GB1196861A - Improvements in or relating to Keyboards for Code-Dialling. - Google Patents

Abstract

1,196,861. Magnetic keyboards. SIEMENS A.G. 10 April, 1968 [14 April, 1967], No. 17163/68. Heading G4H. [Also in Divisions H4 and H1] A keyboard for generating signal codes comprises a plurality of magnetic flux circuits each containing a magnetic contact unit, a flux guide and a permanent magnet, said flux guide and/or said permanent magnet being common to a plurality of contact units, and a plurality of keys each arranged to complete and break different ones of the magnetic flux circuits. In the form of Fig. 1 there is a separate magnet 5 for each contact unit, magnetic circuits being completed through a common member 7 and one of a number of key-operated code members 9 having parts 10, 11 which contact certain ones of the magnets to actuate the associated contact units 3. In a similar form (Fig. 2, not shown) a single magnet underlies all the contact units and each contact element has a flux guide member co-operating with the code parts of members 9. In another form, Fig. 3, the code member 15 attached to the key has a coded pattern of magnetization and flux guides 20 apply the magnetic field to contact units 3. The coded pattern of magnetization may be transversely of the member 15 instead of longitudinally. In the form of Fig. 6 a single magnet 32 is connected in a number of flux paths through contact units 25, the paths being completed by magnetic inserts 31 in sliding keys 24.