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Technology Spotlight: Follow along each day as NAA technology expert Al Robbins posts and comments on one of the >4000 United States patents related to lighter-than-air (LTA).
  • 29 Oct 2013 8:36 AM | Deleted user

    Todays patent is Stone’s only U.S. Patent.

          “One means of maintaining a predetermined pressure within a

    constant volume balloon envelope is to provide said envelope with

    two compartments. A first compartment for containing gas and a

    second compartment or ballonet for containing air. Said

    compartments are located within said envelope. There is no means

    provided for gas or air to flow between said compartments. The

    air compartment or ballonet is adapted to expand or contract as

    the gas volume within the gas or first compartment of said envelope

    decreases or increases respectively. In such cases the gas

    compartment of said envelope is inflated with a lifting gas such as

    helium and the ballonet is adapted to be filled with air from the

    atmosphere through an appropriate opening in the ballonet. As the

    gas volume within said gas compartment changes air is forced

    into or out of the ballonet through the opening to compensate for

    said gas volume change. For example if the gas volume decreases

    air will be forced into the ballonet; and if the gas volume increases

    air will be forced out of the ballonet. The volume of the balloon

    envelope in such instances will remain substantially constant at

    all times and the pressure will be maintained at a predetermined

    magnitude. To the best of my knowledge the prior art does not

    show a ballonet externally located relative to a non-elastic balloon

    gas envelope for maintaining a predetermined pressure within

    said non-elastic envelope.

          Accordingly one object of the invention is to provide a non-

    elastic balloon envelope having an external control for maintaining

    a predetermined pressure within said balloon envelope.”

    NOTE: Two of Stone’s approved claims applied only to tethered 

    balloons, the other four to all gas balloons. His innovation was to 

    maintain a preselected pressure within the shaped, inelastic balloon 

    by pumping gas to (or from) an external, expansible, LTA gas container, 

    which he calls a ballonet. 

    (e.g. This is a two part variable-volume balloon system, without a

    conventional ballonet. Stone doesn’t discuss changes in Lift, Drag or

    Center of Buoyancy as the “ballonet” expands and contracts.) 

    The patent is cited by six modern U.S. patents:

    3,424,,405  Balloon locomotion,

    3,432,122   Combination ballonet and dilation system for balloons,

    3,484,058   Balloon,

    4,125,233  Tethered aerodynamic balloon with integral fins,

    4,705,235   Method and a device for hooking a balloon envelope to a

                       fastener means, and

    5,456,426  Attachment fitting for a wall of a flexible structure.

  • 28 Oct 2013 9:08 AM | Deleted user

    Todays patent is the only U.S. patent issued to Nobile.

          This invention relates to improvements in the construction

    of semirigid airships provided either with a flat girder or with a 

    tubular girder having a triangular or polygonal section.

          In these types of airships the vertical and horizontal rudders

    hitherto have been usually arranged in such a way as to form a

    kind of biplane or a triplane cell directly connected to the 

    framework or girder of the airship, which framework or girder 

    in the case of airships with fiat girder is to that end stiffened to 

    a suitable extent towards the stern.

          Said biplane or triplane cell presents two drawbacks:

       l. It is not fit to satisfactorily withstand the torsional stress due

          to dissymmetrical  loads on the planes;

      2. From the aerodynamic point of view it opposes a greater

          resistance to flight, owing to the lateral position with respect 

          to the envelope.

         To obviate both of these drawbacks, according to this invention

    the said box is substituted by a cruciform system of wings, formed

    by stationary planes acting as keels, and by movable planes in

    alignment with the first mentioned ones and acting as rudders.

    This arrangement also has the advantage of relatively reducing

    the size of the movable planes.

        Said cruciform system of wings is connected with the girder by

    means of an annular cage which is so shaped as to exactly follow

    the external outline of the hull of the airship, upon which it is

    arranged, …”

    NOTE: Neither the text nor the claims mention the possibility that

    the cruciform empennage might be folded, or collapsed, when the

    envelope is deflated. Thus his innovation is a non-rigid airship

    with rigid ends. N.B. Nobile assumes that this innovative end section

    may be attached to any of the existing types of semi-rigid airship

    (internal) keels.

    The USPTO inexplicably failed to list the key classifications 

    of this seminal patent by the remarkable engineer, explorer, 

    scientist, and Italian General:

    244/87 (Rudders and empennage),

    244/96 (Airship control),

    244/125 (Airship hull construction),

    244/127 (Airship load attachment), and equally important

    244/130 (Aerodynamic resistance reducing).

    This patent is cited by a single modern patent:

    2,707,603 "Balloon with rigid fins”.

  • 27 Oct 2013 7:32 AM | Deleted user

    Todays patent is the only patent in which Klemperer and Liebert 

    were coinventors.

    Most of their seventeen U.S. patents were assigned to either 

    Goodyear-Zeppelin or the Wingfoot Corporation.

        “Bow elevators on airshlps have been tried on certain early 

    airships but were later abandoned when it was found that tail fins 

    were indispensable and tail elevators attached to them were so 

    effective as to be sufficient under normal operating conditions.

          More recently, however, conditions have been encountered 

    in which the availability of an additional steering device on the 

    ships bow would appear desirable. Such instances are the checking 

    of a dive from low altitude, the zooming up from a take-off field, 

    or the hurdling of a ground obstacle. In these maneuverings, 

    when performed with the tail elevators alone, the tail of the ship 

    idepressed and sweeps through a lower arc than the path of the 

    center of buoyancy does because the action of the tail elevator is 

    an indirect one. It actually elicits a down force on the tail in order 

    to pitch the ship up so that its own propellers can drive it upwards. 

    Bow elevators, on the other hand, act directly by creating an 

    up force in front of the center of buoyancy in order to pitch the 

    ship upwards. Therefore the danger of the tail fin striking the 

    ground is definitely lessened when the maneuver is assisted or 

    initiated by bow elevators. In hurdling an obstacle the maneuver 

    of climbing the bow over it with up bow elevators and then lifting 

    the tail over it with the tail elevators is especially useful.”

    NOTE: Several of their claims stressed applicability to a vessel moving 

    through a fluid (rather than just an airship or an aircraft in the air). 

    Claims 8, 10, 11, and 18 include provisions for the control surface(s) 

    to be withdrawn inside the vessel when not needed. (Withdrawn, not


    Claim 16 provides for control surface on opposite sides of an airship's 

    body which may be individually adjusted (Angle of attack only).

    Their patent is only cited by three modern patents:

    2,673,047  Foldable-winged craft,

    2,734,701 Airplane with retractable variable-incidence wings, and

    2,743,888 Variable wing.

  • 27 Oct 2013 12:29 AM | Deleted user

    Todays patent is one of Koun’s three patents involving in-flight

    inflation of large buoyant balloons.

           The main object of this invention is to provide means for 

    rendering an aeroplane buoyant when it can be in no other way 

    controlled. The means comprises a plurality of thin silk bags 

    which are mounted upon the wing surface of an aeroplane and 

    are adapted to be filled with hydrogen gas thru a novel type of 

    valve, which when operated, controls the circulation of the gas 

    thru these bags.

         Another object is to provide a buoyancy unit for aeroplanes

    having a plurality of silken bags which communicates with a 

    hydrogen tank, the communicating pipe between the hydrogen 

    tanks being equipped with valves which are operated by a novel 

    type of mechanism.

    NOTE: Although balloonists had struggled for decades to develop 

    safe procedures for inflating a large balloon in light winds, neither 

    the inventor nor the patent examiner appeared to have any 

    reservations concerning automatically inflating multiple large balloon 

    on an aircraft in distress.

    The USPTO should have assigned 244/139 (. Entire aircraft).

    e.g. Devices for safely lowering entire aircraft to the ground.”

    N.B. The balloons are described in the claims as circular; no mention 

    of how these circular balloons are connected to the suspended aircraft.

    Not to continue flailing a dead horse, the patent doesn’t indicate whether

    the aircraft, or the balloons, are expected to be usable after the first activation.

    Curiously, this patent is cited by at least one modern patent:

    P/N 6,412,731 Simplified buoyancy system for avoiding aircraft crashes.

  • 25 Oct 2013 8:53 AM | Deleted user

    Todays patent is Von Siegsfeld’s only U.S. patent.

       “The object of the present invention is an air-balloon which is 

    united by a system of cords with a second smaller balloon to obviate 

    the disturbing movements and variations of the main balloon which

    render accuracy difficult in military and meteorological observations.

    Both balloons are provided with certain special improvements in 

    order to prevent deformation or bumping by the action of the wind, 

    the form of the balloon being essential to the velocity, steadiness, 

    and accuracy of its movement.”

    NOTE: Interesting technique for minimizing the motion of a tethered 

    (Moored?) balloon.This U.S. patent was finally issued five years after 

    it was issued in Germany. (I believe that before his death in 1902, 

    Von Siegsfeld worked with von Parseval in developing the 

    DRACHEN observation balloon. Perhaps one of our members 

    could fill us in on their relationship.)

    The USPTO lists two classifications. Strangely, Google doesn’t

    cite either; it lists only one European classification (B64B1/40).

    This patent is cited by three modern patents, each in turn cited by multiple patents:

     2,960,298 Kite,

     3,072,367 Azimuth-stabilized balloon gondola, and

     4,533,099 Kite.

  • 24 Oct 2013 7:06 AM | Deleted user

    Todays patent is one of Winzen’s fourteen LTA (balloon) patents.

        “The present invention relates to balloons and more particularly 

    to high altitude or stratosphere balloons, capable of carrying a 

    substantial payload.”

    NOTE: The examiner approved twenty four claims. The claims 

    emphasize applicability to balloons NOT TO AIRSHIPS; e.g. the 

    patent doesn’t include 244/128 (Airship gas cell construction and 

    arrangement) or other gas-holders.

    Well written patent in older format. (Searchable on USPTO website

    only by P/N and classifications assigned when the patent was digitized.

    List of earlier patents and other applicable references is on the last page 

    of the patent.)

    This patent is cited by seventeen subsequent US patents, two by Winzen.

  • 23 Oct 2013 1:36 PM | Deleted user

    Todays patent is the only patent issued to Gegner;

    one of three issued to Reid.

          Therefore, an objective of the invention is to present a balloon 

    structure having a tape harness over the balloon envelope which 

    has adequate strength for carrying the load and yet which adds 

    little additional weight to the balloon.

           Another objective of the invention is to provide a tape which 

    obviates many of the inherent difficulties of an adhesive backed tape.

           It is a further object of the present invention to provide an 

    improved seam between the gores of balloons.

          Another object of the invention is to provide a seam which may 

    be quickly and easily made and will not add useless weight to the 


    NOTE: This atent is well worth reading, although it ostensibly applies

    only to fabricating thin-film high altitude balloons. All fourteen claims 

    apply to the balloons, to the improved load-bearing seam, and/or to the 

    method of producing them:

    Claims 1, 2, 3, 8, 12, 13 and 14 apply to the balloon,

    Claims 4, 5, 6, and 7 concern the seams, and

    Claims 9, 10, and 11 concern the method of forming a balloon’s seams 

    and attaching the load-bearing tape.

    Nineteen U.S. and five international patents cite this patent.

    You can link to any or all of them on Google's patent website, but

    strongly recommend against trusting its' OCR versions. 

  • 22 Oct 2013 8:39 AM | Deleted user

    Todays patent is Kuenkler’s second U.S. patent.

    NOTE: Interesting concept, but more moving parts than a helicopter. 

    Although the abstract describes an aerostatic lifting body, and the text 

    discusses the body construction in some detail, all fourteen claims apply 

    only to the drive unit, “for mounting to a vehicle”. N.B. The claims 

    do not include method of attaching the drive unit to a vehicle (airship 

    or aircraft body).

    It would be really interesting to validate a prototype drive unit capable

    of providing a few hundred pounds of thrust, AND of doing so for a 

    few hundred hours before failure.

    Five of the eleven patents which cite it (to date) apply to LTA:

     7,156,342  Systems for actively controlling the aerostatic lift of an airship,

     7,472,863  Sky hopper,

     7,484,936  Buoyancy control system for an airship,

     8,167,236  Hybrid lift air vehicle, and

     8,245,966  Airship and vectored propeller drive therefor.

    One disclosure “Airship for transportation” (201110240794, 

    filed in 2011) also cites it.

  • 21 Oct 2013 11:56 PM | Deleted user

    Todays patent is one of Arnstein’s twenty-one U.S. patents;

    his last patent as sole inventor.

          The principal object of the invention is to provide a wire braced

    main ring which possesses the combined qualities of lightness 

    and rigidity.”

         In building the larger sizes of airships, it is very desirable that 

    the main ring be sufficiently stiff to resist such warping or buckling 

    forces without employing an assembling frame, while it is being 

    incorporated into the hull superstructure. Although main rings have 

    been constructed in which each girder forming one side of the 

    polygonal ring was polygonal in cross-section, or composed of 

    built-up girders, there are certain sizes of airships wherein this type 

    of inherently rigid main ring cannot be utilized to advantage because 

    of its relatively great weight, and its relatively great cross-sectional

     size adversely limits the gas volume of the airship.

          According to this invention, a pair of ring girders mounted in

    spaced relation are provided, and angular girders, preferably of 

    polygonal cross section, are secured therebetween in such manner

    that their apexes project radially inwardly in the median plane of 

    the main ring. Such angular girders embrace two or more sides of 

    the main ring. Wires for bracing the structure are interconnected 

    between the various corners of the ring.”

    NOTE: The patent concerns one part - the main rings -of a Zeppelin-type

    hull. Three of his subsequent, Joint patents, related to improved bulkheads
    for his rigid airships (illustrated but not claimed in this patent).

    This patent has not been cited by any modern patents.

    Anyone interested in rigid airships should also read “When Giants 

    Roamed the Sky”, by Eric Brothers and Dale Topping.

  • 20 Oct 2013 1:25 PM | Deleted user

    Todays patent is one of Huch’s seventeen patents

    related to LTA.

         “This application relates to a process of manufacturing multiple 

    gore balloons and, more particularly, to improved methods of 

    forming successive gores from a continuous strip of thin gas proof 

    sheet material.

          Balloons have been developed in which the balloon body is formed

    from a plurality of individual gores of thin sheet material joined together

    at their adjacent edges. Certain balloons of this type are disclosed and

    claimed in United States Patent 2,526,719, assigned to the same assignee

    as the present invention. Thermoplastic sheet materials of the type 

    preferred for the manufacture of such balloons constitute a major

    portion of the cost of the finished product. Because the gores generally 

    taper or curve from a wide intermediate point toward both ends of the 

    usual gore pattern, previous methods of forming such gores have

    required the use of substantial amounts of material, much of which has

    been wasted.

    NOTE: Huch’s “method invention" reduces waste, and cost, in the 

    balloon manufacturing process. Curiously, none of the assigned 

    classifications apply to balloons:


                    CHEMICAL MANUFACTURE (156/264, 156/251 

                    and 156/258),

    Class 83 CUTTING  (83/17).

    This patent is cited by ten modern US and foreign patents:

      2,792,888  Staple fiber cutter,

      2,837,159  Methods of and apparatus for cutting strip material,

      3,063,889  Method of joining the edges of webs to form a large

                        area film fabrication,

      3,068,137  Large area film fabrication,

      3,663,337  Method and apparatus for making spiral-reefed


      4,877,205  High-altitude balloon and method and apparatus for

                        making it,

      6,234,425  Release fitting for balloons,

      7,611,395  Illuminating balloon inflatable with air,

      EP0025384  Container of symmetric lobed structure, and

      WO1989006205  High-altitude balloon and method and 

                                   apparatus for making it.

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