Multi-turn coil structures and methods of winding same
OwnerLoyal H. Tingley, IIIinventor
Life of this patent
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Abstract
A multi-turn coil structure is wound on a former starting from a central portion of the coil and spirally winding respective lengths of the coil which extend from the central portion around the former in opposite winding directions and in adjacent contiguous planes. This allows outer end portions of the respective windings which constitute input and output leads for the coil each to be accommodated within the bi-planar coil structure. This reduces the overall thickness of the coil compared with conventional structures in which an inner end of the coil structure is extended to the outside in a further contiguous plane adjacent the coil. The structure is particularly suited for miniature wire coils to be used in electronic circuits of security cards.
Claims13
A multi-turn coil structure comprising a single length of wire wound into a pair of planar spiral windings located in adjacent planes, the windings having inner end portions merging together at a point on the wire and spiralling outwardly from the inner end portions in opposite senses respectively, the windings further having outer end portions forming input and output lead elements for the coil, said outer end portions being located in the planes of the respective windings.
In an electronic smart card having a core element of laminated plastic sheets and front and back plastic sheets laminated to opposite surfaces of the core element, one of said plastic sheets of the core element provided with a printed circuit and the other of said plastic sheets of the core element defining a cut-out receiving a miniature wire coil having input and output leads connected to terminals of the printed circuit, the improvement wherein said coil comprises a single length of wire wound into adjacent planar spiral windings in contiguous planes with inner end portions merging together at a point on the wire and spiralling outwardly from the inner end portions in opposite senses respectively, the windings having outer end portions defining the respective input and output leads being located in plane with the respective windings, the coil having an overall thickness of substantially two times the wire diameter.
An element of sheet material having an electronic circuit printed thereon, the circuit including a pair of connectors and the element including a miniature wire coil substantially flat on the sheet with input and output leads electrically connected to said connectors, the coil comprising a single length of wire wound into contiguous planar oppositely wound spiral windings with inner end portions merging together at a point on the wire and outer end portions defining the input and output leads extending from the planes of the respective windings.
A portable smart card having an electronic circuit embedded therein including a miniature wire coil comprising a single wire wound into a pair of contiguous oppositely wound planar spiral windings with inner end portions merging together at a point on the wire and outer end portions defining input and output leads extending from the planes of the respective windings and electrically connected to respective connectors of the circuit.
Dependencies are inferred from the claim text.