Patent GB-190115444-A (GB)
Title: Improvements in Calculating and Number-printing Machines.
Inventor: MALLMAN JAMES
Filed: 1901-07-30
Granted: 1902-01-09
Abstract: 15,444. Mallmann, J. July 30. Calculating - apparatus. -Sliding rack - bars y, pulled under rows of keys q till they strike the depressed ones, set type - wheels 43, and in the return movement (after the impression has been taken on paper 77 by a rocking platen 63) drive adding-wheels 5. The action of the rackbars is due to the reciprocation of a crosshead 32 against the ends of the rack-bars by cranks on a shaft 29 which is geared to a main shaft 25 having a crank handle. The racks are applied to the adding-wheels by a cam 119 on a third shaft acting through levers 117, 115 (not fully shown) on a transverse rocking lever 113 which bears spring fingers. The intermediate lever 115 is pivoted on an arm 125, and, when further addition is not desired, as when the total is to be printed, a special key 122 is struck to put the arm in contact with the rocking bar. The intermediate lever is thus lowered, and the rocking bar is held. The tens are carried by fingers 104 on a cylinder 86 resetting ratchet levers 109 on stepped props 106, which have been wiped aside by odd teeth 105 on the units wheels. The rocking platen is operated, Fig. 8, by a pair of cams 85, bell cranks 82, and coupling-bars 62 with springs 83. When printing is not desired, the platen is locked. The keys release the rack-bars by disengaging pivoted detents 14, 11 from lugs 10, for which purpose sliding bars r between the rows of keys have bevelled ends in contact with the detents, and are shifted by pins t on the keys entering oblique notches s in them. Spring detents 19 retain these bars in their new position, till, at the end of the revolution of the wheels, a transverse slide 22 disengages them by means of pins 23. This slide is also worked by a special key, in case a wrong digit has been struck. The first line of detents is in close order, but the second line is open, so that all the rack-bars on the units side of the operated key move from the first to the second detents. The printing-wheels have a blank division between the zero and the 9 type, and the space between each pair of detents gives the zero the printing position. The units detent of the first line draws a transverse bolt 89 from one of the driving-wheels, but it is returned by one of the cranks. This bolt may also be drawn by hand so as to allow another revolution of the crank handle for making a double space on the paper. In the return movement of the rocking platen, a pawl on the frame feeds the paper. An inking-ribbon 47, connecting a pair of loose reels 45, is wound up by either of them which is driven by one of a pair of ratchet lever, 51 having. pawls 53 that are alternately thrown out of action by hand. The shaft being formed with shoulders, a spring bearing against one end and an arm applied to the other end serve to press the driven reel into frictional contact with the frame, so that it is not then dragged reversely by the pawl. The ratchet levers are operated by studs 52 on the main shift 25. The type-wheels are lockei, while printing, by a bail 79. In order to set the wheels to zero, a special key 130, Fig. 8, on the units side of the machine is struck. A slide 134 shifted by this key draws the bolt 89, holds the platen from action, and raises a plate 138, which fixes the carrying-levers 109 and lifts a detent from a pin on a rack-bar on the other side of the machine. This rack-bar turns the common shaft of the wheels in the same way as the others turn the wheels only, and with the aid of the internal pins and pawls shown in Fig. 15 the wheels are brought to zero. In a simpler arrangement, the shaft is turned by a removable handle, instead of by the prime action.