| Number | Date | Country | Kind |
|---|---|---|---|
| 903061 | Jun 1990 | FIX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 1323345 | Wisner | Dec 1919 | |
| 1516710 | Caputo | Nov 1924 | |
| 3071833 | Tumey | Jan 1963 | |
| 3530540 | Mueller | Sep 1970 | |
| 3687412 | Vaughan et al. | Aug 1972 | |
| 3881856 | Fougea | May 1975 | |
| 3924295 | VerBurg | Dec 1975 | |
| 4634359 | Sartorio | Jan 1987 | |
| 4666387 | Yokota et al. | May 1987 |
| Number | Date | Country |
|---|---|---|
| 1459229 | May 1971 | DEX |
| 2128496 | Dec 1971 | DEX |
| 2042151 | Mar 1972 | DEX |
| 2907508 | Sep 1980 | DEX |
| 304132 | Jun 1971 | SUX |
| 476991 | Oct 1975 | SUX |
| 700334 | Nov 1979 | SUX |
| 2103143 | Feb 1983 | GBX |
| Entry |
|---|
| English abstract DE 2907508. |
| English abstract SU 476 991. |
| English abstract SU 700 334. |
| Betonwerk & Fertigteil-Technik, Heft 6/90, p. 123 (Advertisement with English text). |