GB294328A - Improvements in copying machines - Google Patents

Abstract

294,328. Gledhill, A. H. May 28, 1927. Copying documents, drawings, and the like.- Improvements are described in machines for copying documents, drawings, &c. of the kind comprising an impression roller A, Fig. 1, mounted in pivoted arms a' in a carriage E, which is reciprocated by hand over a duplicating- composition supported on a flat bed, the roller A, in the inoperative position, being raised off the bed and separated from a co-operating, spring- pressed feed roller B, so that a sheet may be inserted between these rollers and up to a front stop, whereupon the roller A is swung down and the sheet is fed out between the rollers as the carriage travels across the bed. (1) To prevent premature engagement between the rollers A, B with consequent forming of a loop of paper in front of the roller A, a promotion b<1>, Fig. 4, is provided on each one of a pair of arms b supporting the roller B, and each arm a' engages a projection b<1> to separate the rollers until the roller A almost arrives at the operative position : the projections b<1> then drop into recesses a<2> in the arms a<1> and allow the rollers to engage. (2) To adjust the pressure of the roller A on the duplicating-composition, and to allow this roller to adjust itself to inequalities in the composition, the carriage is supported at each side on spring-pressed plungers D, Fig. 1, bearing on paths f at the sides of the machine, the pressure being adjusted' by turning screws d. A rough adjustment may be effected by means of the grub screw usually provided in this type of machine. (3) To avoid distortion of the roller A and to cause it to bear uniformly over the whole width of the sheet, a screw adjustable roller C, Fig. 6, is arranged to bear on the roller A at one or more intermediate points.