| # | Country | Total Patents | |
|---|---|---|---|
| #1 | United States | 9 | |
| #2 | Canada | 3 |
| # | Industry | |
|---|---|---|
| #1 | Packaging and shipping | |
| #2 | Electrical machinery and energy | |
| #3 | Mechanical elements | |
| #4 | Machines |
| # | Technology | |
|---|---|---|
| #1 | Elevators and escalators | |
| #2 | Electric motor controls | |
| #3 | Servomotors | |
| #4 | Unspecified technologies | |
| #5 | Gearing | |
| #6 | Winches |
| # | Name | Total Patents |
|---|---|---|
| #1 | Pratt Charles R | 12 |
| Publication | Filing date | Title |
|---|---|---|
| US1911389A | Elevator machine | |
| US1828748A | Hoisting apparatus | |
| US1165121A | Controlling apparatus. | |
| CA139589A | Rotary piston power transmission device | |
| CA139580A | Rotary piston power transmission devices | |
| CA114362A | Elevator | |
| US1048999A | Controlling mechanism for motors. | |
| US958679A | Elevator safety device. | |
| US865205A | Elevator. | |
| US853733A | Elevator safety device. | |
| US763204A | Moving stairway. | |
| US676152A | Elevator safety device. |