Protective device, in particular a tent or marquee, and connection device therefor

A protective device comprising:

• a membrane and a support device for the membrane, wherein the support device comprises an inflatable first support element with a flexible wall which forms a first pressure chamber, wherein the first support element has a first connection port with a first connection opening, wherein the support device has an inflatable second support element with a flexible wall which forms a second pressure chamber, wherein the second support element has a second connection port with a second connection opening, wherein a connection device for connection the first connection port to the second connection port is provided, wherein the connection device has a first connection part for connecting to the first connection port and a second connection part for connecting to the second connection port, wherein the first connection part comprises a main body having two outer threaded cylindrical portions with the first outer threaded cylindrical portion having a smaller radius than the second outer threaded cylindrical portion, wherein the first and second connection parts are connectable to one another in a detachable manner, wherein the connection device has a valve adapted to shut off the first connection opening, wherein the valve comprises a movable valve body, a valve seat and a biasing member which urges the valve body against the valve seat, wherein the second connection part has an actuating element which is arranged in such a manner that it moves the valve body from a closed position to an opened position if the second connection part is attached to the first connection part.