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. 07, 1996
Filed:
Jun. 10, 1994
Henry G Mohr, Carthage, MO (US);
Daniel W Martin, Carthage, MO (US);
Steven M Montague, Carthage, MO (US);
Henry Zapletal, Carthage, MO (US);
L & P Property Management Company, Chicago, IL (US);
Abstract
A curved sample of material is tested for ultimate tensile stress and elongation without prestraightening or premarking of the length of the sample. The sample is gripped at its ends and positioned to extend over convex surfaces mounted adjacent to the grippers on a pair of longitudinally moveable members. The members are moved apart and incremental data of the relative distances between the convex surfaces, representing the length of the sample, are stored. With each of the distance measurements, tensile stress measurements in the wire are made and stored. After the wire breaks, the data is analyzed. The stress versus distance ratios and rates of changes are analyzed to determine the end points of the stress versus length curve for the elastic deformation region, which is taken to begin when the wire has been pulled straight as is detected by a sudden increase in ratio of the tensile force versus sample length, and to end by a decrease the ratio, at the yield point where plastic deformation or permanent elongation of the sample begins. The permanent elongation of the sample ends at the break point of the sample, when it is at its total elongation.