FIG. 4.—FILM PROJECTING APPARATUS.
In projecting pictures of this kind it has been usual to employ shutters operating in unison with the movements of the picture ribbon. After a series of experiments it was found that the same effect of motion could be produced by causing the ribbon itself to have an intermittent movement without the use of shutters at all, which greatly simplifies the apparatus. A film-working apparatus based on this idea is shown in detail at [Fig. 4]. The electric motor operates a main shaft to which it is geared, a worm engaging a gear on the shaft with the main sprocket pulley, and draws the picture ribbon downward at a uniform speed. Back of this shaft may be seen the main shaft, intended to rotate rapidly, on the end of which is a disk having a roller eccentrically fixed thereto. Behind this is a standard supporting spring-tension fingers behind the lens. As the film is drawn forward by the main sprocket pulley, it is quickly pulled downward by each rotation of the rapidly moving eccentric roller on the disk. The sprocket pulley meanwhile takes up the slack of the ribbon, so that at the next rotation the eccentric roller quickly pulls the film down and makes the change; from the sprocket pulley the film is carried to the winding wheel operated automatically from the main shaft by means of pulleys; or, when it is desired to repeat the subject over and over again, the endless film is allowed to drop into folds in a box located under the sprocket pulley, passing out at the rear, upward over pulleys arranged above the spring-tension fingers, then downward between them again to the main pulley.
FIGS. 5 AND 6.—THE JENKINS “KINETOSCOPE” CAMERA.
[Fig. 7] is a diagram of a film-moving mechanism of an English inventor, Mr. Birt Acres, which has been successfully operated in London.
