US3106695A - Traffic control apparatus - Google Patents

Description

A. M. BALTAYAN ETAL 3,106,695 TRAFFIC CONTROL APPARATUS Oct. 8, 1963 Filed May 14, 1958 4 Sheets-Sheet 1 FIG! PARENT STREET "c" s FIG. 3

STREET PARENT INV JOHN L. BARKER AND ARA M. BALTAYAN BY M Gkc0 ATTORNEY ENTORS Oct. 8, 1963 A. M. BALTAYAN ETAL 3,

TRAFFIC CONTROL APPARATUS ONE CYCLE ONE CYCLE 2 |234 45s?s9|o|||2 PHASE"A" RRRRGGYRRR s PHASE"B" e G Y R RR Re G Y R R LEFTTURN RRRGRRRRRRRRR ONE. CYCLE ONE CYCLE F IG. 4

2| 22 23 2&24 252627 28 29 303i 32 PHASE'U'NORTHRR R s as YR R R 66 Y PHASE"C"SOUTH R R R R e G Y R R R s G Y PHASE"D" GGYRRRRGGYRRR INVENTORS JOHN L. BARKER AND ARA M. BALTAYAN BY C mw ATTORNEY Oct. 8, 1963 A. M. BALTAYAN ETAL 3, 06,695

TRAFFIC CONTROL APPARATUS 7 Filed May 14, 1958 4 Sheets-Sheet 3 IIIHI I I I H Illlll Nil?! C14 I I I II I INVENTORS JOHN L. BARKER AND ARA M. BALTAYAN ATTORNEY l Cl2 Oct. 8, 1963 A. M. BALTAYAN ETAL 3,

TRAFFIC CONTROL APPARATUS 4 Sheets-Sheet 4 Filed May 14, 1958 PDX vo I Fll F Q.

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INVENTORS BARKER AND ARA M. BALTAYAN BY Jigsaw? JOHN L.-

.ATTORNEY United States Patent 3,106,695 TRAFFIC CGNTROL APPARATUS Ara M. Baltayan, New Haven, and John L. Barker, Norwalk, Conn, assignors, by mesne assignments, to Laboratory For Electronics, line, Boston, Mass, a corporation of Delaware Filed May 14, 1953, Ser. No. 735,236 19 Claims. (Cl. 3340-67) This invention relates to an improved tralfic signal controller, and more particularly to an auxiliary period timer of great versatility, being easily and quickly converted from an actuated auxiliary period timer to a non-actuated auxiliary period timer or vice versa.

In particular in the illustrative application the auxiliary period timer is used as an advance green timer although the auxiliary period timer is not limited to such use. A11 advance green timer is a device well known in the field of traffic control. It is a parasitic type device which is dependent upon a main traffic controller which, in such combination, is sometimes referred to as a parent controller. During certain periods of the cycle of the parent controller, or upon actuation by t-raflic, the advance green thner cooperates with the parent controller and inserts into the cycle of the parent controller a period, controlled and timed by the advance green timer and during which a green signal is illuminated to one traflic flow, for example nonthbound, While the traflic flow, in the opposite direction, for example southbound, is held with a red signal.

This advance green period terminates, without a clearance interval, by according n'ght-of-way in the usual manner by green signals to both of such trafiic flows, or in other words to south and north approaches on the same street in common. Thus the advance green period is inserted immediately in advance of a regular two-way green period in the traffic signal cycle for example.

In the non-actuated type of advance green timer for such purpose, the advance green period is inserted in each signal cycle regardless of the presence or absence of trafiic demand at such times, whereas in the actuated type of advance green timer the advance green period is inserted only in response to traflic actuation on one of the traffic approaches.

In general the apparatus disclosed herein is a greatly improved electronic trafiic control device capable of use, in combination with a traiiic controller, as an advance green timer. The present invention is presented in three units, including what is hereinafiter referred to as (1) a basic unit, (2) a plug-in jumper assembly and (3) a plug-in relay assembly.

By the addition of one of the plug-in assemblies to the basic unit, a complete apparatus is formed either in the actuated form or the non-actuated form, depending upon which plug-in assembly is employed. The combination of the basic unit and the plug-in jumper assembly forms a non-actuated auxiliary period timer while the combination of the basic unit and the plug-in relay assembly forms an actuated auxiliary period timer.

The unbalanced traffic movements caused in part by the increasing number of vehicles on the road, occasionally cause much congestion at some intersections even though there is provision for control of normal and above normal traffic.

Spasmodic diagonal trafiic flow across an intersection or unbalanced intersection trafiic flow, where a heavy left turn movement opposes only occasional light straight through traific or where occasional light left turn traflic is opposed by a heavy straight through traffic, present problems of which one solution is the staggered presentation of right-of-way to such opposing t-rafiic flows.

The device herein proposed provides a time controlled output which may be used to insert a right-of-way period into a cycle of an associated trafiic controller, which period may be used to stagger presentation of right-ofway to the opposing traflic flows for a brief period, While the device itself may, by partly local adjustment and partly remote control, vary the time of the staggered presentation of right-of-way.

Both actuated and non-actuated forms, by varying the signals controlled by the output circuits are capable of a variety of difierent traific signal control, as well as each form having remote selection between two locally adjusted time controls.

A locally adjustable switch, in cooperation with the remotely controlled time selector, may cause omission of the period of the auxiliary period timer and in the case of the actuated form, may cause an actuation, normally affecting the auxiliary period timer, to affect the parent controller as if the actuation had normally been received via the usual call circuit of the phase of the parent controller with which the auxiliary period timer is associated.

Another locally adjusted, two position switch, associated with the plug-in relay assembly so that such switch is only available in the actuated form, selects between two difilerent types of response to the associated traffic detector actuations.

It is therefore an object of the invention to provide an improved electronic means for inserting a timed signal period into the cycle of a cyclic signal controller at a predetermined point in the cycle.

It is also an object to provide an improved trafiic control device easily and quickly convertible from an actuated device to a non-actuated device through the interchanging of prepared plug-in assembly units in connection with a basic unit.

It is a further object to provide an improved auxiliary traflic signal period control device providing for remote selections between two locally adjusted timed periods therefor.

Another object is to provide an auxiliary trafiic signal period control device including means for elimination of such period with remote control over such means of elimination of such timed period.

It is another object to provide an improved electronic advance green timer.

An additional object is to provide an improved advance green timer capable of ready conversion from traffic actuated control to non-trafiic actuated control and viceversa.

A fiurther object is to provide an improved advance green timer with remote selection between two locally adjusted timing controls for such advance green period.

Additional objects will be apparent from a reading of the description below.

FIG. 1 illustrates, in block form, an intersection controlled by a parent controller in cooperation with an auxiliary period timer with lei t turn lanes for vehicle trafiic approaching the intersection from opposite directions.

FIG. 2 is a signal sequence chart that may be associated with the signals employed at the intersection illustrated in FIG. 1, for example.

FIG. 3 illustrates, in block form, an intersection with opposite traflic flows controlled by signal lights in such a manner that one direction of trafiic flow is controlled only by the parent controller and the opposite trafiic flow controlled by the parent controller in cooperation with the auxiliary period timer.

FIG. 4 is a signal sequence chart that may be associated with the signals employed at the intersection illustrated in FIG. 3 for example.

HS. 5 is a schematic circuit diagram of a two phase, full-actuated tratfic controller here used to represent the parent controller used in cooperation with the auxiliary period timer.

FIG. 5a is a schematic representation of an alternate method of timing control of the parent controller timing circuit that may be substituted for the form illustrated in the lower right part of FIG. 5.

FIG. 6 is a schematic circuit diagram, in the preferred form, of a non-actuated auxiliary period timer, with a terminal strip illustrated on the lower left for connection to the parent controller.

FIG. 7 is a schematic circuit diagram, in the preferred form, of the plug-in relay assembly unit, which unit, when plugged into the receptacle illustrated in the lower part of FIG. 6, in lieu of the connections illustrated connecting certain of the said receptacles of FIG. 6, operates to convert the auxiliary period timer from a non-actuated unit, as presented in FIG. 6, to an actuated unit.

Referring to the several figures in more detail, FIG. 1 illustrates an intersection of street A and street B, for example, with the curb lines of the street formed by heavy dark lines. Employing compass directions such as the top of the diagram north; the bottom south and the left side and right side west and east respectively, it may be said that in the southeast corner, represented by two boxes are a parent controller and an auxiliary period timer interconnected electrically by the lines as illustrated. The interconnecting lines are illustrated in detail below.

In street A formed by broken lines labeled BLN and 131.8 are special left turn lanes for vehicle traffic approaching the intersection along street A, intending to negotiate a left turn at the intersection. It is expected that through and right turn traffic will keep to the right on street A and left turn traffic will avail themselves the use of the left turn lane.

In the left turn lane, formed by broken line BLN, for northbound vehicle traffic, represented by a rectangle labeled NLT, is a vehicle detector which is connected to, and ends calls to the auxiliary period timer. Also, in this certain left turn lane represented by circles labeled LG and LR are two traffic signals, green and red respecrtively which control left turn tratlic in the northbound approach. Both these signals LG and LR are connected to the auxiliary period timer by which they are controlled. Signal LG in the preferred form may be a green arrow indicating right of way to motorists who wish to execute a left turn from the northbound approach while signal LR may be a conventional red signal indicating lack of right of way to motorists who wish to execute a left turn from the northbound approach.

In the left turn lane, formed by broken line BLS, for southbound vehicle trafiic, represented by a rectangle labeled SLT, is a vehicle detector connected in parallel with vehicle detector NLT, to the auxiliary period timer. A green arrow signal, represented by a circle labeled LG is connected in parallel with green arrow signal LG to the auxiliary period timer and red signal LR represented by a circle so labeled is connected, in parallel with the signal LR, to the auxiliary period timer. The signals LG and LR control the southbound vehicle tralfic in the left turn lane formed by line BLS.

The vehicle detectors NLT and SLT are so situated in the respective left turn lanes that a vehicle in such a lane will actuate the respective detector and that vehicles in the road to the right of the respective left turn lane, presumably through and right turn traffic, will not actuate the detector in the adjacent left turn lane.

In the roadway of street A is a vehicle detector NVD, represented by a rectangle. This vehicle detector is located in the right section of the roadway so that northbound .4 through and right turn vehicles will actuate the vehicle detector NVD. The vehicle detector NVD is electrically connected to, and sends calls" to the parent controller.

Also illustrated in the northbound through and right turn traffic lane are three signals, represented by three circles labeled NSG, NSY and NSR, green, yellow and red signals respectively.

Signal NSG is connected to the auxiliary period timer by which it is controlled through cooperation with the parent controller all as described below.

The signal NSY is illustrated connected to the parent controller by which the yellow signal is controlled.

The signals NSR' are illustrated connected to the auxiliary period timer through which the red signal is controlled in cooperation with the parent controller all as described below.

In the southbound through and right turn trafiic lane of the street A intersection approach is a vehicle detector SVD which is connected to the parent controller in parallel with the vehicle detector NVD.

A call to the parent controller via the vehicle detector NVD would be the same as a call to the parent controller via the vehicle detector SVD. Also illustrated in the said southbound lane are three circles labeled NSG, NSY and NSR', representing the green, yellow and red signals respectively used to control the southbound through and right turn trafiic therein. The signal NSG is connected to the auxiliary period timer in parallel with the signal NSG, both being identically controlled. The signal NSY is connected in parallel with the signal NSY to the parent controller by which both signals are identically controlled. The signal NSR' is connected in parallel with the signal NSR to the auxiliary period timer, both signals being identically controlled.

Ln the street B westbound trafiic lane, at the approach to the intersection are three signals, represented by three circles labeled EWR, EWY and EWG. These signals, red, yellow and green respectively, which control westbound traflic approaching the intersection on street B are connected to the parent controller by which they are controlled as are the corresponding red, yellow and green signals EWR', EWY' and EWG respectively controlling eastbound trafiic approaching the intersection on street B. The respective red, yellow and green signals are connected to the parent controller over respective parallel circuits for identical control for each red, yellow and green signal on street B.

A vehicle detector WVD located in the westbound approach to the intersection along street B will be actuated by westbound vehicle traffic in that lane while vehicle detector EVD, located in the eastbound approach will be actuated by eastbound vehicle traffic each approaching the intersection on street B. Both these vehicle detectors are connected in parallel to the parent controller to which they send calls.

It should be understood that FIG. 1 illustrates one type of trafiic control system employing the auxiliary period timer in cooperation with a parent controller where a left turn traflic movement or two left turn trafiic movements are controlled at the same intersection.

By slight circuit modification of the external lighting control circuits other modifications, resulting in other traffic control systems, may be obtained. For example, the signals LR and LR, the red signals controlling left turn tratfic may be "omitted entirely and the signals LG and LG may be associated with the set of signals controlling the respective approach to the intersection so that a green left arrow is illuminated to accord advanced right-of-way to left turn traffic and upon the left turn green arrow being extinguished left turn vehicle tratlic will look to the signals controlling through tratfic for right-of-way. This would allow left turn traffic an advanced right-of-way as well as additional right-of-way to proceed, if their path of intended travel is clear, during right-of-way to through trafiic. In such a control system the green arrow signal would generally be placed with the group of signals controlling other trafiic in the same approach so that all the signals would be together rather than having one signal, the green arrow signal, separated from the other set of signals.

Referring to FIG. 2, a signal sequence chart is presented that may be associated with the traffic control system illustrated in FIG. 1. The signal sequence chart of FIG. 2 includes two consecutive cycles of the parent controller, the first cycle being divided into seven periods, 1 through 6, including 4a, while the second cycle is divided into six periods, 7 through 12. Below each numbered period 1 through 12, including 4a, in a box is a letter R for red, Y for yellow, or G for green, indicating the color of signal displayed during that period. At the left of the diagram is found the phase or traific flow to which the signals at the right are displayed, Phase A represents the signals displayed to through and right turn tratlic both northbound and southbound approaching the intersection on street A, but not left turn traific on street A, and Phase B represents the signals displayed to all traflic whether eastbound or westbound on street B, and Left Turn represents the signals displayed to left turn traflic on street A whether northbound or southbound at the intersection.

Periods l, 2 and 3, like periods 7, 8 and 9 respectively indicate red (R) signals displayed to all traffic except Phase B while Phase B receives right-of-way in periods 1 and 2 and 7 and 8 via a green (G) signal and in periods 3 and 9 a yellow (Y) clearance signal. In period 4a a green signal is displayed to Left Turn while red signals are displayed to Phase A and Phase B. The presence of period 4a indicates that a call for the green arrow signal was received and therefore this was inserted into the cycle before the normal period 4. Periods 4 and 5, like periods 10 and I l accord right-oflway to Phase A while Phase B and Left Turn receive a red signal. Periods 6 and 12 are the yellow or clearance periods for Phase A While red signals remain displayed to all other trafiic.

It should be noted that right-of-way is not accorded to Left Turn in the second cycle. This cycle illustrates a signal sequence Without the green arrow inserted into the cycle.

FIG. 3 illustrates an intersection of two streets, street C and street D employing a traffic control system which differs somewhat from the fllustration in FIG. 1. It is obvious to those skilled in the art that the illustration in FIG. 1 discloses left turn traflic movement control.

As will be more fully described below, a preference is given, in the form of an advance green arrow signal, to left turn trafiic on street A while through and right turn trafiic on street A is held stopped.

FIG. 3, on the other hand presents the solution to a dilierent traflic problem. If, for example, southbound traffic along street C in FIG. 3 were generally heavy with a relatively heavy left turn trafiic movement from that quarter and northbound trafiic was generally light it would seem a proper solution to expedite the ilow of trafiic through the intersection by giving an advance right-of way signal to northbound trafiic so as to clear the lesser northbound trafiic first and then give right-ofway to southbound traflic and, in particular, the left turn traflic Without differentiating between through and left turn southbound traflic from that quarter. This result is obtained by the use of a traffic control system illustrated with a parent controller represented by a box in the southeast corner with electrical connections to an auxiliary period timer represented by box so labeled. A vehicle detector ND, located in the northbound lane of street C is connected to the auxiliary period timer to which it sends calls.

The signals RS, Y S and GS, represented by circles in the northbound lane approaching the intersection on street 6 C control northbound vehicle traific in that quarter. The signals RS, a red signal; YS, a yellow signal; and GS, a green signal, are individually connected to the parent controller by which they are controlled.

A vehicle detector SD, located in the southbound approach to the intersection on street C is connected to the parent controller to which the vehicle detector SD sends calls.

The signals GS, YS and RS, green, yellow and red respectively, represented by the circles so labeled control the vehicle trarc in the southbound approach to the intersection on street C. The signals GS and RS are individually connected to the auxiliary period timer through which they are controlled in cooperation with the parent controller. The signal YS is connected to the parent controller over a parallel circuit with signal YS.

The vehicle detectors EWD and EWD' in the Westbound approach and the eastbound approach respectively are connected in parallel to the parent controller to which calls are sent. The signals SR, SY and SG, red, yellow, and green respectively, which control westbound trailic on street D approaching the intersection and signals SR, SY and 538, red, yellow and green respectively, which control eastbound vehicle trafilc approaching the intersection on street D, are all connected to the parent controller by which they are controlled.

The signals SR, SY, SG, SR, SY and SG' of FIG. 3 correspond to signals EWR, EWY, EWG, EWR', EWY' and EWG of FIG. 1 while detectors EWD and EWD of FIG. 3 correspond to WVD and EVD of FIG. 1 respectively.

Modification of the trafllc control system illustrated in FIG. 3 may be employed to solve other traffic problems. For example trafiic approaching the intersection along street C may be generally heavy with occasionally heavy left turn tratlic from the northbound approach. It may be preferred to give an advance right-of-way to the entire northbound movement on street C while holding the southbound movement when one or more vehicles wish to execute a left turn from the northbound approach to the intersection. T'nis result may be accomplished by modifying the trafiic control system of PEG. 3 to include a left turn lane to the northbound street C approach and by transferring the vehicle detector ND (which is connected to the auxiliary period timer) to the left turn lane. An additional vehicle detector would be placed where vehicle detector ND is now illustrated, however, this added vehicle detector would be connected to the parent controller in parallel with vehicle detector SD of FIG. 3. With such modified traillc control system the actuation of the vehicle detector in the left turn lane would send a call to the auxiliary period timer while actuation of the vehicle detector in the through and right turn northbound approach lane would send a call to the parent controller as would an actuation of vehicle detector SD.

FIG. 4, like FIG. 2, is a signal sequence chart, however, the sequence of signals presented in FIG. 4 may be associated with the traffic control system presented in 1G. 3. Like FIG. 2, FIG. 4 presents two consecutive cycles, one cycle including periods 21 through 26 includ ing an advance green period, period 240, and one cycle, periods 27 through 32 omitting the advance green period.

At the left of the chart is indicated the phase or traflic flow to which the signals, represented by R for red, Y for yellow and G for green, at the right are displayed. Phase C North refers to the northbound vehicle traific on street C approaching the intersection While Phase C South refers to the southbound vehicle trafllc on street C a preaching the intersection and Phase D refers to all the vehicle traffic, whether eastbound or Westbound approaching the intersection on street D.

Periods 2.1 and 22, like periods '27 and 28 indicate a green signal displayed to Phase D and a red signal to both Phase C North and Phase C South. Periods 23 and 29 indicate a yellow signal displayed to Phase D while Phase C North and Phase C South receive a red signal.

Period 24a indicates a green signal as displayed to Phase C North while a red signal is displayed to Phase C South and to all traffic on Phase D.

Periods 24 and 25 are similar to periods 30 and 31 during which periods a green signal is displayed to both Phase C North and to Phase C South, and a red signal is displayed to Phase D.

Period 26, like period 32 illustrates a yellow signal dis played to Phase C North and Phase C South while a red signal is displayed to Phase D.

FIG. 5 is representative of the parent controller and is a part of a traffic control system and apparatus disclosed in United States Patent No. 2,156,138, issued April 25, 1939, to Harry A. Wilcox and John L. Barker, but slightly modified for the purpose of the present invention as described below. The use of the controller here shown is for purposes of illustration and is by no means an attempt to restrict the use of the present invention to combination with the controller of FIG. 5. Such operation of the present invention as described below is typical of the operation with other trafiic controllers with which the present invention may be associated.

FIG. 5, as shown, is a form of two phase, full-actuated type traffic controller, representing for example a device named parent controller in FIGS. 1 and 3 above.

Ordinarily, a single controller of the form illustrated operating independently as a two phase, full-actuated controller transfers right-of-way cyclically or in response to actuation between the main and cross streets, the length of the cycle and the portions of the right-of-way signal cycle accorded to the main and cross streets being dependent on, or modified by, actuation of the vehicle detectors in the streets. The vehicle actuated detectors may be of any type as herein discussed.

The controller may, by manner of example, include a cyclic stepping mechanism having a plurality of contact pairs operated by a cam shaft which is moved step-bystep through a cycle by means of solenoid. The contact pairs control signal illuminating circuits and control circuits.

The solenoid in this embodiment is controlled from a timing circuit employing a. capacitor-gas discharge tube combination permitting variations in timing by the vehicle detectors as will be pointed out. Both minimum and maximum timing circuits are provided. The controller, it will be noted in FIG. 5, is arranged for operation from an alternating current supply (indicated by a plus in a circle and a minus in a circle) and suitable voltage transforming and rectifying arrangements are provided, as for example a. transformer XFR and a thermionic rectifier VLV from which suitable potentials of direct current for operating the gas discharge tubes is obtained (at the terminals indicated by a plus in a square and a minus in a square).

The table at the right of FIG. 5 shows a development of the several cams C1 through C18 plus C29 through C22 and the positions of the cam shaft 1' through 6' in which the various cams are operated to close their respective contacts. In each position of the cam shaft a circuit for charging capacitor QA is completed over one of the interval adjustable resistances VA, IA, VB, IB, LA and LB, which are individually wired to one end of the resistor R1 while the other end is connected to the capacitor QA which is then joined to the ground wire L2.

It will be noted that the present drawing, FIG. 5 here, differs from the presentation in US. Patent No. 2,156,138 but a similar effect is obtained. Maximum timing capacitor QB is charged similarly over adjustable resistors MXA or MXB and through resistor R2 which is connected to QB and then through to ground wire L2 as will subsequently be explained. Adjustable resistors MXA and MXB are shown in straight rather than arcuate form but are equivalent to those of the said patent.

Other modifications of the said patent form included in FIG. 5 are several signal lamps shown as internal parts for convenience, although in actual practice such signal lamps would actually be external to the controller. The two vehicle detectors of the said patent, DEW and DNS, appear in the present form as vehicle detectors WVD and NVD respectively. The line L6 between terminal G and terminal 214 and line L7 between terminal F and terminal 215 are additional modifications, the use of which is described completely herein below. In the lower right of the circuit diagram in the present form, isolated by a box made in broken line form, is an additional modification including terminal 219 and terminal 216 with switch SW11 located between the two said terminals and here illustrated as open. The terminals 0 and Q of the said patent illustration are here represented as connected to the ground wire L2 while several interval timing resistors are shown in straight line form rather than arcuate form.

For purpose of illustration, circuits for the green signal and the red signal of one phase, for example phase A, are illustrated as terminating at terminals 211 and 213 respectively in the present form. It should be understood that during independent operation the respective signal lights would be connected to the terminals 211 and 213 for illumination in proper sequence, a green signal to 211 and a red signal to 213.

Operation of this controller as an independently operating full-actuated controller will now be described.

Accordingly, under this type of operation the terminals 219 and 216 would be connected via closure of switch SW11 while switches PB, here illustrated as open, and PA here illustrated as closed, would both be open.

Terminal G is connected through street A vehicle detector NVD to grounded power when the contacts of the detector are closed. Vehicle detector WVD for street B is connected between terminal F and grounded power when the contacts of the detector are closed. Let it be assumed, for example, that the switches PA and PB are open, and at the moment the cam shaft is standing in position 6, the phase A or street A vehicle interval.

It will be noted that in FIG. 5 herein, all switches including cam contacts are illustrated open except for switch PA, which is illustrated as closed. Although all cam contacts are illustrated as open, it should be assumed that those cam contacts having a heavy black mark in line 6' in the shaft positions chart at the right of FIG. 5 are closed contacts. The several timing intervals corresponding to the shaft positions are hereinafter referred to as A yellow in position 1', B initial in position 2, B vehicle interval in position 3', B yellow" in position 4', A initial in position 5', and A vehicle interval in position 6'. All the relays and the solenoid in FIG. 5 herein are initially deenergized in position 6'.

Power is supplied from the A.C.+ power lead 20 through cam contact C11 to grounded power L2 to cause the phase B (street B) red signal EWR to be illuminated. AC. power is also supplied from 20' through close cam contact C9, here shown leading to line 211, which line is part of the illuminating circuit for the green signal NSG (shown in FIG. 1) of the phase A period. It is here assumed that independent operation would ordinarily illuminate the green signal NSG (shown in FIG. 1) of the phase A, which would be connected between cam contacts C9 and ground lead L2 via the terminal 211.

Meanwhile capacitor QA is being charged by current from the rectifier VLV over D.C. plus lead L3, cam contact C4, a vehicle interval adjusting switch VA, resistor R1, capacitor QA for timing A vehicle interval in position 6.

It will be assumed that a succession of vehicles is passing over detector NVD in street A resulting in intermittent operation of relay ER over a circuit from AC. input 2% through relay ER to terminal G, and via closed contact NVD to grounded lead L2. A circuit shunting 9 capacitor QA over low resistor YD on cam contact C is thus intermittently completed through closed contact E2 from ground line L2, thus reducing the charge on the capacitor QA to reset the vehicle interval timing and extend the A green period.

It now a vehicle arrives on street B and actuates the detector WVD the relay DR is energized by a circuit from the A.C. input 29 to relay DR to terminal F to closed contacts WVD to grounded lead L2. Relay DR is energized and locks in over its contact DI, completing a circuit from AC. input 2i? through relay DR, closed contact D1, cam contact C7 to grounded lead L2. Contact D2 is closed and completes a circuit from grounded lead L2 through contact D2, cam contact 06, through relay AR and tube FA paralleling capacitor QA. Also, contact D3 completes its timing circuit to charge maximum timing capacitor QB from the D.C.+ lead L3 over cam contact Cl, contact D3, phase A maximum interval switch MXA, resistor R2, and capacitor QG to grounded power lead L2. The combination of the variable resistor MXA and resistor R2 is substantially higher in resistance than the combination of variable resistor VA and resistor R1, so that the maximum time limit is considerably longer than the vehicle interval.

Subsequently, due either to a gap of sufiicient size between actuations by the street A traflic, permitting capacitor QA to become charged to the flash potential or ioniz ing voltage of the tube FA, now completed in parallel with the capacitor, or due to the charge on the maximum capacitor QB reaching the flash potential of tube FB, either tube FA or PE will become conducting whereupon either relay AR or DR, as the case may be, is operated. At armature Al or B1 a circuit is thus completed from lead 20 through solenoid SR" to lead L2 while relay AR or :BR is momentarily operated to energize solenoid SR. Energization and deenergization of solenoid SR causes the cam shaft to be advanced by a ratchet mechanism (not shown), to next position, position 1'.

As the maximum timing circuit is initiated upon actuation of the detector in the lane not having right of way it assures that the actuating vehicle will be forced to wait at most no longer than the period of the maximum timing circuit before right of way is transferred.

In its energizing position the solenoid SR completes a circuit over its contact S1, capacitor QA and low resistor YA, short circuiting capacitor QA so that whenever the solenoid operates to advance the cam shaft to the next interval, timing will start with the initial capacitor voltage of substantially zero. Similarly, contact S2 completes a discharge for capacitor QB over resistor YB. In position 1, cam contact C9 opens and cam contact C21 closes so that the phase A yellow signal NSY and the phase B red signal EWR are illuminated and the phase A green signal NSG (shown in FIG. 1) is extinguished. Capacitor QA is charged from lead L3 over cam contacts C13, variable switch LA, resistor R1, capacitor QA and ground lead L2. Tube FA and relay AR are connected across the capacitor over cam contact C6 and relay contact D2, and when the voltage of capacitor QA reaches the flash voltage of the tube PA, the relay AR and solenoid SR are operated, and the cam shaft is advanced to position 2 in the manner described above.

In position 2 the street A yellow signal NSY and street B red signal EWR are extingmished and the right of way is accorded to street B as cam contacts C20 and C22 are closed to illuminate phase A red signal NSR (shown in FIG. 1) through terminal 213 and phase B green signal EWG as shown in FIG. 5.

In order to provide a suflicient period for the starting up of any phase B trafic which may be waiting, an initial non-extendible interval of right-of-way is now timed. Capacitor QA is charged from the lead L3 over cam contact C14, adjustable resistor 13, resistor R1, capacitor QA to grounded lead L2 until the voltage across the capacitor reaches the flash potential of the tube FA,

iii

which then becomes conducting and causes the charge on the capacitor to operate relay AR, and this in turn energizes solenoid SR" advancing the cam shaft to the phase B vehicle interval, position 3, while the signals hold.

Although there is no change in the signal indicating circuits at this particular time the relay DR holding circuit is broken at open cam contact C7. Relay DR had locked in over cam contact D2 to complete a holding circuit, as described previously to cam contact C7, and

now cam contact C7 is open and the circuit is broken de-energizing relay DR and opening contact D1. Now relay DR operates intermittently under control of traflic on street B actuating the detector WVD, thus extending the right-of-way period in a manner similar to that described for relay ER by street A t-rafiic actuation in position 6. Also in position 3, as in position 6', previously explained, the maximum interval or the extendible vehicle interval shall terminate to operate either tube PA or PR and cause the cam shaft to advance to the next position, 4.

Openation of the controller through positions 4 and 5' is similar .to that described for positions 1' and 2 excepting, of course, that the right-of-way is leaving phase B tratfic in position 4' with the yellow signal EWY illuminated by closure of cam contacts C10 and right-o f-way is being accorded in position 5' to phase A trafllc for an initial non-extendible interval. The charging circuit in position 4 extends through cam contact C2 adjustable resistor LB, resistor R1, capacitor QA to grounded lead L2 for timing the clearance interval of phase B. in position 5 the charging circuit is through cam contact C3, adjustable resistor IA, resistor R1, capacitor QA to grounded lead. At the end of the interval in position the initial interval of phase A, the cam shaft is advanced in a manner previously explained, into position 6 thus completing one entire cycle of the controller, whereupon the cycle described is repeated in accordance with the trafi'ic actuations.

If transfer of right-of-way from one road to the other at the end of the vehicle interval position 3 to 6' occurs by operation of the maximum time circuit relay BR, contact B2 closes to place a controller in condition to remember vehicle cutoii so that the right-of-way will be retransferred :to them as soon as possible. This'is obtained by momentarily connecting relay DR and ER. For instance, if right-o f-way is on street B and waiting vehicle or vehicles on street A have energized and locked in relay ER, and if street B vehicle interval position 3 is terminated by operation of relay BR, a circuit to energize relay DR is completed from the A.C. plus lead 29 to relay DR, contact B2, contact Ell, cam contact C18 '00 grounded power lead L2. Solenoid SR which operates immediately upon energization of relay BR provides at contact S3 a lock-in circuit over contact D1 for relay DR, which holds until the cam shaft has been moved to position 4, where the lock-in circuit over cam contact C7 becomes operative. If Tighter-way on street A is terminated by operation of the maximum timing circuit, relay ER is left energized to cause subsequent retransfer to street A.

The arterial or recall switches PA and PB when closed, insure right-of-way will return to the associated phase even in absence of tratfic thereon. Their effect, as will be seen from the circuit, is to simulate operation of the detectors while their associated phase is not receiving right-of-way, although they cannot produce any extension effect when their respective phase has rightof-way. By closure of one recall switch, l or example, switch PA as illustrated, the controller of FIG. 5 may he operated as a semiactuated controller, with street A detector NVD disconnected from terminal G and relay ER operated only by switch PA in cooperation with cam contact C18. Accordingly, when right-of-way is transferred to street B for the duration of the positions 2' and 3' the street B initial and vehicle intervals enengization of relay i it ER by the circuit from the AC. power lead 26 through relay ER, switch PA (when closed), cam contact C18 to grounded power lead L2 causes right-of-way to be retransferred to street A by operation of either the minimum or maximum timing circuits. Accordingly, in semi-actuated operation the right of way will normally remain on street A being transferred to street B for a predetermined minimum period in response to actuation of the street B detector WVD. The right-of-way will remain on street B for an additional period if the-re are further actuations of the detector WVD within the maximum limit. However, right-of-way is then retransferred to street A from which it cannot again be transferred before expiration of a minimum period comprising the initial interval, position 5' and a vehicle interval, position 6 in which the minimum timing capacitor QA charges without any discharge or resetting to the flash potential of its associated tube PA.

The independent operation of the trafiic signal controller represented in FIG. 5, having been described, which is similar to its operation as a parent controller in absence of actuation of the auxiliary period timer, it will now be described more fully how the said traific controller of FIG. 5 is used in a traflic control system in coordination with [the auxiliary period timer, the subject to the present invention, in accordance with the present invention.

Line L7 is connected between terminal F and lead 215 which lead is connected in a manner described below to auxiliary period timer. Through lead 215 a call for phase B is registered as described below, while line L6 in FIG. 5 is connected between terminal G and lead 214, which lead is connected to the auxiliary period timer to register a call for phase A, as described below, when the respective circuits to the auxiliary period timer are completed to ground.

In order that the timing of the cycle of the parent controller is stopped during the time of the inserted period, as later described, the switch SW11, which has heretofore been assumed to be closed, is opened, as illustrated in FIG. 5, and the AC. input is connected through lead 219 through certain contacts of the auxiliary period imer and through lead 216 as is completely described below.

By opening or closing the contacts as the case may be, the auxiliary period timer can either open or close the power circuit between lead 219 and lead 216 and thereby control the timing of the parent controller by control of the power operating the transformer XFR. Another method of control of timing shall be discussed hereinafter with reference to FIG. 5a. The above described connections to control the power circuit to the transformer XFR in the parent controller controls the timing in the parent controller and will eficctively increase the time of the cycle of the parent controller, whenever the auxiliary period timer inserts the auxiliary period into the cycle of the parent controller.

Other connections and reactions Within the auxiliary period timer having additional effect on parent controllers will become apparent by the description below.

FIG. 5a illustrates an alternate method or arrangement for external control of the timing of the parent controller during part of the operation of the auxiliary period timer as described.

FIG. 5a in effect represents a modification of a part of FIG. 5, more directly, that part of FIG. 5 in the broken line box in the lower right corner of FIG. 5. With FIG. 5 modified as shown in FIG. 5a, the parent controller of FIG. 5 has its timing power supply circuit connected between the input through line 26' to transformer XFR controlled by a contact TRI of relay TR which relay is externally controlled by the auxiliary period timer instead of having such power connection itself extend externally through the auxiliary period timer. The modification also inverts the action of the means of stop timing, by having the relay TR energized 1.? to interrupt timing power, so that the external control circuit can operate this relay and thus the external circuit will be closed only to stop timing. When the external circuit is open the relay TR is deenergized thus maintaining the contact TR]. closed.

FIG. 6 is a schematic circuit diagram of the preferred embodiment of the non-actuated form of auxiliary period timer. The circuit of the auxiliary period timer as presented in FIG. 6 is composed of two sections, the basic unit, and the plugin jumper assembly unit. The basic unit is that part of the circuit diagram to the right of the broken line BL and that part of the circuit diagram above the female receptacles F1 through F14, but including the female receptacles. The plug-in jumper assembly unit, here illustrated as connected to, or plugged into, the basic unit via male plugs N7, N9, N20 and N12, is shown below the female receptacles of the basic unit. The combination of the basic unit and the plug-in jumper assembly unit connected together as illustrated in FIG. 6 form a non-actuated auxiliary period timer.

The basic unit presented in FIG. 6 may be converted into an actuated auxiliary period timer by merely rcmoving the plug-in jumper assembly unit illustrated in FIG. 6 and inserting into the female receptacles of the basic unit the plug-in relay assembly unit, illustrated in the preferred form in FIG. 7, by plugging the male plugs of the plugin relay assembly unit, illustrated at the top of the circuit diagram of FIG. 7 (labeled M1 through M14 exclusive of M12) into the corresponding female receptacles of the basic unit.

Generally, the non-actuated auxiliary period timer is illustrated with connections to a terminal strip TS at the left of the diagram. The terminal strip TS represents a common junction for the interconnecting lines between the auxiliary period timer and the parent controller. A broken line BL indicates that the terminal strip TS is external to the circuit of the auxiliary period timer.

A positive A.C. supply, on the order of volts for example, is represented by a plus in a circle with a common ground return represented by a minus in a circle. A DC. supply, on the order of volts for example is represented by a plus in a square. A low voltage A.C. supply, on the order of 12 volts for example is represented by a plus in a circle in a square.

A potential divider PDX consisting of several resistors is connected between the DC. supply and the common ground return.

Four relays TSR, RR, LTR and TR, all illustrated as deenergized, individually control the several contacts arranged below the respective relay.

Two potentiometers 35 and 36, each with a terminal labeled PD+ for connection to a point on the potential divider PDX are illustrated just below the potential divider PDX. One potentiometer, as determined by the relay TSR, is selected for controlled charging of the timing capacitor 33 through a circuit including several contacts and a limiting resistor 37. The charging circuit, of which the potentiometers 35 or 36 form a part, is part of an electronic timing circuit which includes a dual triode vacuum tube 39, capacitors 38, 40 and 41, resistors 44, 45, 46 and 37 and relay TR. Although other types of timing circuits and/or methods may be employed with similar effect and efiiciency the preferred embodiment employs this electronic timing circuit. The electronic timing circuit employed herein is similar to that disclosed and claimed by Peter C. Brockett in his application No. 677,993, dated August 13, 1957, and assigned to Eastern Industries, Incorporated, the assignee of the present application. There are no claims made herein under the particular type timing circuit per se.

Indicator lamps 47 and 48, used to indicate which potentiometer 35 or 36 has been selected as part of the charging circuit for the capacitor 33 are illustrated with 13 lamp 48 illuminated and lamp 4'7 extinguished indicating potentiometer 3-5 is connected in the charging circuit.

In the lower right hand section of the diagram are four circles labeled LG, LR, GX and RX. These circles represent signal lamps with signals GK and RX, green and red respectively, associated with the parent controller, as explained below and signals LG and LR, green and red signals respectively associated directly with the auxiliary period timer.

A vehicle detector, represented by a pair of open contacts labeled VD is illustrated below the signals with a switch 50 illustrated above the vehicle detector. The switch 50 may be a second vehicle detector or a pushbutton.

The vehicle detectors herein referred to may be any of the well known type designed to close a pair of contacts. Such vehicle detector may be either pressure or sound sensitive, magnetic, electronic or mechanical, d signed for use above, under or in the surface of the roadbed.

The several signals, the switch 56 and the vehicle detector VD are here illustrated as internal parts for convenience although such parts are external to the circuit of the auxiliary period timer.

Referring momentarily back to 1, the green signals NSG and NSG' re illuminated by the same circuit as signal GX in FIG. 6 and therefore it may be said that signal GX is similar to signals NSG or NSG. The red signals NSR and NSR of FIG. 1 are illuminated by the same circuit as signal RX in FIG. 6 and therefore it may be said that signal RX is similar to signals NSR or NSR. The signals LG and LG of FIG. '1 are similar to the signal LG of FIG. 6 while the signals LR and DR of FIG. 1 are similar to signal LR of FIG. 6. The vehicle detectors NLT and SLT of FIG. 1 are comparable to vehicle detector VD (or switch 50) of FIG. 6.

At the bottom of the circuit diagram in FIG. 6 are fourteen terminals labeled F1 through F14 inclusive, which represents 14 individual female receptacles arranged to receive one of two plug-in assembly units, either/the plug-in jumper assembly here illustrated in FIG. 6 below the female receptacles or, in lieu thereof, to receive the plug-in relay assembly unit illustrated in FIG. 7.

A switch 49, the energizing illustrated in a broken line box 59 is in circuit for the relay TSR. The switch, here illustrated as an internal past for convenience, is external to the circuit and is use-d for remote control of the relay TSR being operated by a time clock, or some master control device, or manually.

A switch 51, with contact 51a closed and contact 511) open is illustrated below the indicator lamps. This switch is physically associated with the potentiometer 35 so that when the adjusting knob of the potentiometer 35 is set in the oil position the contacts of switch 51 are reversed. Full operation of the auxiliary period timer requires the contact 51a of switch 51 closed regardless of the condition of relay TSR or contact of switch 5-1 closed and relay TSR energized. The effects of the reversal of switch 51 on the auxiliary period timer and the parent controller is explained below.

A description of the electronic timing circuit shall now be discussed. The electronic timing circuit is designed to energize the relay TR at the end of a timed period by a rapidly increasing surging-lil e flow of current through the relay from the DC. supply through leads 55 and 56, the coil of relay TR, lead 57, plate 62-, cathode 63 (of tube 39), lead 64, resistor 46 to grounded lead 75.

Normally, when the electronic timing circuit is inactive or when it is timing, prior to the end of its timed period, there is no current flow in the left side of tube 39 between plate 62 and cathode 63 because grid 65 holds this section of the tube biased beyond cut-off. However, under such conditions current is flowing from id the DC. supply through leads 55 and 56, the coil of relay TR, lead 57, resistor 44-, point 67, resistor 45, lead 66 to grounded lead 75. The amount of current flowing in this last described circuit is insufficient to energize the relay TR.

At point 67 a lead 68 is connected to obtain a potential for the grid 70 of the right hand section of tube 39. In the last described circuit the combination of resistors 44 and and the impedance of the coil of relay TR serves as a potential divider with the point 67 being particularly selected so that the potential at point 67 is approximately 62% of the 13.0. input. With such potential applied to the grid 70, plate current will normally flow from the DC. supply through leads and 69', plate 76 and cathode 77 of the right hand section of tube 39, resistor 46 to grounded lead 75.

The left side of tube 39 is normally [held inactive ecause the potential on cathode 63, connected to cathode 77 via load 64, is relatively high so that the bias of this tube section is high in absence of counteracting potential on the grid controlled by timing capacitor 38.

The capacitor 40, connected in shunt with resistor 46 serves to hold the cathode potential relatively steady. The capacitor 41, connected in shunt with resistor 45 normally serves to hold the potential on grid relatively steady.

The capacitor 38 is a timing capacitor which applies any charge thereon to the grid 65, so that as a charge on capacitor 38 increases, the potential applied to the grid 65 increases thereby reducing the cut-off bias of the lefit section of the tube. The timing capacitor 38 is charged from the DC. supply through part of the potential divider PBX to a point PD+ through potentiometer 35, if relay TSR is deenergized so that its contact 80 is closed or through potentiometer 36, if relay TSR is energized so that its contact '81 is closed, through lead 84, contact of relay LTR, contact 86 of relay RR,

' lead 87, resistor37 to capacitor 38.

The amount of time it takes to charge the capacitor '36 sufiiciently to apply a potential on the grid 65 to reduce the bias on the left half of the tube section above cut-off is determined by the amount of resistance in the charging circuit. By adjustment of the otentiometers 35 and 3 6 which are calibrated to vary the period timed by the electronic timing circuit on the order of 500,000

ohms per second for example, each potentiometer may permit a different timed period.

When the charge on the timing capacitor 38 becomes sufiiciently high, the cut-off bias on the left section of the tube 39' is overcome and the plate 62 begins to pass pl-aite current. In very rapid successive reactions the voltage drop across the coil of relay TR is increased which reduces the voltage drop across the potential divider resistors 44 and 4-5. This reduces the potential applied at point 67 and the grid 78. The reduction in the potential applied to the grid 76 reduces the plate current through the right section of the tube 39'. The reduction in plate current of plate 76 tends to reduce tithe cathode potential on both cathodes which causes the left section of the tube to pass additional plate current through plate 62 which current is drawn through the coil of relay TR. With heavier current flow through the left side of the tube 39- the current flow through the resistors 4'4 and 45 is reduced which reduces the potential at point 67 thereby reducing the potential applied to grid 70 thereby cutting off the plate current at plate 76. This results in a rapid surge of plate current through the tube 39 via plate 62 and cathode 63 thus causing the relay TR to become energized. The energization of relay TR indicates the end of the timed interval.

Referring now to FIG. 7, the preferred embodiment of the plug-in relay assembly unit is presented in schematic circuit form. At the top of FIG. 7 labeled M1 through M14, exclusive of M12 a series of male plugs are illus- V trated which plugs are arranged to plug into the corresponding female receptacles, illustrated in FIG. 6, of the basic unit to combine to form an actuated auxiliary period timer.

Three relays DR, XR and LTD are illustrated as deenergized, with their respective contacts arranged beneath each relay. A capacitor 149 is connected across the terminals of the relay DR to make the relay DR a delayed action relay. A double position ganged switch 150/15051, the use of which shall be explained below, is illustrated in its up position with contact 156 closed and 159a open.

Let it now be assumed that the auxiliary period timer, in its actuated form is employed in a trafiic control system at an intersection such as presented in FIG. 1, for example. The plug-in jumper assembly consisting of the male plugs N7 connected to N12 and N9 connected to N19 illustrated plugged into the basic unit in FIG. 6 would now be removed and the plug-in relay assembly unit of FIG. 7 would be plugged into the basic unit of FIG. 6 with the male plugs M1 through M14, exclusive of M12 plugged into the respective female receptacles F1 through F14 with receptacle F12 without an external connection.

Let it further be assumed that signal LG and LR of PEG. 6 represent the signals LG and LG and LR and LR of FIG. 1 and that signals NSG and NSG of FIG. 1 are represented by signal GX of FIG. 6 while signals NSR and NSR of FIG. 1 are represented by signal RX of FIG. 6. Let it also be assumed that the vehicle detectors NLT and SLT of FIG. 1 are represented by vehicle detector VD of FIG. 6.

The connections between the auxiliary period timer and the parent controller will be assumed to be through leads 213, 211, 214, 215, 219 and 216 as illustrated in FIG. 6. The lead 217 will be assumed not connected for the present purposes.

Let it be assumed that the parent controller is at rest in its position 6' of the cam shaft. This is the phase A or street A green rest position. In position 6' a green signal would be displayed to both northbound and southbound trafiic on street A and a red signal to eastbound and westbound trafiic on street B and a red signal to any traffic in the left turn lane, both north and south on street A. This signal display is indicated in periods 5 and 11 of FIG. 2. The lead 211 from the parent controller would be energized from the A.C. input in the parent controller in FIG. 5 through lead cam contact C9 through lead 211 to the junction on the terminal strip TS in FIG. 6 through lead 99, contact 91 of relay LTR, lead 94 to signal GX, the green signal for through md right turn trafiic, both northbound and southbound is illuminated. With the lead 211 energized the relay XR of FIG. 7 is energized via a circuit that may be traced from the lead 211 through the junction on the terminal strip TS in FIG. 6, through leads 90 and 95, female receptacle F5, male plug MS of FIG. 7, lead 96, the coil of relay XR, lead 97 to grounded lead 75, the gounded lead between FIGS. 6 and 7 being joined by female receptacle F14 and male plug M14.

At this time the lead 219 would also be energized from the A.C. input in the parent controller in FIG. 5 through lead 21)" and lead 219 to the junction on the terminal strip TS in FIG. 6, through lead 98, contact 99 of relay RR, contact 161 of relay LTR, lead 104 10 a junction on the terminal strip TS through lead 216 to the parent controller in FIG. 5 through lead L10 to the transformer XFR. This last described circuit is the power supply circuit for the transformer XFR from which the timing power for the parent controller is obtained. When, as will be described below, the auxiliary period timer inserts its period into the cycle of the parent controller and the contact 101 of relay LTR will open, with contact 99 of relay RR closed, to interrupt the power supply to the transformer XFR and stop the timing within the parent controller.

a green signal, to grounded lead 75. Thus r The signal LR, the red signal of the left turn lanes of street A, is illuminated via a circuit from the A.C. supply, represented by a plus in a circle through leads 105, 105 and 107, contact 198 of relay LTR, lead 109, signal LR to grounded lead 75.

To complete the signal display at the intersection of FIG. 1 a return to FIG. 5 is necessary where it will be found that the signal EWR is illuminated by the parent controller from the A.C. input through cam contact C11, signal EWR to grounded lead L2. The signal EWR in FIG. 5 is comparable to the signals EWR and EWR of FIG. 1.

With the auxiliary period timer at rest the parent controller may cycle, as described above, without interference from the auxiliary eriod timer. In position 1 of the parent controller the lead 211 from the parent controller to the terminal strip TS will become deenergized by the opening of cam contact C9 of FIG. 5 and the signal GX of P16. 6 will be extinguished and the relay XR of FIG. 7 will become deenergized. The yellow signal NSY, in FIG. 5, is illuminated to traffic on street A via closure of cam contact C21 in FIG. 5.

In position 2, 3', and 4 of the parent controller, the lead 213 will be energized thereby energizing the relay RR in the auxiliary period timer. The energizing circuit for the relay RR would follow from the A.C. input through lead 20 in FIG. 5, through cam contact C22 to lead 213 to the junction on the terminal strip TS in FIG. 6 through lead 110, the coil of relay RR, lead 113 to grounded lead 75. With the relay RR energized closure of some of its contacts etfect the timing power circuit of the parent controller; the illuminating circuit for the signal LR; the illuminating circuit for the signal RX; a discharge circuit for the timing capacitor 33 and prevents the possible charging of the capacitor 38.

The contact 99 of relay RR is opened and contact 114 is closed so that the timing power circuit of the parent controller is completed from the A.C. input of the parent controller in FIG. 5 through lead 20', lead 219 to the junction on the terminal strip TS in FIG. 6, through lead 98, contact 114 of relay RR, lead 104 to the junction on the terminal strip TS through lead 216 to the parent controller in FIG. 5, lead L10 to the transformer XFR.

With closure of contact 115 of relay RR a circuit to shunt contact 1&3 LTR is completed so that if the relay LTR would become energized to open its contact 108 the signal LR would remain illuminated via a circuit that may be traced from the A.C. input through lead 105, contact 115 of relay RR, lead 116, lead 169 to signal LR to grounded lead 75.

The illuminating circuit for the signal RX may be traced from the A.C. input through lead 165, lead 106, contact 11 7 of relay RR, lead 118, to signal RX to grounded lead 75.

A discharge circuit for the timing capacitor 38 is completed from the charging side of the capacitor 38, through resistor 37, lead 37, contact 119 of relay RR, lead 120 to grounded lead 75, and through leads 66 and 71 to the ground side of capacitor 33. If there was any charge on the capacitor 3 8 such charge would be dissipated through the discharge circuit so that the charging of the capacitor 38 would begin with the charge on the capacitor at substantially zero, with respect to ground. The charging circuit for the capacitor 38 is maintained open at open contact 86 of relay RR.

In positions 5 and 6 of the parent controller, the lead 211 is energized and the lead 213 is deenergizcd which causes the relay RR to become deenergized and the relay XR (FIG. 7) to become energized and extinguish the signal RX and illuminate the signal GX, the circuit having been previously traced.

With the parent controller in its position 6" and the auxiliary period timer at rest, let it now be assumed that a vehicle crosses over one of the vehicle detectors in one of the left turn lanes. With closure of the contacts of the vehicle detector VD a circuit to energize the relay LTD (FIG. 7) is completed from the low voltage A.C. input (FIG. 6) through lead 123, contact 124 of relay TR, lead 125, female receptacle F11, male plug M11 of FIG. 7, lead 126, the coil of relay LTD, lead 127, lead 128, lead 129, contact 150 of switch Bil/150a, lead 130., lead 131, male plug M7, female receptacle F7 of FIG. 6, lead 133, contact 51a of switch 51, contact 134 of relay TSR, lead 135, female receptacle F9, male plug M9 of FIG. 7, lead 136, male plug M13, female receptacle F13 of FIG. 6, lead 137, through vehicle detector contacts VD to grounded lead 75. When the vehicle crosses over, and eventually off of the vehicle detector, the contacts VD will open to break the energizing circuit just recited, however, the relay LTD does not become .deenergized since the relay LTD locks-in over its own contact 138. The lock-in circuit may be traced from the low voltage A.C. input through lead 123, contact 124 of relay TR, lead 125, female receptacle F11, tmale plug M11 of FIG. 7, lead 126, the coil of relay LTD, lead 127, contact 138 of relay LTD to grounded lead 75.

The relay LTD closes its contact 139 and a circuit to energize the relay DR of FIG. 7, is completed from the DC. input in FIG. 6 through lead 55, female receptacle F1, male plug M1 of FIG. 7, lead 143, resistor 141 to capacitor 140, which capacitor charges and thus delays the energization of relay DR. When the capacitor 149 is charged (after approximately 40 to 60 milliseconds, for example) the relay is energized from the charged side of capacitor 140 through lead 144, the coil of relay'DR, lead 145, contact 139 of relay LTD, lead 146, contact 147, of relay XR, lead 148, lead 149 to grounded lead 75.

While the capacitor 140 is charging and before the relay DR becomes energized a circuit is completed to the parent controller to supply a ground connection for the relay DR (shown in FIG. thereby causing a phase B call to be completed to the parent controller so that the parent controller may be advanced in its cycle so that the parent controller may move into position to have the auxiliary period'timer insert its timed period into the cycle of the parent controller.

The circuit producing the phase -B call by energizing the relay DR (FIG. 5) may be traced from the A.C. input in FIG. 5 through lead 20" to the coil of relay DR through terminal F, lead L7 to lead 215, to the junction of the terminal strip TS in FIG. 6, lead 1533, contact 154 of relay RR, female receptacle F4, male plug M4 in FIG. 7, lead 155, contact 156 of relay DR, lead 157, contact 158 of relay LTD to grounded lead 75. When the relay DR of FIG. 7 becomes energized the contact 156 of relay DR will open to prevent any additional phase B calls being sent by the auxiliary period timer. This prevents any extension of the phase B vehicle interval of the parent controller. I

With a call for phase B in the parent controller the parent controller moves into its position 1, as previously described.

With the parent controller in position 1' the lead 211 is deenergized and the relay XR becomes deenergized. The deenergization of relay XR opens contact 147 of relay XR which contact .is in the energizing circuit for relay DR. Relay DR becomes deenergized and releases slowly because of capacitor 140 which discharges through the coil of relay DR,

When the parent controller advances into its position 2 the lead 213 becomes energized so that the relay RR becomes energized via a circuit previously described. With relay RR then energized a circuit is completed to energize the relay DR in FIG. 7 from the DC. input in FIG. 6 through lead 55, receptacle F1 to male plug M1 in FIG. 7 through lead 143, resistor 141 to charge capacitor 140. When capacitor 140* becomes charged the relay DR becomes energized through a circuit that may be traced from the charged side of capacitor 140, through lead 144, the coil of relay DR, lead 145, contact 139, of relay LTD,

lead 146, lead 159, male plug M3, to FIG. 6 and female receptacle F3, contact 160 of relay RR, lead 161 to grounded lead 75.

Between the energization of relay RR of FIG. 6 and relay DR of FIG. 7 a circuit is completed to supply a ground connection for the relay ER of the parent controller in FIG. 5 so that a call is put in to return the parent controller to phase A after phase B. This call circuit may be traced from the A.C. input in the parent controller in FIG. 5 through lead 20', the coil of relay ER, terminal G, lead L6 to lead 214 which is connected to the terminal strip TS in FIG. 6 through lead 164, contact 165 of relay RR, con-tact 166 of relay LTR, lead 167, female receptacle F6 to FIG. 7, male plug M6, lead 168, contact 169 of relay LTD to grounded lead 75.

With the parent controller in its position 2., 3', and 4' the relay R-R will remain energized and, as previously described when the relay RR is energized, the signal RX is illuminated through a circuit previously described. With both relays RR and DR now energized a circuit is completed to energize the relay LTR from the A.C. input in FIG. 6 through lead 105, lead 170, the coil of relay LTR, lead 172, contact 174, point 175, lead 176 to female receptacle F10 to FIG. 7, male plug M10, lead 177, contact *178 of relay LTD, lead 179, contact 1811 of relay DR, lead 183, lead 149 to grounded lead 75'. When the relay LTR is energized it closes its contact 173 which shunts contact 174 of relay R-R from the lead 172 to point 175 so that the relay LTR locks in through its own contact 173. Contact 85 of relay LTR is closed to prepare the charging circuit for the capacitor 38; contact 184 of relay LTR is also closed to shunt contact 117 of relay RR when contact 117 opens as relay RR becomes deenergized thus the signal RX will remain illuminated; contact 1118 opens so that the signal LR will be extinguished as contact 115 of relay RR opens; contact 101 is opened so that the timing power supply circuit of the parent controller will be opened when the relay RR becomes deenergized and opens its contact 114 and closes its contact 99; and contact 91 of relay LTR opens to prevent the illumination of signal GX when the lead 211 becomes energized while contact 185 of relay LTR closes to prepare a circuit for the illumination of signal LG.

When the parent controller advances into its position 5 the lead 213 becomes deenergized as cam contact C22 of FIG. 5 opens. The relay RR becomes deenergized and opens its contact 119 and closes its contact 86 thus completing the charging circuit for the capacitor 38 as previously described.

The contact 117 of relay RR opens but is shunted by closed contact 184 of relay LTR to maintain the illumination of signal RX. The contact 99 of relay RR is closed but the power supply circuit for the parent timing 'is broken at open contact 101 of relay LTR.

With the power supply circuit now open the timing within the parent controller stops and the parent controller is held suspended while the auxiliary period timer controls the signals giving right-of-way at the intersection. The contact 160' of relay RR, in the energizing circuit for the relay DR is open but the relay XR is now energized since the lead 211 from the parent controller is energized thus energizing the relayXR which relay closes its contact 147 to complete a parallel circuit to ground for the relay DR as previously described.

With the lead 211 energized the signal LG is illuminated by power applied through the energized lead 211 through the junction on the terminal strip TS, lead 90, contact 185 of relay LTR, lead 188, signal LG to grounded lead '75.

At the termination of the period as determined by the charge in the capacitor 38 the tube 39 will pass plate our rent between plate -62 and cathode 63 and energize the relay TR. The relay TR will open its contact 124 and break the energizing circuit for the relay LTD of FIG. 7

thereby causing the relay L'ID to become deenergized.

139 to cause the The relay LTD will open its contact 178 relay DR to become deenergized, and open its contact to cause the relay LTR to become deenergized.

With the relay LTR deenergized the contact 185 opens to extinguish signal LG and contact 91 closes to illuminate signal GX from energized lead 211. The contact 187 of relay LTR opens and contact 101 of relay LTR closes to complete the power supply circuit for the timing power of the parent controller. Contact 184 of relay LTR opens to extinguish the signal RX while contact 108 closes to illuminate the signal LR through circuits as previously described.

When the relay LTR becomes deenergized the contact 85 opens to interrupt the charging circuit of the capacitor 38. Prior to deenergization of relay LTR the capacitor 38 discharges somewhat through the tube 39 from the grid 65 to cathode 63, lead 64, through resistor 46 through ground lead 75, lead 66, lead 71 to the capacitor 38 while the left section of tube 39 was conducting. The bias of the tube section including plate 62, grid 65 and cathode 63 is increased to cutoff and the current flow through this section is blocked. The right section of the tube including plate 76, grid 70 and cathode 77 resumes normal current flow and the flow of current through the relay TR is reduced thereby deenergizing the relay TR.

With relay TR deenergized the contact 124 closes and the auxiliary period timer now clear of all calls awaits further calls of trafiic.

The operation of the actuated auxiliary period timer has been considered with the switch 150/ 150:: in its up position with contact 150 closed and 150a open. With the switch 150/ 150a in its up" position it has been seen that the only call via the vehicle detector VD that efiects the parent controller is the call that energizes the relay LTD of FIG. 7. Any subsequent call, while the relay LTD is energized is blocked in the circuits of the auxiliary period timer. If, when the switch 150/15011 is in its up position a call is received via the vehicle detector VD when the parent controller is in its position or 6 the call will be remembered by the auxiliary period timer, by causing the relay LTD to become energized thus the up position may be called the memory position.

Let it now be assumed that the switch 150/ 150a is in its down position with contact 150 open and contact 150a closed.

The traffic control system illustrated in FIG. 3 is a system that could employ switch 150/ 1504 in its down position and obtain the desired results. The signals LG and LR of FIG. 6 would not be used on such intersection control as shown in FIG. 3. The circuits would merely be disconnected at leads 188 and 109 of FIG. 6. Further, the signals GX and RX would be similar to the signals GS and RS respectively of FIG. 3, and signals GS and RS would be connected to the parent controller through leads 211 and 213 respectively, all as shown in FIG. 3. The single vehicle detector ND of FIG. 3 would be comparable to the vehicle detector VD of FIG. 6 while the vehicle detector SD of FIG. 3 would be comparable to vehicle detector NVD of FIG. 5.

Under this type of arrangement a call via actuation of the vehicle detector VD of FIG. 6 (or ND of FIG. 3) will effect the auxiliary period timer at all times except when the parent controller is in its positions 5 and 6'. During positions 5' and 6' of the parent controller the lead 211 would be energized to energize the relay XR of FIG. 7 through a circuit previously described. With relay XR of FIG. 7 energized its contact 189 is opened and its contact 190 is closed, so that an actuation on the vehicle detector VD of FIG. 6 (or ND of FIG. 3) would be completed to the parent controller supplying a ground connected from ground lead 75 through the closed contacts of vehicle detector VD, lead 137, female receptacle F13 (all in FIG. 6) to FIG. 7 through male plug M13, lead 136, male plug M9 to FIG. 6 through female recep- 20 tacle F9, lead 135, contact 134 of relay TSR if relay T SR is deenergized, contact 51a to lead 133, or if relay TSR is energized through contact 191 of relay TSR to lead 133 to female receptacle F7 to FIG. 7 through male plug M7, lead 131, lead 132, contact 190 of relay XR, lead 192, contact 150a, lead 194 to junction 195, male plug M2 to FIG. 6 through female receptacle F2, to lead 164 to a junction on the terminal strip TS to lead 214 which lead is connected to the parent controller of FIG. 5 as previously described, thereby putting a call into the parent controller for phase A. If the parent controller were in its position 6 at the time the call is received the call would affect the parent controller and act to extend the vehicle interval as if the call had been received from the vehicle detector SD. Such call or calls during position 6' have the efiect of extending the vehicle interval to the maximum limit as previously described in connection with independent operation of the parent controller.

If, on the other hand, an actuation of the vehicle detector VD of FIG. 6 (or ND of FIG. 3) should occur when the parent controller is in its positions 1', 2, 3 or 4' such actuations would attect the auxiliary period timer by energizing the relay LTD in FIG. 7, if such relay were in a deenergized condition. Such energizing circuit may be traced from the low voltage A.C. input in FIG. 6 through lead 123, contact 124 of relay TR, lead 125 to female receptacle F11 to FIG. 7 through male plug M11, lead 126, the coil of relay LTD, lead 127, lead 128, contact 189 of relay XR, lead 132, lead 131 to male plug M7 to FIG. 6 through female receptacle F7, lead 133, contact 51a of switch 51, contact 134 of relay TSR, lead 135, female receptacle F9 to FIG. 7 through male plug M9, lead 136 to male plug M13 to FIG. 6 through female receptacle F13, lead 137, vehicle detector contact VD to grounded lead 75'.

Additional calls on the vehicle detector VD of FIG. 6 (or ND of FIG. 3) do not effect the auxiliary period timer once the relay LTD (of FIG. 7) has become energized.

When the parent controller moves into its position 5' and the auxiliary period timer has registered a call, the timing power circuit of the parent controller is opened as previously described, and the signal GS, connected directly to the parent controller through lead 211, as shown in FIG. 3, -will be illuminated to give right-of-way to northbound traffic on street C while the signal RS of FIG. 3 which is comparable to signal RX of FIG. 6, is illuminated to hold the southbound trafiic on street C. At the termination of the timed period the signal RX (of FIG. 6) or RS (of FIG. 3) will be extinguished and signal GX (of FIG. 6) or GS (of FIG. 3) will be illuminated.

The relay TSR of FIG. 6, may be used for remote selection of the timing potentiometers 35 or 36. The switch 49 may be controlled locally or remotely by manual means or by a time clock or some master control apparatus for selection between the two potentiometers 35 and 36. When the relay TSR is deenergized so that contact is closed to place potentiometer 35 in the charging circuit of the capacitor 38, the contact 198 is also closed to complete the illuminating circuit for the indicator lamp 48 from the A.C. input through lead 105, lead 199, lamp 48, contact 198 of relay TSR, lead 71, lead 66 to grounded lead 75.

If the energizing circuit for the relay T SR should he completed by closure of the switch 49, the circuit, complete from an A.C. supply, for example as shown in FIG. 6 through lead 105, lead 200, the coil of relay TSR, switch 49 to grounded lead 75, would cause the relay TSR to become energized. The contact 80 of relay TSR would open and contact 81 of relay TSR would close. This reversal of contacts would eliminate the potentiometer 35 from the charging circuit of the capacitor 38 and insert potentiometer 36 into the charging circuit of ca- 21 pacrtor 38. The contact 198 of relay TSR would open extinguishing the lamp 48 and contact 197 of relay TSR would close to complete a circuit to illuminate the lamp 47 via a circuit that may be traced from the A.C. input through lead 105, lead 199, lamp 47, contact 197 of relay TSR, lead '71, lead 66 to grounded lead 75.

With the switch 51 in contact with contact 51a it is obvious that a vehicle actuation across vehicle detector VD could be completed to energize the relay LTR regardless of the condition of the relay TSR, through either contact 134 or 191.

If, however, the adjusting knob on the timing dial of the potentiometer 35 were turned to the oif-position the switch 51, which is actually located at the end of the shaft of potentiometer 35, would be reversed in position and would then be connected to the contact 51b. With the relay TSR deenergized so that its contact 134 is closed, an actuation of the vehicle detector VD would not energize the relay LTD but would supply a ground to the lead 214 from the parent controller the circuit being traced from the grounded lead 75 back through the contacts VD, lead 137, to female receptacle F13 to FIG. 7 through male plug M13, lead 136 to male plug M9 to FIG. 6 through female receptacle F9, lead 1135, contact 134 of relay TSR, contact 51b of switch 51, lead 52, female receptacle F8 to FIG. 7 through male plug M8, lead 53, through point 195, male plug M2 to FIG. 6 through female receptacle F2, lead 164 to a junction on the terminal strip TS to lead 214 to the parent controller in FIG. to apply a ground connection to the detector relay ER which is, in effect, a call to phase A. Since the relay LTD did not become energized the relays DR and LTR also remain tdeenergized and although the parent controller receives a call for phase A the auxiliary period timer does not insert an auxiliary period into the cycle of the parent controller. Such actuation would be similar to an actuation of the vehicle detector NVD of FIG. 5 and cycle the parent controller if such controller was not then in a position giving phase A the right-of-way. v

Attention is now directed to the preferred non-actuated embodiment of the auxiliary period timer as disclosed in the circuit diagram in FIG. 6. It will be noticed that several of the leads terminating with the female receptacles are interconnected by the plug-in jumper assembly. The receptacle F7 is connected to receptacle F12 through male plug N7, lead 205 and male plug N12 and receptacle F9 is connected to receptacle F10 through male plug N9, lead 206 and male plug N10.

The non-actuated form of auxiliary period timer inserts a period into the cycle of a parent controller, as does the actuated form, but the parent controller is not itself cycled by the action of the non-actuated auxiliary period timer. The call circuits leading into the parent controller placing a ground on leads 214 and 215 (as previously explained) are not connected to the plug-in assembly which forms part of the non-actuated period timer nor is the detector circuit of the basic unit connected through the plug-in jumper assembly.

The relay RR is energized in the non-actuated auxiliary period timer each time the parent controller moves into its position 2', the circuit being similar to that described relative to the actuated form of auxiliary period timer. 9

With the relay RR energized, the relay LTR is energized through a circuit that may be traced from the A.C. supply through lead 105, lead 170, the coil of relay LTR, lead 172, contact 174 of relay RR, point 175, lead 176, receptacle F10, male plug N10, lead 206, male plug N9, receptacle F9, lead 135, contact 134 of relay TSR, if relay TSR is deenergized, contact 51a of switch 51 to lead 133, or if relay TSR is energized through its contact 191 to lead 133, receptacle F7, male plug N7, lead 205, male plug N12, receptacle F12, lead 207, contact 208 of relay TR, lead 71, lead 22 66 to grounded lead 75. When the relay LTR becomes energized, it closes its contact 173 to shunt contact 174 of relay RR from the lead 172 to point 175 thereby locking-in through its own contact.

It will be noticed that the energizing circuit for the relay LTR, when relay TSR is deenergized, follows through switch '51, if the potentiometer 35 were turned down and the switch 51 were turned 01% so that switch 51 would be in contact with contact 51b then the energizing circuit for the relay LTR would not be complete since lead 52, which is connected to contact 51b of switch 51 is not connected to any external circuit at receptacle F8.

With the relay LTR energized the timing power circuit of the parent controller would be interrupted, as previously described, relative to the actuated form of auxiliary period timer when the relay RR becomes deenergized (in posit-ion 5 of the parent controller).

The timed period would be inserted by the nonactuated auxiliary period timer, into the cycle of the parent controller and at the end of the period the relay TR would be energized, all as previously described.

With the energization of the relay TR its contact 208 is opened to open the energizing circuit of the relay LTR. The relay LTR becomes deenergized and the timing power supply circuit for the parent controller is again completed at contact 101 of relay LTR.

The relay TR becomes deenergized and closes its contact 208 so that when the relay RR is again energized the energizing circuit for the relay LTR will be completed.

The changeover from the actuated form to the nonactuated form of auxiliary periodytimer can be accomplished by removing the plug-in relay assembly (illustrated in FIG. 7) and inserting the plug-in jumper assembly without any change of wiring.

Although the description above is described relative to the use of one auxiliary period timer, actuated'and non-actuated in combination with a full actuated twophase trafiic controller, as parent controller, such description is not meant to limit the use of an auxiliary period timer to such combination.

An actuated auxiliary period timer or a non-actuated auxiliary period timer [may be used in association with a full actuated or a semi-actuated trafific controller, on either of its phases, or a full-actuated traffic controller operated as a semi-actuated controller, or a non-actuated traflic controller. The type of traffic controller, either actuated :or non-act uated, does not change or control the type of auxiliary period timer, either actuated or non-actuated, used in association with such trafiic controller.

Attention is now directed to FIG. 5a, the alternate method of control of parent timing. FIG. 5a thusj illus trating ta modification of the part of FIG. 5 in closed, broken line box in the lower night corner, is presented with switch SW11 closed, relay TR deenergized and contact TRl of relay TR closed completing a circuit from the A.C. input through line 20 .to'closed switch SW11,

closed contact "PR1 to line L10 to transformer XFR. In

FIG. 5a the lead 219 is not a part of the parent controller timing circuit but is instead an output of the parent controller into the auxiliary period timer to be used for the 'energization of the relay TR with the circuit following through contacts of the auxiliary period timer to lead 217 to the relay TR to ground.

The method of control of the timing used by the connections as shown in FIG. 5 requires certain relays in the auxiliary period timer to be energized to open their contacts and open the circuit between input 20" which is connected to the auxiliary period timer via lead 219 and lead 216 which is connected to the line L10 tothe transformer XFR. In such case, the contacts in the control circuit through the auxiliary period timer would normally be closed and open only to stop the timing of the parent controller. When the alternating method, as shown in FIG.

a, is used to control the timing in the parent controller in lieu of the method illustrated in the broken line box in FIG. 5, the lead 219 serves as an output line of the parent controller for external control of relay TR by connection to lead 217 to energize relay TR which relay when energized opens its contact TR1 to interrupt the timing power supply circuit of the parent controller. Such energization of the relay TR requires completion of the energizing circuit within the auxiliary period timer to effectively stop the timing of the parent controller. Thus the external circuit within the auxiliary period timer would normally have an open circuit and normally keep the relay TR deenergized.

When such timing control method as illustrated in FIG. 5a is employed, the lead 219 of the FIG. 5a (which would now be part of FIG. 5) s connected between the AC. input lead of FIG. 5a (FIG. 5) and the terminal strip TS of FIG. 6. The normally open contact 187 of relay LTR of FIG. 6 maintains the open energizing circuit for relay TR of FIG. 5a. When the relay LTR is energized, during the inserted interval of the auxiliary period timer, the energizing circuit for the relay TR is completed from the AC. input in FIG. 5 through lead 20, lead 219 to FIG. 6 to terminal strip TS, lead 98, contact 99 of relay RR, contact 187 of relay LTR, lead "196 to terminal strip TS, lead 217 to FIG. 5 to relay TR to ground. The relay thus energized would open its contact TR1 and open the timing power supply circuit of the parent controller.

The preferred form of auxiliary period timer, both actuated and non-actuated, provides for both forms of timing control of parent timing, as described.

Although the description above, of the actuated form, related to an actuation of the vehicle detector associated with the auxiliary period timer while the parent controller was at rest, it is obvious that such actuation may occur at any time during the cycle of the parent controller. If such actuation, to operate the auxiliary period timer, would occur when the parent controller is in its phase B positions (position 2', 3 or 4'), a call to phase B would not be completed to the parent controller because of open contact 154 of relay RR in the phase B call circuit. However, the subsequent phase A call would be the same as previously described.

It the switch 150/1501: were in its down position (contact 150 open and contact 150a closed) and an actuation on the vehicle detector associated with the auxiliary period timer were received while the parent controller is in its position 5' or 6', such actuation would, as previously explained, effect the parent controller, not the auxiliary period timer. However, it should be noted that under such circumstance a phase B call to the parent controller would not be completed since the relay XR of the auxiliary period timer would be energized and would thus prevent the energization of relay LTD. With the relay LTD remaining deenergized its contact 158 in the phase B call circuit would remain open.

It will be obvious to those skilled in the art that numerous combinations of usage, too numerous to be individually mentioned here, are possible because of the great versatility and flexibility of the auxiliary period timer. In considering the many features, including the variation of the time of the auxiliary period, the remote selection between locally adjusted time controls, the fact that remote elimination or inclusion of such period is possible, in both the actuated and non-actuated forms, the fact that the actuated form may produce either an extension effect on the parent controller or a memory effect on the auxiliary period timer itself, via actuation of the vehicle detector associated with the auxiliary period timer, it is obvious that the many possible combinations are inherent in the auxiliary period timer itself without the necessity of employing different types of trafiic controllers, as parent controllers to obtain the variety of trafiic control systems.

Although the preferred embodiment of the device has been described and illustrated,

including some of the 24 various forms, it will be understood that various changes in the form, details and arrangements of parts, combinations thereof and mode of operation and usage may be made without departing from the spirit of the invention, Within the scope of the appended claims.

We claim:

1. In a traflic control system for the intersection of a plurality of roads at least one of which has two approaches from substantially opposite directions and having the usual stop and go signals for the respective roads including a set of such stop and go signals for each of said two approaches, said system also having a primary trailic signal controller for operating said signals through the usual traffic control signal cycle including go periods in sequence for the respective roads and including one period for normally operating the go signals for both of said two approaches and the stop signals for the other road; an auxiliary controller for cooperating with said primary controller to interrupt temporarily the normal operation of the go signals to one of said two approaches at the beginning of their go period and to hold the stop signal on said one approach of said two approaches while allowing operation of the go signal on the other approach of said two approaches to provide an advance green period for said other approach, said auxiliary controller including means for timing said advance green period and for temporarily replacing the timing of said primary controller, said timing means including a plurality of individual manually adjustable timing controls and means adapted for remote control for selecting one or another of said timing controls alternatively to be effective for such timing for said advance green period.

2. A combination as in claim 1, and including indicator signal means for showing which of said plurality of timing controls is effective for such timing.

3. A combination as in claim 1, and including a manually controlled selective device for preventing said auxiliary controller from so providing said advance green period when a desired one of said plurality of timing controls is selected, whereby the insertion or omission of the advance green period maybe remotely controlled.

4. A combination as in claim 1, and which includes tratfic actuated means for controlling the operation of said auxiliary controller to so insert said advance green period only in response to traffic actuation thereof.

5. A combination as in claim 1, and which includes traffic actuated means for the approach to which the advance green is to be accorded for controlling the insertion of said advance green period by said auxiliary controller in response to traflic actuation, and manually controlled selective means for alternatively connecting said tr-aific actuated means to so control said auxiliary controller and connecting said traflic actuated means directly to prolong the go period of the primary controller for said last named approach.

6. An auxiliary period timer for operation with a primary traffic signal controller for inserting a timed auxiliary signal period in the signal cycle of said primary controller, said signal period including a go signal operated in one direction and a stop signal operated in the opposite direction at the beginning of the normal period for operation of go signals in both said one direction and said opposite direction, when operated therefor, said period timer including a trafiic actuated relay means plugjack mounted therein for so operating said auxiliary period timer for providing said signal period in response to traffic actuation, and an auxiliary plug-jack connection means for replacement of said traffic actuated relay means for so operating said auxiliary period timer for providing said signal period cyclically in said signal cycle without traffic actuation.

7. An auxiliary period timer as in claim 6 and including a plurality of individually adjustable timing means for timing said auxiliary signal period when selected, and electromagnetic means adapted for remote control for selection of a desired one at a time of said individually adjustable timing means .for providing ditferent timing at selected times.

8. An auxiliary period timer as in claim 7, and including means associated with one of said adjustable timing means and manually settable for effectively omitting said auxiliary period from the signal cycle when said one timing means is selected for control of said auxiliary period timer.

9. An auxiliary period timer for operation with a primary trafiic signal control er having a cycle of trafiic signal periods and, said auxiliary period means controlled by said primary controller for operating said timer to interrupt the normal said cycle of said primary controller and insert an auxiliary signal period at a particular part of said cycle, a plurality of individually adjustable timing means for superseding temporarily the operation of said primary controller and for timing said auxiliary signal period when selected, and means for remote control for selection of a desired one at a time of said individually adjustable timing means, and means individually associated with said timing means by said selecting means for indicating which of said timing means is so selected for such timin 10. An auxiliary period timer as in claim 9, and in which said means controlled by said primary controller for so operating said auxiliary period timer for inserting said auxiliary signal period includes a circuit including plug-jack connection terminals in said timer requiring cross connection for so operating said timer, and cooperating plug-jack means for providing said cross connection.

11. An auxiliary period timer as in claim 10 and in which said cooperating plug-jack connection means includes optional first alternate means for direct crossconnection for insertion of said auxiliary period cyclically in the cycle of said primary controllers and second alternate means including relay means for providing said cross connection in response to actuation by traflic controlled by said auxiliary signal period, whereby one or the other of said alternate means may be employed to'convert from direct non-actuated control of insertion of said auxiliary period to traffic actuated control of such insertion.

12. An auxiliary signal controller for providing a timed signal period in cooperation with and in a particular part of the signal control cycle of a primary traffic signal controller providing successive go signal periods for operation of traffic signals for interfering trafiic movements and with the usual corresponding stop signal periods in connection therewith, said primary controller having output circuits for operation of the respective go and stop signals for providing normally in its cycle the respective go and stop signal periods and having a timing control circuit for timing such periods, said auxiliary controller including input circuit means and first relay means connected thereto for connection to one of said stop signal control output circuits of the primary controller for control of said first relay means, further input circuit means in said auxiliary controller for connection to a go signal control output circuit in said primary controller for a traffic movement controlled by said last named stop signal control output circuit, second relay means and input circuit means therefor in said auxiliary controller and including a [contact of said first relay means for control of said second relay means, output circuit means in said auxiliary controller for operation of a desired stop signal for said timed signal period and including contacts of said first and second relay means for control of said last named output circuit for operation of said desired stop sign-a1, [further output circuit means in said auxiliary controller and including a contact on said second relay means for connecting said further output circuit means to said further input circuit means for operation of a desired go signal when said further input circuit means is timer including 26 controller except during said rtimed signal period, timing means in said auxiliary con troller for timing said timed signal period and having an operating circuit for said timing including further contacts of said first and second relay means, and said timing means having means operated at the end of its timing of said timed signal period for controlling operation of said second relay means for reversing its contacts to switch [from said desired stop signal controlling output circuit to said further desired go signal controlling output circuit and to stop its timing, and additional circuit means in said auxiliary controller including additional contacts of said first and second relay means for connection with said timing control circuit of said primary controller to stop the timing of said primary controller during the timed signal period of said auxiliary controller and to permit the timing of said primary controller to continue at other times.

13. An auxiliary signal controller as in claim 12, and in which said timing means in said auxiliary controller includes a plurality of timing adjustment means, and additional realy means adapted for external control for selection between said timing adjustment means for effecting the timing of its timed signal period.

14. An auxiliary signal controller as in claim 13, and including indicator means and circuit means therefor including contacts on said additional relay means for selectively operating said indicator means to indicate which of said timing adjustment means is effecting said timing.

='l5. An auxiliary signal controller as in claim 14, and including switch means associated with one ofsaid timing adjustment means for selectively connecting and disconnecting said second relay means for permitting its such operation and preventing its such operation, whereby said timed signal period of said auxiliary controller may be eifectively permitted in the signal cycle or omitted therefrom by external control along with selection of the associated timing adjustment means.

16. An auxiliary signal period controller as in claim 12 and in 'Which the operating circuit means for said second relay means includes output and input terminal connections in said auxiliary controller and a removable cross-connection means for connecting between the last mentioned output and input terminal connections.

17. An auxiliary signal period controller as in claim 12 and in which the operating circuit means for said second relay means includes output and input terminal connections in said auxiliary controller and a removable cross-connection means for connecting between the last mentioned output and input terminal connections, and further cross-connection means for substitution for the first cross-connection means and including further relay means for controlling operation of such second relay means in response to actuation by traflic in a trafiic movement permitted to proceed during said timed signal period of said auxiliary controller.

18. An auxiliary signal period controller as in claim 16 and further said cross-connection means including further relay means for controlling operation of said second relay means in response to actuation by traific in a trail-1c movement permitted to proceed during said timed signal period of said auxiliary controller, and said auxiliary controllerhaving a terminal for trafiic actuated device, and a corresponding connecting terminal in said cross-connection means for connecting said traffic actuated, device to said further relay means for such traflic actuated control of the latter.

19. An auxiliary signal period controller as in claim 12 and in which said primary controller is traflic actuated, and said auxiliary controller includes traific actuated means for controlling operation of said second relay means for so prowiding said timed signal period, and timed relay means controlled by said last mentioned traffic actuated means for simulating trafiic actuation of energized by the primary connection of an external 27 said primary controller -to cause it to proceed to said par- 2,133';157 ticular part of its cycle. 2,750,576 2,834,001 References Cited 1n the file of thls patent 2,883,643 UNITED STATES PATENTS 5 2,883,644 2,105,443 Renshaw Jan. 11, 1938 2,883,645

28 Turner Oct. 11, 1938 Beaubien June 12, 1956 Wilcox May 6, 1958 Du Vivier Apr. 21, 1959 Barker Apr. 21, 1959 Du V-ivier Apr. 21, 1959

Claims (1)

1. IN A TRAFFIC CONTROL SYSTEM FOR THE INTERSECTION OF A PLURALITY OF ROADS AT LEAST ONE OF WHICH HAS TWO APPROACHES FROM SUBSTANTIALLY OPPOSITE DIRECTIONS AND HAVING THE USUAL STOP AND GO SIGNALS FOR THE RESPECTIVE ROADS INCLUDING A SET OF SUCH STOP AND GO SIGNALS FOR EACH OF SAID TWO APPROACHES, SAID SYSTEM ALSO HAVING A PRIMARY TRAFFIC SIGNAL CONTROLLER FOR OPERATING SAID SIGNALS THROUGH THE USUAL TRAFFIC CONTROL SIGNAL CYCLE INCLUDING GO PERIOD IN SEQUENCE FOR THE RESPECTIVE ROADS AND INCLUDING ONE PERIOD FOR NORMALLY OPERATING THE GO SIGNALS FOR BOTH OF SAID TWO APPROACHES AND THE STOP SIGNALS FOR THE OTHER ROAD; AN AUXILIARY CONTROLER FOR COOPERATING WITH SAID PRIMARY CONTROLLER TO INTERRUPT TEMPRARILY THE NORMAL OPERATION OF THE GO SIGNALS TO ONE OF SAID TWO APPROACHES AT THE BEGINNING OF THEIR GO PERIOD AND TO HOD THE STOP SIGNAL ON SAID ONE APPROACH OF SAID TWO APPROACHES WHILE ALLOWING OPERATION FO THE GO SIGNAL ON THE OTHER APPROACH OF SAID TWO APPROACHES TO PROVIDE AN ADVANCE GREEN PERIOD FOR SAID OTHER APPROACH, SAID AUXILIARY CONTROLLER INCLUDING MEANS FOR TIMING SAID ADVANCE GREEN PERIOD AND FOR TEMPORARILY REPLACING THE TIMING OF SAID PRIMARY CONTROLLER, SAID TIMING MEANS INCLUDING A PLURALITY OF INDIVIDUAL MANUALLY ADJUSTABLE TIMING CONTROLS AND MEANS ADAPTTED FOR REMOTE CONTROL FOR SELECTING ONE OR ANOTHER OF SAID TIMING CONTROLS ALTERNATIVELY TO BE EFFECTIVE FOR SUCH TIMING FOR SAID ADVANCE GREEN PERIOD.

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