TENDON SLEEVE FOR HIGH-ALTITUDE BALLOON AND SYSTEM FOR MAKING THE SAME

A system for forming a tendon sleeve on an atmospheric balloon is described herein, the system comprising a coupling assembly including a seam coupling mechanism that forms a seam joint between a first gore panel and a second gore panel, the seam joint is spaced from respective first and second lateral edges of the first and second gore panels to form first and second edge flanges, and an edge coupling mechanism that forms an edge joint between the first and second edge flanges and closes a tendon sleeve, the edge joint spaced from the seam joint, the tendon sleeve includes a tendon sleeve passage between the seam joint and the edge joint and between the first and second edge flanges. The system also includes a tendon positioning mechanism that positions a tendon within the tendon sleeve passage. A tendon sleeve formed by this system is also described herein.

BACKGROUND

This document pertains generally, but not by way of limitation, to balloons and inflatable bladders having atmospheric application. Lobed balloons are used in high-altitude ballooning. Lobed balloons, in some examples have a relatively high curvature that allows for larger diameter balloons using relatively thin material for the balloon material. In at least some examples, payloads including instruments, communications equipment and the like are coupled with or suspended from the lobed balloon. The payloads, in some examples, are configured to conduct operations (e.g., observation, communication and the like) at the high altitudes lobed balloons reach, for instance an altitude of around 20 miles.

Examples of lobed balloons are constructed with a lightweight material that is provided in shaped panels of material, e.g., a gore pattern, that extend from top apex to a bottom apex and taper from near a midpoint toward the top and bottom apexes. The shaped gore panels are bonded to one another along their respective longitudinal edges to form the balloon. The balloon with gores arranged in this fashion includes a plurality of longitudinal seams extending from the top to the bottom of the balloon, with one seam between adjacent shaped panels (or gores). The wider midpoint of each of the shaped panels provides the outwardly curving shape of the balloon with respect to the narrower top and bottom apexes.

SUMMARY

This disclosure describes atmospheric balloons including sleeves for securing tendons to the balloon, where the tendons provide structural integrity to the balloon during high-altitude operation of the balloons. The sleeves are formed by coupling together adjacent gore panels that form the balloon membrane in such a way that a portion of each adjacent gore panel forms an edge flange. The respective edges flanges are coupled together to form a sleeve with a passage in which the tendon is received. This disclosure also describes systems and methods for forming the tendon sleeves.

In an example, an atmospheric balloon system is described herein. The balloon system comprising a balloon including a balloon membrane having a plurality of gore panels, a plurality of tendons extending from near an upper apex to a lower apex of the balloon, and a plurality of tendon sleeves each located at intersections between adjacent gore panels. Each of the plurality of tendon sleeves includes first and second edge flanges of respective adjacent gore panels, a seam joint coupling the first and second edge flanges, and an edge joint coupling the first and second edge flanges, the edge joint spaced from the seam joint to form a sleeve passage between the seam joint and the edge joint and the first and second edge flanges, wherein one of the plurality of tendons is received within the sleeve passage of the tendon sleeve.

A system for forming a tendon sleeve on an atmospheric balloon is also described. The system includes a coupling assembly comprising a seam coupling mechanism that forms a seam joint between a first gore panel and a second gore panel, the seam joint is spaced from respective first and second lateral edges of the first and second gore panels to form first and second edge flanges, and an edge coupling mechanism that forms an edge joint between the first and second edge flanges and closes a tendon sleeve, the edge joint spaced from the seam joint. The tendon sleeve includes a tendon sleeve passage between the seam joint and the edge joint and between the first and second edge flanges. The system also includes a tendon positioning mechanism, the tendon positioning mechanism positions a tendon within the tendon sleeve passage.

A method of forming a tendon sleeve on an atmospheric balloon is also described. The method includes coupling a first gore panel comprising a first lateral edge to a second gore panel comprising a second lateral edge by forming a seam joint spaced from the first and second lateral edges, coupling the first and second edge flanges together at an edge joint spaced from the seam joint to form a tendon sleeve with a tendon sleeve passage between the seam joint and the edge joint and the first and second edge flanges, and positioning a tendon within the tendon sleeve passage.

DETAILED DESCRIPTION

The following Detailed Description describes an improvement of high-altitude balloons that are designed for stratospheric flight. The balloons include tendon sleeves for securing tendons at a seam between adjacent gore panels of the balloon. The tendon sleeve allows for a simple structure that secures a tendon to a substantially fixed position by using a portion of each of two adjacent gore panels to form the tendon sleeve. In some examples, the methods and systems described herein provide for substantially simultaneous formation of the joint between the adjacent gore panels, formation of the tendon sleeve, and coupling the tendon and the tendon sleeve to the balloon.

The methods and systems described herein eliminate or reduce the need for separate manufacture of the tendon sleeve, as well as the need to wind the tendon and sleeve onto a secondary spool before attaching the tendon sleeve to the balloon. The systems and methods described herein, therefore, simplify the process of manufacturing atmospheric balloons formed from gore panels as well as simplifying the design of the balloon itself. The systems and methods described herein provide for a more efficient manufacturing process, reducing waste and balloon weight. As described in more detail below, the systems and method described herein also allow for easier formation of foreshortened tendons. The systems and methods described herein also allow for formation of prefabricated (e.g., precut) tendons, or non-prefabricated tendons, depending on what is better for the particular application.

The tendon sleeves described herein are formed on a balloon that is used for long duration stratospheric flight of payloads. In some examples, the balloon has limited steering capability along the flight path occurring as a result of varying wind directions at flight altitudes.

FIG. 1shows an example of a high altitude balloon system100. The example high altitude balloon system100includes a balloon102comprising one or more chambers104,106. The balloon102is sometimes referred to as a pumpkin balloon102or a lobed balloon102. The balloon102includes an upper apex108and a lower apex110. A balloon membrane112encloses the one or more chambers104,106. The balloon membrane112is formed from a plurality of gore panels114coupled together along gore panel seams116. The gore panels114cooperate to collectively form the balloon membrane112

In some examples, a payload118is coupled to the balloon102, such as by being suspended from the balloon102. In some examples, the payload118includes instruments, or communication devices, or both, or includes other structures or devices to provide additional functionality to the balloon system100, such as a propulsion system. In an example, instruments in the payload118provide for observation beneath and around the balloon system100. In some examples, communication devices in the payload118allow for communication, e.g., transmission of information, reception of information and the like.

In an example, the payload118includes a balloon volume controller that controls the volume of each of the one or more balloon chambers104,106. In an example, the balloon volume controller controls one or more blowers that are mounted to the payload118or to the balloon102and that blow atmospheric air into an air ballast chamber104to control the relative volume of the air ballast chamber104relative to a lift gas chamber106that contains a lift gas, such as helium, within the balloon102.

The lift gas chamber106is separated from the air ballast chamber104within the balloon membrane112. In an example, the air ballast chamber104and the lift gas chamber106are separated by a deflectable diaphragm120positioned within the balloon102. In an example, the deflectable diaphragm120is coupled across the balloon102by extending inwardly from a circumferential edge122of the balloon102. The deflectable diaphragm120is interposed between the air ballast chamber104and the lift gas chamber106during construction of the balloon102. As the balloon102is formed, the deflectable diaphragm120is coupled to the gore panels114to accordingly form a triple layered dual chamber balloon102with the deflectable diaphragm120interposed and coupled between an upper portion of the gore panels114and a lower portion of the gore panels114. In an example, the lift gas chamber106is formed by the upper portions of the gore panels114and the deflectable diaphragm120, and the air ballast chamber104is formed by the lower portions of the gore panels114and the deflectable diaphragm120.

In some examples, the deflectable diaphragm120is coupled across another portion of the balloon102other than at the circumferential edge122. In an example, the deflectable diaphragm120has a smaller perimeter than the circumferential edge122and is coupled to the balloon membrane112closer to either the upper apex108or the lower apex110. In another example, the deflectable diaphragm120is provided as a nested balloon formed of a second membrane within the balloon membrane112. In an example, the deflectable diaphragm120is a ballonet coupled with the balloon102at one of the upper apex108or the lower apex110.

The balloon system100also includes a plurality of tendons124extending from the upper apex108to the lower apex110. The tendons124are distributed around the balloon membrane112to provide structural integrity to the balloon102and maintain the balloon volume constant (e.g., constant, near constant, substantially constant, or the like after inflation and during flight of the high altitude balloon system100. Examples of tendons124include, but are not limited to, cables, biodegradable filaments, or the like.

Each of the tendons124is secured within a tendon sleeve126at one of the gore panel seams. The tendon sleeves126are coupled to the balloon membrane112at the gore panel seams116. The tendon sleeves126maintain the tendons in a distributed fashion around the balloon outer surface. In an example described in more detail below, each tendon sleeve126is formed from excess portion of the film material that forms adjacent gore panels114that are sealed together so that the tendon sleeves126are integrally coupled to the gore panels114.FIG. 2shows a close up view of a few of the gore panels114with tendons124fed through corresponding tendon sleeves126at the gore panel seams116of the balloon system100.

In an example, each of the plurality of tendons124is coupled to the upper apex108and the lower apex110. In an example, an upper apex plate128is mounted to the balloon membrane112at the upper apex108and a lower apex plate130is mounted to the balloon membrane112at the lower apex110. The plurality of tendons124are coupled to the upper apex plate128and the lower apex plate130. In an example, each of the apex plates128,130includes a plurality of tendon anchors, wherein an upper end of each of the plurality of tendons124is coupled to a corresponding one of the plurality of tendon anchors of the upper apex plate128and a lower end of each of the tendons124is coupled to a corresponding tendon anchor of the lower apex plate130.

FIG. 3shows a close-up view of an example tendon sleeve200formed by sealing adjacent gore panels202together to form a gore panel seam204and to form the tendon sleeve200.FIG. 4shows a cross-sectional view of the example tendon sleeve200.FIG. 3shows the tendon sleeve200after it has been formed, but before the balloon has been inflated, whileFIG. 4shows the tendon sleeve200after inflation of the balloon, e.g., after injection of a gas such as a ballast gas or a lift gas, e.g., helium, into a balloon interior206. Optionally, in an example, the tendon sleeve200is positioned along the interior of the balloon, for instance, the tendon sleeve200is on the opposed side of the gore panels202along with the balloon interior206. In an example, one or more, and in some examples all of, the tendon sleeves126of the balloon system100shown inFIGS. 1 and 2are formed in the form of the example tendon sleeve200ofFIGS. 3 and 4.

As shown inFIGS. 3 and 4, each of the adjacent gore panels202includes a lateral edge208, and the adjacent gore panels202are coupled together at an intersection between the adjacent gore panels202to form a seam joint210between the adjacent gore panels202. In an example, the seam joint210is spaced from the lateral edges208of the adjacent gore panels202. The spacing between the gore panel lateral edges208and the seam joint210forms an edge flange212being formed for each adjacent gore panel202. In an example, the edge flanges212of the adjacent gore panels202are each formed of a strip of the film material of a corresponding gore panel202that protrudes from the seam joint210. In an example, the edge flanges212are each a portion or region of a corresponding gore panel202that extends from the seam joint210to a corresponding one of the lateral edges208.

The example tendon sleeve200ofFIGS. 3 and 4is formed from the edge flanges212by coupling the lateral edges208of the edge flanges212together to form a sleeve (e.g., of the material that makes up the gore panels202). In this way, the tendon sleeve200is positioned on or adjacent to the balloon membrane (which is collectively formed by the gore panels202) at an intersection between the adjacent gore panels202. In an example, the adjacent gore panels202are sealed together at the seam joint210, for example so that the seam joint210comprises a seam seal that seals the polymeric material of polymeric gore panels202together. The seam seal formed at the seam joint210prevents (e.g., minimizes, stops, prevents, reduces, or the like) leaking of the lift gas or the ballast gas from the balloon interior206. As used herein, the term “seal,” when referring to sealing a polymeric material of the gore panel202at the seam joint210, includes, but is not limited to, the polymeric material of the gore panels202being coupled together substantially continuously at a macromolecular level so that at least 99% (on a weight flow rate basis) of the passage of the lift gas through the seam joint210is via intermolecular diffusion, such as at least 99.5%, for example at least 99.9%, or all (100%), of the passage of the lift gas though the seam joint210is via intermolecular diffusion, rather than via the flow of lift gas through openings along the seam joint210.

The edge flanges212are coupled together proximate to the lateral edges208of the adjacent gore panels202by an edge joint214. In an example, the edge joint214is formed by coupling the edge flanges212at a plurality of points at or near the gore panel lateral edges208. The seam joint210, the edge joint214, and the edge flanges212act together to form the tendon sleeve200. The tendon sleeve200encloses a tendon sleeve passage216that is bounded by the seam joint210, the edge joint214, and the edge flanges212, as inFIG. 4. A tendon218is positioned between the edge flanges212. Because, in an example, the edge flanges212are a portion of the gore panels202that are coupled together at the seam joint210and the edge joint214, the tendon218positioned inside the tendon sleeve passage216is correspondingly secured to the gore panels202and to a balloon formed by the gore panels202. In an example, the edge joint214comprises an edge seal along or proximate to the lateral edges208so that the edge flanges212are sealed together to form the tendon sleeve200.

In an example, each tendon sleeve200is formed using the material of the gore panels202rather than forming a separate sleeve that is coupled to the balloon membrane separately. This simplifies the design and manufacture of the balloon. As demonstrated below, the tendon sleeve200described herein allows for systems and methods where the tendon sleeve200is formed, the tendon218is positioned in the tendon sleeve200, and the tendon sleeve200is coupled to the balloon membrane (formed from the plurality of gore panels202) all simultaneously (e.g., at the same time, substantially the same time, within a few seconds of each other or the like) no that all three functions are performed within a short period of time by one or more manufacturing operations or in a consolidated manufacturing operation. Alternatively, in an example, one or more of the operations of forming the seam joint210, positioning the tendon218, and forming the edge joint214are performed separately, either with the same manufacturing operation but separated in time or with more than one manufacturing operation. For example, the seam joint210and positioning of the tendon218are performed simultaneously (e.g., at the same time, substantially the same time, within a few seconds of each other or the like) and with the formation of the edge joint214occurring at a later time.

FIGS. 5-10show aspects of an example system300for forming a tendon sleeve at a seam between adjacent gore panels in order to manufacture an atmospheric balloon. In an example, the system300makes the tendon sleeve200described with respect toFIGS. 3 and 4, by joining portions of adjacent gore panels202together at a seam204by forming a seam joint210and an edge joint214, which encloses and secures a tendon218along the seam204.

In an example, the system300includes one or more feed mechanisms for feeding a pair of gore panels202, e.g., a first gore panel and a second gore panel, to be coupled together with a coupling assembly302in such a way that the tendon sleeve200is formed with a tendon218positioned in the tendon sleeve passage216formed by the tendon sleeve200. Alternatively, in an example the gore panels202remain stationary, and at least the coupling assembly302moves along the lateral edges208of the gore panels202to form the tendon sleeve200and position the tendon218within the tendon sleeve passage216.FIGS. 5-7 and 10include an arrow304representing the direction of relative motion of the gore panels202relative to the system300, e.g., the that the gore panels202travel when being fed through the coupling assembly302, e.g., from a feed end of the coupling assembly302toward an exhaust end.

In an example, each gore panel202comprises a sealable polymeric membrane material. In an example, each gore panel202comprises polyethylene or a co-extruded polyethylene and ethyl vinyl alcohol (EVOH) film.

The coupling assembly302includes a seam coupling mechanism306to couple the gore panels202being fed to the system300together to form a seam joint210at the seam204between adjacent gore panels202. In an example, the seam coupling mechanism306comprises a band sealer, such as that shown inFIGS. 5-7 and 10. The seam coupling mechanism306couples the adjacent gore panels202together at the seam204to form the seam joint210between the adjacent gore panels202. In an example, the seam coupling mechanism306includes a band sealer. The band sealer of the seam coupling mechanism306compresses the gore panels202together and heats a band of the compressed gore panels202to cause one or both of the gore panels202s to temporarily melt or flow, creating a band of molten material that forms the seam joint210. The seam coupling mechanism306is positioned relative to the lateral edges208of the gore panels202so that the seam joint210is spaced from the lateral edges208. This spacing of the seam coupling mechanism306from the lateral edges208of the gore panels202results in the gore panels202forming the edge flanges212that protrude from the seam joint210toward the lateral edges208(see, e.g.,FIGS. 3,4, and 10). In an example, the seam coupling mechanism306joins the gore panels202together so that the seam joint210comprises a seam seal between the adjacent gore panels202.

As described above, the edge flanges212are coupled together at or near the lateral edges208of the gore panels202by an edge joint214so that the edge flanges212form a tendon sleeve200to secure a tendon218to a balloon membrane collectively formed by the gore panels202. The tendon218is thereby secured by the tendon sleeve200to an atmospheric balloon formed by the balloon membrane at a seam204formed between the recently coupled gore panels202(e.g., as with the tendon sleeves126shown inFIG. 2). Therefore, in an example, the coupling assembly302includes an edge coupling mechanism308to couple the pair of edge flanges212together with an edge joint214at or proximate to the lateral edges208of the gore panels202to form the tendon sleeve200. In an example, shown in the system ofFIGS. 5-7 and 10, the edge coupling mechanism308also seals the pair of edge flanges212together to form the tendon sleeve200, e.g., so that the edge joint214comprises an edge seal at or near the lateral edges208.

As shown inFIG. 10, the edge coupling mechanism308also includes a cutting station to cut off an excess portion310of each of the edge flanges212(e.g., the material not needed for the edge joint214). In an example, the edge coupling mechanism308both cuts the excess portions310from the edge flanges212and couples the edge flanges212together. In an example, the edge coupling mechanism308is spaced from the seam coupling mechanism306by a specified distance, e.g., from about 2 centimeters (cm) (about 0.8 inch) to about 10 cm (about 4 inches), such as about 5 cm (about 2 inches) to about 7.5 cm (about 3 inches), where the spacing distance between the seam coupling mechanism306and the edge coupling mechanism308defines the width of the edge flanges212, and thus the width of the tendon sleeve200that is formed by the coupling assembly302.

Referring again toFIG. 10, in an example, the cutting station of edge coupling mechanism308comprises a hot knife structure312, referred to hereinafter simply as a “hot knife312.” The hot knife312cuts the material of the gore panels202including the excess portions310from the edge flanges212. The hot knife312is heated at least to a melting temperature of the material of the gore panels202so that the hot knife312melts through the edge flanges212and cuts off the excess portions310from the edge flanges212.

In an example, the edge coupling mechanism308, including the hot knife312, is configured to both cut the excess portions310from the edge flanges212, and to simultaneously (e.g., at the same time, substantially the same time, within a few seconds of each other or the like to said cutting) couple the edge flanges212together to form the edge joint214. As described above, the hot knife312is heated at least to a melting temperature of the material of the gore panels202and thus of the edge flanges212. Because the hot knife312melts the edge flanges212as it cuts them, the melted portion of the edge flanges212are placed in close proximity to one another so that the edge joint214is formed by the melted portions of the edge flanges212merging together before resolidifying. In an example, the edge coupling mechanism308includes a mechanism to compress the edge flanges212together at the lateral edges208while the portions of the edge flanges212are melted (e.g., melted, liquefied, softened, or the like) to form the edge joint214between the edge flanges212.

In an example, the coupling assembly302includes an anvil314with a slot316configured to receive the hot knife312. In an example, the coupling assembly302also includes one or more rollers318or other structures to clamp the edge flanges212of gore panel membrane material together. The two edge flanges212are clamped between the one or more rollers318and the anvil314while the hot knife312is inserted into the slot316so that the hot knife312will pass through both of the edge flanges212. The clamping of the edge flanges212between the one or more rollers318and the anvil314puts the edge flanges212in close proximity so that when the hot knife312melts the edge flanges212to cut off the excess portions310of the edge flanges212, the melted portions of the edge flanges212are coupled together to form the edge joint214and complete the tendon sleeve200.FIG. 5shows a perspective view of the coupling assembly with the hot knife312raised above the anvil314in a ready position.FIGS. 6 and 10shows a perspective view of the hot knife312after it has been lowered to an operational position with the hot knife312inserted into the slot316in the anvil314.FIG. 10also shows the one or more rollers318moved into close proximity with the anvil314to clamp the gore panels202between the one or more rollers318and the anvil314.

In an example, the coupling assembly302also includes a gore panel divider.320that separates the gore panels202being coupled together. In an example, the gore panel divider320guides the gore panels202into a position to be coupled by the coupling assembly302, e.g., by the seam coupling mechanism306and the edge coupling mechanism308.FIG. 7shows a view of the feed end of the coupling assembly302(e.g., with the direction of motion304of the gore panels202being shown as being into the page and away from the viewer inFIG. 7, as represented by the symbol {circle around (×)}.FIG. 7also shows an end view of the gore panel divider320. In an example, the pair of gore panels202are fed to the coupling assembly302so that a first gore panel202is positioned on one side of the gore panel divider320, e.g., the top gore panel positioned above the gore panel divider320inFIG. 7, and a second gore panel202is positioned on the other side of the gore panel divider320, e.g., the bottom gore panel202positioned below the gore panel divider320inFIG. 7. The gore panel divider320is secured to the coupling assembly302to position the gore panel divider320relative to the one or more coupling mechanisms of the coupling assembly302, such as the seam coupling mechanism306and the edge coupling mechanism308.

FIGS. 8 and 9show the gore panel divider320disconnected from the coupling assembly302.FIGS. 7-9show details of an example gore panel divider320. The example gore panel divider320ofFIGS. 7-9, in an example, the gore panel divider320includes a divider member322to separate the gore panels202, e.g., so that the gore panels202are joined and/or sealed at desired locations. In an example, the divider member322comprises a sheet of metal or another material. In an example, the gore panel divider320also includes a guide member324that guides at least one of the gore panels202into a specified location and/or alignment with respect to the coupling assembly302, e.g., with respect to one or both of the seam coupling mechanism306and the edge coupling mechanism308. In an example, the guide member324includes a bearing surface326that is engaged by an edge of one of the gore panels202as the gore panels202are fed through the coupling assembly302. The engagement between the edge of the gore panel202and the bearing surface326acts to guide the gore panels202into the specified position with respect to one or both of the seam coupling mechanism306and the edge coupling mechanism308. In an example, the divider member322and the guide member324of the gore panel divider320are both made from the same sheet of material, such as a sheet of metal that has been bent or otherwise shaped to provide the divider member322and the guide member324.

The gore panel divider320also includes an assembly mounting structure328provides a location to mount the gore panel divider320to the coupling assembly302, such as with fasteners330(as shown inFIG. 7). In an example, the gore panel divider320also includes an anvil mounting structure332to provide a location to mount the gore panel divider320such as with fasteners or other mounting structures or devices. Mounting of the gore panel divider320maintains or substantially maintains the position of the gore panel divider320relative to one or both of the seam coupling mechanism306and the edge coupling mechanism308during operation of the system300.

In an example, the system300includes a tendon positioning mechanism to position the tendon218at a specified position and orientation relative to the edge flanges212while the tendon sleeve200is being formed, e.g., while the gore panels202are coupled together with the seam joint210to form the seam204and the edge flanges212are coupled together with the edge joint214to form the tendon sleeve200. In an example, the tendon positioning mechanism is included as part of the gore panel divider320, as described in more detail below). In an example, the tendon positioning mechanism is separate from the gore panel divider320.

In an example, the tendon positioning mechanism comprises a tendon positioning guide, such as the tendon positioning guide334that is part of the gore panel divider320, as inFIGS. 8 and 9. The tendon positioning guide334is positioned relative to the coupling assembly302so that the tendon positioning guide334is positioned within the tendon sleeve passage216when the seam joint210and edge joint214are formed, as inFIG. 10. A tendon218is temporarily secured to the tendon positioning guide334such that the tendon218is placed between the edge flanges212of the gore panels202and between the seam joint210and the edge joint214, as shown inFIGS. 3, 4, and 10. In other words, the tendon positioning guide334is positioned so that as the gore panels202are fed through the coupling assembly302and are coupled together, the tendon positioning guide334is within the tendon sleeve passage216as the tendon sleeve200is being formed. The positioning of the tendon positioning mechanism, e.g., the tendon positioning guide334, in the tendon sleeve passage216causes the tendon218to be positioned within the edge joint214as well.

In an example, as shown inFIGS. 8 and 9, the tendon positioning guide334is coupled to and extends from the divider member322of the gore panel divider320so that the tendon positioning guide334will be positioned between the gore panels202, e.g., vertically between the gore panels202, and between the seam coupling mechanism306and the edge coupling mechanism308, e.g., laterally between the coupling mechanisms306,308, as shown inFIG. 10. In an example, the tendon positioning guide334is an integral part of the gore panel divider320, as shown inFIGS. 8 and 9. A tendon218is temporarily secured to the tendon positioning guide334with a securing structure, such as via an eye336at or proximate to a distal end of the tendon positioning guide334to which a tether338is secured, as shown inFIG. 10. The secured tendon218is then pulled into the tendon sleeve passage216as the tendon sleeve200is formed.

A tendon positioning mechanism or structure that positions a tendon218to be pulled into the tendon sleeve200, and in particular pulled into the tendon sleeve200while the tendon sleeve200is being formed, such as the tendon positioning guide334shown in the figures, allows for a prefabricated (e.g., precut to a specified length) tendon218, or a non-prefabricated tendon (e.g., one that is cut close in time to the manufacture of the balloon). The tendon positioning mechanisms or structures described herein also allow for pre-tensioned or untensioned tendons. In some examples, the coupling assembly302and the tendon positioning guide334provide for foreshortened tendons218. As used herein, the term “foreshortened,” when referring to a tendon that is to be used to provide structural support for an atmospheric balloon, can refer to a tendon with a specified length that is shorter than the corresponding length of the gore panels being supported by the tendon, for example the length of the gore panels114between the upper apex108and the lower apex110of the balloon system100shown inFIG. 1. Foreshortened tendons allow the tendons to continue to provide structural support to the balloon membrane when the low temperatures associated with atmospheric flight cause the gore panel material to contract faster than the tendon material contracts due to differences in coefficients of thermal expansion. Foreshortened tendons continue to carry the load of the balloon after the gore panel material has thermally contracted due to the low temperatures experienced at high altitudes,

FIG. 10shows a perspective view of the system300in operation.FIG. 10shows the gore panels202being fed to the coupling assembly302from the back of the system300, as indicated b the arrow for the direction of motion304. As the gore panels202are fed to the coupling assembly302, the seam coupling mechanism306(e.g., a band sealer) couples the gore panels202together by forming the seam joint210, for example by pressing the two gore panels202together (as inFIG. 7) and applying heat in a band to form the seam joint210at the seam204between the gore panels202. In an example, the seam joint210is a seam seal. Substantially simultaneously, the edge coupling mechanism308couples the edge flanges212of the gore panels202together by forming the edge joint214at the lateral edges208of the edge flanges212. In an example, the edge joint214is an edge seal. In an example, the edge coupling mechanism308also cuts off excess portions310of the edge flanges212, for example with the hot knife312melting through the edge flanges212. As described above, in some examples, the edge coupling mechanism308includes one or more rollers318and an anvil314to clamp the edge flanges212together and a hot knife312that cuts and couples the clamped edge flanges212together to substantially simultaneously form the edge joint214and cut off the excess portions310of the edge flanges212.

FIG. 10also show the tendon218being positioned in the tendon sleeve passage216by a tendon positioning guide334as the tendon sleeve200is being formed, e.g., as the seam joint210and the edge joint214are being formed. The tendon218is secured to the tendon positioning guide334, such as by tying the tendon218to a tendon securing structure on the tendon positioning guide334(e.g., the eye336) or by securing an intermediate securing structure (e.g., the tether338) to the tendon securing structure on the tendon positioning guide334(e.g., at the eye336) and then securing the intermediate securing structure (e.g., the tether338) to tendon218, as shown inFIG. 10. As the gore panels202are fed to the coupling assembly302, friction between the edge flanges212of the gore panels202and the tendon218causes the tendon218to be threaded through the tendon sleeve200so that the tendon218is positioned within the tendon sleeve passage216when the gore panels202are coupled together at the seam joint210and the edge joint214.

FIG. 11shows a schematic diagram of another example system400that forms a tendon sleeve at a seam between adjacent gore panels for securing a tendon to an atmospheric balloon. The system400shown inFIG. 11is an alternative to the system300. Like the system300ofFIGS. 5-7 and 10, the system400includes an example coupling assembly402for coupling adjacent gore panels404together. Like the coupling assembly302of the system300, the example coupling assembly402shown inFIG. 11includes a seam coupling mechanism406to couple a first of the gore panels404, e.g., the top most of the gore panels404, to a second of the gore panels404at a seam joint408. The seam joint408is spaced from the lateral edges410of the gore panels404, resulting in a pair of edge flanges412that protrude from the seam joint408. The coupling assembly also includes an edge coupling mechanism414to couple the pair of edge flanges412together by forming an edge joint416at or proximate to the lateral edges410to form a tendon sleeve418with a tendon sleeve passage420. The example system400shown inFIG. 11also includes a tendon positioning mechanism422that positions a tendon424within the tendon sleeve passage420.

Like the coupling assembly ofFIGS. 5-7 and 10described above, the seam coupling mechanism406of the example system400shown inFIG. 11is a band sealer, referred to hereinafter as the seam joint band sealer406. In an example, the seam joint band sealer406compresses the gore panels404together and applies heat, such as via a heating bar426, to melt the polymeric material of the gore panels404so that the gore panels404are combined at a relatively wide seam joint408. In an example, the edge coupling mechanism414of the system400inFIG. 11is also a band sealer, referred to hereinafter as the edge joint band sealer414. In an example, the edge joint band sealer414joins the gore panels404together at or near the lateral edges410of the edge flanges412to form the edge joint416and at least partially close the tendon sleeve418. In an example, the edge joint band sealer414compresses the edge flanges412together and applies heat, such as via a heating bar428, to melt the polymeric material of the edge flanges412so that the edge flanges412combine at a relatively wide edge joint416. In an example, each of the heating bars426,428of the seam joint band sealer406and the edge joint band sealer414, respectively, comprise a heating and cooling bar426,428that also cools the locations of the seam joint408and the edge joint416, respectively, to solidify the melted and joined portions of the gore panels404and the edge flanges412, respectively, to form the seam joint408and the edge joint416, respectively. A cutting station, such as a hot knife430, is also provided to cut off excess portions of the edge flanges412.

The tendon positioning mechanism422shown inFIG. 11is different from that shown in the example system300ofFIGS. 5-7 and 10. The example tendon positioning mechanism422shown inFIG. 11includes a tendon guide channel432positioned between the seam joint band sealer406and the edible joint band sealer414. A tendon guide, such as a tendon guide tub434, is located within the tendon guide channel432to provide a space between the gore panels404. A tendon feed mechanism436feeds the tendon424to the tendon guide tube434, such as with a tendon eye guide438, so that the tendon424will be in the tendon sleeve passage420when the tendon sleeve418is formed. In an example, a first of the gore panels404(e.g., the top gore panel404inFIG. 11) is directed to one side of the tendon guide tube434(e.g., above the tendon guide tube434). A second of the gore panels404(e.g., the bottom gore panel404inFIG. 11) is directed to an opposite side of the tendon guide tube434from the first of the gore panels404(e.g., below the tendon guide tube434). The positioning of the first and second gore panels404results in the tendon guide tube434being located in the space that will become the tendon sleeve passage420, such that when the tendon424is fed into the tendon guide tube434, the tendon424is positioned within the tendon sleeve passage420when the tendon sleeve418is formed. As the tendon424and the gore panels404are fed to the coupling assembly402, the tendon424is positioned within the tendon guide tube434, and thus between the gore panels404and also between the seam joint408and the edge joint416formed by the seam joint band sealer406and the edge joint band sealer414, respectively.

In an example, the bands of both the seam joint band sealer406and the edge joint band sealer414are mounted on the same wheel shaft, which allows the band speed of both bands to be controlled by the same drive mechanism. This, in turn, provides for substantially synchronized formation of the seam joint408and the edge joint416. In an example, the heating bars426,428are configured with a groove or channel cut therethrough, with the tendon guide (e.g., the tendon guide tube434) extending the length of the heating bars426,428.

Further details regarding balloons and balloon systems in which the tendon sleeves of the present disclosure can he used are described in: U.S. Provisional Patent Application Ser. No. 61/734,820, titled “High Altitude Balloon,” filed on Dec. 7, 2012; U.S. patent application Ser. No. 13/827,779, titled “High Altitude Balloon System,” filed on Mar. 14, 2013; and U.S. Provisional Patent Application Ser. No. 62/103,790, titled “High Altitude Balloon Apex Assembly,” filed on Jan. 15, 2015; the disclosures of which are incorporated herein by reference as if reproduced in their entirety.

In order to provide further detail regarding the aspects of the atmospheric balloon system, the tendon sleeve, the system for forming tendon sleeves, and the method for forming tendon sleeves described herein, the following non-limiting list of Embodiments is provided for illustrative purposes.

EMBODIMENT 1 includes an atmospheric balloon system. The balloon system includes a balloon comprising a balloon membrane having a plurality of gore panels, a plurality of tendons extending from near an upper apex of the balloon to near a lower apex of the balloon, and a plurality of tendon sleeves each located at an intersection between adjacent gore panels. Each of the plurality of tendon sleeves includes first and second edge flanges of respective adjacent gore panels, a seam joint coupling the first and second edge flanges, and an edge joint coupling the first and second edge flanges, the edge joint spaced from the seam joint to form a tendon sleeve passage between the seam joint and the edge joint and between the first and second edge flanges, wherein one of the plurality of tendons is received within the tendon sleeve passage.

EMBODIMENT 2 includes the atmospheric balloon system of EMBODIMENT 1, wherein the edge joint is near to respective lateral edges of the first and second edge flanges, and the seam joint is spaced from the respective lateral edges, relatively.

EMBODIMENT 3 includes the atmospheric balloon system of either one of EMBODIMENTS 1 or 2, wherein the seam joint includes a seam seal at the intersection between respective adjacent gore panels.

EMBODIMENT 4 includes the atmospheric balloon system of any one of EMBODIMENTS 1-3, wherein the edge joint includes an edge seal between the first and second edge flanges.

EMBODIMENT 5 includes a system for securing a tendon on an atmospheric balloon. The system includes a coupling assembly comprising a seam coupling mechanism that forms a seam joint between a first gore panel and a second gore panel, the seam joint is spaced from respective first and second lateral edges of the first gore panel and the second gore panel to form first and second edge flanges; and an edge coupling mechanism that forms an edge joint between the first and second edge flanges and closes a tendon sleeve, the edge joint spaced from the seam joint, the tendon sleeve including a tendon sleeve passage between the seam joint and the edge joint and between the first and second edge flanges. The system also includes a tendon positioning mechanism that positions the tendon within the tendon sleeve passage.

EMBODIMENT 6 includes the system of EMBODIMENT 5, wherein the coupling assembly forms the seam joint and the edge joint substantially simultaneously.

EMBODIMENT 7 includes the system of either one of EMBODIMENTS 5 or 6, wherein the coupling assembly forms the edge joint and the tendon positioning mechanism positions the tendon in the tendon sleeve passage substantially simultaneously.

EMBODIMENT 8 includes the system of any one of EMBODIMENTS 5-7, wherein the coupling assembly forms the seam joint and edge joint substantially simultaneously with the tendon positioning mechanism positioning the tendon in the tendon sleeve passage.

EMBODIMENT 9 includes the system of any one of EMBODIMENTS 5-8, wherein the seam coupling mechanism comprises a seam sealing mechanism that forms a seam seal between the first gore panel and the second gore panel.

EMBODIMENT 10 includes the system of EMBODIMENT 9, wherein the seam sealing mechanism comprises a first band sealer.

EMBODIMENT 11 includes the system of either one of EMBODIMENTS 9 or 10, wherein the edge coupling mechanism comprises an edge sealing mechanism to form an edge seal between the first and second edge flanges.

EMBODIMENT 12 includes the system of EMBODIMENT 11, wherein the edge sealing mechanism comprises a second band sealer.

EMBODIMENT 13 includes the system of any one of EMBODIMENTS 5-12, wherein the tendon positioning mechanism comprises a tendon positioning guide.

EMBODIMENT 14 includes the system of EMBODIMENT 13, wherein the tendon positioning guide guides the tendon into position between the first and second edge flanges and between the seam joint and the edge joint to secure the tendon within the tendon sleeve.

EMBODIMENT 15 includes the system of either one of EMBODIMENTS 13 or 14, wherein the seam coupling mechanism is adjacent to the edge coupling mechanism.

EMBODIMENT 16 includes the system of EMBODIMENT 15, wherein at least a portion of the tendon positioning guide is between the seam coupling mechanism and the edge coupling mechanism.

EMBODIMENT 17 includes the system of any one of EMBODIMENTS 5-16, further comprising a cutting station.

EMBODIMENT 18 includes the system of EMBODIMENT 17, wherein the cutting station cuts an excess portion of each of the first and second edge flanges.

EMBODIMENT 19 includes the system of any one of EMBODIMENTS 5-18, wherein the edge coupling mechanism cuts excess portions of the first and second edge flanges while coupling the first and second edge flanges together at the edge joint.

EMBODIMENT 20 includes the system of any one of EMBODIMENTS 5-19, wherein the edge coupling mechanism comprises a hot knife.

EMBODIMENT 21 includes the system of EMBODIMENT 20, wherein the hot knife cuts and couples the first and second edge flanges together at the edge joint.

EMBODIMENT 22 includes the system of either one of EMBODIMENTS 20 or 21, wherein the coupling assembly comprises an anvil with a slot for receiving the hot knife.

EMBODIMENT 23 includes the system of any one of EMBODIMENTS 5-22, wherein the coupling assembly comprises a gore panel divider that separates a portion of the first gore panel and a corresponding portion of the second gore panel.

EMBODIMENT 24 includes the system of EMBODIMENT 23, wherein the portion of the first gore panel and the corresponding portion of the second gore panel that are separated by the gore panel divider are adjacent to the seam coupling mechanism.

EMBODIMENT 25 includes the system of either one of EMBODIMENTS 23 and 24, wherein the portion of the first gore panel and the corresponding portion of the second gore panel that are separated by the gore panel divider are adjacent to the edge coupling mechanism.

EMBODIMENT 26 includes any one of EMBODIMENTS 23-25, wherein the tendon positioning mechanism extends from the gore panel divider between the seam coupling mechanism and the edge coupling mechanism.

EMBODIMENT 27 includes a method for forming a tendon sleeve on an atmospheric balloon. The method includes coupling a first gore panel having a first lateral edge to a second gore panel having a second lateral edge at a seam joint spaced from the first and second lateral edges to form respective first and second edge flanges from the first and second gore panels, coupling the first and second edge flanges together at an edge joint spaced from the seam joint to form the tendon sleeve with a tendon sleeve passage between the seam joint and between the edge joint and the first and second edge flanges, and positioning a tendon within the tendon sleeve passage.

EMBODIMENT 28 includes the method of EMBODIMENT 27, wherein coupling the first and second gore panels and coupling the first and second edge flanges are substantially simultaneous.

EMBODIMENT 29 includes the method of either one of EMBODIMENTS 27 or 28, wherein coupling the first and second edge flanges and positioning the tendon are substantially simultaneous.

EMBODIMENT 30 includes the method of any one of EMBODIMENTS 27-29, wherein coupling the first and second gore panels, coupling the first and second edge flanges, and positioning the tendon are substantially simultaneous.

EMBODIMENT 31 includes the method of any one of EMBODIMENTS 27-30, wherein the seam joint includes a seam seal.

EMBODIMENT 32 includes the method of EMBODIMENT 31, wherein coupling the first and second gore panels at the seam joint includes sealing the first gore panel to the second gore panel to form the seam seal.

EMBODIMENT 33 includes the method of any one of EMBODIMENTS 27-32, wherein the edge joint includes an edge seal.

EMBODIMENT 34 includes the method of EMBODIMENT 33, wherein coupling the first and second edge flanges together at the edge joint includes sealing the first edge flange to the second edge flange to form the edge seal.

EMBODIMENT 35 includes the method of any one of EMBODIMENTS 27-34, wherein coupling the first and second edge flanges together at the edge joint includes coupling the first and second edge flanges near the first and second lateral edges.

EMBODIMENT 36 includes the method of any one of EMBODIMENTS 27-35, further comprising cutting the tendon to a specified length.

EMBODIMENT 37 includes the method of EMBODIMENT 36, wherein cutting the tendon to the specified length is performed before positioning the tendon in the tendon sleeve passage.

EMBODIMENT 38 includes the method of any one of EMBODIMENTS 27-37, wherein coupling the first and second gore panels is performed with a seam coupling mechanism.

EMBODIMENT39includes the method of any one of EMBODIMENTS27-38, wherein coupling the first and second edge flanges is performed with an edge coupling mechanism.

EMBODIMENT 40 includes the method of any one of EMBODIMENTS 27-39, wherein positioning the tendon in the tendon sleeve passage is performed with a tendon positioning guide.

EMBODIMENT 41 includes the method of EMBODIMENT 40 wherein the tendon positioning guide is positioned relative to the seam coupling mechanism and the edge coupling mechanism so that at least a portion of the tendon positioning guide is within the tendon sleeve passage when the seam joint and the edge joint are formed.