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:
Nov. 10, 1998
Filed:
Sep. 08, 1997
Jerry D Hielkman, Franklin Park, IL (US);
Gary A Sparks, Crystal Lake, IL (US);
David J Treadwell, Crystal Lake, IL (US);
MPC Products Corporation, Niles, IL (US);
Abstract
A solenoid has a multistage telescoping plunger which together produce a single stroke. Each plunger stage has a separate air gap individually associated therewith. As the first air gap closes responsive to movement of a first telescoping plunger stage, a portion of the stator becomes magnetically saturated; however, magnetic material has moved with the first plunger stage in order to bridge the saturated position which switches the flux path to a second air gap via a second of the telescoping plunger stages. An advantage is that the solenoid has a long stroke with a high pulling force on both the initial and the final ends of a continuous stroke formed by the separate movements of the first and second plunger stages.