Oscillating Mechanism for a Power Tool

Patent metadata

Field	Value
Publication number	US-2016290453-A1
Application number	US-201415103989-A
Country	US
Kind code	A1
Filing date	Dec 4, 2014
Priority date	Dec 20, 2013
Publication date	Oct 6, 2016
Grant date	—

Abstract

An oscillating power tool includes a drive motor (M) producing rotary motion and an oscillating mechanism ( 30 ) for converting the motor rotary motion to an oscillatory side-to-side movement. The oscillating mechanism ( 30 ) includes a link ( 32 ) driven by an eccentric shaft ( 16 ) of the motor (M), a drive arm ( 40 ) that drives the hub ( 45 ) of the working tool (B) in oscillating motion, and a bearing arrangement ( 37 ) between the drive arm ( 40 ) and the link ( 32 ) that isolates relative rotation and translation between the components while still imparting an oscillatory motion to the drive arm ( 40 ).

First claim

1 . A power tool comprising:
a drive motor having an eccentric drive shaft; a tool holder adapted to support a working tool for oscillating rotational motion; and an oscillating mechanism disposed between said eccentric drive shaft and said tool holder, said oscillating mechanism including:
a link mounted on said eccentric drive shaft for eccentric movement upon rotation of said drive shaft; and
an elongated drive arm having;
a first end coupled to said link in a manner to isolate relative rotation and translation between said link and said drive arm while still imparting an oscillatory motion in one direction to said drive arm; and
a second end engaged to said tool holder to transfer the oscillatory motion to oscillating rotational motion of said tool holder.

2 . The power tool of claim 1 , wherein:
said link includes an upper link mounted on said eccentric drive shaft and a lower link offset from said upper link, said lower link defining a cylindrical opening; and said second end of said drive arm is a spherical end slidably disposed within said cylindrical opening to permit relative rotation and axial translation between said drive arm and said lower link.

3 . The power tool of claim 2 , wherein said lower link includes a cylindrical bushing defining said cylindrical opening.

4 . The power tool of claim 2 , wherein said lower link includes a roller bearing having a loose fit with a small amount of play between the inner race and the rollers of the bearing, and/or between the rollers and the outer race of the bearing.

5 . The power tool of claim 2 , wherein said upper link includes a bearing between said upper link and said eccentric drive shaft.

6 . The power tool of claim 2 , further comprising a counterweight mounted on said eccentric shaft opposite said lower link.

7 . The power tool of claim 1 , wherein:
said tool holder includes a central hub supporting the working tool; and said first end of said drive arm includes a threaded shaft extending through said central hub and a threaded nut for engaging the threaded shaft to fix said drive arm to said central hub.

8 . The power tool of claim 1 , wherein:
said drive motor defines a longitudinal axis; said eccentric drive shaft includes an eccentric portion offset from said longitudinal axis; and p 1 said link is mounted on said eccentric portion.

9 . The power tool of claim 8 , wherein:
said eccentric drive shaft includes an end portion aligned with said longitudinal axis, with said eccentric portion between said motor and said end portion; and the power tool includes a housing defining a bearing support for supporting said end portion of said eccentric drive shaft.

10 . The power tool of claim 1 , wherein;
the drive motor defines a longitudinal axis; said tool holder is supported along said longitudinal axis; and said elongated drive arm is angled between said link and said tool holder.

11 . The power tool of claim 1 , wherein:
said eccentric drive shaft includes two eccentric portions; said link is mounted to one of said two eccentric portions; and a second link is mounted to the other of said two eccentric portions, said second link coupled to a second drive arm for another working tool.

12 . An oscillating mechanism for a power tool, the oscillating mechanism engaged between an eccentric drive shaft of the power tool and a tool holder adapted to support a working tool for oscillating rotational motion, the oscillating mechanism comprising:
a link mountable on the eccentric drive shaft for eccentric movement upon rotation of the drive shaft; and an elongated drive arm having;
a first end coupled to said link in a manner to isolate relative rotation and translation between said link and said drive arm while still imparting an oscillatory motion in one direction to said drive arm; and
a second end engageable to the tool holder to transfer the oscillatory motion to oscillating rotational motion of said tool holder.

13 . The oscillating mechanism of claim 12 , wherein:
said link includes an upper link mountable on the eccentric drive shaft and a lower link offset from said upper link, said lower link defining a cylindrical opening; and said second end of said drive arm is a spherical end slidably disposed within said cylindrical opening to permit relative rotation and axial translation between said drive arm and said lower link.

14 . The oscillating mechanism of claim 13 , wherein said lower link includes a cylindrical bushing defining said cylindrical opening.

15 . The oscillating mechanism of claim 13 , wherein said lower link includes a roller bearing having a loose fit with a small amount of play between the inner race and the rollers of the bearing, and/or between the rollers and the outer race of the bearing.

16 . The oscillating mechanism of claim 13 , wherein said upper link includes a bearing mountable on the eccentric drive shaft.

17 . The oscillating mechanism of claim 13 , further comprising a counterweight mountable on said eccentric shaft opposite said lower link.

18 . A power tool comprising:
a drive motor having an eccentric drive shaft; a tool holder adapted to support a working tool for oscillating rotational motion; and an oscillating mechanism disposed between said eccentric drive shaft and said tool holder, said oscillating mechanism including:
a link mounted on said eccentric drive shaft for eccentric movement upon rotation of said drive shaft; and
an elongated drive arm having;
a first end coupled to said link in a manner to isolate relative rotation between said link and said drive arm while still imparting an oscillatory motion in one direction to said drive arm; and
a second end engaged to said tool holder to transfer the oscillatory motion to oscillating rotational motion of said tool holder.

19 . The power tool of claim 18 , wherein:
said link includes an upper link mounted on the eccentric drive shaft and a lower link offset from said upper link, said lower link defining a cylindrical opening; and said second end of said drive arm is a pivotably mounted within said cylindrical opening to permit relative rotation between said drive arm and said lower link.

20 . (canceled)

Assignees

• Bosch Gmbh Robert

Inventors

• Rubens Jeremy
• Terrazas Moreno

Classifications

• B24B23/04

  with oscillating grinding tools; Accessories therefor · CPC title

• F16H21/52 Primary

  for interconverting rotary motion and oscillating motion · CPC title

• B27B19/006

  with oscillating saw blades; Hand saws with oscillating saw blades · CPC title

• B24B47/12

  by mechanical gearing or electric power (B24B47/16 takes precedence) · CPC title

• A61B17/142

  with reciprocating saw blades, e.g. with cutting edges at the distal end of the saw blades · CPC title