| Number | Name | Date | Kind |
|---|---|---|---|
| 5217191 | Smith | Jun 1993 | |
| 5564669 | Wu | Oct 1996 | |
| 5816554 | McCracken | Oct 1998 |
| Entry |
|---|
| Portable Pipe Hangers, Inc. Catalogue; pp. 9, 29, Sec. 07730/Sec. 15060 (1997/1998). |
| Brochure re: Portable Pipe Hangers, Inc. "Specifications for Standard Models" 1997/1998. |