GB775232A - Improvements in apparatus for simultaneously discharging materials - Google Patents

Abstract

<PICT:0775232/III/1> Apparatus for simultaneously spraying two materials such as paint, disposed in a container 7, and a hardening agent, disposed in a container 8, comprises a positive displacement pumping device having two separate pumping chambers 13, 19 containing pistons 16, 17 respectively joined by a shank 36. Under the action of compressed air introduced into the top of the container 7, paint is forced through conduit 12 to pump chamber 13. As the differential piston moves upwardly hardening agent from container 8 is sucked through a conduit 20 into pump chamber 19. Compressed air introduced at 33 passes through a valve chamber 42 and conduit 31 to close a valve 22 in the conduit 12, through conduit 34 to close a valve 27 in conduit 20 and through a conduit 35 to act on the top of the piston 16. A spray gun 1 has a compressed air supply 4, a connection with the chamber 19 through a conduit 3, and a connection with chamber 13 through a conduit 2. The spray gun has a trigger 5 which controls material and air valves in the gun. When the trigger is pressed these valves are opened and material is delivered to the gun as the pistons 16, 17 descend under the action of the compressed air above piston 16. Valve chamber 42 is automatically vented to atmosphere when the gun 1 is hung on a hook 37. In a modification, an arrangement for varying the proportions of feeding the materials comprises an adjustably pivoted arm 56, Fig. 2, one end of which is attached to a piston 17 working in a fixed cylinder 19 and the other end of which is attached to a cylinder 14 slidably mounted on a piston 16. Paint is fed to the space above the piston 16 through a bore 55 in the piston rod 52. The pivot point 57 may be adjusted within a slot 60 in the arm 56 for adjusting the proportions of feeding materials.