Patent ID: 11945091
Assignee: MAKITA CORPORATION
Field: Machine tools (Mechanical engineering)
Classification: CPC B | IPC B

Claim 8:
9. A power tool, comprising:
a motor having a rotation output;
a reducer (i) configured to reduce the rotation output from the motor and (ii) including
a preceding internal gear (i) in a preceding stage and (ii) configured to be rotatable at a first reduction ratio;
a succeeding internal gear (i) in a succeeding stage succeeding the preceding internal gear and (ii) configured to be rotatable at a second reduction ratio different from the first reduction ratio,
an engagement member (i) radially outward from the preceding internal gear and the succeeding internal gear and (ii) configured to be switchable between a first position and a second position, the first position being a position at which the engagement member is engaged with the preceding internal gear and restricts rotation of the preceding internal gear, the second position being a position at which the engagement member is engaged with the succeeding internal gear and restricts rotation of the succeeding internal gear,
at least two stages of planetary gears aligned in an axial direction, the planetary gears in the at least two stages being configured to revolve within the preceding internal gear and the succeeding internal gear,
at least two stages of carriers aligned in the axial direction, the carriers supporting the planetary gears, and
an operation unit operable to switch the engagement member selectively to either the first position or to the second position; and

an actuator configured to be actuated by the rotation reduced by the reducer, wherein
the engagement member has a middle portion that is supported and two ends that are swingable,
the engagement member, the preceding internal gear and the succeeding internal gear are configured such that:
when the engagement member is in the first position, the engagement member has a first end of the two ends engaged with an outer circumference of the preceding internal gear, and
when the engagement member is in the second position, the engagement member has a second end of the two ends engaged with an outer circumference of the succeeding internal gear,
the reducer is housed in a cylindrical case, and
the operation unit includes
an annular member (i) located rotatably on an outer circumference of the case and (ii) including a first pressing portion and a second pressing portion alternating with each other circumferentially, the first pressing portion being configured to press the first end of the engagement member from outside in a radial direction of the case to switch the engagement member to the first position, the second pressing portion being configured to press the second end of the engagement member from outside in the radial direction to switch the engagement member to the second position, and
a rotational operation member configured to rotate the annular member on the outer circumference of the case by a predetermined angle.