Title:
ELECTRIC TOOL
Document Type and Number:
WIPO Patent Application WO/2010/021251
Kind Code:
A1
Abstract:
Disclosed is an electric tool equipped with a speed-changing device that automatically changes speeds in response to an increase in external torque added to a spindle, wherein the screw-tightening operation can be performed faster than with the prior art. In the high-speed, low-torque mode prior to an automatic speed change, an extremely high output rotational frequency is set to a degree such that an output torque is insufficient to perform screw tightening to the end. The output rotational frequency prior to the speed change is set in a range of approximately 4.5‑6.0 times that of the output rotational frequency after the speed change. Thus, with the initial screw tightening the work can be performed quickly with a higher rotational speed than with the prior art, and after the automatic speed change the screw tightening can be completed with a large output torque.
Inventors:
ITO AKIHIRO (JP)
Application Number:
PCT/JP2009/064026
Publication Date:
February 25, 2010
Filing Date:
August 07, 2009
Export Citation:
Assignee:
MAKITA CORP (JP)
ITO AKIHIRO (JP)
ITO AKIHIRO (JP)
International Classes:
B25B21/00; B25B23/14; B25F5/00
Foreign References:
| JP2008531310A | 2008-08-14 | |||
| JP2003145449A | 2003-05-20 |
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)
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