Low distortion pipe coupling device

A pipe coupling device for releasably coupling a pair of pipes with peripheral end flanges together, comprising:

• a first arcuate retainer having a first end, a second end, and a groove with an inner gripping surface extending between said first and second ends for receiving a first portion of each of the peripheral end flanges of the pipes therein;
• a second arcuate retainer having a first end, a second end, and a groove with an inner gripping surface extending between said first and second ends of said second arcuate retainer for receiving a second portion of each of the peripheral end flanges of the pipes therein, said first and second retainers forming a circumferential loading line with the peripheral flanges of the pipes at its areas of greatest concentration of forces therebetween;
• a hinge including a plurality of first links and a plurality of second links with each of said first and second links being pivotally coupled to said retainers adjacent said first ends of said retainers by first and second pivot pins, respectively, each of said first and second links simultaneously engaging said first and second pins to simultaneously carry a portion of a coupling load applied to the peripheral flanges of the pipes by said coupling device, said first and second links having a line of force extending between said centers of said pins, and said first links being positioned on one side of the peripheral flanges of the pipes and said second links being positioned on the other side of the peripheral flanges of the pipes to straddle the peripheral flanges of the pipes, said first and second links being positioned close to said circumferential loading line;
• and
• a latch pivotally coupled to said second end of said first retainer by a third pivot pin and releasably coupled to said second end of said second retainer by a tension bolt with a nut threadedly coupled thereon.

A pipe coupling device for releasably coupling a pair of pipes with peripheral end flanges together, comprising:

• a one-piece first arcuate retainer having a first end with a first pivot point adjacent thereto, a second end with a recessed retaining surface adjacent thereto, and a groove with an inner gripping surface extending between said first and second ends for receiving a first portion of each of the peripheral end flanges of the pipes therein;
• a second one-piece arcuate retainer having a first end with a second pivot point adjacent thereto, a second end with a third pivot point adjacent thereto, and a groove with an inner gripping surface extending between said first and second ends of said second arcuate retainer for receiving a second portion of each of the peripheral end flanges of the pipes therein;
• a hinge pivotally coupling said first ends of said first and second retainers;
• and
• a latch having a tension bolt with one end pivotally coupled to said third pivot point at said second end of said second retainer by a pair of gusset plates and a nut threadedly coupled on the other end of the tension bolt for releasably engaging said recessed retaining surface at said second end of said first retainer, said latch having a coupling load line of force extending along its axis between said third pivot point and a contact point on said recessed retaining surface for pulling said second ends of said retainer together, said coupling load line of said latch being canted to extend substantially parallel to a tangent line extending through a point on said second end of said first retainer and non-tangently diverging from said second end of said second retainer, said latch engaging said contact point of said retaining surface at said coupling load line of force to apply an outwardly extending resultant pulling force on said second end of said first retainer away from the peripheral flanges of the pipes, and said latch pulling said second end of said second retainer at said third pivot point to apply an inwardly extending resultant pulling force on said second end of said second retainer inwardly towards the peripheral flanges of the pipes.