Patent GB-719933-A (GB)
Title: Improvements in or relating to character selecting mechanisms for composing machines
IPC: B41B7/00
Filed: 1950-03-10
Abstract: 719,933. Typewriters; type - bar - making. OAKLEY, J. L. D. (Export Printer's Art, Inc.). June 11, 1951 [March 10, 1950], No. 6142/50. Classes 100 (3) and 100 (4). A character selecting mechanism operated by a typewriter or like machine comprises a number of longitudinally movable type or matrix bars carrying identical columns of characters, alternate bars being arranged in reverse direction, and means to cause each bar to be stopped at selected characters to form a line of characters. The mechanism is coupled to an ordinary typewriter A by linkage 2-10 and comprises a bed B, Fig. 1, of rocking bars 12, one bar to each character and which operate plungers in a carriage C which moves parallel to and in consonance with the typewriter carriage. The carriage C does not move on operation of the typewriter space-bar. These carriage plungers set, at each letter space, a series of stops 36 frictionally mounted in a fixed framework D. There are as many columns of stops as there are letter-spaces or columns of travel of the carriage C and each column of stops has a stop for each character on the character bars 38, Fig. 10, which move to engage the selected stop 36. Each rocking bar 12, Figs. 2, 3, is carried by arms 17 pivoted on pins 20, 21 in the bed B, and is formed with a series of teeth 18 which engage alternately a row of plungers 31 and a row of fingers 40 in the carriage C which, as later described, operate a plunger 31 in a different position. There are as many teeth 18 as there are pairs of character bars and since the characters in each pair of arms are arranged in reverse order, the required character will be in a different position requiring operation of a different stop 36 and plunger 31. The carriage C comprises end channels 23, Fig. 5, side bars 25 and a central structure comprising upper and lower guide plates 27, 26 for the plungers 31 and inner side plates 29, 30 which together with the side bars 25 pivotally support a series of finger levers 39 which are operated from the fingers 40, and a series of plunger levers 41 which are operated by connecting-rods 42 from the finger levers 39. The interconnection between the levers 39 and 41, is such that a character bar with reversed order of characters is set by the correct plunger. E.g., if the rocking bar 12 representing the character W is operated in one column and the carriage C is positioned to engage a plunger 31 (marked X, Fig. 5), a stop 36X is set, see Fig. 10, necessitating a long travel of the left-hand character bar 38 to set the character W at the operating line; at the next letter space in which the righthand bar 38 (Fig. 10) is used, the rocking bar now engages the finger 40, marked 7, Fig. 5, and through lever 39, and rod 42, rocks the plunger lever 41 at the far end of the carriage so that a stop 36Y, Fig. 10, is set which allows only a short travel for the bar to register the character W in line with other character. The connection from the plunger lever 41 to the plunger 31 is made by an arm 43 engaging an apertured widened portion 31a of the plunger 31. To accommodate the necessary number of levers 39, 41 they are arranged on both sides of the central structure of the carriage. To avoid damage to the mechanism should letter-spacing take place before the plungers 36 are restored by a resetting bar 37, Fig. 2, the lower guide plate 26 is slotted so that the lower end of the plunger may pivot to the left and be restored by a spring 33 after the resetting is complete. Similarly if letter-spacing occurs before the rocking bar 12 is restored the finger 40 moves the bar rightwardly against a compression spring 22 which restores the bar after it has been returned to normal.