Patent GB-189826925-A (GB)
Title: Improvements in and connected with Calculating Machines.
Inventor: JOHNSON JAMES YATE
Filed: 1898-12-20
Granted: 1899-08-19
Abstract: 26,925. Johnson, J. Y., [Universal Calculator Co.]. Dec. 20. Type-writers and like machines.-Relates to calculating apparatus and means for printing the results. One row only of ordinary keys K, numbered 0-9, is employed, the rack bars BC which operate the counting-wheels and printing-mechanism being mounted in a carriage RC sliding on bars 3, 4 across the machine step by step, so as to bring each bar in turn to the setting- mechanism operated by the keys. The keys at their lower ends carry wedge-shaped projections f, f<1>, increasing in size on one side as they diminish on the other, which strike cross-bars r, r<1>, and so rock towards one another the levers m, m<1>; the latter of these operates a plunger m<4> which, coming in contact with the arm lg of the rack-bar BC immediately in front of it, pushes it forward till the bar m meets it, the exact setting position of the rack being thus determined. The pawl 2, engaging the teeth bt<1>, temporarily prevents the rack-bar from being returned by its spring 98. Graduated plates rb, showing through an aperture in the casing, indicate to what numbers the rack-bars have been set. The carriage is moved one step, whenever a key is actuated, by spring mechanism controlled by an escapement. For this purpose a pin 5 on the key strikes a cross-bar 6, and rocks the levers 7, one at each side of the machine, the shaft 8, and the hooked lever 9, so as to draw down an escapement detent 14*. On the side of the carriage are two racks 12, 13, the former fixed and the latter capable of one tooth movement under the action of a spring. When the detent is drawn down, it disengages the rack 13 and engages the rack 12, the former at once moving a step. When the key is released, the detent rises again, engaging the rack 13, whereupon the whole carriage moves a step, so that the next rack-bar BC is brought into position for 'setting.' After the apparatus has been completely set, the handle 34 on the operating-lever 33 is forced down, and, by means of the crank 29 and link 28, the whole carriage is thrown forward. The link 28 is connected to a short crank 95, the pin of which works in a slot 4<a> so that, as the carriage moves forward, it rises and brings the rack-bars into gear with the pinions of the counting-discs (not shown), and turns them the required amounts. In the return stroke, under the action of springs 35, the crank and slot connection allow the rack-bars to drop out of gear before their backward movement commences. As the detent pawls 2 pass under a rocking bar 99 in the return stroke, their tails 2<b> are depressed, since the rocking bar movement is limited in one direction, and the released rock-bars RB spring back to zero position. A spring mechanism, wound up by the actuation of the handle 34, slides the carriage back across the machine to its initial position just as it reaches the end of its return stroke, a special arrangement of controlling-pawls being provided to ensure correct movement. A complete stroke of the handle is ensured by a pawl 601 on an arm 600 of the carriage, which in the forward stroke runs over the plate 603 in engagement with the rack 602. but returns below it. A somewhat similar arrangement, shown at 174, 175, 176, ensures a complete depression of each key, while, whenever a key is partly depressed, a bar with locking-pins is slid laterally under the pins 5 of all the other keys, so as to lock them against depression. The pinions of the counting- wheels are held against rotation, except just at the time required for their movement, by a series of detent arms mounted on an axis which is rocked, to bring them in and out of action, by a crank and bell-crank lever actuated by a cam bar 72 moving with the carriage. This bar actuates the 'carrying' mechanism of the counting-wheels, which consist of a series of slides with 'carrying' pawls at their ends moved into position for actuation by pins on the next lower wheels engaging inclines on the slides as the wheels turn from 9 to 0. During the return movement of the carriage, after registering, a series of projecting pins, arranged helically about a rotary shaft, strike in succession all the slides that have been so moved, their pawls advancing the corresponding counting-wheels one digit. The counting-wheels have a frictional connection with their shaft, and means are provided by which, on turning an external handle, the detent arms of the wheels are first lifted out of action and the shaft then turned backwards, carrying the wheels to zero by friction, after which they are arrested by their slide-actuating pins coming in contact with the bases of the inclines of the slides. In addition to the ordinary keys K, a series of cipher keys CK for setting up two or more ciphers or, in conjunction with the ordinary keys, such numbers as 700, 9000, &c., are provided. Each such key carries a pin p<3> for actuating the levers 128 by a cross-bar 128<a>, and so rocking the shaft 129 and the finger 130 thereon. At the bottom of each key is a wedge-shaped piece p<4> (the pieces being of different sizes according to the number of ciphers to be set up), which, acting on a slide and connecting-mechanism, rocks the shaft 145 and forked arm 146 proportionately to the number of ciphers marked on the key. The forked end of the arm traverses a governing pawl and slide mechanism, and in conjunction with the finger 130 so actuates the controlling-mechanism of the escapement that the carriage is enabled to make two or more steps at one time before being arrested. When, as in the process of multiplication, repeated operations have to be made with the carriage in one position and the rack-bars set to the same number (the multiplicand), the key x ¸ is pressed, and latches down under the casing of the instrument. Through the lever 184 and connecting-rod 183, the rocking bar 99 is freed so that it can swing in either direction and does not free the detents 2 of the rack-bars after each actuation, while through the lever 186 and mechanism not shown the means for releasing the carriage so that it returns across the machine to its initial position are thrown out of action. To move the carriage from the thousands position to the hundreds, hundreds to the tens, and so on, as the multiplication proceeds, an independant key actuating a special controlling-pawl in the escapement mechanism is used. Subtraction is performed by the method of complementary numbers, and division by repeated subtractions. The movements of the carriage are checked near the limits of the stroke in either direction by the contact of an arm 684 with adjustable stops 683<a> on the piston-rod 681 of an air dash-pot provided with a regulating-cock. To print the details of the processes, a number of type-wheels are mounted on an axis carried by a frame capable of vertical movement. In the forward movement of the rack-bar r b they latch themselves by a spring catch 186 to sliding frames, having racks for setting the type-wheels, but in the return stroke drop out of connection. leaving the printing-wheels set. A toggle mechanism is then actuated which lifts the printing-frame so as to force the type-wheels against an impression and feed roller, after first bringing a cross-bar into the teeth of the printing-wheels to hold them accurately in position. Near the end of the return stroke of the carriage, a projection on an extension thereof strikes a rocking frame which, engaging with the rack frames, returns them and the printing-wheels to their initial positions. Duplex paper strips are carried by spools on a pivoted frame, and are then led through adjustable guides over the impression and feed roller ; the frame can be secured in operative position by hooks on a pivoted handle, by which also it can be thrown back to examine the work or insert the strips. Stops in the extension of the cam bar 72 act on a lever carrying a pawl by which the driving-ratchet of the feed-roller is turned step by step. The inking-ribbon passes from one to other of two spools placed side by side. over a series of rollers and across the duplicate strips, the arrangement being such that the ribbon slackens when the printing frame is thrown back. The two spools are formed with ratchet teeth on their flanges engaged by driving-pawls, one of which is always thrown out of action by a pivoted frame. This frame is rocked automatically to reverse the feed by the pull of the ribbon, when exhauste drawing forward a lever to which it is attached and throwing over the plate. Means are also provided for throwing the printing-mechanism out of action when, as in multiplication &c., it is not required.