Patent GB-496220-A (GB)
Title: Improvements in typewriting machines
IPC: B41J1/04
Filed: 1937-05-26
Abstract: 496,220. Typewriters. FAIRWEATHER, W. C. (Underwood Elliott Fisher Co.) May 26, 1937, No. 14580. [Class 100 (iv)] Type-lever machines; case-shift mechanism; paper-carriages ; letter-spacing mechanism ; inkribbon mechanism.-A typewriter is assembled from units comprising (1) a base, (2) a skeleton frame supporting type-actions, case-shift mechanism, and ribbon-feeding mechanism, (3) an overhanging carriage-track frame, and (4) a mask for the skeleton frame and base, the skeleton frame being secured in the base, and the carriage-track frame being secured to corner-posts on the base. The letterspacing, back-spacing, tabulating and other mechanisms may also consist of detachable units. The construction enables a local dealer to build up from a stock of units typewriter having the desired action, length of carriage &c., the same base and mask being used in all the constructions. In the machine shown in Fig. 1, a type-lever action, and case-shift, universal-bar, and ink-ribbon mechanisms are supported as a unit on a sheet-metal frame A, Fig. 10, comprising a back 38 and bent-off sides 51. The action comprises type-levers 24 detachably mounted in a detachable shiftsegment 55 and connected to the key-levers 22 by links 31, 26 and radial sub-levers 28. The key-levers are pivoted on a comb 39 secured to the back 38 and pass through a comb 48 connecting the sides 51. The sub-levers are pivoted in posts 35 secured to the bottom bar 64 of a frame 62 to which is secured the shift-segment 55. The frame 62 is mounted on rock-arms 58, 60 mounted in the frame A, a shaft 61 connecting the arms 60 being provided with an arm 74 co-operating with a lever 72 operated by the shift-key 71. The shift-movements are limited by stop-screws 74a, 74b mounted in ears 74c. To render the machine compact, the key-levers 22 are formed with cranked parts 33 for accommodating the bar 64 and sub-levers 28. A universal bar 76, mounted on a rock-shaft 78 in the frame A, co-operates with fingers 75 on the key-levers, and pins 109 on the spacebar levers 105. The shaft 78 is connected by linkage 79, 80, 81 to a stub-shaft 82 which is mounted in ears on. the back 38 and is provided with a striker 83 for the dog-rocker 163, and an arm 84 for operating an adjustable ribbon-vibrator 85. A ribbon feeding and reversing unit comprising spool-shafts 113 and a driving-shaft 110 is mounted on a crossbar 122 secured to flanged parts 125 of the sides 51. A ratchet-wheel 115 on the shaft 110 co-operates with a pawl 132 carried by a lever 130 abutting on a thrust-link 129 connected to an arm 136 on the shaft 78. The frame A is secured within a sheet-metal base B, Fig. 11, comprising a floor 140, bent-up sides 141, 142, a back 146, and a front 147. The back is riveted to flanges 149 on the sides. The frame A rests on the floor 140 and is secured by screws 52c passing through flanges 53, 54. The base is provided with rubber feet 150. The dog-rocker 153 and escapement-wheel 158 are mounted in a frame 166 which is secured to a bracket 168 on the back 146 of the frame B. The carriage-unit C comprises front and rear bars 178, 179 and crossbars 180, 181, and is secured to flanged corner posts or risers 189, 190, on the base B by screws 177 and dowels 192. A front-track 175 for the carriage 161 is secured to horns 182 on the cross-bars 180, and a rear track 176 is secured to the rear bar 179. A spring drum is mounted on the rear bar. For use with long carriages, a carriage-unit having extended front and rear bars is employed. The framework is enclosed in a sheet-metal mask 194, Fig. 19, comprising sides 290, a detachable back 300, and cross-plate 295, and a preferably integral flanged front-bar 292. The sides extend to the top of the cross-bars 180 of the carriage-unit, and have cut-outs for receiving the horns 182, and shoulders 187, 188, Fig. 17, on the cross-bars. The mask is secured to the floor 140 of the base B by means of screws passing through ears 294. Paper-supports.-To permit of minute adjustment of the platen, the platen-shaft 197, Fig. 1, is mounted at each end in a pivoted arm 284 co-operating with an adjustable slide 286 having a slot 287 which is slightly inclined from the vertical and co-operates with a guide-pin 289 and a clamp-screw 288. Line-locking devices; alarms.-The carriageunit C, Figs. 1 and 17, supports a rock-shaft 199, carrying a stop-rail 201 provided with an arm 217 having a lug 232 which co-operates with a lug 223 on a rod 224 engaging a lever 225. When a tongue 215 on the carriage 161 strikes the line-locking stop 216, the arm 217 is depressed, and a trip-arm 220 operates a bell-hammer 221. On further movement of the carriage, the arm 217 is depressed further, and the lever 225 is moved into the path of the escapement-striker 83, to lock the keyboard. A release-key 228 is connected to the rod 224. Tabulating - mechanism.-Stop-rods 256, Fig. 1, and operating-levers 253 therefor are mounted as a unit in a bracket 257 which is secured to the back 146 of the base B and comprises a housing for the stop-rods, and arms 263 supporting a pivot 254 for the operating-levers. The housing is received by a recess 304 in the back 300 of the mask 194. Denomination-keys 252 are guided by a comb 268 on the base B and have forks engaging pins 265 on the levers 253, the arrangement permitting ready detachment of the keys. The stop-rods 256 engage a short universalbar 273 in connection with a thrust-link 276 which abuts on a carriage-releasing lever 173 mounted on the escapement-supporting frame 166. Back-spacing mechanism.-This mechanism is supported as a unit on a bracket 239, Fig. 1, which is secured to escapement-supporting frame 166. The mechanism comprises a shaft 241 carrying a back-spacing key-lever 245, and provided with an arm in connection with a back-spacing member co-operating with the feed-rack 160.