Improvements in film-feeding devices for cinematographs

摘要

501,188. Kinematograph apparatus. BOSCH GES., R. Aug. 24, 1938, No. 24868. Convention date; Aug. 24, 1937. [Class 97 (i)] The claw arm of an intermittent feed mechanism wherein the arm embraces a cam, and the arm and cam have different coefficients of expansion, comprises two or more plates side by side, and resiliently connected in a manner tending to reduce the effective size of the cam aperture. The arm may comprise two plates a1, a2, each of synthetic resin containing textile fabric, and having apertures b embracing a steel cam d. The plate a1 has an extension el carrying claws f, and a lug i1 linked by a compression spring h to a lug i2 on the plate a2, the'plate a2 being carried by a pivot pin g on the plate a1. The plates have slots w engaging a fixed, but rotatable, bush x, eccentrically mounted, and have weightreducing holes z ; the hole in the plate a2 receiving the pin g may be of larger diameter than the pin. The cam may be screwed to discs k m, the disc m being secured to a driving shaft o, and being provided with a knob v, covered with heat-insulating material, to permit hand adjustment. A groove for lubricant may be provided round the aperture b in the face of the plate a3 contacting with the plate a1, and lubricating grooves r u may also be provided, the .groove u being in a ring t pressed by a spring s. A third plate may be provided on the side of the plate a1 remote from the plate a2 and be connected to the plate a1 by a spring tending to displace it in one direction or the other.