GB240673A - Automatic apparatus for luminous projections - Google Patents

Abstract

240,673. Levillain, J. F. Nov. 22, 1924. Transparencies, travelling.-An optical projection apparatus for advertising &c. by the automatic successive display of slides comprises an intermittently rotated slide carrier, cam operated mechanism for rotating the carrier and raising the slides, and a stop device for positioning the carrier. The slide carrier 1<a> is in the form of a drum having slots 2, Fig. 4, for the radially arranged slides 1 and provided with a ratchet wheel 16 adapted to be intermittently rotated by means of a ratchet bar 14 which is reciprocated in one direction by a rocking lever 20 operated by a cam 23 and is withdrawn by means of a spring 17. The shaft 24 carrying the cam 23 is driven by an electric motor 34 and also carries a second cam 27, Fig. 5, which oscillates a lever 25 pivoted at one end 26 and having at its other end a pivoted spring-pressed slotted extension 33 engaging a pin 30 on a push-rod 3. The push-rod raises the slide which is to be displayed into the frame 5 arranged in the optical system, not shown, and carrying a sliding counterweight 10 which returns the slide after it has been displayed. The slotted extension 33 forms a lost motion connection which prevents injury to any slide which may become wedged. The stop motion consists of a pivoted stop 8 having a finger 9 adapted to register with the accurately spaced faces 6 of notches in alignment with the slide slots 2. The stop is normally pressed into the disengaged position by a spring 11 and the counterweight 10 carries a spring or arm 12 adapted to engage a notch in the stop and return it to the registering position.