Method and apparatus for bulge forming and bending tubes
AssigneeTools for Bending, Inc.
InventorsLarry D. Campbell, Gary Demartelaere, Ronald R. Stange
Life of this patent
Estimating the term…
Abstract
There is provided a device and manner for bulge forming and bending a tube or hollow extrusion, such as a pipe or conduit. The one portion of the length of the tube is bulge-formed to define a radially expanded, contoured section of the tube, while another portion of the tube length is bent to define an angle or curve in the tube. The device employs a radially expandable mandrel which serves both as the expandable member for bulge-forming the tube, as well as a bending mandrel to stabilize the tube against wrinkling or collapse during bending.
Claims32
A method for expanding a portion of a tube, said tube having a longitudinal axis, the method comprising:
- disposing a resilient, radially expandable mandrel within the portion of said tube, the mandrel having a free end and a stationary base end;
- pulling the free end of said mandrel axially toward the base and thereby axially compressing said mandrel to cause radial expansion of said mandrel under sufficient force to radially expand said tube surrounding said mandrel;
- and
- bending another portion of said tube about the axis of said tube.
A method for forming a tube, said tube having a portion to be expanded and a portion to be bent, the method comprising:
- placing a resilient mandrel within said portion to be expanded;
- radially expanding said mandrel to apply a deforming force to said portion to be expanded;
- radially contracting said mandrel;
- disposing said mandrel at least partially within said portion to be bent;
- and
- bending said portion to be bent while said mandrel is at least partially within said portion to be bent.
An apparatus for bulge-forming a portion of a tube, said tube having a longitudinal axis, said apparatus comprising:
- a resilient, radially expandable mandrel disposable within said portion of said tube, said mandrel comprising first and second compression members at opposite ends;
- and
- means, disposed at least in part between said compression members, for axially compressing said compression members to cause radial expansion of said mandrel including at least one bendable tendon means connected to said first compression member and extending axially at least partially through said mandrel for drawing said first compression member axially toward said second compression member to compress said mandrel axially between two said compression members.
Apparatus for forming a tube said tube having a portion to be expanded and a portion to be bent, said apparatus comprising:
- an elastically flexible and expandable mandrel disposable within said portion to be expanded;
- means for radially expanding said mandrel to apply a deforming force to said portion to be expanded;
- means for disposing said mandrel at least partially within said portion to be bent;
- and
- means for bending said portion to be bent while said mandrel is at least partially within said portion to be bent.
Dependencies are inferred from the claim text.