that in all positions of the controller one or other of the red signals will 65 be showing and therefore the connection de scribed will be effective no matter in what posi~ tion the controller is brought to rest. For the purpose of switching the controllers on and off a further common wire I6 is provided 70 which connects with the switch contact CSS3 at the master point and a relay CS in each con troller. The operation of the switch CSS dis connects the master timer insofar as its control function is concerned by opening the circuit to 75 the valve recti?er VLV at springs CSSI and CSSZ, individual controllers becoming disconnected. Arrangements are also provided by means of a 10 special manual switch at each controller whereby the all red feature may be brought into action at that particular point only. When this manual key is operated, the springs ABS! and ARSZ are actuated, thereby disconnecting the circuit for the 15 green and amber signal lamps and also connect ing together the red signal lamps so that both sets show simultaneously regardless of the posi tion of the controller. In case it should become necessary under cer 20 tain circumstances for a particular controller to be operated‘ manually, the required circuit changes are brought about by the operation of a further key which actuates the springs MAN! and MANZ to disconnect thetiming circuit of the con troller and also connects the solenoid S in circuit with a push» button PB. The operation of the push button by the officer in charge causes the controller to step through its cycle and any de sired time periods may be allowed. 30 As already explained, a supervisory lamp MFA is provided which is located in a conspicuous posi tion at the master timer and arranged to ?ash in synchronism with the stepping switch. Failure of the switch to step due to some mechanical 35 trouble will therefore be evident by the failure of the supervisory lamp to light and the traffic engi neer is thus acquainted of the fault. An indica tion is also given of the blowing of the main fuse or similar trouble in which event the lamp is ex tinguished. 40 ' In case the master'timer. is switched on at a time when certain of the controllers are out of phase, the correct phase setting between each will be restored when the stepping switch in the 45 master timer has made one complete revolution. The application of the progressive system of control to an existing system of road-pad-operat ed controllers is also contemplated according to the invention. In this connection it will be real ized that when a system of road-pad-operated controllers for example of the type described in British speci?cation No. 356,102 previously re ferred to, is working under heavy traf?c condi tions, the occurrence of the maximum timing pe riodwill be the rule rather than the exception, and under these circumstances the controllers become in e?ect ?xed time controllers working on their maximum timing limits. In the appli cation of the invention to such systems it is pro 60 posed to associate each controller with a master timer in much the same manner as that disclosed in'the accompanying drawings and arranged so that control will only be exercised therefrom when the controller attains its maximum timing limit. For this purpose it is proposed to so modi fy the existing controllers that when the maxi mum timing limit is reached the signals will not immediately change but rather the circuits will be put into a condition such as to be responsive 70 to the regulating pulses from the master timer. This is best achieved by placing the maximum timing circuit in each controller under the con~ trol of the relay which is operated from the mas ter timer. With this arrangement when a number 4 of ' controllers attain their maximum timinglimit they will be-temporarily held'in this condition and thereupon released progressively under the control of the relays operated fro-m the master. timer. It will be understood however, that the master timer and associated control relays are operated continuously but their operation is only 10 effective when the controllers in question are signal. Thus, the right of way is being given to thehighway ‘and vehicles may proceed on that street. At the same time, contact 65 is closed 10 The actual circuits might be similar'to those shows a traffic control arrangement of generally similar type provided with neon lamp timers. Referring now to Figurev 3 illustrating an en 15 largement of the diagram outlined in heavy dash lines in Figure 2, the operation of this embodi ment of a road pad operated controller will be described. In this illustration road pads or traf ?c detectors are omitted from the main street 20 designated as A and provided only in the cross street designated as B. The right of way is ac corded to cross street B upon actuation of a traf ?c detector in this street ‘and after a period of right of way in this street which varies between 2.5 a minimum and a maximum depending upon the frequency of further traffic actuation in this street the right of way'is automatically trans ferred to the main street A. It is accorded to this street for a minimum period before it can be 30 transferred again to street B, in response to actu ation in the latter street. Timing means is also provided so that in the event of absence of actua tion on street B for a relatively long period the right of way may be automatically transferred to 35 the cross street to care for pedestrian tra?ic or any cross traf?c which-may have failed to actuate the road pad. The apparatus can readily be ar ranged to disconnect this timing means so that right of way will remain continuously on street A 40 until actuation by traf?c on street B. The construction of the apparatus illustrated in allowing current to flow from wire 98 through contact 65, resistance I05, wire I06, wire I01, wire I08, condenser I09 and wire 99, and the voltage of condenser begins to build up at a rate determined by the value of resistance I05. Assume that this 15 resistance is adjusted so that condenser I09 is charged up to the critical voltage of tube H0 in thirty seconds. However, even though condenser I09 reaches the critical voltage of tube H0, tube H0 does- not become conducting because its dis 20 charge circuit is open at contact 93 and in addi tion is open at armature III and contact II2. In applying applicant’s invention to this appara tus the discharge circuit also includes the con tacts c2 of the master control relay C and is held 25 open until contacts 02 close. Thus, the system remains inactive and right of way continues to be shown to the highway. i If a vehicle approaches on the cross street op erating one of the vehicle actuated control de 30 vices located there, the circuit between wires I0 and II willbe closed momentarily allowing cur rent to flow from wire 98 through wire I I3, relay II4, circuit II and I0, wire H5 and wire 99. This would effect only a momentary closure of relay 35. H4 were it not for the locking circuit consisting of contact IIS, armature II'I, wire II8, contact 62, (contact 62 being made in position F), and wire II9, this locking circuit being made when relay II4 operates. When relay II4 operates, it 40 closes contact between armature II I and contact I I2 partially, completing the circuit shunting con Fig. 3 is similar to that illustrated as a part of denser I09 through wire I20, so that as soon as the individual controller in Figure 2 particularly contacts 02 of the master control relay have closed the circuit through the tube H0 is com 45 pleted. Tube IIO becomes conducting and the energy stored in condenser I09 discharges in the arrangement of the cam shaft and means for operating the cam shaft and in the use of a condenser and discharge tube timing arrange ment. In Figure 3 it will be noticed that there are 16 cams and 56—'II represent contacts operat ed by these cams. The scheme of representation shown under through relay 9'! operating it momentarily. This closes contact between armature I00 and contact IOI, energizing magnet 29 which in turn rocks the notching mechanism. As soon as the core numeral 12 is as follows: In one position, for ex of the solenoid has been fully attracted, circuit ample, A, contacts 51, 60, 62, 63 and 61 are closed. If magnet. 29. is now energized and de-energized between wires 89. and 90 is made which shunts resistance I2I directly across‘ the terminals of condenser I09. Resistance I2I is of a very low the cams will be notched or shifted to position B. 60 As will appear later, when all traffic has ceased on street B, the apparatus will eventually come to rest in position F. In this position contact 56 is closed lighting the A street green signal, and contact 59 is closed lighting the B street red working on their maximum timing limits. disclosed in British speci?cation No. 355,741 which 50 andwire 99., Wires 98 and 99 are connected to a source of. power. 50 Contacts 62 and 63 remain closed. Contacts 51, value, its only purpose being to prevent arcing, 60 and 61 are now open, but contacts-58, GI and 69 are closed. The operation is similar as the cams when switching mechanism 94 closes. This al lows any energy remaining in condenser I 09 to be are notched successively to positions C, D, E and F. In this ?gure the notching magnet 29 is again indicated and whenever energized, operates the 3 switch members 93, 94, and 95 which represent schematically the 3 circuit closers operated by the plunger of solenoid 29. Member 93 is the one dissipated in resistance I2I, tube IIO becomes non-conducting, the energizing circuit of relay 60 9‘! is consequently broken, armature I00 sepa which is made as soon as the motion of the plunger starts and 94v and 95 are the two which are made at the end of the motion of the plunger upon energization of the solenoid. Elements 96 and 91 represent relays, and whenever either re lay is energized, magnet 29 is energized because current flows from wire 98 through wire 3|, mag net 29, wire 30, and, in case relay 91 was ener gized, through armature I00, contact IOI, wire rates from contact IM and magnet 29 becomes de-energized. This allows the notching mecha nism to return to its normal position, and in so doing, to shift or notch the cams from position F to position A. In position A, contact 51 is closed, lighting the A street yellow signal, and contact 60 is closed, lighting the B street yellow signal. At the same time contact 93 is closed insuring that the dis 70 charge circuit of condenser I09 through the tube IIO shall remain closed regardless of subsequent I02 and wire 99 and, in case relay 96 was ener action to relay II4. At the same time contact 61 is closed allowing current to ?ow from wire V gized through armature I03, contact, I04, wire I02 98. through contact 61, resistance I22, wire I23, 75 2,129,446 wire I24, wire I25, conidens‘eril26" and wire 99, and in a similar manner the voltage of condenser I26 begins to build up at‘a rate determined by the value of resistance I22. Assume that the period required is 2 seconds. At the end of two seconds, condenser I26 reaches'the critical voltage of tube I 21 and the energy stored in condenser I 26 dis charges through tube I2'I and relay 96. Relay 96 operates, closing circuit between armature vI03 and contact I04, energizing magnet 29, which in turn rocks the notching mechanism. When the ceed, as'previously described, and the cams will be moved from position E to position F.‘ We have reached the'c‘onditionv described at the beginning, and charging of condenser I09 starts, contact-65 being made. But. after condenser I09 has reached the critical voltage of tube IIO, it does not dis charge through said tube because the discharge circuit is open, as described previously. I have ‘thus described the- operation of the device assuming that only ‘one car approached on the cross street. It will be‘ noticed that after solenoid core has moved to its extreme energized . right‘ of way has been showing on the highway for a certain length of time, right of way is im position, switching device 95 closes circuit be tween wires SH and 92, placing resistance I20 di 15 rectly across the terminals of condenser I26. Re~ sistancev I20 is similar to resistance I2I' and per forms the same functionyfor condenser I26 that resistance I2I performs for condenser I09. The remaining energy of condenser I26 being dissi pated in resistance I28, relay 96 becomes de-ener gized, de-energizing magnet 29 which allows the notching mechanism to again move forward the cams, which shift from position A to position vB. In position B, contact 58 is closed lighting‘ the 25 A street red signal, and contact 6I is closed light ing the B street green signal. The right of way is ‘now being given ,to B street and the vehicle which approached there may cross. In position B, contact 69 is closed and current ?ows into con 30 denser I26 through resistance I29, and condenser I26 reaches the critical voltage of tube I2'Iin 3 seconds. At this moment tube I2'I becomes again I09, but,-no"discharging of condenser I09 can take place iuntil‘it has been charged to the critical voltage of tube H0, and this cannot take place until‘right of way has been showing on the high way for ya certain length of time. ‘ ' 25 If right of way-has been transferred to the cross streetin response to a vehicle approaching there, and a second 'vehicle approaches on the cross street before the end of the '7 second period which is timed in position C, relay I I4 will operate, caus 30 ing armature I32 to touch contact I35, which shunts resistance I36 across the terminals of condenser I26,’ atthe same time interrupting the charging circuit of condenser I26.‘ It, will be advancing the cams from position B to position C‘. noticed that the length of time circuit between 35 In moving from position B to position C, there is wires I0 and II remains closed depends entirely no change in the signal lights, contact ‘58 and upon the length of time the wheel of the vehicle I 6| remaining closed. is on ramp 5. And this again upon the speed of the vehicle. vehicle is travelling, the longer time, and the faster the vehicle Contact 62, however, is open, which breaks the locking circuit of relay II4 which drops to its de-energized position. In addition, contact 'II is closed, and since relay ‘I I4 is de-energized, current flows from wire 98 through resistance I30, contact I3I, armature I32, contact ‘II, wires I23, I24 and I25, condenser I26 and wire 99, and similarly the voltage of con denser I 26 begins to build up at a rate determined by resistance I30. Assume that this resistance is set so that condenser I26 builds up to the critical voltage of tube I21 in '7 seconds. Assuming that no further cars approach on the cross street, then after’! seconds, condenser I26 will discharge through tube I 21, performing the very same steps of the notching operation described'previously. This notches the cams from position C to posi tion D. ' ‘ ' - In position D, contacts 51 and 60 are again made, lighting both the A and B street yellow lights. In addition, contact 68 is made which closes the charging circuit of condenser I26 through resistance I33. Assuming that resist 60 ance I33 is set to charge condenser I26 upv to the critical voltage of tube I2‘I in 2 seconds, then con denser I26 will discharge after 2 .seconds and the 65 lock in, closing the discharge circuit of condenser 20 in the very same manner previously described, conducting and the notching operation proceeds s. in mediately'callable to the cross street, should a; vehicle approach there. But if a vehicle should 15 approach on the crossstreet atv any time after the cross street‘has- lost right of way, and before right'of Way has been given to the highway fora certain length‘of time, relay “4 will operate and notching operation will proceed again as described previously, shifting the cams from position D to position E. ’ - 1 ‘ In this position, contacts 56 and 59 are made, lighting the A street green signal and B street red signal, and the right of way has returned to 70 the highway. At the same time contact ‘I0 is made which charges condenser I26 through re sistance I34 as previously described. Assume that the period timed, as determined by the setting of resistance I34, is 5 seconds. Then after 5 75 seconds, the advancing operation will again pro depends entirely The slower the is this length of 40 is travelling, the shorter is this length of time. Consequently, ad justableresistance I36 is shunted across the ter minals of condenser I26 for a period of time de pendent entirely upon the speed of the vehicle 45 operating relay II4. If the vehicle is moving slowly, this time will be longer and practically all the energy stored in condenser I26 will be dissi pated in resistance I36, and thus when the ener gizing circuit is re-established, charging of con 50 denser I26 will start with practically no stored energy in the condenser, and the time required to charge it up to the critical voltage ‘of tube I2'I will be practically 7 seconds. I‘f‘the vehicle is travelling fast, the time of discharge, and con sequently the amount of discharge will be small. Thus, when the energizing circuit is re-estab lished, charging of condenser I26 will start with some remaining stored energy, and the period timed will'be the‘ period necessary to charge con 60 denser. 126 from the voltage existing at the mo ment to the critical voltage of tube I2‘I. The time period will be shorter by the amount of ti'methat' would have been'necessary to charge condenser I26 from zero voltage to- the voltage to which it had been reset. Thus it appears that the amount of reset depends upon the length of time the energizing circuit is interrupted. ‘ As soon as‘ tra?ic ceases to approach on B street, condenser I26 will discharge through tube I2‘I, ‘notching or advancingthe cams to position D, and from then on the operation is asdescribed above. ‘ ‘ ‘ ' Should vehicles approach continuously on B street, continually resetting condenser I26, right 75' 6 2,129,446 ofpway would remain ‘indefinitely-on the cross street to the disadvantage-of the highw'ayrunless some limitation is~imposed upon the length of time the cross street may retain right of way. It of right of way to the B street in the absence of tra?ic‘actuation can be disconnected by means of va switch which may conveniently be placed in the ‘timing circuit between cam contacts '66 and will be noticed that in position C, contact“ is timing resistance I39’. 7 closed which allows charging current to ?ow into In describing the operation of the system, I condenser I09 through resistance I31. Assume have shown the device as exhibiting the signal that resistance I31 isso adjusted that condenser lights in the usual sequence, namely, green, yel I09 will reach the critical voltage of tube “0m 20 low, red, ‘yellow, green. It frequently is desirable seconds. This condenser is notresetby approach to omit the showing of yellow when the shift is 10 ing vehicles, and if traf?c'continues at the end from red to'green, and continue to show a red of 20 seconds, condenser I09 will discharge . light while a yellow light is being ‘given to the through'tube I I0,‘operating relay 9'! which ener street ‘which is losing right of Way. ‘ This can be gizes magnet 29, and the mechanism, notches to easily accomplished by providing that the cam 15 position D as described previously, provided con under contact 51 operates the contact only in 15 tacts 02, forming a part-of the discharge circuit position A, that the cam under contact 58, oper through the tube, are closed. It will be seen ates the contact through position B, C‘, and D, that themaster timer through relayC is able to that the ‘cam under contact 59 operates the con controlthe transfer of right of wayfrom'street B tact through positions E, F, and A, and that'the 20 by-the maximum timer. Thediiference is that cam under contact '60 operates the contact in relay 9‘! also operates armature I38>which touches position D only. Obviously by'su'itable arrange contact I39 which allows ‘current to-?ow through ment of the cams any other desiredsignal se relay H4, operating it. The energizing circuit quence'may be obtained. ' made at armature I38 is only-momentary and For the purpose of manual-operation a switch 25 relay I I4 would not‘remainenergized, (its locking I40 vis opened, ‘thus disconnecting the timing circuit ‘being broken at contact 62) were it not'for mechanism from the lights. The lights may be contact device 9-3 which is made as soon as ‘notch operated vmanually by simply ‘pressing push but ing mechanism 26 begins-to move. This com pletes circuit between wires ‘I8 and ‘I9 whichpro 30 vides a temporary locking circuit. Contact'62 is made. in position D and as a matter of fact, is made slightly before the notching mechanism has completed its clockwise notching movement, and is so *adjusted that contact‘62 is made just before circuit between‘wires 18' and ‘His broken, maintaining relay H4 in ‘an energized position. Thus, while some vehicles have lost right of Way before they have had su?icient time to cross the intersection, the system remains in such'a condi 40 tion that without requiring any‘addition'al ‘actu ation of the B street vehicle actuated device, right‘of way will'revert to B ‘street at-‘the'end of the highway right of way period. It will be noticed that right of way is being 45 given to -B street in position B although the re settable timer has not begun to‘ operate. This period, in this case -3 seconds, is the period pro 50 by omitting'the direct connection'between relay 91' and'armature III which would be employed where this controller is used as an isolatedlsys temlindependent of any master control and ‘by 45 running this circuit through'the contacts 02 of the "master ~control relay C. It will be'noted as vided to allow ‘one or more'vehicles'which may be described above that the discharge tube 'I'I0'and waiting» on B street to get into ‘motion, and pre sumably the last of such waiting vehiclesis actu ally-in motion when the‘ mechanism’ notches the the relay-'91 are a part of the timing 'circuit'serV ingas armaximum timer in position C of the cams through‘ the 'cam‘contact 64 and also serving as a minimumtimer ‘on street A'in positioniF ‘of'the camsthroug'h the cam contact 65. Thus it will beseenthatthe ‘operation of the maximum'timer cams to. position C. I ' If no vehicles are waiting on B street, ‘right of way will be given to the highway ‘and may re 55 main ‘there inde?nitely, thuspreventing'pedes trians fro-m crossing the highway. It is some times desirable to provide-a system-‘which will occasionally shift right of way'to the‘ cross street even though there are no vehicles waiting there 60 on, stopping the highway traffic and ‘allowing pedestrians to- cross the‘highway. Thls'may ‘be accomplished‘ through contact’ Eli-which is made in position F. ' This charges condenser I26 through resistance I39’, and this resistance is 65 adjusted so that condenser I26 is‘charge'd to the critical voltage'of tube I-2'I‘ in Zminutes. "This notches the cams to position A-‘and~ fromithen ‘on they automatically advancethemselves through the succeeding positions. Of- course, should vehi 70 cles approach while cams are in position C, they will reset condenser‘ I26, as-v described. previously. But ‘if no vehicles at'all-a-pproach right of way will shortly be returned to the highway and highway traffic may proceed. 75 ton III, which, uponeach functioning, energizes magnet'29 thus advancing the cams through their cycle ‘andrin so doing transfers right of way from one-‘vehiclelane to the other. ‘Referring further to Figure 3 and the con densed illustration shown in Figure 2 themaxi mum'timing circuit in this case‘ is that associated with'the'condenser I09 and the'discharge circuit therefor-‘has 'to be closed over contacts '63 or 'arma'ture‘I‘I I. In the arrangement contemplated according to the invention this discharge circuit would ‘only be completed by the relay responsive to the controlling pulses from the master timer. 40 As‘illustrated this control may be provided‘for ' It will be obvious that this "automatic transfer‘ in position C’ on the cross street will be controlled 55 by the ‘master ‘control relay C and it will alsocbe seen‘that the'completion of the time‘rperiod to permit transfer of right of way to the cross street in response to cross street‘ actuation will‘in'posi tion‘F' also'be under the control ofmaster ‘control relay C, thus‘permittin'g the‘ master timer to con trol the transfer of right of way to the cross street in response'to ‘actuation and also to control‘ the retransfer' of'right of way to the main street in the’event ofrtra?ic on the cross street being suf ?ciently heavy to produce extension of’ the cross street right‘o‘f way period up to the maximum. Referring now to Figure 4 the present‘inven tionvis'shownlv-applied to "govern operation of a tra?ic signal controller of the full-actuated type, having: detectors in'both main and cross streets. Such'a'full-actuated controller is disclosed in British Patent ‘356,102, and application of the invention to this type controller provides for controlling the instant of releaseofl right of way 60 65 70 75 7 2,129,446 from each street if the right of way is prolonged up to a maximum. In Figure 4 there is represented timer I39 of British Patent 356,102 and when current is applied at its terminals E, E it times the maximum dura tion of right of way for traf?c on one of two in tersecting streets, for example, ‘A street, causing release of right of way from A street by the sepa ration of armature 51 from contact 56 at the end of the maximum time period. Timer I3‘! is the corresponding maximum timer for the other or B street controlling release of right of way from B street by its armature 86 and contact 81. Each of these timers serves as a time delay relay, the 15 time delay period being determined by a con denser-gas discharge tube timing unit. When current is applied to terminals E, E of timer I39, relay I1 is energized closing armature 2| against contact 2|] to complete a charging circuit for con When con denser 24 has acquired a voltage above the con ducting potential of gas discharge tube 26, and assuming the contact 02 closed, a circuit parallel 20 denser 24 over high resistance I 9.‘ ling condenser 24 is completed through tube 26 25 and relay 2'! is energized by the charge stored in the condenser. Relay 21 looks in via its con tacts 30 and its armature 51 breaks at contact 56 a control circuit for causing transfer of right of Way. When current is disconnected from ter 30 minals E, E relay I‘! is deenergized, at contact 20 the condenser charging circuit is interrupted, and at contact 32 a circuit is completed via low re sistance 33 to completely discharge the condenser in preparation for timing the next interval. 35 In accordance with the present invention as shown in Figure 4, the circuit through tube 24 and relay 2'! parallelling the condnser is not com pleted unless or until relay C is energized by the master timer to close its contacts 02. Thus, after 40 the condenser charging period of the maximum timer I39 is completed, the instant at which right of way may be released from A street by operation of relay 2'! to separate contacts 56—51 is deter mined by the time of operation of relay C by the master timer. Similarly, termination of the B street right of way by maximum timer I31 is governed by the time of operation of relay B. In this way at one or more full-actuated controllers the transfer of right of way at the end of the maximum period may be controlled by a master timer in accordance with the invention. The term “controller” is used herein broadly to designate the mechanism located at the indi vidual intersection for .operating the signals through their cycle of right of way indications and in the present embodiment this controller includes a timing device for determining the time periods of display of the di?erent right of Way and cautionary change indications in. the cycle, but which timing device is normally superseded in effect by an external timer in de termining the period of the right of way indi cations in certain parts of the cycle. This ex ternal timer is designated herein as “master ‘ timer” or “master timing means” for convenience in distinguishing from the individual or local controller and as representative of its functions of maintaining the cycle of the individual local controllers in predetermined time relation. The master timer it will be observed includes a tim ing device providing closely spaced periodic im pulses, and a cyclic switching device having dis tributing units for providing impulses at differ ent preselected points in the cycle to the indi 75 vidual controllers, all the units being operated in unison step by step by the impulses of the tim ing device. In this respect the master timer acts as a common timing means for the several individual local controllers. In the embodiment shown in Fig. 3 the controller is operated by its timing device subject to modi?cation of the tim ing by tra?ic actuated means. It will be understood that various changes in construction and rearrangement of the parts of my system might be made without departing from 10 the spirit of my invention as de?ned in the claims. I claim:— - I l. A signalling system for interfering lanes at a crossing including signals to accord and in 15 terrupt right of way over said lanes, means, when operative, operating to cyclically accord right of way to the respective lanes for periods of time for the control of traf?c, said means including a de vice for predetermining the time of the begin 20 ning and ending of the said periods, a control station, means including timing mechanism at said station for sending spaced impulses spaced cyclically, the said second cyclic operation being of less duration than the ?rst cyclic operation, 25 and means responsive to said impulses to affect said device to shorten said periods by advancing the time of ending of said periods. . . 2. A signalling system for an intersection of tra?ic lanes, including signals to accord and in 30 terrupt right of way in said lanes, controller means operating to cyclically accord right of way alternately to the respective lanes, said means in cluding a timing device for determining the time periods of said accord of right of way, a control 35 station, means including timing mechanism at said station for sending cyclically spaced impulses, the said second cyclic operation being of less duration than the ?rst cyclic operation, and means in said controller responsive to said im~ 40 pulses to a?ect said device to shorten said periods at a certain point in the cycle of the ?rst cyclic operation to normally control said ?rst cyclic op eration. - 3. In a tra?ic control system for a plurality of 45 intersections of tra?ic lanes having at each in tersection a signal and controller operating the same through a cycle for according‘v right of way successively to such lanes at such intersection, a central master timer normally operating 50 through a shorter time cycle than the cycle of said controller for controlling the phase relation between such controllers and maintaining them in step with the master time cycle, said master timer comprising a periodic impulse generator, a 55 step-by-step rotary switch having a plurality of contact positions and connected to be stepped periodically and cyclically through such positions in the master time cycle by said impulse genera tor, said switch having a plurality of contact 60 banks and cooperating energized wipers, and a common driving magnet operated by said gen erator, for operating said wipers in unison from step to step on said contact banks, each said controller including timing means operating dur 65 ing a part of its cycle to time accord of right of way and cause transfer of right of way from one lane to the next at the end of its timing period, each bank having a plurality of spaced contacts arranged to be successively energized by one of 70 said wipers, and means connecting one of said contacts in each of said banks to a separate one of said controllers to accelerate the respective timing means of the several controllers at prede~ termined positions of said switch normally to 75 8 2,129,446 control the relation of such transfers of right of waybypsuch controllers to the master time cycle. 4. A signalling system including, in combina tion, a plurality of signallingameans ,to-be in stalled:one adjacent each of apluralityofiinter sections of traffic lanes and adapted/to ‘accord and interrupt right of ,way in said lanes, a plu rality of controllers forsaid intersections and connected each to one of said signalling means to operate the same through a time cycle to transfer right of :way alternatelybetween the in tersecting lanes, impulse responsive means indi vidual to each controller and adapted onaccord of right of way to one lane to be operated to cause 15 transfer of right of way to another of the inter predetermined-state .of charge on the ‘same to activate said driving means, and control means adapted vwhen'operated in a part of said con troller cycle :for connecting said resistance be tween said. condenser and power leads, and means forming apart of said .master timing meansand connected to said controller to oper ate periodically said control means, and further means in said controller including a higher re sistance and normally ‘connected to said con 10 denser to similarly vary the charge on the same butat a considerably slower rate than said ?rst named charge‘varying means such that if said ?rst namedcharge varyingmeans fails to oper , atezthe slower rate chargingmeans will vary the 15 secting lanes by said signal and thereby control the time cycle of the signal, a ‘master timing charge on said condenser to the point where said driving meansis activated. means connected to all of said controllers and '7. A signalling system including in combina tion, signalling means at‘an intersection of traf ?c lanes and adapted to accord and interrupt right ‘of way in such lanes, a cyclically operat ing electrically driven controller for operating the comprising a cyclic step by step. rotary switching 20 device for supplyingimpulses to said impulsere sponsive means in the several controllersat vdif ferent predetermined points in its .cycle ,for de termining the time phase relation of .such trans fer of right of way by said controllers, said I25 switching device including a plurality of impulse units one for each controller to havea different phase relation with said switching. device, driving means for stepping said switching device and impulse units in unison through ‘such cyclepa con denser, power leads and a resistance connected to said condenser to vary its charge overanin terval of time, an electronic :tube 'connected‘to said condenser and operable'responsive to a pre determined state of charge on’said condenser to 35 activate-said driving means, :means acting upon operation of said tube .to ‘reset ‘said condenser charge, and means'for adjusting said resistance to vary said time interval and proportionately vary the time cycle of all said controllers. signalling means to transfer right of way between thelanes'periodically at a certain time rat-e, mas~ ter timing means, av single circuit connecting said master timer to said controller, said master timer operating cyclically to‘transmit to'said controller electrical impulses'of different values at differ ent times over said circuit, means forming a part of said controller and responsive to only one of said impulses to cause said controller to operate more-rapidly through portions of its cycle, and further means forming a part of said controller and responsive to the other impulse to cause said controller to operate more rapidly through an other portion of its cycle. 8. A traf?c control system for a plurality of intersections of tra?ic lanes, including in combi nation right of way signalling means at each in 5. A signalling system, includingiln combina tion. signalling means-to be :installed adjacent tersection, traffic actuated means in one of the , an intersection of tra?ic lanesand adapted to lers one at eachintersection and connected to accord andinterrupt right of way in said;lane's, a cyclically operating controller for said inter 45 section and connected to said :signalling :means to control the same,.master timing means con— nected to said controller to control the .operation thereof, said controller including -a condenser, said signalling means and adapted to operate the power leads and a resistance connectible to said 50 condenser to vary the charge on the same over an interval of time, a switchingdevice connected to said signals to operate the same, driving :means for said switching device, an electronic tube con nected to said condenser and operabl‘e'responsive lanes at each intersection, a plurality of control same through a cycle in which right of way is accorded alternately to the lanes for time periods, ‘ means forming a part of each said controller and connected ‘to be operated by actuations of the traf?c actuated means associated therewith to prolong the accordof right of way in the lane of said trai?c actuated means beyond said time 50 period, means in each said controller to provide when 'operative'a maximum time limit to such prolonged :accordof ‘right of way in such lane, and:a‘:masteri'timerrconnected to all of said con to activate said driving means, and'control‘means trollerslfor periodically rendering said maximum limit=means operative in the several controllers when operable connecting said ‘resistance be in .:pre-‘determined.time relation, whereby if traf to a predetermined state of charge .on the same tween said condenser and power leads, and means forming a part of' said master 'timing 60 means to operate periodically said, control means. ?c .ractuation at the respective intersections is su'?icient'toprolong right of way up to themaxi~ mum limitthe periods of accord of right of Way 6. A signalling system, including in combina in'the lanes of vthe'tra?ic ‘actuated means will tion, signalling means to be installed'at an inter be-maintained‘in pre-determined time phase re lation ‘at the several intersections. 9. A "traffic control system 'for a plurality of intersections of "tra?ic-lanes having at each in tersecti'on‘ signalling means, traf?c actuated means: in the lanes, a controller connected to said actuatedameans and to said signalling means for section of trailic lanes and adapted‘ to accord‘and interrupt right of way in said lanes,.agcyclically operating controller for said intersection ‘and connected to said signalling means to control the same, master timing means‘connected to said controller to control the operation thereof, said controller including a condenser, power leads 70 and a resistance connectible to said condenser to vary the charge on the same over an interval of time, a switching device'connected to said sig nals to operate the same, driving‘means for‘said switching device, an electronic tube connected to said condenser and-operable’responsivetoa operating-said signalling means to transfer and accord right of Way'to the lanes alternately for 70 time periods in‘response to actuation of said traf ?c‘ actuated-‘means, said time periods being ex tendable‘v in responseto further actuation in a lane having right of way, maximum timing means comprising: a; condenser, means for; charging said 75 \ 2,129,446 condenser at a slow rate and means when con nected to said condenser responsive to a prede termined charge on said condenser to limit ex tension of said time periods, and a master timer operating for cyclically connecting said respon sive means to said condenser in each controller in a predetermined time relation with the others whereby transfers of right of way occurring by operation of said maximum timing means at all 10 intersections take place in predetermined time relationship. 10. A traffic control system for the intersection of interfering tra?ic lanes includingsignalling means adapted to accord and interrupt right of 15 way in the lanes, tra?ic actuated means in the lanes, a controller connected to said signalling means and said traffic actuated means and hav ing alternate signal control positions through which it is adapted to operate to cause said sig 20 nalling means to accord right of way alternately in the respective lanes in response to actuation 9 of the tra?‘ic actuated means, said controller in cluding a timing device energized in one such alternate position forv timing such accord of right of way and prolonging such accord of right of way responsive to actuation of the tra?'ic actu ated means during such accord of right of way to the lane of the latter tra?ic actuated means, cir cuit means for operating the controller from such one position to the other to cause the signalling means to interrupt such accord of right of way 10 when the circuit of said circuit means is com pleted, a second timing device operating at the end of a maximum time period in such one po sition to prepare said circuit for completion and maintaining said circuit so prepared thereafter 15 while said second timing device remains operated in such one position, and said system including a cyclic master timer for periodically completing said circuit when prepared. PERCY BAILEY RENSI-IAW.