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:
Aug. 11, 1992
Filed:
Apr. 10, 1991
Eric Day, Longmeadow, MA (US);
AIL Corporation, Columbia, SC (US);
Abstract
An inexpensive type of linear solenoid actuator for moving a plunger along a straight line, while providing a force on the plunger due to the actuator which does not vary greatly over the length of stroke of the plunger; a spring opposes the force exerted on the plunger by the solenoid, so that the plunger will assume any of a range of positions in response to different currents through the solenoid. The plunger has a first larger portion of magnetic material sliding in a first bearing; a tapered second magnetic portion extending forwardly from the first portion; a magnetic third portion of substantially cylindrical form extending forwardly from the tapered portion; and a front non-magnetic portion sliding in a second bearing and supporting the front end of the plunger. The second bearing is in a magnetic end piece having substantial axial width. The stroke of the plunger is preferably such that the forward end of the magnetic third portion moves from a first position near the adjacent end of a magnetic end piece in which the second bearing is mounted, to a second position well within or outside the other end of the magnetic end piece.