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US2658191A
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Electric signal for trackless trolley coaches
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US2700760A
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Detector for worn carbon inserts
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US2664472A
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Automatic electric frog
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US2494409A
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Trolley frog switch
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US2494311A
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Trolley frog approach end
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US2361358A
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Vehicular actuated switch
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US2268962A
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Trolley frog
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US2357289A
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Trolley contactor
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US2302890A
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Trolley contactor
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US2253756A
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Electric switch
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US2268016A
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Trolley switch control system
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US2302898A
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Control for electric track switches
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US2202471A
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Trolley contactor
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US2199941A
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Trolley frog and approach end
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US2268922A
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Automatic control for trolley frogs
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US2171278A
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Vehicle-controlled selective system
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US2171865A
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Selective control system
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US2292820A
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Double trolley line switch
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US2076101A
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Trolley contactor
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US2039493A
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Sealing means for electric switch ground boxes
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