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. 21, 1990
Filed:
Jul. 11, 1988
William C McDonald, Houston, TX (US);
Gerard T Pittard, Houston, TX (US);
John H Cohen, Houston, TX (US);
Gas Research Institute, Chicago, IL (US);
Abstract
A method of rapid earth excavation without damaging buried pipe, cable or other underground objects utilizes drills and augers having soft cutting edges and/or control of the torque and weight of the boring apparatus. In one embodiment, the bit of a drill, or bottom end of an earth auger is equipped with inserts formed of soft polymeric material. Another embodiment of an earth auger apparatus has soft polymeric material on the leading cutting surface of the flight, or the auger flight may be formed of soft polymeric material. The flexibility and low abrasion of the polymeric material prevents damage to the object contacted. Another embodiment has a dual concentric auger with a small earth-auger rotatably mounted inside the shaft of a larger auger and driven independently such that each is capable of providing and maintaining a torque adequate to create a given hole diameter but sufficiently below that which would damage the object expected to be encountered. Another embodiment has an indicator mounted forward of and below the leading cutting surface of the auger to warn the operator of a buried utility or to automatically stop the auger before the cutting surface contacts the buried utility.