Air compressor having quick coupling device

An air compressing device comprising:

• a cylinder housing,
• a piston slidably engaged in said cylinder housing,
• a piston rod extended from said piston, and
• a motor attached to said cylinder housing and coupled to said piston rod with a coupling device for moving said piston relative to said cylinder housing in a reciprocating action, in order to generate a pressurized air,
• said cylinder housing including an outlet tube extended outwardly therefrom and communicating with said cylinder housing for receiving the pressurized air from said cylinder housing, and including an outlet port provided on said outlet tube and having a bore formed in said outlet port and communicating with said outlet tube for receiving the pressurized air from said outlet tube and said cylinder housing, and including an anchor plate extended from said outlet port, and
• a facility including a coupler for engaging with said outlet port and said anchor plate and for detachably securing said coupler and said facility to said outlet port of said outlet tube and for allowing the pressurized air to be supplied to said facility, said coupler including a base plate, and two arms extended from said base plate and spaced from each other for forming a space between said arms and for forming a retaining space in said coupler and for engaging with said anchor plate, and said coupler including an inwardly folded flange extended from each arm for partially closing said space and for engaging with said anchor plate, and said anchor plate including two rounded corners oppositely formed thereon for allowing said coupler to be rotated relative to said anchor plate, said facility including a mouth extended into said coupler for engaging into said bore of said outlet port of said outlet tube.