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 fig3 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 fig1 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.