EXTERNAL CASING SPEAR Russian patent published in 1999 - IPC

FIELD: pipe catching tools. SUBSTANCE: relates to tools intended for extracting tubular members from pipes. Casing spear has body with cone in its lower part. Installed inside body is collet having tapered surface. Internal tapered surface has annular shoulder which is displaced towards center. Surface of shoulder is perpendicular to longitudinal axis of body. Tapered part of body operates within permissible limits of elastic deformation. Application of aforesaid embodiment of external casing spear allows for substantial increase of tool lifting capacity due to excluding grow of radial component forces and transmission of subsequent growing axial load to annular shoulder through collet end face. EFFECT: higher efficiency. 2 dwg