US2477957A - Lamp housing - Google Patents

Description

Aug. 2, 1949. J, BRlsKlN LAMP HOUSINGl Filed March 19, 1945 5w M Kr/16315 Patented Aug. 2, 1949 LAMP HOUSING Jack Briskin, Chicago, 111., assignor to Revere Camera Company, Chicago, Ill., a corporation of Delaware Application March 19, 1945, seria1No.'5s3,422 (ci. 24o-47) 3 Claims.

This invention relates to improvements in lamp housings, and in particular to a lamp housing for use in a motion picture projector.

Motion pictureprojectors are provided with an incandescent bulb of great light intensity. The amount of heat radiated therefrom is often sufficient to soften the glass of the bulb, particularly when the bulb is enclosed in a lamp chamber. It has been the practice to provide such a lamp chamber for the bulb, and said chamber is provided with exterior radiating fins. A blower is provided for blowing a blast of -cold air through the chamber. However, in spite of this construction the chamber wall heats t such an extent that it tends to maintain the temperature within the chamber at an undesirably high level.

It is an object of this invention to provide a lamp housing within the chamber which will serve to obstruct the direct radiation from the bulb to the lamp chamber.

It is a further object to provide improved heat dissipating means for such a housing whereby an increased amount of heat may be removed from the interior of the lamp chamber by an air blast.

It is a further object to provide an improved lamp housing embodying means for spacing the bulb in the center of the lamp chamber to effect a more uniform distribution of the heat radiated to the surrounding parts.

Other objects, features and advantages will become apparent as this description proceeds.

With reference now to the drawings, in which like reference numerals designate like parts,

Fig. 1 is an elevation of a motion picture projector showing the usual lamp chamber;

Fig. 2 is an elevation of a preferred embodiment of this invention; and

Fig. 3 is a section taken along line 3--3 of Fig. 2, and also showing in dotted lines the relationship of the lamp housing to the bulb and to the lamp chamber.

The projector Ill shown in Fig. 1 is provided with the usual lamp chamber II. The projector also embodies the usual blower, not shown, which blows a blast of air through the lamp chamber for cooling the bulb, The lamp chamber is provided with exterior radiating iins 20.

The lamp housing I2, as shown in Fig-s. 2 and 3, is adapted to fit within the lamp chamber II. The lamp housing comprises a web portion I3 which is provided with radially disposed interiorly directed fins I4, and with radially disposed exteriorly directed ns I5. The length of the exterior ns I5 is such as to cause the general configuration of the lamp housing to conform to the interior of the lamp chamber II, as shown in Fig. 3. In particular, this is effected by making certain of the' exterior ns I5 longer than the others, as indicated by the reference numeral I6. The lamp housing is also provided with an opening 2| through which a beamof light may be projected to the other parts of the projector.

It will be seen that the web portion I3 provides a barrier to interrupt the heat radiation from a bulb I9 which i-s disposed within the lamp chamber. The interior fins I4 provide a series of interior channels I1, and the exterior fins I5 provide a series of exterior channels I8. These channels completely lill the space between the exterior of the bulb I9 and the inner surface of the lamp chamber Il, and thus serve to canalize the air blast, and provide maximum surface contact between the air bla-st and the lamp housing. The ins I4 and I5 conduct away a considerable proportion of the heat received by radiation by the web portion I3. Furthermore, the interior edges of the interior fins I4 are closely adjacent to or in contact with the surface of the bulb I9,

f thus tending to further reduce the temperature at the bulb surface.

The operation of this device is such that a much greater proportion of the radiated heat is removed fromthe interior of the chamber Il than when such a lamp housing is not used, or wh-en only iin-s are used, Without the web portion. It has been found that with a projector operating at a speed of fourteen frames per second, that the temperature at the bulb surface is reduced from about 800 degrees F. to 590 degrees F., by the use of this improved lamp housing.

The lamp housing may be an integral die cast structure, or it can be fabricated from a slotted cylindrical member, which constitutes the web portion I3, in combination with the slotted interitting fins, which constitute the interior and exterior ns I4 and I5,

Although only a preferred embodiment of this invention has been shown and described herein, it will be understood that various modifications and changes may be made without departing from the spirit of this invention. The appended drawings and foregoing description are deemed to be illustrative only, and the invention is limited only by the appended claims.

Y I claim:

1. A lamp housing comprising a substantially cylindrical web portion provided with a series of inwardly extending heat radiating ns and a series of externally extending heat radiating fins,

3 the ns of said rst series and said second series extending in opposite directions from the same part of said cylindrical web portion and lying in radial planes with respect to the axis thereof,

2. In a motion picture projector, in combination with an incandescent bulb and a chamber therefor, a substantially cylindrical member surrounding saigl bulb for interepting radiation from said, bulb, and having a series of inwardly extending heat radiating fins and a, series of externally extending heat radiating fins for spac` ing said member from said bulb and frontiN .the walls of said chamber the fins of both of said series lying in radial planes withV respect Ito .the axis of said cylindrical member.

3. In a motion picture projector, in combination with an incandescent bulb `and a chamber therefor, a lamp housing disposed between said bulb and the walls of said chamber, and surfrounding said bulb, said lamp housing comprisme a substantially -cylindreal wniirlueus web portion -hafying substantial non-.reflecting inner and outer surfaces, a series o f inwardly extendingsubstantially radially disposed heat radiating ns formed integrally with said web portion, and` a kseries of externally extending substantially radially disposed-heat radiating ns formed inf tegrally Withrsa'id vweb portion, the inner edges of said inwardly extending fins substantially abutting said bulb, and the outer edges of said externally radiating ns substantially abutting the wall of said housing so that the entire space between the surface of said bulb and the surface of the side walls of said chamber is divided into a series of vertically disposed channels through which air guay be blown, the Qns qfffbpth series extending the samev part ai` said web portion.

JACK BRISKIN.

REFERENCES CITED The following reierenlcas are of record in the file Yef this patent;

UNITED s TA'IEs PA'I'ENTS Number Name Date 1,555,712 Hasselkus Sept. 29, 1925 2,007,499 Westberg July 9, 1935 2162,39# Worrell June .13,V 1.839 2,:2t22. Eliatetal. Sent- S. 1.9.41 2,385,5264 MeNalb -f-m- Sept.. 25, 19,4;5Y

FoRmGN PATENTS Number @emitir De?? 411.170 Great Britain-n.-f-e-ff 19?#V

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