Traitement en cours

Veuillez attendre...



Aller à Demande


Note: Texte fondé sur des processus automatiques de reconnaissance optique de caractères. Seule la version PDF a une valeur juridique

[ EN ]


[0001] This invention relates to a box assembly for a vehicle, such as a pickup truck, and more specifically to a vehicle box assembly employing roll-formed panels, and to an improved method of constructing the panels.

[0002] The upwardly-opening box assembly associated with vehicles such as pickup trucks and the like have, for many years, employed a large plurality of stamped metal panels for defining the box. Forming the box predominantly from stamped sheet steel panels, however, results in structural and
economic factors which are less than desirable.
[0003] A principal disadvantage associated with using stamped sheet steel panels is that such panels require a greater quantity of material than is optimally desired, and result in the formed members having greater weight than desired. It is known that stamping involves forming a three-dimensional shape from a flat sheet steel of rather thin gauge, and during stamping the three-dimensional deformation of the sheet steel necessarily causes stretching of the steel, particularly at those locations which are subjected to the greatest three-dimensional deformation. This stretching can typically be in the range of from 8% to 10%, and the thickness of the sheet steel at the stretched locations can be
significantly reduced by this degree. Such significant thickness reduction results in areas of the sheet being of significantly reduced strength, and these reduced strength areas can dictate and control the design of the overall stamped part, thereby requiring initial use of a sheet
thickness greater than would otherwise be required.
[0004] Stamping large sheets to define large three-dimensional panels, such as for a vehicle box assembly, also often results in undesired surface stretch marks or blemishes in the finished product. The stamping operation also
typically requires that the sheet be significantly oversized relative to the finished product to permit trimming of the sheet around the entire peripheral edge, and this results in significant waste.
[0005] A further and significantly disadvantageous factor associated with use of stamped sheet steel panels for vehicle box assemblies is the cost associated with the manufacture of the required stamping tools, the significant number of such tools required to form the different stamped panels, and the necessarily large and complex construction of such tools.
[0006] Several currently known constructions for vehicle box assemblies employing a significant number of stamped sheet steel panels are illustrated by Figures 1-4. In Figure 1, a box assembly 10 as associated with a pickup truck employs right and left upright inner side panels 11 and 12,
respectively, joined to an upright inner front panel 13. The bottom of the box assembly is closed by a generally horizontal bed 14 which, in this conventional construction, employs a multiple-piece construction defined predominantly by a center bed panel 15 which extends throughout the full length of the bed and has a width which generally corresponds to the
transverse 'width between the wheel well openings. The bed regions forwardly and rearwardly of the wheel well openings are defined by separate small bed panel sections 16 and 17 which are rigidly joined, as by welding, to the center bed panel 15 and to the adjacent upright side panels. The rear of the bed assembly defines a conventional access opening which, in a known manner, is closed by a swingable tailgate. In this known construction of the bed assembly, each of the front panel, right side panel, left side panel and bed are formed as stamped steel sheet members, all different, and in fact the bed in this example is formed by a plurality (here five) of stamped members. The wheel well covers 18, which are also typically separate stampings, are welded to the respective side panel and to the bed during the assembly process.
[0007] Figure 2 illustrates another known construction of a box assembly which is virtually identical to the box assembly of Figure 1 described above, except that the bed 14' in Figure 2 is constructed as a one-piece stamped panel having wheel well openings formed in opposite sides thereof.
[0008] Figure 3 illustrates improvements to a box assembly for a pickup truck, which improvements are illustrated in detail in U.S. Patent No. 6 644 721, owned by the Assignee hereof. The box assembly in Figure 3 is constructed generally the same as the box assembly in Figure 1 except that the center floor pan 15 in Figure 3 is constructed as a one-piece roll-formed member which provides improved performance and weight reduction.
[0009] Figure 4 depicts another improved construction of the box assembly. This improved box construction generally corresponds to Figure 2 except that the full-sized bed member 14' is constructed as a roll-formed member, rather than as a stamped member. This roll-formed construction of the
one-piece bed member is disclosed in Assignee's U.S. Patent No. 6 128 815.
[0010] As a known alternative construction for the box assembly illustrated by Figure 1, the side panel, the adjacent wheel well cover and adjacent front and rear side bed panels can be formed as a one-piece stamping, a different such stamping being required for each of the right and left sides of the box assembly. Such stamping, due to its size and complex three-dimensional shape, requires complex and costly tooling.
[0011] Accordingly, it is an object of this invention to provide improved roll-formed component parts for a vehicle box assembly, which component parts provide improved
characteristics with respect to construction, assembly and cost efficiencies with respect to materials, assembly and tooling, and which at the same time retain or provide improved performance characteristics with respect to the assembled box assembly.
[0012] More specifically, the improved roll-formed
components of the present invention are believed to provide the assembled box assembly with improvements with respect to reduction in overall weight, reduction with respect to
material usage and cost, simplification with respect to required assembly, handling and manipulation, significant reduction with respect to tooling costs, and an ability to utilize the same tooling to facilitate manufacture of multiple or different sized parts.
[0013] The invention relates to an improved manufacturing process for forming an integral side/floor panel for a vehicle box which is roll-formed to facilitate, in a preferred
embodiment, the forming of a top rail, a horizontal shelf and reinforcing ribs extending lengthwise of the roll-formed panel, to facilitate cutting of the roll-formed panel into any desired length, and to permit the same roll-forming tooling to be utilized for both right and left side panels as well as panels of different lengths. The process permits simultaneous forming of multiple panels, such as roll-forming a pair of panels in side-by-side relationship so as to be effectively mirror images of one another, thereby simultaneously providing right and left panels and at the same time facilitating simultaneous stamping of wheel well openings therein and forming of the top rails thereon, with the roll-formed sheet being split lengthwise to facilitate simultaneous forming of side-by-side panels.
[0014] According to the present invention, there is
provided an improved box assembly for a vehicle, such as a pickup truck, which box assembly employs a pair of large roll-formed panel members each defining an inner side panel and part of the floor or bed, thereby permitting minimal usage of material in terms of both square footage of material as well as material thickness, minimizing cost and weight of the box assembly, and resulting in panels of substantially uniform thickness throughout the longitudinal and transverse
directions thereof. The use of large roll-formed panels is also desirable since it permits the panels to be formed from high strength steel if desired, specifically sheet steel having a yield strength in the range of from about 50,000 psi to about 100,000 psi, which high strength steel is typically not feasible for use with large stamped panels.
[0015] Other objects and purposes of the invention will be apparent to those familiar with constructions and processes similar to those described herein upon reading the following specification and inspecting the accompanying drawings.

[0016] Figure 1 is a top plan view of a conventional pickup truck box assembly which illustrates a first conventional construction of the assembly.
[0017] Figure 2 is a top plan view similar to Figure 1 but illustrating a second conventional construction of the box assembly.
[0018] Figure 3 is an exploded view of a box assembly corresponding generally to Figure 1 but illustrating a known variation of the bed assembly.
[0019] Figure 4 is an exploded perspective view
illustrating the box assembly of Figure 2 but illustrating a known variation of the bed assembly.
[0020] Figure 5 is an exploded perspective view showing the parts associated with a vehicle box assembly, including a quarter panel constructed in accordance with a method
according to the present invention.
[0021] Figure 6 is a fragmentary end elevational view illustrating the manner in which a roll-formed center bed panel cooperates with a side bed member.
[0022] Figure 7 is a flowchart which illustrates a
preferred method of forming the quarter panel illustrated in Figure 5.

[0023] Figure 8 is an enlarged cross-sectional view of the roll-formed sheet as taken generally along line 8-8 in
Figure 7.
[0024] Figure 9 illustrates solely the center portion of the deformed sheet as shown in Figure 8.
[0025] Figure 10 illustrates solely the center portion of the deformed sheet shown in Figure 8 but illustrating a variation thereof.
[0026] Figure 11 is a vertical transverse sectional view showing the inner side panels and floor of a vehicle box assembly according to a further embodiment of the invention, and illustrating the construction thereof solely by a pair of integrated panel members.
[0027] Figure 12 is a cross sectional view of one of the panel members of Figure 11 as shown in a nonfolded condition when exiting a rolling mill.
[0028] Figure 13 shows the panel member of Figure 12 in its folded L-shaped cross-sectional configuration.
[0029] Figure 14 is a perspective view of the folded panel member as used to construct the box assembly of Figure 11.
[0030] Figures 15 and 16 contain a flow chart which
diagrammatically illustrates a process for roll-forming a panel, and subsequent processing to effect forming of the panel member of Figures 11-14.
[0031] Certain terminology will be used in the following description for convenience in reference only, and will not be limiting. For example, the words "upwardly", "downwardly", "rightwardly" and "leftwardly" will refer to directions in the drawings to which reference is made. The words "upwardly" and "downwardly" will also be used in reference to the surfaces or parts associated with the box assembly which respectively project upwardly or downwardly when the box.assembly is in it's normal assembled position on a vehicle. The words "front" and "rear" will be used with reference to those directions which normally connotate the front and rear of a vehicle when the box assembly is mounted thereon. The words "inwardly" and "outwardly" will refer to directions toward and away from, respectively, the geometric center of the box assembly, or designated parts thereof. Said terminology will include the words specifically mentioned, derivatives thereof, and words of similar import.

[0032] Referring to Figure 5, there is illustrated an embodiment of an improved vehicle box assembly 161,
specifically a box assembly for a pickup truck, incorporating therein roll-formed quarter (i.e., integrated floor/side) panels 162 constructed in accordance with an improved process according to the present invention. Only the right floor/side panel 162 is illustrated in Figure 5, the left floor/side panel being omitted for clarity of illustration, but it will be understood that the left floor/side panel is typically substantially a mirror image of the right floor/side panel.
[0033] The box assembly 161 includes a floor or bed 122 supported on a plurality of underlying cross rails such as a front rail 123, plural intermediate rails 124 and a rear rail 125. An upright front panel 126 projects upwardly adjacent a front edge of the bed 122, a side panel 127 projects upwardly adjacent each side of the bed, and a wheel well housing 128 cooperates between each side panel 127 and the respective side portion of the bed 122. The rear edge of the side panel cooperates with an upright or post 129.
[0034] In the box assembly 161, the bed 122 is defined by multiple bed sections, including a main center bed section 131 which extends lengthwise throughout the full length of the bed but has a width which is sized so as to extend generally only between the wheel wells, whereby the center bed section 131 has a generally rectangular profile in plan view. The
opposite sides of the bed are in turn completed by side bed sections 131A, with each section 131A being defined primarily by front and rear side bed portions 132 and 133, respectively, which are disposed respectively forwardly and rearwardly of the wheel well opening 163, and extend sidewardly from the side panel or wall 127 to the center bed section 131.
[0035] In this construction of the box assembly, the side panel 127 and the bed panel section 131A are formed as a monolithic one-piece roll-formed panel member 162 which is herein referred to as a quarter or integrated floor/side panel. A separate one-piece wheel well housing 128 which is typically of a one-piece stamped construction is fixed to the panel 162 to close off the wheel well opening 163. In the present invention, this one-piece panel 162 is preferably provided with a shelf portion 136 formed therein at a location directly above the wheel well opening 163, but downwardly of a top channel-shaped reinforcing rail 139. The shelf portion 136 defines a generally flat bottom wall 137 which faces upwardly and extends horizontally throughout the length of the side panel 127 so as to effectively merge with a similar horizontal shelf which is preferably associated with a front panel 126.
[0036] As to the front panel 126, it is preferably a monolithic one-piece roll-formed panel.
[0037] With respect to the center bed panel 131, it is preferably defined by a monolithic one-piece member which is roll-formed in a longitudinal direction from sheet steel. The bed member 131, in transverse cross section, is defined by a plurality of generally parallel and sidewardly spaced raised channels or ribs 141 (Figure 6) ' which alternate with
intermediate valleys or depressions 142.
[0038] The upright side panel 127 defined by the roll-formed integrated panel member 162 is roll-formed of thin sheet metal to form therein a plurality of reinforcing ribs 135 which extend lengthwise, together with the horizontal shelf structure 136 located above the wheel well opening, and the channel-like top rail 139. The side bed section 131A defined by the integrated panel member 162 is also roll-formed in the longitudinal direction so as to be preferably provided with one or more upwardly projecting reinforcing ribs or channels 154 extending longitudinally thereof, and is
additionally provided with a downwardly-projecting securing flange 156 extending along the free edge thereof.
[0039] Referring to Figure 7, there is diagrammatically illustrated an economical and high production rate process for simultaneously roll-forming two quarter panels 162 in side-by-side relationship as the panels are sequentially roll-formed in the lengthwise direction of the sheet.
[0040] In this process, a wide but flat and substantially continuous metal (i.e. steel) sheet 54 is withdrawn from a roll 51 supported on the cradle 53, with the sheet 54 being fed into and through a notcher 57 which in this embodiment creates pairs of aligned notches 58 which project inwardly from opposite edges of the sheet at predetermined intervals therealong. The notched sheet 54 then passes into and through a rolling mill 61 which, through a plurality of different roll stages, effects reshaping of the flat sheet so that the sheet 62 leaving the rolling mill 61 is deformed so as to have a cross section which, as illustrated in Figure 8, will
ultimately yield pairs of generally identical or symmetrical quarter panels at defined distances therealong.
[0041] The flat metal sheet 54 during roll-forming thereof within the rolling mill 61 is shaped, as shown in Figure 8, to define a pair of adjacent and identical inner or floor panel sections 131A which are transversely joined so as to be disposed on opposite sides of the longitudinal centerline or center plane 113. These floor panel sections 131A in turn join to identically shaped outer or side panel sections 127. Each side panel section 127 has reinforcing ribs 135, shelf 137 and outer rail (i.e. top rail) 139 roll-formed so as to extend longitudinally along the roll-formed sheet. The floor section 131A and the side panel section 127 are still in a generally flat relationship to one another, with the reference line 166 being a location at which subsequent bending will occur.

[0042] In this illustrated embodiment the adjacent floor panel sections 131A are joined together by a center rib or channel 181 (Figure 9) having a width, as defined by the top wall 182, substantially greater than the width of the adjacent ribs or channels 154 associated with the floor panel sections 131A. This increased width of the center channel 181 enables subsequent severing or cutting lengthwise along the
longitudinal centerline 113, with the cut edge portions at this centerline 113 being subsequently bent downwardly to define the edge flanges 156 substantially as indicated by dotted lines in Figure 9. These edge flanges 156 are
associated with a resulting rib or channel 155 which is a partial, typically a half, width channel for cooperation with a half-width channel 146 which extends along the edge of the roll-formed center floor panel 131 to provide a construction corresponding to that illustrated by Figure 6. This channel 146 also defines an edge flange 148, so that flanges 148 and 156 abut and can be welded together.
[0043] The roll-formed continuous sheet 62, after departing the rolling mill 61 (Figure 7), is fed into and through a cut off device 64, such as a flying die, which transversely cuts the deformed sheet generally along a line which aligns with the pair of opposed notches 58 to create a cut-off or severed roll-formed blank 162F. The blank 162F is then supplied to a work station 171 which effects cutting or slitting of the blank 162F longitudinally along the centerline 113 throughout the length thereof so that the blank 162F is severed into two blank pieces 162F' which are substantially identical but disposed sidewardly adjacent in mirror image relationship. The severed blank pieces 162F' are then fed to a forming or rolling station 172 which engages the lengthwise edges of the severed blanks, namely the edges created by the centerline slitting, so as to progressively deform this edge to create the downwardly-turned edge flange 156. The edge-flanged blank members, either individually or jointly, are then supplied to a hole forming station 173, such as a die press, which can either individually or simultaneously act on one or both of the blank members 162F' to effect forming of the wheel well openings 163 therein, as well as any other required openings or notches. This forming or pressing station 173 will also normally effect trimming of the end edges of the blanks, and the shaping or cutting of any desired securing flanges as associated with the wheel well opening and/or the end edges of the blank. The blanks 162F' , either individually or
simultaneously, are then transferred to one or more forming stations 174 which cooperate with the blank to effect suitable reshaping of the securing flanges, such as bending or cold working, so that the flanges project transversely relative to the respective panel portion. The formed blank, having openings formed therein and flanges formed and shaped thereon, is then fed to a bending station 175, such as a bending or wing press, which effects relative bending of the floor portion 131A and side panel portion 127 toward one another generally about the region 166 so as to cause these portions to project in generally perpendicular relationship to one another. The roll-formed and L-shaped panel member 162 is then discharged from the press 175 and possesses the
structural shape and connections required for its assembly as part of a vehicle bed arrangement.
[0044] In the process described above, the blank 162F' is preferably severed and the edge flanges 156 formed thereon prior to punching of the wheel well openings 163 since the edge flanges 156 provide significant reinforcement along the longitudinal edge of the floor section, which is highly desirable inasmuch as the punched wheel well opening 163 extends sidewardly between the edges 164 and 165 (Figure 5) thereof, which edge 165 is positioned closely adjacent this edge flange 156.
[0045] As a modification of the roll-formed profile illustrated by Figures 8-9, the enlarged center channel
181 can be replaced by an inverted narrower but deeper center channel 18'3 as illustrated in Figure 10. With this arrangement, the roll-formed blank can be longitudinally severed by effectively removing the bottom wall 184 of the channel 183, whereby the side walls of the channel 183 then effectively function as the edge flanges 156 of the blanks 162F' . The bottom wall 184 can be removed by a double cutting wheel which can effect longitudinal severing downstream of the rolling mill 61, but upstream of the cut off device 64.
Alternately, the bottom wall 184 can be removed by means of a punching operation, which punching operation can be carried out at the forming station 173 by punching out the bottom wall 184 substantially simultaneously with the punching of the wheel well openings 163.
[0046] With the box assembly 161 illustrated by Figure 5, all of the critical panels including the front panel, the quarter panels and the center floor panel can be effectively roll-formed so as to provide economies with respect to
material usage, finished box assembly weight, part
manufacture, and assembly of the box. The wheel well housing 128 is the only principal stamped component, which component is welded in a conventional manner around the edges of the wheel well opening 163 formed in the shaped one-piece roll-formed integrated floor/side panel member 162.
[0047] When roll-forming panels for the box assembly in accordance with the present invention, it will be recognized that the width of the flat steel sheet, as provided in the coil, will substantially correspond to the width of the pair of finished panels if flattened out into a planar condition, whereby trimming of the sheet or of the finished panel is generally unnecessary, and minimal usage of sheet material is achieved. Further, the roll-forming of the critical panels effectively eliminates or at least greatly minimizes
stretching (i.e., thickness reduction) of the sheet during shaping of the panel, whereby a steel sheet of reduced
thickness can hence be initially utilized to permit forming of the panel, particularly in comparison to stamped panels, and the resulting roll-formed panels are substantially of uniform thickness throughout. This hence minimizes the finished weight of the panel, reduces material costs, and greatly simplifies required tooling which significantly reduces tooling costs, and at the same time provides tooling having a significantly greater degree of flexibility. As to the actual design of the rolling mill or roll-former, it will be
appreciated that the design of roll-formers involves the application of conventional techniques known to those of ordinary skill in the roll-forming art, whereby further description and explanation of the roll-former is believed unnecessary.
[0048] Referring now to Figures 11-14, there is illustrated a box assembly 210 according to another embodiment of the invention. The box assembly 210 incorporates many of the desirable features described above, but is believed to provide improved overall structural properties and economics by permitting the bed floor and the inner right and left side wall panels to be defined by and assembled from only two monolithic one-piece integrated side/floor panel members. The two panel members are preferably formed by roll-forming a thin metal (i.e. steel) sheet, whereby only a single roll-formed panel configuration is required. Subsequent forming
operations, such as punching or die forming, carried out on the roll-formed configuration then create right and left panel members which can be assembled to define both the floor and the opposed side panels of the box assembly.
[0049] The box assembly 210 (Figure 11) includes a floor or bed 211 extending sidewardly between opposed upright sidewall panels 212 which, due to their right and left disposition, are typically substantially mirror images of one another. In this construction, the floor 211 and sidewall panels 212 are defined and formed by two preformed monolithic one-piece integrated side/floor panel members 215R and 215L which define the respective right and left sides of the box assembly throughout the lengthwise extent thereof, with the preformed panels 215R and 215L being substantially identical except for being substantially mirror images (i.e. right and left panel members) .
[0050] The right panel member 215R as shown in Figure 13 includes a floor section 216 which joins through a lengthwise extending bend or corners 218 to an upright side panel section 217 so that sections 216 and 217 extend in generally
perpendicular relation and define an L-shaped cross section. The floor section 216, when the opposed panels 215R and 215L are seated on a plurality of conventional cross rails (one shown at 219) , is fixed to the cross rails, such as by
[0051] The floor section 216 is preferably provided with one or more raised reinforcing channels or ribs 221 extending in parallel throughout the length thereof. The ribs 221 define valleys or recesses 222 therebetween as defined by a base wall 223. A down-turned edge flange 224 extends
lengthwise along the free edge of the floor section 216. This flange 224, in the preferred embodiment, extends substantially along the lengthwise-extending upright center plane or
centerline 225 of the box assembly. The floor section 216 in the illustrated embodiment has a base wall 226 which adjoins the edge flange 224, and has a width about one-half the width of base wall 223 so that the adjacent base walls 226 when assembled as shown in Figure 11 define a substantially normal width recess 222 thereabove.
[0052] The floor section 216 also includes a base wall section 227 which adjoins the corner 218. This base wall section 227 has a width which equals or slightly exceeds the width of the wheel well opening 228 (Figure 14) which is formed in the panel member, which opening 228 is closed in a conventional manner by a separate wheel well housing 229.
This base wall section 227 can also be provided with one or more raised reinforcing ribs 239 extending lengthwise thereof if desired.
[0053] In the preferred embodiment as described above, the overall width of the floor section 216, as defined between the edge flange 224 and the corner 218, is substantially one-half of the overall width of the floor 211.
[0054] Considering now the sidewall section 217, it has a reinforcing rail 231 extending lengthwise along the upper edge thereof. This rail is defined by a downwardly-oriented channel-shaped structure, the one leg 232 of which defines the free edge of the metal sheet which forms the panel member 215. The top rail 231 can have either a rounded or a rectangular shape. A shelf structure 233 is formed in the sidewall section 217 and is spaced downwardly from the top rail 231 and extends parallel therewith throughout the lengthwise extent of the sidewall section. This shelf structure 233 defines thereon a narrow horizontal shelf or wall 234 which is
accessible from the interior of the box assembly.
[0055] Sidewall section 217 also preferably has one or more reinforcing ribs or channels 237 which extend lengthwise of the sidewall section and are deformed from the base panel wall 236.
[0056] The forming of the panel members 215R and 215L for creating a box assembly 210, according to a preferred process, will now be described with reference to the flow chart of Figures 15-16.
[0057] A thin and substantially continuous flat metal (i.e. steel) sheet 241 is fed from a coil to a notching device 242 which, at predetermined distances along the sheet,
corresponding substantially to the length of the panel member 215, forms a slot or notch 243 which opens inwardly from the sheet edge 244 through a distance sufficient to compensate for forming of the top rail 231. The other sheet edge can also be notched to compensate for the edge flange 224, but such is normally not necessary. The notched sheet 241 is then fed into and through a multi-stage rolling mill 247 which effects progressive deforming of the sheet so that the sheet on exiting the rolling mill has a cross-sectional profile as illustrated in Figure 12. In the deformed condition, the sheet has the rail 231 extending along one edge thereof, and the edge flange 224 extending along the opposite edge thereof. [0058] The deformed continuous sheet is then fed to a cutoff press 248 which perpendicularly cuts across the sheet in alignment with each of the notches 243, thereby creating separate flat but deformed panel members 215.
[0059] The identical panel members, as roll-formed, are then subjected to subsequent forming steps, as diagrammed in Figure 16, to create the right and left panels.
[0060] More specifically, the panel members are then fed into presses 251R and 251L which form the wheel well opening 223 in the panel members. Since this opening is typically not located at a lengthwise midpoint of the bed, separate right and left panels must be formed. The presses 251R, 251L also will typically effect other trimming, such as at the end edges of the panel, and shaping of attachment flanges at the ends and at the opening. Presses 251R, 251L may be separate or combined.
[0061] The panel members are then acted on at subsequent forming dies or presses 252R, 252L which effect shaping of the attachment flanges.
[0062] The panel members discharged from tools 252R, 252L are then sent to and acted on by presses (i.e. wing presses) 253R, 253L which cause bending or rolling to effect forming of the corner 218 so that the floor and side sections 216, 217 project perpendicularly in an L-shape. The finished panel members 215R and 215L are then discharged from the presses 253R, 253L.
[0063] The pair of panel members 215R and 215L can then be positioned on a plurality of parallel cross rails in opposed relationship so that the opposed edge flanges 224
substantially abut, as shown in Figure 11. The abutting edge flanges 224 are welded together, and the floor sections of the panel members are welded or otherwise fixed to the cross rails. The abutting edge flanges 224 effectively extend along the lengthwise centerline of the floor. The edge flanges 224 can be recessed at locations corresponding to the cross rails, or alternately the cross rail can be provided with a clearance notch to accommodate the edge flanges.
[0064] With a bed assembly constructed as defined above, the front of the bed may be closed by use of any conventional front panel, but use of a rolled-formed front panel is
[0065] With this embodiment of the invention (Figures 11- 14), the panel member 215R, 215L is a monolithic one-piece member formed dominantly by roll-forming from thin metal sheet, with only a single roll-formed configuration being required to permit subsequent forming of right and left panel members which are substantially identical but mirror images.
[0066] While the two panel members are preferably joined at the centerline by abutting edge flanges, it will be recognized that the adjacent edges of the right and left panel members 'could be slightly elevationally different (rather than
flanged) so as to overlap one another to create a lap joint. Such joint, however, is believed less desirable than the edge flange joint described above.
[0067] The process illustrated by Figures 15 and 16, as described above, is also obviously applicable to permit forming of the integrated side/floor panel 162 shown in
Figure 5.
[0068] The roll-forming of the panels as described above, is advantageous inasmuch as this enables the panels to be more readily formed using high strength steel sheets, particularly steel sheets having a yield strength in the range of from 50,000 psi to about 100,000 psi . High strength steel sheets can be more readily shaped and deformed by roll-forming so as to provide panels having the desired three-dimensional
contour, specifically permitting use of deeper draws or formations than is typical with stamping, thereby additionally providing design opportunity to utilize thinner materials and provide greater weight reduction while also providing more severe (i.e. deeper) three-dimensional shapes.

[0069] When forming large openings in roll-formed panels, such as wheel well openings as described above, it will be understood that the opening can be punched into the continuous sheet at a location upstream of the roll mill. Such punching operation, using either a flying die or a static die, effects formation of a developed opening, that is, an opening which is oversized to compensate for the subsequent deformation of the sheet during rolling. Forming the opening after roll-forming, however, is normally preferred.
[0070] The overall assembly of the box utilizing the improved panels of this invention is, for the most part, conventional whereby further description thereof is believed unnecessary.
[0071] Although particular preferred embodiments of the invention have been disclosed in detail for illustrative purposes, it will be recognized that variations or
modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention.