Patent ID: 7357278
Filing Date: 2008-04-15
Classification: B05B

Abstract:
1. A metering valve for dispensing a substance from a container that includes a nozzle that is actuated by compression to dispense the substance from the container, the nozzle being automatically returned to a rest position by means of a resilient member that is coupled between the nozzle and the container, the metering valve comprising: an assembly of first, second and third coaxial cylindrical parts; wherein the first part has an upper section and a lower section that has a diameter less than a diameter of the upper section, the upper section including a collar for placement between an upper rim of a neck of the container and a cap that closes a container opening defined by the neck resulting in the first part being fixed with respect to the container; wherein the second part is disposed within an interior of the first part and has an upper portion of increased diameter relative to a lower portion thereof, the upper portion being configured to function as a plunger and slidingly travel along the upper section of the first part, the second part having vents formed therein in an intermediate portion between the upper and lower portions thereof, the lower portion of reduced diameter being received and guided within an interior of the lower section of the first part, the upper portion that functions as the plunger having an inner cylindrical projection, wherein an inner chamber is defined between facing surfaces of the first and second parts; wherein the third part includes a hollow cylindrical rod that is attached at its upper end to the nozzle such that an axial opening extending through the rod is in communication with a passage formed in the nozzle for dispensing a dose of the substance, the rod having a lower end section for placement inside the container, the lower end section having a reduced diameter relative to an upper end section that terminates in the upper end, the rod having a pair of outwardly extending peripheral ribs proximate its lower end for defining contact positions with respect to the inner cylindrical projection of the second part, the rod having vents formed proximate a location where the lower end section begins, the vent being configured for passage of the substance from the inner chamber towards the axial opening of the third part for dispensing through the nozzle; wherein filling of the inner chamber with the substance is effected by recovery movement of the subassembly defined by the second and third parts which are axially movable relative to the container while the first part is fixed, the recovery movement being produced by the resilient member, the substance to be metered entering through the vents of the second part and the aligned vents of the third part during actuation of the metering valve assembly; and wherein the rod of the third part includes an arrangement of protruding helical ramps that are axially displaceable by applying a force to the metering valve, the helical ramps being arranged opposite complementary shaped fixed ramps that are formed on an inner surface of the cap, the rod further having protuberances located above the helical ramps and the inner surface of the cap further includes complementary grooves in which the protuberances can coincide for rotation thereof which corresponds to a coupling rotation of the opposing ramps of the rod and cap so tat return of the rod after a metering cycle by action of the resilient member has the effect of automatic rotation of the rod itself when the helical ramps impinge on the fixed ramps of the cap and the protuberances coinciding simultaneously within the grooves of the cap to signify a safety abutment position in which the metering valve cannot be actuated without positive rotation of the rod by moving the nozzle.