Filling apparatus for high-altitude balloons
Aspects of the disclosure provide a fill port apparatus for filling high altitude balloons, such as those used in communications networks, with lighter than air lift gasses. For instance, the fill port apparatus includes a tubular body portion having a passageway extending between a first end and a second end of the tubular body portion. The fill port apparatus also includes an attachment structure arranged at the first end of the tubular body portion. This structure is configured to attach to a top plate of a balloon envelope. The fill port apparatus also includes a plurality of energy directing structures arranged on an interior surface of the tubular body portion. These energy directing structures extend into the passageway from the interior surface and are each configured to contact at least one other of the plurality of energy directing structures when the tubular body portion is welded to itself.
1. A method of filling a balloon envelope of a balloon with lift gas, the balloon having a top plate arranged at an apex of the balloon, and a fill port apparatus being attached to the top plate, the method comprising:
attaching a filling device to a first end of a tubular body portion of the fill port apparatus, the tubular body portion having a passageway extending between the first end of the tubular body portion and a second end of the tubular body portion, the tubular body portion further including a plurality of energy directing structures arranged on an interior surface of the tubular body portion and extending into the passageway from the interior surface;
filling the balloon envelope with lift gas by providing lift gas at the first end via the filling device such that the lift gas passes through the passageway and enters the balloon envelope through the second end of the tubular body portion; and
creating a weld by vibrating the plurality of energy directing structures, the weld forming a seal across the tubular body portion and preventing lift gas from escaping from the balloon envelope via the passageway.
2. The method of claim 1 , further comprising, cutting the tubular body portion in order to remove a portion of the tubular body portion.
3. The method of claim 1 , wherein the plurality of energy directing structures are arranged in a helical configuration such that the weld includes at least two of the plurality of energy directing structures crossing one another.
4. The method of claim 1 , wherein creating the weld include using an ultrasonic welding machine.
5. The method of claim 1 , wherein creating the weld includes melting the plurality of energy directing structures via the vibrating.
6. The method of claim 5 , wherein creating the weld includes allowing the plurality of energy directing structure to cool after melting the plurality of energy directing structures.
7. The method of claim 1 , wherein the plurality of energy directing structure and the tubular body portion are of a same material.
8. The method of claim 7 , wherein the material includes plastic and creating the weld causes the material of the plurality of energy directing structures to heat up and melt.
9. The method of claim 1 , wherein the plurality of energy directing structures are arranged in a helical configuration prior to creating the weld.
10. The method of claim 1 , wherein the plurality of energy directing structures include a first energy directing structure arranged to extend around an entire circumference of the interior surface of the tubular body portion prior to creating the weld.
11. The method of claim 10 , wherein a portion of the plurality of energy directing structures are arranged to extend away from the first energy directing structure.
12. The method of claim 1 , wherein the fill port apparatus includes at least one welding guide arranged on an exterior surface of the tubular body portion, and wherein the method further comprises prior to creating the weld, using the at least one welding guide to determine a location for creating the weld, and wherein creating the weld further includes using the determined location.
13. The method of claim 12 , wherein the at least one welding guide is one of a pair of welding guides, and together the pair of welding guides indicate an area on the exterior surface that corresponds to locations of the plurality of energy directing structures on the interior surface, and wherein determining the location includes using both welding guides of the pair of welding guides.
14. The method of claim 12 , further comprising:
after creating the weld, using the at least one welding guide to identify a cutting location; and
cutting the tubular body portion using the identified cutting location in order to remove a portion of the tubular body portion.
15. The method of claim 1 , wherein creating the weld further includes causing one of the plurality of energy directing structures to contact at least one other of the plurality of energy directing structures.
16. The method of claim 1 , wherein creating the weld includes crushing opposing sides of the tubular body portion towards one another.
17. The method of claim 1 , wherein the plurality of energy directing structures project no more than 1 mm into the passageway.
18. The method of claim 1 , wherein the fill port apparatus includes a radial projection and wherein attaching the filling device to the first end of the tubular body portion includes forming a seal with the fill port apparatus.
19. The method of claim 1 , wherein a second end of the tubular body portion includes a flange, and the method further comprises attaching the flange to the top plate prior to attaching the filling device to the first end of the tubular body portion.
20. The method of claim 19 , wherein attaching the flange includes heat sealing the flange to the top plate.