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Publication numberUS3597606 A
Publication typeGrant
Publication dateAug 3, 1971
Filing dateJan 3, 1969
Priority dateJan 3, 1969
Also published asCA920562A, CA920562A1
Publication numberUS 3597606 A, US 3597606A, US-A-3597606, US3597606 A, US3597606A
InventorsKarl W Abendroth
Original AssigneeGen Signal Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Warning-light housing
US 3597606 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

United States Patent Karl W. Abendroth Rochester, N.Y.

Dec. 3, 1969 Aug. 3, 1971 General Signal Corporation [72] Inventor [21 App]. No. [22] Filed [45] Patented [73] .Assignee [54] WARNING-LIGHT HOUSING 10 Claims, 6 Drawing Fl [52] 0.8. (I 240/41.3, 240/1 1.2, 240122, 240/41.36, 240/47, 2401103 [51] Int. Cl. F21v 13/04 [50] Field else-rel 240/41.3, 10.66, 11.2, 22, 23, 27, 28, 41.36, 41.5, 41.55,103

[56] References Cited UNITED STATES PATENTS 1,915,842 6/1933 \Vinkler 240/103 2,010,834 8/1935 Wottring 240/41.3 X

2,063,781 1/1937 Wendel 2,211,258 8/1940 Delfel...... 240/103 X 2,245,755 6/1941 Carpenter 240/8.4 X 2,387,038 10/1945 Owens 240/103 X 3,049,614 8/1962 Eikenberry 240/41.3 3,076,891 2/1963 Moore 240/10.66 3,119,567 1/1964 Schwartz.... 240/47 3,204,093 8/1965 Heenan 240/41.3 3,286,039 11/1966 Smith 240/1 1.2

Primary Examiner-Samuel 8. Matthews Assistant ExaminerRichard M. Sheer Attorney- Harold S. Wynn ABSTRACT: A waming-light housing of unitized construction having an integral reflector and lens. A receptacle is mounted to the housing and the receptacle, lens, and reflector are each in a fixed predetermined position relative to the other. The reflector surface has distributed random irregularities for uniform dispersion of light.




WARNING-LIGHT HOUSING BACKGROUND OF THE INVENTION This invention relates to light signals and in particular to a warning-light-signal housing of unitized construction.

There are a great number of light-signal housings in the prior art, however, they are hampered by various problems in maintenance, critical focusing and resistance to environmental conditions. A typical apparatus has a great many individual parts, and in addition, lamps of this type often must be powered in remote areas, and as a consequence, batteries must be supplied. It is therefore desirable to get as much light projected over the proposed field of view with as little power drain as possible. In addition, warning-light housings of the prior art must be equipped with apparatus for critically adjusting the position of the light source so that it is within the focus of the reflector. This requires expensive and complex apparatus and a time-consuming focusing procedure.

Another basic problem of prior art warning-light housings is the effect of environment of the device over the years. These devices are susceptible to corrosion, and must be periodically painted, further the lends may be damaged by objects cast at it from any number of sources. As a result, field repairs are necessitated which are costly and time consuming.

This invention has for its purpose the solution of the above problems by installation of a new and economical structure.

It is therefore an object of this invention to provide an economical and simply constructed warning-light housing.

It is another object of this invention to provide an optical system of greater efiiciency.

It is yet another object of the invention to provide a housing which reduces damaging effects of environment.

SUMMARY OF THE INVENTION In accordance with the present invention there is provided a warning-light housing of unitized construction. The housing consists of an arcuate reflector integrally molded into a base member having an access port. A lens member and receptacle are also mounted to the base member. The lens member, receptacle and integral reflector are each aligned in a predetermined position relative to the other.

In accordance with another aspect, the invention provides a reflector having substantially uniformly distributed random irregularities over its surface which slightly disperses light. The reflector is generally of an arcuate concave shape.

In accordance with yet another aspect of the invention a circular background is provided having the shape of substantially uniformly concentrically spaced waves along a radially transverse direction.

For a better understanding of the present invention, together with other and further objects thereof, reference is had to the following description, taken in connection with the accompanying drawings.

. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional side elevation of the preferred embodiment of the invention.

FIG. is a sectional elevation of a prior art device.

FIG. 3 is a front elevation of the preferred embodiment of FIG. 1 with a sectional segment removed.

FIG. 3A is a sectional elevation of FIG. 3 along line 3A-3A.

FIG. 4 is a schematic diagram used in the discussion of focusing techniques.

FIG. 5 is a schematic diagram used in the discussion of aiming procedures.

DESCRIPTION OF THE PREFERRED EMBODIMENT The "preferred embodiment of the invention is now described with reference to FIG. 1. The housing includes a number of integrally constructed molded component parts.

The material used in the preferred embodiment is molded plastic from the polycarbonate and polyethylene groups, but is is obvious that any suitable material can be used. The molding of components does not merely means separately molded components but a combining of functions of various components into one or more unitized parts. The housing 10 includes an integral reflector 12 and provides a receptacle 13 for accepting a lamp 14. Windows 15 and a vent screen 9 are placed in the sides of the base 11. A door 16 is movably mounted on the base 11 by a hinge 20. The door 16 is of integral construction comprising a ring 19 to which is mounted a hood l7 incorporating a lens 18.

The lens 18 is in a predetermined position with respect to the reflector 12 when the door 16 is closed. A backgroundforming member 22 is mounted over the hood 17 about the ring 19. The reflector 12 has uniformly distributed random irregularities 28 over its surface which is shown in detail in FIG. 4, the purpose of the irregularities 28 is more fully explained hereinafter. The receptacle 13 is in a predetermined position such that a filament 31 in the bulb 14 will lie substantially at the focus of the reflector 12. As indicated in FIG. 1, the bulb 14 is constructed so that the filament 31 has a fixed relation with bulb-alignment pins 32; the filament 31 is shown parallel to and at a fixed distance from the pins. It should be noted that any bulb arrangement of precise alignment may be used.

The door 16 movably mounted on the base 11 permits access to the interior of the housing 10. Hinge 20 is used in this particular embodiment because it is compatible with prior art devices now in use as shown in FIG. 2. It is of particular advantage to this embodiment that it be compatible with the currently used devices for a number of reasons. One important reason is that old systems can be repaired by use of the replacement parts of the new device, e.g., the lens 41 may be damaged and it is advantageous and time saving to replace not only lens 41 but also ring 42, hood 43, and background 44. This not only accomplishes repair but more importantly updates the equipment to the latest design features.

Background-forming member 22 has a different configuration from prior art devices and is mounted on the door 16 by means of a snap-fit. As shown in FIG. 3A, a lip 23 of background-forming member 22 is rigidly held by the combination of ridge 24, groove 25, and stop 26 on the door 16. By exerting pressure on the body of the background-forming member 22, the lip 23 gives way and passes over ridge 24 and lip 23 snaps into groove 25. It is obvious that although a snap fit is used in this illustration, a one-piece mold of the door 16 and background-forming member 22 could be easily accomplished by a change in tooling.

Another aspect of the background-forming member 22 design is illustrated in FIGS. 3 and 3A. It has no mounting screw holes as in the old type background but is molded as a single piece having a snap-fit construction. Background-forming member 22 is made of a semirigid black plastic in the preferred embodiment and will withstand the effects of vibration, vandalism, and adverse weather conditions. The side view shown in FIG. 3A illustrates that background-forming member 22 is not a thick plastic mold but rather a thin plate which has waves 36. The waves 36 provide compliance yet give a great deal of strength. This construction which is not only economically advantageous but also extremely durable, makes the background-forming member 22 design extremely useful in railroad application.

As previously pointed out, the door 16 includes a lens 18, and a ring 19 and a hood 17 as one molded part.Referring to the prior art device of FIG. 2, a lens 41, a hood 43, and a ring 42 are fastened together and then installed on the base 45. The advantages of the simplified construction of the preferred embodiment are thusly apparent. For example, in a particular application of the lamp used as a grade-crossing warning light, a red-colored lens 18 is used. To implement this requirement, the entire door 16 including the lens 18, hood l7, and ring 19 are molded out of red plastic, and the lens 18 is masked while the interior of the door is painted black. Thus the door 16 is not only simply constructed, but weather resistant because the paint is not exposed to the environment therefore obviating rapid deterioration. The windows of the base 11 may be incorporated in any number of ways similar to the lens 18 construction but in this embodiment they are snap fit into place, serving to allow viewing to determine whether the signal is operating. Various combinations of mold-snap fits and multicolor molding may be used depending on the situation and the application desired.

The vent screen 9 is integrally molded into the bottom of the base member 11 and allows air circulation within the unit for temperature equalization.

In view of the foregoing description of the alternative construction techniques, unitized does not necessarily means one signal mold. It means rather that any number of molded component parts compatible with the prior art devices are provided, while many parts not essential to the functioning of the apparatus are removed, e.g., fasteners are eliminated by molding and snap-fit construction. It is therefore important to not that unitized refers more precisely to an optimum number of molded components preferably compatible with prior art designs.

As was indicated earlier in the discussion, the preferred use of the invention is in a highway grade-crossing signal and in that particular application, a red-colored lens 18 is required. In such application it is desirable that a reflective material be used which resists corrosion effectively. Gold is a material which while quite expensive meets the required criteria. By present state-of-the-art techniques, a very small amount of gold can be vacuum deposited on the surface of the reflector 12. Gold, while not the best reflective material, reflects the red spectrum with sufficient efficiency for the application shown in the preferred embodiment. In addition, only a small amount of gold is necessary in vacuum depositing. It should be recognized, however, that the surface could be coated with other reflective materials such as chromium, aluminum or silver, well known to those skilled in the art for different applications.

Turning to FIG. 4, a detail sectional view of the reflector R having a rippled surface" is shown. The reflector R in the preferred embodiment is generally the shape of a parabola but any surface which reflects light rays on a substantially parallel configuration is sufficient as will be pointed out later. The reflector need not strictly conform to a true parabolic section because the rippled surface" introduces an intentional error factor. Thus the less precise requirement for surface accuracy reduces the cost of the device, among other advantages. This reflector 12 may be used not only as the preferred embodiment of FIG. 1, but may be mounted in the rear of the prior art device of FIG. 2 in place of the smooth reflector 46. In either application, the reflector R displays its unique characteristics.

The "rippled surface reflects a substantially full and evenly distributed beam of light with only a slight spread or divergence of the rays. In conventional smooth surface parabolic reflectors if a light source is placed at the focus F, rays of light emanating from the source follow the path FSN, while the reflected ray SN is parallel to the reflector axis AA. However, if the surface of the reflector is not accurately formed, the rays will follow paths FSU or FSD. Assuming a segment of the surface area of the reflector is not shaped properly, then a portion of the available light is reflected away from its intended path. This phenomenon can be observed in prior art reflectors and is referred to as a dark spot". If, however, the entire surface of the reflector R is substantially the shape of a parabola as shown in FIG. 4, and the surface has uniformly distributed random irregularities, then the light reflected with the source at focus F is substantially uniformly projected about the axis AA. That is, the beam of reflected light while diverting from axis AA, depending on the degree of irregularities in the surface, is quite uniform in illumination. If observed, the reflector exhibits no dark spots," the multiple irregularities on the surface of the reflector tend to cancel the effects of slight surface errors and give a uniform beam of light.

To enable a more incisive understanding of this phenomenon, assume n number of points in the surface of the reflector R, when n is large and the uniform random irregularities over the reflector surface are very slight, there will be a reflected distribution of light rays diverging slightly from a direction along axis AA. This results in a distribution centered about AA. The rippled reflector 12 of FIG. 1 approaches this condition and as the reflected light is observed, it appears to be uniformly distributed. The slight errors or irregularities over the surface of the reflector 12 give the illusion of a uniform beam of light.

The use of the rippled mirror further makes critical focusing unnecessary, so that the complex focusing apparatus 29 used in the prior art device of FIG. 2 is eliminated and the simplified receptacle 13 of FIG. 1 may replace it. Further, since the reflected light beam from the rippled surface is purposely divergent about the axis AA, placing of the light source at the precise focus is unnecessary. The foregoing is demonstrated with reference to FIG. 5. The focus F of the reflector lies in the axis AA. The plane P is normal to the axis AA and a circle of radius r lies in the plane P. For purposes of the preferred embodiment of FIG. 1, the filament 31 although preferably normal to the plane P along axis AA and evenly distributed on each side of focus F, need only intersect the plane P within the perimeter of the circle of radius r. Practically speaking, if r is sufficiently small, i.e., in the order of one thirty-second of an inch, this results in in a normally sufficient amount of light being reflected.

It is important with respect to FIG. 5 to note that if the filament is not quite in the focus F, then the reflected cluster of light rays will have a direction slightly different from axis AA. When the filament of the lamp is precisely in the focus F, the axis of the reflector r is colinear with the axis of the axis of the reflected light beam, however, if the filament is slightly out of focus, the beam oflight will have an axis BB slightly askew of AA. This direction can be measured by the angle 0, formed by the intersection of the line drawn from the position of the filament 31 at F to the vertex of the reflector V and the axis of the reflector along AA. When the filament 31 is in the circular area defined previously, then this angle F 'VA is very small and the direction of the beam of light can be adjusted by aiming the housing 10 rather than adjusting the filament 31.

In a typical illustration of the signal light of FIG. 1, the housing 10 is mounted on a highway standard (not shown) to a nipple extension 48 by nipple connection 33. The housing 10 is free to rotate horizontally about the nipple extension 33 and tilt vertically about the nipple extension 48. To achieve optimum intensity, the housing is moved while being observed at a reference position on the highway. In other words, if a substantial beam of light is passed through the lens 18 down the highway, it can be aimed at a specific reference without the necessity of focusing, therefore eliminating an expensive and time-consuming procedure.

While this unit will operate satisfactorily with the usual 10 volt-l8 watt lamp, it is suggested that a 24 volt-50 watt lamp be used. This yields a very good indication on 24 volts AC, and a satisfactory indication on 10 volts battery during power off. Battery drain during this situation is comparable to that of the 10 volt-l 8 watt lamps. While most colors do not permit this phenomenon to occur with enough efficiency to be useful when used in conjunction with a red lens, the effect is a signal as efficient as any signal available in the art.

Another innovation, in the optical system used, of this invention is that the light is projected where it is most needed. Prior art devices generally project a beam of light at a relatively constant intensity over a wide angle of observation. The lens 18 shown in FIG. 3 is a combination ofa center area 47 and a spread light area 46. The spread light area is an area having a series of prisms which spread some of the light down and to the sides for close up and peripheral viewing, while the center area 47 is not a lens at all in that it has no focal point. It is a center area 47 of molded plastic and has properties of plane glass. It is not intended for the center lens area 47 to disperse the, light beam, rather the rippled mirror 12 affects this purpose. ln conjunction with prior art reflectors, lens 18 projects the majority of a beam of light of high intensity over a narrow angle of observation, with little or no spread and disperses some light down and to the sides. The majority of the light is projected over the center beam 47 with slight spread and a minimal amount is dispersed down and to the sides over a large angle of the order of 30 in the spread light area 46. With the addition of the divergence introduced by a rippled mirror reflector, it spreads the high intensity beam to approximately 5. This combination of wide angle low intensity at close range and high intensity small angle at long range is useful particularly in highway grade-crossing warning signals.

Thus, it is seen that the optical system of this invention harnesses the normally deleterious effects of reflector distortion and produces a more efficient and reliable light source'at lower cost. It uses that which has heretofore been considered useless and troublesome to a constructive end.

The embodiment of this invention as shown in FIG. 1 combines various features, including, unitized construction of component parts adaptable to existing housings, a more resilient device, more effective utilization of the available light, a simple manufacturing and installation procedure, and overall cost reduction and produces a signal housing having improved characteristics over prior art devices.

While there has been shown what is at present considered to be the preferred embodiment of the invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention.

What I claim is:

l. A warning-light housing of unitized construction comprising:

a base member having an access port;

a concave arcuate reflector integrally mounted to the base member;

a lens member mounted to the base member;

a receptacle mounted to the base member;

the lens member, the receptacle and the reflector each aligned in predetermined position relative to the other and a background-forming member of substantially circular shape, the background-forming member having means for attachment to the warning light housing, and the background-forming member having a shape substantially concentrically waved along a radially transverse direction.

2. The housing of claim 1 wherein the reflector has substantially uniformly distributed random irregularities over its surface.

3. A warning-light housing of unitized construction comprising:

a base member having an access port;

a door mounted to the base member for closing the access port;

a concave arcuate reflector integrally mounted to the base member;

a receptacle mounted to the base member;

a lens integrally mounted to the door such that when the door is in a closed position, the lens, the reflector and the receptacle are each aligned in predetermined position relative to the other and a background-fonning member of substantially circular shape, the background-forming member having means for attachment to the warninglight housing, and the background-forming member having a shape substantially concentrically waved along a radially transverse direction.

4. The warning-light housing of claim 3 wherein the reflector has unifonnly distributed random irregularities over its surface; and a hood is mounted to the door about the periphery ofthe lens.

5. The warning-light housing of claim 4 wherein; the receptacle has a terminal block attached thereto for electrical connection with alight source, and the receptacle holds the light source in an aligned predetermlned position relative to the lens and reflector so that no focusing adjustment is necessary.

6. The warning-light housing of claim 5 wherein;

a mounting nipple is attached to the base member;

a window is mounted in the side of the base member; and

a vent is mounted in the side of the base member.

7. The warning-light housing of claim 6 having an integrally mounted receptacle.

8. A warning-light housing comprising:

an arcuate concave reflector,

the reflector having substantially uniformly distributed random irregularities over its surface of producing uniform light dispersion; and

a background-forming member of substantially circular shape, the background-forming member having means for attachment to the warning-light housing, the background-forming member having a shape substantially concentrically waved, along a radially transverse direction.

9. The reflector of claim 8 having substantially the shape of a parabolic section wherein:

a reflective material is deposited upon the surface, the reflective material selected from the group consisting of gold, silver, chromium, and aluminum.

10. A warning-light housing of unitized construction comprising in combination:

a base member of tubular cylindrical shape, the base having an open and closed end; I

an integral reflector mounted in the closed end of the base with the concave surface facing the open end, being substantially the shape of a parabolic dish, and having uniformly distributed random irregularities over its concave surface;

the concave surface plated with a reflective material;

a receptacle mounted to the base member having a terminal block attached for electrical connection;

a window 'mounted in the base member for side viewing;

an integral vent mounted in the bottom side of the base, and

an integral mounting nipple attached at the top side of the base;

a door movably mounted to the base member, the door being tubular cylindrical shape having an open end and a closed end, the open end of the door mating with the open end of the base when the door is in a closed position,

the cylindrical shape of the door extends from the open end and is out along a bias with the central axis of the door to form a hood as an integral part of the door,

a lens is formed in the hood closing the end of the door along the bias;

a background-forming member having the shape of a circular plate,

the background-forming member has an aperture in the center so as to fit about the hood, and a shape substantially concentrically waved along a radially transverse direction;

a lip protrusion is extending about the aperture formed in the background-forming member;

a plurality of ridge, stopping and groove members disposed about the periphery of the door,

the groove, ridge and stopping members holding the background-forming member in place,

the body of the background-forming member fitting into the groove against the stopping member and the ridge holding the lip protrusion of the background-forming member in opposite directions.

Patent Citations
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US1915842 *Oct 29, 1932Jun 27, 1933Westinghouse Electric & Mfg CoIlluminating apparatus
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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3694945 *Nov 5, 1970Oct 3, 1972Jakob DetikerOptical element for illumination
US3780285 *Jul 24, 1972Dec 18, 1973Minnesota Mining & MfgTraffic light conversion kit
US6267491Oct 25, 1999Jul 31, 2001Grote Industries, Inc.Lens retention means for vehicle lamp assembly
U.S. Classification362/310, 362/348, 362/362
International ClassificationF21S8/00
Cooperative ClassificationF21W2111/02