US1665560A - Variable traffic signal - Google Patents

Description

April 10, 1928. 1,665,560 R. o. NELSON VARIABLE TRAFFIC SIGNAL Filed May'16, 1925 2 She ets-Sheet 1 r 42 I 7 8a jflflniar B08591 0. IVE: $0M 5 April 10, 1928.

R. o. NELSON YARIABLE TRAFFIC SIGNAL 'f7 .9% R '28 l .23 $4- 2 Sheets-Sheet 2 jrzyfzfor B06597 Q/Va son PATENT, OFFICE.

ROBERT 6L,NELSON, OF PORTLAND, OREGON VARIABLE TRAFFIC SIGNAL.

Application and m 16, 1925. Serial No. 30,865.

This invention relates to traflic controlling and regulating devices, and the primary object is to provide an automatic signalling device at the intersection of a main or arterial highway and a cross road which ordinarily accommodates a lesser amount of trafiic, whereby the right-of-way will be constantly maintained on the big way untll a vehicle on the cross road approaches the intersection, whereupon the signalling system will be reversed, by being actuated by such vehicle, to give it the right-of-way across the highway, after which the right-of-way sig-i na s again revert to the highway or main traiiic. A further object consists in providing means whereby the right-of-way will be automaticall alternated for periods of, for instance, t irty' seconds to each road when trailie is constantly approaching the intersection on the cross road. Still further and more specific objects will be disclosed in the course of the following specification, reference bein had to the accompanying drawings, w erein:

Figure 1 is a plan view of a street or road intersection, showing the position of the tri ger switches in the cross road.

Figure 2 is a sectional elevation through one of the trigger switches.

Figure 3 is .a diagrammatic plan view showing the wiring and connections of the electrical control system.

Figure 4 is a plan view of a magnetic "switch employed in the circuit system.

Figures 5 and 6 are end and side. views, respectively, of theswitch shown in Figure 4. v

Figure .7 is a sectional line 7-7 in' Figure 4.

Figure 9 is an elevation of an alternator used in the device. r

Figures 8, 10, 11, 12, and 13 are sectional views as seen substantially on the respective lines- 8-8, 10-10, 11-11, 12-12, and 13-13, in Figure 9.

. Referring to the drawingsmore particu larly and by reference characters A designates a north and south street or read, hereinafter referred to as the highway, which is crossed by an east and west street B, hereinafter designated as the cross road, and at r the middle point of the intersection is a conventional signaling standard C, in the base of which may be arranged the control box D. The signals may be of any of the well known types in which the Stop and v elevation on the HEISSUED 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. Thus in Figure 3 I have indicated signal lamps R, R as the red or stop lamps for the highway, and these lamps are circuitously connected with the lamps G, G, which are thegreen or Go lamps of the cross road; while the R, R Stop lights for the cross road are connected in circuit with and are simultaneously energized with green Go lamps G, G, which give the right-ofway to the highway traflic, and stop the cross road trafiic.

The circuit controlling mechanism (later to be described) which controls the two cir-' cuits to the lamps in the signal, is preferger switches may be greatly varied and modified but a preferred form is illustrated in Figure 2 and is substantially the same as the trigger switch shown in Figure 3 of my copending application for patent Ser. No. 695,- 596, which was filed on February 27, 1924, for automatic variable traiiic regulator. It consists, primarily, of a box or casing 13 which is imbedded in the street, and has a plate 10 pivotally secured therein, as at 11. Theswinging end of the plate 17 has a flange 12 which tends to keep the box closed when the plate is. in its raised position. The plate 17 is normally retained in an inclined or raised position as shown, by a spring 14, but when travelledover by the wheel of a vehicle, is depressed to a flush or horizontal position where it steps. A pair of switch terminals 15 and 16 are respectively secured to the plate 10 and box 13, and close together when the plate is depressed, and thus close a circuit through wires 17 and 18 which lead 30 the control box through a suitable conuit.

tBefor'e tracing the circuits in-an-d to the control box and'to the lighting group and trigger switches, the mechanistic mechani- 32. A solenoid 23is mounted on the base and serves, when energized, to pull a lever 24 down against the yielding tension of a spring 26.. When ,the solenoid is de-energized, the spring 26 tends to restore the lever 24to its upper position, as shown in Figures 5 and 6. This upward movement is retarded, however, by an air check consisting of a pivoted cylinder 28 in which operates a piston 27 which is connected-to the outer extremity of the lever 24. A second lever member '29 is arranged parallel with the lever 24, and, like the latter, is pivoted at its rear end to the wall 31, while the forward ends of both lovers are guided by being slidable in vertical slots in the'wall 32. The lever 29 is yicldingly raised by a spring 33, and is depressed #by alaterally projecting finger 25 of the lever 24. WVhen the lever 29 is released by the finger25 it is retained in its" lowered position by a bell crank catch member 37 which is pivoted on 32 and retained by a spring 38. When the lever 24 now returns to its fullupward positions, it moves the member 37 to release the lever 29, whereupon the latter may also return to its upward position. The terminal of a wire 39 is mounted at the-'outer'end of the lever 29 so that it will close a switch with a wire 43 the terminal of which is stationary on the wall 32. 39ris also a supply wire to the solenoid 23. The lever 24*is arranged to be retained in its lowered position by a bell-crank hook member 34, which is retained in engagement by "a magnet 35, supplied by wires 43 and 59, but Which is released by a. spring 36, when the magnet is de-energi'zed.

The alternator indicated in Figure 3 and shown more in detail in Figures 8 to 13, inclusive, will now be described as follows: A shaft 4O is journaledin suitable end brackets 40. A drum 50is rigidly secured on the shaft to rotate with it, and a drum 51 is rotatably mounted on the shaft. The drum 50 has a. ratchet wheel 49 adapted to be engaged by a timing unit or mechanism when a circuit is closed through the wires 43 and 54. The timer T may be of any common and well known construction which is capable of lifting and dropping an arm or dog 68 at regular intervals so as-to turn the ratchet wheel 49 the length of one tooth for each elevation of the dog. A pawl 67 is brought to bear against the ratchet wheel 49 by a magnet- 66 which is also placed in the circuit 4354. It will thus be seen that the pawl 67 will prevent the reverse rotation of the ratchet wheel when the latter or lug 70 or 71 on the drum. As the with the lever 24 road trafiic to actuate being rotated allow the wheel t sition when the timer is inactive and the circuit 43- 54 is broken.

Within the drum 51 the shaft is enlarged as at 40 {Fig 11) and to it is fastened one end of a coil spring 69, the other or outer end of whichis secured tothe inner face of the drum. Now when the shaft is rotated,

by the drum 50, the spring 69 winds itself about the shaft. tionary, against the-rotatingtendency of the spring, by a pawl 72, which is held against the periphery of the drum by a spring 73, and releasably engages the stop shaft 40 continues to rotate it will be evident that the spring tension would soon become excessive, and-t0 relieve this tension (without reversing the drum) 1 provide the drum 50 with a pair of diametrically opposed tripping lugs 7 3 and 74, which at certain intervals in the movement of the drum 50 act against a projection 76 of the pawl 72, and releases the latter from the lugs 70, 71. To

prevent the drum 5,1.from returning too rapidly, when so released, Tprovide a small governor 78 which is operatively associated with the drum through gears 77 and 52.

'VVhen the ratchet wheel 49 is freed from the timer T, the spring 69 will reverse' the direction of the shaft and also the drum 50. This reverse movement iswchecked, however, by thearm 76 of the" pawl 72, which engages either of the teeth 74 or 73 to stop the drum 50 in an initial position.

An essential F or primary alternator is mounted on the drum- 50 and consists of a peripheral path 48448 (Figs. 9, 10) having alternating conducting and non-conducting areas which rotate in contact with brushes- 44 and 45,-which are yieldingly retained in contact with the path by springs 47, and which are terminals for wires 42 and 41, respectively. The conducting areas 48 are supwires 48 from a member 46 on the shaft 40, which in turn is supplied through its journal in the bracket 40 by the wire 54. The initial position of the drum is such that the terminal brush 45 will have contact with an intermediate point .on one of the areas 48. I The circuit wiring will now be set forth.

Wires 21 and 22 represent the power sup-" ply, which, for convenience :in tracing we can assume .to be negative in wire 22. When there is no cross therewill bea closed circuit through the elements 21, 54, 40 40, 46, 48 48, 45, re, and 22, thus lighting the lamps R, R and G G and giving a constant right-of-way to the traffic on the highway. Now when an east or west bound vehicle approaches the intersection on the cross road, it depresses initial popositive in wire 21, and

the switches E or F the plate 10 of the trigger switches E or F,

and in so doing closes a circuit between the wires 17 and 18, and energizes the solenoid 23, via 39 and 18, resulting in the closing of a contact between the terminals 39 and 43 as above described; The wire 43 now gives a negative supply to the. magnet 35 and the timer T of the alternator, and the wire 54 carries a positive charge to the timer and to the contact areas48. Thus the timer is actuated as soon as the contact between 43 and 39 is made. A branch 59 of the wire 42 carries a positive charge, when the terminal 42 has contact with'48of the alternator, to the retention magnet 35, and consequently the magnet 35 is'energiz'ed while 4339 is closed. When a circuit is closed through wires 42, then the signal lampsG, G and R R are supplied, signalling the right-of-way to the highway traflic as 57 is the negativewire to all the lamps, and when the wire 41 is. charged then the opposite lamps G,- G, R, and R are energized, to signal the right-of-way to traflic on the cross road.

In order that a bell signal of short duration may be given, as the right-of-way is changed from one direction to theother, I provide a thermal switch in each of the circuits of 41 and 42. Each of these switches is constructed so that it will break the circuits through wires 63 and 64, to the bell 61, shortly after the current starts flowing in 41 or 42. To avoid short circuits separate circuits are provided for the/bell by way of a negative wire 62 to the wire' 57.

Having now described the construction and action of the device and its various parts, it will be understood, that the right-.

of-way wall be constantly retained on the highway until approaching cross traffic has depressed. one of the trigger switches E or F. and for a brief period of time thereafter, such eriod bein half the length 0 contact area 40 (Fi 10), thus permitting a steady flow of tra c on the highway as long as possible, and shortly after the circuit 17-18 is closed by a cross road vehicle, the right-of-way will be transferred to the cross road, and the vehicle will be given ample time, to .cross the highway.

'This time will of course, be determined by to render about fifteen seconds or,

'viding, however, that such modificationsa highway lamp circuit and a cross-road lamp circuit, a time controlled switch asso-- ciated with said circuits for alternately open ing and closing the same, said switch being normally idle in an initial position, so as to normally retain the highway circuit closed and permit highway trafiic to cross the intersection, means actuated, by avehicle ap-,

proaching the intersection on the'cross road for actuating the switch so as to alternately de-energize the highway circuit and energize the cross road circuit to successively signal the right-otway to the cross road and highway, said means including the time controlled switch and being operative for automatically restoring the switch and the lamp circuits to their initial conditions.

. 2. A street crossing signal system including a pair of signal circuits, one circuit including a signalto indicate Stop and the other to indicate Go, switching means nor;

mally maintaining the Go signal circuit closed and the Stop si nal circuit open and movable through a cycle to first reverse and then restore to'normal the circuit conditions, normallyinactlve t1me controlled means for moving. said swltchmg means throu h its.

cycle, vehicle actuated means for rendering sa d tnnecontrolled means active, and means operated by the switch at the end of its cycle the time controlled means again inactive.

3. A. street crossing signalling system including a pair of signal circuits, one circuit including a signal to indicate Stop and the other to indicate Go, switching means movable through a cycle for alternately energizing said circuits,-normally inactive time controlled means for moving said switchin means through its cycle, vehicle actuate means for rendering said time controlled means active, and means including the switch its for, restoring the time controlled means to its inactive condition.

" 4. A street crossing signalling system includinga pair of signal circuits, one cirthe other to indicate Go, switching means movable through a cycle for alternately energizin said circuits, normally inactive-time control ed means for moving said switching means through its cycle, vehicle actuated means for rendering said time controlled means active, and means 0 erated by the switch at the end of its time cycle, for rencuit including a signal to indicate Stop and flexing" "iimc cnmrniicd nicnns again in- .i sheet crnssing signaiiing system insin n pair of signal circnitsynnc circuii; inciuciing a signal to indicate Stop and the c'tiicr i0 indicate G0, the G0 signal circnii; which is narmally closed and the Stow signal circuit open, a normally inactive chime controlled switching means for successiveiy and aiiernately reversing the open ture,

ROBERT 0. NELSON

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