360{20 {0 Reflex reflector

[57] ABSTRACT

A reflex reflector which when vertically oriented spatially is adapted to continuously retro-reflect incident light rays horizontally striking such anywhere within an included angle of about 360°. Such reflector uses four reflective surfaces, arranged into two pairs of two surfaces each, the surfaces of each pair being in opposed, parallel relationship to each other, the pairs being oriented at 90° relative to each other. Each surface has reflex reflector facets adapted to retro-reflect over an angle of ± 45°.

Claims, 17 Drawing Figures

<img file="US3905680A_D0001.tif" />

PATENTED SEP 161975

3,905,680

S“KI 1 OF 2

<img file="US3905680A_D0002.tif" />

P/OTQW 1 61975

3,905*680

<img file="US3905680A_D0003.tif" />

<img file="US3905680A_D0004.tif" />

4.5ΰ $ /0°

<td> /50</td><td> /.75</td><td> 2.00</td><td colspan="2"> 2.25</td><td> '7______ν__</td><td> 2.25 ----y---</td><td> 2.00 --</td><td> /.75 —X—</td><td> /50 --X-</td>

<td> - 50°</td><td> X 4&lt;ο°</td><td> —y- 3ο^α</td><td> —λ-- 20^β</td><td> —X /</td><td> &lt; Λ</td><td> 20°</td><td> 30°</td><td> 40*</td><td> 50°</td>

4,50 ψ /Ο

3,905,680

360° REFLEX REFLECTOR

BACKGROUND OF THE INVENTION

FIG. 6 is an isometric view of another embodiment of a reflex reflector of this invention;

FIG. 7 is an isometric view of another embodiment

In many applications for reflex reflectors, there is a need for horizontal 360° viewability such as, for example, on bicycles, on construction sites, on airport runways, on entrances to side lanes, and the like. Because of their inherent retro-reflective properties, it is necessary to employ a plurality of prior art standard reflex reflectors of the molded plastic type with flat faces in order to achieve full 360° viewability since individual such reflectors with flat faces are characteristically viewable over angles of only about ± 30° horizontally measured on either side of the face thereof. There is thus a strong and long felt need in the art for a simple, economical, reflex reflector construction employing molded plastic (e.g. acrylic resin, polycarbonate, or the like) which can provide 360° viewability horizontally.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to reflex reflector bodies adapted to retro-reflect incident light anywhere within an included angle of about 360°, measured in one plane. Such a body characteristically has four retro-reflective, generally planar surface portions. These portions are arranged into two pairs of two portions each. Each portion of each pair is generally in opposed, parallel relationship to the other thereof. One such pair is normally disposed relative to the other thereof. Support means hold each pair in fixed, substantially nonoverlapping adjacent relationship to the other thereof. The interrelationship between said portions is such that, when they are each vertically oriented spatially, incident light rays which strike said body anywhere within an included angle of about 360° in a horizontal plane extending through said body are adapted to be retro-reflected.

It is an object of this invention to provide a reflex reflector body horizontally viewable anywhere within an angle of 360° using only four flattened reflective faces.

It is another object to provide such a reflector body which uses both wide angle and standard reflex reflective molded facets in each such face.

A further object is to provide a 360° reflex reflector using only one or two reflective bodies and having only a few retro-reflective surfaces therein.

A still further object is to provide an optimized construction for a 360° reflex reflector, horizontally measured.

Other and further aims, objects, purposes, advan tages, utilities, and features will be apparent to those skilled in the art from a reading of the present specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is an isometric view of one embodiment of a reflex reflector of the present invention;

FIG. 2 is a transverse sectional view taken along the line II—II of FIG. 1;

FIG. 3 is a plan view of the embodiment of FIG. 1 illustrating how 360° reflex reflection is achieved therewith;

FIG. 4 is an isometric view of another embodiment of a reflex reflector of this invention;

FIG. 5 is a plan view of the embodiment of FIG. 4;

of a reflex reflector of the present invention;

FIG. 8 is an isometric view of another embodiment of a reflex reflector of the present invention;

FIG. 9 is an isometric view of another embodiment of a reflex reflector of the present invention;

FIG. 10 is an isometric view of another embodiment ¹⁰ of a reflex reflector of the present invention;

FIG. 11 is an enlarged isometric view of one embodiment of a pin;

FIG. 12 is a top plan view of the hexagonal pattern produced by a plurality of pins in a retro-reflective re¹⁵ flector;

FIG. 13 is a side elevational view of one cube comer in a retro-reflective reflector body;

FIG. 14 is a plot of the characteristic retro-reflected light intensity produced by a plurality of facets of the type shown in FIG. 13;

FIG. 15 is a series of plots illustrating the manner in which the field of reflected light changes as the pin centers are angled from a vertical position to a position in25 clined to the vertical;

FIG. 16 shows illustrative plots for a reflector of the type having both standard reflector facets and wide angle reflector facets; and

FIG. 17 is a plot illustrating the relationship between 30 angle of reflected light and intensity of reflected light at such angle both horizontally and vertically for a combination of wide angle and standard reflectors in a single reflector body.

DETAILED DESCRIPTION 35

Turning to the drawings there is seen in FIGS. 1 and 2 one embodiment of a reflex reflector body of the present invention herein designated in its entirety by the numeral 15. Body 15 is adapted to retro-reflect in40 cident light over an included angle of at least 360° measured in one horizontally extending plane 16. The body 15 has four retro-reflective generally planar surface portions designated, respectively, as 18, 19, 20 and 21. Two of these portions, portions 18 and 21, are gener45 ally in opposed, parallel relationship one with the other, and the remaining portions, portions 19 and 20, are likewise in generally opposed, parallel relationship to each other. Portions 18 and 21 extend normally in relation to portions 19 and 20. Preferably, and as ⁵⁰ shown, portions 18, 19, 20 and 21 have substantially identical surface reflective characteristics and each preferably has a similar perimetric shape.

Each of the portions 18, 19, 20 and 21 has incorporated thereinto at least three different groups of retroreflective, prismatic facets. The facets in each group are identical to one another. In one group, the facets are adapted to retro-reflect incident light striking such group at an angle ranging from about 0° up to about ± 30° measured normally thereto in one direction within one plane (such as a plane 16, 26 or 27 in FIG. 1, for example). The other two such groups are adapted to retro-reflect incident light striking such at an angle ranging from an angle which is not greater than the maximum retro-reflectance angle of such one group up to an angle which is at least about ± 45° measured from a normal thereto in such plane, one of such other groups being retro-reflective on one side of such nor3,905,680 mal, the other of such groups being retro-reflective on the other side of such normal.

Thus, in the embodiment 15, using portion 21 as representative each of two different types of facets are arranged into at least two groups integrally formed in each of the surface portions 18, 19, 20 and 21. In each of the portions 18, 19, 20 and 21, any convenient arrangement or pattern of such groups may be employed. Thus, portion 21 is divided into three such groups of facets, one group being designated 23, a second group being designated 24, and a third group being designated 25. The group 23 facets are adapted to retroreflect incident light striking same at angles ranging from about 0° up to about ± 30° (measured in plane 27). The group 24 facets are adapted to retro-reflect light striking same at angles ranging from an angle not greater than about 30° up to an angle which is about 45° to the left of perpendicular or normal line 28 in plane 27 with respect to incident light rays striking surface portion 23 in plane 27. The group 25 facets are adapted to retro-reflect light striking same at angles ranging from an angle not greater than about 30° up to an angle which is about 45° to the right of perpendicular 28 in plane 27. Such portions 19, 20 and 21 are similarly divided into groups.

In the embodiment 15, each of the surface portions 18, 19, 20 and 21 has a generally square configuration, but any convenient perimetric configuration may be employed for purposes of this invention.

The interrelationship between such groups and such portions 18, 19, 20 and 21 is such that, when such portions 18,19, 20 and 21 are each vertically oriented spatially, incident light rays horizontally striking such within an included angle of about 360° extending horizontally are retro-reflected. In order to enhance retroreflectance viewability characteristics of a body 15, it is preferred to have the respective portions 16, 17, 18 and 19 be further adapted to retro-reflect incident light striking same at angles ranging from about 0° up to about ± 20° (and more preferably ± 30°, and still more preferably ± 45°) measured normally thereto above and below such one plane therethrough, such as plane 27 through representative portion 21. Thus, when the body 15 is oriented so as to have its portions 18, 19, 20 and 21 vertically spatially oriented, this direction is vertical with respect to the other direction which is horizontal. Such characteristics are achieved by selection of facet groups and by arrangement thereof, as those skilled in the art will appreciate.

The body 15 is formed of two subassemblies 30 and 31, of which subassembly 31 is representative (see FIG. 2). Each subassembly is formed of two pieces of molded transparent plastic, such as an acrylic resin, a polycarbonate resin, or the like, one piece being designated 32, the other 33. Each piece 32 and 33 has an outer flattened face 35 and 36, respectively and an inner face 37 and 38, respectively. Each inner face 37 and 38 has molded thereinto the retro-reflective facets hereinabove discussed (not drawn to scale in faces 37 and 38 in FIG. 2). Around the perimeter of each inner face 37 and 38 is formed an inwardjy turning shoulder 39 and 40, respectively, which continuously extends about side and end edges of each piece 32 and 33. The outside edge of each shoulder 39 and 40 is adapted to make mating opposed engagement with the other thereof to form subassembly 31, the shoulders 39 and 40 being conveniently sealingly bonded to each other by means of an adhesive (not shown), or the like. Each subassembly 30 and 31 is equipped with an ear 41 molded one half into each piece forming same (such as pieces 32 and 33 of subassembly 31). Ears 41 aid in mounting a body 15. Any convenient or conventional means for mounting may be employed for mounting a body 15, as those skilled in the art will appreciate. Subassembly 30 is conveniently mounted to subassembly 31 by a pin 42 which extends one half into each of a channel formed in respective subassemblies 30 and 31 as shown in FIG. 1. Any convenient means may be used to secure such subassemblies 30 and 31 together.

Body 15 (see FIG. 3) is adapted to have 360° retroreflective characteristics because each surface portion 18, 19, 20 and 21 thereof is adapted to retro-reflect incident light rays striking same over ± 45° as indicated above in reference to portion 21 and groups 23, 24 and 25 thereof. Thus, portion 18 retro-reflects through a 90° angle 44, portion 19 retro-reflects through a 90° angle 45, portion 20 retro-reflects through a 90° angle 46, and portion 21 retro-reflects through a 90° angle 47, so 360° retro-reflection of body 15 is achieved. Preferably, each portion 18, 19, 20 and 21 is adapted to retro-reflect through an angle greater than 90° so that an overlap between adjacent retro-reflected light areas from each portion 18, 19, 20 and 21 can occur to some extent so as to avoid any possibility of low retro-reflected light levels in overlap regions which might make the body 15 harder to discern by a viewer located at a comer area from body 15. Those skilled in the art will appreciate that operability of the present invention does not depend upon reflectivity from any one reflective surface in any given hypothetical plane, such as 26, 21 or 16, or on either side of any given normal in such plane. Body 15 is suitable for use on construction sites, airport runways, vehicles, and the like.

In FIGS. 4 and 5 is illustrated an alternative embodiment of a reflector of this invention which is designated in its entirety by the numeral 48. Here a pair of triangles 49 and 50 are integrally interconnected together at their adjoining or common apexes 51. Each outside, vertically spaced edge 52 and 53 of respective triangles 49 and 50 is equipped with an ear 54 and 55 for mounting purposes. Conveniently, each triangle 49 and 50 may be formed similarly to subassembly 31 of body 15 and then the two triangles 49 and 50 joined together at apexes 51 by an adhesive or the like (not shown). A pin (not shown) such as in body 15 may be employed to secure the triangles 49 and 50 together analogous to body 15. Faces 56, 57, 58 and 59 are each similar to each other. Each flattened outside face 56 and 57 of triangle 49, and each such face 58 and 59 of triangle 50 has three groups of facets therein. For example, face 56 has groups 60, 61 and 62, and face 58 has groups 63, 64 and 65 molded thereinto. Groups 60 and 61 and groups 63 and 64 are each analogous in properties to groups 24 and 25 of portion 21 of body 15, groups 62 and 65 are each analogous in properties to group 23 of portion 21 of body 15.

In FIG. 6 is shown another embodiment designated in its entirety by the numeral 67. Body 67 is adapted for use as a sign post or directive arrow combination. Construction of body 67 can be similar to that used for body 15.

In FIG. 7 is shown another embodiment designated in its entirety by the numeral 68. Body 68, like body 48,

3,905,680 is suitable for use on a bicycle or the like. Construction can be similar to that used for body 15.

In FIG. 8 is shown an embodiment designated in its entirety by the numeral 69 which is similar to body 68 except that here a rod 70 is extended through the members 71 and 72 to secure such together in the indicated normal desired relationship. Rod 70 at its bottom end is fitted, as by crimping, threading, or the like, with a yoke 73 adapted for mounting body 69 to a frame member (not shown), such as a bicycle basket, handlebar, fender, axle shaft, or the like. The upper end of rod 70 is threaded and fitted with washer 74 and nut 75 for clamping the entire body 69 together.

In FIG. 9 is shown an embodiment which is designated in its entirety by the numeral 77. Each of the reflectorized subassemblies 78 and 79 of body 77 can be constructed analogously to subassembly 31 of body 15. The subassemblies are adapted to be mounted in vertically spaced relationship to each other, as illustrated, by means of a core bar 80 which extends internally through diagonal corner portions of respective diamond shaped subassemblies 78 and 79, subassembly 78 being fitted with a socket internally (not shown) in its upper comer 81. In manufacture, it is convenient to seal the halves of each subassembly 78 and 79 around bar 80.

In FIG. 10 is shown an embodiment which is designated in its entirety by the numeral 83. Body 83 is similar to body 77 except that in body 83 subassembly 84 is not only vertically spaced from subassembly 85 but is additionally horizontally translated in relation thereto, (although the lower left hand comer of subassembly 84 is spatially positioned immediately above the right hand comer of subassembly 85, as shown in FIG. 10). Body 83 is useful with an obstruction such as wall member 86 that interfere with the normal reflective function of subassembly such as 84. Body 77 has a similar utility.

The interrelationship between a group of facets in a retro-reflective reflector which is adapted to retroreflect at an angle of ± 30° in one direction compared to a group of facets in such reflector adapted to retroreflect at a side angle of up to about ± 45° is illustrative by FIGS. 11 through 19. In th manufacture of retroreflective reflectors of the type used in the present invention a plurality of so-called pins 150 may be employed. Each pin, as shown here, is hexagonally shaped. The transverse distance B between flat sides is variable, but is typically of the order of about 0.094 inches while distance A between opposing sides is similarly variable, but is typically about 0.108 inches. Three intersecting facets 151, 152 and 153 are formed at the forward end of each pin 150. Each facet 151,152 and 153 traverses two sides of the hexagonal pin and has an apex coinciding with the axis 154 of each pin 150. Each facet has an angle relative to the axis of about 35 /4°.

The pins are arranged into a pattern, such as shown in FIG. 12, and an electroform mold, or the like, is made using such pin pattern, the electroform being concurrently made by electroplating nickel or the like onto and over a plurality of aligned pin 151 heads. In such process the high points are reversed in mirror image fashion in the product mold (over the former low points in the pins) and vice versa, all as those skilled in the art will appreciate. From the product mold, a reflector element is molded. A section of the resulting reflector is shown in FIG. 13. When a reflector body hav ing a plurality of individual facets, such as those shown in FIG. 13, is caused to retro-reflect incident light, a characteristic pattern of reflected light results, in solid line form shown by an isocandle per foot candle curve in polar coordinates. When the facets of FIG. 12 are rotated through 180°, a similar characteristic pattern as shown by the dotted line in FIG. 14 is produced. However, when one tilts the axis 154 of each of a plurality of pins 151 arranged in a pattern such as shown in FIG. 12 from the vertical position shown in FIGS. 11-13, through increasing angles of common inclination, there is produced a changing family of characteristic patterns of reflected light, such as shown in FIG. 15, each succeeding plot 156,157, and 158 representing an isocandle per foot candle curve in polar coordinates, each curve representing a greater inclination angle for a group of pins, which are electro formed into a mold, and then the mold used to make a reflector body. The plots of FIGS. 14 and 15 are not for any specific reflectors, but only are given herein to illustrate the principles involved, which are known already to those skilled in the art.

When one tilts the axes 154 of such a plurality of such pins 151 in the opposite direction, then is produced a changing family of characteristic curves like those in FIG. 15, but reversed.

When one combines into a single reflector body both the type of composite reflex reflectance shown in FIG. 14 with the type shown in FIG. 15, and, in addition, uses two standard sections such as shown in FIG. 12 but with each section oriented 180° with respect to the other, there is produced in a single reflector body both such types of reflect reflectance, that shown in FIG. 14 sometimes being known as a “standard” reflector having a characteristic reflectance value generally given as ± 30°, that shown in FIG. 15 sometimes being known as a “wide angle” reflector having a characteristic reflectance value which can range very widely from about 10° to 88°, though values between about 25° and 70° are particularly and preferably useful. Such a combination reflector body displays a plot of retroreflectance angle versus reflected light intensity as shown in FIG. 16, lines 159, 160, and 161. Line 160 is produced by the so-called standard retro-reflector facets, line 159 is produced by the so-called wide angle retro-reflective facets sensitive to light on the right side of the ordinate 162, and line 161 is produced by the socalled wide angle retro-reflective facets sensitive to light on the left side of the ordinate 162.

If, for example, the number of standard facets is increased, the amount of reflected light increases (see dotted line 163). If, for example, both the number of wide angle facets and their respective angles of inclination are increased for both right and left hand members, the dotted lines 164 and 165 result. United States government federal standards for a bicycle reflector comprising such a combination of left and right wide angle reflector groups in combination with a centrally viewable standard reflector are shown in the illustrative plot of FIG. 17. By combining different pin groupings at different respective facet axis angles one can produce an unlimited gradation of retro-reflectance characteristics in a given retro-reflector, so that any given reflector can be produced by one skilled in the art within the limitations of pins, materials of construction, design standards, and the like, using known technology.

3,905,680

Other and further embodiments and variations of the present invention will become apparent to those skilled in the art from a reading of the present specification taken together with the drawings and no undue limitations are to be inferred or implied from the present disclosure.