| 摘要 |
Magnetic control apparatus (32) for intensifying a magnetic field to actuate a magnetic control member (34) and for preventing simultaneous actuation of a pair (34, 36) of magnetic control members. In one (32) of several embodiments a pair (38, 40) of selectively movable magnets each respectively produces a magnetic field which, when a magnet is moved into position, is directed by a pair (42, 54) of elongated bars across the pair (34, 36) of control members to actuate one of the members in response to the field. The pair (42, 54) of bars bypass the magnetic fields from the control members (34, 36) when both magnets (38, 40) are in such a position to attempt to actuate the control members (34, 36). The pair (42, 54) of elongated bars intensify the magnetic fields at the control members (34, 36), thereby permitting the use of relatively weak magnets at a substantial distance from the members (34, 36). The pair (42, 54) of bars also provide a magnetic interlock, preventing undesirable simultaneous actuation of the members (34, 36). The apparatus (32) can be used on a pedal (100) of a fork lift truck to actuate one member (34) to shift a transmission into forward drive and to actuate the other member (36) to shift the transmission into reverse drive. Also disclosed is magnetic control apparatus (10) to perform only the function of field intensification. |
