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. 27, 1982
Filed:
Apr. 14, 1980
Hiroshi Kusumi, Honjo, JP;
Masami Wada, Tsuchiura, JP;
Hitachi Construction Machinery Co. Ltd., Tokyo, JP;
Abstract
A swivel joint to be located at the upper end of a drill string in reverse circulation drills to support loads occurring on the drill string, the swivel joint including a fixed outer housing, a center housing rotatably mounted in the outer housing through bearings, a hollow inner housing vertically slidably fitted in the center housing, and an upper lid fixedly mounted on the outer housing to close the inner and center housings, the inner housing having at the upper and lower ends thereof flanged projections extending toward the center housing to restrict the range of the vertical sliding movement of the inner housing and being, after imposition and release of a downward thrust, slid upward within a range defined by a spacing between the flanged projection at the lower end of the inner housing and the lower end of the center housing subject to an upward thrust acting thereon, thereby preventing transmission of the upward thrust to the outer housing.