| 摘要 |
524,733. Adjusting wireless apparatus. NAAMLOOZE VENNOOTSCHAP PHILIPS GLOEILAMPENFABRIEKEN. April 1. 1939, No. 10248. Convention date, April 4, 1938. [Class 37] The rectilinear motion of a push-button control for tuning or switching operations in a radio receiver is converted into a rotary motion of the controlled member by means of a helical transmission. The push-buttons 5, 6 press inwards a plate 8 mounted in a rod member 9, which moves axially in the sleeve portion 16 of a drum 37 by virtue of axial and coinciding grooves 10, 11, 12, 13 which together form housings for the balls 15, 14. Two spiral ballgrooves 21, 22, 23 of substantially V-section are provided in member 9 and co-operate with balls 19, 20 and a V-section circular track in member 17, rotation of which consequent on axial movement of member 9 is transferred through slots 35 and pin 36 to the tuning condenser spindle 33. A ball thrust-bearing 25 is provided and a spring 30 opposes the tuning movement, thus taking-up play and restoring the spindle to its initial position when the button is released. For manual tuning, knob 39 operates drum 37 through a cord drive the members 16, 9. 17, 33 then rotating together. Axial movement of member 16 is prevented by a fixed stud 41 engaging a circular groove in the member. |
