Патент USA US2126614код для вставки
Aug. 9, 1938. F. J. BUECHEI., .JR 2,126,614 AUTOMATIC TRAFFIC SIGNAL SYSTEM Filed May 2, 1923 3 Sheets-Sheet 1 Aug. 9, 1938. F. J. BUECHEL, JR 2,126,614 AUTOMATICy TRAFFIC SIGNAL SYSTEM Filed May 2, 192s " s sheets-sheet 2 Aug. 9, 1938. ` F. -J. BUECHEL, JR _ AUTOMATIC TRAFFIC SIGNAL 2,126,614 SYSTEM Filed May 2, 1925 5 Sheets-Sheet 3 7 Franci @Hiob/wan Patented Aug. 9, 1938 2,126,614 v'fl-fm'r~ls1o `-ÁsTATlss PATENT AoI-îr-‘lciaz ’ >AUTOMATIC TRAFFIC SIGNAL SYSTEM , Francis Jpßuechel, Jr.. Rochester, N. Y., assign or, by `mesne- assignments, to Automatic `Signal Corporation, a corporation `of Delaware ' l application May 2.1928, serai No. l274,499 ' viz claims. V(o1. 177-337) This invention relates to improvements in auto- - for travel of vehicular trailic across the intersec tion on the north and south streets. matic traiiic control signals. ` ` , .» Figure 3 is a fragmentary view, partly dia ' " The primary object of this invention is the pro vision- of an improved automatic trañic signal ` grammatic, and in side elevation, of the control 5 device adapted to be used at the intersection of mechanism for the improved automatic traliic ` crossing streets for automatically regulating the traflic on the street according to the relative posi signal'arrangement. Figure 4 is a plan view of an electro-magnetic tioning of vehicular trañîlc upon the streets. Advantage has been taken in the present inven 10 tion of the fact that cars travel in group forma tion upon busy streets whereon the travel is regu lated by means of trafiìc signal lights. In each group of vehicles it will be noted that they travel operating apparatus for the control mechanism. Figure 5 is a sectional view taken substantially in rather uniform spaced relation along the street illustration is shown only a preferred embodiment of the invention the letters A and B may respec 16 as they approach the intersection, and that there is a considerable space between the last car of a line or group and the advancing car of the next group coming down the street towards the inter section. The present invention utilizes this fact, 20 and suitable control mechanism is used for shift ing signals when the space interval between cars is such that the elapsed time required for spaced’ vehicles to pass a predetermined location adjacent an intersection will be suiliciently great to war rant a change of signals. ' onthe line 5-5 of Figure 3. Á . 10 Figure 6 is a sectional view taken through a vehicle operated street switch. In the drawings, wherein for the purpose of 15 tively designate intersecting east and west, and north and south streets, as shown in Figures l and 2 of the drawings. Lamp signals 69 and 10 maybe placed at the 'opposite sides of the inter section, at the eastern and western sides on'the 20 street A. Similarly, lamp signals 1I and 12 may be placed on the street B, at the north and south sides of the intersection. These signals are of the two lamp type; the green light preferably being nearest the curb, and a red light oi.’ each being 26 remote from the nearest curb. Other lighting~ A further object of the invention is the provi sion of improved automatically operated traiiic arrangements maybe provided, if desired, and signal apparatus adapted to be placed at street indeed these signals may be mechanically oper ated if desired. On the right sides of the street A intersections for regulating the changing of ve 30 hicle signals in accordance with the amount of `at opposite sides of the intersection, looking in the 30 vehicular travel and relative time spacing of the direction of travel of traffic towards the intersec same upon the streets; the improved apparatus `tion, street switches 13 and 14 may be placed, and being entirely automatic in operation and em bodying means for changing the signals after 35 minimum and maximum periods of time, depend ing whether there is little or much vehicular trailic on the streets. » ' Other objects and advantages of this invention will be apparent during the course of the i'ollow 40 ing detailed description. - In the accompanying drawings, forming a part of this specification, and wherein similar refer» ence characters designate corresponding parts throughout the several views, Figure 1 is a diagrammatic representation of the wiring of the improved traiiic signals and~ switches therefor, showing the control arrange ment for the signals in position for operating the in similar locations on the street B, street switches 15 and 16 may be placed on the northern and southern sides of the intersection. These street 35 switches are adapted to cooperate in connection with the control mechanism of the invention sub sequently described, in automatic regulation of 'the lights of the signal lamps BS to 12 inclusive. Dummy policemen 11 may be placed in the middle of each of the streets at each side of the street intersection, to insure that vehicular traffic will all pass over the street switches as the vehicles approach the street intersection. ’ In Figure 6 is Ishown a longitudinal section of one of the street switches, it being understood that all of the street switches 13 to 16 inclusive embodies the same construction. The length of the switches are arranged transverse or at green lights or “go” signals on the east and west streets, and the red or “sîop” signals on the north right angles to the run of the street, and each includes a switch box 'I8EL sunk in the street, and south streets. Figure 2 is a diagrammatic representationrof the details illustrated in Figure 1, with the posi 55 tion of parts as they are about to reverse, that is, and providing a compartment therein normally closed by a movable plate or cover 18, the upper surface of which is arranged to lie ilush with the street surface. The switch box 18‘L is provided . 2 2,126,814 with shoulders 32 to limit the extent to which the plate 13 may be pressed into the box com partment. Normally spaced contacts 18 arid 30 the groove in the upright shaft or screw I when are carried on the facing surfaces of the cover slidably positioned, to the bottom platform E. Springs 23, shown in‘Figure 4 of the drawings, 13 and box 13i respectively, in insulated relation thereto, and connected in circuit .arrangement with the signal lamps in a relation to be subse quently described. Springs 3I hold the top plate or cover 18 so that the contacts are spaced from 10 each other, and these springs have sufficient strength to allow only the excessive weight of an automobile to cause engagement of the contacts 13 and 30. ` . A control unit C is provided for regulating the opposed travel of traillc on the streets A and B in a minimum or a maximum time, depending upon the amount of vehicular tramo on the street and the maximum time which it shall be allowed to travel on any one street. This control mech anism C includes a frame work which 'is only partially shown, including upper and lower spaced stationary platforms D and E. A verti cally positioned screw or spirally grooved shaft the solenoids are energized-to permit said trips or tracers to drop on the rods on which they are - hold. the arms I4 against stop pins 24, and in this position, with the solenoids de-energized the trips will havetheir pins I3 engage in the groove of the screw or shaft I. g In spaced relation with the rods 4, 5, 5 and _1, and in respective diametrically opposed relation from the screw or shaft I, other rods 25, 23, 21 and 23 are provided, as shown in Figure 5 of the drawings, 'and elsewhere, which are parallel with the'shaft I and the rods 4 to 1 inclusive, and bear at their upper and lower ends in the plat forms D and E for reciprocation in said plat forms, so that the upper ends thereof may be extended above the upper surface of vthe platform D for operation of certain switches for a purpose 20 to be subsequently described. 'I'hese last men tioned rods respectively support adjustable knobs 30, 3|, 32 and 33, which are cylindrical in forma I has a bearing at its upper and lower ends in . tion and are adjustably clamped to the respec the platforms D and E, as shown in Figure 3 -' tive rods by `means of set screws 32", more par of the drawings, and the spiral groove therein extends from end to end and is continuous. A Prime mover or motor 45 is provided,v having a geared connecttion 45n with a drive shaft 2 ar ranged transversely below the lower end of the groove shaft I and below the platform E; bevel or miter gears 3 being'provided for gearing the drive shaft 2 with the groove shaft or screw I for drive of the latter. Rods 4, 5, 3 and 1 are supported in parallel relation with the grooved shaft I, in uniformly spaced relation thereabout, bearing at their upper and lower ends in the plat forms D and E for oscillation. ’I'he upper ends of said rods extend above their upper bushings 40 or bearings in the top platform D and are there provided with collars 3 which prevent the longi tudinal moving of the said rods with respect to their platforms D and E. Trips or tracers 9, I0, II and I2 are vertically slidable upon the rods ticularly shown in Figure 3 of the drawings. Each of these knobs is provided with an annular flange 33Il thereabout, which the trip or tracer slidable on the adjacent rod is adapted to engage when » the tra'cer has been elevated by the groove screw 30 I sufficiently to engage the flange 33‘, and thus to force the respective rod 25, 25, 21 or 23 at its upper end through the platform D for switch closing purposes, to be subsequently mentioned. At the upper ends the rods 25 to 23 inclusive are each provided with an enlarged insulation head 33 which holds the rods from falling thru the platform D and serves the additional pur pose of insulating the switches 31, 33, 3l and 40 from the respective rods 25, 26, 21 and 23. 40 ’I'hese switches 31 to 40 inclusive are mounted on the top of the platform D and are each com- . posed of two spring members 4I and 42, mounted at an end .of each in an insulation block 43. The rods 25 to 23 inclusive are so respectively 45 3 and 5 of the drawings. Each of these trips‘is mounted with the switches 31 to 40 inclusive that provided with a radially disposed pin I3 which when the said rods are elevated the upper insu projects radially into the groove of the shaft or lated heads thereof will engage the lower switch screw I and is removable therefrom by reason yarms 4I of the respective switches, and press the 50 of circumferential movement of the tracer or same into engagement with the upper switch arm trip which respectively carries the pin. These 42 for closing a circuit for purposes which will 50 45 4, 5, 6 and 1 respectively. as shown in Figures 1, pins I3 extend through the cylinder of the trips or tracers, into sliding engagement in vertical slots or grooves I3l which are provided in the rods for the respective pins I3. The pins I3 operating in the grooves of these rods 4, 5, 6 and 1 prevent the cylinder bodies of `the tracers or trips from turning on the rods, and for a purpose which will be subsequently described. 60 l The upper ends of the rods 4, 5, 6 and 1 extend above the top surface of the platform D and are there provided with rigid radially extending arms I4, best shown in Figure 4 of the drawings. On the top surface of the platform D are provided solenoids I9, 20, 2I and 22, which respectively slidably support armatures I5, I6, I1 and I3. These armatures are respectively pivoted at their outer ends to the outer ends of the arms I4 of the rods 4, 5, 6 and 1 in order that when the 70 solenoids are energized the respective armatures will be drawn in and the rods 4, 5, 6, and 1 turned slightly on their axes. Inasmuch as the trips or tracers 9, I 0, II and I2 are slidably positioned upon these rods against rotation, it is apparent 75 that the pins I3 thereof will be disengaged from be subsequently described. As part of the control mechanism, a cam 44 is provided, having five grooves 44“, 44h, 44", 444, and 44° thereinf» The grooves 44* and 44b extend 55 about 90° around the circumference of the cam 44, in diii'erent planes. The grooves 44° and 44d extend about 180° about the circumference of the cam 44 in different planes. „ There are two of the grooves 44e, of crescent shape formation, each 60 slightly less than 180°, and located in the same plane. These cam grooves are more particularly shown in the sectional views thru the cam 44, in Figure 1 of the drawings. The cam 44 is keyed upon a shaft 2*. Rotatable and slidable on this 65 shaft 2" is a sprocket wheel 41, which is con nected with a sprocket Wheel 41Il keyed on the shaft 2 by means of a chain belt 45. The sprocket Wheel 41 has a clutch part 43 thereon adapted to mesh with a clutch part 48‘ keyed on the 70 shaft 2‘. The clutch for keying the cam 44 on the shaft 2l` includes a clutch lever 50 pivoted at 53 intermediate its ends; a spring 49 being pro-v vided for normally urging the clutch lever 53 against a stop 52, so as to disengage the clutch 75 3 2,126,614 parts 48 and 48", asshown in Figure 3 of the in a coopera-tive relation with the electro-magnets, drawings.' The clutch lever 58 is really an arma ture for the electromagnets 5|, which are mount 83 as will be subsequently described. This set of electro-magnets I I8 has a single armature III. normally held in engagement with a contact |I2 by means of a spring ||3 when the electromag `nets ||8 are de-energized. When energized the electro-magnets I|8 draw the armature III into ed upon a suitable frame 5|’~, and in a circuit for the purpose of attracting the armature to rotate the cam 44 in order to shift the signals on the streets at an intersection, ‘in a relation to be subsequently described. engagement wlth'another contact ||4 provided - Plungers or rods 54 are slidably positioned upon 10 a supporting block 55 above the cam 44, having ends which extend for operation in each of the ' grooves 44‘, 44D, 44C, 44d and 44e of the cam. These plungers are held against the cam 44 by therefor, and for a purpose to be subsequently described. ` 10 « As before mentioned, the operation of the signal is dependentîupon the elapsed time necessary for spaced vehiclesV traveling toward an intersection means of springs 55e. At its upper end above> _ from the same direction to reach ai predetermined the block 55 each of the plungers has an insula- ' point adjacent the intersection. When the group ' tion tip 51, which is annularly grooved, and which receives the movable end of a switch arm 64. Switches 58 and 59 are respectively operated by the plungers as controlled in the grooves 44“L and 20 44”; switches 68 and 6I are controlled by the of vehicles traveling on the street with the "go” signal are closely spaced as they approach the in tersection the signallight will remain thus until the spacing of the vehicles at opposite sides of the intersection, on the street which has the “go” 20 plungers 54 as operating in the grooves 44° and signal set are such that a change is desirable in 44d, and a switch 62 is operated by the plunger 54 which cooperates in the grooves 44e. Each of the signals. The travel of vehicles on‘a street may be so light and the vehicles so irregularly the switches 58, 59, 68 and 6| includesvupper and spaced thereon that it is desirable for'the signal' 25 lower spring switch arms 63 and 65, mounted on an insulation block 68, and between which the ' switch arm 64, which is also carried by the block 68, operates to alternately engage and close cir cuits through the switch arms 63 and 85. The 30 switch 62 includes the top spring switch arm 66 secured in an insulation block 68, and a second switch arm 61 mounted on this> block 68, and at its opposite end connected with the insulation cap “go” to remain on for á. minimum time.' Also, it A25 may be desirable that a switch in signals occur if the travel of vehicles is so` heavy on the street‘ y that after a maximum time a change in the sig nal lights should occur. 'I'he control mechanism takes care of all of these features. The control parts may be conveniently divided into several parts as follows:--~ I One of the street controls may. include the rod 51 of the slide plunger 54 which operates in the grooves 44e of the cam 44, as shown in Figure 1 4, its tracer 9, the rod 25, its knob 38, the switch 31, solenoid I9 and electro~magnet 96.' of the drawings. Another street light control mayinclude the> rod 5, with its trip or tracer I8, the rod 26 with its knob 3|, the switch 38, solenoid 28 and electro ' _ As part of the operating circuit there are iive sets of electro-magnets which cooperate in circuit regulating relation with the solenoids I9 to 22 inclusive. 'I'hese sets of electro-magnets com prise a set consisting of two electro-magnets 83 having upper and lower armatures 84 and 85 cooperatingtherewith; the upper armature when attracted by the electro-magnets 83 engaging four contacts 86, 81, 88 and 89. The bottom armature has one-contact 98 which it engages when at tracted by the electro-magnets 83. The second magnets |82. A . ' A third control which may be conveniently termed the minimum control, may include the rod 6, with its trip II, rod 21 with its knob 32, switch 39, solenoid 2|, and electro-magnets 9|. The fourth control which may be conveniently ltermed the maximum control may include the rod 1 with its trip I2, rod 28 with its knob 33, switch 48, solenoid 22, and electro-magnets 83. set of electro-magnets 9| has also upper and lower „ With the motor 45 running the drive shaft 2 is armature 92 and 93 respectively, each of the same rotated and due to its geared connection, the having one contact which it engages when at shaftY I is rotated. Normally the pins I3 of the tracted by a magnet. Thus the armature 92 has trips 9, I 8, II and I2 engage in a groove of the a contact 94 and the armature 93 has a contact shaft I and by reason thereof the trips 9, I8, I I 95. The third set of electro-magnets 98 has and I2 will elevate along their rods 4, 5, 6 Vand 1 upper and lower armatures 91 and 98; the upper respectively, until they engage the flanges of the armature 91 having contacts 99 and |88 which are knobs 38, 3|, 32, or 33. 'I'he knobs v38 and 3| are engaged when the armature 91 is attracted by fastened on the rods 25 and 28 at a certain height the velectromagnets 96. The lower armature 98 by means of thumb screws 32e so that it will take has a single contact I 8| which is engaged when ` the trips 9 and I8 the same time to rise from the the lower armature is attracted by the magnets bottom platform and reach said knobs, raising 96. The other set of electro-magnets |82 has them slightly, and since they are fastened to the also upper and lower armatures I 83 and |84. The rods 25 and 26, elevating these rods and pressing upper armature |83 has contacts |85 `and |86 the bottom members 4I of the switches 31 and 38, which are engaged when the armature is at against the top arms 42 thereof, and closing said'L tracted. The lower armature |84 has a single switches. The time elapsing for the climbing up contact |81 which it engages when the lower wardof the trips 9 and I8 on their rods is deter armature is attracted by the electro-magnets |82. mined upon according to the time which elapses Normally the armatures 84, 85, 92, 93, 91, 98,> |83 between the passing of cars over the street and4 |84 are disengaged from their contacts, with switches. At dull times of the day the minimum the electro-magnets thereof de-energized, and the control establishes a minimum time that the sig armatures held against stops |88 by means of nals are to remain on and off. For example, this 70 springs |89 which individually actuate the same may be established at eight seconds, as determin to move them away from the electro-magnets. ing the time between changes of signals, entirely Another set of electro-magnets |.I8 is provided, independent of the extent of vehicular traiiic. which are controlled by the switch B2 ina manner The knobV 32 which forms parts of the minimum - to be subsequently described, for shifting current control is set at a certain height on the rod 21, 4 D, 126,6 14 so um it takes the tracer or mp l | eightV seconds to rise from the bottom platform to the knob 32 connected by wire` |33 with the switch 1I, and the bottom arm 3l of this switch is connected by and raise it slightly, to close the members of the ` a wire |22 to the street switch 13. These switches switch 3,3, causing electricity to pass through the 13 and 15 receive negative current from the wire said switch. For various reasons it is desirable to |I1 as shown in the wire connections. It will limit the passing of traffic to a certain~ length of time, say thirty seconds independent of the extent of vehicular traillc. 'Ihe maximum control has thus be noted that the street switches 13 and 14 are in an operative circuit for the street A on which trame is now passing. ` the knob 33 set at a certain height on the rod 2l, so that itwili take the tracer |2 thirty seconds to Referring' further t'o the operation, with'the y knobs u, u, n and u ci' the control mechanism rise from the bottom platform and trip the `knob IC set in their proper position, and the- street 10 33 to raise the rod 23 sufiicient to close the switch 4l. y s - The closing of the4 circuits throughout the vari switches 13 and 14 in position to be closed by vehicular trame in order to operate details of` the control mechanism; the tracers 3, Il, |I and ous solenoids,lelectro-magnets, and switches will - |2, at the instant that 4the green lights dash in be referred to during the description of the opera tion. A generator or> source of current III'A is the signals 30 and 1l all begin to rise simultane ously from the bottom platform E, inasmuch as, provided, from which positive and negative wires vthe pins I3 thereof operate in the groove of the |23 and I I1 respectively lead on’ into the wire sys tem, and from these main wires | I1 and |23 vari ous branchecircuits are provided to the dißerent details of the system. Referring to the switch I3 which controls the red and green signal lights of the signal lamps 63 and 10, it will be notedlthat the member 34 of this switch $3 is connected to a positive wire IIS which branches oif from the main positive wire |23. With the details as ar ranged in Figure 1 for travel of traillc on the east and west streets of the intersection, the center arm 64 is making contact with the bottom member 35 o_f the switch. shaft I.- Every time that a vehicle vpasses over the street switch 14, contact is made and a cir vcuit from this switch 14 closes thru the wire II‘I, zo wire |20, switch 3l in its lower position, wire III, ‘and solenoid I3. The solenoid I3 receiving posi tive current at all times from wire |23 becomes energized and draws in its armature I5, and by reason of the arm connection I4 a slight turn is given to the control rod 4. The turn is sutllcient to remove the pin I3 of the trip 9 from the groove of shaft |, permitting the trip or tracer 3 to drop against the bottom platform E, from the This bottom member y position to which it had climbed on the rod 4, 3l is connected by the wire IIS to the green lamps of the signals 39 and 10; these lamps, as weil as the red lamps of the signals 33 and 10 being sup plied with negative current from the wire II1 as shown in the circuit. It is therefore obvious that with the switch 53 in this position the green lights will be illuminated and indicate to trafilc the clear passage across the intersection on the Ó street A, or in an east and west direction. 'I'he switch I! controls the flashing of the green and red lamps on the signals 1I and 12 for controlling traillc on the north or south streets B across the intersection, and inasmuch as the center arm 64 of this switch is connected to the positive current wire I II, and is making contact with the upper switch arm 63, the red signal lamps of the sig nais 1I and =12 will be illuminated for stopping passage of traillc on the street B across the inter ~ section. It is of course apparent that the switches prior to the time that the vehicle crossed the street switch 14. Every time that a contact is made in the switch 14, with the cam 44 set as shown in Figure 1, this operation will take place. 35 Similarly, when a contact is made in the other street switch 13 of the east and west street A, current flows through the wires II1 and |22 lead ing therefrom, to the closed portion (see Figure 1) of the switch 6I, into wire I2I and into sole 40 noid 2li. This solenoid 20 receives its current from wire I 23 at all times, and upon energiza tion it draws itsy armature I6 thereinto, and through the arm I4, a slight turn is given to the rod 5, suiiicient to remove`the pin I3 of the trip or tracer I0 from the groove of the shaft I, and permitting the tracer I Il to drop to the bot tom platform E, from the height to which it has elevated prior to the time that the vehicle passed over the street switch 13. Of course as soon as 33 and l! are thus> positioned by reason of the ¿the vehicle leaves the switches 13 and 14 the riding of the plungers 54 on the cam 44 with re current is broken in the circuit therewith and the spect to the grooves provided for these respective ‘ ~ springs 23 will pull the solenoid-cores back into switches. theirposition shown in Figure 4, and throw the _The switch 60 controls the ñow of current into pins I3 of the trips 9 and Ill into the groove the system through the street switches 14 and 13. With the plunger 54 in the groove 44" of the cam 44, as shown in Figure 1, the center member 34 of the switch 60 is making contact with the bottom arm 65,. This center member 64 of this particular switch is connected by a wire I I9 to the solenoid I3 which forms part of the street control system, and the bottom’member 65 of this switch is connected by a wire |20 to the street switch 14 on the street A. Negative current is supplied to the switches 14 and 1€ thru the wire I I1 as shown. The switch 6| controls the ilow of current through the switches 13 and 15. As shown in Figure 1, the plunger 54 of this switch 6| is operating in the groove 44d of the. cam 44, and pulls the center member 64 down into contact with the bottom switch -arm 65. 'I‘he center member 64 of this switch is connected by a wire I2I with the solenoid 20, forming part of .the street control mechanism. The top arm 63 is of the shaft |, and the «trips 3 and Ill again be 55 gin to rise upon their respective rods; it of course being understood that the shaft I is rotating all oi' the time. - So long as the total time required for each of the tracers 9 and I0 to reach and slightly lift 60 their respective knobs 3U and 3|, is longer than the time which elapses between successive oper ations of the respective street switches by the rear of one car and the'i‘ront of the next car 65 following, in the _line of cars approaching the same, the said tracers or trips 9 and II! will not >reach their respective knobs 30 and 3|. How ever, when the time interval of street switch operation by successive cars passing the signal 70 becomes greater than the predetermined time, the trips will operate against the knobs 30 and 3|, for achieving the results mentioned. Assuming that there is a large amount of traillc passing in both directions on the street 75 5 A. AIi' the minimum control is set for eight sec contact |00 is directly "connected with negative onds, and 'the trame has been passing across the intersection on the street A forthis'length of current supply wire | I1, and inasmuch as arma ture 91 engages the same at this time, negative time, the tracer> || will reach and lift the knob >current passes to contact |00 into armature 91, and into wire |26, from which electro-magnets 32, and inasmuch as thelatter is fastened to the rod 21, said rod will be lifted and pressed against the member 4I of the switch 39, pressing against the top member 42, and thus closing this switch. The bottom switch arm 4| receives neg 10 ative current from the wire ||1, as‘shown in the operating circuit in_ Figures 1 and 2 of the draw ings. and the contact in the` switch 39 being made, the current will pass from wire ||1, thru the switch 39, into wire |24, and into the set 15' of electro-magnets 9|. IPositive current is re ceived by electro-magnets 9| from wire |25, switch contact II2, armature III, and wire |23, energizing the magnets 9| and causing the ar matures 92 and 93 to close against their respec tive contacts 94 and 95. Simultaneously with the energizing of electro-magnets 9|, the solenoid 2| is energized, receiving _negative current from wire now receive the negative current. Solenoid I9 now also receives its negative current from con tact |00, inasmuch as the negative current from contact |00 passes through armature 91, and into contact 99 and wire |21, into wire ||9 to this 10 solenoid I9. This extr'a source of negative elec tricity from contact |00 is now necessary, since as soon as solenoid I9 was energized, and rod 4 ` turned, the tracer 9 became disengaged with >shaft ` I permitting it to fall to the bottom platform E, and likewise permitting knob 30 and its rod 25 to drop and release the contactsof switch 31. Were it not that the negative current is now - supplied from contact |00, the electro-magnets 96 and solenoid I9 would not remain in a state 20 of energization, as they now should. ` A similar operation occurs when the spacing e |I1, switch 39, wire -I24, and positive current `of the vehicles in the street A, passing .west at all times from wire |23, as can be understood - from the diagrammatic wiring in Figure 1. Con tact 94 is connected with the negative current wire ||1, and the armature 92 engaging contact 94 will permit the negative current to pass into armature 92 and into wire |24, from which the electro-magnets 9| and solenoid 2| now receive a supply of negative current. Remembering now that as soon as solenoid 2| became energized, the armature I1 was drawn in and the rod 6 slightly turned, removing the pin I3 of tracer || from the grooved shaft I, and permitting thetracer II to drop to the bottom platform E, it is ap parent that knob 32 and rod ,21 fastened thereto will likewise be permitted to drop the distance they were raised, and the members 4| and 42 of 40 the switch 39 become disengaged, opening this -switch and permitting the circuit through the switch 39 to open. However, in View of the neg ative current passing through the armature 92, the wire |24 is now receiving its negative cur wardly over the intersection is such that the tracer I0 has ample time to rise and trip the knob 3| before the next vehicle operates the street switch 13 to prevent such operation. Trip ping of the knob 3| elevates the rod 26 and engages the contacts 4| and 42 of the switch 38, negative current then passing from wire II1, 30 >through the closed switch 38 into wire |28 and into> the electro-magnets |02, for energizing them. Positive current is of course received by these electro-magnets |02 from wire |25. Upon energization the electro-magnets- will attract the armatures |03 |05, |06, and The armature mits negative and |04 for engaging the contacts |01 in their respective relations. |03 engaging the contact |05, per current to flow from wire |28 through the armature |03 into Contact |05, and 40 through wires |29 and I2| into solenoid 20. This solenoid is energized, receiving positive current from wire |23. Contact |06 being directly con nected with negative current wire II1, with the .armature |03 engaging the same, the current 45 _rent thru engagement of this armature with the contact 94. Subsequent to this, if the vehicles will pass therefrom into wire |28, from which passing on the street A in an eastward direction electro-magnets |02 now receive their negative are successively- spaced farther apart than will current. Solenoid 20 now receives this negative permit them to reach the switch adjacent the .current from' contact |06, inasmuch as the neg 'intersection within a predetermined elapsed time ative current from contact |06'passes through 50 and by which the streetfcontrols were set, the wires |29 and I2I in the relation above described, tracer 9 will have ample time to rise and .reach and maintains the solenoid 20 energized; this be its knob 30, and lift it slightly, causing the rod ing necessary since as soon as it was energized the rod 5 was turned and the tracer I0 permitted 25 keyed therewith to ride and press the bot tom 'arm 4| of the switch 31 against the top arm to drop, to diseñgage the contacts of the switch 55 42 thereof.` This of course happens >because the 38 through dropping of the rod 26. Thus, not street switch 14 was not operated soon enough withstanding the opening of the switch 38 the by vehicular trailìc to cause a trip of the tracer electro-magnets |02 and solenoids 20 remain en ‘ _ -9 prior to the time that it caused closing of the ergized. From the above it will be apparent that the 60 switch 31. In this switch the bottom arm 4| receives negative current from Wire |I1, which electro-magnets 9|, 95 and |02 are now all ener gized, and attracting their respective armatures passes into wire |26 and into> the set of electro magnets 96. Positive current is received bythese 93, 98 and |04 in engagement with the contacts electro-magnets from wire.|25 through contact 95, |0I and |01 respectively provided therefor. This permits current to flow from the wire II1 ||2, armature ||I,'and lines |23, and energiza tion of thel electro-magnets 96 will cause the through these various armatures and contacts into electro-magnets 83, which now become ener armatures 91 and‘ 98 thereof to engage the re gized, inasmuch as they receive positive current spective contacts 99, |00, and |0| provided there for, as shown in Figures 1 and.2 of the drawings, from the wire |25. It will be noted that al1 three Since armature 91 engages contact 99, negative sets of armatures 9|, 96, and |02 must be ener current from Wire |26 passes through armature gized with their contacts before negative currentv 91 into contact 99, and into wire |21 and thus is permitted to enter the electro-magnets 83. into wire I I9, and into solenoid I9., which now Upon energizing of the electro-magnets 83, the` becomes energized, inasmuch as it receives posi armatures 84 and 85 will be attracted and closed 75 tive current from wire |23, at all times. The into engagement with the contacts provided 15 6 2,126,614 therefor. The armature 84 engages the contacts 88, 8l', 88 and 89, and the amature 85 engages the upper arm 83, andas the upper arm 83 is the contact 90 provided therefor. -Inasmuch as armature 84 is connected with the wire ||1 for’ receiving negative current therefrom at alltimes, _ it is apparent that itwill pass the same onto the contacts 88,81, 88 and 89 upon energizing of the electro-magnets 83. From contact 88 the 10 negative current goes into the wire |30, through electro-magnets 83, and solenoid 22, energizing the latter, and releasing its tracer I2 which has not yet reached the knob 33. Since contact 80 is directly connected with the positive current wire |23, current from this wire now passes thru 15 contact 98, armature 85, wire |3I, and ~into elec tro-magnets 5| which control the clutch of the cam 44, energizing the electro-magnets 5|, and attracting the armature 50. This moves the clutch part 48 intoengagement with the clutchE) G) part 48e, and engages the clutch for keying the cam 44 to theshaft 2*. The cam 44 now revolves, and makes nearly one-half of a revolution. Dur ing this turn the plunger 54 for the switch 82 will rise from the groove 44* in> Which'it reposed, 25 towards the outer surface of the cam 44, until the switch members 88 and 81 of the switch 82 engage. The switch member 81 of said switch is directly connected to the positive current wire |23, and the current therefrom passes into the 30 switch arm 88 and into the wire |32, and into electro~magnets I | 0, to energize the latter, inas much as they are connected to circuit ||1. Electro-magnets |I0 now draw the armature III thereof from contact ||'2 over to its other con 35 tact I I4. This breaks the circuit thru the electro magnets 83, 9|, 98 and |02, and de-energize the same. All of the armatures of these electro magnets 83, 9|, 98 and |02 are Ínow pulled by their springs |09 into engagement with .stops |08, to their normal inoperative position, and it is connected by'wire |33 through the red signal lamps of the signals 88 and 10, the latter are operated on the streets A for stopping travel oi' traffic thereon across the intersection. For the switch 59 the center arm 84 has been moved into engagement with the lower arm 85, by'rea son of the dropping of the plunger 54 of said switch into the groove 44h, and as the bottom member 85 of this switch is connected by wire 10 |34 to the green signal lamps on the signals 1| and 12, the latter are thus operated to indicate to trailîc on the streets B that it may travel across the intersection. In the switch Si: the plunger 54 thereof has been elevated to the outer periphery of the cam 44, so that the center arm »84 now engages the upper arm 83 thereof, and as the upper arm 83 is connected by wire |35 to the street switch 18, the latter upon depression Will operate a circuit through the switch 80 in 20 cluding the details above described. In the ^switch 8| the plunger 54 has been elevated to the outer periphery of the cam 44, to engage the center contact 84 with the arm 83, sending the current thru wire |38 tothe street switch 15, 25 so that upon depression of the latter the current Will'be closed thru the contacts of the switch 8| « as thus engaged for operating details of the con trol mechanism in .the cycle above described. The signal now has completed one half of the 30 cycle and it is ready for travel of traftlc on the street B across the intersection. While the cam 44 is making its half revolution during the signal switching operation, it will be noted that for a short time the red lights are showing in all the signals 89 to 12 inclusive, by reason of the design of thecam groove 44a and'44b, which are only ap proximately 80° in length, so that during about a 90° travel of the cam 44 all of the red signals will be on which permits ample time for the vehicles and pedestrians who have started across the intersection to pass the signal before the switch in red and green signals takes place. The above operation contemplates the condition 45 23 for a short arcuate movement, _until the arms ’ where traflic on the streets having the right of I4 engage the stops 24, engaging the pins I3 way has crossed the street switches within the` 45 of these trips 9, I0, || and |2 in the groove of predetermined time so that the street controls the shaft I, and resetting the trips for movement have not been able to operate duringthe minl along their respective rods. y mum period, but that sometime between the oper thus apparent that the current thru the solenoids I9, 20, 2| and 22 will also be broken, permittingthe rods 4, 5, 8 and 1 with their respective trips or tracers 9, I0, || and I2 to be pulled by’springs 50 When the armature III was shifted as above ~ ation of the minimum control and before the ex described upon energization of its electro-magnet, the current was broken in electro-magnets 83. This allows the armature 85'to disengage from contact 90. This breaks the current in electro 55 magnets 5I, and the clutch disengages before the cam 44 makes a complete half revolution. The cam stops at a point where the plunger 54 of the switch 82 is still on the outer edge of the cam 44. However, armature I || engaging contact ||4 sends positive current to wire |3| and into electro-magnets 5|, permitting the clutch to re main engaged and the cam 44 to finish its half revolution. As soon as the cam 44 finishes its half revolutionV the plunger 54 of the switch 82 65 drops into the abrupt end` of one of the grooves 44°, disengaging the switch arms of the switch 82. The positive current through'the electro-mag nets I|0 is then broken and the amature ||| is pulled back against the contact I|2 by means of 70 the spring II3, breaking the current through electro-magnets 5| and permitting the clutch 48 to disengage and stop revolution of the cam 44. The above operation of the cam 44 for a half' revolution has now operated the plunger 54 of the switch 58 so that the center arm 84 engages piration of the thirty-secondl maximum period, 50 traffic has become so straggly as to permit a trip operation 'of switches 31 and 38 and a change in » signals. Automatic periodic alternation of the right of way to the respective streets is deter mined by operation of the minimum controls when heavy traffic approaches the street intern ,sectionI too late to reach the street switches be fore their controls have operated and before the minimum control has operated. However, if the vehicles passing along the street A are closely 60 spaced so that the street switches 13» and 14 will be operated continuously, or at least one of them operated without permitting the trip operation of the switch 31 or 38 therefor, at the end of the Ythirty second period the tracer or trip I2 will 85 reach the knob 33, and lifting the rod 28 will con tact the arms 4| and 42 of the switch 40, for clos ing the latter. Inasmuch as its'switch arm 4| is directly connected with the negative supply wire II1, this current will pass through the wire I 30 into the electro-magnets 83, with the result that they will be energized. Negative current from armature 84 is sent through the contacts 88, 81, 88 and 88, which in turn delivers the cur 15 7 2,126,614 rent to'electro-magnets 83, 9|, $8 and |02 re spectively, engaging their armatures with their occur, giving the street B the right of way, then the actuation of the B` street switch, since the contacts, and thence to the /solenoids i9, 20, 2| and 22, disengaging all tracers from the groove in the shaft I, and the same operations follow as above described for a shifting in the signals. 'Thus if the maximum control is set for a cer-~ tain time, and the traiiic is greater than can pass B street switches are now connected with the street controls because of the street B now having the right of way, will reset its particular street control, giving it a fresh start in its upward movement. _ ’ - Assuming that street A has the right of way in in that time, the maximum control will cause an 10 operation which will change the lights in- the dication, which is maintained as such on account signals, regardless of the two street controls in on A street. Ii?` said actuations continue for thirty seconds, at the end of this period the max the mechanism C. - _ Insoi'ar as the signals are concerned, when " there is no traiilc on either street A.~or B, the 15 right of way indication is given alternately from one >street to the other. remaining on each street for a period of time equal to the time at which the minimum control is set, which is eight seconds. Thus, as soon'as the right of way indication is 20 given to a street, the trips or tracers of both of the street controls commence their upward move ment. Since there is no trailic to actuate the street switches and thus cause a resetting of the street controls, which `means a loss in its upward of continuous closely spaced switch actuations imum control will function, since it is set at thirty seconds. Notwithstanding the fact that the street controls have not operated their re spective electro-magnets on account of the closely occurring A street switch actuations, there will .be a change in signals. Since street A has the right of way‘its street switches arev connected with the street controls: the street switches of 20 street B being free and disconnected. Hence if actuation of a switch on B street occurs 15 sec movement, they will reach their complete prede onds, let us say, after the ñrst switch actuation on A street, nothing will happen to change the signalling, since the B street switch actuation determined upward travel and thus cause «an willl have no effect. operation of their respective electro-magnets in, let us say, three seconds. But since the minimum control is so arranged in connection with the street controls that it also must have caused an operation of its respective electro-magnets, to ef feet a change in signals, no shifting in signals will have yet occurred. It will be remembered that f If B street has the “green” or right of way‘in- ' dicatìon. and there is‘n'o traffic on said B street. said right of way indication will remain on B street for a timey equal to the time at which the 30, minimum control is set, which is eight seconds. Therefore, if an actuation of an A street switch takes place while the “green” indication is given as soon as the trips of the street »controls begin t9 B street. and consequently the “red” indication their upward movement, the trip of the minimum to Astreet, nothing will happen to change the control also begins its upward movement. Since signals since the A street switches are free and ` .the street controls have actuated their respective disconnected from the street controls which are electro-magnets, it will only be necessary for the then’in' operative relation with the B street ' .minimum control to cause an operation of its switches, since the latter4 has the ‘-‘go” signal. The advantages embodied in the present in 40 40 respective electro-magnets tol cause a change in signals. Since the minimum control is set atl vention of connecting each switch separately to eight seconds, this change in right of way indi an operating mechanism are generally as cationwill occur eight seconds after the previous .followsz_ change in signals, which will be iive seconds after ' ' First-Such .an arrangement is particularlyv 45 the street controls have~ completed Atheir par- ` Ladapted for operation at intersections of main ticular function. The same-will then continueb streets or highways, where traffic is relatively with the other streets, etc., alternately from heavy'on both streets, whereas signals which have Vone street to the other for periods of eight sec the switches in th‘e same street connected to a onds each. The signals will operate in this man single operating mechanism are useful -only where 50 ner so long as there is no trafiic present on the- a mainstreet intersects with a subordinate street and thus are not efficient controllers of tramo ' `When an A street switch actuation is followed ` where two main streets intersect. street. ‘ within eight seconds‘by a‘B street switch actua tion nothing will happen so f_ar as signal change 55 is concerned. In this connection it must be re membered that the street which has the right of way, also has its street switches connected -with the street controls; the street switches of the other streets being disconnected. Any actuation 60 vSecoml.--'I'he operation of the signal is directly` controlled by the density of trañic approaching each side of the street, effecting a more uniform . land accurate regulation of trai’iic and accomplish ing this in a quicker and more efilcient manner than is possible if the street 'switches were con nected to one operating mechanism. In the pres.. of them does not produce any eiîect on the signal A ent arrangement traiïic must be relatively heavy 60 mechanism. It`will be observed that the same street controls are used in operative relation with the street switches in both streets; said street controls being shifted from one set of -street switches to the other set with the changing of 65 the right of way indications. Thus, when the street switches of one street are connected with the street controls, the street switches in the other street are free and disconnected and it is obvious that if s’treet A has the right of way any actuation of the street switches in 'street B will not produce any effect on the signalling mecha nism. However, if during the time elapsed be tween the last actuation of the A street switch ‘Il and the B street switch, a change in signals should on at least one side of the street having the right of'way indication to hold said indication, else a change in signals will occur. In signal arrange ments where the street switches are connected to one operating mechanism a straggling car from one side of the cross street,-and then another straggling car from the other side occurring Within the predetermined time will keep the right _ Jof Way on said cross street. In the present ar rangement cars must pass in a continued stream, 70 each within the predetermined time interval of the preceding car, from at least one side of the street to hold the indication on said street. A straggling car from one side and then another straggling car from the other side, even if within 8 2,126,614 the same predetermined interval of time of each other will not hold the right of way indication on said street. It is therefore seen that signals em ploying one operating mechanism' for two street switches do not operate directly and uniformly according to the density of traillc on the street, as the present signal does.' Itis apparent from the foregoing that a novel tramo signal system has been provided, which is truly automatic, dependent upon a novel operation incident to the well known tendency of motorists to travel in groups, with greater -distances between the successive groups than occur between .the vehicles of any one group. The operation is not, 15 however, dependent upon the group traveling of vehicles, but operates according to the time inter val with which the street switches are operated by vehicular trailic. Various changes in the shape, size, and arrange io ment of parts may be made to the form of the operating circuit and details of the invention herein shown and described, without departing from the spirit of the invention or the scope of 'the claims. I claim: 1. Ina trailic signal system the combination with a pair of intersecting streets, a right of way indicating means for each of the streets at the intersection, a vehicle actuated switch inA each street at each side l of the intersection, a cam, switch means operated by the cam for operating the right of way indicating means, a control unit including a plurality of normally open switches', means adapted to close the switches after the passage of a predetermined interval of timefin cluding solenoids for tripping said means to pre vent closing of the switches, said solenoids being normally inoperative, means electrically connect ing the solenoids with the vehicle actuated street switches, including the switch means operated by the cam above mentioned, means for -actuating the cam including an electro-magnetically oper ated clutch, and means connected between said normally open switches and the electro-magnet 45 of the electro-magnetically operated clutch for causing an engagement of the clutch upon closing of a predetermined number of the normally open switches. ` v 2. A trafilc control system for the intersection of'two streets with each `stree’t having two oppo ‘site approaches to the intersection, including in combination, electric rlght'of way signals for the respective streets, cyclic‘switch mechanism hav ing alternate switching positions for energizing the respective signals alternately, a vehicle actu ated 'device in each approach of each street. a constantly rotating threaded central shaft, three other shafts arranged parallel and closely adja cent to the central shaft each such other shaft being slotted along its length collars fitted on said other shafts to slide freely along the length thereof and having projections engaging vthe slots of their respective shafts and adapted normally to engage also the thread of said central shaft to be driven along their respective shafts from one end towardv ~the other over a time period and adapted to be disengaged from said central shaft and returned to said one end when their respec tive shafts are turned axially, contact members positioned to be actuated by the respective collars upon the latter having been driven from the end of the shafts for certain distances along such shafts by engagement with the central shaft, electromagnetic means adapted to be energized by actuation of the respective contact members to turn the respective shafts and disengage the re spective collars from said central shaft and in cluding switch means operated by actuation of the respective contact members and maintained operated after each individual actuation thereof until all three contact members have been `actu ated to then shift s‘aid cyclic mechanism from one position to the other, switch means operated by said cyclic mechanism in being so shifted to de energize said electromagnetic means again, and. further switch means. operated by said cyclic mechanism for connecting the electromagnetic means for two of said other shafts respectively to the respective vehicle actuated devices of the two approaches of one street while the right of way signal therein is energized to be energized mo 15 mentarily by momentary actuation of their re spective devices to return their associated collars momentarily to said one end of the respective shafts. 3. A traffic control system as in claim 2 and 20 additionally including a fourth shaft, collar and contact member of the same character as said other three shafts, with the last named contact member positioned further along its shaft than the other contact members, and additional elec tromagnetic means energized directly by said last named contactmember when .the latter is actuated by its collar to shift said cyclic switch mechanism to said other position if it has not 30 already been so shifted by the ilrst mentioned electromagnetic means and also to turn said fourth shaft and collar to return the latter collar to the corresponding one end of its shaft. 4. A traffic control system forintersection of two streets with _each street having two opposite approaches to the intersection, including in com bination, right of way signals for the respective streets, cyclic operating means `for said signals and having alternate operating positions to indi cate right of way alternately to the respective 40 streets, a vehicle actuated device in each approach of each street, two time controlled switch means initiated by said cyclic operating means in said one position and operating at definite times from vsuch initiation, means associated with the cyclic operating means for connecting said additional time controlled switch means with the respective vehicle actuated devices in the respective ap proaches of said one street having right of way so as to reinitiate timing of the switch means for one approach by each actuation of the vehicle actuated device therein, and means including both said time switches and dependent on oper ation of both such switches at completion of their time periods to shift said cyclic operating means to its other position to'indicate right of way to the other street. 5. A traiîic control system as in claim 4 addi tionally including a maximum time controlled 60 switch means initiated by said operating means in ' said one position and operating at a considerably longer time period than the other two time con trolled switch means to shift said operating means to said other position if the latter hasv not already 65 been so shifted by operation of said other time controlled switch means. 6. A traffic control system for the intersection of two streets with each street having two op posite approaches to the intersection, including in combination, iight of Way signals for the re spective streets, cyclic operating means for said signals and having alternate operating positions to indicate right of way alternately to the re spective streets, a vehicle actuated device in 9 2,126,614 each approach of each street, minimum time controlled switch means initiated by said cyclic additional time controlled switch means initiated operating means when the latter is in one position to indicate right-of wayto one street and oper ating at a minimum time from such initiation, two additional time controlled switch means initiated tion and operating at a time from such initiation - means in said one position and operating at a means in said one position and operating at a considerably longer time than said minimum v from such initiation to shift said operating means by said cyclic operating means in said one posi shorter than said minimum, means associated with‘the cyclic operating means for connecting said additional time controlled switch means with therespective vehicle actuated devices in the re by said cyclic operating means in said one posi tion and operating at a time from such initiation spective approaches of _said one street having shorter than said minimum, means associated right of way so as to reinitiate timing of the 10 with the cyclic operating'means for connecting switch means for one approach by each actuation 10 said additional time controlled switch ‘ meansl of the vehicle actuated device therein, means in with the respective vehicle actuated devices in cluding said minimum timel switch and'both said additional time switches and dependent on opera the respective approaches of said one street hav ing right of way so as to reinitiate timing of the tion of all three of these switches at completion switch means for .one approach by each actuation of their time periods to shift said cyclic operating of the vehicle actuated device therein, and means means to its other position to indicate right ol.' including said minimum time switch and both way to the other street, and means individual to said additional time switches and dependent on each of said time switch means to maintain the respective switches operated uponA and after com operation of all three of these switches at comple tion of th'eir time periods to shift said cyclic pletion of their respective time periods and until 20 operating means to its other position to indicate said shifting means operates to shift said cyclic operating means to said other position._ right of way to the other street. 10. A traiïic control system as in claim 9 addi 7. A trame control system as in'clairn 6 addi tionally including a maximum time controlled - tionally including a maximum time controlled switch means initiated by said cyclic operating switch means initiated by said cyclic operating 25 considerably longer’ time than said minimum from suchinitiation to shift said operating means to said other position if it has not already been so shifted by`operation of the other time switch to said other position if it has not already been` so shifted by operation of the other time switch means. means. - ' ' ' 11. A traiilc control system for the intersection of two streets with each street having two oppo site approaches to the intersection, including in combination, electric right of way signals for the respective streets, cyclic switch mechanism hav 8. A traiiic control system for the intersection of two streets with each street having two oppo site approaches to the intersection, including in combination, right of Way signals for the respec tive streets, cyclic operating means for said sig ing alternate switching positions for energizing the respective signals alternately, a vehicle actu nals and having alternate operatingpositions to indicate right of way alternately to the respective streets, a 'vehicle actuated device in each ap 40 proach of each street, two time controlled switch ated device in each approach of each street. three time delayed switch means connected to have means initiated by 'said cyclic operating means in said one position and operating at definite times from such initiation, means associated with the cyclic operating means for connecting said ing the right of way signal on one street and as additional time controlled switch means with the respective vehicle actuated devices in the respec tive approaches of said one street having right of way so as to reinitate timing of the switch means for one approach by each actuation of the vehicle actuated device therein, means including both said time switches and dependent on'opera tion of both such switches at completion of their time periods to shift said cyclic operating means to its other position to indicate right of way to the other street, and means individual to each of said time switch means to maintain the respec their timing initiated by said cyclic switch mech anism when the latter is in one position energiz adapted to operate their respective switches at completion of their respective timing, the ilrst 45 of said switch means having a time period serving as a minimum for said cyclic switch mechanism in said one position, and the other two switch means having timing periods shorter than such - minimum, switching means associated with said tive switches operated upon and after comple tion of their respective time periods and until said shifting means operates, irrespective of further >operation of the vehicle actuated means con» nected to the time switch means during such right of way on said one street. < 9. A trailic control system for the intersection of two streets with each street having two oppo site approaches to the intersection, including in combination, right oi way signals for therespec tive streets, cyclic operating means for said sig nals and having alternate operating positions to .indicate right of way alternately to the respective 70 streets, a vehicle- actuated device in each ap proach of each street, minimum time controlled switch means initiated by said cyclic operating means when the latter is in one position to indi cate right of- way to one street and operating „ at a minimum time from such initiation, two cyclic switching mechanism to connect saidother. two time delayed switch means to the respective vehicle actuated devices of the two approaches of said one street in said one position of said> cyclic switch mechanism to reinitiate either one ct said other time switch means by each actua tion of its connected vehicle actuated device to delay completion of its time period, and means including the switches of said three time switch means and operative only when all said three switches are concurrently operated to shift said cyclic vswitch mechanism to its other position to energize the right of way signal for the other street. - “ 12. A trame control system as in claim il addi tionally including a maximum time controlled switch means initiated by said cyclic operating means in said one position and operating at a considerably longer time than said minimum 70 from such initiation to shift said operating means „ to said other position if it has not already been so shifted by operation o! the other time switch means. - FRANCIS J. BUECHEL, Jlr.