US Patent 9371924 One-piece flap device, injection-moulded from elastic material

A one-piece flap device made of elastic material, which separates two distinct volume spaces. The one-piece flap device includes:a) a substantially cylindrical body including a through conduit,b) a flap that seals an aperture of the through conduit of the body when the flap is in a closed position and is within said body, andc) an arm connecting the body of the device to the flap.The arm is in an elastic stress position regardless of the position of the flap when inside said body.