Electrohydraulic drive unit for wings of doors or the like

摘要

The electrohydraulic drive unit for wings of doors or the like has a piston (9) which can be displaced counter to the force of a closing spring (10) by means of a pump (2) when the solenoid valve (8) is closed, until the end position corresponding to the open position of the wing coupled to the piston (9) is reached. If the pump (2) is then stopped while the solenoid valve (8) remains closed, the closing spring (10) displaces the piston (9) due to slight leakage in the hydraulic system. As soon as this displacement has reached a predetermined slight amount, the pump (2) is briefly put into operation again, with the result that the piston (9) and the wing are once more moved into the abovementioned end position.