US2423832A - Inflatable, collapsible, military pontoon bridge - Google Patents

Description

* July`15, 1.947. u J, ,1 GEARQN 2,423,832

INFLATABLE, GOLLAPSIBLE, MILITARY PONTOON BRIDGE Filed DBG. 21. 1942 2 Shee'iS-Sheet 2 Patented July 15.9 1947 INFLATABLE; COLLAPSIBLE, MILITARY PONTOON BRIDGE i J ames J. Gearon, Chicago, Ill.

Application December 21, 1942, Serial No. 469,715

Cl. 11d-0.5)`

Claims.

My invention relates to an improvedk pontoon bridge which is especially adapted for military and similar emergency uses. To this end I have devised a novel pontoon bridge which is characterized by its ability to be readily assembled for use, and which may be quickly knocked down into a compact form for its transportation or storage in a limited space. These are essential advantages gained when this bridge is used for moving military forces across a body of water. Furthermore, the appurtenances andthe pontoons are equally capable of ready assembly in the form of a dependable raft without the employment of extraneous appliances other than those which are employed for the bridge assembly.

Another feature of my improvements resides in the provision of a pontoon which comprises a body of predetermined and denite shape when it is in either an inilated or a collapsed condition, which is of importance since the required space for storage or transportation may be readily calculated or estimated in advance of the actual work of disassembling the bridge and collapsing the pontoons. The bridge structure is characterized by the relatively small period of time which is required to assemble it for service or to knock down the structure when not needed.

One of the objects of my invention is to utilize a novel construction and improve the efliciency and operation of a bridge or raft of the type contemplated herein.

Another object of my invention is to .provide several inner tubes or air compartments to overcome damages caused by leaks or punctures.

Another object of my improvements resides in the provision of a pontoon bridge new indesign and which is adapted to perform its functions in an efficient manner.

A further object or aim of the present invention is toprovide a pontoon bridge which is made up of sturdy and dependable parts which are capable of withstanding the speedy action and severe usage which is demanded in modern military service.

The novel improvementswhich I have disclosed herein are of compact arrangement; they are ex'- ceedingly dependable in operation; and the structure is economical to produce in that it may be readily made from commercially available materials.

The above-mentioned as well as other objects, aims, and advantages of my improvements will be obvious to persons who are skilled in the art after the construction and operation of my pontoon bridge is understood from the within description. I prefer to practice my invention and to accomplish the objects thereof substantially in the manner hereinafter described, and as more particularly pointed out in the appended claims. For a better understanding of these improvements, reference is now made to the, accompanying drawings which form a part of this specica- In the drawings:

Figure 1 is a top plan of a portion of a bridge or raft embodying my invention and showing several inated pontoons.

Figure 2 is an edge view in elevation looking at the ends of the pontoons shown in Figure 1.

Figure 3 is a longitudinal side view of one of the pontoons as it appears when inilated.

Figure 4 is a vertical end'view in elevation of two pontoons showing an end brace therefor.

Figure 5 is a top plan of two pontoons showing the means for aligning the same.

Figure 6 is a top plan of the ends of two pontoons in juxtaposition or close assembly for use as a raft.

Figure 7 is a diagrammatic view of an end of a pontoon in a collapsed or deflated condition..

Figure 8 is a top plan of the novel hook assembly used as an accessory for assembling my pontoon bridge structure.

Figure 9 is a side elevation of the hook shown in Figure 8. I

Figure 10 is a sectional view in a transverse plane to illustrate the manner of using the hook disclosed in Figures 8 and 9.

Figure 11 is a. diagram which shows several superposed bridge plates assembled with several hooks such as shown in Figures 8 and 9 for the purpose of building plates up to different levels.

I1; will be understood that the drawings are of a more or less schematic character, and that they disclose a typical or preferred embodiment of my invention and the manner in which it may be assembled. In these drawings, the same reference characters are used for the purpose of identifying like parts wherever these parts may appear in the different views.

Briefly stated, my pontoon bridge or raft comprises a plurality of inflatable buoyant floats having reinforcing angle-metal frameworks at their tops and provided with laterally anged side members which are utilized for connecting adjacent floats to each other in spaced relation. Specially devised hook members are employed for connecting the iloats, and locking members are provided for connecting end to end arranged iloats. In order to support the roadway or platform, angle-metal stringers are mounted in a novel manner Von the reinforcing frames. All of the foregoing will now be described in detail in connection with the drawings. J

In view of the fact that the floats or pontoon units are all of the same construction, only a single unit will be described in order to avoid confusing terminology. Each float or pontoon comprises a hollow envelope or outer casing I which is preferably constructed of woven fabric such as a heavy water-proof canvas, and when it is inflated under a normal or low pressure it has a cross-sectional shape such as diagrammatically shown in Figure 2 which is substantially semicylindrical with an approximately ilat top surface. This fabric envelope surrounds an elastic or expansible air tube 2 that may be of rubber or similar material that is adapted to be inflated through a suitable valve 3 by means of a compression or similar pump. The upper portions of the end walls of the envelope or casing have horizontal angle metal strips 4 secured to them by rivets so that the lateral flange of these strips project outwardly from the end wall as seen in Figure 3. The side margins of the top wall of the fabric pontoon envelope have longitudinally disposed angle metal strips 5 secured to them by rivets and the upright flanges of these strips are spaced inwardly from the margins of the float as will be seen in Figure 2. The end strips 4 and side strips 5 constitute a rectangular framework surrounding and attached to the inflatable envelop I. This framework, being of a rigid character, will tend to maintain the rectangular top wall of the envelop in a stretched and taut condition thereby holding down to a minimum the tendency of the top wall to bulge upwardly when desirably inflated. Even though there may be y some upward bulging of this taut top region of the envelop when inflated, this'is not serious enough to interfere with the operation of the pontoon float because of the overall weight of the stringers, platform members, and roadway which is supported by rails 5 is ample to maintain proper assembly of the bridge components. The angle metal strips 4 and 5 provide a definite and efficient reinforcement for the upper portion of the pontoon to assist in maintaining the top thereof in rectangular outline. The upright flanges of the angle strips 5 are adapted to support the stringers 6. These stringers 6 are preferably inverted channel beams which are disposed with flat web uppermost and have notches I made in the lower portions of their langes, to rest upon and provide seats for the upright flanges of the l angle strips 5 in the manner shown in Figures 2 and 3. The roadway or platform, which usually consists of heavy planking, is laid across these stringers in the customary manner.l This planking, however, is not shown in'the drawing as it forms no portion of my invention.

Near the upper portions of the semi-cylindrical or bottom wall of 'the fabric pontoon envelope there are angle metal strips 8 which are riveted to said wall at locations in a horiozntal plane below the outwardly projecting flanges of the end angle strips 4. These angle strips 8 have their flanges projecting outwardly and when the pontoon is being collapsed or deflated they assume the positions shown in Figure 7. These angle strips 8 'further assist in reinforcing and providing rigidity to the upper portions of the pontoon, and as shown in Figure 7 they do not interfere with the deilating of the fabric envelope but on the contrary vthey assist in the collapsing of it into a predetermined shape having definite dimensions.

The metal framework of each pontoon is spaced in a pattern designed to distribute the weight imposed on the top surface of the pontoon body so that the maximum amount of balance and buoyancy is achieved. It will be appreciated the pontoon envelop need not be inflated tightly to its fullest capacity to accomplish the desired buoyancy effect thereof, and under such condition the walls of the envelop will retain their approximate normal shapes so that if there is any bulging of said walls it would be more or less incidental and would be so slight as to'be hardly noticeable. The envelop will thus tend to retain its generally semicylindrical shape the top of which is restrained in its rectangular outline by means of the angle metal frame members extending longitudinally and transversely around the top. The drawings, being of a diagrammatic or schematic character as previously stated, do not show bulged walls as it is apparent such characteristic would probably not be present except upon the inflation of the envelop with extremely high pressure.

Under ordinary conditions, the bridge may be assembled in the manner above described and as shown in Figures 1, 2, and 3, and the constituents of the bridge will be retained securely in assembly due to the fact that the stringere 6 which support the roadway planking are interlocked by means of the notches 'I with the flanges of the angle strips 5. It may be desired, however, to more rigidly connect the adjacent portions of the pontoons to prevent movement of one pontoon with respect to the next pontoon, and one type of connecting means is shown in Figure 4 wherein S- shaped hooks 9 are engaged in holes made in the angle strips 8 and in an intermediate tie-brace These hooks may be placed between both ends of two of the pontoons to hold said pontoons in proper position and next to each other. Another form of connection between adjacent pontoons is shown in Figure 5, which structure consists of a rectangular plate II having a plurality of pulleys I2 mounted thereon with their axes vertically disposed. The cables I3 pass around these pulleys and have their end portions connected to the anglev strips 8. As shown in Figure 5 one end of each cable is provided with a loop I4 which extends through an aperture in the angle strip and the other end of this cable is provided with a turn-buckle I5 for tightening the cable with its ends fastened and its intermediate portions. running around one of the pulleys. Also short 'cables I6 may similarly be connected at their ends to the angle strip pieces 8 with their intermediate portions running around the pulleys. In this arrangement the proper alignment and dispositionof the adjacent pontoons may be effectively adjusted and the'pontoons will-thereafter be maintained in theirproper spacing from each other.

In Figure 6 there is shown'a pair of pontoons disposed closelyy together, to provide a raft, and they are locked together by means of the novel spring hooks shown in Figures 8, 9, and 10, to be later described. In this structure the stringers 6 are provided with spaced bearing lugs I'I for journaling the trunnions of suitable clamping members I8 which are mounted thereon for hinging movement so that they willextend over and other.

for an anchor which maybe used to stabilize the bridge and to prevent its displacement by the current of the river which has been bridged.

As shown in Figure 6, the free ends of the hinged members I8 are provided with holes or apertures I8a which are preferably shaped in the form of a figure-8 or two overlapped circles. Spring hooks such as shown in detail in Figures 8, 9, and 10 are adapted for cooperation with the apertures I8a for securing adjacent floats to each YAlthough the figure-8 apertures are shown on the hinged members I8 it will be understood that similarly shaped apertures may be proximate faces of the body members kare ta# pered outwardly as contemplated in Figure 8 to increase yieldability since their mid-portions are secured together by rivets or otherwise. The lugs I4a and I5a are of semi-circular cross-section so that two side by side lugs form a circle and they are adapted to be separated after insertion in the apertures I8a to seat in the opposite portions of the flgure-8 shape of said apertures. This separation of the lugs is performed by means of tapered wedges I6 depending from the outer free ends ofthe spring arms I'I which are mounted for swinging movement upon a pivot pin I8 that projects from the mid-portion of the body members I4 and I5. Spring coils I9 are formed in the arms I1 intermediate the pivot pin I8 and the outer ends of said arms, and the internal diameters of said coils are sufficient to permit insertion tive use of the fastening devices, a proper alinement may be secured by building up to a. proper height on the low frame with suitable nested hollow fillers X or other means as shown in Fig. I I s0 that the lugs Ila and I5al of the tie-clamps may be inserted into the coaxial bores of these llers.

While I have describedvmy invention in detail in its present preferred form or embodiment, it will be obvious to those skilledin the art, after understanding my improvements, that various changes and modifications may be made therein without departing from the spirit or scope there of. I intend in the appended claims to cover all such changes and modifications.

What I claim is:

l. A float for pontoon bridges, rafts, and the like, comprising. an inflatable envelope having a normally flat rectangular surface region and a region normally arcuate in cross-section, said envelope being disposed with its flat surface uppermost; a combined envelope-reinforcing and platform supporting frame secured to the upper portion of said envelope and having said flat surface region secured taut thereto to restrict upward bulging thereof; and longitudinal members extending along the sides of said envelope, said longitudinal members adapted for cooperation with devices. for connecting the float to an adjacent float.

2. A float for pontoon bridges, rafts, and the like, comprising an inflatable envelope having a i normally flat rectangular surface region and a therethrough of the prongs of a double-claw bar whereby the arms may be flexed upwardly and swung laterally to dispose thev wedges I6 at the outer meeting portions of the spring body members I4 and I5 so that said wedges may be forced in between them to thereby separate or spread the adjacent pair of lugs I4a and I5a to force the latter in the outer portions of the apertures I8a. f

This locking position of the parts'just described is illustrated in'detail in Figure 10..

When the bridge has been dismantled with the parts disassembled, the inflation valves are opened to exhaust the air from the pontoons thereby deflating the envelops which will then.l collapse 'so that the semi-cylindrical wall of each will be snug against the flat top wall in the manner shown by means of the diagram in Figure 7. In this collapsed condition, the longitudinal angles 8 along opposite sides of the envelop will assume the relative positions in Figure '7 wherein they are shown as being adjacent the end edges of the end strips or angles 4 and with their normally outwardly disposed flanges pointing upward in a vertical direction. Figure 11 shows a number of bridge plates built up and held together by the improved spring fastening hooks, thus illustrating how the fastening device may be used either on top of two plate sections or on. the bottom of them thus holding the plates together in close formation for assembling different parts of the structure.

When the frames on adjacent floats do not aline in a level horizontal plane to permit effecregion normally arcuate in cross-sectionI said envelope being disposed with its flat surface uppermost; an inflatable elastic air compartment within said envelope; a combined envelope-reinforcing and platform supporting'frame secured to the upper portion of said envelope and having said fiat surface region secured taut thereto to restrict upward bulging thereof; and longitudinal members extending along the sides of said envelope,

said longitudinal members adapted for cooperation With devices for connecting the float to an adjacent float.

3. A float for pontoon bridges, rafts, and the like, comprising an inflatable fabric body having a normally flat rectangular surface region and a region normally arcuate in cross section, said fabric body being disposed with its flat surface uppermost; a combined fabric body-reinforcing and platform supporting frame secured to the upper portion of said fabric body and having said fiat surface region secured taut thereto to restrict upward bulging thereof; clamp plates hingedly mounted cnsaid frame; means for operatively connecting a clamp plate to a corresponding plate on another float; and longitudinal members extending along the sides of said fabric body, said longitudinal members adapted for cooperation With devices for `connecting the float to an adnecting a longitudinal member of one float to they longitudinal member of an adjacent float; and

7 channel stringers mounted upon the supporting frames of a plurality'of floats.

5. Inapontoon bridge, a. plurality of floats each comprising an inflatable envelope having a, normally flat rectangular surface regionand a region normally arcuate in cross-section, said envelope being disposed with its flat surface uppermost; and an infiatable collapsible rubber body within said envelope; combined envelope-reinforcing and platform supporting frames secured to the upper portions of said envelopes and having said flat surface region secured taut thereto to restrict upward bulging thereof; lateral and longitudinal members extending along the sides and ends of said envelopes; devices connecting a longitudinal member of one float tothe longitudinal member of an adjacent float; and channel stringere mountedupon the supporting frames of a D111- rality of floats.

6. In a pontoon bridge, a plurality of floats each comprising an inflatable fabric body having a normally iiat rectangular surface region and a region normally arcuate in cross-section, said fabric body being disposed with its flat surface uppermost; combined fabric body-reinforcing and platform supporting frames secured to the upper portions of each fabric body and having said flat surface region secured taut thereto to restrict upward bulging thereof; longitudinal members extending along the sides of said fabric bodies; hingedly mounted clamp plates mounted on said frame; devices adapted for interlocking engagement with opposing clamp plates; devices connecting a longitudinal member of one float to the longitudinal member of an adjacent float; and stringers mounted upon the supporting frames of a pluralityy of floats.

'7. A collapsible float for pontoon bridges, rafts, and the like, comprising an inflatable fabric body having a normally flat rectangular surface l region and a region normally arcuate in crosssection, said body being disposed with its ilat surface uppermost; longitudinal and transverse angle-metal strips providing a rectangular reinforcing frame secured to the top of said fabric body and having said flat surface region secured taut thereto to restrict upward bulging thereof; and longitudinal side members extending along opposite walls of said fabric body below the plane of said frame and adapted for connection with the side member of an adjacent float, the said frame and side members disposed to facilitate collapsing of the float into a fiat condition for storage in a constricted space.

8. A pontoon bridge comprising a plurality of inflatable float bodies each having a normally fiat rectangular region and a region normally arcuate in cross-section, said bodies when in use being disposed with the flat regions uppermost; reinforcing angle-metal strips secured to f the upper portions of saidoats and provided with fastening apertures .and being arrangedvto normally hold the at regions. taut to restrict upward bulging thereof; stringers supported by certain of said v angle-metal strips above said floats;v and devices connecting adjacent floats, said devices each consisting of yeldable arms having lateral sde-by-side hooks at their ends for entry into the aforesaid apertures; and wedges adapted to engage and separate said arms to urge said hooks into firm engagement with said apertures.

9. A collapsible float for pontoon bridges, rafts, and the like, comprising an inflatable fabric body having a normally flat rectangular region and a region normally arcuate in cross-section, said oat when in use being disposed with its flat surface uppermost; longitudinal and transverse angle-metal strips providing a rectangular reinforcing frame securedto the top of said fabric body and having said flat surface region secured taut thereto to restrict upward bulging thereof; longitudinal side members extending along opposite walls of said fabric body below the plane of said frame; relatively movable clamp arms adapted for engagement with said side members for connecting adjacent floats; and wedging devices for causing relative movement of said clamp arms.

10. A pontoon bridge comprising a plurality of inflatable float bodies; reinforcing frames secured to the upper portions of said bodies and provided with apertures said frames being adapted to hold taut the upper regions of said iioats thereby to restrict upward bulging thereof; and devices connecting adjacent floats, said devices comprising oppositely disposed yieldable arms; laterally disposed side-by-side hooks at opposite ends of said arms for entry into the aforesaid apertures; and Wedges adapted to engage and separate said arms to urge said hooks into flrm engagement with said apertures; a spring bar pivoted intermediate its ends on said yieldable arms; and laterally disposed wedges at the ends of said spring bar, said wedges adapted to be inserted between said arms to move the said hooks away from each other and into rigid engagement with the respective apertures.

JAMES J. GEARON.

REFERENCES CITED The following references are of record in the file ofv this patent:

UNITD STATES PATENTS Number Name Date 1,723,213 Smith Aug. 6, 1929 522,348 Martini July 3, 1894 1,470,459 Lonsinger Oct. 9, 1923 1,279,097 Fredeen Sept. 17, 1918 2,085,156 Hill June 29, 1937 659,883 Webster Oct. 16, 1900 1,093,987 Gleason Apr. 21, 191,4 1,671,642 Hopkinson May 29, 1928

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