| 1929 UNION SWITCH SIGNAL CO Railway Switch Controlling |
| 1929 JAN Automatic Railroad Crossing Gate Signal |
| 1929 JOHN LONG Electric Railway Signal Lantern |
| 1929 RYDER Motor Vehicle Signal Patent Print Art |
| 1929 GEN RAILWAY SIGNAL CO Magnetic Car Retarder |
| 1929 WEATHERS Ornamental Traffic Signal Patent 49343 |
| 1929 THOS J CORCORAN LAMP CO Motor Vehicle Signal |
| 1929 NEW YORK AIR BRAKE CO Signal System Patent |
| 1929 JOSEPH KLIMALA Railway Signal Patent Print |
| 1929 WATERHOUSE Design Traffic Signal Patent 49344 |
| 1929 PAUL EBERSPACHER Traffic Signal Patent |
| 1929 EMANUEL AUFIERO Warning Signal Patent Print |
| 1929 SMITH Railroad Crossing Signal Patent Print |
| 1929 UNION SWITCH SIGNAL CO Automatic Train Recorder |
| 1929 SCOTT LOUIS Marine Signal Light Patent |
| 1929 RENN A RATHBURN Signal Switch Motor Vehicles |
| 1929 UNION SWITCH SIGNAL CO Railway Signaling |
| 1929 SPENCER Traffic Signal Lamp Post Patent 49346 |
| 1929 BUCKLEY Signal For Airships Patent Print |
| 1929 BLANKENSHIP Railway Crossing Signal Patent |
| 1929 BLANKENSHIP CASPER Cab Signal Patent Print |
| 1929 THOMAS Electric Signal System Patent Print |
| 1929 HOWE WINTHROP Light Signal Patent Print Art |
| 1929 UNION SWITCH SIGNAL CO Motor Controlling |
| 1929 WESTINGHOUSE AIR BRAKE CO Electric Signal System |
| 1929 BALDER Housing Taxi Call Signal Patent 49384 |
| 1929 TAYLOR Signal Attachment Locomotives Art |
| 1929 SCOTT Theft Alarm Signal Motor Driven Vehicles |
| 1929 MCFARLAND Signal For Railroad Crossings Art |
| 1929 CHICAGO RAILWAY SIGNAL SUPPL Lamp Adjusting |
| 1929 SPARKS WITHINGTON CO Diaphragm Signal Art |
| 1929 DAVIS Railway Crossing Signal Patent Print |
| 1929 EWING Signal Control Apparatus Patent Print |
| 1929 SCOTT Marine Signal Light Patent Print Art |
| 1929 CARDWELL Automatic Railroad Grade Crossing Signal |
| 1929 CRITCHFIELD ROBERT Sound Signal Patent |
| 1929 DANIEL HEWITT Highway Signal Patent Print |
| 1929 CAMPBELL CHARLES Signal System Patent Print |
| 1929 ERNST WILCKENS Signal Buoy Patent Print Art |
| 1929 OTTO Electric Railway Signal Lantern Patent |
| 1929 UNION SWITCH SIGNAL CO Railway Switch Operating |
| 1929 REITZ Railway Crossing Signal Patent Print |
| 1929 YATARO MIYAOKA Car Door Signal Patent Print |
| 1929 ERNST Signal Buoy Patent Print Art |
| 1929 SCHOOLEY Railway Signal Torpedo Patent |
| 1929 WITHINGTON Diaphragm Signal Patent Print |
| 1929 STANLEY Automatic Railroad Grade Crossing Signal |
| 1929 UNION SWITCH SIGNAL CO Railway Signaling System |
| 1929 CASSELL Motor Vehicle Signal Patent Print |
| 1929 GEN RAILWAY SIGNAL CO Light Signal Patent |
| 1929 MILLER CHARLIE Railway Signal Patent Print |
| 1929 ROBERT Railway Signal Locking Device Patent |
| 1929 CHARLES WAINWRIGHT Signal Whistle Patent |
| 1929 UNION SWITCH SIGNAL CO Train Stop System |
| 1929 GEORGE ZINT Signal Patent Print Art |
| 1929 WILLIAM JONES Crossing Signal Patent Print |
| 1929 LEITNER Signal Means For Automobiles Patent |
| 1929 SPENCER New Traffic Signal Lamp Post Patent 49347 |
| 1929 JOHNSON Signal Switch Motor Vehicles Art |
| 1929 DELCO REMY CORP Sound Signal Patent Print |
| 1929 pc Oil Fields at Signal Hill, Long Beach CA |