US2009258A - Traffic signal - Google Patents

Description

my 23 @35 F. w. GRISWOLD Z I TRAFFIC SIGNAL A Original Filed Sept. 18, 1926 4 SheetSShee l 99 y `|||||||||||llim 45% lla WMM

TRAFFIC SIGNAL Original Fild Sept. l, 1925 4 SheetS-Sheet, 2

my 23 i935. F W @H ,SWOLD www@ TRAFFIC S IGNAL Original Filed Sept. 18, 1926 4 Sheets-Sheet 3 JUHY 23 W35 F. W. GRISWOLD l @0992 TRAFFIC SIGNAL original Filed sept. 18, 1926 4 sheets-sheet 4 [IH IHM 172 2207507 FHA/wf f lf/mwa@ Patented July "23, 1935 UNI-TED STATE 'raarrio sniNALY Frank W. Griswold, Minneapolis, Minn.,5assignor,

by mesne assignments, to Griswold Signal Comi panyya corporation VApplication September 18, 1926, SerialNo. 136,285 f Renewed February 6, 1931 v6 claims.V (ci. 177-327) .This invention relates tol-,a traffic signal suchl asnow used at the intersections of two thoroughfares such as intersecting streets, railways, or the intersection of a railway anda roadwayor street. 5 If one signalis to be used .at such an intersection, the vpreferable place for the same is at the center Aof the intersection where it can be 'seen-by all vehicles and also berplainlyseen by pedestrains crossing the thoroughiares. If'the signal is not to endanger trafiic, it must be so constructed that when a vehicle collides therewith the -vehicle and signal vwill not be damaged. lf'the signal is. to be used at modern city street intersections, itfmust` also be of such asize thatY it can be disposed between the street car tracks. Y One form of traiiic signal which'has been rvery successfully used at -such intersections is that shown in applicants prior Patent No. 1,760,270, granted May 27, 1930. With such a signal it has been found that at certain times it is quite diflicult to see the illuminated sidesr ofthe signal, as when the sun Vis lshining on the signal. If the wiring circuits for the signal become damaged, both pairs of charactersat one side of the signal might be illuminated, thus confusingthe vehicle operators. Y

f It is an object of this invention, therefore, to

provide la signal which is positively non-glare inoperation, one ln which bothA the Stop and 30.. Go7 signals cannot be simultaneously. .displayed for one street, and one which can be easily, inex-V pensively and efficiently operated.

It is another object of theinvention to provide a trafcsignal so mountedin the street intersection that it can he swung down substantially into Contact with the street in Vany direction and having a rotating member therein withV characters thereon fork simultaneouslyfdirecting traffic to proceed on one street and to stop on another, to- 40.V gether with means for periodically partially rotating said member to characters at adjacent sides of said signal.

It is another object of theV invention to provide a traffic signal'comprising a'standard ymounted to be swung down substantially into contact with thezsurrounding surface and to loeA automatically returned to normal position, .which standard has a movable vmember therein having characters thereon for simultaneously directing traflic toproceed on one thoroughfareand to stop-on another and alsof'hasa motor therein for periodically moving said member alternately to display said charactersr at. adjacentsides 'of said standard.

It is still another object ofy the invention to' kv provide a'traflic signal comprisingI a standard alternately display the signal'andpartly'in vertical section;

having mounted therein a revoluble member having characters at opposite sides thereofadapted simultaneously to be displayed to directiltraiclto proceed on one thoroughfare and stoplon another, adriving meansin said standardfor, periodically partially turning said member and a connection between said'vdriving means and memberinclud-- ing a slipping clutch. f It is stillanother object of theinventionto provide such a signal as, setv forth inthe .preced-- ing paragraph in whichv a resilient .means is also disposed between said driving means andrew?" lublernember. f A It is stillfurther an objectof the inventionlto provide a traffic signal comprising 'afstandard having mounted therein a revoluble member hav` ing characters. on the. sides thereof-adapted simulard having a rotatablemember therein with chaliacters at'the sides thereof adaptedl tobe displayed simultaneously'to direct' traine: to. .proceed on one of said streetsand to sto'pitraiiic.on.thel other, with meansfor periodically.-partiallyjotating said memloer` alternately 'tofdisplay said characters at adjacent sidesof .said standard, said standard being `quite narrow, so -jthatlthe same can'be disposed .between ,adjacent street car tracks onva city street.

I These and other objectsand advantages .ofthe invention will be fully set.y forth lin the following description made in connection with the' accom-i panying drawings, in which Alike reference'y characters refer to similar parts throughout thesev- Veral views and in which:-

Y Fig. l isa view partly side elevation off-'the Fig.' 2isr a view in ce'ntral'vertical` section-offra portion of the signal; i'

lFig. 3 is a view in' central vertical. sectionzof. another and upper part ofthesignaI;

Fig. 4 is ahorizontal" section takenfonfllneiQ-l of Fig. 2, as indicated vby theearrows;

Fig. 5 is a view partlyffinsidefelevation 1and 50y partly .in vertical section of the clutch used;

Figr lis a View in sideelevation of vthe..sprix ig structure used; i i, Eig. 7i isa/.view in horizontalesection; taken-.on imei-, 1 :of lig.ol as indicated.by..fthe arrows;

6054, having a central Fig. 8 is a horizontal section taken on line 8 8 of Fig. 9, Figs. 4 and 8 being on an enlarged scale;

Fig. 9 is a view in side elevation of a partial assembly of the signal;

Fig. 10 is a View in side elevation as seen from the rightofFig. 9, some parts being broken away and others shown in. vertical section;

Fig. l1 is a bottom plan view of the clutch shown in Fig. 5, certain parts being broken away;

Fig. 12 is a view in horizontal section taken on line 2 4 2 of Fig. 3, as indicated by the arrows;

Fig. 13 is a top plan View of the parts shown in Figs. 9 and 10;

Fig. 14 is a bottom plan View of said parts;

Fig. l5 is a diagrammatic view showing connections of the ilasher to the motor and its coils and to a source of power, the view also showing the connections for the lamps; and f Figs., 16 and 17 are detail views of features of Fig.. 15.

lReferring to the drawings, a traflic signal is shown, adapted to be disposed in the thoroughfares, preferably adjacent the center of the intei-section of ,twol or more thoroughfares, the material of'said thoroughfares being indicated at 2U having a surface 20a which would bethe surface of the street when the device is used at a street intersection. A casing Y2| illustrated as cylindricalin form is disposed in the material 20 andy a' plurality of circumferentially arranged brackets 22 are secured to the inner sides of said casing.y Said brackets have adjustably mounted thereon the auxiliary brackets 23 having upwardly projectingVV plates 23a. extending radially of 'casing 2| v and having curved surfaces 23h whichform, the .supporting members for a spherical member or ball 24 forming the base of the' signal standard. A cable 25 of special construction extends through a boss 24a formed in the ball 24 and through an opening therein, this cable being anchored to said boss by a clamp 25a secured thereto. The cable 25 is surrounded some distance below the ball by an apertured plate 25 to which are secured a plurality o f radially vextending strong tensile coiled springs??? anchored at. their outer ends to hooks 28a secured in thewall of casing 2|. Cable 25 at its lowerend has secured thereto a clamp 28 which is, anchored by a hook 29 to a plate 3|). The plate 3i) has connected thereto the upper endsof a plurality of strong tensile springs 3|' secured attheir lower ends to another plate 32 which is securely anchored by a hook 33 to a member disposed in the bottom of the casing 2| (not shown).r While the cable 25 mighty be of various constructions,v in the embodiment of the invention illustrated, and in practice, a special cable of thewell known Roebling type is used, passage therethrough This passage is utilizedas aconduit to carry the, electrical conductors 34 whichhave some slack `below the.:lower end ofithe cable and extend'through a conduit 35 communicating with the side of the casing 2|, said conduit and conductors passing to atiming mechanism 36'. The'specic form of timing 'mechanism'used` forms no part of the present invention, vand any suitable well known form of 4standard Vtiming mechanism may b e used. rl'he casing 2| is provided with a cover 31 'extending fromthe outer side thereof to substantially the sidesof the ball 24.

v""I'hej ball y24fl1as an upwardly extending iiange 2419 to which'is secured a standard 40. While this standard may be variously made, in the embodiment of the invention illustrated and in one form which has been found very suitable in practice, the same is made of pressed steel plates 40a, (see Fig. 12), having their corners bent or curved substantially at right angles and suitably nested and secured together in any suitable manner as by boltsv or spot welding. Bolts 24e extend through the lower end of these plates through the holes 40d securing the standard to the flange 24h of the ball 24. To column 48 has secured thereto at its top portion a member 4| to which is bolted, by the bolts 42, a cap member 43 having a, pointed top and sides which substantially aline with the sides of said standard and are provided with openings 43a at the four sides of said standard. Said standard also has elongated openings 4Gb in each of the four sides thereof adjacent its upper end and also has smaller openings 49o through the four sides thereof some distance below the openings 4Gb. Secured in said standard a short distance above the ball 24 is a motor 44. This motor in practice has been of the electrical type and comprises a simple reversible motor and'one which can have the current thereon at all times and one which can be held from rotation with the current thereon. An armature shaft 44a of the motor extends upwardly and has a half clutch 45 secured thereto meshing with the half clutch 45 secured to the lower end of a shaft 4'! which extends centrally upward through the standard 40 and has another half clutch 48 secured to its upper end. The half clutch 48 engages a similar half clutch 4S which is of cylindrical shape and is secured toA a.V friction plate by the rivets 49a extending therethrough and through said plate and having convex heads. A friction plate 5| shown as square orrectangular in form is disposed at each side of the plate 50 which isY illustrated as circular in shape, which friction plates may be made of friction ber or sheet packing material. The lower plate 5| has a metal plate 52 therebelow having a central opening surrounding the member 49 and the upper plate 5| has a metal member 53 surmounting the same which is shown as of a shape similar to plate 5|. The plates 5|, 52k and 53 are traversed by the headed and nutted bolts 54 having the coiled compression springs 55 thereon between plates 52 and the nuts 56 thereon, one of which nuts forms a jamb nut. It will be noted from Fig. ll that the bolts 54 pass outside of the plate 5|). The plate 53 is secured by the rivets 51 to a cylindrical member 58, said rivets having countersunk heads in said plate and member. The member 58 is secured by set screw 59 to al short stud or shaft 68 extending upwardly from said member and having an upper portion journaled in a bracket 6| secured within the sides of the standard 40. Between members 6| and 58 is disposed a yoke 62 substantially of U-shape and having disk portions at its top and bottom havingtherethrough apertures with parallel sides adapted to fit a hattened section 50a of the stud 60 which is disposed between members v6| and 58 so that said yoke is non-rotatable relatively to said stud. A pair of collars 63 surround the stud 60 between the ends of the yokek 62, which collars have cylindrical holes therethrough. A coiled torsion spring 64 surrounds collar 63 and is also disposed between the end portions of yoke 62. The ends 64a of the wire or rod formingthe spring 64 extend at each side respectively of the Vertical member 62a of the yoke 62 and also extend at each side respectively of the pin 6|a which is secured in and depends from the member Si'. The Vstud 6) has a collar or disk portion 50h at the upper portion thereof, from which extends upwardly a short portion @ed which is securely fastened to af small pinion 65. The pinion '65 meshes atopposite sides thereof with planetary gears 66 carried by a bar or block 6l extending thereacross and across the topl of gear 65, The gears are mounted on bar 6l by the headed and nutted bolts 68 which have enlarged portions on which the gears 56 are journaled. The gears 65 in turn mesh ywith the orbit gear 6s held between the member 6I and an upper member 'l0 also secured to thecolumn by the screws'l l The bar 6! has a shaft 68a extending upwardly centrally thereof journaled in ball bearings 'l2 mounted in the member 'le and held in place by the collar 13 bolted to 'member lil, which bearings are spaced by the collar lll. The upper end o'f shaft 68a has keyed thereto the members 'l5 to which is non-rotatably secured a member or shell 18. The shaft 58a has a nut l'i at its `upper end engaging the top of member 'l5 and the member TF6 has a plurality of circtunferentially spaced pins 'i8 secured therein adapted to seat in corresponding holes formed in member '55, |The member 'lll has bosses: 'ma projecting inwardly at right angles to each other and in which are secured headed bolts 'Elib having jamb nuts lilo for holding the same in place, which bolts form stop means adapted to ,be engaged by the bar @l when the same is rotated. A washer of felt orsimilar material 'i9 is disposed between the upper end` of member l@ and the lower end of member l5 and adapted to exclude dust or dirt from the bearing l2.' 'Ihe member 'le forms the bottom member of the unit shown in Figs. 9 and i0. This unit is, as shown in Figs. i3 and i4, substantially squarein horizontal cross section and has a ring t@ at its upper end having a squared portion Sila at its lower side. Plates 8l extend between the members 'lli and 8b, being secured to the sides of members 'l5 and the portion Sec by the small headed screws 82. The edges of the plates El are, as shown, bent substantially at an angle of and overlap at the corners of members 76 and Si! which are also formed at a similar angle. Reinforcing corne-r plates Sib are disposed at the inner sides of said unit and secured as by spot-welding to plates 8 l. The plates 8l at opposite sides of the saiduhit have characters or letters 35 cut therefrom in stencil form, adapted to direct traffic to stop or halt on a thoroughfare, and in the lembodiment of the invention illustrated, these characters are shownas the letters Stop. The plates 8l at their inner sides have secured thereto transparent colored panes 83 made of glass' Celluloid; or other similar material, which panes, in the rear of the 'characters Stop are preferably red in color. The letters Stop also have at the outer side of the plate El a border 35 surrounding the same which may be formed by a layer of paint, enamel, or thin layer of sheet material. This border-is also of the same color as the transparent pane back of the letters and preferably red. At the other opposite sides of said unit, the plates 8l. have openings iatherethrough over which are secured the auxiliary plates 3d. These plates have cut therefrom characters 31 adapted to direct traino to proceed on a thoroughfareand in the embodiment of the invention illustrated these characters are shown as the letters Go.` The letters Go are also backed by transparent material such as glass or celluloid, and such material is preferably green in color. The unit shown in Figs. 9, vl0, and l2 to'll is rotatable in standard di) and a plurality of circumferential/ly spaced. rollers depend frcmthe member 4 I being journaled on headed and nutted bolts 89 secured inmember n Il l, which rollers 88 have their outer sides disposed substantially in the circle forming the inner periphery of the member B and act asguide means inthe rotation'of "said unit. The member 4I also has secured therein and depending therefrom, rods Sliv converging toward Vtheir lower ends and having saidfends secured to a plate 9|. rIrian guiar plate'me'mbe'rs @l2 surround the rods 90 and are held thereby between member 4| and plate Q i. A plurality of plates 93 are held between the ymembers 92 and carry electric light sockets 9G in wh-ich'are disposed the lamp bulbs Q5. The -members QQ to @l thus -form `a light frame which is stationary inside of the rotatable lunit shown `in Figs 9 and 10. A socket 96 is secured to the upper side ci member il by the bolts Si in which is disposed the lamp bulb 98. The member 43 has smallpanes of Ytransparent material Q9 at the foursides thereof surrounding the lamp 98. The column lll also has panes of transparent material itil secured at the inner sides thereof covering the openings lec. bracket ill lsecured to one side thereof carrying a lamp socket itl? in `which is disposed the'lamp M33 which is in alinement with the openings 46c and panes im).

The timing mechanism or flasher 36 and the connections to the motor M and its coils, as well as the connections for the various lamps, are clearly disclosed in Figs. l5, i6 and 17. As there shown, the timing mechanism consists of an insulating drum rotatable in the vdirection of t e arrow on said drum. Said drum has thereon a plurality of conducting segments indicated` 36o, dtd, 3de, Blij, andllm, respectively. The segments the and dbf are arranged opposite each other, in spaced relation, as best shown in Fig. 16. The segments and Stm are also disposed opposite each otheras best shown in Fig. 17, said segments 357s and lmbeing somewhat shorter the segments 3de and 36j.. The segments 365e' and 36o! are arranged adjacent each other at the same sidel of the vrotatable insulating drum as disclosed in Fig. l5. A conducting element '35a connects the segment 3Go with thefsegment 355e 'and a conductingelement 36o connects the segment Stdwith the segment Etf. Also, a'conducting elementconnects the conducting segment Sdlc with l the conducting segment` 3de, and a conducting element connects the segment dem with the conducting segment 3dr. `"The conducting segments are otherwise independent of each other. A lead wire ted extends from a source of power to a brush 361' arranged to wipe the segments 365e and Suf, and a lead wire Mc extends fromfs'aid source of power to a brush 35h also arranged to wipe said segments 35e and 3&1 and disposed opposite the brush A lead wire Mb extends between the field winding of Mlm the motor M and abrush 3th arranged to wipe the segment 36d, and a lead wire Ma extends between said field winding anda brush 35o', arranged to wipe the segment 3de, the brushes 36a and Sib being disposed opposite each other. The lamps 95 and 98 are connected in parallel across the lead wires sdc and Md to be permanently lighted, as will be evi'- dent. A short lead wire connects the lamp lds to the lead -wire'lll-c, and a lead wirellf connects said lamp to ja'brush 357' arranged-tto wipe the segments 35k and l35m and-'disposed 'opposite rThe. standard lll also has a the brush 36h and adjacent the brush 361'. A conductor 44g extends from the battery 44h or other source of power to the brush 441' and a con ductor 44j extends from the other brush 44k to the battery 44h, or other source of power. Brushes 441' and 44k supply current for the armature circuit. The manner in which the timing mechanism operates will be apparent. Vxfhen the brush 361' is engaging the segment 36f the motor will be rotated in one direction, the motor eld circuit being traced from one side of the source of power 44h through the lead wire 44d, brush 361', segment 36j, the conducting element 36o between segment 36j and segment 36d, segment 36d, brush 36D and lead wire 44h to field winding 44m, and thence through lead wire 44a, brush 36a., `segrnent36e, the conducting element 3611 between segment 36e and segment 36e, segment 36e, brush 36h and lead wire 44e back to the other side of the source of power. When the brush 361' is engaging the segment 36ey the motor will be rotated in directi-on opposite the direction before mentioned, the motor circuit being traced in reverse direction from the source of power 44h through said lead wire 44e, brush 36h, segment 36f, the conducting element 36o between segment 36f and 36d, segment 36d, lead wire 44h, field winding 44m, lead wire 44a., brush 36a', segment 36e, the conducting element 3611, between segment 36e and 36e, segment 36e which is now under brush 361', brush 361' and lead wire 44d to the battery or source of power 44h. The curre-nt thus passes through the field Winding 44m in a direction opposite to that previously set forth.

The segments 36k: and 36m are arranged to be alternately engaged by the brush 36g' only at or near the time the motor is being reversed. When the brush 36j is engaging the segment 36k the closed circuit for the lamp |03 is traced from the source through lead wire 44d, brush 361', segment 36e, the conducting element between segment 36e and segment 36k, segment 35k, brush 36:1', lead wire 44j to the lamp |03, and thence through lead wire 44e back to the source. When the brush 367' is engaging the segment 36m the circuit for lamp |63 is through lead wire 44d, brush 361', segment 36f, the conducting element between segment 36j and segment 36m, segment 36m, brush 365i, lead wire 44], lamp |03, and lead wire 44C. The above mechanism for reversing the motor or timing mechanism is merely diagrammatic and it will be understood that other forms of timing mechanism may be used. The invention is not directed to any particular timing mechanism.

In operation the signal will be suitably placed at the intersection of two or more thoroughfares and the signal is preferably placed adjacent the center of the intersection where it can be readily seen. The standard is so mounted and constructed that should it be struck by a vehicle such as an automobile, it will not be damaged and will not damage said vehicle. The standard will swing downwardly, the ball 24 rotating on its supporting members 23a and pulling on the cable 25 which will flex the springs 21 and 3|. After the vehicle has moved over or passed the standard, or the pressure is relieved on the standard, the same will be brought to its normal position by the springs 21 and 3| pulling on the cable 25. The timer 36 will be connected to some suitable source of current and electrical current will be furnished to operate motor 44 and to illuminate the lamps 94, 98 and |03. The motor 44 is reversed at regular intervals by the timing mechanism 36. VWhen the motor turns in one direction it revolves shaft 41 and operating through the clutch comprising the members 5|, it turns member 58 which is secured to shaft 60. Shaft is thus rotated and in turn rotates the pinion 65. Pinion 65 rotates the gears 66 and these move around the orbit gears 69 thus turning the bar 61. The said bar continues to turn until one end thereof strikes one of the stop bolts 10b when the arm is brought to a stop.

When bar 61 strikes one of the stop bolts 10b, said bar and shaft 60 are stopped. The motor 44 is thus stopped or braked. The motor, however, rotates a short distance and the clutch comprising the plates 5| slips to permit this extra movement of the motor. The motor is thus not brought to a sudden stop and the motor thus does not always stop in the same position.

After the short extra movement, however, the

motor is stopped and held stopped and the current is continuously supplied to the motor so that the same exerts a torque on the shafts 44a, 41 and 60. The signal unit shown in Figs. 9 and l0 is thus held in one position with its flat sides in alinement with the flat sides of the standard, so that the characters on said units are displayed at the sides of the standard. When the shaft 6U was turned, the yoke 62 was also turned,

owing to the fact that it is connected to the flat side of shaft 60 and spring 64 was wound up or flexed in one direction, one end of said spring being moved by the side of said yoke and the other end held by the pin Bla. After the signal has been turned to the position described and held there for a desired length of time, the timer 36 will operate to reverse the current through conductors 34 to the motor 44 so that said motor now revolves in an opposite direction. When the motor starts to turn, the spring 64 also unwinds or returns to normal position and this spring exerts a turning impulse on the shaft 60. This gives a start or an initial movement to the signal unit shown in Figs. 9 and 10 and to the shaft 60. The motor, as well as shafts 44a, 41 and 60 and bar 61, are again rotated in the reverse directi-on until it again strikes the other stop bolt 10b. The bar is thus stopped and the signal unit shown in Figs. 9 and l0 is again stopped with its sides in alinement with the sides of the standard, except that the word Stop is now alined with the side with which the word Go was previously alined. The motor is thus again braked and revolves a short distance owing to the slipping of the clutch comprising disks 5| and is then brought to a stop. The current still flows to the motor and the motor still exerts a torque on the parts as previously described. The spring 64 is wound in the opposite direction and is in position again to exert a starting movement on the parts when the motor is again reversed. The signal unit comprising parts 8D, to 86 which is shown in Figs. 9, 10 and l2 to 14, is thus periodically rotated in reverse directions through substantially The corners of said signal unit, which corners are formed by plates 8|, pass into openings 4Gb when the said unit is oscillated. The lamps are continuously lighted and it is unnecessary to periodically light and extinguish the lights in the operation of the signal. The signal is perfectly visible in daylight without the lamps 95, as the characters forming the word.Stop are colored red, and the characters forming the word Go are colored green. The border 85 about the stencilopening in the wordfftop 'also yaccentuates the visibility v,of even in a very poor light the'signal is quite distinguishable. ,c l

Lamp 98 at the'top `of the signal isalso` contiiiuously illuminated and continuously shows a red light through, thel transpaieinty'panes 93 which, asV stated, arepreferably red, The lamp H33 is periodically illuminated by the timer Y33 just before the motor M `is reversed and then extinguishedk just as thev motor is reversed. This lamp, therefore, constitutes a trahie change signal and indicates that thesignal is about` to change.-

The spring 64 iss-o placed that when the cur-l rent is off the 'motor 44,' the spring will turn the signal unit shown in Figs. 9 and l0 so that the sides are out of alinement with the sides of the standard 46 or so that the sides of said unit or the central line of said sides are alined With the bisector of the angle at the corners of the standard. When the signal is thus not being operated, neither the Stop nor the Go sign will be displayed and traffic can proceed on the streets or thoroughfares of the intersection Without being controlled. There will thus be no confusion or congestion if for any reason the signal should lcease to operate.

From the above description it is seen that applicant has provided a very efficient traffic controlling and directing signal. The device is absolutely non-glare in operation and the signals can be plainly and distinctly seen at all times no matter how the sun is shining on the signal.

Only one set of characters are used at each side of the signal so there is no chance for more than one set of characters to be displayed. All of the operating mechanism except the electrically controlled timing device are carried in the standard, and as stated, the standard can be struck by a vehicle without damage. The present signal also requires fewer lamps than the signal disclosed in applicants previously filed application and the signal is operated with much less expense. The signal is now in operation in many places,

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the parts, without departing from the scope of applicants invention, which, generally stated, consists in a device capable of carrying out the objects above set forth, in the novel parts and combinations of parts disclosed and defined in the appended claims.

What is claimed is:- j y 1. A traliic signal adapted to be disposed at the intersection of two or more thoroughfares having in combination, a turnable signal unit having opposite sides with characters thereon adapted to be displayed in alinement with said thoroughfares for simultaneously directing traffic to proceed on one thoroughfare and to stop on another, a motor, driving means connecting said motor and unit including a slipping clutch, a spring disposed between said clutch and unit and adapted to be placed under stress when said unit is turned by said motor and driving means, and stop means for limiting the rotating movement of said unit whereby said motor may rotate after said unit is stopped and means for reversing said motor at regular intervals whereby said spring will exert an initial rotating movement on said unit.

2. A traflie signal adapted to be disposed at the intersection of two or more thoroughfares havthe characters and ing in combination, anl elongated hollow' standard of comparatively rsmall transverse dimension and substantiallyy square and uniform inliorizontal cross section, said standard having openings in its sides atits upper portion, a turnable hollow member centrally mounted in said standard and having lopposite faces adapted tobe arranged in alignment with and be visible through the openings in said standard, said faces having characters thereon adapted to simultaneouslyy directv traffic to proceed on one thoroughfare and to stop traic Von another, illuminating means projecting intol said member, supporting means securednto the bottomof said `member and extending downwardly therefrom in said standard, a motor mounted in said standard below said vmember andrhaving an armature shaft.. projecting Aupwardly in axial alignment with said member, means disposed Without said standard for periodically reversing said motor, gear means connecting said armature shaft and said downwardly extending means, and stops for said member whereby said member is turned degrees with each reversal of said motor.

3. A traffic signal adapted to be disposed at the intersection of two or more thoroughfares having in combination, an elongated standard of coinparatively small transverse dimension having pairs of opposite sides and having openings in said sides at its upper portion, an oscillatable signal member mounted within said standard about an axis extending longitudinally of said standard and having opposite faces visible through said openings with characters thereon for directing traffic to proceed on one thoroughfare and to restrain traffic on another, a rotatable block mounted in said standard below said signal member and axially aligned therewith, laterally spaced gears carried by said block, a gear disposed co-axially with said block and signal member disposed between and meshing with said gears, an annular lgear secured to said standard with which said first mentioned gears also mesh, a shaft secured to said second mentioned gear and extending downwardly into said standard, said signal member being connected to said block, and a rotatable motor mounted within said standard having its armature shaft axially aligned with and connected to said last mentioned shaft. 4. A traii'ic signal adapted to be disposed at the intersection of thoroughfares having in combination, a turnable member having opposite sides adapted to aline vwith said thoroughfares, said sides of said member having traffic directing characters thereon, an electric motor for turning said member, connecting means between said motor and said member, stopping means for limiting movement of said member to aline said sides with said thoroughfares, and slipping means constituted as a part of said connecting means, said slipping means being adapted to rst brake the movement of said motor upon the operation of said stopping means and to immediately thereafter gradually bring said motor toi a dead stop while a torque is yet exerted by said motor upon said connecting means.

5. A traffic signal adapted to be disposed at the intersection of thoroughfares having in combination, a standard having sides alining with said thoroughfares and openings through said sides, a turnable member having sides adapted to lie adjacent said openings to aline with said thorough- `fares, said sides of said member having traffic tween said motor and said member, stopping means for limiting movement of said member to aline said sides of the member with said thoroughfares, and slipping means constituted as `a part of said connecting means, said slipping means being adapted to rst brake the movement of said motor upon the operation of saidfstopping means and to immediately thereafter gradually bring said motor to a dead stop vWhile a torque is yet exerted by said motor upon said connecting means. v

6. A signal for directing trafc on a thoroughfare, having in combination, a casing', a sign having a traii'lc directing legend thereon turnable to positions to restrain traffic and direct traic to proceed on said thoroughfare and to an intermediate position where traflic is neither restrained or directed to proceed by said signal, a shaft in said casing, 'means connecting said sign to said shaft, electrically actuated means for turning said shaft and sign alternately and periodically to said positions to restrain and to direct traiic to proceed, respectively, mechanically operated means for turning said shaft and sign to an intermediate position upon the failure of said electrically actuated means, a reduction gearing connection between said shaft and both of said means, and stop members for limiting turning movement of said sign in opposite directions so that said sign is turned substantially 90 degrees between said position to restrain traffic and said position to protect traic.

FRANK W. GRISWOLD.

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