International projectionist (Jan-Dec 1950)

Radically new, single-unit conical shutter builtin only 1 Ya inch from aperture at narrowest point of light beam affords ultra-sharp cutoff and maximum light transmission, with fewer parts, less gearing and quieter operation. Shutter is adjusted by simply turning a knurled knob atop the projector housing. need for changing the relationship of drivera gear to the driving gear, and there is the added advantage of equal wear on the contacting parts. 24-Tooth Sprocket Another innovation on the Simplex X-L projector is that hoth upper and lower sprockets have 24 teeth, 8 more than the conventional type, and they operate at only 240 r.p.m., a reduction in speed of 33 1/3% over ordinary sprockets. This increase in the number of sprocket teeth has two obvious advantages: (1) the greater radius enables a wider bend, a better wrap of the film and minimizes the danger of weak patches coming apart and eases the transit of damaged film, and (2) the reduction in speed should effect a substantial decrease in sprocket, gear and bearing wear. Reduced Mechanical Load Both sprocket assemblies are unitconstructed as an aid to improved performance, easier maintenance. The main gear drive assembly of the Simplex X-L, a single vertical unit, is extremely simplified. This simplified gearing, operating in sealed ball bearings, Simplex engineers emphatically state, effects a reduction in mechanical load over conventional practice of 80% at the start and of 66 2/3% while the mechanism is running. Since the great majority of projector breakdowns are caused by excessive mechanical load in both starting and running the mechanism, the Simplex X-L gear assembly should practically eliminate gear stripping and effect a radical decrease in running wear and in operating costs. The entire gear train turns on sealed ball bearings, with sleeve bearings having been eliminated. Friction is completely suppressed, thus reducing the mechanical load over-all. The gears in this assembly are of case-hardened, polished, finest-quality steel meshed with a phonolic fabric made especially for gears. Contributing importantly to long gear life in the Simplex X-L is the fact that during the necessary frequent framing operation all gear teeth always mesh with the same mated gear, thus effecting an even distribution of wear for all teeth on both gears. Unique Focusing Screenscope The micromatic Screenscope is a projection "first." This built-in unit utilizes an 8-power lens with prism to insure swift, precise focusing of every type of film print. Guesswork is eliminated, as the projectionist need only sight through the Screenscope while he manipulates the focusing knob positioned handily nearby The Simplex X-L intermittent movement is of completely new design. The flywheel is mounted directly on the cam, which enables the elimination of intermediate gearing and results in less wear, quieter operation and sharply reduced maintenance costs. A film of filtered oil flows over all working surfaces and carries away even the most minute particle of every foreign substance, without permitting a single drop of oil to reach the film. 'W Upper and lower sprockets (left) have 24 teeth, 8 more than usual. Operating at only 240 r. p. m., a reduction in speed of 33-1/3%, they reduce load and wear on all components. Greater radius affords a wider bend, a better wrap of film, minimizes patches pulling apart and eases transit of damaged film. Both sprocket assemblies unit -constructed. Intermittent movement (right) designed to eliminate intermediate gearing and to reduce wear. White markings and pointer at fore end, the frame lock indicator, give instant visible evidence of positive lock between star and cam for accurate framing. Simplified gear train, a single vertical unit, assertedly reduces mechanical load over usual practice by 80% at the start and by 66-2/3% while running. During framing all gear teeth always mesh with same mated gear teeth for even wear distribution. Gear train turns on sealed ball bearings. Oil reservoir is at bottom of compartment. One of the best operating aids yet developed, another projection "first," is the frame lock indicator. Heretofore no projector provided a certain means for determining whether the star and cam of the intermittent movement were in a true locked position, a requisite for correct framing. The distinct white lines and pointer on the knob at the fore end of the intermittent movement give instant visible evidence of a positive lock between star and cam. Here again, guesswork has been eliminated by a positive aid to precise, quick and easy operation. Film Gate — Trap Assembly Another marked advance in projection practice is apparent in the Simplex X-L film gate. The extra-long tension shoes exert an equally exact tension on both edges of the film. These tension shoes are practically self-adjustable laterally to accommodate varying film widths. The knob marked "Increase" operates a 5-step control which locks at each position and applies the correct tension for all types of film prints — new and green, old and shrunken, a trifle thicker or thinner. Again chance and guesswork have been supplanted by positive, visible evidence of correct operating conditions. The film trap has a curved plate which enables proper positioning of the film between the guide rollers and insures a true, direct path to the guide rails. Just INTERNATIONAL PROJECTIONIST • February 1950 15