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. 03, 1990
Filed:
Oct. 05, 1988
Toshio Mukai, Hamamatsu-city, Shizuoka Prefecture, JP;
Other;
Abstract
A rotary gad for a ground drill includes an elongated front body having a front end and a rear end with front spiral blades being disposed on the outside of the front body. The front body has an elongated front axial passage, and a front core rod is disposed in the front axial passage. The front body is rotatable about the front core rod. The front core rod has a front end and a rear end. An elongated rear body has a similar construction and a pushing section is provided on a rear axial passage in the rear body. The pushing section has a front side and a rear side. A rear ball element is disposed between the rear side of the pushing section and the front end of a rear core rod, and a front ball element is disposed between the front side of the pushing section and the rear end of the front core rod. Coupling means couple the front and rear bodies to provide for rotation of the front and rear bodies in opposite directions about the front and rear core rods.