Trigger dispensing device with valve means

A trigger dispensing head applicable to a bottle of a trigger dispensing device for dispensing a product, the trigger dispensing head comprising:

• a cylinder chamber annularly delimited by a cylinder wall having an inner surface, and by a bottom wall at the bottom;
• a piston that is manually operable to translate along an axial direction;
• a pressure chamber onto which the piston operates;
• a sleeve at least partially accommodated in the cylinder chamber, comprising an annular end wall defining a bottom opening of the sleeve, wherein the sleeve, the cylinder wall and the bottom wall define a valve compartment;
• a suction duct adapted to put an inner compartment of the bottle in communication with the pressure chamber, comprising a suction mouth projecting axially from the bottom wall;
• a dispensing duct adapted to put the pressure chamber in communication with an external environment;
• valve means for adjusting a flow of the product from the suction duct to the pressure chamber during a suction step and from the pressure chamber to the dispensing duct during a dispensing step, comprising a valve element in one piece, housed in the valve compartment, the valve element comprising:
• a tubular portion consisting of an annular valve wall extending along a valve axis, between a rear end defining a rear opening and a front end defining a front opening, said annular valve wall being fitted on the suction mouth;
• a flexible flap connected in a cantilevered manner to the front end of the annular valve wall, radially projecting internally, provided, on a side facing the rear opening, with a shutter portion adapted to create a seal with the suction mouth for forming suction valve means;
• and
• an annular membrane radially extending externally from the annular valve wall, adapted to abut against the annular end wall of the sleeve, creating a seal with the bottom opening for forming pre-compression valve means.