Patent ID: 11858100
Assignee: MILWAUKEE ELECTRIC TOOL CORPORATION
Field: Machine tools (Mechanical engineering)
Classification: CPC B | IPC B

Claim 9:
10. An impact power tool adapted to impart axial impacts to a tool bit, the impact power tool comprising:
a housing;
a motor supported by the housing, the motor defining a motor axis;
a spindle coupled to the motor for receiving torque from the motor to cause the spindle to rotate;
a reciprocating impact mechanism that is operable to create a variable pressure air spring within the spindle, the impact mechanism including
a piston that reciprocates along a reciprocation axis to induce the variable pressure air spring, and
a crankshaft configured to convert continuous rotational motion from the motor to reciprocating linear movement of the piston, the crankshaft defining a crank axis that is perpendicular to the motor axis;
a transmission that transfers rotation from the motor to the spindle, the transmission including an intermediate shaft having a first gear engaged with a second gear supported on the spindle to transfer rotation to the spindle, the intermediate shaft defining a rotational axis that is parallel with the crank axis; and

a mode selection member rotatable to switch an operation of the impact power tool between a first mode, in which, the motor is drivably coupled to the piston for reciprocating the piston and rotating the spindle, a second mode, in which, the motor is decoupled from the piston but the spindle is rotated, and a third mode, in which, the motor is drivably coupled to the piston for reciprocating the piston but the spindle does not rotate;
wherein a center of gravity of the impact tool is positioned between the crank axis and the rotational axis.