Industrial mats having cost effective core structures

Abstract

A mat that includes first and second side beams, a core structure located between and connected to the side beams, with the support structure including longitudinal members and having a height that is less than that of the side beams, a plurality of joining rods that attach the side beams to the support structure, with the joining rods passing through the sides of the side beams and the sides of the longitudinal members of the support structure; one or more elongated members attached to the upper portion of the support structure to form with the beams the top surface of the mat, and one or more elongated members attached to the lower portion of the support structure to form with the beams the bottom surface of the mat. If desired, steel plates can be provided between the beams and longitudinal members to increase the strength and ruggedness of the mat.

What is claimed is: 
     
         1 . A mat having substantially flat top and bottom surfaces and comprising:
 first and second side beams having a height, width and length with a top surface, sides, and a bottom surface;   a core structure located between and connected to a side of first and second side beams, with the support structure having a height that is less than that of the side beams, a width and a length, with the support structure comprising first and second longitudinal members;   a plurality of joining rods that attach the side beams to the support structure, with the joining rods passing through the sides of the side beams and the sides of the longitudinal members of the support structure;   one or more first elongated members attached to the upper portion of the support structure, wherein the top surface of the mat is formed by the top surfaces of the beams and the first elongated member(s); and   one or more second elongated members attached to the lower portion of the support structure, wherein the bottom surface of the mat is formed by the bottom surfaces of the beams and the second elongated member(s).   
     
     
         2 . The mat of  claim 1  wherein the first and second longitudinal members are rectangular beams or members that provide flat side faces for contact with the side beams; the side beams are made of solid cut wood or engineered lumber; the first and second elongated members have the same thickness and are boards or sheets made of solid cut wood, engineered lumber, plastic or recycled materials; and the elongated members are bolted to the support structure. 
     
     
         3 . The mat of  claim 2  wherein the side beams are timbers of engineered lumber or oak or other hardwoods, or are solid or filled or unfilled hollow rectangular plastic members that optionally may be reinforced, the longitudinal members are timbers of pine or other softwoods, and the first and second elongated members are boards of uniform width which are spaced to provide water drainage between adjacent boards. 
     
     
         4 . The mat of  claim 1  wherein the side beams have width and height dimensions of between about 1×6 inches and about 24×24 inches and a length of between about 4 and 60 feet; the longitudinal members have width and height dimensions of between about 1×5 inches and about 24×22 inches, wherein the height and length of the longitudinal members is 0.5 to 2 inches less than that of the side beams on each peripheral side of the longitudinal members. 
     
     
         5 . The mat of  claim 4  wherein the beams have width and height dimensions of between about 8×8 inches and about 16×16 inches and lengths of between about 6 and 30 feet; and the longitudinal members have width and height dimensions of between about 8×6 inches and about 16×14 inches, wherein the height and length of the longitudinal members is about 1 to 2 inches less than that of the side beams on each peripheral side of the longitudinal members. 
     
     
         6 . The mat of  claim 3  wherein between 2 and 4 longitudinal members of pine or softwood timbers are present and the mat further comprises a metal plate located between each pair of adjacent beams or longitudinal members, wherein each metal plate has a thickness of between about ⅛ inch and about 1 inch, wherein the height and length of the plates are essentially the same as to 2 inches less than that of the longitudinal members on each peripheral side of the steel plates. 
     
     
         7 . The mat of  claim 6  wherein the plates are steel plates having a height and length of about ½ inch to 2 inches less than the height and length of the longitudinal members on each peripheral side of the plates. 
     
     
         8 . The mat of  claim 1  wherein the side beams have the same dimensions and are attached to the longitudinal members to locate their upper surfaces about 1 to about 3 inches above the longitudinal members and to locate their lower surfaces about 1 to about 3 inches below the longitudinal members, wherein the first and second plurality of elongated members each have a thickness of about 1 to about 3 inches to provide the substantially flat upper and lower surfaces of the mat. 
     
     
         9 . The mat of  claim 1  wherein some of the first and second plurality of elongated members and adjacent longitudinal members have one or more openings to provide access to one or more of the joining rods to facilitate lifting or manipulation of the mat. 
     
     
         10 . The mat of  claim 1  wherein the first side beam is sized to provide about one half the height of the mat, with the first side beam attached to an upper portion of the support structure such that the upper surface of the first side beam extends above the support structure by about 1 to about 3 inches; and wherein the elongated member or members adjacent the first side beam have a thickness of about 1 to about 3 inches. 
     
     
         11 . The mat of  claim 10  wherein the second side beam is sized to provide one half the height of the mat and is attached to the second side of the support structure in a lower position such that the lower surface of the second side beam extends below the support structure by about 1 to about 3 inches; wherein the first side beam of one mat sits upon the second side beam of an adjacent mat to form an interlocked structure of conjoined mats; and wherein the second plurality of elongated members adjacent the second side beam have a thickness of about 1 to about 3 inches. 
     
     
         12 . The mat of  claim 1 , wherein the first side beam is sized to provide about one half the height of the mat, with the first side beam attached to an upper portion of the support structure, or the second side beam is sized to provide one half the height of the mat and is attached to the second side of the support structure in a lower position, or both the first and second beams are sized as recited in this claim in order to facilitate and form an interlocked structure of conjoined adjacent mats. 
     
     
         13 . The mat of  claim 1  which includes lighting elements embedded in the elongated members to provide light to assist in the use of the mat during the night or on days that are dark due to poor weather conditions. 
     
     
         14 . An inventory of industrial mats having different core or internal constructions of wood, engineered wood, thermoplastics, elastomers, thermosetting plastics, metal, or of coated or encapsulated components, wherein each mat having a different core or internal construction includes identification means that indicates the core or internal construction of the mat. 
     
     
         15 . The industrial mats of  claim 14 , wherein the identification means comprises an external color code, a radio frequency identification (RFID) tag, or an alphanumeric indicator applied to an outer surface of the mat or that is provided upon a plate that is applied to an outer surface of the mat. 
     
     
         16 . The industrial mats of  claim 14 , wherein the identification means comprises an external color code that is placed in the same position on each mat for easy identification. 
     
     
         17 . The industrial mats of  claim 16 , wherein the external color code is placed along a longitudinal side of each mat so that the color coding is visible when the mats are stacked upon each other. 
     
     
         18 . The industrial mats of  claim 14 , wherein the identification means comprises a RFID tag that is attached to the mat and that can be scanned to identify the core or internal construction of the mat. 
     
     
         19 . The industrial mats of  claim 14 , wherein the identification means comprises an external alphanumeric indicator that is applied to an outer surface of the mat or that is provided upon a plate that is applied to an outer surface of the mat. 
     
     
         20 . The industrial mats of  claim 14 , wherein each mat has a color that indicates a potential use or non-use of the mat or that identifies a particular customer or used of the mat.