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:
May. 15, 1990
Filed:
Jul. 15, 1988
Alan L Bartlett, New Braunfels, TX (US);
Detex Corporation, New Braunfels, TX (US);
Abstract
An apparatus and method to generate high intensity sound having a strong directional characteristic. The apparatus preferably uses a sound element (e.g. piezo sounder) which is capable of generating a high intensity, power efficient sound, but which has poor directional characteristics because of its high frequency (e.g. 3000 Hz). The apparatus drives the sound element with a variable frequency signal which sweeps across the resonant bandwidth of the sound element. The sweep rate of the frequency shift is less than about 1200 Hz which gives the sound a directional characteristic--resulting in periodic bursts of high intensity sound that is strongly directional. The apparatus may be incorporated into a wide variety of applications where high intensity, power efficient, strongly directional sound is desirable. In the preferred embodiment, the sound generator of the present invention is incorporated into a personal alert warning device worn by fireman or other safety personnel to emit a directional sound if the wearer becomes disabled.