GB146247A - Printing plates and methods of making same - Google Patents

Abstract

146,247. Litchfield, I. W. July 3, 1919, [Convention date]. Printing-surfaces; holders for type-bars; stereotype and type-bars.-A relatively thin printing- plate is constructed by joining together lines of type of reduced depth by means arranged at the back of the type-bars so as not to increase their depth. Lines of type 1, Fig. 3, as produced by a type-bar casting machine or built up from single type, of the height of the usual electrotype, are united by reinforcing-members such as 19, Fig. 6, preferably of steel, placed or pressed into transverse grooves 17 which are then filled with a plastic substance such as lead, lead-wool or soldsr. The members 19 and grooves 17 may be of any suitable size and shape. If the cambered member 19 is used, the edges may be serrated to increase the grip. A galley 7 having a fixed end and side 8 and an adjustable end and side 9 operated by a screw 11 and secured in adjusted position by a screw 12, may be used for clamping the lines of type 1, which may be constructed with shoulders 6, during the removal of the 'backs of the type and the cutting of the grooves 17. Grooves 5 may be cast or cut in the type, and reinforcing rods may be secured in the parts of the grooves 5 remaining after the type is reduced, or the grooves may have undercut recesses to receive the rods. The back of the plate is finished to a plane surface, and the plate is secured to a backing member which may be of a special form when the shoulders 6 are provided or bevelled so that the blocks usually used for retaining electrotypes may be used. In the construction shown in Fig. 15, the finished plate 23 is secured to a backing-member 35 by flanged members 36 provided with projections 37 engaging grooves 26 formed in the sides of the plate. The lines of type may be originally cast or built up of type of reduced thickness, formed or cast with transverse grooves and joined together in any of the methods described. A modified form of clamping-galley is shown consisting of a lower part and an upper part, the latter having projections to engage grooves in the ends of the lines of type so that on securing the upper part the lower part may be removed to expose the backs of the lines of type for cutting the grooves; or, the galley may have recesses to expose only those parts which are to be grooved. The lines of type may be formed with reduced backs 41, Fig. 16, the remaining parts 42 being of the required final thickness, and grooves 43 may be cast initially or formed after the backs 41 are removed.