| 摘要 |
<p>490,527. Electromagnetic switches. FERRANTI, Ltd., NORRIS, E. D. T., and NEWTON, N. Feb. 12, 1937, No. 4177. [Class 38 (v)] [Also in Group XXXV] Fig. 1 shows a relay, which may be of the kind described in Specification 465,058 and comprises earthing coils k, m in the respective circuits controlled by the relay contacts. To prevent the resetting action from moving the switch a beyond its mean position, a catch plate p has notches s, t co-operating with a tongue q rigidly attached to the relay arm e, and an electromagnet x brings a tongue. u into the path of the tongue q each time a relay circuit is closed. A dashpot z delays the withdrawal of the tongue u by gravity. In a modification, a tongue 9, Fig. 4, on the relay arm e lies between the poles of an electromagnet 10 when the relay is in its mean position, the magnet being energized as in the previous arrangement. In a further form, Fig. 5, three mutually rigid vanes 13, 14, 15 are pivoted at 26 to the relay arm e. The vane 15 is weighted and lies in an oil bath. The remaining vanes frictionally engage a fixed plate 12 when resetting occurs.</p> |
