US2590748A

US2590748A - Electric circuit for controlling traffic signals

Info

Publication number: US2590748A
Application number: US785380A
Authority: US
Inventors: Blanchet Ovila Joseph
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-11-12
Filing date: 1947-11-12
Publication date: 1952-03-25
Anticipated expiration: 1969-03-25

Description

March 25, 1952 o. J. BLANCHET ELECTRIC CIRCUIT FOR CONTROLLING TRAFFIC SIGNALS Filed Nov. 12, 1947 I20 V. AC.

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Patented Mar. 25, 1952 UNITED STATES PATENT OFFICE ELECTRIC CIRCUIT FOR CONTROLLING TRAFFIC SIGNALS Claims.

This invention relates to electric supply and control circuits for the lamp bulbs of traffic signal casings, and especially to a circuit for traffic signal casingscontaining spare lamp bulbs and means for shifting a new lamp bulb into operative position to replace a bulb which has been burnt out.

The principal object of this invention is to provide an electric circuit having devices therein for automatically completing a circuit through a motor, disposed to rotate a carrier in which several spare lamps are mounted, so as to put a fresh lamp into connection with the supply conductors when necessary, and so arranged as to work properly in conjunction with the regular circuit which causes the stop and go lights to glow in succession for the period necessary to produce safe traific conditions.

A further object is to provide a circuit for a traffic signal unit having extra lamp bulbs for relay purposes, designed so as to energize an extra signal when all spare lamp bulbs are exhausted; thus giving warning that the unit must be equipped with new lamps at once to avoid suspension or interruption of service.

The nature and advantages of the invention are made plain in the following description and the characteristics are defined in the appended claims. But the disclosure is explanatory only and I may adopt variations in details without deviating from the essential features wherein the invention resides.

On the drawings,

Figure 1 shows an outline of a supply and controlling circuit according to this invention, with spare lamps to be shifted into operative position when required; and

Figure 2 shows a panel carrying operating members in said circuit.

The numeral l indicates the terminal of the bulb of the same group into position to be energized. Thus interruption of the operation of the traffic signal unit is prevented. Whenever a red lamp is to be illuminated, current is delivered to terminal 4, conductor 6 to a closed switch I; andfrom the switch the same conductor is continued to the terminals r-r of the lamp RI which is then in circuit. The current returns by Way of wire 8, a series transformer enters this shunt circuit to energize the secondary of the transformer 12, the circuit of which contains a half-wave rectifier l3 and a coil l4 bridged by a condenser. The coil is connected by a plunger, not shown, to pull a switch member I5, normally held open by any suitable means

chief supply lead

2, and 3 the terminal of the return wire of the supply circuit. A mechanical circuit controller or timer, not shown, connects the supply lead 2 alternately to the

terminals

4 and 5 to energize one of a group of red lamps RI, R2 and R3; and then one of a set j; of green lamps G1, G2 and G3 in succession at predetermined intervals. These lamps are mounted in a casing and are associated, asset forth in my prior application for patent upon out, in such a manner as to bring a-new lamp such as a spring, not shown, into position to close a circuit from the lead 6 through a conductor l6, switch 15, conductor", the windings l8 and lead H] to the return conductor I0.

The windings 18 represent a motor which is connected to a rotary support carrying the red lamps, which, for example, are three in number, but of course they can be more or fewer. As soon as current flows in the motor, the support is actuated to shift the lamp R2 into contact with the terminals r; the motor 18 being coupled to the support 8 by suitable gearing not shown herein. The motor has one terminal connected to the fixed terminal 20 of a switch, the movable member 2| of which is united to the conductor 22 attached to a conductor 24 leading to the supply terminal I. This switch arm 2| is normally held in open position by a cam 23 and can be actuated by a spring, not shown, to engage the terminal 20 when the cam permits. The arrangement is such that the cam 23 allows the switch to move to closed position as soon as the support S has turned far enough to connect in the lamp R2 between the terminals 1'. The motor and the support S then rotate no further. The motor stopsas soon as the new lamp is connected, because the coil M is then deenergized and the switch I5 opens. But a circuit to keep the motor alive is closed. when the switch 2| again engages the terminal 20. .The cam 23 is geared to turn one complete revolution while the support S turns through only a quadrant. As soon as the lamp R2 is in circuit, the current flows therethrough and deserts the coil l2 because the resistance II is too great. The solenoid I4 is thus deenergized and the switch l5 opens. The coil of the motor I8 then receives no more current, but the

switch points

20 and 2| are in contact. Therefore, current can flow from the terminal I through the wire 24 to the

switch points

20 and 2| and through the coil [8 back to the return wire Ill.

The coil 9 is not enough to energize the secondary circuit containing the switch-closing coil I4 by itself; and this coil I4 is not energized till the primary coil l2 receives current. The current flowing in the coil 9 during operation of one of the lamps RI, etc., only primes the circuit containing the coil l4 and makes this circuit active more quickly when a lamp burns out.

In case all the lamps of the red group have been destroyed, the shifting of the support S will only bring one of the defective lamps into, position when the coil [4 closes the switch 15 and current is supplied to the motor coil l8. Hence, the circuit will not be established across the terminals r-r. At this stage, however, the support S, which carries a conductive segment in the right place, bridges two terminals r--r, one of which is united to the wire 24 and the other to a wire 25, which runs to a-lead 26 connected to a coil 21 adjacent the switch I. This coil now opens the switch I, and the circuit of the coil 21 is completed through the wire 28 back to the conductor H]. No more current is now supplied to the burnt out lamp terminals rr.

The circuit also contains an amber lamp supplied from a terminal A connected to the same timer as the terminals I, 4, 5, to light up between the green and red signals. When the circuit for the amber color is closed current from the line flows to the timer, the terminal A, lead 39, switch point 31, switch blade 38, held, as by a spring, not shown, against the point 31, lead 40, the amber lamp, and wire 28 to the return wire Hi. When, however, all the lamps of the red or green group are burnt out, this amber lamp is made to flash repeatedly to indicate that replacement is necessary.

Whenthe coil 21 opens the switch I it also pulls the switch blade 38 against another switch point 36 on the side opposite the point 31. Some current in the wire 26 now flows to wire 3| and a fixed terminal 32, which is engaged by a switch blade 33, held against it by suitable means. The switch blade is moved up and allowed to drop by a toothed wheel 34, operated by any suitable means whenever a set of lamps is used up. When the switch is closed and opened by the wheel 34, current flows intermittently through a wire 35 to the fixed terminal 36. The terminal 36 is joined by a wire 39 to the amber lamp, which now flashes till the attendant corrects the condition by taking out the burnt bulbs and replacing them with new ones.

The same action occurs when a lamp in the green group burns out, or the whole group is destroyed. The circuits and switches for this group are marked with corresponding numerals distinguished by the addition of the prime mark. The timer allows current to flow to the terminal 4.

The resistance H is only a blocking resistance to prevent the relay circuit associated therewith from operating till failure of the illuminating de- "vices takes place.

Having described my invention, what I believe to be new is:

1. An energizing electric circuit comprising a device for consuming electric current, a movable support for the device, supply conductors leading to said device, a relay circuit associated with said circuit, an electric motor, a circuit therefor connected to the relay circuit, means connected to said supply conductors for maintaining said relay circuit inoperative except upon failure of said device, the motor being coupled to the support, a switch in said relay circuit to connect said conductors to said motor circuit upon operation of the relay to cause the motor to actuate the support, another circuit leading to said motor, and means operated by said motor to close said other circuit when the relay opens and the motor stops.

2. The energizing circuit as set forth in claim 1, wherein said relay circuit is operatively connected to said supply conductors, and said means for preventing operation of said relay circuit is a blocking resistance.

3. An energizing electric circuit comprising a device for consuming electric current, a movable support for the device, supply conductors leading to said device, a relay circuit associated with said circuit, an electric motor, a circuit therefor connected to the relay circuit, means connected to said supply conductors for maintaining said relay circuit inoperative except upon failure of said device, the motor being coupled to the support, a switch in said relay circuit to connect said conductors to said motor circuit upon operation of the relay to cause the motor to actuate the support, another circuit leading to said motor, and means operated by said motor to close said other circuit when the relay opens and the motor stops, said conductors and said relay circuit containing means for priming the latter while same is inoperative.

4. The energizing circuit as set forth in claim 3 wherein said relay circuit is operatively connected to said supply conductors, and said means for preventing operation of said relay circuit is a blocking resistance.

5. An energizing electric circuit comprising a device for consuming electric current, a movable support for said device, supply conductors leading to said device, a relay circuit associated with said circuit, an electric motor, a circuit therefor connected to the relay circuit, means connected to said supply conductors for maintaining said relay circuit inoperative except upon failure of said device, the motor being coupled to said support, a switch in said relay circuit to I connect said conductors to said motor circuit upon operation of the relay circuit, to cause the motor to actuate the support, another circuit leading to said motor, and means operated by said motor to close said other circuit when the relay circuit opens and the motor stops, in combination with a circuit for opening the circuit of saidsupply conductors, a signal device, and means for intermittently energizing said signal device when the circuit of said conductors is broken, the relay circuit being coupled to the supply conductors, and said means to prevent the relay circuit from operating being a blocking resistance in one of said conductors, and said conductors and relay circuit containing means for keeping the relay circuit in primed condition.

OVILA JOSEPH BLANCHET.

(References on following page) REFERENCES crrm') The following references are of record in the file of this patent:

: UNITED STATES PATENTS Number 5 Name Date 1,708,430 Perdue Apr. 9, 1929 1,749,444 Rae Mar. 4, 1930 1,955,616 Wallace Apr. 17, 1934 Number