Patent ID: 7798426

Claim:
A fluid reservoir for a gravity-fed spray gun comprising: a rigid thermoplastic outer framework, the framework defining a cavity having a fill opening; a collapsible liner positioned within the fill opening of the outer framework, the liner being formed from a thermoplastic material, the liner having a comparatively rigid closed base, and side walls, or wall in the case of a cylindrical liner, which are thin in comparison to the base, the closed base and sidewall(s) defining a fill opening, wherein the liner is capable of standing unsupported on the base with the side walls, or wall, extended and upright, and wherein the liner has no pleats, corrugations, seams, joints or gussets, and no groove at the internal junction of the side wall(s) with the base; and a removable lid located in the fill opening of the liner, wherein the lid contains a fluid outlet and fits sufficiently tightly on the liner such that the lid and liner are held together, wherein the fluid outlet of the lid is adapted to be connected to a gravity-fed spray gun, and the combination of the outer framework and liner have fill openings which are inverted when connected to a spray gun in normal operation.