USRE27125E

USRE27125E - Means for removing glare op a light beam

Info

Publication number: USRE27125E
Authority: US
Priority date: 1969-01-21
Filing date: 1969-01-21
Publication date: 1971-05-25

Abstract

A SEALED-BEAM HEADLAMP INCLUDES A COAXIAL LENS AND REFLECTOR, AND AN INCANDESCENT FILAMENT HICH GENERATES A LIGHT SOURCE. A TRANSPARENT PLATE IS INTERPOSED BETWEEN THE FILAMENT AND THE LENS TO DIVIDE THE HEADLAMP INTO A HERMETICALLY SEALED, EVACUATED FILAMENT COMPARTMENT AND A NON-EVACUATED LOUVER COMPARTMENT. A FRAME WHICH IS FIXEDLY MOUNTED IN THE LOUVER COMPARTMENT IS MAINTAINED STATIONARY WITH RESPECT TO THE LENS AND THE PLATE. A PLURALITY OF LOUVERS ARE ROTATABLY MOUNTED IN THE FRAME, THE LOUVERS BEING SPACED-APART AND MECHANICALLY COUPLED FOR SIMULTANEOUS ROTATION SEQUENTIALLY THROUGH A FULLY CLOSED POSITION AND A FULLY OPEN POSITION. A DRIVE MECHANISM COOPERATES WITH THE LOUVERS COUPLING TO ROTATE THE LOUVERS IN UNISON AT SUCH RATE THAT A BEAM OF LIGHT PASSING THROUGH THE HEADLAMP LENS APPEARS UNINTERRUPTED. ALTERNATIVELY, THE LOUVERS MAY BE MOUNTED FOR OSCILLATION RATHER THAN ROTATION OR A SUITABLE LOUVER COUPLING DEVICE MAY BE PROVIDED TO ROTATE ADJACENT LOUVERS IN OPPOSITE DIRECTIONS.

Description

May 25, 1971 J. F. STEEL MEANS FOR REMOVING GLARE OF A LIGHT BEAM 4 Sheets-Sheet 1 Original Filed Doc. 14. 1964 I N VENTUR. (/bM/v E 57'! BY we M eA/5s s May 25, 1971 J, STEEL Re. 27,125

MEANS FOR REMOVING GLARE OF A LIGHT BEAM Original Filed Dec. 14, 1964 4 Sheets-Sheet z May 25, 1971 J, STEEL Re. 27,125

HEARS FOR REMOVING GLARE OF A LIGHT BEAM Original Filed Dec. 14, 1964 4 Sheets-Sheet 5 I.\'VE.\'TOR. C/bH/v F 57554 H pm $40 //7- rue/wise May 25., 1971 J. F. STEEL Re. 21,125

MEANS FOR REMOVING GLARE OF A LIGHT BEAM Original Filed Dec. 14, 1964 4 Sheets-Sheet 4 1K EXTOR (JOHN/. 5755/.

United States Patent 27,125 MEANS FOR REMOVING GLARE OF A LIGHT BEAM John F. Steel, P.0. Box 401, Palm Beach, Fla. 33480 Original No. 3,333,094, dated July 25, 1967, Ser. No-

421,742, Dec. 14, 1964, which is a continuation-in-part of Ser. No. 406,973, Oct. 26, 1964. Application for reissue Jan. 21, 1969, Ser. No. 802,277

Int. Cl. F21v 11/04 U.S. Cl. 240-4611 9 Claims Matter enclosed in heavy brackets II] appears in the original patent but forms no part of this reissue specification; matter printed in italics indicates the additions made by reissue.

ABSTRACT OF THE DISCLOSURE A sealed-beam headlamp includes a coaxial lens and reflector, and an incandescent filament which generates a light source. A transparent plate is interposed between the filament and the lens to divide the headlamp into a hermetically sealed, evacuated filament compartment and a non-evacuated louver compartment. A frame which is fixedly mounted in the louver compartment is maintained stationary with respect to the lens and the plate. A plurality of l uvers are rotatably mounted in the frame, the louvers being spaced-apart and mechanically coupled for simultaneous rotation sequentially through a fully closed position and a fully open position. A drive mechanism cooperates with the louver coupling to rotate the louvers in unison at such rate that a beam of light passing through the headlamp lens appears uninterrupted.

Alternatively, the louvers may be mounted for oscillation rather than rotation or a suitable louver coupling device may be provided to rotate adjacent louvers in opposite directions.

Cross-Reference to related application [This application is a continuation-in-part of my application Ser. No. 406,973, filed Oct. 26, 1964, and now abandoned, for Automobile Headlamp] The original of this application is a continuation-in-part of my application Ser. No. 406,973, filed Oct. 26, 1964, and now abandoned, for Automobile Headlamp.

Background of the invention (1 Field of the invention This invention relates to beam-type lighting devices, and more particularly to a unique apparatus and method for reducing glare of a light beam, as in automobile headlamps and the like.

(2) Description of the prior art As is well known, a person facing a strong light beam often is momentarily blinded by its glare. In the case of automobile headlamps, for example, one of the most dangerous obstacles to night driving is the glare of the headlamps of oncoming cars. All too often, a driver proceeds with his headlamps on high beam along unlightcd stretches of roadways, and fails to dim his lights when he approaches cars coming in the opposite direction. All too often, too, the driver of the car coming from the opposite direction is blinded by the glare from the high beam lights, and is caused to lose control of his car and have an accident.

Also, while driving on highways at night where there is a considerable flow of traffic, the driver is often compelled to drive continuously on low beam" with consequent poor lighting and little or no warning of poor or unlighted objects which he is approaching. Many accidents occur be- "ice cause such a driver travels at too high a speed while on low beam" to permit him to avoid collision with an object after it is within the range of the beam and he is aware of it.

Another common problem with nighttime driving is that conditions are often such that a driver must frequently manipulate the foot switch for the headlamps and switch them back and forth between high and low" beam operation. It is well known that frequent surges of current through a filament both in turning a light on and in turning it off, constitute a major factor in reducing the life of the filament, and its lamp. Accordingly, it often happens that a filament, such as the "high beam filament, burns out while driving, under circumstances in which the driver is forced to travel a considerable distance without the benefit of high" beam operation where it is dangerous to be without the benefit of that light source.

It is also known that persons working under strong light beams, e.g., as in movie studios, or on outside construction jobs at night, are often temporarily blinded by the lights and unable to carry on their work.

In the past, it has been proposed to reduce such glare by rotating louvers outside a lamp to interrupt the beam at a frequency such that the light appears uninterrupted. While this reduces glare, it has the disadvantages that the louvers are exposed to dirt and moisture, are easily damaged, dnd require undue time, effort and expense to maintain in proper working order.

The mounting of a motor and louvers inside such a lamp has not hitherto been possible without damage to moving parts and a serious shortening of filament life. In this connection, it should be noted that a motor and louvers positioned inside such a lamp would be subjected to considerable heat damage at the high temperatures required to fuse the lens to the reflector. Further, the moving parts would be incapable of desired operation in the high vacuum required for the filament. Reducing the vacuum would inherently shorten filament life, as would direct exposure of the filament to contaminants from the motor and louvers.

Summary of the invention My invention embraces a lamp having a lens and reflector wherein its interior is divided into an evacuated filament compartment and a non-evacuated louver compartment, and includes a transparent plate sealed to a reflector to define the evacuated filament compartment; the lens being secured to the transparent plate to provide the louver compartment; and an assembly of louvers carried by a stationary frame in said second compartment and adapted to be operated to so interrupt the beam that light passing through the lens appears uninterrupted. The invention eliminates the aforementioned disadvantages of the prior art, and has as its objects the following:

It is an object of my invention to provide a unique apparatus and method eliminating objectionable glare of a light beam.

It is another object of my invention to effect operation of an automobile headlamp on high beam" only without objectionable glare, and to permit elimination of low beam lights and switching circuits heretofore used.

It is another object of my invention to provide a unique lamp construction with built-in means for rhythmically interrupting the beam and thereby reducing the total emitted light power to a level such that objectionable glare from the lamp is avoided without altering the light pattern or distance of the beam.

A further object of my invention is to provide a unique lamp construction having a built-in light interrupting mechanism which is composed of a minimum number of component parts of a simple design and rugged construction, capable of reliable operation over a long operating life.

Brief description of the drawings The above and other objects of my invention will become apparent from the following description taken in conjunction with the accompanying drawings of an illustrative embodiment thereof, in which:

FIG. 1 is a front elevation view of a lamp construction in accordance with my invention, showing the arrangement of a plurality of louvers adapted for movement between a partially closed position and a fully open position, partly broken away to show the arrangement by which the output shaft of a motor effects vertical movement of a pulsating frame for operating the louvers;

FIG. 2 is a bottom plan view of the lamp of FIG. 1, partly broken away to show the front and rear compartments of the lamp, with the rear compartment being hermetically sealed, and with all of the movable parts being located in the front compartment and supported on a transparent mounting plate;

FIG. 3 is a side elevation view of the lamp of my invention, partly broken away to show more clearly the relative positions of the support bars and the pulsating frame, and showing the manner in which the electric motor is supported in the mounting plate that separates the two compartments;

FIG. 4 is an enlarged side elevation view taken of the are designated at 4 of FIG. 3;

FIG. 5 is a front elevation view of the mounting plate;

FIG. 6 is a side elevation view of the mounting plate, showing more clearly the electrical connections of the motor well;

FIG. 7 is an enlarged perspective view of a portion of one end of a louver, showing the tabs on the louver riveted to the support bar and pulsating frame;

FIG. 8 is a perspective view of the pulsating frame;

FIG. 9 is a perspective view of the two louver support bars;

FIGS. 10 and 11 are enlarged perspective views of a louver showing the tabs struck therefrom;

FIG. 12 is a front elevation view of a lamp of my invention in which the louvers are rotatable;

FIG. 13 is a sectional view taken along the line 1313 of FIG. 12;

FIG. 14 is a bottom plan view of the lamp of FIG. 12, partially broken away to show the interior thereof;

FIGS. 15-17 are perspective views of exemplary louvers employed in the lamp of FIG. 12;

FIG. 18 is a fragmentary sectional view taken along the line 18-18 of FIG. 12; and

FIG. 19 is a sectional view taken along the line 1919 of FIG. 18.

Description of illustrative embodiments Referring to FIGS. l3, there is shown an automobile headlamp 20 in accordance with my invention which contains a plurality of horizontal louvers 21 which are located between the filament 22 and the front lens 23. In accordance with my invention, the louvers 21 are adapted to be moved to and from a fully open position, i.e., horizontal, at such a frequency or rate that the beam of light emitted appears to be uninterrupted. The lamp is adapted to emit only the so-called high beam," but due to the periodic diminishing of the emitted light, the total light power emitted is considerably less than that of an uninterrupted beam, and is at such a level that the objectionable glare presented by an uninterrupted beam is removed.

I have discovered that by rhythmically interrupting the light with such louvers, at a rate such that the light appears uninterrupted, the emitted beam is made to appear as a soft or buffered light, which is devoid of the glare of high illumination, but which allows the benefit of high illumination.

With reference to FIGS. 2 and 3, the lens 23 is separated from the reflector 25 of the lamp housing by a transparent glass plate 26. As best seen with reference to FIG. 3, the transparent plate 26 and the reflector 25 are shaped adjacent their peripheries for interlocking engagement, and are sealed [bonded] together by conventional glass bonding techniques. In addition to sealing [bonding] the transparent plate 26 to the reflector 25, the chamber or compartment 27 defined by these elements is evacuated and filled with gas as desired.

Again referring to FIG. 3, and also to FIGS. 5 and 6, the transparent plate 26 is formed with a small, hollow protuberance 28 which extends into the compartment 27. Extending through the back wall of the protuberance 28, and bonded thereto, are a pair of ceramic supports 30 through which wire leads 31 extend into the well 29 in the protuberance. At their opposite ends, theshort leads 31 extend through another ceramic support 32.

In assembly the transparent plate 26 and the reflector 25, the ceramic support 32 is located in an opening in and bonded to the back Wall of the reflector 25, in the same manner as the conventional ceramic supports for the leads of the filament 22.

Again refereing to FIG. 3, the well 29 is shaped to receive a motor 35, which is held in place by means of a spring clip 36. When the motor 35 with the spring clip 36 around it is inserted into the well 29, electrical terminal receptacles (not shown) in the motor housing are forced over the springs or inner ends of the wire elements 31. When the reflector 25 is positioned in place on the automobile so as to cause the filament 22 to be heated when the lighting switch is turned on, the external or plug ends of the wire connections 31 are simultaneously connected to a power source for setting the motor 35 into operation. schematically, electrical connections for the filament 22 and the motor 35 to a power source are illustrated in FIG. 3 as being connected through respective switches 38, 39 in which the movable contacts are mechanically connected to a dashboard control knob 40 for opening and closing the switches simultaneously.

The shaft of the motor 35 carries a pinion 41 on the outer end thereof. The pinion 41 is in meshing engagement with a large gear 42 which is supported for rotation on a bracket secured to the motor housing. As best seen in FIGS. 1 and 3, the gear 42 carries an off-center pin 43 on its outer face. Thus, when the motor 35 is in operation, the pin 43 rotates in a circle.

The transparent plate 26 is a mounting plate for the louver construction as well as the motor 35. The louvers 21 are secured to parallel vertical bars 46, 47 (see FIGS. 8 and 9 along with FIGS. l4 and 7) which have horizontal end portions terminating in the transparent plate 26, and the

vertical rails

48, 49 of a pulsating frame 50. The end portions of both support bars 46, 47 are horizonal and terminate in the transparent plate 26, and the frame 50 has a horizontal bar 51 adjacent its lower end which has an opening 52 in an enlarged center portion 53 thereof into which the pin 43 of the gear 42 extends.

With this arrangement, as the gear 42 and pin 43 rotate, the frame 50 moves up and down and the louvers 21 are made to pivot on the support bars 46, 47.

As is apparent, any suitable means may be employed for attaching the louvers 21 to the support bars 46, 47 and the

rails

48, 49 to permit the desired movement of the frame 50 and pivotal movement of the louvers. Preferably, the number, construction and arrangement of parts are such as to permit their formation and assembly at little cost in time, materials and labor. In the form of the invention illustrated, the louvers are designed to be formed and provided with integral tabs to be riveted to the support bars and the rails in a single stamping and forming procedure.

Referring to FIG. 10, each louver 21 is formed from a rigid, rectangular sheet element, e.g., stainless steel, indicated in phantom at 56, which is somewhat wider than the louver to be made. The sheet 56 is stamped to form an element in the shape of a trapizoid, with small

integral tabs

57, 58 extending from the longer of the parallel sides. Additionally, tabs 59. 60 are struck from the sheet 56 to extend at right angle to the face of the sheet, whereby spaced openings 59' and 60' are formed in the face of the sheet. Also, the

tabs

57, 58 are bent toward the side of the sheet from which the struck

tabs

59, 60 extend, and the ends of the

tabs

57, 58 are bent at right angles so as to lie in the planes of the struck

tabs

59, 60. Still further, all of the tabs 57-60 when formed are punched to provide holes for receiving connecting pins or rivets. As best seen in FIG. 11, the confronting edge portions of the coplanar portions of the

tabs

57, 59 are so formed that the upper tab 57 is rounded and nests in a fillet in the lower tab 59.

The louvers 21 are assembled on the

support rods

46, 47 by locating the openings 59', 60 over the support bars 46, 47 and passing the louvers along these bars to the positions in which they are to be connected to the

bars

46, 47 and rails 48, 49. For each louver, its

lower tabs

59, 60 are pivotally connected by rivets to the support bars 46, 47, and the upper tabs 557, 58 are pivotally connected by rivets to the

rails

48, 49 of the frame 50.

After the louvers 21, the support bars 46, 47, and the frame 50 are assembled as above described, they are mounted in place simply by inserting the ends of the support bars 46, 47 into snug fitting sockets provided in integral projections 62 formed in the front surface of the transparent plate 26. When the support bars 46, 47 are thus being positioned, the opening 52 in the bar 51 of the frame 50 slips over the pin 43 of the gear 42.

After the louver assembly is in place, the system can be tested for operation before securing the lens 23 to the transparent plate 26. In the lowermost position of the pin 43, and hence the frame 50, the louvers 21 are in a horizontal position, as indicated in dotted lines in FIG. 4. In the uppermost position of the pin 43, the louvers 21 are depressed at an angle below the horizontal, e.g., 45 degrees, such that there is still sufficient light passing through the transparent plate 26 from the reflector 25 to permit the driver of the automobile to see a short distance in front of him. Thus, if for some reason the motor 35 ceases to operate when the frame 50 is in the uppermost position, the driver will not be without suiiicieut light for driving purposes.

Preferably, the parts are so shaped that the frame 50 needs to undergo only a very short stroke in moving the louvers from their semi-closed position to the fully open position. To aid in this respect, I have formed the support bars 46, 47 with rounded projections 65 on their rear edges, and formed the

rails

48, 49 of the frame 50 with rounded projections 66 on their forward edges (see FIGS. 4, 8 and 9). At the time the support bars and the frame are formed, rivet holes are punched in the

rounded projections

65, 66. As will be apparent, the formation of the support bars and frame can be accomplished with a quick stamping and punching operation.

As best seen in FIG. 4, the projections 66 in the uppermost position of the frame 50 are disposed slightly above and in near touching relation with the projections 65. Still further, there is a slightly overlapping relation between the projections, so that the distance between horizontal projections of their axes is less than the actual distance between their axes. With this arrangement, the frame 50 cannot move directly downward in causing the louver to move to a horizontal position, but must move slightly rearwardly during its downward movement. Such movement causes the louvers 21 to pivot on their support bars 46, 47, with a minimum total stroke for the frame 50. For example, in one construction I obtain full open position for the louvers with a total stroke of only three-eighths of an inch for the frame 50.

In securing the lens 23 in place, it is not necessary to employ the high heat required for bonding the transparent plate 26 to the reflector 25. In fact, it is preferable that such heat not be employed as it might tend to damage the motor 35 and louvers. Still further, it is preferable to secure the lens in place so that whenever it is necessary or desired, it can be removed to permit the motor 35 and/or the louver assembly to be repaired and/or replaced. Thus, the lens 23 may be secured to the transparent plate 26 by any suitable mechanical ring clip, or the like, which permits such removal.

As previously indicated, the form of lamp construction of my invention, as illustrated in FIGS. 12-19, is one in which the louvers are rotatable. In this embodiment, the lamp 20' does not employ any movable frame, but rather is provided only with a single tixed frame 70 which supports the motor and all of the louvers. Through suitable drive connections, the louvers are caused to rotate in synchronism with the output shaft of the motor, and at a speed such as to cause the desired rhythmical interruption of the beam for removing objectionable glare.

In the embodiment of FIGS. 12-19, I show an arrangement of ten louvers 71-80, wherein five of the louvers, shown as

alternate louvers

71, 73, 75, 77, 79 are adapted to be driven from one end of the motor output shaft 81, and wherein the remaining

louvers

72, 74, 76, 78, 80 are adapted to be driven from the other end of the motor shaft 81.

To this end, the motor shaft 81 is supported at its ends for rotation in the frame 70, and

respective gears

82, 83 are secured to the ends of the motor shaft. Looking at the left end of the motor shaft 81, the gear 82 meshes with a gear 84 on the louver 71, whereby to effect rotation of the louver 71 with the motor shaft 81. Rotation of the louver 71 imparts rotation to the

louvers

73, 75, 77, 79 therewith by means of a toothed belt 85 (see FIG. 13 along with FIG. 12) which meshes with respective pulley wheels 86-90 on the

louvers

71, 73, 75, 77, 79.

Looking at the right end of the motor shaft 81 in FIG. 12, the gear 83 is in meshing engagement with a gear 91 on the louver 71, and this in turn meshes with a gear 92 on the louver 72. Thus, the louver 72 is caused to rotate in a direction opposite to that of the louver 71.

Louvers

72, 74, 76, 78, 80 are arranged for rotation in the same direction by means of a belt 93 which is like the belt 85 and which engages respective pulley wheels on those louvers.

Although alternate louvers are made to rotate in opposite directions, nevertheless they are arranged so that they simultaneously reach the horizontal positions in which they are fully open, i.e., present minimum interference to light passing from the reflector 25' through the transparent plate 26' and the lens 23'.

FIGS. 15-19 show best how I form the louvers and the frame, and how the louvers are formed so that they can be rotatably mounted in the frame. In essence, the louvers are formed with integral gears, pulley teeth and bearing elements as needed. Preferably, this is done by plastic molding techniques, wherein each louver is molded as a plastic element having integral bearing elements and the requisite gears and pulley wheels.

Referring to FIG. 15, the louver 71 is shown as a flat rectangular element with spaced

gears

84, 91, a pulley wheel 86 immediately adjacent the gear 84, a cylindrical bearing element 95 adjacent the pulley wheel 86 at one end, and a cylindrical bearing element 96 adjacent the gear 91 at the other end of the louver. The bearing

elements

95, 96 elfectively constitute spacers between the main body of the louver and the end portions thereof, and the

slots

97, 98 formed thereby are utilized to permit the louver to be rotatably supported in the frame, as will be more fully explained below.

Referring to FIGS. 16 and 17, the

louvers

72, 73 are also formed with

integral bearing elements

95, 96 in

slots

97, 98, precisely as in the manner of the louver 71 of FIG. 15. However, the louver 72 includes only the one gear 92, and a pulley wheel 99 is located between the gear 92 and the bearing element 96, and the louver 73 is formed with only the one pulley wheel 87 thereon located adjacent one bearing element 95.

It will be recognized that the remaining louvers 74-80 are formed precisely in the manner of the louver 73 of FIG. 17, i.e., with only one pulley wheel and the bearing elements.

To provide a better understanding of how the motor shaft 81 and the louvers are supported for rotation by the frame 70, reference will be made to FIG. 18, along with FIGS. 12 and 13. The frame 70 is formed as a split frame comprising two

portions

100, 101 which, following assembly of the motor and louvers, are secured together at their upper and lower ends, as indicated at 102.

The innermost frame portion 101, i.e., the portion adjacent the transparent plate 26' is provided with integral tabs 103 adjacent its upper and lower ends, which are adapted to be secured, as at 104, to the transparent plate 26. To this end, the transparent plate 26' is formed with integral projections 105 into which the fastening elements 104 extend for securing the frame to the transparent plate.

The

frame portions

100, 101 are formed with semicircular grooves along their lengths so that when they are assembled together, they form openings 107 for the ends of the motor shaft 81 and openings 108 for the

hearing elements

95, 96 of the louvers. Before the outer frame portion 100 is secured in place, the ends of the shaft 81 and the bearing elements of the louvers 71-80 are located in the corresponding semi-circular grooves in the inner frame portion 101. With the outer frame portion 100 secured in place, the frame provides circular bearing surfaces for the motor shaft 81 and the bearing

elements

95, 96 of the louvers. In this connection, it will be apparent that irrespective of how the frame is formed, or of what material, the walls of the

openings

107, 108 are made to form smooth bearing surfaces for the motor shaft and the bearing elements of the louvers.

It will be appreciated that before securing the

frame portions

100, 101 together, the louvers 71-80 and the motor 35' are arranged with the various gears in meshing engagement and with the belts 85, 93 encircling the pulley wheels which they are to turn. After the frame portions are locked together, the motor housing is secured to the frame, as indicated at 109, so as to hold it stationary while the shaft is rotating.

In this latter connection, it should be noted in both embodiments that while the compartment defined by the transparent plate and refle tor is evacuated, the compartment defined by the lens and transparent plate is not. Thus, I insure long filament life as in conventional lamps, while operating the motor and louvers in a compatible environment separted from the vacuum and intense heat in which the filament operates.

In the embodiment of FIGS. 12-19, the arrangement for making external connections to the motor is different from that shown in FIGS. l-ll In this connection, and referring to FIGS. 12-14, the motor], and has leads 31' extending [extend] out of the upper portion of the lens 23', and along the back of the reflector and they are connected at their ends (see FIG. 14) to the electrical terminals for the filament 22'. Thus, the motor and filament circuits are connected in parallel to the same source of power. When the dashboard control knob is operated to turn the headlamps on, power for operating the motor is supplied from the same source which heats the filament 22.

In order to provide a space in the upper part of the lens 23 for the motor leads 31' to extend to the exterior of the headlamp, the lens 23' preferably is formed with a pair of parallel grooves for this purpose. Thus, when the lens 23 is located in position to be secured to the transparent plate 25', the motor leads 31' are positioned to insure that they are captured within the grooves of the lens 23. Preferably, of course, the motor leads are insulated along their lengths, and the grooves in the lens 23' are dimensioned to engage the insulation with sulficient firmness to establish an effective seal against entry of moisture through the grooves to the interior of the compartment defined by the lens 23' and the transparent plate 26'. Also, the insulation provides a protective barrier against heat between the wires and the real wall of the reflector 25'.

To further illustrate the results obtained with my invention, one arrangement which has been built and tested utilizes a set of ten louvers adapted for rotation across the beam of a 5% inch sealed beam headlamp. The louvers were rotated at speeds ranging up to 3400 r.p.m.

It was found that so long as the speed is sutficiently high that the eye could not perceive any flutter, the particular speed of rotation does not appreciably atfect candlepower measurements made while the louvers were spinning. It was also found that the beam, as viewed through the spinning loubers, was soft or buffered but still allowed the benefit of high beam illumination.

From the foregoing, it will be apparent that the various structures shown and described herein are illustrative and that various modifications can be made without departing from the spirit and scope of my invention. Accordingly, I do not intend that my invention be limited, except as by appended claims.

I claim:

1. A lamp structure comprising:

a reflector;

a transparent plate sealed to said reflector and defining therewith a second compartment; said transparent plate having a motor well opening into said second compartment] a lens bonded to said transparent plate and defining therewith a first compartment B], said transparent plate having a motor well opening into said second compartment;

a filament between said reflector and transparent plate;

a motor mounted in said motor well;

a first pair of parallel bars [rods] in fixed spaced relation to said transparent plate in said second compartment;

a second pair of parallel bars [rods] between said first pair of rods and said transparent plate;

a plurality of louvers;

means connecting each louver to both pairs of bars;

[rods] means releasably holding said motor in said well;

leads for said motor extending to the exterior of said housing;

a bar connecting the bars [rods] of said second pair and having an opening therein;

a rotary element having an integral offset pin extending into said opening; and

means for effecting rotation of said rotary element from said motor, whereby said pin subjects said bar and second pair of bars [rods] to reciprocal movement.

2. A lamp structure comprising:

a reflector;

a transparent plate sealed to said reflector;

a lens bonded to said transparent plate;

a filament between said reflector and transparent plate;

a plurality of parallel horizontal louvers between said lens and transparent plate;

a rectangular frame, said louvers having spaced bearing elements disposed in the rotatable in the sides of said frame;

a motor having a motor housing and a shaft extending out of the ends of the housing [thereof], the ends of said shaft being rotatably supported in the sides of said frame, said motor being located above the uppermost louver;

gears on said shaft adjacent the ends thereof;

a pair of gears on the uppermost louver in mesh with corresponding gears on the shaft;

a gear on the louver adjacent the uppermost louver in mesh with out of the gears on the uppermost louver;

a single pulley wheel near one end of each louver adjacent the frame, the pulley wheels on adjacent louvers being on opposite sides of the frame;

a belt encircling and drivingly engaging the pulley wheels on one side; and

a second belt encircling and drivingly engaging the pulley wheels on the other side, said belts and pulley Wheels having meshing teeth.

3. A lamp structure as defined in claim 2, wherein the ends of said filament are connected through said reflector to electric terminals; and means connecting electric leads between said terminals and said motor.

4. A lamp structure as defined in claim 2, wherein said frame is formed of two rectangular elements, each having spaced semi-circular grooves in both sides thereof, said rectangular elements being secured together to that the grovoes therein are aligned and form cylindrical openings in the sides of the frame, the "ends of the motor shaft being disposed for rotation in one pair of said cylindrical openings, and each louver having its bearing elements disposed for rotation in respective pairs of said cylindrical openings.

5. A lamp structure as defined in claim 4, wherein one rectangular element of the frame is secured to the transparent plate.

6. A lamp structure as defined ni claim 2, wherein the upper most louver and the bearing elements, gears and pulley wheel thereon are plastic and molded together, the second uppermost louver and the bearing elements, gear and pulley wheel thereon are plastic and molded together, and each remaining louver and the hearing elements and pulley wheel thereon are plastic and molded together.

7. A lamp structure comprising:

a reflector and a transparent glass plate heat-sealed at their peripheries and defining a first compartment;

a lens engaging said transparent plate and defining therewith a second compartment;

a filament in said first compartment adapted to be heated to cause said reflector to form a beam of light to pass through said transparent plate and said lens;

a row of parallel louvers in said second compartment;

means in said second compartment supporting said louvers for rotational movement in unison, said supporting means including parallel bars [rods] supported at their ends by said transparent plate, said louvers extending between and being rotationally supported at their ends by said bars [rods];

means in said second compartment for rotationally moving said louvers through positions parallel to the axis of the beam of light at a rate such that the beam of light passing through the lens appears uninterrupted;

and securing means for holding said lens in engagement with said transparent plate, said securing means being characterized in that it is applied to the lens and the plate without heat.

8. A lamp structure comprising:

a filament in said first compartment adapted to be heated to cause said reflector to form a beam of light 10 to pass through said transparent plate and said lens;

a row of parallel louvers in said second compartment;

means for rotationally moving said louvers through positions parallel to the axis of the beam of light at a rate such that the beam of light passing through the lens appears uninterrupted, said moving means including a motor in said second compartment;

means operable by said motor to rotate the louvers so that adjacent louvers rotate in opposite directions;

9. In a sealed-beam headlamp of the type including a coaxial lens and reflector, and a filament adapted to be heated to generate a light source, the reflector forming a beam: of light which passes through the lens, the improvement in combination therewith comprising:

a transparent plate interposed between the filament and the lens and secured at its periphery to the lens and the reflector, the plate dividing the headlamp into a hermetically sealed, evacuated filament compartment and a non-evacuated louver compartment,-

a frame fixedly mounted in the louver compartment and being maintained stationary with respect to the lens and the plate;

a plurality of louvers each having bearing portions at either end, the louvers being rotatably mounted in the frame in spaced-apart relationship;

means for mechanically coupling the louvers for simultaneous rotation sequentially through a fully closed position in which the louver surfaces are perpendicular to the axis of the lens and the reflector and through a fully open position in which the louver Surfaces are parallel to the axis of the lens and the reflector; and

means for operating the mechanical coupling means to rotate the louvers in unison at such rate that the beam of light passing through the lens appears uninterruprea'.

References Cited The following references, cited by the Examiner, are

of record in the patented file of this patent or the original patent.

UNITED STATES PATENTS 2,541,834 2/1951 Robinson 24046.1l 3,032,646 5/1962 Chieger 240-46.59X 3,034,029 5/1962 Logan 24046.11X 3,049,962 8/ 1962 Denecke 24046.07X 3,275,820 9/ 1966 Szankowski 240-46.]1X

FOREIGN PATENTS 1,083,812 6/1954 France 240-4611 540,291 6/ 1955 Belgium 24046.l l

SAMUEL S. MATTHEWS, Primary Examiner R. M. SHEER, Assistant Examiner US. Cl. X.R. 240-4629 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent RE 27,125 Dated June 14, 1971 Inventods) John F. Steel It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col

line

29, "are" should read --area-;

32, "of" should read to- 24, "refereing" should read -referring-;

23, "557" should read -57--;

54, "AQFJGULIQd" should read "berm mind";

21, "loubers" should read louvers- 28, theshould be inserted after "by";

33, "second" should read --first-;

37, "first" should read second-;

68, "the" should read --and-;

4, "ont" should read one;

20, "to" should read -so-;

21 "grovoes" should read grooves-; and

30, "hi" should read in-.

Signed and sealed this 21st day of September 1971.

ZDJJAELD M.F'LETCHER, JR.

attesting Officer ROBERT (IO'HSCHALK Acting Commissioner of Patents