WO2021243383A1

WO2021243383A1 - Hybrid access mat with a steel interlocking system and reinforced lifting slots

Info

Publication number: WO2021243383A1
Application number: PCT/VN2021/000010
Authority: WO
Inventors: Ngo Xuan BINH
Original assignee: Binh Ngo Xuan
Priority date: 2020-05-27
Filing date: 2021-05-26
Publication date: 2021-12-02

Abstract

The present invention relates to a 2-ply wooden access mat with an interlocking system and a steel lifting slot consisting of: multiple longitudinal wooden bars (1) arranged parallel to each other; many transverse wooden bars (2) are connected to some or all of the transverse bars (2) by a bolt-nut fasterner system (4) through the wooden layers; the steel lifting slots (5) are arranged in between the transverse wooden bars (2), which are effective for the forks of a forklift to be inserted easily when manipulating, moving, lifting and lowering the plate; the first and the second transverse steel bars (3.1, 3.2) are arranged at the ends of the lower layer of wood and are connected to the ends of the longitudinal wooden bars (1) by the bolt-nut fasterner system (4), in which on the first and the second transverse steel bars (3.1, 3.2), there is a steel female-male interlocking mechanism to easily link and disassemble two adjacent mats. At least one male connector (3.11) of the interlocking is designed with an L-shaped protrusion to strengthen the connection between the two mats when joined together, and the male connector (3.12) in the middle is designed with a hole to hook the crane.

Description

HYBRID ACCESS MAT WITH A STEEL INTERLOCKING SYSTEM

AND REINFORCED LIFTING SLOTS Technical field of the invention

The present invention presents a road access mat system which is widely used in various fields such as road and bridge, civil construction, industry, oil and gas exploitation and military. More specifically, the present invention relates to road access mats design to be laid on soft ground for creating a solid pavement system so that heavy vehicles can move on it. Moreover, the road access mat according to the present invention can be used as temporary yards to gather materials and equipment.

Background of the invention

In the prior art, a majority of traditional access mats are mainly made from mixed hardwoods, as oak or pine with a structure of two or three layers of wooden bars.

US. Patent No. 2,819,026 disclosed a roadway which can be easily put together by unskilled labor. The road way can be made from a plurality of sections. Each section generally includes two layers made from a plurality of parallel bars (usually by wood). The upper layer is attached perpendicular to lower layer to create a solid surface. The layers are also arranged in such a way that they form a plurality of interlocking systems to help road sections connect with each other together for vehicle running over.

U.S. Patent No. 4,289,420 disclosed an access mat system that is made from a plurality of wooden mat. Each mat includes two wooden layers made from a plurality of wooden bars. Wooden bars are laid in parallel in one layer and perpendicular to another layer that also form an interlocking system. The wooden layers are fastened together with many bolts. Those wooden bars are arranged in a way that has a protruding and indent form to create an interlooking system. The ways in which that makes the mats possible to be interlocked when joining two adjacent mats, thereby creating a continuous surface to ensure that vehicles and people move on safely.

US. Patent. No. 4,600,336 and US. Patent No. 5,087,149 discloses two types of interlocking wooden mats for supporting heavy equipment and vehicles. Generally, these patents disclose the mats that include two or three layers of wooden planks. A special feature of those inventions is to introduce an interlocking system by which the mat can be interlocked with each other at both sides at longitudinal edges and transverse edges. Moreover, the mat may be provided loops of cable for lifting and transporting.

US. Patent No. 4,875,800 discloses a temporary support structure used on muddy and marshy areas that includes a plurality of mats. Each mat generally includes two layers. Each layer comprises a plurality of parallel bars that are laid in a perpendicular way to other bars in another layer of the mat. A special feature of this type of structure is that a top mat is placed downwarly on another bottom mat faced upwardly. In that way, the two mats are inter-locked together and in succession to create a continuous surface.

US. Patent 4,973,193 discloses a matting system that includes 4 different configurations of interlocking mats. Each type of mat consists of one to three layers of wooden bars fastened in a parallel and perpendicular way to each other. On the field, the mats are assembled and stacked one on over another with overlapping parts to create interlocking systems among mats. Thus, such kind of arrangement can create a stable surface for supporting the operation of heavy vehicles and equipment on soft soil areas.

In addition, several other patents such as No. US 6,945,732 B2, US 6,474,905 Bl, US 20020110418A1 also disclose different types of access road mats, each type generally includes two or three layers and each layer includes a plurality of bars or boards. Such bars or boards are also arranged in different configurations but a way that interlocking systems can be formed and the mat can be laid interlocking one another to create a contineous surface. Moreover, several other patents such as US 10, 273,638 Bl, US 2016/0222598 Al, US 2016/0235234 Al also disclose access mats in rectangular shapes and generally the mats are also designed with interlocking systems. The mats according to the embodiments of these patents are also formed by a plurality of aggregate or laminated wooden bars or panels. These designs are intended to increase the strength or utility of the mat.

In general, in the prior art, it was known that the interlocking system is a very important part of the access mat system, which enables the access mats to be connected to each other in order to create a flat, continuous surface for vehicles to move on. However, the male connectors of the interlocking system in existing road access mat in general and in the above patents or patent applications are made mainly from wooden bars, so it is easy to be broken or damaged during transportation and during operation. Moreover, the difficulty in repair and replacement of this type of the interlocking makes the mats likely to be discarded and not used, increasing operational costs for customers.

Additionally, in the prior art, there are several designs related to 2-ply wooden mats, consisting of a vertical layer and a longtitudinal layer. Two-ply wooden mats have a significant advantage over three-ply wood, which is lighter in weight, lower in stiffness, and easier to adapt to a variety of uneven terrain. However, it is difficult to arrange an interlocking system with two male and female connectors in such a two-layer access mat. If so, usually the male connector is located on the upper layer of the mat, so when it is installed on the adjacent mat, it cannot be inserted under the bottom layer of the adjacent mat, reducing the connection efficiency. When the vehicle running on top of the mats, the interlocking system may be sliped out causing the adjacent mats to slide aparts, leading to unsafety. Therefore, the existing two-ply wooden access mat system does not meet the requirements of use.

In addition, traditional road access mats are difficult to be handed by forklift. These types of mats do not have a place to put the forks of the forklift, so it is difficult to be handed and manipulated. Although crawler carts with grabbing buckets have been designed to work with such kind of access mats, however, this type of vehicle is still expensive and not available in many construction sites and factories. Also, it is more difficult for dismanting and loading traditional mats from the container due to the lack of hook or lifting accessories.

Summary of the invention

The objective of the present invention is to overcome the disadvantages mentioned above.

In order to meet the objective, the present invention discloses a 2-ply wooden access mat with a steel interlocking system and a reinforced lift slots as presents in the claim 1 that includes: many longitudinal wooden bars (1) are arranged parallel to each other to form the upper layer of the mat; many longtitudinal wooden bars (2) are arranged parallel to each other to form the lower layer of a mat and they are arranged below the upper layer mentioned above; each longitudinal timber (1) is connected to some or all of the longtitudinal bars (2) by bolts (4) installing through these bars; a number of steel bars designed as lifting slots (5) are interspersed between the transverses (2), each lifting slot (5) consists of base mats (5.1) and side mats (5.2), two sides of each steel lifting slot (5) has protrusions (5.3) with holes for mounting the bolt- nut system (4) that are used to connect the steel lifting slots (5) with the longitudinal wooden bars (1); the first transverse (3.1) is arranged at one end of the lower wooden layer and it is connected to the ends of the longitudinal bars (1) by bolts and nuts (4), in which male connectors (3.11 and 3.12) are designed on the first transverse (3.1) and it is protruding from the outer edge of the transverse (3.1); and the second transverse (3.2) is arranged at the other end of the lower wooden layer and is connected to the ends of the upper longitudinal bars (1) by bolt-nut systems (4), in which on the second transverse (3.2), female connectors (3.21) are recessed into the inside of the mat, where: each female connector (3.21) of the mat is designed to fit with the corresponding male connector (3.11 and 3.12) of other mats to form a male-female interlocking mechanism between the two adjacent mats, to easily link or disassemble them, and at least one of the male-female interlocking devices has a male connector (3.11 and 3.12) that is protruding towards the top wooden layer and the corresponding female connector (3.21) has slots for accepting the male connectors, thereby increasing the efficiency of hook insertion between two mats when joining together.

According to a preferred embodiment as mentioned in claim 2 of the claims, at least one of the male connectors (3.11 and 3.12) has a hole for the hook to be inserted.

According to a preferred embodiment as mentioned in claim 3 of the claims, the male connector (3.12), which has a hole for the hook to be inserted, is located in the middle part of the mat .

According to a preferred embodiment as mentioned in claim 4 of the claims, the male connector (3.12), which has a hole for the hook to be inserted, is not designed with a convex toward the upper wooden layer.

According to a preferred embodiment as mentioned in claim 5 of the claims, the first transverse (3.1) has three male connectors (3.11 and 3.12), of which two side male connectors (3.11) near the edge are designed with convexs, and the middle male connector (3.12) has a hole for threading the hook.

According to a preferred embodiment as mentioned in claim 6 of the claims, the mat consists of two steel lifting slots (5) positioned in the middle of the mat.

According to a preferred embodiment as mentioned in claim 7 of the claims, the protrusions (5.3) with through holes for mounting the bolt-nut system (4) are arranged between the longitudinal wooden bars (1) and tranverse wooden bars (2), and the steel lifting slots (5) are connected to both the longitudinal wooden bars (1) and the tranverse bars (2) by bolt-nut systems (4).

According to a preferred embodiment as mentioned in claim 8 of the claims, the first tranverse bar (3.1) and the male connectors (3.11 and 3.12) are internally reinforced with steel mats (3.14).

Brief description of the drawings

The present invention as summarized above will now be described with reference to the accompanying drawings of specific embodiments so as to demonstrate the subject matter and advantages of the present invention with additional clarity and details. However, it is to be understood that the embodiments disclosed herein are only the typical embodiments and are not intended to limit the scope of the present invention. In the drawings:

FIG. 1 is a perspective view of the first embodiment the mat of the present invention;

FIG. 2 is a bottom perspective view of the mat of FIG. 1;

FIG. 3 is a top plan view of the mat of FIG.1 ;

FIG. 4 is a plan view of bottom surface of the mat of FIG. 1;

FIG. 5. is a top plan view of the bottom layer when the top layer of the mat of FIG. 1 is not installed;

FIG. 6. is a longitudinal side view of the mat of FIG. 1;

FIG. 7 is a cross-section of the mat of FIG. 1 (Cross-section A-A in FIG.6);

FIG. 8 is a perspective view and a cross-section of reinforced lifting slots of the mat of FIG. 1; FIG. 9 is a perspective view of male connectors and female connectors of the interlocking system of the mat of FIG. 1;

FIG. 10 is a perspective view of inner structure of the male connectors of the mat of FIG. 1 with additional reinforced bars;

FIG. 11 is a digramatic perspective view of two adjacient mats of FIG. 1 being connected one to another to create a continous surface.

Detailed description of the invention

The present invention will be described in detail with reference to the FIG.s from FIG. l to FIG. il.

The two-ply wooden access mat with interlocking systems and steel lifting slots (bars) of the present invention has a structure consisting of the following components.

Multiple longitudinal bars 1 are arranged parallel to each other to form the upper layer of the mat, for example rectangular in shape. It is the best that these wooden bars are rectangular in shape and have the same dimensions, so that they are both easy to manufacture and easy to create a flat surface suitable for pavement requirements.

Many tranverse bars 2 are arranged parallel to each other to form the lower layer and arranged below the upper layer. Preferably, these transverse bars are also in rectangular shape, with the same size, and the length of each bar is equal to the width of the upper layer. It is both easy and convenient to manufacture and attach to the upper layer.

Each longitudinal wooden bar 1 is connected to some or all of the longtitudinal wooden bars 2 by bolt-nut fasteners 4 attached through the upper and lower layer. It is better that each longtitudianal bar 1 is attached to all transverse bars 2 to ensure the rigidity of the mat. For the purpose of increasing the rigidity of the mat according to the present invention and in order to increase some other benefits, supporting for operational work such as for the movement and the installation of the mats, a steel bar system is arranged to support the access mat. This system is applied against the underside of the upper layer and interspersed with transverse bars of the lower layer. This steel bar system consists of the first transverse bar 3.1 and the second transverse bar 3.2 at the ends of the mat combining with an interlocking system. Steel lifting slots (bars) 5 are arranged in the middle of the two steel tranverse bars and separated by a certain distance so that the forklift can lift and lower the mat conveniently. This steel bar system is also attached to the underside of the upper layer, including longitudinal wooden bars by bolt-nut fasterners 4.

Specifically, a number of steel lifting slots (bars) 5 are arranged between longtitudinal wooden bars 2. Each steel lifting slot 5 includes base mat 5.1 and side mats 5.2, forming a steel bar in the form of C-shaped, two sides of each steel lifting slot 5 have protrusions 5.3 with through holes for mounting bolt-nut fasterners 4 to connect steel lifting slots 5 to longitudinal wooden bars 1. Preferably, the protrusions 5.3 are flattened and arranged in pairs, each pair connected to a longitudinal bar 1 of the upper layer. As an implementation for example, these steel lifting slots 5 have the same length and thickness as transverse bars 2.

For an implementation plan, as an example, each mat has two steel lifting slots 5 designed in the middle and longtitudinally of the mat. Preferably, these two bars are arranged symmetrically to the transverse center axis of the mat. These two C-shaped steel lifting slots 5 form slots where the lifts of a forklift can be placed, so the distance between the two bars as well as the C-width (for example the distance between the two side mats 5.2) must be ensured that the forklift can insert the fork to move the mat easily.

For an implementation plan, as an example, the steel lifting slots 5 are also connected to both longitudinal wooden bars 1 and transverse wooden bars 2 by bolt-nut fasterners 4. Figure 5 shows steel lifting slots 5 and thin protrussion 5.3 without bolt-nut fasterners 4 installed. Figure 8a is a perspective view of the lifting slots and Figure 8b is a cross-sectional view of steel transverse lifting slots 5. After placing steel lifting slots 5 against the underside of the upper layer, a number of transverse bars 2 will be placed against the side edge of the C-shaped steel slots 5 and pressing on the protrusions 51. After that, the bolt - nut fastemer system 4 will be installed through the longitudinal wooden bars 1, the through hole of the protrusions 5.3 and the longtitudinal wooden bar 2 and then tighten them into a solid block. Figures 3 and 4 show the steel lifting slots 5 and the protrusions 5.3 after being combined with the upper layer by a bolt-nut system 4. The structure of the mat in such a manner creates more favorable conditions for moving, installing or lifting the overall mat.

According to an implementation plan, the first two transverse bar 3.1, the second bar 3.2 have the same length and thickness as the wooden transverse bars 2, these two transverse bars are arranged at the ends of the lower wood layer and are connected with the ends of longitudinal bars 1 by bolt-nut fastemer 4 through holes 3.13 in the first steel transverse bar 3.1 and holes 3.22 and protrusion 3.23 in the second transverse bar 3.2.

The first steel transverse bar 3.1 has steel male connectors 3.11 and 3.12 that are designed to protrude from the outer edge of the steel transverse bar 3.1. The second transverse bar 3.2 is provided with 3.21 female connectors recessed inside the mat, where each female connector 3.21 of the mat is sized to match with the male connectors 3.11 and 3.12 of the other mat respectively to form a male-female interlocking mechanism between two adjacent mats. This design helps to easily connect or disassemble them. At least one of the above female-male interlocking devices has male connectors 3.11 and 3.12 designed with convex protrusions protruding toward the upper layer. A corresponding female connector 3.21 has grooved response to accept the convex protrusions, thereby increasing the efficiency of connection between the two adjacent mats, longitudinally aligning the mats. According to one implementation plan, a male connector is designed with a convex part forming an L shape. In one implementation plan, at least one of the male connectors 3.11 and 3.12 has a hole for installing the hooks. The advantage of this design is that the user can insert the crane hook here to move the mat from the container as well as to move it underground by simply using a crane hook. According to one implementation plan, the male connector 3.12, which has a hole for installing the hook, is designed at the middle of the transverse edge of the mat. According to one implementation plan, the male connector 3.12, which has a hole for the hook to be inserted, is not designed with a convex protrusion. According to an implementation plan, the first transverse bar 3.1 has three male connectors 3.11 and 3.12, of which the two male connectors 3.11 near the edge are designed with a convex protrusion, and the male connector 3.12 in the middle has a hole for threading the crane hook. According to one implementation plan, the first transverse bar 3.1 and male connectors 3.11 and 3.12 are both reinforced internally with steel bars 3.14, for example, internally welded. That helps the male connectors to significantly increase impact collision resistance, bending resistance, contributing to the longevity of the mat.

When the access mats are stacked longitudinally together, the male connectors 3.11 and 3.12 of a mat will be installed into the female connectors 3.21 of the adjacent mat, creating a flat and continuous surface, for the vehicles operating above. The panels, when interlocked, will limit movement in both longitudinal and transverse directions.

Advantages of the present invention

Experimental results show that the access mats with interlocking systems according to the present invention, although having a lower stiffness than the conventional three-layer wood access mats, they are more suitable for many different types of terrain. Meanwhile, the total weight of the mat is significantly reduced compared to the three-ply wood panel. The reduction in weight will significantly reduce manufacturing and transportation costs as well as handling cost during use.

The use of supporting steel bars helps to design the mat with only two layers of wood but it can be arranged with an interlocking system with longitudinal male connectors and male connectors installed to the female connectors lying below adjacent mat. This is an important design that the traditional two-layer wood mats could not be arranged before. The steel interlocking system design provides a longer overall service life of the mat. Especially, the male connectors of the interlocking systeam are hard to be damaged, broken during use, moving and do not have to be replaced during use. Thus, reducing costs and saving time. Furthermore, the design of the steel parts makes shaping very easy. With that advantage, the access mat according to the present invention is designed with the male connectors of the interlocking with convex protrusion, making it easier to install and hook to the adjacent mat, increasing the efficiency of the connection between the mats. In addition, the male connector is also designed with an additional hook, making it easy to move the mat and remove it from the container. This is a design that traditional mat does not have this utility.

With lifting slots arranged on the mat, it makes lifting, lowering and moving the mat easier by forklift. So that, the forklift can put the fork into the C-slots of the lifting slots easily and conveniently. In addition, the design of the steel lifting slots position is also taken into account the weight balance of this mat, making it possible to load or transport multiple mats at the same time.

Claims

1. A hybrid two-ply access mat with a steel interlocking and reinforced lifting slots includes: a plurality of longitudinal wooden bars (1) are arranged parallel to each other to form the upper layer of the mat; a plurality of transverse wooden bars (2) are arranged parallel to each other to form the lower layer of the mat and arranged below the upper layer; each longitudinal wooden bar (1) is connected to some or all of the transverse wooden bars (2) by means of bolt-nut fastemers (4) installing through these bars; a number of steel lifting slots (5) are interspersed between the transverse bars (2), each steel lifting slot (5) consists of base plate (5.1) and side plates (5.2), two sides of each steel lifting slot (5) have convex protrusions (5.3) with through holes for mounting the bolt-nut fastemer system (4) and to connect the steel lifting slot (5) with transverse wooden bars (1); the first transverse steel bar (3.1) is arranged at one end of the lower layer of the mat and connected to the ends of the longitudinal wooden bars (1) by the bolt-nut fastemer system (4). Where the first transverse wooden bar (3.1) is designed with male connectors (3.11 and 3.12) and welded protmding from the outer edge of the transverse steel bar (3.1); and the second transverse steel bar (3.2) is arranged at the other end of the lower wooden layer and is connected to the ends of the longitudinal wooden bars (1) above by the bolt-nut fastemer system (4), in which on the second transverse steel bar (3.2), female connectors (3.21) are recessed into the inside of the mat, where: each female connector (3.21) of one mat is sized to fit with the corresponding male connector (3.11 and 3.12) of the other mat to form a female-male interlocking mechanism between the two mats adjacent to each other, to easily link or disassemble them, and at least one of the above female-male interlocking devices has a male connector (3.11 and 3.12) that is designed to protrude towards the upper layer and the corresponding female connector (3.21) has a slot to accept the male connector, thereby increasing the efficiency of insertion between two plates when joining together.

2. The access mat according to claim 1 , in which at least one of the male connectors (3.11 and 3.12) has a hole for the hook.

3. The access mat according to claim 2, in which the male connector (3.12) has a hole for the hook, is located in the middle of the transverse edge of the mat.

4. The access mat according to claims 2 or 3, in which the male connector (3.12), which has a hole for the hook, shall not be designed with a convex toward the upper wooden layer .

5. The access mat according to any of the claims 2 to 4, in which the first transverse steel bar (3.1) has three male connectors (3.11 and 3.12), of which two male connectors (3.11) near the edges are designed with a convex, and the male connector (3.12) in the middle has a hole for threading the hook.

6. The access mat according to any of the above claims, in which it consists of two steel lifting slots (5) positioned between the two transverse steel bars at two ends.

7. The access mat according to any of the above claims, in which the protrusions (5.3) with through holes for mounting the bolt-nut fastener system (4) are arranged between the longitudinal wooden bars (1) and the transverse wooden bars (2), and the steel lifting slots (5) are connected to both the longitudinal wooden bars (1) and the transverse wooden bars (2) by bolt-nut fastemer system (4).

8. The access mat according to any of the above claims, in which the first transverse wooden bars (3.1) and male connectors (3.11 and 3.12) are internally reinforced with steel plate (3.14).