Doser-dispenser for at least one pasty and/or liquid product

A doser-dispenser for at least one pasty and/or liquid product contained under pressure in at least a first storage reservoir, said doser-dispenser comprising in a first cylindrical housing, an upper supply chamber connected by a supply conduit to said first reservoir, and a lower dosing chamber separated from said supply chamber by a doser piston fixed to the lower end of a control member penetrating in said first housing, said doser piston being slidable in tight manner in said first housing and provided with a central passage adapted to be obturated by an intake valve having a first obturation member urged by a return spring, said intake valve being guided with respect to said doser piston and cooperating with a valve seat surrounding said central passage, a dispensing chamber downstream of the dosing chamber and an ejection valve in said dispensing chamber having a second obturation member loaded by a second spring,

• characterized in that:
• the control member of the doser-piston is constituted by a first control;
• tube having one end adjacent to said intake valve which is obturated in tight manner;
• said first obturation member of the intake valve is situated on a side of the supply chamber and is carried by a lower closed end of a second control tube guided in the first control tube and extending beyond the lower end thereof;
• a first bellows surrounds a first section of said first control tube penetrating into said housing to form an annular space between said first bellows and said first section of the first control tube which is permanently connected to the outside atmosphere;
• the upper end of said first bellows surrounding the first control tube is fixed in tight manner to a housing wall traversed by said first tube and the lower end of the first bellows is fixed in tight manner to the lower end of said first tube;
• a second bellows surrounds the second control tube, over a section thereof extending beyond the lower end of the first control tube, said second bellows having an upper end fixed in tight manner to the lower end of the first tube below the first bellows, while a lower end of the second bellows is fixed in tight manner to the lower end of the second control tube or to said first obturation member carried on said second control tube, said second control tube having an upper end part guided in tight manner in the first tube and including, at said upper end part, a control piston which separates the volume of the first tube into an upper chamber and a lower chamber, one of which is connected to atmosphere and contains said return spring acting on said first obturation member, the other of said chambers being capable of being connected alternately to a source of compressed air or to atmosphere, the pressure of compressed air established in said other chamber acting on said first obturation member in a direction opposite that of said return spring thereof.