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A magnet holder assembly for a clutch includes a magnet holder and first and second permanent magnets. The magnet holder includes a body portion, a first groove defined in the body portion, a second groove defined in the body portion adjacent to the first groove, and a flange extending from the body

A magnet holder assembly for a clutch includes a magnet holder and first and second permanent magnets. The magnet holder includes a body portion, a first groove defined in the body portion, a second groove defined in the body portion adjacent to the first groove, and a flange extending from the body portion opposite the first groove and extending in a different direction than the first groove. The flange has a connection feature for securing the magnet holder to a rotatable component of the clutch. The first permanent magnet is radially retained by the first groove in the body portion, and the first permanent magnet has a beveled edge configured to mate with the first groove. The second permanent magnet is radially retained by the second groove, and the first permanent magnet and the second permanent magnet have magnetic orientations arranged substantially opposite one another.

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1. A magnet holder assembly for an eddy current drive of a clutch, the assembly comprising: magnet holder comprising: a body portion;a first groove defined in the body portion;a second groove defined in the body portion adjacent to the first groove; anda flange extending from the body portion opposi

1. A magnet holder assembly for an eddy current drive of a clutch, the assembly comprising: magnet holder comprising: a body portion;a first groove defined in the body portion;a second groove defined in the body portion adjacent to the first groove; anda flange extending from the body portion opposite the first groove and extending in a different direction than the first groove, wherein the flange has a connection feature for securing the magnet holder to a rotatable component of the clutch;a first permanent magnet radially retained by the first groove in the body portion, wherein the first permanent magnet has a beveled edge configured to mate with the first groove; anda second permanent magnet radially retained by the second groove, wherein the first permanent magnet and the second permanent magnet have magnetic orientations arranged substantially opposite one another. 2. The assembly of claim 1, wherein the body portion of the magnet holder has a curved configuration. 3. The assembly of claim 1, wherein the flange comprises: a first portion having a generally rectangular perimeter shape, the first portion extending from an edge of the body portion; anda second portion having a generally trapezoidal perimeter shape, wherein the first portion of the flange is arranged substantially parallel to the second portion of the flange. 4. The assembly of claim 1, wherein the first groove comprises a dovetail shaped groove in the body portion of the magnet holder. 5. The assembly of claim 1 and further comprising: a first retention feature on the flange for radially retaining the magnet holder assembly relative to the clutch. 6. The assembly of claim 5, wherein the first retention feature is a substantially cylindrical pin-like member extending from the flange. 7. The assembly of claim 5 and further comprising: a second retention feature on the flange, wherein the second retention feature is spaced from the first retention feature. 8. The assembly of claim 1 and further comprising: a stop located on the body portion of the magnet holder, wherein the first permanent magnet includes a locating feature configured for cooperative engagement with the stop, and wherein the locating feature is positioned relative to the magnetic poles of the first permanent magnet such that cooperative engagement of the locating feature and the stop ensures that the first permanent magnet has a first magnetic orientation relative to the magnet holder. 9. The assembly of claim 1, wherein the first and second grooves in the body portion of the magnet holder each extend in a substantially axial direction. 10. The assembly of claim 1, wherein an adhesive secures the first permanent magnet within the first groove in the magnet holder. 11. A clutch apparatus comprising: a rotatable input member;a spring housing rotatably fixed to the input member;a cover rotatably mounted relative to the input and axially moveable relative to the input, wherein at least a portion of the cover comprises a material capable of conducting eddy currents;a first magnet holder removably attached to the spring housing and rotatably fixed thereto, the first magnet holder defining a first radial retention groove;a first permanent magnet carried by the first radial retention groove in the magnet holder, wherein the first radial retention groove restricts movement of the first permanent magnet in a radial direction while providing a magnet access passage in another direction through which the first permanent magnet can pass, and wherein the first permanent magnet is positioned in an opposing relationship relative to the material of the cover capable of conducting eddy currents; andan adhesive securing the first permanent magnet within the first radial retention groove of the first magnet holder for limiting movement through the magnet access passage,wherein axial movement of the cover selectively engages and disengages a frictional torque coupling between cover and the input member, andwherein in a frictionally disengaged axial position the cover is configured to rotate with the input by way of an eddy current coupling at a speed different from that provided by the frictional torque coupling. 12. The clutch apparatus of claim 11, the first magnet holder comprising: a body portion, wherein the first radial retention groove is defined in the body portion, and wherein the body portion of the first magnet holder has a curved configuration; anda flange extending from the body portion opposite the first radial retention groove, wherein the flange has a connection feature for securing the first magnet holder to the spring housing. 13. The clutch apparatus of claim 12, wherein the flange comprises: a first portion having a generally rectangular perimeter shape, the first portion extending from an edge of the body portion; anda second portion having a generally trapezoidal perimeter shape, wherein the first portion of the flange is arranged substantially parallel to the second portion of the flange. 14. The clutch apparatus of claim 13, the spring housing further comprising: a first inset, wherein the flange of the first magnet holder engages the first inset to attach the first magnet holder to the spring housing. 15. The clutch apparatus of claim 14, wherein the first inset is located at an outer diameter portion of the spring housing and has a first portion and a second portion, wherein the second portion of the inset extends between opposite faces of the spring housing, the second portion of the inset having a shape corresponding to that of the second portion of the flange of the first magnet holder, and wherein the first portion of the inset is located adjacent to the second portion of the inset and is configured as a recess at one face of the spring housing, the first portion of the inset having a shape corresponding to that of the first portion of the flange of the first magnet holder. 16. The clutch apparatus of claim 11 and further comprising: a piston axially moveable with respect to the spring housing as a function of fluid pressure in an adjacent fluid chamber, wherein the cover is secured to the piston to axially move therewith, and wherein a spring is operatively engaged between the spring housing and the piston. 17. The clutch apparatus of claim 11, wherein the first radial retention groove comprises a dovetail shaped groove in the body portion of the first magnet holder, and wherein the first permanent magnet has a shape that corresponds to that of the first radial retention groove. 18. The clutch apparatus of claim 11 and further comprising: a first retention feature on one of the spring housing and the flange of the first magnet holder, wherein the first retention feature is a pin member extending from the flange; andan opening on the other of the spring housing and the flange of the first magnet holder, wherein the first retention feature extends at least partially into the opening for radially retaining the first magnet holder assembly relative to the spring housing. 19. The clutch apparatus of claim 18 and further comprising: a fastener engaged between the flange of the first magnet holder and the spring housing. 20. The clutch apparatus of claim 11 and further comprising: a stop located on the body portion of the magnet holder, wherein the first permanent magnet includes a locating feature configured for cooperative engagement with the stop when the first permanent magnet is engaged with the first groove only when the first permanent magnet is arranged with a first magnetic orientation. 21. The clutch apparatus of claim 11 and further comprising: a second radial retention groove defined in the body portion of the first magnet holder adjacent to the first radial retention groove; anda second permanent magnet engaged with the second radial retention groove, wherein the first permanent magnet and the second permanent magnet have magnetic orientations arranged substantially opposite one another. 22. The clutch apparatus of claim 11 and further comprising: a second magnet holder removably attached to the spring housing and rotatably fixed thereto, wherein the second magnet holder is circumferentially spaced from the first magnet holder, and wherein the second magnet holder carries one or more additional permanent magnets. 23. The clutch apparatus of claim 11, wherein the portion of the cover that comprises the material capable of conducting eddy currents is arranged radially outward from the first permanent magnet such that the cover at least partially surrounds the first magnet holder. 24. The clutch apparatus of claim 11, wherein the first radial retention groove of the first magnet holder extends in a generally axial direction. 25. A two-speed retro-fit kit for use with an on/off friction clutch that includes a rotatable input member, an existing spring housing rotatably fixed to the input member, a spring for biasing the spring housing, and an existing cover rotatably mounted relative to the input and axially moveable relative to the input, the kit comprising: a replacement spring housing for replacing the existing spring housing of the clutch, wherein the replacement spring housing includes a plurality of insets circumferentially spaced from one another;a plurality of magnet holder assemblies each comprising: a body portion;a first radial retention groove defined in the body portion;a second radial retention groove defined in the body portion adjacent to the first radial retention groove;a flange extending from the body portion, wherein the flange has a connection feature for securing the first magnet holder to the replacement spring housing at the first inset;a first permanent magnet engaged with the first radial retention groove in the body portion; anda second permanent magnet engaged with the second radial retention groove in the body portion, wherein magnetic orientations of the first permanent magnet and the second permanent magnet are arranged to be opposite one another; anda replacement cover with a least a portion comprising a material that conducts eddy currents positioned near the first and second permanent magnets to transmit torque between the spring housing and the cover through an eddy current rotational engagement whenever the clutch is frictionally disengaged. 26. A method for converting an on/off clutch to a two-speed clutch, the method comprising: removing an existing output member;removing an existing spring housing;attaching a new spring housing having an inset to an existing input member;attaching a first magnet holder to the new spring housing, wherein the first magnet holder carries a first permanent magnet; andinstalling a new output member so as to be rotatable and axially moveable relative to the new spring housing, wherein the new output member includes a first portion positioned adjacent to the first permanent magnet, and wherein the first portion of the output member comprises the material capable of conducting eddy currents. 27. The method of claim 26, wherein an existing piston plate remains in place, and is not removed.