Patent GB-1040701-A (GB)
Title: Optical slide projector
IPC: G03B23/06
Filed: 1963-02-22
Abstract: 1,040,701. Slide projectors. EASTMAN KODAK CO. Feb. 22, 1963 [Feb.23, 1962], No. 7189/63. Heading G2J. A slide projector with manual or automatic control means as disclosed in Specification 899, 932 has a circular, rotatable slide tray 86 mounted on top which is indexed in a forward or reverse direction to bring slides into register with the projection gate, each slide being lowered under gravity to the projector position 74 and then returned to the tray. The casing has openings 12, 18, 20, 29 for air cooling by means of a fan, and has a carrying handle 22. Random selection of slides for projection is possible and two powers of illumination are available. Manual or motordriven rack and pinion focusing is used. Remote control is mentioned. Slide tray 86 is formed of concentric cylindrical walls with radial spacers 117 defining slide compartments as in Fig. 3 (not shown), the rim 126 of the outer wall having numerals for each slide. Annular metal disc 132 is supported on annular shoulder 130 of the tray as is Fig. 5 (not shown) and has an opening 138 to permit heated air to circulate over the slides. Latch 142 releasably holds disc 132 in a fixed position with respect to base 131 of the tray, the tray being manually rotated until notches 156, 158 in the tray engage lip 64 and bay 70 extending from the top of frame 4 when the tray drops and indexing pins 129 engage inserts 85 on the frame. Tray 86 is now in the loaded position with the "O" compartment aligned with index 66, and may be indexed for projection relative to disc 132. Slides are retained in the tray by a corner ring secured by a bayonet fitting. Drive and timing mechanism. Motor 47 drives cam shaft 174 and timing wheel 184 through gears and clutches. Timing wheel 184 has four lobes 204, 206, 208, 210, see Fig.13 (not shown) of different lengths, and is axially adjustable on shaft 186 by means of a bell-crank 194, pivoted at 196, through a manually rotatable four-sided cam as in Fig. 11 (not shown). As wheel 184 rotates, a selected number of lobes, depending on the axial position of the wheel, engage pivoting spring-biased arm 212 to release temporarily end 222 of helical clutch spring 224, see Fig. 16 (not shown). Spring 224 then contracts to drivingly hold shaft 186. Arm 212 may also be pivoted to release spring 224 by means of electromagnet 220. The timing of the automatic slide-charging can thus be varied, or when no lobes engage arm 212, manual slide charging is possible. A safety clutch is provided between shaft 174 and the cams 234, 236, 238, 240, 242, 244 mounted thereon. Slide lifter mechanism, comprises a lever 257, pivoted at 250 and carrying a lifter plate 260, which is actuated by engagement with cam 234 during one complete revolution. Shutter mechanism, comprises shutter blades 286 pivoted at 288, 290 as in Fig. 15 (not shown) have slots which receive pin 278 on a lever 268, pivoting at 270, whose other end has a cam follower engaging cam 236. Slide tray positioning mechanism comprises a lever 292 whose follower 294 engages cam 238 to import a reciprocating motor to the lever. Positioning element 302 on the end of lever 292 has a projection 78 which moves between pins 129 on tray 86 to prevent rotation thereof. Pressure pad mechanism comprises a lever 310 pivoting at 312 whose follower 314 engages cam 240 and whose other end engages arm 320 of a U-shaped pad 322 pivoting on spindle 324 as in Figs. 24, 24g (not shown) to allow fingers 326 to grasp and then release a slide. Indexing mechanism comprises a plate 330 whose follower 332 engages cam 244. Pin 342 entering slot 340 allows plate 330 to slide until pawl 80 engages pins 129 for forward or reverse indexing when the pawl follows cam surfaces 366 or 368 on slot 364 in a plate 362 adjustably pivoted on frame 282 at 84. Pawl positioning mechanism comprises a lever 372 whose follower 376 engages cam 242 to provide reciprocal motion. The opposite end of the lever pivotally supports plate 384 on stud 386 so that pins 400, 402 on the plate enter arcuate slots 398, 399 in bracket 396 on the frame 282. As lever 322 is moved forward, pin 402 engages end 420 of a plate 404 pivoting at 406; plate 384 then pivots about pin 402 with pin 400 moving in slot 398 so that lug 388 on plate 384 moves wire 392 which in turn moves arm 350 and pawl 80 into engagement with surface 366 for forward indexing. For reverse indexing, solenoid 408 is energized to pivot plate 404 and withdraw its end 420 from the path of pin 402 and into the path of pin 400. Editing or out of sequence projection is possible by use of select button on lever 422, pivoting on shaft 200, whose end engages a bell-crank to disengage cam follower 332 from cam 244 so that pawl 80 remains clear of pins 129 as the projector is half-cycled. Emergency release of the slide tray is possible at any time if the slide-changing mechanism becomes inoperative.