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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 Nov 2013 8:19 AM | Deleted user

    Todays patent was Aelsson’s only patent.

          “It is a principal object of the present invention to provide an air 

    evacuated, hollow structure constructed of a rigid ceramic material 

    which is strong and durable.

          Another object of the invention is to provide an improved, sturdy

    aerial vehicle which operates on a vacuum lifting principle thus 

    eliminating the use of an expensive or explosive lifting gas.

          A still further object of the invention is to provide a relatively 

    simple and economical method of constructing a rigid ceramic air 

    evacuated hollow structure.

    NOTE: This patent is a classic example of the first of Charles 

    Burgess’ Seven LTA Fallacies; a Vacuum Lift device. 

    (Chapter 11 in his 1927 text, AIRSHIP DESIGN.)

    A sphere encloses the greatest volume for a given amount of surface

    area; and a thin-walled one-piece ceramic sphere would have been 

    the lightest weight device possible prior to the development of new 

    super-materials. It might even have been possible to install an orifice

    and valve without introducing micro-faults in the sphere. However, 

    in addition to Burgess’ cautions:

      How small a device can be produced that would support its own 

      weight under standard sea-level conditions?

      How large can one be made, assuming an oven big enough

      to hold it? 

    We still don’t have effective Non-destructive inspection standards 

    for ceramics.

      How might you install, and constrain, a large sphere in an airship?

      What happens when a vacated sphere (or its fitting) fails in service?

      Assuming the airship isn’t destroyed when a ceramic sphere 

      disintegrates, where could the ship go to remove and replace the 

       failed sphere?

    I assume that regulatory authorities would require one, or more, 

    prototype sphere(s) to be cycled to failure before authorizing use of 

    such a dangerous device.

    Perhaps most important, how much power will be required by the 

    vacuum pump system(s) required to establish and maintain the 

    extremely low pressure needed to provide useful lift.

    This patent is cited by 

    P/N 4,026,499 Glass balloons and method for making same.

  • 28 Nov 2013 7:23 AM | Deleted user


    Todays patent is one of Corbett’s six patents related to airships.

         One of the principal objects of the invention consists in providing 

    a mast to which the airship is secured at or about its center of resistance, 

    for the purpose of reducing the movement of a moored ship to the 


         Another important object consists in the provision of a swing or 

    cradle type mooring mast, which allows the whole ship freedom to roll, 

    pull or surge ahead with respect to the mast, and especially advantageous 

    in this connection is the provision of weights suspended from the swing 

    or cradle, which serve to dampen the movements of the moored ship 

    gradually as distinguished from positively and non-yieldingly, as is

    ordinarily the case.

          A further object of the invention is to provide a rotatable mooring 

    mast having lateral extensions connected preferably with the ship’s car

    on opposite sides of the ship, whereby rotation is communicated to the 

    mast as the moored ship shifts in the wind.”

    NOTE: Corbett was one of the more innovative of the small airship 

    designer, builder and operators during the inter-war period. Unfortunately 

    his concept appears to have been lost in translation to patent language. 

    This was his only patent involving mooring. It is one of very few 

    mooring patents that even mention required modifications to the airship. 

    Unfortunately Corbett describes a slack-wire swing, rather than 

    a net, seemingly a singular connection with the airship.

    On the negative side (as written): Shifting winds will provide little 

    or no rotational force to the moored airship; and, There are no provisions

    for access to the airship from the mast, or for lowering the airship to

    ground level. 

    Only three of the fourteen claims involve a movable (transportable) mast.

    Cited only by P/N 5,516,065 “Landing and anchoring mechanism for an airship”.

  • 27 Nov 2013 6:06 AM | Deleted user

    Today’s patent is one of Struble’s twenty-two U.S. Patents.

         A dirigible-shaped inflated balloon having an internal 

    curtain with a superpressuring line attached to the curtain, 

    the superpressuring line then being attached to a collapsible

    tube and passing outwardly of the body of the balloon, 

    whereby the volume of the body may be changed by pulling on

    or releasing the superpressuring line, the superpressuring line 

    then includes an elastic section; it passes about the rotor of a

    generator and through an annular tube on which the generator

    is located to a remote tethering or operating location, and 

    inelastic support lines are attached to the body member and to

    the annular tube. The body member may be provided with 

    inflatable, retractable fins for stabilization and a reflective 

    surface may be formed on the nose of the balloon.

         The present invention relates to a dirigible-shaped inflated

    balloon with means for superpressuring the balloon from a 

    remote position through a tether or load cable.”

    Struble describes a variable volume, multi-lobed aerostat; its pressure

    is regulated by an unusual tether system. The reflective surface is 

    described as a passive communications device; no other payload or 

    purpose is discussed in the patent. 

    NOTE: No indication that the internal volume of the aerostat might

    be compartmented, or contain other pressure control devices, such

    as ballonets. No discussion regarding when, why, how, or how much

    the tail fins were to be inflated (Claim 7). Claim 14, 15, and 16 apply 

    to a reflective surface (passive communication device); no mention 

    of any other payload. No hint that such a volumetric control might

    be useful in a non-rigid airship.

    This patent is cited only by patent application No. 20120286089,

    "Strain reduction on a balloon system in extreme 

    weather conditions”.

  • 26 Nov 2013 6:03 AM | Deleted user

    Todays patent is the second and last of Rall’s U.S. Patents.

          “My invention relates to air ships of the combined balloon and

    air plane class such as shown in my Patent No. 995,033, issued 

    June 13, 1911, and has for its object the provision of an 

    improved construction of balloon supports, improved construction

    of air planes and means to automatically control the expanse of 

    air plane surface to keep the ship at all times in equilibrium.”

    This patent is one of many which propose what Burgess later 

    described as one of the six common airship fallacies -

            Combined heavier and lighter-than-air craft.

    NOTE: Rall apparently believed that flexing (opening the gap) in his 

    V-shaped plane would decrease the lift, without significantly 

    increasing the drag on that particular wing. No discussion regarding 

    the extent of opening, or means of preventing flutter of this flexible 

    planeRall does not indicate how to launch his airship with a 

    useful payload.

    The text mentions, briefly, that the gas cells provide sufficient 

    buoyancy to lift the empty airship. (Page 2 lines 42 through 44):

             the sections formed by the rods 1, 2 and 3, 4 and 5 and 

              braces 6 have bags 41 of balloon cloth or other suitable 

              fabric that are inflated with gas and operate to lift the 

              vessel unloaded…”

    None of the approved claims even mention a buoyant gas.

    Even so, the USPTO should have assigned the appropriate 


    244/25 (Airship with sustaining wings), and/or possibly 244/5

    (Airplane, weight diminished by buoyant gas), as well as

    244/96 (Airship control) and

    244/127 (Airship load attachment).


  • 25 Nov 2013 5:10 AM | Deleted user

    Todays patent is one of Jaray's twelve U.S. patents, all assigned to

    Luftschiffbau Zeppelin.

          “It is well known to persons skilled in the art that the safety 

    valves must be arranged to open and blow off of themselves 

    whenever the admissible gas pressure acting on the wall of a 

    gas cell is exceeded. However, all the safety valves hitherto in use, 

    and quite especially the spring-loaded valves, involve a number 

    of serious drawbacks. In order to avoid these drawbacks it has 

    already been proposed to utilize the variations of form of the gas 

    cells resulting from the differences of pressure arising at different

    altitudes. However, the systems in question were rather complicated,

    requiring either special diaphragms or compensators.

          The present invention, while making use of the changes of form

    spoken of, entirely dispenses with all such devices and merely 

    provides means near the outer surface of the cell and operated

    by a shifting of the wall of the cell for opening this valve.”

    NOTE: This patent discloses a “new and improved” safety valve; 

    to automatically protect the lifting gas cells in rigid airships, such as 

    the Zeppelins, in the event of excessive internal pressure.

    A similar mechanism could be incorporated in a ballonet, but

    Zeppelin had never exhibited any interest in either non-rigid or 

    semi-rigid airships.

    The USPTO assigned one aeronautical classification, 244/99 

    (Gas release); none from other classes, such as 137 FLUID 


    This patent is not cited by any modern patents.


    Jaray is best known as the man who introduced “streamlining” to the transportation industries: airships, aircraft, automobiles and trains. 

    His company licensed automobile designs to Audi, Chrysler, Ford, 

    Mercedes-Benz, Tatra, and several now-forgotten European 

    manufacturers in the late 20’s and 30’s. However, his only U.S. patents

    are the dozen assigned to Luftschiffbau Zeppelin. None of the twelve 

    mention the existence of earlier German patent(s).

  • 24 Nov 2013 8:13 AM | Deleted user

    Today’s patent is the second of Burgess’ patents issued on this date.

    Both were submitted on January 28, 1925.

         In existing rigid airships difficulty is experienced in maintaining

    the desired tension in the outer cover cloth and the difficulty is likely 

    to become greater when the diameter of the hull and the spacing

    of the longitudinals are increased.

          In the present invention it is proposed to obtain a nearly constant

    tension in the outer cover by means of special light and resilient 

    secondary longitudinals intended solely to support the outer cover, 

    and placed between the main longitudinals.”

         “Such a construction provides a resilient longitudinal girder 

    which may be erected initially with a slight camber beyond the fair 

    lines of the hull and subsequently drawn by the tension of the outer

    cover indicated at 8 into the fair lines. These resilient longitudinals

    1 and 5 will then press against the outer cover 8, assisting to keep 

    it tight, in spite of stretching which may occur after it is laced

    to the main or secondary longitudinals.

          It will thus be seen that the present invention provides a simple 

    and practical construction for secondary longitudinals adapted to 

    support the outer cover of rigid airships.”

    NOTE: None of the three approved claims even mention the airship’s 

    outer cover, so there is some justification for the USPTO neglecting 

    to cite either:

      244/126 (Airship skin construction), or

      244/130 (Aerodynamic resistance reducing).


    In his seminal 1927 textbook for airship designers and aeronautical

    engineering students (AIRSHIP DESIGN, Ronald Press Company), 

    Burgess emphasizes,

              “The design of airships, particularly of the rigid type, 

              is mainly a structural problem; and theoretical aerodynamics

              has nothing like the relative importance which it bears in 

              airplane design.”

    Unfortunately few modern inventors, designers or patent examiners 

    appear to be aware of his teachings.

    Neither his patents nor his textbook has been cited by any modern patent

    or patent application.


    Burgess devoted chapter 11 of his book to six common airship “fallacies”:

    1. Vacuum airship
    2.Compressing air or gas
    3.Artificial control of superheat
    4.Combined heavier and lighter-than-air craft
    5.Channel through hull to reduce resistance, and
    6.Wind screen at mooring mast.

    Worldwide Aeros hopes to disprove two of his “fallacies” with its 

    small-scale Aeroscraft.

  • 23 Nov 2013 9:24 PM | Deleted user

    Todays patent is one of ten U.S. patents wallis assigned to 

    Airship Guarantee Co. Ltd.

          “According to the present invention, instead of locating the 

    main loads, such as the cars or coaches for the passengers and 

    crew so that they are situated, or project outslde the streamline 

    of the airship, we locate them within the streamline or outer 

    envelope thereof and thereby avoid the wind resistance offered by 

    the projecting structures hitherto used. To this end the cars or 

    coaches forming the said main loads may be suspended from one 

    of the upper longitudinal girders, usually at the points where the 

    said girder joins the transverse frames, and located symmetrically 

    on each side of the airship within spaces formed between the outer 

    envelope of the airship and the hydrogen gas bags. Communication 

    may also be established between the nose and tail of the airship 

    and the said cars or coaches by means of corridors disposed 

    longitudinally of the airship and suspended on each side thereof 

    between the outer envelope and the gas bags. Communication may

    also be established between the cars or coaches disposed respectively 

    on each side of the airship or between the aforesaid longitudinally

    disposed corridors by means of transversely positioned staircases

    formed preferably within the transverse frames, the latter, to this end,

    being constituted by built-up space frame girders which are 

    preferably triangular in cross section.”

    NOTE: This patent is not cited by any modern patents. 

    It probably would have been if the USPTO had included all 

    applicable classifications, or as a minimum those covered by 

    the approved claims:

     244/118.5 (Passenger or crew accommodations),

     244/125 (Airship hull construction),

     244/126 (Airship skin construction and arrangement),

     244/128 (Airship gas cell construction and arrangement), and

     244/130 ( Aerodynamic resistance reducing).

    N.B. The application was filed five years before the first flight of 

    his  R-100 in December 1929.

    BOMBERGUY has posted a 10 minute montage of photos 

    and newsclips of the R101 (the final minute is about the R100) 

    on YOUTUBE.  Includes close-ups of mooring at the top of 

    the Mast at Cardington. Notice the contemporary transport 

    aircraft and automobiles.


  • 22 Nov 2013 8:34 PM | Deleted user

    Todays patent is one of the more unusual modern LTA patents.

    Unlike Colting’s earlier airship patent, all Figures apply to 

    spherical airship.

    Hokan Colting, was co-founder of Thunder and Colt in England. 

    He founded 21st Century Airships, Inc., in Canada in 1988. 

    His prototype 2-man low-speed spherical airship was followed 

    by a large four-engine spherical airship.

    The company’s current website (www.theflyingyacht.com) provides 

    some of the history of his airships, but the company now concentrates 

    on developing a very low altitude flying boat, which it defines as not 

    an airship. (Supposedly not requiring FAA or CAB certification).

    NOTE: All twenty-five claims apply exclusively to a substantially

    spherical airship”. None of the ten issued patents which cite it mention spherical airships:

      7,487,936  Buoyancy control system for an airship,

      7,552,893  Airship & method of operation,

      7,866,601  Lenticular airship,

      8,052,082  Optimized aerodynamic, propulsion, structural and 

                        operations features for lighter-than-air vehicles,

      8,109,462  Lenticular airship,

      8,297,550  Lenticular airship and associated controls,

      8,418,952  Lenticular airship,

      8,448,894  Method and apparatus for a mobile aerial sustained 

                        solar power-plant,

      8,453,449  Vertical axis solar powered generator, and

      8,459,589  External pressurization system for lighter than air vehicles.

    Colting and 21st Century have obtained Canadian, German, and 

    other international patents on this unusual high-altitude spherical 


    N.B. Several of the approved claims are obvious or nonsensical:

    The ship can carry sensors; communications equipment; it may reflect 

    E/M radiation; It might be operated remotely; It may be refueled in 

    flight  (if a refueling machine could approach and maintain station 

    with it. No mention of reballasting.)

    Neither the text, nor any of the 25 claims, indicate that the lifting gas 

    might be contained in more than one inner cell or at different pressures.

    Only a single pusher propeller (electric or otherwise) is claimed; no 

    indication of force or maximum airspeed delivered.

    No mention of towing or reshaping the profile while repositioning.




  • 21 Nov 2013 6:24 PM | Deleted user

    Todays patent is Settle’s only patent.

         “The principal object of my invention is to provide a device for

    picking up ballast water while the aircraft is under way over a 

    body of water.

          Another object is to provide a device for the ballasting of 

    airships while moored or riding at a floating mast.

          A further object of my invention is to provide means for 

    restoring and/or maintaining the static equilibrium in counter 

    action to tendencies to change such equilibrium caused by the 

    consumption of liquid fuel in the engines, superheating effects, 

    correction for change in trim caused by the landing and launching 

    of airplanes from the airship, and other like causes, thereby 

    obviating the necessity of valving of the lifting gas.

          A still further purpose of my invention is to provide an improved 

    water ballast apparatus so as to dispense with such commonly 

    known cumbersome water recovery apparatus which depends upon

    utilizing the engine exhaust for collection of water by the

    condensation of moisture in the exhaust gases.”

    Check http://en.wikipedia.org/wiki/Thomas_ G._ W._Settle

    "Tex" Settle, USNA class of 1918. Pioneering balloonist; 

    Communications Officer on the  USS  SHENANDOAH and 


    Designated NA (LTA) # 3350 in 1927.

    Retired as Vice Admiral USN. 

    NOTE: Settle was either a LT or LCDR when he filed this patent

    application. However, he was one of the very few regular Navy 

    officers, and pilots experienced with large airships. The first figure 

    illustrates just  one version of his water pick-up system, using a 

    "cloud car" as a low-altitude extension of the large airship. (The 

    cloud car could be safely lowered to near the water surface, 

    without endangering the airship itself.) As a Naval machine,

    the airship would always have access to water, albeit generally 


  • 20 Nov 2013 9:03 AM | Deleted user

    Todays patent is third of Lake’s four aeronautical patents.

    Most of his 150-plus patented inventions related to submarines, 

    boats, engines, or concrete construction.

       This invention relates to an improvement in heavier-than-air

    flying machines, and particularly to improvements in the 

    constructions shown in Letters Patents granted to me June 2, 1908, 

    and July 20, 1909, Nos. 889,693 and 928524, respectively.

          In the Construction shown in my aforesaid patents, I employ 

    hollow chambers designed to be filled with a gas lighter than the

    atmosphere to thus render them buoyant, the object of the

    construction being to provide the ship with sufficient buoyancy

    to permit of a gradual descent in the event of the propelling 

    mechanism being thrown out of order. My present construction

    obviates the necessity of the employment of these normally buoyant 

    chambers, and …..”

    NOTE: This is the first and only time that a Lighter-than-air gas is 

    mentioned in this patent. The earlier patents should have been 

    classified as 244/5 (Airplane, weight diminished by buoyant gas),

    (Actually assigned 244/30 and 244/29 respectively.) This patent 

    applies exclusively to a heavier than air aircraft.

    Unfortunately, even though most older patents have been digitized

    and entered into the USPTO’s digital data base, they aren't adequately

    searchable, and are frequently misclassified (failing to assign 

    appropriate classifications, and as in this case have been assigned an incorrect classification.)

    This patent has been cited by two U.S. Patents:

       2,479,125  Variable attitude helicopter airplane, and

       2,558,501  Aircraft propeller rotatable about the 

                         external periphery of the aircraft body.

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