Patent Publication Number: US-9422010-B2

Title: Vehicle bed frame assembly, system and method

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. Ser. No. 12/614,207 filed Nov. 6, 2009, which itself is continuation-in-part of U.S. patent application Ser. No. 11/738,010 filed Apr. 20, 2007, which has been abandoned. Both of the foregoing referenced applications are expressly incorporated herein by reference. This application is related to U.S. Pat. Nos. 7,469,957; 8,052,204; 8,276,980 and 8,177,293, all expressly incorporated herein by reference. 
    
    
     BACKGROUND 
     Exemplary embodiments herein generally relate to vehicle frame assemblies. Across different vehicle models or types, it can be desirable to have many different vehicle lengths, or particular sections of such vehicles with many different lengths. For example, in a pickup truck, a cab area may include two full-sized doors, four full-sized doors, or two full-sized doors and two half-sized doors and a bed length of this type of vehicle can vary, e.g., from about 1.2 meters to about 2.4 meters. Accordingly, many possible combinations of cab length and bed length are possible. Of course, other types of vehicles can have variable lengths or sections with variable lengths, such as sport utility trucks, sport utility vehicles, minivans, crossovers, sedans, coupes, etc. 
     In conventional vehicle frames and constructions thereof, each such combination is a different vehicle model having a dedicated frame structure. Providing each vehicle model with its own dedicated frame structure, which conventionally is assembled from a collection of stamped parts, can be expensive and can make it difficult to efficiently manufacture several variable length vehicles on a single assembly line. 
     Some vehicle manufacturers employ a body-on-frame construction to provide some limited flexibility in varying vehicle designs. When body-on-frame construction techniques are employed, complete body assemblies (e.g., a cab structure or a bed structure) are mounted to a ladder frame. This allows the completed body assemblies to be modified and/or substituted without substantially changing the underlying ladder frame and/or other completed body assemblies mounted to the ladder frame. In the case of pickup trucks, for example, a cab assembly can be redesigned from one model year to the next without requiring substantial redesigning of the underlying ladder frame. In addition, a single ladder frame can support different types of cabs (regular, extended cab or full size) and/or different types of beds. In addition, ladder frames can be extended or lengthened by adding an auxiliary ladder frame to the main ladder frame. This could be used to support an extended bed or cab, or could be used to support an elongated vehicle (e.g., a livery vehicle). Drawbacks of body-on-frame designs include weight concerns causing lower performance and higher fuel consumption, compromised handling due to lack of torsion flexing and less ability to incorporate crumble zones for improved crash safety. 
     SUMMARY 
     According to one aspect, a floor frame system for use on a plurality of vehicle types having varying longitudinal floor lengths includes at least a first vehicle type having a first floor frame assembly with a first longitudinal length and at least a second vehicle type having a second floor frame assembly with a second longitudinal length that is longer than the first longitudinal length. The first floor frame assembly includes a center frame member, a pair of side sill members flanking the center frame member and a plurality of cross members extending between the side sill members and interconnected to the center frame. The second floor frame assembly includes a center frame member, a pair of side sill members flanking the center frame member and a plurality of cross members extending between the side sill members and interconnected to the center frame member. 
     One or more of the center frame member of the first and second floor frame assemblies and the side sill members of the first and second floor frame assemblies has a cross-sectional profile that remains constant along at least a longitudinal portion thereof allowing the one or more members to be cut a first location along the longitudinal portion corresponding to the first longitudinal length when included the first floor frame assembly and at a second location along the longitudinal portion corresponding to the second longitudinal length when included in the second floor frame assembly. 
     According to another aspect, a floor frame assembly for a vehicle includes a center frame member, side sill members flanking and spaced apart from the center frame member, and a plurality of spaced apart cross members extending between and interconnecting the side sill members and the center frame member. One or more of the center frame member and the side sill members has a cross-sectional profile that remains constant along at least a longitudinal portion thereof. The longitudinal portion has a first portion length when installed on a first vehicle type having a first floor frame longitudinal length and a second portion length when installed on a second vehicle type having a second floor frame longitudinal length. 
     According to still another aspect, a floor frame system includes a floor frame assembly having a roll-formed longitudinal frame component. The roll-formed longitudinal frame component is formed at a first length when used on a first vehicle type having a first floor assembly with a first longitudinal length and formed at a second length when used on a second vehicle type having a second floor assembly with a second longitudinal length. 
     According to a further aspect, a frame system for a vehicle includes a vehicle frame assembly having a roll-formed longitudinal frame component. The roll-formed longitudinal frame component is formed at a first length when used on a first vehicle type and formed at a second length when used on a second vehicle type. 
     According to still a further aspect, a frame construction method for forming vehicle frames having varying longitudinal floor lengths is provided. In the method according to this aspect, at least one first longitudinal frame component having a defined cross-section of a first longitudinal length is formed for a first vehicle type. The longitudinal frame component is installed on a first floor frame assembly of the first vehicle type. Also, at least one second longitudinal component having the defined cross-section of a second longitudinal length is formed for a second vehicle type. The second longitudinal component is installed on a second floor frame assembly of the second vehicle type. 
     In a vehicle frame assembly having a front frame assembly comprised of a front frame cross member and front frame side members extending rearwardly from the front frame cross member, and a floor frame assembly comprised of side sill members connected at forward end portions to the front frame side members and a plurality of cross members extending between the side sill members, a frame joint, between a first front frame side member of the front frame side members and a first side sill member of the side sill members includes, according to one aspect, an upper wall of the first front frame side member overlapping an upper wall of the first side sill member along a region where the first front frame side member meets with the first side sill member, and a lower wall of the first front frame side member overlapping a lower wall of the first side sill member along the region. 
     In a vehicle frame assembly having a rear frame assembly comprised of at least one rear frame cross brace and rear frame side members extending forwardly from the at least one rear frame cross brace, and a floor frame assembly comprised of side sill members connected at rearward end portions to the rear frame side members and a plurality of cross members extending between the side sill members, a frame joint between a first rear frame side member of the rear frame side members and a first side sill member of the side sill members includes, according to one aspect, an upper wall of the first rear frame side member overlapping an upper wall of the first side sill member along a region where the first rear frame side member mates with the first side sill member and a lower wall of the first rear frame side member overlapping a lower wall of the first side sill member along the region. 
     According to another aspect, a vehicle frame joint includes a side sill member of a floor frame assembly and a forward or rearward frame side member angularly oriented relative to the side sill member and connected to the side sill member to transfer load forces thereto. The frame side member has an upper wall overlapping an upper wall of the side sill member along a region where the frame side member mates with the side sill member and a lower wall overlapping a lower side sill wall of the side sill member along the region. 
     In a vehicle frame assembly having a floor frame assembly comprised of side sill members and a plurality of cross members extending between the side sill members, a frame joint between a first cross member of the plurality of cross members and a first side sill member of the side sill members includes, according to one aspect, an upper wall of the first cross member overlapping an upper wall of the first side sill member along a region where the first cross member mates with the first side sill member and a lower wall of the first cross member overlapping a lower wall of the first side sill member along the region. 
     According to still another aspect, a vehicle frame joint includes a side sill member of a floor frame assembly and a connecting frame member having an upper wall overlapping an upper wall of the side sill member along a region where the connecting frame member mates with the side sill member and a lower wall overlapping a lower wall of the side sill member along the region. 
     In a vehicle frame assembly having a front frame assembly comprised of a front frame cross member and first and second inner members extending rearwardly from the front frame cross member, and a floor frame assembly comprised of side sill members, a center frame member and a plurality of cross members extending between and interconnecting the side sill members and the center frame member, a frame joint between the first and second inner members and the center frame member includes, according to one aspect, first and second spaced apart side walls of the center frame member integrally formed with and extending from a center wall of the center frame member. First and second spaced apart side walls of the first inner member are integrally formed with and extend from a center wall of the first inner member. The first side wall of the first inner member is contiguous with and blends into the first side wall of the center frame member and the second side wall of the first inner member is contiguous with and blends into the second side wall of the center frame member. First and second spaced apart side walls of the second inner member are integrally formed with and extend from a center wall of the second inner member. The first side wall of the second inner member terminates at the second side wall of the first inner member and the second side wall of the second inner member is contiguous with and blends into the second side wall of the center frame member thereby providing a primary load path from the first inner member to the center frame member and a secondary load path from the second inner member to the center frame member. 
     In a vehicle frame assembly having side sill members, a center frame member and a plurality of cross members extending between and interconnecting the side sill members and the center frame member, a frame joint between at least one cross member of the plurality of cross members and the center frame member includes, according to one aspect, a first segment of the at least one cross member spanning between a first side sill member of the side sill members and the center frame member and a second segment of the at least one cross member spanning between a second, opposite side sill member of the side sill members and the center frame member. A lower wall of each of the first and second segments overlaps a lower wall of the center frame member. An upper wall of each of the first and second segments overlaps an upper wall of the center frame member. 
     According to a further aspect, a vehicle frame joint includes a center frame member of a floor frame assembly and a cross member segment connected to the center frame member and extending laterally toward an associated side sill member. The cross member segment has a lower wall overlapping a lower wall of the center frame member and an upper wall overlapping an upper wall of the center frame member. 
     According to one aspect, a bed frame system for use on a plurality of vehicle types having varying longitudinal bed lengths includes at least a first vehicle type having a first front frame assembly, a first floor frame assembly, and a first rear frame assembly, and at least a second vehicle type having a second front frame assembly, a second floor frame assembly, and a second rear frame assembly. The first rear frame assembly includes at least one longitudinal frame member having a first longitudinal length. The second rear frame assembly includes at least one longitudinal frame member having a second longitudinal length. One or more of the longitudinal frame members of the first and second rear frame assemblies has a cross-sectional profile that remains constant along at least longitudinal portion thereof allowing the one or more members to be cut at a first location along the longitudinal portion corresponding to the first longitudinal length when included in the first rear frame assembly and at a second location along the longitudinal portion corresponding to the second longitudinal length when included in the second rear frame assembly. 
     According to another aspect, a bed frame assembly for a vehicle includes at least one longitudinal frame member having a cross-sectional profile that remains constant along at least a longitudinal portion thereof. The longitudinal portion has a first portion length when installed on a first vehicle type having a first bed frame longitudinal length and a second portion length when installed on a second vehicle type having a second bed frame longitudinal length. 
     According to still another aspect, a bed frame system includes a bed frame assembly having a role-formed longitudinal frame component. The roll-formed longitudinal frame component is formed at a first length when used on a first vehicle type having a first floor frame assembly with a first longitudinal length and formed at a second length when used on a second vehicle type having a second floor frame assembly with a second longitudinal length. 
     According to a further aspect, a bed frame construction method is provided for forming vehicle bed frames having varying longitudinal bed lengths. In the method according to this aspect, at least one first longitudinal frame component having a defined cross-section of a first longitudinal length for a first vehicle type is formed. The first longitudinal frame component is installed on a first bed frame assembly of the first vehicle type. Also, at least one second longitudinal frame component having the defined cross-section is formed of a second longitudinal length for a second vehicle type. The second longitudinal component is installed on a second bed frame assembly of the second vehicle type. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an underside portion of a vehicle frame for a first vehicle type comprised of a first floor frame assembly and a first bed frame assembly. 
         FIG. 2  is a perspective view of an underside portion of a vehicle frame for a second vehicle type comprised of a second floor frame assembly and the first bed frame assembly. 
         FIG. 3  is a perspective view of an underside portion of a vehicle frame for a third vehicle type comprised of the first floor frame assembly and the second bed frame assembly. 
         FIG. 4  is a perspective view of an underside portion of a vehicle frame for a fourth vehicle type comprised of the second floor frame and the second bed frame assembly. 
         FIG. 5  is a perspective view of a frame joint between a front frame side member and a side sill member. 
         FIG. 6  is a bottom plan view of the frame joint of  FIG. 5 . 
         FIG. 7  is a sectional view of the frame joint of  FIG. 5 . 
         FIG. 8  is a side sectional view of the frame joint of  FIG. 5 . 
         FIG. 9  is a perspective view of a frame joint between first and second inner members of a front frame assembly and a center frame member of a floor frame assembly. 
         FIG. 10  is a bottom plan view of the frame joint of  FIG. 9 . 
         FIG. 11  is a top plan view of the frame joint of  FIG. 9 . 
         FIG. 12  is a perspective view of a frame joint between a cross member and a center frame member, both of a floor frame assembly. 
         FIG. 13  is a top plan view of the frame joint of  FIG. 12 . 
         FIG. 14  is a perspective view of a frame joint between a cross member and a side sill member, both of a floor frame assembly. 
         FIG. 15  is a sectional view of the frame joint of  FIG. 14  with a floor panel attached thereto. 
         FIG. 16  is a perspective view of a frame joint between a side member of a rear frame assembly and a side sill member of a floor frame assembly. 
         FIG. 17  is a bottom plan view of the frame joint of  FIG. 16 . 
         FIG. 18  is a top perspective view of the frame joint of  FIG. 16 . 
         FIG. 19  is a sectional view of the frame joint of  FIG. 16 . 
         FIG. 20  is a side sectional view of the frame joint of  FIG. 16 . 
         FIG. 21  is a perspective view of a frame joint between a cross member and a center frame member, both of a floor frame assembly. 
         FIG. 22  is a bottom perspective view of a frame joint of  FIG. 21 . 
         FIG. 23  is a top plan view of the frame joint of  FIG. 21 . 
         FIG. 24  is a perspective view of the vehicle frame of  FIG. 1  shown with further frame components installed. 
         FIG. 25  is a perspective view of the vehicle frame of  FIG. 2  shown with further frame components installed. 
         FIG. 26  is a perspective view of the vehicle frame of  FIG. 3  shown with further frame components installed. 
         FIG. 27  is a perspective view of the vehicle frame of  FIG. 4  shown with further frame components installed. 
         FIG. 28  is a partial perspective view of the vehicle frame of  FIG. 24  shown with still further vehicle frame/body components installed. 
         FIG. 29  is a view of the vehicle frame similar to  FIG. 28  but shown with portions broken away to show load paths through a rear frame assembly of the vehicle frame. 
         FIG. 30  is a schematic view of a frame system for building vehicle frame assemblies for first and second vehicle types comprised of exclusive parts, common parts and variable length parts. 
         FIG. 31  is a process flow diagram showing a frame construction method for forming vehicle frames having varying longitudinal lengths. 
         FIG. 32  is a perspective view of an underside portion of a vehicle frame having a rear frame assembly suitable for use in a SUV vehicle. 
         FIG. 33  is a schematic plan view showing vehicle frame assemblies with alternate rear frame assemblies. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings, wherein the showings are for purposes of illustrating one or more exemplary embodiments and not for purposes of limiting same,  FIG. 30  schematically shows a frame system  10  for a vehicle, and particularly for use on or in connection with a plurality of vehicle types having varying longitudinal frame lengths, including overall frame length, frame section length and/or frame component length. As illustrated, body-in-white (BIW) assembly for at least a first vehicle type occurs at  12  and BIW assembly for at least a second vehicle type occurs at  14 . From the BIW assembly  12 , vehicle frame assemblies result for at least the first vehicle type as indicated at  16 . Likewise, vehicle frame assemblies for at least the second vehicle type result from the BIW assembly  14  as indicated at  18 . As used herein, vehicle type is used simply to distinguish between vehicle frame assemblies. In some cases, vehicle type can be associated with different vehicle models; however in other cases a single vehicle model can comprise multiple vehicle types and thus different frame assemblies. 
     As shown, the vehicle frame assemblies  16 ,  18  can be formed at  12  and  14  from common parts  20 , variable length parts  22  and exclusive or custom parts  24 ,  26 . The common parts  20  can be, for example, stamped components that are used on a variety of vehicle types, particularly the vehicle frame assemblies  16 ,  18  of at least the first vehicle type and the at least a second vehicle type in the illustrated embodiment. The variable length parts  22  can include longitudinal frame components that have a cross-sectional profile that remains constant along at least a longitudinal portion thereof allowing these parts to be commonly formed for variable length frame assemblies of different vehicle types and cut at different locations for forming these parts of variable lengths. For example, the variable length parts  22   a  that are provided to the BIW assembly  12  can be longitudinal frame components having a first longitudinal length, whereas the variable length parts  22   b  provided to the BIW assembly  14  can be longitudinal frame components having a second longitudinal length. These longitudinal frame components  22   a ,  22   b  can have common cross-sections and thus amenable to being formed of varying longitudinal lengths in a cost effective manner. 
     In one example, the longitudinal frame components  22   a ,  22   b  are roll-formed components formed by a roll-form process and cut to a desired length (e.g., a first longitudinal length for the first vehicle type and a second longitudinal length for the second vehicle type). Roll-forming could be the process used when the longitudinal components  22   a ,  22   b  are formed of steel, for example, though this is not required. In another example, the longitudinal components are extruded components formed by an extrusion process and cut to a desired length (e.g., a first longitudinal length for the first vehicle type and a second longitudinal length for the second vehicle type). Extrusion could be the process used when the longitudinal components are formed of aluminum, for example, though this is not required. In still another example, some other process could be used to form the variable length longitudinal components, including but not limited to press braking, stamping, etc. 
     The custom or exclusive parts  24 ,  26  can be stamped, roll-formed, extruded or otherwise formed, and are generally used on less than all vehicle types or models (i.e., making them “exclusive” to a particular vehicle type or types). For example, the parts  24  can be exclusive to only the first vehicle type assembled at  12  and the parts  26  can be exclusive to only the second vehicle type assembled at  14 . In the illustrated embodiment, the first vehicle type vehicle frame assemblies  16  can have roll-formed longitudinal frame components  22   a  having first longitudinal lengths and the second vehicle type frame assemblies  18  can have roll-formed longitudinal frame components  22   b  with second longitudinal lengths. Accordingly, roll-form longitudinal frame components can be formed at  22 , particularly formed at a first length when used on the first vehicle type in  12  and formed at a second, longer length when used on the second vehicle type in  14 , though other forming processes could be employed (e.g., extrusion, press brake, etc.). 
     Turning to  FIGS. 1-4 , vehicle frame assemblies  30 - 36 , or at least underside portions thereof, are shown for four vehicle types. More specifically,  FIG. 1  illustrates a frame assembly  30  for a first vehicle type, which could be employed as the underside portion of the first vehicle type frame assemblies  16  in  FIG. 31 .  FIG. 2  illustrates a frame assembly  32  for a second vehicle type, which could be employed as the underside portion of the second vehicle frame assemblies  18  in  FIG. 31 .  FIG. 3  illustrates a frame assembly  34  for a third vehicle type and  FIG. 4  illustrates a frame assembly  36  for a fourth vehicle type. Of course, the use of four vehicle types in  FIGS. 1-4  is merely illustrative as more or less than four vehicle types could be employed in the framing system(s) disclosed herein. In any case, each of the illustrated frame assemblies  30 - 36  can be formed from common parts, variable length parts and exclusive parts as described in connection with the vehicle frame system of  FIG. 31 . 
     In particular, the common parts can be parts that are identical and used on multiple frame assemblies for multiple vehicle types. For example, a common part, such as a floor frame cross member, could be used on all four of the frame assemblies  30 - 36  of  FIGS. 1-4 . Variable length parts (e.g., roll-formed parts, extruded parts, press brake parts, etc.) are those parts having cross-sectional profiles that remain constant along at least a longitudinal portion thereof and can be cut to a desired length for use on different vehicle types. Finally, exclusive parts can be those parts that are specifically formed for use on a particular vehicle type or on less than all vehicle types. In the FIGS., common parts will generally be described once and their reference numbers will generally be identical on all of the drawings. Variable length parts will also generally be described once with like reference numbers used on all of the drawings, however a prime symbol (′) will be used to distinguish between variable length parts having different longitudinal lengths (and to distinguish between subassemblies including variable length parts). Custom parts, which are only used on some vehicle types, will be described individually as they relate to the particular vehicle type (or types) on which they are used. 
     The illustrated frame assemblies  30 - 36  will be described for use in association with sport utility trucks (e.g., pickup trucks), though this is merely illustrative and it is to be appreciated by those skilled in the art that the concepts of the subject disclosure could easily be adapted to other classes of vehicles, such as sport utility vehicles, vans, cars, crossovers, etc. The frame assembly  30  of the first vehicle type has a first floor frame assembly  42  with a first longitudinal length. The first floor frame assembly  42  includes a center frame member  44 , a pair of side sill members  46 ,  48  flanking the center frame member  44  and a plurality of cross-members  50 ,  52 ,  54 ,  56  extending between the side sill members  46 ,  48  and interconnected to the center frame member  44 . The frame assembly  32  of  FIG. 2  for the second vehicle type has a second floor frame assembly  42 ′ with a second longitudinal length that is longer than the first longitudinal length of the first floor frame assembly  42  of  FIG. 1 . The second floor frame assembly  42 ′ includes a center frame member  44 ′, a pair of side sill members  46 ′,  48 ′ flanking the center frame member  44 ′ and the same plurality of cross members  50 ,  52 ,  54 ,  56  extending between the side sill members  46 ′  48 ′ and interconnected to the center frame member  44 ′. As will be described in more detail below, each of the cross-members  50 ,  52 ,  54 ,  56  can be generally U-shaped in cross-section and can have a forward wall, a rearward wall, and lower wall interconnecting the forward and rearward walls, which can also be referred to as side walls. 
     One or more of the center frame members  44 ,  44 ′ of the first and second floor frame assemblies  42 ,  42 ′ and the side sill members  46 ,  48  and  46 ′,  48 ′ of the first and second floor frame assemblies  42 ,  42 ′ can have a cross-sectional profile that remains constant along at least a longitudinal portion thereof allowing the one or members to be cut at a first location along the longitudinal portion corresponding to the first longitudinal length when included in the first floor frame assembly  42  and at a second location along the longitudinal portion corresponding to the second longitudinal length when included in the second floor frame assembly  42 ′. In the illustrated embodiment, the longitudinal portion of the one or members is an entire longitudinal extent thereof, though this is not required. Moreover, as described in reference to the variable length parts  22  of  FIG. 31 , the one or more members having varying longitudinal lengths can be roll-formed members. 
     In the illustrated embodiment, the one or more members can include all of the center frame members  44 ,  44 ′ and the side sill members  46 ,  48  and  46 ′,  48 ′. As an example, the center frame members  44 ,  44 ′ can be roll-formed and merely cut at different lengths as appropriate for use on the respective floor frame assemblies  42 ,  42 ′. Likewise, the side sill members  46 ,  46 ′ can be roll-formed and cut to the appropriate lengths for use on the respective floor frame assemblies  42 ,  42 ′ and the side sill members  48 ,  48 ′ can be roll-formed and cut to the appropriate lengths for use on the floor frame assemblies  42 ,  42 ′. The cross-members  50 - 56  of the each of the floor frame assemblies  42 ,  42 ′ can be common with one another (i.e., common parts). That is, a plurality of cross members  50 , for example, can be formed and one cross-member of this plurality can be used on the floor frame assembly  42  and another of this plurality can be used on the floor frame assembly  42 ′. As a result, the floor frame assembly  42 ′ has a longer longitudinal length than the floor frame assembly  42 . This could be used, for example, to support varying cab structures. For example, the floor frame assembly  42  of  FIG. 1  could be used in a vehicle type having four doors, including two full-size front doors and two smaller rear doors, though this is not required. By comparison, the floor frame assembly  42 ′ of  FIG. 2  could be used for a vehicle type having four full-size doors, though this too is not required. 
     One of a plurality of rear frame assemblies can be secured to each of the first floor frame assembly  42  of the first vehicle type and the second floor frame assembly  42 ′ of the second vehicle type. In particular, a common rear frame assembly  58  is shown secured respectively to the floor frame assemblies  42 ,  42 ′ by connecting to rearward ends of the side sill members  46 ,  48  and  46 ′,  48 ′. In the illustrated embodiment, the rear frame assembly  58  can be an underside frame portion for a load-carrying bed frame (e.g., about 5 foot or 1.2 meter bed). Alternatively, other rear frame assemblies could be connected to the floor frame assemblies  42 ,  42 ′. 
     For example, with reference to  FIGS. 3 and 4 , an elongated rear frame assembly  60  is shown connected, respectively, to the floor frame assemblies  42 ,  42 ′. The rear frame assembly  60  can be, for example, the underside portion of an elongated load-carrying bed frame (e.g., about a 6 foot or 2.4 meter bed). Except for the rear frame assembly  60 , the underside frame assembly  34  of  FIG. 3  is the same as the underside frame assembly  30  of  FIG. 1  and the underside frame assembly  36  of  FIG. 4  is the same as the underside frame assembly  32  of  FIG. 2 . Accordingly, in  FIGS. 1 and 2 , first rear frame assembly  58  having a first longitudinal length is secured to the floor frame assemblies  42 ,  42 ′ and, in  FIGS. 3 and 4 , second rear frame assembly  60  having a second longitudinal length that varies relative to the first longitudinal length (e.g., is longer) is secured to the floor frame assemblies  42 ,  42 ′. 
     Another example is shown in  FIG. 32 , wherein a frame assembly  300  includes a floor frame assembly  302  having a front frame assembly  304  and a rear frame assembly  306  attached thereto. As is illustrated, the rear frame assembly  306  can be specific to a sport utility vehicle (SUV), for example. The floor frame assembly  302  could be one of the floor frame assemblies  42  or  42 ′ and the front frame assembly  304  could be the same front frame assembly as illustrated in  FIGS. 1-4 . With further reference to  FIG. 33 , the frame assembly  300  is shown again along with a plurality of other frame assemblies  312 ,  314  and  316 . These other frame assemblies are illustrated to show that many different types of rear frame assemblies can be used with the subject disclosure. For example, the frame assembly  312  includes a rear frame assembly specific to a minivan, the frame assembly  314  includes a rear frame assembly specific to another SUV, and the frame assembly  16  includes a rear frame assembly specific to another sport utility truck (SUT). Of course, other variations are possible. 
     In the vehicle frame assemblies  30 - 36  of  FIGS. 1-4 , a common front frame assembly  62  is secured to each of the floor frame assemblies  42  and  42 ′, though this is not required. As will be appreciated by those skilled in the art, through employing a common front frame assembly  62  and/or employing common rear frame assemblies  58  or  60  across a number of different vehicle types, economies are gained due to the use of a complete subassembly, which can be formed by welding a group of stamped parts together, and then installed on a variety of vehicle types. Taken together, each of the vehicle frame assemblies  30 - 36  includes the front frame assembly  62  that extends in front of the vehicle firewall, the center or floor frame assembly  42  or  42 ′, which defines a cab or passenger compartment of the vehicle, and the rearward or bed frame assembly  58  or  60 , which extends rearwardly from the floor frame assembly  42  or  42 ′ along the rear portion of the vehicle (i.e., rear passenger compartment or bed, for example). Together, these frame assemblies or subassemblies can form an underside of a unibody frame for the assembled vehicle. 
     By the foregoing, a floor frame system is provided wherein a frame assembly, such as floor frame assembly  42  or  42 ′, includes at least one variable length longitudinal frame component, such one or more variable length roll-formed longitudinal frame components, for example. These longitudinal frame components can include the center frame members  44 ,  44 ′ and/or the side sill members  46 ,  46 ′ and/or  48 ,  48 ′. The longitudinal frame components can be formed at a first length when used on a first vehicle type having a first floor frame assembly with a first longitudinal length (e.g., the first floor frame assembly  42 ) and formed at a second length when used on the second vehicle type having a second floor frame assembly with a second longitudinal length (e.g., floor frame assembly  42 ′). In one exemplary embodiment, the longitudinal frame components are roll-formed and include at least one of the first side sill member  46 ,  46 ′, the second side sill member  48 ,  48 ′ or the center frame member  44 ,  44 ′. In another exemplary embodiment, the roll-formed longitudinal frame components include both center frame members  44  and  44 ′ and all of the side sill members  46 ,  46 ′,  48 ,  48 ′. In a further exemplary embodiment, the longitudinal frame components, e.g., members  44 ,  44 ′,  46 ,  46 ′,  48 ,  48 ′) are formed by a process other than roll forming (e.g., extrusion, press braking, stamping, etc.) and then cut to the desired lengths. 
     In the illustrated floor frame assemblies  42  and  42 ′, the center frame members  44  and  44 ′, as well as the side sill members  46 ,  46 ′ and  48 ,  48 ′, extend along a substantial portion of the longitudinal lengths of the first and second floor frame assemblies,  42 ,  42 ′. In particular, in the illustrated floor frame assemblies  42  and  42 ′, the side sill members  46 ,  46 ′ and  48 ,  48 ′ extend along an entire longitudinal extent of the respective floor frame longitudinal lengths. These roll-formed longitudinal components can have cross-sections that remain constant along entire longitudinal lengths thereof, though this is not required. 
     The front frame assembly  62  that is common to all of the illustrated vehicle frame assemblies  30 - 36  typically defines at least a portion of an engine room. The front frame assembly  62  is secured to respective forward portions of the center frame member  44  or  44 ′ and the side sill members  46 ,  48  or  46 ′,  48 ′. In the illustrated embodiment, the front frame assembly  62  includes a front frame cross-member  64  and front frame side members  66 ,  68  that extend rearwardly from the front frame cross-member  64 . As is known and understood by those skilled in the art, the side members  66 ,  68  can include portions to support the front suspension of the vehicle. In addition, the side members  66 ,  68  include first and second outer arms  70 ,  72  that, respectively, extend rearwardly and downwardly toward the first and second side sill members  46 ,  48  (or  46 ′,  48 ′), and include first and second inner arms  74 ,  76  that, respectively, extend downwardly and inwardly toward the center frame member  44  (or  44 ′). As will be described in more detail below, the inner arms  70 ,  72  merge with one another and the center frame member  44  (or  44 ′) to form a Y-shaped center joint that is disposed along a longitudinal centerline of the vehicle. The outer arms  74 ,  76  merge with forward ends of the side sill members  46 ,  48  (or  46 ′,  48 ′) and the cross-member  30 , the forward-most cross member, to form front frame to side sill frame joints described in further detail below. 
     As already mentioned, the rear frame assemblies  58  or  60  can be formed in various lengths to accommodate elongated beds of varying lengths and/or elongated rear passenger compartments of varying lengths, though this is not required. Both rear frame assemblies  58 , 60  include rear frame side members  82 ,  84  and a plurality of cross braces  86 ,  88 ,  90  extending therebetween. The side frame members  82 ,  84  extend from the side sill members  46 ,  48  (or  46 ′,  48 ′) to the rear cross brace  90 . The cross braces  86 ,  88 ,  90  include front cross brace  86 , middle cross brace  88 , and rear cross brace  90 . The front and middle cross braces  86 ,  88  cooperate to define supports for the rear wheels and the rear suspension (not shown). The rear cross brace  90  extends between rear or distal ends of the side frame members  82 ,  82 . On the longer rear frame assembly  60  shown in  FIGS. 3 and 4 , a supplementary cross brace  92  also extends between the side members  82 ,  84 . 
     With brief reference to  FIG. 31 , a frame construction method will now be described for forming vehicle frames, and will now be particularly described in relation vehicle floor frames assemblies that have varying longitudinal lengths (e.g., vehicle floor frame assemblies  42  and  42 ′). In  100 , at least one first longitudinal frame component having a defined cross-section of a first longitudinal length is formed for a first vehicle type. As already described, this could include the center frame member  44  and/or the side sill members  46 ,  48  in the illustrated embodiment. The formed longitudinal frame component or components are then installed in  102  on a first floor frame assembly of the first vehicle type (e.g., first floor frame assembly  42 ). In  104 , at least one second longitudinal component having the same defined cross-section is formed of a second longitudinal length for a second vehicle type. This could include the center frame member  44 ′ and/or the side sill members  46 ′,  48 ′ in the illustrated embodiment. In  106 , the formed second longitudinal frame component or components are installed on the second floor frame assembly of the second vehicle type (e.g., the second floor frame assembly  42 ′). 
     By this method, longitudinal frame components can be formed for different vehicle types wherein the longitudinal frame components have different longitudinal lengths. The same longitudinal frame component (e.g., center frame member or side sill member) can be formed at a first length for a first vehicle type and at a second length for a second vehicle type. Such forming can include roll-forming the frame components or could include some other forming process (e.g., extrusion, press brake forming, stamping, etc.). The longitudinal frame components can have cross-section profiles that are constant along at least a longitudinal portion of the components, or along an entire longitudinal extent of the components as is common in parts formed by at least roll-forming and extrusion techniques. 
     The described method allows floor frame assemblies (e.g., floor frame assemblies  42  and  42 ′) to be economically formed of different longitudinal lengths, which otherwise may not be economical, e.g., when floor frame assemblies are formed entirely from custom-made stamped parts. Instead, using the foregoing method, floor frame assemblies can be formed from a plurality of common stamped parts together with variable length parts (e.g., roll-formed parts), which can be desirably cut to predetermined lengths according to the desired length of the vehicle type (or a frame section thereof) in which the frame component or part is to be incorporated. If needed, an additional number of custom or exclusive parts can be used to accommodate other aspects of a particular vehicle type. 
     In the illustrated embodiment, the first floor frame assembly  42  of  FIGS. 1 and 2  includes the front cross-member  50 , disposed forwardly adjacent the Y-shaped center joint, the first and second side sill members  46 ,  48  extending longitudinally at the lateral sides of the first floor frame assembly, the center frame member  44 , the second cross-member  52  disposed rearwardly adjacent the Y-shaped center joint, the intermediate cross-member  54  disposed rearwardly of the second cross-member  52 , and the rear cross-member  56  disposed at a rearward end of the center frame member  44 . On the floor frame assemblies  42 ′ of  FIGS. 2 and 4 , which can be used to accommodate larger cab areas, such as those fitted with four full-sized doors, the side sill members  46 ′,  48 ′ are used as these extend rearwardly a greater distance beyond the rear cross-member  56  than those on the relatively shorter floor frame assembly  42 . Also, the center frame member  44 ′ is used as it extends rearwardly a greater distance to bridge the wider gap between the cross members  54  and  56  on the second floor frame assembly  42 ′. In both of the floor frame assemblies  42 ,  42 ′, the front ends of the side sill members  46 ,  48  or  46 ′,  48 ′ are connected to the front frame assembly  64  and the rear ends of the side sills are connected to the rear frame assembly  58  (or  60 ). 
     As already mentioned, the center frame members  44  and  44 ′, the first side sill members  46  and  46 ′, and the second side sill members  48  and  48 ′ of the illustrated embodiments have respective matching cross-sections along entire longitudinal extents, though this in not required. Specifically, in the illustrated embodiment, the center frame members  44  and  44 ′ have matching cross-sections with one another, the first side sill members  46  and  46 ′ have matching cross-sections with one another, and the second side sill members  48  and  48 ′ have matching cross-sections with one another. Accordingly, further details will only be provided in connection with the members  44 ,  46  and  48  of the first frame assembly  42  and, unless indicated otherwise these further details are equally applicable to the members  44 ′,  46 ′,  48 ′ of the second frame assembly  42 ′. 
     With reference specifically to  FIG. 1 , each of the side members  46 ,  48  is an elongated continuous frame member having a generally C-shaped cross-section with an open side of the respective side sill member facing laterally away from the vehicle. As will be described in further detail below, the open interior of the side sill members  46 ,  48  can hold one or more bulkheads. A portion of a doorframe member  110  ( FIGS. 24-27 ) can be disposed over the open side of each of the side sill members  46 ,  48  and can serve as an outer cover thereof. The side sill members  46 ,  48  can connect to the front frame assembly  64 , the rear frame assembly  58  (or  60 ) and the cross members  50 - 56  through a plurality of frame joints, particularly vehicle frame side sill joints that will be described in further detail below. 
     The center frame member  44  can be situated approximately halfway between the side sill members  46 ,  48  so as to generally extend along the longitudinal centerline of the vehicle. Specifically, with brief reference to  FIGS. 9 and 10 , the center frame member  44  can include a pair of side walls  44   a ,  44   b  extending upwardly from a center or base wall  44   c . The center frame member  44  can also include an upper wall formed as a pair of flanges  204 ,  206  extending from distal portions of the side walls  44   a ,  44   b . The lower wall  44   c  can include a recess  44   d  providing the center frame member  44  with a generally W-shaped cross-section The recess  44   c  can accommodate a center bearing and a drive shaft (neither component shown). The center frame member  44  can be connected to the cross-members  50 - 56  and to the front frame assembly  64  through a plurality of joints, particularly vehicle center frame joints that will be described in further detail below. 
     Exemplary vehicle frame side sill joints are shown in  FIGS. 5-8 and 14-20 . As will be described below, each of these joints includes one of the side sill members  46  or  48  and at least one connecting frame member (e.g., outer arms  70 , 72  of the front frame assembly side members  66 ,  68 , side members  82 ,  84  of the rear frame assembly  58 , the cross members  50 - 56 , etc.). In each joint, the connecting frame member has an upper wall overlapping an upper wall of the side sill member  46  or  48  along a region where the connecting frame member mates with the side sill member  46  or  48  and a lower wall overlapping a lower wall of the side sill member  46  or  48  along the same region. All overlapping relations between frame components can serve as suitable weld locations for welding mating frame components to one another, though other connection methods could be used. While each side sill joint described below is described in detail in connection with the first side sill member  46  and the adjacent frame component connected thereto, it is to be appreciated and understood that a like joint is formed between the second side sill member  48  and a corresponding connecting frame component, though no further discussion of these other joints is provided. 
       FIGS. 5-8 AND 16-20  particularly show a side sill frame joint wherein the side sill member  46  connects to either the front or rear frame assemblies  58  or  64 . As shown, the side member  66  or  82  of the front or rear frame assembly  58  or  64 , both of which correspond to the side sill member  46 , is angularly oriented relative to the side sill member  46  and connected to the side sill member  46  to transfer load forces thereto. In these joints, the side member  66  or  82  has an upper wall overlapping an upper wall  46   a  of the side sill member  46  along a region where the side member mates with the side sill member  46  and lower wall overlapping a lower wall  46   b  of the side sill member  46  along the same region.  FIGS. 5-8  particularly show a frame joint between the side sill member  46  and the front frame side member  66  (specifically to the outer arm  70  thereof) and  FIGS. 16-20  particularly show a frame joint between the side sill member  46  and the rear frame side member  82 .  FIGS. 14-15  particularly show a frame joint between the side sill member  46  and the cross member  52 , which is generally the same as the frame joint between the side sill member  46  and the cross member  54 . 
     With reference now specifically to  FIGS. 5-8 , the frame joint between the first side sill member  46  and the front frame side member  66  will now be described. The frame joint includes an upper wall  66   a  of the first front frame side member  66 , and particularly of the first outer arm  70 , overlapping the upper wall  46   a  of the first side sill member  46  along a region  120  where the side member  66  mates with the side sill member  46 . The illustrated frame joint also includes a lower wall  66   b  of the side member  66 , and particularly of the first outer arm  70 , overlapping the lower wall  46   b  of the side sill member  46  along the same region  120 . The overlapping portions of the walls  66   a ,  66   b  can be formed as flanges or flanged portions if desired. Moreover, these overlaps at the region  120  can be suitably employed for a welded connection between the side member  66  and the side sill member  46 . In addition, this arrangement allows the mating between the side sill member  46  and the side member  66  along a full height dimension of both of these components with substantially zero offset between the mated components. 
     As already discussed, the side member  66  is angularly oriented relative to the side sill member  46 . In this regard, the side member  66 , and particularly the first outer arm  70  thereof, also includes a side wall  66   c  integrally formed with the upper wall  66   a  and the lower wall  66   b . Like the side member  66 , the side wall  66   c  is angularly oriented relative to the side sill member  46  and includes a flange  122  overlapping a side wall  46   c  of the side sill member  46  that is formed integrally with the upper and lower walls  46   a ,  46   b  of the side sill member  46 . The overlapping flange  122  can also be suitably employed for a further welded connection between the side member  66  and the side sill member  46 . As shown, the walls  66   a - c  extend continuously beyond a forward terminal end  124  of the side sill member  46 . 
     As shown in  FIG. 7 , the side sill member  46  can include a bulkhead  126  orthogonally oriented relative to a longitudinal length of the side sill member  46 . The bulkhead  126  can be located at about a location where the flange  124  overlaps the side wall  46   c  of the side sill member  46  (e.g., slightly forward of such location). The side sill member  46  can include another bulkhead  128  that is also orthogonally oriented relative to the longitudinal length of the side sill member. In the illustrated embodiment, the bulkhead  128  is U-shaped (i.e., includes two orthogonally extending walls) and is received forward of the bulkhead  126 . 
     The first cross member  50  intersects the side member  66 , and particularly the outer arm  70  thereof, adjacent the region  120  and further forms the illustrated joint with the side sill member  46  in the illustrated embodiment as the cross member  50  is secured directly to the side sill member  46 . As shown, the cross member  50  has a lower wall  50   a  that overlaps the lower wall  46   b  of the side sill member  46  at a location forward of the region  120 . More specifically, the lower wall  50   a  includes a flange  130  that overlaps the lower wall  46   b  of the side sill member  46 . In addition, the cross member  50  has first and second side walls  50   b ,  50   c  extending upwardly from the lower wall  50   a  to give the cross member  50  a U-shaped profile. The first side wall  50   b  extends from the side sill member  46  continuously through the side frame member  66 . A portion of the second side wall  50   c  is formed from a separate reinforcement member  130  received within the member  66  and extending from the side wall  66   c  toward the side sill member  46 . 
     Opposite the side wall  66   c , another side wall  66   d  is formed in part by a separate reinforcement member  132 . The reinforcement member  132  and thus the side wall  66   d  extend continuously from the side sill member  46  to the first side wall  50   b  of the cross member  50 . The reinforcement member  132  forms a secondary load path from the side member  66  to sill member  46 , whereas the upper wall  66   a , the lower wall  66   b  and the integrally formed side wall  66   c  form primary load paths from the side member  66  to the side sill member  46 . The reinforcement member  132  can include a flange  134  that overlaps the side wall  46   c  of the side sill member  46 . The bulkhead  128  can be located slightly forwardly adjacent a location where the flange  134  overlaps the side wall  46   c  of the side sill member  46 . 
     The side wall  46   c  of the side sill member  46  defines an opening  136  that registers with an open end of the outer arm  70  of the side member  66  and through which access to the interior of the outer arm  70  may be gained to facilitate welding attachment of the stiffening member  132  to the side sill member  46 , such as with a welding arm, shown in phantom in  FIG. 7 . 
     With reference to  FIG. 5 , a bridge member or bulkhead  138  is disposed within the inner arm  74  and serves to operatively link or interconnect the cross member  50  across the inner arm  74 . The bridge member or bulkhead  138 , which can be a U-shaped member having a pair of side walls and a bottom wall, is disposed within the open interior of the inner arm  74 , extends between the inner arm outer wall  74   a  and inner wall inner wall  74   b , and serves to communicate loads laterally between the inner and outer walls. Flanges at each end of the bridge member side walls are affixed to the inner and outer walls  74   a ,  74   b  of the inner arm  74 , while the bridge member bottom wall is affixed to the inner arm bottom wall  74   c.    
     With reference now specifically to  FIGS. 16-20 , the frame joint between the side sill member  46  and the rear frame side member  82  will now be described. This joint connects the rear frame assembly  58  to the floor frame assembly  42 . The illustrated frame joint includes an upper wall  82   a  of the first rear frame side member  82  overlapping the upper wall  46   a  of the side sill member  46  along a region  140  where the rear frame side member  82  mates with the side sill member  46 . A forward end of the side member  82  is laterally open and rests against the side sill member  46 . The frame joint also includes a lower wall  82   b  of the rear frame side member  82  overlapping the lower wall  46   b  of the side sill member  46  along the same region  140 . The overlapping portions of the walls  82   a ,  82   b  can be formed as flanges or flanged portions if desired. Moreover, these overlaps at the region  140  can be suitably employed for a welded connection between the side member  82  and the side sill member  46 . In addition, this arrangement allows the mating between the side sill member  46  and the side member  82  along a full height dimension of both of these components with substantially zero offset between the mated components. 
     As shown, the side member  82  is angularly oriented relative to the side sill member  46 . The side member  82  can also include a side wall  82   c  integrally formed with the upper wall  82   a  and the lower wall  82   b . Like the side member  82 , the side wall  82   c  is angularly oriented relative to the side sill member  46 . The side wall  82   c  can also include a flange  142  overlapping the side wall  46   c  of the side sill member  46 . The overlapping flange  142  can also be suitably employed for a further welded connection between the side member  82  and the side sill member  46 . The walls  82   a - c  of the side member  82  extend continuously beyond a rearward terminal end  144  of the side sill member  46  in the illustrated embodiment. 
     The side sill member  46  can include bulkheads  146 ,  148  both orthogonally oriented relative to the longitudinal length of the side sill member  46 . The bulkhead  148  can be located forwardly adjacent about a location where the flange  142  overlaps the side wall  46   c  of the side sill member  46 . The bulkheads  146 ,  148  can be positioned along the side sill member  46  at locations about where the side frame member  82  connects to the side sill member  46 . In particular, the bulkheads  146 ,  148  can be positioned at either end of the region  140  or slightly spaced apart from ends of the region  140  as is shown in the illustrated embodiment. 
     In addition, this joint can further include an upper reinforcing or gusset member  154  overlapping the upper wall  82   a  of the side member  82  and the upper wall  46   a  of the side sill member  46 . A lower or underside reinforcing member  156  can overlap the lower wall  46   b  of the side sill member  46  and can be secured to the side member  82  as will be described below. In the illustrated embodiment, the reinforcing member  156  includes a first section  156   a  that overlaps the lower side  46   c  of the side sill member  46  and a second section  156   b  that is oriented approximately orthogonally relative to the first section  156   a  and relative to a longitudinal length of the side sill member  46 . By this arrangement, the second section  156   b  can close an otherwise open rearward end of the side sill member  46 . A side member reinforcing member  158  can form a second side wall of the side member  82  spaced apart from the other side wall  82   c  that extends from the upper surface  82   a  to the lower surface  82   b . The member  158  can include an orthogonally extending flange  158   a  to which the second section  156   b  of the underside reinforcing member  156  is attached to connect the member  156  to the side member  82 . 
     In the illustrated embodiment, the reinforcing members  154 ,  156 ,  158  can be disposed in the otherwise open space between a rear end of the side sill member  46  and the side member  82 , and can serve to integrate the side member  82  and the side sill member  46  along a significant length, and thereby assists in transferring loads between the floor frame assembly  42  and the rear frame assembly  58 . By this arrangement, rear impact loads can be transferred through the side member  82  to the side sill member  46  and also through the reinforcement members  154 ,  156 ,  158  so as to efficiently and effectively distribute loads between the rear frame assembly  58  and the floor frame assembly  42 . 
     The side sill member  46  can define an opening  150  aligned with a forward end of the side member  82  and through which welding implements can be inserted into the interior of the side member  82  to facilitate welded attachment of the side sill member  46  to the side member  82 . The side wall  46   c  can also define another opening  152  through which access to the underside of the reinforcement member  146  can be gained to facilitate welding attachment thereof to the side sill member  46 . 
     With reference now specifically to  FIGS. 14-15 , the frame joint between the first side sill member  46  and the cross member  54  will now be described, though it should be appreciated that this joint could be used between any of the cross members  50 - 56 . The illustrated frame joint includes an upper wall  54   b  of the cross member  54  overlapping the upper wall  46   a  of the side sill member  46  along a region  160  where the cross member  54  mates with the side sill member  46 . The illustrated frame joint also includes a lower wall  54   a  of the cross member  54  overlapping the lower wall  46   b  of the side sill member  46  along the same region  160 . These overlaps at the region  140  can be suitably employed for a welded connection between the cross member  54  and the side sill member  46 . In addition, this arrangement allows the mating between the side sill member  46  and the cross member  54  along a full height dimension of both of these components with substantially zero offset between the mated components. 
     In the illustrated embodiment, the cross member  54  includes a first stamped member forming the lower wall  54   a  with a flange  162  that overlaps the lower wall  46   b  of the side sill member  46  and a pair of spaced apart upwardly extending side walls  54   c ,  54   d  each with flanges (only flange  164  shown) that overlap onto the side wall  46   c . The cross member  54  also includes a second stamped member  166  forming the upper wall  54   b . The second stamped member  166  includes a flange  168  that overlaps the upper wall  46   a . All these overlaps by the flanges facilitate a welded connection between the cross member  54  and the side sill member  46 . In addition, the side walls  54   c ,  54   d  include flanges  170 ,  172  for supporting a floor panel  174  of the floor frame assembly  42  as shown in  FIG. 15 . The floor panel  174  is also supported by the second stamped member  166 . 
     By using the second stamped member  166 , which can also be referred to as an insert, enhanced structural connectivity is provided to the joint between the cross member  54  and the side sill member  46 —more than could be provided by the floor panel  174  alone. This can improve stiffness of the joint as well as efficient load transfer between the parts comprising the joint. Further, the connections between the insert  136 , the cross member  54 , and the side sill member  46  at the top and bottom of the side sill member  46  allow for smooth load paths, which efficiently transfer forces from the side sill into the cross member and floor panel. 
     Exemplary vehicle center frame member joints are shown in  FIGS. 9-13 and 21-22 . As will be described below, each of these joints includes the center frame member  44  and at least one connecting frame member (e.g., the inner arms  74 ,  76  of the front frame assembly  62 , the cross-members  50 - 56 , etc.).  FIG. 9-11  particularly show a center frame member joint wherein the center frame member  44  connects to the inner arms  74 ,  76  of the front frame assembly  62 .  FIGS. 12-13 and 21-22  show joints between the center frame member  44  and the cross-members  50 - 56 . In each of these joints, a cross-member or segments of the cross-member are connected to the center frame member  44  and extend therefrom laterally toward an associated one of the side sill members  46 ,  48 . Further, the cross-member or cross-member segment has, in these joints, a lower wall that overlaps the lower wall  44   c  of the center frame member  44  and an upper wall that overlaps an upper wall of the center frame member as will be described in more detail below. All overlapping relations between the frame components can serve as suitable weld locations for welding mating frame components to one another, though it is to be appreciated that other connection methods could be used.  FIGS. 12 and 13  particularly show a joint or joints between one of the cross-members  50 - 54  or segments thereof and the center frame member  44 .  FIG. 21-22  show a pair of joints between the center frame member  44  and the rearward-most one of the cross-members (i.e. cross member  56 ) or segments thereof. 
     With reference now specifically to  FIG. 9-11 , a frame joint between the first and second inner members  74 ,  76  and the center frame member  44  will now be described. The frame joint includes the first and second spaced apart side walls  44   a ,  44   b  and the center wall  44   c  of the center frame member  44 , the walls  44   a ,  44   b  being integrally formed with and extending from the center wall  44   c . The joint also includes first and second spaced apart side walls  74   a ,  74   b  of the first inner arm member  74  integrally formed with and extending from a center wall  74   c  of the first inner member  74 . The first side wall  74   a  of the first inner member  74  is contiguous with and blends into the first side wall  44   a  of the center frame member  44  and the second side wall  74   b  of the first inner member  74  is contiguous with and blends into the second side wall  44   b  of the center frame member  44 . 
     In addition, first and second spaced apart side walls  76   a ,  76   b  of the second inner member  76  are integrally formed with and extend from a center wall  76   c  of the second inner member  76 . The first side wall  76   a  of the second inner member  76  terminates at the second side wall  74   b  of the first inner member  74  and the second side wall  76   b  of the second inner member  76  is contiguous and blends into the second side wall  44   b  of the center frame member  44  thereby providing a primary load path from the first inner member  74  to the center frame member  44  and a secondary load path from the second inner member  76  to the center frame member  44 . 
     A reinforcing wall member  180  extends from the second side wall  74   b  of the first inner member  74  toward the first side wall  44   a  of the center frame member  44  to transfer loads from the first side wall  76   a  of the second inner member  76  to the first side wall  44   a  of the center frame member  44 . As shown in the illustrated embodiment, the reinforcing wall member  180  has a first end  180   a  connected to the second side wall  74   b  of the first inner member  74  at a location about where the first side wall  76   a  of the second inner member  76  terminates, and has a second end  180   b  connected to one of the first side wall  74   a  of the first inner member  74  and/or the first side wall  44   a  of the center frame member  44 . Specifically, in the illustrated embodiment, the second end  180   b  is shown connected to the first side wall  74   a  adjacent the location about where the first side wall  74   a  engages and connects with the first side wall  44   a  of the center frame member  44 . The reinforcing wall member  180  can have a longitudinal length generally aligned with a longitudinally extending portion of the first side wall  76   a  of the second inner member  76  (i.e., a portion adjacent the second side wall  74   b  of the first inner member  74 ) to define a load path from the first side wall  76   a  of the second inner member  76  through the reinforcing wall member  180  to the first side wall  44   a  of the center frame member  44 . 
     As best shown in  FIG. 10 , the center wall  76   c  of the second inner member  76  overlaps the center wall  74   c  of the first inner member  74 , which can be suitably used for welding these components to one another. As shown, the side walls of both the center frame member  44  and the first and second inner members  74 ,  76  can include flanges at distal ends thereof that define a surface to which the floor panel  174  can be secured against (e.g., via welding). The joint formed by the center frame member  44  and the side members  74 ,  76  is generally a Y-shaped joint in the illustrated embodiment. In addition to the respective side walls of the side members  74 ,  76  generally overlapping and/or merging with the side walls  44   a ,  44   b  of the center frame member  44 , respective raised portions of the side members  74 ,  76  are generally aligned with, and generally serve as an extension of, raised center section  44   d  ( FIG. 10 ). 
     The reinforcing wall member  180  is generally formed as an upstanding wall having its first end  180   a  formed as a shallow or short portion that rests upon the raised portion of the first inner arm bottom wall  74   c , and the second end  180   a  formed as a relatively taller or deeper portion that rests upon the sunken portion of the first inner arm bottom wall  74   c . Each of the shallower and deeper portions have protruding base flanges  180   c  that rest upon, and can be welded to, the bottom wall  74   c  of the inner arm  74 . The shallower and deeper portions formed by the ends  180   a ,  180   b  also include side flanges  180   d  that rest upon, and are welded to, the side walls  74   a ,  74   b  of the inner arm  74 . The reinforcing wall member  180  can also include flange portions  182 ,  184  that extend outwardly to lie along, and be connected to, respective flanges provided by the first and second side walls  74   a ,  74   b  of the inner member  74 . 
     By including the reinforcing wall member  180 , the Y-shaped center joint has a generally X-shaped load path (illustrated by dashed lines in  FIGS. 10 and 11 ) whereby longitudinal loads can be effectively transferred from the front frame assembly  62  to the floor frame assembly  42  and, more specifically, to the center frame member  44  and to the cross-members  50 - 56  secured thereto. For example, should a longitudinally-directed compressive load be applied to the second inner arm  76 , such load can be effectively distributed to the first and second walls  44   a ,  44   b  of the center frame member  44 . Likewise, should a longitudinally-directed compressive load be applied to the first inner arm  74 , such load can be effectively distributed to the inner and outer side walls  44   a ,  44   b  of the center frame member  44 . The flanges of the inner arm side walls  74   a ,  74   b  and  76   a ,  76   b , together with the flanges  204 ,  206  of the side walls  44   a ,  44   b , can provide a support surface for floor panel  174 , which can be welded thereto. Accordingly, the floor panel  174  can be integrally secured to and over the inner arms  74 ,  76 , the cross-members  50 - 56 , and the center frame member  44 . This can assist in managing stress flow from the front frame assembly  62 , through the Y-joint, and into the floor frame assembly  42 . As such, front crash loading can be efficiently and effectively transferred from the front frame assembly  62  to the floor frame assembly  42 . Notably, a full height of the inner arms  74 ,  76  is mated to a full height of the center frame member  44 , which can advantageously increase or maximize stiffness of the joint and enhance load transfer characteristics between the frame components  44 ,  74 ,  76 . 
     With additional reference to  FIGS. 12 and 13 , a frame joint between at least one of the cross-members  50 - 56  and center frame member  44  will now be described. In particular, the frame joint between the cross member  52  and the center frame member  44  will be described in  FIG. 9-13 . With brief reference to  FIG. 1 , the cross-member  52  includes a first segment  190  spanning between the first side sill member  46  and the center frame member  44  and a second segment  192  spanning between the second, opposite side sill member  48  and the center frame member  44 . As best shown in  FIG. 12  concerning the first segment  190 , a lower wall (e.g., lower wall  192   a ) of each of the first and second segments  190 ,  192  overlaps the lower wall  44   c  of the center frame member  44  and an upper wall of each of the first and second segments  190 ,  192  overlaps an upper wall of the center frame member  44  as will be described in more detail herein. 
     With continued reference to  FIG. 12 , each of the first and second segments  190 ,  192  includes a respective lower wall  194 , a pair of spaced apart side walls  196 ,  198  extending upwardly from the lower wall  194 , and the upper wall formed by at least one flange (e.g., flanges  200 ,  202  on the segments  190  and  192 ) extending from distal ends of the side walls  196 ,  198 . As already described herein, the center frame member  44  includes the center or lower wall  44   c , the pair of spaced apart side walls  44   a ,  44   b  extending upwardly from the lower wall  44   c  and an upper wall, which can be formed by at least one flange (e.g., flanges  204 ,  206  in the illustrated embodiment) that extend from respective distal ends of the pair of spaced apart side walls  44   b ,  44   c . As shown, the at least one flange (e.g., flanges  200  and  202 ) of the first and second segments  190 ,  192  overlaps the at least one flange (e.g., flanges  204 ,  206 ) of the center frame member  44  and thereby provide a support surface for the floor panel  174 . 
     In addition, each of the pair of spaced apart side walls  196 ,  198  of the first and second segments  190 ,  192  includes respective flanges  208 ,  210  overlapping the first and second side walls  44   a ,  44   b  of the center frame member  44 . Further, the lower walls  194  of each of the segments  190 ,  192  can include a flange  212  ( FIGS. 10 and 12 ) that overlaps the center wall  44   c  of the center frame member  44 . As with the other joints described herein, the overlapping flanges in this joint can be suitably employed for a welded connection between the segments  190 ,  192  and the center frame member  44 . In addition, as indicated by the dashed line in  FIG. 12 , this arrangement also allows the mating between the segments  190 ,  192  and the center frame member  44  along a full height dimension of all of these components with substantially zero offset between the segments  190 ,  192  and the center frame member  44 . Attaching about the entire height of the center frame member  44  can advantageously increase or maximize stiffness of the joint and enhance efficient load transfer between the frame components. 
     The cross-member  52  comprised of the segments  190 ,  192  can further include at least one reinforcement member extending between adjacent ends of the first and second segments  190 ,  192  (i.e., the ends that are secured to the center frame member  44 ). This at least one reinforcement member can be received within the center frame member  44  between the first and second side walls  44   a ,  44   b  thereof. In the illustrated embodiment, this at least one reinforcement member includes a first reinforcement wall  220  extending between and aligned with first side walls  196  of the first and second segments  190 ,  192  and a second reinforcement wall  222  extending between and aligned with the second side walls  198  of the first and second segments  190 ,  192 . The first and second reinforcement walls  220 ,  222  can include respective lower flanges  224  that extend toward one another and are disposed upon, and fixed to, an upwardly facing, lengthwise extending surface of the center frame member  44 . The first and second reinforcement walls  220 ,  222  can also have respective upper flanges  226  that extend away from one another. The upper flanges  226  can be in contact with, and welded to, the floor panel  174 . The floor panel  174 , which is disposed over the union of the center frame member  44  and the first and second cross-member segments  190 ,  192 , can serve as an integral part of the overall joint, and can help to manage the stress flow from one of the cross-member segments  190  or  192  through the center frame member  44  and the reinforcement walls  220 ,  222 , and into the other of the segments  190 ,  192 . 
     As shown in  FIG. 13  and indicated by the dashed lines therein, the first reinforcement wall  220  defines a first load transfer path from the first side wall  196  of the first segment  190  to the first side wall  196  of the second segment  192  (or vice versa) and the second reinforcement wall  222  defines a second load transfer path from the second side wall  198  of the first segment  190  to the second side wall  198  of the second segment  192  (or vice versa). The side walls  44   a ,  44   b  of the center frame member  44  interrupt the first load path defined by the first reinforcement member  220  thereby defining this first load path as a secondary load path relative to the load paths defined by each of the pair of side walls  44   a ,  44   b . Likewise, the pair of side walls  44   a ,  44   b  of the center frame member  44  interrupt the second load path defined by the second reinforcement member  22  thereby defining this second load path as another secondary load path relative to the load paths defined by each of the pair of side walls  44   a ,  44   b.    
     With reference now specifically to  FIG. 21-23 , the frame joint between the rearmost cross-member  56  and the center frame member  44  will now be described. Similar to the cross-member  52  described above, cross-member  56  includes a first segment  230  spanning between the first side sill member  46  and the center frame member  44  and a second segment standing between the second, opposite sill member  46  and the center frame member  44 . As best shown in  FIG. 22 , the lower wall  234  of each of the first and second segments  230 ,  232  overlaps the lower wall  44   c  of the center frame member  44 . In particular, the lower walls  234  of the first and second segments  230 ,  232  can include flanges to  250  that overlap the center frame member  44 , particularly the center wall  44   c  thereof. In addition, as will be described in more detail below, an upper wall of each of the first and second segments  230 ,  232  overlaps an upper wall of the center frame member  44  (e.g., the upper wall formed by the flanges  204 ,  206 ). 
     As shown, each of the first and second segments  230 ,  232  includes the lower wall  234 , a pair of spaced apart side walls  236 ,  238  extending upwardly from the lower wall  234  and the upper wall formed by at least one flange (e.g., flanges  240 ,  242 ) extending from distal ends of the side walls  236 ,  238 . The at least one flange of the first and second segments  230 ,  232  (e.g., flange  242 ) overlaps the at least one flange (e.g., flanges  204 ,  206  of the center frame member  44 ) and thereby provide a further support surface for the floor panel  174 . In the illustrated embodiment, the flanges  240  of the first and second segments  230 ,  232  do not overlap the flanges  204 ,  206  of the center frame member  44 . Though not shown, the side walls  238  of the first and second segments can also include a respective flange (similar to flange  210  in  FIG. 12 ) that overlaps a respective one of the side walls  44   a ,  44   b  of the center frame member  44 . The overlaps of the segments  230 ,  232  onto the center frame member  44  can be suitably employed for a welded connection between the segments  230 ,  232  and the center frame member  44 . In addition, this arrangement allows the meeting between the segments  230 ,  232  and the center frame member  44  to occur along a full height dimension of all of these components with substantially zero offset between mated components. 
     The cross-member  56  formed by the segments  230 ,  232  can additionally include at least one reinforcement member extending between adjacent ends of the first and second segments  230 ,  232  (i.e., the ends connected to the center frame member  44 ). This at least one reinforcement can be received within the center frame member  44  between its first and second side walls  44   a ,  44   b . In particular, in the embodiment illustrated in  FIG. 21-23 , this at least one reinforcement member can include a first reinforcement wall or member  244  extending between and aligned with side walls  236  or the first and second segments  230 ,  232  and a second reinforcement wall or member  246  extending between and aligned with the side walls  238  of the first and second segments  230 ,  232 . 
     In this arrangement, as best indicated in  FIG. 23  by the illustrated arrows, the first reinforcement wall  244  defines a first load transfer path from the first side wall  236  of the first segment  230  to the first side wall  236  of the second segment  232  (and vice versa) and the second reinforcement wall  246  defines a second load transfer path from the second side wall  238  of the first segment  230  to the second side wall  238  of the second segment  232  (and vice versa). However, the side walls  44   a ,  44   b  of the center frame member  44  interrupt the load path defined by the reinforcement wall  246  thereby defining its load path as a secondary load path relative to the load paths defined by each of the side walls  44   a ,  44   b  of the center frame member. The reinforcement wall  244  provides an uninterrupted path between the walls  236  of the first and second segments  230 ,  232 . In the illustrated embodiment, the second reinforcement wall  244  abuts each of the first and second segments  230 ,  232 , particularly the walls  236  thereof, and extends continuously there between. 
     Flanges  252  of the walls  236  of the first and second segments  230 ,  232  extend over, and are secured to, the reinforcement wall  244 , which extends across the otherwise open end of the center frame member  44 . The reinforcement member  244  also includes an upper flange  254  which is contiguous with the flanges  240  of the first and second segments  230 ,  232 . The reinforcement member  244  can serve to stiffen the rear end of the center frame member  44 , while leaving an opening beneath through which a driveshaft, etc. can pass. 
     With reference to  FIG. 24-27 , the vehicle frame assemblies  30 - 36  are shown with further structural or frame components installed. For example, the doorframes  110  are shown installed on the sides of the vehicle frame assemblies  30 - 36 . In addition, the top door rails  260  are installed and cooperate with the doorframes  110  to define door openings. A dividing wall  262  extends between the doorframe members  110 , particularly between rear ends of the doorframe members  110  at about a location disposed between the floor frame assembly  42  (or  42 ′) and the rear frame assembly  58  or  60 . A rear top rail  264  is spaced vertically above the dividing wall  262  and also extends between the doorframe members  110  to define a rear window opening. 
     The rear frame assemblies  58  ( FIGS. 24 and 25 ) and rear frame assemblies  60  ( FIGS. 26 and 27 ) are also shown with additional frame components installed. In particular, in the rear frame assemblies  58  of  FIGS. 24 and 25 , upper rails  270 ,  272  having respective first longitudinal lengths extend from respective rear cab pillar or pillar areas  274  to a rear bed pillar  276 , where the rear cab pillars  274  formed at respective intersections between the doorframe members  110  and the dividing wall  262 . The upper rails  270 ,  272  are each respectively supported by support beams  278 ,  280  extending from the rear frame side members  82 ,  84  upward to the upper rails  270 ,  272 , respectively. As will be described in more detail below, this arrangement provides multiple load paths to dissipate energy in the event of a rear-end collision and also provides flexibility in manufacturing, thereby reducing manufacturing costs. 
     The rear frame assemblies  62  of  FIGS. 26 and 27  can be similarly constructed, though frame rails  270 ′ and  272 ′ have respective second longitudinal lengths that are longer than the respective first longitudinal lengths of the frame rails  270 ,  272 . Like the upper rails  270 ,  272 , the upper rails  270 ′ and  272 ′ extend from respective rear cab pillar areas  274  to rear bed pillars  276  and are supported by support beams  278  and  280 . In addition, a supplementary support beam  282  can also be provided to further support the relatively elongated upper rails  270 ′ and  272 ′. The supplemental support beams  282  extend from respective rear frame side members  82  or  84  forward of the beams  278 ,  280  and extending toward the rear cab pillar area  274 . 
     In the vehicle frame assemblies  30 - 36  illustrated in  FIG. 24-27 , one or more of the longitudinal frame members of the first and second rear frame assemblies  58 ,  60  can have a cross-sectional profile that remains constant along at least a longitudinal portion thereof allowing these one or more members to be cut at a first location along the longitudinal portion corresponding to the first longitudinal length when included in the first rear frame assembly  58  and at a second location along the longitudinal portion corresponding to the second longitudinal length when included in the second rear frame assembly. In the illustrated embodiment, these one or more longitudinal members include the upper bed rails  270 ,  272  and  270 ′,  272 ′. As shown in these members, the longitudinal portion is an entire longitudinal extent of the longitudinal members, though this is not required. To facilitate such cutting at a first location or a second location, the longitudinal members (i.e., the upper rails) can be roll-formed. 
     It is to be appreciated that the roll-formed upper bed rails  270 ,  272  and  270 ′,  272 ′, can be used in vehicle types where the floor frame assemblies are common with one another, such as the first vehicle type of  FIG. 24  and the third vehicle type of  FIG. 26 . Alternatively, the roll-formed longitudinal frame components for the rear frame assemblies  58 ,  60  can be used with first and second vehicle floor frame assemblies that vary relative to one another, such as shown in  FIGS. 26 and 27 . As already discussed herein, the vehicle frame assemblies  30 - 36  can all be included as part of a unibody frame, thus the longitudinal members (e.g., the upper rails  270 ,  272  and  270 ′,  272 ′) can be comprised within a unibody frame. 
     By the foregoing, it is to be appreciated that a bed frame assembly for a vehicle is disclosed including at least one longitudinal frame member having a cross-sectional profile that remains constant along at least a longitudinal portion thereof (e.g., the upper bed rails  270 ,  272  and  270 ′,  272 ′). This longitudinal portion can have a first portion length when installed on a first vehicle type having a first bed frame longitudinal length (e.g., the vehicle type depicted in  FIG. 24 ) and a second portion length when installed on a second vehicle type having a second bed frame longitudinal length (e.g., the second vehicle type depicted in  FIG. 27 ). The longitudinal portion that has a cross-sectional profile that remains constant can be the entire longitudinal extend of the longitudinal frame component. For example, the upper bed rails  270 ,  272  and  270 ′,  272 ′ each have a cross-sectional profile that remains constant along an entire longitudinal extent of these frame components. Moreover, the upper bed rails  270 ,  272  and  270 ′,  272 ′ extend along substantial portions, respectively, of the first bed frame longitudinal length and/or the second bed frame longitudinal length. 
     With brief reference to  FIG. 31 , a bed frame construction method for forming vehicle bed frames having varying longitudinal bed lengths will now be described. In  100 , at least one first longitudinal frame component having a defined cross-section of a first longitudinal length is formed for a first vehicle type. In  102 , the formed first longitudinal frame component is installed on a first bed frame assembly of the first vehicle type. The at least one first longitudinal frame component formed and installed in  100  and  102  can be the upper bed rails  270 ,  272 . In  104 , at least one second longitudinal frame component having the same defined cross-section is formed of a second longitudinal length for a second vehicle type. In  106 , the formed second longitudinal component is installed on a second bed frame assembly of the second vehicle type. The at least one second longitudinal component can be the bed rails  270 ′,  272 ′. Moreover, as already described herein, the steps of forming the bed rails  270 ,  272  and  270 ′,  272 ′, can include roll-forming these components. 
     With reference to  FIGS. 28 and 29 , further details will be described in connection with the upper frame rails  270 ,  272  of the first vehicle type ( FIG. 24 ) but such details are applicable to the other vehicle types unless indicated otherwise. Both an inner panel (not shown) and an outer panel  290  can be joined to the upper rails  270 ,  272  to form a load-carrying bed, and particularly side walls thereof. An upper-transition joining portion  292  can be employed to join forward ends of the upper rails  270 ,  272  to the respective rear cab pillar areas  274 . In particular, the upper-transition joining portion  292  can be a stamped member and can function as a transition joint between the associated upper bed rail  270  or  272  and a stamped member. For example, the upper-transition joining portion  292  can join the front portion of the upper bed rail  272  to the adjacent rear cab pillar area  274 . 
     The forward support beam  278  can be generally vertically oriented and can be generally perpendicular to the upper rail  270  or  272 . The rear-diagonal support beam  280  can be diagonally oriented with respect to the bed rail  270  or  272 . Both of the support beams  278 ,  280  associated with each of the upper rails  270 ,  272  can be one-piece roll-formed members, though this is not required. 
     As shown in  FIG. 29 , energy load paths represented by arrows are shown. The load paths are paths that the energy load resulting from a rear-end collision would likely travel. As the drawing shows, the load from a rear-end collision would likely be disbursed through each member comprising the rear frame assembly  58  or  60 . More specifically, such a load would be transmitted upward through the supports  278 ,  280  and the rear bed pillar  276  to the adjacent upper rail  270  or  272  and then to the rear can pillar area  274 . As shown, the load is distributed over multiple load paths which advantageously allows for better energy absorption and dissipation. 
     The frame assemblies described herein are described as including several variable length components, such as roll-formed members. These members are disclosed as being combined with several stamped members to provide an efficient method of manufacturing a vehicle frame assembly, while advantageously improving rigidity and safety. It should be noted, however, that the roll-formed members can be replaced with stamped members. While this may increase manufacturing costs over the utilization of roll-formed members, the improved efficiency and safety realized from the frame assemblies disclosed herein would not be sacrificed. 
     As is generally known in the art, roll-formed components, such as the side sill members  46 ,  48 , the center frame member  44  and the upper bed rails  270 ,  272  (and the longitudinally elongated equivalents of these frame components), can be formed in a continuous process by dispensing sheet steel from a roll, punching the sheet steel, if desired, and then forming the steel into the desired shape by passing the steel through a series of progressive roller dies. Such forming can be very economical and can provide an “endless” length of identical roll-formed parts that may thereafter be cut to a desired length. Accordingly, the right and left side sills for any vehicle model or type can be easily formed by cutting identical-length pieces from a continuous or uninterrupted length of “side sill stock.” Similarly, a particular center frame member can be formed by cutting a predetermined length from an endless or uninterrupted piece of “center tunnel or frame stock.” Still further, rear frame assembly longitudinal frame components (e.g., upper rails  270 ,  272 ) can be formed by cutting a predetermined length from an endless or uninterrupted piece of upper rail stock. 
     In practice, the side sill member stock, the center frame member stock, the upper rail stock, etc. can be formed at a location that is geographically remote from the location of final vehicle assembly, and shipped to the manufacturing facility. For example, a stack of a particularly desired length of side sills may be shipped on one pallet, while a particularly desired length of center frame members may be shipped on another pallet. Alternatively, stacks of center frame members and corresponding side sill members can be shipped together on one pallet, or a center frame member and a pair of side sill members can be shipped together as a kit. Further, in some situations it may be desired to roll-form the side sill members and the center frame members at an assembly facility such that the side sill members and the center frame members are cut from the respective stock lengths shortly before being delivered to the frame loading station for integration into the lower frame assembly. As will be apparent to one skilled in the art from the foregoing, although the roll-formed components are all formed in the same general way, the location and timing of manufacture of the roll-formed components is flexible and easily adapted to various manufacturing and assembly environments. 
     It will be appreciated that various of the above-disclosed and other features and functions, or alternatives or varieties thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.