Abstract: A system for spraying accurately controlled quantities of a liquid mixture of two or more fluids from a plurality of fixedly positioned spray nozzles is disclosed. The nozzles are spaced to provide a substantially uniform flow pattern over a predetermined width. The fluids are supplied to separate manifolds and are distributed to the nozzles by separate feed lines running from the manifolds. All of the feed lines from a given manifold are of equal length to maintain essentially identical pressure drops. A holding tank is provided in the line between a fluid supply and its manifold to provide a fixed static pressure head from which to draw fluid.

Abstract: An improved hot air knife for use in removing excess solder from a circuit board in a mass soldering system of the type described in U.S. Pat. Nos. 4,410,126 and 4,401,253 is described. In the present invention the hot air knife comprises a commercially available square tube, one of whose edges has been cut to provide the air knife outlet. Inside this tube, there is provided a second round tube for introducing hot air into the space between the round tube and the square tube. This inner round tube has holes facing away from the outlet slit of the square tube, preferably at least 45 degrees on both sides of a plane extending from the outlet of the square tube to the opposite corner of the square tube. In a preferred embodiment of the invention there is also provided at least one baffle in the volume between the outlet holes from the inner tube and the outlet slot for the air knife.

Abstract: A soldering system is described in which a fluid stream is directed onto a solder board substantially immediately following the deposition of molten solder onto the boards. The apparatus includes a pair of concentric slotted tubular shells wherein one shell rapidly rotates relative to about the other to create a plurality of different angles of impingement of the air on each area of the bottom surface of the circuit board.