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:
Apr. 24, 1984
Filed:
Jul. 21, 1982
Carel J Brest van Kempen, Salt Lake City, UT (US);
Other;
Abstract
A method for controlling parametric variations in processes where one variable is subject to an exponential change with time. One application is particulary advantageous in underground mine roof bolting using mechanical anchors where a device utilizing the method can be employed to install mine roof bolts at varying initial tensions in such a manner that the bolt tensions found among a population of roof bolts converge to one tension value within one or two hours after installation due to individual differences in tension decay rate. Since roof bolt tension decay bears an exponential relationship to time, variability in bolt tension which develops after mentioned convergence has taken place is small for a long period of time, in marked contrast to a conventional installaton which is characterized by bolt tension variability which grows rapidly into a far wider range immediately after installation. An extension of said mine roof bolting application further allows an exact assessment of mine roof movements using the roof bolts themselves. A device embodying the invention in mine roof bolting as described, senses the roof bolt tension decay rate during the installation process and automatically tensions the roof bolt to a value appropriate to achieve tension convergence as described.