| 摘要 |
1,044,874. Magazine slide projectors. FRANKE & HEIDECKE G.m.b.H., [trading as ROLLEI-WERKE FRANKE & HEIDECKE]. March 6, 1964 [March 8, 1963], No. 9650/64. Heading G2J. A magazine slide projector with a forward or reverse indexing mechanism and having an electric drive as in Specification 965, 558, includes a bridging switch 8 actuated by the magazine movement to render inoperative a drive controlling, cam-operated switch 2 by short-circuiting either the forward, or the reverse, manually actuable drive switches 3, 4 by means of a change-over switch 9. Magazine 16 is then indexed according to a slide projection sequence determined by the setting of the switch 8, which is actuated by engagement with the cam-shaped shaft 20 of the gear 18 driven by rack teeth 19 on the magazine. Each tooth on gear 18 corresponds to a single indexing step and with the square cam in Fig. 1, (not shown) switch 8 is alternately closed and opened as the magazine advances so that alternate slides are projected. At the end of its travel, lug 17 on magazine 16 trips pin 13 to actuate change-over switch 9 and reverse the magazine to project the alternate remaining slides. In a more complex system, shaft 20 may be part square and part triangular in section and may operate two switches 22, 23 in place of switch 8, while gear 18 may then have twelve teeth. The projection lamp is switched off during each slide change, and fully automatic projection is possible. |
