US1666041A - Traffic signal - Google Patents

Description

April 10, 1928.

F. BUCHANAN TRAFFIC SIGNAL Filed Sept. 24. 1924 2 Sheets-Sheet 1 IN VEN TOR.

A T TORN E Y.

.April 10, 1928.

F. BUCHANAN 2 Sheets-Sheet 2 Patented Apr. 10, 1928.

UNITED STATES FRANK BUCHANIA N, OF SYRACUSE, NEW YORK, ASSIGNOR TO CROUSE-HINDS COMPANY,

PATENT OFFICE.

OF SYRACUSE, NEW YORK, A CORPORATION OF NEW YORK.

TRAFFIC SIGNAL.

Application filed September 24, 1924. Serial No. 739,744.

This invention relates to signals and particularly to traflic signals, such as are used and are coming into more extensive use to signal and direct traffic at the street intersections of cities, and has for its object a traffic signal utilizing colored lights, and means by which the si nal in which the light is on has wide visi ility and is not rendered invis ible or ineffective or less effective by dayli ht or strong sunlight conditions, and in w iich the signals, which are intended to be off or inactive, will not give the effect of being on or active by daylight or bright sunlight conditions, and also by which the sunlight cannot enter the signal and give the effect of a so-called phantom signal.

The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed.

In describing this invention, reference is bad to the accompanying drawings in which like characters designate corresponding parts in all the views.

Figure'l is a front elevation of a'traflic signal embod ing my invention. Figure 2 is an enlarge vertical sectional view taken on line 2-2,- Figure 1.

Figure 3 is a fragmentary face view of one of the lens.

Figure 4 is an enlarged fragmentary view of the lens.

Figures 5 and 6 are enlarged sectional views taken on line 55, 66, Fig. 4.

Figure 7 is a view similar to Fig. 2 of another form of my signal.

In traflic signals embodying electric lights and colored lenses as for instance, signals which embody a red light, which when on signals the traflic to stop, and a green light which signals go or an amber light to signal the trafiic that the signal is to be changed from red to green or green to red, it is difiicult, if not impossible under. certain day light conditions for the observer to determine which signal is operated. For instance, in bright sunlight there is oftentimes very little contrast between the signals in which the lamps are on and those in which the lamps are off for the reason that some of the sunlight ra s reflect off from the colored lenses or pass through the lenses and are re flected by the reflector back through the colored lenses, so that, the observer cannot determine whether a green or a red signal is intended to be displayed, and hence, mistakes the signal.

Also under certain conditions, as late in the afternoon, when the sun is well down toward the horizon, the sunlight shines in through one signal and out through :1 diametrically opposite signal giving a phantom signal, this being particularly so when one lamp is used to give light to two 0pposite signals, that is, when one lamp supplies the light to two red signals or two green signals or one green and one red which are opposite each other.

The object of the present invention is a signal in which the contrast between a signal in which the lamp is on is so great uuder most severe daylight conditions that the observer cannot mistake the signal and in which it is impossible or diflicult for the sunlight to pass through the lenses.

This traffic signal comprises a. casing or housing of any suitable construction. a light source or lamp means for projecting the light, including a lens formed to widely diffuse the light rays to prevent direct rays from passing through the lens from the outside thereof, and preferably also including a reflector.

The casing or housing may be of any suitable form, size and construction, it here bein illustrated as including a box 1. The lig t source is usually an incandescent electric lamp 2 located in the housing, the lamp being controlled by a suitable switch. The lamp 2 is located in juxtaposition to a concave or parabolic reflector 3 in the housing and to a lens 4.

The lens 4 is supported by the housing and is provided with light diffusing means or screen means for preventing direct rays of sunlight from passing through the lens, and also preventing rays of light from the lamp or from the inside of the housing from passing straight through the lenses, but on the contrary, causing them to be refracted laterally in all directions at wide angles. Usually, the lens is provided with a refracting or screening surface on one side thereof preferably its inner side, such screening or refracting surface being reticulated in form resembling a fine mesh screen, and comprising ribs 6, 7,. arranged at an angle to each other, which form depressions 8, the ribs 1 being arranged close together, so that, the

depressions are minute. Such ribs are preferably rounding, as shown in Figs. 4 and 5, the depressions being rounding as shown in said figures.

Preferably the color is given to the light by the lens which is red, green or amber or any other desired color.

Owing to the screen surfaces on the lenses, greater visibility is given to the signal in which the lamp 2 is illuminated and great contrast given between a signal that is illuminated and those that are not illuminated, so that, the observer cannot become confused as to which signal is illuminated, as when an ordinary lens or an ordinary colored semaphore lens is used. Furthermore the signals have great visibility even in strong sunlight, and a great contrast compared with other signal lenses reflecting the sunlight, or in which the sunlight can pass through the lenses and reflect back through it and give a phantom signal.

Furthermore, in signals in which a lamp 2 is arranged between two lenses 4 facing in opposite directions, the sunlight cannot ass through one lens and out through the ot er, and give a phantom signal. In case a col ored lamp or a colored glass is used in connection with a white or clear glass lens provided with my screen means, is used, the reflection of sunlight from the lenses that are not illuminated by lamp is a flat white color and hence, there is an even greater contrast between the signals. In Fig. 7 is shown a plain colored glass 9 between the White diffusing lens and the lamp.

Visors 10 are usually employed to shade the lenses from sunlight, and hence, increase the visibility and contrast. Such a visor 10 is here shown as carried by a ring 11, having circumferentially extending open slots 12 for receiving screws 13. The rings also serve to hold the lenses in position.

As is well known to those skilled in the art, signaling in the daytime by means of electric lights and lenses has not been satisfactory, on account of the low visibility of the signals in sunlight and of the lack of contrast between the signals, that are illuininated and those which arenot, for the reason that the sunlight reflects strongly from the signals that are not illuminated by the lamp, and gives the effect to the observer that the signal is on. My signal is of marked advantage for the reason that it has great and wide visibility and great contrast in the brightest sunlight, owing to the wide diffusing feature or screen which spreads a wide even flare of light and prevents sun light from being reflected from the reflector and also widely spreads sunlight that does strike and is reflected from the lenses so that the visibility of a signal illuminated by sunlight is low, and nil compared with the signal lens that is illuminated by the lamp and the reflector.

What I claim is:

1. In a tratlic signal, the combination of a casing, a light source in the casing, a signal lens in the casing in line with the light source and in front of the same, said lens being formed with a reticulated surface substantially coextensive therewith and consisting of ribs crossing each other at an angle and forming rounding depressions between the intersections,- said surface resembling a fine mesh screen.

2. In a traffic signal, the combination of a. casing, a light source in the casing, a signal lens in the casing in line with the light source and in front of the same, said lens being formed with a transparent reticulated surface substantially coextensive and consisting of ribs crossing each other at an angle and forming rounding depressions between the intersections, said surface resembling a fine mesh screen and a reflector in the rear of the light source.

3. In a trafiic signal, the combination of a casing, a light source in the casing, a signal lens in the casing in line with the light source and in front of the same and a reflector in the rear of the light source, said lens being formed with a transparent reticulated surface consisting of ribs crossing each other at an angle and forming rounding de pressions between the intersections, said surface resembling a fine mesh screen and a visor for the lens.

In testimony whereof, I have hereunto signed my name, at Syracuse, in the county of Onondaga, and State of New York, this 15th day of September, 1924.

FRANK BUCHANAN.

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