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. 03, 1976
Filed:
Feb. 04, 1974
Robert L Spaw, Houston, TX (US);
Other;
Abstract
A single length of insulated, stranded steel cable extends vertically through a bin or other material container and functions as a radiating antenna for an electrical signal transmitter. The reactance of the antenna, which varies as a function of the level of material in the container adjacent the antenna, is inductively linked to an oscillator circuit in the transmitter. The transmitter's signal which is altered in frequency with changes in the antenna's reactance is combined with that of a constant frequency reference signal. The frequency of the resulting difference signal is employed to form a remote indication of the material level and to provide control information for automatically maintaining or varying material levels.