Patent ID: 8378610
Filing Date: 2013-02-19
Classification: F16H

Abstract:
1. Linear actuator comprising a reversible DC-motor, a transmission, a spindle in driving connection with the DC-motor through the transmission, a spindle nut arranged on the spindle and secured against rotation, such that it is displaceable between two end stop positions on the spindle, at least one end stop switch for interrupting the current to the DC-motor in the two end positions of the spindle nut or signaling of the end stop position, a position determination system for determining the position of the spindle nut on the spindle, wherein the position determination system comprises at least one further switch that could be activated by the spindle nut and a microprocessor containing a calculation model, which calculation model includes i) one or more of the physical parameters of the actuator and which as input has ii) dynamic values for absorbed power, and where the spindle nut's activation of the at least one end stop switch and the at least one further switch iii) gives a signal for calibration of the position of the spindle nut on the spindle calculated from the calculation model.