The Radial-Tooth, Variable-Pitch Sprocket

A unique sprocket tooth whose driving face is a plane lying on a radius of the sprocket is used to improve longitudinal registration of the film over that obtained with conventionally shaped, curved-profile teeth. By supporting the film or films by means of an appropriately decentered drum while the films are in engagement with this sprocket, shrinkage accommodation is effected by virtue of the varying effective pitch of the sprocket. The variable-pitch effect also makes it possible to strip the film off the sprocket. — Calculated and measured flutter in sound prints and measured steadiness in picture prints made on a sprocket of this type in a 16-mm continuous contact printer are found to be substantially independent of film shrinkage and to be markedly better than in prints made on conventional printers.

Print ISSN

0898-042X

Published

1951-12

Content type

Original Research

DOI

10.5594/J01217