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:
Mar. 21, 1989
Filed:
Jan. 25, 1988
Carl R Wilson, Texico, IL (US);
James A Neese, Flora, IL (US);
Sparton Corporation, Jackson, MI (US);
Abstract
An electric horn has a diaphragm driven by a plunger which is vibrated by a coil having a pole piece. A small air gap between the plunger and the pole piece is required to assure that they will not touch during vibration. The gap is adjusted by assembling the horn with the gap small enough to permit the plunger to be pulled into contact with the pole piece by magnetic force when a preset direct current is applied to the coil. After assembly a calibration procedure is to apply the preset current to the coil, mechanically pull the pole piece away from the plunger until the diaphragm force overcomes the magnetic force causing the plunger and pole piece to separate, electrically detect the time of separation, and then stop or optionally pull the pole piece an additional fixed amount to set the required gap. Apparatus automatically performs the calibration procedure.