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:
Jan. 05, 2021
Filed:
Jul. 13, 2018
Shandong University of Science and Technology, Qingdao, CN;
Wei Lu, Qingdao, CN;
Qianting Hu, Qingdao, CN;
Guansheng Qi, Qingdao, CN;
Weimin Cheng, Qingdao, CN;
Jinliang Li, Qingdao, CN;
Dong Wang, Qingdao, CN;
Zhen Liu, Qingdao, CN;
SHANDONG UNIVERSITY OF SCIENCE AND TECHNOLOGY, Qingdao, CN;
Abstract
A ground wellhole dedicated protective pipe, disposed inside a ground wellhole for gas extraction of a mining-induced area, includes a casing, and a chain inside the casing and slidable relative to the casing. The chain includes a chain formed by a plurality of chain drums through serial connection, and a detachable connecting piece connecting between chains. A plurality of air holes is opened in the chain drum along an axial direction of the chain drum.