Patent ID: 8707626

Claim:
A system comprising: a panel retained in a track allowing substantially horizontal movement of the panel along a predetermined path, the panel having an upper surface with a longitudinal cavity therein; a channel having a C-shaped profile is disposed within the longitudinal cavity of the panel, the channel holding a plurality of permanent magnets therein; an elongate ferromagnetic plate disposed above the channel and parallel to, the the track of the panel; a plurality of springs disposed in the cavity between the panel and the channel, the plurality of springs biasing the plurality of permanent magnets toward the ferromagnetic plate; and wherein the channel includes a plurality of lugs on a bottom surface thereof, a plurality of manually operated clamps each having a curved arm that passes through a respective one of said lugs to control a distance between the plurality of magnets and the ferromagnetic plate by releasably compressing said plurality of springs to move the channel within the cavity.