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:
Aug. 08, 1989
Filed:
Jan. 03, 1989
James D Hoeffel, Centerville, OH (US);
Richard E Elliott, Dayton, OH (US);
Wally C Hoppe, Dayton, OH (US);
James S Nevitt, Bellbrook, OH (US);
Systems Research Laboratories, Inc., Dayton, OH (US);
Abstract
An apparatus for maintaining the end of a probe carrying a sensor, such as an eddy current probe, a predetermined distance from a workpiece includes a housing in which a piston is permitted to move. Air under pressure, introduced into a first chamber formed within the housing, acts on a first surface of the piston to urge it toward the workpiece. An air bearing is used to permit the almost friction free axial movement of the piston within the housing. Some of the air passes from the first chamber through a restricted opening in the piston into a second chamber and is vented toward the workpiece. The pressure in the second chamber will vary as a function of the distance of the end of the probe to the workpiece surface. The piston is provided with a second, larger, surface area exposed to the variable pressure in the second chamber, and as a result, the piston is urged away from the workpiece. The pressures acting in the two surfaces work together to maintain the piston, and the sensor, a constant distance from the workpiece.