Motion Picture Herald (Nov-Dec 1946)

NEWS AND VIEWS OF THE MARKET AND ITS SOURCES OF SUPPLY Motiograph's New Model AA Projector the post-war Motiograph projector, designated Model "AA", has been placed in production, the company has announced. Displayed at the Tesma-Tedpa convention in Toledo in November, it represents comprehensive redesigning of the Motiograph mechanism, with many details aimed at making operating routine and servicing easy. The housing of the new Motiograph is a one-piece casting enclosing all the working parts of the mechanism, including the twin rotor type double rear shutter, which supplants the barrel type shutter of the Model K (the new shutter was described in Better Theatres of August 24th). The entire housing is 15 inches high, 11 inches deep, and 18 inches long. All the major castings are made of strong aluminum alloy. DRIVE FEATURES Hardened steel gears meshing into laminated bakelite gears run on grease-packed double-row ball bearings, which are rigid Drive side of Motiograph AA with cover removed. ly supported by studs locked into the mechanism center frame. No further lubrication is required as long as the bearings are kept clean. Power from the drive shaft at the bottom of the mechanism is transmitted by gear combinations to the ball-bearing supported vertical shaft just back of the intermittent movement flywheel. This shaft passes through and is keyed to a wide movable pinion, which meshes .with the drive pinion on the intermittent movement cam shaft, thus permitting the movement to be shifted vertically for picture framing. Furthermore, the position of the wide pinion with respect to its mating pinion on the movement is adjustable to provide a continuously variable shutter timing control, which may be operated with the projector running. The main drive is made in the form of a socket shaft into which the soundhead drive unit may be clamped in order to eliminate the need for oiling of the sound reproducer's projector drive assembly, and to provide rugged construction at this critical point. SPROCKET SYSTEM The film enters the projector through a fire trap unit having four quenching rollers running on grease-lubricated pivot bearings. Between both upper and lower rollers there is a long chute to aid in the quenching action. The feed sprocket engages six full perforations instead of four. For alignment and proper engagement of the intermittent sprocket and film, the tension shoe assembly is made part of the intermittent unit itself. Double pad rollers on this sprocket insure sufficient engagement between sprocket teeth and film perforations to block pulsating film travel. The film path below and to the right of the lower feed sprocket is completely clear of all obstructions, with the exception of the cast stripper for this sprocket. This allows plenty of space in this region for the possible eventual addition of such auxiliary equipment as double film attachment and control track pickup facilities. For the former, the stripper mounting boss is so located and designed as to permit the substitution of another double pad roller assembly for the stripper, so the bottom of the feed sprocket may be used to feed the separate sound track film to the sound reproducer, with the picture film going across the top of the sprocket and thence by an external chute to the picture film takeup magazine. There is likewise adequate clearance below the feed sprocket to accommodate the feed and guide rollers of a Operating side of Motiograph AA mechanism, above showing film path, below with film gate open. new double film type of sound reproducer requiring no external chute and no projector modifications. FILM GATE DESIGN The film gate, when opened forward, provides a full inch of clearance between tracks and tension shoes, allowing adequate finger room for threading and for routine cleaning. The two long film tension shoes extend the full length of the film tracks, and for perfect alignment they are combined into a single rigid unit of hardened steel. This unit is held to the gate assembly by studs at the top and bottom, which engage a gunlock mechanism within the gate body. The studs snap into operating position as they enter their locating slots in the gate body face, and are instantly released by pulling out a small plunger near the top of the gate body. The shoe unit is therefore readily removable for 32 BETTlrR THEATRES. DECEMBER 14, 1946