US1795952A - Highway danger reflector - Google Patents

Description

c'. A. JAMES HIGHWAY DANGER REFLECTOR Filed Dec. 29. 1927 March '10, 1931.

' F/GJ lug mn Ihven/ar [/ere/ana A. James.

' Patented Mar. 10, 1931 UNITED STATES PATENT OFFICE CLEVELAND A. JAMES, OF- PHILADELPHIA, PENNSYLVANIA, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, TQ ROBERT P. SHICK, OF PHILADELPHIA, PENNSYL- VANIA HIGHWAY DANGER. asrmcroa Application filed December 29, 1927. Serial No. 248,231.

The object of my invention is to provide a reflector, preferably of pressed glass, which shall have capacity for returning a beam of light to its source-when said source is either directly in front of the plane of the reflector or when positioned to the right or left thereof, whereby the beam oflight would impinge upon the reflecting'surface at an angle thereto less than a right angle.

My invention has particular utility as a danger signal for highways, such as at railroad crossings, or at turns or dangerous positions in roadways traversed by automobiles, and wherein the beam of light from the headlights of approaching vehicles impinges upon the reflecting surfaces of the danger signal when properly placed in position with respect to the roadway or railroad crossing, the construction being such that the said beam of light is reflected back to the driver of-the automobile and thereby indicates necessity for caution. The reflected light is usually returned as a red, amber, green or other colored beam, in accordancewith the highway regulations under the State laws. The same advantages of a danger signal of this character for highways may be equally eflective when the reflectors are employed at street crossin s within city limits.

Furt ermore, my invention is adapted for use for advertising purposes wherein the sign having words made up of these reflectors may be illuminated by a light derived from a passing automobile. Where the signs are located at elevations, they may be illuminated by spot-lights suitably positioned more or less in the line of vision of. the ublic on the streets, whereby the light is re ected back to and beyond the spot-light and within the vision of the observer.

More particularly, my invention comprises an extended area, the surface of which is made up of a plurality of reflecting units arranged in parallel relation, "each unit embodying the principles or essential features of the reflector disclosed in Letters Patent No. 1,552,166 granted to me on September 1,

19 25, and, as defined therein, comprising two reflectorsat right angles to each other and with their reflecting faces facing one another,

one of the reflectors having a plane surface and the other being grooved, the grooves running at right angles to the plane reflector and each groove being composed of two plane surfaces placed at right angles to one another; and wherein further, each unit has its plane and grooved reflecting surfaces respectively in angularly juxtaposition with corresponding surfaces of adjacent units, and wherein also the planes of the plane reflecting surfaces fornr'a greater angle with the general plane of the reflector than is formed therewith by the planes of the grooved surfaces.

The invention further comprehends a plurality of parallel reflector units as above described, wherein the adjacent units are reversed with respect to each other, whereby the adjacent plane surfaces incline in opposite directions relatively to the general plane of the-reflector and form grooves at the back of an angularity less than a right angle, and the corresponding grooves of the a jacent units at-the back also incline in opposite directions to said general plane of thereflector and form general grooved portions having an angularity greater than a right ang e.

My invention also comprehends other features of construction which, together with those above enumerated, are morefully described hereinafter and pointed out'in the claims.

Referring to the drawings: Fig. 1 1s a plan view of a reflector embodying my imand positions of the coacting reflecting surfaces and the direction of ,a light ray reflected thereb v Each 0 the units has a flat front face 2 and embodies a plane reflecting surface 4 and a grooved reflecting surface-5,- the latter made up of a plurality of reflecting grooves 8 di-- as a colored beam of light, the glass mass 6 is given the desired color at the time of molding the glass, or, if desired, the outer surface 2 may be provided with a translucent or trans parent colored layer The reflecting surfaces 8, comprising each groove, are arranged along their length at right angles to each other as shown in Fig. 3, and said surfaces are arran ed at right angles to the plane reflecting sur ace 4 as indicated in Fig. 2, so that there are three reflecting surfaces each arranged at right angles to the other and constitutin a triple reflector structure which is repeate along the lengthof the unit, whereb the beam of light entering through the p ane surface 2 will impinge upon one of the reflector surfaces and, after being reflected successively from the remaining two surfaces of each triplereflector structure, is reflected back 'to the source. This operation will take place with every portion ofthe reflecting structure where the reflecting surfaces 8, 4, 8, occur in juxtaposition, and

which, together,'form, as it were, a trihedral,

' reflector but whose axis would be at an angle to the plane surface 2, as indicated by the dotted line 7-7 in Fig. 2. It is further pointed out that the reflecting surfaces 8 each are similar to a-quadrilatcral figure of a trapezoidal form, wherein two opposite sides are of different lengths and parallel, and one end at right angles to the parallel sides, as will be readily seen by an examination of Figs. 1 and 6. This shape for the reflecting surfaces 8 is important, because if it were not, for this feature, the beam of light would not be reflected from the entire surface of the plane reflector surface 4. For example, if the reflect ing surfaces 8 were limited to two sides of a square, then the reflection of the beam of light passing through those two sides would emerge from a square portion only of the surface 4 instead of its entire surface correspending to any pair of reflectin surfaces 8.

Considering the structure as s own in the drawing, and confining consideration for the moment to one of the parallel units, it may be said that a beam of light projected upon that unit will illuminate every portion of the unit and be returned to the source, and, therefore, would give the maximum efliciency possible. If the reflecting surfaces 8, 8, were made to corres 0nd to two sides of a square, then the reflection from the surface 4 would only approximate two-thirds of the efliciency of the structure, as shown, and this for the reason that under the assumption the capacity-for reflection from'the surface 4 would be reperpendicular to the general plane of the sur-' face 2 of the reflector, corresponding to the dotted line 9--9 of Fig. 1; and similarly, the adjacent plane surfaces 4, 4, of adjacent reflectors should lie in a plane perpendicular to the plane of the general surface 2 indicat/ed by dotted lines 101O of Fig. 1, and parallel to the plane 9--9. With these pro visions, the entire surface of the reflector will be illuminated and reflect back the beam of light to the source.

Considering now the feature wherein the adjacent units are reversed in respect to their plane and corrugated surfaces, the benefits from this may be explained as follows While the maximum efficiency results by a beam of light which projects at right angles to the surface 2 of the reflector and while the beam of light will be reflected back to the source when the angle of the surface 2 of the reflector is oblique to the line or direction of the-beam of light, the efliciency of this reflect-ion will decrease with the increasing of the angle of the incident rays with the said surface 2 of the reflector, and this is true whether the angle is in the direction of the arrow :0 or 3 (Fig. 2), as compared with the results when the beam is directed at right angles to the surface 2 as indicated by the arrow 2. If we turn the angle of the reflector (Fig. 2) sufliciently to bring the beam of light corresponding to the arrow :1; at right angles to the plane reflector surface 4?) and in alinement with the grooved reflector surfaces 8, it is manifest that those surfaces no longer act as reflectors, and consequently the triple reflector effect of that unit woulddisappear, and this same action would, of course, result with each of the alternate units. If, on the other hand, the reflector was turned in the. opposite direction, so that the beam of light corresponding to the arrow y would impinge at right angles to the surface 4a, then said surface would be put out of action as a reflector and the triple reflector effect lost, as in tor. Itwill, therefore, respond to beams of light coming from a right handed or left handed approach, For example, if the approach of the beam of light took place anywhere between the right and left angle indicated by the arrows s, .2, there would be full illumination by reflected light, and, moreover, if the beam of lightwas projected from a position between the arrows sand t, (either at the right or left side), the efliciency of the reflector would be diminished as the light beam changed from s to t proportionally to the extent that the light passed through the reflector surfaces 4a and 46 without being reflected to the surfaces 8. If the beam of light is then caused to be projected in the direction of the arrows w or y, and hence respectively at right angles to the surfaces 4a and 4?), said surfaces would cease to be reflectors and, therefore, the unit having" the surface 4a would cease to be a reflector for the beam corresponding to the arrow :1 and similarly, with respect'to the arrow :0, if the beam came from the extreme opposite direction. However, in practice, the normal angles in which the beam may project'u on the reflector with approximate full e oiency would be within the scope of the arrows s, s, and would gradually lose in efliciency on the alternate units as the angle of the beam shifted to a greater angle, namely, from s to t, but at all times the reflection for the angular approach of the beam would be the same, whether it approached from the right or from the left hand direction. For these reasons, the reflector embodies equal efliciency when the light comes from either the right i or the left direction.

These features are not possible in any other construction of pressed glass triple reflectorthat I am aware of, for in the case of re fleeting surfaces in the form of semi-cubes, which is eflicient when the beam of light is projected upon it at right angles to its general surface, the reflection of the light fades out entirely when the approach is from the right or from the left, accordin as to the installment of the reflector. As ar as I am aware, the present reflector is the only one which gives good positive reflection back to the source from an approach, both from the right side and the left side, and with a maxi mum efliciency when the approach is directly at right angles to the plane of the reflector.

By making the reflector of pressed glass and with a multiplicity of reflecting units, it is manifest that an extended area of reflecting surface can be provided with relatively small depth, and'furthermore, is more accurate in its construction in that it may be produced by being pressed in molds, of definite shape and size. Furthermore, it is easily kept clean, as the only surface that requires attention is the flat surface 2, since the reflecting surfaces of the parts 4 and 8 are the surfaces formed, in shaping the back and as this is not affected by mereaccumulation of dust, it is not materlal as to accumulations of anythin on that surface that does not scratch or a rade the surface.

As in pressed lass reflectors of the characterhereln described the prismatic ortions thereof are located at the back and ence at the side that would be in contact with the support, it is advisable to provide means of sustaining the reflector in such manner that the prismatic portions will not contact with the support. This is easily accomplished by providing a flanged rim about the side edges of'the glass and which has a depth sufficient to extend slightly beyond the prismatic portions of the ack, as will be readily understood by reference 'to Figs. 2 and 3, and in which 15 represents the said flan es. These flanges rest 11 on the boards or ot er supports for the re ectors and permitthem to be clamped in position without injury to the prismatic portions.

V My improved refle tor in its preferred form and as shown is formed of a glass plate having its front surface flat and its rearsurface formed with a prismatic construction comprising a plurality of parallel grooved portions 4, 4, each of the surfaces of which grooves are at an angle to each other of approximately and interposed transversely grooved portions 5, 5, extending obliquely in opposite directions at right angles from the faces of two adjacent parallel grooves and forming an angle to each other of approximately 100, and said transverse grooves each formed of oblique surfaces 8, 8, of trapezoidal shape and arranged in pairs at right angles to each other.

In Fig. 4 I have shown a slight modification of the structure shown in- Fig. 1, in that the units where they have the grooved portions 5 in abuttin relation, said units are relatively shifted longitudinally to the extent of a half groove. Even though this is done, there is no change or shifting of the relation between the grooved reflecting surface 5 and the plane reflecting surface 4, and consequently the said shifting, as shown in Fig. 5, or any other extent of shifting longitudinally of the unit, may be made without interfering with" the efliciency of the device. ,In Fig. 5, [have shown my improved reflector as made of sheet metal, as distinguished from being pressed out of solid glass,

but in this case there will be no color to the .ing a sheet metal reflector of the recessed type, and if employed with the glass, the

color of the; glass may control the color of the beam. Such a metal reflector would be the same as what is shown in Fig. 5, if. the glass 13 was removed. Moreover, if the glass 5 13 was crystal glass, it might be used with the metal backing 14 and with a colored sheet 12 for imparting color; or, if desired, the crystal glass may be removed,-leaving the reflector 14 and the colored glass screen 12 j m in the relation shown.

It will now be apparent that I have devised a novel and useful construction which embodies the features of advantage enumerated as desirable, nd while I have in the present 15 instance sho n and described the preferred embodiment thereof which has been found in practice to give satisfactory andreliable results, it is to be understood that I do not restrict myself to the details, as the same are susceptible of modification in various particulars without departing from the spirit or scope of the invention.

Having now descibed my invention, what 1 claim and desire to secure by Letters Patent 1S: r

1. A reflector forreturning aloe-am of light in the direction of the source, composed of a plurality of elongated reflecting units arranged in parallel relation, each unit comv posed of. two reflecting-surfaces placed at right angles to each other so .as to face each other, one of the reflecting surfaces being a plane surface and the other having its refleeting surface formed with grooves arranged at right angles to the plane surface and each groove composed of two plane reflecting surfaces of relatively small area placed at right angles to each other, and the juxtaposed units arranged in reverse rela- 40 tion, so that the plane surfaces of adjacent units are arranged at anangle to each other less than a right angle, and the grooved surfaces of adjacent units are arranged at an angle to each other greater than a right angle, and. whereby the reflecting area of'th'e reflector, as a whole, reflects back light rays from the source when said source is positioned either directly in front of the reflector or when positioned equally to the right and to the left of the said front position.

2. The invention according to claim 1, wherein further, colored means is provided for causing the reflected light from all of the reflecting surfaces to be colored before be- 5 ing returned to its source.

3. The invention according to claim 1, wherein the reflector is formed of a plate of pressed glass having'a plane surface at the front and the back surface pressed and no -shaped to provide the reflecting surfaces.

4. A reflector formed of a pressed glass -late havi-ng its. front face fiat and its rear ace formed with prismatic construction comprising a plurality of parallel grooved portions each of' whose surfaces are at an angle.

to each other less than a right angle, and interposed transversely grooved portions extending obliquely in op osite directions at right angles from faces 0 two adjacent parallel grooves and forming an angle to each other greater than a right angle, and said transverse grooves each formed of oblique surfaces arranged in pairs at'right angles to each other.

5. The invention accordin to claim 4, wherein further, the pressed g ass plate carries colorin means to impart a color to the reflected liglit.

6. A reflector formed of a pressed glass plate having its front face flat and its rear face formed with prismatic construction comprising a plurality of parallel grooved portions each of whose surfaces are at an angle to eachother of approximately and interposed transversely grooved portions extending obliquely in opposite directions at right angles from faces of two adjacent parallel grooves and forming an angle to each other of approximately 110, and saidtransverse grooves each formed of oblique surfaces of trapezoidal shape and arranged in pairs at right angles to each other.

In testimony of which invention, I hereunto set my hand.

CLEVELAND A. JAMES.

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