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1954-55 Theatre Catalog, 12th Edition, Page 329 (293)

1954-55 Theatre Catalog, 12th Edition
1954-55 Theatre Catalog
1954-55 Theatre Catalog, 12th Edition, Page 329
Page 329

1954-55 Theatre Catalog, 12th Edition, Page 329

calibrated control and no guesswork involved.

A most obvious advantage of the automatic crater positioning system is that it frees the operator from the necessity of constantly supervising the are. This is a great boon to the operatOr particularly with the new projection systerms which require a great deal more attention than the older projection systems. Due to the fact that the positioning of the positive crater is taken care of automatically, he is assured that he has a white light on the screen at all times and, relieved on this score, he can devote himself to the care of other technical features of projection which are not on an automatic basis and which require continual attention. It is a tribute to the excellence of the Excelite that many exhibitors have installed them in the last year solely for the reason that in their 3-D presentation it is necessary to maintain the light between the two lamps at a constant volume. In other words in this presentation each .eye sees the light produced by one lamp and to obtain the 3-D illusion theSe lights have to be of constant color, the same power and same intensity.

Another tribute to the Excelite is in the case of Cinerama wherein three projectors are operating simultaneously to project on one screen. Here small color differences would be readily apparent as well as small differences in the intensity of illumination. Here again the Excelite lamp was chosen because of its excellence in maintaining constant color .and constant illumination intensity. Further proof of the excellence of the Excelite lamp lies in the fact that it was chosen for the world premiere of nThe Robe" in CinemaScope in the Roxy Theatre in New York City, where several different types of older lamps have been tried .and found deficient in desirable qualities for this presentation.

Simplified Construction

The construction of the Excelite is straightforward, simplified. With individual motors each feeding one carbon, the feeding arrangement is simplified to .a great extent and does not necessitate any kickoff feed device from one carbon to the other such as ball clutches or other methods of taking the variable feed for both carbons off of one motor. Each carbon feed is derived from its respective motor through a geared down reduction head which is integral with the motor and this shaft is coupled direct to the carbon feed heads themselves.


The Excelite 135, with its greatly expanded light output, makes the use of a heat filter necessary, so the manufacturer furnishes the Refiect-O-Heat filter as standard equipment. This dichroic type filter makes use of numerous interference layers which are depositcd by vacuum process on pyrex glass and which have the peculiar property of selectively rcficcting un VIEW oi the burner mechanism. This is a variable ratio feed lump that can be set by the operator to feed at any current needed.


wanted heat portions of the energy from the aperture. This filter allows the wanted, or visible, portions of the energy spectrum to pass through, while renecting back and away from the film the undesirable and unusable portions of the energy spectrum, thus allowing the film to run in the projector without buckling or damaging when the high intensities are utilized. The point where it becomes necessary to insert the filter in the beam to project the film varies with the individual projector and with the type of film that is being projected. Generally speaking, for amperages of 110 or above, the use of this filter is mandatory. to insure against film damage.

The design of the Excelite is such that it is very easy to keep the lamphouse clean from soot and carbon ash. The entire rear door of the lamphouse swings open and the entire bottom of the lamp can be brushed out through the rear door so that any carbon ash deposit which collects in the base of the lamp can be swept out without any danger of sweeping it into the interior mechanism of the lamp, and thereby causing feeding difiiculty.

Easin Maintained

Beyond the fact that it makes for easy interchangeability of the various elements so as to burn different currents in the lamp, unit construction permits easy removal of the elements for inspection in servicing. The operator is able to remove any part and interchange it with similar units from a spare lamp or to make quick repairs on the bench where the operator can get at the seat of the trouble without the necessity of taking the whole lamp apart. These

interchangeable parts are generally fastened by a minimum number of quick fastening screws or, in the case of the control tube, by simply unplugging from the socket in the manner in which you remove a vacuum tube from a radio set. The control relay is removed very easily, being mounted on a tube socket base. The positive and negative heads are mounted separately to the base by means of quick fastening screws and either of these assemblies can be removed in about 30 seconds. The negative and positive motors are likewise fastened by three screws and the electrical connection to the motor is broken by simply pulling out by a three prong plug.

The motors are lubricated and sealed, consequently there is but little exposed gearing susceptible to abrasive carbon dust collection. The fact that these gears are sealed in the head of the motor reduces the frequency of necessity for lubrication.

The parts near the positive feed head are all easily accessible from the outside of the lamphouse and can be lubricated in .a matter of seconds. Each of the feed motors has a fan mounted on its motor shaft. Air from these fans is led into the lamphouse where it keeps the entire base under pressure. The air can be withdrawn from the base through the heads and up through the air stream tube which projects the air over the arc. The air which is allowed to escape up through the positive head aids in keeping this positive feed head operatat low temperature.

The Excelite 135 is a most economical lamp in terms of carbon and current consumption for producing screen illumination in the range of 20,000 to 25,000 lumens.
1954-55 Theatre Catalog, 12th Edition, Page 329