新颖性:The tool has a mandrel (1) connected with a driving block (6) that is connected with an upper supporting block (5) and a lower supporting block (8). The driving block is formed with an axial through hole and provided with an opening elastic lock ring (7) that is arranged on the lower supporting block. The lower supporting block is formed with a gear groove and a wellhead. The up ........(请QQ直接登录后查看全文)