Patent ID: 8354909
Filing Date: 2013-01-15
Classification: G09F,H01F,Y10T

Abstract:
1. A detachable cover attachment system comprising: a base structure; and a removable cover, said removable cover capable of being attached to said base structure by magnetic force interaction between said base structure and said removable cover; said base structure comprising a base structure attachment section, said base structure attachment section comprising a first plurality of magnetic field sources, said first plurality of magnetic field sources having a plurality of north magnetic polarities and a plurality of south magnetic polarities, said base structure attachment section having at least one base structure non-magnetic region disposed between at least two magnetic field sources of said first plurality of magnetic field sources, wherein said base structure non-magnetic region does not substantially produce a magnetic field; and said removable cover comprising a cover attachment section, said cover attachment section comprising a second plurality of magnetic field sources, said second plurality of magnetic field sources having a plurality of north magnetic polarities and a plurality of south magnetic polarities, said cover attachment section comprising at least one cover attachment non-magnetic region disposed between at least two magnetic field sources of said second plurality of magnetic field sources, wherein said cover attachment non-magnetic region does not substantially produce a magnetic field, said base structure attachment section and said cover attachment section being movable relative to each other along a linear range of positions corresponding to a linear spatial force function, said linear spatial force function for said linear range of positions comprising one and only one peak attract spatial force and a plurality of off-peak spatial forces, said plurality of off-peak spatial forces having a greatest off-peak spatial force, wherein said peak attract spatial force for said linear range of positions is between three and five times the greatest off-peak spatial force.