Patent ID: 6854530
Filing Date: 2005-02-15
Classification: B25C,B25D

Abstract:
1. A method for driving an electric percussion tool, said electric percussion tool including a solenoid having a first end and a second end and a middle portion, a plunger core partially engaged in said first end of said solenoid, and a spring member, said method comprising: energizing said solenoid to draw said plunger core from said first end of said solenoid toward said middle portion of said solenoid, de-energizing said solenoid, to allow said plunger core to move from said middle portion of said solenoid toward said second end of said solenoid with a moment of inertia of said plunger core, applying a spring biasing force of said spring member against said plunger core to force said plunger core to move partially into said second end of said solenoid, and energizing said solenoid again to draw said plunger core from said second end of said solenoid toward said middle portion of said solenoid, and to allow said plunger core to move from said middle portion of said solenoid toward said first end of said solenoid with a moment of inertia of said plunger core.