US 11,992,920 B2
Power tool
Kengo Tamura, Hitachinaka (JP); Junichi Toukairin, Hitachinaka (JP); and Yoshihiro Komuro, Hitachinaka (JP)
Assigned to KOKI HOLDINGS CO., LTD., Tokyo (JP)
Appl. No. 16/632,201
Filed by KOKI HOLDINGS CO., LTD., Tokyo (JP)
PCT Filed Aug. 31, 2018, PCT No. PCT/JP2018/032392
§ 371(c)(1), (2) Date Jan. 17, 2020,
PCT Pub. No. WO2019/065086, PCT Pub. Date Apr. 4, 2019.
Claims priority of application No. 2017-190508 (JP), filed on Sep. 29, 2017.
Prior Publication US 2020/0215667 A1, Jul. 9, 2020
Int. Cl. B25B 21/02 (2006.01); B25B 23/00 (2006.01)
CPC B25B 21/02 (2013.01) [B25B 23/0035 (2013.01)] 10 Claims
OG exemplary drawing
 
1. An electric tool comprising:
a housing;
a motor accommodated in the housing and rotatable;
an anvil supported by the housing and rotatable about an axis; and
an impact mechanism configured to convert a rotational force generated by the motor into a rotational impact force about the axis, and to apply the rotational impact force to the anvil;
wherein the anvil comprises:
a base portion rotatable relative to the housing;
an end bit attachment portion to which an end bit is attachable, and having a plurality of flat surface portions;
a plurality of corner portions each connecting two neighboring flat surfaces of the plurality of flat surface portions together; and
a connecting portion integrally connecting together the base portion and the end bit attachment portion, the connecting portion having:
a sloped surface portion, a diameter of the sloped surface portion being gradually reduced in a direction from the base portion toward the end bit attachment portion;
a plurality of uniform diameter surface portions, a front end of the sloped surface portion being connected to rear ends of the plurality of uniform diameter surface portions, front ends of the plurality of uniform diameter surface portions being connected to respective ones of the rear ends of the plurality of corner portions; and
a plurality of first recessed portions that are recessed from the connecting portion and arranged around a circumference of the connecting portion at positions corresponding to positions of the flat surface portions, wherein each of the first recessed portions includes:
a front curved end portion formed at a rear end of a corresponding one of the plurality of flat surface portions, the front curved end portion being positioned between two corner portions of the plurality of corner portions and having an arcuate shape having a rearmost portion positioned at a center of the front curved end portion in a leftward/rightward direction;
a rear curved end portion formed rearward of the front curved end portion; and
a curved surface portion located between the front curved end portion and the rear curved end portion,
the front curved end portion and the rear curved end portion being curved with respect to an axial direction of the anvil and aligned with respect to each other in the axial direction,
wherein the connecting portion has an outer peripheral surface portion where the plurality of recessed portions is formed, and
wherein each first recessed portion is recessed, in the axial direction from the end bit attachment portion toward the base portion, from connecting points where the first recessed portion is connected to two cross-sectional parts of the plurality of uniform diameter surface portions in a cross-section taken along a plane parallel to the flat surface portion and passing through the recessed portion.