Multi-Position Magnetic Detents

• US 20110199171A1
• Filed: 04/27/2011
• Published: 08/18/2011
• Est. Priority Date: 06/07/2007
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Prest, Christopher D.
• Granted Patent: US 8,424,162 B2
• Time in Patent Office: Days
• US Class Current: 335/296
• CPC Class Codes: G06F 1/1616 with folding flat displays, e.g. laptop computers or notebooks having a clamshell configuration, with body parts pivoting to an open position around an axis parallel to the plane they define in closed position
• CPC Class Codes: G06F 1/1679 for locking or maintaining the movable parts of the enclosure in a fixed position, e.g. latching mechanism at the edge of the display in a laptop or for the screen protective cover of a PDA G06F1/1681 takes precedence
• CPC Class Codes: G06F 1/1681 Details related solely to hinges hinge details related to the transmission of signals or power are classified in G06F1/1683
• CPC Class Codes: H01F 7/0242 Magnetic drives, magnetic coupling devices
• CPC Class Codes: Y10T 29/24 Hinge making or assembling

Abstract

Various embodiments for magnetic detent assemblies provide for detent devices with improved performance and manufacturability. In one embodiment, magnetic detent assemblies provide for custom detent positions and custom force profiles by including a pair of unitary magnetic components each having a special geometry. In an embodiment, the changing area of overlap (and hence magnetic flux) between the magnetic components can give rise to the custom detent positions and custom force profiles. In a specific embodiment, the magnetic components can comprise an N-point star shaped geometry, where the number and distribution of the start wings can be varied to define customized detent positions and the contour of the star wings can be varied to create customized force profiles. In other embodiments, devices such as laptop computers and docking stations for handheld electronic devices can implement multi-position detent hinges with the magnetic detent assemblies.

Claims

1. A detent assembly comprising:

a first body including a first magnetic component characterized by a first geometry; and

a second body positionable in proximity to the first body and including a second magnetic component characterized by a second geometry;

wherein the first body and the second body are adapted to move relative to each other, and

wherein the first geometry and the second geometry are adapted to generate magnetic fields between the first magnetic component and the second magnetic component in such a way as to define a plurality of detent positions between the first body and the second body, and

wherein the detent assembly is adapted to create a first threshold magnetic force holding the first body and the second body in a first detent position and a second threshold magnetic force holding the first body and the second body in a second detent position, wherein the first threshold magnetic force is greater than the second threshold magnetic force.

2. The detent assembly of claim 1, wherein the first geometry and the second geometry form areas of overlap, wherein the areas of overlap formed by the first geometry and the second geometry are a predetermined function of the relative positions of the first body to the second body, and wherein the area of overlap for the first detent position is greater than the area of overlap for the second detent position.

3. The detent assembly of claim 1, wherein the first magnetic component has a first surface section with the first geometry, and wherein the second magnetic component has a second surface section with the second geometry.

4. The detent assembly of claim 3, wherein the first body and the second body are adapted to move relative to each other, wherein the movement is such that an amount of overlap of the first surface section and second surface section with each other changes during the movement, and wherein the first surface section and second surface section at least partially overlap during the full range of movement of the detent assembly,

5. The detent assembly of claim 3, wherein the first surface section is contiguous and entirely magnetic with a same first polarity, wherein the second surface section is contiguous and entirely magnetic with a same second polarity that is opposite the first polarity, and wherein the first surface section is opposite the second surface section.

6. The detent assembly of claim 1 wherein the second body is adapted to move relative to the first body along a single axis of rotation.

7. The detent assembly of claim 6 wherein the first geometry and the second geometry are characterized by an N-point star shaped geometry.

8. The detent assembly of claim 7 wherein the N-point star shaped geometry comprises N asymmetric wings, where at least one pair of the N wings is spaced at a different angle than another pair of the N wings.

9. The detent assembly of claim 7 wherein the N-point star shaped geometry comprises N asymmetric wings, where at least one of the N wings is shaped differently from another of the N wings.

10. The detent assembly of claim 9 wherein the N asymmetric wings comprises a first shape and a second shape, where the first shape is an elongated version of the second shape.

11. The detent assembly of claim 10 wherein at least one of the N asymmetric wings comprises the first shape, and at least one of the rest of the N asymmetric wings comprises the second shape.

12. The detent assembly of claim 1 wherein the second body is adapted to move relative to the first body along one linear dimension.

13. The detent assembly of claim 1 wherein the first magnetic component comprises a magnetic or ferromagnetic material and the second magnetic component comprises a magnetic, ferromagnetic, or ferrous material.

14. The detent assembly of claim 1 wherein at least one of the first magnetic component and the second magnetic component includes an electromagnetic subcomponent.

15. A method of manufacturing a magnetic detent assembly, the method comprising:

fabricating a first magnetic component having a first geometry;

disposing the first magnetic component in a first body;

fabricating a second magnetic component having a second geometry;

disposing the second magnetic component in a second body; and

positioning the first body in proximity to the second body such that the first geometry of the first magnetic component and the second geometry of the second magnetic component create a magnetic force profile between the first body and the second body,

wherein, the magnetic force profile defines a plurality of detent positions when the first body is moved relative to the second body, and

wherein a magnetic force at a first detent position is greater than the magnetic force at a second detent position.

16. The method of claim 15 wherein the second body moves relative to the first body along at least a single axis of rotation.

17. The method of claim 16 wherein the first geometry and the second geometry are characterized by a N-point star geometry.

18. The method of claim 15 wherein the magnetic force profile in the absence of external forces align the first body with respect to the second body along one of the plurality of detent positions.

19. A detent assembly comprising:

a first body including a first magnetic component characterized by a first geometry; and

a second body positionable in proximity to the first body and including a second magnetic component characterized by a second geometry;

wherein the first body and the second body are adapted to move relative to each other,

wherein the first geometry and the second geometry are adapted to generate magnetic fields between the first magnetic component and the second magnetic component in such a way as to define a plurality of detent positions between the first body and the second body, and

wherein at least one of the first magnetic component and the second magnetic component includes an electromagnetic subcomponent, wherein portions of the electromagnetic subcomponent are independently energizable.

20. The detent assembly of claim 19, further comprising:

a control circuit coupled to the electromagnetic subcomponent.

21. The detent assembly of claim 20, wherein the control circuit is configured to allow a user to adjust the number of detent positions.

22. The detent assembly of claim 20, wherein the control circuit is configured to allow a user to specify one or more preferred detent positions that are more dominant than other detent positions.

23. The detent assembly of claim 19, wherein both the first magnetic component and the second magnetic component include an electromagnetic subcomponent, wherein portions of each electromagnetic subcomponent are independently energizable.