US2015435A - Vehicle timed automatic traffic signal - Google Patents

Description

Sept. 24, 1935. w NE|LL 7 2,015,435

VEHICLE TIMED AUTOMATIC TRAFFIC SIGNAL Filed June 13, 1930 2 Sheets-Sheet 1 96 J as r\ l 1 1 S 1 as 50 X6 5/ WNZ. B M' W ATTORNEY Sept.

C. W. NEILL VEHICLE TIMED AUTOMATIC TRAFFIC SIGNAL Filed June 13, 1930 2 Sheets-Sheet 2 1 a wsnwmsQvo. 2 flkkghmg Rmher QvossRed Grossd a \Y mumsRefi 4- \ghumaied (muss Go Qmss Amber NVENTOR ATTORNEY5.

Patented Sept. 24, 1935 PATENT OFFICE VEHICLE TIMED AUTOMATIC TRAFFIC SIGNAL Charles W. Neill, Syracuse, N. Y., assignor to Grouse-Hinds Company, Syracuse, N. Y., a corporation of New York Application June 13, 1930, Serial No. 461,010

7 Claims.

changes the signal indications on the respective streets in an arbitrary manner regardless of the actual number of vehicles using the intersecting streets. Improvements'over this old style of arbitrary timer have recently been made, a notable example of which is the normally go traffic signal which indicates go to traflic on a main highway at all times except when a vehicle approaches on the intersecting cross street. Vehicle actuated means located in the trafilc lane on the cross street operate the trafiic signal to shift the go signal, which is normally displayed to the highway, to the cross street for a predetermined length of time sufiicient to permit the vehicle approaching the intersection from the cross street to clear the intersection, after which the normal go signal on the highway is restored. While this type of signal is a great improvement over the old style arbitrary timer, it is open to certain objections. The go signal for the cross street is displayed for a predetermined length of time which must be sufiiciently long to permit the slowest moving vehicle to clear the intersection during this go period. With fast moving traffic the go period on the cross street will persist for a much greater length of time than is actually needed by the cross street trafiic. Thus trafiic on the main highway is held up unnecessarily.

The principal object of this invention is to provide a traffic signal of the vehicle actuated type which will display a go signal to approaching traffic on a cross street for a period of time which is dependent on the speed of the traflic. Thus a long period will be provided for slow moving traffic and a short period for fast moving traffic. Unnecessary'delay of highway traffic is thereby avoided.

A further object of the invention is to provide a trafiic signal which has improved time extension means for extending the go period for a cross street in proportion to the numberof vehicles approaching on the cross street.

A further object of the invention is to provide a traffic signal of the vehicle actuated type in which the go period for a cross street will be dependent on the speed of the cross street traffic, the traffic signal also having means for displaying a go signal indication to highway traffic for a predetermined minimum period of time.

A further object of the invention is to provide a traflicv signal of the vehicle actuated type which has improved means for remembering cross street traffic which actuates the vehicle actuated means just after the end of a cross street go period or during a minimum highway go period.

A further object of the invention is to provide improved switching means for changing the signal indications with the conventional amber period following the go signal indication without the use of cam timing means.

A further object and advantage is to provide vehicle actuated means which will be responsive to vehicles approaching from one direction but which will not start the traific signal operating mechanism after a vehicle strikes a portion of the vehicle actuated means in sweeping a wide turn at the intersection.

Other objects and advantages of the invention will become apparent and will be pointed out as the description proceeds.

The invention consists in the novel features and 20 in the combinations and constructions hereinafter set forth and claimed.

In describing this invention reference is had to the accompanying drawings in which like characters designate corresponding parts in all 2 the armatures for controlling the signal circuits during the various signal periods.

Location of vehicle actuated detectors A traffic signal S is located in any convenient position so as to be visible to vehicles approaching on the intersecting streets. As shown in Figure 1 the signal S is of the type which is located in the center of the intersection. Two vehicle actuated means or detectors D, D are located in the cross street on both sides of the intersection. These detectors are placed in the lane of the approaching trafiic which will ordinarily be to the right of the center line of the street. The detectors D and D may be set in any spaced relation relative to one another. It is preferable, however, for the first detector D to be set back a sufiicient distance from the intersection so that the signal will have time to change before the vehicle reaches the intersection thus permitting the vehicle to cross the intersection without stopping or slowing down. Since it is conventional practice to display an amber signal to the highway before changing the signal indication to stop, the detector D should be set back from the intersection sufficient distance to permit the highway amber period to elapse before the vehicle on the cross street reaches the intersection. The detector D operates the signal operating mechanism to change the signals so as to display a go signal to the cross street and stop signal to the highway, this stop signal may be preceded by the conventional amber.

The detector D starts the operating mechanism to restore the normal highway go signal and cross street stop signal. It is desirable that the detector D be so located in the cross street that any traffic on the cross street, which is waiting for a change in the signal, will stop over the detector D or before reaching the d tector D but will not cross the detector D before stopping. Local conditions may determine the position and relation of the detectors D' and D with respect to the intersection and to each other.

Any suitable vehicle actuated means may be used as the detector D or D Vehicle actuated means such as a depressible treadle similar to that shown in the patent to Nelson No. 1,665,560 issued April 10, 1928, may be used. However, in connection with the apparatus here disclosed, the contacts of the treadle are normally closed, and are opened by a vehicle passing over the treadle.

Effect of operation of the first detector The vehicle actuated means are arranged so as to break the circuit to magnetic relays I6 and H. When a vehicle actuates the detector D the relay Ill will be de-energized and permit the armature l2 to drop. When the detector D' is no longer under the influence of the vehicle the armature 12 will again be drawn up by the relay [0, into the position shown in Figure 2.

When a vehicle actuates the detector D the relay l I will be de-energized and will permit the armature l3 to drop. When the detector D is no longer under the influence of the vehicle, the armature l3 will again be drawn up into its raised position by the relay II. I

As a vehicle approaches the intersection on the cross street, it will actuate the detector D to cause the relay It to permit the armature 22 to drop on the contacts l5 and [6. The contact [5 is hot at all times and when the armature :2 drops on these contacts l5 and I 6, power will flow through the armature I2 and the resistance l1, stick relay I8, and resistance l9, to the ground.

The stick relay i8 will be energized to throw its armature 20 into engagement with the contact 2|. This establishes a new circuit from the contact 15 through the armature 12, contact it, stick relay 22, armature 20, contact 2|, stick relay l8, and resistance 19 to the ground. The stick relay 22 will attract its armature 25 into engagement with the contact 26. This establishes a new circuit from the armature l3, which is hot at all times, through the contact 30, armature 25, contact 25, stick relay 22, armature 25!, contact 2|. stick relay l8, and resistance l9, to

the ground. This last described circuit will stick the relays 22 and i8, and the breaking of the circuit at contact l5 when the armature l2 rises after the vehicle on the cross street passes the detector D will have no effect on the relays.

A conductor 35 connected to the circuit between the stick relay [8 and resistance I9, leads to a coil 35 of a motor 31. The motor may be of any conventional type suitable to operate the switching mechanism, and which is provided with forward and reverse coils. The motor here shown is of the induction disk type provided with the coils 36, 89, to rotate the disk in opposite directions. When the operating mechanism is in normal position, as shown in Figure 2, the coil 36 is grounded through a stick relay 38 and brush 39, which contacts with a grounded conductor segment as of the commutator 4|.

The purpose of the resistance ll is to obtain a voltage drop across the stick relay 22 and the purpose of the resistance i9 is to obtain a voltage drop across the motor coil 36.

When power is supplied to the motor coil 36 the motor 3': will operate in a forward direction, clockwise, as shown in Figure 2, and turn the shaft 42 on which the commutator 4| is mounted.

As the commutator 4i turns in a forward or clockwise direction the grounded conductor segment 4!! will move into contact with a brush 45 which connects with an armature 46 of the stick relay 38. The brushes 39 and 45 are so spaced with relation to one another that the grounded conductor segment 48 will contact with the brush 45 before it breaks its contact with the brush 39. When the brush .5 makes contact with the grounded conductor segment 49 a new circuit will be established from the stick relay 38 through a contact 48, armature 4t, and brush 45 to the grounded conductor segment 49. This circuit will stick the relay 36 after the contact between the brush 39 and grounded conductor segment 63 is broken.

Operation during forward rotation The signal lights are c erated by suitable switching means, here shown as relay operated switches. The operation of the signals by these switches will be described later. The switches are operated by relays 5S and 5E which connect with suitable crushes on the commutator The relay 5! is connected by a conductor with a contact 53. When the relay 38 is operated to attract the armature 45 contact is established between the contacts 53 and armature 65. The armature 45 is of the double type being made up of two conductor sections insulated from one another. That part of the alt nature 45 which engages with the contact 48 connects with the brush 45. The part of the armature 45 which engages with the contact 53 connects with a brush 4 5 As the commutator 4! turns in a forward or clockwise direction, the grounded conductor segment do will come into contact with the brush 45 A new circuit is thus established through the relay 53, one side of which is connected with a suitable source of current, conductor 52, contact 53, armature 46, and brush 45 to the grounded conductor segment ie. The flow of current through the relay to will cause the armature 55 to be drawn to the left in Figure 2, to change the si nal indications so as to display the highway amber; the cross red remaining unchanged.

As the commutator 4| turns in a forward direction, a hot conductor segment 69 will come in contact with a brush 6| which connects with the relay 5|. The other side of the relay 5| is connected with a contact 62, but during the forward movement of the commutator 4 I the armature 46 is out of engagement with the contact .BZ and there is therefore no complete circuit through the relay 5|.

As the commutator 4| continues to: rotate in a forward direction the grounded conductor segment 40 will come into contact with a brush 65. This provides an additional ground connection for the relay 5|], but is of no importance during the forward rotation of the commutator 4 I.

When the commutator 4| has rotated in a forward direction until the insulated segment El comes under the brush 45, the ground connection of the relay 38 will be broken and the armature spring 68 into engagement with the contact 62,

a circuit is established from the hot conductor segment 68 through the brush 6|, relay 5|, contact 62, armature 4B, and brush 45,'to the grounded conductor segment 48, the end of which is now located between the brushes 45 and 45 When this circuit is established through the relay 5| the armature I'll will be moved to the left in Figure 2 to change the signal indications to display the highway red and cross street go signals.

The operating mechanism will now remain in this position until a vehicle actuates the detector D Efiect of operation of the second detector When a vehicle actuates the second detector D the relay II will permit the armature iii to drop out of engagement with the contact 3% and into engagement with a contact 12.

The breaking of the circuit between the armature l3 and the contact 38 will cut ofi the supply of power to the armature 25 and stick relay 22. This will cause the stick relay 22 to break, a spring 13 being provided to withdraw the armature 25 from the contact 26 when the relay 22 becomes deenergized.

The source of power to the stick relay l8, through the stick relay 22 is broken, but a new circuit is established from the armature 53 through the contact 72, and armature 28 to the contact 2| and stick relay I8. The break in the current while the armature l3 moves from the contact 30 to the contact 12 is of such short duration that the stick relay l8 will not break.

When a vehicle has passed the'second detector D the relay II will again attract the armature l3 and the contact between the armature l3 and contact 72 will be broken. This will break the circuit, just described, to the stick relay l8 and a spring 15 will draw the armature 20 to the left in Figure 2, out of engagement with the contact 2| and into engagement with contacts 16 and Ti. The contact 16 is hot at all times and a new circuit is established fromthe contact 16 through the armature 29, contact 11, conductor 18, motor coil 80, conductor 8|, contact 62, armature 46, and, brush 4%, to the grounded conductor segment 40. The flow of current through the motor coil 30 will cause the motor to rotate in a reverse direction so as to turn the commutator 4| in a counterclockwise or reverse dire tion.

Operation during reverse movement of the motor As the commutator 4| rotates in a counterclockwise or reverse direction the grounded conductor segment 48 will'move into contact with 1 the brush 45, but during reverse movement the armature 46 will occupy the position shown in Figure 2 and no circuits are connected with that portion of the armature 46 which connects with the brush 45. 15

The commutator 44 will continue to rotate in a reverse direction and bring the insulated segment 85 under the brush 65. This will break the circuit through the relay 5! and the armature 55' will be drawn to the right in Figure 2, by a 20 spring 86. This movement of the armature 55 will cause a change in the signals so that the cross amber signal is displayed, the highway red signal remaining unchanged. The position of the brush 65 is adjustable so as to determine how 25' long the cross street go signal will persist afterthe commutator 4| begins its reverse rotation.

A brush 95!, which is also adjustable, is set so that the hot conductor segment 60 will contact with this brush 90 at the same time that the position, shown in Figure 2, the insulated segment 61 will come under the brush 5| and cut off the supply of power to the relay 5 I. The armature 1|] will then be drawn to the right by a spring 88. This movement of the armature it will restore the signals to their original condition displaying the highway go and cross street red signals. The insulated segment 85 will come under the brush 45? thus breaking the ground connection of the motor coil 88 and the motor 31 will stop, the commutator 4| coasting slightly until it reaches the position shown in Figure 2.

Minimum highway go period The operating mechanism illustrated in Figure 2 provides a minimum highway go period.

When the insulated segment 85 comes under the brush 65,during reverse rotation of the com- :mutator 4|, the relay 59 is deenergized and the armature 55 moves to the right to change the cross street signal to amber as previously described. v The commutator 4| continues its reverse rotation until the insulated segment 61 comes under jthe'brush 6|. The signals are then changed to their normal position of highway go and cross street red, but the time of this change may be adjusted by changing the position of the brush 6|. The time required after the insulated segment 6'| has come under the brush 6| for the commutator 4| to complete its reverse rotation and move through the first part of a following forward rotation, provides a minimum period for the go signal on the highway.

The time between the contact of the insulated I segment with the brush 65 and the contact of the This is to prevent time ex- 35:

insulated segment 61 with the brush 6| will be the cross street amber period and these brushes 65 and El should be so adjusted with respect to one another that a cross street amber period of prope duration is obtained.

The motor coil may be so wound, or so placed with respect to the motor 31, that the reverse rotation of the motor 31 is at a slower rate than was the forward rotation. This is highly desirable in connection with the setting of the brushes of the operating mechanism so as to obtain the desired minimum highway go period. The maximum highway go period will depend entirely upon the density of the cross street trafiic since the go signal is normally displayed to the highway at all times unless a vehicle crosses the vehicle actuated means in the cross street.

Time extension feature The apparatus is designed so as to start a reverse rotation of the operating motor to restore the signals to their normal position within a very short time after a vehicle passes the second detector D The length of time, after a vehicle passes the detector D before the cross street go signal changes to amber is adjustable by changing the position of the brush 65 as above described. This time will depend on the width of the intersection and should be just sufficient so that when added to the cross street amber period a vehicle will be permitted to clear, or almost clear, the intersection before the display of the highway go signal.

In order to obtain efiicient handling of the traflic, it is necessary that means be provided by which the go period for the cross street can be extended in order to permit a group of vehicles to cross during the same period. The time extension is provided by the operating mechanism shown in Figure 2.

If a vehicle crosses the detector D at any time during the cross street go period and after the vehicle ahead of it has actuated the second detector to start reverse movement of the motor, the stick relays 22 and I8 will be operated in exactly the same manner as previously described in connection with the first vehicle to cross the detector D. No current will flow through the conductor 35, however, because the ground connections of the conductor 35 are broken; the brush 39 is incontact with the insulated segment 61, and the armature 46 is not in engagement with the contact 48. When the relay I8 is energized by this second vehicle passing across detector D, the armature 20 is drawn to the right and the circuit from the contact 15 to the motor coil 80 is broken thus stopping the motor. The motor will remain stopped and the signals will remain in position displaying a go signal to the cross street until the second vehicle has passed over the detector D Reverse rotation of the motor will then be resumed, the mechanism operating as in the case of the first vehicle to cross the detector D If the second vehicle does not reach the detector D, until after the cross street go signal has changed to amber, no time extension of the amber period will result. The stick relays 22 and I 8 will be operated but they will not stop the reverse rotation of the motor. Power to continue the reverse rotation of the motor will be supplied from the hot conductor segment 60 which comes into contact with the brush to supply power to the motor coil 80, when the cross street signal changes to amber.

Memory feature When a second vehicle on the cross street reaches the detector D during the cross street amber period, or during the cross street stop period, but before the operating mechanism has completed its reverse rotation, means are provided by which the mechanism remembers such second vehicle.

This second vehicle will stick the relays 22 and I8 as previously described. When the commutator 4| has moved in a reverse direction until the ground conductor segment 40 contacts with the brush 39, a circuit will be completed from the stick relay 8 through the conductor 35, motor coil 36, relay 38, and brush 39 to the grounded conductor segment 40. The armature 46 will be drawn to the left, thus breaking the ground connection of the motor reverse coil 80. The motor will thus drive the operating mechanism forward to give a cross street go signal to the waiting vehicles.

Signal switching means The operation of the signal lights by the switching means is illustrated in Figure 3. The relay 55, when energized, draws the armature 55 to the left to engage the contact point 95. When the relay 50 is not energized the armature 55 is When neither of the relays 50 or 5| is energized 40 and both armatures 55 and 10 are in their normal position, as shown in Figure 3, the signals will be in their normal position displaying highway go signal and cross street red signal. The circuit will be readily understood by reference to Figure 3, and may be traced from the armature 10 through the contact 98, highway go signal, contact 96, and armature 55 to the ground. The cross street red signal is in a parallel circuit which may be traced from the armature 10 through the contact 98, and cross street red signal to the ground.

When the relay 50 alone is energized, the armature 55 is drawn into engagement with the contact thus breaking the circuit through the highway go signal and establishing a circuit from the armature 16 through the contact 98, highway amber signal, contact 95, and armature 55, to the ground.

When both the relays 50 and 5| are energized, a circuit is established from the armature 15 through the contact 91, and highway red signal, to the ground. A parallel circuit is established from the armature 10, through the contact 91, cross street go signal, contact 95, and armature 55, to the ground.

When the relay 5| only is energized the circuit through the highway red signal remains, but the parallel circuit is now from the armature 10, through the contact 91, cross street amber signal, contact 96, and armature 55, to the ground.

While I have illustrated my invention in a preferred embodiment, various changes and modifications may be made therein without departing from the spirit of the invention as set forth in the appended claims.

What I claim is: l

1. A traffic signal for directing traffic at the intersection of two highways, including signals normally indicating go to one highway and stop to the other, and means for shifting and reshifting said signal indications to the respective highways,

said shifting mechanism including first and second vehicle actuated means located in one of said highways, and arranged to be successively actuated by traffic approaching the intersection on said highway, signal switching mechanism operable, upon actuation of the first vehicle actuated means, to move in one direction from initial position to reverse said signal indications and operable, upon actuation of the second vehicle actuated means, to move in reverse direction to reshift said signal indications back to normal and maintain said indications in reshifted position a predetermined minimum length of time before said signals can again be shifted from original position.

2. A traflic signal for directing traffic at the intersection of a highway and a cross street including a signal device having signals normally indicating go to the highway and stop to the cross street, and having a caution signal to indicate signal changes, means for shifting and reshifting said go-stop signals and operating said caution signal, including a first and second vehicle actuated means located in spaced apart relationship in the cross street, and arranged to be successively actuated by trafiic approaching the intersection on said cross street, switching mechanism operable, upon actuation of the first vehicle actuated means, to shift said highway go signal to caution and after a predetermined time to shift the cross street stop signal to go, and the highway caution signal to stop, and operable, upon actuation of the second vehicle actuated means, to shift the cross street gosignal to caution and subsequently the highway stop signal to go and the cross street caution to stop, and maintain the signals in said reshifted position a predetermined minimum period of time before they can again be shifted by actuation of the first vehicle actuated means.

3. A traffic signal for directing traffic at the intersection of a highway and a cross street including a signal device having signals normally indicating go to the highway and stop to the cross street, and having a caution signal to indicate signal changes, means for shifting and reshifting said go-stop signals, and operating said caution signal, including a first and second vehicle actuated means located in spaced apart relationship in the cross street, and arranged to be successively actuated by traffic approaching the intersection on said cross street, switching mechanism operable, upon actuation of the first vehicle actuated means to shift said highway go signal to caution, and subsequently shift said caution signal to stop on the highway and go on the cross street, and said switching mechanism being operable, upon actuation of the second vehicle actuated means, to reshift the cross street go signal to stop and the highway stop signal to go, and cause said highway go signal to persist a predetermined minimum length of time before said sig nals can again be shifted.

4. A highway traffic signaling device for intersecting highways including signals normally indicating go to one highway, and stop to the other, mechanism for shifting and reshifting said signals to reverse and to restore the indications to the respective highways, said shifting mechanism including first and second vehicle actuated means located in one of said highways in spaced apart relationship, and arranged to be successively actuated by traffic approaching the intersection on 5 signals can again be shifted by actuation of the 15 first vehicle actuated means. I

5. In a highway traffic signaling device for intersecting highways including signals normally indicating go to one highway, and stop to the other, means for shifting and reshifting said sig- 20 nals to reverse and restore the signal indications to the respective highways, said shifting means including a first and a second detector located in one of said highways in spaced apart relationship, and arranged to be successively actuated by 25 traffic approaching the intersection on said highway, and switching means operable, upon actuation of the first vehicle actuated means, to shift said signal indications from go to stop on one highway, and stop to go on the other highway, 30 and operable, upon actuation of the second Vehicle actuated means, to reshift said signal indications to their-initial display, and operable, upon a subsequent actuation of the first vehicle actuated means during the reshifting of the signals, 5

cluding signals normally indicating go to the 4 1 highway and stop to the cross street, and also including a caution signal to indicate signal changes, means for shifting and re-shifting said go-stop signals, and operating said caution signal, including first and second vehicle actuated means 50 located in spaced apart relationship in the cross street, and arranged to be successively actuated by traflic approaching the intersection on said cross street, said shifting and re-shifting means also including switching mechanism operable, upon actuation of the first vehicle actuated means, to shift said highway go signal to caution, and subsequently shift said caution signal to stop, and shift the stop signal on the cross street to go, and said switching mechanism being further operable upon actuation of the second vehicle actuated means to reshift the cross street go signal to caution, and subsequently shift said caution signal to stop on the cross street, and said stop signal to go on the highway, and cause said signals to 5 display go to the highway and stop to the cross street for a predetermined minimum time before said signals can again be shifted, and said shifting mechanism being further operable upon actuation of the first vehicle actuated means during the display of the go signal on the cross street to arrest said reshifting until subsequent actuation of the second vehicle actuated means.

7. A traflic signal for directing traffic at the intersection of a highway and a cross street including signals normally indicating go to the highway and stop to the cross street, and also including a caution signal to indicate signal changes, means for shifting and re-shifting said go-stop signals, and operating said caution signal, including first and second vehicle actuated means located in spaced apart relationship in the cross street, and arranged to be successively actuated by traflic approaching the intersection on said cross street, said shifting and re-shifting means also including switching mechanism operable,

upon actuation of the first vehicle actuated means, to shift said highway go signal to caution, and subsequently shift said caution signal to stop, and shift the stop signal on the cross street to go, and said switching mechanism being further opation of ,the first vehicle actuated means during 10 the display of the cross street caution signal, or the highway go signal, to cause said signals to again be shifted from their normal indication to stop on the highway and go on the cross street.

CHARLES W. NEILL.

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