Miter saw

Patent metadata

Field	Value
Publication number	US-10882123-B2
Application number	US-201615053733-A
Country	US
Kind code	B2
Filing date	Feb 25, 2016
Priority date	Feb 25, 2015
Publication date	Jan 5, 2021
Grant date	Jan 5, 2021

Abstract

A miter saw includes a base assembly and a saw unit pivotably coupled to the base assembly. The saw unit includes a saw arm, a brushless motor supported by the saw arm, and power electronics positioned outside the motor for supplying power to the motor. The power electronics are coupled to a structural component of the miter saw to utilize the entire mass of the structural component as a heat sink to dissipate heat generated by the power electronics.

First claim

What is claimed is:

1. A miter saw comprising:
a base assembly including
a base,
a turntable pivotably coupled to the base about a vertical miter axis, and
a bevel arm pivotably coupled to the turntable about a horizontal bevel axis; and

a saw unit including
a saw arm pivotably coupled to the bevel arm about a chop axis,
a brushless motor supported by the saw arm,
a plate coupled to the saw arm,
a circuit board electrically coupled to the brushless motor, the circuit board positioned relative to the plate as to be encapsulated by a potting material on the plate;
a bracket directly attached to the saw arm, the bracket having a length transverse to the chop axis of the saw arm, the bracket spaced from and oriented perpendicular to the circuit board, and
field-effect transistors for supplying power to the motor, the field-effect transistors electrically coupled to the circuit board, the field-effect transistors directly attached to the bracket at a location away from the motor and the circuit board to utilize the saw arm as a heat sink to dissipate heat generated by the field-effect transistors.

2. The miter saw of claim 1 , wherein heat from the field-effect transistors is conducted into the saw arm via the bracket, and into the bevel arm via a joint defining the chop axis.

3. The miter saw of claim 1 , wherein the saw arm includes a cavity in which the field-effect transistors and the bracket are positioned.

4. The miter saw of claim 3 , wherein the circuit board and the plate are positioned within the cavity.

5. The miter saw of claim 4 , wherein the cavity of the saw arm is between the chop axis and the brushless motor in a direction transverse to the chop axis.

6. The miter saw of claim 1 , wherein the bracket is made from aluminum.

7. The miter saw of claim 1 , further comprising a power tool battery pack electrically connected with the field-effect transistors and operable to power the brushless motor.

8. The miter saw of claim 7 , wherein the field-effect transistors are positioned outside the power tool battery pack.

9. The miter saw of claim 7 , wherein the saw unit includes a battery pack mounting portion that selectively receives the power tool battery pack along an insertion direction for the power tool battery pack to power the field-effect transistors, and wherein the insertion direction is perpendicular to the longitudinal axis of the bracket.

10. The miter saw of claim 9 , wherein the insertion direction is perpendicular to the plate.

11. The miter saw of claim 10 , wherein the insertion direction is parallel to a rotational axis of the brushless motor.

12. The miter saw of claim 1 , wherein the saw unit includes a handle to be gripped by an operator for pivoting the saw unit about the chop axis.

13. The miter saw of claim 12 , wherein the brushless motor is positioned between the handle and the field-effect transistors in a direction transverse to the chop axis.

14. The miter saw of claim 1 , wherein the field-effect transistors are positioned along the length of the bracket.

15. The miter saw of claim 14 , wherein heat generated by the field-effect transistors is conducted into the saw arm via the bracket, and into the bevel arm via a joint defining the chop axis.

Assignees

• Milwaukee Electric Tool Corp

Inventors

• Brewster Mike
• Crabb Taylor
• Adams Josh
• Cunningham Steven
• Rose David
• Richards Daryl S
• Holly Jeffrey S
• Thiele John W

Classifications

• B23D47/132

  of means to position the saw blade at a specified angle when adjusting about an axis perpendicular to the work support surface · CPC title

• B27G19/025

  with guards for tool · CPC title

• Y10T83/853

  Indicates tool position · CPC title

• Y10T83/828

  With illuminating or viewing means for work · CPC title

• B23D45/048 Primary

  the saw blade being adjustable according to angle of cut · CPC title