Pivotal back-up pads for welding
AssigneeCrutcher Resources Corporation
InventorTalbert D. Connell
Life of this patent
Estimating the term…
Abstract
An improved back-up pad apparatus for use in externally welding abutting ends of pipe comprises a plurality of arcuate back-up pads positioned to face the interior of the weld. Each arcuate pad is mounted on a support shoe for radial movement into and out of biased engagement with the interior cylindrical surfaces of the pipes. The arcuate pads are pivotally supported by the support shoes and biased about axes parallel with the centerline of the pipe to permit retraction of the pads without interference. Preferably, the pads are constructed of hard anodized aluminum material.
Claims11
A back-up pad apparatus for use in externally welding a joint between ends of pipes in a pipeline, which comprises:
- a plurality of arcuate back-up pads having curvatures complementary with the interior surfaces of the pipes to substantially span the inside circumference of the joint;
- support shoe means connected to each of said back-up pads intermediate the ends thereof and pivotally supporting said pads for radial movement into and out of engagement with the interior surfaces of said pipes at the joint;
- means for biasing each of said back-up pads for pivotal movement in the same direction;
- and
- means for selectively effecting radial movement of said support shoe means and the back-up pads supported thereon.
A back-up pad apparatus for use in externally welding the joint between ends of pipes in a pipeline having a centerline, and which is particularly suited for use with a pipe clamping mechanism having a plurality of clamp shoes selectively actuated in radial directions by piston rods into and out of clamping engagement with the inside surfaces of the pipes, said apparatus comprising:
- a plurality of back-up pads arranged end to end and circularly with each pad defining a segment of an arc complementary with the inside surfaces of the pipes;
- said back-up pads being sufficiently wide to substantially span the joint, and having substantially semicylindrical ends;
- support shoe means slidably mounted on certain ones of said piston rods for pivotally supporting each of said back-up pads for radial movement and for rotation about axes substantially parallel with the centerline of the pipeline;
- means for individually biasing said back-up pads for pivotal movement in the same direction;
- and
- means for resiliently biasing said support shoe means outwardly so that the back-up pads are moved into and out of engagement with the inside surfaces of said pipes at the joint responsive to actuation of the pipe clamp shoes.
Dependencies are inferred from the claim text.