Patent ID: 7223195
Filing Date: 2007-05-29
Classification: B23B,B23Q,B25B,B25F,F16H

Abstract:
1. A portable power tool, comprising: a housing having a first portion and a second portion, the first portion defining a handle for carrying the portable power tool; a motor received in the second portion of the housing, the motor having a motor output member; a trigger coupled to the housing, the trigger being movable to activate the motor; a driven member; and a transmission assembly coupled to the housing and 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 assembly having a plurality of planetary transmission stages, each of the planetary transmission stages including a ring gear and a set of planet gears meshingly engaged with the ring gear, wherein at least one member of the transmission assembly may be configured in a first condition, which renders at least one of the planetary transmission stages operable in an active mode, and a second condition, which renders at least one of the planetary transmission stages operable in an inactive mode, wherein the transmission assembly is operable in at least three overall speed reduction ratios, wherein at least three planetary transmission stages transmit torque in sequence between the motor output member and the driven member in each overall speed reduction ratio and wherein the ring gear associated with each of the at least three planetary transmission stages is not meshingly engaged to the set of planet gears of another of the at least three planetary transmission stages; wherein the transmission assembly further includes a speed selector having only one switch member, the only one switch member forming a portion of an exterior of the portable power tool and being slidably movable between a first position, a second position and a third position, the at least one member of the transmission assembly being coupled to the only one switch member and at least one of the plurality of planetary transmission stages, the at least one member of the transmission assembly being movable in response to movement of the only one switch member to cause the plurality of planetary transmission stages to cooperatively operate in one of the overall speed reduction ratios that corresponds to an associated one of the positions in which the only one switch member is disposed; wherein at least two of the planetary transmission stages are operable in the active mode for performing a speed reduction and torque multiplication operation and in at least one of the at least three overall speed reduction ratios.