METHODS FOR FORMING SHIELD MATERIALS ONTO INDUCTIVE COILS

• US 20150371768A1
• Filed: 06/20/2014
• Published: 12/24/2015
• Est. Priority Date: 06/20/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Graham, Christopher S., Jol, Eric S., Brzezinski, Makiko K.
• Granted Patent: US 9,460,846 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01F 1/147 Alloys characterised by their composition treatment thereof for enhancing their electromagnetic properties C21D8/12
• CPC Class Codes: H01F 27/02 Casings
• CPC Class Codes: H01F 27/28 Coils; Windings; Conductive connections
• CPC Class Codes: H01F 27/288 Shielding
• CPC Class Codes: H01F 27/36 Electric or magnetic shields or screens movable for varying inductance H01F21/10
• CPC Class Codes: H01F 27/366 made of ferromagnetic material
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction
• CPC Class Codes: H02J 7/0044 specially adapted for holding portable devices containing batteries H02J7/0045 takes precedence
• CPC Class Codes: Y10T 29/49021 Magnetic recording reproducing transducer [e.g., tape head, core, etc.]

Abstract

Methods of and systems for directing flux from a transmit coil to a receive coil within an inductive power transfer system are disclosed. For example, a transmit coil may be shielded with a contoured shield made from a ferromagnetic material. The contoured shield may contour to several surfaces of the transmit coil so as to define a single plane through which flux may be directed to a receive coil.

Claims

9-1. The shield of claim 1, further comprising an adhesive layer disposed between the shield and the annular coil.

10-2. The shield of claim 9, wherein the adhesive layer comprises a heat activated film.

13. An inductive charging system comprising:

an electronic device comprising;

a rechargeable battery;

a receive coil electrically associated with the battery; and

a first shield contoured over at least two surfaces of the receive coil defining a receiving area of the receive coil for concentrating magnetic flux therethrough.

14. The inductive charging system of claim 13, further comprising:

an inductive charging device comprising;

a housing comprising an interface surface for receiving the electronic device;

a transmit coil within the housing and positioned below the interface surface; and

a second shield contoured over at least two surfaces of the transmit coil defining a transmitting area of the receive coil for concentrating magnetic flux therefrom;

wherein;

the transmitting area is oriented to face the interface surface.

15. The inductive charging system of claim 14, wherein when the electronic device is received on the interface surface, the receiving area is oriented to face the transmitting area.

16. A method of manufacturing a contoured shield for an electromagnetic coil comprising the operations of:

forming a shield sheet comprising a plurality of petals;

placing the shield sheet on a first surface of the electromagnetic coil; and

folding each of the plurality of petals to contour to the surface of the electromagnetic coil.

17. The method of claim 16, further comprising:

positioning a heat activated film between the shield and the electromagnetic coil to form a shielded coil assembly;

heating the shielded coil assembly to activate the heat activated film.

18. The method of claim 16, further comprising disposing a filler material between adjacent petals.

19. The method of claim 16, further comprising press fitting the contoured shield and electromagnetic coil assembly onto a mold having a selected shape.

20. The method of claim 19, wherein the selected shape is a cone.