Abstract: A fluid mixing device for, for example, mixing of the pigment carrier and the hardener of a two-component paint, comprising a mixing chamber and a resilient membrane dividing the mixing chamber into two compartments. The compartments have separate inlets and a common outlet, the common outlet being arranged so as to continuously communicate with one of the compartments but to be open toward the separate inlets only when the membrane is pressed off a seat surrounding the outlet. The membrane, which is formed with a central opening for maintaining the continuous communication between the outlet and one of the compartments, is preloaded toward its seat so as to break the communication between the outlet and the other of the compartments as the ratio between the fluid pressures in the compartments is below a certain level. The mixing device may be incorporated in the handle of a spray gun, wherein a mixing tube is connected at its outlet to accomplish a final mixing.

Abstract: A spraying device for applying, through an injection opening, a coating material such as anticorrosion oil onto the inner walls of a hollow body, comprising a spray gun provided with an atomizing nozzle and an interchangeable front piece connected down stream thereof. The front piece comprises an ejector barrel for introduction through said injection opening and a positioning collar rigidly attached thereto, the positioning collar. The latter being adapted to define the position of the ejector barrel during spraying. A control unit connected to the spray gun comprises means for determining the duration of each spray operation from the very moment the trigger of the spray gun is pulled.