International projectionist (Jan-Dec 1947)

requirement of instantaneous positive action. Now available is the Automatic Safety Sprocket which meets all the aforementioned requirements with a large margin to spare. Sealed within the sprocket is an extremely accurate speed-sensitive mechanism which needs neither adjustment nor maintenance, it is simple to install because it comes on an adapter Lracket made for each type of projector. To install on a Super Simplex simply remove the three screws holding the back plate and replace with the Super adapter bracket (Fig. 1). Mounted thus the speedsensitive mechanism within the Automatic Safety Sprocket operates a switch that is connected with the closing coil of the changeover dowser. In threading the projector a normal lower loop is made which rides on the Safety Sprocket. During normal projector operation the Safety Sprocket is rotated at 360 r.p.m. by the film. Because of the Sprocket's location it is apparent that any danger of fire will immediately result in speedy positive action. A blown fuse or frozen bearing will slow the Sprocket; loss of loop, torn sprocket holes or a film break will stop the Sprocket. Immediately any of these events occur the Sprocket will instantly cause the changeover dowser to close before a fire can start. Use of the standaid changeover dowser obviates the need for a separate dowser. Detailed information regarding the Automatic Safety Sprocket is available from Control Engineering Corp., 1069 Market St., San Francisco, Calif. committees of the SMPE. Longer life for release prints and quieter operation in theatre projection rooms are among improvements achieved by the new technical developments. Included in the list, which have been forwarded to the American Standards Assoc, with recommendation that they be submitted to the International Organization for Standardization for acceptance as world standards, are the following: For 16-mm silent film, camera and projector apertures; for 16-mm sound film, camera and projector apertures; 8-mm silent film, camera and projector apertures; projection reels for both 35 and 16-mm film; 8-mm projection reels; 16-mm sound and 16-mm silent film splices; negative and positive; 16-mm projector sprockets; 8-mm eight-tooth sprocketc; 35-mm sixteen-tooth sprockets, and SPEAKING OF SPEAKERS SMPE's 18 New Standards to ASA Eighteen new equipment standards for the motion picture industry, designed not only for improvement of operations in this country but also to aid the expanding foreign markets, have been developed by seven sub Herewith the correct representation of Altec Lansing's intriguing "Iron Lung," which most effectively demonstrates visually the action of the diaphragm in "Voice of the Theatre" loudspeakers. This picture appeared upsidedown in I. P. for January. This evidence of human fraility contrasts sharply with Altec Lansing speakers which unfailingly function perfectly irrespective of locale, positioning, climate or other adverse factors which bedevil less efficient units. U. L. approved . . . eliminates fire hazard. MicroSwitch safety cut-off — when door opens, motor stops! Motor does not transmit torque to operating parts. Reel-drive Dog . . . prevents broken keys. Available through Theatre Supply Dealers. GoldE Manufacturing Co. 1220-R West Madison St. Dept. R, Chicago 7 Low Maintenance Cost • Positive Friction .". . Will Not Clinch Film American recommended practice for motion picture engineering nomenclature. The aforementioned new standards are in addition to 26 others already forwarded by the SMPE to the ASA during 1946. An interesting study of color motion picture printing is also under way. Reels Can't Fly Off / PUT MORE LIGHT ON YOUR SCREEN 0 All reflectors gradually deteriorate to a state where replacement cost is insignificant. A drop of onlylO%in reflective efficiency results in a corresponding decrease in screen brilliancy, and represents a loss amounting to 10% of the cost of your current and carbons. Replace yours now, and regularly. Available for all types and makes of arc lamps. NATIONAL ■miif.uwcnai 'There's a Branch Near You' STRONG COPPER OXIDE AND TUBE TYPE RECTIFIERS The modern means of converting A.C. to D.C. as an ideal power supply for projection arc lamps. Low original, operating and maintenance costs. Quiet operation. Distributed through leading independent theatre supply dealers. THE STRONG ELECTRIC CORP. 87 City Park Ave., Toledo 2, Ohio The World's Largest Manufacturer of Projection Arc Lamps L INTERNATIONAL PROJECTIONIST • February 1947 33