Spraying apparatus for the production of foamed plastic materials for use as fillers and insulations

Claim 1

A FOAM-PRODUCING SPRAYING APPARATUS COMPRISING, AT LEAST TWO COAXIALLY RELATED PIPES FORMING INNER AND OUTER CHAMBERS HAVING AN UPSTREAM AND DOWNSTREAM END; CONDUIT MEANS CONNECTED TO THE UPSTREAM END OF SAID RESPECTIVE INNER AND OUTER CHAMBERS FOR DIRECTING A SUPPLYOF MIXABLE FLUID MATERIAL THERETO; MECHANICAL PRE-FOAMING MEANS DISPOSED IN THE OUTER CHAMBER PROMOTING THE FORMATION OF FOAM IN THE FLUID MATERIAL PASSING THERETHROUGH PRIOR TO MIXTURE WITH THE FLUID IN THE INNER CHAMBER; RESTRICTING MEANS ON THE DOWNSTREAM END OF SAID INNER CHAMBER CONTROLLING THE EMISSION OF FLUID FOR MIXTURE WITH THE PRE-FOAMED FLUID MATERIAL; AND A CHAMBER-FORMING MEMBER SECURED TO SAID PIPE FORMING SAID OUTER CHAMBER AND FORMING A MIXING CHAMBER DOWNSTREAM OF SAID INNER AND OUTER CHAMBERS AND IN WHICH SAID SUPPLY OF PRE-FOAMED FLUID MATERIAL AND FLUID FROM THE CHAMBERS ARE MIXED PRIOR TO LEAVING SAID APPARATUS.