| Number | Name | Date | Kind |
|---|---|---|---|
| 1869951 | Worthington | Aug 1932 | |
| 3143807 | Christie | Apr 1964 | |
| 3324556 | Everett | Jun 1967 | |
| 3494037 | Arber | Feb 1970 | |
| 3977085 | Sandifer | Aug 1976 | |
| 4162577 | Cosman | Jul 1979 | |
| 4199867 | Cass | Apr 1980 |
| Entry |
|---|
| Description of a pendulum design machine which was in existence approximately 35 years ago. |