US2135525A

US2135525A - Automatic variable traffic regulator

Info

Publication number: US2135525A
Application number: US695596A
Authority: US
Inventors: Anna J Nelson
Original assignee: Engineering & Res Corp
Current assignee: Engineering & Res Corp; ENGINEERING AND RESEARCH Corp
Priority date: 1924-02-27
Filing date: 1924-02-27
Publication date: 1938-11-08
Anticipated expiration: 1955-11-08

Description

Nov. 8, 1938.

R. O. NELSON AUTOMATIC VARIABLE TRAFFIC REGULATOR Filed Feb. 27, 1924 2 Sheets-Sh eat 1 33 POW ER. SUPPLY a I K /l 27 --2f L H 26 0 RoBERT 0. NELSON GHQ-away,

Nov. 8, 1938.

R. o. NELSON AUTOMATIC VARIABL E TRAFFIC REGULATOR Filed Feb. 27, 192 2 Sheets-Sheet 2 (for nu,

o intersection by the last vehicle having the right-- Patented Nov. 8, 1938 um'rso STATES PATENT 'OFFICE AUTOMATIC VARIABLE TRAFFIC REGULATOR Robert 0. Nelson, Los

Angeles, Calif.; Anna 3.

of Connecticut Application February 27, 1924, Serial No. 695,596

32 Claims.

This invention relates to traffic regulating devices and one of the objects is to provide an automatically variable, electrically controlled and operated mechanism for giving the right-of-way to the first vehicle approaching the intersection of two or more roads. A second object is to so construct the mechanism of the regulator that it will signal the right-of-way to waiting vehicles immediately after the crossing of the of-way in the other or cross direction, regardless of the length of time it may have waited if the stay is less than a predetermined period of time, such, for instance, as thirty seconds. The device is also designed so that it will limit the stopping time of a waiting vehicle to a certain predetermined number of seconds, when cross trafflc has the right-of-way in the other or cross direction. Further objects will be disclosed in the course of the following specification, reference being had to the accompanying drawings illustrating one practical embodiment of the invention, and in which:

Fig. 1 is a diagrammatic view of units of apparatus and the connections between the latter which provides. trafflc control system;

--Fig. 2 is a schematic view of a straight intersection and showing a system installed to provide for traflic regulation;

Fig. 3 is a sectional side view of one oi the traflic actuated controls;

Fig. 4 shows in elevation, and in somewhat enlarged form,'one or the units ofapparatus as shown in Fig. 1;

Fig. 5 is a fragmentary enlarged side elevation of one of the circuit closers embraced in the unit as shown in Fig. 4;

Figs. 6 and. 'l are transverse sectional views,

taken respectively along the lines 8-5 and and in the directionof the arrows as shown in Fig. 4; a Figs. 8 and 9 areviews similar to Fig. 7 but illustrating contact paths or circles which form a part of the unit of Fig. 4, and additional to the contact path or circle illustrated in Fig. '7;

Fig. 10 is a view similar to Fig. 4, but showing different units 01' apparatus from that illustrated in the preceding figure; K

Figs. 11, 1-2, 13 and 14 are transverse sectional views taken along the lines |ll 'l, |2--l 2, l3l3, and |4|l, respectively, and in the direction of the arrows as indicated in Fig. 10; and

Fig. 15 is a view similar to Fig, 14, but showing the parts in a difl'erent position.

Referring to the drawings more particularly and by reference characters A designates a north and south street or road or lane, which is crossed by an east and west street or lane B, and at the middle point of the intersection is a conventional signaling device C, in or under which is arranged the control box D. The signal may be of any of the well known types in which the stop" and go signs are electrically lighted and alternated so that when the sign reads stop in one direction it will read "go in the other or cross direction, and vice versa and thus indicate rightof-way at the intersection of the two lanes A and B. Thus in Fig. 1 I have indicated signal lamps R, R as the red or stop lamps for the A street, and these lamps are connected with the lamps G, G which are the green or go lamps of B street; while the RI, Rl,,stop lights for B street are connected in circuit with and are simultaneously energized with green "go lamps GI, GI, which give the right-of-way to A street traflic, and stop the B street trafllc.

The circuit controlling mechanism (later to be described) which controls the two circuits to the lamps in the signal, is contained within the control box D,- and the-traflic situation is indicated and communicated to this mechanism through auxiliary circuits which are controlled by what I conveniently term trafllc actuated controls. These, as shown, may take the form of trigger switches H, I, J, K, L, M, N, and 0, which are 'closed' by the passing of vehicles over them. These switches are secured in the streets A and B and are arranged in the path of travel of the vehicles about as shown in Fig. 2.- The rear switches I, K, M and 0 are arranged close to the intersection while the front switches H, J, L and N are preferably arranged about about sixty. feet from the intersection to indicate the approach of cars from any direction. To insure the registering of each vehicle these switches are preferably arranged in groups of two duplicates arranged side by side where necessary to insure proper coverage of the path of approaching traffic, and are wide enough to insure operation by any vehicle passing thereover. The two switches forming each group are connected in. parallel with each other and since both switches of each group perform identical functions, only one of each pair is indicated in Fig. l, and it is obviousthat where one switch is of sufliclent width to cover the path of approaching trafilc only one ifled, but a preferred form is illustrated in Fig. 3

and consists of a box or casing |5 which is imbedded in the street, and has a plate |1 pivotally secured therein as at l8. The swinging end of 'the plate H has a segmental flange l9 which or horizontal position where the flange I9 strilres a shelf or stop 22. A pair of switch terminals 23 and 24 are respectively secured upon the box l5 and plate i1, and come together when the plate is depressed, and thus close a circuit through wires which are led to the control box by suitable conduits.

Four circuits are controlled by the trigger switches and are respectively indicated by wires 25, 25 from switches H, J,

wires

21, 28 from switches I, K,

wires

29, 30 from switches L, N, and wires 3|, 32 from switches M, O. The

wires

25, 21, 29, and 3| are branches of the positive supply wire 33 to the entire system, and 34 designates the main negative supply wire. 1

Before describing the entire electrical system, the mechanisms, which, except for the trigger switches, are preferably all contained within the control box D, may be detailed as follows: 7

The signal timing mechanism includes a pair of magnetically actuated drums F and P which are rotatably mounted upon hollow, dead shafts 35. In the present embodiment these drums are identically constructed and therefore only one will be described. Attention being invited to Figs.

' 1, 2, 4, 5 and 6, it will be seen that one end of the drum is provided with a ratchet wheel 35,

adapted to be successively rotated the length of one tooth by a spring pawl 31, on an armature 38 which is moved by a magnet 38. A coiled spring 48, having one end secured to the dead shaft 35 and the other end to the drum, tends to keep the drum in its initial, nonactuated, or normal position, which position is determined by a stop 4| (on the drum) which meets an exten- "sion 42 of a supporting standard 43. When the drum is in this normal position and as shown in Fig. 5 an extension of the stop 4| contacts with "a spring terminal 44 and holds the latter normally away from a point terminal 45 thus keeping open a circuit through wires 45 and 41. when the magnet 38 is energized the drum is rotated, closing a circuit through wires 45 and 41. A dog 48, which is held against the ratchet wheel by a spring 48 resists the return of the drum, but a magnet 55 is arranged, when energized, to lift the dog and free it of the ratchet. A beak 5| is arranged at theother end of the dog membenand is depressed when the dog is lifted, and is so coordinated with the dog that the ratchet wheel 35 is permitted toreturn (by reason of the drum spring 40) the distance of one tooth by one impulse to the magnet 50.

On the surface of the drum are three pathways for brushes 52,058 and 54, which are the terminals respectively of

wires

55, 55 and 51, in drum F, and of

wires

58, 59 and 50- in drum P. The contact terminals of these wires are insulated from the members mounting the same. Parts of the brush paths are insulated, as shown in black, while the remaining portions, which form contacts with the brushes, are supplied by

individual wires

59, 5| and 58, in drum F, and by

wires

55 and 55, in drum P, and these wires are accommo- 1, 10, 11, 12, 13, 14 and 15,

dated by the hollow shafts or axles 35, this having been especially illustrated in Figs. '1, 8 and 9. The wires 5| and 55 arebranches of the main positive wire 33. When the F drum is in normal position the circuit is open between 58 and 55, and between 51 and 55, but is closed between the wire 5| and the brush 53 and wire 55. Any position of the'drum oiI normal reverses the open or closed conditions of these circuits. When the drum P is in normal position the circuit is open between 55 and 58, and between 55 and 58, but is closed between the

wires

55 and 53. Any position of the drum ofi normal reverses the open or closed conditions of these circuits similar to drum F. It may here be noted (see Fig. 6) that one tooth is missing in the ratchet wheel 35, and this limits the rotations of the drum by the armature 38, but, as the number of vehicles which can register between the approach" triggers H, J, L,

and N and the crossingtriggers I, K, M and 0.

is limited, due, for example, to the spacing which must be maintained between the vehicles, it is not necessary to provide for a greater number of registration teeth in the ratchet wheel. The entire

magnetic escapemcnt mechanism

48, 48, 55 and 5| is mounted on a large armature 52 pivoted as at 53. This armature, 'when lifted by the magnet 54, lifts the dog 48 and beak 5| so that the drum may be returned to its normal position.

The mechanical features of a pair of drums designated'as U and V, and illustrated in Figs. will now be described.

Drum U consists of a shell 55'- which is rigidly secured to but insulated from a flive" axle 55. A gear 51 is slidably keyed on but insulated from the axle 55, and rotatesthe drum when in mesh with a gear 58 which is insulated from the frame. The gear 51 is shifted into and out of mesh with the gear 58 by a fork 58 which is controlled by a solenoid 15 and a spring 1|. When the solenoid is energized the gears are meshed, but when dethe spring 1| restores the gear 51 to On the surface of this energized normal or idle position.

'drum 55 is a pathway 15 for a pair of contact brushes 12 and 13 insulated from each other, and which are carried by a rocker arm 14, tiltably mounted on a supporting rod 15. This pathway is divided into equal lengths of segmental "contact periods and no contact periods, which alternate on the surface. Thus, if the drum is rotated by the gear 58, it will be seen that for thirty seconds the brush 12 has active contact followed by thirty seconds of no contact, while the reverse is true for brush 13. These brushes are so arranged that when one has active contact with the drum the other does not, and vice versa. and the brush 12 has such contact when the drum is in normal position and for the first period of rotation thereof. The contact plates in the pathway are supplied by wire 18 via axle 55.

To insure the return of the drum 55, to its initial position when gear 51 is freed from the gear 58, I provide a coil spring 18, in a housing 83. This spring is under initial tension and is additionally wound up by the rotation of the shaft 55 when gears 51 and 58 are meshed. It conse-' returned by the spring 19. Since the drum may continue to revolve indefinitely means are provided for relieving the spring 19, as follows: Escapement dogs 85 and 86, which co-act with teeth 81 and I38 on the housing 80, are mounted on the member 83 from which projects the stop 82. The housing 00 is rotatable upon the shaft 65, and is prevented from revolving, as the spring tension increases, by the engagement of dog 85 with tooth Si or 88. As either of the teeth or stops M or 94 lift the stop 82 during the forward rotation of the drum 65*, however, it releases the tooth 85 and permits the housing torotate one half a revolution. Thus the tension of the spring 19 will be substantially uniform at all times. I The gear 68 is arranged upon a shaft 89' which is rotated by a motor T adapted to turn the shaft at a uniform speed. I

As previously stated the gear 68 only meshes with the gear 61 at certain times, but it is constantly in mesh with a gear 89 of the drum V, which I will now proceed to describe. This drum consists of an axle 90 and a'cylindrical member 9I,.rotated by-the gear 89. Two pathways 92 and from the members mounting the same. In what may be termed the initial position the terminal '95 of a wire 91, to the brush 94, will not receive a contact until one-half a revolution of-the drum or pathway is completed, at which time (for instance forty seconds) it will wipe the point contact 98 (see Fig. 14), which is supplied by a wire I01, via the axle 90. These terminal-pointsor contacts 98 and I06 are insulated from each other in their respective pathways-as illustrated in Figs. 14 and 15. The axle 90 is insulated from the frame and from drum 9I. If, however, a magnet 99 (or I00) is energized in the meantime the brush 94 is lifted above the contact where it is retained bya hook IOI, or I02, suspended from a bar I03. Thusno contact will be formed, as shown in Fig. 15. The hooks IOI extend laterally below the surface of the path- I ways 92, 93, where they are tripped by diametrically opposed pegs I04, I05, just after the terminal points 98 or I06 have passed beyond the contact position with terminal 96.

tact 96 to rest in rubbing contact on the pathway of drum 9I,,the hook IN is supported by bearing against the end of the brush 94 until the brush is again lifted by energization of magnet 99. Thus a failure of impulseto magnets 99, I00 during any forty second period will permit a point contact between the terminals of wires I01 and 91. (or I08 for magnet IlJIl). The circuit systems or electrical connections may be described as follows:

The main positive supply wire or cable 33, in

; addition to the trigger switch branches 25, 21,

29 and 3|, has the branch 6|, to the middle brush path of drum F; a branch 65, -to the two left hand brush paths of drum P; a branch I09, to an armature I I0; a branch III, to an armature M2; the branch I01, to the shaft so; and a After the hook IOI. is so tripped to allow the terminal concorresponding magnets of drum P; branches I2I and I22 of magnets 99 and I00, respectively; and a branch 523 to the timer motor T.

Assuming now that the vehicle actuated or' trigger switches H or J are closed indicating the approach of an east or west moving vehicle, two impulses (if a four wheel vehicle) will be sent through wire 20, thus energizing the magnet- 39 (of drum P) and causing the drum to be rotated two teeth ofi normal, the negative supply to the I magnet being wire I20. Brush 52 and wire 58 will now have contact with wire 56, wire 59 will break contact with wire 65, and wire 60 will have contact with wire 65. The wire :56, however, is not a live wire unless the drum F is normal, at which time the circuit will be completed through the wire 6| to the main supply wire 33. Granting this condition, the'wire 58 includes in its circuit a solenoid I24, and continues as wire I35 to give a positive supply to the signal lamps R, R, G and G, which signals the right-of-way to traffic traveling east and west on street B. The wire 59 which, when the drum P is normal, gives a positive supply to the contact plate in path I26 of drum F, is now dead. The wire 60 which now has' a positive supply from wire 65 gives a positive supply to contact plate in path I21 of drum F but that is as far as it gets since there is no 4 contact with wire 51 when drum F isnormal. Now as the vehicle proceeds to cross'the intersection it depresses and closes the triggerswitches I or K and the consequent impulses in wire 28 causes the magnet 50 (drum P) to Ilift the escapement 48 twice, thus releasing the drum twoteeth back to normal. In normal position again, the wire 58 becomes dead, the signal lights go out, the wire 59 gets a positive supply, and the wire 60 is dead.

The action is the same in drum F when a vehicle is crossing the intersection either north or south. The wire carries impulses that put drum F off of normal. The wire 55 now becomes positive charged, if the drum P is normal, and energizes a solenoid I35, and continues as wire I29 to give a positive supply to the .signal lamps RII, R1 of east and west traiiic, and GI, GI to north and south traffic. The wire 56 which gives a positive supply to contact plate in brush path drum so that it can return back the distance of two teeth to normal. I

It will thus be seen that when both, drums F and P are off normal, the

wires

55, 56 and 58 are dead, and the wires 60 and 51 are live with a positive charge. The wire 51 includes initscircuit the solenoid 10 which brings the drum U into rotation by intermeshing of gear 61 with the contacts on the contact arm I34, through one set of lamps, to wire II4,-and return wire 34. -This circuit also charges the contact plates of the path 16, one of which is in contact with either '

brush

12 or 13 as the drum rotates, and thus alternates the supply in wires I32 and I33, at intervals of thirty seconds. The first current of supply, however, passes through the brush I1 I and wire I32. The

wires

132 and 133 end in terminals on a switch arm I34, which is swung to' that side, and consequently when the other drum is of! normal both solenoids would be dead and the arm I34 would remain where 'it was last attracted. Terminal wires I31, I38, I39 and I40 are so arranged and connected that the wire the I32, during the first period of charge, would supply the signal lamps of the first drum to go off normal, and the wire I33 would connect with the signal lamps of the other drum. Thus, as long as both drums are off normal the signal lamps will alternate the trafiic right-of-way at thirty second intervals.

It is evident that tramc is far from uniform, and that odd arrangements of wheels, horse drawn vehicles and motor cycles, etc., would not always give the same number of impulses at both crossings and approach trigger switches. As long as traflic is waiting in both directions, so that both drums F and P are off normal, there will be no difliculty, as the signals would continually operate and alternate at thirty seconds intervals. when, however, a drum is oif normal, and no trafllc is waiting to cross in the direction signaled, complications which would disqualify the entire system might result; and to overcome this I provide the drum V, the function of which might be described as follows:

The magnets 33 and Hill are energized simultaneously with the drum magnet 33, via

wires

30 and 26, respectively, wires [2! and I22 giving the negative supply. Now, as previously explained, if no impulse is received in, for instance, magnet 33 via wire 33, during any forty seconds inter,- vals, contact 38 will remain on bar 32 and an impulse is sent through wire 91 from wire I01.

This passes to; a magnet I42, and the switch 4l43 (if the drum F is off normal) to the magnet 34. The magnet I42 lifts the armature or contact terminus 0 of the positive supply wire I33, to insure a steady supply in the wire 31 until the drum F is restored to normal, which represents no trailic waiting in the direction represented, and this should be correct if no crossing is made within forty seconds after the approach impulse.

It should be understood that in expressions such as within a time limit", within a predetermined time, and the like, occurring in'some of the claims, the term within" is used broadly as the equivalent of not later than in the sense that it includes the last instant of time.

Thus, among others, the several objects of invention as specifically afiorded are achieved. 'As before brought out, numerous changes in structure and rearrangement of the parts might be resorted to without departing from the spirit of this invention; it being obvious that the system may be amplified or modified both functionally and structurally according to the means at the intersection where the-particular installation is being made.

What is claimed as new, and desired to be protected by Letters Patent, is:

l. A tramc control system of trafllc lanes, said system including signalling for the intersection I means to accord and interrupt rlght-of-way to traflic approaching the intersection in such lanes, operating means for said signalling means, vehicle actuatable controls disposed in said lanes ,in advance of theintersection, means for connecting said controls to said operating means for operation of the latter to cause the signalling means to afford right-of-way to either one only of said lanes upon actuation only of the control therein, time controlled means for preventing accord of right-of-way to said one lane beyond a determined time interval of absence of actuation in both lanes after and measured from any such actuation of said control in said one lane, and further time controlled means forming a part of said operating means and responsive to actuation of the vehicle actuated control in a second lane for causing-in the event of continued control actuations in said one lane-said operating means to transfer right-of-way to said second lane prior to expiration of the determined inter val as timed by the first mentioned time controlled means.

2. A traffic control system for two intersecting streets including in combinationelectric signals normally deenergized and adapted when energized to display indications to accord right-ofway to the respective streets, trafiic actuatable means located at a distance from the intersection in each of said streets and adapted to be actuated momentarily by the passage of traffic thereby in approaching the 'intersection, rotary switching mechanism connected to said signals and trafiic actuatable means and having signal interlocking means including separate switching positions for the respective signals to prevent concurrent energlzation of the right-of-way signals in both streets, said mechanism including means operated by momentary actuation of the traffic actuatable means in either one only of said streets to immediately operate said switching mechanism to one position to energize one of said signals to accord right-of-way to said one street, and means operated by following actuation in said one street while right-of-way is so accorded to maintain such right-of-way, said mechanism also including means operated by momentary actuation of trafllc approaching on the other street after the one street and while right-of-way is accorded to said one street to condition said mechanism for subsequent transfer of energization to the right-of-way signal on said other street in the other position of said switching mechanism and to maintain said mechanism so conditioned to cause transfer of rightof-way to said other street immediately upon cessation of trafiic on said one street, said control mechanism also including means for assuring deenergization of said signals again following said transfer within a time limit from cessation of traffic in said other street while traflic is absent from said one street.

3. A vehicle, control system for the intersection of two vehicle lanes including signalling means to accord and interrupt right-of-way in such lanes, operating means for said signalling means, means responsive to the approach of a vehicle toward said intersection over either one of such lanes to cause said operating means to accord right-of-way through said signalling ating means and responsive to the approach of a vehicle in the second of the two vehicle lanes to transfer right-of-way through said signalling means to said second lane upon the spacing of such vehicles in said one lane exceeding a predetermined amount while said one lane has rightof-way in its favor, and timing means connected with said operating means and said signalling means to cause transfer of right-of-way to said second lane within a maximum time limit from such approach of trafiic in said second lane as indicated by the responsive means and in the event that the right-of-way is maintained up to such limit on said one lane by vehicles thereon whose spacing does not exceed such predetermined amount.

4. A trafiic control system for the intersection of two vehicle lanes, including signalling means to accord and interrupt right-of-way and transfer right-of-way between such lanes, means responsive to the approach of a vehicle only in one of such lanes to operate said signalling means to I accord right-of-way to said one lane and internalling means for transferring right-of-way to rupt right-of-way in the second lane, means responsive to the subsequent approach of a vehicle in said second lane while right-of-way is so accorded to said one lane to potentialize said sigsaid second lane, means responsive to the approach of additional vehicles in said one lane following the first vehicle therein while right-of-way is so accorded to said one lane to cause said signalling means to prolong such accord of right-ofway in said one lane and delay such transferring of right-of-way, and means providing a maximum time limit to such prolongation of accord of right-of-way from such potentialization whereby transfer of right-of-way to said second lane is assured within said time limit.

, 5. A trafiic control system for the intersection of two vehicle lanes, including signalling means to accord and interrupt right-of-way and transfer right-of-waybetween such lanes, means responsive to the approach of a vehicle only in one of such lanes to operate said signalling means to accord right-of-way to said one lane and interrupt right-of-way in the second lane, means responsive to the subsequent approach of a vehicle in said secondlane while right-of-way is so accorded to said one laneto potentialize said signalling means for transferring right-of-way to said sec-- ond lane, means responsive to the approach of additional vehicles in said one lane following the first vehicle therein while right-of-way is so accorded to said one lane'to cause said signalling means to maintain right-of-way in said one lane longer than bysaid first vehicle and to correspondingly delay such transferring of right-ofway, and means for causing transfer of right-ofway to said second lane at a predetermined time limit from such potentialization in the event right-of-way is so maintained by additional vehicles in said-one lane up to such time limit.

6. A trailic control system for intersecting streets including in combination right-of-way signalling means forthe respective streets, traflic responsive means in each street, rotary switching devices one for each street, each switching device having a normal inactive position and an 011 normal position and adapted to be rotated from said normal position to said off normal position by traffic approaching on its associated street,

' a timelimit release mechanism connected to each latter means and connected with each such device for returning it to normal position within a time limit from any cessation of traflic approaching on its associated street, energimng circuits for the respective right-of-way signals passing through both of the switching devices so as to operate the signalling means to accord initially right-of-way to whichever street has its rotary switching device ofl. normal only while the other device is on normal and to prevent accord of right-of-way to the other street and maintaining said right-of-way even though said other device is subsequently rotated to 011 normal position while said first device is oif normal, and locking 1 members associated with said devices for main taining said other device oif normal when so rotated by traflic approaching in said other street and waiting for right-of-way while the first menoiT normal positions and adapted to be rotated from said normal position and through a number of said ofi normal positions by. vehicles approaching on its associated street the number of such latter positions through which it is rotated being proportional to the number of such vehicles, means in the switching devices cooperating to operate the signalling means to accord right-ofway in whichever street has its rotary switching device 011 normal while the other device is on normal, and means connected with each said rotary switching device to restore it back through such successive ofi normal positions to normal position upon the passage of all such tramc from its associated street.-

8. A trafflc control system for intersecting streets, including in combination, right-of-way signalling means, tramc responsive means in each street and including one means located at a distance from the intersection and adapted to be actuated by trafiic approaching theintersection on'the street and another located near the intersection and adapted to be operated by trafflc crossing the intersection 'on such street, rotary switching devices, one for each street, having a. normal position and a plurality of successive of! normal positions for operating said signalling means, means operated by a plurality of actuations of the distant responsive means in either one street only to rotate its associated switching device from normal position through a number of such ofl. normal positions corresponding to the number of such actuations, means connected with said device to maintain it in off normal position after each such actuation, and means operated by a corresponding plurality of actuations of the near responsive means in said one street to interrupt said last named means and cause said device to return back through such of! normal positions to normal position, and means operated by said device in its off normal position, to operate said signalling means to accord right-of-way to said one street; whereby right-of-way is normally accorded to said one street upon traflic the intersection. Y

9. In a traflic signal system for intersecting streets, a signal device for indicating go and stop signals on the streets, means for substantially immediately initiating the operation 0'! the signal device upon an impulse received when a vehicle approaches the intersection from either one of the streets, and means for causing the go" signal to be given only to the street first receiving an impulse and then causing the go" signal to be given only to the other street receiving a subsequent impulse while the go signal is so indicated to the first street, each for predetermined periods beginning with the first impulse on said other street and in response to subsequent impulses received by the signal initiating means for both streets and continuing throughout said predetermined periods.

10. A traflic control system for two intersecting streets, including. in combination electric signals normally deenergized and adapted when energized to display indications to accord right-ofway to the streets, control mechanism for operating said signals responsive to trafllo in the streets, said mechanism having means to prevent concurrent energization of the right-of-way signals in both streets, and including means responsive to traflic approaching on only one of the streets to immediately energize one of said signals to accord right-oi-way to said street and maintain said one signal so energized in response to further trafllc in said one streetjandmeans responsive to trafllc' approaching on the other street after the one street and while right-of-way is accorded to said one street to condition said mechanism to cause subsequent transfer oi rightoi-way to said other street immediately upon cessation of traific on said one street, and means for assuring deenergizationof said signals within a time limit from cessation oi. trailic in both streets.

11. In a traillc signal system for intersecting streets, 8. signal device for indicating go and "stop signals to each street, means associated with one street for receiving energizing impulses from traflic on said street for operating the signal deviceto indicate go to that street and ,stop to the cross street, means associated with the cross street for receiving energizing impulses from trailic on said cross street to operate the signal device to indicate go to the cross street and "stop to said one street, and means cooperating with both of said impulse receiving means and operated when the means associated with said cross street is energized subsequently to the means associated with said one street and as long as both remain energized to determine the maximum time at which go signal indication shall be so taken from said one street and given to said cross street in response to and measured from the first or said impulses received by said cross street means.

12. In a trafllc signal system for intersecting streets, a signal device for alternately indicating go signals to one street and stop signals to he cross street, impulse receiving means for one street and associated means in said one street for energizing said impulse receiving means to street and stop on the cross street in response to traffic solely on said one street, impulse receivingmeans for the cross street and associated means in the cross street for energizing said means subsequently to cause go" to be indicated to said cross street and stop to said one street in response to traffic on said cross street, and

substantially immediately indicate go on one means for associating the concurrent operation of said impulse receiving means for said streets including a timing means to determine the maximum time at which the go signal shall be given to the cross street and the stop" signal to said one street in response to and measured from the impulse received by said cross street means and the maximum time at which the last-named signals are reversed in response to and measured from a further-impulse from said one street, whereby go and stop signals shall be alternately given to said streets at maximum times when the impulse receiving means are repeatedly and concurrently energized.

13. A vehicle control system .to be installed at the intersection of two vehicle lanes including signalling means to accord and interrupt rightoi-way to vehicles moving over such lanes, op-

crating means for said signalling means, means responsive to the approach oi a vehicle over one of said lanes to cause said operating means to function to accord through said signalling means right-oiway to such vehicle and to maintain such 'right-oi-way in the case of vehicles following the first vehicle in the same one lane and within a predetermined spacing interval from said first vehicle and from each other, means responsive to the approach of a vehicle over the second of the two lanes to potentialize said operating means for transfer of right-oi-way to said second lane, and means forming a part of said operating means to assure that such transfer of right-ofway to said second lane will occur before the exp'iration oi. a predetermined interval of time measured from and following such operation of the vehicle responsive means in said second lane regardless of the vehicles following within .such predetermined spacing in said one lane.

14. A traffic control system to be applied at the intersection of two vehicle lanes and including signalling means having right-of-way according means and right-of-way interrupting means for each lane, operating means for said signalling means, vehicle actuatable means in each lane and connected to said operating means, normally inoperative timer means for activating when operative said operating means for alternating through said signalling means the rright-oi-way between the said lanes for predetermined periods, and means responsive only to substantially continuous vehicle actuation on both lanes to cause said timer means to become and be maintained operative to time said periods, said timer means becoming inoperative again immediately upon cessation of vehicle actuation in one of said lanes.

15. A trailic control system to be applied at the intersection of two vehicle lanes and including signalling means having right-oi-way according means and right-of-way interrupting means for each lane, operating means for said signalling means, vehicleactuatable means in each lane and connected to 'said operating means, normally inoperative timer.means for activating when operative said operating means for alternating through said signalling means the right-oi-way between the said lanes and for maintaining such right-of-way for predetermined times, and means responsive to vehicle actuation on both lanes to cause said timer means to become operative, and means responsive to subsequent cessation of ve hicle actuation only on a lane to which rightof-way is accorded to cause said timer to return to inoperative condition and to cause substantially immediate transfer of right-of-way to the other lane.

16. A traflic control system for two intersecting streets; including in combination, electric signals adapted to be illuminated when energized'to display indications according right-of-way in one street while interrupting right-of-way in the other street, control mechanism for maintaining said signalling means normally deenergized in the. absence of traflic on either street, and operating to energize said signals immediately inresponse to the approach of traflic only on said one street, and means operated by the approach of traific on said other street when said signals are so energized to provide a time limit to such energization of said signals from such approach of traffic on ,said other street to assure deenergization of such signals interrupting right-of way in said other street within such time limit.

17. A trafllc control system for two intersecting streets, including in combination electric signals adapted to be illuminated when energized to display indications according right-oiway in one street while interrupting right-of-way in the other street, control mechanism for maintaining said signalling means normally deenergized in the absence of traflic on either street, and operating to energize said signals immediately in response to the approach of traflic only on said one street and to maintain such signals energized in the event of closely spaced following traflic in said one street, and means operated by the approach of traflic on said other street, when said signals are so energized to provide a time limit to such energization of said signals from such approach of trafflc on said other street to assure'deenerg'ization of such signals interrupting right-oi-way in said other street within such time limit, in the event .of continuation of approach trafflc.

18. A traffic control system for two intersecting streets, including in, combination electric signals normally deenergized and adapted when energized to display indications to accord right-ofway alternately to the streets, control mechanism responsive to trafiic in the streets and opersting in response to traihc only on one street to energize said signals immediately to accord right-of-way to said one .street, and adapted to operate in response to traflic only on the other street to energize said signals immediately to accord right-of-way to said other street, and means nism responsiveto'traflic in the streets and operating in response to traflic only on one street to energize said signals immediately to accord right-of-way to said one street, and adapted to operate in response to trafiic only on the other street to energize said signals immediately to accordright-of-way to said other street, and means associated with said control mechanism to cause alternation of right-of-wayat determined time intervals through said'signals in the event of continued approach of traffic in both streets,-and protective means to insure deenergization of said signals within a maximum time i i i of such following a limit after cessation of traflicin both streets and if such signals remain energized up to such limit.

20. A tramc control system for two intersecting streets, including in combination electric signals normally deenergized and adapted when energized to display indications to accord rightof-way alternately to the streets, control mechanism responsive to traflic in the streets and operating responsive to'traflic approaching on only one of the streets to immediately energize said signals to accord right-of-way to said street, and means responsive to traffic approaching on the other street after the one street and while rightof-way is accorded to said one street to cause transfer of right-of-way to said other street im mediately upon cessation of traflic on said one street, and means connected with said control mechanism and operating within a predetermined time aft'er and beginning with such trafiic approaching on said other street to cause transfer of right-of-way to said other'street in the event of continued traillc approaching on said one street during such predetermined time.

21. A traflic control system for intersecting streets, including in combination right-of-way signalling means for the respective streets, traflic responsive means for each street, rotary switching devices one for each street, each switching device having a normal inactive position and connected with the traffic responsive means of its associated street so as to be rotated to an off normal position by tramc approaching on its associated street, energizing circuits for the re-- spective right-of-way signals passing through both said switchingdevices to operate the signalling means to accord right-ofTWay in whichever street has its rotary switching device oiT normal while the other device is on normal, and a timed rotary switching mechanism having an energizing circuit closed through both said de-' vices only in their off normal positions and having alternate switching positions to energize the,

said right-of-way signal alternately to accord right-of-way alternately first to the street whose device was first off normal, and then to the other street for determined time intervals and a time limit release mechanism for said devices and connected to the respective trafic responsive means to have the time limit reset by actuation of the latter means and connected to the-respective said devices so asto return the latter to normal position at the expiration of such time limitafter an actuation-in the absence of resetting of said time limit .by a subsequent actuation within such time limit,

22. A traflic control system for intersecting streets, including in combination right-of-way.

signalling means, traffic responsive means in each street and including one means located at a distance from the intersection and adapted to be actuated by traflic' approaching the intersection on the street and another located near the intersection and adapted to be operated by traffic crossing the intersection on such street, rotary switching devices for operating said signalling means'and having a normal inactive position and a plurality of successive of! normal positions, one

such device being provided for each street, means operated by one actuation of the distant responsive means in one street to rotate its associated switching device to the first oii normal position and by subsequent actuations of said distant responsive means to rotate said device successively through said successive otf normal positions,

-,means operated by each actuation of the near responsive device to rotate said device back one position toward normal whereby after all traillc which approached has passed the said device will be restored to said normal position, and means operated by said device in its ofi normal position to operate said signalling means to accord right-of-way to said one lane.

23. A trafllc control system for intersecting streets, including in combination right-oi-way signalling means for the respective streets, traffic responsive means in each street and including one means located at a distance from the intersection and adapted to be actuated by trafllc approaching the intersection on the street and another located near the intersection and adapted to be operated by trailic crossing the intersection on such street, rotary switching devices one for each street having a normal position and an off normal position for operating said signalling means, and means operated by actuation of the distant responsive means in one street to rotate its associated switching device to of! normal position, a locking member connected with said device to maintain it in oil normal position after such actuation, and means including a release member for said locking member operated by actuation of the near responsive means in said one street to interrupt said locking member and cause said device to return to normal position, energizing circuits for said signals paming through said switch devices such that one cit-'- cuit is'energized by said device in its oil normal position to operate said signalling means to accord right-of -way to said one lane, and a time limit release mechanism. for said device and connected to thedistant responsive means to have its time limit reset by actuation of the latter so as to operate within a time limit after the last such actuation of the distant responsive means to restore said device to its normal position in the event it has notbeen already restored by actuation of the near responsive means.

24. A traffic control system for intersecting streets, including in combination right-of-way signalling means, trafic responsive means in each street and including one means located at a distance from the intersection and adapted to be actuated by traflic approaching the intersection on the street and another located near the intersection and adapted to be operated by trafflc crossing the intersection on such street, rotary switching devices one for each street having a normal'position and an off normal position for operating said signalling means, and means operated by actuation of the distant responsive means in one street to rotate its associated switching device to oil normal position, means connected with said device to maintain'it in oil normal position after such actuation, and means operated by actuation of the near responsive means in said one street to interrupt said last named means and cause said device to return to normal position, means operated by said device in its off normalpositiorr to operate said signalling means to accord right-of-way to said one lane, and a timed cyclic signal switch connected to said signalling means and having an energizing circuit connected with the several switching devices and so as to be operated by the latter when they are all off normal to cause right-of-way to be successively accorded to the streets for predetermined time intervals.

25. A trailic control system for the intersection 4 oi. two traflic lanes and including signalling means for according and interrupting right-of-way to the said lanes, normally inactive timer means operative when active to cause said signalling means to alternately accord right-of-way to the several lanes and for timing the alternating periods oi right-oi-way, means responsive to the approach of a vehicle in only one lane to cause accord of right-of-way substantially immediately to said one lane and means responsive only to the approach of a vehicle in the second lane while rightoi-way is so accorded to said one lane to render said timer active to start such timing.

26. A trafiic control system for the intersection of two traflic lanes and including signalling means for according and interrupting right-of-way to said lanes, tramc actuatable means in each lane,

operating means for said signalling means to cause accord oi, right-of-way to eitherlane in which the traflic actuatable means is first actuated, means forming a part of said operating means and operable upon actuation in either one lane while right-of-way is so accorded to the other lane to assure the transfer of right-of-way from said other lane to said one lane within a predetermined maximum period from such actuation in said one lane in the event of continued accord of right of way to said other lane up to such maximum.

2'7. A tramc control system for intersecting traflic lanes and including signalling means for according and interrupting right-oi-way to said lanes, operating means for said signalling means andincluding one mechanism responsive to the approach and passage of individual vehicles in one of said lanes so as to accord right-of-way to said one lane upon the approach of such vehicles and to terminate right-of-way upon the passage of such vehicles, a corresponding mechanism for the other lane, interconnecting means to prevent the according of right-of-way to one lane while rightof-way is accorded to the other lane, and time controlled means for terminating right-oi-way on either lane to which it is accorded within a predetermined time limit after the last vehicle approaches on such lane and in the event such right-of-way is not previously terminated by action of said mechanisms upon passage of trafllc.

28, A trafllc control system for intersecting trafllc lanes and including signalling means for according and interrupting right-of-way to said I lanes, operating means for said signalling means and including one mechanism responsive to the 'approach and passage of individual vehicles in one of said laries so as to accord right-of-way to said one lane upon the approach of such vehicles and to terminate right-of-way upon the passage of such vehicles a corresponding mechanism for the other lane, interconnecting means to prevent the according of right-of-wayto one lane while right-of-way is accorded to the other lane, and time controlled means for terminating right-of- .way on either lane to which it is accorded within a predetermined time limit after the last vehicle approaches on such lane and in the event such right-of-way is not previously terminated by ac-' tion oi. said mechanisms upon passage of traflic and further time controlled means operable as long as both of said mechanisms are operated in response to the approach of trafllc to alternate right-of-way between the lanes of said mechanisms for predetermined times.

29. A traflic control system .to be applied at the intersection of two vehicle.lanes and including signalling means for according and interrupting right-of-way to the said lanes, normally inactive timer means operative when active to cause said signalling means to display right-of-way alternately to the lanes and for timing the period of such alternating display, and means responsive solely to vehicles concurrently present in both lanes for immediately activating said timer means for starting such timing.

30. In a traflic signal device, the combination with a signal adapted to be disposed at the intersection of two or more thoroughfares and having trafiic directing means thereon'adapted to be displayed alternately to direct traffic to proceed on one thoroughfare and restraining traflic on another thoroughfare, a trailic operated device for one of said thoroughfares, means actuated by operation of said device for setting the signal to direct traffic to proceed on said thoroughfare, a

trailic operated device on the other thoroughfare, means actuated by operation ofsaid last mentioned device for setting the signal for trafiic to proceed on said last mentioned thoroughfare, means actuated by operation of said first men-. tioned traffic operated device in so setting the signal and in a plurality of subsequent operations thereof while the signal is so set for preventing the signal being set by operation of said last mentioned trailic operated device for a certain definite period of time, and means whereby said means actuated by operation of said last mentioned traflic operated device will change the signal as soon as said period of time has elapsed to' direct traffic to proceed on the thoroughfare in which said last mentioned trafiic operated device is located.

31. A vehicle control system to be arranged at the intersection of two vehicle lanes and comprising signalling means including right-of-way according means and right-of-way interrupting means for each lane, operating means for said signalling means, vehicle actuated means associated with said lanes and connected to said operating means to govern the functions of the latter and to control said signalling means to accord right-of-way to that lane over which a vehicle is approaching the intersection subsequent solely to the operation of the vehicle actuated means of such lane by such vehicle, means for maintaining the right-of-way so accorded, further vehicle actuated means in such lane for releasing the rightofway maintaining means so as to extinguish such right-of--way, upon passage of such vehicle and means forming a part of said operating means and functioning in absence of proper operation of said further vehicle actuated means to extinguish the right-of-way so accorded within a predetermined time interval after the last operation of the first named vehicle actuated means.

32. A vehicle control system to be arranged at the point of intersection of two vehicle lanes and comprising signalling means for according and interrupting right-of-way in each lane, operating means for said signalling means, vehicle actuated means associatedwith said lanes and connected to said operating means to govern the functions of the latter to control said signalling means to substantially forthwith accord right-of-way to that lane over which a vehicle is approaching the intersection and in response to the operation of the vehicle actuated means of such lane, means for maintaining the right-of-way so accorded, means functioning in response to operation of the vehicle actuated means of the second lane and during right-of-way period of such first lane to potentialize said operating means to transfer right-of-way to said second lane, and means acting upon the expiration of a predetermined period of time from such operation of the vehicle actuated means in the second lane to cause such transfer of right-of-way by said signalling means in the event the operating means has continued to give the right-of-way to such first lane.

ROBERT C. NELSON.

CERTIFICATE OF CORRECTION; Patent No. 2,1 5,525. November 19 ROBERT o. NELSON.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, second column, line 69, for drum 65" read drum 65 page 11,, first column, line l O', for "magnet" read magnets; and second column, line 9, claim 1, for the word "afford" read accord; line 11, same claim, after "therein" and before the comma, insert and maintain right of way in said one lane by continuedactuations only of the control therein; line 16, after "means" insert having a-shorter time period than the first time controlled means and; line 19, same claim 1, after "lane" insert during accord of right of way to said one lane; page 6, first column, line 68, claim 12, before "substantially" insert operate the signal device to; lines 72 and 75, same claim, for "said means subsequently to" read the latter impulse receiving meanssubsequently to operate said device to; and second column, line for "given" read transferred; lines 7, 8, 9 and 10, same claim 12, for "and the maximum time at which the last-named signals are reversed in response to and measured from a further impulse from said one street" read in the event that the latterimpulse occurs while "G0" is indicated to said one street and to determine the maximum time at which the :signals so transferred are thereafter next reversed; line 11 after "concurrently" insert so; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case inthe Patent Office.

. Signed-and sealed this 2nd day of January, A. D. -19LLo.

Henry Van Arsdale,

(Seal) Acting Commissioner of Patents.