Electromechanical surface texturing

Patent metadata

Field	Value
Publication number	US-9713865-B2
Application number	US-201514728882-A
Country	US
Kind code	B2
Filing date	Jun 2, 2015
Priority date	Jun 2, 2015
Publication date	Jul 25, 2017
Grant date	Jul 25, 2017

Abstract

Magnetic apparatuses and systems for shaping parts are described. One or more magnets can be used to direct a magnetically responsive fluid having magnetically responsive particles around surfaces of a part. The magnetically responsive fluid can include abrasive particles that follow movement of the magnetically responsive fluid across surfaces of the part and remove material from the part until the part takes on a desired shape. The magnetic apparatuses can be configured to provide a rough cut, similar to machining process, and/or a fine cut, similar to polishing or buffing process, to the part.

First claim

What is claimed is:

1. A method of shaping a workpiece, the method comprising:
positioning a fixture such that walls of the fixture cooperate with a portion of a workpiece surface to define a channel for holding a magnetically responsive fluid having magnetically attractable particles and abrasive particles, wherein only the portion of the workpiece surface is immersed within the magnetically responsive fluid; and
causing a magnetic field of a magnet arranged with respect to the workpiece to move the magnetically responsive fluid in a path across the portion of the workpiece surface, wherein movement of the magnetically responsive fluid provides a cutting action sufficient for the abrasive particles to remove material from the portion of the workpiece surface resulting in the workpiece taking on a predefined shape.

2. The method of claim 1 , further comprising filling the channel with the magnetically responsive fluid via an inlet of the fixture.

3. The method of claim 1 , further comprising emptying the channel of the magnetically responsive fluid via an outlet of the fixture.

4. The method of claim 1 , wherein the magnetically attractable particles and the abrasive particles both provide the cutting action that removes the material from the workpiece.

5. The method of claim 1 , wherein the magnetically responsive fluid includes carrier fluid that includes organic fluid, aqueous fluid, or a combination thereof.

6. The method of claim 1 , wherein the workpiece is fixed with respect to the fixture during a shaping operation.

7. The method of claim 1 , wherein more than one magnet is used to move the magnetically responsive fluid.

8. The method of claim 1 , wherein the abrasive particles are characterized as having a first diameter, the method further comprising:
moving a second magnetically responsive fluid comprising a second type of abrasive particles across the portion of the workpiece surface, the second type of abrasive particles characterized as having a second diameter smaller than the first diameter.

9. A magnetic shaping apparatus, comprising:
a fixture including walls that cooperate with a portion of a workpiece surface to define a channel configured to hold a magnetically responsive fluid having magnetically attractable particles and abrasive particles suspended in a carrier fluid, wherein the fixture is configured to immerse only the portion of the workpiece surface within the magnetically responsive fluid; and
a magnet arranged with respect to the workpiece such that the magnet directs movement of the magnetically responsive fluid in a path across the immersed portion the workpiece surface, wherein movement of the magnetically responsive fluid provides a cutting action sufficient for the abrasive particles to remove material from the immersed portion of the workpiece surface resulting in the immersed portion of the workpiece surface taking on a predefined shape.

10. The magnetic shaping apparatus of claim 9 , wherein the magnet includes a permanent magnet, an electromagnet and/or a superconducting magnet.

11. The magnetic shaping apparatus of claim 9 , wherein the magnet is an electromagnet that is supplied electric current by a power supply.

12. The magnetic shaping apparatus of claim 11 , wherein a magnetic flux of the electromagnet is varied during a shaping operation.

13. The magnetic shaping apparatus of claim 9 , wherein the magnetic shaping apparatus includes two or more magnets, wherein polarities of the two or more magnets are switched during a shaping operation.

14. The magnetic shaping apparatus of claim 9 , wherein the fixture is fixed with respect the workpiece during a shaping operation the magnetically responsive fluid.

15. The magnetic shaping apparatus of claim 9 , wherein the fixture includes an inlet and an outlet for the magnetically responsive fluid.

16. A magnetic shaping apparatus for shaping a workpiece, comprising:
a fixture including walls that cooperate with a portion of a workpiece surface to define a channel for holding a magnetically responsive fluid having magnetically attractable particles and abrasive particles, wherein the fixture is configured to immerse only the portion of the workpiece surface within the magnetically responsive fluid;
an electromagnet arranged with respect to the workpiece such that a magnetic field of the electromagnet directs movement of the magnetically responsive fluid in a path across the portion of the workpiece surface, wherein movement of the magnetically responsive fluid provides a cutting action sufficient for the abrasive particles to remove material from the workpiece; and
a power supply configured to supply varying amounts of electric current to the electromagnet, wherein an amount of electric current supplied to the electromagnet is associated with a strength of the magnetic field.

17. The magnetic shaping apparatus of claim 16 , wherein the magnetically attractable particles are comprised of a ferromagnetic material.

18. The magnetic shaping apparatus of claim 16 , wherein the abrasive particles are comprised of a non-metallic material.

19. The magnetic shaping apparatus of claim 18 , wherein the abrasive particles are comprised of one or more of zirconia, titania, and alumina.

20. The magnetic shaping apparatus of claim 16 , wherein the magnetic shaping apparatus additionally includes a permanent magnet and/or a superconducting magnet.

Assignees

• Apple Inc

Inventors

• Castillo Alfredo
• Raghavan Adithya
• Muller Peter R

Classifications

• B24B31/102

  using an alternating magnetic field · CPC title

• B24B31/003

  whereby the workpieces are mounted on a holder and are immersed in the abrasive material · CPC title

• B24B1/005 Primary

  using a magnetic polishing agent · CPC title