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. 01, 1990
Filed:
Jan. 09, 1989
Harold L Swartz, Phoenix, AZ (US);
Warren W Stansberry, Phoenix, AZ (US);
Schaevitz Sensing Systems, Inc., Phoenix, AZ (US);
Abstract
Disclosed is a fluid level sensor including a float mounted for movement in a mounting tube by a pair of spiral springs which are relatively rigid in a radial direction but relatively flexible in a longitudinal direction. At the top of the float a magnet is located and at the top of the mounting tube, a Hall effect device is located. As fluid enters the mounting tube through apertures in the lower portion, the float is gradually buoyed and moves closer to the Hall effect device changing its electrical output. Because the springs position the float inside the mounting tube, striction and hysteresis in conventional float supports is eliminated as well as wear between the float and the outer tube. Measurement range may be changed by changing float length and outer tube length as well as the spring constants themselves.