Magnetic property retention
AssigneeApple Inc.
InventorWilliam F. Leggett
Life of this patent
Estimating the term…
Abstract
A method and an apparatus for retaining magnetic properties of a magnet while undergoing manufacturing processes are presented. Ferrous materials with relatively good magnetic permeability are disposed adjacent to poles of magnet substantially containing magnetic field lines from the magnet within the ferrous materials. When the magnetic field lines are thereby substantially contained, the magnet can be exposed to elevated temperatures without losing magnetization strength. Adhesives, particularly adhesives that cure when exposed to elevated temperatures can be used with magnets configured to contain magnetic field lines without having the magnets lose magnetic strength.
Claims20
A method for attaching a magnet to a lid of a personal computing device, the method comprising:
- receiving a magnet and a magnetic shunt wherein the magnet and the magnetic shunt are shaped to fit within the lid of the personal computing device and sized to provide an attraction force between the magnet and attractor plates within a base portion of the personal computing device;
- attaching the magnetic shunt to the lid with an adhesive;
- attaching the magnet to the magnetic shunt with the adhesive;
- placing a magnetic keeper on the magnet, wherein the magnetic fields from the magnet are substantially contained within the magnetic shunt and the magnetic keeper;
- heating the magnet, the magnetic shunt and the adhesive to a predetermined temperature for a predetermined amount of time;
- and
- removing the magnetic keeper.
A method for reducing a curing time of an adhesive used for bonding a magnet while preserving magnetic properties of the magnet, the method comprising:
- receiving the magnet;
- affixing the magnet to a support structure with an adhesive, wherein the adhesive is configured to cure relatively faster at elevated temperatures;
- attaching magnetic keepers to each magnetic pole of the magnet;
- heating the magnet, adhesive, magnetic keepers and support structure to a predetermined temperature;
- and
- removing at least one magnetic keeper.
A fixture for curing an adhesive used for bonding a magnet while preserving magnetic properties of the magnet, the fixture comprising:
- a structure configured to receive the magnet and a magnetic shunt;
- a temperature sensitive adhesive configured to cure at elevated temperatures disposed between the magnetic shunt and the structure and disposed between the magnetic shunt and the magnet;
- and
- a magnetic keeper removably attached to the magnet and configured to substantially contain magnetic field lines from the magnet.
Dependencies are inferred from the claim text.