|
| US4031590 | 9 sept. 1975 | 28 juin 1977 | Midcon Pipeline Equipment Co. | Pipe scraper |
| US4353143 | 15 oct. 1980 | 12 oct. 1982 | | Sweeping apparatus |
| US4562608 | 29 juin 1984 | 7 janv. 1986 | | Chimney cleaning brush |
| US5195392 | 14 mai 1990 | 23 mars 1993 | Niagara Mohawk Power Corporation | Internal pipe inspection system |
| US5329824 | 15 juil. 1993 | 19 juil. 1994 | Niagara Mohawk Power Corporation | Centralizer for internal pipe inspection device |
