Power tool and accessory mount device

Patent metadata

Field	Value
Publication number	US-12477978-B2
Application number	US-202217983871-A
Country	US
Kind code	B2
Filing date	Nov 9, 2022
Priority date	Mar 18, 2022
Publication date	Nov 25, 2025
Grant date	Nov 25, 2025

Abstract

A power tool and an accessory mount device are provided. The device includes a driven member, a plate, and a flyweight comprising a first flyweight portion configured to translate along the first direction and contact the plate. The flyweight includes a second flyweight portion configured to translate along the second direction. The flyweight is positioned at a hinge between the first flyweight portion and the second flyweight portion and is configured to rotate along the hinge to push the first flyweight portion to the plate and translate the plate and the driven member along the first direction toward the first end when a rotational speed threshold about the first axis is exceeded.

First claim

What is claimed is:

1 . An accessory mount device for a power tool, the device defining a first axis around which the device is rotatable and a first direction co-directional to the first axis, the device defining a first end and a second end separated along the first axis, and the device defining a second direction extending radially from the first axis, the device comprising:
a driven member; a plate; an upper housing comprising a centerbody extending along the first direction; a spring extending along the first direction through the centerbody at the upper housing; a flyweight comprising a first flyweight portion configured to translate along the first direction and contact the plate, the flyweight comprising a second flyweight portion configured to translate along the second direction, wherein the flyweight is positioned at a hinge between the first flyweight portion and the second flyweight portion, and wherein the flyweight is configured to rotate along the hinge to push the first flyweight portion to the plate and translate the plate and the driven member along the first direction toward the first end when a rotational speed threshold about the first axis is exceeded; and a flyweight latch configured to translate substantially along the second direction when a threshold speed about the first axis is exceeded.

2 . The accessory mount device of claim 1 , wherein the second flyweight portion comprises a counterweight to the first flyweight portion.

3 . The accessory mount device of claim 1 , the device comprising:
a first lug; and a second lug, wherein the first lug and the second lug comprise an interdigitated structure extending into one another.

4 . The accessory mount device of claim 3 , wherein the driven member comprises a driven member detent extending inward along the second direction toward the first axis, and wherein the driven member detent is configured to abut a first lug detent extending outward along the second direction.

5 . The accessory mount device of claim 3 , wherein the first lug and the second lug comprise substantially star-shaped structures.

6 . The accessory mount device of claim 3 , wherein the interdigitated structure comprises respective interfaces at the first lug and the second lug comprising castellations.

7 . The accessory mount device of claim 3 , wherein a detent structure extends from the second lug into an opening at the first lug.

8 . The accessory mount device of claim 3 , wherein the first lug and the second lug are positioned within the driven member and above the plate along the first direction.

9 . The accessory mount device of claim 1 , the flyweight comprising a substantially L-shaped, V-shaped, or arcuate geometry.

10 . The accessory mount device of claim 1 , the device comprising:
a lower housing into which the driven member, the plate, and the flyweight are disposed, the lower housing comprising a centerbody extending along the first direction; and a spring extending around the centerbody at the housing, wherein the lower housing contacts the spring to provide an opposing force along the first direction relative to the flyweight pushing the plate along the first direction.

11 . The accessory mount device of claim 1 , the device comprising:
a post extending along the first direction, wherein the flyweight latch is rotatably coupled to the post to allow the flyweight latch to translate substantially along the second direction.

12 . The accessory mount device of claim 11 , the device comprising:
a cap coupled to a lower housing, wherein the post extends through the cap, and wherein the spring couples to the flyweight latch, and wherein coupling of the spring and the flyweight latch fixedly retains the upper housing to the lower housing.

13 . The accessory mount device of claim 1 , wherein the spring comprises a contact portion at which the flyweight latch contacts the spring when translated substantially along the second direction.

14 . The accessory mount device of claim 1 , the flyweight latch comprising a first latch portion having a lower mass than a second latch portion, wherein the first latch portion is configured to contact the spring at a contact portion.

15 . A power tool, the power tool comprising:
a power tool housing including a port configured to be electrically connected with a power source; a trimmer head electrically connected to the power source to rotate the trimmer head, the trimmer head defining a first axis around which the trimmer head is rotatable and a first direction co-directional to the first axis, the trimmer head defining a first end and a second end separated along the first axis, and the trimmer head defining a second direction extending radially from the first axis, the trimmer head comprising: a driven member; a plate; an upper housing comprising a centerbody extending along the first direction; a spring extending along the first direction through the centerbody at the upper housing; a flyweight comprising a first flyweight portion configured to translate along the first direction and contact the plate, the flyweight comprising a second flyweight portion configured to translate along the second direction, wherein the flyweight is positioned at a hinge between the first flyweight portion and the second flyweight portion, and wherein the flyweight is configured to rotate along the hinge to push the first flyweight portion to the plate and translate the plate and the driven member along the first direction toward the first end when a rotational speed threshold about the first axis is exceeded; and a flyweight latch configured to translate substantially along the second direction when a threshold speed about the first axis is exceeded.

16 . The power tool of claim 15 , the trimmer head comprising:
a first lug; and a second lug, wherein the first lug and the second lug form an interdigitated structure extending into one another.

Assignees

• Techtronic Cordless Gp

Inventors

• Hoffman Ronald J
• Holman Christopher A

Classifications

• A01D34/4163

  by triggered line feedout, e.g. bump-feeding · CPC title

• A01D34/4165 Primary

  Mounting of the cutter head · CPC title

• A01D34/416 Primary

  Flexible line cutters · CPC title