摘要 |
This invention relates to a magnetic tensioning device comprising a rotatable outer housing and a magnetic assembly positioned in the interior of the outer housing. A space is provided between the outer housing and the magnetic assembly. A plurality of magnetic particles are positioned in the space between the magnetic assembly and the outer housing. The magnetic particles are held in place by the magnetic flux from the magnetic assembly and the magnetic particles magnetically couple the magnetic assembly and the outer housing. Means for varying the size of the space between the magnetic assembly and the outer housing is provided. The varying of the size of the space varies the magnetic flux from the magnetic assembly and changes the magnetic coupling between the magnetic assembly and the outer housing.
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