Patent GB-191511254-A (GB)
Title: Improvements in Combined Typewriting and Computing Machines.
Inventor: FAIRWEATHER WALLACE CRANSTON
Filed: 1915-08-04
Abstract: 11,254. Fairweather, W. C., [Underwood, J. T.]. Aug. 4. Adding and subtracting apparatus; differential mechanism.-Typewriting-machines of the Underwood type, as described in Specification 10,449/09, are combined with adding and subtracting apparatus and arranged so that the typewriter escapement device controls the operative or inoperative position of the rack actuating the totalizing - counter. Initial movement of the rack serves to free the master actuating-wheel of the counter and also to lock the typewriter carriage carrying the totalizer. A full-stroke device is provided for the return of the rack, whereby a second lock for the counteractuating wheel is operated and the rack is held out of engagement until the return movement is complete, whereupon the locking-device is released. The keys are provided with differential cam-slots rocking a universal bar, connexion between which and the counter is broken on the depression of a shift key. Key-interlocking devices are provided, which are also actuated to prevent depression of the keys when punctuation marks or spaces are to be inserted between the different denominations. The change from addition to subtraction is effected by the movement of the bi - chrome lever. Differential actuation of the counter-actuating mechanism is effected by cam-plates 74 secured to the key-levers, the plates being provided with slots 81 of varying slope, with which engages a universal rod 77, Fig. 26, carried by arms 79 loose on a shaft 80. Each slot is provided with an idle portion 82 which allows full depression of the key to operate the escapement device. A pin 84 on an arm 79 engages a notched curved lever 86, which is pivoted to a lever 88 carried by the shaft 80 and is connected by a link 95 to the counter-actuating mechanism. Adjusting for recording only.-Connexion between the universal bar 77 and the link 95 is broken to allow recording only on the movement of the shift frame 58, shown diagrammatically in Fig. 32, whereby, through a link 90, a lever 91 is caused to lower the lever 86 away from the pen 84. Where it is desired to record without using the shift key, the ribbon-shifting lever 72 is operated to disengage the counter-driving mechanism as described below. Adding and subtracting.-The link 95 serves to reciprocate a rack 100, Fig. 7, through cranks 96, 98 and a link 99, the rack being in gear with a broad pinion 103. A wheel 106 secured to the pinion 103 is adapted to drive the master actuating- wheel 101 of the counter in either direction to add or subtract, according as it is in direct engagement with a wheel 108 on the shaft of the wheel 101, or in indirect engagement therewith through a wheel 110 bearing a wheel 107 engaging the wheel 108, as shown in Fig. 13 and diagrammatically in Fig. 31. Such a change in direction is effected by a longitudinal movement of the shaft 105 of the pinion 103 through a lever 112 on rocking the ribbonchanging lever 72. In the intermediate position of the lever 72, the wheel 106 is disengaged to allow recording only as stated above. The master wheel 101 is adapted to drive the totalizer through an intermediate series of wheels 114, Fig. 13, which are in engagement with the totalizer-wheels 115 and also serve as transfer-wheels. Operating - means. - Disengagement of the actuating-rack. At the end of a key depression, the rack is disconnected from the pinion 103 by the movement of the universal frame 48, Fig. 32, controlling the escapement mechanism of the typewriter carriage. The swinging frame 49 of the part 48 rocks, through a link 151, a shaft 153 bearing an arm 154, a pin on which engages a slot in the rack. Another slot is engaged by a second pin which is carried by one arm of a three-armed lever 159 connected by a link 161 to an extension 162 of the arm 154. The parallel motion thus formed moves the rack downward out of engagement with the pinion 103, which is locked by a tooth on an arm 163 of the three-armed lever 159. On the return of the depressed key by its spring, the rack is returned to its initial position. Full-stroke mechanism. - To ensure complete return of the rack a full-stroke mechanism is provided, comprising a pawl 167 adapted to engage ratchet teeth on the lower surface of the rack when in the depressed condition. To prevent the rack from being prematurely raised, an extension of the pin 168, forming the pivot of the lever 159 with the link 161, is adapted to be engaged in its lowest position by a catch 171, which locks it against forward movement. On the full return of the rack, the catch is raised by being struck by a shoulder on the operating-link 98. Selecting denomination. - The totalizer frame, bearing the numeral-wheels 115, Fig. 13, and the intermediate transfer and counter actuating wheels 114, is supported by rollers and guides and is moved step by step over the master-actuating-wheel 101 by its connexion with the typewriter carriage, such connexion consisting of a spring catch 121 which engages a notched bar 119 on the carriage. The catch can be disengaged from the bar when manual adjustment of the totalizer is desired in order to alter the position of the computing-zone. Interlocking.-The typewriter carriage with the totalizer is locked against movement while a digit is being registered by a tooth 138, Fig. 7, carried by a bell-crank lever 137 and forced into engagement with a rack 135 on the carriage on the first movement of the rack. An arm 144 engaging the lever is rocked when an arm 141 on its shaft is forced out of a notch 140 in the rack. When not in engagement with the rack 135, a tooth 139 on the lever 137 serves to lock the master wheel 101. Transfer mechanism.-Loose on the shaft of the master wheel 101 is a series of transfer pinions 209 equal in width to the normal numeral-wheels 115, the highest wheel 115 in each denomination being double the width of the others to allow the insertion of punctuation marks. The wheels 209 are arranged to break step with the intermediate wheels 114, which are of the same width as the corresponding numeral-wheels. The teeth of the wheels 114 are half the width of those of the wheels 209, except in the case of the transfer teeth 210, which are equal to or double the width of the wheels 209. In operation, at the transfer point, the teeth 210 engage consecutive wheels 209, the higher of which moves, through the next wheel 114, the next higher counter-wheel. Justifying-means for the intermediate wheels 114 and the transfer-wheels 209 are provided, those for the first-named consisting of wings which are carried by the frame supportiug the totalizer-actuating mechanism and extend up to the highest wheel on one side and the master wheel on the other. Each wheel 209 is provided with a spring detent 215, Fig. 11, lightly held in engagement with the teeth by spring pushes 224 and bellcrank levers 223 and strongly held by a spring- depressed universal bar 217. An additional locking- means for the wheels comprises a series of levers 226 pivoted on a shaft 227 carried by the totalizer frame and provided with bevelled ends 228 adapted to engage the levers 216 and prevent them from moving. At the transfer point, teeth 230 on the levers 226 fall into recesses 231 in the wheels 114 and free the pawls 215, the bail 217 having been raised by the movement of the lever 137 due to the forward movement of the rack. Keyboard interlocks.-The locking of all the keys on the depression of one is effected by links 178 carried by the keys. Teeth 181 on the links are adapted to be engaged by spring-depressed pawls 182, which are rocked into engagement, after the depression of a key, by the rotation of the pawl shaft 183. A link 191, Fig. 32, connects the pawl shaft to a crank on the shaft 153, which is rocked at the end of a key stroke by the universal frame 48. The depression of more than one key at a time' is prevented by a crowding-lock comprising pairs of pivoted arms 195, Fig. 28, between each of which flanges 193 on the parts 178 protrude. The depression of one part 178 forces all the arms 195 together to prevent the depression of a second. Punctuation.-This arrangement is also used to prevent the depression of a numeral key when a punctuation mark is to be placed between the denominations. Pins 200 mounted on the totalizer carriage depress a lever 204 to insert one end of a lever 208 between a stop 199 and a part 195, thus preventing the depression of a numeral key. On printing a comma &c., the carriage is advanced and the lock removed.