Patent GB-934824-A (GB)
Title: Improvements in or relating to devices for projecting motion picture films
IPC: G07F17/16
Filed: 1960-08-11
Abstract: 934,824. Kinematographic selective projection apparatus. COMPAGNIE D'APPLICATIONS MECANIQUES A L'ELECTRONIQUE AU CINEMA ET A L'ATOMISTIQUE. Aug. 11, 1960 [Aug. 31, 1959], No. 27861/60. Class 97 (1). Apparatus for the selective projection of one of a plurality of films comprises a generally cupshaped rotatable magazine 2 carrying pairs of spools 25, 25a for different films, means for selectively bringing any film into the projection position by rotation of the magazine, a common feed and projection system outside the magazine supporting an arm 22 carrying the projection lamp 21, the arm in its idle position being located within, but clear of the magazine and when brought into its operative position, bearing on the film extending between the associated spools, and maintaining it in the projection position. A selector knob 17 (Fig. 1) operates known selector mechanism 18 which switches off the driving motor 14 for the magazine 2 when the latter has rotated to that position where the chosen film 13 (stored on supply spool 25a and permanently connected to take-up spool 25) has arrived in line with the guide track 35 of the projection assembly 3, all the working parts of which, and a sound head, are carried on a frame 24. The " loading arm " 22, pivotally connected to the frame at 23, has protruding portions provided with rollers for bearing on the film and tensioning it around the sprockets 27 and 36. One of the rollers 32 (see Fig. 3) is carried on a spring-loaded lever 31, the purpose of which will be explained below. The positioning of the magazine operates a switch to energize motor 42 geared to a lever 43 which pivots arm 22 into the position shown in Fig. 3, whereby switch 47 is actuated to stop the motor 42 and also to start motor 48 which drives (through coupling not shown) a pressure roller 43a for driving the take-up spool. If, at this instant, the film has not been properly tensioned, lever arm 31 will exert no pressure on switch 34 which will remain operative causing arm 22 to repeat its loading motion until the film is properly tensioned and switch 34 is depressed. When the film has been nearly completely unwound, perforations 70 (Fig. 9) provided at its ends, allow the protrusion of a spring-loaded finger 60 (Fig. 7) mounted in the spool hub whereby the tip 76 of the spring projects beyond the edges of the spool flanges and trips a switch 49 to stop motor 48, then trips a further switch 57 to cause motor 42 to lift arm 22, lever 43 then activating switch 58 to stop motor 42. Simultaneously, switch 49 has also started rewind motor 50. The latter is reversed by the closing of a switch when rewind is almost completed (in a manner similar to that just described, though because of the increased rewind speed, a chock-absorbing device is included in the switch-tripping mechanism) whereby (see Fig. 4) the spooldriving pressure roller 51 carried on a pivotable arm 52 geared to the driving spindle, is withdrawn from the spool and switch 56 activated to stop motor 50. The latter may be carried on the magazine. Specification 421,099 is referred to.