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:
Jun. 20, 1989
Filed:
Oct. 20, 1987
Raymond F Gastgeb, Doylestown, PA (US);
Pennwalt Corporation, Philadelphia, PA (US);
Abstract
A structural member having a piezoelectric transmitter film and a piezoelectric receiver film adhered thereto. The transmitter film produces a vibration upon activation by a voltage controlled oscillator which forms part of a phase-lock loop circuit. The vibrations of the structural member generate electric signals on the receiver film, which feed into a phase comparator. The other input of the phase comparator is the output signal of the voltage controlled oscillator. The phase comparator will output a dc signal proportional to the difference in phase between the two signals. When the structural member becomes damped, the phase comparator will go into saturation, thereby producing a voltage which can activate an alarm signal or other device.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile