Patent ID: 7591490

Claim:
A coupling device for a quick-release connection of a pipe with an outlet for a pressurized medium, comprising: a connecting part having an outlet, a contracting surface thereon and a quadratic periphery with outwardly and circularly curved corners forming an outwardly arched enlarged area at each of said corners, said contacting surface having a recess with a base and a border surrounding said outlet, each of said corners having a threaded bore; an end flange fixed on an end of a pipe, said end flange having an end surface and a peripheral face and being received in said recess with said end face engaging said base and with said peripheral face engageable with said border to protect against radial displacement of said end flange; clamping screws anchored on said connecting part and directly engaging spring washers that directly engage a rear surface of said end flange opposite said end surface to press said end surface against said base, each said threaded bore receiving one of said clamping screws and positioned relative to said recess such that said peripheral face at said end flange overlaps one of a head and a nut on each of said clamping screws; and a sealing element interposed between said end flange and said base.