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:
Sep. 22, 1981
Filed:
Jun. 18, 1979
Thomas L Elliston, Fort Worth, TX (US);
Hydra-Rig, Inc., Fort Worth, TX (US);
Abstract
A portable workover rig for handling a pipe string in a well casing includes a base platform and a collapsible mast which is movable from a reclining transport position to an erect elevated position of use. The mast is supported for free-standing operation by a carriage assembly including a cantilever support base mounted on the base platform for pivotal movement from the transport position to the position of use. The carriage assembly includes lift arms coupled in parallel relation intermediate the cantilever support base and the rig support platform for maintaining the cantilever support base in parallel alignment with the base platform. Hoisting and snubbing operations are performed by drawworks including a linear hydraulic actuator carried on the base platform, a traveling block supported for vertical movement along the mast by hoist and snub cables, and traveling sheaves carried by the actuator through a stroke pathway which is oriented transversely with respect to the mast. A vertically adjustable stack assembly is provided for accommodating the varying elevations of existing wellhead flange connections and for anchoring the rig platform to the wellhead casing. A powered drill sub assembly includes upstanding stab receptacles anchored to the top side of the traveling block and stab elements supported for vertical reciprocal movement between retracted and extended positions to permit displacement of the power sub relative to the traveling block during makeup and breakout operations.