A dispenser for dispensing a substance, such as a liquid lipstick or other
product, has a body defining a variable-volume storage chamber for
storing the product. A dispensing portion is connected with the body and
defines a bore coupled in fluid communication with the storage chamber
for receiving product therefrom, and an outlet aperture coupled in fluid
communication with the bore. A piston is received within the bore, and a
one-way valve is mounted on the dispensing portion for dispensing metered
amounts of product therethrough. The one-way valve has an
axially-extending valve seat, and an axially-extending visco-elastic
valve cover seated on the valve seat and defining a normally-closed,
axially-extending seam therebetween forming a fluid-tight seal between
the valve cover and valve seat. The flexible valve cover is movable
relative to the valve seat, and the seam is connectable in fluid
communication with the outlet aperture to allow the passage of product
through the seam and out of the dispenser. An actuator is drivingly
connected to the piston for moving the piston within the bore and
dispensing a predetermined amount of product within the bore through the
outlet aperture.