US1964325A - Signaling means - Google Patents

Description

June 26, 1934. Q s LEBBY 1,964,325

Filed April 30, 1923 s Sheets-Sheet 1 m 0R Sun's 55 88 TORNEYIS.

June 26, 1934. 5 LEBBY 1,964,325

- S IGNALING MEANS Filed April 30, 1928 3 Sheets-Sheet 2 1 1 3 INVENTOR 1 5742's: LE5 Laser.

S. L. LEBBY SIGNALING MEANS June 26, 1934.

Filed April 50, 1928 3 Sheets-Sheet 3 1 INVENTOR STATES 5 LEBBK BY HZ A ORNEYAI Patented June 26, 1934 SIGNALING MEANS States Lee Lebby, Corning, N. Y., assignor to Corning Glass Works, Corning N. Y., a corp oration of New York Application April 30, 1928, Serial No. 274,021

' 2 Claims. (01. 177-329) This invention relates to the art of light projection and more particularly to an improvement in signaling means.

In many prior types of signals considerable 5 difliculty has been experienced in securing a sufl'iciently wide spread of the light rays to make the signal visible when the person approaching it is at a Considerable angle from the axis thereof. I have discovered that this can be overcome 'by providing the cover glass for the signal with a suitable arrangement of retracting flutes and prisms.

It is therefore an object of this invention to i provide a newand improved signal.

It is a further object of this invention to provide a signal which will have a. much greater spread than any signal heretofore known.

It is also an object of the present invention to provide a signal which'refracts the light downwardly for a close-up indication in conjunction with a wide lateral distribution of light.

It is a particular feature=of this invention to provide a cover glass which will produce an improved light distribution.

With the above and other objects in view,

proved cover glass;' Fig. 2 is-a vertical section on the line 2-2 of Fig. 1;

Fig. 3 is a side elevation, partly in section, on theline 33 of Fig. 1;

Figs. t, 5 and 6 are diagrammatic views showing the light distribution produced by my new cover glass in combination with a suitable reflector, Fig. 4 being a vertical section on the line 44 of Figs. 5 and 6, Fig. 5 being a horizontal section on the line 5-5 of Figs. 4 and 6, and Fig. 6 being an inside elevational view showing the light distribution j rom the side refracting lenses. K

Referring to the accompanyin drawings, it will be seen that my improved signal consists of 'a reflector 8, a light source 9, and a cover glass 10, the light source 9 being shown as a point light source for simplicity of illustration and being placed at the common focal point of the reflector and the cover glass.

As best shown in Figs. 1-3, my improved cover glass 10 consists of a central convex body portion 11 provided with a continuous, rearwardlyextending conical flange 12. The front face 13 of portion 11 is preferably smooth, but its rear face 14 is provided with a series of vertical flutes 15, each of which is of substantially semi-cylindrical cross-section.

Each flute 15 is also providedwith a small flute 0 16, which increases in thickness from top to bottom, the flutes 16 on one row of main flutes 15 being staggeredwith respect to the flutes 16 in adjacent rows. r

The main flutes 15 are provided to spread the 5 light horizontally, as shown in Fig. 5, x e maximum rays from this portion of the signal being designated A and A. The small flutes 16 are designed to produce a downward deflection of a portion of the light for a close-up indication, as shown by the rays B.B' in Fig. 4, produced by the lower part of the cover glass, it being understood that similar rays (not shown) are produced by the upper part of the cover glass. The main body of the light rays from the reflector 8 is 75.

projected as a bundle of horizontally extending. rays. The portion of these rays transmitted by the upper half of the cover glass is indicated dia-- I grammatically in Fig. 4 by the'rays 0-0, anda corresponding bundle of rays (not shown) 0 would be transmitted by the lower half of the cover glass. a

With the flutes 15 alone it' would be difllcult to get aneflicient spread of even but I have found that by providing the inside of the flanged g5 portion 12 with a pair of side refracting lenses 18 it is possible to utilize a large angle of the direct light source rays by refracting them into two oppositely. directed vertically concentrated bundles, each of which is substantially unrefracted 90 in a horizontal direction," thus forming fanshaped beams of horizontally extending rays D-D' and E-E at substantially right angles to the rays C-C'. These rays are produced by light which would otherwise be lost but which I utilize by directing them into wider spreadangles of the horizontal beam to produce an extension of the spread to approximately 180, thus giving about 90 additional spread.

For some purposes. and as shown in Figs. 2-5, I alsoprefer to provide the exterior of the flanged portion 12 with a series of circular prisms 19 which extend all the way aroundthe cover glass and bend the light forwardly so that the. maximum spread with the particular mirror and cover glass shown is limited to 160.

Although I have herein indicated the reflecting meansBasamirror of the type shown and de-' scribed in my application Serial Number 38,514, V filed June 11, 1925, it should be understood that scope of the following claims.

the operation of my cover glass will be substantially thesame as indicated above regardless of the type of mirror used, provided the focal point of the mirror, which is where the light source is placed, is coincident with the focal pointof the cover glass. If this condition is satisfied the mirror can be of various types, such as parabola, a Mangin mirror,'an aplanatic mirror, or any other mirror producing approximately parallel light.

It will be understood that in practice the light source 9 is a commercial lamp, but I have herein merely shown it as a point light source to avoid confusion in the diagrammatic illustration of the light rays. The only difierence in the rays when produced by a suitable commercial light source andby a point light source is that with the former there is an overlapping of the light rays which would cause confusion in a diagrammatic showg. -It will therefore be apparent that I have produced a new and improved type of signal which gives a verywide lateral spread in addition to a close-up indication, and that my invention is susceptible of various modifications within the If desired my cover glass may be provided merely with the .main flutes, or merely with the main flutes and smaller flutes on the front portion, and in certain other cases it may be desirable to utilize the side" refracting lenses without the main and smaller flutes, or to substitute other refracting media for the side refracting lenses, but to obtain maximum efliciency, especially for highway crossing signals, I prefer to utilize all of the refracting means set forth above. v

I claim:

1. In an optical system a reflector for projecting a main beam of light and having its principal focus within the main beam, a fluted cover glass in the beam for spreading the latter in one plane,a conical flange on the cover glass and light condensing members on the flange having a common focus which coincides with the focus of the reflector, the condensing members being so disposed with relation to the flutes on the cover glass that the beam projected thereby willjoin the main beam and form a continuation thereof without perceivable interruption.

2. In an optical system, the combination of a light source, a retracting cover glass having a conical flange, said flange having at the sides thereof prismatic light-condensing elements extending longitudinally of said flange and having a focal relationship'with said light source. the several condensing elements decreasing in width toward the smaller end offsaid conical flange.

' i STATES LEE LEBBY.

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