Motography (1912)

October 26, 1912. MOTOGRAPHY 31 19 Motor Driven Projectors Made Safe A New Device WHEN a motion-picture safety device receives the official O. K. oi the National Board of Fire Underwriters after months of exhaustive tests, and is subsequently granted a permit to operate by Chicago's Electrical Inspection Bureau, one may feel pretty -ure that it is successful. It will surprise some of our readers to learn that one of the projecting machines in the Orpheum theater, on State street. Chicago, is being driven by an electric motor instead of the old-fashioned hand crank. That this can be done in a city which is normally opposed to motor drive is due to a device which has achieved the official approval above indicated. The reason why so many municipalities have legislated against motor drive for projecting machines is quite obvious. Relieve the operator of the burden of turning the crank, and he is apt to neglect the machine. If he is away from it. and the film sticks or breaks, the motor does not stop. It goes on whirling away, the safety shutter on the machine does not close, and the film catches fire at the gate before he can reach it — for it only takes three seconds of the arc's rays on the stationary film to ignite it. It is an easy matter, of course, to arrange a spring switch for the motor, the theory being that the operator must hold the switch closed with his hand or foot, thus enforcing his presence. No such spring switch can be made, however, which cannot be kept closed by substituting a weight or a wedge for the hand or fo t. Nevertheless, motor drive is the only satisfactory method of operating a projecting machine — or any other piece of machinery, for that matter. The operator has plenty of intelligence and a thorough knowledge of the art of projection; but he cannot use his brains or his knowledge to advantage while he is handicapped by the necessity of turning a crank. Give him the freedom insured by motor drive, and if he is the right sort he will use his knowledge in improving the show. Make him an engineer instead of an operator, a mechanician instead machine, and gradually the whole efficiency of the art will be raised. It was a realization of these facts that set Frank II. Foude of the < >rpheum theater to work on the problem of a -ate. efficient motor drive and protective equipment. That he has succeeded i attested by the approval of the authorities and the enthusiastic support of Manager Samuel I. Levin of the ( )rpheum. The features of the device are as follows: If the film -tops for any reason whatever, the arc is shut ofi*. If the film breaks, the same thing happens. Unless the film eing properly wound upon the take-up reel, neither the arc nor the motor will operate. It i impossibl turn the rays of the arc upon the film unless the film i moving at a safe rate of speed. In short, if anything happens out of the ordinary the ar ul instantly and the motor stops. All this i accomplished without any material change in the projecting machine. Furthermore, the device may be attached or adapted to any type of machine. The additions consist of a governor, seen at the right hand end the -haft in the photograph, an electrical circuit breaker at the back of the machine, and the special takeup arrangement. At the risk of becoming technical. which is rather difficult to avoid in describing machinery. we will enter into the details of the devi Referring to Fig. 1. TO designate the take-up reel which is driven by a belt // passed over tiie pulley 12 and ordinarily over a pulley carried by a shaft journaled in a bearing / ,\ driven by the gear // of the machine and upon which is keyed the last of the film carrying sprockets. The invention consists in enlarging the bore of the bearing ii to receive a bearing forming sleeve 15 in Appearance of Projecting Machine with which the -haft 16 is journaled. -aid -haft being provided intermediate its length with a film-carrying sprocket 17. which is secured again si rotation on the shaft in any preferred manner. fournaled upon the sleeve 15 is the gear iS, which meshes with the gear // of the picture machine proper, and al-o journaled upon this sleeve and secured to the as to revolve therewith, i a pulley /o over which the drive belt of the take-up reel W is passed. It will thus be seen that the take-up reel will be driven directly from the machine in the customary manner, but