Patent 5734244 Issued on March 31, 1998. Estimated Expiration Date: May 15, 2016. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
318/452, Plural, diverse conditions or with time-delay means318/560, POSITIONAL SERVO SYSTEMS (E.G., SERVOMECHANISMS)318/567, Program- or pattern-controlled systems318/608, Phase comparison700/186, Digital positioning technique700/254Compensation or calibration
An appliance which, through motor-driven operation, is movable toward a closing edge, in particular, for use with window regulators and sliding roofs of automotive vehicles. For this purpose, the number of revolutions of the motor is permanently detected, with the number of revolutions of the motor being measured in successive measuring intervals. The number of revolutions is to be a measure of the force acting on the pane. Respectively the last four measured values are detected in a sliding register and are subjected to evaluation. For this purpose, first a start-up value is detected. The start-up value respectively is the third last measured value ni-3 if the difference D between the current measured value and the third last measured value does not exceed a predetermined differential threshold Dmax. For, in that case, the start-up value remains unchanged. Subsequently, the difference A is formed between the start-up value and the current value ni. If the latter is above a predetermined response threshold Amax, the anti-clamping system responds. This means that the driving motor is turned off and, optionally, is inverted in the direction of rotation thereof. More specifically, the forces acting on the pane are successively integrated from one measured interval to the next as long as there is some sort of increase from one measured interval to the next. As soon as the integration value A reaches the response threshold Amax, the anti-clamping system responds. In this way a sensitive and rapidly responding protection against clamping is realized, wherein error signals based on fluctuations in the frictional resistance of the pane guide are suppressed.
English Translation of the International Preliminary Examination Report for Application PCT/EP94/02868
Search Report of the German Patent Office for Application No. P4330904.