US2107906A

US2107906A - Lamp support for projectors

Info

Publication number: US2107906A
Application number: US70768A
Authority: US
Inventors: Stephen C Rogers
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1936-03-25
Filing date: 1936-03-25
Publication date: 1938-02-08
Anticipated expiration: 1955-02-08

Description

Feb. 8, 1938. ,5 g, ROGERS LMEP'SUfFQRI FOR PROJECTORS Filed March 25, 1936 2 Sheets-Sheet l Inventor: -Stephe'n C. R0 era y JV 3 zfis Attorney- Feb. 8, 1938. S. ROGERS 2,107,906

LAMP SUPPORT FOR PROJEC TORS Filddflarch 25, 1936 2 Sheets-Sheet 2 49 Z if i Inventor: Stephen C. Rogevs,

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Patented Feb. s, 1938 PATENT OFFICE 2,107,906- LAMP. SUPPORT FOR PROJECTORS StephenC. Rogers, Lynn, Mass. assignor to General Electric Company; a corporation of New York Application March, 25, 1936,'Serial No. 70,768 4 Claims. ((1240-41) 1 My invention relates to lamp mountings for projectors and more particularly .to projectors "which may be adjusted bodily to project their respective beams above or below thehorizontal. One object of my invention, is. to provide a lamp mounting which will be automatically adjusted to hold the lamp in a predetermined position responsive to. each change of theangular position of the projector.

gFor a better understandingof my invention, together with other and further objects thereof, reference is had to the followingdescription, taken in connection with the accompanying drawings, and its scope will be pointed outin the appended claims.

Referring to the accompanying drawings, Fig. 1 illustrates, partly in section, a projector (equipped with a lamp support built in accordance with my invention; Fig. 2 illustrates the same projector tilted so as to project its beam downwarclly, the lamp support holding the lamp in the I same position as in Fig. 1; Fig. 3 is a fragmentary View illustrating the connection between the projector and lamp'support whereby the lamp sup:

port ismaintainedinthe predetermined operatiIi-g/ position, irrespective of the angular adjust- -ment of the projector,; and Figs. 4 and 5 illustrate a side and front View respectively of a modifica- V tion of my invention.

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1 ;1n the operation of enclosed floodlights, the enclosed incandescent lamps sometimes develop I hot spots, the temperature of which rises high J I enough to soften the glass of the lampand there i by ruin the lamp. The hot spots usually occur above the filament when the lamp is operated horizontally and are apparently caused by the heat rising from the filament. In order to avoid the occurrence of such hot spots, I operate the lamp verticallywith the base and the neck part of the lamp directly above the filament and, in

- accordance with my invention, provide a support which will maintain this vertical position of the lamp throughouttherange of angular adjustment' of the projector.

I In this vertical position the heat from the filament risestoward' the neck part of the lamp which is usually protected by a mica disc and as a result of such operation I am the pivots I and II. the pins I l and I4 and the distances between pins housing 4 is pivoted on a yoke support 6 by means of stationary pivot pins I mounted on diametrically opposite sides of the housing. In Figs. 1 and 2 only the pivot pin on the farther side of the housing is shown. Fig. 1 illustrates the pivot pin behind the reflector 5. In Fig. 2 the reflector is broken away to better illustrate the pivot and the lamp supporting mechanism. The projector lamp 8 is mounted in a socket 9 which is in turn supported by a U-shaped support it. This lamp support 10 is pivoted at its ends on pins. II also mounted at diametricallyopposite sides of the housing 4 and moves between the inside surface of the housing 4 and the outer surface of the reflector 5 whereby it does not interfere with the projection of light.

Fig. 3 is an enlarged perspective view of the pivot end of the support 10 and its moving mechanism. This view is taken of the side opposite to that illustrated in Figs. 1 and. 2 in a; direction looking in through the front of the housing 4. The housing pivots 1 and the lamp support pivots l l are recessed in the housing so as to bring the support l close to the inner surface of the housing and give it room to move between this surface and the reflector. V

The p'ms II which comprise the pivots for the support ID are spaced from the pivot pins '3 of the housing and are arranged on an axis parallel to the pivotal axis of the casing. This axis is preferably located in the focal plane of the reflector 5. The lamp 8 is to be operated in a vertical position with its filament in focus with the reflector in all positions of the housing about its pivots 1. In order to bring about this opera tion, the ends of the support are provided with arms l2 projecting beyond the pivotal points I! and are respectively connected to the stationary pivot pins 1 by links [3, pins l4 and I5 and links Hi. The links 16 are rigidly attached to the inner ends of the pivot pins 1 and are located in recesses IT in the housing 4. They are preferably arranged parallel to the yoke 6 and extend downwardly from the pin 1. The link I3 is pivoted to the extension I2 and the link l6 by the pins I4 and I5 and is free to move angularly and relativelyto both extension 12 and link 16. Referring to Figs. 1 and 2, the pins 14 and I5 are spaced a distance equal to the distance between Also the distances between 1 and I5 are equal, thereby forming a parallelogram, the sides of which remain parallel irrespective of the angular relation between them.

In operation the housing 4 is moved about its pivots 1 and held in any position by a clamping mechanism l8. The link I6 and support H] are mounted vertically. In view of the above-described characteristics of the connecting mechanism, the support It! simply moves about its pivot II and remains parallel to the link I6 and also vertical. It is, of course, not necessary to have the linkage mechanism on both sides of the lamp support. A linkage mechanism on only one side of the housing can be made sufliciently strong to move the support Ill.

With the above described arrangement th lamp support remains in a substantially vertical position between the housing and reflector wall during movement of the housing about its pivots and does not interfere with the projected beam. The lamp projects into the reflector through a slot [9 wherein it can move relatively to the reflector when the projector is moved about its pivot. The upper end of the support l0 containing the socket 9 projects into a recess 28 which is built into the housing 4.

In Figs. 4 and 5, I have illustrated a side view, partially in section, of a projector provided with a modification of my invention. In this modification the axis of tilt of the projector casing coincides with the mounting axis of the lamp bracket. Referring to this in detail, we find casing 4 pivoted on yoke 6 by pins 2| and 22. The pins are rigidly mounted in the yoke and project through bearings 23 and 2 5 in the sides of the casing 4 respectively. Brackets 25 and 26 are riveted to the ends of the pins respectively and support the lamp socket '9. The lamp 8 projects through the slot 19 into the reflector 5, its light source being in the focus of the reflector. The upper end of the support with socket 9 projects into a recess 2 When the projector is tilted, this recess moves relatively to the support and socket.

Fig. 5 illustrates a sectional view along lines 5-5 in Fig. 4 It will be evident from this View and that of Fig. 4 that the focus of the reflector, 7

light source and the' axis of tilt of the casing coincide on a common axis. When the casing 4 is, therefore, tilted the lamp remains in line with the yoke and the reflector 4 moves about its own focal point. In this modification the brackets 25 and 28 also move between the reflector and housing wall so that they do not interfere with the light beam.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a light projector, the combination of a housing, a yoke support for said housing provided with pivot pins about which said housing is arranged to move, a reflector in said housing, a lamp, a support for said lamp arranged between said reflector and housing and pivoted upon the wall of said housing, a connection between said lamp support and said pivot pins comprising an arm rigidly attached to one of said pivot pins, a connecting link pivotally connected to said bracket and said lamp support, the distance between the connecting link pivots being equal to the distance between the yoke pivot and the lamp support pivot and the connecting link being parallel to a line drawn between the housing pivot and the lamp support pivot whereby the lamp support is maintained in a predetermined position relatively to said yoke irrespective of the movement of said housing about its pivots.

2. In a light projector, the combination of a yoke, pivot pins rigidly supported by said yoke, a casing pivotally mounted on said pins and provided with a recess, a reflector mounted in said casing and provided with a slot, a lamp pro jecting from said casing into said reflector through said slot having its light source in focus with said reflector, and a support for said lamp comprising a bracket arranged between said casing and. reflector formovement relatively to said casing and reflector during movement of said casing about its pivot, and arranged to support said lamp in said recess and said slot and retain the said lamp subtantially stationary in a predetermined operating position.

3. In a light projector the combination of a casing, a support therefor comprising a yoke and pivot pins attached to the yoke and arranged horizontally, thereby providing an axis of rotation for said casing in a vertical plane, a reflector in said casing, a lamp therein and a support for said lamp pivotally mounted within said casing, and a linkage mechanism connected between said lamp support and said casing support whereby said lamp support is moved about its pivot responsive to movement of said casing about its pivot in a manner to hold said lamp in focus with said reflector and in a substantially constant vertical operating position during the rotation of said casing about its pivot.

4. In a light projector the combination of a casing, a support therefor provided with horizontal pivots about which said casing may be positioned, a reflector in said casing, a lamp mounted Within said casing in a substantially vertical position and in focus with said reflector, a pivoted support for said lamp, and means for connecting said casing support to said lamp support for holding said lamp support in a position to maintain said lamp in focus with said reflector and in said substantially vertical position during the movement of said casing about its pivot.

S'I'EPI-IEN C. ROGERS.