SHOCK ABSORBER

摘要

A shock absorbing tool for use in pipelines and oil wells, particulary in combination with perforation guns comprises a central mass (40) supported on two springs (30, 50) between the end terminal members (10, 20). The shock wave is absorbed in the free oscillation of the mass. The mass is constituted by a piston assembly (404, 416). A steel rope (70) permits the shock absorbing tool to be manoeuvred within the bore hole without damage to the springs.