| 摘要 |
A floor switch mounted on an elevator shaft wall has a housing from which a shaft extends. An arm has one end attached to the shaft and an opposite end atta ched to a roller. The roller is engaged by a switching vane mounted on an elevator ca r during up and down travel of the car in the shaft. As the car passes the switch the vane rotates the arm and the shaft to move a lever which is coupled to actuate s witch contacts in the housing. To avoid the engagement of the roller by the vane, a ma gnetic switch is mounted in the housing and is responsive to a magnet mounted on the ca r. The magnet mounted on the car passes the magnetic switch shortly before the vane is to engage the roller and the magnetic switch connects a coil in the housing to e lectrical power. The coil retracts an armature which is coupled to the lever to move the r oller out of the path of travel of the vane.
|
