US3245075A - Traffic signal light shroud - Google Patents

Description

April 5, 1966 H. N. sTAA-rs 3,245,075

TRAFFIC SIGNAL LIGHT SHROUD Filed Feb. 24, 1964 FIEE United States Patent O 3,245,075 TRAFFIC SIGNAL LIGHT SHRGUD Henry N. Staats, 1344 Avenue, Deerfield, lil. Filed Feb. 24, 1%4, Ser. No. 346,866 1 Claim. (Cl. 340-382) This invention relates to a traffic signal light shroud and more particularly to a new means for confining a traic signal light to viewing :by only the drivers of vehicles moving in the direction for which the signal light is placed for control.

Traffic si-gnal lights at road intersections are generally aimed to the trailic they are to control. In some instances the complication of the terrain, the direction o-f the streets or roads or the number of streets or roads complicates the problem of so placing the lights that they may be viewed by the traflic that is intended to respond to the light and not viewed by the other traiiic. In the past various hoods, split tubes, and short and long tubular members have been placed in front of the lense of the traic light aimed at the traffic intended to view that light. These means have been sometimes quite long in an attempt to direct the light only to particular traiiic. Means utilized have been only partially successful due to the yfact that reflections ot of the interior of the tubes have been suiiiciently bright to permit the light to be viewed by cross traiiic and thus create a confusing and unsafe condition. The dull black paint of prior shrouds has served only to diminish the amount of the reflection that would be obtained over a glossy surface but has not been able to eliminate the reections causing the diiiiculties. Many bad accidents have occurred as a result of the confusion caused by a driver being able to see more than his own particular set of traflic lights which he should obey and by those drivers whose driving habits are such as to make them want to jump a light ahead of receiving the green signal, the starting time being determined by an observation of the cross traics caution signal.

The principal object of this invention is to provide a new and improved shroud for traic lights which effectively and thoroughly prevents cross traiiic from viewing a light which it is not intended to see.

Another object is to provide a new shroud which prevents light from a traffic signal to be reflected olf of surfaces of the shroud to the outside.

Another object is to provide a light shroud for a trafiic signal equipped with means for trapping all lig-ht from the signal impinging upon surfaces of the shroud so that none of the reiiecting light is visible from outside the shroud.

A further object is to provide new and improved baffles of unique form which are capable of trapping all signal light impinging upon the wall of a tubular member extending outwardly in front of the signal light.

Other objects, features .and advantages of the prevent invention will be apparent from the following description of the preferred embodiments thereof illustrated in the accompanying drawings, in which:

FIGUR-E 1 is a side elevational view of a typical threelight trahie signal with tubular shrouds thereon;

FIGURE 2f is a fragmentary View of one of the trahie signal lights of FIGURE l as it appears generally to a driver in a vehicle in cross traffic;

FIGURE 3 is a front elevational view partially in section taken substantially along line 2-2 in FIGURE 1 showing the balance of the traffic light in phantom;

FIGURE 4 is a top plan view of the tratlic light shown in FIGURE 1;

FIGURE 5 is a fragmentary horizontal sectional View through the tubular member of the light shroud taken 3,245,075 Patented Apr. 5, 1966 ICC substantially along line 5-5 in FIGUREI 1 but enlarged thereover yet smaller than actual size;

FIGURE 6 is an end section looking into the righthand end of the tube shown in FIGURE v5;

FIGURE 7 is a fragmentary view like FIGURFI 5 showing an alternate construction; and

FIGURE 8 is a cross sectional View through the bafiie means illustrated in FIGURE 7.

Trafc lights vary considerably in the number of lights and their placement upon supporting framework, posts, arms, cables and the like. It is not intended herein to disclose the various mounting of tratlic lights either in number or kind as it forms no part of the present invention. In FIGURE 1 a somewhat typical installation of a three-light system mounted upon a pipe standard 10 comprises three boxes 11, 12 and 13 stacked in the order speciiied. Within the boxes there is located a lamp behind an opening closed by a colored glass lense lending the usual green, amber or red color to the traffic signal. At the front of the box there is usually a door 14 mounted upon hinges 15 and secured in place by a thumb screw type of latch 16, whereby the door may be opened to gain ,access to the lamp within the box. A tubular shroud 17 may extend forwardly Ifrom a mounting ring 1S secured as by four mounting screws 19 to the front of the door. Some manufacturers mount a hood or shroud to the door in other fashions and by other means. A similar tubular shroud 20 may extend 'forwardly from the light housing 12 and a similar shroud 21 may extend forwardly from the light housing 11. It maybe noted in FIGURE 1 that the tubular shrouds are directed downwardly fro-m the horizontal, this being a typical installation Where the light is mounted in an elevated position above the roadway and the shrouds are aimed at the oncoming traic.

The tubular shrouds are intended to keep cross traic from viewing a light intended to control traiiic on the other streets at an intersection. Many trac light installations are made on the corners of the intersection, off but near the roadway. In such instances the appearance of a shroud such as 17 by the cross traic would be substantially that illustrated in FIGURE 2. It may be noted that the side wall 22 of the shroud 17 is visible in part adjacent the outer extremity Z3 of the tube to the driver of a car stopped at the intersection but in cross trafic so out of posit-ion to look down the length of the tube to the lense of the traiiic light. The problem, confusion and accidents have occurred because the side wall 22 of the tubular member has been lighted by the traffic signal light suiiiciently to be viewed 'by the cross traiiic driver.

yThe present invention effectively and absolutely prevents any light from the traiiic signal from impinging upon surfaces of the tubular member in a fashion that permits such reected light to be viewed from outside the tubular member. The basic means -by which such reflected light is prevented from being viewed is illustrated in FIGURES 5 and 6.

In the horizontal sectional view of FIGURE S a typical metal tubular member 17 is shown as extended outwardly from the lense 25 so as to be directed toward the oncoming traffic which the light is intended to control. A number of baffles is mounted on the interior of the tubular member adjacent its outer extremity 23. The operational characteristics of the baffles are such that light 'from the traffic signals may irnpinge upon one side of the baiiie facing the lense, but the opposite side of the ibaie facing the outside will remain always in shadow. When painted a dull black, the baie fades into the dull black appearance of the shroud itself and is not at all visibly present to the cross traic.

The baiiies may be the smallest in number if each is a part of a right circular cone, assuming the tubular member 17 to be a circular cylindrical member, the baille being a surface generated in a particular manner. Beginning with the baille 26 at the outer extremity of the tube, its generatrix Z7 should extend from the extremity 23 of the tube toward a point 28 in the plane of the lense but radially outside of the tube. The point 28a on the diametrically opposite side also lies on a circle about the lense and in the plane of the lense which the generatrix 27 shown in two positions on FIGURE 5 would move in from the cone of which the baille 26 is a part. The apex of .the cone would be at the point 29 between the lense and the outer extremity 23 of the tube and on the center line of the tube.

It may be observed that a light ray 30 from the outer extremity of the lense directed toward the baille 26 may light the inside surface whereupon such light would be reflected to the wall of the tubular member 17 and trapped. The outer surface of the baille 26 would remain in shadow.

Each of the succeeding baflles 31, 32, 33, 34 and 35 is a part of a cone in which the generatrix extends from the base of the baille against the inside wall of the tubular member t the locus of points in the plane of the lense illustrated by the points 28 and 28a. The base of each succeeding baille may conveniently be placed substantially radially opposite the inner extent of the baille. It has been shown that under this circumstance generally la fair number of bailles may be used so that only the side facing the lense will be lighted and the opposite side shall remain in shadow under all circumstances.

A number of baffles is used to line the wall of the shroud sufficiently from the extremity Z3 toward the lense as found necessary in the particular installation to maintain the outer facing surface on the bailles in shadow. In some installations a tube as long as three feet has been used in front of a traillc light. With the present invention such tubes should be made much shorter and the reilections will be completely eliminated, thus eliminating the need for the long tube.

While the installation of FIGURES and 6 basically illustrates the mode of operation of the present bailles, manufacturing expediencies permit the baille structure to be made in convenient forms. In FIGURE 7 a typical tubular member 37 is shown with a baille section 38 of a vinyl material formed with ilve individual baille ns or fnlike members extending inwardly from an integral or a common base 39. The fins 40 should be very thin and if sufficiently close together, may be extending inwardly from the wall of the tubular member but a short distance. The angle a between the fins and the wall should 4be the same and no smaller than the angle b between the baille 35 and the wall of the tube 17 shown in FIGURE 5. Preferably, the angle of all the fins will be made the same for convenience in manufacture. A typical structure is illustrated in the cross section of FIGURE 8 where the entire member is extruded in a vinyl material of dull black color, the ilns being integral with the base 39. A suitable length of the extrusion is cut on a bias and then placed inside the tubular member 37. When the joint in the baille section is placed at the top of the tube or at the bottom of the tube, it is generally in a location where it can not be viewed by traillc and thus is inconsequential.

A typical iln such as the fin 40 may be individually made or made in a gang of fins as illustrated in FIG- URES 7 and 8. Many tubular like sections are about eight inches in diameter and it has been found that a iin about one-fourth inch in length with about one-fourth inch distance between the iins or bafiles will sufficiently trap light on the interior of the tube while not diminishing materially the size of the traillc signal to be viewed. In certain instances a single fin and base may be spirally placed in the tube if desired with the lap in the spiral being at the top or bottom of the tube.

The foregoing detailed description has been given for clearness of understanding only and no unnecessary limitations should be understood therefrom as some modifications will be obvious to those skilled in the art.

I claim:

A traillc signal 4light shroud for preventing reflection of light to lateral traillc vehicle drivers, comprising: a tubular member extending outwardly from the signal light toward oncoming trailic moving toward the light in the direction of the extent of the tubular member, a plurality of frusto-conical baille members axially spaced in close proximity of each other within said tubular member and extending inward from substantially the outer end of said tubular member, the axes of said frustoconical members being substantially the axis of said tubular member, the projected apexes of said frusto-conical members ing inward toward the signal light source, each baille having a ilrst surface directed toward the light source and an opposite surface facing outward said tubular member being in shadow relative to the light source.

References Cited by the Examiner UNITED STATES PATENTS 1,266,524 5/1918 one 24o-46.41 1,864,418 6/1952 Ehlers 240-46.o1 2,190,526 2/1'940 wens 340-582 2,540,389 2/1951 Powier 340-84 FOREIGN PATENTS 464,952 9/1928 Germany. 62,573 3/1926 sweden.

NEIL C. READ, Primary Examiner.

W. C. GLEICHMAN, I. I. LEVIN, Assistant Examiners.

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