Patent GB-648391-A (GB)
Title: Method of and means for controlling the spacing between lines in a line-by-line printing machine
IPC: B41B15/02
Filed: 1947-07-29
Abstract: 648,391. Platen line-printing machines. LUDLOW TYPOGRAPH CO. July 29, 1947, No. 20492. Convention date, March 30, 1942. [Class 100 (ii)] [Also in Group XX] A method of controlling the spacing of lines in a line-printing machine of the kind in which the impressing type and the surface on which it is desired to print are relatively movable to print a succession of spaced lines comprises assembling a column of elements having heights corresponding to the heights of the type characters from which the lines are to be printed, interspaced with elements having heights corresponding to the desired spacing between the lines, and employing the assembled column in association with means operable to move the surface on which it is desired to print relatively to successive lines of type, in a spaced relationship predetermined by the assembled column. The machines described are for photographic printing of the characterbearing elements, but it is stated that by eliminating elements necessary to photographic printing, similar machines can be used for ink printing a line at a time. As shown in Figs. 4 and 5, a machine for photographic printing of character-bearing elements has a base frame 56 with a partition 58 with rails 60 on which slides a carrier 61 having a lug 63 extending downwardly through a slot 64 to which is attached a rod 65 by which the carrier is reciprocated. A removable cover 74 has an opening 76 in which type bodies composed in a stick are inserted and supported by spring-urged rods 87, and which is covered by a housing 88. The housing is removed, and the carrier 61 moved to its extreme left-hand position. A holder 70 for the sensitive material 69 has a removable cover 71 and is placed on the carrier and located thereon by dowels 62. The cover 71 engages a dowel 72 in a projection 73 of the frame 56, acting as a stop for the carrier 61. The cover 74 is replaced, and a slide 79 thereon is moved to the right to prevent light from entering by the opening 76. Within housing 88 is a movable housing 100, open at the bottom, normally drawn upwards by springs 101, and having a projection 111. Housing 88 has an opening 89 on one side at the bottom. On the same side of the housing slides a shutter plate 97 with a projection 112 resting on the projection 111 of the movable housing 100, so that the opening 89 is uncovered when the housing 100 is in its upper position. The first line of type to be printed is composed in a stick, and is inserted in the opening 76 through opening 89. The type elements may be of the kind described in Specification 633,898, [Group XX]. The movable housing 100 has on two sides lugs such as 113 in Fig. 4, projecting through slots in housing 88. Cables 117 fastened at one end to lugs 113 pass over idler pulleys 119 and are fastened at the other end to pulleys 122 fast on a shaft 121 journalled in the frame 56 and rotatable by a handle 123. A locating plate 126 holds the shaft in one of three positions. In one position housing 100 is raised by springs 101, as shown in Fig. 5. In the second position, housing 100 is lowered until its lower end abuts the stick 91 containing the type elements. This movement allows the plate 97 to drop into position to close the opening 89, and the shutter 79 is moved away from the opening 76. A column of blocks 34, which has been prepared by assembling in a column blocks of heights corresponding to the heights of the type lines and the intervening line spaces, is placed against a part 56a of the housing 56, the block corresponding to the first line to be printed is removed, and the rod 65 is moved by the handle 67 until the projection 65a abuts the remaining blocks. This moves the carrier 61 and holder 70, and since the cover 71 is held fixed, a part of the sensitive surface 69 is uncovered and brought below the type elements. The handle 123 is moved to its third position, moving housing 100 down further to force the type elements into contact with the sensitized surface. Exposure is effected by a lamp 105 in the top of housing 100, controlled by a switch 107 (Fig. 4) or by an automatic timer. The handle 123 is returned to its second position and shutter 79 moved to close the opening 76. The handle is then returned to its first position, and the stick of type elements removed and replaced by the elements for the second line. The first spacing block and the block corresponding to the second line are removed, and the process repeated until the printing is complete. In a modification, the carriage 61 is moved by a threaded rod engaging a thread in the projection 63, instead of by the rod 65. The threaded rod has a handle at its outer end and a circular scale, by which it is rotated between printing operations by an amount proportional to the height of the corresponding blocks, the various settings of the scale being obtained from a column of assembled blocks. In a second modification, the blocks representing lines have sloping faces cut into, rising from, or extending across their upper parts, the spacing blocks having horizontal upper faces, the assembled column thus presenting a racklike appearance. Between printing operations, a pawl, pivoted to the rod 165, is rocked against the action of a spring, and the carriage 61 is moved by a handle until the pawl engages the face of the next block. In a third modification, the blocks have raised portions at one side of less than half the width of each block, the raised portions for the blocks corresponding to each set of line and space being on opposite sides. The rod 65 is rotatably connected to the projection 63, and extends through a fork fixed beyond the blocks. A handle is keyed to the rod 65 and held in the fork. A spring is fixed at one end to a collar fast on rod 65 and at the other end to a loose collar with a depending projection. The carriage 61 is constantly urged to the right by a cable connected to a weight, but retained by the engagement of the projection with the raised surface of one of the. blocks. To move the carriage between printing of successive lines, the handle is rocked to move the projection to the other side of the blocks. The carriage moves forward until the projection engages the raised portion of the next block. In an automatic machine, the handle may be moved by a part of the machine whenever a line is printed.