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. 07, 2004
Filed:
Jan. 23, 2003
Wolfgang Kliemannel, Lemförde, DE;
ZF Lemförder Metallwaren AG, Stemwede-Dielingen, DE;
Abstract
The present invention pertains to a locking and unlocking mechanism, which is equipped with an electromagnet ( ) and is used preferably to embody a key and/or shift lock function in motor vehicles. Its basic object is to design such a mechanism such that the generation of noise during the transition from one state into the other is reduced compared with prior-art solutions. To accomplish the object, a pulsating voltage in the form of a direct voltage-rated pulse width signal (PWM voltage) is sent to the electromagnet ( ). The effective value of the PWM voltage is increased over at least three voltage pulses from an off-load voltage value to a preset final voltage value at the beginning of a phase of energization and it conversely drops, again over at least three voltage pulses, to the off-load voltage value at the end of the phase of energization, in a time-controlled manner by means of a circuit unit ( ) associated with a pulse width modulator ( ).