Abstract: Disclosed herein is a power tongs, including a rotary head and a circular plate loosely mounted on the head, with a flexible member secured at one end to the plate. The flexible member is wrapped around the pipe to be torqued and the free end of the member is tensioned around the pipe by means of a lever that is pivotally supported on the plate, the lever having an outwardly extending arm that is engaged by a pin extending upward from the rotary head as the tongs are operated. The flexible member distributes radial loads over the surface of the pipe to prevent crushing of the pipe and damage to its surface.

Abstract: A power tong is disclosed having a pipe gripping device including plural jaws activated by independent expansible chamber linear motors. An air-driven hydraulic pump, whose output pressure is limited by an adjustable relief valve, supplies fluid to the jaw motors. The jaw force can thus be closely controlled, independent of tongs torque.

Abstract: A control system for power tongs comprises two tongs torque limiters, one of which limits tongs torque to a very low (hand-tight) level; the other limits torque at full make-up to, for example, 2000 ft.-lbs. The hand-tight torque limiter is manually or automatically disabled after the hand-tight level is reached. The system enables the operator to verify that the threads are properly engaged before applying full torque to the connection. The tongs have a very high reduction ratio, so that torque rises very slowly and can be more accurately controlled. The high torque limiter includes a normally closed shunt valve in series with an adjustable choke, the latter of which enables one to maintain a substantial, adjustable, residual torque on the pipe even after the shunt valve opens.

Abstract: A control system for power tongs comprises two tongs torque limiters, one of which limits tongs torque to a very low (hand-tight) level; the other limits torque at full makeup to, for example, 2000 ft. lb. The hand-tight torque limiter is manually or automatically disabled after the hand-tight level is reached. The system enables the operator to verify that the threads are properly engaged before applying full torque to the connection. The tongs have a very high reduction ratio, so that torque rises very slowly and can be more accurately controlled.

Abstract: The power tongs control system described herein includes a hydraulic load transducer in the tongs snub line, the transducer output controlling a shunt valve between the hydraulic lines leading to and from the tongs drive motor. At a predetermined threshold tongs torque, a switch is actuated by contact with a Bourdon tube connected to the transducer output closure of the switch causing the solenoid actuator to open the shunt valve and thereby halt operation of the tongs. A timer is provided to maintain the tongs in the disabled configuration for a period of time following initial cut off. Also disclosed is an adjustable choke valve in series with the shunt valve so that even following the opening of the shunt valve, substantial torque is maintained upon the pipe by the tongs.

Abstract: A scraping tool for cleaning well casing bores comprising an elongated support body, at least a pair of opposed sets of scraper blades mounted in slots in the body, an intermediate undercut between the sets of scraper blades, and locking mechanisms disposed in the undercut for retaining the scraper blades in the slots. A unique method for forming and assembling the scraping tool is also disclosed. Such method includes the steps of machining the scraper blades while retaining same on the support body, and turning the support body to develop a compound curve on each blade element.

Abstract: A dual string spider having a body of two halves pivotally secured at one side and releasably secured at the other side with bowls extending through the body and open to each other, gripping means for each bowl, an actuator for each gripping means, and bars extend through the body halves to divide the bowls and to center well strings in their respective bowls.

Abstract: A dual string elevator having a body with a pair of tapered bowls extending vertically therethrough, lifting projections extending outward from the body in positions aligned with the bowls to prevent bending of a string supported in one of the bowls, a set of gripping slips for each bowl, an actuator for each set of gripping slips, each actuator being mounted in a recess in the body aligned with and spaced outward from the bowls and pivotal links for connecting the actuators to their set of gripping slips whereby the slips are moved out of the bowls and lowered into the bowls into pipe gripping position responsive to the movement of the actuators.

Abstract: A control system for power tongs comprises two tongs torque limiters, one of which limits tongs torque to a very low (hand-tight) level; the other limits torque at full makeup to, for example, 2000 ft. lb. The hand-tight torque limiter is manually or automatically disabled after the hand-tight level is reached. The system enables the operator to verify that the threads are properly engaged before applying full torque to the connection. The tongs have a very high reduction ratio, so that torque rises very slowly and can be more accurately controlled.