Patent ID: 8678776

Claim:
A method for determining an extent of air leakage in a vacuum generating device, having an ejector device, the ejector device having an inlet connected with an air supply conduit and whose suction side is connected with a suction channel, which is connected with a suction gripper, and which has a pressure detection installation for detecting the vacuum in the suction channel, wherein the vacuum in the suction channel is regulated in that the air supply of the inlet is turned off at a time t 1 once the vacuum pressure has reached an upper switching value P SO and is switched on again at a time t 2 once the vacuum pressure drops to a lower switching value P SU and remains on until a time t 3 when the upper switching value P SO has been reached, and wherein a regulating time t R which has passed between a shutting off of the air supply at time t 1 and either a subsequent restarting at time t 2 , or a renewed shutting off of the air supply at time t 3 , is detected and compared with at least one predetermined reference time value in order to generate an electrical diagnostic signal as a function of the result of the comparison, and wherein the regulating time is a measure of how quickly the vacuum in the suction channel decays and the electrical diagnostic signal is determinative of an extent of leakage in the vacuum generating device.