| 摘要 |
<p>599,139. Actuation of switches. DICKINSON, F. H., and LONDON PASSENGER TRANSPORT BOARD. Feb. 13, 1945, No. 3598. [Class 38(v)] [Also in Group XXXV] A switch mechanism comprises a number of co-operating switch actuating members interconnected by a multiplying gear train so that one of the members may revolve many times without repeated actuation of the switch and one switch may be restored after actuation only when the mechanism has been restored to its original condition. A shaft 28 drives a cam 37 cut away at 38 and also, through successive stages of reduction gearing the notched cams 40, 41 and 42; the shaft also drives a notched disc 52 whereby a switch arm 53 is operated to engage contact 58 or 59 according to the sense of rotation of shaft 28. When operated the arm 53 is held by a notch 55 or 56 on a lever 50 pivoted at 51 and carrying projections riding on cam 38 the notched cams 40-42. Repeated rotation of shaft 28 in the original sense has no effect on switch arm 53, which is only restored or operated in the reverse sense when the shaft 28 has retraced all its revolutions in the original sense to bring all the notches on the cams into register with the respective projections on lever 50.</p> |
