Abstract: A running gear for hoists and suspended loads has a running rail with two spaced-apart travel tracks that support axially spaced-apart running wheels. An electric motor is coupled to a self-locking worm gear for directly driving one of the running wheels. The running wheels are rotatably supported in a frame to which an assembly for hoisting suspended loads is secured. In order to prevent the running gear from rolling and pitching during braking, which can cause increased wear of the running gear and the running rail, a control unit is provided which is operatively connected to the electric motor and determines a start-up rate during the start-up phase of the motor from an average increase of the motor torque as a function of time, and decreases the motor torque as a function of time at a slower rate than the start-up rate for slowing down the running gear.

Abstract: A process and apparatus for positioning an object being moved along a path to a destination using a pole changing three-phase induction motor having at least two fixed driving speeds. The object is initially accelerated along the path of movement to the highest driving speed of the motor, during which the acceleration curve is determined and stored. The acceleration data is then used to calculate the location along the path in advance of the destination at which the motor is switched off and braked until reaching the next lower driving speed, whereupon the motor is operated at the next lower driving speed for a predetermined path length. The motor is then again switched off and braked until its driving speed reaches zero closely proximate the destination, at which point a motor in a gear assembly attached to the motor is operated for final low speed positioning of the object at the destination with a high degree of accuracy.