GB302114A - Improvements in and relating to machines for printing sacks, sheets and the like - Google Patents

Abstract

302,114. Macdonald, D. J., and Macdonald, Ltd., D. J. May 7, 1928. Rotary machines; gripper mechanism. - A machine for printing on sacks, sheets, &c. comprises one or more printing-couples 13, 17, 14, 18, Fig. 1, for printing on one side of the sack, and a similar set for printing on the reverse side, the sacks being taken from a pivoted feed board 37 by grippers 22 carried by endless chains 23, or the like, guided by tracks 21 secured to the framework and driven by sprockets 24. The grippers comprise bars 25 which grip the whole width of the sack, carried by lever arms 26, 27, Fig. 4, normally pressed together by springs 29 and fitted with pins 30, 31. The pins 30 normally engage track 21, and the pins 31 engage a supplementary track 32 to open the grippers to receive the edge of a sack which is placed by the operator over the front end of the pivoted table 37. The sack is then trailed by the grippers through the printing-couples, the rollers 13, 14, being formed with flats 13a, 14a to permit passage of the grippers. The trailing sheet is supported by stationary feed boards or by bands, and a driven band may assist in the final delivery of the sheet when the grippers are opened by a track similar to the track 32. When released from the grippers, the front end of the sack is taken by an operator. To relieve the chains 23 of the weight of the grippers, rollers 34 on the grippers move over rails 35.