Patent GB-330005-A (GB)
Title: Improvements in and connected with ink-ribbon mechanism for typewriting machines
IPC: B41J35/22
Filed: 1929-03-05
Abstract: 330,005. Tugwood, R. J., (G.M.S. Products, Inc.). March 5, 1929. Ink-ribbon mechanism.-In duplicating-arrangements for typewriting-machines, one or more auxiliary ribbons arranged along the printing lines are fed when the platen is rotated in the reverse direction, or preferably when the platen is rotated in either direction. Relay feedmechanism controlled by the platen and associated with automaticreversed means may be employed, the feed being preferably independent of the extent of rotation of the platen. Multicolour auxiliary ribbons may be employed, adjustable guides being provided to displace the ribbons for colour selection. In the attachment shown in Fig. 1, the auxiliary - ribbon mechanism is mounted on a frame 36 which is connected by parallel links 37, 38 to brackets 29 on the carriage 21 and is connected by links 41 to the platenshift frame 24. Spools 56, 57, Figs. 1 and 11, for the auxiliary ribbon 59 are mounted on plates 43, 44 on the frame 36. Guides 51, 52 for the auxiliary ribbon are connected by parallel Jinks 50, 54.to the plates, the links 50 being connected by a rock-shaft 45 provided with a fingerlever having a locking-pin 47. The auxiliary ribbon passes over rollers 62, 65 on the guides and is diverted into the printing line by inclined slots 63, 64 in the guides. The finger-lever is displaced to effect multicolour or maximum-wear adjustment of the auxiliary ribbon or to remove it from the printing line, adjustment occurring without formation of slack. When the platen is shifted the ribbon mechanism moves therewith as a unit. The spools are driven by a shaft 87, Fig. 3, associated with the automatic-reversal means described below, and driven by a spring drum 153 which is released when the platen 22 is turned in either direction through a large or small arc. The drum spring 152, Fig. 7, is connected to a shaft 151 which is connected by a friction coupling 155, Fig. 7, is connected to a shaft 151 which is connected by a friction coupling 155 to a drum 154 provided with a pawl 160 engaging a ratchet-wheel 159 on a bevel-gear 88 meshing with a bevel-gear 89 on the shaft 87. A yoke 163, suspended by links 167 from the frame 36 and connected to a spring 175, is formed with a bar 164 engaging the platen, and a finger 173 normally engaging a stop 174 on the drum 154. The drum is formed with a cam 177, Fig. 3, flanked by ribs 178 converging towards the stop. When the platen is rotated in either direction through one or more line-spaces, the yoke 163 is moved forwards or backwards and the finger 173 releases the stop 174, thereby permitting the spring 152 to drive the shafts 151, 87. At the end of a revolution a finger 172 on the yoke engages the cam, the yoke is rocked, and the bar 164 is raised. Thereupon, one of the ribs 178 co-operates with the finger to retract or advance the yoke, and when the cam releases the finger 172, the yoke drops and the finger 173 engages the stop 174 and arrests the drums and shafts. At each operation the spools 56, 57 make one revolution and impart a long feed to the auxiliary ribbon. If the platen is rotated continuously the auxiliary ink-ribbon receives continuous feed. The spring 152 can be wound by means of a drum 182, Fig. 7, provided with handles 185, and a pawl 183 engaging teeth on the drum 153. A pawl 181 on the frame 36 prevents reverse movement of the drum 153, and the coupling 155 slips if the spring is over-wound. On return of the carriage, the spring is wound automatically by means of a band 187, Fig. 1, which is attached to the framework and the drum 182 and winds on and off the drum during forward and return movement of the carriage. The band may be caused to wind on the drum by means of a spring, or preferably by means of a band 189 which is attached to drum and framework and winds on and off the drum during forward and return movement of the carriage. A spring connecting the band to the framework permits shift of the frame 36. The spring drum 153 may be replaced by an electromotor. The spools 57, 56 are secured by feathers and screws 149', 149, Fig. 3, to a sleeve 91 and a shaft 98 respectively, the sleeve being revoluble in the plate 44, and the shaft being revoluble in a sleeve 90 which is revoluble in the plate 43. The shaft 87 is revoluble in the sleeves and a bracket 42 and is provided with sliding clutches 112, 113 for engaging the sleeves 90, 91, a longitudinally movable rod 114 having forks 115, 116 engaging the clutches. A coiled spring 150 connecting the shaft 98 to a drum 92 on the sleeve 90 maintains tension in the auxiliary ribbon. Cams 94, 105, frictionally coupled by means of spring-urged discs 95, 106 to the sleeves 90, 91, have helical rims engaging pins 125, 126 on collars 119, 120 having limited longitudinal freedom on the rod 114, springs 128, 129 being arranged between the forks and collars. The pins co-operate with stops 127, 127' on the cams to limit movement thereof. The ribbon on the spools engages spring-urged arms 130, 131 which are secured to rock-shafts 132, 133 and have lugs 145 for engaging lugs on spring-urged arms 137, 138 loosely mounted on the rock-shafts and forming obstructions for collars 147, 148 on the rod. When the ribbon is winding on the spool 57 or 56, the clutch 113 or 112 is engaged, the cam 105 or 94 compresses the spring 129 or 128, and the rod is obstructed by the arm 137 or 138. When the spool 56 or 57 is empty, the arm 130 or 131 drops into a slot in the core of the spool, the arm 137 or 138 is raised, and the spring 129 or 128 moves the rod to the right or left to effect quick reversal of the feed. The ratchetcoupling 160 permits the ribbon to be fed manuallv bv means of cranks 162, 162' on the screws 149, 149'. Ink ribbons. - When two or more auxiliary ribbons are employed they are secured together at the ends and wound on the same spools, the outer ribbons being slightly longer than the inner to compensate for the difference in length of the coils of ribbons. Web-feeding arrangements.-Web rolls 72, 73, 74, Fig. 1, are supported on the above-mentioned brackets 29 on the carriage 21, the webs being interleaved with the auxiliary ink-ribbons and passing through guide-slots 78, 79 in a cross-bar 35, over a guide-roller 80, around the platen 22, and over a shelf 81 at the front of the platen. The roll 72 may consist of plain and transparent webs, the transparent web passing in front of one of the auxiliary ink-ribbons. Web-cutting arrangements.-A knife 82, Fig. 1, for cutting the above-mentioned webs is secured to arms 83 pivoted to blocks which are adjustable in slots 85 in the shelf 81 and are secured by screws 86.