US1758143A - Rigid airship - Google Patents

Description

v May 13, 1930.

c. D. BURNEY ET AL 1,758,143

RIGID AIRSHIP Filed Aug. 20, 1927 3 Sheets-Sheet l y 13, 1930. v c. D. BURNUEY ET AL 1,758,143

RIGID AIRS-HIP Filed Aug. 20, 1927 3 Sheets-Sheet 2 May 13, 1930.

c. D. BURNEY ET AL 1,758,143

RIGID AIRSHIP Filed Aug. 20, 1927 3 Sheets-Sheet 3 Patented May 13, 1930 UNITED STATES PATENT CHARLES DENNISTON EBUBNEY, BARNES ILLE WALLIS, AND JOHN EDWIN PLE, WESTMINSTER, LONDON, ENGLAND, ASSIGNOBS TO AIRSI-IIP GUARAN'IEEE COMPANY, LIMITED, OF WESTMINSTER, ENGLAND, BRITISH COMPANY RIGID Amsrnr Application filed August 20, 1927, serial No. 214,328, and in Great Britain September 17,1926.

This invention relates to rigid airships. In rigid airships the main structureof the hull usually consists of longitudinal girders and transverse frame members, the latter be= ing usually in the form of polygonal rings.

frame or ring members are constituted by relatively shallow girders, for example by girders the depth of which is of the order of approximately 2% orunder ofthe diameter of the frame, it isessential that the frame shall be provided with a system of bulkhead wiring which will not only be adequate to restrain deflection of the ring members under the load imposed upon them during nor-' mal flight when both the gas bags located on contiguous sides of the bulkhead wiring are fully inflated, but which will also be of such a strength or character that, if one of the gas bags becomes deflated, the tension set up in the bulkhead wiring, due to the end pressure of the contiguous inflated gas bag or bags as it or they protrude or tend to protrude laterally into the space formerly occupied by the deflated bags, will not throw too great a comprcssioninto the transverseframe members.

It has heretofore-been impossible to comply with both these conditions in a satisfactory manner, for, if the bracing wires are put in either hand taut or with initial'ten- 40' sion in order to brace a light and shallow transverse frame under normal conditions, then, under abnormal conditions, and when a gas bag is deflated the end pressure of the contiguous inflatedbag or bags on the bulkas head wiring sets up aihighdegree of compression in the frame members which might cause failure or deformation 1n a light or narrow frame and therefore in certain cases might impose secondary forces and/0r bendingmoments in theilongitudinal girders. On

the other hand if the frames are madesuifie ciently strong or sufficiently. deep to resist deformation or any stresses set up in the defiated bag condition the additional Weightof such frames, to provide for a circumstance which is actually of abnormal .or unlikely occurrence, is objec'tionableto a high degree in a structure where the maximum degree of lightness consistent with strength is .the'desideratum; o

According to one feature of the present invention the wires constituting the bulkhead wiring of each transverse frameare so Y'ar ranged that they radiate outwards in all die rections and at-asuitable distance apart from a point located at .or about the axis of the ship, but the outer ends of the fwires or certtam of the wires, are'connecte'd' toca-tenaries the ends-of whicha're in turn attached to the I transverse frame members at ;thepoint where they are intersected by the longitudinal girders.

The; adoption of this arrangement ensures an even distribution of the lateral loading in the bulkhead wiring to all members of the transverse' frame, especially in cases where, as-des'cribed in co-pending application Serial No. 2l4 036, filedArugust 19,1927 a connec tion is made,'from-the point wherezeach cate nary joins the frame members, to the 'eir-.

cumferential mesh Wiring surrounding each gas bag. This system is employed in coin= bination with an axial restraint, thatis to say the centres of the radially arranged bulkhead wires are interconnected by a stranded wire or cable running axially of the ship,,or

connected i012} centrally arranged and rigid girder runningaxially of thexship' as herein:- a-fter moreparticularly described.

In the foregoing arrangementall the radiallyarranged wires in each panel e. the wires connected to the same catenary) are hand taut (i. e. have an initial tension :of approximately 50' to 100 lbs.) in order to brace the frame under normal conditio-ns'zand to transmit to the framework in a more satisfactory manner than heretofore the lateral loading of the bulkhead wiring under-ab normal or deflatedlbag conditions. According, however, to a further feature of the present invention and to a preferred arrangement only the radially arranged end wires of each panel have initial tension or are hand taut and, disposed between the taut wires of each panel, is a catenary to which a number. of radially arranged and initially slack wires are attached, each catenary extending between a polygonal side of the transverse frame and having each of its ends attached to 'the frame at the points where it is intersected by a longitudinal girder. The taut wires are attached to theframe members at the same point and/0r contiguous to the slack wires According to another feature of the pres ent invention an axial restraint is provided at or about the centre of thebulkhead wiring. The axial restraint may be constituted by a stranded wire cable running axially of the ship through the gas bags and having its ends secured to the framework at the nose and tail of the ship. The use of a cable, however, is open to certain disadvantages in that it extends under the influence of the lateral loading onthe bulkhead wiring, so that it is diificult to determine whether or not the centre'of theradial wiring is restrained in the plane of the transverse frame. Furthermore, the cable has to be located in position. when the gas bags are partially inflated, and, apart from the fact thatleakage of the lifting gas occurs, or is liable to occur, at the openings through which the cable enters and leaves the gas bags, the attachment of the cable in position is very troublesome. Instead of a cable, therefore, it is preferred to provide an axial restraint constituted by a rigid girder which is preferably constructed in sections and which has its'ends restrained at the nose or tail of the ship in such a manner as to transmit the loads which may occur in the axial girder into the longitudinal girders of the hull. In order to accommodate the rigid girder a central opening or core is provided through the axis of each gas bag, the openings being prefer v ably linedwith heavier material than that of which the bag itself is composed. The axial girder may be of space frame construction and of triangular cross section and be built up from sections which arejoined together in a detachable manner at points in or about the plane of the bulkhead wiring.

In order that the said invention may be clearly understood and readily carried into effect the same will now be described more fully with reference to the accompanying drawing, in which Figure 1 is a cross-section of an airship fitted with a system of tight and slack bulkhead wiring constructed according to the present invention, as also with an axial restraintconstituted by a built-up space frame girder, part only of the slack wiring as also the covering network being shown.

Figure 2 is a typical section showing the a bulge of the gas bag between the taut radialwires when the adjoining gas bag is in deflated condition.

Figure 3 is a view on anenlarged scale showing a panel constituted by a catenary, a pair of tight wires and a number of slack wires. 7 y

Figure 4 is a sectional view showing diagrammatically on an enlarged scale the relative bulge at'half radius of the tightand slack wires of a panel when in deflated bag condition.

Figure'5 is a detail view-showing one method which may be adopted for connecting the ends'ofthe catenaries, as also the tight wire to theframework of the airship.

Figure 6 is a detail view showing one method that may be adopted for connecting the inner ends of the tight and slack wires to a hub located at the axis'of the ship.

v Figure 7 is acorresponding view to Figure 6,showing in greater detail the construction of the said hub.

Figure 8 is a diagrammatic view of an airship constructed according to the present invention showing the axial girder which extends lengthwise of the ship, and v Figure 9 is a detail view showing on a larger scale the hub at the axis of the ship to which the ends of the taut and slack-radial wires are attached, as also a portion of a spider which is mounted on the said hub and by means of which the axial girder is secured in position. 7 I a A, A are the transverse frame members and B, B the longitudinal girders, C is the axial girder which restrains the gas bags in the plane ofthe transverse frame A, D, D are the hubs at the axis of the ship and E, E are the spiders for coupling together the parts of the girder G constituting the axial restraint, F,'F are the tight wires of the bulkhead wiring and G, G are the slack wires.

H, H are the slack catenary wires for attaching the slack wires of the bulkhead wiring to the transverse frame members. I is a cord netting covering the corner gaps between the catenaries of .the'circumferential mesh wiring which surrounds the gas bags and the bulkhead wiring catenaries. J is a cord netting interlaced between the taut and slack wires, F, F and G, G to prevent undue bulging of the gas bag through the said wires; K (Figure 2) is an inflated gas bag andK is a deflated gas bag, the gas bags throughout the ship being provided with an axial trunk K to accommodate the axial girder C. In the example shown at Figure 1 the airship is provided with a corridor L extending lengthwise of the ship and the slack wires G in the panel above the same are of shorter length than those of other panels;

A suitable mode of attaching'the catenaries mes es H, H and the taut wires-I F consists in bringing the-end of a taut 'wlre F and each end of a pairof 'contiguous-catenaries H, H within a socket piece H and locating the latter within, or attaching it to the transverse frame A, turnbuckles H H? being pro vided towards the ends of the catenary wires and the taut wires to effect the necessary adjustments. By means of this preferred arrangement there is provided a primary systemof'radiallyarranged-and hand taut wires F, F which is adequate to brace or restrain deflections of the relatively light transverse frames A, A under, normal conditions butnot adequate to cope with abnormal ordeflated gas bag conditions, and a secondary-system of slack radial wires G, G 'disposed between the taut wires F, F which normally hang.

more or less loosely and only come intoaction duringabnormal or deflated gas bag conditions, and which, by virtue of theirinitial slackness, are free to curve or bulge outwardly beyond the plane of the tight wires under deflated bag'conditions, so that, for an equal lateral loading they sufler less tension than the tightwires.

In theevent of a bag becoming "deflated both the tight and the-slack wires are bulged outwardly as shown at Figures 2 and 4 by the end pressure of the contiguous "inflated gas bag. K beyond'the plane of the transverse frame A, but the slack wiresG, G as a whole bulge beyond the tight wires while the gas bag itself protrudes through .and beyond the spaces betweenall the radial wires,'thuscausing theprotruding inflated gas bag to assume a fluted or "cantaloupe-like configuration As the ends ofthe catenary to which-the slack wires G, G are attached are not anchored to the taut wires F, F but independently attachedtothetransverse frame A their radial tension is separately transferred to the frame at each-corner of .the'polygon, and not to or through thetaut-bracing wires *F, F.

; Owing to this arrangement the total radial loading in the bulkhead wires in deflated gas bag conditions which istransferred as a compressional force to the transverse frame members fromthe connections'at each polygonal anglethereof is lessthan wouldbe the case if'all the wires of the bulkhead wiring were initially taut in-normal bag conditions, as has invariably been thecase in allprevious proposalsto use a relatively narrow 'or shallow frame. The cordnet is-prefer-ably provided to restrain undue bulgingof thegas bag inthe spaces between the SYStGIIl-Ofilfidially arranged wires and this cord network covers both the'taut andthe-slackwires, If desired, and in cases where the point of connection of the taut wires and-the ends ofithe catenaries does not pass through the centroid of either or both the transverse frame members and the intersecting longitudinal girders I a connection may be made from the said point of attachment to the circumferential mesh wiring by means of a strop or otherwise as described in our co-pending application Serial No. 214,036, filed August 1 9, 1927. The longitudinal girders and the transverse frame members may also be so arranged that they intersect one another in such a manner thattheir centroids are coincident and the lift and shear wiresmay be attached at or approximately at the said coincident centnoids, a suitable method of obtaining this result being described in our co-pendingpatent application Serial No. 21i,028, 'filedAugust 19,1921. 1

I In view ofthe fact that the resultant normal pressure on the bulkhead wiring is greater at the top than at the :bottom of the bag, it is highly desirable, in order to prevent the occurrence of unequal stresses or bending moments in the framework, that the inward radial loading due to endwise pressure on the'bulkhead wiring in deflated bag conditions should beequal at eachcorner of the polygon. To this end thedegree of slackness initially imparted to the slack wires of each successive panel can be made progressi-vely greater from a minimum at the bottom of the airship to .a maximum at the top thereof. i i

This result can readily be obtained by Joeating theycatenaries H, H in place and thereafter, by means of the aforesaid turnbuckleslFP, H located between the ends of the catenaries and'their connections to the transverse frame, slackening out or otherwise adjusting them to the predetermined extent; Attheir inner ends the :taut andithe slack wires are attached to the hub 51) as shown more clearly at 'Figuresfi and 9. and'if desired turnbuckles may also be provided foradjusting the endsof the taut-wires.

A suitable method-of detachably connectingzthe"various sections of the girder to one another in cases --'.where the girder is of :triangular space frame construction, constituted, as in the example illustrated,.- by fthree tubular members connected together "by bracing members, is shown more clearly ,at'

Figure 9 where a member .E (which is termed a spider) is providedihaving three radial arms e (oneacomplete armonly'being shown eachlarmlbeing provided at its outer extremity with a socket '6 which accommodates a'connecting piece having screw-+threaded; ends to which the endunembers ofithe triangular space frame girder .on contiguous sides thereof are attached by removable coupling rings. iProjecting laterally.of the spider and attached thereto :at the centre thereof in: any suitable mannenmay'be a; stub shaft e onwhich a pair of plates, constituting part of the hubjlD are mounted, the plates being spaced apart by angularly displaceable fittings to which the ends of'thetautiand slack wires of the bulkhead wiringraresecured. The said stub-shaft 6 may also be provided with bollard pieces to support the ends of cables 0! from which the fuel tanks, ballast, etc., may be suspended.

In locating the axial girder C in position a gas bag is suitably arranged around each section of the girder and bound in place. Thereafter the sections are hoistedinto place and coupled together by the coupling pieces carried on the spiders E, the binding for the gas bags is then removed and they are allowed to hang from the axial girder C. The provision of an axial girderhas the advantage that each gas bag issupported at half its height during the filling'operation instead of lying on the bottom of the airship,

and, especially in the larger sizes of airships where the gas bags are of great capacity, this arrangement is advantageous in that it allows the supported bags to fill out in a position where damage to the bag is unlikely to occur. Moreover, in deflated bag condition the bag is supported on the girder section at the axis of the ship where it may be possible to effect a repair without removing both the girder section and the damaged bag from the ship. As, in deflated gas bagcondition, the girder section in the bay containing the damaged bag will be in compression and the remaining girder sections of each side thereof in tension, means may be provided for retracting the portions of the girder on each side of the section containing the damaged gas bag to relieve the said-section from compression and enable it to be removed.

The provision of an axial restraint constituted by a rigid sectional girder fixes definitely the centres of the bulkhead wiring in the plane of each transverse frame. If desired, the space frame girder constituting the axial restraint may be used for leading controls, etc., along theship, orf enlarged so as to form an access passage extending from the bow to the stern of the ship. 7

What we claim and desire to secure by Letters Patent of the United States is 1. A rigid airship'in which the wires constituting the bulkhead wiring radiate outwards in all directions, and at a suitable distance apart, from a point located at or about the axis of the ship, the outer ends of the wires, or certain of them, being connected to catenaries, the ends of said catenaries being attached to the framework of the airship at the points where the transverse frame members are intersected by the longitudinal glrders.

2. A rigid airship in which the bulkhead wiring comprises a number of initially taut wires and a number of'initially slack wires all radiating from a common point in proximity to the axis of the ship.

3. A rigid airship in which the bulkhead wiring comprises a number of initially taut wires and a'number of initially slack wires all radiating from a common point in proximity to the axis of the ship and the inner ends of the slack wires are attached to a point at or about the axis of the ship and the outer ends are connected to catenaries, the taut wires being also radially arranged with their inner ends'attached to a point at or about the axisof the ship; the ends of said catenaries as also'the outer ends of the taut wires being connected to the framework of the airship at the points where the transverse frame members areintersected by the longitudinal girders.

4. A rigid airship as claimed in claim 3, in which the contiguous ends of a pair 'of catenaries as also the end of a taut wire are brought within a socket piece which is located within or attached to the transverse frame.

5. A rigid airship as claimed in claim 3, in which turnbuckles or other tautening devices are provided to enable any necessary adjustment of the taut wires, the slack wires and the catenaries to be effected.

6. A rigid'airship as claimed in claim 3, in which connections are made from the point of attachment of the catenaries to the circumferential mesh wiring. V

7. A rigid'airshipas claimed in claim 3, in which the intersectin longitudinal girders and the transverse frame members are so arranged that. their centroids are coincident.

8. A rigid airship as claimed in claim 3 in which the degree of slackness initially imparted to the slack wires .of each successive panel is made progressively greater from a minimum at the bottom of the airship to a maximum at the top thereof. v

i 9. A rigid airship as claimed in claim 3 in which an axial restraint is provided at or about the centre of the bulkhead wiring.

10. A rigid airship as claimed in claim 3, in which an axial restraint constituted by a rigid girder is provided in proximity to the center of the bulkhead wiring, thetaut and slack wires being attached thereto.

11. A rigid airship, comprising in combination longitudinal and transverse rigid members, provided with an axial restraint constituted by a rigid girder constructed in removable sections, bulkhead wiring attached to said transverse members and to said girder, and means whereby the portions of said girder on opposite sides of any one of said removable sections (other than the end sections) may be retracted from said sec tion to permit of its removal. 7

CHARLES DENNISTON BURN EY.

BARNES NEVILLE WALLIS.

JOHN EDWIN TEMPLE.

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