The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 25, 1984
Filed:
Nov. 23, 1982
Siefried Huber, Johannesberg, DE;
Manfred Merkator, Wiesbaden, DE;
Black & Decker Inc., Newark, DE (US);
Abstract
A control circuit arrangement for an electromagnetically operated power tool has a primary circuit including a solenoid and a semi-conductor switch, in series, the semi-conductor switch being capable of being triggered into a conducting state upon application of a trigger signal from a trigger control circuit. The trigger control circuit is actuated upon closure of a main trigger switch which is connected in series with the solenoid and the semi-conductor switch in the primary circuit for supplying current to the solenoid. Thus, should the semi-conductor switch fail due to a short-circuit, the power supply is disconnected from the solenoid the moment the operator releases the main trigger switch so protecting the solenoid. The semi-conductor switch is preferably a thyristor. An additional circuit is preferably provided for preventing the thyristor from firing a second time if the main switch remains closed. A delay circuit is also preferably provided for delaying firing of the thyristor until some time after the main switch has been closed to prevent arcing and damage to the main switch contacts.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile