Method of and arrangement for controlling the operation of a hand-held electrical device
First Claim
1. A method of controlling operation of an electrical hand-held device, in particular, screwdrivers, hand drills, hammer drills, and the like, having an axially displaceable output shaft, an electric motor for driving the output shaft, an actuating coupling for connecting the output shaft with the electric motor and clutching upon application of pressure to the output shaft, and a speed controller for controlling a speed of the electric motor, said method comprising the steps of:
- sensing a respective position of one of the output shaft and the coupling and generating, upon clutching of the output shaft actuating coupling, a speed acceleration signal; and
in response to the speed accelerating signal, accelerating the electric motor from a predetermined idle speed to a predetermined working speed.
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Accused Products
Abstract
An electrical hand-held device, such as a screwdriver or the like, includes an output shaft, a drive motor for driving the same, an actuating coupling for connecting the output shaft with the drive motor, a distance sensor for sensing a coupling position, and a speed controller which, in response to a signal generated by the distance sensor, controls operation of the drive motor. The controller causes the drive motor to accelerate to a high speed and maintain this speed during the screwing process when a rearward pressure is applied to the output shaft and the coupling is in its clutching position.
37 Citations
7 Claims
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1. A method of controlling operation of an electrical hand-held device, in particular, screwdrivers, hand drills, hammer drills, and the like, having an axially displaceable output shaft, an electric motor for driving the output shaft, an actuating coupling for connecting the output shaft with the electric motor and clutching upon application of pressure to the output shaft, and a speed controller for controlling a speed of the electric motor, said method comprising the steps of:
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sensing a respective position of one of the output shaft and the coupling and generating, upon clutching of the output shaft actuating coupling, a speed acceleration signal; and in response to the speed accelerating signal, accelerating the electric motor from a predetermined idle speed to a predetermined working speed. - View Dependent Claims (2)
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- 3. An electrical hand-held device comprising an axially displaceable output shaft, an electric motor for driving the output shaft, an actuating coupling for connecting the output shaft with the electric motor, a speed controller for the electric motor, distance sensor means for sensing one of a clutched and a declutched position of the actuating coupling and, for the clutched condition of the coupling, communicating a speed acceleration signal to the speed controller, the speed controller, in response to the speed acceleration signal, accelerating the electric motor from a predetermined idle speed to a predetermined working speed and maintaining the motor speed at the predetermined working speed.
Specification