Patent GB-1019740-A (GB)
Title: Improvements in or relating to a feed mechanism for inked ribbon
IPC: B41J33/48
Filed: 1963-06-11
Abstract: 1,019,740. Typewriters; ink-ribbon mechanisms. MITE CORPORATION. June 11' 1963 [June 20, 1962], No. 23288/63. Heading B6F. Ink-ribbon mechanisms.- An ink ribbon feed mechanism comprises a first spool holder 70, Fig. 3, with a ratchet wheel 72 co-operating with a forward feed pawl 78, a second spool holder 74 with a ratchet wheel 76 co-operaing with a reverse feed pawl 80, linkage 82, 84, 86 to reciprocate the feed pawls and a ribbon feed reversing arm 136 to make a first check dog 88 operative and a second check dog 90 inoperative while both feed pawls remain in operative positions. The ink ribbon 32 is fed from the supply spool 34 past guides 134, 138, 132, 38 and then advanced to a slotted guide 126, a direction reversing roller 40, the lower run of the ribbon then passing over printing station 118, slotted guide 126, roller guides 42, 122, 120 and wound on the take-up spool 36. The slotted guide 126 (Fig. 4, not shown), is provided with upper and lower slots 154, 152, respectively, to separate the upper and lower ink ribbon runs at the printing station. To effect automatic ribbon reverse feed a ribbon-endsensing arm 136 which is provided with ribbon slots 138, 140 is responsive to engagement by eyelets on the ends of the ink ribbon, which pivot the arm 136 about pivot 142 and the arm in turn rocks an arm carrying the check dogs 88, 90 to disengage the feeding check dog and engage the reverse feed check dog the toggle action being provided by a spring 150. The feed pawls 78 and 80 are always in operative position but the pawl co-operating with the supply spool is momentarily disengaged during each ribbon feed action to permit rotation of the spool by means of tails 114, 116 engaging eccentrics 110, 112, respectively, during reciprocation of the link 84. The eccentrics 110, 112 are adjustable for variation of the length of ink ribbon feed. The spools 34, 36 are mounted on spool holders which are rotatably mounted on a spindle 70 (Fig. 6, not shown) pivoted to a fixed mounting plate 162, and carrying the respective ratchet wheels on sleeved hubs 164 provided with a convex spool retaining spring 168. The ratchet wheels have pins 170 which enter a mating hole in the ink ribbon spool to rotate the spool therewith. Keyboard arrangements; counting apparatus; locking detices.-A keyboard 56, in Fig. 1, may be slid beneath the main frame and locked in that position, a release lever 58 which is movable sideways being provided to unlock the keyboard. The keyboard is provided with a gear 512 (Fig. 1A, not shown) which meshes with a gear 218 when the keyboard is pulled forward into its operating condition. The keyboard is provided with two counters having digit wheels 60, 62, one of which indicates the number of characters transmitted before signalling carriage return and the other may be preset by a knob 63 to warn or signal when a desired number of characters for a single line has been transmitted the signal being given by a glow lamp 61. Paper, strip, web feeding and guiding arrangements.-A paper tape 24, Fig. 1, is supplied from a tape roll 26 and guided through a channel guide 27 past an angularly disposed directionchanging idler 28 over a type cylinder 30. The tape then passes through a perforator 44 and the printed and punched tape is displayed at 46 over a track 48 and finally enters a reader at 52. When a page printer is provided it is located at P (Fig. 2, not shown) and is supplied with a web of paper from a roll 25, and guided over the top of the printer over a directionchanging roller 31. Error detection.-On discovering an error in the printed and perforated tape, an error marking device 64, Fig. 1, is slid along its guiderod 69 until a pointer reaches the error, whereupon the handle 64 is depressed to put an error perforation through one edge of the tape to notch the tape. A wider tape may be provided with a hole in lieu of the notch. Sound-deadening and shock-absorbing stands, supports and pads.-The entire assembly may be mounted on shock mounts as at 35.