US2029217A - Traffic signaling system and apparatus - Google Patents

Description

L L E B H H TRAFFIC SIGNALING SYSTEM AND APPARATUS Filed Oct. 1, 1932 Invenbow: Howor'd H. Be,

by k

His Attorney.

Patented Jan. 28, 1936 UNITED STATES PATENT OFFICE TRAFFIC SIGNALING SYSTEM AND APPARATUS Howard H. Bell, Schenectady, N. Y., assignor to General Electric Company, a corporation of New York Application October 1, 1932, Serial No. 635,776

Claims.

so that the Go, Stop and Caution signals I operate in unison, or at certain timed relations,

with each other. In either of these two systems of operation, which are often referred to as the non-progression or progression systems, re-

spectively, it is desirable at certain times to eX- tend the green or Go period beyond the normal length of time, along any one street, in order to enable the increased traffic to how rapidly through that street. 6

it is the main object of my invention to provide apparatus whereby such green or Go pc- 29 riod may be extended in either a progression or a non-progression system at any predetermined.

time of day or during any predetermined number of cycles of operation.

My invention will be better understood from 25 the following description when considered in connection with the accompanying drawing and its scope will be pointed out in the appended claims.

The single figure in the drawing illustrates diagrammatically a system of .trafiic control em- 30 bodying my invention. The system as illustrated, includes a program device Ill, 3. master timing unit H, and individual signal units l2, of which two are shown connected to the common energy source indicated by conductors l3 and I4.

5 Each unit 12 includes a driving motor l6 and switching means I! to operate the signals I8 in a predetermined sequence. The signals l8 are indicated as two groups of three signal lights each, indicating one set for the mainstreet trafiic and 40 another for the cross-street trafiic. The lights are marked G, A and R meaning green, amber and red respectively. The motor [6 drives the switching mechanism I! through shaft l9 and releasable clutch which is operable by elec- 45 tromagnet 2|. The energization of magnet 2| is controlled by a cam 22 mounted on shaft l9 and switch 23 whose contact 24 engages contact 25 only when the dose 21, of the supporting spring 29 for contact 25, falls into groove 28 of the 50 cam 22.

The master timer II is driven by a motor 30 through shaft'3l, and a clutch 32 operated by an electromagnet 33. Upon the shaft 3| a cam 22 is mounted and provided with a groove 28, both 55 corresponding to cams 22 and grooves 28 respectively. The cam 22 of the master timer operates a double throw switch 35 of which main contact 36 is mounted on a spring 31, the nose 3'! of which slides on the surface of cam 22. The contact 35 normally engages a contact 38, but en- 5 gages a contact 40 when the nose 3? has fallen into groove 28.

The operating magnet 33 of the master timer clutchdi is controlled by the switch 35, by a time delay relay #2 and program device 56. The relay 16 t2 comprises a driving motor 43 of which the armature d3 drives a worm td mounted on shaft 6'5. One end of shaft 55 is mounted in arm 46' of a bell-crank 46 which is pivoted at 5'? and may be rotated by a magnet 28. When this magnet is 15 energized, it attracts arm and thereby lowers arm 56' which carries the end of the worm shaft 65. The magnet 58 and the winding of motor 43 are, connected in series and are always energized and deenergized simultaneously. When, 24 therefore, the worm M is lowered, it is also rotated, and thereby drives a wheel 50 which it engages only when in the lowered position. The wheel is mounted to rotate freely about a shaft 5! being connected thereto only by a spiral spring 25 52. The spring 52 is arranged to return the wheel 55 to its starting position every time the worm 54 is moved out of engagement with the wheel 5%]. The starting position of the wheel 50 is determined by an adjustable stop 53 against 30 which a pin 54, mounted in the wheel 56, comes to rest. The position of the adjustable stop de-. termines the timing of the relay as will hereinafter he explained.

Upon rotation of the wheel 50 the pin 54 ro- 35 tates in a clockwise direction until it engages and trips a pivoted latch 56. The tripping of the latch 56 permits a spring 51, which is attached to the bell-crank 46 and which is placed under tension when the worm 44 is brought into en- 40 gagement with the wheel 56, to move a pivoted contact member 55 and thereby break a circuit between the contacts 56 and 55 and through the relay 42 as will be hereinafter explained.

The program device to is provided with two or 5 more arms 60 and 6| which may be set to any desired position and their efiect is to close a circuit between the relay 42, specifically contact 55, and the source of energy, or conductor l3, during predetermined periods of the day.

In operation, the cams 22 periodically close switches 23 which. energizes clutch magnets 2|, the circuit being, conductors l3 and 65, magnet 2!, switch 23, common conductor 66, contacts 38, and 36, conductor 61 back to line 14. If, 55

therefore, this circuit is completed the magnet 2! opens the clutch 20 and thereby stopsthe signal mechanism l1 and keeps it stopped until the circuit through the magnet is broken.

The master. timer I I, meanwhile also moves corresponding cam 22 and when the groove 28' reaches the position corresponding to that of the grooves 28 the contacts 36 and 38 separate and the-circuit to the clutch magnets 2| is broken. The speed of rotation and the shape of the cams are so arranged that the individual timers are started and open switches 23 before the master .timer again closes its contacts 36 and 38. The

i clutch magnets 2| are thereby deenergized', the

clutches 20 are closed, and the earns 22 moved sufliciently to open the switches 23 before the clutch magnet circuits are again closed at contacts 36 and 38. It is therefore evident that in this system the cams 22 cannot pass the circuit closing position of switches 23 until the master opens the clutch circuits. The signals I! are thereby maintained in synchronism with the master timer.-

- For the sake of carrying out my invention, it

, once during each cycle of operation and when the signals are operated in progression, that is, a certain time relation between the starting instants of the various signals exists, to select an instant in which all the signals on the systemare green or indicate that signal which it is desired to temporarily increase during that cycle.

The extension of a green signal, in accordance with my invention is obtained by the use-of the program device II and time delay relay 42 as follows: The master timer switch 35 is a double throw switch. When it opens its contacts, 36 and 38, it simultaneously closes its contacts 36 and 40. This closes a circuit from line conductor l4 through conductor 61, contacts 36-and 40, conductor 68, and clutch magnet 33. Clutch magnet 33 is connected in multiple with the winding of motor 43 and operating magnet 46 by cnductors 69 and 10; the magnet and motor 43 being in series with each other through conductor II. This circuit is completed to the other line conductor l3 through conductor I2, contacts 56 and 55, conductor I3, program device I6 and conductor During that part of the day in which the program device closes the circuit through itself, the circuit through the clutch magnet 33, coil 48 and motor 43 is closed every time the. contacts 36 and 40 engage. The magnet 33 then opens clutch 32 and thereby stops rotation of the cam 22. The energization of the coil 48 and the motor 63 starts wheel 50 rotating for a period determined by the angular distance between the pin 53 and the clutch 56 which is obtained by the adjustment of stop 53. Whenwheel 50 has moved pin 53 into engagement with latch 56 the spring 51 separates the contacts 55 and 56 thereby opening the circuit through clutch coil 33, the operating coil 48 and motor 43 of the relay 42. The worm 44 is moved out of engagement with wheel 56 and contact 55 again moves into engagement with contact 56 and latch 50. The apparatus is then again ready for operation during the following cycles of operation, until the program device breaks the circuit.

During normal operation of the system the master cam 22' rotates continuously and breaks the clutch circuits for the individual timers only long enough for them to restart and break the same circuit by opening the switches 23. When the master timer is thereforestopped in that position, in which it breaks the timer clutch circuits and closes its own clutch circuit due to the program switch being closed, it is necessary to provide means to maintain the individual timer clutch circuits closed. For this purpose a contact I is provided on the core 33' of the master clutch coil 33. This contact 15 is arranged to enengage, contacts 16 and 11, which are attached to conductors 66 and 61 respectively, only when the clutch coil 33 is energized and the master timer therefore stopped. The circuit through contact 15 provides a shunt across the synchronizing contacts 36 and 38 and thereby the synchronization period, which is normally only momentary, is lengthened by that period during which the master timer is stopped.

It is therefore clear that in the above-described system, with the apparatus described, it is possible to select any particular signal and prolong it for a predtermined period, as determined by the adjustment of the time delay relay, during any number of cycles of operation occurring during predetermined parts of the day.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. In a traflic control system, the combination of a plurality of signaling units provided respectively with a series of corresponding signals,

means located in each unit for continuously operating said signals 1115 a predetermined sequence, means for'synchronizing said units including means for periodically stopping the operating means for each unit, means for restarting each unit only when said units are in synchronism, and means for'delaying the operation of the restarting means for a predetermined period of time at preselected-ones of said restartingoperations.

2. In a traflic control system, the combination of a plurality of signaling units provided respec tively with green, amber and red signals, means for operating the signals in sequence and in re-- curring cycles including a switching mechanism,

a motor, and an electrically operated clutch between the motor and said mechanism, an operating circuit therefor, means for synchronizing said motors including a master controller, provided with a cam, a corresponding cam operated by each of said units respectively, a switch on each unit operated by'its respective cam for closing the circuit to the clutch in said unitand a switch cooperating with said master cam for breaking the clutch circuits of said units, and

means for periodically stopping said master cam and unit cams including a program device for determining the'cycles of operation during which the cam shouldbe stopped, and a time delay relay in series with said program device for determining the length of said stop period.

3. In a trafilc control system, the combination of a series of trafiic signaling units' operable through a signaling cycle, means for operating said units individually, means for stopping said operating'means at a predetermined instant in each cycle, a master timer arranged to restart said units simultaneously and thereby synchronize said operating means, and means for delaying the operation of said master timer a predethe signals in each unit in a predetermined cycle, means for operating corresponding signals in a predetermined time relation with respect to each other, means for periodically synchronizing said signal operating means including means for stopping said operating means at a predetermined instant in the operating cycle, and means for simultaneously restarting the means of each of said series of units, and means including a program device for delaying the operation of said starting means for a predetermined length of time during predetermined operating cycles whereby the time of the signal indicated by each unit during the synchronizing operation is correspondingly extended.

5. In a traflic control system, a plurality of sigsaid operating naling units provided respectively with a series of corresponding signals, means for operating said signals in a predetermined cycle, means for stopping said operating means at a predetermined instant in each operating cycle, a master timer for simultaneously restarting said operating means of each of said plurality of units, and means for controlling said master controller comprising a normally inactive time delay relay for delaying said restarting operations a predetermined time interval respectively and a program device for eifecting operation of said relay during the predetermined restarting operations which are to be delayed.

, HOWARD H. BELL.

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