Patent ID: 9713387
Date: 2017-07-25
CPC Classifications: A47C

Claim:
1. An electromotive furniture drive for adjusting a movable part of a piece of furniture, said electromotive furniture drive comprising: an output element; at least one adjusting drive including at least one electric motor and a revolution speed reducing gear mechanism coupled to the at least one electric motor, said revolution speed reducing gear mechanism being coupled in driving relationship to the output element to linearly displace and/or rotatably move the output element, wherein the output element, upon reaching a predetermined position, actuates at least one member selected from the group consisting of an end switch, a reference switch, and a switching unit; at least one control device comprising a positioning apparatus which is configured to position the output element, said positioning apparatus including a control block having a counter and a memory device for evaluating pulses of a back-EMF of the at least one electric motor; at least one operating unit operatively connected to the at least one control device to operate the at least one adjusting drive; and at least one monitoring apparatus configured to monitor a pulse-width ratio of a detected back-EMF of the at least one electric motor, said at least one monitoring apparatus comprising at least one filter unit with a pulse former and a load monitoring device with a pulse-width ratio detector, a comparator, and a signal generator, said pulse width ratio detector being configured to detect the pulse-width ratio of the detected back-EMF of the at least one electric motor, said comparator comparing the detected pulse width ratio with a predetermined value and causing the signal generator to generate a signal for control of the at feast one electric motor for throttling the at least one electric motor.