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:
Jul. 01, 1997
Filed:
Dec. 22, 1994
Colin John Wilson, Hertfordshire, GB;
David Roy Withers, Cambridgeshire, GB;
Ewan Stuart Bewley, London, GB;
Perkins Limited, Cambridgeshire, GB;
Abstract
A method of operating a two-coil solenoid valve of the type including an armature member located in a housing for movement between a first electromagnet and a second electromagnet, each electromagnet being located adjacent to a respective end of the armature member and being switchable between an on state and an off state. In order to move the armature member from a first position closely adjacent to the first electromagnet to a second position closely adjacent to the second electromagnet, the electromagnets are controlled to be at the same initial switched state and subsequently one of the electromagnets is switched to the other switched state for a first predetermined period sufficient to allow the resultant pull exerted on the armature member to be such that the armature member is caused to move towards the second electromagnet. The duration of the first predetermined period is such that the one electromagnet is switched back to its initial switched state before the armature member reaches the second position.