Spray gun having valved flexible liner

Claim 1

A SPRAY GUN COMPRISING A BODY HAVING A NOZZLE SECTION, A HANDLE SECTION, A LIQUID CONTAINER-SUPPORTING SECTION, AND A LIQUID PASSAGE EXTENDING THROUGH SAID NOZZLE AND CONTAINER-SUPPORTING SECTIONS, SAID PASSAGE HAVING A RELATIVELY SHORT SECTION OF RELATIVELY GREAT CROSS-SECTIONAL AREA IN SAID CONTAINER-SUPPORTING SECTION AND A RELATIVELY LONG SECTION OF RELATIVELY SMALL CROSS-SECTIONAL AREA IN SAID NOZZLE SECTION, A UNITARY LINER OF FLEXIBLE SHEET MATERIAL LINING SAID LIQUID PASSAGE FROM END TO END THEREOF AND CONFORMING TO THE CONTOURS OF SAID PASSAGE, SAID CONTAINERSUPPORTING SECTION HAVING AN ANNULAR EDGE PORTION CONSTITUTING THE MOUTH OF SAID PASSAGE, SAID EDGE PORTION HAVING AN INTERNAL ANNULAR SHOULDER, SAID LINER HAVING AN END PORTION OVERLYING SAID SHOULDER, AND A CONTAINER-HOLDING BRACKET CARRIED BY SAID CONTAINER-SUPPORTING SECTION AND HAVING A THREADED MEMBER ACUTABLE TO EXERT CLAMPING PRESSURE ON SAID LINER END PORTION AND SHOULDER TO RETAIN SAID LINER IN POSITION, SAID LINER BEING OTHERWISE UNATTACHED TO SAID CONTAINER-SUPPORTING SECTION TO PERMIT WITHDRAWAL THEREFROM, AN ARM PIVOTALLY MOUNTED IN SAID BODY AND ENGAGING THE EXTERIOR SURFACE OF SAID RELATIVELY LONG SECTION OF SAID LINER, A SPRING IMPOSING PRESSURE ON SAID ARM TO COLLAPSE SAID LINER AND CLOSE SAID LIQUID PASSAGE, AND A MANUALLY OPERABLE LEVER MOUNTED ON SAID BODY AND ENGAGING SAID ARM TO MOVE SAID ARM AGAINST THE ACTION OF SAID SPRING AND OUT OF COLLAPSING ENGAGEMENT WITH SAID LINER.