Patent ID: 8662861

Claim:
An ejector device configured to generate a negative pressure by compressed air that is fed from an external source (P) of compressed air to an ejector ( 1 ) supported in the ejector device, the ejector device comprising: a valve assembly configured to control feeding of the compressed air to the ejector, the valve assembly comprising a primary valve ( 5 ; 50 ) arranged in a compressed-air duct ( 2 , 2 ′) and a secondary valve ( 6 ; 60 ) arranged in the compressed-air duct downstream of the primary valve, in the direction of flow of the compressed air from the external source (P) to the ejector; an air suction duct ( 3 ) by which negative pressure is fed from the ejector to a gripping member ( 4 ) driven by negative pressure; a ventilation duct ( 74 , 79 ) that is open to atmospheric pressure; a vent valve ( 7 ; 70 ) arranged in the ventilation duct open to atmospheric pressure, the vent valve being biased towards an open state which provides air communication between the gripping member and atmospheric pressure via the air suction duct and the ventilation duct, the vent valve being configured, when in a closed state, to prevent communication between the gripping member and atmospheric pressure; and a flow duct ( 73 ) communicating air pressure from the compressed-air duct ( 2 , 2 ′) to the vent valve ( 7 ; 70 ); wherein the primary valve ( 5 ; 50 ) in open state sets the vent valve ( 7 ; 70 ) under pressure of compressed-air which closes the vent valve, and wherein the primary valve ( 5 ; 50 ) in closed state connects the vent valve ( 7 ; 70 ) with atmospheric pressure via an exhaust ( 56 ) from the primary valve to atmosphere.