| 摘要 |
1,096,186. Mixing apparatus; spray-producers. PERAMETERS CO. Ltd. Feb. 3, 1966 [Feb. 11, 1965], No. 5946/65. Headings B1C and B2F. Mixing: A mixing gun for polyurethane foams has a mixing chamber with two limbs 5, 33 at right angles, and supplied through non-return valves 6 and 7 with metered liquids comprising a polyisocyanate, and a mixture of polyol and catalyst; a low boiling-point liquid pre-expanding agent is supplied through line 8. The chamber has an outlet valve 40 which in operation is set to open at a pressure in excess of that at which the pre-expanding agent will volatilize. The supply of the latter is regulated by a needle-valve (9, see Fig. 4, not shown) and controlled by an obturating diaphragm (26) which can be deflected by compressed air to interrupt communication between two ports (27, 28). The gun may be fitted with an extension chamber (54, see Fig. 6, not shown) having baffles (56, 57) and an outlet valve (55) set to open at a lower pressure than the valve 40. The extension chamber may be supplied through a non-return valve (61) and inlet (63). There are air and solvent supply ports for purging the gun. Spraying. The gun may alternatively be fitted with a spraying device, Fig. 7, having a tube 65 extending into a bore 75 in a spray head 71. Air is supplied to a chamber 68 and issues from the annular clearance between the tube 65 and bore 75, and from two pairs of passages 76 of which one pair issues into the conical outlet 74 at 45 degrees to its axis and the other pair at 15 degrees. |
