MAGNETIC LOCKING SYSTEM

• US 20100237970A1
• Filed: 01/12/2010
• Published: 09/23/2010
• Est. Priority Date: 03/19/2009
• Status: Active Grant

• Current Assignee: Credo Technology Corporation, Robert Bosch GmbH
• Original Assignee: Credo Technology Corporation, Robert Bosch GmbH
• Inventors: Liu, Jie
• Granted Patent: US 8,217,743 B2
• Time in Patent Office: Days
• US Class Current: 335/295
• CPC Class Codes: B23D 47/025 of tables
• CPC Class Codes: B27B 5/29 Details; Component parts; Accessories
• CPC Class Codes: H01F 7/0226 PM with variable field strength H01F7/0284 takes precedence
• CPC Class Codes: H01F 7/04 Means for releasing the attractive force
• CPC Class Codes: H01F 7/20 without armatures cores H01F3/00; coils H01F5/00 ; shaping metal by applying magnetic forces B21D26/14; electromagnets specially adapted for NMR applications G01R33/381

Abstract

Preferred embodiments of the present magnetic locking system can be used for releasably locking a first component to a second component. In one embodiment, the locking system includes a ferro-magnetic member associated with the first component, where the ferro-magnetic member is made of a ferro-magnetic material, and a housing attached to the second component and positioned adjacent to the ferro-magnetic member. Preferably, the housing includes first and second blocks that sandwich an intermediate block. Further, the first and second blocks are each preferably made of a ferro-magnetic material and the intermediate block is made of a non-ferro-magnetic material. Additionally, there is also an aperture formed within the housing, with a permanent magnet rotatably seated within the aperture. The magnetic locking system preferably includes a switch mechanism that is operatively connected to one of the permanent magnet and the housing, wherein the switch mechanism is configured and arranged to rotate the housing and the permanent magnet relative to each other between an “on” position and an “off” position.

Claims

1. A magnetic locking system for releasably locking a first component to a second component, said locking system comprising:

a ferro-magnetic member associated with the first component;

a magnet housing attached to the second component and positioned adjacent said ferro-magnetic member, wherein said magnet housing includes first and second blocks that sandwich an intermediate block, and further wherein said first and second blocks are each made of a ferro-magnetic material and said intermediate block is made of a non-ferro-magnetic material;

an aperture formed within said housing;

a permanent magnet rotatably seated within said aperture;

a switch mechanism operatively connected to one of said permanent magnet and said housing, wherein said switch mechanism is configured and arranged to rotate said housing and said permanent magnet relative to each other between an on position and an off position.

2. The magnetic locking system according to claim 1, wherein said aperture is defined by a portion of said first block, a portion of said second block and a portion of said third block.

3. The magnetic locking system according to claim 1, wherein:

said permanent magnet is of a generally cylindrical shape and creates a magnetic field;

said on position is defined when said permanent magnet is positioned within said aperture such that said magnetic field extends generally transverse to said first block, said second block and said intermediate block; and

said off position is defined when said permanent magnetic is positioned within said aperture such that said magnetic field extends generally perpendicular to said magnetic field of said on position,

whereby, when considered outside of said housing, said magnetic field defined during said on position is much greater than that defined during said off position.

4. The magnetic locking system according to claim 1, wherein:

said permanent magnet includes a north pole section and a south pole section, whereby a magnetic direction extends from said south pole to said north pole;

said on position is defined when said magnetic direction is transverse to said first, second and intermediate blocks; and

said off position is defined when said magnetic direction is aligned with said first second and intermediate blocks, whereby said magnetic direction during said on position is generally perpendicular to said magnetic direction during said off position.

5. The magnetic locking system according to claim 1, wherein:

said permanent magnet is of a generally cylindrical shape and is magnetized along its diameter such that said permanent magnet includes a semi-cylindrical north pole section and a semi-cylindrical south pole section;

said first block and said second block each include an upper surface, a lower surface, a front surface, an inner side surface facing said intermediate block and an outer side surface facing away from said intermediate block;

said intermediate block includes an upper surface, a lower surface, a front surface, a first side surface facing said first block and a second side surface facing said second block;

said off position occurs when said permanent magnet is aligned within said aperture such that said north pole faces towards one of said upper surface of said intermediate block or said lower surface of said intermediate block and said south pole faces toward the other of said upper and lower surfaces of said intermediate block; and

said on position occurs when said permanent magnet is rotated relative to said aperture by approximately 90 with respect to said off position.

6. The magnetic locking system according to claim 1, wherein said first block and said second block are made of the same ferro-magnetic material.

7. The magnetic locking system according to claim 1, wherein said first and second blocks are made of iron, and said intermediate block is made of aluminum.

8. The magnetic locking system according to claim 1, wherein said first and second blocks are made of iron, and said intermediate block is made of brass.

9. The magnetic locking system according to claim 1, wherein said ferro-magnetic member is a plate made from a material including iron.

10. The magnetic locking system according to claim 1, wherein:

said first component is a base of a miter saw; and

said second component is a miter saw table, wherein said miter saw table is configured and arranged to rotate with respect to said base.

11. The magnetic locking system according to claim 10, wherein:

said ferro-magnetic member is a plate affixed to an upper surface of said base;

said ferro-magnetic housing is affixed to a lower surface of said table; and

said switch mechanism includes a cam and an actuation beam that cooperate with each other to rotate said permanent magnet within said aperture.

12. The magnetic locking system according to claim 1, wherein:

said first component is an arm rigidly attached to a table of a miter saw; and

said second component is a bevel post attached to a saw assembly of a miter saw, wherein rotation of said bevel post with respect to said arm angles the saw assembly with respect to the table in order to enable bevel cuts.

14. The magnetic locking system according to claim 10, wherein:

said ferro-magnetic member is a plate affixed to an upper surface of said base; and

said electromagnet is affixed to a lower surface of said table.

13. A magnetic locking system for releasably locking a first component to a second component, said locking system comprising:

a ferro-magnetic member associated with the first component;

an electromagnet attached to the second component and positioned adjacent said ferro-magnetic member; and

a circuit for providing current to said electromagnet, including a power source and a switch,

wherein said first component is a base of a miter saw, and

further wherein said second component is a miter saw table, wherein said miter saw table is configured and arranged to rotate with respect to said base.