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US 5,856,731 AGranted
Electric screwdriver
AssigneeMetabowerke GmbH
InventorHermann Rottmerhusen
Life of this patent
Estimating the term…
Abstract
A universal motor which operates an electric tool is controlled by a phase-gating controller for determining variable rotational speeds. The phase-gating controller can be switched over to wave-packet-controlled phase-gating control mode in order to be able to switch over between a continuous speed-torque characteristic and pulsating operation.
Claims13
An electric screwdriver comprising:
- a universal motor;
- phase-gating controller means;
- first connection means connecting said phase-gating controller means and said universal motor;
- wave-packet controller means;
- and
- second connection means connecting said wave-packet controller means and said phase-gating controller means.
3 more elements
An electric screwdriver comprising:
- a universal motor;
- and
- phase-gating controller means for determining variable rotational speed of said universal motor, with said phase-gating controller means capable of a wave-packet controlled phase-gating control mode and with said wave-packet controlled phase-gating control mode capable of controlling said universal motor for a jerky rotational speed in a range of speed which extends to the point of standstill.
An electric screwdriver comprising:
- a universal motor;
- and
- phase-gating controller means for determining variable rotational speed of said universal motor, with said phase-gating controller means capable of a wave-packet controlled phase-gating control mode and with said wave-packet controlled phase-gating control mode capable of controlling said universal motor for a jerky rotational speed;
- with said phase-gating controller means comprising:
- a triac;
- integrated circuit means with said integrated circuit means connected to said triac for the purpose of starting said triac, with said integrated circuit means having an enable terminal;
- oscillator means, with said oscillator means having oscillator output means, with said oscillator output means connected to said enable terminal of said integrated circuit means;
- said oscillator means comprising;
- a first actuator means;
- and
- a second actuator means with said first actuator means determining the drive frequency of said integrated circuit means in said phase-gating controller means and with said second actuator means determining the pulse width of the drive frequency of said integrated circuit means in said phase-gating controller means.
8 more elements
Dependencies are inferred from the claim text.