Patent GB-633957-A (GB)
Abstract: 633,957. Calculating-apparatus. FELT & TARRANT MANUFACTURING CO. July 11, 1947, No. 18465. Convention date, June 15, 1945. [Class 106 (i)] In a calculating-machine having a number of denominational orders of digit keys for controlling the operation of an accumulator actuating mechanism, there is provided means operable upon partial depression of any one of the keys for locking all the other keys of the same order against depression, means operable by this locking means for preventing operation of the actuating mechanism in all the other orders, and means automatically operable only upon complete depression of all of such partially-depressed' keys for releasing the other two means. Any digit key partially-depressed is locked in such partially-depressed position. Yieldable means hold the key-retaining means, and allow forced return of the partially-depressed keys to normal position without damage to the machine. The machine is key-driven, the digit keys 25 of each order acting on a cantilever column actuator 26 having a rack 28, Fig. 2, which meshes with an accumulator pinion 29 whereby, on the up-stroke of the actuator under spring action, the pinion is clutched to a wheel 31 connected by gearing 33 to a numeral wheel pinion 36. To ensure accurate extent of movement of the column actuators 26, in each order there are even and odd key stop levers 50, 51, Figs. 2 and 7, pivoted at one end at 52, adapted in the final portion of the downward movement of the keys to be depressed by the latter to swing an associated stop lever 54 or 55 to engage a lug 56 with one of a series of teeth 57 in the rear edge of the rack 28 of the column actuator 26. Actuation of the accumulator during downward movement of the column actuator 26 is prevented by a detent lever 108 which engages the wheel 31. In each denominational order an auxiliary key lock lever 86, pivoted at one end at 85, has shoulders 87 engaged by lateral projections on the keys 25, and a roller 88, Fig. 7, resting on one arm 89 of a lever 90 pivoted on the actuator 26. A spring 93 connects the upper end of the lever 90 to the actuator. A link 95 pivoted on the lever 90 by a pin-and-slot connection is urged forwardly by a spring 96. The forward end of the link is pivoted to a pivoted swinging link 98 to which is pivoted a lever 103, one end of which has a pin 106 engaging a slotted arm 107 of the detent lever 108. The final downward movement of a key 25, through the levers 50 or 51 and 54 or 55, disengages the detent 108 from the accumulator wheel 31. Key locking and error correcting mechanism. Means is provided for locking the various denominational orders of the accumulator actuators and the digit keys 25 depressed to effect such actuation, whenever one or more such keys is released prior to completion of a full downward stroke of the keys. This means includes a lateral extension 111 (not shown) on each lever 103 normally resting on an extension on the actuator 26 to limit rocking movement of the lever 103 by a spring 105 until a key 25 has been depressed beyond a certain point, when the key engages the actuator to release the lever 103 which throws the detent lever 108 into locking position. At this point, the nose of the lever 103 which normally extends above a square shaft or bail 114, Fig. 7, supported in spring-urged rockable arms 115, Fig. 18, on a bar 116, is now forwardly of and in horizontal alignment with the bail. A partially-depressed key 25 will not be returned since the detent lever 108 engaging the wheel 31 prevents the actuator being raised, and only results in a slight horizontal movement of the bail 114, allowed by a cross-rod 118 passing through a slot 119 therein. A latch lever 121 (not shown) overlying a projection on the lever 103 rests on the bail 114 when a digit key 25 is depressed and, on the horizontal movement of the bail as described above, slips down into a position to latch the bail against return. The latch is released when the key 25 is fully-depressed. The stem 27 of each key 25 has a forwardlyextending recess adapted to engage with one of a number of teeth 152, Fig. 2, on the key lock lever 86, when the latter is'moved forwardly on depression of a key, so that the key is locked to the column actuator 26 throughout substantially a complete full down-and-up key stroke. A depending key-lock actuating lever 153, Fig. 7, pivoted at 154, is pivoted to a link 156 slotted at its rear end to engage a pin 158 on the associated lever 86. A spring 159 is arranged between the pin and a lug on the link. A recess in the lever 153 normally engages a roller on the column actuator 26. On depressing a key 25, initially the key lock lever 86 moves downwardly relatively to the actuator 26 to move the lever 103 forwardly, then the actuator is depressed so that the roller on the latter acts upon a roller on the lever 153 to move it forwardly, and, through the link 156 and spring 159, to move the key lock lever 86 forwardly, to engage the tooth 152 with the stem 27 of the key 25. Locking of all column actuators 26 whenever any digit key 25 is partially-depressed and released except the actuator in the row in which a key has been mismanipulated, is effected by means including pivoted pawls 171, Figs. 7 and 18, adapted to engage hooks 172 on the actuators 26 not depressed. These pawls are moved by a cross-rod carried by the arms 115 on depression of a key 25. Means to prevent the pawls 171 returning to normal position upon corrective actuation of a key 25, so that all the actuators are then locked, comprises a pivoted latch lever 182 having one notched end 183 normally resting on the bail 114 under spring action, but adapted to swing down so that its notched end engages the bail when the latter is moved rearwardly by the error control mechanism described above. The arms 115 carrying the bail cannot then release the pawls 171, and the entire keyboard is locked. To release the keys thus locked, an error release key 186, Fig. 2, on a lever 187 pivoted at 188, is depressed. A downward extension of the lever 187 abuts the lower end of a spring-urged bell-crank lever 189, Fig. 18, which is pivoted on a shaft 185, and moves this lever to lift the latch lever 182 out of engagement with the bail 114. Means is also provided to achieve this result whenever the cancelling- mechanism is actuated to zeroize the accumulator. A cancelling-crank 71 operates on a lever 74 and link 76, through a link 73, to rock an arm 77 on a shaft 78. The arm 77 engages a second arm 80 secured to the shaft 78 to rock the latter to swing the frame carrying the gears 33 out of engagement with the wheels 31. A shaft 75 to which the lever 74 is secured is also rocked, whereby an arm 81 thereon, co-operating with each detent lever 108, rocks the bellcrank lever 189 to release the latch lever 182 from the bail 114. Selectively-operable means to render ineffective the above-described means for locking partially-depressed keys following corrective actuation thereof, comprises an error correction control key, 196, Fig. 18. This key is connected by a pin-and-slot connection to the rear end of a link 197, the front end of which is slotted to engage over the rock shaft 75 and has a lug engageable by a pin 75<SP>1</SP> on the shaft. The pin 75<SP>1</SP> releases the key 196 during zeroizing operations. A shoulder on the key 196 cooperates with a cross-shaft 200 when the key is depressed and moved rearwardly by a spring 201. A lever 203 pivoted at 204 for limited movement is connected to the key 196, and has an extension 206 overlying the forward end of the latch lever 182. When the key 196 is in depressed condition, the latch lever 182 is released if in active position, and complete depression of all digit keys 25 which have been locked in partially-depressed condition causes immediate automatic unlocking of the entire keyboard upon complete depression of the last of such keys. Forced return of partiallydepressed keys 25 to normal position does not result in injury to the machine in view of the spring connection 159 between the actuator 26 and key lock lever 86. Crowding locks. A series of pivoted key locks 164, Fig. 7, is arranged between each adjacent pair of recessed key stems 27, the aggregate spacing between all adjacent extensions 166 of the locks in an ordinal series being equal only to the thickness of one key stem, so that depression of any key in one order will swing the adjacent locks away from the stem of that key to block movement of all other keys in that order.