US2057186A - Signaling system and mechanism therefor - Google Patents

Description

Oct. 13, 1936. E. R. FREEBERG 2,057,186

SIGNALING SYSTEM AND MECHANISM THEREFOR Filed Feb. 7, 1934 3 Sheets-Sheet 1 41 54: 4?: 57 fi5: 2 M a a s 2 TD F 0 WEI? SUPPLY INVENTOR ERNEST P2. FREEBERG ATTORN EY Oct. 13, 1936. FREEBERG 2,057,186

SIGNALING SYSTEM AND MECHANISM THEREFOR Filed Feb. 7, 1954 5 Sheets-Sheet 3 TU PUWEP SUFPLY fist- 9 INVENTOR ERNEST R. FREEBERG ATTORNEY Patented Oct. 13, 1936 UNITED STATES PATENT OFFICE SIGNALING SYSTEM AND MECHANISM THEREFOR chusetts Application February 7, 1934, Serial No. 710,151

7 Claim.

This invention relates to signaling systems in which visual or other signaling aspects are alternatively or successively given, and is particularly suited for embodiment in signaling systems for controlling and directing vehicular highway traffic.

The rate of movement of vehicles upon main or so-called arterial highways has increased during the past decade to so great an extent that,

10 if warning is merely given to drivers of vehicles that the right of way has been withdrawn from the highway upon which they are traveling and has been given to those who are likely to cross their path, Vehicles which are approaching the crossing point or intersection at a time when a stop indication is given for them, are likely to be moving so rapidly that they will be unable to bring their vehicles to a stop before reaching the intersection; and, hence, will unavoidably enter upon or cross same at a time when the vehicles or pedestrians who have been given a "procecd signal have moved into their path.

The situation thus developed is aggravated by the psychological tendency to attempt to get across the intersection without being delayed by the passage of traflic which is waiting to move across the path. Thus, it has been found that if, in a cycle of signal changes, an interval is provided for clearing the intersection during which so stop" signaling aspects for all trafllc are displayed, drivers of approaching vehicles are prone to rely on such supposed period of grace when the stop signal appears, and to therefore speed up instead of slowing down their rate of movement. In fact, the result seems to be that inasmuch as they are permitted to pass the stop signal for at least a short interval after it appears, they arelikely to misjudge, to a greater or less extent, the time when other trafhc will have actually moved into their path, depending upon the differing degrees of their impatience upon various occasions, so that there comes an occasion when they reach the crossing or point of intersection at the very time it is occupied by another, while traveling at an especially rapid rate, thus intensifying the seriousness of the consequences.

If the development of such situations is to be prevented, it appears indispensable that when a highway trairlc signal displays such a stop aspect, all approaching vehicles shall be required to stop short of it. However, in order to make it possible for the drivers of vehicles to do this, it is essential that warning shall be given them for a time in advance of the display of the stop indication which is sufiicient for them to arrest their movement before they reach the signal; and it is, of course, equally essential that such warning shall be of a kind which is calculated to be understood by all drivers having ordinary 5 comprehension of the significance of the various aspects of highway trafiic signals.

It is a further object to provide a trafllc control signal display which flashes either a stop" or a go" signal for intervals of progressively de- 10 creasing duration and/or for durations separated by intervals of extinguishment of progressively decreasing duration.

In instances wherein a signal is flashed with progressively decreasing durations of the interl5 vals between flashes, the durations of the displays themselves being substantially unchanged,

a resulting characteristic signal display is ob tained which gives an opposite visual impression from that given in instances wherein durations 20 of the flashes are progressively decreased and the durations. of the intervals between flashes are held either substantially constant or are also progressively decreased.

In the first instance the ratio of duration of 25 intermittent signal display with relation to the duration the intervals between such displays, increases so that the display approaches a continuous one.

Such increased ratio has a very desirable effect 30 on the movements of traflic when such intermittent display applies to the red or stop signal.

For example, the driver of a vehicle approaching an intersection and observing a flashing red signal, with the red display seemingly becoming 35 more and more prominent, is not only psychologically urged to be on the alert for a change in signals, but is also given what might well be termed a subconscious suggestion that he should bring his vehicle to a stop even though 40 he knowns the green signal may persist long enough for him to get across.

As a result of such urge, drivers of vehicles are more likely to retard their speed at intersections and not attempt to beat the light.

Furthermore, when the green or go light is flashed in accordance with the second instance,

1. e., with the durations of flashes progressively decreased either with or without decreases in the durations of intervals between such flashes, another desirable psychological urge is presented which tends to cause drivers to stop their vehicles due to the decrease in the amount of display of the "go signal. As a result of the tendency Just 55 set forth, drivers of vehicles are deterred from attempts to beat the light.

It is, therefore, a general object of this invention to provide a signaling system and mechaniism therefor whereby a warning will be given when the signaling aspect is about to change, and in which such warning will be given by intermittently displaying or indicating a signaling aspect about to become efiective.

It is a more specific object of this invention to display such a warning in a manner which will progressively indicate the increasing proximity of the time when the impending change will become effective.

Further objects are to provide embodiments of this invention which may be inexpensively produced, which will be durable, readily understood and will require a minimum of attention for purposes of maintenance, and which facilitate utilization of existing installations with a minimum of revision and extension.

For better understanding of this invention, reference may be had to the annexed drawings and the detailed descriptions thereof hereinafter contained, in which certain embodiments of this invention are illustratively indicated; however, it should be understood that although the embodiments so indicated are practical, they are by no means the only ones which this invention may assume, and they are given without intent to imply limitation to the particular details and arrangements therein shown, except insofar as such details and arrangements are defined in the appended claims.

Similar reference characters indicate corresponding parts in the accompanying drawings, in which Figure 1 diagrammatically indicates a simplified form of so-called pre-timed" highway traffic signaling equipment, embodying an aspect of this invention;

Fig. 2 correspondingly indicates the manner of applying another aspect of this invention to such a system;

Fig. 3 similarly indicates another embodiment of this invention for supplying results corresponding to those afforded by the system of Fig. 2;

Fig. 4 is a chart indicating the relative duration and times of occurrence of the color periods incident to a cycle of the operation of the system indicated by Figs. 1, 2 and 3;

Fig. 5 indicates the application of this invention to signaling equipment suited for response to vehicle or pedestrian movements and/or subject to coordination of activity with other signaling equipment; and

Figs. 6, 7, 8 and 9 are charts indicating the rel ative duration and times of occurrence of color periods which may be provided, in accordance with this invention, by revision of the movement, formation, arrangement and manner of connecting the cams and contacts of Figs. 1, 2, 3 or 5.

Referring to Fig. 1, a so-called traflic signal controller is generally indicated at C and a group of signal lights situated at a highway intersection is correspondingly indicated at S The controller indicated at C is illustrative of any one of various well-known types of traffic signal controllers which comprise circuit controlling mechanism and actuating means therefor. In this schematic illustration, the actuating means is exemplified by the motor 2| which acts through the gears 22 and 23 to drive the shaft and the circuit controlling mechanism is exemplified by the cams 3", 32 33 and 34 which are driven by the shaft 24 and the pairs of circuit controller contacts 42 43 and which are operatively associated with said cams, respectively.

The signal lights R R G G are provided for governing the movement of traffic which approaches the intersection along the vertically disposed one of the indicated highways which, for convenience, is designated by the word Main and the lights R, R, G, G are provided for governing the movement of traffic which approaches the intersection along the other of the indicated highways which, for convenience, is designated by the word Cross".

It will be understood by those skilled in this art that the controller C may include facilities whereby adjustments may be readily effected of the time intervals which intervene between recurrences of given signaling aspects in the cycle of the operation of the controller as well as in the relative proportions of such cycle time which are allotted to one and the other of the alternate signal manifestations, for coordinating the activities of two or more of such controllers, for rendering the controller responsive to tramc movements in one or more of the affected trafllc channels, and for controlling and regulating traflic movements at intersections involving more than two highways or thoroughfares, besides providing facilities for meeting other of the multifarious situations presented by the various phases of traflic control problems; however, such facilities are here omitted in the interest of simplicity and clearness, as it is believed that those skilled in this art are familiar with expedients whereby such characteristics may be readily associated to a needful extent in a controller embodying the aspect of this invention to which Fig. 1 is particularly directed.

The conductors 5H and 52 connect the motor 2l with the power supply; the conductor 53 connects conductor 52 with one terminal of each of the lamps R R R ,R ,G 6", G G; the conductor 54 connects the conductor 5| with one of the contacts of each of the pairs of circuit controller contacts M 42 43 and the conductor 55 connects the other of the pair of circuit controller contacts with the lamps R R and the conductors 56 51 and 58 correspondingly connect the remaining contacts of the pairs 42 43 and 44 with the lamps R", R ;G G ;and G G= ;-respectively.

The cam 3" is so formed as to continuously permit closure of the contacts 4 I during approximately one-half of each revolution of the shaft 24 and the cam 32 is so formed as to permit continuous closure of contacts 42 during the remainder of each revolution of the shaft 24 The cam 33 is so formed as to cause continuous separation of the contacts 43 throughout all of that half of each revolution of the shaft 24 during which cam 3| permits continuous closure of the contacts M and the cam 34 is so formed as to cause continuous separation of the contacts throughout all of the other half of each revolution of the shaft 24 From the foregoing it will be apparent that during approximately one-half of each revolution of the shaft 24 the contacts 43 will be continuously closed, thus causing the lamps G G to be lighted and to thereby provide a go" signaling aspect for the traflic approaching the intersection along the Main" thoroughfare; and that, during the remainder of each revolution of the shaft 24 the contacts will be closed so that the lamps G, G will be lighted, to thereby provide a go signal for traffic approaching the intersection along the Cross thoroughfare. It will further be evident that so long as contacts 43 are closed, contacts 42 will also be closed, thereby providing a stop signal for traffic approaching the intersection along the Cross" thoroughfare throughout the time that a go signal is provided for traific approaching the intersection along the Main thoroughfare; and, correspondingly, whenever contacts 44 are closed, contacts will also be closed, thereby correspondingly providing a stop signal for traflic approaching the intersection along the Main thoroughfare throughout the time that a go signal is provided for traffic approaching the intersection along the Cross thoroughfare.

A group of teeth 3| l is formed in the periphery of cam 3| in such position that they will be carried past the co-engaging one of the contacts just after the main or continuously raised portion of said cam 3I has withdrawn therefrom incidental to counter-clockwise rotation of said cam, to the end that when the contacts have been held continuously open by the main raised portion of the cam 3H, and while the cut-away portion of the cam 33 is still being presented to the contacts 43 the notches between the teeth 3| I will permit a series of closures of the contacts so that the red or stop signal lamps R R will repeatedly flash just prior to the extinguishment of the green or go signal lamps G G and just prior to the continuous lighting of the lamps R R which occurs while the cut-away portion of cam 3| is presented to contacts A similar group of teeth 32H is formed in the periphery of cam 32 for like actuation of contacts v42 so that the lamps R R will be caused to repeatedly flash during burning and just prior to extinguishment of the lamps G G.

The times of the occurrences of changes in the signaling aspects effected by the lighting and extinguishing of the signal lamps. with relation to the contours of the cams, is further illustrated by the chart of Fig. 4, which is representative of one revolution of shaft 24 and hence one cycle of the operation of the mechanism.

In this chart, the upper band RR is representative of the red lamps R R of Fig. 1, and the band directly below same marked GG is representative of the green lamps G, G, all of which lamps are provided for controlling the movements of Main" highway traffic.

The shaded portions of these bands indicate the times during the cycle when the lamps of the represented group are lighted, and the blank portions of these bands represent the times when these lamps are extinguished.

The line 3I0 is a development along a horizontal plane of the periphery of the cam 30, and the line 330 is a corresponding development of the periphery of the cam 33 The bands RR and GG correspondingly represent the lamps R R and G, G of Fig. 1, and the associated lines 320 and 340 correspondingly represent the peripheries of cams 32 and 34 01 Fig. 1.

The operation of the system of Fig. 1 is as follows:

Upon application of a suitable source of power supply to the conductors SH and 52 the motor 2I will run and, through the action of the reduction gearing 22 23 will cause rotation of the shaft 24 at the desired speed, so that the time occupied by each revolution of this shaft will be that desired for a cycle of signaling aspects.

Assuming that, at the time of the application of electrical energy to the conductors 5| and 52 the shaft 24 is so positioned that the raised portions of cams 3N and 34 have just been withdrawn from their associated contacts, the lamps R R1111 will be lighted, thus providing a stop aspect to traflic approaching the intersection along the Main thoroughfare, and the lamps G G will be lighted, thus providing a go aspect to traflic approaching the intersection along the Cross thoroughfare.

With cams formed as shown in Fig. 1, such aspects will continue for approximately one-half of a revolution of the shaft 24 However, during the latter portion of such half revolution, contacts 42 will be permitted to momentarily close through presentation of the notch between the continuous raised portion of cam 32 and the first of the teeth 32 I whereupon the lamps R R will be lighted. When the shaft 24 is thereupon rotated for a slight additional distance, the first of the teeth of the group 32 I will cause separation of the contacts 42 and consequent extinguishment of the lamps R, R. This action will be repeated as the notches between the others of the teeth of the group I'I'M are presented to the contacts 41".

Through the resultant flashing of the lamps R, R, drivers of vehicles approaching the intersection along the Cross thoroughfare, who would otherwise reach and fail to clear the intersection after a "go signaling aspect had been given to Main thoroughfare trafiic, will be given warning preceding the impending signal change by a time such that they will have opportunity to stop their vehicles before reaching the intersection.

As the last of the teeth of the group 31H is withdrawn from the path of the co-engaging one of the contacts 42 the raised portion of the cam 34 will cause separation of the contacts 44 so that lamps G, G will be extinguished at the commencement of the interval during which lamps R R are continuously lighted. At the same time, the raised portion of cam 33 will be withdrawn from the co-engaging one of the contacts 43 and the raised portion of the cam 3l will cause separation of the contacts 41 thereby causing the lighting of the lamps G G and the extinguishment of the lamps R R Thus there will be provided a stop signaling aspect for trafiic approaching the intersection along the Cross thoroughfare and a go signaling aspect for trafiic on the Main" thoroughfare.

Thereafter, during further rotation of the shaft 24 the signaling aspect just described will continue until the notch preceding the first of the teeth of the group 3H permits closure of the contacts 41 whereupon the lamps R R will be flashed, and a warning signal will be given for traflic approaching the intersection along the Main thoroughfare corresponding to that already described as resulting from the actuation of contacts 42 by the notches between the teeth of the group 32l When the last of the teeth 3| I has been thus withdrawn from the path and thereby permitted closure of the co-engaging one of the contacts M the lamps R R will be continuously lighted; the raised portion of the cam 33 will cause extinguishment of the lamps G G by separating the contacts 43 the raised portion of the cam 34 will be withdrawn from the co-engaging one of the contacts 44 thereby causing lighting of the lamps G, G; and the raised portion of the cam 32 will cause separation of the contacts 42 sothat lamps R, R will be extinguished. Thus there will be provided a stop signaling aspect for traflic approaching the intersection along the Main thoroughfare and a go" signaling aspect for trafiic on the Cross thoroughfare.

If, for any reason, it is desired to provide such a flashing signal for warning the traflic approaching along one of the highways, without providing a corresponding signal for traffic approaching along the other highway, a continuation of the raised portion may be substituted for one or the other of the groups of teeth 32F, 3H I It is evident from the foregoing, that, as indicated by the chart of Fig. 4, the warning flashes resultant from operation of a system such as that of Fig. 1, and all the intervals therebetween, will be of substantially uniform durations, respectively. However, it is believed to be distinctly advantageous to provide a larger number of flashes for such a warning signal, than can (for reasons believed to be well understood by those skilled in this art) be readily provided for with an arrangement such as is indicated by Fig. 1, and it is further desirable to cause such flashes to occur at a progressively increasing rate, or, in other words, with progressively decreasing intervals therebetween.

The arrangement diagrammatically indicated by Fig. 2 accomplishes the result of thus progressively decreasing the interval between the flashes of each group, as well as increasing the number of flashes in the group, while permitting a construction as compact and sturdy as that indicated by Fig. 1.

The lamps R R G G RF, RF, 65, of Fig. 2, correspond to the similarly designated lamps of Fig. 1.

In the controller C of Fig. 2, the motor 2|", the reducing gearing represented by 22 23 the shaft 24 the cams 33 and 34 the contacts M 42 43 and 44 and the conductors 5| and 58 inclusive, correspond with similarly indicated parts of Fig. 1.

The cams 3| and 32 are similar in contour to the cams 3H and 32 other than in that continuations of the raised portions are substituted for the groups of teeth 3 and 320, respectively. The cam 3P carries a pin 3l2 and the cam 32 carries a pin 32!, the purposes of which pins will be hereinafter more fully explained.

The cam 35 is fixed upon the shaft 24 and cooperates with the contacts 45 and 46 so that, during substantially one-half of each revolution of said shaft, the cam 35 will permit closure of the contacts 45 and hold the contacts 46 open, and throughout a corresponding portion of the other half of each revolution of said shaft said cam will permit the closure of the contacts 46 and hold contacts 45 open.

An auxiliary shaft 6|? hasthe pinions 62 and 63, and the ratchet wheel 64 fixed thereon, and the toothed wheel 65 is loosely journaled upon said shaft. The ratchet dog 61 is pivotally mounted upon the wheel 65 the free end of said dog being urged into engagement with the teeth of ratchet wheel 64 by the spring 68.

The contact. H is tensioned for movement toward, and the free end thereof is disposed in the path of the teeth of the wheel 65*, so that, upon rotation of said wheel, said contact will be moved into and out of engagement with the contact 12 The teeth of the wheel 65 vary in pitch from widely spaced teeth such as the teeth 13 and 14, to closely spaced teeth such as the teeth 15 and 16; so that, upon counter-clockwise rota.- tion of said wheel at substantially uniform rate, from the position where tooth 13 engages contact H to that in which tooth 16 engages said contact, the intervals between engagements of adjacent ones of said teeth will be of progressively decreasing duration.

The conductor 8! connects contact H with conductor 54 the conductor 82 connects contact 12 with one of the contacts 46; conductor 83 connects conductor 82 with one of the contacts 45; conductor 84 connects the other'one of the contacts 46 with conductor 56 and conductor 85 connects the other of the contacts 45 with conductor 55 The rack bars 9! and 92 engage the pinions 62 and 63, respectively; these bars being supported by studs 94 94 94 94 which project through slots 95 permitting lengthwise movement of said bars while engaging their respective pinions, for imparting desired rotation to the auxiliary shaft 6l Inasmuch as the bars 9| and 92 are interconnected through the shaft 6| and their associated pinions 62 and 63, respectively, each will respond to actuation of the other.

The springs 96 96 are applied to the bars 9| and 92 for lifting them to the limit of movement permitted by their supporting studs 94*, and the upper ends 91, 91, of said rack bars extend into the paths of the pins 3l2 and 322 respectively, so that, when the shaft '24 is rotated by the motor 2 l the pins 3l2 and 322 will each, one after the other, engage and then disengage its respective rack bar, thereby efiecting simultaneous movement of said rack bars against the tension of their associated springs 96*, 96 The arrangement of said bars 9! and 92 with relation to the paths of movement of said pins in and 322 respectively, is such that, when one or the other of said pins engages its associated rack bar, it will move same to an extent such as will cause one revolution of the auxiliary shaft 6! and will then move out of the path of the cooperating end 91 of such bar, whereupon the parts will be returned to their normal position by the springs 96 96 The pin am is so situated with relation to the raised portion of the cam 3P, that said pin will engage the bar 9| during intended counterclockwise rotation of the shaft 24 sufliciently in advance of the withdrawal of the raised portion of said cam from engagement with the con-- tacts 4|, that the resultant rotation of the auxiliary shaft 6| 2 will have been completed just before the raised portion of the cam 3l is withdrawn to thereby permit the contacts 4 P to close. The pin 322 is correspondingly located with reference to the raised portion of cam 32.

The cam 35 is so positioned upon the shaft 24 as to permit closure of the contacts 45 throughout actuation of the rack bar BI by the pin 3l2 32', 33, 34 and 35'. The resulting lighting and extinguishment of the lamps of signal S will correspond to that hereinbefore described in connection with Fig. 1, insofar as the continuous lighting and extinguishment of said lamps is concerned; however, the flashing of the red lamps shortly before the extinguishment of their associated green lamps is accomplished in a distinctly different manner, as will now be described.

Assuming that the cam 33 has permitted the contacts 43 to remain closed until a time when the "Main" thoroughfare red lamps R lt should commence flashing, the pin 3|2' will be carried into engagement with the upper end 91 of the bar 3|", so that the continued rotation of shaft 24 will cause said bar to move downwardly in engagement with pinion 32, and thereby rotate shaft 6i.

Such rotation of shaft 8i will cause ratchet wheel 34 to drive wheel 65', acting through ratchet dog Bl, in a counter-clockwise direction. thereby consecutively bringing the teeth of wheel 85' into engagement with contact ll", so as to repeatedly move same into engagement with contact 12'. Throughout such rotation of wheel the cam 35 will permit closure of the contacts the various parts being shown in Fig. 2, as positioned approximately midway the rotation of shaft 6| responsive to the movement of rack bar 3| by pin 3l2". Upon each closure of the contacts II and 12', a current path will be established from conductor 5P, through conductor 54*, conductor 8|, contacts H and I2, conductors 82 and 83, contacts 45, conductor 85, conductor red lamps R R conductor l3 to conductor 52". It is therefore evident that the lamps R R will be briefly lighted or flashed" during the successive engagements of the various teeth of the wheel 65*, and that, during the rotation of such wheel, the intervals between such flashes will progressively decrease, due to the progressive decrease in the spacings between such teeth. It will also be evident that the durations of the flashes will be substantially uniform.

Following the disengagement of tooth 16 from contact H pin 3I2 will be carried by cam 3| out of the path of the upper end 91 of bar 9|, whereupon springs 96', 96 will act through bars 3" and 32 to cause clockwise rotation of shaft 6| to an extent corresponding to the counterclockwise rotation imparted to said shaft through actuation of the bar ill by the pin 3l2=.

The wheel 6."! will not rotate with the shaft 6| during such clockwise movement, being permitted by the dog 61 to remain in the position where the contact ll rests between the teeth 16 and 13, contact 1| thus being out of engagement with contact 12 Immediately following the termination of the counter-clockwise rotation of the wheel 65, the rise of the cam 33 will act to separate contacts 43 and thus cause extinguishment of lights G", G, and the rise of cam 3| will be withdrawn so as to permit contacts 4| to close and thereby effect continuous lighting of the lamps RP, R whereby a stop signaling aspect is given to trafllc approaching the intersection' along the Main thoroughfare. At substantially the same time, the rise of cam 32 will effect separation of contacts 42 and thus extinguish lamps R R, and the rise of cam 34 will be withdrawn and thereby permit closure of contacts 44, and thus cause lighting of the lamps G, G", so as to provide a "go" signaling aspect for the Cross thoroughfare.

In the course of subsequent rotation of the shaft 24', the rise of cam 35 will effect separation of contacts 45, and will be withdrawn and permit closure of contacts 46; after which, in suitable timed relation prior to release and consequent closure of contacts 43 and 42 by cams 33 and 32", respectively, pin 322', carried by said cam 32', will engage the upper end 9! of bar 32', and thereby cause rotation of shaft 6i and resultant operation of contact H as hereinbefore more fully explained.

During such operation of contact ll, resultant from engagement of pin 322 with the upper end 91 of bar 92', each time that said contact II is pressed against contact I2 a current path will be established from conductor ii, through conductors 54' and 8|, contacts II and 12, conductor 32, contacts 46, conductors 34 and 58', through lamps R, R", and conductor 53 to conductor 52; thereby causing the lamps R,

-R, to be flashed during the engagement of each of the teeth of the wheel 35, as hereinbefore more fully described.

From the foregoing, it will be evident that the general results of the operation of a signaling system arranged in accordance with Fig. 2 is substantially the same as is indicated in the chart in the upper portion of Fig. 4, except that the red flashes will be more numerous, and will be separated by intervals of progressively decreasing duration, as exemplifled by the band 2, of the chart of Fig. 4 which shows the uniformity of duration of the flashes and the progressive decrease of the spaces therebetween, the time interval represented by these bands being equivalent to that embraced between the lines a, b as they intersect the bands RR, GG, RR and GG of this chart.

Referring next to Fig. 3, it will be observed that there is here disclosed an arrangement for operating a pair of flashing contacts H and '12 from a wheel 65 which differs in a number of respects from the arrangement of Fig. 2.

The cams iii and 32 are associated with contacts and 42 and are flxed upon the shaft 24 It should be understood that contacts corresponding to 43 44 45 and 46 of Fig. 2, or structure providing equivalent functions, should be made operative incidental to rotation of the shaft 24 The pins M2 and 322 are carried by the cams ill and 32 for cooperation with the levers 9| and 92 so that, as the shaft 24 revolves, said levers will be successively engaged by saidpins and thereby swung through a predetermined path.

The levers BI and 92 are pivoted at 84 94 in comparatively close proximity to the paths of the pins M2 and 322 respectively; and the free ends of the portions of said levers which extend from their pivots away from the paths of said pins have secured thereto flexible members or straps Ilil, I02 which extend around and are secured to the cam shaped members I03, I04 which are fixed upon the sleeves 36 and 31, respectively, which sleeves are loosely journaled upon the shaft H The springs 96 96 are so applied to the cams I03, I04 as to resiliently oppose rotation imparted thereto when the pins 3| 2 and 322 act, one after the other, to swing their associated levers 9| and 92 The discs I05 and H16 are fixed upon the sleeves 36 and 31, respectively; and, hence, are journaled upon the shaft GI and rotate with the cams I03 and I04, respectively.

The ratchet wheels I01 and I08 and the wheel 65 are fixed upon the shaft 5|, and the ratchet wheel I0! is connected with the disc I05 through the ratchet dog I09, so that when the pin 3I2 acting through the lever 9F and strap IOI causes rotation of the member I03, the wheel 65 will be caused to rotate therewith; but when the member I03 is rotated in the opposite, direction in response to its spring 96 the dog I09 will permit the wheel 65 to remain unaffected thereby. A corresponding connection (not shown) enables the disc I06 to drive ratchet wheel I00.

The peripheries of the cam members I03 and I04 are of such contour that the movement imparted to the levers 9| and 92 by their respectively associated pins 3I2 and 322 will cause rotation of their associated cams at a progressively increasing speed. As the teeth of the wheel 65 are all of the same pitch, it will therefore be evident that the rotation of said wheel, resultant from the rotation of the shaft 24 will be at a progressively increasing speed, so that the flashes .ofthe signal lamps caused by the actuation of the contacts H and I2 which result from such rotation of wheel 65 will be of durations and will be separated by intervals both of which will progressively decrease, as indicated by the band 3- of the chart of Fig. 4.

Referring next to the arrangement diagrammatically indicated by Fig. 5, it will be observed that a signaling system embodying the structural characteristics there indicated is suited for response to vehicle or pedestrian movements as well as being suited to coordination of activity with other signaling equipment.

As in the instances of Figs. 2 and 3, certain of the equipment indicated by Fig. 5 substantially corresponds in structure and function with similar parts which are hereinbefore described in detail, and it is therefore deemed unnecessary to here repeat such description.

The shaft 24 which is driven by the motor 2I through suitable reduction gearing 22 23 drives cams 20I, 202, 203, 204 and 205, in suitable angular relationships to cams 3", 32 33 and 34 which latter cams substantially correspond with cams SP, 32 33 and 34 of Fig. 1.

The contacts 2, 2I2, 2I3, 2I4 and 2I5 are associated with the cams 20I, 202, 203, 204 andv 205, respectively.

The periphery of cam 20I is so formed as to permit closure of contacts 2 during those portions of each revolution of the shaft 24 when the teeth 3| I and 32I of the cams 3I and 32 are being carried past the contacts 4| and 42 respectively. The periphery of cam 202 is so formed as to effect separation of contacts 2I2 during and substantially throughout each closure of contacts 2I I, as permitted by cam 20I, and for further effecting separation of contacts 2I2 during a. portion of each occasion when cam 33 permits closure of contacts 43 The purposes of such controls of contacts 2 and 2I2 will be hereinafter more fully explained.

The periphery of cam 203 is so formed as to permit closure of contacts 2I3 just prior to that separation of contacts 2| 2 which occurs during closure of contacts 43 The periphery of cam 204 is so formed as to permit closure of contacts 2 I4 throughout each revolution of shaft 24 other than for a brief interval shortly after cam 34 has permitted closure of contacts 44 and the periphery of cam 205 is so formed as to permit closure of contacts 2I5 only during the early portion of that part of the revolution of shaft 24 during which cam 3I permits continuous closure of contacts M for reasons which will be hereinafter more fully explained.

It will be understood by those skilled in this art that adjustment may be effected of the relative durations of those portions of the operative cycle which are permissive for trafllc movements along the Main and Cross thoroughfares by varying the angular extent of the raised portions of cams 33 and 34 and of the solid raised portions of the cams 3| and 32 through the utilization of well-known expedients. The presence of facilities for effecting such adjustments is diagrammatically represented by the pointer handle 22I and the associated bars 222, 222.

Associated with the controller C just described, there is provided a relay having a magnet 23I, together with sets of contacts 232 and 233; an adaptation switch 250; a flasher 234, which may be of any well-known and commercially available type having facilities for effecting intermittent interruptions of current flow therethrough as, for example, a so-called thermo-flasher; and tramc responsive equipmentcomprising a transformer having a primary winding 24I, a secondary winding 242, an associated bridge rectifier 243, a relay having a winding 244 supplied through said rectifier, to control the set of contacts 245 and move the contact 241 into engagement with the contact 246 and thereby force it away from contact 248.

Signal lamps situated at the highway intersection S are responsively connected with the controller C and the so-called master controller" shown at M is provided for coordinating the operation of the local controller C with that of other local controllers. It will, however, be readi ly understood that a local controller, such as C may be operated independentlyof any master controller, as will be hereinafter more fully explained.

The master controller M comprises a motor 260 which acts through suitable reduction gearing 26I and 262, to drive the disc or cam 263, for controlling the pair of contacts 264 in such manner that said contacts will be caused or permitted to close for a suitable and preferably brief interval during each revolution of said disc.

An adjustable resistance 265 affords facilities for effecting variations in the speed of the operation of motor 260, and a second adjustable resistor 266 is provided for eflecting variations in the speed of the motors of associated local controllers, as will be hereinafter more fully explained.

The double pole three-way switch 250 comprises the arms ,25I and 252, the contacts 253, 254 and 255 associated with arm 25I, and the contacts 256, 251 and 258 associated with arm 252; the arms 25I and 252 being connected by the insulating link 259 for simultaneous movement, for purposes which will be hereinafter more fully explained.

The conductors 40I, 402 convey energy from a suitable source of electric power supply to the signal lamps provided at the highway intersection S and to the transformer primary winding 24I, through conductors as follows: conductor 403 connects conductor 40I with one terminal each of the amber signal lamps A A A A conductor 404 connects conductor 40I with one of the contacts 232. and conductor 405 connects the other of said contacts with one of the terminals of each of all of the remaining signal lamps. Conductor 406 connects conductor 40! with one terminal of transformer primary winding 24! and conductor 40! connects the other terminal of said winding to conductor 402. Conductor 408 connects conductor 402 to one of the contacts of each of the pairs 2 I5, 4!, 42 43 and 44 and, through a flasher 234 to one of the contacts of pair 233; the other contact of said pair being connected through conductor 400 with the remaining terminals of amber lamps A, A, A, A", and the remaining contact of the pair 2!5. Conductor 55 connects the remaining one of the contacts of the pair 4! with the remaining terminals of the Main thoroughfare red lamps R R and the conductors 56 51 and 58 correspondingly connect the remaining contacts of the pairs 42, 43 and 44 with the remaining terminals of the Cross" thoroughfare red lamps R, R, the Main" thoroughfare green lamps G, G, and the Cross thoroughfare green lamps G, G, respectively.

The conductors 42! and 422 supply power from a suitable source to the master controller M, and electrical connections are provided within said controller as follows: conductor 43!, which serially includes adjustable resistor 265, connects supply conductor 42! with one terminal of motor 260, and conductor 432 connects the other terminal of said motor to conductor 422. One terminal of adjustable resistor 266 is connected to conductor 42!, and conductor 433 connects the other terminal of said resistor with terminal 442 of local controller C Conductor 434 connects conductor 422 with terminal 44! of the local controller, and conductors 435 and 436 connect the respective contacts of the pair 264 with terminal 443 of said local controller and supply conductor 42!, respectively. Conductor 43! connects supply conductor 42! with terminal 444 of said local controller C It will be understood that conductors 42! and 422 may be connected with the same source of electrical energy as conductors 40! and 402, or to a different source, as convenience may require.

Conductors are provided in local controller C in association with terminals 44!, 442, 443 and 444 thereof, as follows: conductor 45! connects terminal 44! to one terminal of the motor 2l and conductor 452 connects the other terminal of said motor directly with one of the contacts of each of the pairs 2!2 and 2!3, and serially through adjustable resistor 453 with one of the contacts of pair 2! conductor 454 connects conductor 45! with one end of relay winding 23!, and the other end of said winding is connected through conductor 455 to an end of conductor 456, the other end of said conductor 456 being connected to terminal 444; conductor 45! connects conductor 456 to the remaining terminal of pair 2!!; terminal 442 is connected to contact 256 of switch 250 through conductor 458 and through conductor 450 to the other of the contacts of pair H2; and conductor 459 connects contact 254 of said switch to terminal 443; said contact 254 being also connected, through conductor 460 to contact 258 of said switch.

Dotted lines are shown proceeding from terminals 44!, 442, 443 and 444, which lines are representative of conductors which may be supplied for correspondingly connecting similar terminals of other local controllers.

One of the relay contacts 245 is connected through conductor 46! with switch arm 26! and is also connected through conductor 482 with the remaining one of the contacts 2"; the other one of the pair 245 of relay contacts is connected through conductor 463 with switch arm 262.

One end of transformer secondary winding 242 is connected through conductor 464 with traflic responsive circuit controllers TRC, 'IRC which are situated in the path of traflic approaching the intersection along the The other end of transformer secondary winding 242 is connected through conductor 465 to one of the alternating current input terminals of bridge rectifier 243, the other A. C. input terminal of said rectifier is connected through conductor 466 to relay contact 246. Relay contact 24! is connected through conductor 46! to one of the pair of contacts 2, and the other contact of said pair is connected to the intermediate terminal of transformer secondary 242 through conductor 468. Conductor 469 connects relay terminal 248 with remaining terminals of traffic responsive circuit controllers TRC, 'I'RC. Conductors 410 and 41! connect the ends of relay winding 244 with the D. C. output terminals of bridge rectifier 243, respectively.

Relay contacts 232 are so associated with winding 23! as to be closed responsive to efl'ective energization of said winding; and contacts 233 are so associated as to be open during such energization.

Contacts 245 are so associated with relay winding 244 as to be closed responsive to effective energization of said winding, and contact 24! is so associated as to be moved into engagement with contact 246 responsive to such energization and thereby causing the separation of contacts 246 and 248.

The operation of a system arranged in accordance with Fig. 5 is as follows:

Assuming that the arms 25! and 252 of adaptation switch 250 are resting upon contacts 253 and 256, respectively, and that suitable electrical energy is applied to conductors 40!, 402, 42! and 422, the controller C will be rendered traffic re sponsive, and will operate independently of master controller M. Relay winding 23! will be energized through a current path extending from power supply, through conductors 42! and 431 to terminal 444, and thence through conductors 456 and 455 to one end of said winding; and thence through said winding and from the other end thereof through conductors 454 and 45! to terminal 44! and thence through conductors 434 and 422 to the power supply. The resultant energization of winding 23! will cause separation of contacts 233, and closure of contacts 232. Such closure of contacts 232 will complete a current path from the power supply through conductors 40! and 404, through contacts 232 and conductor 405 to one of the terminals of each of the signal lamps R R G G, R, R05, G05 Gc5 When the parts responsive to rotation of shaft 24 are positioned as shown by the drawing, signal lamps 1%, R and G, G will be lighted, through current paths rendered effective at contacts 42 and 43 as hereinbefore more fully described, and motor 2 will be energized through the establishment of a current path from the power supply through conductors 42! and 43! to terminal 444, thence through conductors 456 and 451, contacts 2!!, adjustable resistor 453, and conductor 452 to one terminal of motor 2! and from the other terminal of said motor through Cross thoroughfare. L

conductor 45| to terminal 44|, and thence through conductors 434 and 422 to the power pp y- The energization of motor 2|, through the current path just indicated, will cause rotation of the shaft 24 thereby bringing one after another of the notches between the teeth 4H of cam 3| into the path of the co-operating one of the contacts 4| to thereby cause flashing of the signal lamps R3 R as hereinbefore more fully explained.

After the final one of the teeth 3| I has been thus withdrawn from the co-engaging one of the contacts said contacts will be and remain closed throughout approximately one-half of a revolution of the shaft 24 Upon rotation of the cam 3| to the position which permits such continuous closure of the contacts cams 202 and 205 will have been moved to positions permitting closure of their associated contacts 2|2 and 2 5, respectively, and cam 33 will have moved to a position where it separates contacts 43 and, upon slight additional rotation thereafter, cam 20| will effect separation of its associated contacts 2| 7 Such closure of contacts 2|5 will cause lighting of the amber lamps A A, A A, through a current path as follows: from the power supply through conductors 40! and 403 to one of the terminals of each of said lamps, from the opposite terminals of said lamps through conductor 409, contacts 2|5, and conductors 408 and 402 to the power supply. The concurrent separation of contacts 43 will cause extinguishment of signal lamps G 6 Because of the circuits and conditions thus established, red and amber signals will be given to all traffic which, pursuant to the rules effective in certain localities, establishes a so-called pedestrian period during which pedestrians may move freely across the intersection, and vehicles are forbidden entrance thereupon.

The closure of contacts 2|2 established a connection from power supply conductor 42| through adjust-able resistor 266 and conductor 433 to terminal 442, thence through conductor 450 and contacts 2|2 to conductor 452; thus replacing the current path there interrupted at contacts 2| I, which path extends from power supply through conductors 42|, and 431 to terminal 444, and thence through conductors 456 and 451, to and through contacts 2| I, and adjustable resistor 453 to conductor 452.

After the pedestrian period signaling aspect just described has been maintained for a desired time, the continued rotation of the shaft 24 will move the cams 205 and 32 to positions where they separate their respectively associated contacts 2|5 and 42 and the cam 34 will thereupon have moved to a position where it permits closure of contacts 44 Such separation of contacts 2| 5 and 42 will cause extinguishment of all of the amber signal lamps and of the Cross thoroughfare red signal lamps, R, R, and such closure of contacts 44 will cause lighting of the Cross thoroughfare green signal lamps G, G; since the Main" thoroughfare red signal lamps R R were previously lighted through continuous closing of contacts 4| there is thus provided a stop aspect for traflic approaching the intersection along the Main thoroughfare and a go" aspect for traffic approaching the intersection along the Cross thoroughfare. Shortly after the commencement of this signaling aspect. the continued rotation of shaft 24 will cause the raised portion of cam 204 to momentarily effect separation of its associated contacts 214, for a purpose which will be hereinafter more fully explained.

When such signaling aspects have been maintained for a desired time, the continued rotation of shaft 24 will withdraw the continuous raised portion of cam 32 from contacts 42 so that flashing of the lamps R R will occur as the notches between teeth 32| are presented to the co-engaging ones of contacts 42 in the manner hereinbefore more fully explained. During such flashing of said lamps, the cam 20| will be so positioned as to permit closure of contacts 2| and the cam 202 will be so positioned as to effect separation of contacts 2| 2, thereby placing the speed of operation of the motor 2| in control of the adjustable resistor 453, instead of the adjustable resistor 266.

From the foregoing it will be apparent that the speed of the motor 2 during the red flashing periods" may be varied by adjustment of the resistor 453, so that the time occupied by such flashing periods will be in accordance with the practical conditions obtaining at the intersection S without thereby effecting the extent of the times during which trafiic movements are permitted along the Main and Cross thoroughfares, respectively.

Immediately after the final one of the teeth 3i2| has been withdrawn from the co-engaging one of the contacts 42 the continued rotation of shaft 24 will carry cams 3| and 34 to positions where they will effect separation of their respectively associated contacts 4| and 44 and will carry cams 33 to a position where it permits closure of contacts 43 thereby causing a stop signaling aspect for Cross thoroughfare trafllc and a go aspect for Main thoroughfare traffic, in the manner hereinbefore more fully explained.

Shortly after the establishment of signaling aspects as just referred to, cam 203 will reach a position where it permits closure of its associated contacts 2|3, and cam 202 will thereupon I reach a position in which its raised portion 202| will eifect separation of contacts 2|2.

Such separation of contacts 2|2 will interrupt the current path theretofore supplying motor 2| and said motor will come to rest unless an alternate current path is established through contacts 2|3, in a manner which will be more fully described. a

The traflic responsive circuit controllers indicated at TRC. TRC in the Cross thoroughfare near the intersection S may be of any wellknown type providing facilities whereby pedestrians wishing to cross one of the thoroughfares at the intersection and/or vehicles approaching the intersection along the Cross thoroughfare, may effect closure of normally open contacts.

Upon closing the contacts of either of the circuit controllers TRC, 'I'RC a current path is established from transformer secondary winding 242, through conductor 464, through the closed contacts of such circuit controller TRC, through conductor 469, contacts 248 and 246, and conductor 466 to one of the A. C. input terminals of bridge rectifier 243, and from the other input terminal of said rectifier through conductor 465 to the other end of transformer secondary winding 242. Current will thereupon flow through the path just indicated because of excitation of primary winding 2 from the power supply tion of winding 244, as-J'ust described, an ener-' through conductors 401 and 406 to one end of said winding 241, and from the other end of said winding through conductors 401 and 402 to the power supply.

The alternating current flow through bridge rectifier 243 resultant from closure of one of the circuit controllers TRC, TRC will cause direct,

current energization of relay winding 244, because of theconnection of the ends of said winding through conductors 410 and 411 with the respective direct current output terminals of bridge rectifier 243.

Such energization of relay winding 244 will cause contact 241 to move into engagement with contact 246 and move the latter away from contact 248; and will, at the same time, causecontacts 245 to close.

When contact 241 is thus brought into engagement with contact 246, a so-called lock-up" current path for relay winding 244 is established, which excludes a portion of transformer secondary winding 242 and conductor 464, controllers one of the A. C. input terminals of bridge rectifier 243, and from the other A. C. terminal of said rectifier, through conductor 466, contacts 246 and 241, conductor 461, contacts 214 and conductor 7 468 to the intermediate terminal of transformer secondary winding 242; thereby effecting energization of relay winding 244, through the action of the rectifier 243, and the conductors 410 and 411.

If contacts 213 are closed at the time that contacts 245 are closed responsive to energize.-

gizing current path for motor 21 will be established from the power supply through conductor 421,v adjustable resistor 266, conductor 433 to terminal 442, thence through conductor 458 to adaptation switch terminal 256, thence through arm 252, conductor 463, contacts 245, conductor 462 to contacts 213, thence through conductor 452 to one terminal of said motor. From the other terminal of the motor such current path leads through conductor 451 to terminal 441 and thence through conductors 434 and 422 to the power supply, thereby establishing a path which will cause starting and operation of motor 21 If, however, the contacts 213 are open at the time that contacts 245 are closed, operation of motor 21 will be maintained through the current path provided through conductor 452, contacts 212, and conductor 450 to the aforesaid terminal 442 until contacts 213 have closed, after which the operation of said motor 21 will be maintained through the current path including contacts 213, as just referred to, notwithstanding opening of contacts 212 by raised portion 2021 of cam 202, and the cycle of operation hereinbefore more fully explained will be repeated.

During such cycle of operation, and shortly after establishment of a signaling aspect permissive for vehicles approaching the intersection along the "Cross thoroughfare, the raised portion of cam 204 will be brought into engagement with and cause separation of contacts 214, thereby interrupting the loclr-up current path for relay winding 244; whereupon contacts 245 will be opened and contact 241 will move away from contact 246, permitting the latter to move into engagement with contact 248; whereupon, the ensuing rotation of shaft 24 will quickly withdraw the raised portion of cam 204 from contacts I 214 permitting said contacts to close and thereby rendering the lock-up circuit effective for maintaining energization of winding 244 following the next succeeding closure of a contactor TRC. k

Next assuming that the arms 251 and 252 of adaptation switch 250 are resting upon contacts 254 and 251, the controller C will be responsive to master controller M, and will operate independently of the circuit controllers 'I'RC, TRC.

In other words, after the motor 21 has become deenergized, because of the separation of the contacts 21 1 by cam 201 and the concurrent separation of contacts 212 by the raised portion 2021 of cam 202, reenergization of said motor will be effected upon closure of contacts 264 of master controller M through a current path from power supply through conductors 421 and 436, through contacts 264, and conductor 435 to terminal 443; thence through conductor 459, contact 254, switch arm 251, conductor 461, conductor 462, closed contacts 213, and conductor 452 to a terminal of said motor.

During such operation, the resistors 265 and 266 should be so relatively adjusted that the speed of disc 2651 will be somewhat less than that of shaft 24 in orderthat the motor 21 will become deenergized whenever the raised portion 2021 of cam 202 effects separation of contacts 212, and said motor 21 will be thereafter reenergized when the raised portion of cam 263 is withdrawn from contacts 264, permitting closure of said contacts.

It will be evident that if it is desired to lengthen the duration of the go signaling aspect for the Main thoroughfare, this can be accomplished by decreasing the speed of motor 260, through adjustment of resistor 265. If it is desired to increase the duration of go" signaling aspect for the Cross thoroughfare, this can be accomplished by decreasing the speed of motor 21 by suitable adjustment of resistor 266; which change in speed will not, however, be effective during the flashing red periods, as motor 21 is then supplied through adjustable resistor 453 instead of adjustable resistor 266 during such periods.

When the switch arms 251 and 252 of switch 250 are resting upon contacts 255 and 258, the controller C will be rendered responsive to actuation of contactors 'I'RC, TRC only during closures of master controller contacts264; so that, so long as said controllers TRC, TRC are not operated, a go signaling aspect may be given for traffic approaching the intersection along "Main thoroughfare; and following actuation of either of said controllers TRC, TRC, energization of motor 21 and consequent rotation of shaft 24 will be initiated only at a time when contacts 264 of master controller M'have closed; to the end that if a number of local controllers are associated with the master controller M, the controller C will effect discontinuance of the go signaling aspect for ,Main thoroughfare traffic only upon occasions which have intended timer. relation to the operation of master controller M.

From the foregoing it will also be apparent that, if the arms HI and 252 are positioned as previously described upon contacts 253 and 256, the master controller M need not be supplied; in which event the adjustable resistor 266 may, if needed, be inserted between terminal 442 and conductors 450 and 458.

As previously explained, the relay winding 23f receives energization through a current path extending from power supply, through conductors 42l and 431 to terminal 444, and thence through conductors 456 and 455 to and through said winding, through conductors 454 and 4M to terminal I, and thence through conductors 434 and 422 to power supply.

From the foregoing it will be apparent that in situations where conductors 4M and 402 are connected to a power supply other than that which supplies conductors 42l and 422, failure of such supply to cause eifective energization of relay winding 23!, would permit contacts 232 to separate and contacts 233 to close.

Since, as previously explained, connection of the power supply to the lamps R R G 6 R, R, G, G is dependent upon closure of contacts 232, it will be evident that the separation of contacts 232 will cause the extinguishment of any of such lights which would otherwise be lighted throughout such time. Furthermore, the closure of contacts 233 causes the amber lamps A A A A to be lighted through the establishment of a current path as follows: from power supply through conductors 40l and 403 to one terminal of each of said amber lamps, thence, through said lamps and from the remaining terminals thereof through conductor 409, contacts 233, conductor 408 and flasher 234 to and through conductor 402 to the power supply.

The inclusion of flasher 234 in the current path just traced causes, in a well-known manner, an intermittent lighting or flashing of the amber lamps which, pursuant to the rules effective in certain localities, establishes a so-called caution" signal.

It will be apparent to those skilled in this art that various re-arrangements of cam periphery configurations, contacts and'electrical connections may be made, pursuant to this invention so as to provide different signalling aspect cycle components such, for example, as are indicated by the charts of Figs. 6, '7, 8 and 9.

Fig. 6 is a chart indicating a cycle having a period in which a green or go" signaling aspect is provided for Main thoroughfare traflic, during the latter portion of such period a flashing amber aspect is concurrently provided which is followed by a steady amber aspect which commences before the termination of the green aspect and persists for a short time thereafter and until the commencement of a steady red aspect; a corresponding cycle of color changes in reverse order being provided for the "Cross thoroughfare.

The chart of Fig. '7 indicates a color cycle for each thoroughfare comprising a steady green portion which persists until the commencement of a steady red portion, a flashing green portion being provided concurrently with the early part of the red portion.

The chart of Fig. 8 shows a color cycle comprising a steady green portion, followed by a flashing green portion, which, in turn, is followed by a steady red portion.

The chart of Fig. 9 indicates a cycle for each thoroughfare comprising a steady green portion during the latter part of which there is a flashing amber period followed by a steady amber period, and following the green portion there is a second flashing amber period followed by a steady amber period, following the termination of which there is a steady red portion.

Obviously, other structures may be devised which may embody the invention herein set forth. The drawings and description thereof are therefore to be considered in an illustrative and not in a limited sense; and it should be understood that the language used in the following claims is intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention, which, as a matter of language, might be said to fall therebetween.

ed with said conductors for operation from said source and for alternately closing respective current paths for said lamps continuously throughout desired intervals measured by the running of said mechanism, in combination with means operable responsive to running of said mechanism during continuous closure of the connection for said "go" lamp for repeatedly effecting a series of comparatively brief closures of the connection to said stop lamp, the durations of said closures and of the time intervals therebetween progressively decreasing, to indicate the increasing proximity of the termination of such continuously effective closure.

2. In a signaling system, a source of electrical energy, stop" and go signaling lamps, conductors for operatively connecting said lamps with said source, circuit controller mechanism associated with said conductors-for operation from said source and for alternately closing respective current paths for said lamps continuously throughout desired intervals measured by the running of said mechanism, in combination with means operable responsive to running of said mechanism during continuous closure of the connection for said "go lamp for repeatedly effecting a series of comparatively brief closures of the connection to said stop lamp, said closures separated by time intervals of progressively .decreasing duration, whereby to indicate the increasing proximity of the termination of such continuously effective closure.

3. In a signaling system, a source of electrical energy, stop and "go signaling lamps, conductors for operatively connecting said lamps with said source, circuit controller mechanism associated with said conductors for operation from said source and for alternately closing respective current paths for said lamps continuously throughout desired intervals measured by the running .of said mechanism in combination with means operable responsive to running of said mechanism during and adjacent a terminus of the continuous closure of the connection for one of said lamps for repeatedly effecting a series of comparatively brief closures of the connection to the other of said lamps, which connections are effective for time intervals, measured by the running of said mechanism and of progressively decreasing duration.

plurality of signaling aspects, each aspect eflective between some predetermined termini for indicating occasion for permissive and restrictive governing of an activity; circuit controller mechanism associated with said means for rendering said aspects alternately effective throughout intervals measured by the running of said mechanism, in combination with means operable at a progressively increasing speed for causing intermittent display of a signaling aspect at a progressively increasing frequency and for progressively decreasing durations during and adjacent an interval terminus whereby to indicate the proximity of said terminus.

5. In a signaling system, signals for displaying diverse aspects, each aspect effective between some predtermined termini for indicating occasion for permissive and restrictive governing of an activity, mechanism operable for establishing times for varying the display 01' said signaling aspects,

in combination with means for effecting, during a portion of the display of one of said signaling aspects, a series of comparatively brief displays of another of said signaling aspects and whereby said brief signal displays will be separated by time intervals of progressively decreasing duration, whereby to indicate the increasing proximity of the impending change.

6. In a traflic signaling system comprising signals having diverse aspects for governing traflic movements, means operable for eflecting displays of said signals in accordance with a predetermined sequence of presentation, in combination with means for effecting intermittent display of one of said signals, for indicating the proximity of a change of signal display pursuant to said sequence of presentation, such intermittent displays characterized by progressive decreases of durations and of time intervals therebetween.

7. In a traflic signaling system comprising signals having diverse aspects for governing traific movements, means operable for eflecting displays of said signals in accordance with a predetermined sequence of presentation, in combination with means for effecting intermittent display of one of said signals for indicating the proximity of a change of signal display pursuant to said sequence of presentation, such intermittent displays characterized by progressive decreases of the durations thereof.

ERNEST R. FREEBERG.

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