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. 17, 2001
Filed:
Sep. 22, 1997
Hiromitsu Yamamoto, Minato-ku, JP;
Hiroyasu Ishiguro, Minato-ku, JP;
Japan Drilling Co., Ltd., Tokyo, JP;
Abstract
A dual hoist derrick system for deep sea drilling, capable of elevating a very long and massive heavy object involved in a drilling for deep sea, is provided with a normal drilling hoisting system and a heavy load hoisting system arranged on a single derrick in parallel. The derrick is mounted on a skid movable in a horizontal direction. The skid is provided with a cut broader than a blow-out prevention device, so that the skid may travel to a position of the blow-out prevention device to lift up the blow-out prevention device. The system contributes to speeding up in hoist speed of offshore drilling units for deep sea, reducing working hours and improvement in safety.