Patent GB-798285-A (GB)
Abstract: 798,285. Calculating-apparatus. AKTIE-BOLAGET ATVIDABERG-FACIT. Oct. 12, 1956 [Oct. 14, 1955], No. 31201/56. Class 106 (1). In a ten-key machine wherein the digits of a factor are set successively on toothed rings 61 or other elements of a setting-up mechanism, each key 109 is adapted to displace a corresponding toothed segment 105, having the appropriate number of teeth, laterally into mesh with a companion wheel 102 whereby the digit value is set upon rotation of the segment. The setting-up mechanism shown is that described in Specification 760,883, and comprises toothed rings 61 for setting both factors as well as the calculation (multiplication or division) to be performed. The set factors, with the calculation symbol between, are displayed at a window 66 by indicator segments 61a. In the present machine, the segments 105 are keyed to a driving shaft 103 and the downward arm 109b, Figs. 1 and 2, of each key lever 109 is adapted to cam a pivoted arm 106 laterally, the arm 106 shifting the corresponding segment 105 along the shaft 103 and into mesh with its wheel 102. The wheels 102 are all secured to a shaft 72, and a wheel 73 on this shaft meshes with successive toothed rings 61 of the setting-up mechanism upon step-shifting of the mechanism as successive digits are keyed. The key levers 109 are adapted also to rock a yoke 117 clockwise to the position shown in Fig. 4, an arm 117b of the yoke then releasing a pivoted plate 113 so that the plate rocks clockwise under the action of a spring 114, and closes contacts 122 to start the driving motor for the shaft 103. The motor drives a wheel 133, Fig. 2, which rotates freely on the shaft 103 and is formed with lateral teeth 113a adapted to be engaged by teeth 132b on a clutch member 132 slidably keyed to the shaft 103. A catch 126 initially holds the clutch member 132 disengaged from the wheel 133 against the action of a spring 136. When the plate 113 rocks, it trips the catch so that the teeth 132b and 133a engage and the shaft 103 is driven through one revolution by the motor to transmit the digit keyed to the engaged ring 61. Towards the end of the revolution, a cam 123 restores the plate 113 counterclockwise which allows a spring 111 to return the actuated key lever 109, the yoke 117 also returning and its arm 117b relocking the restored plate 113. If the operator maintains the key depressed, a pawl 120 pivoted to the arm 117b snaps up into locking engagement with the plate 113, in place of the arm 117b, in order to prevent repeat actuation. A segment (not shown) on the actuating shaft 103 normally engages a star-wheel 236 on the shaft 72 to lock the shaft 72 against rotation. The shaft 72 is correctly indexed by engagement of a spring- pressed ball 137 with apertures in the star-wheel. Clearing set factors. Provision is made for reversely driving the shaft 103 for clearing the setting-up mechanism. Operation of the clearing key rocks an arm 141 and catch 130, Figs. 2 and 10, which releases a clutch member 134, similar to the clutch 132, for axial movement by the spring 136 into engagement with lateral teeth on a wheel 135. This wheel is driven in the reverse direction to the wheel 133 and the shaft 103 is, therefore, reversely driven to clear the mechanism. A part revolution overdrive is imparted through the clutch 134, the clutch 132 being then temporarily engaged to bring the shaft 103 into normal position.