Rotary motion control device

A fishing reel comprising:

• a) a reel housing;
• b) a spool, said spool rotatably supported within said housing;
• and
• c) a brake, said brake rotor comprising a rotor connected to said spool and rotatable therewith, a magnetorheological material, said magnetorheological material is in contact with said rotor, a first set of magnets having alternating magnetic orientation, a second set of magnets having alternating magnetic orientation, said first and second sets of magnets are adapted for selective alignment with respect to each other so that said magnetic orientation of one of said first and second magnet sets may be repositioned relative to the other of said first and second magnet sets to modulate the overall field strength of said magnetic sets and cause a change in the viscosity of said magnetorheological material whereby the shearing force on said rotor is increased or decreased and said spool is selectively braked.

A method for controlling the rotary motion of a rotating member, comprising the steps of:

• a) immersing the rotary member in a magnetorheological material;
• b) providing a plurality of permanent magnets;
• c) subjecting the magnetorheological material to a magnetic field generated by the magnets;
• and
• d) varying the position of the magnets relative to each other to modify the magnetic field strength in the magnetorheological material thereby changing the viscosity of the magnetorheological material to increase or decrease the drag of the magnetorheological material on the rotating member.