| 1942 BOLZ Audible Signal Device Patent Print Art |
| 1942 UNION SWITCH SIGNAL CO Approach Control |
| 1942 LLOYD RITTENHOUSE Chime Signal Patent Print |
| 1942 JOHN KELLY Vehicle Signal Light Patent |
| 1942 UNION SWITCH SIGNAL CO Approach Control System |
| 1942 EGGERT Gas Flow Control Valve Signal Lights |
| 1942 UNION SWITCH SIGNAL CO Electrical Relay Art |
| 1942 BENITO Signal Pontoon For Submarines Patent |
| 1942 UNION Railway Signal Control Indication |
| 1942 NICHOLSON Railway Signal Control Circuit |
| 1942 A E RITTENHOUSE CO INC Chime Signal Patent |
| 1942 UNION SWITCH SIGNAL CO Remote Control System |
| 1942 MILDEBRATH Hand Brake Signal Patent Print |
| 1942 UNION SWITCH SIGNAL CO Railway Braking Art |
| 1942 B J BANDY Sewing Machine Signal System Art |
| 1942 BLOSSER Railway Signal Control Circuit Art |
| 1942 UNION SWITCH SIGNAL CO Stationary Contact |
| 1942 UNION SWITCH SIGNAL CO Railway Signal System |
| 1942 GEN RAILWAY SIGNAL CO Railway Signaling System |
| 1942 UNION SWITCH SIGNAL CO Electrical Control |
| 1942 UNION SWITCH SIGNAL CO Railway Track Circuit |
| 1942 UNION SWITCH SIGNAL CO Railway Signaling |
| 1942 GEN RAILWAY SIGNAL CO Timing System Patent |
| 1942 SUBMARINE SIGNAL CO Diaphragm Whistle Art |
| 1942 UNION SWITCH SIGNAL CO Circuit Controller |
| 1942 UNION SWITCH SIGNAL CO Signaling Art Print |
| 1942 E INGRAHAM Audible Signal Clock Art Print |
| 1942 ABRAHAM Distress Signal Patent Print Art |
| 1942 UNION SWITCH SIGNAL CO Control Art Print |
| 1942 UNION Railway Signal Control Circuit Art |
| 1942 STERN Signal Art |
| 1942 SWANSON FRANK Signal Structure Patent Print |
| 1942 EMIL AGER Audible Signal Clock Patent Print |
| 1942 SCHWARZE ELECTRIC COMPANY Signal Patent |
| 1942 PORTABIE LAMP & EQUIPMENT COMP Signal Art |
| 1942 GEN MOTORS CORP Warning Signal System Art |
| 1942 BELL TELEPHONE LABOR INC Audible Signal |
| 1942 GEN RAILWAY SIGNAL CO Coded Track Circuit Railways |
| 1942 WINDHAM Sewing Machine Signal System Patent |
| 1942 HARRY QUENON Signal PORTABIE LAMP EQUIPMENT COMP |
| 1942 REINHOLD SCHWINZER Chime Signal Patent |
| 1942 TRIUMPH EXPLOSIVES INC Signal Flare Patent |
| 1942 THOMPSON Railway Signal System Patent Print |
| 1942 GORDON Warning Signal System Patent Print |
| 1942 NACHOD UNITED STATES SIGNAL Track Instrument |
| 1942 UNION SWITCH SIGNAL CO Railway Signaling System |
| 1942 UNION SWITCH SIGNAL CO Decoding Art Print |
| 1942 UNION SWITCH SIGNAL CO Electromagnetic Switch |
| 1942 UNION Point Signal Control System Railways Like |
| 1942 YOUNG Railway Signal Control Indication |
| 1942 DICKSON Point Signal Control System Railways Like |
| 1942 UNION SWITCH SIGNAL CO Switch Indication Circuits |
| 1942 UNION SWITCH SIGNAL CO Remote Control Art |
| 1942 RAYMOND T KELLY Vehicle Signal Light Patent |
| 1942 ABRAHAM HARGREAVES Distress Signal Patent |
| 1942 WALLACE TIERNAN INC Sound Signal Art Print |
| 1942 MACKAY Sound Signal Apparatus Patent Print |
| RADIO NEWS NOVEMBER 1942/ U.S. ARMY SIGNAL CORPS ISSUE |
| 1942 ARMY SIGNAL CORP MILITARY RADIO NEWS TANK GUN MOTU |
| 1942 Union Switch & Signal Ad CTC Expedites War Traffic |