Electric tool

• US 20030089511A1
• Filed: 06/11/2002
• Published: 05/15/2003
• Est. Priority Date: 11/12/2001
• Status: Abandoned Application

• Current Assignee: Nidec Shibaura Company Limited (Nidec Corporation)
• Original Assignee: Nidec Shibaura Company Limited (Nidec Corporation)
• Inventors: Saito, Fumiaki, Tsuneda, Yukio
• Application Number:
  US10/166,877
• Publication Number:
  US 20030089511A1
• Time in Patent Office: Days
• US Class Current: 173/217
• CPC Class Codes: B25B 21/00 Portable power-driven screw or nut setting or loosening tools; details or components, e.g. casings, bodies, of portable power-driven tools not particularly related to the operation performed B25F5/00; for mounting or dismounting wheels B60B29/006; Attachments for drilling apparatus serving the same purpose machines B23P19/06
• CPC Class Codes: B25F 5/001 Gearings, speed selectors, clutches or the like specially adapted for rotary tools

Abstract

To provide a cordless electric tool promoting a fastening function or a cutting function by facilitating to control a rotational number of a motor from a low speed region to a high speed region, reducing generation of vibration or noise and achieving small-sized formation and light-weighted formation, there is provided a cordless electric tool constituted by a brushless direct current motor 3, an output shaft 5 connected to the brushless direct current motor 3 via a speed changing device 4, a motor driving circuit 7 and a control portion 8 of the driving circuit and using a charge type battery 11 as a drive power source.

Claims

1. An electric tool which is a cordless electric tool comprising a motor, an output shaft connected to the motor via a speed changing device, a motor driving circuit and a control portion of the driving circuit and using a charge type battery as a drive power source:

wherein the motor is a brushless direct current motor.

3. The electric tool according to claim 1 or 2:

wherein the electric tool is an electric driver, an electric driver drill, an electric impact driver or an electric wrench.

2. An electric tool comprising:

a brushless direct current motor constituting a power source of the electric tool;

a first operating member for changing a maximal rotational speed of the brushless direct current motor;

a second operating member for changing a rotational speed of the brushless direct current motor within a range of the maximal rotational speed of the brushless direct current motor set by the first operating member; and

controlling means for controlling a rotational state of the brushless direct current motor;

wherein the controlling means comprises;

maximal rotational speed signal outputting means for outputting a maximal rotational speed signal in correspondence with a displacement of the first operating member; and

rotational speed signal outputting means for constituting a maximal level by the maximal rotational speed signal outputted from the maximal rotational speed signal outputting means and outputting a rotational speed signal in correspondence with a displacement of the second operating means to thereby drive to rotate the brushless direct current motor.