Power tool
AssigneeMakita Corporation
InventorAkira Naito
Life of this patent
Estimating the term…
Abstract
A power tool is less likely to generate noise. A power tool includes a housing, a field fixed to the housing and including a field coil, an armature rotatable relative to the field and including a commutator, two brushes that come in contact with the commutator, and a brush holder unit holding the two brushes. The brush holder unit includes two contact rails electrically connectable to the field coil, two first terminals that each come in contact with either of the two contact rails, two second terminals each electrically connectable to a corresponding brush of the two brushes, and a choke coil located between at least one of the two first terminals and at least one of the two second terminals.
Claims17
A power tool, comprising:
- a housing;
- a stator fixed to the housing, the stator including a field coil;
- an armature rotatable relative to the stator, the armature including a commutator;
- two brushes configured to come in contact with the commutator;
- and
- a brush holder unit holding the two brushes, the brush holder unit including
- a stationary housing,
- two contact rails held by the stationary housing and electrically connectable to the field coil, each of the contact rails including
- a rail portion being arc-shaped, and
- a terminal portion intersecting with the rail portion,
- a movable housing holding the two brushes and movable relative to the stationary housing,
- two first terminals held by the movable housing, each of the two first terminals being configured to come in contact with either of the two contact rails in response to movement of the movable housing,
- two second terminals held by the movable housing, each of the two second terminals being electrically connectable to a corresponding brush of the two brushes, and
- a choke coil located between at least one of the two first terminals and at least one of the two second terminals,
- wherein
- each of the two contact rails includes an arch to come in contact with the either of the two first terminals,
- the stationary housing includes a rectangular portion, and
- the terminal portion includes a distal end received in the rectangular portion.
Dependencies are inferred from the claim text.