30,426. Howieson, J. T. Dec. 29. Adding-apparatus of the single-bank motordriven type, wherein the numeral keys merely select in turn the numeral wheel of the totalizing-counter which shall be actuated and determine the extent of its differential actuation, is described as constituted by the numeral keys of a typewriter and an adding-attachment to which the keys are coupled at a certain predetermined position of the typewriter carriage. The keys, in addition to actuating the differential mechanism, control jointly with the typewriter carriage a number of rotary helical denomination selectors which rotate to select the numeral wheel to be actuated and move longitudinally to couple such wheel to its actuating-spindle. The transfer and reversing mechanism for the machine is described in Specification 28,058/10. Specification 18,853/02 is also referred to. Selecting denomination.-At the sides of the adding-machine, just in front of the typewriter, are posts 31, 32, Figs. 3<a> and 3<b>, connected by a cross-bar 33 supporting, about midway, a box 34 through which pass slide-rods 35, 36 with racks engaging pinions 46, Fig. 11, upon vertical shafts 42 within the hollow posts. At their lower ends these shafts carry other pinions for engagement with selector-operating rack-bars 48, one at each side of the machine, moving parallel to the side-frames and normally forced forwards by springs applied to the vertical shafts. From the forward end of the rack-bar 48 the rotation of a helical denomination selector 63 is derived and similarly in the case of the other rack-bar and its selector. Each selector consists of a number of disks 97, each slotted at one point 99, and supporting a helical band having pins 98 adapted to approach closely the fingers 90 in turn as the selector revolves, while upon the depression of a numeral key the whole selector moves to the right and clutches the selected numeral wheel to the main counting-wheel shaft 69 by means of the bellcrank lever 88. Simultaneously the disks 97 of all other denominations engage the lock-out levers 95 and thereby positively keep the numeral-wheels out of engagement. At the selected denomination the gap 99 in the disk is opposite the lock-out lever which thus remains inoperative. The movement of the bell-crank lever to clutch a wheel also withdraws a pair of oppositely-disposed detents from engagement with the wheel. Totalizing-counters.-There are two sets of numeral wheels, one for each selector. Each wheel is formed from a flat ring having at its periphery a flange 71, Fig. 64, bearing the numerals on its outer surface and mounted, together with a pinion 72, so as to rotate in a fixed vertical plate of the framework. Also in one part with the numeral wheel is a locking- ring 73 having as many teeth as there are positions of the wheel and a smaller annular transfer-receiving wheel 75, the internal teeth of which are utilized for clutching the wheel to the counter-spindle 69, which is the actuating- member. Upon the squared portions of this spindle are sliding clutch members 83, one of which is adapted to slide in and out of engagement with the internal teeth 77 of each numeral wheel by a laterally-moving finger 90 of the bell-crank lever 88. Attachments and connexions to typewriters; keyboards; full-stroke mechanism.-Pins upon the feet of the typewriter frame take into grooves in the top-plate of the adding-machine casing, and when the typewriter is pressed forwards they pass down inclines into openings in the plate from which they may be disengaged by pressing the typewriter rearwards. Extending across the machine near to the numeral keylevers of the typewriter is a bar 114, Fig. 44, with a series of upwardly-extending arms 115 which at certain positions of the side-racks 48 are caused by cams thereon to swing together rearwards. For each key there is provided upon the rod 124 a rotatable cam-disk 126 and escapement anchor 128, 129, 130 formed in one piece, the cam-disk having an edge cam 131 and a tappet cam 132. The disk is rotated by means of a rod 133 with a bent upper end for engagement with slots in a plate attached to a numeral key and in the corresponding arm 115 respectively, the rearward rocking of the arm being necessary to ensure that the key and rod may move together. The arms 129, 130 of the camdisk co-operate with a wheel 135, having laterally projecting faces, to compel a fullstroke of a key and to prevent overthrow, the return of the key being impossible until fully depressed. The movement of the disk also effects, through the cam 132 and universal bail 144, the endwise coupling movement of the selector, while the edge cam, as described in Specifications 28,362/10 and 28,363/10, actuates mechanism whereby a differential drive from a spring motor contained within the casing is transmitted to the main actuating spindles of the counters. Column-spacing.-The point at which the typewriter carriage, in its lateral movement, begins to drive the selector and associated parts is controlled by tripping-devices 6, Figs. 3<a> and 62, of which two or more are adjustably mounted upon the transverse bar 4 of the carriage and have cam-plates 178 at front and rear for controlling the slide rods 36, 35 of the left and right selectors respectively. Each plate has a limited vertical movement and has two downwardly-depending cam-lugs 180, 181 of which the lug 181 is bent forwardly at the point; an upper cam-surface 185 enables the plate to be depressed by a finger lever 187 at will, a restoring spring being provided. Upon each slide rod is mounted a plate 188 carrying a pivoted dog 190 of which the left end normally abuts against part of a stationary framework 193, 34 and thereby locks the selector driving-spring; but as the carriage moves to the left the cam-lug 180 depresses the left end of the dog, the hook 192 of which catches beneath the bar 193, thus freeing the slide-rod and associated parts and simultaneously coupling them by means of the hook 194 to the other cam-lug 181, so that the slide-rod moves to the left under the control of the carriage escapement. This movement continues for a column space, whereupon the left end of the dog 190 strikes the pillar supporting the guidehar 193 and the selector is arrested, the carriage going on; upon the return of the carriage, engagement of the cam-lug 181 with the hook 194 restores the slide-bar and rewinds the selector driving-spring, the connexion ceasing when the cam-surface 195 meets the stationary lug 196. The co-operation of these parts with the selector locking-ring and key full-stroke arrangements ensures that upon the partial depression of a key the slide-bar and lever 190 will remain stationary, and if by the spacing-key the carriage has been moved to the left it is only necessary to push the carriage back until it is arrested by the hook 194, whereupon the key may be fully depressed. There may be as many tripping-devices upon the carriage bar as there are columns to be printed and summed. Interlocking.-Provision is made for preventing any change in the denomination selected while a numeral wheel is clutched to the actuating shaft, and a further interlock is provided with the differential actuating - mechanism. Upon the lateral movement of a selector a cam tooth 213, Fig. 11, thereon engages a fixed toothed ring 214 whereby rotation is prevented until the selector returns. In order to release the main shaft 156, Fig. 7, of the differential actuating-mechanism the arm 204, suspended from a link 205, is swung forwards and at its lower end extends over the selector reciprocating bail 144, which is thus prevented from rising and thereby the selector from disengagement with its toothed locking-ring. Keyboard interlocks.-The cam-disk and escapement-anchor of each numeral key has a slot taking over a fixed tube 207, Fig. 42, provided with a cut for receiving a shoulder 210 of the cam-disk slot. Within the tube are blocks 211, movable endways, the number and size of which are such that only one key can be depressed at a time. Punctuation.-For the insertion of commas and the decimal point, the selector has at certain points pairs of pins in the same transverse plane but at an angular distance equal to that of a single selector movement, whereby at this point the depression of a key does not affect the coupling of a different numeral wheel, suitable slots being provided for the lock-out levers. Adjacent to the numeral-wheel reading- apertures are smaller apertures adapted to display marks on an adjustable slide indicating the system of punctuation in use.