Abstract: A method for locking an internally threaded end piece such as a head piece, a tail piece, an end or sealing nut to a mandrel for a down hole tool to obviate the need for pins, set screws, and the like, to provide a more robust assembly. In two embodiments the threaded end piece is locked to the mandrel in a swaging operation.

Abstract: A bypass plunger includes a unibody, or one-piece hollow body and valve cage, retains a dart valve within the valve cage portion using a threaded retaining nut secured by crimple detents, and includes sealable flow parts. A series of helical grooves surround the central portion of the outer surface of the hollow body of the plunger to control spin during descent. A canted-coil-spring disposed within the retaining nut functions as a clutch. The valve cage includes ports that may be configured to control flow through the plunger during descent. Other embodiments include clutch assemblies using canted-coil springs with split bobbins, and surfaced valve stems surfaced.

Abstract: A bypass plunger formed as an integral one-piece hollow body-and-valve cage unit retains a dart valve within a valve cage section of the hollow body with a threaded retaining nut that may be secured by crimple means. A boundary zone, defined along the plunger body, where the integral valve cage section adjoins the plunger body, is configured with a uniform outer diameter to maximize the plunger body wall thickness and durability of the one-piece bypass plunger. The valve cage may have flow ports configured with ramps at an angle with the longitudinal axis to control flow through the flow ports during descent of the bypass plunger. A clutch assembly using garter springs with split bobbins may be disposed within the valve cage portion of the one-piece bypass plunger.

Abstract: A bypass plunger includes a plunger body that includes a head portion located at one end of the plunger body and a tail portion located at an opposite end of the plunger body. The head portion includes at least one flow port, and the tail portion includes at least one passageway. A valve component is disposed within an internal bore of the plunger body and is movable between an open position and a closed position. At least one plug is located within a respective one of the flow ports and/or a respective one of the passageways, and is configured to reduce or prevent flow through the respective flow port or the respective passageway.

Abstract: A bypass plunger combines a unitary or one-piece hollow body-and-valve cage, retains a dart valve within the valve cage portion of the hollow body using a threaded retaining nut secured by crimple detents. A series of helical grooves surround the central portion of the outer surface of the hollow body of the plunger to control spin during descent. A canted-coil-spring disposed within the retaining nut functions as a clutch. The valve cage includes ports that may be configured to control flow through the plunger during ascent. Other embodiments include clutch assemblies using canted-coil springs with split bobbins, and valve stems surfaced to achieve specific functions. Combinations of these features provide enhanced performance, durability and reliability at reduced manufacturing cost, due primarily to the simplicity of its design.

Abstract: An automatic release valve assembly for a bumper spring, comprising a hollow cylindrical valve seat sleeve having a plurality of flow ports and flow passages disposed in the sidewalls thereof; a valve ball sized to engage by contact with a robust valve seat; a multiple coil spring disposed over the sleeve portion of the valve seat sleeve; wherein the valve seat sleeve, ball, and coil spring are enclosed within a hollow cylindrical housing. The housing includes within its bore a central region of a plurality of parallel, elongated and interleaved grooves and ridges to permit released fluid to flow and to stabilize the operation of the valve assembly.

Abstract: A bypass plunger combines a unitary or one-piece hollow body-and-valve cage, retains a dart valve within the valve cage portion of the hollow body using a threaded retaining nut secured by crimple detents. A series of helical grooves surround the central portion of the outer surface of the hollow body of the plunger to control spin during descent. A canted-coil-spring disposed within the retaining nut functions as a clutch. The valve cage includes ports that may be configured to control flow through the plunger during ascent. Other embodiments include clutch assemblies using canted-coil springs with split bobbins, and valve stems surfaced to achieve specific functions. Combinations of these features provide enhanced performance, durability and reliability at reduced manufacturing cost, due primarily to the simplicity of its design.

Abstract: A bypass plunger combines a unitary or one-piece hollow body-and-valve cage, retains a dart valve within the valve cage portion of the hollow body using a threaded retaining nut secured by crimple detents. A series of helical grooves surround the central portion of the outer surface of the hollow body of the plunger to control spin during descent. A canted-coil-spring disposed within the retaining nut functions as a clutch. The valve cage includes ports that may be configured to control flow through the plunger during ascent. Other embodiments include clutch assemblies using canted-coil springs with split bobbins, and valve stems surfaced to achieve specific functions.

Abstract: An improved latch structure for a two piece ball and sleeve bypass plunger comprises a single retaining ring installed in a groove formed in the inside diameter of the sleeve portion of the bypass plunger. The cross section profiles of the groove and the associated retaining ring are smaller in the radial direction. The depth of the groove in the sleeve is substantially reduced to provide increased wall thickness and robustness of the sleeve along the diameter of the sleeve, thereby extending the useful life of the bypass plunger.

Abstract: A minimum parts bypass plunger includes a main shaft or pushrod extending through a hollow plunger body that incorporates flow passages formed in the adjacent surfaces of the pushrod or the internal bore of the plunger body. The pushrod is retained within the plunger body by respective head and tail pieces or caps that are locked to the plunger body by 360 degree crimps around the head and tail pieces. A one piece clutch is supported in the head piece. The pushrod, has an integral valve head that closes the flow passages when seated against a seat in the plunger body.

Abstract: A bypass plunger combines a unitary or one-piece hollow body-and-valve cage, retains a dart valve within the valve cage portion of the hollow body using a threaded retaining nut secured by crimple detents. A series of helical grooves surround the central portion of the outer surface of the hollow body of the plunger to control spin during descent. A canted-coil-spring disposed within the retaining nut functions as a clutch. The valve cage includes ports that may be configured to control flow through the plunger during ascent. Other embodiments include clutch assemblies using canted-coil springs with split bobbins, and valve stems surfaced to achieve specific functions.

Abstract: A clutch assembly formed as a circular split bobbin assembly for resisting reciprocating motion of a shift rod or dart valve stem in a bypass plunger. The split bobbin may include at least one circumferential groove disposed in its outer radius, and a tension band member disposed in each circumferential channel to secure the split bobbin assembly around the shift rod or valve stem and wherein the tension band member has a cross section aspect ratio R<1.

Abstract: A dart valve assembly includes a dart valve and a clutch that restrains the movement of the dart valve within the bore of a dart valve cage or plunger body between a closed and an open position. The clutch includes a clutch bobbin formed of a synthetic material, and both the inside diameter of the clutch bobbin and the outside diameter of the dart valve stem of the dart valve assembly are configured with a sequence of alternating ridges and grooves to improve clutch action through reduced friction.

Abstract: A bumper spring assembly having a one piece mandrel including an integral head piece is further configured with a cage assembly retained on the mandrel with a cage nut locked to the mandrel to obviate the need for pins, set screws, and the like, to provide a more robust assembly. In two embodiments the cage nut is locked to the mandrel in a swaging operation. Improved flow of fluids through and around the bumper spring assembly are also provided.