Patent GB-498039-A (GB)
Title: Improvements in typewriting machines
IPC: B41J35/22
Filed: 1937-06-29
Abstract: 498,039. Typewriters. ROYAL TYPEWRITER CO., Inc. June 29, 1937, No. 18084. Convention date, July 23,1936. [Class 100 (iv)] A typewriting-machine comprises a carriage including a platen, a carbon strip spool journalled on the carriage, a carbon strip feeding means mounted on the carriage, means for guiding the strip from the spool along and in front of the platen to the feeding means, and means for first operating the carbon strip feeding means and subsequently effecting an unwinding of the strip from the spool. Line-spacing mechanism; web-feeding arrangements; paper carriages and supports.-The carriage B is mounted to run on front rail 9, Fig. 3, and rear rail 10, which is vertically adjustable by means of screws 16 and slot 19, Fig. 2, and which is engaged by rollers 31 carried by adjustable eccentric bearings and by runners 30. The work sheets W, Fig. 14, are fed over rolls 33, horizontal guides 36, rolls 37, 38, up across the front of the platen C, behind a guide bar 78 and into the grip of work clamp F, which may be fed vertically for line spacing on a frame G. The cylindrical platen. C has adjustably secured to its ends by split clamps 46, 47, Fig. 1, heads carrying eccentric hubs 43 on which the platen swings on an axle pivoted in the carriage. The platen can be swung upward and backward by a lever 50 secured to the hub 43 and actuated by a link 52 from a lever 55 secured to an axle 56. A line-space lever 57 carries a cam face 60a, Fig. 1, which engages a roller 61 on a lever 62, and operates, through a link 64, a lever 68, Fig. 3, secured to the shaft 56. To return the platen and lever 57, a spring-biassed lever 71,73, Fig. 4, engages a roller 70 on an extension of lever 55. In the writing position the swing- ing and geometrical axes and the typing line of the platen are coplanar, and the platen projects in front of the roller 38 and clamp F. When it is swung back, the tension on the webs W is released, so that the carbon strips S will not be dragged during line spacing. To maintain the work webs in close contact with the platen, the guide bar 78, carried by two arms 80, Fig. 14, pivoted to arms 84, is provided. While the platen is being rocked back, the bar 78 is slid forward by the action of links 93 connected to the levers 55 and 68. The bar is pressed into position by springs 96, which in the over-centre position also maintain it out of position during threading of the webs. The clamp F comprises a plate x, Fig. 33, carrying, on a spindle 115, Fig. 2, pinion wheels 116, engaging fixed racks 119 on the channelled side members 102, 103 of the frame G, so as to maintain the clamp horizontal. A ratchet bar 121 is fixed to the member 102, and a sliding feed ratchet bar 123 has projections 125, 126 sliding behind pins on the rack 119 and bar 121. A pair of pawls 130, 131 engage the bars 121, 123, but may be disengaged by finger levers 135. A spring-pressed clamping plate y grips the webs to the plate x, so that as the bar 123 is reciprocated by a lever 138 and link 137 the web is line spaced. For varying the spacing, the screws securing the bar 121 are removed, the link 137 is slid sideways off its headless connecting pin 137a, and the bars 121, 123 are lifted out through the top of the frame and replaced by others. The lever 138 is connected by an adjustable eccentric pivot 142 to a link 143, which is pivoted to lever 145. A roller 148 on the line space lever 57 engages a toe 147 on the lever 145, after the roller 61 has left the cam face 60a and passed on to a dwell 60b, so that movement of the lever 57 first moves the platen and bar 78 and then, while they remain in shifted position, line spaces the webs. Ink ribbon mechanism.-The ink ribbon spools s are carried in sets of three on three horizontal shafts 173, Fig. 2, carried by a plate 150. The plate 150 is slidably supported by rollers 158, 153 carried by the platen carriage and engaging respectively over the top edge of the plate and in slots 152 at the bottom of the plate. The plate can thus slide relative to the carriage between an adjustable eccentric back stop 160 and a screw front stop 161. The plate is normally drawn towards the stop 160 by a spring 221 secured at one end to the plate and at the other end to a screw 217, provided with a D-section portion sliding through a corresponding hole in the carriage and with an adjusting nut 222. Each shaft 173 is supported at one end by the plate 150 and carries three brake shoes 177, Fig. 27, sliding radially in a slot 175 in the shaft, pressed outwards by springs 183 and guided by pins 179. The outer end of each shoe is formed as a cam surface 178, so that the spools s can be successively slid on to the shaft, and if less than three are placed on the shaft, they will be retained by the outer shoe 177 projecting beyond the surface of the shaft. Each spool comprises a disc 163 with a ratchet edge, an outer longitudinally slotted annulus 167 and an inner annulus 166. Between the annuli are placed spring-pressed fingers 171, whose toothed ends project through the slots in the annulus 167 to engage a paper tube 170 on which the carbon paper is wound. Each ratchet disc 163 is adapted to be engaged by a pawl 186a, Fig. 2, pivoted on a shaft 185, drawn towards the disc by a spring 189 but normally restrained by universal bails 193, 194, 195, pivoted on the shafts 185. The bail 195 is controlled by an arm 200 and the bails 193, 194 by a horizontal push-rod 204 coupled to the arm 200 and guided by pin and slot on the plate 150. The arm 200 is connected by a link 214, Fig. 1, with a bell-crank lever 212, connected by a link 210 to the link 64. The rear ends of the shafts 173, 185 are supported and closed by pivoted latches 233, which also engage annular notches on the shafts 185. The carbon strips S are led round horizontal guide pins 223, round vertical rollers 224 mounted in echelon on a shelf 225 attached to the carriage, round a roller 226, along the printing line to a roller 227 and to ribbed feed rollers 229. The rollers 229 are rotated from the line space lever 57 by pawl-and-ratchet mechanism and a link 230, Fig. 4. Operation of the lever 57 then first moves platen C and bar 78 to relieve tension on the webs, feeds the carbon strips by means of the rollers 229 and latches the carbon spools by the latches 186a. Consequently the carbon strips are tightly stretched and the spool carrying plate 150 is moved to the right, Fig. 2, against the action of the spring 221. Secondly, the webs are line spaced and the carriage may be shifted. When the lever 57 is released, the spring 75 on the lever 71 returns all the parts to their rest positions, the latches 186a are disengaged and the spool frame returns to rest position, unwinding the carbon strips as it does so. Specifications 498,040 and 498,124 are referred to.