Reciprocating tool

Patent metadata

Field	Value
Publication number	US-2016303668-A1
Application number	US-201615045692-A
Country	US
Kind code	A1
Filing date	Feb 17, 2016
Priority date	Apr 17, 2015
Publication date	Oct 20, 2016
Grant date	—

Abstract

A reciprocating tool includes a motor, a crank, a connecting rod, a rod, a tool bit, and a counter weight. The tool bit is mounted such that the action portion is positioned on a side opposite to a side with the rod central axis or the extended line of the rod central axis viewing from the rotational center of the crank. The first eccentric shaft and the second eccentric shaft are disposed such that at a position where the first eccentric shaft causes the rod to reach TDC, the second eccentric shaft causes the counter weight to reach BDC or a point before the BDC, and at a position where the first eccentric shaft causes the rod to reach the BDC, the second eccentric shaft causes the counter weight to reach a point before the TDC.

First claim

What is claimed is:

1 . A reciprocating tool comprising,
a motor; a crank rotated by the motor; a connecting rod coupled to a first eccentric shaft of the crank; a rod coupled to the connecting rod; a tool bit with an action portion, the tool bit being mounted on the rod, and the action portion acting on a workpiece; and a counter weight coupled to a second eccentric shaft of the crank, wherein the crank has a rotational center which is not disposed on an extended line of a central axis of the rod, the tool bit is mounted such that the action portion is positioned on a side opposite to a side on which the rod is coupled to the connecting rod, and the first eccentric shaft and the second eccentric shaft are disposed such that,
at a position where the first eccentric shaft causes the rod to reach TDC, the second eccentric shaft causes the counter weight to reach BDC or a point before the BDC, and
at a position where the first eccentric shaft causes the rod to reach the BDC, the second eccentric shall causes the counter weight to reach a point before the TDC.

2 . The reciprocating tool according to claim 1 , wherein
a plurality of the counter weights are disposed across the rod central axis.

3 . The reciprocating toot according to claim 1 , wherein
when the counter weight moves from the BDC to the TDC, the second eccentric shaft is rotationally moved such that the center of gravity of the counter weight moves to the side with the rod central axis or the extended line of the rod central axis viewing from the rotational center of the crank.

4 . The reciprocating tool according to claim 2 , wherein
when the counter weight moves from the BDC to the TDC, the second eccentric shaft is rotationally moved such that the center of gravity of the counter weight moves to the side with the rod central axis or the extended line of the rod central axis viewing from the rotational center of the crank.

5 . The reciprocating tool according to claim 1 , wherein
the second eccentric shall is disposed to have an angle from 180° to 195° with respect to the first eccentric shall viewing in the rotation direction of the crank.

6 . The reciprocating tool according to claim 1 , wherein
a phase whew the counter weight reaches the BDC delays with any angle in a range of 0° to 15° from a phase where the rod reaches the TDC.

7 . The reciprocating tool according to claim 1 , wherein
a phase where the counter weight reaches the TDC delays with any angle in a range of 8° to 23° from a phase where the rod reaches the BDC.

Assignees

• Makita Corp

Inventors

• Sugino Yudai
• Ukai Tomohiro

Classifications

• B23D49/162 Primary

  Pad sawing devices · CPC title

• Y10T74/18208

  Crank, pitman, and slide · CPC title

• Y10T83/8824

  With provision for dynamic balance · CPC title

• B23D51/161 Primary

  with dynamic balancing · CPC title

• B23D51/16

  of drives or feed mechanisms for straight tools, e.g. saw blades, or bows · CPC title