GB289914A - Method and means for effecting registration of printing plates for use in multi-colour printing, applicable for other purposes - Google Patents

Abstract

289,914. Corey, J. A. Jan. 20, 1927. Printing-surfaces. - Relates to registering- devices for adjusting sets of printing-plates on mounting-blocks in multi-colour printing, or sets of photographic plates or transparencies on the glass plate of a photographic printing-apparatus, or for other purposes, and particularly to devices of the kind having lateral guide-members over which can move a longitudinal guide-member having a straight-edge or locating-bar adjustable along it. According to the invention, adjustable locking-members are provided for holding the 'longitudinal guide-member and the locating-bar in adjusted position, and independent means is provided for effecting a fine adjustment of these parts. In a construction adapted for registering printing-plates, a mounting board or plate a is provided with parallel guide-members b and with a transverse bar c, to form a three-sided frame, within which mounts for the printing-plates are secured by the aid of locking-bars g, which can be set in various position by means of pins engaging holes a<1>, the mounts being fixed by means of wedges or printers' quoins. A longitudinal guide-member d is adapted to slide over the lateral guide-members b, and carries a sliding shoe e, to which is hinged a locating-bar f. Two locating-pins f<1>, f<2>, one of which is adjustable, are carried by the locating-bar, and are adapted to engage holes in the bevelled margins of the printing-plates. The pins are movable vertically in the locating-bar to effect their engagement and disengagement, or two pins may be mounted in a crosshead carried by a sliding rod. The pins may be carried by an adjustable extension of the locating-bar. The guide-members b are recessed to receive racks b<2>, which are engaged by toothed locking-blocks d<1>, d<2> at opposite ends of the longitudinal guide-member d, one of the locking- blocks being retractable by means such as an eccentric. The racks b<2> can be adjusted endwise by means of micrometer devices b<5>, so as to give a fine adjustment to the guide-member d. The member d also carries a rack d<3>, which is engaged by a movable toothed block e<1> on the sliding shoe e, that carries the locating-bar. The rack d<3> can be finely adjusted by means of a micrometer device d<5>. Scales are provided on the guide-members b, d. The units to be adjusted may have registration marks instead of holes, and other co-operating means than the locating-pins may then be used. The mounting- frame may be dispensed with, or replaced by a frame separate from the guide-members. The toothed racks may be replaced by plain bars, and friction or other locking-devices may be employed.