GB884466A - Improvements in or relating to optical slide projectors - Google Patents

Abstract

884,466. Optical slide projectors. KODAK Ltd.. Nov. 3, 1959 [Nov. 3, 1958], No. 37224/59. Class 97(1). An optical slide projector includes a shutter which is movable between one position in which it intercepts the projection beam and another position in which it is removed from the beam and a latch which holds the shutter in the intercepting position and is released automatically when a slide is introduced into the projection beam whereupon the shutter is permitted to move to its inoperative position. The slide projector shown has a track 3 for guiding a slide magazine, the slides from which are in turn lifted by grippers 8 into a member 5 having a projection aperture 6. The grippers 8 are secured to a frame support 9 which is linked at 15 to a rod 13 pivoted at 14 and having a lug 16 which rides in a groove 17 of a cam 36, rotatable through gears 18, 19 by a crank 22, 23. A shutter flap 27 is disposed in front of the projection aperture, this flap having depending arms 25 which are pivoted at 26, and have attached thereto a pin 31 adapted to engage the surface of the cam 36. In operation, the cam 36 is rotated so as to raise a slide by means of the grippers 8 into the projection position, such slide being inserted between the wall 42 containing the projection aperture 6 and a pressure pad 37 which has a limited movement in the direction of the projector axis. The movement of the pressure pad caused by the introduction of a slide results in the disengagement of a hook 41 on the pad from a lip 29 on the shutter flap, so that springs 32 move the shutter to open position. Further rotation of the cam causes ejection of the slide and through the engagement of the cam surface with the pin 31 brings the shutter back to its closed position where the lip 29 engages with the hook 41 a pressure pad.