Power tool gear-train and torque overload clutch therefor

A hand-held motor driven power tool, comprising:

• a motor housing having a front end and a rear end,
• a motor disposed in the motor housing and having a motor spindle driven by the motor during use,
• a gear box having a gear box front end and a gear box rear end, the gear box rear end proximate to the motor housing front end,
• a gear train disposed in the gear box and including an input gear connected to the motor spindle, an output spindle for driving a tool bit, and at least one gear reduction between the input gear and the output spindle arranged so that, during use, the output rotates at a higher or lower rate relative to the motor spindle,
• a clutch mechanism arranged to interrupt drive between the motor and the output spindle when a torque force applied to the output spindle exceeds a predetermined threshold,
• a manually operable dial connected to the clutch mechanism for varying the threshold at which drive is interrupted;
• and
• wherein the dial is located between the motor housing front end and the gear box rear end.

A hand-held motor driven power tool, comprising:

• a motor housing,
• a motor disposed in the motor housing and having a motor spindle driven by the motor during use,
• a gear box located forward of the motor housing,
• a planetary gear train disposed in the gear box and including an input gear connected to the motor spindle, an output spindle for driving a tool bit, a first stage ring gear and a second stage ring gear located between the input gear and the output spindle,
• a clutch means for interrupting drive between the motor and the output spindle when a torque force applied to the output spindle exceeds a predetermine threshold,
• a manually operable clutch adjustment means for varying the threshold at which drive is interrupted;
• and
• wherein the clutch adjustment means is located between the motor housing and the second stage ring gear.