Off-highway truck body floor design

A truck body floor includes a truck body floor frame and a floor plate attached to and supported by the truck body floor frame. The truck body floor frame includes two frame rails extending along a longitudinal length of the truck body floor, and a plurality of bolster structures attached to both of the two frame rails and extending across a width of the truck body floor. The plurality of bolster structures includes at least one layered bolster structure having an inner bolster and an outer bolster that is at least partially flush with and attached to the inner bolster.

CROSS REFERENCE TO RELATED APPLICATIONS

This patent application claims the benefit of U.S. Provisional Patent Application No. 61/525,691, filed Aug. 19, 2011, and U.S. Provisional Patent Application No. 61/525,681, filed Aug. 19, 2011, which are incorporated by reference.

TECHNICAL FIELD OF THE INVENTION

The present invention generally relates to an off-highway truck body and more particularly to the floor and sides of such an off-highway truck body.

BACKGROUND OF THE INVENTION

Off-highway trucks, such as those of the present invention, are typically used in quarries, steel mills, power plants, mines, and landfills. Off-highway trucks of this type can often carry or haul two hundred (200) to four hundred (400) ton plus payloads, which in truck body volume can translate from as much as one hundred sixty (160) cubic yards to three hundred twenty (320) cubic yards (and greater) in size. (To put this into perspective, a typical on-highway tandem axle dump truck is ten (10) cubic yards in size.) As such, the floors of the bodies on such off-highway trucks can easily be greater than sixteen (16) feet wide and often can exceed thirty (30) feet wide.

Off-highway trucks with carrying capacities of four hundred (400) tons or more are commonly used for hauling a variety of materials in various off road environments. As the generic name, “off-highway”, implies these vehicles are limited to off-highway, private road use and are typically used in mining environments. The typical norm for these off-highway vehicles is to operate on unpaved gravel or aggregate roads of varying quality. As mining operations in particular advance, new temporary roads are continually being constructed and old roads are abandoned. Thus, such ‘mine’ roads can be undulating and at times have extremely soft/poor under footing; causing the chassis of the off-highway trucks operating on these roads to twist and/or turn and at times rack their very frames along with the truck bodies sitting on the off-highway truck chassis.

The loading of these off-highway trucks, particularly with two hundred (200) to four hundred (400) ton plus payloads, needs to be carried out efficiently and quickly for the owners of such off-highway trucks to achieve the needed return on investment and payback on their off-highway trucks. A typical cost for these off-highway trucks is between twelve thousand ($12,000.00) and sixteen thousand ($16,000.00) dollars per ton of hauling capacity, such that a two hundred (200) ton hauling capacity off-highway truck might cost about $2,800,000.00 and a four hundred (400) ton capacity off-highway truck might cost about $5,600,000.00.

When one considers the costs for such off-highway trucks, the ‘hourly’ owning operating cost of such vehicles is in the ‘range’, for a two hundred (200) ton capacity truck, of about $220.00 per hour and, for a four hundred (400) ton truck, of about $380.00 per hour. Considering these owning—operating cost rates, it is ideal for these off-highway trucks to be operating and hauling as much material as possible each and every hour of operation. Consequently, at about $3.70 and $6.30 per operating minute, in the above examples, every minute that the trucks are not moving material comes at a real and quantifiable expense.

A typical off-highway truck haul cycle includes:a. Loading,b. Hauling the load to a dump point,c. Dumping the load, andd. Returning to a loading point for the next load.
Typical complete haul cycles can be anywhere from fifteen (15) minutes to over sixty (60) minutes. The typical haul cycle is fifteen (15) to twenty (25) minutes. Assuming an average twenty (20) minute haul cycle, the loading of an off-highway truck should be quick and efficient, as every minute spent by an off-highway truck being loaded adds a minute to the total vehicle haul cycle.

In typical off-highway truck high-production haulage operations the goal is to have a vehicle loaded in three (3) to four (4) minutes or less. Typical off-highway truck loading tools, whether they be large power shovels (either cable operated or hydraulic operated) or front end loaders, have a forty five (45) second to one (1) minute loading cycle. Thus by straight forward calculation to fill a four hundred (400) ton nominal capacity off-highway truck in three (3) to four (4) minutes will require four (4) to a maximum of five (5) shovel passes. For a nominal four hundred (400) ton capacity truck this means shovel or loader bucket capacities of at least eighty (80) to one hundred ten (110) tons per pass. Today, such shovel bucket capacities are achievable with loading shovels such as P&H 4100 or Caterpillar 7495 electric rope shovels.

With a loading shovel ‘bucket’ of a nominal one hundred (100) ton capacity to load a four hundred (400) ton capacity truck in a minimal amount of time, extremely significant truck body floor loading ‘impacts’ will occur as one hundred (100) ton plus buckets of material are repeatedly dropped on the truck body floor. These loading ‘impacts’ normally occur at or near the longitudinal center of the truck body floor. This area of the truck body floor, that is regularly load ‘impacted’ by material, can be referred to as the “sweet spot” of a truck body floor. Further, since off-highway truck bodies are normally “open ended” to facilitate the dumping out of hauled material, the truck body floor “sweet spot” typically extends along the center of the truck body floor from a short distance behind the truck body front wall rearward to a position slightly behind the off-highway truck chassis ‘dump body pivot’ or hinge connection.

The intensity of loading impacts on the truck body floor “sweet spot” is partially determined by the actual materials being loaded into and hauled by the off-highway truck body. For example:1. Material such as plain alluvial dirt which rarely freezes into solid chunks (e.g., in more temperate climates) will cause relatively mild truck body floor impact2. Material that has low tensile strength, such as coal that easily breaks up on impact, causes only mild truck body floor impact3. Material that does break up relatively easy; but, contains little abrasive materials will be fairly easy on a truck body floor4. Material that will break up when thrown against itself is only marginally harder on a truck body floor5. Material that has high tensile strength and only breaks up in a mechanical crusher will impact a truck body floor life considerably more6. Material that does not easily break up other than when mechanically crushed and that has highly abrasive qualities (such as having silica sand or quartz content) impacts the truck body floor “sweet spot” fairly extremely

The floors of high-capacity off-highway truck bodies range in width from a nominal twenty (20) feet, up to and in excess of thirty (30) feet in width. With truck body floor structures of this width it is very important that the anchor and corresponding interconnections between the truck body floor and off-highway truck chassis are extremely substantial.

Rear dump, truck body floors typcially interface with an off-highway truck chassis at a minimum of at least four different points including:1. the truck body to off-highway truck ‘dump chassis pivot’ or hinge point, that the truck body pivots about when dumping,2. the truck body ‘frame rails’ which sit on the off-highway truck chassis and may be disposed on rubber frame pads between the body frame rails and off-highway truck chassis,3. at the truck chassis hydraulic hoist, where body hydraulic dump cylinders connect to the truck body, and4. some point near the front of the truck body via a chassis—body guide or stabilizer, that is disposed on the underside of the truck body floor and/or on the outside front wall of the truck body.

Of these four points between the truck body to off-highway truck chassis interface, only the truck body to truck chassis ‘dump body pivot’ interfaces and constrains/retains the truck body on the off-highway truck chassis. As such, to keep a truck dump body from falling off of the off-highway truck chassis, tremendous dynamic loads in the truck body to chassis pivot area do occur in maintaining truck body stability on the off-highway truck chassis.

Such dynamic loads occur in normal off-highway truck operation, as the off-highway truck traverses undulating and curved off-highway truck haul roads. These dynamic forces can often be further exacerbated by a commonplace off center truck body loading condition. In fact, it is rare that in loading an off-highway truck body, the loads will be perfectly centered on the off-highway truck body/chassis.

On a typical two hundred forty (240) ton capacity off-highway truck with a truck body floor width approaching twenty five (25) feet the actual truck body pivots are only slightly more than five (5′ 3″) feet apart. Further, on a four hundred (400) ton capacity off-highway truck with a truck body floor width of around thirty (30) feet, the truck body pivots are only about seven and one half (7′ 6″) feet apart. Comparing an off-highway truck body floor width with the width of the truck body to chassis anchor point, it is relatively easy to recognize that significant cantilever stresses occur at the truck chassis to truck body anchor or pivot points, with these cantilever stresses being further amplified by any off center truck body load placement.

In fact, on a two hundred forty (240) ton capacity off-highway truck there is typically about ten (10) feet of body floor cantilevered on either side of the off-highway truck chassis body support, and on a four hundred (400) ton capacity off-highway truck there is often more than eleven (11) feet of body floor cantilevered to either side of the off-highway truck chassis body support. Of course, this cantilever effect is further multiplied by any off center load placement. Considering that the truck body center floor support area anchors these cantilevered truck body floor side areas on either side of the truck body center floor area, it is clear that the truck body center floor area must be able to withstand considerable load stresses.

Moreover, in the dumping of an off-highway truck body, it is the truck body center floor, where the off-highway truck chassis hydraulic dump cylinders are anchored. As such the “body floor sweet spot” is subjected to combined loading stress, extreme hauling stress and dumping stresses.

Other factors considered in the design and production of large off-highway truck bodies include the size of materials used to produce the truck body. For instance, the maximum width of most steel plate (as limited by steel mill production capabilities) is ten (10) feet, although there are a limited number of steel mills which can produce steel plate twelve (12) feet or more in width. However, to obtain the very high quality, high strength steel utilized in truck bodies ten (10) foot wide steel plate is a common limit. To further complicate the steel plate issue, the common steel strength for steel plate used in off-highway truck bodies is one hundred seventy five thousand (175,000) to two hundred thousand (200,000) pounds per square inch (psi) yield strength. However, the typical highest strength weld materials that can be used to join steel plates of the strength used in a truck body is eighty thousand (80,000) to one hundred (100,000) pounds per square inch yield. With these disparities in strength between the steel plates and the welds used to join them, it is desirable to minimize and wherever possible eliminate weld “butt” joints, and wherever possible for body structural members to be joined by overlapping or intertwining so that the inherent strength of the basic steel being used can be fully achieved.

In the design of off-highway truck bodies another important consideration is the transport of an assembled off-highway truck body. In today's world, transport of large over width loads can, at best, be a challenge and can sometimes be impossible. In the Eastern half of the United States of America, shipping anything wider than sixteen (16) feet in some areas is impossible. Even in areas where it can be done, the cost to ship structures of this width can approach $100.00 per mile of load movement. In contrast, in the Western United States of America, movement of over-width off-highway truck bodies (those over twenty (20) feet in width) can be done for $10.00 to $15.00 per mile. In other parts of the world, shipping width constraints may be smaller or larger than sixteen (16) feet wide, but rarely are shipping widths of twenty seven (27) to thirty (30) feet wide allowed without severe restrictions. In some cases this may mean that truck body component work must be initiated at one point, and completed truck body components then shipped to a fabrication point near the actual location of use, and the truck body then assembled at or near the final point of use. The degree to which the truck body components are assembled or completed at an initial point is typically dictated by the actual shipping constraints of the final delivery point of use.

There are several available options for truck body fabrication and shipping. These include:1. full assembly and completion of a truck body at the initial point of fabrication, in which, due to shipping constraints, the typical overall truck body width may be limited to sixteen (16) feet,2. initial truck body component assembly at a first point of fabrication, followed by shipment of truck body components (in kit form) to an intermediate finish point of fabrication for final assembly, and subsequent delivery to final delivery location, and3. complete truck body component assembly at the initial original point of fabrication, shipment of fully fabricated truck body assemblies to an intermediate finish point of assembly, and subsequent delivery to final delivery location.
Other options are available for fabricating and shipping truck bodies, but the above three options are the most common.

To use an analogy from nature, the loadings and load distribution on an off-highway truck body floor can be compared with that of a “tree”. The trunk of a tree is like the center of an off-highway truck body, with the truck body floor supports extending outward off of the truck body center floor being much like the limbs of a tree. The roots of the tree are further analogous to the pivot connection point of the truck body to the off-highway truck chassis.

Today, in the off-highway truck operating arena it is commonly held that if a truck body floor lives a truck body lives. But, once an operator has to start working on and repairing a truck body floor, then that truck body floor and associated truck body components (body sides, body front wall, and body canopy) are close to the end of their useful life. Because of the high stresses that can and do occur in the area of the truck body to chassis pivot connection, when combined with the truck body floor “sweet spot” loading impacts, it is this area of the truck body to chassis interfaces, i.e., the truck body pivots, the truck body frame rails, and the truck hoist mounts that off-highway truck body floor failure normally begins.

In designing off-highway truck bodies, numerous factors should be taken into consideration, including:1. the rocking and rolling stresses imparted on a truck body floor in the ‘dynamic’ operation of off-highway trucks that occurs when travelling over less than ideal ground or road support conditions,2. the dumping of an off-highway truck body and the ‘dynamic’ stresses occurring in the area of the hydraulic dump cylinders and truck body floor attachment point as loaded truck bodies are raised and lowered,3. the high cost of owning and operating an off-highway truck and the need to operate the off-highway truck and truck body at its maximum productive capabilities,4. the need for off-highway truck fast ‘loading point’ turn around and loading-point bucket sizes that are 20 to 25% of an off-highway trucks carrying or hauling capacity,5. the loading impacts (dependent on body application) on the body “sweet spot”,6. the off-highway truck chassis to truck body connection stresses in the truck body “sweet spot” area,7. the actual application in which the off-highway truck will be used, and the intensity of load impacting that can be expected to occur,8. the critical nature of the off-highway truck chassis to truck body interface in conjunction with the amount of truck body floor that is cantilevered outside the pivot points between the off-highway truck chassis and truck body,9. the availability of large-width steel plates and the need to overlap and/or intertwine body components wherever possible in the joining of different steel members, and10. truck body shipping constraints from the initial point of off-highway truck body manufacture to a potential point of final truck body assembly, and then delivery to the ultimate off-highway truck body user.

In considering all of the above truck body design criteria, it can be appreciated that the design and construction of the center of a truck body floor is crucial to the total success and longevity of large off-highway truck bodies. High structural loads can often occur in the off-highway truck body floor center chassis connection area. This area, in particular, of an off-highway truck body needs to be designed to withstand all the rigors that an off-highway truck body dump body pivot may be subjected to.

SUMMARY OF THE INVENTION

In an embodiment, the present invention provides a truck body floor including a truck body floor frame and a floor plate attached to and supported by the truck body floor frame. The truck body floor frame includes two frame rails extending along a longitudinal length of the truck body floor, and a plurality of latitudinal bolster structures attached to both of the two frame rails and extending across a width of the truck body floor. The plurality of latitudinal bolster structures includes at least one layered bolster structure having an inner bolster and an outer bolster, with the outer bolster at least partially flush with and attached to the inner bolster.

In another embodiment, the invention provides a method of providing a truck body floor that includes constructing a central truck body floor segment at a first location, where the central segment includes two frame rails extending in a longitudinal direction of the central truck body floor segment, a plurality of latitudinal bolster structure central segments, at least one of which includes an inner bolster and an outer bolster, and a central floor plate section supported by the frame rails and bolster structure central segments. The central truck body floor segment being sent to a second location for assembling the truck body floor components including (center floor [one piece] and side floor pieces [two]) at the second location.

DETAILED DESCRIPTION

FIG. 1shows a truck body2for an off-highway truck. The truck body2includes a truck body floor4, two side walls6and a front wall8. A canopy10extends forward from the top of the front wall8in order to cover the front of a corresponding truck chassis, and particularly the operator's cab of the off-highway truck. InFIG. 1, only the upper surface, of floor plate12of the truck body floor4is visible. In contrast, inFIG. 2the frame14of the truck body floor2is partially visible through the cutout provided in the floor plate12, and inFIG. 3the truck body floor frame14can be seen in its entirety from below.

The truck body floor frame14includes two frame rails16running along the length of the truck body2, where the length extends from the front wall8and canopy10to a rear edge18of the truck body floor4. The frame rails16are positioned toward the center of the truck body2, with respect to the truck body width and run substantially parallel to each other. The truck body floor frame14also includes a series of bolster structures20extending across the width of the truck body floor, where the width extends from one side wall6of the truck body2to the other. Together, the frame rails16and bolster structures20support the floor plate12. In the illustrated embodiment, the floor plate12is supported directly by both the bolster structures20and the frame rails16. The bolster structures20are held within appropriately sized openings within the frame rails16, so that a strong connection between these elements is formed, and so that the top of the bolster structures20and frame rails16can both be flush with and support the floor plate12. The two substantially parallel frame rails16also include pivot36, where the truck body2is connected to the off-highway truck chassis. The pivot36acts as a hinge point for the truck body when the truck body is pivoted to dump the loads held inside the truck body.

As shown inFIGS. 4A and 4B, which show the truck body floor4alone, each of the bolster structures20has a layered or doubler construction including an inner bolster22and an outer bolster24, which are coupled to one another with respective faces of the inner bolster22being flush against opposing faces of the outer bolster24. Specifically, in the illustrated embodiment, the inner bolsters22are formed as a channel that is layered within the outer bolster24, which is formed as a similar but larger channel and interlocked with the smaller channel. Thus, as shown inFIG. 4B, the inner bolster22includes a web26and opposing flanges28that are placed flush against a corresponding web30and flanges32of a respective outer bolster24. Thus, the outer bolster24forms a layer of the bolster structure20over a portion of the inner bolster22. In an embodiment, the inner and outer bolsters22,24are welded together, although other forms of connecting the corresponding faces of the bolsters is also possible. By using both inner22and outer bolsters24, the layered or doubler bolster is effectively doubled wherever both bolsters22,24are present. Preferably, the outer bolsters24are shorter than the inner bolsters22and disposed at the center of the length of the inner bolsters22, as shown inFIGS. 4A and 4B. As a result, the bolster structure20has a thickness that is larger at the center of the truck body floor than at the sides of the truck body floor. This concentrates the layered doubler portion of the bolster structures20in the center of the truck body2, around the connection points with the off-highway truck chassis, where the loads and associated stresses are concentrated. The bolster structures20, which include inner22and outer bolsters24, are able to compensate for the extreme cantilever side floor loads that a truck body floor is exposed to because of the doubling of the layered center bolster structural support provided immediately under the center of a truck body floor.

While the illustrated embodiment shows each of the bolster structures20as including the layered bolster configuration, with both an inner bolster22and an outer bolster24, it is also possible for some of the bolster structures20along the length of the truck body floor4to be formed by a single bolster component. For example, if only some of the bolster structures20included the layered doubler bolster structure, these doubled bolster structures could be concentrated near the pivot36of the truck body disposed on the body frame rails16. In a specific example, the truck body floor frame14may only include the doubled bolster structures, each including an inner bolster22and outer bolster24, on either side of the pivot36. The load capacity of the bolster structures20could likewise be concentrated in certain locations by varying the length of the outer bolster24. For example, the outer bolsters24could be longer near the pivot36, or could increase in length from the front of the truck body floor toward the rear. For stronger support of loads in the truck body, it is preferable that the length of the outer bolsters24be longer than the distance between the two frame rails16, so that each outer bolster24can be supported by both frame rails16. On the other hand, it is typically not necessary that the outer bolsters24extend far toward the side walls6of the truck body. For example, the outer bolsters24may in some cases be less than half of the width of the truck body2and accordingly, also in some cases be less than half the width of the inner bolsters22.

In the embodiment shown inFIGS. 2-4, the bolster structures20include the outer bolster24at the center of structure20and the inner bolster22extending along the entire length of the bolster structure so as to correspond to the entire width of the truck body. While truck bodies having bolster structures20with this construction are perfectly adequate functionally, their use can be limited due to shipping constraints. As explained above, if the truck body width is large, the shipping of the truck body, or even just the truck body floor, in a single piece may be against regulations. Thus, the embodiment shown inFIGS. 2-4, including bolster structures20with members22extending across the entire width of the truck body2, may be most appropriate where the width of the truck body is less than a certain size, or where the truck body will be assembled nearby or on site.

In instances where a large truck body is required and assembly on site is not practical, it may be advantageous to use an embodiment of the truck body shown inFIGS. 5 and 6. Similar to the embodiment shown inFIGS. 2 and 3, the truck body ofFIGS. 5 and 6includes a body floor4, two side walls6, a front wall8and a canopy10. Likewise, the body floor4, shown alone inFIGS. 7A and 7B, includes a frame14with a pair of body frame rails16and a plurality of bolster structures20extending along a length of the body frame rails. Further, the bolster structures are doubled toward the center of the width of the truck body floor4, with an inner bolster22and an outer bolster24. However, in contrast to the embodiment shown inFIGS. 2-4, the inner bolsters22of the truck body floor ofFIGS. 7A and 7Bdo not extend across the entire width of the truck body. Instead, the ends of the bolster structures20as shown inFIG. 7B, at the outer sides of the truck body width, are formed by outside interlocking bolsters38. Thus, each of the bolster structures20include an outside interlocking bolster38disposed at each end to support the loads toward the outer sides of the truck body. In the illustrated embodiment, these outside interlocking bolsters38, are formed as channels, similar to the inner and outer bolsters22,24. Thus the outside interlocking bolsters38can fit inside or outside (inside shown) the inner bolsters22for attachment thereto. For example, the outside interlocking bolsters38can have an inner end portion that is set inside the inner bolster22so as to overlap with inner bolster22. This overlapped section of the inner bolster22and interlocking outside bolster38can then be welded together for a secure connection between the outside interlocking bolsters38and doubled central bolsters. The overlap may be, for example, between six (6) to twenty four (24) inches.

The embodiment shown inFIGS. 5-7has the advantage that it can be partially assembled into assembly pieces that are within any potential shipping constraints. For example, as shown inFIG. 7C, the truck body floor can be assembled in three pieces, including a central truck body floor segment40and two outside truck body floor segments42. An exploded view of these components40and42is shown inFIG. 7Cand assembly of such is further illustrated byFIG. 7D. To fabricate the central truck body floor segment40, the frame rails16can be connected with central segments45of the bolster structures20, including the layered inner bolster22and outer bolster24. In addition, the central truck floor body segment40can also be outfitted with a central floor plate section44, which may be composed of one or more steel plates. Likewise, the outside truck body floor segments42can be assembled by attaching each of the interlocking outside bolsters38to an appropriate outside floor plate section46for the right or left side of the body floor.

The assembly of the central truck body floor segment40and outside truck body floor segments42, allows for a partial assembly of components that are not subject to shipping constraints, followed by a final assembly of the truck body floor at a new location. For example, the central truck body floor segment40and outside truck body floor segments42can be fabricated in a first location. These three segments40,42can then be shipped to a second location, where the outside segments42are attached to the central segment40. This can be accomplished by inserting the outside bolsters38within the inner bolsters22until the central floor plate section44meets outside floor plate sections46. The floor plate sections44,46and bolster components22,38can then be assembled to one another at the second location. Alternatively, the central truck body floor segment40could be assembled in a first location, and then shipped along with components of the outside segments42, which could be added to the central truck body floor segment40at the second location.

Any of the additional features described below and shown inFIGS. 8-13can also be included in the construction of a body floor4as shown inFIGS. 3 and 4or the central floor body segment40and outside body floor segments42as shown inFIGS. 4 and 5.

FIGS. 8-14show various additional features that can be included in embodiments of the present invention. Each of the features illustrated in these drawings can be used in combination with any of the other illustrated features. Moreover, while the embodiments shown inFIGS. 8-14includes the interlocking outside bolsters, each of these features can also be used with a truck body floor having bolster structures including an inner bolster22that stretches across the entire width of the truck body, in a one-piece floor constructions, such as inFIGS. 2-4.

FIG. 8shows an embodiment of a truck body floor4including super stiffeners50disposed within the channel formed by the bolster structure20. The super stiffeners50include an elongate flat plate52that attaches to the web26of the inner bolster22and a scalloped stiffener plate54extending up from the flat plate52. The scalloped stiffener plate54extends along the longitudinal length of the flat plate52, curving back and forth from one edge of the flat plate52to the opposite edge. A top end56of the scalloped stiffener plate54attaches to the underside of the truck body floor plate12. Preferably, the super stiffeners50are disposed centrally along the length of the respective bolster structure20so as to be centered with respect to the truck body width. As illustrated, in embodimentFIG. 8that use interlocking outside bolsters38, the length of the super stiffeners50can be longer than inner bolster22so as to extend into interlocking bolsters38. Of course, it is also possible for the length of the super stiffeners50to be shorter than inner bolsters22, or varied in length from one bolster structure20to another. Likewise, it is also possible that the super stiffeners50be used in certain bolster structures20and left out of other bolster structures20within the same truck body.

FIGS. 9A and 9Bshow another embodiment of at truck body floor4that includes half funnels60, each extending from a side surface62of the frame rails16to the bolster structure22. As a result, the half funnels help distribute loading between the frame rails16and bolster structure22. The half funnels60have the shape of a tapering channel that taper outward from a narrow end64that fits tightly over a section of the bolster structure22to a wide end66that is disposed flush against the side surface62of a corresponding frame rail16. The half funnels60shown inFIGS. 9A and 9Bare disposed outside of the two frame rails16. However, it is also possible to include half funnels60between the frame rails16, so that such a half funnel is disposed against an inside surface of the respective frame rail. While the half funnels60are illustrated as extending from the frame rails16to the inner bolster22, it is also possible for the half funnel60to extend to the outer bolster24, particularly if the outer bolster is longer than shown inFIGS. 9A and 9B, or to extend to the interlocking outside bolster38.

In another embodiment, the half funnels60can be used in combination with the super stiffeners50shown inFIG. 8. Such a combination is shown, along with additional features, for a truck body having a one piece floor construction inFIGS. 2 and 3, and for a truck body having a three piece floor construction inFIGS. 5 and 6.

FIGS. 10A and 10Bshow another embodiment of a truck body floor4including tapered hoist mounts70. To utilize the tapered hoist mounts70, two of the bolster structures20include tapered flanges72that taper toward one another as they extend toward the floor plate12. Thus, the tapered flanges72are each disposed at an angle that is not perpendicular to the corresponding web. The tapered hoist mounts70include corresponding tapered supports74that abut the tapered flanges72to attach to the corresponding bolsters20. In addition, an extension76of the hoist mounts70may also extend outward past the flanges72to attach to the lower web of the bolsters20directly. The tapered construction of the hoist mount70and bolsters20, provides added support to the hoist mounts70against the bolsters20in comparison to a connection between a hoist mount and a vertical bolster flange, since that construction requires the hoist mount to bolster connection itself to provide support to the hoist mounts. With the construction shown inFIGS. 10A and 10B, the hoist mount70securely transfers loads from the hoist connection78, where the hoist cylinders are mounted to the bolster structures20of the truck body floor4.

In another embodiment, the tapered hoist mounts70can be used in combination with the super stiffeners shown inFIG. 8, with the half funnels shown inFIGS. 9A and 9B, or with both of these features. A combination including all three features, along with additional features, is shown for a truck body having a one piece floor construction inFIGS. 2 and 3, and for a truck body having a three piece floor construction inFIGS. 5 and 6.

FIG. 11shows another embodiment of a truck body floor4including tapered frame rail plates at the front of the truck body floor. As illustrated inFIG. 11, each of the frame rails16includes a frame rail plate80that runs along the lower portion of the frame rail16for substantially the entire length of the frame rail16. At the front end of the frame rail16, the frame rail plate80includes a tapered section82that tapers outward as the frame rail plate80extends upward to join the truck body floor plate12.

In another embodiment, the tapered frame rail plates80can be used in combination with the super stiffeners50shown inFIG. 8, with the half funnels60shown inFIGS. 9A and 9B, with the hoist mounts70shown inFIGS. 10A and 10B, or any combination thereof. A combination including all four of these features, along with additional features, is shown for a truck body having a one piece floor construction inFIGS. 2 and 3, and for a truck body having a three piece floor construction inFIGS. 5 and 6.

FIG. 12shows another embodiment that includes the tapered frame rail plates shown inFIG. 11. In addition, the embodiment shown inFIG. 12also includes frame rail support plates84, which extend from the frame rail plate80up to the floor plate12at the front of the truck body floor. In a specific embodiment, the frame rail support plates84are disposed at a front end of the truck body floor4and include a front edge86that extends along an edge of the tapered section82of the frame rail plate80. Further, the rear edge88of each frame rail support plate84can be shaped to fit against the front-most bolster structure20and/or to the floor plate12.

In another embodiment, the tapered frame rail plates80and frame rail support plates84can be used in combination with the super stiffeners50shown inFIG. 8, with the half funnels60shown inFIGS. 9A and 9B, with the hoist mounts70shown inFIGS. 10A and 10B, or any combination thereof. A combination including all five of these features, along with additional features, is shown for a truck body having a one piece floor construction inFIGS. 2 and 3, and for a truck body having a three piece floor construction inFIGS. 5 and 6.

FIGS. 13A and 13Bshows another embodiment of a truck body floor4that includes front to rear bolsters90. The front to rear bolsters90are each disposed between two adjacent bolster structures20and include front and rear edges92,94that attach to the respective neighboring bolster structure. In the illustrated embodiment, the front to rear bolsters90are disposed at the center of the truck body floor4and configured as a channel with outward tapering flanges these front to rear bolsters90can also be disposed at the sides of the truck body floor. It is also possible to use channels with vertical flanges or to include the front to rear bolsters90only between certain pairs of bolster structures20.

In another embodiment, the front to rear bolsters90can be used in combination with the super stiffeners50shown inFIG. 8, with the half funnels60shown inFIGS. 9A and 9B, with the hoist mounts70shown inFIGS. 10A and 10B, the tapered frame rail plates80shown inFIG. 11, the frame rail support plates84shown inFIG. 12, or any combination thereof. A combination including all of these features, along with additional features, is shown for a truck body having a one piece floor construction inFIGS. 2 and 3, and for a truck body having a three piece floor construction inFIGS. 5 and 6.

FIGS. 14A-Cshow an embodiment of a truck body2that has a tapered construction that widens toward the rear end of the truck body2. Thus, the truck body floor4tapers outward from the front of the truck body to the rear of the truck body and the side walls6move away from one another toward the rear of the truck body2. This tapering of the truck body2enables easier unloading of material held in the truck body2when the truck body is lifted to dump the material. Due to the outward tapering of the side walls6, the walls move away, in relative terms, from the material as it moves toward the rear end of the truck body. Accordingly, frictional forces at the side walls are reduced, which eases removal of the material and minimizes any sidewall wear.

To compensate for the outward tapering of the truck body2, the bolster structures20can also widen from the front of the truck body to the rear of the truck body, such that the bolster structure20at the front of the truck body is shorter than the bolster structure at the rear of the truck body, as shown inFIG. 14C.