Method and apparatus for bending corrugated pipe

A method of providing a desired bend angle in a length of corrugated pipe having first and second ends and alternating, annular ridges and valleys spaced along that pipe length between said ends, said method comprising the steps of:

• (A) engaging said pipe length between a pair of cooperating bending dies in the vicinity of the first end with at least one pipe end spaced above a planar support surface, said bending dies being on opposite sides of the corrugated pipe for grasping the pipe solely on the outside of the pipe,
• (1) one bending die having an arcuate seat engaging only a pair of adjacent ridges at the heel of the bend and the second die having an arcuate seat engaging only the valley intermediate said pair of ridges in opposing relationship to the one die at the throat of the bend;
• (B) moving said dies one relative to the other so as concurrently to reform the configuration of the valley and change the linear spacing between said adjacent ridges to effect a segmental arc bend thereat;
• and
• (C) effecting additional segmental arc bends, where necessary, over a consecutive sequence of valleys and ridges of said pipe length directly related to the desired bend angle.

A method of providing a desired bend angle in a length of corrugated pipe having first and second ends and alternating, annular ridges and valleys spaced along the pipe length between said ends, said method comprising the steps of:

• (A) engaging said pipe length between a pair of cooperating bending dies in the vicinity of the first end with the pipe ends spaced above a planar support surface, said pair of dies being located on opposite sides of the corrugated pipe for grasping the pipe solely on the outside of the pipe, one bending die having an arcuate seat engaging only a pair of adjacent ridges at the heel of the bend angle and the second die having an arcuate seat engaging only the valley intermediate said pair of ridges in opposing relationship to the one die at the throat of the bend angle;
• (B) maintaining the pipe second end spaced above the support surface;
• (C) controlling the radial position of the pipe around the longitudinal axis of the pipe;
• (D) moving said dies one relative to the other so as concurrently to reform the configuration of the valley and change the linear spacing between said adjacent ridges to effect a segmental arc bend thereat;
• and
• (E) effecting additional segmental arc bends, where necessary, over a consecutive sequence of valleys and ridges of said pipe length directly related to the desired bend angle.

An apparatus for providing a bend angle in a length of corrugated pipe having first and second ends and alternating, annular ridges and valleys spaced along that pipe length between said ends, successive ridges being uniformly formed along the pipe at substantially a certain distance, said apparatus comprising:

• a die set consisting of a pair of cooperating bending dies arranged on opposite sides of the corrugated pipe to receive therein the pipe length in the vicinity of the first end and for grasping the pipe only on the outside of the pipe, the first bending die having a pipe engaging surface that is only an arcuate, half cylindrical surface seat extending along a first axis, which has a width, as measured along said first axis, of substantially said certain distance, engagable only with a pair of adjacent ridges at the heel of the bend angle and the second die having an arcuate, half cylindrical surface seat extending along a second axis parallel to said first axis, which has a width, as measured along said second axis, substantially less than said certain distance and is centrally located relative to said width of said first bending die seat, engagable only with the valley intermediate said pair of ridges in opposing relationship to the one die at the throat of the bend angle;
• and
• movement means for moving the dies one relative to the other so as functionally to engage the pipe length between the pair of dies and concurrently to reform the configuration of the valley and change the linear spacing between said adjacent ridges to effect a segmental arc bend thereat;
• the segmental arc bends being effected, where necessary, over a consecutive sequence of valleys and ridges of said pipe length directly related to the desired bend angle.

An apparatus for providing a bend angle in a length of corrugated pipe having first and second ends and alternating, annular ridges and valleys spaced along that pipe length between said ends, said apparatus comprising:

• a bending tool arranged to receive therein the pipe in the vicinity of the first end, said bending tool comprising a die set consisting of a pair of cooperating bending dies on opposite sides of the corrugated pipe for grasping the pipe only on the outside of the pipe and movement means, the first die having an arcuate seat engagable with only a pair of adjacent ridges at the heel of the bend angle and the second die having an arcuate seat engagable with only the valley intermediate said pair of ridges in opposing relationship to the one die at the throat of the bend angle, the movement means for moving the dies one relative to the other so as functionally to engage the pipe length between the pair of dies and concurrently to reform the configuration of the valley and change the linear spacing between said adjacent ridges to effect a segmental arc bend thereat;
• a planar, support surface extending from said bending tool substantially perpendicular to said pair of dies;
• and
• fixture means retained on said support surface and engaging said pipe length at said second end, said fixture means for maintaining the pipe second end spaced above the support surface and for controlling the radial position of the pipe around the longitudinal axis of the pipe while the segmental arc bend is effected;
• there being additional segmental are bends effected, where necessary, over a consecutive sequence of valleys and ridges of said pipe length directly related to the desired bend angle.