Flexible elongated inductor and elongated and flexible low-frequency antenna

• US 10,056,687 B2
• Filed: 03/02/2017
• Issued: 08/21/2018
• Est. Priority Date: 03/04/2016
• Status: Active Grant

• Current Assignee: Premo, SL.
• Original Assignee: Premo, SL.
• Inventors: Rojas Cuevas, Antonio, Navarro Perez, Francisco Ezequiel, Canete Cabeza, Claudio
• Primary Examiner(s): Baltzell, Andrea Lindgren
• Application Number:
  US15/448,212
• Publication Number:
  US 20170256857A1
• Time in Patent Office: 537 Days
• Field of Search: 343788
• CPC Class Codes: H01F 27/022 Encapsulation
• CPC Class Codes: H01F 27/24 Magnetic cores
• CPC Class Codes: H01F 27/263 Fastening parts of the core together
• CPC Class Codes: H01F 27/266 Fastening or mounting the core on casing or support on coil H01F27/30
• CPC Class Codes: H01F 27/28 Coils; Windings; Conductive connections
• CPC Class Codes: H01F 3/08 made from powder powder coatings on sheets H01F3/02; on strips or ribbons H01F3/04; on wires H01F3/06
• CPC Class Codes: H01F 3/10 Composite arrangements of magnetic circuits
• CPC Class Codes: H01Q 1/085 Flexible aerials; Whip aerials with a resilient base
• CPC Class Codes: H01Q 1/3241 particular used in keyless entry systems
• CPC Class Codes: H01Q 7/08 Ferrite rod or like elongated core

Abstract

The inductor comprises a winding arranged around a core formed by at least two rigid magnetic elements connected in an articulated manner forming an oblong assembly, each comprising: a head end A provided with a circular convex curved surface and a tail end B provided with a circular concave curved configuration, in relation to a transverse axis of the tail, parallel to the transverse axis of the head, and the configuration being complementary to said circular convex curved configuration. The head end A is coupled to the tail end B forming an articulated attachment, and the transverse axes of the head and tail coincide in the coupling area, providing a joint having a variable, adjustable angle, wherein the assembly of said two or more rigid magnetic cores is surrounded by a flexible polymer casing, including magnetic charges that work together to prevent magnetic flux dispersion in the coupling gaps or interstices between the magnetic cores.

Claims

1. A flexible elongated inductor comprising a winding made from a conductive element arranged around a core formed by at least two rigid magnetic cores, made from ferromagnetic material, connected in an articulated manner to one another at their ends, forming an oblong assembly, wherein each of the at least two magnetic cores comprises:

a head end A, provided with a circular convex curved surface in relation to a transverse axis of the head; and

a tail end B, provided with a circular concave curved configuration in relation to a transverse axis of the tail, parallel to the transverse axis of the head, said circular concave curved configuration being complementary to said circular convex curved configuration,

wherein the head end A of one of said magnetic cores is coupled through contact surfaces with the tail end B of an adjacent magnetic core, forming an articulated attachment, wherein said transverse axes of the head and tail of the at least two magnetic cores are coupled to one another coinciding in the coupling area, providing a joint having a variable, adjustable angle, and

wherein the oblong assembly of said two or more rigid magnetic cores is surrounded by a flexible polymer casing, including magnetic charges that work together to prevent magnetic flux dispersion in the coupling areas or interstices between said at least two magnetic cores, said flexible polymer casing including microfibers, microparticles and/or nanoparticles of a soft ferromagnetic material present alone or in any combination thereof inside the polymer matrix of said polymer casing, providing said magnetic charges.

2. The flexible elongated inductor according to claim 1, wherein each of the magnetic cores connected in an articulated manner has a rectangular cross section.

3. The flexible elongated inductor according to claim 1, wherein said articulated attachment includes at least one transverse retention configuration formed by a projection and a recess complementary to one another, defined in said head end A and tail end B, respectively, and formed from said ferromagnetic material of the mentioned magnetic cores, preventing said retention configuration from being misaligned in a transverse direction of the magnetic cores coupled to one another.

4. The flexible elongated inductor according to claim 2, wherein said articulated attachment includes at least one transverse retention configuration formed by a projection and a recess complementary to one another, defined in said head end A and tail end B, respectively, and formed from said ferromagnetic material of the mentioned magnetic cores, preventing said retention configuration from being misaligned in a transverse direction of the magnetic cores coupled to one another.

5. The flexible elongated inductor according to claim 1, wherein the flexible elongated inductor has a length greater than 15 cm.

6. The flexible elongated inductor according to claim 5, wherein the flexible elongated inductor has a maximum length of about 60 cm.

7. The flexible elongated inductor according to claim 3, wherein the flexible elongated inductor has a length greater than 15 cm.

8. The flexible elongated inductor according to claim 7, wherein the flexible elongated inductor has a maximum length of about 60 cm.

9. The flexible elongated inductor according to claim 1, wherein said microfibers, microparticles and/or nanoparticles of a soft ferromagnetic material represent about at least 50% of the total weight of the core.

10. The flexible elongated inductor according to claim 4, wherein said magnetic core has a rectangular prismatic configuration, said projection and recess being defined on respective opposing, smaller rectangular faces of both ends A and B of the magnetic core.

11. The flexible elongated inductor according to claim 10, wherein said projection and said recess adopt a central position in relation to the assembly of rigid magnetic cores coupled to one another at their ends A and B.

12. The flexible elongated inductor according to claim 10, wherein said projection and said recess adopt a side position in relation to the assembly of rigid magnetic cores coupled to one another at their ends A and B.

13. The flexible elongated inductor according to claim 11, wherein said projection and said recess have a width being 10% of a largest width of the rectangular prismatic body, or have a width being 60% of the largest width of the rectangular prismatic body.

14. The flexible elongated inductor according to claim 1, wherein the inductor has at least 5 magnetic cores coupled to one another and a total extension providing a sag of 2 cm for a length of 30 cm.

15. An elongated flexible antenna formed by a flexible inductor according to claim 1.

16. The elongated flexible antenna according to claim 15, wherein the winding made from a conductive element comprises a conductive wire or a conductive foil.

17. The elongated flexible antenna according to claim 16, wherein said antenna is an LF antenna operating in a range of frequencies of 20 KHz to 300 Khz.