| 摘要 |
Mechanism for feeding a picture slide magazine in such a way that picture slides can be taken out of the magazine in the same order in which they are placed in the magazine, for delivery to two separate projector units of a dual slide projector, and then can be returned to the magazine still in proper order. Two indexing gears rotate in opposite directions about a common axis of rotation. Each gear carries index pins or projections which cooperate with a star wheel or modified Geneva gear as the indexing gears rotate, and the star wheel or Geneva gear drives two pinions which engage a toothed rack on the slide magazine. As two indexing pins located relatively close to each other on one indexing gear pass the star wheel, they rotate the star wheel through two increments, to feed the magazine through two steps in one direction. As a single pin on the other indexing gear moves past the star wheel in the opposite direction, it turns the star wheel through one increment in the opposite direction, thus feeding the magazine through one step in the opposite direction. Thus the magazine is moved with the "pilgrim step" movement necessary when picture slides from a single magazine are to be projected alternately in two separate projector units and are then to be returned in proper order to the original magazine. |
