MXPA99003112A - Platform and cover for truck, cable dissipators - Google Patents

Abstract

The present invention relates to a receptacle for a cargo vehicle, characterized in that it comprises, in combination a pair of side walls, a front wall, a bottom panel joining the side walls and the front wall, and the receptacle is made of a material thermoplastic, at least a portion of the thermoplastic material includes dispersed electrically conductive material

Description

PLATFORM AND COVER FOR TRUCK, CARGO DISSIPATORS BACKGROUND OF THE INVENTION The invention relates generally to platforms and linings for cargo vans (uncovered), cargo vehicles and the like, and more particularly with a platform or liner that has improved electrical charge dissipation characteristics. Coatings for motor vehicles, particularly platform liners for cargo vans and cargo vans provide many benefits. First, such platform linings provide a resilient barrier between the cargo area and the truck's true platform which absorbs energy and reduces dent and damage to the platform when transporting heavy loads. Secondly, the coatings protect the vehicle's platform or the interior of the water, salt and other possible more corrosive materials which can be transported in the vehicle. The emphasis on reducing the weight of the passenger vehicle generated a similar emphasis on behalf of light and medium duty truck manufacturers. One of the areas that has become focus of such weight reduction is the box REF: 29835 or vehicle platform. By replacing the metal box or platform with a non-metallic material, for example thermoplastic, the platform provides obvious and relatively significant weight reduction, and other advantages. Resistance to oxidation or corrosion and dents are two of the accompanying advantages. A drawback that accompanies the relatively large components made of thermoplastic material or other organic materials is their ability to be electrically charged and their inability to rapidly dissipate such charges. This electrical activity is considered undesirable and the products which do not show this activity therefore become desirable. The present invention is directed to such a product.

BRIEF DESCRIPTION OF THE INVENTION A truck platform or liner for installation on the platform of a cargo truck or cargo vehicle exhibits improved electric charge dissipation characteristics. The truck platform of the preferred embodiment is made of high density polyethylene (HDPE) or a similar thermoplastic material engineered containing carbon black particles or other conductive material dispersed therebetween. In a first alternative mode, the platform defines two interposed layers. The upper layer of HDPE or similar material includes dispersed carbon black particles or other conductive material, while the lower layer is free of such particles. In a second alternative embodiment, an HDPE truck platform liner or similar material includes dispersed carbon black or other conductive material. A third alternative embodiment comprises a truck bed liner that defines an interposition of two layers with carbon black or a similar conductive material in the top layer. A fourth alternative embodiment of platform or platform liner includes an open or enervated mesh fabric which has carbon black or other conductive material dispersed therein. The mesh or enervated is secured to the upper surface of the HDPE prepared coating, preferably by autogenous bonding. The platforms and coatings according to the present invention provide improved dissipation of static electricity charge and therefore improve the safety with respect to possible static discharges. Therefore, it is an object of the present invention to provide a truck platform made of thermoplastic material containing dispersed particles of conductive material.

A further objective of the present invention is to provide a polyethylene truck platform of high density (HDPE) having dispersed conductive particles which provides improved electric charge dispersion characteristics. A further objective of the present invention is to provide a coating for a cargo truck or cargo vehicle made of HDPE containing dispersed particles of conductive material. A further object of the present invention is to provide a coating for a cargo truck or cargo vehicle made of HDPE, which provides improved load dissipation characteristics. A further objective of the present invention is to provide a truck or liner platform comprising two layers of HDPE or a similar material, one of which includes dispersed particles of conductive material. A further objective of the present invention is to provide a platform or lining for a truck, HDPE or similar material having a conductive fabric or an enervate attached to the upper surface of the platform or the liner. Additional objects and advantages of the present invention will become apparent with reference to the following description of the preferred embodiment and alternative embodiments and the accompanying drawings in which like reference numerals refer to the same component, element or feature.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a cargo truck having a non-metallic box or platform incorporating the present invention; Figure 2 is a fragmentary, highly enlarged sectional view of a truck platform according to the present invention, taken along line 2-2 of Figure 1; Figure 3 is a fragmentary, highly enlarged sectional view of a truck bed according to a first alternative embodiment of the present invention, taken along line 2-2 of Figure 1; Figure 4 is a perspective view of a cargo van and a conventional metallic box or platform having a non-metallic platform coating according to the second alternative embodiment of the present invention; Figure 5 is a fragmentary, highly enlarged sectional view of the platform covering according to the second alternative embodiment of the invention, taken along line 5-5 of Figure 4 / Figure 6 is a view in fragmentary, highly enlarged section of a platform liner, according to a third alternative embodiment of the present invention, taken along line 5-5 of Figure 4; Figure 7 is a fragmentary, enlarged, top plan view of a fourth alternative embodiment of the platform or platform liner according to the present invention; and Figure 8 is a fragmentary, highly enlarged sectional view of a fourth alternative platform or platform cladding mode, according to the present invention, taken along line 8-8 of Figure 7.

DESCRIPTION OF THE PREFERRED MODALITY OF MODALITIES ALTERNATIVES Referring now to FIGS. 1 and 2, a non-metallic cargo truck platform incorporating the present invention is illustrated and designated with reference numeral 10. The non-metallic platform 10 is a unitary structure preferably molded of an engineered thermoplastic such as high density polyethylene (HDPE) or a similar material. The platform 10 includes outer side walls which are uniformly joined with parallel, generally opposite, side walls 14. The inner side walls 14 are interrupted by the gaps 16 of the wheels which are suitably sized and located to receive the respective rear tires 18 of the loading truck or the light or medium working load vehicle 20. The opposite inner side walls 14 are joined with a transversely extending front wall 24, which can define a single interconnecting panel that joins the opposite inner side walls 14 or with a double wall panel having interior and interior panels. exteriors which are interconnected and joined with the inner side walls 14 and the respective outer side walls 12. The pair of inner side walls 14 and the front transverse wall 24 are all joined and interconnected with the lower panel 26. To improve the strength and rigidity of the lower panel 26, a plurality of corrugations 28 are preferably defined which extend substantially longitudinally throughout. A plurality of fasteners such as mushroom head and square neck bolts 30 or similar devices extending through the lower panel 26 securing the platform 10 to the transverse supports or members 32 which, in turn, are secured to a frame or frame 34 of the cargo van 20. Typically, the non-metallic bed 10 includes back lighting and tail mounts 36, which operate in accordance with conventional practice. A tailgate assembly 32 is pivotally positioned through the open end of platform 10 of the cargo truck. The cargo van or vehicle 20 also includes a conventional cab 40 and front tire and wheel assemblies 42. With reference now to figures 2 and 3, the non-metallic platform 10 and particularly a portion of the plurality of corrugations 28 of the lower panel 26 are illustrated in cross-section. In Figure 2, the lower panel 26 which, as indicated, is preferably made of high density polyethylene (HDPE) or similar engineering-grade thermoplastic material, which has been extruded into a sheet and then formed to size and Desired configuration includes conductive particles 44 dispersed from carbon black or similar material which is shown to be greatly enlarged for purposes of illustration. If it is carbon black, the conductive particles 44 may be the same or similar to a product called XC-72 manufactured by the Cabot Corporation or the product called Ketjenblack EC-300 J manufactured by Akzo Nobel Chemicals, Inc. Other conductive materials such as fibers of carbon or other metallic particulate materials such as aluminum or copper powders or flakes are also suitable. Preferably, the carbon black conductive particles 44 represent approximately 18% to 22% of the total weight of the material. Based on the choice of the conductive material and the substrate, however, conductive particles 44 in the range of 5% to 25% by weight can be used. When a thicker carbon black such as Cabot XC-72 is used, it has run well at 18% to 22% carbon black by weight. A finer carbon black such as Ketjenblack EC-300 J from Akzo Nobel provides similar performance when used at approximately 8% to 12% by weight. The resulting product shows a surface resistivity not greater than 1 x 109 ohms, and preferably less or a volume resistivity not greater than 1 x 109 ohms-centimeters, and preferably less. It should be understood that the higher weight percentages of conductive material decrease the resistivities in both surface and volume, and vice versa. However, the mixtures having the above conductive material, the established weight percentages and the resistivities are significantly below those established and do not appear to confer any apparent benefit in terms of operation. In Figure 3, a first alternative mode of vehicle platform 50 is illustrated. The overall structure of the vehicle platform 50 is the same as that of the platform 10 of the preferred embodiment and includes the outer and inner side walls 12 and 14, the front wall 24 and the lower panel 26. The first alternative embodiment of the vehicle platform 50, however, comprises a composite or interposer having a first lower layer 52 of conventional HDPE or a similar thermoplastic material engineered, and a second layer or upper layer 54 of HDPE or another material similar to the first layer 52, except that an additive has been added with dispersed conductive particles 56 such as carbon black to weight percent and the electrical resistivity discussed directly above. In the first alternative vehicle platform 50, it is preferably co-extruded from a suitable extrusion machine (not shown) and then shaped as necessary on the platform 10 of the vehicle, illustrated in Figure 1. It will be appreciated that the first embodiment alternative of the truck platform 50 shows substantially the same electrical load dissipation characteristics as the truck platform 10 of the preferred embodiment. However, because they are constituted by an interposition of materials to which only conductive particles 56 are added to the upper layer or second layer 54, it uses a smaller amount of conductive material per vehicle platform 50. Additionally, since the first layer 52 contains no additives, its strength can be optimized. Although the electrical and load dissipation activity of the truck platforms 10 and 50, according to the present invention is not fully understood, it is considered that the conductive particles 44 of carbon black or other material form a conductive matrix of conductive paths continuous through vehicle platforms 10 and 50 and thus disperse what would otherwise be isolated areas of electric charge on a platform or the lining of a platform. By such dispersion, the electrical charges are dissipated in the atmosphere in its entirety or a significant portion of the surface area of the platforms 10 and 50, and are therefore cleaned or safely grounded. Although carbon black conductive particles 44 have been found to be the most suitable additive or additive agent from the standpoint of weight, color and cost, other materials such as carbon fibers or conductive metals such as aluminum, powder copper or flake, as indicated above, or other conductive particulate materials produce this same function and purpose. Therefore, these materials as well as other conductive materials operating analogously and metals are considered to be within the scope of this invention.

Referring now to Figures 4 and 5, a second alternative embodiment of the invention is illustrated. The present invention can also be used in a platform coating. A conventional cargo truck 60 includes a cab 62 and front tire and wheel assemblies 64. The illustrated conventional cargo truck 60 includes a conventional metal box or platform 66 having formed sidewalls 68 of steel. The side walls 68 are joined with the transversely extending front wall 74 and both the side walls 68 and the front walls 74 are joined to the lower panel 76 which defines the area for receiving the load of the loading truck 60. Typically, lower panel 76 includes longitudinal corrugations 78. The connecting portions of the inner side walls 72 with the lower panel 76 are a pair of holes of the symmetrical wheels 82 which receive the rear tire and wheel assemblies 84. A rear door 86 is pivotally and transversely positioned in the rear opening of the box or platform 66 and rear light and tail assembly 88 are also mounted on the side walls 68 of the platform 66. Positioned in the interior of the platform 66 and with a length, width and height complementary to the corresponding interior dimensions of the platform 66 is the second alternative embodiment of the invention, a lining 90 of a truck platform. The truck bed liner 90 includes side walls 92 positioned generally vertical and a front wall 94. The truck bed liner 90 includes a rail 96 which rests on top of the side walls 68 of the platform 66. The side walls 92 of the liner and the forward wall 94 join with the bottom panel 98. The side walls 92, the forward wall 94 and the lower panel 98 are preferably formed as a unitary coating from a single sheet of extruded HDPE or other thermoplastic material engineered. The hollows of the wheels 100 complementary to the hollows of the wheels 82 of the truck platform 66 are defined by the platform liner 90. Preferably, the lower panel 98 of the sheath 90 includes a plurality of longitudinally oriented corrugations 102 which correspond to the corrugations 78 in the lower panel 76 of the box or platform 66. Referring now to Figure 5, it will be appreciated that the extruded material , formed and corrugated of the platform liner 90 includes particles 106 of conductive material such as carbon black or other conductive material uniformly dispersed therethrough. As indicated above, with respect to the preferred embodiment 10, the carbon black conductive particles 106 constitute approximately 18% to 22% by weight of the thermoplastic material of the platform coating 90. Also as indicated above, carbon black, carbon fibers or other conductive particulate material may be used in a weight percent range from about 5% to 25%. Regardless of the materials chosen, as indicated above, it is desirable to obtain a surface resistivity of not more than 1 x 109 ohms and preferably less, or a resistivity in volume not greater than 1 x 109 ohms-centimeters, and preferably lower. Therefore, it will be appreciated that except for the physical configuration of the second alternative embodiment of the truck bed liner 90, its purpose and benefit as well as the constituent materials may be the same. Referring now to Figures 4 and 6, a third alternative embodiment 110 of the invention is illustrated which is similar to the first alternative embodiment of the vehicle platform 50. However, it is a platform liner instead of a truck platform. As such, it includes the side walls 92, the front wall 94 and the bottom panel 98. It may include the rail 96. The platform liner 110 of the third alternative embodiment is a composite material or interposition construction having a first lower layer 112 of HDPE or a similar thermoplastic material subjected to engineering and a second layer or upper layers 114 of HDPE or other material similar to the first layer 112, except that it includes or is added with dispersed conductive particles 116 such as carbon black or other material described above to the percentages by weight and resistivities described above. The third alternative embodiment of composite material of the deck 110 is preferably coextruded from a suitable extrusion machine (not shown) and then formed as needed to conform to the loading truck platform., such as a metal box or a platform 66, illustrated in Figure 4. It will be appreciated that with the upper conductive layer 114 of the third alternative embodiment of the truck bed liner 110 substantially the same electrical load dissipation characteristics are shown as in the other modalities discussed above, especially in the first alternative mode of the vehicle platform 50. However, because it is constituted by an interposition of materials to which the conductive particles 116 such as carbon black are added only to the upper layer or second layer 114, both layers 112 and 114 can be optimized for operation . That is, the necessary electrical conductivity is obtained by the upper layer 114 while the lower layer 112 provides the optimum resistance.

Referring now to FIGS. 7 and 8, a fourth alternative embodiment of the platform or platform liner according to the present invention is illustrated and designated with the reference number 120. The platform 120 of the fourth alternative embodiment may be a platform 10 such as that illustrated in Figure 1, or a platform liner 90 such as that illustrated in Figure 4. As such, the platform or the platform liner 120 of the fourth alternative embodiment includes side walls and a front wall and includes a lower panel 122 having corrugations 124 which improve rigidity and strength of the lower panel 122 and which also correspond to and conform to the corrugations 78 in a lower panel of a truck platform , as illustrated in Figure 5. The platform or platform liner 120 of the fourth alternative embodiment is preferably made of high density polyethylene or other thermoplastic material subject to engineering as described above. On the surface of the lower panel 122, and preferably autogenously bonded thereto is a mesh fabric 126 which defines interstices 128 with a generally rectangular or diamond shape. The mesh fabric 126 preferably has a similar composition of polyethylene, polyolefin elastomer or other thermoplastic material engineered to those described above with respect to the other embodiments, or polypropylene.

The material of the mesh fabric 126 has as additives or is mixed with between 5% or 25% by weight of a conductive material 130 such as carbon black or carbon fibers or other materials described above. The conductive material 130 which is in the range of 18% to 22% has been found to be preferable. It will be appreciated that the mesh fabric 126 that includes the conductive material 130 in this manner also provides a conductive means through which electrical charges can develop on the platform or platform liner 120 and which dissipate into the atmosphere. The mesh fabric 126 has been found to be particularly efficient in this respect due to the large surface area versus the volume ratio of the mesh fabric 126 and hence the large proportion of surface area versus conductive material 130. The manufacture of the platform or platform liner 120 of the fourth alternative embodiment and particularly the attachment of the mesh fabric 126 to the lower panel 122 is preferably obtained after a flat panel is extruded from an extrusion machine (not shown), but before it gets cold. At this time, the mesh 126 containing the conductive material 130 is placed on the surface of the extruded panel after it has been treated to the flame but before it is formed under vacuum in the platform or platform liner 120. Through the vacuum forming operation, the filaments of the mesh fabric 126 will be pressed or pushed into the upper surface of the lower panel 122 of the platform or platform covering 120 so that they are intimately bonded and restrained mechanically in it. Electrostatic charge dissipation tests have been carried out on various samples of thermoplastic material platform and platform coatings containing conductive material, according to MIL Spec. MIL-B81705-B. The conductive material present in all samples is carbon black XC-72 from Cabot Corporation. Samples A and B are corrugated HDPE, according to the preferred embodiment and the first, second or third alternative embodiments. Sample C is a recorded platform or a platform liner, and Sample D is a platform or platform liner, according to the fourth alternative embodiment. The surface resistivities obtained are the result of many variables, the most significant of which, from the point of view of the conductive material, is its particle size. Therefore, a carbon black finer than Cabot's XC-72 carbon black such as Ketjenblack EC-300 J from Akzo Nobel can be used in small quantities of up to 50% and perhaps larger and still obtain good results with as little as approximately 10% carbon black. Such finer carbon black and other conductive materials, however, are typically more expensive and therefore simply represent an alternative instead of a targeted choice. The surface resistivities shown below in Table I are the average values of three separate measurements made on each sample.

It will be appreciated that while the invention has been described as a box or platform liner for a cargo truck in the various embodiments, the invention is equally suitable and is designed for use in other transportation and coating applications such as minivans, sport utility vehicles and cargo vans. These various applications are consistent and encompassed by the inventor insofar as the main purpose and object of the invention of a platform or a coating having characteristics of electric charge dissipation is provided. The foregoing description is the best mode designed by the inventor to carry out this invention. However, it is evident that an apparatus incorporating modifications and variations will be obvious to those familiar with the technique of loading platforms and platform coatings. To the extent that the foregoing description represents the best mode contemplated by the inventor for carrying out the invention and as it is designed to allow any person familiar with the relevant art to practice this invention, it should not be considered to be limited. by the same but that should be considered to include such obvious variations mentioned above and that is limited only by the spirit and scope of the following claims. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects or products to which it refers.

Claims (31)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. A receptacle for a cargo vehicle, characterized in that it comprises, in combination a pair of side walls, a front wall, a bottom panel that joins the side walls and the front wall, and the receptacle is made of a thermoplastic material, at least a portion of the thermoplastic material includes dispersed electrically conductive material.
2. 2. The receptacle for a cargo vehicle, according to claim 1, characterized in that the receptacle is a vehicle platform.
3. 3. The receptacle for a cargo vehicle, according to claim 1, characterized in that the receptacle is a platform covering.
4. 4. The receptacle for a cargo vehicle, according to claim 1, characterized in that the receptacle is made of high density polyethylene.
5. 5. The receptacle for a cargo vehicle, according to claim 1, characterized in that the conductive material is carbon black.
6. 6. The container for a cargo vehicle, according to claim 1, characterized in that the thermoplastic material is a composite material having a lower layer of thermoplastic material and an upper layer of thermoplastic material containing the dispersed electrically conductive material.
7. The receptacle for a cargo vehicle, according to claim 1, characterized in that it further includes a mesh secured to the lower panel and wherein the electrically conductive material is dispersed in the mesh.
8. The receptacle for a cargo vehicle, according to claim 1, characterized in that the thermoplastic material includes dispersed electrically conductive material, which shows a surface resistivity of 1 x 109 ohms or less.
9. The receptacle for a cargo vehicle, according to claim 1, characterized in that the thermoplastic material includes dispersed electrically conductive material that exhibits a resistivity in volume of 1 x 109 ohms-centimeters, or less.
10. 10. A loading platform for a cargo van and the like, characterized in that it comprises, in combination a pair of opposite side walls, a front wall having ends that are joined to the side walls, and a bottom panel that is joined to the front wall and the pair of side walls, the platform is made of a thermoplastic material containing dispersed electrically conductive material.
11. 11. The loading platform for a cargo van and the like, according to claim 10, characterized in that the receptacle is made of a high density polyethylene.
12. 12. The loading platform for a cargo truck and the like, according to claim 10, characterized in that the electrically conductive material is carbon black.
13. 13. The loading platform for a cargo van and the like, according to claim 10, characterized in that the thermoplastic material is a composite material having a lower layer of thermoplastic material and an upper layer of thermoplastic material, and a material electrically driver.
14. 14. The loading platform for a cargo truck and the like, according to claim 10, characterized in that the conductive particles form a conductive matrix in the thermoplastic material.
15. 15. The loading platform for a cargo van and the like, according to claim 10, characterized in that the thermoplastic material containing the electrically conductive material shows a surface resistivity of 1 x 109 ohms or less.
16. 16. The loading platform for a cargo van and the like, according to claim 10, characterized in that the thermoplastic material containing the electrically conductive material shows a volume resistivity of 1 x 109 ohms-centimeters or less.
17. 17. A liner for a cargo vehicle, characterized in that it comprises, in combination a pair of separate side walls, a bottom panel joining the side walls, and side walls and the bottom panel made of thermoplastic material and having at least a portion of the thermoplastic material including dispersed conductive particles .
18. 18. The lining for a cargo vehicle, according to claim 17, characterized in that the thermoplastic material is high density polyethylene.
19. 19. The coating for a cargo vehicle, according to claim 17, characterized in that the conductive particles are carbon black.
20. 20. The lining for a cargo vehicle, according to claim 17, characterized in that it includes a front wall that joins the side walls and the bottom panel.
21. 21. The liner for a cargo vehicle, according to claim 17, characterized in that the thermoplastic material includes supplied conductive particles which exhibit a surface resistivity of 1 x 109 ohms or less.
22. 22. The liner for a cargo vehicle, according to claim 17, characterized in that the thermoplastic material includes supplied conductive particles that show a volume resistivity of 1 x 109 ohms-centimeters or less.
23. 23. The lining for a cargo vehicle, according to claim 17, characterized in that it also includes a mesh fabric placed on the bottom panel, the mesh fabric includes conductive particles.
24. 24. A device for receiving cargo for a vehicle, characterized in that it comprises, in combination a panel adapted for horizontal positioning and to receive cargo, at least two side walls extend from the panel, the panel is made of a thermoplastic material to which An additive has been added and it has a surface resistivity of less than 1 x 109 ohms.
25. 25. The device for receiving cargo, according to claim 24, characterized in that the thermoplastic material to which an additive has been added includes conductive particles.
26. 26. The device for receiving charge, according to claim 25, characterized in that the conductive particles are carbon black.
27. 27. The device for receiving cargo, according to claim 24, characterized in that it also includes a front wall that joins the two side walls.
28. 28. The device for receiving cargo, according to claim 24, characterized in that the thermoplastic to which an additive is added is HDPE and includes carbon black in the range of 5 to 25% by weight.
29. 29. The device for receiving cargo, according to claim 24, characterized in that it also includes a front wall that joins the side walls and the panel, the side walls and the front wall define a loading truck platform.
30. 30. The device for receiving cargo, according to claim 24, characterized in that it also includes a front wall that joins the side walls and the panel, the side walls and the front wall define a loading truck bed liner.
31. 31. The device for receiving charge, according to claim 24, characterized in that the panel shows resistivity in volume of less than 1 x 109 ohms-centimeters.