Patent GB-191415924-A (GB)
Title: Improvements in Printing Mechanism for Calculating Machines.
Inventor: THOMPSON WILLIAM PHILLIPS
IPC: B41J11/36
Filed: 1913-06-17
Granted: 1914-08-17
Abstract: 15,924. Thompson, W. P., [Duco Adding Machine Co.]. June 17, 1913. Relates to printing-mechanism for calculating- machines in which a platen carrying the record paper is moved for impression from typewheels. Specifications 14,044/13, and 15 923/14, 15,925/14, 15,926/14, and 16,001/14, [all in Class 106 (i), Calculating &c.], are referred to. Platen-impression arrangements; line-spacing mechanism.-(1) The platen 7, Fig. 3, is secured to a shaft 19 journaled in arms 20 on a shaft 21, which can be rocked in either direction, for impression from the item type-wheels 102 or the total type-wheels 103, by mechanism (not described) connected to a slide 60, Fig. 1, geared to a sector 90, which is secured to the main operating-lever. (2) The line-spacing wheel 72, Fig. 8, is loose on the shaft 21 and is secured to a loose pinion 58 gearing with a pinion 59 secured to the platen shaft 19. The line-spacing pawl 73 is pivoted to a bell-crank lever 75 connected by a latch 76 to a pin 87 on a plate 88 secured to the sector 90. The pawl is normally held disengaged from the wheel 72 by a spring which holds the tail 85 of the pawl against a stop 79. A spring 81 normally holds a lug 78 on the bell-crank lever against the stop 79. When the main operating-lever is rocked, the plate 88 draws the latch to the left and thereby causes the pawl to engage and actuate the line-spacing wheel. A stop 99 then engages an incline 76<a> and trips the latch, the spring 81 and the pawl spring then retnrning the latch, the bell-crank lever 75, and the pawl to the normal position shown. The pin 87 re-engages the latch during the return movement of the main operating-handle and the plate 88. Overthrow of the platen is prevented by a star-wheel 140 engaging a detent 138, which is pivoted at 137 to a member 132, described below, and is tensioned by a spring 139. (3) Impression is effected on the part of the record paper 5 which is initially at the bottom of the platen, mechanism of the following character being provided for rotating the platen to bring this part of the record paper into position for impression from the type-wheels 102 or 103. This mechanism comprises a segment 132 which is loose on the platen shaft 19 and is formed with a slot 133 engaging a fixed pin 134. The segment 132 gears with a segment 106 loose on the shaft 21 and provided with a slide 108, which is formed with a tooth 124 adapted to engage a ratchet-wheel 105 secured to the pinion 58. A member 115 normally engages the end 113 of the slide and holds the tooth 124 clear of the ratchet-wheel 105. The member 115 is mounted by slots on rods 42, 116 and is provided with a pin 119 held by a spring 121. in engagement with a projection 123 on a rocking plate 120, which is mounted on the rod 42 and is formed with a notch 126 engaging a pin 125 on the plate 88. In operation, the pin 125 engages the wall 128 of the notch just before the completion of the line-spacing feed and rocks the plate 120, the projection 123 moving away from the pin 119 and permitting the nose 124 of the slide 108 to engage the ratchet-wheel 105 and thereby couple the segment 106 to the p:nion 59 through the gearing described above. During the further movement of the main operating-lever, the platen is swung for impression, and the rocking of the segment 132 causes the platen to rotate clockwise, if the platen is swung to the left for impression from the type-wheels 102, or counter-clockwise if the platen is swung to the right for impression from the type-wheels 103, the rotation thus imparted to the platen causing the part of the record paper which is initially at the bottom of the platen to be presented to the type-wheels 102 or 103. During the return of the platen to the normal position, the segment 132 rotates the platen through the same arc as that imparted during the impression stroke, but in the oppesite direction. At the end of the return movement of the platen, the pin 119 is lifted by the projection 123 on the plate 120, and the nose 124 is lifted out of the ratchet - wheel 105. During the backward and forward movement of the plate 120, the pin 119 rides on a part 130 of the plate which is concentric with the rod 42. Web feeding, guiding, and cutting arrangements.-The record web 5, Figs. 1 and 3, is fed through a slot 6 in the casing 1, and thence round the platen 7 and out of the slot adjacent to a knife 8, the platen being provided with guides 26, 27. The web is pressed against the platen by two pairs of feed-rollers 14 carried by levers 17, 18, which are pivoted on the arms 20 and are drawn together by a spring 26, a depressible button 29 adapted to engage the levers being provided for releasing the feed-rollers. The web passes over a tensioning-rod 10 carried by bell-crank levers 12 connected to springs 11. Platen-roller couplings.-The platen roller 7 can be rotated manually by means of a clutch member 32, Fig. 11, journaled in the casing 1 and formed with a groove 34 adapted, when the clutch member is pushed inwards, to engage a rib 22, Fig. 1, on the platen shaft 19. The clutch member is normally held clear of the platen shaft by a spring 35. Platen rotation for inspection of writing. The platen 7 is rotated forward to bring the last printed item into view outside the casing and is then rotated backwards by means of a handlever secured to a rock-shaft 40, Fig. 5, which operates mechanism of the following character. An arm 44 secured to the rock-shaft is provided with a pin 45 engaging slots 46, 48 in a rack 47 and a plate 49, which are pivoted to an arm 51 loose on the shaft 40. The rack is adapted to engage a pinion 53 secured to the loose pinion 58, referred to above, gearing with a pinion 59 on the platen shaft 19. The rear ends of the plate and the rack normally abut on a stop 52. When the hand-lever is pushed to the rear, the pin 45 rides along the offset end 56 of the slot 46 and lifts the rack into engagement with the pinion 53 and clear of the stop 52. The pin then moves idly along both slots until it engages the offset end 57 of the slot 48 and lifts the plate clear of the stop. The pin then engages the ends of both slots and carries the plate and the rack backward, the platen being thereby rotated, and the maximum rotation being determined by the engagement of the arm 44 with the rod 43. The top of the stop 52 is curved and is adapted to engage the plate and the rack and cause them to jam at the end of the stroke and thereby hold the platen in the set position so as to permit the operator to release the hand-lever. When the hand-lever is pulled slightly to the front, a spring 54, Fig. 1, connected to the rcckshaft 40 returns the parts to the initial position and rotates the platen backward. The pin 45 engages the offset 57 and pushes the rack and the plate forward until the arm 51 engages the rod 42, the pin then moving idly along the slots until the arm 44 engages the rod 42, and permitting the plate and then the rack to drop to the initial position. Owing to the idle movement of the pin in the slots, the rack is brought to rest before it is disengaged from the pinion 53, and overthrow of the platen during the backward rotation is prevented. To prevent operation of the slide 60, Fig. 1, during the operation of the mechanism described above, the rock-shaft 40 is provided with a cam 55 engaging a bell-crank lever 69 arranged to be moved into the path of a lug 70 on the slide. Ink-ribbon mechanism.-(1) The ink ribbon 654, Fig. 4, is guided adjacent to the type-wheels 102, 103 and other type-wheels by means of guides 657, 701, spring guides 658, Fig. 3, being provided for holding the ink ribbon clear of the type-wheels. (2) A multi-colour ribbon may be employed, the guides being arranged so that the item type-wheels 102 print in a different colour from the total type-wheels 103. (3) The ink ribbon passes between two spools 655, Fig. 4, journaled on a plate 682 and provided with automatic feed and reversal mechanism of the following character. A sliding bar 667, actuated bv a slotted lever 660, Fig. 1, from the main slide 60, carries on a pivot 674 two pawls 673 which are in alternate engagement with ratchetwheels 672 on the spools. The heels 675 of the pawls are pressed by springs against the top edges of a U-shaped slide 677 mounted by pins 693 and slots on the bar 667 and formed on each of the top edges with parts arranged at different levels, so that by shifting the slide to the right or the left on the bar, one pawl is moved into engagement with its ratchet-wheel and the other pawl is disengaged. The slide is shifted by means of bell-crank levers 685, 689, pivoted at 687 to the plate 682 and formed with spring arms 686, 691, which are held against the ribbon on the spools by springs 698. When either spool is nearly empty, the end of the bellcrank lever 685, or a hook on the end of the bell-crank lever 690, is brought into engagement with one of two lugs 688 on the sl'de 677, and on forward or backward movement of the bar 667, the slide is shifted to the left or the right. The slide is held in the set position by a spring 695 engaging one of two notches in the bar 667. The heels 675 of the pawls engage bell-crank levers 680 formed with detents 679 which engage the ratchet-wheels alternately. The plate 682 is pivoted on pin 683 and can be lifted for the purpose of silencing the feed. The plate is held in the normal position by a latch 703 engaging a rod 177.