Dedent system

Abstract

The invention provides a dedent system, which comprises a bullet shank and a cable shank. The bullet shank comprises a male shank portion and a first latching portion. The first latching portion comprises a first contacting surface and a locking hole, and the locking hole is tilted such that an opening on the first contacting surface is closer to the male shank portion than a portion of the locking hole which is farther from the first contacting surface. The cable shank comprises a female shank portion and a second latching portion. The second latching portion comprises a second contacting surface and a locking bump. The female shank is connected to a cable, and the locking bump is tilted such that a portion of the locking bump on the first contacting surface is farther to the female shank portion than the a tip portion of the locking bump.

1 . A dedent system for repairing a pipe damaged with dents comprising:
 a bullet shank comprising a male shank portion and a first latching portion, wherein the first latching portion comprises a first contacting surface and a locking hole provided through the first contacting surface and the male shank portion is configured to be connected with a mandrel, and wherein the locking hole is tilted such that an opening on the first contacting surface is closer to the male shank portion than a portion of the locking hole which is farther from the first contacting surface; and   a cable shank comprising a female shank portion and a second latching portion, wherein the second latching portion comprises a second contacting surface and a locking bump provided on the second contacting surface, wherein the locking bump is configured to engage with the locking hole of the bullet shank, wherein the female shank is configured to be connected to a cable, and wherein the locking bump is tilted such that a portion of the locking bump on the first contacting surface is farther to the female shank portion than the a tip portion of the locking bump,   wherein the bullet shank and the cable shank are connected by engaging the locking hole and bump so as to be engaged under a force in a first direction parallel to the axis of the cylinders and easily disengaged from each other under a force in a second direction perpendicular to the axis of the cylinders.   
   
   
       2 . The dedent system of  claim 1 , wherein the male shank portion of the bullet shank has a shape of cylinder, wherein the first latching portion of the bullet shank has a shape of half-cylinder sharing an axis with the male shank portion. 
   
   
       3 . The dedent system of  claim 2 , wherein the first contacting surface of the latching portion of the bullet shank is substantially flat and parallel to the axis of the cylinders, wherein the locking hole of the bullet shank is substantially perpendicular to the axis of the cylinders, and wherein a cross-section of the locking hole is oblong. 
   
   
       4 . The dedent system of  claim 1 , wherein the female shank portion of the cable shank has a shape of cylindrical tube, wherein the second latching portion of the cable shank has a shape of half-cylinder sharing an axis with the cable shank portion, and wherein the second contacting surface of the second latching portion of the cable shank is substantially flat and parallel to the axis of the cylinders. 
   
   
       5 . The dedent system of  claim 4 , wherein the locking bump of the cable shank extends substantially perpendicularly to the axis of the cylinders, wherein the locking bump of the cable shank is configured to lock with the locking hole of the bullet shank, and wherein the first and second contacting surfaces contact each other over most of the first and second contacting surfaces. 
   
   
       6 . The dedent system of  claim 1 , further comprising:
 a pipe holding device for holding the pipe having a near end and a far end in position, comprising a processing deck for supporting the pipe in position, an overhanging deck for holding and positioning the pipe, and a pipe stopper for aligning and stopping the pipe against the force exerted by the mandrel driven by the winch;   the mandrel, with a cross section and size adapted to be pulled through the interior of the pipe from the far end to the near end, having a first edge, a second edge, and a side surface;   the cable having first and second ends, wherein the first end is queued into the pipe and detachably attached to the first edge of the mandrel at the far end of the pipe;   a winch disposed at the near end of the pipe and connected to the second end of the cable for winding up the cable; and   a slope disposed by the cable and tilted from the far end of the pipe to the near end of the pipe,   wherein the mandrel is pulled by the winch with the cable, wherein the mandrel travels through the pipe to push out from inside and remove the dents on the surface of the pipe, and wherein the slope is configured to return the mandrel from the far end to the near end.