| 1931 GEN KONTROLAR COMPANY INC Chime Patent |
| 1931 GEN ELECTRIC Indicator System Patent Print |
| 1931 GEN RAILWAY SIGNAL CO Signaling System Railroads |
| 1931 GEN Intermittent Inductive Train Control System |
| 1931 PIERCE RAYMOND Tank Car GEN AMERICAN TANK CAR CORP |
| 1931 GEN ELECTRIC Electric Clock Patent Print |
| 1931 GEN STEEL CASTINGS CORP Railway Vehicle Underframe |
| 1931 GEN ELECTRIC Ship Propulsion Patent Print |
| 1931 GEN RAILWAY SIGNAL CO Track Instrument Art |
| 1931 GEN STEEL CASTINGS CORP Locomotive Structure |
| 1931 GEN MOTORS CORP Running Board Support Art |
| 1931 GEN Locomotive Spring Equalizing System Art |
| 1931 GEN ELECTRIC System Producing Music Art |
| 1931 GEN MOTORS CORP Loading Equipment Patent |
| 1931 GEN STEEL CASTINGS CORP Railway Car Structure |
| 1931 GEN Oil Electric Locomotive Platform Art |
| 1931 GEN Locomotive Tender Structure Art Print |
| 1931 HICKS HARLIE Bumper GEN MOTORS CORP Patent |
| 1931 GEN Interlocking System Railroads Art Print |
| 1931 GEN RAILWAY SIGNAL CO Interlocking Railroads |
| 1931 GEN Train Dispatching System Railroads Art |
| 1931 GEN ELECTRIC Sewing Machine Patent Print |
| 1931 GEN ELECTRIC Propulsion Multiple Screw Ships |
| 1931 GEN STEEL CASTINGS CORP Railway Truck Centering |
| 1931 GEN Light Signal System Railroads Art Print |
| 1931 GEN AMERICAN TANK CAR CORP Supporting Structure |
| 1931 GEN ELECTRIC Musical Instrument Patent |
| 1931 GEN PAINT CORP Method Loading Wrapped Pipe |
| 1931 GEN ELECTRIC Spring Suspension System Art |
| 1931 GEN Traffic Controlling System Railroads |
| 1931 GEN MOTORS CORP Transmission Ignition Lock |
| 1931 GEN ELECTRIC Light Projector Patent Print |
| 1931 GEN MOTORS CORP Bumper Patent Print Art |
| 1931 GEN Brake Railroad Switch Machines Art |
| 1931 GEN MOTORS CORP Journal Box Car Frame Construction |
| 1931 GEN STEEL CASTINGS CORP Cab Underframe Art |
| 1931 GEN RAILWAY SIGNAL CO Railway Track Circuit |
| 1931 GEN Railway Traffic Controlling System Art |
| 1931 GEN ELECTRIC VAPOR LAMP CO Support Means |
| 1931 GEN ELECTRIC Gear Backlash Compensator Art |
| 1931 GEN ELECTRIC Ship Propulsion System Patent |
| 1931 GEN AMERICAN TANK CAR CORP Tank Car Patent |
| 1931 GEN MOTORS RES CORP Coincidental Lock Art |
| 1931 GEN ELECTRIC Electrically Wound Clock Art |
| 1931 GEN RAILWAY SIGNAL CO Switch Machine Railroads |
| 1931 GEN STEEL WARES LTD Railway Lantern Patent |
| 1931 USS AKRON (zeppelin) cover -GEN. DEL. AUSTIN, TEX. |