Method and appartus for the measurement of the load in an elevator

An apparatus for the measurement of the load in an elevator cage supported in a carrying frame by spring elements, the cage being movable with respect to the frame and the cage and frame together are movable in an elevator shaft by a hoist cable guided over a drive pulley, a motor control drives the drive pulley and executes travel commands received from an elevator control, said apparatus comprising:

• a signal transmitter for measuring a movement of the elevator cage relative to an elevator shaft due to passenger loading and unloading,
• a travel signal generator for generating a travel signal corresponding to the movement of the elevator cage relative to the elevator shaft,
• an evaluating unit, said evaluating unit comprising a first converter for ascertaining a first load magnitude corresponding to the travel signal,
• said first load magnitude influencing a motor current controlled by the motor control.

A method for the measurement of a load in an elevator cage, the elevator cage mounted for movement relative to a carrying frame and to an elevator shaft and moved relative to the carrying frame and elevator shaft by load changes within the elevator cage, said method comprising:

• evaluating a first signal corresponding to the movement of the elevator cage relative to the elevator shaft;
• evaluating a second signal corresponding to a cage load;
• evaluating a third signal, based upon the first signal and the second signal;
• transmitting the third signal to a motor control to control a motor current.

An apparatus for the measurement of a load in an elevator cage, the elevator cage mounted for movement relative to a carrying frame and to an elevator shaft and moved relative to the carrying frame and elevator shaft by load changes within the elevator cage, said apparatus comprising:

• means for evaluating a first signal corresponding to the movement of the elevator cage relative to the elevator shaft;
• means for evaluating a second signal corresponding to a cage load;
• means for evaluating a third signal, based upon the first signal and the second signal;
• means for transmitting the third signal to a motor control to control a motor current.