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:
Oct. 04, 1977
Filed:
Mar. 03, 1976
Edward Alfred Donegan, St. Catharines, CA;
TRW Canada Limited, , CA;
Abstract
A percussive drill extension rod having first and second externally threaded ends, a rod zone therebetween, and a substantially round, internal bore in the threaded ends and rod zone along the longitudinal axis of the extension rod, with particular relative dimensions designed to improve performance and reduce costs. The first threaded end of the extension rod has an outside diameter (TD) in the range of about 1.25 to about 2.5 inches, and the rod zone has an outside diameter (RD) within a range from about equal to the outside diameter (TD) of the first threaded end to about 1.1 times the outside diameter (TD) of the first threaded end. The first threaded end has a cross-sectional area (TDX) derived from the specific outside diameter of the threaded end (TD) selected from the given range of about 1.25 to about 2.5 inches. The rod zone has an annular cross-sectional area (RX) equal from about 0.64 to about 0.76 times the circular cross-sectional area (TDX) based upon the outside diameter (TD) of the first threaded end, the internal bore in the rod zone having a diameter (RB) equal to 2 (.sqroot.(circular cross section (RDX) based on the outside diameter (RD) of the rod zone minus the annular cross section (RX) of the rod zone) divided by .pi.). The first and second threaded ends may have equal outside diameters or unequal in which case such an extension rod is commonly called a jumbo rod.