GB445052A - Improvements relating to apparatus for simple arithmetical calculations - Google Patents

Abstract

445,052. Teaching arithmetic; indoor games. WEINER, B., 506, Jirhskova ctvrt, Branik, and BLUMAYER, E., 14, Arbesovo nam., Smichov, both in Prague. Nov. 16, 1934, No. 33061. [Classes 132 (ii) and 146 (ii)] A device for use in teaching arithmetic which may be used as a toy or game or for time tests in psychological response experiments comprises two groups or sets of contacts each connected to one of a number of insulated contact plates arranged in a pile and each corresponding to a digit. The contacts can be selectively engaged by movable contacts so as to set up a circuit corresponding to the problem to be solved, this circuit being completed when other movable members adapted to be set for a trial solution are set to the correct solution. When a circuit is completed a bell is rung or during the setting operation an indicating device is operated to indicate the time elapsing before completion of the calculation. In the form shown in Figs. 1, 2, and 4 for multiplication a frame 4 mounted on pivoted arms 2, 3 carries a pair of contact bars 6 with sets of contacts 7 adapted to co-operate with pins or plugs inserted in holes in insulated plate packs 8, 9. Each pack as shown in Fig. 5a consists of ten insulated metal plates numbered 0 to 9 supported by wooden plates 12, 12<1>. The pins are arranged in accordance with the units and tens of the partial products and in order that each pin may make contact with one plate the perforation corresponding to any given pin is larger than the pin except where the pin makes contact with its corresponding plate. A plate 13 with contact strips 14, 15, and 16, on its under surface is arranged above the contacts 7 and above the contacts of arms 10, 11. The contact strips 14 have leads 17, 18 extending to contacts over which can pass the double contacts of an arm 41 that co-operates with contact strips 19, 20. The data is set by manipulating numbered segments 22, 23 and the answer setting segments 24, 25 are set to show the result; if correctly set an electric circuit through a supply battery is completed to ring a bell or to indicate the time taken. A modified arrangement of contacts for adding or subtracting is described. The indicating device as shown in Fig. 13, and 14, comprises an electromagnet 88 which when the circuit is completed attracts its armature 86 to bring a projection thereon into the path of a stop 89 on a disc 82 driven by gearing from a spring barrel 71. The spring barrel carries a stop disc 74 with a projection 76 that engages the end 85 of an escapement lever 83 when the result segment 24 has been restored to its normal position. When the segment is moved to a number selecting position the lever 83 is rocked to free the projection 76 which rotates until the electromagnet is energized. Graduations on the barrel give an indication of the time taken. A modified form of indicating device is described.