1. Field of the Invention
The present invention relates to lighter-than-air balloons, and more particularly, to lighter-than-air balloons having a rigid skeleton.
2. Description of the Related Art
Generally, it has been difficult to fabricate balloons with continuously curved shapes, and well-defined corners, or edges. Most balloons are formed in spherical shapes in order to allow the greatest volume for the least surface area. Also, the thin material of the balloon naturally becomes spherical as pressure is increased. To achieve the desired non-spherical shape, then, it is necessary to provide a supporting frame to maintain the thin material of the balloon. However, in the past, the weight of such frames, even when the most efficient materials for such purposes were selected, typically required a displaced volume of such size that fabrication for home use or the like would have been impractical. Consequently, helium balloons are typically formed in spherical shapes with some type of tethering device attached for maintaining control of the balloon's elevation.
U.S. Pat. No. 4,032,086, issued Jun. 28, 1977 to W. Cooke, discloses an aerostat or aquastat in which a sealed envelope of flexible material is mounted on a flexible frame which can be caused to expand the envelope after it has been evacuated of internal gas, thereby setting up a vacuum or partial vacuum condition in the envelope. By controlling the frame to adjust the volume of the envelope, the lift or buoyancy of the device can be controlled in flight or precisely determined before ascent.
U.S. Pat. No. 4,038,777, issued Aug. 2, 1977 to S. Schwartz, discloses a gas filled, balloon-like object capable of defining a non-spherical shape. A high modulus graphite impregnated epoxy material is used to prevent distortion of the inflated object. Strings or weights are required to prevent upward ascent of the balloon.
U.S. Pat. No. 4,113,206, issued Sep. 12, 1978 to D. Wheeler, discloses a lighter-than-air apparatus, including a thin, pliable air-tight cuter envelope disposed in overlying relationship over a light-weight, coarse-opening inner frame of a spherelike shape.
Other devices relating to balloons and lighter-than-air apparatuses include U.S. Pat. No. 2001/0003505 A1 issued Jun. 14, 2001 to T. Bertrand, which discloses a lighting apparatus secured to a balloon by string under tension; U.S. Pat. No. 4,925,426 issued May 15, 1990 to C. Lovik, which discloses an open skeletal frame of rigid rod-like formers made of thin strands of plastic, wire, or the like and which permits the insertion of an uninflated balloon of conventional shape and size into the interior thereof so that upon inflation of the balloon, the latex sidewall material of the balloon projects outwardly through the openings of the formers to produce bulbous projections; U.S. Pat. No. 5,115,997, issued May 26, 1992 to J. Peterson, which discloses a tethered surveillance balloon having a relatively low lift-to-weight ratio; U.S. Pat. No. 5,115,998, issued May 26, 1992 to L. Olive, which discloses a double-walled, annular balloon which requires less gas to inflate than its volume would indicate; U.S. Pat. No. 5,334,072, issued Aug. 2, 1994 to M. Epstein, which discloses an inflatable body, such as a balloon, and holder assembly therefore; U.S. Pat. No. 5,882,240, issued Mar. 16, 1999 to B. Larsen, which discloses a toy blimp; U.S. Pat. No. 6,276,984, issued Aug. 21, 2001 to K. Komaba, which discloses a balloon having adhering members disposed upon its surface; Japanese Patent No. 1238890, published Sep. 25, 1989, which discloses plastic film balloons in animal and other complex shapes.
The invention is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
Once the structural member 26 is secured in the channel portion 20, the structural member 26 provides a substantially rigid skeleton for the balloon 10 so that the balloon 10 may maintain its desired shape once it has been inflated with gas. The rod member 26 has a weight which is calculated to counterbalance the buoyant effect of the gas so that the balloon 10 is prevented from floating upwards when filled, the balloon 10 simply floats at the height at which it is released. Stated differently, in one embodiment, the weight of the rod (and any connector) is selected to cause the balloon to be neutrally buoyant under ambient conditions when the chamber is inflated to a known pressure with a lighter than air gas.
Although only one structural member 26 is depicted in the drawings, for some shapes, it may be necessary to use a plurality of structural members 26 of varying sizes (not shown). For such shapes, for example those with a plurality of curves or angles, a plurality of apertures may be provided at various points on the balloon 10 so that the structural members 26 may be easily inserted into the channel portion 20. The structural members 26 can then be connected to one another using the connector 32, as previously described.
In one embodiment, additional heat welds are used within the sleeve to provide a well-defined seat 334 for the ends of the structural member 226 to reduce movement of the structural member 226 in the sleeve 232. In one embodiment, the sleeve is open at both ends and defines a channel for the structural member. A throughway connector may be used to hold the structural member 226 together. For example, the sleeve may run circumferentially around the lenticular shaped balloon described with reference to
In one embodiment, a structural member may be a rod having substantially any shaped cross section. While rod with circular cross section is suitable for use in embodiments of the invention, square, triangular, dogbone and substantially any other cross sections are contemplated. Structural members having a thickness much less than their length or width are also contemplated.
In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however be evident that various modifications and changes can be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.
This application claims priority from and is a continuation-in-part of U.S. Non-provisional patent application Ser. No. 10/366,387, filed Feb. 14, 2003, entitled RIGID HELIUM BALLOONS, the contents of which are incorporated by reference herein in their entirety.
Number | Date | Country | |
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Parent | 10366387 | Feb 2003 | US |
Child | 10643780 | Aug 2003 | US |