US1918480A - Light signal - Google Patents

Description

E. W. MOORE LIGHT SIGNAL July 18; 1933.

Filed Nov. 5, 1927 lNV NTOR WZZ ;ATTORNEY Patented July 18, 1933 UNITED STATES PATENT OFFICE EDNIUND W. MOORE, OF ROCHESTER, NEW YORK, ASSIGNOR T0 GENERAL RAILWAY SIGNAL COMPANY, OF ROCHESTER, NEW YORK LIGHT SIGNAL Application filed November 5, 1927.. Serial No. 231,292.

This invention relate'sin general to light signals, and has more particular reference to such signals which continue to give distinctive indications upon failures which would normally result in dark indications.

In light signals, such as is particularly used in railway signalling, it is very important, in avoiding danger, to prevent failures of such signals since, when such failures result in dark signals, conditions are'not so completely safeguarded as when the light signal is arranged to nevertheless continue its active indication.

With the above and other objects in view it is proposed, in accordance with this invention, to provide a light signal which includes, in combination witha doublet lens combination of lenses, a single incandescent bulb containing a main filament and a reserve filament, whereby both filaments can be readily positioned close to the inner lens of the doublet combination as is necessary, in such lens-systems, for being on focus. The single bulb is carried in a socket mounted on an adjustable bracket andprovided with sighting means for determining when the laiilf is properly positioned. i

i ea11s,',controlled in accordance with traffic conditions, is arranged tomomentarily energlze both of the filaments, together with means for immediately or shortly thereafter tie-energizingthe reserve filament while continuing the energization of-thenmainfilament, and to operate, upon breakage or burning out of the main filament, to cut the reserve filament into energization. The main filament is placed on focus, whereas the reserve filament is positioned ofi focus and above thereof, whereby to give a somewhat diminished, and also slightly depressed,

beam suflicient for being picked up and recognized by the engineman as the distinctive signal'indication, but of such a character as to advise him, and place him on hlS notice, that the signal requires attention.

Further objects, purposes and characteristic features of the present invention will appear as the description progresses, reference being had to the accompanying drawing showing, solely by wayof illustration,

two filaments 10 and 11, which are respechaving a removable rear door 2, and a large opening 3 in the front of the casing within which 1s positioned a doublet lens combination comprising lenses 4 and 5, there being a sunshade or visor 6 fastened to the casing.

Carried by a retainin ring 7 for the inner lens 5, is'an adjusting iracket B carrying a lamp base receiving socket 8, in which is received an incandescent lamp W The bracket Bgcan be adjusted-to'move the" socket 8 in threeplanes substantially at right angles to each other, whereby to position the lamp 9 'at'the" desiredipoint in the casing relativeoto the doublet lens, and for a detailed description of this" adjusting.

bracket referencesho'uld be had to co-pend-" ing application SJ N.f131,4 66 filed August2 5, 1926, now Patent No. 1,822,105.' '1

Also carried by the retaining ring 7 isa sighting device S, for determining when the lamp is properly adjusted, and for a detailed description of the construction and operation of this device S, reference shouldbe had to co-pending application S. N..131,467, filed August 25', 1926, now Patent No. 1,794,586.

Positioned within the bulb of lamp are tive'ly main and reserve filaments, the lament 10 when properly positioned being on focus, while the filament 11 is ofl of focus and above thereof.

As shown in Fig. 2, the light signal is controlled in accordance with traflic conditions,- as for example, by means of a track relay TR, connected across track rails 30, toin turn control a line relay L which in turn controls the energization of the lamp filaments.

For automatically maintaining the reserve filament 11 de-energized, while the main filament is energized when conditions correspond to energization of the signal exist, is a light-out relay OR. The energy for energizing the light signal is derived fromthe secondary of a transformer T, the primary of which is fed from any suitable desired source of electrical energy.

As shown in Fig. 2, traffic conditions correspond to the energization of the light signal. With relay TR energized, its finger 31 is attracted, to thereby energize relay L, through a circuit obvious from the drawing.

With relay L energized, and its contact finger 12 in attracted position, energy from the secondary of transformer T momentarily energizes both of the filaments 10 and 11 through circuits including; secondary of transformer 'T, contact finger 12 and front point of relay L, wire 13, and then, in multiple; first through filament 10, wire 14, and

relay CR to the common'point 15, and, sec- 0nd, through reserve filament 11, wire 16, re-

actance 17 (which is chosen to equal the reactance of relay CR), wire 18, and contact finger and back point 19 of relay CR to the common point 15; and thence, by wire 20, back to the secondary of transformer T Light-out relay GR is arranged to pick up on energization to thus break the above traced energizing circuit for reserve filament 11 at its contact finger 19, without affecting the energization of main filament 10.

Let us now assume that the main filament 10 burns out, is broken, or due to any other cause breaks the circuits passing through relay CR. On de-energization of relay CR, its contact finger 1 9 assumes retracted positlon, to energize reserve filament 11 through its energizing circuit as described just above with regard to the momentary energization of reserve filament 11 on initial energization of the light signal.

This reserve filament, as shown, and as explained above, is oil focus,-and above focus, whereby to give a weaker beam. than that of the ma n filament, and to direct this weaker beam slightly downwardly from the direction of the beam from the main filament. In certain conditions it has been found desirable to arrange the reserve filament to give a beam of per cent of the intensity of that of the main filament, and to position it so that its beam will be projected in a direction depressed from the main beam from 2 to 3. In all events, the reserve filament 11 is so 0- sitioned that its projected beam, while being weaker than the main beam, and depressed downwardly therefrom, will still be sufiicient for the engineman to readily pick up the light signal indication, while at the same time being advised by the different characteristics of this indication from the usual indication, that something is wrong with the light signal, and that inspection and repair be .ment lamp and given to rectify conditions.

It should be borne in mind, that in order to readily, or in fact, possibly, place the two filaments, main and reserve, in the desired relative position one to the other, they should both be placed in a single incandescent bulb rather than in two separate lamp bulbs.

Furthermore, it is most important,in order to utilize a large solid angle of the total light flux emitted 'that a doublet lens combination be used. It is well known by those skilled in this art that the focal point of a doublet lens combination lies nearer to the inner surface of the inner lens of the combination, than does the focal point of either of the two component lenses making up the combination, whereby a larger solid angle of light fluX can be availed of, than without such a doublet combination. With such a combination, however, of lenses, it would be difficult, or perhaps impossible, to place the two filaments in question close enough to the inner surface of the inner lens if the filaments were placed in separate lamp bulbs. It therefore appears quite obvious that the characteristics of the doublet lens combination used, and of the two filaments in a single lamp bulb, mutually cooperate with each other to permit their needful combinative combination.

It is, of course, wholly within the purview of this invention, to employ the double filaits automatic control means, in light signals other than that shown and described above. For example, it can be advantageously used in a light signal of the type which employs a single light source and a movable spectacle carrying several different color glasses, all with a single casing, whereby'a single light unit displays several signal indications.

In concluslon, 1n accordance with this invention, when traflic conditions are such as to cause energization of track relay TR, the two filaments 10 and '11 are momentarily. energized, after which, the light-out relay CR will operate to de-energize the reserve, filament, providin the main filament is intact, until such time as the main filament fails, whereupon relay GR is de-energized and cuts in the reserve filament 11 to give the desired reserve indication, which is suflicient for the engineman to pickup the indication, and at the same time to advise him, due to the somewhat diminished and depressed beam, that inspection and repair of the light signal is necessary. p

The above rather specific description of the invention is given solely by way of illustration, and is not intended in any manner whatsoever, in a limiting sense. Obviously, the invention can assume various different physical forms and is susceptible of numerous modifications, and all such forms and modifications, are intended to be covered by this application, as come within the appended claims.

Having described my invention, I now" 1. In a light signal for railway signal sys* tems, a casing, a doublet lens system. in the front of the casing, a lamp bulb within the casing and projecting into the cup portion of the inner lens, a main filament and a reserve filament in the bulb, and means for automatically causing energization of the reserve filament upon failure of said main filament, the main filament being adjusted on the focus of said lens system, and the reserve filament positioned off, and above, such focus whereby to indicate failure of the main filament by the lessened intensity and the position of the beam produced by the reserve filament.

2. Ina light signal, a casing, a doublet lens combination in thefront of the casing, a single incandescent bulb positioned at the focus of said lens combination, a main filament in the bulb and on focus, a reserve filament in the bulb and'ofi focus, and means for automatically cutting the reserve filament out of an energizing circuit when the main filament is intact and is in an energizing circuit, and for energizing the reserve filament upon failure of the main filament during its energization whereby to indicate failure of the main filament by the lessened intensity and the position of the beam produced by the reserve filament.

EDMUND W. MOORE.

Images