Patent GB-286928-A (GB)
Title: Improvements in typewriting machines
IPC: B41J35/30
Filed: 1927-05-25
Abstract: 286,928. Fairweather, W. C., (Underwood Typewriter Co.). May 25, 1927. Ink-ribbon mechanism. -In a duplicating- arrangement, particularly for use in condensedrecord work, an auxiliary ink-ribbon for typing on a record sheet or the like is carried by spools on the carriage and is directed along the printing line by guides which can be lifted, or lifted and swung outwards, to permit of insertion of an outer sheet or the recordsheet respectively; the spools are associated with feed - mechanism which is operated by the linespacing mechanism and is silenced when the guides are lifted; the guides are provided with clamps for preventing the auxiliary ribbon from forming slack when the guides are lifted, the clamps being released when the feed-mechanism is operative; a shield for preventing the auxiliary ribbon from soiling the outer sheet consists of a tape stretched between adjustable supports ; a support is provided for preventing the auxiliary ribbon from sagging below the printing line; the auxiliary-ribbon guides may be arranged on being lifted and swung outwards to release paper-fingers holding the record-sheet. The apparatus shown in Figs. 1, 6, and 18 is provided with auxiliary and main ink-ribbons X, 125 for typing on a record sheet B and a superposed narrower sheet. C respectively. The mechanism for feeding and guiding the auxiliary ribbon X is mounted on a frame comprising brackets 28 scoured to the carriage 22 and connected by a cross-bar 47 and shafts 30, 31, 31a and 32, the shafts being supported at the middle by a bracket 160. The auxiliary ribbon passes between spools 53, 54, Figs. 1 and 6, mounted in U-shaped brackets 49, 50 secured to the bar 47. The core 62 of each spool is mounted on a sleeve 63 running on a spindle 55 which passes through a boss 57 on the wall 51 of the bracket and is threaded into a boss 56 on the wall 52. The sleeve is attached to a ratchet-wheel 64 provided with a pin 65 entering a hole 66 in the core. The ratchet-wheel is braked by means of a flange 60 on a sleeve 59 mounted on the boss 57 and urged by a spring 61 having its ends soldered to the wall 51 and flange. On withdrawing the spindle, the spool and ratchet-wheel can be detached. The ratchet-wheels are operated by normally-disengaged pawls 68 which are pivoted on arms 67 on the shaft 31a and are so arranged that only one pawl is operative at a time, the shaft being moved axially by means of knobs 78 to reverse the feed. A V-spring 77 and a V-disc 76 co-operate to retain the shaft. A crank 44 on the shaft engages link 43 having a slot engaging a pin 42 on an arm 34 which rocks on the shaft 30 and is coupled by a link 40 to the line-spacing slide 24. At each operation of the line-spacing lever, the arm 34 rocks the shaft 31a, and one of the pawls is operative to feed the auxiliary ribbon. The auxiliary ribbon is guided vertically by fingers 103 and is guided along the printing line by inclined slots 93 in plates 92, which are secured to a bar 90 and are offset to bring the auxiliary ribbon into a plane parallel to that of the main ribbon 125. The plates 92 are pivoted on pins 94 on the bar 90 and are secured by screws 95 passing through slots, the arrangement permitting adjustment of the plates to take up slack at either edge of the auxiliary ribbon. The bar 90 is secured to arms 85 suspended from studs 84 on arms 83 secured to the shaft 31. The studs run in slots 80 formed in plates 79 secured to the bar 47, the slots being concentric with the shaft. The arms 85 have studs 87 running in intersecting arcuate slots 82, 81 in the plates. To render inoperative the auxiliary ribbon and to permit insertion or removal of the sheet C, the auxiliary ribbon is moved upwards and slightly rearwards by raising a lever 98 on the shaft 31, the studs 87 riding up the slots 82 and constraining the bar 90. On further raising the lever 98, the auxiliary ribbon is swung forwards and upwards to permit insertion or removal of the sheet B, cams 99 on the arms 85 abutting on pins 100 and causing the studs 87 to enter and ride up the slots 81. The shaft 31 is retained in the normal or displaced position by means of spring-urged levers 121 cooperating with noshed discs 117 on the shaft. The auxiliary ribbon is clamped to the plates 92 by means of fingers 107 formed on pivoted arms 105 connected to springs 110, the fingers preventing the formation of slack when the auxiliary ribbon is raised by means of the lever 98. During the feed-movement of the auxiliary ribbon, the fingers 107 are automatically released by means of levers 113 which abut on lugs on the arms 105 and have pins 116 engaging notched discs 112 on the shaft 31, the shaft having a ratchet-wheel 33 driven by a pawl 37 on the arm 34. When the auxiliary ribbon is raised, a pin 101 on one of the arms 83 rocks the link 43 by riding in a slot 102, the link being thereby released from the pin 42 and the feed of the auxiliary ribbon being silenced. A shield for preventing the auxiliary ribbon from soiling the sheet C consists of a tape 126, Fig. 1, stretched between supports 127 which are adjustable on the bar 90 to correspond to the width and position of the sheet, and are secured by screws 130. The supports are each formed with an inclined guide-slot 128 and a tape-clamping finger 129. One of the supports 127 or a separate member has a hook which is passed under the auxiliary ribbon and prevents it from sagging. Sheet feeding and guiding arrangements.-The record sheet B, Fig. 18, is held in contact with the platen by means of paper-fingers 141, which are released automatically when the abovedescribed auxiliary ribbon X is swung forward; or manual releasing-means may be provided. The paper-fingers are secured to arms 140 adjustable on the shaft 32, each arm being associated with a collar 143 provided with a strip 144 loosely engaging a slot 146 in the shaft, a spring 147 being connected to the strip and arm. A crank 137 on the shaft engages a slotted link 138 connected to the above-mentioned disc 117 on the shaft 31. When the lever 98 is raised to move the auxiliary ribbon to inoperative position, the link moves idly and the paper-fingers' remain at rest. When however the lever 98 is raised further to swing forward the auxiliary ribbon, the link rocks the shaft 32 and the paper-fingers are released. The above-described automatic means may be replaced by a thumb-lever pivoted to an arm secured to the shaft 32 and connected to a spring which normally holds a shoulder on the thumb-lever in contact with a stop-pin. On pushing rearwards the thumb-lever, the arm is rocked to release the paper-fingers, and a groove in the thumb-lever co-operates with the stop-pin to retain the paper-fingers in the released position. The cross-bar 90, Fig. 1, supporting the ribbonguides serves also as a sheet-guide. A collating- table 123 is arranged above the printing line. The paper-fingers may be employed also for holding an extra-wide sheet A and a carbon sheet A<1> which are arranged under the sheet B. When a tallystrip is employed it is wound on to a spool 134 geared to the shaft 30.