| 2327429 | Remote control system | 1943-08-24 | ||
| 2269856 | Direct current impulse operated selector switch | 1942-01-13 | ||
| 2049615 | Automatic switching system | 1936-08-04 | ||
| 2014011 | Remote control apparatus | 1935-09-10 | ||
| 1919046 | Selective calling circuits | 1933-07-18 | ||
| 1888985 | Selective signaling system | 1932-11-29 | ||
| 1814524 | Remote control system | 1931-07-14 |
| GB713631A |