Patent ID: 7992909
Filing Date: 2011-08-09
Classification: E21B

Abstract:
1. A single joint elevator for gripping a tubular segment to be hoisted by a hoisting member, comprising: a first jaw retainer having a proximal end pivotally coupled to a proximal end of a second jaw retainer for movement of the retainers between an opening position for receiving a tubular segment and a closed position for engaging the tubular segment, each jaw retainer securing at least one jaw between the proximal end and a distal end, and each jaw having at least one gripping surface for engaging the tubular segment; a powered door pivotally coupled to the distal end of the first jaw retainer for selectively securing to the distal end of the second jaw retainer, the powered door including a pivotable collar, a linear actuator assembly supported by the pivotable collar, and a linkage mechanism for selectively closing the door and clamping the distal end of the second jaw retainer to the distal end of the first jaw retainer, wherein the linear actuator assembly selectively clamps the first and second jaw retainers with sufficient force for the jaws to grip and support the tubular segment for lifting; wherein the linear actuator assembly includes a fluid powered motor, a drive screw rotatably coupled to the fluid powered motor, and a sliding plate cam that moves linearly with the linear actuator assembly to act upon the linkage mechanism; wherein the drive screw threadably engages a stationary screw collar secured to the pivotable collar; and wherein the linear actuator acts upon the linkage mechanism to selectively move the powered door into a closed position during a first phase of actuation and selectively clamps the distal end of the second jaw retainer during a second phase of actuation.