GB1011023A - Improvements in or relating to document feeding apparatus for typewriters and like business machines - Google Patents

Abstract

1,011,023. Typewriters. INTERNATIONAL BUSINESS MACHINES CORPORATION. March 2, 1964 [March 28, 1963], No. 8652/64. Heading B6F. Platen and feed roller rotation for condensed record work; line-spacing key actions; linespacing arrangement.-A sheet-feeding mechanism for a typewriter having a single rotatable type head 1, Fig. 1, which is movable longitudinally of the platen, comprises a rotatable platen 2, drive means including can 15, levers 11, 12 and pawl 4, Fig. 7, for rotating said platen and control means, including linespacing programme drum 47 having pins 79, said control means being rotated through gears 74, 75 in accordance with the rotation of the platen and adapted to stop said drive means after the platen has rotated through an angle determined by the disposition of said pins 79 protruding on the outer periphery of the programme drum 47. To effect line-by-line spacing a key lever 46, Fig. 1, is depressed which operates a link 71 to rock a bell-crank 65 and lift a flange 61 of a plate member 60 until a projection 55 on a plate member 48 clears a flange 56 on a fixed bracket 57. A spring 59 then moves the plate member 48, 60 towards the right until the flange 61 abuts the flange 56 causing thereby arm 50, 52 to swing and disengage a control pawl 26 from a shoulder 25 of a clutch disc 24. The disc 24 then rotates to a position in which a tooth 31 of a drive pawl 30 engages a ratchet wheel 32, fast with a continuously rotating shaft 16, to drive a cam 15, which rocks a bellcrank 12 to drive a pawl 4, Fig. 7, via a link 11 and bell-crank 9, into engagement with a ratchet wheel 5 fast with the platen 2. The rotating platen drives the programme drum 47, via gears 74, 75, which has a plurality of pins 79 disposed about its periphery the spacing of the pins corresponding to a line space. For normal line spacing all the pins 79 are disposed to protrude on the outside of the periphery in the manner of a fixed pin 79a, each of the pins 79 engaging in succession a hook 91 of a slidable finger 90, when the platen has been rotated through one line space to move the plate members 48 and 60 to the left, whereby the arms 50 and 52 are swung back to enable the control pawl 26 to re-engage the shoulder 25 of the disc 29, which rotates to disengage the drive pawl 30 and stop the line spacing cam 15. To effect long feeds for typing on standard forms the programme drum 47 is first set by rotation of the platen whereby all the pins 79 are returned to their inoperative positions by camming them back flush with the outer periphery of an annular flange 77 by manual lifting of a member 80 having a cam portion 87. The key lever 46 is then depressed and the platen rotated by the drive cam 15 until it is stopped by the fixed pin 79a provided on the programme drum 47 so that it starts from a reference position for each form typed. A programme setting form 103 is then inserted under the platen from the rear until it engages stops 101, Fig. 1, which locate the form at a fixed point when the drum is in its reference position. The platen is then rotated manually to feed the form until the first line to be typed is at the typing station. As the platen is rotated the drum 47 is turned accordingly. With the form in the first line position a member 80 is depressed manually and its hook displaees a pin 79 into its operative position and the manual rotation of the platen is repeated for all subsequent line positions. After setting the pin for the last line, the key lever 46 is again actuated to cause the cam 15 to drive the platen and programme drum 47 until the pin 79a displaces the finger 90 which in turn through plate members 48, 60, arms 50, 52 and control pawl 26 stops the drum 47 at its reference position. The last operation of the key lever 46 results also in the ejection of the forms. The first form to be typed on may now be inserted. Detents for platens.-To prevent the platen 2 from rotating when the pawl 4 is disengaged from the ratchet wheel 5 a detent 21, engaging the ratchet teeth, is provided. Sheet-gripping, clamping and guiding arrangements.-To insert the form 103 each time in the same position from which it may be fed by rotation of the platen a cam 117, Fig. 3, is turned to displace an arm 116 and force a further arm 114 against a flange 115 of a bellcrank 108, which pivots feed rollers 104, 105, Fig. 4, out of engagement with the platen. Simultaneously, a stop member 100, having stop fingers 101, supported on portions 125 extending from pivotal members 122 is brought into contact with the platen 2 through springs 121 acting on the members 122. After the forward edge of the form 103 is moved into engagement with the stop fingers 101 the cam 117 is turned clockwise to re-engage the feed rollers 104, 105 with the platen and lower the stop fingers 101 to their inactive positions. Specification 873,920 is referred to.