# Patent

## Title
Platform trailer with extruded floor panel cross members

## Abstract

A platform trailer includes first and second aluminum beams. The first and second beams are defined with an arch. A platform is supported on the first and second beams. The platform includes a plurality of extruded aluminum panels that each extend from a left lateral end abutted with the left side rail to a right lateral end abutted with the right side rail. The extruded aluminum panels are abutted in series with the first end wall of one panel abutted with the second end wall of an adjacent abutted panel such that the respective upper walls of adjacent abutted panels of the platform together define an upper, cargo supporting surface of the platform. The platform is arched to correspond with the arch of the first and second beams. A method for constructing the platform trailer is also disclosed.

## Background
CROSS-REFERENCE TO RELATED APPLICATION
This application is a divisional of U.S. application Ser. No. 11/983,047 filed Nov. 5, 2007, now U.S. Pat. No. 7,770,928, which claims priority from and benefit of the filing date of U.S. provisional application Ser. No. 60/856,436 filed Nov. 3, 2006 (Nov. 3, 2006) and both said prior applications are hereby expressly incorporated by reference into the present specification.


BACKGROUND
FIGS. 1A and 1B are left (driver side) and right (passenger side) elevational views, respectively, of a conventional semi-trailer T adapted to be connected to and pulled by a conventional tractor/truck (not shown). The trailer T comprises a forward end FT and a rear end RT spaced-apart from each other on a longitudinal axis L. FIGS. 2A and 2B are plan and cross section views of the trailer T as taken along view lines A-A and B-B of FIG. 1A, respectively. Referring also to these drawings, it can be seen that the trailer T further comprises a cargo-supporting platform P including left and right laterally spaced-apart sides LP,RP. The platform P is supported by and connected to a chassis C that includes first (left) and second (right) spaced-apart beams B1,B2 that extend parallel to each other and to the longitudinal axis L from the forward end FT to the rear end RT. Each beam B1,B2 defines an I-beam profile comprising an upper flange F1 and a lower flange F2 (FIG. 2B) connected by a web BW. The beams can be steel or aluminum and are often fabricated by welding or otherwise abutting and welding together or otherwise connecting two separate T-shaped aluminum extrusions.
A kingpin K is located at the forward end FT of the trailer T, centrally located between and connected to the beams B1,B2, and is adapted to be engaged by a fifth-wheel of an associated tractor/truck for towing the trailer T. The rear end RT of the trailer includes at least one and typically at least two axle assemblies A connected to the chassis, e.g., to the lower flanges F2 of beams B1,B2. Each axle assembly A comprises at least one left and at least one right rotatable wheel and tire assemblies W for movably supporting the trailer T on a road or other surface. The trailer T further comprises a dolly assembly D, typically located axially between the kingpin K and an axial midpoint of the trailer T. The dolly assembly D includes support feet DF that are selectively lowered to support the forward end FT of the trailer T when the kingpin is not connected to an associated tractor/truck (the dolly assembly D is omitted from the background of FIG. 2B for clarity).
The platform P comprises left and right side rails RL,RR that delimit the opposite lateral sides LP,RP of the platform, respectively. These side rails RL,RR are each typically defined as one-piece or monolithic extrusions of aluminum alloy (often referred to herein simply as “aluminum”) having a profile such as that shown in FIG. 2B and that extend in one piece from the forward end FT to the rear end RT of the trailer T, and that lie in respective vertical planes that are parallel to the webs BW of beams B1,B2 and the longitudinal axis L (the profiles of the side rails RL,RR are typically mirror images of each other as shown herein). The side rails RL,RR are often arched as shown in FIGS. 1A and 1B with an apex of the arch oriented upward and located between the forward and rear ends FT,RT.
The platform P, itself, comprises left, middle and right sections PL,PM,PR that each comprise one or more wood and/or metal longitudinally extending platform members PK, each of which extends longitudinally from the forward end FT to the rear end RT of the trailer T, as one-piece or otherwise to define an upper cargo-supporting surface P1. Typically, the platform members PK comprise aluminum extrusions and/or wooden planks or the like. Regardless of the material used to define the platform members PK, it should be noted that they extend longitudinally between the forward and rear trailer ends FT,RT, but do not extend transversely between the left and right side rails RL,RR, i.e., each platform member PK fills only a fraction of the space between the left and right side rails RL,RR. In the illustrated trailer embodiment, the upper flange F1 of each beam B1,B2 also defines part of the platform P, with the upper flange F1 of the first (left) beam B1 connected to both of the left and middle platform sections PL,PM and the upper flange F1 of the second (right) beam B2 connected to both of the right and middle platform sections PR,PM.
In each of the left, middle, and right sections PL,PM,PR, the platform members PK extend in a longitudinal direction that is parallel to the axis L and beams B1,B2, but platform members PK from each section PL,PM,PR do not extend transversely from one section PL,PM,PR to another section PL,PM,PR. If the beams B1,B2 and side rails RL,RR are arched, the platform members PK are correspondingly arched. As such, to support the longitudinally extending platform members PK, the platform P of trailer T must further comprises a plurality of transversely extending cross members CM located beneath the platform members PK at axially spaced intervals along the entire length of the trailer T. The cross members CM are welded or otherwise connected to and extend between the left and right side rails RL,RR, passing through and typically welded to the beams B1,B2 (in some cases the cross members CM comprise three separate sections cross member sections located respectively beneath and supporting the left, middle and right platform sections PL,PM,PR instead of a single member that passes through the beams B1,B2). These cross members CM can have a variety of shapes, e.g., I-beam, U-shaped, C-shaped, etc. and be defined from a variety of materials such as steel or aluminum, e.g., aluminum extrusions. The use of cross members CM increases labor and material costs, and the cross-members create an uneven underside P2 to the platform P which increases wind drag and/or includes locations for dirt, ice and other debris to accumulate between the cross members.
SUMMARY
In accordance with one aspect of the present development, a platform trailer includes a chassis comprising first and second aluminum beams each including an upper flange and a lower flange connected by a web. The first and second beams are arranged parallel to each other and each extend from a forward end to a rear end in the direction of a longitudinal axis of the trailer. The first and second beams are each defined with an arch comprising an upwardly oriented apex located between the forward and rear ends. At least one axle assembly connected to the chassis and includes a left wheel and tire assembly and a right wheel and tire assembly. A platform is supported on the first and second beams of the chassis. The platform includes spaced-apart left and right side rails and a plurality of extruded aluminum panels that each extend from a left lateral end abutted with said left side rail to a right lateral end abutted with said right side rail. Each of the panels comprises an upper wall, a lower wall spaced-apart from the upper wall, and first and second spaced-apart end walls that are connected to and extend between the upper and lower walls. The extruded aluminum panels are abutted in series with the first end wall of one panel abutted with the second end wall of an adjacent abutted panel such that the respective upper walls of adjacent abutted panels of the platform together define an upper, cargo supporting surface of the platform. The platform is arched to correspond with the arch of the first and second beams.
In accordance with another aspect of the present development, a method for constructing a platform trailer includes constructing a platform subassembly comprising plurality of extruded aluminum panels that each extend from a left lateral end to a right lateral end. Each of the panels includes an upper wall, a lower wall spaced-apart from the upper wall, and first and second spaced-apart end walls that are connected to and extend between the upper and lower walls. The extruded aluminum panels are abutted in series with the first end wall of one panel abutted with the second end wall of an adjacent abutted panel such that the respective upper walls of adjacent abutted panels define an upper, cargo supporting surface of the platform subassembly. A force is exerted on the platform subassembly to form an arch in the platform subassembly. While the force is applied to maintain the arch in the platform subassembly, first and second parallel, spaced apart arched beams are welded to the platform subassembly. The force is then removed from the platform subassembly after said first and second arched beams are welded to the platform subassembly.
In accordance with another aspect of the present development, a method for constructing a platform trailer includes constructing a platform subassembly comprising plurality of extruded aluminum panels that each extend from a left lateral end to a right lateral end, each of said panels comprising an upper wall, a lower wall spaced-apart from said upper wall, and first and second spaced-apart end walls that are connected to and extend between the upper and lower walls. The extruded aluminum panels are abutted in series with the first end wall of one panel abutted with the second end wall of an adjacent abutted panel such that the respective upper walls of adjacent abutted panels define an upper, cargo supporting surface of said platform subassembly. The constructing step includes welding the adjacent abutted panels to each other such that said platform subassembly defines a built-in arch. First and second parallel, spaced apart arched beams are then welded to said platform subassembly.



BRIEF DESCRIPTION OF DRAWINGS
FIGS. 1A and 1B are left (driver side) and right (passenger side) elevational views, respectively, of a conventional semi-trailer T adapted to be connected to and pulled by a conventional tractor/truck (not shown).
FIGS. 2A and 2B are plan and cross section views of the trailer T as taken along view lines A-A and B-B of FIG. 1A, respectively.
FIGS. 3A and 3B are left (driver side) and right (passenger side) elevational views, respectively, of a semi-trailer T′ formed in accordance with the present invention and adapted to be connected to and pulled by a conventional tractor/truck (not shown).
FIGS. 4A and 4B are plan and cross section views of the trailer T′ as taken along view lines A-A and B-B of FIG. 3A, respectively.
FIG. 4C is a sectional view of the platform P′ as taken at line C-C of FIG. 4B, and shows first and second extruded floor panels XP (i.e., first panel XP1 and second panel XP2) of the platform P′.
FIG. 5 illustrates the extrusion profile of an individual panel XP formed in accordance with the present invention.
FIG. 6 illustrates the extrusion profile of an alternative floor panel XP′ that is identical to the panel XP except as otherwise shown and/or described.
FIG. 7 illustrates one method of manufacturing a trailer platform including an arch according to the present development.
FIGS. 8A and 8B illustrate another method of manufacturing a trailer platform including an arch according to the present development.
FIGS. 9 and 10 illustrate alternative profiles for the beams B1,B2.



DETAILED DESCRIPTION
FIGS. 3A and 3B are left (driver side) and right (passenger side) elevational views, respectively, of a semi-trailer T′ formed in accordance with the present invention and adapted to be connected to and pulled by a conventional tractor/truck (not shown). Except as otherwise shown and/or described herein, the trailer T′ is identical to the prior art trailer T and, as such, like components of the trailer T′ relative to the trailer T are identified using the same reference characters used in the description of the trailer T, in some cases without repeating the above descriptions. The trailer T′ comprises a forward end FT and a rear end RT spaced-apart from each other on a longitudinal axis L.
FIGS. 4A and 4B are plan and cross section views of the trailer T′ as taken along view lines A-A and B-B of FIG. 3A, respectively. Referring also to these drawings, the trailer T′ further comprises a cargo-supporting platform P′ including left and right laterally spaced-apart sides LP,RP. The platform P′ is supported by and connected to a chassis C including first (left) and second (right) spaced-apart beams B1,B2 that extend parallel to each other and to the longitudinal axis L from the forward end FT to the rear end RT. Each beam B1,B2 defines an I-beam profile comprising an upper flange F1 and a lower flange F2 (FIG. 2B) connected by a web BW. The beams are defined from aluminum alloy (sometimes referred to herein simply as “aluminum”) extrusions, e.g., fabricated from first and second T-shaped extrusions that are arranged with their bases abutted and welded or otherwise connected together so as to define the illustrated I-beam profile. The upper flanges F1 can extend horizontal or flat (i.e., in a horizontal plane) between the forward and rear trailer ends FT,RT or, as shown in FIGS. 3A and 3B, are preferably arched between the forward and rear trailer ends FT,RT, so that at least the upper flange F1 of each beam B1,B2 follows a convex arch with the apex of the arch oriented upward toward the platform P′ between the forward and rear trailer ends FT,RT.
A kingpin K is located at the forward end FT of the trailer T′, centrally located between and connected to the beams B1,B2, and is adapted to be engaged by a fifth-wheel of an associated tractor/truck for towing the trailer T′. The rear end RT of the trailer includes at least one and typically at least two axle assemblies A connected to the chassis C, e.g., to the lower flanges F2 of beams B1,B2. Each axle assembly A comprises at least one left and at least one right rotatable wheel and tire assembly W for movably supporting the trailer T′ on a road or other surface. The trailer T′ further comprises a dolly assembly D, typically located axially between the kingpin K and an axial midpoint of the trailer T′. The dolly assembly D includes support feet DF that are selectively lowered to support the forward end FT of the trailer T′ when the kingpin K is not connected to an associated tractor/truck (the dolly assembly D is omitted from the background of FIG. 4B for clarity).
The platform P′ comprises left and right side rails RL′,RR′ that delimit the opposite lateral sides LP,RP of the platform, respectively. These side rails RL′,RR′ are each typically defined as one-piece or monolithic extrusions of aluminum having a profile such as that shown in FIG. 4B and that extend in one piece from the forward end FT to the rear end RT of the trailer T. The side rails RL′,RR′ lie in respective vertical planes that are parallel to the webs BW of beams B1,B2 and parallel to the longitudinal axis L (the profiles of the side rails RL′,RR′ are typically mirror images of each other as shown herein). If the beam flanges F1 are arched, the side rails RL′,RR′ are correspondingly arched. The side rails RL′,RR′ include lower flanges RF for slidably mounting a winch or clip for securing a cargo-retaining strap, and include mounting slots CP for securing chain plates.
The platform P′ is further defined by a plurality of one-piece extruded hollow cross member floor panels XP each arranged transverse, preferably perpendicular, relative to the longitudinal axis L. Each panel XP is connected to and extends in an uninterrupted fashion from the left side rail RL′ to the right side rail RR′ and preferably meets the rails RL′,RR′ at a right angle. As shown in FIG. 4A, the platform P′ comprises: (i) a left section PL defined between the left side rail RL′ and the lateral center of the beam B1; (ii) a middle section PM defined between the lateral centers of beams B1,B2; and, (iii) and a right section PR defined between the lateral center of beam B2 and the right side rail RR′. Because each extruded panel XP extends to and entirely between the left and right side rails RL′,RR′ in one-piece, the left, middle and right platform sections PL,PM,PR are each partially defined by every extruded panel XP of the platform P′.
As shown in FIG. 4A, each panel XP includes first (front) and second (rear) edges or sides E1,E2, and longitudinally adjacent panels XP are abutted with the first edge of a panel XP abutted with the second edge E2 of the adjacent panel, so that laterally extending seams S are defined and extend to and between the left and right side rails RL′,RR′. As such, due to the shape of the panels XP as described in further detail below, the platform P′ comprises and upper or top (cargo-supporting) surface P1′ that is smooth and uninterrupted except for the seams S, and also comprises a lower or bottom surface P2′ that is likewise smooth and uninterrupted except for the seams S so as to reduce wind drag and to prevent undesired accumulation of ice, mud or other debris. The adjacent abutted panels XP are preferably fixedly secured to each other at the seams S by welding, adhesive, snap-fit, friction fit, or otherwise. If welded, it is preferred that the weld(s) extend along the seam S uninterrupted at least from the left side rail RL′ to the right side rail RR′. Most preferably each weld extends uninterrupted from and between the left and right lateral ends DL,DR (FIG. 4B) of each panel XP so that at least part of the weld of the seam S is received into the floor receiving channels NL,NR of the left and right side rails RL′,RR′. As shown in FIG. 4C, each seam S can be welded with an upper weld WU located adjacent the platform upper surface P1′ and/or with a lower weld WL located adjacent the platform lower surface P2′. Preferably, the panels XP are interconnected so as to define the platform P′ to have an arch to conform with an arch defined by the upper flanges F1 of beams B1,B2.
FIG. 4C is a sectional view of the platform P′ as taken at line C-C of FIG. 4B, and shows first and second extruded floor panels XP (i.e., first panel XP1 and second panel XP2) of the platform P′. The smooth and uninterrupted upper and lower platform surfaces P1′,P2′ are readily apparent in FIG. 4C, as is the seam S defined where the panels XP1,XP2 are abutted at their respective edges E1,E2.
With reference also to FIG. 5, the profile of an individual panel XP formed in accordance with the present invention is shown. The panel XP is preferably defined as a monolithic member, most preferably as an extrusion of aluminum, i.e., an aluminum alloy such as 6061-T6 aluminum alloy or another suitable aluminum alloy, having the illustrated profile. The panel XP comprises an upper wall 12a with a smooth planar or other flat outer surface 12 as oriented upward to define, together with the other panels XP of platform P′, the cargo-supporting upper surface P1′ of the platform P′. The panel XP further comprises a lower wall 12b with a smooth planar or other flat outer surface 12bs oriented downward to define, together with the other panels XP, the lower surface P2′ of the platform P′. As used herein, a “flat surface” is intended encompass a perfectly smooth, planar surface and also a flat surface having a surface texture defined therein by ribs, grooves or the like that do not change the overall orientation or direction of the surface, e.g., grooves having a depth less than or ribs having a height less than the thickness of the walls 12a,12b. The upper and lower outer surfaces 12as,12bs lie in respective horizontal planes and are arranged in parallel spaced-apart relation to each other. The upper and lower walls 12a,12b can have the same minimum thickness but, because the upper wall 12a is in contact with the cargo while the lower wall 12b is not, it is preferred that the upper wall 12a have a minimum thickness T1 that is greater than the minimum thickness T2 of lower wall 72b to reduce weight and material cost while providing the required strength where needed.
With reference again to FIGS. 4C and 5, in an alternative embodiment, the extruded panel XP1 has a larger minimum wall thicknesses T1 for its upper wall 12a as compared to the panel XP2, so that the platform section constructed with the thicker panels XP1 has a stronger upper surface P1′. This alternative structure allows for selective sections of the trailer platform P′ to be constructed with the stronger panels XP1 (e.g., a steel coil cargo carrying region or a rear region where a lift truck moves onto and off of the platform P′) for added strength and allows other lower-stress sections of the trailer platform P′ to be constructed with the lighter-weight panels XP2.
The upper and lower walls 12a,12b are joined by opposite first and second end walls 12c,12d which, in the illustrated embodiment, are arranged in parallel spaced-apart relation to each other in respective vertical planes. The end walls 12c,12d comprise respective mating conformations such as the illustrated male rib 12r and female groove 12g. As shown in FIG. 4C, the rib 12r and groove 12g are sized for close sliding receipt of the rib 12r of a first panel XP1 into the groove 12g of a second panel XP2 abutted with the first panel so that a plurality of the panels XP define the platform P′. This mechanical connection of the panels XP1,XP2 increases strength and facilitates a subsequent bonding operation by suitable means such as the preferred welding operation or, alternatively, adhesive and/or fasteners for permanently securing the panels to each other to define the platform P′. More particularly, as is also apparent in FIG. 4C, the panels XP1,XP2 are defined so that when they are abutted to define a platform P′, the abutted panels cooperate to define first and second welding grooves V1,V2 adapted to receive the welds WU,WL, i.e., each panel XP1,XP2 defines half of each groove V1,V2. Alternatively, the grooves V1,V2 can receive an adhesive used to permanently affix the panels XP1,XP2 to each other.
Referring again specifically to FIG. 5, each panel XP defines at least one support wall in its profile, such as the illustrated primary I-beam cross-member 14. The one or more primary I-beam cross-members 14 are preferably equally spaced or distributed between the end walls 12c,12d. The primary I-beam cross-member 14 (only one illustrated in FIG. 5) comprises a support web 14a that spans the space between walls 12a,12b and first and second flanges 14b,14c arranged transversely relative to the support web 14a. Preferably the web 14a lies in a vertical plane and the flanges 14b,14c are perpendicularly connected to the web 14a. The flanges 14b and 14c have respective symmetrical first and second halves 14b1,14b2 and 14c1,14c2. The flange halves 14b1,14b2 each define a thickness T3 and the flange halves 14c1,14c2 each define a thickness T4.
In the illustrated embodiment, the thicknesses T3,T4 of the flanges are maximized and are greater than the respective wall thicknesses T1,T2 adjacent support web 14a, and taper as the distance from the support web 14a increases, until the thickness T3,T4 is equal the minimum thicknesses T1,T2 of walls 12a,12b, respectively. For added strength, the maximum thickness T3 of flange 14b is preferably greater than the maximum thickness T4 for flange 74c to provide added strength to upper (cargo carrying) wall 12a and to reduce weight/material for lower wall 12b. Each panel XP thus defines at least two horizontally-extending hollow cores 15 separated from each other by a primary I-beam cross-member 14. Although the I-beam cross-member 14 is shown with tapered flanges 14b,14c, the flanges 14b,14c can alternatively have respectively constant thicknesses, e.g., the wall thicknesses T1,T2, respectively.
In addition to the primary I-beam cross-member(s) 14, each panel XP further defines first and second partial or half I-beam cross-members 18a,18b that are preferably mirror-images of each other. More particularly, the first half I-beam cross-member 18a comprises a web defined by the end wall 12c, and first and second half-flanges 18a1,18a2 that are connected to and project transversely from the end wall 12c. The half-flanges 18a1,18a2 have respective thicknesses T5,T6 that are preferably but not necessarily maximized and greater than the respective wail thicknesses T1,T2 adjacent end wall 12c and that taper as the distance from end wall 12c increases until the thicknesses are equal to the minimum wall thickness T1,T2, respectively.
Similarly, the second half I-beam cross-member 18b comprises a web defined by the end wall 12d, and first and second half-flanges 18b1,18b2 that are connected to and project transversely from the end wall 12d. The half-flanges 18b1,18b2 have respective thicknesses T7,T8 that are preferably but not necessarily maximized and greater than the respective wall thicknesses T7,T8 adjacent end wall 12d and that taper as the distance from end wall 12d increases until the thickness are equal to the minimum wall thicknesses T1,T2, respectively.
Referring again to FIG. 4C, those of ordinary skill in the art will recognize that when the first and second floor panels XP1,XP2 are abutted, with the rib 12r seated in groove 12g and walls 12c,12d in contact or very closely adjacent, and when the grooves V1,V2 are filled with a welding bead or adhesive, the first half I-beam cross-member 18a of the first panel XP1 and second half I-beam cross-member 18b of the second panel XP2 together define a full secondary I-beam cross-member 114 that has a structure that is at least substantially identical to the one or more primary I-beam cross-members 14. As such, platform P′ defined from a plurality of interconnected panels XP will comprise at least one primary I-beam cross-member 14 defined as part of each panel XP, and another secondary I-beam cross-member 114 defined at the seam S between each pair of abutted panels XP. As such, the platform P′ includes integral cross-members comprising the primary I-beam cross-member 14 of each panel XP and the secondary I-beam cross-members 114 defined by each pair of abutted interconnected panels XP. Accordingly, the platform P′ need not comprise separate transverse cross-members such as the cross-members CM described above in relation to the trailer T. Instead, as shown in FIG. 4B, the platform P′ is self-supporting on the beams B1,B2 so that the lower surface P2′ of the platform P′ is more aerodynamically efficient owing to the absence of external cross-members.
FIG. 6 illustrates an alternative floor panel XP′ that is identical to the panel XP except as otherwise shown and/or described. The floor panel XP′ can be used in place of all or some of the floor panels XP used to define the platform P′. For example, the panels XP′ are used where a higher-strength platform P′ or section thereof is required, e.g., a steel-coil cargo carrying section or a region expected to receive repetitive lift truck travel or other extreme forces. The panel XP′ comprises in its extrusion profile as shown including at least two integral I-beam cross-members 14′ instead of a single I-beam cross-member. As such, at least three hollow core regions 15′ are defined, but each hollow core region 15′ has a width that is smaller than a corresponding width of the hollow regions 15 of floor panel XP to increase the strength of the panel XP′ relative to the panel XP. Of course, the panel XP′ can include four or more voids 15′ if additional cross-members 14′ are included for even more strength.
Referring again to FIG. 4B, the left and right side rails RL′,RR′, comprise respective inwardly directed floor receiving channels NL,NR that receive and retain the opposite left and right ends DL,DR of each panel XP between upper and lower horizontal channel walls N1,N2. The floor-receiving channels NL,NR also include an inner vertical channel wall N3 that extends between and interconnects the upper and lower horizontal channel walls N1,N2 so that the floor-receiving channels are C-shaped in cross-section in the illustrated embodiment. As part of the extrusion profile or otherwise, the left and right side rails RL′,RR′ each comprise a stand-off nib F that prevents the panel edges DL,DR from contacting the inner channel wall N3. As such, any water that enters the core 15,15′ of a panel XP,XP′ through a puncture can flow laterally outward into the floor-receiving channels NL,NR for drainage from the trailer T′. Preferably, the upper and/or lower channel walls N1,N2 are welded or otherwise fixedly secured to the upper and lower platform surfaces P1′,P2′ for added strength and so that the side rails RL′,RR′ can be used as anchor locations for cargo hold-down systems.
The platform P′ is connected to the beams B1,B2 by any suitable means. As shown, welds WP are used to secure the underside P2′ of platform P′ to the upper flanges F1 of the beams B1,B2. For each beam B1,B2, first and second welds WP are located at first and second (left and right) interfaces of the beam upper flange F1 with the lower surface P2′ of the platform P′. Each weld WP preferably extends continuously and uninterrupted along the interface between the beam B1,B2 and the platform underside P2′ for the axial length of each beam. Additionally or alternatively, fasteners M such as bolts, U-bolts or the like are passed completely or partially through the platform P′ and secured to the upper flanges F1 of the beams B1,B2 as shown in broken lines. Also, struts or braces or “outriggers” TS can optionally be used to connect the left side rail RL′ (or the underside P2′ of the left platform section PL) to the beam B1 and to connect the right side rail RR′ (or the underside P2′ of the right platform section PR) to the beam B2, which further fixedly secures the platform P′ to the beams B1,B2. In such case, the struts TS are welded in position and/or are connected using fasteners.
The platform P′ is preferably arched to conform with an arch of at least the upper flanges F1 of the beams B1,B2 as shown in FIGS. 3A and 3B. Various structures and methods can be used to provide a platform P′ that is arched to conform to the arch of the beams B1,B2. In one embodiment, it is contemplated that the platform P′ comprise separate sections of floor panels XP, wherein each section comprises a single panel XP or two or more interconnected panels XP as shown in FIG. 4C, but wherein the separate floor sections or one or multiple interconnected panels are not connected to each other to allow the platform P′ to have a non-planar, e.g., arched, configuration that follows the arch of the beams B1,B2. In another embodiment as shown in FIG. 7, the panels XP (shown only diagrammatically) are welded together at the seams to define a platform subassembly PA′ with a built-in arch that corresponds to the arch of the beam B1,B2. The side rails RL′,RR′ are then fitted and welded to the platform subassembly PA′ to define a platform P′, and the platform P′ is then fitted to the upper flanges F1 of the beams B1,B2 and welded or otherwise secured to the beams as described above.
Referring to FIGS. 8A and 8B, another embodiment is diagrammatically illustrated. In such embodiment, a platform subassembly PA′′ (which is preferably the entire length of the platform P′, but can be only part of the platform length) is constructed by welding together a plurality of panels XP at the seams S as shown in FIG. 4C. The platform subassembly PA′′ is flat or otherwise shaped without an arched configuration that corresponds to the arch of the beams B1,B2. The platform subassembly PA′′ is preferably inverted and supported on a support surface SS which can be flat or, as shown, can include a concave form CC shaped to correspond with the desired arched shape for the finishes platform P′. The beams B1,B2 (only beams B1 is visible) are inverted and then engaged with the platform subassembly PA′′ and are used to urge the platform subassembly PA′′ against the support surface SS with a force F1 so that the platform subassembly PA′′ deforms and conforms to the arched configuration of the upper flanges F1 of the beams B1,B2 (the force F1 is preferably applied to both beams B1,B2 simultaneously). It is most preferred that the beams B1,B2 be welded to the platform subassembly PA′′ along the full axial length of the upper flanges F1 of both beams B1,B2 via welds WP at the interface of the beam upper flanges F1 with the platform subassembly PA′′ while the force F1 is continuously applied, to provide a prestressed welded structure including the beams B1,B2 and the platform subassembly PA′′. The platform subassembly PA′′ is preferably provided as a complete platform P′, i.e., the platform subassembly includes the side rails RL′,RR′, or the side rails RL′,RR′ can be applied after the platform subassembly PA′′ is connected to both beams B1,B2. The resulting prestressed, welded structural unit including the beams B1,B2 and platform P′ is resistant to sagging when loaded which provides a structural and an aesthetic benefit. The arch of the platform P′ is defined herein as having a longitudinal axis that is perpendicular to the longitudinal axis L of the trailer T′, such that each panel XP extends parallel to the longitudinal axis of the arch.
FIGS. 9 and 10 illustrate alternative profiles for the beams B1,B2. FIG. 9 shows a first alternative beam profile B1′,B2′ in which the upper and lower flanges F1′,F2′ are shaped differently from each other, with the upper flange F1′ defining a lateral width LW1 and a thickness FT1 smaller than a corresponding lateral width LW2 and thickness FT2 of the lower flange F2′. The beam B1′′,B2′′ of FIG. 10 is similar, but the lower flange F2′′ is asymmetric in the sense that a fillet FL is defined between the web BW and flange F2′′ on a first lateral side of the web, while the opposite lateral side of the web BW joins the flange F2′′ with a non-filleted connection FL′. This structure is believed to provide superior strength and durability by eliminating stress concentrations.
The present invention has been described with reference to preferred embodiments. It is not intended that the invention be limited to the preferred embodiments, and this specification is intended to be construed literally and/or according to the doctrine or equivalents to encompass modifications and alterations to the fullest possible extent.

## Claims

1. A method for constructing a platform trailer, said method comprising:
constructing a platform subassembly comprising plurality of extruded aluminum panels that each extend from a left lateral end to a right lateral end, each of said panels comprising an upper wall, a lower wall spaced-apart from said upper wall, and first and second spaced-apart end walls that are connected to and extend between the upper and lower walls, wherein said extruded aluminum panels are abutted in series with the first end wall of one panel abutted with the second end wall of an adjacent abutted panel to define a seam between each pair of adjacent abutted panels, such that the respective upper walls of adjacent abutted panels define a cargo supporting surface of said platform subassembly and said respective lower walls of said adjacent abutted panels define a lower surface of said platform subassembly, said step of constructing a platform subassembly comprising connecting each pair of adjacent abutted panels to each other by welding said pair of adjacent abutted panels to each other at said seam;
applying force to said platform subassembly to deform said platform subassembly into an arched shape and contacting respective flanges of first and second parallel spaced apart arched beams to said lower surface of said platform subassembly such that said arched shape of said platform subassembly conforms to said arched first and second beams, wherein each of said panels of said platform subassembly is oriented transversely relative to said first and second beams such that each of said panels contacts the respective flanges of both said first and second beams; and,
welding said respective flanges of said first and second parallel, spaced apart arched beams to said lower surface of said platform subassembly while said platform subassembly is held in its arched shape in contact with said respective beam flanges.

2. The method as set forth in claim 1, wherein said step of applying force to said platform subassembly comprises urging said respective flanges of said first and second beams into said lower surface of said platform subassembly while supporting said upper surface of said platform subassembly on a concave form.

3. The method for constructing a platform trailer as set forth in claim 2, wherein said platform subassembly is inverted during said step of applying force such that said upper surface is oriented downward and said lower surface is oriented upward when said force is applied.

4. The method for constructing a platform trailer as set forth in claim 1, wherein said platform subassembly is inverted during said step of applying force such that said upper surface is oriented downward and said lower surface is oriented upward when said force is applied.