Flow control element with pinholes for spill-resistant beverage container
A spill resistant container (e.g., a sippy cup) including a flow control element including a membrane defining multiple pinholes for controlling the flow of liquid through a drinking spout. The flow control element is mounted on a cover that screws onto a cup-shaped body such that the membrane is positioned between liquid stored in the cup-shaped body and the drinking spout, which is formed on the cap. The flow control element is formed from a suitable elastomeric material (e.g., soft rubber, thermoplastic elastomer, or silicone) such that the membrane stretches when subjected to a differential pressure. The pinholes are formed by puncturing the membrane using one or more pins having a substantially circular cross-section and sized such that each pinhole is closed by the surrounding elastomeric material when the pins are removed.
1. A spill-resistant beverage container comprising:
a cup-shaped body defining a storage chamber;
a removable cap mounted on the cup-shaped body, the cap including a top wall having at one side an upwardly extending drinking spout defining an outlet passage; and
a flow control element including a membrane formed from an elastomeric material that is mounted below the drinking spout such that the membrane is located between the storage chamber and the outlet passage,
wherein the membrane defines a plurality of pinholes formed such that each pinhole is closed by the elastomeric material surrounding said each pinhole when the membrane is subjected to normal atmospheric conditions, thereby preventing passage of a liquid from the storage chamber to the outlet passage, and each pinhole is opened when the membrane is subjected to an applied pressure differential that causes the membrane to stretch, thereby facilitating liquid flow from the storage chamber to the outlet passage, and
wherein the membrane has a circular outer perimeter having a diameter of 0.25 to 1.5 inches and a thickness of 0.01 to 0.1 inches, and wherein the plurality of pinholes comprises a number greater than ten.
2. The spill-resistant beverage container according to claim 1 , wherein the number of pinholes is greater than thirty.
3. The spill-resistant beverage container according to claim 1 , wherein the flow control element further comprises a cylindrical wall surrounding the membrane, and a plurality of pull-tabs extending perpendicular to the cylindrical wall.
4. The spill-resistant beverage container according to claim 3 , wherein a thickness of the pull-tabs is 0.06 to 0.1 inches, and wherein a thickness of the cylindrical wall is 0.04 to 0.08 inches.
5. The spill-resistant beverage container according to claim 3 , wherein the pull-tabs and the membrane are formed at a first end of the cylindrical wall.
6. The spill-resistant beverage container according to claim 3 , wherein the pull-tabs is located at a first end of the cylindrical wall, and the membrane is located at a second end of the cylindrical wall.
7. The spill-resistant beverage container according to claim 1 , wherein flow control element comprises one of silicone, thermoplastic elastomer, and soft rubber.
8. A flow control element for a beverage container, the flow control element comprising a membrane formed from an elastomeric material and defining a plurality of pinholes formed such that each pinhole is closed by elastomeric material surrounding said each pinhole when the membrane is subjected to normal atmospheric conditions, thereby preventing passage of a liquid through the membrane, and each pinhole is opened when the membrane is subjected to an applied pressure differential that causes the membrane to stretch, thereby facilitating liquid flow through the membrane, wherein the membrane has a circular outer perimeter having a diameter of 0.25 to 1.5 inches and a thickness of 0.01 to 0.1 inches, wherein the plurality of pinholes comprises a number greater than ten, wherein the flow control element further comprises a cylindrical wall surrounding the membrane, and one or more pull-tabs extending perpendicular to the cylindrical wall.
9. The flow control element according to claim 8 , wherein the number of pinholes is greater than thirty.
10. The flow control element according to claim 8 , wherein a thickness of the pull-tabs is 0.06 to 0.1 inches, and wherein a thickness of the cylindrical wall is 0.04 to 0.08 inches.
11. The flow control element according to claim 8 , wherein the pull-tabs and the membrane are formed at a first end of the cylindrical wall.
12. The flow control element according to claim 8 , wherein the pull-tabs are located at a first end of the cylindrical wall, and the membrane is located at a second end of the cylindrical wall.
13. The flow control element according to claim 8 , wherein flow control element comprises silicone.
14. The flow control element according to claim 8 , wherein flow control element comprises thermoplastic elastomer.
15. The flow control element according to claim 8 , wherein flow control element comprises soft rubber.
16. A method for manufacturing a flow control element for a beverage container, the flow control element comprising a planar membrane formed from an elastomeric material and defining a radial axis, the method comprising:
stretching the membrane by applying a tensile force along the radial axis; and
piercing the stretched membrane using a sharp object to form a pinhole such that the pinhole is closed by elastomeric material surrounding the pinhole when the tensile force is removed and the membrane is subjected to normal atmospheric conditions, thereby preventing passage of a liquid through the membrane, and such that the pinhole is opened when the membrane is subjected to an applied pressure differential that causes the membrane to stretch, thereby facilitating liquid flow through the pinhole.
17. The method according to claim 16 ,
wherein the membrane has a circular outer perimeter defining a diameter, and
wherein stretching comprises stretching the membrane along the radial axis such that the diameter is increased by an amount in the range of 1 to 10%.