US2251504A

US2251504A - Traffic signal

Info

Publication number: US2251504A
Application number: US149574A
Authority: US
Inventors: Theodorc E Steiber
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-06-22
Filing date: 1937-06-22
Publication date: 1941-08-05
Anticipated expiration: 1958-08-05

Description

Aug- 5, 1941-v T. E. sTElBER 2,251,50/4

TRAFFIC SIGNAL Filed June 22, 1937 2 sheets-Sheet 1 AAug. 5, 1941. T. sTElBER TRAFFIC SIGNAL Filed Jun 22, 1.937

Fig. 3

2 Sheets-Sheet Patented Aug. 5, 1941 TENT OFFICE TRAFFIC SIGNAL Theodore E. Steiber, Bridgeport, Conn., assignor of one-half to Arthur A. Johnson, Bridgeport,

Conn.

Application June 22, 1937, Serial No. 149,574- 12 Claims. (Ci. 177-337) This invention relates to a signal device and more particularly to the type of device for controlling traiiic.

In current systems of operating traffic lights, a yellow caution signal is displayed to indicate a change of light from stop to go, or go to stop This signal does not indicate how soon or how much time is left for the go or stop signal to remain lighted. A 4driver approaching the intersection has no means of telling whether the caution signal has been displayed for only a short time or Whether its period of operation is about terminated, and does not know whether he can proceed through the signal or whether he should stop.

According to the present invention, a signal is provided in which the stop and the go lights are operated in the predetermined manner so as to indicate to a driver approaching the intersection that the lights are changing and approximately the amount of change that has taken place.

Preferably, according to the present invention, a plurality of lights are used to illuminate each signal; All of these lights are lighted during the period in which the stop or go signal is displayed. During the interval when it is desired to change the lights the individual lights in at least one of the signals will be extinguished seriatim. rThis indicates to the operator of an automobile approaching the intersection that a certain portion of the changing time has elapsed and gives him a fairly accurate idea when the other signal will be displayed and become controlling.

According to the present invention, the go signal on one side of the frame, for example north and south, is connected to the stop signal on the east and west and vice versa. The circuits for these signals are controlled by a means which will be operated only during the period in which a change in signal is to be made and which will cause the lights to extinguish seriatim in one set of signals and at the end of the seriatim operation cause all of the light sources in the other set of signals to be immediately flashed on.

It will be obvious that this operation will tend to decrease the number of traic accidents which occur due to the operator failing to know that the caution light has been displayed for a long period and that the signal is about to change.

Care must be taken in using this mode of operation that the controlling means must function accurately for each operation. Accordingly, an electro-magnetically operated latch may engage the contact drum controlling the operation of the lights or some portion of its drive and prevent the drum from over'running so that the period of operation is always uniform and regular.

Further features and advantages will be apparent from the following specification taken in connection with the drawings.

In the drawings:

Figure 1v shows a perspective View of the traffic signal.

Fig. 2 shows a diagrammatic View of the traffic signal lights and the controlling circuit therefor.

Fig. 3 shows a vertical section of the traffic light.

Fig. 4 shows adetailed View of the controlling mechanism with the latch omitted.

Fig. 5a shows a developed plan view of the surface of the contact drum showing the positions of the conta/cts thereon.

Fig. 5b is a developed plan view of the surface of a modification of the contact drum for use with signal lamps adapted to be connected in parallel.

The traffic light according to the present invention is shown as embodying one for use with a two-way intersection. It is obvious that the light may be designed for any number of intersections. Y The preferred form of .the trahie signal herein disclosed comprises a housing I0 adapted to be suspended or supported in any desired manner. The housing I0 has a generally horizontally extending portion I I. Secured to the underside of portion II and depending therefrom is a vertically extending portion I2 of narrower dimensions, as shown in Fig. 3. The upper portion II of the housing is provided with horizontally disposed apertures I3 one for each approaching lane of traffic. The lower portion I2 of the housing has a plurality of vertically disposed apertures I4 one for each approaching lane of traic. A stop signal I5 for controlling traic, for example in an east-west direction, is mounted in the housing and comprises three light sour-ces or signalling units Ia, I5b and I5c, as shown in Fig. 2. A stop signal I6 also mounted in the upper portion II for controlling trailic in the north-south directionand comprises three light sources or signailing units IBa, I6b and Hic.

The light sources herein disclosed are preferably luminous gaseous discharge tubes although other signalling means may be used in order to obtain the desired result. These tubes are constructed so as -to be generally Ushaped, the legs of the U being positioned behind the opposite apertures in the walls of the upper portion Il and the section of the tubes between the legs of the U being made with a slight transverse bend, as shown in Fig. 3, so that all of the tubes may be positioned in the casing with the legs or signalling portions disposed in the same general horizontal plane ehind the apertures. These tubes are mounted in the casing on a plurality of sup-ports il' which extend behind the operative legs of the tubes and hold them in a position to be displayed or to illuminate the signalling aperture. The supports Il have an extension l projected up in back of the tubes to shield the same from lighting up apertures opening in the opposite direction. These surfaces i3 are finished so as to produce a light-reflecting surface for the tubes. ln each corner ofthe frame, as shown in Fig. 2, a partition it* is provided connecting the supports and shielding members to the frame to prevent the light from giving a false signal to trafiic coming in the opposite direction. The portion of the tubes extending between the operative legs of the U may be rendered opaque by coating them with suitable material to also prevent them from giving a false signal.

The depending portion I2 of the housing IU contains a signal 2t for controlling the east-west traffic and comprising tubes Or signalling units 2te, 2th and 2Go. A signal 2| is also provided in housing portion I2 for controlling traic in the north-south direction and comprises tubes or signalling units 2 la, 2 ib and 2 lc. These tubes are preferably luminous gaseous discharge tubes although any suitable signalling means may be used in place thereof. These tubes are formed in the shape of a U and are nested one within the other as shown in Figs. 2 and 3. The legs of the U, as shown in Fig. 2, are positioned behind the opposite apertures in the housing |2 and are shielded from one another by a plurality of shields 22 which prevent the giving of false signals and which also form reiiecting surfaces for the tubes.

Mounted in the upper portion of the housing l| is a supporting frame 23 upon which is secured a plate 2li. The plate extends over the area of the upper section and provides an adequate mounting for the necessary mechanism for energizing and controlling the lights. A transformer 25 for energizing the luminous gaseous discharge tubes is mounted on the plate so as to be carried by the unit. The mechanism for controlling the various tubes so as to give the desired signals as will be more fully explained is also mounted on this plate. A dome 40 is secured to the top of the housing so as to overlie the top of the upper portion and is projected upwardly to provide ample space for the transformer and control unit for the light. In an upwardly projecting portion at the center of the dome is an insulating bushing lll of rubber or similar insulating material which will make a water-tight bushing through which a pair of leads i2 for the transformer and a pair of leads i3 for the motor are carried. These leads are the only ones which need be connected to the trahie light. The leads from the motor go to the usual control box 55 containing mechanism comprising a switch for closing the circuit to the motor whenever it is desiredY to change signals and to display a caution signal during the interval between the change to warn approaching drivers that the signal is about to change.

According to the present invention, the lights in the signals are so operated as to indicate to the driver approaching the intersection the interval of time in general that has elapsed since the caution signal has been initiated so that he may determine whether or not be should proceed or stop,

In the preferred form of the present invention, the stop lights facing trafiic in one direction are connected to operate with the go lights in the other direction and vice versa so that these signals will operate together.

The desired control for the lights may take various forms such as relay systems and the like, but according to the persent invention it is achieved by employing a drum 38 having stepped contact surfaces 39 thereon. This drum is mounted on a shaft 31 supported by a supporting bracket 21 mounted on plate 24 and is driven from a motor 26, also mounted on plate 24. The motor has a worm 3| secured to its shaft and cooperates with a worm gear Si] on a shaft 29 supported in a pair. of bearings 28 of the supporting bracket 21. The shaft 29 has secured thereto a friction plate 32. Mounted to slide on the shaft 29 is a sleeve carrying a plate 33 having a friction face 34. The plate 33 is spring pressed so that its friction face cooperates with the plate 32 to form a slip connection between the motor and the drum. The sleeve has mounted thereon and rotating therewith a worm 35 meshing with a worm gear 35 on the shaft ill which carries the contact drum. As shown in the present invention, the drum will turn during one change of lights. This however is optional and may be varied to suit varying conditions, for example the drum may make one revolution to accomplish the same result by having contacts extend around the entire surface.

An insulating block 44 is carried by the supporting bracket 2l. A contactor is mounted on the block and extends into cooperative relation with the drum to control one set of lights. This contactor comprises three insulated contacts 45a, 5b and 45o which engage the drum at the under surface thereof. A second insulating block 46 is carried by the supporting bracket and has mounted thereon a contactor comprising insulated contact elements 47a, 47h and 47o which engage the upperside of the drum 180 from contacts 45a, 45h and 45o and control the other set of lights.

As shown in Fig. 2 the pairs of tubes 29a, and 2id, 2th and 2|b, and 20c and 2|c are connected at one end respectively to one side of each of the three secondary windings of the transformer and the said tubes are connected at their other ends in the following manner. The three horizontal red east-West tubes |511., |519A and |5c are connected in series with the vertical green north-south tubes 2 la, 2 Ib` and 2 |c, and the three horizontal northsouth'red tubes Ita, |611 and Ic are connected with the three vertical green east-west tubes 20a, 2Gb and 2SC. It will be seen, therefore, that when connected in this manner the stop light on one side of the frame or housing operates with the go light on the opposite side of the frame. The tubes are connected to the contacts which when engaging the Contact portions 39 of the control drum in such a manner so as to close the circuits to the tubes, the contact 45a is connected to and controls the tubes |5a and 2|a so that they operate at the same time. Contact @55a is connected to the tubes |5bl and 2lb and contact d50 is connected to |50 and 2|c so that each pair operate together. Similarly contact 47a is connected to tubes la and 20a. Contact Bib is connected to tub-es |611 and 2lb and 41C is connected to tubes 16e and Zlc. From the above connections, it will be seen that when the separate contacts close the circuit to the transformer through contacts 39 the pairs of tubes connected thereto will be energized.

A developed plan view of the drum for controlling the lights according to the present invention is shown in Fig. 5a. The contact surfaces formed on the drum extend through 180 so that one half of a revolution of the drum Will complete a change of lights. The Contact surface is formed with a short section 30a which will engage the contact brushes ld and t'l'a for approximately 60 of rotation of the drum. Contact 30?) extends further and will engage contacts 52) and ilb ior a period of about 120 of rotation of the drum. Contact 30C extends for slightly less than 100 of the drum to insure that the lights are extinguished before the other set iiashes on. This Contact engages contacts te and llc for approximately the full length of time required in changing the signal. Contacts 30x, integral respectively Iwith contacts 39u, b, and c, extend around the entire circumference of the drum and engage contacts dal which connect the contacts on the drum respectively to one side of each of the secondary transformer windings. It will be seen that when the drum is in the position shown in Fig. 2, a circuit will be closed through all of the light sources in signals i5 and 2l. When it is desired to change the signal from go to stop, or stop to go, the controller in the usual control box 55 is operated to close the circuit to the motor which causes the drum tc rotate in the direction of the arrow, 2. As the drum rotates, contact 65a will leave the Contact suriace after 60 of rotation of the drum and will cause signal lights Ia and Zia to be extinguished. Continued rotation of the drum for another distance of 60 will cause contact @5o to leave the contact surface and will cause the lights b and Zib to become extinguished. Further rotation of the drum for another 00 will cause the contact idc to leave the contact surface and extinguish the lights itc and le. As the drum Continues to move, the Contact surface will immediately engage all of the contacts fil* to cause all of the lights associated therewith to be energized. rThe inode of operation may be summed up as follows: When it is desired to change the traiicic signal from stop to go, or go to stop, the lights being displayed in the Various directions will be caused to be ex inguished seriatim and immediately upon extinguishing the last light ci one signal, for example the go signal, the entire stop signal on that signalling side flashes on. This operation gives an oncoming motorist an indication of the amount oi time elapsed from the beginning of the caution period so that he can decide instantaneously whether to stop or Whether he can pass the light before the signal changes completely.

Fig. 5b shows a developed plan View of a drum 3B having a modiied arrangement of stepped contacts thereon, adapted to replace drum 38 providing that the luminous gaseous discharge tubes are replaced by light sources adapted to be energized in parallel, such as, for instance, incandescent lamps.

When this is the case, the multiple secondary transformer may be omitted, one power lead ft2 being connected to the Contact 5t while the other power lead i2 is connected to one terminal of each of the vertically disposed light sources 20a, b, and c, and 2id, b, and c. Connections from contacts 45a', b', and c' and contacts 41a', b', and c to light sources l5 and I6 are the same as those shown in Fig. 2 between the said light sources and contacts 45a, b, and c, and 41a, b, and c.

Contact surfaces 30a', b', c', and are spaced respectively to extend over about 60, about 120, slightly less than and 360 of the circumference of drum 30 in the same manner as contact surfaces 39a, h, c, and r of drum 38.

Operation of the signal by rotation of drum 30 is the same as in the case of drum 38 in Fig. 5a.

With the caution signal oi the type disclosed in the present invention, care must be taken to prevent the drum from overrunning since such an occurrence would cause the caution signal to be ineflicient for the purpose designed, namely, to give an indication oi the elapsed time of the caution period. Accordingly, means have been provided for preventing such an occurrence. A 'pair'of pins 43 are positioned on the

worm gear

35, 180 apart and in deiinite spaced relation with respect to the contact surfaces 39. A lever 50 is Ypivoted intermediate its ends to the supporting bracket 2l to a pivot 5i. One end of the lever has a hoek portion adapted to engage the pins on the gear and prevent the gear from further rotation. The other end of the lever is weighted to cause the lever to normally move into hookengaging position. The latter end of the lever is connected to a core 53 operating in a solenoid E9. The solenoid is connected in series in the motor circuit so that when the circuit is closed to the motor by the control switch 55, the initial surge of current will be suicient to raise the core and to release the hook from the pin and, as the motor starts to rotate and move the drum and the starting current decreases, the weight of the lever will be suiiicient to cause the hook to move into position to engage the next pin @.3 on the gear which rotates the drum to hold the drum in a denite position. The slip coupling between the motor and the drum permits the motor to overrun without affecting the drum. If desired the solenoid; may be connected in a separate circuit to the control box 'to be controlled therefrom instead of from the motor circuit as above described.

It will be seen that the drum can only make one half of a revolution for each energization of the motor. If it is desired to alter the length of time required to change from one signal to another, as on highways where high speed requires a longer changing period, the gearing between the motor and the drum may be changed or the speed at which the motor operates may be altered. k

Variations and modifications may be made within the scope of this invention and portions of the improvements may be used without others.

I claim:

1. In a signaling device comprising a housing having a stop and a go aperture, a plurality of light sources for illuminating each aperture; means mounted in the housing for varying in a predetermined manner the number of said light sources which are illuminated in each aperture during a change of the signal from stop to go to give a caution signal, said control means including a periodically driven rotary contact drum; a plurality Vof iixed contactors cooperating there- With to control the illumination of said light sources; and electro-responsive means for arresting rotation of the drum to prevent overrunning thereof upon completion of a change of said signal from stop to go on one side and from go to stop on another side.

2. In a signaling device comprising a housing having a plurality of sides, each signaling side having a stop aperture and a go aperture, a plurality of light sources for illuminating each aperture; means for controlling said light sources in a predetermined manner throughout the period of changing of the signals, to give a caution signal which indicates the extent of lapse of said changing period, said control means including a rotary Contact drum, fixed contactors cooperating therewith to control the illumination of said light sources in a predetermined manner, and electroresponsive means for rotating said drum during a change of the signal from stop to go, and for arresting rotation of said drum upon completion of such a change.

3. In a signaling device comprising a housing having a plurality of sides, each signaling side having a stop aperture and a go aperture, means for illuminating the apertures comprising a plurality of light sources for each aperture; means for controlling said light sources in a predetermined manner to give a caution signal including a rotary drum having stepped contacts thereon; iiXed contactors cooperating therewith to control the circuits of said light sources as the drum rotates; a motor for rotating the drum, periodically operated to change said signal; and means for limiting the rotation of the drum upon completion of a change of said signal from stop to go for each operation of the motor.

4. A signaling device comprising a housing having a plurality of sides, each signaling side having a stop aperture and a go aperture; means for illuminating the apertures comprising a plurality of light sources for each aperture; control means for said light sources, including a rotary insulated drum having stepped contacts thereon, a plurality or" xed contactors cooperating therewith to vary the number of light sources which are illuminated in each aperture in a predetermined manner during a change of the signal; a motor operated at predetermined intervals for rotating the drum; and means for limiting the amount of rotation of the drum, including an electromagnetically operated latch for arresting rotation or" the drum upon completion of a change of the signal from stop to go.

5. A signaling device comprising a housing with a plurality of sides, each signaling side having a stop aperture and a go aperture; means for illuminating the apertures comprising a plurality of light sources for each aperture; control means for said light sources including a rotary insulated drum having stepped contacts thereon; a plurality of fixed contactors cooperating therewith upon rotation of the drum to control the illumination of said light sources in a predetermined manner during a change of said signal; means for rotating the drum, including a periodically operated motor and a slip coupling interposed loetween said motor and said drum; and means for limiting the amount of rotation of the drum for each operation of the motor, including an eletromagnetically operated latch which arrests rotation of the drum upon completion of the change of said signal from stop to go.

6. A signaling device comprising a housing with a plurality of sides, each signaling side having a stop aperture and a go aperture; means for illuminating the aperture comprising a plurality of light sources for each aperture; control means for said light sources including a rotary insulated drum having stepped contacts thereon; a plurality of fixed contactors cooperating therewith upon rotation of the drum to control the illumination of said light sources in a predetermined manner during a change of said signal; a periodically operated motor, including a frictional driving means for rotating the drum; and means for limiting the amount of rotation of the drum, last-named means including a stop means associated with said drum, and an electromagnetir cally operated latch adapted to engage said stop means upon completion of each change of the signal from stop to go.

'7. A signaling device comprising a housing and a plurality of sides, each signaling side having a stop aperture and a go aperture; means for illuminating 'the aperture, comprising a plurality of light sources for each aperture; control means for said light sources, including a rotary insulated drum having stepped contacts thereon; a plurality of fixed contactors cooperating therewith upon rotation of the drum to control the illumination of said light sources in a predetermined manner during the change of said signal; a periodically operated motor for rotating the drum to change the signal; a periodically energized circuit therefor; an electromagnetic means controlled by said circuit for arresting rotation of the drum upon completion of a change of said signal from stop to go during the period of rotation of the motor; and frictional driving means between the motor and said drum, whereby said motor may overrun after operation of the electromagnetic means.

8. A signaling device comprising a housing and a plurality of sides, each signaling side having a stop aperture and a go aperture; means for illuminating the apertures comprising a plurality of light sources for each aperture; control means for said light sources including a rotary insulated drum having stepped contacts thereon; a plurality of xed contactors cooperating therewith upon rotation of the drum to control the illumination of sai-d light sources in a predetermined manner during a change of said signal; means for arresting rotation of said drum upon completion of a change of said signal from stop to go; an intermittently operated motor for rotating said drum; a circuit therefor including an electro-magnetic means actuated by the initial surge of current through said circuit upon energization of the motor, for releasing said arresting means, and permitting rotation of the drum loy the motor for changing the signal from stop -o go.

9. An intersection trailic signal comprising a frame having a plurality of sides, each side having stop and go signals; means for illuminating the signals comprising a plurality of light sources to illuminate each signal, said means comprising at least two circuits, one of which includes the means for illuminating the stop signal for one traiiic direction and the go signal for another traiiic direction, and another circuit including the means for illuminating the go signal for the former and the stop signal for the latter tramo direction; means for controlling the illuminating means to indicate a change from stop to go, said means including a rotary contact drum having stepped contacts thereon; iixed contactors cooperating therewith upon rotation of the drum to operate said circuits alternately, in each case first illuminating all the light sources in the circuit and then extinguishing said sources on both the stop and go sides as the drum rotates; a motor for rotating the drum operated during an interval for changing the signal; and means for arresting rotation of said drum to prevent overrunning thereof upon illumination of all of the light sources in either circuit.

10. A signaling device comprising a housing having a plurality of sides, each signaling side having a horizontal and vertical aperture, the horizontal aperture giving a stop signal and the vertical aperture giving a go signal; means for illuminating the signals, comprising a plurality of light sources to illuminate each of said apertures, said means comprising at least two circuits, one of which includes the means for illuminating the stop signal for one traflic direction and the go signal for another traflic direction, and the other circuit including means for illuminating the go signal for the former and the stop signal for the latter trafc direction; means for controlling the illuminating means to indicate a change from stop to go, said means including a rotary contact drum having stepped contacts thereon, fixed contactors cooperating with stepped, contacts to operate said circuits alternately, in each case first illuminating all the light sources in the circuit and then extinguishing said sources in sequence on both the stop and go sides as the drum rotates; a motor for rotating the drum adapted to be operated during an interval for changing the signal; and means for arresting rotation of said drum to prevent overrunning thereof upon illumination of all of the light sources in either circuit,

11. In a signaling device comprising a housing having a stop and a go aperture, a plurality of light sources for illuminating each aperture;

means for controlling said light sources in a predetermined manner throughout the period of changing of the signal to give a caution signal which indicates the extent of lapse of said changing period, said controlling means including two relatively movable contact members, one of which carries stepped contacts and the other carrying a plurality of contacts cooperating therewith to control the circuits of said light sources in a predetermined manner upon relative motion of the contact members; driving means for eiecting relative motion of said contact members, periodically operated for changing said signal; an-d electro-responsive means for limiting the relative motion of said members upon completion of a change of said signal from stop to go for each periodic operation of said driving means.

12. In a signaling device comprising a housing having a stop and a go aperture, a plurality of light sources for illuminating each aperture; means for controlling said light sources in a predetermined manner throughout the period of changing of the signal to give a caution signal which indicates the extent of lapse of said changing period, said controlling means including two relatively movable contact members, one of which carries stepped contacts and the other carrying a plurality of contacts cooperating therewith to control the circuits of said light sources in a predetermined manner upon relative motion of the contact members; electro-responsive driving means for effecting relative motion of said contact members, periodically operated to change said signal; and electro-responsive means for limiting the relative motion of said members upon completion of a change .of said signal from stop to go for each periodic operation of said electro-responsive driving means.

4 THEODORE E. STEIBER.