Patent GB-915855-A (GB)
Abstract: 915,855. Digital electric calculating-apparatus. BURROUGHS CORPORATION. Jan. 2, 1961 [Jan. 11, 1960], No. 92/61. Class 106 (1). A multiplying machine has a number of electrical devices such as switches each storing or registering one digit and has means, preferably controlled by a travelling paper carriage of the machine, for rendering effective a selected one of several groups of the storage devices, in which a desired multiplicand factor is stored for the selection of corresponding partial product digits and their transmission to a product accumulator. The invention is applied to the combination described in Specification 902,672 of a mechanical key-set accounting-machine as described in Specification 709,181 with electrical multiplying circuits and the accumulator described in Specification 902,671, in which the number wheels are frictionally driven for varying periods under the control of solenoids. Storage devices.-Each of the twelve actuators 14, Fig. 4, of the machine constantly meshes with a pinion 56 coupled by a spring 59 to a pinion 57 engaging a storage gear 61. An amount may be transferred from one of the totalizers of the accounting machine by taking a sub-total, detents allowing the gears 61 to assume the appropriate differential positions at the mid-cycle position and then locking the gears 61 during the return of the racks 14. Each gear 61 carries contacts 61a moving over a printed circuit 64 so as to connect a common lead to one of ten digit leads. Selecting factors from storage devices.-The twelve storage devices form a twelve-digit store 22, Fig. 5, for multiplicand factors by which each of twelve denominational leads 24 is connected to that one of nine digit leads 23 corresponding to the multiplicand digit stored in that order. Pulses representing alternately right- and left-hand partial product digits are applied to the leads 23 from function table circuits set successively in accordance with the multiplier digits as described in Specification 902,672. The digit pulses are passed over the leads 24 to column-shifting circuits and thence to the product accumulator 25. In the present arrangement, normally closed relay contacts 70, 71, 72 are included in the leads 24, the relay 72 controlling six leads and the relays 70 and 71 controlling three each. Thus, by energizing two of the relays, the circuits including the leads 24 controlled by the third, and only these circuits, will be effective. The relays are energized in pairs over a diode circuit 69 in accordance with the position of a switch 67. This switch, Fig. 3 (not shown), is positioned under the control of control projections of different lengths carried by the paper carriage. The switch 67 also determines the extent of an overall columnshift between the leads 24 and the accumulator 25, the arrangement being such that the factors are given their correct denominational values irrespective of the groups of storage devices in which they are stored. The relay selection circuits as a whole are rendered effective by a further control projection of the paper carriage which closes contacts 68. In a modification, Fig. 7, the sizes of the factors selected by the relays 70, 71, 72 may be varied by two hand-set selector switches. One of these with four wipers 8-7, 7-6, 6-5 and 5-4 enables from one to four digits to be added to the four digits normally controlled by the relay 72 whereas the other associates from one to four digits with the relay 70 or renders that relay completely ineffective.