Patent GB-451011-A (GB)
Abstract: 451,011. Calculating - apparatus. FAIRWEATHER, W. C., 65, Chancery Lane, London.-(Underwood Elliott Fisher Co. ; 342, Madison Avenue, New York, U.S.A.) Oct. 22, 1935, No. 29095. [Class 106 (i)] A combined typewriting and computing machine in which the numeral keys operate a corresponding actuator adapted to effect the rotation of a master wheel to actuate the totalizer is provided with a full-stroke mechanism to prevent a second key from being depressed until the entire train of mechanism operated by the first key is fully returned to normal position. The actuators have full-stroke racks, and each rack cooperates with an independently pivoted dog and means is associated with each of the dogs to prevent depression of the second key. The invention is shown applied to an Underwood typewriter Figs. 1 and 6, with a platen carriage supporting a truck carrying a totalizer 31. The numeral keys 25 are connected by links 43<a> to corresponding actuators 43 provided with cam slots 49 arranged according to the digital value of the key. When a key is depressed its actuator is rocked and a shaft 47 has a rocking movement imparted thereto by the engagement of the cam slot with a roll 48 on the corresponding arm 46 that is secured to the shaft 47. On the shaft 47 is an arm 50 having a pin 51a on which is mounted a link 51 connected to a gear sector 52 slidably mounted to engage the pinion 58 or 53 of a reversing mechanism for driving the pinion 58 and the master-wheel 63 in one or other direction for addition and subtraction. The pinion 58 is normally uncoupled from the master wheel 63 and a slidable dog clutch 66 on the shaft 59 is effective to render the connection operative. A series of full-stroke pawls 103 is pivotally mounted on a rock shaft 101 and each pawl has a finger 104 to trail an edge of its actuator 43. The pawls are individually pivoted and are formed with an elongated slot 110 to permit a limited rocking movement. On the initial downward movement of the actuator the pawl is displaced and the shaft 101 is rocked against the action of spring 124, Fig. 4, into the position shown in Fig. 11, thereby an arm 113 on the shaft through co-operation with its roll 114 in a cam slot 115 of a lever 117 rocks the lever 117 to lock the totalizer in position by teeth 120 thereon engaging a rack 122. The rocking of the shaft 101 is utilized to rock the clutch 66 for which purpose the shaft carries cams 138, 139, Fig. 10, which engage the arms 136 of a three armed lever 131 mounted on a stud 130 carried by a cross-bar 129, the upstanding arm being provided with a roll 132 engaging the groove 134 of the clutch 66. The upstanding arm is formed with an aligning blade 142, Fig. 2, which aligns the numeral drums during the return movement of the clutch to inoperative position. An auxiliary aligning blade 145 is also provided to align the lower denominations and receives its movement from the roll 114 through a camslot arm. This arm is composed of two parts an arm 147 and arm 149, Fig. 3, mounted on the pivot pin of the lever 117 and provided with a tooth 156 which holds the master wheel 63 when in its uncoupled position, During this initial movement the lever 117 through a projection 162 rocks a lever 89, Fig. 4, so as to disengage the Geneva transfer pinion of the lower denomination to prevent interference during the continued movement of the actuator when the value is entered in the totalizer through the master wheel and transmission gears 75, 76, 77. At the end of the down stroke of the actuator the full-stroke pawl escapes from the corner of the actuator edge and the spring 124 restores the shaft 101 thereby rocking the clutch lever 131 and the locking lever 117. On the upward or return stroke of the actuator the inner end of the pawl slot abuts the pin 111, and thereby holds the shaft 101 against rocking movement and thus has the effect of locking all the other actuators against operation until the trailing pawl escapes from the returning actuator as it reaches home position. During the greater part of the key lever stroke all the other keys are locked by the projecting 94 on the link 43a co-operating with rods 93 forming a crowding lock. A modified form of the invention is shown in Fig. 16, in which each actuator 43 has a tongue 175 which on the initial downward movement of the actuator engages a toe 176 so as to rock a shaft 177 which through an arm 178 andlever 180 operates the clutch 66 to couple up the master wheel 63. The full-stroke pawls 183 constructed as shown in Fig. 17 for relative movement to the supporting shaft 184 co-operate with the serrated edges of their respective actuators in the normal manner, the toe 176 of the displaced actuator snaps off the upper end just in advance of the fall down stroke so that the shaft 177 returns to open the clutch. Near the end of the return stroke the displaced toe holds the shaft 177 and the other toes in position to block the movement of all the other pawls 183.