GB1494711A - Cinematographic film viewer - Google Patents

Abstract

1494711 Cinematograph viewer EVERLASTING CREATIONS Ltd 12 Nov 1975 46686/75 Heading G2E A cinematograph viewer has a delay device which causes the film to pause temporarily with each frame aligned in the viewing aperture; two guide walls for the film, one fixed and one movable, define a narrow space in the loading position and a wider space in the viewing position, and a further guide-member holds the film away from the delay device in the loading position and allows it to make contact in the viewing position. There are in fact two fixed guide walls 25, 26, and two movable guide walls 27, 28. The latter form part of a plate pivoted at 55 (Fig. 15). The plate has a pin and slot linkage with a lever 30 pivoted at 30a. Figs. 9 and 15 show the plate pivoted so that there is only a narrow space between guides 25, 27 and between guides 26, 28. This is the loading or threading position. The film 49 enters between guides 17, 18, is carried between a guide 24 and a drive sprocket 22, then between guides 26, 28 to the film gate 29. From here it is guided by a plate 37 to pass round a roller 21 and between guides 25, 27 to the drive sprocket again, and thence between guides 16, 17 to a take-up spool. To change over to the viewing position, lever 30 is pivoted clockwise, which draws the guides 27, 28 down into the viewing position of Fig. 14 (not shown) and Fig. 9, the pairs of guides 25, 27 and 26, 28 now being more widely spaced apart. The film is now viewed, as shown in Fig. 8, through an eye-piece 15. The delay device comprises a pin 33 mounted on the film gate 29, and which is also coupled to the lever 30. In the viewing position the pin is in contact with the film, and engages in the perforations in the film sufficiently to cause the film to halt temporarily with each frame aligned with the viewing aperture Fig. 16 (not shown). Tension therefore increases in the film, and the roller 21, which is on a movable bearing, moves from the dotted line position to the full line position (Fig. 17). This draws the film away from pin 33, so that the film is released for further movement and roller 21 returns to its original dotted line position.