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:
Feb. 24, 1987
Filed:
Dec. 20, 1985
Daniel S Snyder, Norwalk, OH (US);
Clevite Industries Inc., Glenview, IL (US);
Abstract
A liquid level indicator system is provided for sensing the presence of liquid at a preselected level in a liquid containing container. A piezoelectric reed transducer is disposed in the container for detecting vibrational movement and for producing an electrical signal in response to the vibrational movement. Operationally coupled to the transducer is a paddle which is sized to be immersed in the liquid when the liquid is present at the proper level. Immersion of the paddle in the liquid inhibits the transducer from vibrating due to fluid resistance against the paddle and accordingly inhibits an electrical signal output from the transducer. A control circuit is provided for sensing the electrical signal generation and for generating an alarm signal representative of low liquid level. A tubular housing is provided for containing a level of liquid representative of liquid level in the liquid container. The reed is preferably tuned to a preselected natural frequency sympathetic to ambient system vibrations. Where the indicator system is desired to be used in an environment containing no ambient vibrations, an oscillator driver is provided for communicating a driving frequency to the reed for vibrating the reed at its natural frequency.