Patent GB-182841-A (GB)
Title: Improvements in and relating to adding machines
IPC: G06C7/06
Filed: 1921-02-07
Abstract: 182,841. Alexander, A. E., (Peters-Morse Manufacturing Corporation). Feb. 7, 1921. Adding-apparatus.- A multiple-bank, keyset, handle - operated adding-machine has a removable self - contained keyboard cooperating with differential stop-bars pivoted to the actuating-racks; and the error and re. peat keys are located at the handle side of the machine for convenient manipulation. Keyboards; error keys; multiplying by repetition.-The keys, each of which has its stem bifurcated to form a stop leg 26<b>, Fig. 6, and an abutment 26<c> for the subjacent differential stop-bar 40, are mounted in a box-like structure composed of side, front and back plates connected together by tongues and slots and by screw-bolts. The keyboard is hingedly supported at the rear by a rod 50, Fig. 5, and rests at the front upon a rod 19 and is latched in position so that it can readily be removed from the machine. Between the banks of keys are stationary rods 30 each supporting swinging plates 32, 33 forced by common springs into contact with keys of the neighbouring banks. Plates 33 serve in conjunction with teeth on the key stems as key detents whiles the other plates 32 co-operate with camsurfaces on the stems so as to be deflected by depression of the keys and thereby remove stop arms 32b fromin front of the corresponding differential stop-bar. The keys are released automatically at the end of the operation by means of a three-armed lever 231 pivoted at 230, spring-controlled at 232 and rocked clockwise and anti-clockwise as the operating handle 5 is brought forward and returned. The forward arm of this lever carries a one-way stop-pawl which on the up-stroke wipes past a pin 129 on an arm extending from a pivoted comb 34 the tines of which bear against the detent plates 33. On the return stroke, the pawl rocks the comb and so releases all depressed keys. For correcting errors in setting, this comb may be directly moved by depressing a key lever 128 overlying the pin 129. The automatic release of the keys may be prevented by shifting a repeat lever 240 so as to place its lower end into the path of a pin 241 on the lever 231 which is thus prevented from operating. Differential mechanism.-The differential stopbars 40 slide upon the rod 19 and are pivotally connected at their rear ends 41 to the actuating rack-bars 74 pivoted at 152. The arrangement is such that normally the ends 41 lie to the rear of the vertical plane through the axis 152 so that when the bars are released and spring forward tn take up the setting corresponding to the keys depressed the bars have a curvilinear motion in addition to the rectilinear movement and certain ot the stops corresponding to unset values are thereby enabled to clear the depressed key-stems. By this means the stops on the bars may be spaced at greater intervals than the keys. Printing totals.-The total lever 94 is connected by link 97, Fig. 8, bell crank 99 and link 104 with a lever 106 provided with a pin 109 to bear upon a comb 36 pivoted at 37 and having its prongs arranged adjacent the plates 32, Fig. 6, referred to above. When the total lever is shifted therefore for printing totals, this comb swings the plates so as to remove the stop arms 32b from the differential stop-bars which are thereby free for subsequently taking up their setting. A link 111 pivoted to the comb 36 at 110 is connected by pin and slot 112 with the keydetent controlling comb 34 so that setting the lever 94 for total-printing also releases any keys that may have been depressed. The pin and slot connection 112 permits the comb 34 to be operated by the error key 128 without disturbing the comb 36.