Patent ID: 7874464

Claim:
A device for containing and dispensing a product, comprising: a base portion; a piston secured to the base portion; a first and second protrusion formed around a circumference of the piston; a housing configured to be secured to the base portion, the housing including a first end configured to receive the piston and a second end having at least one discharge hole to dispense the product; and at least one aperture formed on a portion of the piston, wherein when the base portion and housing are secured together, an airtight seal is created between the first and second protrusion and an inside surface of the housing, and wherein air is able to flow through the at least one aperture into a chamber, the chamber being formed by the first and second protrusion, the inside surface of the housing, and a portion of an outer surface of the piston, wherein the first and second protrusions have a first diameter, and the portion of the outer surface of the piston in an area of the chamber has a second diameter smaller than the first diameter, wherein the at least one aperture is formed in between the first and second protrusions in the portion of the outer surface of the piston having the second diameter, wherein the piston includes a flange formed around the circumference of the piston and spaced apart from a main body of the piston to form a gap between the main body and the flange, the gap having a first end located towards a dispensing side of the device and a second end located at an end opposite the first end, wherein the aperture is located at the second end such that when air is forced into the gap due to the seal formed by the first protrusion the air flows in a direction substantially away from a dispensing movement direction of the piston and through the aperture into the chamber, and wherein the second protrusion includes a plurality of slits formed thereon, such that side surfaces of the plurality of slits are spaced apart when pressure within the device is increased, and the side surfaces of the plurality of slits are configured to contact each other when pressure within the device has decreased.