US2119593A - Traffic signal system - Google Patents

Description

June 7, 1938. A. F. MARTEL TRAFFIC SIGNAL SYSTEM Filed April 20. 1936 2 Sheets-Sheecl FIG.

' INVENTOR; MARTEL ADELARD F.

ATTORNEY June 7, 1938. V MARTEL 7 2,119,593

TRAFFIC SIGNAL SYQSTEM Filed April 20, 1936 2 Sheets-Sheet 2 FIG. 2.

FLA SHER INVENTOR ADELARD F. MARTEL BY M ATTORNEY Patented June 7, 1938 TRAFFIC SIGNAL SYSTEM Adelard F. Martel, Burlingame, C'alif., assignor of one-half to George W.

Calif.

Gates, Burlingame,

Application April 20, 1936, Serial No. 75,357

1 Claim.

This invention relates to improvements in trafflc signal systems and more particularly to combined control and timer apparatus for signal systems put into operation by a trafic trip switch buried in the trafiic lane. The present signal system is particularly useful for intersections of main highways and less travelled lateral cross roads.

Among the objects of the invention is to provide simple and reliable control means for oper ating the traffic signals to clear the right of way for a predetermined period when a vehicle depresses the trip switch buried in the crossroad trafiic lane.

Another object is to enable an uninterrupted flow of trafiic along the highway except when a vehicle approaches the intersection from the crossroad.

. Another object is to provide for alternate timed stop and go signals on the highway when a succession of vehicles are travelling on the crossroad.

Another object is to conserve the consumption of current at night when the trafiic is light while 35 still providing for adequate trafiic signalling.

Other objects and advantages appear as the description progresses.

In this specification and the accompanying drawings the invention is disclosed in its preferred form. However, it is to be understood that it is not limited to this form because it may be embodied in other forms within the purview of the claims following the description.

In the two sheets of drawings:

Fig. 1 is a side elevation of the control box showing the control and timer unit.

Fig. 2 is a schematic diagram of the electrical circuits included in the system.

In detail the construction illustrated in the drawings, referring more particularly to Fig. 2

comprises the tripper l buried in the pavement of the lateral road and is operable by the wheels of vehicles passing thereover. It is of the general type illustrated and described in detail in my Patent #1,962,451 entitled Trafiic signal con trols. The tripper is adapted to close the switch 2 which is interposed in an electrical circuit consisting of the source of electromotive force 3, the

conductors 4 and 5, the solenoid 6, and the conductors 1, 8, and 9 leading back to the current source 3.

The lever I0 is pivoted at H on the base 52 within the control box l3. The ferrous core i4 engages the lever I0 and extends into the sole- 5'5 noid 6. The solenoid 6 is mounted on the bracket 15 fixed on the standard I6 extending upward from the base l2.

The lever Ill has the non' conducting block I! thereon with the bus-bars i8 and I9 fixed therein. The contacts 2ll-20 and 2I-2l are mounted 5 on the insulating panel 22 on the bracket I5 and are adapted to be engaged by the bus-bars i8 and I9 when the solenoid 6 is energized. The contacts 2l2l complete the circuit of the motor 23 which includes the conductors 9, 8, and 24 leadin ing from the current source 3 to the contacts, the conductor 25 connecting the contacts 2! to the motor, and the conductor 26 which leads back to the current source.

The motor 23 is mounted on the support 2! on i=5 inoperative position by the roller 38 on the disk "25 32. The spring 39 urges the lever 36 toward the operative position. The con-conducting arm 43 is pivoted on the lever 36 at M and has the busbar 42 set therein opposite the contacts 4343. These contacts are mounted on the insulating 3D block 44 fixed on the bracket extension 45 on the standard 16.

The movement of the lever 35 is transmitted to the arm 49 by the pin 46 operating in the arcuv ate slot 41. The spring 48 resiliently engages 35 one end of the slot 41 against the pin 46. The assembly operates to produce a snap switch action to avoid arcing when the bus-bar 42 is disengaged from the contacts 43. When the lever 36 is operated to disengage the bus-bar from the contacts, '40 the friction between these spring contacts 43 and the bus-bar causes the bus-bar to remain in engagement with the contacts against the tension of the spring 48awhich urges it therefrom. As the movement of the lever 36 progresses, the pin '45 46 arrivesat the end of the arcuate slot 41. The continued movement of the lever 36 then forces the bus-bar 42 outward from the contacts 43. When the bus-bar 42 is once released from the contacts, the spring 48 snaps it away therefrom 5 0 in the manner of the usual snap switch.

The contacts 4343 are connected in parallel with the contacts 2 I2l and serve as an auxiliary motor switch in the operation of the system as later described.

3|. in the circuit of the solenoid'6 between the conclear the revolving roller 38. I V

The substantially semicircular lever surbase 21. v

The lever 5| has the cam 54 which is adapted to be engaged by the revolving roller 38 to swing the lever 5| into its secondary position. The cam 55 is similarly adapted to cooperate with the roller 38 to restore the lever 5| to its original position. The cam 55 is secured to the lever 5| by the screw 56. Interspaced screw holes 51 are provided in the lever 5| so that the position of the cam 55 can be moved to adjust the timing of f the two phases of the signal operation.

The non-conducting arms 58 and 59 are'pivo ted on the ends ofv the lever 5| at 69 and 6|. The pin andslot' connections 62 and 63 and the . springs 64 and 65 provide a'resilient cooperation between the lever 5| and the arms 58 and 59 similar to that previously set forth in describing the snap action of the arm 49 on the lever 36.

The bus- bars 66 and 61 set in the arm 58 cooperate with the contacts 69-68 and 69-69 on the insulating block I0. This block is fixed on the lug 3| extending laterally from the standard The switch contacts 69-68 are interposed ductors I and 8. 7

The conventional signals H-I-I are placed at the side of. the main highway near the intersection. The signals C-C' are similarly mounted on thecross road. The signals are provided with the usual green, amber, and red lamps or other conventional indicia for regulating traffic,

The green lamps II, I2 in the highway signals and the red lamps 13, I4 in the cross road signals are in an electrical circuit including the current source 3, the conductors 9 and 8, the switch contacts 69-69, the conductor I6 leading to the lamps and the conductor II leading back to the source 3. The amber lamps '18, I9, 80, SI of all of the signals'are in a circuit controlled by the switch contactsZIi-ZU previously described. The contacts are connected to the current source 3 by "the conductors-9, 8' and to the amber lamps 18 to BI' by the conductor 82. The conductor 11 completes the circuit from the lamps back to the source 3. The warning signallamps 84, 85 are connected in parallel with the lamps I8 and BI in, a mesh consisting of the conductors 86, 81, 88. These lamps are placed some distance along the highway .from the intersection to forewarn the approaching motorists. The thermal flasher switch 89 may be interposed in the circuit of the lamps 84, 85 to increase their effectiveness.

The circuit including the red lamps 99, 9| on the highway and the green lamps 92, 93 on the crossroad is controlled by the'switch contacts 94-94. The non-conducting arm 59 has the bus-bar 95 thereon for cooperation with the contacts 94-94; The contacts 99 are connected to the current source 3 by the conductors 9, 8 and to the signal lamps by the conductor 96." The conductor 11 connects the lamps back to the source 3 to complete the circuit.

The trafficbell 98 is placed at the intersection to direct attention to changes inthe visual traf- V The pin fic signals. It is interposed in a circuit controlled by the non-burning contacts 99-99 on the resilient metal strips I09, IllI which are mounted on the insulating blocklfi. The lever I92 is pivoted on the block I0 and has the roller I93 impinging on the strip I99. The cam I94 on the lever 5| engages the lever I92 and is arranged to swing this lever to close the contacts 98-9 9. When the lever 5| is swung from one of its operative positions to the other, as later described, the cam Iii i operates the lever I02 to close the contacts 99. The time the contacts 99 are closed is brief. Its

duration depends upon the time required for the roller 39 to operate the cams 54 and 55 to swing the lever 5| between its two operative positions. The contacts are supplied with current from the source'3 through the conductors 9, 8 and are con- I nected to the traffic bell98'by the conductor I95. The conductors I66, I'I lead back to the source.

A modified control mechanism is provided for signaling during the hours of light traffic atnight. The'modifiedcontrol and timer-is similar, except in details, to that above described. The same reference numerals with the addition of the prime character are used to indicate similar parts in the modified structure. The night signal control can be mounted in the same control box I3.. In

the night control, the contacts 69-59 and the bus-bar 6! are omitted. This maintains the green lamps II, IE- on the-highway and the red lamps I3, I4 on the crossroad unlighted. The volume of traflic during certain hours does not warrant the expenditure ofcurrent to maintain the signals continuously illuminated. The contacts 99-99' controlling the traffic bell 98 can be similarly omitted in residential districts where it is desirable to preserve quiet at night. The disk 32 is driven at a greater speed than the disk 32 so as to provide for a more rapid sequence of signals than is possible with the more congested traflic in daytime;

The time switch I01 selectively governs the operation of the day and night control mechanisms.

The switch I6? either connects the conductor 9 to theconductor 8 which feeds all of the switch contacts in the day control or it connects the conductor 9 to the conductor 8 which is similarly in circuit with the night control. The times of the.

operation of the switch can be regulated by the manual'knob I98 (see Fig. 1).

The manual switch I 99 is wired in parallel with. J

the time switch I9! and enables an officer to continue the operation of the day control at night when necessary. The switch H9 is provided to cut out the time switch I01 when the'manual switch is being used.

The signal system operates substantially as follows: Assuming the time switch I9! is in polamps remain illuminated except when a vehicle approaches from the crossroad thus maintaining the main highway unobstructed as long as no vehicle enters the intersection from the crossroad.

The driver of a vehicle approaching the intersection from the crossroad is directed 'by suitable road signs to drive over the tripper i. This closes the switch 2 and energizes the solenoid 6 through the conductors l, 5 and I and the switch contacts 88-68. The core l4 attracted into the solenoid swings the lever Ill and closes the contacts 2826 and 2 I-2I. The core l4 remains in this operative position even after the solenoid 6 is deenergized by the automatic opening of the switch 2 after the vehicle haspassed over the tripper i.. The switch contacts 20-40 complete the previously traced circuit of the amber lamps l8, 19, 80, 8! and the flashing signal lamps 8G, thus warning the oncoming traflic of the impending change of signals.

The switch contacts 2i2l complete the circuit also previously traced of the motor 23. The motor then drives the disk 32 at the predetermined constant speed. The revolution of the roller 38 on the disk 32 carries it beyond the end of the switch lever 36. The spring 39 then swings the lever 38 downward to engage the bus-bar 42 in the contacts 4343. These closed contacts maintain the motor circuit closed after the contacts 2l-2i have been opened by the restoration of the lever H1.

The continued revolution of the roller 38 after a predetermined interval carries it into engagement with the cam 5-! and swings the lever 54 on its pivot 52. This engages the bus-bar in the contacts 94-9t. This closes the circuit previously described and illuminates the red lamps S9, 9! in the highway signal and the green lamps 92, 93 in the crossroad signal.

The bus-bars 66 and 6'! simultaneously snap out of engagement with the contacts 6868 and ESQ-59. The breaking of the contacts 69 opens the circuit of the green lamps 11,12 on the arterial and the red lamps i3, M on the lateral. The opening of the contacts 68-68 opens the circuit of the tripper switch 2 and the solenoid 6. This enables the vehicles on the crossroad to pass over the tripper when the green light is showing without energizing the solenoid 6.

The movement of the lever 5| produced by the roller 38 causes the cam I04 to swing the roller I63 on the lever I02 against the resilient strip H30 to close the contacts 9999. This rings the trafiic bell 98 through the circuit previously traced at the time the signals are changing.

While the lever 5| is being moved by the roller 38 the pin 5!) engages the upper end 19 of the lever H! and restores it to the inactive position shown in Fig. 1. This opens the contacts 2020, 2i-2I. The opening of the contacts 2fl2!l breaks the circuit previously described of the amber lamps 18 to BI and the warning signal lamps 84, 35. The contacts 2 l-Zl are interposed in the circuit of the motor 23 as previously described. However, the operation of the motor is continued due to the closed switcl'i contacts 45-43 which are wired in parallel with the contacts 2l--2 l After a predetermined time interval, the roller 38 revolves into engagement with the cam 55 and restores the lever 5! to its original position. This opens the contacts 9494 and opens the circuit of the red lamps 9!], 9! on the arterial and the green lamps on the lateral. The closing of the contacts 6969 illuminates the green lamps H, 12 on the highway and the red lamps 13, 14 on the crossroad. Closing the contacts 68 again completes the circuit of the solenoid 6 so that the next vehicle passing over the tripper I will energize the solenoid.

After the roller has continued to revolve for another predetermined interval, it comes into operative engagement with the lever 36., The lever is thus swung on its pivot 37 and snaps the bus-bar 42 out of engagement with the contacts 43-43. If the tripper has not been operated by a vehicle in the lateral passing thereover, the opening of the contacts 4343 halts the motor 23 leaving the control unit in readiness for another cycle of operation initiated by a vehicle passing over the timer.

If the tripper has been operated during the latter phase of the operation of the control and timer, the energization of the solenoid 6 closes the contacts 2I2i. The operation of the lever 36 by the roller 38 disengaging the bus-bar 42 from the contacts 33- 33 thus will not halt the operation of the motor because of the closed contacts ZI-Zl. The control unit then, without pausing, will pass through another cycle of operation.

At a predetermined time, the time switch I01 reverses itself opening the circuits through the wire 9 and closing the circuits fed by the wire 8'. This places the night control unit into operation.

The operation of this control is substantially It is desirable 1 similar to that above described. to drive the disk 32 at a greater speed than the disk 32 to permit more rapid control of a lighter volume of traffic. The contacts 5464 being omitted, the green lamps H, 72 on the highway and the red lamps 73, M on the crossroad are not illuminated.

Having thus described this invention, what is claimed and desired to be secured by Letters Patent is: V V

In a trafiic signalling system, a motor circuit including an electric motor, and two switches in parallel for energizing said motor when either is closed, a disc driven by said motor, lugs on said disc spaced in the direction of rotation of the disc, means operated by one lug to open one of said switches when engaged by the lug, a lever in the path of the second of said'lugs and movable to switch opening and switch closing position for operating the second of said switches, means operated by trafiic for moving said lever to switch closing position whereby the motor is energized and the disc rotated and the first lug moved away from said one switch opening position, means to thereupon close said one switch, the second lug thereafter moving said lever to open the second switch, an arcuate control element having a cam thereon in the path of the first lug to shift the position of said control element upon engagement by said first lug, a second cam circumferentially adjustable on said control element, and adapted to restore said control element to its original position upon engagement by said first lug, trafiic signals, and means to display one group of signals when the control element is in one position, and a second group when the control element is in the original position.

' ADELARD F. MARTEL.

Images