Patent GB-262919-A (GB)
Abstract: 262,919. Marks, E. C. R., (Elliott-Fisher Co.). Nov. 28, 1925. Adding-apparatus; connections to typewriters; full-stroke mechanism.-In a typewriter adding- machine, such as the Elliott-Fisher machine illustrated, various devices are employed for ensuring the correct actuation of the master pinion 7 and the control of the carriage by the numeral keys of the typewriter or the non-print keys 8 connected with the numeral keys by a link 78 and a pin and hook 80. Actuation. The actuating pawl 15 is mounted on an arm 14 toothed to mesh with a sector 17 secured to a shaft 19 rocked differentially by the keys by means of graduated arms 23. On each key-lever 24 is pivoted a catch-pawl 28 weighted at 29 and formed with a cam slot embracing a pin 31 on the adjacent arm 23. When the keylever is depressed to rock the arm the slot causes the catch-pawl to rock clockwise to place its flange 32 below a flange 33 on the arm so that the key-lever cannot return without the arm. Overthrow, preventing. Each key-lever 24 is formed with a cam edge 37 to. rock, by means of a pin 36, arm 35, shaft 34 and connections 38, 39, a pawl 40 into engagement with a ratchet on the master pinion to stop it at the end of the actuating stroke. Reverse rotation of the pinion is prevented by a detent 42. Actuating - pawl engagement, controlling. Mounted adjacent the path of the actuating-pawl 15 is a curved arm 45, Fig. 12, pivoted at 47 and adapted to hold the pawl in engagement with the ratchet wheel on the pinion 7 throughout the stroke, for which purpose a projection 46 on the pawl runs beneath the arm. A rock-shaft 52 is provided with depending arms 53 each having a cam 54 co-operating with a lug 55 on the adjoining key lever. During the actuating stroke of the key the shaft 52 is consequently rocked clockwise and through an arm 51 and pin 49 shifts the arm 45 into effective position. When the key rises the shaft is rocked back again and beyond its normal position to raise the arm well above the pawl so that this may return freely. Master pinion, aligning. A toothed pawl 56, Fig. 12 pivoted at 57, normally embraces a tooth of the pinion but during the actuating stroke and consequent upon the rocking of shaft 52, the pawl is displaced counterclockwise by a nose 59 on the arm 51 engaging a pin 58 on the pawl. Carriage, locking. When the aligning pawl 56 is displaced as above described, it bears upon one end of a lever 60 and rocks it clockwise to raise a rod 62 and lock the carriage in position during the actuation. Key-lever full-stroke mechanism. To ensure complete return of a key-lever after depression, it is provided with a ratchet bar 64, Fig. 23. to co-operate with a spring-controlled pawl 65, having a rule-joint connection with an arm 67 fixed to the shaft 52. When the key is depressed this shaft is rocked clockwise as stated above and the pawl is moved to ineffective position. Upon termination of the down stroke, the shaft is returned and consequently the pawl 65 engages the ratchet bar to ensure complete ascent of the key. Spacing of carriage, effecting. The carriage escapement mechanism, not shown, is controlled by a wire 69, Fig. 23, adjustably engaged by a bell-crank lever 71 connected with a rock-shaft 74 having a series of arms 75 engaged by hooks 77 on the key-levers 24.