US3499179A

US3499179A - Bridges

Info

Publication number: US3499179A
Application number: US665083A
Authority: US
Inventors: Robin Trench Weld
Original assignee: UK Secretary of State for Defence
Current assignee: UK Secretary of State for Defence
Priority date: 1966-09-01
Filing date: 1967-09-01
Publication date: 1970-03-10
Anticipated expiration: 1987-03-10
Also published as: DE1658630B2; DE1658630A1; GB1137278A; SE327429B

Description

March 10, 1970 R. 'r. WELD 3, I

BBBBB ES R. T. WELD March 10, 1970 BRIDGES 5 Sheets-Sheet 2 Filed Sept. 1, 1967 R. T. WELD March 10, 1970 BRIDGES 5 Sheets-Sheet 5 Filed Sept. 1, 1967 March 10, 1970 R. T. WELD 3,499,179

BRIDGES Filed Sept. 1, 1967 5 Sheets-Sheet 4 FIG. 4.

March 10, 1970 R. 'r. WELD 3,499,179

BRIDGES Filed Sept. 1, 1967 5 Sheets-Sheet 5 United States Patent 9,176/ Int. Cl. E0ld /14 us. or. 14-21 14 Claims ABSTRACT OF THE DISCLOSURE A bridge or like load carrying structure comprises a plurality of connected sections. Each section has a row of spaced members arranged along the length of each lower edge of an adjacent section. Compression faces extend along the upper edge of each section, and connecting members are provided for retaining the compression faces of adjoining Sections in face to face juxtaposition. Guides and stop plates are provided for assisting in the assembly process. Pontoons may be attached to the bridge structure to provide or increase buoyancy, and motor-driven propellers may be used for mobility.

This invention relates to bridges and similar load carry- 9 ing structures and in particular to such structures which arebuilt up in sections so that they may be readily transported for example by aircraft. Suchscctions must be made so that they can be quickly connected together and disconnected, which operations must be capable of being performed, many times without damaging or reducing the strength of the connections.

One convenient construction for the sections of a bridge is of a hollow box-like form, the upper side of the connected structure providing a roadway and arranged to withstand compressive stresses whilst the lower side of the structure withstands tensile stresses. Thus connections made between the lower sides of two sections must be capable of withstanding considerable tensile forces whilst the connections between the upper side of the sections must withstand mainly compressive forces, together with small tensile forces which may be generated on assembly of the bridge.

With a hollow box-like form of bridge section it is possible to connect the sections together and use them as a raft or a floating bridge and if necessary connect pneumatic floats to the sections to increase buoyancy. For this use of bridge sections the connections at both the upper and lowerside of the sections must be capable of withstanding both compressive and tensile forces.

The object of this invention is to provide connections for connecting together sections to form a bridge or a raft which connections are easily and quickly made.

According to this invention a bridge or similar load carrying stucture comprises a plurality of sections joined together, the lower edges of adjoining sections being connected by interlocking a plurality of spaced members along the edge of one section withta plurality of corres ponding, cooperating spaced members along the edge of the adjoining section, the upper edges of the sections being provided with compression faces which are brought into face to face juxtaposition and retained by suitable connecting members. The connecting members may conveniently be T'headed bolts carried by one section and engaging in elongated apertures in the adjoining section.

Additionally, adjacent the upper sides of the sections shear pins or dowels may project from one section into sockets in the other section.

3,499,179 Patented Mar. 10, 1970 Certain forms of the invention, as used to construct a bridge or raft, are described by way of example only with reference to the accompanying drawings, in which:

FIG. 1 is a pictorial view of a bridge spanning a ditch,

FIG. 2 is an exploded view of part of the bridge showing the sections, a

FIG. 3 is a similar exploded view of part of a raft or floating bridge, a cover plate being omitted from one section 15 to show the underlying construction,

FIG. 4 is a broken, side elevation of one section of a bridge,

FIGURE 4a is a fragmentary view of one of the bridge sections illustrating the details of a kerb and its supporting structure,

FIG. 5 is a detail of a connecting bolt, and

FIG. 6 is a detail of interlocked lugs.

The bridge, shown in FIGS. 1 and 2, comprises a number of hollow, rectangular, box-like sections 1, connected together to form the main structure of the bridge, and

having tapered ramp sections 2 connected to the ends of the main structure. When connected together, the longer sides of the sections 1 lie tranversely across the bridge with the shorter sides of the sections formingthe sides of the bridge. Kerbs 3 are hinged to the sections 1 on their upper surfaces, parallel to and adjacent the shorter edges, which kerbs are rotated into an inclined position 3a and retained there by struts 22 when the bridge is assembled, and folded flat 3b when the sections are being transported. Struts 22 are more clearly shown in FIGURE 4a and comprise a simple hinged rod 22a having 'a stirrup 30 at the lower end thereof which clips onto a small bar 32 on the deck of the bridge when the kerb is in an upright position. in the folded position of kerb 3, struts 22 clip onto retaining bars 34 located in recesses 23 in the short sides of the sections 1. Along the lower edge of each of the longer sides of each section 1 are a number of spaced lugs 4 of Tshaped form having legs 4b and head 4a when seen in plan. These lugs 4 are either formed integrally with plates or bars 5 which are secured to the sections 1 or are secured direct to the sections, e.g. by bolting The lugs 4 are shaped and spaced in such a way that apertures 4c, between the heads 4a of lugs 4 and the said lower edge of the section 1 to which they are secured, are large enough to contain the heads 40 of lugs 4 attached to an adjoining section. The gaps between the heads 4a of neighboring lugs 4 on a section l are wide enough to permit the insertion thercbetwcen of the leg members 4b of lugs 4 attached to an adjoining section, but narrow enough to ensure that when two sections 1 are attached together with the legs 4b of the lugs 4 of each section passing between the heads 4a of the lugs 4 of the adjoining section, each head 4a is retained in apertures 4c behind heads 4:: of lugs 4 on the adjoining section. Moving the sets of lugs 4 into their interlocking position is helped by the provision, on each section, of an upstanding guide 6 tapered transversely as shown at 6a which may be, as shown, an integral part of an end ing, which guide 6 engages with an end lug 34 on the adjacent section during assembly to guide the adjacent section into position. Stop plates 24 (FIG. 4) are provided, one at each end of one longer side of each section 1 just below lugs 4. These plates 24 extend outwardly with their upper faces flush with the lower faces of the lugs, 4 their outermost edges being level with those faces of the lugs 4 closest to thevside of the section 1 to which said lugs 4 and said stop plates 24 are attached. The stop plates 24 prevent thelugs 4 of an interlocked adjoining section 1 from descending, through the apertures 4c, below the lugs 4 associated with the stop plates 24 during connection of the upper edges of the sections. Thereafter the lugs cannot disengage until the upper edges are disconnected. Along the longer sides of each section and at the upper edges thereof are compression faces 7, normally vertically disposed, which withstand the compressive forces between the upper edges of the sections of the bridge. Chamfered dowels 8 project perpendicularly from the compression faces of each section 1 and engage in holes 9 in the compression faces of adjacent sections to resist shearing forces between two connected sections. T- shaped locking bolts 10 carried by each section project perpendicularly through the compression faces 7 and through elongated apertures 11 in the compression face of the adjoining section wherein they are secured by being rotated through 90 by handles 12 (FIG. fixed to the locking bolts 10. if desired, the bolts may incorporate cam-actuated tightening devices operating as follows. A collar 13, surrounding the shank 14 of each locking bolt at the junction with its handle 12, engages a cam surface 130 in the section carrying the said shank 14, so that the compression faces 7 of connected sections are drawn and held closer together. The bolts thus serve to keep the dowels 8 in engagement with the corresponding holes 9, and to resist tensile forces.

To build a bridge across a ditch or river, two sections 1 are connected together by maneuvering one section into position so that the heads 4a of its lugs 4 are located above the apertures 4c behind the heads of lugs 4 on the other section, and lowering it until its lugs 4 rest on the stop plates 24 so that the lugs 4 of the two sections interlock, assistance in positioning being given by the engagement of the end lug 34 with the tapered guide 6. The locking bolts 10 are then operated to lock the two sections together. Further sections are then added as required. The ramps 2 are then connected to the two end sections in a manner similar to the connections between each section, and arranged to rest on the river banks. After raising the kerbs 3, the bridge is ready for use.

To enable the bridge to be built across rivers and the like with difl'ering bank heights or to form a floating bridge, articulated sections 15 (FIG. 3) are fitted between the ramps 2 and the main part of the bridge. These allow the ramps 2 to be arranged at differing inclinations to the main part of the bridge depending upon the ground slope under the ramps. The articulated sections 15 are in two

parts

15a and 15b pivotally connected together near their lower edges by hinges 16 which extend transversely of the bridge. Each section 15 is similar to the sections 1 in that T-shaped lugs 4 and T-shaped locking bolts 10 are provided along the longer vertical side of

parts

15a and 15b remote from the hinges 16. On the upper surface of the articulated sections 15, above the hinge 16, cover plates 17 are arranged to cover any gap between the two parts of the articulated sections; the cover plates 17 are attached to one of the said parts 15a and slide on the upper surface of the other part 15b. The angle between the parts 150 and 15b of the articulated sections may be adjusted for example by means of hydraulic rams (not shown) located within the parts 154 and connected to the parts 15b by means of rods 21 attached to their pistons. These rams are preferably of a (known) type incorporating a slow bleed to permit automatic adjustment to changes in water level .without being responsive to rapidly applied loads as are applied by the crossing of a vehicle.

The sections of the bridge may be connected together to form a raft as shown in FIG. 3, the buoyancy of which can be increased by securing pnuematic floats 18 to the sides of the sections 1. Additionally, hollow sponsons 19 may be secured at the corners of the raft. These sponsons 19 may have stowage space for outboard motors 20 which can, when required, be secured as at 20a to the outside of the sponsons 19 in any suitable known manner to propel the raft. Both floats and sponsons may be secured in any suitable manner to the sections, the method of securing them does not form part of the present invention and will not be further described.

The articulated bridge sections 15 and ramps 2 can be secured to the ends of the raft to build a floating bridge. Carrying handles 25 may be provides as required.

I claim:

1. A bridge or like load carrying structure comprising a plurality of connected sections, each of said sections having upper edges adapted to be connected to the upper edge of the next preceding and the upper edge of the next succeeding section, respectively, and lower edges adapted to be connected to the lower edge of the next preceeding and the lower edge of the next succeeding section, respectively; a row of interlocking members placed in a spaced relationship along said lower edges for connecting said lower edges forming continuous joints, said interlocking member comprising T-shapcd lugs the heads of said T-shaped lugs being at these ends of said lugs remote from the section to which they are attached, said lugs being adapted to interlock by engagement of said heads of the lugs on one section and the spaces between the lugs on the adjoining section; surfaces formed on said upper edges for providing opposed compression surfaces for connected sections and connecting means for retaining said compression surfaces in face-to-face juxtaposition.

2. A structure as claimed in claim 1 wherein the connecting means comprises T-headed bolts carried by one section and engaging in elongated apertures in an adjoining section.

3. A structure as claimed in claim 2, wherein are provided, cam-actuated tightening devices associated with said bolts for drawing and holding the compression faces closer together.

4. A structure as claimed in claim 1, wherein shear pins are provided on the sides of at least some of the sec tions for engagement in sockets in adjoining sections to prevent relative shearing movement between the sections.

5. A structure as claimed in claim 1, incorporating sections of scaled, hollow, rectangular box like form.

6. A structure as claimed in claim 1, incorporating end sections in the form of ramps, tapered in the vertical plane.

7. A structure as claimed in claim 6, incorporating at least one articulated section, inserted between said ramps and other sections of the structure whereby the angle between the load carrying surface of the ramps and that of the other sections may be adjusted.

8. A structure as claimed in claim 1 wherein at least one articulated section is inserted between other sections of the structure whereby the angle between two portions of the load-carrying surface of the structure may be adjusted.

9. A structure as claimed in claim 1, having pneumatic floats attached thereto to increase its buoyancy.

10. A structure as claimed in claim 1, incorporating at least one sponson to which an outboard motor may be attached when the structure is used as a raft.

11. A structure as claimed in claim 1, wherein folding kerbs are provided along those edges of the sections which will form the sides of the load-carrying surface.

12. A structure as claimed in claim 1, incorporating hollow rectangular, box-like sections connected together to form the main, intermediate portion of the structure; ramp sections, tapered in the vertical plane, and connected to said portion to form end portions of the structure; said connecting means comprising T-headed bolts carried by one section and engaging in elongated apertures in an adjoining section and cam actuated tightening devices, associated with said bolts, for drawing and holding the compression faces of adjoining sections closer together.

13. A structure as claimed in claim 12 incorporating- Refcrencos Cited UNITED STATES PATENTS 3/1952 Blackhall 94--8 7/1961 Storey 14-27 XR 2/1962 Gillois et al. 14-27 5/1962 Storoy 14-27 XR 10 3,323,157 6/1967 Vaugoyeau 14-27 XR 3,386,117 6/1968 Sterner 14--27 FOREIGN PATENTS 1,060,280 6/1969 Germany.

US. Cl. X.R. 114--0.5