| # | Country | Total Patents | |
|---|---|---|---|
| #1 | United States | 11 | |
| #2 | Canada | 1 |
| # | Industry | |
|---|---|---|
| #1 | Machines | |
| #2 | Mechanical elements | |
| #3 | Audio-visual technology | |
| #4 | Machine tools | |
| #5 | Packaging and shipping | |
| #6 | Transport |
| # | Technology | |
|---|---|---|
| #1 | Unspecified technologies | |
| #2 | Gearing | |
| #3 | Turning | |
| #4 | Unspecified technologies | |
| #5 | Advertising | |
| #6 | Containers for goods storage | |
| #7 | Vehicle parts | |
| #8 | Clutches and brakes |
| # | Name | Total Patents |
|---|---|---|
| #1 | Campbell Leon J | 12 |
| Publication | Filing date | Title |
|---|---|---|
| US1800928A | Transmission mechanism | |
| US1865233A | Closure for collapsible tubes | |
| US1365657A | Transmission-lock | |
| US1394607A | Variable-speed-transmission mechanism | |
| US1158370A | Operating device for punch-press clutches. | |
| US1058149A | Safety attachment for high-speed drills. | |
| US1048035A | High-speed drill. | |
| US1035152A | Speed-transmission mechanism. | |
| US1135354A | Transmission-gearing. | |
| US960271A | Seal-lock. | |
| US765766A | Seal for cars, &c. | |
| CA226937A | Variable speed transmission mechanism |