Patent GB-514291-A (GB)
Abstract: 514,291. Calculating-apparatus. WEBB, C. F. May 28, 1938, No. 15979. [Class 106 (i)] In a calculating machine of the key-controlled multiple-bank type, each bank of keys comprises a bar extending longitudinally below the keys and movable relatively to the keys on depression thereof, but adapted to be arrested out of its initial position on the finger release of a key incompletely. depressed, thereby serving to prevent restoration of the mis-operated key and also depression of the remaining keys in the machine. Each bank of keys is associated with a driving bar 26, Fig. 4, to which is pivoted one arm 30 of a V-shaped member pivoted at 28, to a locking bar 37 ; while the second arm 31 pivots on a fixed bar 23 passing across the machine. A similar and parallel bar 42 carries a member 32 also pivoted to the locking bar 37. Upon depression of the key, the driving bar 26 is moved downwards and the locking bar 37 is moved longitudinally to the left. This bar 37, Fig. 13, is provided with L-shaped slots 75 of varying length which limit the longitudinal movement of the bar and, consequently, the downward movement of the kev. The movement of the bar 37, Fig. 4, is transmitted to an arm 56 pivoted at 57 through a link 58, and a roll 55 on this arm, sliding in a slot 54, moves a sector 48 accordingly. As the key reaches the bottom of its stroke it engages one of a number of projections 69, Figs. 4 and 5, and rotates a shaft 68 which has a depending arm 65 with a projection lug 67 having a cut-away portion or step. Movement of the arm 65 allows a U-shaped arm 52 pivoted at 53 to be moved a small distance to the left under the influence of an arm 61 slotted to engage a pin 51 on the arm 52 and urged by a spring 63 attached at one end to a short arm 39 on the member 32 and at the other to an arm 59 integral with the arm 61 and pivoted at 33. This movement of the arm 52 at the end of the key's downward stroke engages the rack 48 with the totalizer wheel 49 and on the return movement of the key and the driving bar 26, the roll 55 is moved along the cam slot 54 causing the rack to rotate the wheel 49. Near the end of its travel, the roll enters a portion of the slot forming a small arc about the centre 57 and, consequently, during this stage of the movement, the rack is positively brought to rest before disengagement from the totalizer which occurs when a pin 28 on the V-shaped member 30 engages a short arm 64 integral with the arm 61 thereby returning the latter, and the U-shaped arm 52 to their original positions. The stepped arm 65, Fig. 5, is returned by a spring 70. If the key is not depressed fully by the operator, its lower end fails to reach the projection 69 to release the U-shaoed arm 52 and, consquently, the item is not added to the totalizer. Moreover, a pawl 77, Fig. 12, arranged to engage ratchet teeth 76 formed in the locking bar 37 but normallv released therefrom by an arm 60, Fig. 4. prevents the return of the locking bar 37. Hence, the hooked end 74, Figs. 5 and 13, of the key shank, not being in register with the foot of the L-shaped slot, is held down while, for the same reason, the rest of the keys in the bank cannot be depressed. The pawl 77, Fig. 12, is pivoted to a member 79 pivoted at 80, and, owing to the force exerted by the locking bar 37 the member 79 is rotated and its arm 81 depresses a bar 83 running across the rear of the machine, which, moving out of the path of projections 89, releases a series of hooked members 87 to engage slots in the locking bars and so lock all the other keys in the machine. Subsequently, when the mis-operated key has been located and fully depressed, the item is added to the totalizer in the manner described and the key is fully returned. The locking bar for this bank is then engaged by a hook 87. The keyboard is unlocked by moving a lever 92, Fig. 1. pivoted at 93 and: fixed to a bar 94, Fig. 12. passing across the rear of the machine. The bar 94 engages the vertical arms of the hooked members 87. disengaging them from the locking bars, the bar 83 being moved upwardly by a spring to re-latch them. The lever 92, Fig. 1, is linked by a pin-and-slot connection to the usual zeroizing lever 95 to enable the machine to be zeroized, if desired, after a false stroke without a separate actuation of the lever 95. In this latter event, the pawl 77 is disengaged from the ratchet teeth of the locking bar by the engagement of the bar 94 with the opposite end of the pawl 77. Specification 514,290 is referred to.