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A multi-speed transmission assembly for a rotary power tool. The transmission assembly includes a plurality of transmission stages, with at least two of the transmission stages employing a movable reduction element that permits the transmission stage to be operated in an active mode and an inactive

A multi-speed transmission assembly for a rotary power tool. The transmission assembly includes a plurality of transmission stages, with at least two of the transmission stages employing a movable reduction element that permits the transmission stage to be operated in an active mode and an inactive mode. The movable reduction elements are coupled to a switching mechanism that switches the reduction elements in a predetermined manner to provide at least three-gear reduction or speed ratios.

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What is claimed is: 1. A portable power tool comprising: a housing; a motor; a driven member; and a multi-stage transmission at least partially received in the housing, the multi-stage transmission receiving torque from the motor and outputting torque to the driven member, the multi-stage transmiss

What is claimed is: 1. A portable power tool comprising: a housing; a motor; a driven member; and a multi-stage transmission at least partially received in the housing, the multi-stage transmission receiving torque from the motor and outputting torque to the driven member, the multi-stage transmission having a first gear set, a second gear set and a third gear set, the first gear set including a planet carrier and a plurality of planet gears, the planet carrier rotatably supporting the plurality of planet gears, the second gear set including a ring gear that is not in meshing engagement with the planet gears of the first gear set, the third gear set having a ring gear; wherein the multi-stage transmission is operable in at least three overall gear ratios, wherein the ring gear of the third gear set may be selectively non-rotatably coupled to the housing to inhibit relative rotation therebetween, wherein the ring gear of the second gear set may be selectively non-rotatably coupled to the housing to inhibit relative rotation therebetween, and wherein the ring gear of the second gear set may be selectively coupled to the planet carrier of the first gear set for rotation therewith. 2. The portable power tool of claim 1, wherein the third ring gear is movable between a position where it is non-rotatably coupled to the housing and an opposite position where it may rotate relative to the housing. 3. The portable power tool of claim 1, wherein the second ring gear is movable between a position where it is non-rotatably coupled to the housing and an opposite position where it meshingly engages the planet carrier of the first gear set. 4. The portable power tool of claim 1, wherein torque is transmitted from a first one of the first, second and third gear sets to a second one of the first, second and third gear sets and then to a remaining one of the first, second and third gear sets. 5. The portable power tool of claim 1, further comprising a switch for changing an overall gear ratio in which the multi-stage transmission is operating. 6. The portable power tool of claim 5, wherein the switch includes a wire clip that is configured to translate about a longitudinal axis of the multi-stage transmission to effect a change in the overall gear ratio in which the multi-stage transmission is being operated, wherein translation of the wire clip is employed to non-rotatably couple the ring gear of the second gear set to the housing and to couple the ring gear of the second gear set to the planet carrier of the first gear set. 7. The portable power tool of claim 6, wherein the wire clip includes a body portion that extends outwardly about a portion of the ring gear of the second gear set. 8. The portable power tool of claim 1, wherein the multi-stage transmission further includes a transmission sleeve which is coupled to the housing, at least a portion of the second gear set being disposed in the transmission sleeve, the transmission sleeve having an interior surface with a plurality of teeth that form a torque transmission path that is employed to non-rotatably couple the ring gear of the second gear set to the housing. 9. The portable power tool of claim 8, wherein the plurality of teeth on the interior surface of the transmission sleeve form another torque transmission path that is employed to non-rotatably couple the ring gear of the third gear set to the housing. 10. The portable power tool of claim 1, further comprising a wire clip that is configured to translate about a longitudinal axis of the multi-stage transmission to effect a change in an overall gear ratio in which the multi-stage transmission is being operated, wherein translation of the wire clip is employed to non-rotatably couple the ring gear of the second gear set to the housing and to couple the ring gear of the second gear set to the planet carrier of the first gear set. 11. The portable power tool of claim 10, wherein the transmission sleeve includes a pair of slotted apertures, each of the slotted apertures being configured to receive therethrough an associated tab that is formed on the wire clip. 12. The portable power tool of claim 11, wherein the tabs are configured to transmit a manual input applied to an actuator of a speed selector that is located on an exterior side of the transmission sleeve to a portion of the multi-stage transmission on an interior side of the transmission sleeve. 13. A portable power tool, comprising: a housing; a motor having a motor output member; a driven member; a transmission in the housing, the transmission being configured to receive a rotary input from the motor output member and to produce a rotary output that is transmitted to the driven member, the transmission having a plurality of planetary transmission stages, wherein a member of the transmission may be axially positioned between a first condition, in which at least one of the planetary transmission stages is operable in an active mode, and a second condition, in which at least one of the planetary transmission stages is operable in an inactive mode, and wherein the transmission is operable in at least three overall speed reduction ratios, at least three planetary pear reductions transmitting torque between the motor output member and the driven member in each of the at least three overall speed reduction ratios; and a speed selector having a switch and an actuator, the switch being coupled to the housing, a portion of the switch forming a portion of an exterior surface of the portable power tool so as to be manipulate-able by a user of the portable power tool, the actuator engaging the member of the transmission and moving the member of the transmission in a predetermined manner in response to movement of the switch. 14. The portable power tool of claim 13, wherein the switch permits the transmission of the portable power tool to be selectively operated in one of only three overall speed reduction ratios. 15. The portable power tool of claim 13, wherein the member is an annular structure having a plurality of internal teeth that meshingly engage teeth formed onto a planet carrier associated with one of the plurality of planetary transmission stages when the at least one of the planetary transmission stages is in the inactive mode. 16. The portable power tool of claim 15, wherein the annular structure includes a plurality of external teeth that meshingly engage teeth formed onto the housing when the at least one of the planetary transmission stages is in the active mode. 17. The portable power tool of claim 15, wherein the annular structure is a ring gear associated with a single one of the plurality of planetary transmission stages. 18. The portable power tool of claim 13, wherein the switch is slidably coupled to the housing. 19. The portable power tool of claim 18, wherein the actuator includes a selector body that is configured to rotate in response to movement of the switch. 20. The portable power tool of claim 13, wherein the actuator includes at least one wire clip, the wire clip extending at least partially about the member. 21. The portable power tool of claim 20, wherein the wire clip has a half-moon portion and a pair of tabs that are generally perpendicular to the half-moon portion. 22. The portable power tool of claim 21, wherein the member includes a circumferentially extending groove into which the half-moon portion is disposed. 23. The portable power tool of claim 21, wherein the tabs are coupled to the switch. 24. The portable power tool of claim 23, wherein the actuator includes a cam slot into which the tabs are disposed. 25. A power tool comprising a housing, a motor for driving an output spindle through a multi-speed transmission, and a speed selector, the transmission providing at least three planetary gear reductions between the motor and the output spindle and being selectively operated in at least three speed ratios, each planetary gear reduction including a ring gear, at least two of the ring gears being axially translatable between a first position and a second position, the speed selector engaging the transmission to selectively provide at least three of the following operating conditions: a first one of the ring gears is maintained in the first position and a second one of the ring gears is maintained in the first position; the first one of the ring gears is maintained in the first position and the second one of the ring gears is maintained in the second position; the first one of the ring gears is maintained in the second position and the second one of the ring gears is maintained in the first position; and the first one of the ring gears is maintained in the second position and the second one of the ring gears is maintained in the second position. 26. The power tool of claim 25, wherein a plurality of teeth are formed about the exterior of the first one of the ring gears. 27. The power tool of claim 25, wherein the second one of the ring gears does not rotate relative to the housing when maintained in the first position and rotates relative to the housing when maintained in the second position. 28. The power tool of claim 27, wherein the second one of the ring gears is meshingly engaged to a planet carrier when maintained in the second position. 29. The power tool of claim 25, wherein the first one of the ring gears meshingly engages planet gears associated with one of the planetary gear reductions when the first one of the ring gears is maintained in the first position, and wherein the first one of the ring gears meshingly engages an element in another one of the planetary gear reductions when the first one of the ring gears is maintained in the second position. 30. The power tool of claim 29, wherein the element in the another one of the planetary gear reductions is a planet carrier.