Patent GB-390653-A (GB)
Title: Improvements in or relating to supplemental ink-ribbon mechanism for making copies in typewriters and like machines
IPC: B41J35/22
Filed: 1932-05-03
Abstract: 390,653. Ink-ribbon mechanism. THORNBLADE, C. H., 669, Dexter Horton Building, Seattle, Washington, U.S.A. May 3, 1932, No. 12755. [Class 100(iv).] One or more ink-ribbons, in addition to the usual ribbon, are provided extending along the front of the platen of a typewriter and mechanism is associated with the platen and carriage for advancing the ribbons as the carriage is moved, the ribbons being acted on by continuously-operating take-up mechanism. The ribbons 2, 21, Fig. 1, are carried by spools A .. D supported on extensions 92 of the carriage 9 in such a position as not to interfere with the platen handles 93, line-space lever 91, or similar parts. The spools are carried by spindles 10, 10<1>, Figs. 7-9, the two at each end of the machine extending into casings 94, and carrying gear wheels 12, 12<1> engaging respectively with gear-wheels 31, 32 on opposite ends of a container in which is located a spiral spring 3. One end of the spring is secured to a flange 30 on the gear-wheel 31, and the other end to a spindle 33 connected by a ratchet wheel 35 and pawl 34 to the gear-wheel 32, so that the gear-wheels are urged in opposite directions and tend to rotate the spools on the spindles 10, 10<1> to take up the slack in the ribbons 2, 2<1>. Tension is initially placed on the spring by means of a key 33<1> secured to the lower end of the spindle 33. The spring is connected to the spindle 33 by means of a dog pivoted in a recess in the spindle and normally spring-pressed into an aperture in the end of the spring which is loosely coiled about the spindle. If the spring is suddenly released and tends to cause the spindle to overwind, the dog is forced back into the recess and disconnected from the spring, so as to avoid breakage. Secured to the spindles 10, 101 above the cover 95 of the casing 94 are ratchet wheels 13 connected to the spools by pins 14 which engage apertures in the lower ends of the spools, the pins being sufficiently long to engage the spools when the latter are raised axially on the spindles to the limit allowed by nuts 11 thereon. Each ratchet wheel 13 is under the control of three pawls 15, 16, 17. The pawl 15 is carried by the cover 95 of the casing 94, and is normally in engagement with the ratchet wheel. The pawl 16 acts to feed the spool in order to wind up the ribbon and is carried by an extension 41 of an arm 4 mounted to pivot about the spindle 10 or 10<1>, or by an arm 40 connected by a pin and slot to the extension 41 and pivoted about the spindle 10<1> or 10. The pawl 17 is a locking-pawl and is normally held out of engagement with the ratchet wheel by a coned portion 19 on the bottom of the spools 1 which contacts with a head 18 on the pawl, the head lying in a groove 18<1> above the coned portion 19. In order to throw the pawls 15, 16 out of action when necessary, shields 50, 51 are formed on arms 5 pivoted about the spindles 10, 10<1>, the arms being provided with collars 54 on which the arms 4, 40 are pivoted and which are journalled on bosses on the cover 95 of the casing 94. When the arms 4, 40 are oscillated from normal position, one of the pawls 16, e.g. that associated with the spool A, feeds the spool forward, while the pawl 16 associated with the spool D drags over the ratchet wheel which is held stationary by its pawl 15, and the pawls associated with the spools B, C are held out of contact with their ratchet wheels by the shields 50, 51. On the return movement, the pawl associated with spool A drags over its ratchet wheel which is held stationary by a pawl 15, the respective pawl 16 feeds forward the spool D, and the pawls associated with spools B, C are still held out of operation by the shields 50, 51. The amount of feeding effected at each oscillation of the arms 4, 40 is determined by means of depressions 55 on the arms 5 engaged by projections 57 on a resilient member 58 secured to the cover 95. A depression 56 on each arm 5 is also adapted to be engaged by the projection on the respective member 58 in order to position the shields 50, 51 to render the pawls 15, 16 inoperative. To enable an arm 5 to be moved when the spool is lifted on its spindle, the looking pawl 17 can be withdrawn by means of a hook 60 on an arm 6 pivoted on the arm 5 which is movable into engagement with the head 18. To lock the spools against movement they are raised on their spindles to release the pawls 16. In a modification, Geneva stopwheels 45, 45<1>, Fig. 18, are mounted on the spindles 10, 10<1> and engage with a star wheel 46 carrying a gear-wheel 46<1> adapted to be engaged by one of a pair of intermeshed gear-wheels 48, 48<1> carried by an arm 49 which can be moved and held by means of a spring-pressed pin 49<1> and notched segment 63 in position for engaging either or neither of the gear-wheels 48, 481 with the gear-wheels 46<1>. The Geneva stop-wheels are connected to the spools 1 by a spring-pressed pin. Oscillation of the arms 4, 40 is preferably effected in conjunction with the movement of the carriage. An arm 7, Fig. 1, is carried by brackets 97 on the carriage and is connected by links 74 to the arms 4 at each end of the carriage. A coiled spring 70 surrounds the rod and is connected at its ends to one of the brackets 97 and to the rod 7. A detent 72 is pivoted in a recess in the rod 7 and normally projects so that, during movement of the rod, it engages with a stop 73. The rod is therefore held against further movement while the brackets 97 continue to move with the carriage and extend the spring 70. During this movement the arms 4 are swung relatively to the spools in counterclockwise direction and feed one of the spools. A sleeve 75 adjustably connected to one of the brackets 97 slides over the rod 7, and at a predetermined point forces the detent 72 inwardly, releases the rod 7, and allows it under the influence of the spring 70 to return to normal position relatively to the carriage, thus causing the arms 4 to return to normal position and effect the rotation of the other feeding-spool. In a modification, the platen-shift lever 91 is provided with an extension 91<1>, Fig. 17, connected to a sleeve 77<1> slidable on the rod 7. On movement of the lever 91, the spring 70 is compressed between a collar 78 fast on the rod 7 and a bracket 97, a buffer spring 79 being provided between the collar 78 and sleeve 77<1>. Movement of the lever 91 thus effects the feeding of the ribbons. The ribbons are guided in front of the platen by pins which are supported on an arcuate slide guided on an arcuate bracket carried by the carriage 9 so that the ribbons can be raised away from the platen, a catch being provided to hold them in raised position.