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. 18, 1985
Filed:
Jun. 06, 1984
Rolf Diederichs, Erfstadt-Bliesheim, DE;
Klaus Volkmann, Bergisch-Gladbach, DE;
Krautkramer-Branson, Inc., Lewistown, PA (US);
Abstract
A resonant sensing device for measuring the hardness of a workpiece to be tested includes a diamond tipped rod adapted to be resonant and for determining the hardness of a workpiece to be tested is brought into forced contact with such workpiece. The difference in resonant frequency of the rod between its not-constrained condition and its constrained condition (forced contact) is a measure of the hardness of the workpiece. The present invention describes a circuit wherein during a first time interval an up/down counter accumulates the counts arising from the oscillations of the not-constrained rod. During the ensuing interval of the same duration, the counter counts down the accumulated count responsive to the oscillations of the constrained rod. As the counter reaches the zero count condition, which condition is reached before the expiration of the time interval, the counter becomes coupled to an adjustable frequency calibration oscillator and for the remainder of the interval the counter accumulates counts from the oscillations of the calibration oscillator. At the end of the interval, the accumulated count is a measure of the hardness of the workpiece.