Foam pig with textured surface
US4797239A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 9, 1987 |
| Grant date | Jan 10, 1989 |
| Priority date | — |
| Expiry date | Apr 9, 2007 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29L2031/7406
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method of making a foam pig having a highly textured and tough surface for use in cleaning the interior wall of a pipe line, the pig being formed by heating a metallic mold which defines the exterior configuration of the pig, injecting urethane base foam mixture into the heated mold, and curing the injected urethane foam before removing the cured pig from the mold. The mold should be heated to a temperature sufficient to produce a tough surface texture on the completed pig defined by closely spaced indentations of about one-half to three millimeters in depth, the indentations being formed by bubbles in the urethane foam base mixture on the surface of the mold.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.