Power tool having hammer mechanism

A power tool configured to linearly reciprocally drive a tool accessory along a driving axis to perform a hammering operation and to rotationally drive the tool accessory around the driving axis to perform a drilling operation, the power tool comprising:

• a housing;
• a motor having a motor shaft;
• a final output shaft configured to removably hold the tool accessory;
• a first intermediate shaft that rotates together with rotation of the motor shaft around an axis parallel to the driving axis, the first intermediate shaft being immovable relative to the housing in a direction parallel to the driving axis;
• a hollow shaft disposed coaxially around the first intermediate shaft and being selectively rotatable together with the first intermediate shaft;
• a rotary body disposed coaxially around the hollow shaft and being rotatable together with the hollow shaft;
• an oscillating member operably coupled with the rotary body and configured to generate linear reciprocating motion in response to rotation of the rotary body;
• an engagement member coupled with the first intermediate shaft so as to rotate together with the first intermediate shaft, the engagement member being movable relative to the first intermediate shaft in parallel to the driving axis between an engagement position and a disengagement position, the engagement member being engaged with the hollow shaft in the engagement position and being disengaged from the hollow shaft in the disengagement position;
• and
• a movable support supporting the final output shaft, the rotary body and the oscillating member within the housing and being biased by at least one elastic member;
• wherein:
• the hollow shaft is immovable relative to the housing in the direction parallel to the driving axis, and
• the movable support, the rotary body, and the oscillating member are movable relative to the hollow shaft in the direction parallel to the driving axis.

A power tool, comprising:

• a housing;
• a motor having a motor shaft that is rotatable about a first axis;
• an output shaft configured to removably hold a tool accessory and having a driving axis;
• a first intermediate shaft configured to be rotated by the motor shaft around a second axis that is parallel to the driving axis;
• a driving mechanism configured to rotationally drive the output shaft around the driving axis using rotational motion from the motor shaft, the driving mechanism including a motion converting mechanism configured to convert rotational motion of the first intermediate shaft into reciprocating linear motion to axially hammer the output shaft along the driving axis;
• an intervening member disposed between the first intermediate shaft and the motion converting mechanism;
• a transmitting member configured to rotate together with the first intermediate shaft around the second axis and to be axially movable relative to the first intermediate shaft in a direction of the second axis;
• a movable support that supports the output shaft and the motion converting mechanism within the housing such that the movable support, the output shaft and the driving mechanism are movable together as a movable unit relative to the housing in a direction parallel to the driving axis;
• and
• at least one elastic member biasing the movable support in the direction parallel to the driving axis;
• wherein:
• the motor shaft is immovable relative to the housing in a direction of the first axis;
• the first intermediate shaft and the intervening member are immovable relative to the housing in the direction of the second axis;
• the transmitting member is axially movable relative to the first intermediate shaft in the direction of the second axis between an engagement position and a disengagement position;
• in the engagement position, the transmitting member is engaged with the intervening member such that rotation of the first intermediate shaft causes the intervening member to rotate;
• in the disengagement position, the transmitting member is disengaged from the intervening member such that rotation of the first intermediate shaft is not transmitted to the intervening member and thus the first intermediate shaft is rotatable relative to the intervening member;
• and
• the motion converting mechanism includes a rotary body coupled to the intervening member such that the rotary body and the intervening member rotate together, the rotary body being movable with the movable unit relative to the intervening member in the direction parallel to the driving axis.