Reduction of Loop-Length Variations in Non-Slip Printers--

Compensation for varying degrees of film shrinkage is accomplished in the Bedford non-slip printer by changes in the length of a loop of film between a sprocket and the printing point. This involves uncertainty of synchronism by the amount that the loop, as first threaded, differs in length from the final running loop. For most purposes, the present designs do not cause greater change in loop-length than may readily be tolerated. - For certain purposes, especially if this type of printer is to be employed for 16-mm. films, there may be too much departure from synchronism. A guide-roller arrangement is described by which the necessary change of angle of approach of the raw stock to the printing point is attained with comparatively small change of loop length. - Several possible arrangements are considered and other features of the non-slip printer are discussed.