US3624386A - Arc lamp - Google Patents

Abstract

The disclosure embraces an arc lamp construction utilizing a lamp comprising a gas-filled envelope containing spaced electrodes in combination with magnetic forces for controlling the arc flame, and a mounting for the gas-filled lamp adjustable to control the relative position of the arc with respect to a reflector.

Description

United States Patent Inventor Harold M. Plumadore Toledo, Ohio AppL No. 792,387 Filed Jan. 21, 1969 Patented Nov. 30, 1971 Assignee The Strong Electric Corporation Toledo, Ohio ARC LAMP 7 Claims, 11 Drawing Figs.

U.S. Cl 240/44.2, 240/41 A Int. Cl F2lv 19/02 Field of Search 240/442,

[56] References Cited UNlTED STATES PATENTS 2,757,277 7/1956 Pennow 240/41 2,767,343 10/1956 Yaeger 313/161 3,168,986 2/1965 Jeffree et al. 240/442 Primary Examiner-Samuel S. Matthews Assistant Examiner-Richard L. Moses Attorney-Harry O. Ernsbcrger ABSTRACT: The disclosure embraces an arc lamp construction utilizing a lamp comprising a gas-filled envelope containing spaced electrodes in combination with magnetic forces for controlling the arc flame, and amounting for the gas-filled lamp adjustable to control the relative position of the are with respect to a reflector PATENTEU NUV30 I971 SHEET 1 BF 4 INVENTOR. wwm M flu/lmwmf PATENTEU W30 ism SHEET 2 [IF 4 INVIL'NTUR. #414 040 M Plum/00a;

,47 TOP/VfV PATENTEDuuvaomn 3,624,386

SHEET 3 [IF 4 INVENTOR. HAWflAfi M PAM/400M ARC LAMP Arc lamps of the type wherein an arc is established by current flow through spaced carbon electrodes have been used extensively for cinematography, television casting and illumination for theatrical purposes. In such lamps the electrodes at the region of the arc are unconfined and the light rays from the incandescent ionized gases at the arc are projected from a reflector to a desired area. In lamps of this character the electrodes are consumed comparatively rapidly requiring frequent replacement. The constant consumption of the electrodes results in deposition of oxide particles upon the reflector requiring frequent cleaning of the reflector in order to main -tain efficient light projection.

Endeavors have been made to utilize a lamp of a character wherein electrodes are confined in a transparent envelop filled with an inert gas, such as xenon, the electrodes being spaced to provide an arc source of light. Heretofore, if the xenon lamp were mounted with the elongated lamp body in a horizontal position, the incandescent gases or are flame tend to be offset vertically upwardly from the axis of the electrodes. Therefore present practice is to mount the lamp with the axis of the electrodes in a vertical position. Operation of the lamp in a vertical position rendered it impossible to use an efficient form of optical system in a light projector. Such lamp used in other than a vertical position effected an overconcentration of heat at an adjacent region of the transparent envelop, such as an envelope of quartz, resulting in damage to the envelope.

The present invention embraces an arc lamp construction utilizing a gas-filled electrode illuminating means for producing an arc wherein the longitudinal axis of the lamp construction is disposed in a substantially horizontal position in association with means for confining the incandescent gases of the arc flame substantially at the region between the adjacent extremities of the electrodes whereby a high efficiency of illumination from the arc is attained.

An object of the invention resides in an arc lamp arrangement utilizing an elongated lamp construction wherein electrodes are disposed in a sealed transparent envelope filled with an inert gas, such as xenon, in combination with magnetic means disposed with respect to the arc between the electrodes to stabilize and maintain the arc flame centralized in the region between the electrodes thereby eliminating concentration of heat from the are at any localized region of the confining envelope.

Another object of the invention resides in a mounting means for an elongated type of gas-filled electrode arc lamp in a light utilization apparatus, the mounting means providing for universal adjustment of the lamp facilitating the accurate positioning of the are at the focal point of a reflector of the apparatus.

Another object of the invention is the provision of an arc lamp construction embodying an arc source of light provided by current flow between electrodes sealed in a gas-filled envelope wherein one end region of the elongated lamp is pivotally supported and the other end region rendered ad justable in vertical and transverse directions for accurately positioning the region of the are at a focal point of the reflector, the arrangement including the establishment of magnetic forces acting in a direction to confine the flame of the arc to a centralized region at the adjacent extremities of the electrodes.

Another object of the invention resides in an arc lamp construction wherein an elongated xenon lamp is disposed substantially horizontally in a lamp housing, and means for circulating air through the housing to convey away heat developed by the arc and to cool the current conductors at the ends of the xenon lamp.

Further objects and advantages are within the scope of this invention such as relate to the arrangement, operation and functions of the related elements of the structure, to various details of construction and to combinations of parts, elements per se, and to economies of manufacture and numerous other features as will be apparent from a consideration of the specification and drawing of a form of the invention, which may be preferred, in which:

FIG. I is a side elevational view of an arc lamp light projecting structure embodying a form of the invention;

FIG. 2 is a top plan view of the arc lamp structure shown in FIG. 1;

FIG. 3 is a vertical longitudinal sectional view taken substantially on the line 3-3 of FIG. 2;

FIG. 4 is a longitudinal horizontal sectional view with the xenon lamp removed, the view being taken substantially on the line 4-4 of FIG. 3;

FIG. 5 is an enlarged fragmentary detail view taken substantially on the line 5-5 ofFlG. 3;

FIG. 6 is an elevational view taken substantially on the line 6-6 of FIG. 3 illustrating one position of an arc flame control means;

FIG. 7 is a fragmentary sectional view taken substantially on the line 77 of FIG. 6;

FIG. 8 is a fragmentary view of a portion of the gas-filled lamp illustrating the relative position of the arc flame stabil ized between the electrodes;

FIG. 9 is a view illustrating a modified position for the arc flame control means;

FIG. 10 is a view illustrating a form of electromagnetic means for controlling the arc flame, and

FIG. 11 is a view similar to FIG. 9 illustrating a modified position for electromagnetic means for controlling the arc flame.

While the invention is illustrated in a projection arc lamp especially adapted for cinematography, television casting and theatrical lighting, it is to be understood that the invention may be used with other forms of lamp construction such as searchlights and the like.

FIGS. 1 through 4 illustrate a projection lamp construction embodying a form of the invention. The projection lamp construction is inclusive ofa housing 10 of substantially rectangular shape elongated in the direction of light rays projected from a reflector. The lamp structure has a base construction 12, preferably of cast metal, which supports an upper portion or section 14 of the housing fashioned of sheet metal. The sheet metal portion 14 of the housing is fashioned at one side with an opening normally closed by a movable door 16, the door being pivotally supported by pivot pins mounted in lugs or bosses 18 provided on the upper portion of the housing.

The upper portion of the housing 10 is equipped with a baf fle or member 20, particularly shown in FIG. 3, secured to the roof 21 of the housing by means of brackets 22. The baffle 20 is fashioned with a vent stack 24 through which air is vented from the housing 10 to convey away the heat from the arc lamp. Mounted upon a raised portion 26 adjacent the rear portion of the base 12 is a pedestal or support means 28 hav ing forwardly extending projections 30 to which is secured a reflector mounting means or supplemental frame 32 particularly shown in FIG. 3.

Supported upon the mounting means 32 is a reflector 35 preferably of ellipsoidal shape adapted to reflect or project rays of light from the arc forwardly through an opening in the front of the housing 10. The reflector mounting frame 32 is equipped with peripherally spaced spring clips 36 which engage the rear surface of the reflector 35. The reflector is held in engagement with the spring clips 36 by a latch member 37 pivotally supported on a lug 38, the latter carried by the reflector supporting frame 32. The latch member 37 is illustrated in FIG. 3 in reflector retaining position and is adapted for pivotal movement to facilitate removing the reflector.

Light rays from the reflector 35 are projected through an opening 40 in the housing section 14 and through an opening 41 in a supplemental housing 42 secured on the front panel of the housing 10. A douser screen or light impeding member 43 is secured to a shaft 44 journaled in bosses 45 carried by the supplemental housing 42.

The shaft 44 extends exteriorly of the douser or supplemental housing 42 and is equipped with a handle 46. The douser or light impeding member 43 is shown in open position in FIG. 3 and is manually movable about the axis of the shaft 44 for closing the opening 41 to interrupt the projection oflight.

The lamp 48 providing the arc source of light is of elongated construction and includes enlarged end terminal regions 50 and -2, the end construction 50 supporting a cathode electrode 54. the enlarged portion 52 supporting an anode electrode 56, the tips or extremities of the electrodes being spaced apart as shown in FIG. 3 to provide a gap 57 in which the arc is formed by electric current flow between the electrodes. A current conductor 58 sealed in the end region 50 is connected with the electrode 54 and with an igniter 59 of conventional construction for initiating operation of the lamp, the igniter being supported on the pedestal 28. A power switch 61 controls current supply to the electrodes, and an igniter switch 65 is provided for energizing the igniter 59 for striking the are between the electrodes.

Conductor 60 is sealed in the end region 52, and is connected with the electrode 56 and with a power supply. The current supply is preferably AC current rectified to direct current with a minimum current ripple. The lamp is fashioned with an elongated transparent envelope 62 fashioned of quartz of good optical quality, the envelope having an intermediate spherically shaped portion 64 adjacent the are which is formed between the tips of the electrodes.

The envelope 62 is filled with an inert gas under pressure, such as xenon. The focal point of the reflector 35 is at the gap 57 on the horizontal axis of the electrodes. The lamp 48 is adjustable so that the arc may be adjusted to the most efficient light projecting position with respect to the reflector 35 whereby maximum illumination efficiency may be attained.

Referring particularly to FIGS. 3 and 4, the base structure 12 is fashioned with boss portions 66 and 67. Each of the bosses is bored to provide a journal support for a rotatable shaft 69. Rotatably mounted on the front sidewall of the base 12 is a knurled knob 70 which is connected with one end of the shaft 69 by a flexible cable 72 of conventional construction of a character for transmitting rotation of the knob 70 to the shaft 69. A pedestal or member 74 provides a support for one end region of the xenon lamp construction 48.

The pedestal 74 is fashioned with a boss 76 which is bored to accommodate the shaft 69, the pedestal 74 being slidable along the shaft. The pedestal 74 is fashioned with a second boss 78 having a thread bore accommodating a threaded portion 79 of the shaft 69 which is threaded into the threaded bore in the boss 78. Through this arrangement, rotation of the knob 70 effects rotation of the shaft 69 through the flexible cable 72 for adjusting the lamp supporting pedestal or member 74 lengthwise of the housing 14. the direction of adjustment being dependent upon the direction of rotation of the central knob or member 70.

The member 74 is fashioned with a bifurcated projection 81 which straddles a pin 82 threaded into a bore in a projection 83 integrally formed on the base member 12. The pin 82 is locked to the projection 83 by a locknut 84. The pin 82 extending between the furcations of the bifurcated portion 81 is ofa diameter to facilitate sliding movement of the member 74 relative to the pin 82. The pin 82 serves to maintain the member 74 for adjustment in a rectilinear direction lengthwise of the housing without pivotal movement of the member 74.

The pedestal or member 74 is fashioned with an upwardly extending web portion 86 which, as shown in FIG. 5, is fashioned at its upper end with an opening 88 having chamfered entrance regions 90. A lamp mounting bracket 92 has a bifurcated portion, the furcations 94 straddling the upper portion of the web 86. The furcations 94 are respectively fashioned with a smooth bore and a threaded bore to accommodate a bolt 96 which extends through the opening 88 in the web 86 to mount the bracket 92 on the web 86 of member 74.

The web portion between the furcations 94 is ofa thickness or dimension to accommodate limited relative swivel move ment of the bracket 92 with respect to the web 86 to facilitate adjusting movement of the other end region of the lamp. The lamp support bracket 92 has a semicylindrical recess or cradle 98 which receives an elongated cylindrical portion 63 of the xenon lamp envelope 62.

The portion 63 is embraced by a clamp member 100 which may be drawn into snug engagement with the lamp portion 63 by screws 101. Through this arrangement. the lamp may be adjusted lengthwise along the axis of the reflector 35.

Means is provided engageable with the other end region of the xenon lamp 48 for adjusting the said end region vertically and transversely of the axis of the reflector to secure accurate positioning of the arc in the space 57 with respect to the light projecting surface of the reflector 35, this arrangement being shown particularly in FIGS. 3 and 44 The pedestal or member 28 at the rear of the reflector is fashioned with a boss 104 and a second boss 106 spaced transversely from the first boss as shown in FIG. 4. The boss 104 is bored to journally support a shaft 108. The boss 106 is provided with a threaded bore to receive a threaded tenon 109 of the shaft 108. Journally supported upon means carried by the base structure 12 at the front side thereof is a rotatable knob or member 110. A flexible cable 112 has one end secured to the rotatable knob and the other end secured to an end of the shaft 108.

A movable carriage 114 is mounted upon the shaft 108. The carriage 114 is fashioned with a first projection or boss portion 116 having a bore therein receiving the shaft 108, the bore being slightly larger than the diameter of the shaft to accommodate slidable movement of the carriage along the shaft.

The carriage 114 is fashioned with a second projection or boss portion 118 provided with a threaded bore accommodating the threaded tenon 109 on the shaft 108. The carriage 114 is equipped with a member or block 120 having a generally V- shaped notch 122 for receiving and supporting an end region of the xenon lamp construction 48.

As shown in FIG. 3, the enlarged region 50 of the lamp con struction is nested or cradled in the V-shaped notch 122 provided in the block or member 120. A rotatable control knob 126 is journaled by means supported by the base structure 12. The pedestal 28 is fashioned with a horizontally extending projection 128 having a vertically arranged threaded bore accommodating a threaded stub shaft 130. The movable carriage 114 is fashioned with a horizontal pad or projection 132 which is engaged by the upper end of the threaded stub shaft 130, as shown in FIG. 3.

One end of a flexible cable 134 is connected with the control knob 126 and the other end of the cable 134 fixedly secured to the lower end of the threaded stub shaft 130. As will be apparent from FIG. 3. rotation of the stub shaft 130. having threaded connection with the projection I28, elevates or lowers the end region of the lamp construction 48 depend ing upon the direction of rotation ofthe stub shaft 130.

Rotation of the control knob 110 is transmitted by the flexible cable 112 to rotate the shaft 108. rotation of the shaft 108 moving or adjusting the carrier 114 in a transverse direction depending upon the direction of rotation of the knob 110.

As the end region 50 of the xenon lamp 48 is nested in the notch or cradle 122 of member or block 120, this end region of the lamp 48 will be moved transversely causing slight pivotal movement of the lamp construction 48 about a vertical axis through the opening 88 in the web 86 accommodating the screw 96 so that the tips of the electrodes 54 and 56 are adjusted transversely of the longitudinal axis of the reflector 35 to effect transverse adjustment of the arc.

Manual rotation of the control knob 126 is transmitted through the flexible cable 134 to the vertically disposed threaded stub shaft 130. As the upper end of the stub shaft engages the pad 132 on the carriage 114. the adjustment end region 50 of the lamp construction 48 will be elevated or lowered depending upon the direction of rotation of the knob 126 and the stub shaft 130. Through this arrangement the lamp construction 48 is pivotally moved in a vertical plane about the horizontal axis of the screw 96 whereby the tips of the electrodes 54 and 56 may be adjusted vertically whereby the position of the arc may be vertically adjusted with respect to the axis of the light-reflecting surface of the reflector 35 Heretofore it has not been practicable to utilize a xenon lamp in a substantially horizontal position for several reasons. The body of incandescent ionized gases of the arc is normally distorted upwardly by the intense head in the region of the arc causing a concentration of heat at a localized region of the quartz envelop above the arc.

This thermal instability sets up or establishes severe stresses in the quartz envelope which weaken the lamp structure and as comparatively high pressure exists within the quartz envelop, the envelope is liable to be fractured by the effects of the localized heating and internal pressures.

Due to the vertical distortion of the body of incandescent ionized gases providing the light source, the light transmitted to the reflector does not emanate from a comparatively small focal area but from the large area of the distorted body of incandescent gases between the electrodes This condition results in very inefficient diffused reflected light and impairs the control of light rays projected from the reflector.

In the arrangement of the invention means is provided exerting forces on the ionized body of incandescent gases of the arc for eliminating the vertical distortion or distention of the gases and stabilizing incandescent gases in a sphere or ball-like body centrally disposed between the tips of the electrodes. Magnetic forces are employed for performing this function. Referring particularly to FIGS. 3, 4, 6 and 7. one form of means for establishing magnetic forces is illustrated and includes an L-shaped bracket 136 secured to the base portion 137 of the base 12 by screws 138.

Secured to an upwardly extending portion 139 of the bracket 136 is a magnet support means or block 140. The upwardly extending portion 139 of bracket 136 is fashioned with a vertical slot 142 which accommodates securing screws 143 extending into threaded openings in the block 140.

The block 140 is fashioned with a bore to accommodate a bar magnet 146 of the permanent magnet type such as an Al nico magnet held in position by a setscrew 141. The block is bored to position the bar magnet 146 with its longitudinal axis disposed transversely of the longitudinal axis of the lamp 48 and transversely of the housing as illustrated in FIGS. 4 and 6.

As shown in FIG. 3, the bar magnet 146 is disposed with its central region substantially vertically beneath the region of the arc established between the tips of the electrodes. In reference to the position of the magnet in respect of polarity the south pole or negative pole end 148 is disposed at the left side of a vertical plane A-A through the longitudinal axis of the lamp 48 and the axis of the reflector 35 viewed from the front of the reflector as illustrated in FIG. 6.

The north pole end or positive pole 150 of the bar magnet is disposed an equal distance to the right side of the plane A-A as viewed in FIG. 6. For most efficient action of the magnetic forces on the body of incandescent gases it is preferable the central position of the magnet be on the plane A-A. although effective results may be attained if the bar magnet 146 is disposed a slight distance in either transverse direction from the central position illustrated in FIGS. 4 and 6.

It is found that by positioning the magnet means 146 in the position described with respect to the body of incandescent gases providing the are light, the body of incandescent gases is drawn downwardly by magnetic forces so that the central region of the body of the incandescent gases is substantially at the axis of the electrodes and that the body of incandescent gases becomes substantially spherical with a minimum of distortion. By stabilizing the body of incandescent gases centrally between the electrodes, there is no concentration of heat at a localized region of the spherical portion 64 of the quartz envelope so that localized thermal stresses are eliminated.

The concentration of the body of incandescent gases into a smaller comparatively spherically shaped volume more nearly approaches a point source of light at the focal point of the reflector so that the rays of light projected from the reflector are better controlled and may be concentrated in a smaller area for illumination purposes. It is also found that by stabilizing the incandescent gases between the electrodes in a spherically shaped body that improved efficiency of light rays are directed to the reflector with an increased intensity in the usable light projected from the reflector. It is also found that the concentration and stabilization of the incandescent body of gases on the central axis of the electrodes improves the light intensity to an extent that the current supplied to the arc may be reduced and still provide an amount of light directed to the reflector to secure efficient projected light.

FIG. 8 is illustrative of the effect of the magnetic forces in stabilizing the body of incandescent gases between the electrodes. The relative position and general shape of the distorted body of incandescent gases without the stabilizing effect of the magnetic forces is indicated in broken lines at 152. In this position the incandescent gases are normally distorted upwardly to a position wherein the region of the spherically shaped portion of the quartz envelope above the distorted body of gases is subjected to a concentration of heat from the gases.

With the use of the bar magnet 146 positioned as shown in FIG. 6, the body of incandescent gases is indicated at 154 in full lines where it will be seen that the body of incandescent gases is more nearly spherical in shape with its center substantially on the axis of the electrodes and at the focal point of the reflector.

The effect of the magnetic forces provided by the magnetic means 146 may be varied by adjusting the relative position of the bar magnet 146 vertically and thereby make possible the most efficient stabilized position of the body of incandescent gases for efficient illumination from the reflector.

The size of the bar magnet 146 and its relative position with respect to the arc vary with the amount of current producing the arc and the strength of the magnetic forces. As an example in utilizing an xenon lamp of 6 kilowatts, a bar magnet 146 of about 1 inch in diameter is disposed with its axis approximate ly 7 inches below the longitudinal axis of the lamp, the length of the magnet bar being between 4 and 5 inches.

It is further found that the spacing between the tips of the electrodes 54 and 56 may vary between 3 millimeters and I2 millimeters depending upon the capacity of the lamp and the size and focal length of the reflector 35 with which the lamp is used. It has been found preferable to utilize a spacing for the electrodes to minimize the volume of incandescent gases in the arc and yet secure efficient light projected from the reflector by reducing the volume of the body of incandescent gases providing the arc.

The light source provided by the stabilized arc more nearly approaches a point providing for better control of light rays from the reflector as well as to promote a reduction in the amount of current for establishing the arc. While the bar magnet illustrated has end surfaces in converging angular planes, it is to be understood that a bar magnet having its end surfaces in substantially parallel planes may be used if desired.

FIG. 9 illustrates a modified positioning for the bar magnet. As shown in FIG. 9, a bracket I36a is secured to the baffle member 20 or to other support means. The bar magnet 146a is mounted in a block 14011 which is adjustably secured to the bracket 136a by bolts 1430. The magnet 1460 is disposed adjacent the upper terminus of the reflector with the axis of the bar magnet 146a in a transverse vertical plane passing through the arc established in the space 57 between the tips of the electrodes.

In this form, the bar magnet 146a is positioned whereby the north or positive pole end is disposed at the left side of the plane AA shown in FIG. 6 viewed from the front of the reflector 35. With the bar magnet 1460 in such position. the magnetic forces repel the normally upwardly distorted body of incandescent gases, forcing them downwardly to stabilize the body of incandescent gases more nearly centrally on the axis of the electrodes.

Such magnetic forces eliminate the distortion of the arc flame or incandescent gases and provide a more nearly spherically shaped body of incandescent gases, thus improving the efficiency of light projected from the reflector and eliminating concentration of heat in a localized area of the spherical portion 64 of the quartz envelope above the body of gases.

FIG. is a view similar to FIG. 7 illustrating an electromagnetic means for stabilizing the incandescent gases of the arc. The arrangement illustrated in FIG. 10 includes a bracket 136!) secured to portion [37 of the base structure 12 of the lamp. A block l40b, adjustable relative to the bracket 136b, is secured in adjusted position by bolts 1431). In this form, the magnetic means is inclusive of a soft iron core 156 surrounded by a coil I58 having leads or conductors I60 and 161 for connection with a current supply, preferably of low voltage.

The electromagnetic means 156, 158 is disposed in a bore in the block 146b, the coil 158 being insulated from the core 156 and from the block 14%. The current flow through the coil is in a direction to establish the south or negative pole end of the core 156 to the right side of the plane A-A, shown in FIG. 6, viewed from the front of the reflector, whereby the electromagnetic forces are effective to eliminate the upward distortion of the body of incandescent gases providing the are as illustrated as 152 in FIG. 8 to stabilize the body of gases in more spherical form centrally between the tips of the electrodes, as illustrated at 154 in FIG. 8.

With the use of an electromagnetic means illustrated in FIG. 10, the stabilization of the body of incandescent gases may be accurately controlled by varying the voltage or amperage of the current flow through the coil 158. The coil 158 is connected with a supply of direct current.

FIG. 11 is a view similar to FIG. 9 illustrating an electromagnetic means disposed above the are produced between the electrodes and on an axis in a transverse vertical plane passing through the gap or space 57 between the electrodes. The bracket l36c carried by the member supports a block 1400 secured to member 136a by bolts 1430. Disposed in the bore in the block l40c is an electromagnetic means comprising a soft iron core 1560 and a coil l58c surrounding the core, the coil being insulated from the core 156a and from the block 1400 and provided with conductors or leads 160C and 161C, for connection with a direct current supply.

With the electromagnetic means 156e, 158C in the position shown in FIG. 11 adjacent the upper terminus of the reflector 35, the current flow through the coil l58c is in a direction opposite to the current flow through the coil 158, shown in FIG. 10. With current flow in the opposite direction, the polarity of the soft iron core 156a is reversed whereby the electromagnetic forces act on the upwardly distorted incandescent gases of the arc to force the gases downwardly whereby the incandescent body of gases is more nearly spherical as illustrated at 154 in FIG. 8 with the center of the body of gases substantially on the axis of the electrodes.

The amperage or voltage of the current flow through the coil 158C may be varied to vary the intensity of the magnetic forces provided by the electromagnetic means to accurately control the position of the body of gases of the arc between the electrodes so as to obtain maximum efficiency of projected light from the reflector 35.

The lamp housing 10 is provided with means for effectively conveying away the heat developed by the arc. Disposed in the housing portion 14 is a blower 165 driven by a motor 166. Air is admitted to the blower through an opening 168 of an annular fitting 16 mounted on the upper panel 21 of the housing structure 14. Air entering the opening 168 is conveyed to the axial region ofthe blower 165 through a flexible tube 170. The tangential outlet portion 172 of the blower is connected by a duct 174 with the hollow interior region 175 of the base structure 12.

The air from the duct 174 flows through an opening in a web 177 of the base structure and through a duct 178 to deliver air onto the end region 52 of the xenon lamp construction. The angularly disposed portion 180 of the base structure is fashioned with openings (not shown) to facilitate flow of air through openings 182 in the reflector support frame 32 and through openings 184 in the base structure to facilitate cooling of components in the rear region of the lamp housing 10. The air delivered by the blower is vented through the stack 24 to the atmosphere.

While the most efficient stabilizing effect of the magnetic means is attained with the magnet positioned either directly below or above the region of the arc, it is to be understood that the magnetic means may be slightly out of a vertical position through the arc and secure effective stabilization of the body ofincandescent gases. The universal adjusting means for the xenon lamp 48 hereinbefore described provides an efficient and effective means for accurately positioning the arc between the electrodes at the focal point of the reflector 35.

It will be seen that through the universal adjustment for the xenon lamp and the utilization of the stabilizing forces of magnetic means for controlling the relative position of the body of incandescent gases at the arc, a most efficient utilization and projection of light from the arc is attained.

Furthermore, in utilizing an are provided in a gas sealed envelope there is no residue deposited upon the reflector surface such as is encountered in the use of an unconfined arc provided between carbon electrodes.

It is apparent that, within the scope of the invention, modifications and different arrangements may be made other than as herein disclosed, and the present disclosure is illustrative merely, the invention comprehending all variations thereof.

Iclaim:

1. In combination, a housing, a lamp in said housing comprising an elongated sealed envelope containing an inert gas and electrodes spaced to provide an are by the passage of electric current between the electrodes, a reflector arranged to project light from the arc, lamp supporting means in the housing, said lamp supporting means including means engaging the lamp adjustable lengthwise of the housing for adjusting the position of the lamp lengthwise of the axis of the electrodes, second adjustable means operatively engaging the lamp for moving an end region of the lamp vertically and transversely of the axis of the reflector, and a permanent magnet spaced laterally of the are between the electrodes, the polarity of the magnet being arranged to influence the position of the incan descent gases at the arc to effect a stabilization of the incandescent gases at the region of are substantially congruent with the focal point of the reflector.

2, ln combination, a housing, a lamp in said housing comprising an elongated sealed envelope containing an inert gas and electrodes spaced to provide an arc by the passage of electric current between the electrodes, a reflector arranged to project light from the arc, lamp supporting means in the housing, said lamp supporting means including means engaging the lamp adjustable lengthwise of the housing for adjusting the position of the lamp lengthwise of the axis of the electrodes, second adjustable means operatively engaging the lamp for moving an end region of the lamp vertically and transversely of the axis of the reflector, a permanent magnet spaced laterally of the are between the electrodes, the polarity of the magnet being arranged to influence the position of the incandescent gases at the arc to effect a stabilization of the incandescent gases at the region of are substantially congruent with the focal point of the reflector, and means supporting the magnet for adjusting the magnet with respect to the region between the tips ofthe electrodes.

3. An arc lamp construction comprising, in combination. a housing including a base portion, an arc lamp in said housing comprising an elongated sealed envelope containing an inert gas and electrodes spaced to provide an arc by the passage of electric current between the electrodes, at reflector, means mounting the reflector in the housing, support means for the lamp, said support means including a first member, rotatable means on the base portion supporting the first member for adjusting said member longitudinally of the housing, clamp means engaging the envelope of the lamp, said clamp means being mounted for limited articulation with respect to said first member, a second member movably mounted on the base portion and engaging an end region of the lamp, first means for adjusting said second member in a direction transversely of the housing, second means for adjusting said second member in a substantially vertical direction, and magnetic means spaced from the region of the arc for influencing the position of the incandescent gases at the region of the arc.

4. The combination according to claim 3 wherein the magnetic means is a permanent magnet, and support means for the magnet for adjusting the distance of the magnet from the region of the arc.

5. The combination according to claim 3 including electromagnetic means spaced from the arc for influencing the position of the incandescent gases at the region of the arc.

6. The combination according to claim 3 including a control member accessible exteriorly of the base portion for adjusting the relative position of said first member, and second and third control members accessible exteriorly of the base portion for manipulating said first and second means for adjusting an end region of the lamp in verticaland horizontal directions.

7. An arc lamp construction comprising, in combination, a

housing including a base portion, an arc lamp in said housing comprising an elongated sealed envelope containing an inert gas and electrodes spaced to provide an arc by the passage of electric current between the electrodes, a reflector, means mounting the reflector in the housing, means supporting the lamp in the housing with the electrodes in a substantially horizontal position, said lamp supporting means including a first member, rotatable means on the base portion supporting the first member for adjusting said member longitudinally of the housing, bracket means engaging the envelope of the lamp, said bracket means being mounted for limited articulation with respect to said first member, a second member movably mounted on the base portion and engaging an end re gion of the lamp, first means for adjusting said second member in a direction transversely of the housing, second means for adjusting said second member in a substantially vertical direction, and magnetic means spaced from the region of the are for influencing the position of the incandescent gases at the region of the arc.

Claims (7)

1. In combination, a housing, a lamp in said housing comprising an elongated sealed envelope containing an inert gas and electrodes spaced to provide an arc by the passage of electric current between the electrodes, a reflector arranged to project light from the arc, lamp supporting means in the housing, said lamp supporting means including means engaging the lamp adjustable lengthwise of the housing for adjusting the position of the lamp lengthwise of the axis of the electrodes, second adjustable means operatively engaging the lamp for moving an end region of the lamp vertically and transversely of the axis of the reflector, and a permanent magnet spaced laterally of the arc between the electrodes, the polarity of the magnet being arranged to influence the position of the incandescent gases at the arc to effect a stabilization of the incandescent gases at the region of arc substantially congruent with the focal point of the reflector.

2. In combination, a housing, a lamp in said housing comprising an elongated sealed envelope containing an inert gas and electrodes spaced to provide an arc by the passage of electric current between the electrodes, a reflector arranged to project light from the arc, lamp supporting means in the housing, said lamp supporting means including means engaging the lamp adjustable lengthwise of the housing for adjusting the position of the lamp lengthwise of the axis of the electrodes, second adjustable means operatively engaging the lamp for moving an end region of the lamp vertically and transversely of the axis of the reflector, a permanent magnet spaced laterally of the arc between the electrodes, the polarity of the magnet being arranged to influence the position of the incandescent gases at the arc to effect a stabilization of the incandescent gases at the region of arc substantially congruent with the focal point of the reflector, and means supporting the magnet for adjusting the magnet with respect to the region between the tips of the electrodes.

3. An arc lamp construction comprising, in combination, a housing including a base portion, an arc lamp in said housing comprising an elongated sealed envelope containing an inert gas and electrodes spaced to provide an arc by the passage of electric current between the electrodes, a reflector, means mounting the reflector in the housing, support means for the lamp, said support means including a first member, rotatable means on the base portion supporting the first member for adjusting said member longitudinally of the housing, clamp means engaging the envelope of the lamp, said clamp means being mounted for limited articulation with respect to said first member, a second member movably mounted on the base portion and engaging an end region of the lamp, first means for adjusting said second member in a direction transversely of the housing, second means for adjusting said second member in a substantially vertical direction, and magnetic means spaced from the region of the arc for influencing the position of the incandescent gases at the region of the arc.

4. The combination according to claim 3 wherein the magnetic means is a permanent magnet, and support means for the magnet for adjusting the distance of the magnet from the region of the arc.

5. The combination according to claim 3 including electromagnetic means spaced from the arc for influencing the position of the incandescent gases at the region of the arc.

6. The combination according to claim 3 including a control member accessible exteriorly of the base portion for adjusting the relative position of said first member, and second and third control members accessible exteriorly of the base portion for manipulating said first and second means for adjusting an end region of the lamp in vertical and horizontal directions.

7. An arc lamp construction comprising, in combination, a housing including a base portion, an arc lamp in said housing comprising an elongated sealed envelope containing an inert gas and electrodes spaced to provide an arc by the passage of electric current between the electrodes, a reflector, means mounting the reflector in the housing, means supporting the lamp in the housing with the electrodes in a substantially horizontal position, said lamp supporting means including a first member, rotatable means on the base portion supporting the first member for adjusting said member longitudinally of the housing, bracket means engaging the envelope of the lamp, said bracket means being mounted for limited articulation with respect to said first member, a second member movably mounted on the base portion and engaging an end region of the lamp, first means for adjusting said second member in a direction transversely of the housing, second means for adjusting said second member in a substantially vertical direction, and magnetic means spaced from the region of the arc for influencing the position of the incandescent gases at the region of the arc.

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