IP Library Granted Patent US 12,544,902
Granted Patent B2
US 12,544,902 · App. 18/855,559 · Granted Feb 10, 2026

Electric tool

Inventors: Hidenori Shimizu (Shiga, JP); Shinji Seko (Mie, JP); Takashi Kusagawa (Osaka, JP)
Assignee: PANASONIC HOLDINGS CORPORATION
B25F5/02B25F5/001B25B21/02
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Quick Facts
Patent No.
US 12,544,902
App. No.
18/855,559
Granted
Feb 10, 2026
Kind
B2
Abstract

An electric tool includes an output shaft, a drive shaft, a transmission mechanism, a plurality of bearings, and a seal member. The plurality of bearings are aligned in an axial direction of the output shaft and rotatably support the output shaft. The seal member has a through hole into which the output shaft is inserted. The seal member is disposed, in at least one space of spaces each sandwiched between each two adjacent bearings of the plurality of bearings, such that an inner circumferential surface of the through hole is in contact with the outer circumferential surface of the output shaft.

Claims (47)

1 . An electric tool comprising:

an output shaft including a holder configured to hold a tip tool;

a drive shaft configured to be rotated by a driver;

a transmission mechanism disposed between the drive shaft and the output shaft to transmit rotation of the drive shaft to the output shaft;

a plurality of bearings aligned in an axial direction of the output shaft to rotatably support the output shaft; and

a seal member having a through hole in which the output shaft is inserted, the seal member being disposed, in at least one space of spaces each between two adjacent bearings of the plurality of bearings, such that an inner circumferential surface of the through hole is in contact with an outer circumferential surface of the output shaft.

2 . The electric tool of claim 1 , further comprising: a housing in which at least part of the output shaft is housed, wherein

the housing supports the plurality of bearings.

3 . The electric tool of claim 2 , wherein the seal member is configured to suppress a foreign substance present outside the housing from entering the housing.

4 . The electric tool of claim 2 , wherein

the seal member is configured to suppress a lubricant agent present in the housing from leaking out of the housing.

5 . The electric tool of claim 2 , wherein

the transmission mechanism includes

a hammer fitted to an outer circumferential surface of the drive shaft such that the hammer is rotatable and is movable forward and backward, the hammer including a plurality of hammer projections and

an anvil including a plurality of anvil projections engageable with the plurality of hammer projections, the anvil being mechanically connected to the output shaft.

6 . The electric tool of claim 2 , wherein

the seal member is made of an oil absorbing material having oil absorptiveness.

7 . The electric tool of claim 6 , wherein

the oil absorbing material is felt.

8 . The electric tool of claim 7 , further comprising a housing in which at least part of the output shaft is housed, wherein

the housing includes a projection located in the at least one space in which the seal member is disposed.

9 . The electric tool of claim 8 , wherein

a dimension of the seal member in the axial direction is smaller than a dimension of the projection in the axial direction.

10 . The electric tool of claim 2 , wherein

the seal member is made of a rubber material.

11 . The electric tool of claim 10 , further comprising a housing in which at least part of the output shaft is housed, wherein

the housing has a projection located in the at least one space in which the seal member is disposed.

12 . The electric tool of claim 1 , wherein

the transmission mechanism includes

a hammer fitted to an outer circumferential surface of the drive shaft such that the hammer is rotatable and is movable forward and backward, the hammer including a plurality of hammer projections and

an anvil including a plurality of anvil projections engageable with the plurality of hammer projections, the anvil being mechanically connected to the output shaft.

13 . The electric tool of claim 1 , wherein

the seal member is made of an oil absorbing material having oil absorptiveness.

14 . The electric tool of claim 13 , wherein

the oil absorbing material is felt.

15 . The electric tool of claim 14 , further comprising a housing in which at least part of the output shaft is housed, wherein

the housing includes a projection located in the at least one space in which the seal member is disposed.

16 . The electric tool of claim 15 , wherein

a dimension of the seal member in the axial direction is smaller than a dimension of the projection in the axial direction.

17 . The electric tool of claim 1 , wherein

the seal member is made of a rubber material.

18 . The electric tool of claim 17 , further comprising a housing in which at least part of the output shaft is housed, wherein

the housing has a projection located in the at least one space in which the seal member is disposed.

19 . The electric tool of claim 18 , wherein

a dimension of the seal member in the axial direction is greater than a dimension of the projection in the axial direction.

20 . The electric tool of claim 19 , wherein

the seal member is in contact with each of the two adjacent bearings.

Assignments (2)
NUNC PRO TUNC ASSIGNMENT Recorded Aug 6, 2026
From: PANASONIC HOLDINGS CORPORATION
To: NEXRA FIELD WORKS CO., LTD.
Reel/Frame 075549/0031 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 9, 2024
From: SHIMIZU, HIDENORI; SEKO, SHINJI; KUSAGAWA, TAKASHI
To: PANASONIC HOLDINGS CORPORATION
Reel/Frame 069518/0138 →
Priority Claims (1)
JP 2022-065394 · Apr 11, 2022 · national
Continuity (1)
Related Publication 20250262741A1 · Aug 21, 2025
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