Case with magnetic over-center mechanism
A case for a portable listening device has a housing and a lid. The lid is attached to the housing with a pivotable joint and operates between an open and a closed position with an over-center mechanism that employs a plurality of magnetic elements.
1. A case for a portable listening device, the case comprising:
a housing having a cavity to receive the portable listening device;
a lid attached to the housing with a pivotable joint such that the housing and the lid are arranged in a clamshell configuration allowing the lid to rotate between a closed position where the lid conceals the cavity and an open position where the lid is angularly displaced from the cavity; and
a plurality of magnetic elements disposed within the housing and the lid, the plurality of magnetic elements configured to create an over-center configuration for the lid where the lid pivots between a first stable position when in the closed position and a second stable position when in the open position, but is in an unstable position in-between the closed position and the open position.
2. The case of claim 1 wherein the plurality of magnetic elements comprises a first pair of magnetic elements configured to repel each other and a second pair of magnetic elements configured to attract each other.
3. The case of claim 2 wherein the first pair of magnetic elements includes a first magnet positioned in the lid adjacent to the pivotable joint and a second magnet positioned in the housing adjacent to the pivotable joint and oriented to repel the first magnet.
4. The case of claim 2 wherein the second pair of magnetic elements includes a third magnet positioned in the lid opposite the pivotable joint and a fourth magnet positioned in a housing wall opposite the pivotable joint and oriented to attract the third magnet.
5. The case of claim 2 wherein when the lid is in the closed position attractive forces between the second pair of magnetic elements over power repulsive forces between the first pair of magnetic elements magnets.
6. The case of claim 2 wherein when the lid is in the open position repulsive forces between the first pair of magnetic elements over power attractive forces between the second pair of magnetic elements.
7. The case of claim 2 wherein both of the magnetic elements of the second pair of magnetic elements are magnets.
8. The case of claim 2 wherein one of the magnetic elements of the second pair of magnetic elements is a magnet and the other magnetic element is a magnetic material.
9. The case of claim 1 wherein the housing includes first and second opposing sidewalls and third and fourth opposing sidewalls that extend between the first and second sidewalls, a bottom wall that extends between the first, second, third and fourth sidewalls, an insert positioned within an interior space defined by the first, second, third and fourth sidewalls and the bottom wall, the insert defining a shape of the cavity, and a receiving opening opposite the bottom wall that communicates with the cavity.
10. The case of claim 9 wherein the cavity is configured to receive one or more listening devices.
11. The case of claim 1 wherein one or more of the plurality of magnetic elements are partially surrounded by a high magnetic permeability material.
12. The case of claim 1 wherein at least one of the plurality of magnetic elements is oriented such that its pole is not aligned with its mating magnetic element when the lid is in the closed position.
13. The case of claim 1 wherein one or more of the plurality of magnetic elements is secured to a spring.
14. A case for a portable listening device, the case comprising:
a housing having a cavity to receive the portable listening device and a receiving opening that communicates with the cavity;
a lid secured to housing with a pivotable joint such that the lid and the housing are coupled together in a clamshell configuration, the lid being operable between an open position in which the receiving opening is exposed and a closed position in which the lid covers the receiving opening; and
a plurality of magnetic elements that cooperate to define an over center position for the lid disposed between the open position and the closed position such that that the lid resists rotating from the open position to the closed position until the lid is rotated past the over center position where the lid is impelled to the closed position.
15. The case of claim 14 wherein the over center position is created by combination of repulsive forces between a first and a second magnetic elements, attractive forces between a third and a fourth magnetic element and a distance of the first, the second, the third and the fourth magnetic elements from the pivotable joint.
16. A case for an electronic device, the case comprising:
a housing having a cavity to receive the electronic device and a receiving opening that communicates with the cavity;
a lid secured to housing with a pivotable joint such that the lid and the housing are in a clamshell configuration, the lid being operable between an open position in which the receiving opening is exposed and a closed position in which the lid covers the receiving opening; and
a plurality of magnetic elements disposed within the housing and the lid, the plurality of magnetic elements configured to create an over center position for the lid such that the lid resists rotating from the open position to the closed position until the lid is rotated past the over center position when the lid is then attracted to the closed position.
17. The case of claim 16 wherein the plurality of magnetic elements comprises a first pair of magnetic elements oriented such that they repel each other and are located proximate the pivotable joint connecting the housing to the lid, with a first magnetic element of the first pair of magnetic elements disposed within the case and a second magnetic element of the first pair of magnetic elements disposed within the lid.
18. The case of claim 17 wherein the plurality of magnetic elements comprises a second pair of magnetic elements oriented such that they attract each other and are located opposite the pivotable joint, with a third magnetic element disposed within the case and a fourth magnetic element disposed within the lid.
19. The case of claim 18 wherein the over center position is created by a combination of repulsive forces between the first and second magnetic elements, attractive forces between the third and fourth magnetic elements, a distance of the first and second magnetic elements from the pivotable joint, and a distance of the third and fourth magnetic elements from the pivotable joint.