This application claims the benefit of prior Provisional Patent Application Ser. No. 60/165,159, filed on Nov. 12, 1999. 
     The present invention relates generally to the field of devices and methods for applying a camber to steel beams, and more particularly to an apparatus and method for applying a cold camber to steel beams such as those used in the manufacture of steel frames for trailers. 
    
    
     BACKGROUND OF THE INVENTION 
     In the construction of steel frames for large trailers of all types, it is well known that it is highly advantageous to apply a camber to the main steel beams of the trailers, whether they are tubes, I-beams or C-channel. When trailer frames with appropriate cambers in their main beams are under load, the main steel beams bend until they are substantially straight, but do not sag, as would have been the case if the main steel beams lacked a camber before being put under load. Heretofore, cambers have been imparted to the main steel beams of trailers by applying heat to the top or bottom of the steel beams as a sharp bending force is applied to the opposite sides of the beams. The result has been cambers in the steel beam with relatively sharp kinks where bending forces have been applied during the heated cambering process. 
     SUMMARY OF THE INVENTION 
     The present invention provides a novel cold cambering apparatus and method for imparting cambers to the steel beams used in the manufacture of frames for trailers that eliminates the sharp kinks imparted to steel beams during the heated cambering process of the prior art. The present invention may be used to impart a cold camber to steel I- and C-channel beams, as well as tubes, either individually, or after they have been incorporated into a trailer frame. It has also been discovered that cold cambering imparts a camber that holds better than a comparable heat induced camber. In addition, the cold camber imparted to steel beams is in the form of a preferred long sweeping arch as opposed to the cambers with sharp kinks typically found in heat-induced cambers of the prior art. 
     One preferred embodiment of the present invention is a cold steel cambering apparatus, comprising, a moveable forward cambering assembly having a forward-most end and a rearward-most end and therebetween a plurality of adjustable beam guides, each having first means to restrain lateral movement of at least one cold steel beam placed on the forward cambering assembly, with a plurality of guides at the ends also having second means to restrain upward movement of at least one cold steel beam placed on the forward cambering assembly; and at least one forward hydraulic lift cylinder positioned midway between the ends and directly under at least one cold steel beam placed on the forward cambering assembly with third means to impart a concave camber to at least one cold steel beam placed on the forward cambering assembly over the forward hydraulic cylinder that is restrained by said first and second means; a moveable rear cambering assembly-aligned with the forward cambering assembly and.having a forward-most end and a rearward-most end and therebetween a plurality of adjustable beam guides,.each having fourth means to restrain lateral movement and fifth means to restrain upward movement of at least ore cold steel beam placed simultaneously on the rear cambering assembly and the forward cambering assembly, and at least one pair of rear hydraulic lift cylinders positioned to be at the rearward-most end portion of the rear cambering assembly and directly under at least one cold steel beam placed on the rear cambering assembly with sixth means to impart an upward camber to at least one cold steel beam placed on the rear cambering assembly over the rear hydraulic lift cylinders and restrained by the fourth and fifth means. 
     Another preferred embodiment of the present invention is a cold steel cambering apparatus, comprising, a cambering assembly having a forward-most end and a rearward-most end and therebetween a plurality of adjustable beam guides, each having first means to restrain lateral movement of at least one cold steel beam placed on the cambering assembly, with a plurality of guides at the ends also having second means to restrain upward movement of at least one cold steel beam placed on the cambering assembly; and at least one hydraulic lift cylinder positioned midway between the ends and directly under at least one cold steel beam placed on the cambering assembly with means to impart a concave camber to at least one cold steel beam placed on the cambering assembly over the forward hydraulic cylinder and restrained by the first and second means. 
     Another preferred embodiment of the present invention is a cold steel cambering apparatus, comprising, a cambering assembly having a forward-most end and a rearward-most end and therebetween a plurality of adjustable beam guides, each having first means to restrain lateral movement and second means to restrain upward movement of at least one cold steel beam placed on the cambering assembly, and at least one pair of rear hydraulic lift cylinders positioned to be at the rearward-mo st end portion of the rear cambering assembly and directly under at least one cold steel beam placed on the rear cambering assembly with means to impart an upward camber to at least one cold steel beam placed on the cambering assembly over the rear hydraulic lift cylinders and restrained by the first and second means. 
     Another preferred embodiment of the present invention is a method of providing a camber to a cold steel beam, comprising, providing a moveable forward cambering assembly having a forward-most end and a rearward-most end and therebetween a plurality of adjustable beam guides, each having first means to restrain lateral movement of at least one cold steel beam placed on the fo rw ard cambering assembly, with a plurality of guides at the ends also having second means to restrain upward movement of at least one cold steel beam placed on the forward cambering assembly; and at least one forward hydraulic lift cylinder positioned midway between the ends and directly under at least one cold steel beam placed on the forward cambering assembly with third means to impart a concave camber to at least one cold steel beam placed on the forward cambering assembly over the forward hydraulic cylinder and restrained by said first and second means; and a moveable rear cambering assembly aligned with the forward cambering assembly and having a forward-most end and a rearward-most end and therebetween a plurality of adjustable beam guides, each having fourth means to restrain lateral movement and fifth means to restrain upward movement of at least one cold steel beam placed simultaneously on the rear cambering assembly and the forward cambering assembly, and at least one pair of rear hydraulic lift cylinders positioned to be at the rearward-most end portion of the rear cambering assembly and directly under at least one cold steel beam placed on the rear cambering assembly with sixth means to impart an upward camber to at least one cold steel beam placed on the rear cambering assembly over the rear hydraulic lift cylinders and restrained by said fourth and fifth means; and at least one cold steel beam to be cambered; adjusting the separation between the rear and forward cambering assemblies in direct relation to the length of at least one cold steel beam of the providing step; first positioning of at least one cold steel beam of the providing step on the forward cambering assembly with the desired center of a forward concave camber to be imparted to at least one cold steel beam of the providing step over at least one of the forward hydraulic lift cylinder; second positioning of at least one cold steel beam of the providing step on the rear cambering assembly with the end of each beam overlaying at least one rear hydraulic lift cylinders; capturing at least one cold steel beam of the providing step with the forward and rear adjustable beam guides; first lifting at least one of the forward hydraulic lift cylinders to bend at least one cold steel beam of the providing step to a point greater than a desired camber in the beam and holding the forward hydraulic lift cylinder at that point; second lifting at least one of the rear hydraulic lift cylinders to bend at least one cold steel beam of the providing step to a point greater than a desired camber in the beam and holding the rear hydraulic at that point; and lowering the forward and rear hydraulic lift cylinders and checking for desired final camber dimensions in the beam. 
     Related objects and advantages of the present invention will be apparent from the following descriptions. 
    
    
     BRIEF DESCRIPTIONS OF THE DRAWING FIGURES 
     FIG. 1 is a perspective view of the front cambering assembly of the preferred embodiment of the present invention. 
     FIG. 2 is a perspective view of the rear cambering assembly of the preferred embodiment of the present invention. 
     FIG. 3 is a right-side view of the front cambering assembly of FIG.  1 . 
     FIG. 4 is a right-side view of the rear cambering assembly of FIG.  2 . 
     FIG. 5 is a sectional front-end view of the front cambering assembly of FIG. 1, taken along line  5 — 5 , illustrating a single beam mounted for cambering. 
     FIG. 6 is a front-end view of the rear cambering assembly of FIG. 2, illustrating a single beam mounted for cambering. 
     FIG. 7 is a representation of the general shape of the desired camber in beams utilized in the manufacture of large trailers. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings, the cold steel cambering apparatus  10  of the present invention comprises independent forward  12  and rear  14  cambering assemblies, both of which are moveable on wheels  16 , 18  respectively, to allow them to be adjustably spaced apart to accommodate beams and frames of varying lengths. The wheels  16 , 18  are mounted to longitudinal lower support beams  20 , 22  and  24 , 26  of the forward  12  and rear  14  cambering assemblies, respectively, which support lower cross support beams  28 , 30 , respectively. Lower cross support beams  28 , 30  directly support upper cross support beams  32 , 34  of the forward cambering assembly  12  and upper cross support beams  36 , 38  of the rear cambering assembly  14 . Upper cross support beams  32 , 36  of the forward  12  and rear  14  cambering assemblies, respectively, are fixed to lower cross support beams  28 , 30 , respectively. Upper cross support beams  34 , 38  are slidingly attached to lower cross support beams  28 , 30 , respectively, with conventional means such that upper cross support beams  34  and  38  slide atop and parallel to lower support beams  28 , 30 , respectively. In the preferred embodiment to date, the lower support beams and the upper and lower cross support beams have been steel I-beams. 
     Mounted to the upper cross support beams  32 , 34 , 36 , 38  are upper support beams  40 , 42 , 44 , 46 , 48 , 50 ; 52 , 54 , 56 , 58 , 60 , 62  all of which have been C-channel steel beams in the preferred embodiment to date. The upper support beams are aligned in parallel relationship with each other and with the longitudinal lower support beams  20 , 22 , 24 , 26 . Upper support beams  40 , 42 , 44  and  52 , 54 , 56  are affixed to the fixed upper cross support beams  32 , 36  of the forward  12  and rear  14  cambering assemblies. Upper support beams  40 , 42 , and  52 , 54 , which are C-channel steel beams in the preferred embodiment to date, are mounted to the upper cross support beams  32 , 36 , respectfully, with their flanges oriented outwardly, thereby forming parallel open channels  64 , 66 , respectively, between them along their entire lengths. Upper support beams  46 , 48 , 50  and  58 , 60 , 62  are affixed to the moveable upper cross support beams  34 , 38  of the forward  12  and rear  14  cambering assemblies, respectively. Upper support beams  46 , 48  and  58 , 60 , also being C-channel beams in the preferred embodiment to date, are mounted to the upper cross support beams  34 , 38 , respectfully, with their flanges oriented outwardly, thereby forming parallel open channels  68 , 70 , respectfully, between them along their entire lengths. 
     Spanning the open channels  64 , 68  and  66 , 70  at right angles are a plurality of slide tracks  72 , which are secured to the upper support beams  40 , 42 , 44 , 46 , 48 , 50 ; 52 ,  54 , 56 , 58 , 60 , 62 . Slide tracks  72  slidingly support beam guides  74 . Beam guides  74  are slidingly mounted in pairs, with the exception of the split single guide  75  mounted on the forward-most end of forward cambering assembly  12 , to the slide tracks  72  to provide lateral support to beams loaded for cambering and to prevent the beams from bending sideways during the cambering process. One of each pair of beam guides  74  and  75  on the forward cambering assembly  12  of the preferred embodiment to date is fixed in position at the edge of open channels  64 , 68  to provide a fixed lateral guide and support for a beam to be cambered. All of these fixed beam guides  76 , 77  are on the same side of either open channels  64 , 68 . Opposite each fixed beam guide  76 , 77  on the forward cambering assembly  12 , noting the exception of guide  75  on forward cambering assembly  12 , is a slidingly adjustable beam guide  78 , the position of which along its slide track  72  is controlled by forward bottom hydraulic pistons  80 . Forward bottom hydraulic pistons  80  allow the adjustable beam guides  78  to be selectively positioned against beams of varying widths that are positioned between the pairs of beam guides  74 , 75 . 
     On the rear cambering assembly  14 , one of each pair of beam guides  74  located above open channel  66  is fixed in position at the edge of open channel  66  to provide a fixed lateral guide and support for a beam to be cambered. All of these fixed beam guides  82  are on the same side of open channel  66 . Opposite each fixed beam guide  82  is a slidingly adjust able beam guide  84  the position of which along its slide track  72  is controlled by rear bottom hydraulic piston  86 . Rear bottom hydraulic pistons  86  allow the adjustable beam guides  84  to be selectively positioned against be ams of varying widths that ar e positioned between the pairs of beam guides  74  over open channel  66  for cambering. 
     Both of each pair of beam guides  74  located above open channel  70  on the rear cambering assembly  14  are slidingly adjustable along their slide tracks  72  with the positions of each controlled by rear bottom hydraulic pistons  88 . The adjustability of both of these pairs of beam guides  74  permits the rear camber ing assembly  14  of the present invention to adjust to a wide variety of rear portions of beams to be chambered. It is in the rear of trailers, for example, where two beams may be overlapped to provide extra strength for axle and wheel assemblies. 
     In the preferred embodiment to date, forward cambering assembly  12  has been provided with eleven pairs of beam guides  741  five each over the open channel  64 , five each over the open channel  68 , and one pair  75  at the forward-most end spanning beams  40 , 48 . 
     Single fixed beam guide  77  is provided at the forward-most end of forward cambering assembly  12 , to allow opening up of the front of assembly  12  by cutting back upper support beams  42 , 44 , 46 . The removal of a portion of the beams  42 , 44 , 46  provides clearance for the under slung hitch of a trailer frame. This allows the centerline of the front camber to be closer to the hitch by approximately five feet, which is important for shorter trailer frames. 
     Fitted into the middle of each open channel  64 , 68  of forward cambering assembly  12  at approximately the midpoint thereof is a front hydraulic lift cylinder  90  to force steel beams upward to impart a concave camber to the beams. To restrain beams at the ends of the desired concave chamber, the four slidingly adjustable beam guides  78  at each end of the forward cambering assembly  12 , as well as fixed beam guide  77 , are further provided with top forward hydraulic pistons  92  that are attached to forward hydraulic piston bolts  94 . Bolts  94  span the gap between the tops of these pairs of beam guides  74  when the slidingly adjustable beam guides  78  are positioned against beams by forward bottom hydraulic pistons  80 , so the bolts  94  are partially received within each and overlie steel beams lying there between. The exception is fixed beam guide  77 , the bolt  94  of which is extendible but is not received within a corresponding beam guide. 
     Bolts  94  will then restrain beams against upward movement at all these locations when front hydraulic lift cylinders  90  move upward against beams mounted in forward cambering assembly  12  to impart a concave camber to the beams. 
     In the preferred embodiment to date, rear-cambering assembly  14  has been provided with twenty-two pairs of beam guides  74 , eleven each over the open channels  66 , 70 . Fitted into the rear-most portions of each open channel  66 ,  70  of rear cambering assembly  14  are a pair of rear hydraulic lift cylinders  96 , 97 , each separately programmable, to force steel beams upward to impart an upward camber to the rear-most portions of the beams. To restrain beams forward of the desired upward camber imparted by the lift cylinders  96 , 97  the slidingly adjustable beam guides  84  along open channel  66  are further provided with top rear hydraulic pistons  98  that are attached to rear hydraulic piston bolts  100 . Similarly, one of each pair of slidingly adjustable beam guides  74  along the same side of open channel  70  is further provided with a top rear hydraulic piston  98  that is attached to a rear hydraulic piston bolt  100 . Bolts  100  span the gap between the tops of each pair of adjustable beam guides  74  when the pairs of beam guides  74  are all positioned against a beam, so the bolts  100  are partially received within each and overlie beams lying there between. Bolts  100  will restrain a beam from upward movement when the rear hydraulic lift cylinders  96  move upward against a beam. As illustrated in FIG. 2, the heights of the pairs of beam guides  74  in the rear cambering assembly  14  grow progressively taller from the front to the rear of rear cambering assembly  14 . Thus, the relative heights of bolts  100  grow progressively taller from the front to the rear of rear cambering assembly  14 . This allows a beam to arc upwardly from the front to the rear of rear cambering assembly  14  as lift cylinders  96  and  97  are raised upwardly. 
     The conventional hydraulic and associated feed tubes, hoses and control lines for all pistons and lift cylinders are not being illustrated in any drawing figures to eliminate unnecessary clutter. All feed tubes, hoses and control lines are located on the forward  12  and rear  14  cambering assemblies and are routed through telescoping tunnels to allow for length change. The hydraulic power supply  77  is illustrated in FIGS. 1 and 3. 
     In the preferred embodiment to date, the operation of all the hydraulic lift cylinders  90 , 96 , 97  and pistons  80 , 92 , 86 , 88 , 98  are controlled by conventional CNC hardware and technology that are well known and understood by those skilled in the art. The computer/control panel  79  that controls the operation of all hydraulic lift cylinders and pistons of the preferred embodiment to date is illustrated in FIGS. 1 and 3. 
     In an operative alignment, the cambering apparatus  10  of the preferred embodiment to date has the forward cambering assembly  12  aligned with the rear cambering assembly  14  such that open channel  64  of the forward cambering assembly  12  is in alignment with the open channel  66  of the rear cambering assembly  14 . The separation between the forward  12  and rear  14  cambering assemblies depends upon the length of the beams to be cold cambered. If a single beam is to be cold cambered, it will be positi oned over open channels  64 , 66  with the beam positioned so that the desired center of the forward concave camber is positioned over the front hydraulic lift cylinder  90  within open channel  64 . The rear cambering apparatus  14  will be positioned relative to the front cambering apparatus  12  such that the end of the beam to be cambered overlays the rear hydraulic lift cylinder  97  within open channel  66 . The slidingly adjustable beam guides  78 , 84  are then positioned to snuggly capture the beam between them and their corresponding fixed beam guides  76 , 82  through the actions of pistons  80 , 92 , 86 , 88 , 98 , which are each provided with a {fraction (5/16)} inch stroke PANCAKE brand cylinder  81  which is a short-stroke, large-bore hydraulic cylinder. The PANCAKE brand cylinders  81  eliminate the need to verify the dimension differences between single beam frames and double beam frames. The PANCAKE brand cylinders  81  permit each adjustable beam guides  78 , 84  to apply the proper snug capture clearance regardless of beam dimensional variations. 
     Next, the piston bolts  94 , 100  extend over the beam. Then front hydraulic lift cylinders  90  in open channel  64  lifts to a selected dimension and is held. The dimension selected will be slightly larger than the desired final camber dimension. Next, the rear hydraulic lift cylinder  96  in open channel  66  will lift up, again to a dimension slightly larger than the desired final camber dimension, and is held five seconds. The front and rear hydraulic lift cylinders are then both lowered and the beam is checked for desired camber dimensions. If the desired dimensions have not been obtained, the hydraulic lift cylinders  90  are raised again in the same sequence, followed by additional dimension checks. It is known that the steel must be over bent wvhen cold cambered to obtain the desired permanent cold camber dimension. When the desired permanent dimensions have been obtained, all hydraulic lifts and pistons are retracted and the beam is removed. 
     The cambering apparatus of the present invention provides flexibility in handling individual beams of 8, 10 or 12 inches. It also permits pre-welded trailer frames having two main beams of 8, 10 or 12 inches and multiple smaller cross beams to be mounted directly on the cambering apparatus  10  and a cold camber applied to the two main beams simultaneously. The relative positions of the open channels  68 , 70  and the open channels  64 , 66  may be changed to accommodate frames of varying widths by utilizing forward frame hydraulic pistons  110 , which are attached to upper support beam  46 , and rear frame hydraulic pistons  120 , which are attached to upper support beam  58 . The sequencing of the cold cambering steps for a completed frame is the same as that set forth above for an individual beam, above. 
     While the preferred embodiment of the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.
A cold steel cambering apparatus and method of use, the apparatus comprising, a cambering assembly having a forward-most end and a rearward-most end and therebetween a plurality of adjustable beam guides, each having means to restrain lateral movement of at least one cold steel beam placed on the cambering assembly, with a plurality of guides also having second means to restrain upward movement of at least one cold steel beam placed on the cambering assembly; and at least one hydraulic lift cylinder positioned directly under at least one cold steel beam placed on the cambering assembly with means to impart a concave or upward camber to at least one cold steel beam placed on the cambering assembly over the forward hydraulic cylinder and restrained by the means to restrain lateral and upward movement.