Abstract: A jaw assembly for apparatus for gripping pipes, the apparatus being of the type having automatic means for exerting increased gripping force upon application thereto, is provided with a member having a concave surface which cooperates with a gripped pipe to override the automatic means for exerting increased gripping force. Having such a member, the jaw assembly of the present invention can exert a predetermined maximum gripping force on a gripped pipe notwithstanding amount of torque applied to the apparatus. Considering angular relationships involving jaw cam angle, the present invention can be manifested in an increasing cam angle jaw for power tongs.

Abstract: A rotary power tong for use in well drilling operations to make up and break out drill strings or similar axially elongated objects having a housing receiving a rotor assembly therein for actuating jaw members into the drill string for rotation of the drill string. The rotor assembly has a generally annular rotor with a plurality of axial bores therethrough positioned in a generally circular pattern adjacent the outer periphery of the rotor. Each axial bore receives a roller assembly comprising a shaft received through the axial bore and secured to the rotor and a roller bearing secured to the bottom of the shaft extending below the rotor. The roller bearing rotates relative to the shaft and rotor. The rotor assembly is received within a circular guide track within the housing such that the rotor assembly load is balanced evenly within the housing providing for a smooth rotational operation of the power tong.

Abstract: A tong assembly for makeup and break out of tool joints including a power tong and a backup tong which is rotatable through a limited rotation with respect to the power tong. During a torquing operation a single, self energizing free jaw and die grips the lower tubing of the tool joint in cooperation with two surfaces of a hardsurfaced bushing. The tool joint is gripped eccentric to the longitudinal centerline of the backup tong, and aligned with the longitudinal centerline of the power tong.

Abstract: Slip mechanisms for selectively gripping and releasing conduit in a well drilling operation, particularly useable as elevators or spiders. Three slips are positioned within a tapered bore of the slip mechanism having a split front opening, and are articulatingly suspended from a vertically movable ring. Upon lowering of the ring the slips move downwardly and inwardly along the tapered bore to simultaneously and evenly grip the conduit. Upon raising of the ring the slips move upwardly and outwardly along the tapered bore and disengage from the gripped conduit. In the disengaged position two of the three slips are circumferentially slidable, through the suspension connection to the ring, to a position spaced from the front opening and adjacent the third slip, whereby the slip mechanism is laterally movable from, or about, the conduit. A funnel shaped guide skirt is mountable on the bottom of the mechanism when operation as an elevator is desired.

Abstract: A turn signal light housing has a translucent lens of arrow shaped configuration mounted on the housing in place of conventional circular lens without any need for modification of the housing.

Abstract: A rotary tong for use in well drilling operations to make up and break out drill strings or similar axially elongated objects which has a secondary camming action provided by the jaw assembly. By use of the inventive jaw assembly a secondary camming action is produced which reduces the cam angle of the primary camming function. The reduced cam angle gives greater gripping force thereby reducing slippage. The secondary camming function also allows the jaw to be used for a greater variety of drill string sizes thereby reducing the need to change tongs or jaw elements when drill string sizes change.

Abstract: An improved kelly is provided with a drive section which has a uniform cross section defined by three generally flat drive sides alternating with three generally arcuate sides. The three arcuate sides are spaced an equal radii from the central axis of the kelly and the three flat drive sides lie in planes that form an equilateral triangle therebetween.The improved kelly is driven by an improved mating kelly drive bushing which has three rollers positioned so as to evenly transmit torque to the three flat drive sides of the kelly simultaneously.

Abstract: A rotary tong used in well-drilling operations to make-up and break-out drill strings which incorporates readily-interchangeable sets of jaws, one of which may be used for drill pipe and the other of which can be used for relatively thin-walled well casing.

Abstract: This invention relates to a door mechanism for a rotary power tong, such as used in well drilling operation. The door is pivoted to one of the bifurcated portions of the tong and a door locking mechanism is used to attach the swinging end of the door to the other bifurcated portion of the tong. At least one contact surface is attached to the door to transmit forces to the door and engage a hook-like member attached to the tong frame. At least one contact member is attached to the frame to transmit forces to the frame and engage a hook-like member attached to the door. Such contact engagements provide for door support in both radial and tangential directions.