US1272505A - Projecting-lamp. - Google Patents

Description

J. G. R. OHARA.

PROJECTING LAMP.

APPLICATION FILED JUNE 22, ma

Patented July 16, 1918.

sA ES UNI JOSEPH. G. R. OHARA, OF ST. LOUIS, MISSOURI,.ASSIGNOR TO EDUCATIONAL MOTION PICTURE MACHINE AND FILM COMPANY, OF ST. LOUIS, MISSOURI, A CORPORATION OF MISSOURI.

PROJECTING-LAMP.

To a w/wmz't may concern:

Be it known that I, JOSEPH G. R. OHARA,

a citizen of the United States, residing at the city of St. Louis, State of Missouri, have invented a certain new and useful Improvement in Projecting-Lamps, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it 'appertains to make and use the same, reference being had to the accompanying drawings, forming part of this specification.

' This invention relates to a form of projecting lantern designed particularly for use in projecting moving pictures from a film of the Sort customarily employed.

In the projecting apparatus nowcommonly usedfor the projection of motion pictures, an electric arc furnishes the source of light, and in conjunction with the use of such a luminant, it is necessary to employ a fire shutter which is automatically interposed between the source of light and the film when the latter becomes stationary for a length of time exceeding the normal exposure period.

It is the purpose of my invention, for one thing, to provide a form of projecting lantern which may be used effectively in the projection of motion pictures, but which renders unnecessary the use of the shutter now commonly employed.

A further use is to provide a lantern for the purpose described which is designed particularly for a portable apparatus which finds great usefulness in private exhibition work, such as class room or lecture work, or the demonstration of the operation of machinery or the like for commercial purposes.

Other objects will be pointed out hereinafter or will become ObVlOUS as the description of the device develops.

In the accompanying drawings, I illustrate the lamp or lantern of my improved construction- Figure 1 being atop view; and.

Fig. 2 a longitudinal vertical section.

Referring to the various parts of the device, by means of the reference numerals applied, it will be understood that numeral 1 indicates a base which is designed to be suitably supported on a tripod or other portable su port, and which is formed with an upwardly extending arcuate flange 2 form- Specification of Letters Patent.

Application filed June 22, 1916.

Patented July 16, 1918.

Serial No. 105,241.

in a seat. \Vithin this seat is disposed a blOCkl of insulating material which extends v out of the seat at the rear thereof, and in which insulating block are seat d the contact terminals '5 for the electrical connecti'ons. Block 4 forms the support for the lamp socket 6 and the parts carried thereby, the same including the Contact spring 7 secured to one of the terminals by the screw 8, and the screw 9 which forms an electrical connection between the other terminal and the metallic socket portion,6 into which the incandescent lamp 10 is screwed in the customary fashion.

Supported on the base 1 is a lower housing portion in the form of a guard 11 having a depending annular'fiange 11 which embraces the arcuate flange 2 and rests in partupon the base 1 and in part upon the insulating block l where the latter projects from th seat formed by the flange 2;. The guard 11 is round and concave with the concave face directed upwardly.

Supported on the guard or lower housing portion 11 is a main housin portion 12 which is of a light pressed metal and of generalglobular form with openings at its bottom, top and ,front portions. This main housing portion is made up of two sections, upper and lower, which are joined on the horizontal median line by a flanged joint 12", the portions forming which are struck outwardly, and which provides an annular still"- ening member about the girth portion of the housing. This intermediate housing por- .tion 12 is supported on the lower housing ortion 11 by means of small brackets 14: which hold the i ntermediatc housing portion spaced apart slightly from the lower housing, portion 11 to provide a ventilative opcning.

Removably su 'nt-ortcd on the intermediate housing portion 12 is an upper housing portion made up of the annular cover portion 15 and the cap portion 16. The annular cover portion is flanged downwardly at 15' to pro vide an annular portion which embraces an upwardly flanged portion 12 of the inter mediate housing portion. The nnular cover portion 15 has a central aperture, above .which is supported the cap portion 16 by means of brackets 17. The cap portion 16 extends some distance beyond the perimcter of said central aperture, but is held annular cover portion 17 to provide an upper an axial. opening of considerably less dianr eter than the diameter oi the barrel portion 18. ll ithin theibarrel port-ion 18 are supported the condensing lenses 20.

The relative diameters of the bulb l and the housing are such that the bulb may be interposed througl'i the top aperture when theupper housing portion is removed, and when screwed into a socket (i will be spaced apart from the el'iveloping housing; portions a, substantial distance, which for the most part, is practically uniform. Inasmuch as the types of incandescent bulbs which give the most intense-light also radiate the greatest amount oi heat, the design of the lamp housing for the purpose of dissipating the heat from the bulbis of great importance, as, if the heat is retained about the bulb, the housing will become heated to a dangerous degree, and the bulb itself will be melted down. In my improved apparatus the pertions of the housing which a re in closest juxtaposition. to the bulb are the portions of the globular intermediate housing portion 12, and said'portions a 3 substnntiallyn uni 1 rm distance from the bulb at all points. Inasmuch as tl'ienmount of heat retained Within "he housing will vary according to the distance of the housing from the bulb, it Will be obvious that by virtue of this uniform spacing of the housing from the bulb, there will be no great divergence in the temperatures at different points about the surface of the bulb, and hence the danger of the bulb being melted down at an excessively heated point, or destroyed by internal strains due to radical, dillcrcnce in temperalllli 'g between the various portions, is obviated. Tl. arrangement of the intermediate housing "ilOil relative to the lower housing Pfill'llfii and to the cap member 16 provii. ui'iiform ventilative inlet and outlet sprees entirely al'iout the lump. Of course, as the air within. the housing becomes heat ed, it will rise nd pass out or. the upper vcntilative oi' ning, admitting cool air through the li, r ventilative fipell'ill f. ln-- asznuch as the latter continuous about the entiiv circumfereme of the lamp, this cool air will be taken in on all sides and will pass up about the c ire periphery of the bulb, thereby e a imifor'rn cooling effect. lit the sa c time the lower housing ll. and. the cap flt sl'nd tl' ventilative 2 turcs and prevent the irojcetion ol the light there t imuoih to the l ner and ceiling,

lineages The relaticnsnip of the lamp socket and the housing portions is such that 'When the lamp is in. piece, the neck portion, where the bulb joins the metallic ferrule, is adjacent to and above the lower ventilative aperture. This is highly important, as it is at this point that the bulb is most susceptible to melting down, and the disposal of the lamp in the position specified places the neck portion Where it receives the incoming cool air from the lower ventilative aperture.

In order that the condensing lenses may be disposed in the proper relationship to the source oi light, and in order that they may receive as many of the direct and reflected rays as possible, I make the barrel portion 18 practically large in diameter as the bulb, as by so doing, I am enabled to reduce the major portion of the housing to the minimum practical size. This relationship between the diameter of the barrel portion and the diameter of the bulb permits my placing the condensing lenses sufhciently close to the latter Without bringing the portions of the housing to which the barrel portion is conjoined too close to the bulb and consequently, this relationship enables me to maintain the ventilative space between the bulb and the front portions of the lantern.

As 2:. means for providing a second point of support for the housing upon the base 1, I provide on. the face of the barrel 18 a bracket 21 formed with a boss having a female thread Opposite the bracket 21 the base 1 is provided with a boss 24: also having a female thread but of opposite pitch to the thread A post 25 having threaded ends which engage the threads in the bracket :21 and the boss 24:, forms an adjustable support whereby the housing is held upon and properly spaced relative to the base 1. A screw 26 seated in bracket 21 passes through the Wall of the barrel 18 at the proper point to engage the holder oi the condensing lenses to retain the lenses in the proper position in the barrel. Slight vertical adjustments of the housing may be made by menipula ion of tin post 2'.

A lantern con L noted in the manner above described particularly simple, yet very ellicient for the purpose intended. it re quires no nice adjustments or careful Watching in operation, the operator has simply to make the proper connection to the contacts 5, and turn on the current. When nitrogen lamp used, the heat is rapidly dissipated and a light of excellent quality and adequate power for the projection of motion pictures is furnished, by virtue of the lantern construction. Moreover, is

unnecessary to employ in conjunction With this form of lantern any on. the

ort of fire shutter the relative housing, lenses,

pro (acting i and diaphragm 19 is such as to'elim'inate the heat ronveying portions of the condensed rays, while projecting an intensely bright beam upon the film. The lamp, of course, 18 readily removable and insertible upon removal of the upper housing portion, and when in place in the socket 6, it is rigidly supported, and protected, so that it is not necessary to remove the lamp from the housing When is desired to transport the apparatus. As one of the most desirable fea tures of a portable apparatus, it will be observed that the construction provides a very light and at the same time very strong lantern, which occupies a minimum amount of space, and is not easily susceptible of disarrangement.

I am aware that the device is susceptible of various changes and modifications not herein specifically illustrated or described, but comprehended within the scope of the invention.

What I claim is:

l. A lantern including means for supporting an incandescent bulb, a. lower housing portion, an intermediate housing portion, and an upper housing portion arranged to encompass a bulb supported on said means and spaced apart from one another to provide vertically spaced apart ventilative openings about the circumference of such bulb v V 2. A lantern including a main housing portion and upper and lower housing portions overlapping said main housing portion and spaced apart therefrom to provide ventilative openings which are spaced apart vertieally, said housing portions cooperating to form a globular inclosure, and a light producing bulb housed within said inclosure and disposed intermediate said ventilative openings.

3. A lantern including a glol'm-shaped main housing portion having apertures at its upper and lower portions, concave lower housing portion spaced apart from said main housing portion and covering the lower one of said apertures, an upper housing portion covering the upper one of said apertures and provided with a circumferential ventilative opening, said housing portions" cooperatin to form a housing having vertically spaced apart circumferential ventil'ative openings and a lateral light-emitting opening, a barrel 4. A lantern including a supporting base,

a lamp socket mounted on said base, a lamp housing mounted on said base and encom- &

passing saidsooket, said lamp housing hav- 111g a removable portion disposed diametrically opposite to said. socket and an aperture at one sideof'sa-id socket, and a cylindrical barrel portion encompassing said aperture and extending laterally from the housing.

5. A housing for porting base, means thereon, a housing supported on the base in position to inclose said means, said housing being provided with a lateral aperture, a barrel portion encircling said aperture and extending laterally from the housing, and a post connecting said barrel and said'base.

6. In a lamp of the class described, the combination of a base, a housing supported thereon and provided with a lower circumferential ventilative opening and an upper ventilative opening, a lamp socket supported within the housing adjacent the lower ventilative opening, and a light-producing bulb supported by said socket Within the housing with its neck portion above the lower ventilativeopening.

7. A lantern including a housing portion, a lamp support disposed in the lower portion of said housing, a light producing bulb supported on said lamp support and With its body portion spa eed apart from the walls of the housing; said housing including a portion removable to permit the removal of the bulb from the lamp support and having a lower ventilative opening below the neck of the bull and an upper 'eutilative opening adjacent the upper extremity of the bulb, the portion of the housing intermediate said ventilative openings being imperforate and inchiding a transparent portion for the passage of light from-the bulb.

In testimony wl'iereof I hereunto aiiix my signature in the presence of tWo Witnesses, this 16tlr'day of June, 1916.

J. Gr. 1;. OHARA.

a lamp including a sup- Witnesses:

M. P. SMITH, M. A. HANDE for supporting the lamp

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