STRENGTHENED RIG MAT SYSTEMS FOR SUPPORTING HEAVY LOADS

Abstract

A rig mat system includes a plurality of rig mats each comprising a rectangular frame and one or more billets supported by the rectangular frame, a link configured to releasably couple the plurality of rig mats together, the link including a link frame comprising a base plate having a plurality of laterally extending arms, and a plurality of connector assemblies releasably connectable to the plurality of arms of the link frame, wherein each connector assembly comprises an externally threaded fastener, an internally threaded nut configured to threadably connect to the externally threaded fastener, and a washer positionable about the fastener and having an elongate central aperture.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. provisional patent application Ser. No. 63/539,043 filed Sep. 18, 2023, and entitled “Strengthened Rig Mat Systems for Supporting Heavy Loads,” which is hereby incorporated herein by reference in its entirety for all purposes.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

BACKGROUND

Rig mats are utilized in many industrial operations (e.g., drilling rigs, construction sites, etc.) and are often configured to support and distribute loads provided by the weight of equipment, machinery, vehicles, and/or personnel of the operation. Rig mat designs encompass many different styles and configurations. For instance, rig mats include plastic mats, hollow rig-matting systems, access mats, rubber mats and steel frame mats. In some applications, steel frame mats may include a plurality of wooden beams supported by a surrounding steel frame. In this arrangement, the bridge load (e.g., weight of industrial equipment positioned on the mat) acts on the wooden beams, which are configured to transfer the bridge load with the steel frame.

BRIEF SUMMARY OF THE DISCLOSURE

An embodiment of a rig mat system comprises a plurality of rig mats each comprising a rectangular frame and one or more billets supported by the rectangular frame; a link configured to releasably couple the plurality of rig mats together, the link comprising a link frame comprising a base plate having a plurality of laterally extending arms, and a plurality of connector assemblies releasably connectable to the plurality of arms of the link frame, wherein each connector assembly comprises an externally threaded fastener, an internally threaded nut configured to threadably connect to the externally threaded fastener, and a washer positionable about the fastener and having an elongate central aperture. In some embodiments, the central aperture of the washer has a central axis which extends orthogonally to a central axis of the fastener. In some embodiments, the washer of each of the plurality of connector assemblies comprises a radially inner washer; and each connector assembly comprises an outer washer having a central aperture in which the inner washer is at least partially receivable. In some embodiments, the central aperture of the outer washer is at least partially defined by a frustoconical inner surface of the outer washer. In some embodiments, the washer of each of the plurality of connector assemblies comprises a first washer; and each connector assembly comprises a second washer having a central aperture defined at least partially by an frustoconical inner surface. In some embodiments, the washer of each of the plurality of connector assemblies comprises a first washer; and each connector assembly comprises a second washer comprising a split-ring formed from a pair of half-rings. In some embodiments, each connector assembly comprises an elastomeric plug configured to couple to a terminal end of the fastener.

An embodiment of a rig mat comprises a support frame comprising a rectangular outer frame formed from a plurality of channels, and a plurality of rails extending through an interior of the outer frame, wherein an exterior surface of the outer frame is defined by a vertical surface and a pair of inclined surfaces extending from the vertical surface at non-zero angles from the vertical surface; and a plurality of elongate billets coupled together and supported within the interior of the outer frame whereby loads applied to the plurality of billets are transferable from the plurality of billets to the support frame. In some embodiments, the pair of inclined surfaces of the outer frame extend at acute angles from the vertical surface of the outer frame. In some embodiments, each of the channels of the outer frame have a pair of lateral ends and an interior passage extending between the lateral ends of the channel. In some embodiments, the plurality of rails of the support frame comprise one or more longitudinal rails extending parallel a central axis of the rig mat and one or more lateral rails extending orthogonal to the central axis of the rig mat. In some embodiments, at least one of the rails has an I-shaped cross-section and includes a central web and a pair of flanges extending, in cross-section, orthogonal to the web. In some embodiments, at least one of a pair of terminal ends of the web of the rail projects longitudinally from the flanges of the rail. In some embodiments, the longitudinal length of the web of at least one of the rails is greater than the longitudinal lengths of the flanges of the rail.

An embodiment of a rig mat system comprises a plurality of rig mats; and a link configured to releasably couple the plurality of rig mats together, the link comprising a link frame comprising a base plate having a plurality of laterally extending arms; and a plurality of connector assemblies releasably connectable to the plurality of arms of the link frame and to the plurality of the rig mats. In some embodiments, the plurality of arms of the link underly the plurality of the rig mats when the plurality of the rig mats are coupled to the link.

An embodiment of a rig mat comprises a support frame comprising a rectangular outer frame formed from a plurality of channels, and a plurality of rails extending through an interior of the outer frame, wherein at least one of the rails has an I-shaped cross-section and includes a central web and a pair of flanges extending, in cross-section, orthogonal to the web and wherein the longitudinal length of the web of at least one of the rails is greater than the longitudinal lengths of the flanges of the rail; and a plurality of elongate billets coupled together and supported within the interior of the outer frame whereby loads applied to the plurality of billets are transferable from the plurality of billets to the support frame. In some embodiments, at least one of a pair of terminal ends of the web of the rail projects longitudinally from the flanges of the rail. In some embodiments, both of the pair of terminal ends of the web of the rail projects longitudinally from the flanges of the rail.

An embodiment of a rig mat system comprises a plurality of rig mats; and a link configured to releasably couple the plurality of the rig mats together, the link comprising a link frame comprising a base plate having a plurality of laterally extending arms; and a plurality of connector assemblies releasably connectable to the plurality of arms of the link frame and to the plurality of the rig mats. In some embodiments, the plurality of arms of the link underly the plurality of the rig mats when the plurality of the rig mats are coupled to the link.

Embodiments described herein comprise a combination of features and characteristics intended to address various shortcomings associated with certain prior devices, systems, and methods. The foregoing has outlined rather broadly the features and technical characteristics of the disclosed embodiments in order that the detailed description that follows may be better understood. The various characteristics and features described above, as well as others, will be readily apparent to those skilled in the art upon reading the following detailed description, and by referring to the accompanying drawings. It should be appreciated that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes as the disclosed embodiments. It should also be realized that such equivalent constructions do not depart from the spirit and scope of the principles disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

For a detailed description of exemplary embodiments of the disclosure, reference will now be made to the accompanying drawings in which:

FIG. 1 is a schematic view of an embodiment of a rig mat system in a first configuration in accordance with principles disclosed herein;

FIG. 2 is a perspective view of the rig mat system of FIG. 1 in a second configuration in accordance with principles disclosed herein;

FIG. 3 is a top view of an embodiment of a rig mat of the rig mat system of FIGS. 1 and 2 in accordance with principles disclosed herein;

FIG. 4 is a zoomed-in top view of the rig mat of FIG. 3;

FIG. 5 is a cross-sectional view along line 5-5 in FIG. 3;

FIG. 6 is a zoomed-in view of the cross-sectional view of FIG. 5;

FIG. 7 is a side view of an embodiment of a billet section of the rig mat of FIG. 3 in accordance with principles disclosed herein;

FIG. 8 is a top view of the billet section of FIG. 7;

FIG. 9 is a side view of an embodiment of a lateral rail of the rig mat of FIG. 3 in accordance with principles disclosed herein;

FIG. 10 is an end view of the lateral rail of FIG. 9;

FIG. 11 is a perspective view of an embodiment of a quad-link of the rig mat system of FIGS. 1 and 2 in accordance with principles disclosed herein;

FIG. 12 is a side view of the connector assembly of FIG. 11;

FIG. 13 is a cross-sectional view along line 13-13 in FIG. 12; and

FIG. 14 is a perspective view of an embodiment of a bi-link of the rig mat system of FIGS. 1 and 2 in accordance with principles disclosed herein.

DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENTS

The following discussion is directed to various exemplary embodiments. However, one skilled in the art will understand that the examples disclosed herein have broad application, and that the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to suggest that the scope of the disclosure, including the claims, is limited to that embodiment.

Certain terms are used throughout the following description and claims to refer to particular features or components. As one skilled in the art will appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name but not function. The drawing figures are not necessarily to scale. Certain features and components herein may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in interest of clarity and conciseness.

In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . ” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices, components, and connections. In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a central axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the central axis. For instance, an axial distance refers to a distance measured along or parallel to the central axis, and a radial distance means a distance measured perpendicular to the central axis.

Referring initially to FIGS. 1 and 2, an exemplary rig mat system 10 is shown in both a first configuration (shown in FIG. 1) and a second configuration (shown in FIG. 2) according to an embodiment. Rig mat system 10 may be formed into a variety of different configurations with the first and second configurations shown in FIGS. 1 and 2 only serving as a couple of brief examples. Rig mat system 10 is generally configured to be assembled in the field at the location of the industrial operation in which rig mat system 10 is to be utilized. Once assembled, rig mat system 10 is configured to physically support various different equipment and personnel of the industrial operation. As will be discussed further herein, rig mat system 10 possess relatively greater strength and durability than conventional rig mat systems, permitting it to support relatively greater or heavier loads than at least some conventional rig mat systems.

Rig mat system 10 includes a plurality of separate and distinct rig mats 10, where the number of rig mats 20 varies (as well as the geometric configuration of the given number of rig mats 20) depending on the given configuration of rig mat system 10. For instance, the number of rig mats 20 and their geometric configuration may be selected based on a desired footprint for the rig mat system 10 in a given industrial application.

The individual rig mats 20 of rig mat system 10 are coupled or linked together via a plurality of links coupled between the plurality of rig mats 20. In this manner, bridge loads applied to one or more individual rig mats 20 of rig mat system 10 may be transferred or shared with other rig mats 20 to help strengthen the rig mat system 10 and maximize the magnitude of the bridge loads which rig mat system 10 is capable of physically supporting. Particularly, in this exemplary embodiment, the rig mats 20 of rig mat system 10 are coupled together via one or more quad-links 100, one or more tri-links or “T-links” 160, and/or one or more peripheral or bi-links 180.

The quad-links 100 of rig mat system 10 are configured to link or couple together up to four separate rig mats 20 such as in a quad or 2×2 configuration. The tri-links 160 of rig mat system 10 are configured to link or couple together up to three separate rig mats 20 such as in a T-shaped configuration. Further, the bi-links 180 of rig mat system 10 are configured to link or couple together a pair of separate rig mats 20 such as in an L-shaped configuration. It may be understood that in some configurations, rig mat system 10 may include one or more of each of links 100, 160, and 180 while in other configurations rig mat system 10 may include fewer than each of the links 100, 160, and 180 (e.g., system 10 may include only quad-links 100 and bi-links 180 but not any tri-links 160). The number of links 100, 160, and/or 180 may be dictated by the desired footprint of the rig mat system 10 for the given industrial operation. Indeed, links 100, 160, and 180, by permitting the coupling of different numbers of rig mats 20, facilitates the formation of a variety of different and unique footprints for the rig mat system 10.

Referring now to FIG. 3, an embodiment of the rig mat 20 of rig mat system 10 is shown. Rig mat 20 has an upper side shown in FIG. 3 upon which machinery, vehicles, and personnel may be supported, and a lower side hidden in FIG. 3 opposite the upper side. Although only the upper side of rig mat 20 is shown in FIG. 3, it may be understood that in this exemplary embodiment the upper and lower sides of rig mat 20 are identical and thus features of the upper side of rig mat 20 described herein apply (in this exemplary embodiment) mutatis mutandis to the lower side of rig mat 20. The lower side of rig mat 20 may be positioned on the ground whereby bridge loads applied to the rig mat 20 may be transferred from the upper side to the lower side thereof, and from the lower side of rig mat 20 to the ground upon which the rig mat 20 is positioned. In addition, rig mat 20 includes four lateral sides defining an outer perimeter of the rig mat 20.

In this exemplary embodiment, rig mat 20 has a central or longitudinal axis 25 and generally includes a plurality of elongate billets 22 (e.g., only some of which are labeled in FIG. 3) and a support frame 30 (e.g., a steel support frame) which provides structural support to the plurality of billets 22. Particularly, loads applied to the billets 22 (e.g., the billets 22 positioned along the upper side of rig mat 20) are transferrable to the support frame 30. In some embodiments, billets 22 each comprise a wooden material such as Douglas fir and other softwoods and/or hardwoods. Billets 22 may thus comprise lumber billets 22 in at least some embodiments. However, in other embodiments, billets 22 may be formed from materials other than wood.

Referring now to FIGS. 3 and 5-8, the plurality of billets 22 in this exemplary embodiment are divided between a plurality of billet sections 21, each billet section 21 comprising a plurality of billets 22 extending longitudinally (e.g., parallel central axis 25 of rig mat 20) and which have been coupled together. In this exemplary embodiment, the billets 22 of each billet section 21 are organized in a single layer (shown particularly in FIG. 5) such that the upper surfaces of each billet 22 defines the upper side of rig mat 20 while the lower surfaces of each billet 22 define the lower side of rig mat 20.

In this exemplary embodiment, each billet section 21 is coupled together by one or more fasteners 24 (e.g., metallic or steel fasteners) shown particularly in FIG. 7 and which extend laterally (e.g., in a direction orthogonal to central axis 25) through the plurality of longitudinally extending billets 22 of the billet section 21. The billets 22 of each billet section 21 are thus mechanically coupled or secured together via the fasteners 24. In other embodiments, the billets 22 of each billet section 21 may not be coupled together via fasteners (e.g., fasteners 24) and instead, for example, may be coupled together via connectors defined by the billets 22 (e.g., tongue-and-groove or dovetail style connectors) and/or adhesives applied to the billets 22.

As shown particularly in FIG. 6, a pair of elongate perimeter recesses 23 are formed along the periphery or perimeter of each billet section 21 along both the upper end and the lower end of the respective billet section 21 in this exemplary embodiment. As will be discussed further herein, perimeter recesses 23 facilitate the coupling of each billet section 21 with the support frame 30. In this exemplary embodiment, perimeter recesses 23 are defined by corresponding L-shaped shoulders formed along the billet section 21 using, e.g., a profile knife. In other embodiments, the shoulders defining perimeter recesses 23 may be inclined for a snugger fit. In addition, in this exemplary embodiment, an outermost billet 22 of each billet section 21 includes an angled relief 26 (shown in FIG. 8) also to facilitate coupling of the respective billet section 21 with the support frame 30.

Referring to FIGS. 3 and 4, as described above, support frame 30 couples with and is secured to each of the billet sections 21 whereby loads applied to the upper side of each billet section 21 is transferred to the support frame 30. In this exemplary embodiment, support frame 30 generally includes a pair of longitudinal channels 32, a pair of lateral channels 40, a plurality of longitudinal rails 50, and a plurality of lateral rails 60. The channels 32 and 40 collectively define a rectangular outer frame of the rig mat 20 extending along the perimeter or periphery thereof where longitudinal channels 32 extend parallel with central axis 25 while lateral channels 40 extend orthogonal to the central axis 25. In this configuration, channels 32 and 40 are coupled together end-to-end (e.g., via welding, one or more fasteners). In some embodiments, channels 32 and 40 each have a cross-sectional height of 6″ (6″ extending between the upper end and the lower end of the rig mat 20); however, the height of channels 32 and 40 may vary in other embodiments.

Referring to FIG. 6, each longitudinal channel 32 includes both an exterior surface and an interior surface extending between a pair of lateral ends 33 of the longitudinal channel 32. Particularly, in this exemplary embodiment, each longitudinal channel 32 has a flared cross-sectional shape in which the exterior surface thereof comprises a vertical surface 34 and a pair of angled or inclined surfaces 35. While in this exemplary embodiment each longitudinal channel 32 is flared, it may be understood that in other embodiments may not be flared and thus may not include inclined surfaces 35.

In this exemplary embodiment, the inclined surfaces 35 of each longitudinal channel 32 extend at a non-zero angle to the vertical surface 34 whereby an acute angle is formed between each inclined surface 35 and the horizontal when rig mat 20 is positioned on the ground. The non-zero angle formed between inclined surfaces 35 and the horizontal assist in handling the rig mat 20. Particularly, inclined surfaces 35 permit the forks of a forklift or similar vehicle to easily slide underneath (e.g., via sliding contact between the forks and inclined surface 35) the inclined surface 35, permitting the rig mat 20 to be picked up by the forklift.

FIG. 6 also illustrates the interface formed between the outermost billet 22 of a given billet section 21 and the longitudinal channel 32. Particularly, in this exemplary embodiment, the lateral ends 33 of longitudinal channel 32 are received snugly within the perimeter recesses 23 formed in the billet 22. The interior surface of longitudinal channel 32 defines an interior passage 36 extending longitudinally along the longitudinal channel 32. As shown in FIG. 6, at least a portion of the billet 22 (e.g., the portion of billet 22 extending directly between perimeter recesses 23) is received within the interior passage 36 of longitudinal channel 32. In addition, while not shown specifically in FIG. 6, it may be understood that the lateral channels 40 of support frame 30 are configured similarly as longitudinal channels 32. Thus, lateral channels 40 include an exterior surface defined by vertical surface 34 and inclined surfaces 35, and an interior surface which defines interior passage 36 and in which a portion of one or more billets 22 is received.

Referring again to FIG. 3, longitudinal rails 50 and lateral rails 60 of support frame 30 are each positioned within the rectangular outer perimeter defined by channels 32 and 40. The ends of longitudinal rails 50 and 60 are coupled to the channels 32 and 40 of support frame 30. Longitudinal rails 50 each extend parallel with central axis 25 while each lateral rail 60 extends orthogonal to central axis 25. Particularly, in this exemplary embodiment, each longitudinal rail 50 extends centrally along central axis 25 while the lateral rails 60 are spaced along the central axis 25. Additionally, in this exemplary embodiment, support frame 30 includes three longitudinal rails 50 extending end-to-end and a pair of lateral rails 60 spaced along central axis 25; however, in other embodiments, the number of longitudinal rails 50 and/or lateral rails 60 may vary from that shown in FIG. 3.

Referring to FIGS. 6, 9, and 10, one of the lateral rails 60 of support frame 30 is shown in detail. In this exemplary embodiment, each lateral rail 60 comprises a central web 62 and a pair of outer flanges 70 coupled to the web 62 providing lateral rail 60 with an I-shaped cross-section. Web 62 extends vertically between the upper end and the lower end of rig mat 20 while flanges 70 each extend orthogonally (e.g., laterally) relative to the web 62. As shown in FIG. 9, the longitudinal length of web 62 is greater than the longitudinal length of each flange 70 whereby the longitudinal ends of web 62 form projections 64 which project longitudinally between the longitudinal ends of flanges 70. In some embodiments, lateral rails 60 may be welded (e.g., via a web plate) to one of the longitudinal channels 32.

In this exemplary embodiment, the projections 64 of web 62 each define an exterior surface comprising a vertical surface 65 and a pair of angled or inclined surfaces 66. Inclined surfaces 66 each extend at a non-zero angle to the vertical surface 65 whereby an acute angle is formed between each inclined surface 66 and the horizontal when rig mat 20 is positioned on the ground. As shown particularly in FIG. 6, the projections 64 of web 62 are at least partially received in the interior passage 36 of longitudinal channel 32. In addition, while not shown specifically in FIGS. 6, 9, and 10, it may be understood that the longitudinal rails 50 of support frame 30 are configured similarly as lateral rails 60. Thus, longitudinal rails 50 include at least one projection 64 which is received in an interior passage (e.g., similar to interior passage 36 of one of the lateral channels 40 of support frame 30. Longitudinal rails 50 may only include a single projection such that an opposing end (opposing the projection) is planar and abuts the web 62 of one of the lateral rails 60 of support frame 30.

Referring to FIGS. 3 and 4, in this exemplary embodiment, support frame 30 additionally includes a plurality of triangular gussets 80 coupled to the channels 32 and 40 and rails 50 and 60 of support frame 30. Gussets 80 couple (e.g., are welded, are secured via one or more fasteners) with the channels 32 and 40 and rails 50 and 60 of support frame 30. Particularly, a gusset 80 is located at each corner of the rig mat 20. In addition, a pair of gussets 80 flank each lateral channel 40 of support frame 30. Additionally, while only the upper end of rig mat 20 is shown in FIGS. 3 and 4, it may be understood that, in this exemplary embodiment, gussets 80 are positioned in the same configuration along both the upper side and the lower side of rig mat 20 such that a first plurality of gussets 80 are positioned substantially flush along the upper side of rig mat 20 while a second plurality of gussets 80 are positioned substantially flush along the lower side of rig mat 20. Further, in other embodiments, the number and locations of gussets 80 may vary from the number and location of gussets 80 shown in FIGS. 3 and 4. As shown particularly in FIG. 4, a circular aperture 82 is formed in each gusset 80. Apertures 82 of gussets 80 may be conveniently utilized as lifting eyes or holes to which rig mat 20 may be attached to a lifting line or cable for transportation through the air (e.g., via a lifting crane supporting the lifting cable).

Referring now to FIGS. 11-13, an embodiment of a quad-link 100 of the rig mat system 10 of FIGS. 1 and 2 is shown in detail. Quad-link 100 generally includes a link frame 102, and a plurality of connector assemblies 120 each securable to the link frame 102. In this exemplary embodiment, link frame 102 includes a substantially flat or planar base plate 104, a vertically extending guide plate 108, and a vertically extending lifting plate 110. The base plate 104 of link frame 102 includes a plurality of equidistantly circumferentially spaced arms 106, each arm having an aperture formed therein proximal a terminal end of the respective arm 106. The base plate 104 of quad-link 100 includes four separate arms 106 which may underly and couple with four separate rig mats 20 of a rig mat system. The number of arms 106 of base plate 104 may vary depending on the number of rig mats which the link 100 is intended to couple together. As an example, tri-link 160 may include a base plate similar to base plate 104 but including only three arms 106. Similarly, and as will be discussed further herein, the base plate of bi-link 180 may include only a pair of arms.

The guide plate 108 and lifting plate 110 both extend centrally and vertically from the base plate 104. Lifting plate 110 includes an aperture or lifting eye 111 formed therein in which a lifting line or cable may be received for conveniently lifting and transporting the quad-link 100. In addition, guide plate 108 and lifting plate 110 are each elongate and extend longitudinally orthogonally relative to each other (e.g., in an X-shaped configuration). In this manner, guide plate 108 and lifting plate 110 collectively define a plurality of circumferentially spaced rectangular receptacles 112 located proximal the center of base plate 104. Receptacles 112 receive a corner of four different rig mats 20 when the rig mats 20 are coupled or linked together via the quad-link 100. Receptacles 112 may be used to guide the different rig mats 20 into desired positions whereby connector assemblies 120 may be connected to the different rig mats 20 to secure the rig mats 20 to the quad-link 100.

As described above, connector assemblies 120 of quad-link 100 releasably fasten or couple one or more rig mats 20 to the quad-link 100. Quad-links 100 (as well as links 160 and 180) are configured to maximize the strength of rig mat system 10 (e.g., maximizing the bridge load which rig mat system 10 may withstand) while providing a convenient means for assembling the rig mat system 10 quickly and conveniently into a variety of different configurations. In addition, while connector assemblies 120 are shown and discussed herein with respect to quad-links 100, it may be understood that links 160 and 180 also include a plurality of connector assemblies such as a plurality of connector assemblies 120.

In this exemplary embodiment, each connector assembly 120 extends along a longitudinal or central axis 125 (shown in FIG. 13) and comprises an elongate, externally threaded fastener 122, an outer lower or base washer 130, an inner lower or base washer 136, an upper or top washer 142, an internally threaded nut (e.g., a hex nut) 146, and an elastomeric plug 150. Fastener 122 extends between a lower or base end and an upper or top end where fastener 122 is externally threaded between the base end and the top end thereof. The externally threaded fastener 122 threadably connects to the nut 146 to capture one of the arms 106 of base plate 104 between the base end of fastener 122 and the nut 146.

As shown particularly in FIG. 13, in this exemplary embodiment, outer base washer 130 has a frustoconical inner surface 132 defining a frustoconical central passage of the outer base washer 130. In this configuration, an inner diameter of outer base washer 130 reduces in magnitude moving from an upper or top end (opposite base plate 104) of outer base washer 130 to a lower or bottom end thereof (proximal or contacting base plate 104). Additionally, in this exemplary embodiment, the outer base washer 130 of connector assembly 120 comprises a split-ring formed from two corresponding half-ring sections such that an average inner diameter of outer base washer 130 may be adjusted (e.g., increased or decreased) by laterally moving the half-ring sections of outer base washer 130 relatively to each other.

The inner base washer 136 of connector assembly 120 has an elongate, central aperture 138 having a central or longitudinal axis 139 (shown in FIG. 11) which extends orthogonal to the central axis 125 of connector assembly 120. In this exemplary embodiment, aperture 138 of inner base washer 136 has a stadium shape; however, in other embodiments, the shape of aperture 138 may vary. For instance, in other embodiments, aperture 138 may have an oval shape. In this manner, inner base washer 136 is permitted to move laterally (within a delimited range) relative to the fastener 122 when the nut 146 of assembly 120 is not forcibly threaded against the inner base washer 136 (thereby frictionally preventing relative movement between inner base washer 136 and outer base washer 130).

Referring now to FIG. 14, an embodiment of a bi-link 180 of the rig mat system 10 of FIGS. 1 and 2 is shown in detail. The embodiment of bi-link 180 shown in FIG. 14 includes features in common with the quad-link 100 shown in FIGS. 11-13, and shared features are labeled similarly. Particularly, bi-link 180 comprises a link frame 182 and a pair of connector assemblies 120 each securable to the link frame 182. In this exemplary embodiment, link frame 182 includes a substantially flat or planar base plate 184, a guide plate 108′, and a lifting plate 110 where both plates 108′ and 110 are attached to the base plate 184.

Unlike base plate 104 of quad-link 100 shown in FIGS. 11-13, base plate 184 comprises only a pair of circumferentially spaced arms 186. Additionally, the guide plate 108′ is shortened relative to the guide plate 108 shown in FIG. 11 given that base plate 184 only includes a pair of arms 186. In this configuration, link frame 182 defines a pair of circumferentially spaced rectangular receptacles 188 located proximal the center of base plate 184. Receptacles 188 receive a corner of a pair of different rig mats 20 when the rig mats 20 are coupled or linked together via the bi-link 180. Receptacles 188 may be used to guide the different rig mats 20 into desired positions whereby connector assemblies 120 may be connected to the different rig mats 20 to secure the rig mats 20 to the quad-link 100.

While embodiments of the disclosure have been shown and described, modifications thereof can be made by one skilled in the art without departing from the scope or teachings herein. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the systems, apparatus, and processes described herein are possible and are within the scope of the disclosure. For example, the relative dimensions of various parts, the materials from which the various parts are made, and other parameters can be varied. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims. Unless expressly stated otherwise, the steps in a method claim may be performed in any order. The recitation of identifiers such as (a), (b), (c) or (1), (2), (3) before steps in a method claim are not intended to and do not specify a particular order to the steps, but rather are used to simplify subsequent reference to such steps.

Claims

1. A rig mat system, comprising:

a plurality of rig mats each comprising a rectangular frame and one or more billets supported by the rectangular frame;

a link configured to releasably couple the plurality of rig mats together, the link comprising: a link frame comprising a base plate having a plurality of laterally extending arms; a plurality of connector assemblies releasably connectable to the plurality of arms of the link frame, wherein each connector assembly comprises an externally threaded fastener, an internally threaded nut configured to threadably connect to the externally threaded fastener, and a washer positionable about the fastener and having an elongate central aperture.

2. The rig mat system of claim 1, wherein the central aperture of the washer has a central axis which extends orthogonally to a central axis of the fastener.

3. The rig mat system of claim 1, wherein:

the washer of each of the plurality of connector assemblies comprises a radially inner washer; and

each connector assembly comprises an outer washer having a central aperture in which the inner washer is at least partially receivable.

4. The rig mat system of claim 3, wherein the central aperture of the outer washer is at least partially defined by a frustoconical inner surface of the outer washer.

5. The rig mat system of claim 1, wherein:

the washer of each of the plurality of connector assemblies comprises a first washer; and

each connector assembly comprises a second washer having a central aperture defined at least partially by an frustoconical inner surface.

6. The rig mat system of claim 1, wherein:

the washer of each of the plurality of connector assemblies comprises a first washer; and

each connector assembly comprises a second washer comprising a split-ring formed from a pair of half-rings.

7. The rig mat system of claim 1, wherein each connector assembly comprises an elastomeric plug configured to couple to a terminal end of the fastener.

8. A rig mat, comprising:

a support frame comprising a rectangular outer frame formed from a plurality of channels, and a plurality of rails extending through an interior of the outer frame, wherein an exterior surface of the outer frame is defined by a vertical surface and a pair of inclined surfaces extending from the vertical surface at non-zero angles from the vertical surface; and

a plurality of elongate billets coupled together and supported within the interior of the outer frame whereby loads applied to the plurality of billets are transferable from the plurality of billets to the support frame.

9. The rig mat of claim 8, wherein the pair of inclined surfaces of the outer frame extend at acute angles from the vertical surface of the outer frame.

10. The rig mat of claim 8, wherein each of the channels of the outer frame have a pair of lateral ends and an interior passage extending between the lateral ends of the channel.

11. The rig mat of claim 8, wherein the plurality of rails of the support frame comprise one or more longitudinal rails extending parallel a central axis of the rig mat and one or more lateral rails extending orthogonal to the central axis of the rig mat.

12. The rig mat of claim 8, wherein at least one of the rails has an I-shaped cross-section and includes a central web and a pair of flanges extending, in cross-section, orthogonal to the web.

13. The rig mat of claim 12, wherein at least one of a pair of terminal ends of the web of the rail projects longitudinally from the pair of flanges of the rail.

14. The rig mat of claim 12, wherein a longitudinal length of the web of at least one of the rails is greater than a longitudinal lengths of the pair of flanges of the rail.

15. A rig mat system, comprising:

a plurality of the rig mats of claim 8; and

a link configured to releasably couple the plurality of the rig mats of claim 8 together, the link comprising: a link frame comprising a base plate having a plurality of laterally extending arms; and

a plurality of connector assemblies releasably connectable to the plurality of arms of the link frame and to the plurality of the rig mats of claim 8.

16. The rig mat system of claim 15, wherein the plurality of arms of the link underly the plurality of the rig mats of claim 8 when the plurality of the rig mats of claim 8 are coupled to the link.

17. A rig mat, comprising:

a support frame comprising a rectangular outer frame formed from a plurality of channels, and a plurality of rails extending through an interior of the outer frame, wherein at least one of the rails has an I-shaped cross-section and includes a central web and a pair of flanges extending, in cross-section, orthogonal to the web and wherein a longitudinal length of the web of at least one of the rails is greater than a longitudinal lengths of the flanges of the rail; and

a plurality of elongate billets coupled together and supported within the interior of the outer frame whereby loads applied to the plurality of billets are transferable from the plurality of billets to the support frame.

18. The rig mat of claim 17, wherein at least one of a pair of terminal ends of the web of the rail projects longitudinally from the flanges of the rail.

19. The rig mat of claim 18, wherein both of the pair of terminal ends of the web of the rail projects longitudinally from the flanges of the rail.

20. A rig mat system, comprising:

a plurality of the rig mats of claim 17; and

a link configured to releasably couple the plurality of the rig mats of claim 17 together, the link comprising: a link frame comprising a base plate having a plurality of laterally extending arms; and

a plurality of connector assemblies releasably connectable to the plurality of arms of the link frame and to the plurality of the rig mats of claim 17.

21. The rig mat system of claim 20, wherein the plurality of arms of the link underly the plurality of the rig mats of claim 17 when the plurality of the rig mats of claim 17 are coupled to the link.