| 1920 ARGYLE Car Door Operating Mechanism Patent |
| 1920 ARGYLE Door Operating Mechanism Patent |
| 1920 TALLY Railway Switch Operating Mechanism |
| 1920 WILLIAM Theater Curtain Operating Mechanism |
| 1920 LANSING Looper Operating Mechanism Sewing Machines |
| 1920 HART Door Operating Mechanism Patent 8801 |
| 1920 COSEY Switch Operating Mechanism Patent |
| 1920 KING Mounting Shuttle Operating Levers Art |
| 1920 ENTPR Car Door Operating Mechanism Art |
| 1920 FULLER Operating Mechanism Whistles Art |
| 1920 KONSTANTINOVICH Ventilator Operating Art |
| 1920 COLLENS Switch Operating Street Railroad Cars |
| 1920 ENTPR Door Operating Mechanism Art Print |
| 1920 SMALLBONE Mounting Shuttle Operating Levers |
| 1920 DUNCAN Bass Drum Operating Mechanism Patent |
| 1920 PHILIP Tail Gate Operating Mechanism Dump Trucks |
| 1920 HALIBURTON Gear Operating Bulkhead Doors Like |
| 1920 FRANCIS Controlling Power Operating Mechanism |
| 1920 ARCHIBALD Door Operating Self Dumping Mine Cars |
| 1920 ALLEN Door Operating Self Dumping Mine Cars |
| 1920 UNION Looper Operating Mechanism Sewing Machines |