Abstract:
A connecter ( 30 ) for connecting a pair of pipe sections ( 32,33 ) together. The connector ( 30 ) includes three internally threaded segments ( 58 ) which are mounted for sliding radial movement in the connector ( 30 ). The connector ( 30 ) is first mounted on an internally threaded female end ( 34 ) of one pipe section ( 32 ) and then the male end ( 40 ) of the other pipe section ( 33 ) is forced within the internally threaded segments ( 58 ) for threaded engagement.

Description:
FIELD OF THE INVENTION 
     This invention relates to a connector for pipe sections and more particularly to a connector mounted in the female end of one pipe section for connecting the male threaded end of a second pipe section to the connector. 
     BACKGROUND OF THE INVENTION 
     Heretofore, quick acting nut or coupling assemblies have been provided in which a threaded nut is quickly positioned on a threaded bolt by pushing of the nut onto the bolt. A jam nut comprising three separate segments which may expand radially are provided. The segments have a radial spring to urge the segments radially inwardly as the segments slide along an inclined or frustoconical surface into and out of engagement with the threads on the externally threaded bolt. For example, U.S. Pat. No. 5,324,150 dated Jun. 28, 1994 shows a quick acting nut assembly in which three radially inwardly biased arcuate segments are provided to engage the threads of a bolt. The arcuate threaded segments are positioned within a casing and frustoconical surfaces are provided between the segments and the outer casing for radial sliding movement of the segments. A radial spring urges the segments into engagement with the external threads on the mounted bolt. An outer cap is provided to hold the segments within the casing and is secured to the outer casing. Detents are provided for the three arcuate segments to retain the segments against rotation within the outer casing. The arcuate segments have an enlarged diameter upper end portion and engage the outer casing along two spaced frustoconical surfaces for support. The segments slide along the pair of inclined or frustoconical surfaces of the casing for inward and outward radial movement relative to the externally threaded male member. 
     It is desired that a quick acting coupling be provided between a pair of pipe sections to permit an upper pipe section to be quickly connected to a lower pipe section. 
     SUMMARY OF THE INVENTION 
     The present invention is particularly directed to a connector or coupling for connecting a pair of pipe sections to each other. The connector is first threaded into an internally threaded end of the lower pipe section and then the upper externally threaded end of the upper pipe section is pushed or lowered within the internally threaded end of the connector. To obtain a fast acting connection of the upper pipe section, three or more radially inwardly biased arcuate female segments are mounted within the casing of the connector for inward and outward sliding radial movement along an inclined frustoconical surface of the casing. The segments have a large diameter lower end portion to provide a relatively large lower end surface for contacting the frustoconical surface of the casing. Radial springs about the segments urge the segments radially inwardly. Detents integral with the body of the casing are secured within grooves of the segments to keep the segments from rotating relative to the connector upon engagement with the externally threaded pipe section. 
     An upper cap having an inclined lower surface contacts the upper inclined surface of the segments to hold the segments in position in the outer casing and to permit inward and outward radial movement of the arcuate segments. The upper pipe section may be secured within the internally threaded female end of the connector with the radial spring holding the female threads on the connector and the male threads on the upper pipe section in mating engagement. For removal, a reverse rotation of the upper pipe section unthreads the upper pipe section from the connector. A relatively large lower frustoconical surface extending inwardly from inner peripheral surface of the connector supports the arcuate segments for sliding movement and provides a bearing surface to facilitate sliding movement of the arcuate segments. 
     It is an object of the present invention to provide a quick acting coupling or connector for connecting the pipe sections to each other. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a longitudinal sectional view of a coupling comprising the present invention and showing an upper pipe section received within the coupling which is threaded within an internally threaded lower pipe section; 
     FIG. 2 is a cross sectional view taken generally along line  2 — 2  of FIG. 1; and 
     FIG. 3 is a longitudinal sectional view of the connector shown in FIGS. 1 and 2 with the pipe sections removed from the connector. 
    
    
     DESCRIPTION OF THE INVENTION 
     The present invention is particularly directed to a coupling or connector generally indicated at  30  for coupling lower pipe section  32  to upper pipe section  33 . Pipe sections  32  and  33  may comprise drill pipe having a length of forty (40) feet and around three and one half (3½) inches in external diameter. Lower pipe section  32  has an upset end or box  34  with an annular upper shoulder  35  and a central bore  36  including tapered internal end screw threads  38 . Upper pipe section  33  has a tapered end portion or pin  40  having external screw threads  42  and an annular shoulder  43 . It is desirable to connect pipe sections  32  and  33  to each other and connector or coupling  30  is effective for connecting pipe sections  32  and  33  to each other. 
     Coupling or connector  30  has a body  44  with an extending externally threaded tapered end portion  46  on one end having external screw threads  48  and a shoulder  45 . The other end has an annular rim or lip  50  with a beveled end  52  about a central bore  54  in axial alignment with bore  36  of pipe section  32 . A sleeve or casing generally indicated at  55  is secured to body  44  and has an inner frustoconical surface  56  extending at an angle A with respect to the longitudinal axis of coupling  30 . Casing  55  has an upper end  59 . Fitting within casing  55  are three arcuate segments  58  having internal screw threads  60  extending at an angle B relative to the rotational or longitudinal axis of connector  30  as shown in FIG.  3 . Angle B is greater than angle A. For example, angle A may be about 50 degrees and angle B about 60 degrees. Since angle B is greater than angle A, an improved threaded connection is obtained between screw threads  42  on pipe section  33  and screw threads  60  on arcuate segments  58 . Also, the angle variance between threads  60  and lower frustoconical surface  56  prevent segments  58  from disengaging pipe section  33  until a rotation of 270 degrees is provided between connector  30  and pipe section  33 . A pair of radial springs  62  extend about segments  58  and continuously urge segments  58  radially inwardly into tight contact with pipe section  33  when pipe section  33  is mounted within segments  58  as shown in FIG.  1 . Segments  58  have upper outer frustoconical surfaces  57  and lower inner frustoconical surfaces  64 . Outer frustoconical surfaces  57  extend at the same angle as frustoconical surface  56 . The inner frustoconical surfaces  64  of segments  58  extend at an angle C relative to the longitudinal axis of connector  30 . Angle C is generally the same as angle A and may be about 50 degrees. The arcuate end  52  of annular lip or rim  50  contacts the inner ends  64  of arcuate segments  58  to provide minimal frictional contact upon radial movement of arcuate segments  58  inwardly and outwardly during operation of connector  30 . To restrain relative rotation of segments  58  relative to sleeve  54 , detents  68  extend radially inwardly from the inner peripheral surface  69  of casing  55  and are formed integrally with casing  55 . Detents  68  are received within grooves  71  in arcuate segments  58  for rotation of segments  58  with casing  55 . 
     Operation 
     When pipe sections  32  and  33  are utilized as drill pipe for lowering within a bore hole, connector  30  is preferably connected to lower pipe section  32  before pipe section  32  is lowered within the bore hole. After pipe section  32  of a drill string is lowered within a bore hole with connector  30  tightly secured thereto, pipe section  33  is then lowered onto the drill string. The weight of pipe section  33  when pin  40  is in axial relation with arcuate segments  58  and received therein forces segments  58  radially outward with lower surfaces  57  of segments  58  sliding along frustoconical surface  56 . Upon abutting engagement of shoulder  43  with shoulder  59  the downward movement of pipe section  33  is stopped and arcuate segments  58  are urged by radial springs  62  into threaded engagement with pin  40 . Subsequent rotation of pipe section  33  relative to connector  30  results in a tight connection between connector  30  and pipe section  33  with connector  30  tightly gripping pipe section  33 . After connection of pipe section  33  the drill string may be lowered within the bore hole and additional pipe sections may be added. Each pipe section has a pipe on one end and a box or upset end on the opposite end. To disconnect pipe section  33  from pipe section  32 , pipe section  33  may be rotated in a reverse direction for unthreading of pipe section  33  from connector  30 . 
     It will be understood by those skilled in the art that the embodiment shown and described is exemplary and various other modifications may be made in the practice of the invention. Accordingly, the scope of the invention should be understood to include such modifications which are within the spirit of the invention.