| Number | Date | Country | Kind |
|---|---|---|---|
| 83 04589 | Mar 1983 | FRX |
| Number | Name | Date | Kind |
|---|---|---|---|
| 410107 | Kennedy et al. | Aug 1889 | |
| 1002907 | Dunn | Sep 1911 | |
| 1546025 | Rendleman | Jul 1925 | |
| 3583193 | Kishikawa | Jun 1971 | |
| 4086801 | Nakajima et al. | May 1978 | |
| 4294094 | Okado et al. | Oct 1981 | |
| 4402206 | Yanazawa et al. | Sep 1983 |
| Number | Date | Country |
|---|---|---|
| 744683 | Jan 1944 | DE2 |
| 2346063 | Mar 1977 | FRX |
| 2464759 | Sep 1980 | FRX |
| 174160 | Oct 1965 | SUX |
| 0623593 | Sep 1978 | SUX |
| 816583 | Mar 1981 | SUX |
| Entry |
|---|
| Patent Abstracts of Japan, vol. 4, No. 105, No. 55-64905, Iron and Steel Engineer, May, 1970, pp. 73-76. |