Patent GB-754003-A (GB)
Title: Justifier for typewriters
IPC: B41J19/64
Filed: 1954-03-09
Abstract: 754,003. Typewriters. INTERNATIONAL BUSINESS MACHINES CORPORATION. March 9, 1954 [March 12, 1953], No. 6819/54. Class 100 (4). A typewriter justifying mechanism for a differential letter-spacing typewriter, comprises an attachment 1 which is manually set after the typing of a trial line so that the spacing between words is expanded or condensed when the space-bar 110 is operated during the typing of the justified copy. The attachment comprises three cams 230, 231, 232 which are moved step-by-step back to a home position by an electromagnet 177 in response to the actuation of the space-bar 110 so that the cams close contacts to energize solenoids for operation of the differential letter-spacing mechanism. The power type-action, the mechanisms for operating tabulating and carriage-return operations, and the letter-space mechanisms are similar to those described in Specification 673,685. After the trial line has been typed the amount of justification necessary is noted from a scale 150 on the typewriter, and the number of words in the line is read from an attachment counter scale 167 which is actuated by the electromagnet 177, Fig. 11, in response to space-bar operations. The appropriate word-space number is then set to a figure on an " Expand " scale 244 equivalent to the expansion required. If the line is to be condensed, a mark 242 is set to the required figure on a " Condense " scale 246. Rotatably fixed with the dial 237 are the three cams 230, 231, 232 with raised portions which operate electrical contacts for the energization of the solenoids 96A, 96B, 96C which when actuated operate bails 52A, 52B and 52C, Fig. 3, to effect the differential letter-spacing escapement mechanism. Operation of the solenoids 96A, 96B, 96C causes 3, 4 or 5 units of space respectively, and, if none are operated, then 2 units of space is permitted by the escapement mechanism. Cam 230 has ten raised portions 230a, each equivalent to one unit of letter-space in width and corresponding in angular position to the word space scale. An eleventh portion 249 is used in conjunction with the condenser scale. Cams 231, 232 are used only in expanding the text and each carries ten raised portions, of widths progressively increasing, from one to ten units. The raised portions of all cams are offset from each other so that only one is effective to operate its electrical contacts at a time. If it is desired to expand the text, e.g. by twelve units, and there are ten word spaces in the line, the figure 10 on dial 237 is set to 12 on the expand scale 244. When the space-bar is operated contacts 126 close and operate the five-unit solenoid 96B because cam 232 is at this time closing contacts 269. Since at this time contacts 254 are closed, due to cam 230 being displaced, a solenoid 282 is energized, which, through a ratchet drive, steps all the cams one unit. At the second actuation of the spacebar, five units of space is again arranged but, at the third actuation, contacts 269 open and contacts 266 close to arrange for the operation of solenoid 96B and effect four units of space. This occurs for a total of eight word spaces so that the normal three-unit space between words has been expanded to accommodate the twelve extra units. When a reduction of space is necessary, the spaces between the words is reduced one unit starting from the first and continuing until the total reduction is obtained. If a line comprises more than ten word spaces the dial 237 is set to ten and justification is effective over the first ten word spaces. The cams and dials are restored during tabulating or carriage - return operations. Specification 655,492 also is referred to.