| 摘要 |
1,214,299. Controlling vehicles. JOSEPH LUCAS (INDUSTRIES) Ltd. 26 March, 1968 [14 April, 1967], No. 17188/67. Heading B7H. [Also in Divisions F2 and H1] An electromagnet, for preventing operation of a gear-box at high engine speeds, has " pull in " and " hold in " coils 18 and two armatures 14, 15 (or one armature 14 and a non-magnetic part 15) biased into engagement by respective springs 16, 17, the spring 16 being stronger than the spring 17 so that when the coils 18 are not energized the armatures are moved away from the fixed core 12. The coils are energized on closure of an engine speed sensitive switch (not shown) when the engine speed is below a predetermined level. The armature 14 is attracted into the coils and the armature 15 or an alternative non-magnetic part will move in the same direction so that its outer end is withdrawn from the gear-box to allow the gears to be operated to select a lower gear. Toward the end of its movement the armature 14 engages a plunger 24 to open contacts 13 and de-energize the " pull in " coil. A non-magnetic spacer may be provided between the armatures 14, 15 (Fig. 2, not shown). If the driver applies pressure to the gear selector lever before the engine speed falls the armature 15 will be trapped and not move until the pressure is removed. |
