US1701399A - vickery - Google Patents

Description

Fbs 51p H. "\\N VCKERY .ADJUSTABLE swlTGH'ING MECHANISM Original Filed March 19, 1925 inventor'. Harry WVcKerg,

His Attorneg.

Patented Feb. 5, 1929.

UNITED STATES PATENT OFFICE.

HARRY W. VICXERY, OF LYNN, MASSACHUSETTS, ASSIGNOR T GENERAL ELECTRIC COMPANY, A. CORPORATION 0F NEW YORK.

ADJUSTABLE SWITCHING MECHANISM.

Application led March 19, 1925, Serial No. 16,765. Renewed August 28, 1928.

My invention relates to time controlled switches for controlling a plurality of translating devices such as lamps and the embodin'lcnthereinafter described is particularly designed for controlling illuminated semaphore signals for street intersections where signals indicative of go, stop and get ready7 are provided to direct traffic at street intersections. The present invention relates to certain improvements in the type of switching mechanism described in my copending application Serial No. 694,142, filed February 20, 1924, which application 1s assigned to the same assignee as the present invention.

A popular type of traiic signal for street intersections comprises a suitable tower or post provided with signals indicative of stop, go and get ready. The stop signals are flashed along one streetwhile the go signals are flashed along the intersecting street, and vice versa, and the get ready signal is flashed for each street just before an interchange in the stop and go signals takes place.

' Usually the traffic conditions change from time to time, and at different times during the day, so that it is desirable to provvide simple means for changing the relative duration of the stop and cgo signals for the two intersecting streets. When the go signal for one street is lengthened the stop7 signal for the same street is shortened, while the go signal for the intersecting street is shortened and its stop signal lengthened.

It will be. appreciated that for each change in this respect it also becomes necessary to change the relative time at which the get ready signal for each street will operate since this Asignal must operate just before each operation of the stop and go signals.

IMy invention relates to a simple switching mechanism whereby these changes may be readily accomplished by a traffic oliicer or other' authorized person without the use of tools or eXtra parts. My improved switching mechanism has the further desirable feature of automatically and correctly changing the relative time of operation of the get ready signal with respect to the stop and go signals when any change in the relative duration of the last mentioned signals is made.

The features of my invention which are believed to be novel and patentable will be pointed out in the claims appended hereto. For a better understanding of my invention reference is made in the following description to the accompanying drawing in which Fig. 1 shows a perspective view of the assembled switch mechanism, Fig. 2 a sectional view of an adjustable cam shaft and friction clutch used in the modification shown in Fig. 1, and Fig. 3 is a schematic showing of the operating parts of the switch mechanism together with the circuit connections.

In Fig. 1, represents a base for supporting the various parts of the switch mechanism in their proper relation. 11 represents a suitable driving motor for operating the switch. I prefer to use a self starting synchronous motor for this purpose since then the signaling device may be synchronized with other signaling devices located at different street intersections of the same street system in accordance with the teachings of copending application, Serial No. 4,580. filed January 24, 1925, entitled Traflic signaling system, Halvorson and Vickery, which application is assigned to the same assignee as the present invention. The speed of the motor is reduced to the desired value by means of gearing contained within the gear casing 1Q and drives a gear wheel 18 meshing with a gear wheel 14 connected by shaft 15 to the operating mechanism of the switch.

Although I do not wish to be limited thereto, I prefer to use. mercury tube switches because of their reliability, and three such switches are represented at 16` 17 and 1S. Switch 16 is tiltablv mounted with a shaft 19, as represented in Fig. 3, and switches 17 and 18 are tiltably mounted with a shaft 20. The shafts 19 and 20 are hollow and turn on a supporting rod 21. Between the motor driven shaft 15 and the mercury tube switches are cams and cam levers for tilting the tubes to open and closed position in the desired sequence which will now be described.

Secured to the operating shaft 15 is a cam 29. which cooperates with a cam lever 28 for ltilting tube 16. Also secured to shaft 15 is a cam member 24 cooperating with a cam lever 25 for tilting tubes 17 and 18. Mounted on shaft 15 is a hollow shaft 26, which shaft Acarries a second set of cam members 27 and 28, also cooperating with cam levers 23 and 25 respectively. The cam levers are at all times held down into contact with their respective cooperating cam surfaces by springs 29. Cam shaft 26 is ordinarily held in fixed relation with operating shaft 15 by a friction clutch. The friction clutch arrangement lis best seen in Fig. 2, and comprises a plurality of pins 30, a collar 31 for supporting the pins, and a compression spring The pins 30 extend through openings in the bushing or hub 33 of cam member 28, and bear agalnst the inner side surface of caml member 24. The collar 31 is free to slide back and forth on shaft 26 and is pressed towards hub with the pins 30 making frictional contact on cam member 24 by means of the spring 32 which is compressed between the collar 31 and t-he hub 34 of Cam 27.

It will thus be seen that cam members 22 and 24 are directly secured to shaft 15 and cam members 27 and 28 are directly secured to shaft 26 and that normally they will all be driven together due to the friction clutch. However, the shaft 26 and with it cam members 27 and 28 maybe adjusted with respect to shaft 15 andcam members 22 and 24 by simply rotating shaft 26 on shaft 15 by hand, one of the cam members 27 or 28 serving as a hand lever for this purpose.

Attention is directed to the shapes of the cams, the arrangement being for counterclockwise rotation. It is seen that both cams 22 and 27 are similar and each will cause a tilting of tube 16 in both directions. Cam member 24, as represented in the drawing, 'is arranged to lower cam lever 25 to tilt tubes 17 and 18 in one direction while cam member 28 is arranged to raise lever 25 to tilt tubes 17 and 18 in the opposite direction. Cam members 24 and 28 may thus be termed a single adjustable cam for operating cam lever 25. `lVhenever cam member 28 is adjusted with respect to cam member 24, cam 27 is similarly adjusted with respect to cam 22, and this feature produces the desired automatic adjustment of the get ready signal to maintain the desired sequence of operation when the relative durations of the start and stop signals are changed.

The switches 17 and 18 are mounted on shaft 20 in such a way that in the raised position of the cam lever one switch is open and the other is closed while the reverse condition of the switches exist when the cam lever is in its lower position. When moving from one position to the other the adjustment is such that the opening of one switch occurs simultaneously, or substantially simultaneously with the closing of the other switch, and vice versa. These switches are thus opened and closed in reverse sequence. 1 have found that the slight jar incident to the dropping of the-cam levers into the various depressions in their respective cams assists in the breaking of the contacts in all the mercury tube switches scheduled to take place at such instances. The raising of cam lever 25 is more gradual than the lowering due to the necessity of making the raising surface of the cam a sloped surface, and if it were not for the slight jar incident to cam 23 dropping off cam 27 the lmercury in tube 17 might cling to the electrodes and prolong the closure when that tube is gradually tilted to the opening condition by cam surface 41. The jarring due to the dropping of the cam levers thus helps to produce the exact timing of the various switching operations and makes it unnecessary to provide excessive tilting ofthe switches.

Before reviewing the operating of the switch mechanism, it will be desirable to mention the circ-uit connections shown in Fig. 3. 35 represents an electric distribution circuit for s'uj'iplying energy for the motor and for the signal lamps. It will be an alternating current circuit where synchronous motors are used. The field 36 of motor 11 is represented as connected across the circuit 35. 37, 38 and 39 each represent a lamp or group of lamps for flashing the signals. These lamps are connected across circuit 35 through the three mercury tube switches; 16, 17' and 18. respectively. 37 represents the get ready signal. 38 represents the go signal for one street and the stop signal for the intersecting street while 39 represents the stop signal for the first mentioned street and the go signal for the intersecting street. As represented in Fig. 3, switches 1G and 18 are tilted to the circuit closing positions, and switch 17 is tilted to the circuit opening position, and accordingly signals 37 and 39 will be energized. In this position of the mechanism, and assuming the apparatus is in operation, cam 22 has just raised lever 23 to close the get ready signaling circuit, indicating` that a change in direction of traliic flow is to take place. lVith the continued rotation of the cams in the direction indicated by the arrow, cam lever 25 will drop off the. step 4l) in its cam. and cause tubes 17 and 18 to tilt to the right, thereby closing signaling circuit 38 and opening signaling circuit 39. Simultaneously cam lever 23 will drop from cam 22 and tilt tube 16 to the right, dcenergizing the get ready signal 37. This condition will continue until shaft 15 has made approximately 1/4th of a revolution, with the adjustment represented, when cam 27 will next raise lever 23 to tilt tube 16 back to closed position to energize the get ready signal 37. Shortly thereafter lever 25 will have been raised by the surface 41 of cam member 28 to a. posit-ion where switch 18 will close and switch 17 will open and simultaneously with this operation lever 23 will drop from cam 27 to again open the getV ready signaling circuit. This condition continues until cam 22 has again raised lever 27 to close the get ready signaling circuit, thus completing the lll) cycle of changes desired for this adjust-ment. Now let us assume that it is desired to make the stop and go signals of equal duration on both streets. Cam meniber 28 is simply moved around to the right until its stepped surface is in alignment with the corresponding surfaces of cam member 24, thereby making the operation of signals 38 and 39 of equal duration. Simultaneously, with this adjustment, cam 27 is also moved an equal distance around to the right so that its proper time relation is automatically n'iaintained for the new adjustment.

Now let up assume it is desired to make a still greater change in the same direction,

that is, make the duration of signal 39 shorter than that of 38. Cam 28 may be adjusted still further to the right so that now lever 25 drops ofi' its stepped part instead of ofi' member 24, and lever 25 is raised by member 24 instead of by member 28. While this produces the desired change in the duration of signals 38 and 39, it will be seen that the cams 22 and 27 no longer are properly timed, and to correct this it will be necessary to loosen the set screws represented at 42 and interchange the positions of cams 22 and 27 on their respective shafts.

A simpler way of making the duration of signal 39 shorter than that of 38 is to reverse the circuitconnections between these signals and switches 17 and 18 as by the reversing switch represented at 43 so that switch 17 controls signal 39, switch 18 controls signal 38, and use the switch mechanism as first described. j

lVith this switching mechanism it will be seen that the adjustment of the cam members 24 and 28 does three things. It lengthens the duration of one signal, shortens the duration ot another signal, and automatically changes the time relation of a third signal to correspond to the new adjustment. Tools-oi` additional parts are not required for the adjustment, and due to the automatic adjustment ot the get ready signal, the liability of making an incorrect adjustment of this signal is eliminated. The adjustment can be quickly made while the device is in operation and at such a time during the cycle ot' operation as not to interfere with the signals. If at any time the traiiic conditions become sutiiciently light as to make the stop and go signals unnecessary` but it is still desired4 to intermittently tlash a precautionary signal indicating a crossing. the reversing switch 43 may be opened leaving only the signal 37 in operation.

Although I have shown and described my invention in conside able detail, I do not wish to be limited to the specific details thereof, as shown and described, but may use such modifications, substitutions or equivalents thereof as are embraced within the spirit of my invention.

j lVhat I ela-ini as new and desire to secure by Letters Patent ot the United States is 1. A switching mechanism comprising a motor, a plurality of switches, switch operating means driven by said motor for opening and closing said switches in a predetermined desired sequence, and common adjusting means included in said switch operating means for varying the time relation of operation between some of said switches and simultaneously with such adjustment varying thc relative time ot operation ot another of said switches to maintain the desired sequence of operation.

2. A switching mechanism comprising a motor, three switches, switch operating means driven by said motor lor opening and closing said switches in a predetermined desired sequence, one switch being opened and closed twice for each opening and closing of the other two switches and common means for adjusting the time relation between the operation of said last mentioned switches, and simultaneously adjusting the time ot operation of said first mentioned switch to maintain the desired sequence of operation.

3. A switching mechanism comprising a motor, a pair of switches, means driven by said motor for substantially simultaneously opening one of said switches and closing the other and vice versa, a third switch, means driven by said motor for opening and closing said third switch in a predetermined time relation with each corresponding operation of said other switches, and a common adjusting means for adjusting the relative duration of closure between said pair of switches and the time ot operation of said third switch to maintain the said predetermined time relation.

4. A switching mechanism comprising a plurality of pivotally mounted mercury tube switches, an electric driving motor, driving mechanism between said motor and said tubes for tipping said switches to open and closed positions in a predetermined desired sequence, and means in said driving mechanism for simultaneously adjusting the relative duration of the open and closed conditions of one switch and the relative time of operation of another switch so as to maintain the desired sequence of operation between them.

5. A switching mechanism comprising a pair of pivotally mounted mercury tube switches, an electric driving motor, driving mechanism between said motor and tubes for substantially simultaneously tilting said switches to open one and close the other and vice versa, a third pivotally mounted mercury tube switch, means driven by said motor for tilting said third switch to open and closed position for each corresponding operation 'of said other switches and in' a predetermined desired sequence therewith, and common adjusting means for adjusting the relative duration of closure of said pair of switches and the time of operdtion of said third switch to maintain the predetermined desired sequence of operation. l

6. A switching mechanism comprising a driving motor, a pair `of mercury tube switches tiltably mounted With a common shaft, a driving connectionbetween said motor and shaft arranged to rotate said shaft back and forth through a'small angle to open and close said switches, the switches being arranged on the shaft so that they open and close in reverse sequence, a third tiltably mounted mercury tube switch, means driven from said'motor for tilting said third switch to closed position just prior to the closure of either of the other switches and to open position substantially simultaneously with the opening of either of the other switches, and a single adjusting means for varying th relative duration of closure of said pair of switches during aI cycle of operation and the relative time of operation of said third switch to maintain the stated operative relation With said other switches.

7. In a switching mechanism, a plurality of pivotally mounted mercury tube switches, stepped cams, cam levers cooperating with said cams for tilting said switches to open and closed positions, means for operating said cams in timedy relation, the arrangement being such that when the cam lever for one switch drops from the step in its cam another switch is timed to open, said parts being structurally united such that the jar incident to the dropping of said cam lever from its stepassists in the opening operation of said other switch.

8. In a switching mechanism, a motor, a pair of switch operating cam shafts driven by said motor, each shaft carrying cam members formiimY an adjustable cam, another cam on each shaft and means for adjusting the relative rotative positions of said shafts to adjust said first mentioned cam and the relative positions of said other cams.

In witness whereof, I have hereunto set my hand this seventeenth day of March, 1925'.

HARRY W. VICKERY.

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