Patent GB-1016278-A (GB)
Title: Typing mechanism
IPC: G06F17/27
Filed: 1964-05-26
Abstract: 1,016,278. Typewriters. INTERNATIONAL BUSINESS MACHINES CORPORATION. May 26, 1964 [June 14, 1963], No. 21795/64. Heading B6F. A typewriter, wherein each character and each of a number of machine functions is selected by actuation of an interposer, has at least one special key-lever movable into one of two positions in the first of which one interposer only is actuated and in the second of which two or more interposers are actuated in a predetermined sequence. In the second position a constantly recurring word or syllable may be automatically typed, or the same letter may be repeated, or a number underlined. As shown, the machine comprises a part-spherical type head 1, Fig. 1, which is rotated and tilted to select a character, and moves along the platen 5 for letter-spacing &c. Selective movement of the head 1 is effected by linkages selectively operated by lugs on the bottom edge of a selected interposer such as 49, Fig. 1, the rear edge of which is moved downwardly into the path of arms 32 on a rotating shaft 31 when the corresponding key 7 is depressed. The shaft 31 is rotated 180 degrees for each printing cycle and is driven by gearing 28 ... 30 from a shaft 12 coupled by a normally inoperative clutch 13 to a motor-driven shaft 9. A special key such as key 7 for printing either the letter " T " or the word " THE " has associated with it three interposers 48, 49, 50. Pivoted on the key 7 is a member 46, Fig. 2b, normally held by a spring 21 in a position where a bar 46a thereon is just above a lug 49a on the centre interposer 49. Partial depression of the key 7 thus causes downward movement of the interposer 49. A lug 49c on the lower edge of the interposer 49 then operates a bail 26 which through a link 27, Fig. 1, pivots a catch 15 to release the clutch 13 and cause the shaft 31 to rotate 180 degrees and effect a printing cycle. A lug 32 on the shaft 31 moves the interposer 49 endwise so that lugs thereon position the type head 1 for printing the letter " T." If it is required to print the word " THE," the key 7 is depressed to its fullest extent in which position it is held by a hook 49b on the interposer 49 engaging a latch 45 on the key. The interposers 48, 50 have on their lower edges lugs to select the type faces " H," " E " respectively and a lug similar to lug 49c to operate the bail 26. On their upper edges are lugs 48a, 50a respectively with inclined edges at their tops. As the interposer 49 returns to its rest position (i.e. rightwardly, Fig. 2e) after effecting printing, its lug 49a engages bar 46a and moves it against lug 48a so as to depress interposer 48 and cause the letter " H " to be printed. Similarly, as interposer 48 returns to its rest position, its lug 48a engages bar 46a with the lug 50a of interposer 50 so as to effect printing of the letter " E." A retaining pawl 51 holds the member 46 in the positions to which it is moved during these operations. As the last interposer 50 returns to its normal position, it moves bar 46a rightwardly against a lug on the latch 45, to uncouple the latch 45 from the hook 49b and permitting all the parts to return to their initial positions. Letter spacing.-A cam 37 on the printing- cycle shaft 31 operates the escapement through follower 38 and link 39 at each printing operation. The escapement can also be operated for letter-spacing by the action of the space bar on a bail 40, connected by members 41, 42, 43 to the escapement. An extension 50c, Fig. 2c, may be provided on the last-operating interposer 50 to engage the bail 40 and provide an additional letter-spacing after an automatic printing operation. Underscoring.-A special key may be provided for underlining, e.g. a two-digit number. In this case, the key is associated with four interposers which in turn cause a back space, a back space, printing of an underline and printing of another underline.