Patent GB-191226772-A (GB)
Title: Improvements in and relating to Calculating Machines.
Inventor: FELT DORR EUGENE
IPC: G06C7/06
Filed: 1912-11-21
Granted: 1913-11-26
Abstract: 26,772. Felt, D. E. Nov. 28, 1911, [Convention date]. Adding - apparatus ; error keys; overthrowpreventing mechanism; zeroizing-mechanism.- In a multiple-bank keyoperated adding - machine of the comptometer type, as described i n Specifications 13,094 / 04, 5387 / 09, 9509/09, 25,766/09, and 1622/10, mechanism is provided to lock the numeral-wheels except when they are performing their proper adding movements, and each denominational-actuator is provided with two locks, one serving to lock the actuator normally and the other to lock it when a key has been incompletely depressed. Depression of a key in any bank lowers a denominational-actuator 26, Fig. 2, the stroke of which is limited by one of a pair of stoplevers 27, 28, adapted on its return stroke to rotate a ratchet-wheel, thereby actuating a corresponding numeral-wheel 20. The numeralwheels are normally locked by a detent 37, which engages a pin-toothed wheel 22 and is pivoted on a bell-crank lever 37<a> which has a spring 39 tending to force the detent out of engagement, but is adapted to be held in position by a catch 40. The catch 40 has a roller 42 which when a key is depressed is engaged by the corresponding depressed stop-lever, and the catch thereby, through a flange 43 and tongue 44, releases the detent. As the actuator rises, a roller 46 thereon engages the detent and raises it into engaging position. If a key is partially depressed, the stop-lever will not release the detent, and consequently the error must be corrected before the machine can be operated. Each actuator is provided with a hook 50 which in the normal position engages a lateral projection 51, Fig. 2<a>, in a depending lever 52, this lever having an off-set 54, which engages a roller on a lever 30 designated a partialstroke lever and is adapted when the lever 30 is depressed to release the hook 50 from the projection 51. The lever 52 has pivoted thereto a connexion 57 which extends over a square bar 58 supported in swing- ing arms 59, and is adapted to cause this bar to move a limited distance when the lever 52 is moved. In the normal position, the actuators lift the connexion 57 above the bar 58 by means of a projection 64 upon the actuators. On the actuators are also hooks 65 engaging hooks 66 supported in holders 67 acted upon by springs 69, which tend to force the holders against a cam-rod 72 mounted on levers 73. If a partial stroke is given to a key, the lever 30 'after depression returns and releases the lever 52, which moves forward and carries the bar 58 with it. The movement of the bar allows the lever 73 to fall, and thereupon the hooks 66 engage the hooks 65, except in the denomination in which the key has been partly depressed. The error is then corrected by depressing this key to its full extent, whereby the actuator returns and becomes locked by the engagement of the hooks 65, 66. To unlock the machine, a key 80, Fig. 16, is provided and is adapted by means of a cross-rod 81 to raise the lever 73 to disengage the hooks. The device which zeroizes the numeral - wheels may also unlock the machine. An operation of the zeroizing- lever oscillates a shaft 91 and, by means of a roller 99 on an arm thereof, rocks a lever 104 to cause a bar 107 to rock stop-levers 105 to arrest the pin-toothed wheels 22 in the manner described in Specification 1622/10. The levers 104 have extensions 110 resting upon the crossrod 81, which is thereby depressed to release the actuators when the zeroizing-key is operated. Pins on the levers 105 keep the detents 37 in the locking position when a key is only partly depressed. The keys shown are similar in construction to those described in Specification 1622/10.