Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.


  1. Advanced Patent Search
Publication numberUS2097785 A
Publication typeGrant
Publication dateNov 2, 1937
Filing dateJul 23, 1930
Priority dateJul 23, 1930
Publication numberUS 2097785 A, US 2097785A, US-A-2097785, US2097785 A, US2097785A
InventorsField Oscar S
Original AssigneeGen Railway Signal Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Light signal for railroads
US 2097785 A
Previous page
Next page
Description  (OCR text may contain errors)

Nov. 2, 1937. o. s. FIELD 2,097,785

LIGHT SIGNAL FOR RAILROADS Filed July 23, 1930 6 Sheets-Sheet 1 Nov. 2, 1937. o. s. FIELD 2,097,785

LIGHT SIGNAL FOR RAILROADS Filed my 23, 1930 e sheets-sheet 2 FIG. V .as

INVENTOR BY 5. d/ATTORNEY Nov. 2, 1937.

FIG.. 3.

O. S. FIELD LIGHT SIGNAL FOR RAILROADS Filed July 23, 1930 I/llf//ll/lll/l//l/ v t INVENTOR Q6. SZM


du ATTORNEY 6 Sheets-Sheet 3 Nov. 2, 1937. o. s. FIELD LIGHT SIGNAL FOR RAILROADS Filed July 23, 1930 e sheets-sheet 4 FIG.. 4. 7

INVENTOR Nov. 2, 1937. Q s FlELD 2,097,785

LIGHT sIGNAL FOR RAILROADS Filed July 25, 1930 6 Sheets-Sheet 5 INVENTOR I ATroRNY BY MMM Nov. 2, 1937. o, s. FIELD 2,097,785

LIGHT SIGNAL FOR RAILROADS I Filed July 23, 1930 6 ShGeS-Sheet 6 MM m ATTQRNEY Patented Nov. 2, 1937 UNITED s'rArss LIGHT SIGNAL FOR, RAILROADS Oscar S. Field, Rochester, N. Y., assigner to G eneral Railway Signal Company, Rochester, N. Y.

Application July V.23, 1930, serial No.' 470,056


This invention relates in general to light signals, and has more particular reference to a light signal wherein a single light source, in cooperation with a movable screen carrying a pluf5Y rality or colored transparent members, operates to give a plurality of diierent signal indications.

The present application .is a continuation in part of applicants `copending application Ser. No. 128,437 filed August 16, 1926, now Patent No. l835,l50 dated December 8, 1931, and entitled Light signals.

Among the objects of the present invention is to provide a light signal of the character in quesy tion which is simple in construction, cheap to 155 manufacture, readily accessible for inspection and repair, and has along useful life.

A further object of the present invention is to provide means to eectually prevent phantomindications due to light from outside of the signal passing into the signal and reecting out again. This is accomplished, broadly, by providing a funnel shaped member running inwardly to the movable spectacle, with longitudinal corrugations on the inner surface of the same, n whereby to cause any light entering the signal to be reflected transversely from the corrugations to thereby diffuse the same.

A further object of the present invention is to` provide an improved means for inserting and x- 'ing in place, a mechanism casing in the signal casing.

A further object is to provide a motor element having a permanent magnetic eld whereby to minimize the requirement for power sources at the signal location, so that primary batteries can be readily used and thereby obviate necessity for a power line or storage batteries.

A further object of the invention is to provide an optical system including condensing lenses whereby light from the single light source can be more economically utilized so that a relatively low powered light source can be used satisfactorily. This permits the use of primary batteries for energizing the light source instead of requiring storage batteries or a power light.

A further object of the invention comprises providing a novel friction ily wheel, carried on the shaft of the armature of the motor element, for preventing rebound when energized position'. v

A further object of the present invention is' to provide'a novel and improved centering means for bringing the motor element, when cle-energized, to its neutral position in an accurate and certain manner. Y

the motor moves to A further object of the present invention is to provide an auxiliary lens, including an arrangement of prisms, for producing a close up indication byreclirecting a portion of the light flux from the light source to an inclined position with reference to the optical axis of the main lens system. The auxiliary lens is arranged for adjustment so as to vary the position of the close up indication about the optical axis of the lens system proper.

Y Further objects, purposes and characteristic features will appear as the description progresses, reference being made to the accompanying drawings, showing, solely by way of example, and in no manner in a limiting sense, one form which the invention can assume. In` the drawings: Fig. v`1 is a side elevational view, with parts shown in section, of a light signal in accordance With'ithe present invention.

Fig.'V 2i`s a sectional view, on line 2 2 of Fig. 3. viewed in the direction of the arrows.

Fig. V3 is a half sectional, half elevational, view onv line 3 3 of Fig. 2, viewed in the direction of the arrows.

Fig. 4 is a sectional view on line 4 4 of Fig. 2, viewed in the direction of the arrows.

Fig. 5 is a sectional View on line 5 5 of Fig. l, viewedin the direction of the arrows.

Fig. 5A is a perspective view of a portion of the auxiliary lens and its mounting.

.j Fig. 6 isa sectional view on line 6 6 of Fig. 5, viewed in the direction of the arrows.

Fig. 7 isa rear elevational view of the auxiliary lens shown in Fig. 6.

Fig. 8 is a sectional view on line 8 8 of Fig. 2, viewed in the direction of the arrows.

,'Fig. 9 isA a fragmentary sectional view, on line 9 9 of Fig. l, viewed in the direction of the arrows. Y

fFig. l0 is a diagrammatic view of the optical system, showing the paths traversed by various of the lightrays emanating from the light source. Fig. 11 is a View similar to Fig. 10, of a modiiiedgform of lens system.

y Referring now to the drawings, and iirst to Fig. 1, there is here shown a signal pole I, on which is carried a cap 2, adjustable horizontally thereon and then xable in adjusted position. The cap 2V has a transverse slot 21 formed therein, with lugs 22 at the inner ends of the slot, to receive threaded bolts 3 and nuts 31 for drawing aiu-shaped strap 32, having an inwardly projecting` pin 41, against the post I, pin 41 fitting into a receiving socket 42, in post I, to thereby anchor the strap to the post, and adjustably connect the cap 2 to the anchored strap.

With this arrangement of. parts, cap 2 can be readily adjusted angularly on post I, by tightening one of the nuts 31, and loosening the other, to thus turn the cap on the anchored strap.

Carried by the cap 2 is a signal casing SC, pivoted as at to the cap 2, and having an adjusting means, comprising a threaded stud and nut 6, for tilting the casing SC in a vertical plane on its pivot point il.

Carried within the signal casing SC is a mechanism casing MC, having a depending bracket 'I, carrying a pin 6 at its lower end for engagement in an aperture S in a lug l! carried by the signal casing. The signal casing has two pins I I, in its sides, for cooperation with two latches I2, pivoted at i3 to the mechanism casing, and biased by springs i4 in a counter-clockwise direction as viewed in Fig. l, whereby to snap the catches I2 over the pins i i and thereby hold the mechanism casing MC in position in the signal casing SC on the two horizontal pins Il and the lower pin 8. The latches I2 have odset lugs I5 for contacting with the upper face of bracket 'l to limit the rotation due to springs I4, when the mechanisrn casing is removed from the signal casing.

Carried on the top of the signal casing SC, is a sighting device including an apertured member i6 and a member l?, carrying cross hairs or the like for defining a point in space, with the aperture 61 and the cross hairs defining a line in space parallel to the optical axis of the lens system in the light signal, whereby to permit readily directing the focussed signal beam to any desired point.

Carried on the front of the signal casing is an adapter i8, having at its outer end a lens I9, shown as a plano-convex lens of. the condensing type, for directing light beams passing therethrough in a substantially cylindrical beam. Carried on the adapter I6 is a sunshade or visor 23, and carried by the signal casing is a background 2I fastened in place by screws or the z like 22.

In combination with the lens I9, is an auxiliary lens 23, carried in a bracket 24 fastened to the adapter lo, the bracket 24, vhaving a lower aperture 25, and two forked, infacing ends 26, for rotatably receiving the lens 23, whereby it can be rotated in the bracket 24 as desired, the bracket 25B being held in place by means of screws or the like 21.

The auxiliary lens 23, as shown best in Figs. 6 and 7, includes a plurality of parallel, spaced,

substantially straight prisms 28, arranged to redirect light passing therethrough in a downward direction at an angle of substantially 40 from the horizontal when the lens 23 is positioned with the top portion, indicated by the word Top, at the top. The functions and advantages of this arrangement of parts of the auxiliaryl lens will appear as the description progresses.

Referring now more particularly to Fig. 2, the mechanism casing MC' is here shown in section, and comprises a preferably transparent bowl 29, held by means of a strap 36 and thumb screws 3I, in position against the main portion 32 of the mechanism casing.

Carried in a socket in the casing portion 32, is a light unit LU, including a light source 33, shown as an incandescent bulb adjustably carried in a mounting 34 soas to position it at one of the conjugate foci of an elliptical reflector 35, the other conjugate focus of the reflector being aoomes at the point 36, immediately to the rear of a movable spectacle 3l carrying a plurality of different colored glasses 38, as more readily seen in Fig. 4. The light unit LU can be readily slipped into place in the casing portion 32 and held therein by a bayonet joint or the like, as shown in the application of which this is a continuation. The mechanism casing is provided with a hand hole 38 for facilitating handing of the same.

In the front of the casing portion 32 is an aperture 46 for receiving a conical member 4I having longitudinal corrugations 42 covering its entire inner surface. These corrugations 42 have sharp edges, and smooth faces, whereby to cause light entering through the plano-convex lens 43, which is positioned over the outer larger opening of the cone member, to be reflected back and forth from one side of the cone to the other, if it strikes on the pointed edges of the corrugations, and if these edges are not so sharp as to substantially prevent any reflection, and to be reflected from one inner face to the other of the various corrugations if it strikes at such points.

Furthermore, if the cone member 4I were to be smooth on its inner surface, then the entire surface would act to rellect light entering from the outside, back and forth across the cone as the light travels inwardly, to prevent any light so entering, from leaving the casing, without rst having passed through the spectacle 38, so as to prevent any washing out or dimming of the color of the signal glass then in controlling position.

It will be noted that the cone member 4I has its inner open `end immediately adjacent the spectacle 3l', whereby any light from outside that reaches the spectacle 31 must either reach it directly and pass therethrough or else be reflected back and forth by the cone member until it is so diiused that it cannot pass out again in a manner to give a phantom indication. Weite there any iiat reecting faces anywhere adjacent the focal point 36, light from the outside might reach the same and be reflected outwardly again to give a false indication, this being particularly the case if such reflecting surface were at the outer side of the spectacle.

By the above arrangement, little or no light from the outside can enter the casing and be reilected out again, without first passing through the spectacle 38, and due to the opening cover 43 being spaced a considerable distance from the focal point 36 and to the fact that no other surface is adjacent this focal point, any such light as does reflect out of the casing before passing through the spectacle 38, reflects from points considerably spaced from the focal point 33, and hence does not ll the opening 40 with the reflected light. Accordingly such light as thus reflects out can at most produce only bright spots at the opening or on the closure for the opening instead of covering the entire opening and thus tending to wash out or gray the color of the indication then in force.

Carried by the casing portion 32, are two spaced side brackets SB, supported by studs 9U. Between these support brackets are carried two boxlike eld members 44, by means of through `bolts 45, with spacers 46 between the substantially parallel sides il of the lield pieces, to permit tightening up the connection without collapsing the eld pieces.

Carried by means of a through bolt 48, and nuts 49, is a permanent magnetic. eld structure including four permanent magnets in the form of four bars 50, two at each side of the bolt 48.

' traction of the .permanent f tion, resti-ng on the Each magnets-f550,\=is spaced by; spacers:|, with the magnetic bars and bolt i48=held together in a bundlev bymeans' offrtwolspacedf" circular washers 52, passing around thessameand fitting into slots 53 in the spacers 5Il .wherebyftohold the entire permanent magnetic field `structure of the motor element in properLpo'sition.' l i;

Carried on spindles 54, pivoted at. 55 :in knife edge bearings, is an armature A,.having`a'narma ,i ture winding 56, on1af core v5.1,wi'th.vanes58l-and 59 pinned to the core f'lbypins'llland heldrigidly in place by .nuts 6|. l Asfcan'y be .readily 'seen in Fig. 2, the vanes 58and 59l are positioned respectively below .and above .ther axis-of the core 51 whereby,.when4 the-winding 56 is energized to make the vanes 'respectively of positive and negative polarity,.the spindle .54 will be rocked either clockwise or counter-clockwiseby'the at# magnetic `field, the permanent magnetic bars 5l!` makingoneof the boxlike eld members 44..positive:and the other negative. By reversingthe polarity on the winding 56, the polarity. ofthe vanes .58 and. 59 can be reversed and hence the direction of rotation reversed. f 1".; n.

Carried by the vane 59 is the spectacle 31, conf nected thereto by 'suitable means, suchas rivets 62, whereby the spectacle can be moved to position any one of its three colored'. glasses v38 in iront ,or thefocal point 36,A the. center glass 38 being positioned at the. focal point; 36. whenV winding 55 is cle-energized, andthe outer glasses 38 being so postioned'when the .winding 55 is energized with one or the other. polarity.

Carried by the vane 58, is acounter-weight 63, for balancing ,the weight `of the spectacle-31. For deiining the energizing positions ofthe varies .58 and 58, theregare provided adjustable stop screws @d against which'` the v'ane-` 58 strikes when it reaches its energized position-in either direction. .8 a f For accurately and positively returning.. the armature and its connectedparts to neutral' position, upon the deenergization ofwinding 56,

- there is provided a centering mechanism.. Fas'- tened to the vane, 58, a plate like arm 65, tothe top of which is fastened: acrown 66 andvto this crown 68 are pivoted two arms 61 each of'which has a longitudinal slot 38 in its lower end for. receiving a pin 39 carriedinthe bifurcated end l@ of a centering weight 'll which 4,is pivotedrat 12. Each centering weight normally .rests on an' adjustable stop screw,13 .whenithe. partsare in neutral position.

With the structure above described, on the armature A moving to an energized position, as for example, clockwise, as viewed in Fig. 4, the left hand arm 31 is raised to thereby raise centering weight ll, whereby, uponthe armature being cie-energized, the centering weight moves the parts back to neutral position. As the same time the right hand arm 51 is permitted to move downwardly due to its slot 68, while the right hand centering weight 1| remains in its neutral posiscrew stop 13.

Carried by one of the centering weights 1|, are movable contacts 14, which cooperate with fixed Contacts and 16 carried on an insulating bar 11 bolted, as by means 18, to the box like field members 41.

When the armature winding 56 is energized, and the vanes 53 and 59 are moved to energized position to cause vane 58 to strike against one of the stop Screws 64, there is a tendency forthe parts to rebound from the stop screws before nally'coming to rest thereagainst. This tendency to rebound `is very effectually prevented by means of a friction ywheel FF, loosely carried onl one of the spindles 54, with a spring 19 sleeved between,` the friction fly wheel and acollar 80 pinned to the spindle 54, whereby to biasA the fly wheel :inwardly to `compress friction discs 8| positioned between the fly wheel and a shoulder 82 on the .core 51.

`With-the arrangement of parts just described, when the armature is moved to energized position, the friction ily wheel FF continues to rotate after thevanes have been brought to a stop, by rotating on the spindle 54, to thereby absorb the kinetic'energy of the parts and prevent the reboundby attempting to carry the rotation beyond the position of the screw stop 64.

Referring' now to thediagrammatic showing in Fig. l0, there is here represented the elliptical reector 35, the light source' 33, the focal point 36, the spectacle 31, the inner plano-convex lens 43, the outer plano-convex lens I9, .and the auxiliary lens 23, in their approximate relative positions occupied in the actual light signal. `The parts are arranged so that light emanating fromthe light source 33, and striking the reflector 35, is concentrated at the conjugate focus 36 of the elliptical reilector, `andthen spreads out suilciently to practically fill any one of the colored glasses 38 carried by the spectacle 31. After passing `.through one of the colored glasses it continues to'spread out tosubstantially cover the inner condensing lens 43. On passing through the lens 43 the light is concentrated surhciently to just cover the outer condensing lens I9 through which it passes to be directed youtwardlyin a substantially lcylindrical beam. AThis is all indicated by the light rays 83, 84, and 85 which are traced in the diagram shown. 1 Light rays passing through the inner condensing lens 43 and Astriking theauxiliary lens 23, as, for instance, the light ray 86, is caused by the prisms 28 of the auxiliary lens 23, to be directed downwardly substantially 40 from the direction at which the ray 86 entered, so that this ray, onpassing through the outer condensing lens I9, follows a path approximately 40 re moved from the cylindrical beam, as indicated by thearrows 81. The various quantitative gures given above with regard to the light rays, canV of course be varied within limits, without departing from the `present invention. For example, the condensing lenses 43 andV I9 might be arranged so as to give a resulting beam from the light signal which instead of being cylindrical, might be slightly conical in either direction from the spherical. Also, the auxiliary lens 23 could be so arranged and have its prisms so proportioned that the depression of the light passing therethrough might be somewhat more or less than the 40 set above.

As was explained above, the auxiliary lens 23 can be turned in its supporting bracket 24 so as to move the top, indicated by Top, in either a clockwise or counter-clockwise direction, whereby to cause the depressed beams passing through the auxiliary lens 23 to lie to one side or the other of the main cylindrical light beam, instead of below it as indicated in Fig. 10. By turning the lens 23, through an angle of 180, the close-up indication can be caused to fall directly above the main cylindrical beam, whereby to produce a close-up indication for a dwarf or low signal. With a high signal the close-up indica- 14 tion is normally positioned, as shown .in Fig. 10, to be directed downwardly instead of upwardly.

By employing condensing lenses to thereby utilize the light iiux to the greatest advantage, it is possible to use a relatively low powered light source 33. By being enabled to use a low powered light source, and by also employing a permanent magnetic eld structure for the motor element, the total amount of energy required tooperate the light signal is out down to such a small Value that primary batteries can be depended on for operating the signal and thus obviate necessity for a power line or storage battery at outlying points where the signals are located. The only power required at the signal location is that required or energizing the armature A, and the low powered light source 33.

A satisfactory indication has been obtained, under bright daylight conditions, at distances of 3500 to 4500 feet, with a light source constituted by a rthree watt, four volt, incandescent bulb. Thus it can be seen that the condensing lens optical system, together with a permanent magnetic eld structure for the motor element, produces a combination which permits the use of primary energy sources for operation of outlyx ing signals.

`It can also be readily seen from the above, that the conical member 4l, for directing light outwardlyy from the spectacle 31, effectually prevents outside light, on coming into the spectacle, from reecting from any point near the conjugate focus 36, and thereby causing a phantom indication.

In the form of lens system shown in Fig. 1l, the lens i3 of Fig. 10, is replaced b-y a piece of plane glass 43; while the outer lenses I9 and 23 of Fig. 10 are replaced by a stepped lens |91 of the Fresnel type, with a bulls eye 231 formed substantially like the auxiliary lens 23 of Fig. 10, to give a close-up indication as shown in Fig. l1.

In the case of the Fig. 10 form, as well as the Fig. 11 form, the optical member 43 and 431 used to seal the front opening in the casing MC, is positioned a considerable distance from the focal point 3S. Accordingly, any light, (usually white light) entering the signal through the front lens i9 or 91, and reflecting from the surface of the inner optical'member 43 or 431, is diffused away from the main beam, on energizing from the signal, and hence cannot wash out the color of the main beam, as might be the case if these inner optical members were positioned substantially at the focal point 36. This is illustrate-d by beam 88 in Fig. 11.

The aboveV rather specific description of one form of. the present invention, is given solely by way of illustration, and is not intended, in any mannerwhatsoever, in a limiting sense. Obviously, the 'invention can assume many different physical forms, and is susceptible of numerous modifications, and all such forms and modifications, as come Within the appended claims, are intended to be covered by this application.

Having described my invention, I now claim:-

l, In alight signal, in combination with a light source, a conical tube positioned to allow light from the source to pass through it from the small tothe large end, to the outside of the signal, and longitudinal corrugations on the inner surface of said tube for diffusing light entering the same from the outside `before such light can reach the'light source.

2. In a light signal, Vin combination with a light source, a. conical tube positioned to allow light flux from the source to pass through it, from the small tothe large end, to the outside of the signal, 'and longitudinal, sharp edged, corrugations covering the inner surface of said tube for-diffusing light entering the same from the outside.

3. Ina light signal, in combination, a casing, a light source in the casing, a signal means, light directing means for directing light from the source through the signal means, an outer opening 'in the casing, .an inwardly tapering hollow cone extending from the outer opening to the signal means, and Vsharp edged longitudinal corrugations completely covering the inner surface of the cone.

4. In a light signal, in combination with a light' source, an inwardly tapering conical tube positioned to allow light flux from lthe source toipass therethrough to the outside of the signal, llongitudinal sharp edged corrugations covering the inner surface of said tube for diffusing lightentering the same from the outside, and a signal glass immediately to the rear of the tube and substantially covering the inner opening of the tube.

5. .In a light signal, in combination with a light source, a vflaring tube positioned to allow light from the source to pass through it from the small tothe large end to the outside of the signal,.and longitudinal corrugations on the inn ner surface of said tube for diffusing light entering the same from the outside before such light can reach the light source.


Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3247367 *Oct 31, 1960Apr 19, 1966Perkin Ehner CorpSolar simulator
US3952978 *Sep 19, 1974Apr 27, 1976Safetran Systems CorporationCantilever arm signal assembly
US7780121Nov 12, 2005Aug 24, 2010General Electric CompanyWayside signal apparatus with adjustable signal position
U.S. Classification246/473.3, 362/257, 246/484
International ClassificationB61L5/18, B61L5/00
Cooperative ClassificationB61L5/1818
European ClassificationB61L5/18A1