International projectionist (Jan-Dec 1939)

Inclusive Simplex SI Equipment For 200-800 Seat Range Theatres THE new Simplex SI mechanism has been designed, manufactured and priced to supply definite demand for projection equipment which will provide better sound and visual projection for moderate size theatres with a seating capacity ranging from 200 to 800 seats. Although moderately priced, the new SI mechanism will give very satisfactory results in the special field for which it is intended. It will enable the theatre owner who has been compelled to use old, worn-out and obsolete equipment, to purchase standard Simplex equipment at a price that compares with the lowpriced inferior equipment now in use. This new SI mechanism has many of the latest and most modern improvements, such as front and rear-shutters, semicentralized lubrication, air deflector and aperture cooling unit, sprocket strippers of the non-wrap-around type, fire shutter safety trip of advance design, and also has many other proven Simplex advantages. "'Hunting-type" gears in the gear train of the SI mechanism have proved very efficient over a long period in other Simplex equipment. This type of gear has an uneven number of teeth, which means that the same teeth do not continue to mesh as the gear revolves. Each tooth in the gear meshes with every other tooth on the mating gear in the course of several revolutions, and this results in an even distribution of wear, prevents the development of high oi low spots, and is an increased assurance of quiet performance. Furthermore, with hunting-type gears it is unnecessary to mark for an exact tooth when the gears are removed temporarily, and they do not have to be put hack in mesh in a certain way. The gears are simply slipped onto their shafts without any regard as to which tooth meshes with another. This, of course, materially reduces maintenance and repair. • Gear Train, Intermittent The SI mechanism is entirely gear driven, but there has been a simplification of the drive, and fewer parts are used than in any gear train which has been employed heretofore in a Simplex professional mechanism. The shutter shaft upper sprocket assembly and intermittent drive assembly are an integral unit. Operating parts are in an oiltype case and operate in an oil bath. Certain dimensional changes have been made in the intermittent movement, but the design is essentially the same as that which has long given thoroughly satisfactory results. The intermittent is completely enclosed, operates in an oil bath, and has long proved that it will sland up under hard grinds. Framing knobs project from either side of the mechanism; in framing, the entire upper drive unit and intermittent assembly move forward or backward as a unit, while the gate and film trap remains stationary, and only a slight change in the loop length brings the picture into frame when this is required. The lower sprocket idler assembly can be mounted in either of two positions to correctly align the mechanism with any type of sound head currently available, by means of two bosses which are provided in the main frame. The gate and film trap assembly is of simplified design which has been thoroughly tested in long practical use and has proved particularly satisfactory where warped film is encountered. • Semi-Automatic Lubrication Although lubrication of the mechanism is semi-centralized, in addition to the gear train, several separate points are provided for parts that require attention from time to time. A special composition is used throughout for bearings and these, being of the self-lubricating type, ordinarily will need no attention. As an additional protection, adequate lubrication is assured by feeding oil to the outer circumference of these bearings, which is absorbed by the bearings and released as required. The level of the lubricant in the upper oil chamber and intermittent oil chamber can be readily seen through the glass windows. Another feature of this mechanism is the new air deflector and aperture cooling unit now manufactured as an attachment or an integral part of the finest Simplex projectors. This unit does four jobs: steadies the light; reduces the heat at the aperture; prevents lamphouse carbon dust and dirt from being drawn into the mechanism, and prevents drawing of gases from the arc lamp into the projection room. The automatic fire shutter, an im 'So this is what you call a 'ground' portant safety factor, operates in the following manner: Should the film for any reason remain stationary at the aperture, the upper loop enlarges above the aperture plate and lifts a curved tripper piece which instantly releases the fire shutter so that absolutely no light reaches the film. Framing and focusing knobs may be manipulated from either side of the mechanism, and a framing light is provided which enables threading in frame without difficulty regardless of the density of the film. This is accomplished by means of a reflector mounted on a fire shutter which reflects a beam of light through the aperture from behind. To increase visibility and encourage cleanliness, the interior of the operating side is finished in white enamel. Lubrication points are conspicuously marked in red. All major assemblies are attached to an auxiliary support casting, which in turn is rigidly mounted on the mechanism casing — making it a very simple matter to remove assemblies for inspection or repair. The new SI pedestal will permit many theatres to discard the three or fivepoint pedestals designed many years ago to support the rather flimsy projection and lamphouse equipment then in use. even before better sound equipment was introduced as an additional burden. The new SI pedestal provides a rigid, sturdy base which is adequate for modern mechanisms, lamphouses, sound heads and magazines. • Pedestal and Lamphouse The pedestal is a vibration-proof base which gives an additional assurance of steadiness on the screen. It is designed somewhat along the lines of the heavier and more expensive models, has a builtin hand-wheel and lock nut adjustment for obtaining the correct angle, and is also provided with sufficient adjustment to accurately align the projection lamp. Allen headless-adjusting screws provided for the four corners of the base permit the equipment to be easily aligned, regardless of any irregularities in the room floor. Some economies have been effected by the elimination of lateral adjustment devices used on other Simplex bases, but the SI pedestal has retained many features of the higherpriced equipment, such as space for installing all wiring in the base itself, adequate plug-in receptacles, and a 100ampere switch and switch box accessible from either side of the projector. The removal of a latch door allows the projectionist or installation engineer easy access for connecting or disconnecting the several electric circuits. The pedestal weighs 225 pounds. The new Simplex low intensity lamp is of advanced design, sturdy and roomy, employing exceptionally large eliptical reflector, 11%". It has an automatic ballbearing arc control motor, ammeter with illuminated scale, arc imager and means for quickly striking the arc. It is equipped with inside dowser which operates from either side of the lamphouse, and a removable ash tray. SEPTEMBER 1939 17