International projectionist (Oct 1931-Sept 1933)

December 1931 INTERNATIONAL PROJECTIONIST 29 NEW ATTACHMENT SOLVES SHIMMING PROBLEM Non-shimming apparatus has been available for some months now, yet we have received recently many requests for information relative as to how best to overcome this problem. The apparatus herein described may be secured from International Projector Corp., New York, which company designed and manufactured this unit following the recommendation of the Projection Practice Committee of the S.M.P.E.—Edhor. SHIMMING has been a very serious problem since the introduction of sound reproducing equipment, but is only prevalent in connection with that equipment known as the D-Spec. attachment. This was the first attachment made and ■consideration was not given at that time to the varying tolerances allowed by the manufacturers of the projector prior to the advent of sound-on-film. It was pointed out that it was not necessary to machine rough castings to which nothing was to be attached when projecting silent pictures, but great difficuky was experienced when sound attachments were added to these unmachined surfaces. It became necessary to use shims running all the way from oneeighth of an inch down to one-thousandth of an inch on the several corners of the mechanism in order to properly line up the projector mechanism with the sound equipment drive. Great Time Loss Obviously, where a breakdown occurred during the running of a show, several hours or more would be required to adjust a mechanism. Since the majority of theatres in this country are equipped with only two sound-equipped projectors, it meant that the theatre where the breakdown occurred would be left with only one projector to run the show, until the repair on the other projector had been completed. This, in turn, made it impossible to give a smooth performance. The matter of solving this difficulty was put up to the manufacturers of both sound equipment and projectors; and an attachment has now been developed NOTES from the SUPPLY FIELD which eliminates the necessity for shimming. This attachment is entirely flexible and by its use the difficulty of replacing mechanisms on this very old-type sound attachment is entirely surmounted, so much so, that mechanisms may be readily changed within fifteen or twenty minutes. For D-Spec. Equipment Figure 1 shows this new attachment. It is only necessary to remove the gear retaining yoke from existing D-Spec. attachments and replace it with the new yoke and idler gears shown in the picture. This yoke is self-centered on the driving spindle for the projector mechanism, and it is only necessary to insert the spindle in the bearing and push it through into the hole provided in the mechanism to receive it. The yoke is then securely locked on the frame of the sound attachment and the bracket carrying the idler gears is then so adjusted as to eliminate lost motion between the gear teeth and the driving unit. The idler gear bracket is then securely locked in place by means of lock nut M. Attachment Method Figure 2 shows the assembly dismantled. At A is the flywheel always pro vided with the sound attachment; this is readily removed by taking out three screws. At B are the lock nut and washers for attaching the new yoke to the sound attachment; at C are the driving gears connecting the mechanism through the idler gears G and H to the main driving gear on the sound unit; at D is the spindle which slides into the hole M in the mechanism and upon which the assembly C revolves; at E are the three screws for attaching protecting cover L after unit is assembled; at F is the selfaligning yoke which carries the idler gear assembly; at G and H are the idler, gears; at / is the adjustable bushing to take out end play in assembly C ; and at K is the adjustable idler gear bracket. No shimming is required when this new attachment is used, regardless^ of the age of the projector on which it is mounted, and it is felt by the designers that this unit satisfactorily solves the problem of replacing mechanisms where the old type sound attachment is used. This attachment is now available from International Projector Corp. NATIONAL CARBON COMPANY REDUCES PRICES PROJECTOR carbons will be cheaper after January 1, according to an announcement of the National Carbon Co., and extra length will be added to one of the high intensity series. The new prices of the various sizes follow: The 12 mm. x 8 SRA size has been priced at $70 instead of $75 per thousand; the 8 mm. x SRA will be reduced from $95 to $80 per thousand; and the high intensity 9 mm. x 20 will sell for $245 instead of $325 per thousand. Two inches have been added to the 13.6 mm. X 20 {now 22) high intensity carbon, the price of which will remain at $400 per thousand. This size is extremely popular for high intensity work. The new SRA series carbons constitute a major advance in carbon performance; while the introduction of the pre-cratered carbon has won the approval of projectionists everywhere. DEVELOP A NEW PAPER LENS WIPER THE Howland Company, Inc., of New York City, is reported to have developed a new paper lens wiper which is said to possess all the softness and smoothness of cloth, is not abrasive, and will clean a projection lens better than anything now available. Samples of the new project are not yet available, but private tests are said to have demonstrated conclusively the superiority of this new product. Paper an Abrasive Previous attempts have been made to utilize paper as a lens wiper but were unsuccessful because of the inability to secure any paper substance which did not act as an abrasive. Camel hair brushes have heretofore been exclusively used for brushing a lens. Figure 1 Figure 2