Patent GB-298095-A (GB)
Abstract: 298,095. Myers, L. C., and Royal Typewriter Co., Inc. May 2, 1927. Adding-apparatus; attachments and connections to typewriters; with several totalizers.-A computing-mechanism described as applied to a typewriter includes a travelling totalizer and means for clearing it automatically when returned to home position. Other features, some of which form the subject-matter of Divisional Application 298,114, include two forms of error-check mechanism to prevent or notify incorrect entry of the total on the column totalizer in the grand totalizer, indicators to show the last digit entered, a separate spring control for the totalizer carriage, and an aligning means for the totalizer trains. The invention is described as embodied in an attachment to a standard form of typewriter and the actuation construction and mounting of the totalizers resemble those set forth in Specification 297,717. Actuation of totalizers. The numeral keys are connected through the spindles 20, Figs. 1 and 6, with racks 24 meshing with differentially toothed gears 33 driving the master pinion 75, Fig. 9, through the unit pinions 40 and reversing pinions 73, 74. The master pinion is engaged successively by the denominational wheels 79 of the column and grand totalizers mounted, together with transfer wheels 81, intermediate wheels 87 and numeral wheels 84, in a slidable counter frame. A spring-controlled pawl 46 normally locking the master pinion is rocked out of engagement during the actuating stroke by means of a cam 38 mounted on each of the differential wheels 33 and adapted to rock and then release a comb plate 55 pivoted at 53<1> and rigid with a crank arm bearing a roller 57 engaging the tail of the pawl. A rearward extension 67 of the pawl co-operates with a fixed rack 68 to prevent actuation of a numeral key in the punctuation positions of the carriage and frame. The cams 38 are ratchet toothed at 61 to be engaged by the comb plate 55 and thus ensure complete return of the key when released. The unit pinions 40 are slid axially into the planes of the differential actuating wheels 33 at each key stroke by means of a lever 52 pivoted at 50 and linked at 47 with the pawl 46. To disable the actuation a lever 66 may be raised manually or automatically to rock the comb plate 55 out of the path of the cams 38. Spacing of totalizer elements and transfermechanism control. The numeral wheels 84 are spaced by a comb plate 89, the rear edge of which is formed with fingers wrapped around a rod 83 to space a series of levers 82 pivoted on this rod. These levers carry the transfer pinions 81, which when disengaged from the wheels 79 are held by detents 100 projecting at 103 through the notched edge of a plate 98 and engaged by the spring fingers 104 of another plate 105. The lower edge of plate 98 is comb-like to guide the ends of the levers 82 and the detents 100. The totalizer gear trains are locked in certain positions by the pinions 79 running on to ribs 109, 110, Fig. 10, forming part of sleeves mounted on the master pinion shaft 106. The rib 109 receives the column totalizer wheels as they move to the left after actuation and the rib 110 does the same for the grand totalizer as this returns to home position. Each of the levers 82 carrying the transfer pinions has an arm 97 to co-operate with two fixed cam rails 113, 114. When the counter frame occupies its right-hand position the grand totalizer is locked by the rib 110 and the transfer pinions of the column totalizer are held disengaged by the action of the rail 114. As the totalizers travel to the left the arms 97 in succession leave this rail and pass or. to the other rail 113 the effect of which is to carry the transfer pinions into gear to permit transfers. Digit indicators. To show to the operator the value of the digit just previously entered there are provided ten arcuate numeral-bearing plates 124, Fig. 6, forming part of levers 122 pivoted at 121 and urged to zero position by springs 127. As an actuating rack 24 makes its operative stroke a lug 126 meets the tail 125 of the corresponding lever 122 and rocks the plate into viewing position where it is held by a detent finger 132 engaging a lug 134. The detent fingers are raised to free the previously set plate by a link connection 137 with the master pinion lock pawl 46. Totalizer frame movement and connections. The frame carrying the totalizers is picked up and moved to the left by the typewriter carriage by means of a dog 139, Fig. 1, and a detent 140 mounted on a rack bar 141, an adjustable plate 145 serving to disconnect and limit the movement of the frame at the desired points. A notch 149 in the plate enclosing the rack bar 141 allows the detent 140 to be turned over to disconnect the totalizer frame from the carriage. The rack teeth on the bar 141 engages a gear wheel 150, Fig. 6, adjustably mounted on a shaft 151 geared at 154 with a rack on the totalizer frame. To relieve the carriage from the work of spacing the frame the latter is urged to the left by a spiral spring 156 encircling a pulley 157 and secured at its ends to a stationary member and to the frame respectively. Inasmuch as the frame is automatically disconnected from the carriage by the plate 145 when the carriage is moved to the extreme right, it is necessary to provide means for holding the frame when returned to home position. This means comprises a bell-crank lever 174, Figs. 1 and 6, one end of which is adapted to block a pin 179 on a bracket fixed to the shaft 151 when the lever is rocked by a cam 172 secured to the shaft 162. This latter shaft is turned counterclockwise, Fig. 6, by the return of the carriage due to the action of a pin 66 on a cam rail 165 carried by the shaft. Error-check arrangements. In one arrangement the depression of an incorrect key when entering the column total into the grand totalizer is prevented. When the grand totalizer is traversed into the computing zone a cam on the totalizer frame rocks a bell-crank lever to remove a latch 192, Fig. 3, from beneath a three-armed lever 193, which thereupon turns counterclockwise and rocks a lever 197, Fig. 6, to throw a plate 200 into the path of lugs 31 on the racks 24. When a rack is operated by a key, therefore, the lever 197 is rocked fully clockwise and by a link 209 and a flexible coupling 208 rocks a shaft 203 carrying sectors 204 so as to position these in co-operative relation with lugs 212 on the racks 24. In gear with the column totalizer transmission pinions 87, Fig. 9, are auxiliary pinions 216 furnished with diametrically arranged pins 217, and when the sectors 204 are raised a link 213 throws a feeler arm 214 upwards into engagement with the pins, thus limiting the ascent of the sectors. If the key depressed agrees with the digit on the column totalizer therefore, the sectors are so positioned that the lug 212 can pass freely through an offset 215 in the sector, but otherwise the rack is obstructed and the key cannot be fully depressed. In a second arrangement the wrong key may be operated but its return is prevented, thus calling attention to the error. In this form an universal pivoted frame 239, Fig. 11, controlled by a spring 241 is rocked by the racks 24, and when the lever 193 is freed, as in the first arrangement, it couples a slidable bracket 248 to the frame 239 and causes the sectors 254 to slide axially into the paths of bevelled lugs 267 on the racks. The sectors and a member 253 are rigid on a shaft 255 capable of slight axial displacement and the member is connected by a spring 250 to the bracket 248 so as to raise the sectors into operative position when a key is operated. If an incorrect key is depressed the sector opposite the rack is not in position to allow free passage of the lug, but the bevelled edge of the lug thrusts the sector aside to allow the stroke to be completed. Return of the key is however prevented by the sector, and in order to unlock the key a disconnect lever 260 must first be operated in order to displace the sectors axially to free the lug. Clearing the column totalizer. After the totalizer frame has been returned to home position the continued travel of the typewriter carriage to its right-hand position effects the counter-clockwise rotation of shaft 162, Fig. 3, as previously stated, by means of the pin 166 and cam rail 165. Rigid with this shaft is an arm 168 pivoted to a rack 232 gearing with a pinion 220 fixed to a disc carrying a pawl 222 co-operating with a ratchet member 224 rigid with a cam 225. As explained above, the lever 193 is unlatched by the movement of the totalizer frame into the grand totalizer computing position and the pawl 222 hitherto disabled by the lever is freed for effective operation. On the return of the totalizer frame, therefore, the rack 232 gives a half rotation to the ratchet member and cam 225, the latter of which thereupon rocks a set of levers 230 from the full line position to the dotted line position in Fig. 3 to engage the pins 217 on the auxiliary wheels 216 of the column totalizer and return the elements of this totalizer to zero. If it is not desired to clear the column totalizer the lever 193 may be re-latched manually to maintain the pawl 222 ineffective upon return of the totalizer frame. Additional aligning mechanism for the totalizer elements. In addition to the master pinion 75 the shaft 275, Fig. 14, supports a loose pinion gearing with the train of wheels several places to the left of that engaged by the master pinion. The loose pinion is aligned at each key operation by a pawl 272, the tail of which is operated by a roller 280 on an extension of the crank arm carrying the roller 57 and rocked by the cam 38.