Patent GB-713338-A (GB)
Title: Electrical relay calculating machine
IPC: G06F7/44
Filed: 1951-07-13
Abstract: 713,338. Digital electric calculating apparatus. HOFGAARD, R. July 13, 1951 (Aug. 16, 1950], No. 16710/51. Class 106 (1) An electrical calculating machine operating on the decimal system by means of a 1, 2, 4, 6, code applied to a series of relays is characterized in that the relay arrangement comprises an eccentric shaft driven by an electric motor into a reciprocating movement through a set of bars, a number of magnets associated with each bar, each magnet being energized to operate multiple switching contacts, and a set of spring members forming a multiple switch controlled by one of the bars so as to ensure correct timing sequence for each set of switch contacts. The preferred embodiment utilizes valves and condensers whereby the number of relays can be reduced to four relays and one transfer relay, three relays for the handling of the even digits and one relay with valves and condensers for handling the odd supplement as well as one transfer relay. An eccentric shaft 1, Fig. 1, is driven by a motor not shown, by means of an arm 2 pivotably mounted on the shaft. The eccentric motion is imparted to give synchronized reciprocating movement throughout a set of bars 3, 3<SP>1</SP>, which are horizontally supported in bearings and are displaceable longitudinally. Immediately beneath each of the bars there is provided a number of magnets, each of which is arranged to operate a multiple contact switch in such a manner that a coil 4 attracts an armature 5. Actuation of the magnet will, apart from movement of associated contacts 6, also move a hook 7 which is supported in the multiple switch set 8, in such a manner that the hook 7 engages a notch 9 provided in the bar 3<SP>1</SP> when this moves to its left hand extreme position, whereby the switch operating bar 8 follows the movement of bar 3<SP>1</SP>. If the hook 7 is lifted prior to engagement of the hook 7 into the notch 9. the hook will slide on the lower surface of the bar 3 and the contacts 6 will operate. A set of spring blades 12 form a multiple switch contact set 13 which is not controlled by a magnet, but by a bar 3 by means of a plate 14 secured to the bar and movable therewith so as to ensure the correct timing sequence for the associated set of switch contacts of which only the fragments 8 and 13 are shown. At the left of Fig. 1 is shown a switch contact set 15 secured to the bottom plate 11 which is also moved in synchronism with the eccentric but with a phase displacement between the movement of these contact sets and the others. The coils of the relays 27-30, Fig. 3, receive current impulses from a machine keyboard by the code leads 35-38 according to the numerical value to be entered, the magnets being associated with their holding circuit by the lead h. The outgoing leads fall into groups which for example may be connected to junction boxes as Gt(0) Gt(1) Gt(2) Gt(4) Gt(6) Gt(8). The suffix "t" indicates that the group belongs to the ten-value in a partial product, with the code value in brackets. Fig. 6 shows a wiring diagram for the addition set of relays. In an adding operation none of the multiple contact switch sets 87, 88 are closed and the relay 71 will be fed across the lead 97, across one of the sets 83, 84 or 85 as long as any one of these sets are closed. The holding circuit of the relay from lead 116 is during the same time interval, interrupted across the contact in the multiple switch set 91. The condenser 81 is charged across the closing contact in the set 90 and timing line 23, Fig. 2, from the accumulator Ba<SP>1</SP>. Relay 71 receives an impulse through timing line 25, Fig. 2, and is held by means of a holding circuit across lead 116. The relay will therefore remain closed until the digit 1 has been recorded. A discharge across the lead 122 will give an impulse to relay 72 in case no relay has been closed during adding operations. If, on the other hand, relay 72 already has a current supply according to timing contact 20, Fig. 2, the discharging impulse will take place across the coil associated with relay 73. Digit 2 will be added during the timing interval 24, Fig. 2. The impulses of the results supplied from the addition devices through the lead groups R are carried to a group of condensers to be stored there temporarily, and from there later, they can be transferred to, for example, a punching machine of known type. The multiple switch sets are connected across a system of timing relays T1-T7, Fig. 8. Relay T1 is closed by pressing key T and the relays T1-T7 will be successively closed according to the timing interval in turn. Specifications 211,137, [Class 106(i)], 492,748, 583,973, and 630,559 are referred to.