04235469 is referenced by 18 patents and cites 10 patents.

An apparatus for insertion into the interior of large diameter pipe or tubing which engages inner portions of the pipe so that the pipe may be lifted and moved. Slip assemblies are wedged into engagement with inner portions of the pipe. The amount of wedging may be varied with a hydraulic cylinder or other suitable power source. Pipe guide members are provided to insure centering of the apparatus within the pipe.

Title
Pipe handling apparatus
Application Number
6/38248
Publication Number
4235469
Application Date
May 11, 1979
Publication Date
November 25, 1980
Inventor
James E Aswell
Houston
TX, US
Lawrence A Denny
Orange
CA, US
Agent
Pravel Gambrell Hewitt Kirk Kimball & Dodge
Assignee
Den Con Tool Company
CA, US
IPC
E21C 19/00
View Original Source