Device for limiting liquid loss, suitable for a pressurized liquid dispenser

A liquid loss-limiting device suitable for a pressurized liquid dispenser with a shut-off valve having downstream an elongated delivery nozzle, comprising:

• (a) a main tubular element adaptable to fasten by one of its two ends to a downstream free end of said nozzle,
• (b) an internal tubular element of smaller diameter rigidly connected to said main tubular element and spaced coaxially therein so as to form axial passages available for the flow of pressurized liquid between the internal tubular element and the main tubular element;
• said main tubular element having an annular downstream facing first bearing surface, said internal tubular element supporting a concentric downstream facing second bearing surface, said second bearing surface being disposed downstream from the first bearing surface, said passages egressing between said first and second bearing surfaces;
• (c) an elastic membrane having the general shape of a truncated cone which with its end of larger diameter resting on said first bearing surface of the main tubular element and with its end of smaller diameter resting on said second bearing surface of said internal tubular element connected thereto;
• (d) a central knob with an enlarged head portion and a stem portion which latter is fastened within said internal tubular element with said head disposed downstream from said membrane, said head portion having a skirt in the shape of a protruding ring portion facing upstream, which ring portion is in contact with the surface of the membrane facing downstream and between its two ends;
• wherein the membrane is elastically deformable so that it can occupy two positions, said positions including:
• (A) a resting position in which the membrane has three support zones comprising the first bearing surface, the second bearing surface and the protruding ring portion of the knob;
• and,
• (B) a deformed position in which the end of larger diameter is raised from the first bearing surface by the stress exerted by pressurized liquid so as to leave a free passage for said liquid, said membrane, however, remaining in contact, in this position, with the second bearing surface and with the protruding ring portion of the knob.