Title:
ELECTRIC TOOL
Document Type and Number:
WIPO Patent Application WO/2010/021252
Kind Code:
A1
Abstract:
With a speed-changing device that automatically changes speed according to the external torque applied to a spindle, there is a usability problem when changing from high-speed, low-torque mode to low-speed, high-torque mode, in that the electric tool rotates in the direction opposite to the screw tightening direction due to kickback, so that the user must grip the handle with great force to keep the electric tool from rotating. Disclosed is an electric tool which is not rotated due to the kickback generated when changing speed. The rotational moment for the purpose of rotating the electric tool (1) about a shaft (J) is larger than the inertial moment (kickback) generated when the speed changes automatically. For this purpose the distance (L) from the shaft (J) to the center of gravity (G) of a battery pack (5) and the weight (W) of the battery pack (5) are made large. When the rotational moment is larger, the electric tool (1) is not as likely to be rotated due to kickback caused by the change in speed.
Inventors:
KONDO TAKAYOSHI (JP)
Application Number:
PCT/JP2009/064027
Publication Date:
February 25, 2010
Filing Date:
August 07, 2009
Export Citation:
Assignee:
MAKITA CORP (JP)
KONDO TAKAYOSHI (JP)
KONDO TAKAYOSHI (JP)
International Classes:
B25B21/00; B25B23/14; B25F5/00
Foreign References:
| JP2003145449A | 2003-05-20 | |||
| JPH04217473A | 1992-08-07 | |||
| JP2008270007A | 2008-11-06 |
Attorney, Agent or Firm:
OKADA PATENT & TRADEMARK OFFICE, P. C. (JP)
Patent business corporation Okada international patent firm (JP)
Patent business corporation Okada international patent firm (JP)
Download PDF: