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1948-49 Theatre Catalog, 7th Edition, Page 406 (393)

1948-49 Theatre Catalog, 7th Edition
1948-49 Theatre Catalog
1948-49 Theatre Catalog, 7th Edition, Page 406
Page 406

1948-49 Theatre Catalog, 7th Edition, Page 406

High-Intensity Projection Arc Lamp

Supply Source for the Great Amount of Distributed Light Needed at Larger Theatre and Drive-In Screens

Probably because of the extremely limited sales field which has made it impossible to manufacture high-current, condenser-type high-intensity projection arc lamps on the same production basis

as other types of projection arc lampsh

very little, if any, development work was done prior to the introduction of the Peerless Hy-Candescent lamp.

The sales field for this type of projection are lamp has recently been broadened by the extreme projection requirements of the automobile drive-in theatre which has become popular during the past several years. Before their advent, however, only the largest theatres, at home and abroad, found that the good light distribution, high light output, and higher operating cost of the condensertype high-intensity arc justified continuance of their use.

To supply these users with an arc lamp of modern design, engineered to meet the operational problems that develop from the intense heat or currents up to and above 170 amperes the Peerless Hy-Candescent lamp in combination with the Hy-Speed f/2 condenser-lens system offers them a means for obtaining a level of screen illumination impossible with projection arcs employing reflectors and the commercially available copper-coated carbon combinations.

Experience with high-current projection are lamps has disclosed that high internal lamphouse temperature was the greatest contributor to troublesome operation of the mechanics of the burner and hence was one of the prime problems to consider (Fig. 1).

Mindful of the general trend toward burning higher and higher are currents and to provide a sufficiently large lamphouse to handle the high heat generated by these arcs, this lamphousing measures 49 inches long, 29 inches high, and 22 inches wide and has a cubical content of approximately 9 feet.

Lamphouse Ventilation

An 8-inch diameter chimney base, instead of the customary 6-inch, is provided to assure sufi'icient cubic-foot-perminute exhaust of the heated air and gases from the lamphouse at a velocity that will not disturb the burning arc.

Built inside the lamphouse top and located directly over the arc, is a conical metal canopy measuring 16 X 16 inches at the bottom, the top of which is connected directly to the 8-inch chimney opening at the top of the lamphouse. This canopy is entirely separate from the lamphouse and it has no pockets or corners, hence it can efficiently conduct

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By CHARLES A. HAHN J. McAuIL-y Manufacturing Co., Chicago 6, Illinois

Summary-This paper* describes mechanics and design of the Peerless Hy-Candescent 120- to 170-ampere projection arc lamp, the Hy-Speed condenser-lens system, and the light heat filter unit.

the are heat and gases directly out of the lamphouse and prevent them from circulating around the interior of the lamphouse.

To ensure egress for the heated air in the rear upper portion of the lamphouse, outside of the canopy, Separate vents are provided in the casting that forms the chimney base so it may exhaust into the projection room.

Normal air intake is provided for by an extremely large opening in the bottom of the rear cover door and through the light cone at the front and, in addition, by a blower connected to the arcfeed motor which alone delivers over 60 cubic feet per minute of air, distributing it over the entire base of the arc-burner mechanism (Fig. 2).

Lamphouse Construction

The lamphouse body is comprised of a formed sheet-steel base of heavy gauge to which are attached the two side frame castings that form the frames for the two side doors as well as the support for the sheet-metal top. These side frames are fastened to the

base and likewise to the front and rear castings at points that have machined surfaces, resulting in a final assembly that is extremely rigid.

Both the right and left side doors are 11/2 inches in thickness, they are doublewalled, hinged at the top, and on their inside walls are each provided with a slidably mounted steel heat baHle plate, opposite the arc. These bafHe plates are removable and present three thicknesses of metal with two air spaces to heatinsulate effectively the outside surfaces of the doors from the high are temperature.

Because of the generous size of the side doors and the fact that the rear cover door is itslip-hingeF mounted, the means for complete accessibility to the burner mechanism are provided (Fig. 2).

Condenser-Lens Mounting

Slidably mounted to the lamphouse front casting is a second casting which functions as the light cone and the support for the condenser-lens mount. It is machined for accuracy and is made manually adjustable up, down, and sideways by conveniently located control knobs.

As the condenser-lens holder, when placed in its support cradle, is carried with this casting it can readily be seen that these adjustments provide a perfect means of aligning the condenser lenses to the optical axis of the projector, independent of the position of the lamphousing proper, as was shown in Fig. 2.

The condenser support cradle is also slidably mounted to this casting, and means are provided thereon for focusing the condensers to the arc crater. The rear dowser, because it is supported by the cradle casting, moves to or away

FIG. l-Hy-Candesceni lump from rear and right-hand side.
1948-49 Theatre Catalog, 7th Edition, Page 406