IP Library › Granted Patent US 12,569,961
Granted Patent B2
US 12,569,961 · App. 17/863,610 · Granted Mar 10, 2026

Impact tool anvil with improved detent pin

Inventor: Zhipeng Dai (Dongguan, CN)
Assignee: MILWAUKEE ELECTRIC TOOL CORPORATION
B25B23/0035B25B21/02F16B2/16
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Quick Facts
Patent No.
US 12,569,961
App. No.
17/863,610
Granted
Mar 10, 2026
Kind
B2
Abstract

An impact tool includes a housing, an anvil extending from the housing, a tool element removably coupled to the anvil, a drive assembly to impart rotational impacts to the anvil, and a detent system supported by the anvil. The detent system includes a detent pin defining a longitudinal center axis and having a notch disposed on only one side of a longitudinal mid-plane containing the longitudinal center axis, and a retaining pin received within the notch. The detent pin is movable relative to the anvil between an extended position and a retracted position, the detent pin is configured to engage the tool element to retain the tool element on the anvil when the detent pin is in the extended position, the detent pin is biased toward the extended position, and the retaining pin engages an end of the notch to limit movement of the detent pin to the extended position.

Claims (52)

1 . An impact tool comprising:

a housing;

an anvil extending from the housing;

a tool element removably coupled to the anvil;

a drive assembly configured to impart rotational impacts to the anvil;

a detent system supported by the anvil, the detent system including:

a detent pin defining a longitudinal center axis and having a notch disposed on only one side of a longitudinal mid-plane containing the longitudinal center axis, the notch including a first surface extending parallel to the longitudinal center axis, a second surface extending along a first lateral edge of the first surface and therefrom at an oblique angle, and a third surface extending along a second lateral edge of the first surface and therefrom at an oblique angle opposite the second surface, and

a retaining pin received within the notch,

wherein the detent pin is movable relative to the anvil between an extended position and a retracted position,

wherein the detent pin is configured to engage the tool element to retain the tool element on the anvil when the detent pin is in the extended position,

wherein the detent pin is biased toward the extended position,

wherein the retaining pin engages an end of the notch to limit movement of the detent pin to the extended position,

wherein the second surface and the third surface extend from the first surface toward the longitudinal mid-plane, and

wherein the first surface, the second surface, and the third surface extend parallel to the longitudinal center axis.

2 . The impact tool of claim 1 , further comprising a motor supported within the housing, wherein the drive assembly is configured to convert a continuous rotational input from the motor into the rotational impacts imparted to the anvil.

3 . The impact tool of claim 2 , further comprising a battery pack configured to supply electrical power to the motor.

4 . The impact tool of claim 1 , wherein the detent system includes a spring configured to bias the detent pin toward the extended position.

5 . The impact tool of claim 1 , wherein the retaining pin is resiliently deformable to bias the detent pin toward the extended position.

6 . The impact tool of claim 5 , wherein the retaining pin is hollow.

7 . The impact tool of claim 6 , wherein the retaining pin includes a slot extending through a wall of the retaining pin.

8 . The impact tool of claim 1 , wherein the second surface and the third surface define an included angle between 90 degrees and 150 degrees.

9 . The impact tool of claim 1 , wherein the first surface, the second surface, and the third surface are curved at the end of the notch.

10 . The impact tool of claim 1 , wherein the detent pin includes a surface hardness and a core hardness, and wherein the surface hardness is greater than the core hardness.

11 . An impact tool comprising:

a housing;

an anvil extending from the housing;

a tool element removably coupled to the anvil;

a drive assembly configured to impart rotational impacts to the anvil;

a detent system supported by the anvil, the detent system including:

a detent pin defining a longitudinal center axis and having a notch, and

a retaining pin received within the notch,

wherein the detent pin is movable along the longitudinal center axis relative to the anvil between an extended position and a retracted position,

wherein the detent pin is configured to engage the tool element to retain the tool element on the anvil when the detent pin is in the extended position,

wherein the retaining pin is resiliently deformable to bias the detent pin toward the extended position,

wherein the notch includes a first surface, a second surface extending along a first lateral edge of the first surface and therefrom at an oblique angle, and a third surface extending along a second lateral edge of the first surface and therefrom at an oblique angle opposite the second surface, an upper edge, and a lower edge, and

wherein the first surface, the second surface, and the third surface extend parallel to the longitudinal center axis between the upper edge and the lower edge of the notch.

12 . The impact tool of claim 11 , further comprising a motor supported within the housing; and a battery pack configured to supply electrical power to the motor, wherein the drive assembly is configured to convert a continuous rotational input from the motor into the rotational impacts imparted to the anvil.

13 . The impact tool of claim 12 , wherein the retaining pin is hollow.

14 . The impact tool of claim 13 , wherein the retaining pin includes a slot extending through a wall of the retaining pin.

15 . The impact tool of claim 11 , wherein the second surface and the third surface define an included angle between 90 degrees and 150 degrees, and wherein the first surface, the second surface, and the third surface are curved at an end of the notch.

16 . An anvil configured to receive impacts from a hammer of an impact tool, the anvil comprising:

a plurality of anvil lugs configured to receive impacts from the hammer;

a driving end portion configured to receive a tool element thereon, the driving end portion including a bore;

a detent pin received within the bore and defining a longitudinal center axis, the detent pin having a notch disposed on only one side of a longitudinal mid-plane containing the longitudinal center axis, wherein the notch has a beveled configuration, and

a retaining pin received within the notch,

wherein the detent pin is movable relative to the anvil between an extended position and a retracted position,

wherein the detent pin is biased toward the extended position,

wherein the retaining pin engages an end of the notch to limit movement of the detent pin to the extended position,

wherein the notch includes a first surface, a second surface extending along a first lateral edge of the first surface and therefrom at an oblique angle, and a third surface extending along a second lateral edge of the first surface and therefrom at an oblique angle opposite the second surface,

wherein the notch defines a first end and a second end, and

wherein the first surface, the second surface, and the third surface extend longitudinally between the first end and the second end of the notch.

17 . The anvil of claim 16 , wherein the first surface, the second surface, and the third surface extend parallel to the longitudinal center axis, wherein the second surface and the third surface define an included angle between 90 degrees and 150 degrees, and wherein the first surface, the second surface, and the third surface are curved at the end of the notch.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 28, 2022
From: DAI, ZHIPENG
To: TECHPOWER ENGINEERING (DONGGUAN) COMPANY LIMITED
Reel/Frame 061246/0995 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 28, 2022
From: TECHPOWER ENGINEERING (DONGGUAN) COMPANY LIMITED
To: MILWAUKEE ELECTRIC TOOL CORPORATION
Reel/Frame 061247/0083 →
Priority Claims (1)
CN 202121592187.0 · Jul 13, 2021 · national
Continuity (1)
Related Publication 20230013436A1 · Jan 19, 2023
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