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. 21, 1992
Filed:
Mar. 08, 1990
Dick T Atkinson, Nashua, NH (US);
James E Aplin, Needham, MA (US);
Arnis Mangolds, Stow, MA (US);
Daniel J Foley, N. Chelmsford, MA (US);
Gas Research Institute, Chicago, IL (US);
Abstract
Methods and apparatus for monitoring the compaction of backfill material in an excavation include hammer structure for impacting backfill material in the excavation, a sensor module for disposition at the bottom of the excavation to be backfilled that includes a transducer for developing an electric signal in response to energy transmitted through backfill material from the hammer structure, and a control module responsive to electric signals from the sensor module for providing an indication of the quality of compaction of backfill material in the excavation.