| Number | Name | Date | Kind |
|---|---|---|---|
| 2849237 | Simithis | Aug 1958 | |
| 3020046 | Hotas | Feb 1962 | |
| 4337939 | Hoyle et al. | Jul 1982 | |
| 5551937 | Kwo | Sep 1996 | |
| 5695438 | Bjornsti | Dec 1997 | |
| 5722919 | Timmer | Mar 1998 | |
| 5971902 | Robertson et al. | Oct 1999 |
| Number | Date | Country |
|---|---|---|
| 1288074 | Feb 1962 | FR |
| Entry |
|---|
| New York Barbells catalog (Undated). |
| Commercial Equipment catalog (Undated). |
| DE-STA-CLAMP catalog (Undated). |