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:
Nov. 10, 1987
James D Chalupnik, Seattle, WA (US);
Joseph L Garbini, Seattle, WA (US);
Jens E Jorgensen, Seattle, WA (US);
Washington Technology Center, Seattle, WA (US);
Abstract
A probe for determining the thickness of an interface gap between two surfaces is disclosed. The probe includes an inflatable bladder, which can be inserted into a gap and inflated, such that the sides of the bladder contact the planes. A distance-measuring device is mounted within the cavity of the bladder and is suitable for measuring the distance between the sides of the bladder. Passive electrical circuitry for use as the distance-measuring device is also disclosed. Passive electrical circuitry has an electrical property that varies as the distance between the passive electrical elements varies. In the case of a probe utilizing capacitive circuitry, three relationally positioned measuring electrodes and a common electrode are mounted within the bladder cavity such that the measuring and common electrical are in facing relationship and move away from each other as the bladder is inflated. When the bladder is inflated with a dielectric fluid, the electrodes are pressed flat against the surfaces. Once the electrodes are separated, a value for the capacitance at each measuring electrode's position is obtained. The capacitance value is indicative of the distance between the surfaces. Two-dimensional gap taper information, as well as single-dimension thickness information, can thus be produced.