2534715 | Photoelectric web controlled sound reproducer | 1950-12-19 | ||
2529374 | Article selector and price-setting unit | 1950-11-07 | ||
2469650 | Multiple push-button switch | 1949-05-10 | ||
2431904 | Push-button switch | 1947-12-02 | ||
2430189 | Indicating switch | 1947-11-04 | ||
2381978 | Impulse transmitter | 1945-08-14 |