To overcome the shortcomings of the shear pin type joint and left-hand thread type joint, a sliding sleeve subsurface safety joint is developed.
为了克服剪钉式和反扣式两种安全接头的不足，研制出一种滑套式井下安全接头。
2
In the light of the disadvantages and limitation of the existing unscrewing type or shearing type safety joints, a hydraulic sleeve type safety joint is designed.
针对现有倒扣式和剪断式安全接头结构上的局限性和缺陷，设计了液压滑套式安全接头。
3
The invention advantageously prevents the brush sleeve (6) from moving beyond the safety position if it is released as a result of a fault.