Abstract:
An assembly for budding a pre-fabricated modular boat dock structure is disclosed. The assembly is designed to be modular so it can be fabricated in a shop environment and then installed by assembling it on site. The assembly is further designed to enable the individual component modules to be powder coated prior to installation so that the pre-fabricated modular boat dock will be rust resistant and have a much longer expected lifespan than a custom boat dock which is built on site would have. The pre-fabricated modular boat dock structure has a pleasing aesthetic appearance after having been powder coated and is useful in extending the life of a boat dock structure used to shelter boats stored immediately adjacent to a body of water.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to dock structures; and more particularly, to a modular dock structure that enables its modular elements to be pre-fabricated and powder-coated. 
     The use of dock structures in and around bodies of water is well known. In the prior art, dock structures have been constructed from a variety of materials, including wood, steel, aluminum, and synthetic fibrous materials. Generally, a dock is a fixed structure which is located near a body of water and commonly extends from a mounting area on a and mass into the body of water at the periphery of the body of water. It is commonly known that dock structures are used to enable pedestrians to physically access a location above a body of water without having to enter the body of water itself. Often, the use of a dock structure is associated with the mooring of a pleasure boat, recreational watercraft, or other types of watercraft which, due to their construction, cannot easily be extracted from a body of water, but are simultaneously difficult to access from a fixed point on the surface of the earth that is not covered in water. 
     In the prior art, dock structures have been constructed such that watercraft of all types can be moored to them and so that pedestrians can access the watercraft at a location above a body of water where the depth of the body of water is sufficient to permit a subject watercraft to be moored such that its hull will not contact the surface of the earth beneath the water which buoys it. 
     Due to the nature of water, it is well known that the materials from which dock structures have been fabricated are highly subject to deterioration, weathering, and other natural phenomena of decomposition. Dock structures constructed of wood are subject to rotting and decomposition of the wood from which they are constructed. Dock structures made of steel are subject to the oxidation process, which is hastened in the presence of water and salt water. Aluminum structures, while more resistant to oxidation processes, are lighter weight and thus less resistant to structural damage due to the application of force (wind, impact damage, and ice) than steel constructed docks. Docks constructed of synthetic, fibrous materials are more brittle than steel constructed docks and are more susceptible to structural impact damage. 
     In general, steel is a desirable material for use in the construction of boat docks, primarily due to its strength and elasticity in comparison with other materials commonly used in the construction of boat docks. However, steel is highly susceptible to oxidation which severely limits the life-span of dock structures constructed from steel. 
     In the prior art of boat dock construction, the classical means of fabricating a boat dock has been to use steel framing members and elements which are custom welded into a frame structure at the site where a boat dock is assembled and installed immediately adjacent to a body of water. Such processes necessitate the use of steel framing members and elements which are welded together and because of the nature of steel are subject to deterioration due to oxidation. Classically, such steel frame constructed boat docks may be painted or otherwise covered to delay oxidation, but suffer from the eventuality that such steel frame construction will be compromised by oxidation. Paint is easily damaged, leading the underlying steel to become exposed rather easily. The use of galvanized steel has likewise been used in the prior art, but produces an unflattering appearance that is much less pleasing to the eye than a powder coated finish. Further, the custom fabrication of a boat dock, on site, is labor intensive. 
     The claimed Pre-Fabricated Modular Boat Dock Assembly enables the modular elements of the frame for the assembly to be created, and mass produced, in a shop or factory setting. Because of the modular construction, the individual modules are able to be powder coated in advance of installation and then assembled on site without the need of weldments to connect the modular framing members and elements. The claimed design enables the modular framing members and elements to be attached to one another using standard fasteners, such as nuts and bolts, resulting in a boat dock structure that is entirely powder coated and extremely resistant to oxidation and deterioration while simultaneously having a pleasant, finished appearance. Powder coating is not easily damaged by the types of stresses and damage to which boat dock structures are commonly subject. Thus, constructing a modular boat dock that has modular framing members and elements that are capable of being powder coated before installation is highly desirable. 
     It is a primary object of this invention to provide an improved dock structure. 
     Another primary object of the invention is to provide an improved modular dock structure utilizing uniformly fabricated structural members. 
     Yet another object of this invention is to provide an improved modular dock structure that is capable of being effectively powder coated prior to assembly and installation. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention includes a modular dock structure that can employ a variable number of dock structure modules to construct a modular dock structure containing bays in which various watercraft can be stationed while not in active use. The basic configuration of the dock structure module which forms the basis for the modular dock structure utilizes two or more walkway modules which are spaced apart to define an empty space or bay between the opposing walkway modules between which a watercraft can be positioned. Extending upward from the walkway modules are vertical side modules which form a superstructure above the walkway modules and are connected by transverse upper cross members which connect the opposing vertical side modules together to form a rectangular configuration elevated above the walkway modules upon which a roof can be constructed. The roof provides a shelter to any watercraft stationed between the adjacent walkway modules. In its simplest form, the dock structure module consists of two walkway modules, two vertical side modules, one on the left and one on the right, and two upper cross members all of which modular members are connected by a series of couplers. In the simplest formulation, two single rear tube couplers are used on the landward side of the dock structure module and two single front tube couplers are used on the waterward side of the dock structure module to join the two upper cross members and two vertical side modules into the rectangular shape upon which a roof can be positioned. 
     A dock structure module then can be mounted upon various types of piling driven into the bed of a body of water or into the earth. One aspect of the invention is the novel modular construction that is able to be produced in a shop or factory setting rather than but as a custom project on site. The novel modular construction of the dock structure module is of sufficiently small size that each individual module and coupler element of the dock structure module can be powder coated prior to transporting the modular elements to a job site for installation and assembly. The novel design of the dock structure module enables it to use no weldments on the powder coated finish at the time it is assembled on-site, so that powder coating applied to the dock structure module is not destroyed or damaged by the welding process because all of the involved modular elements of the dock structure module are assembled with nuts and bolts or other mechanical fasteners that do not damage or destroy the integrity of the powder coating applied to the modular elements of the dock structure module. 
     The modular elements can be cut to predetermined lengths so they can be pre-fabricated and constructed in an efficient and cost effective way so as to avoid the labor intensive nature of building a custom sized dock structure on site. 
     The several modular elements of the dock structure module can all be fabricated from steel and powder coated to resist corrosion, oxidation and deterioration due to the elements and other impact damage. It is a purpose of the invention to provide the ability to powder coat the steel, modular members and elements of the dock structure module which cannot be done effectively in applications where a dock structure is custom built on site. It is likewise a purpose of the invention to provide a powder coated finish to the steel, modular members and elements of the dock structure module so that any weldments that are made in the structure are hidden from view and therefore the powder coating that is on the visible portion of the dock structure module is not disrupted or damaged by oxidation processes, and does not need to be maintained with the regularity that a painted surface would require. 
     The modular dock structure comprised of one or more dock structure modules can be finished with other adjacent structures (storage room, boat house, etc.) to have a pleasing aesthetic appearance. It is the intent of the design to provide a berth upon which to construct a roof structure to protect the walkways and watercraft stationed between the walkways from the elements, weather, etc. Similarly, pre-fabricated concrete, tile, wood or other decking can be affixed to the upper most surface of a walkway module to provide a stable structure upon which persons can walk and rest a variety of implements, while providing access to watercraft positioned in the bay area of the dock structure module. 
     The modular design of the dock structure module enables a virtually unlimited number of associated dock structure modules to be linked together to create a modular dock structure suitable for stationing a multitude of watercraft. Another aspect of the modular dock structure is that dock structure modules can be configured with a boat hoist. Such a boat hoist, in one embodiment, is retained by angle iron tracks affixed to opposing sides of each vertical side module. In the preferred embodiment, the upper side member of each vertical side module is a steel I-beam and the lower flange of the I-beam is used to support and retain a boat hoist that is adjustable longitudinally along the length of the upper side member enabling such a boat hoist to be adjusted for the purpose of balancing watercraft lifted on the boat hoist without the necessity of welding or drilling on the dock structure module or vertical side module and thus without damaging powder coating applied to the dock structure module. Either configuration enables a watercraft stationed between adjacent walkway modules to be lifted from the body of water in which the given dock structure module is located so that such watercraft can be stored, cleaned, and removed from the body of water and accessed via the adjacent walkway modules. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of the modular dock structure; 
         FIG. 2  is a perspective view of a dock structure module and illustrates configuration in its simplest form; 
         FIG. 3  is a perspective view of the walkway module shown in  FIG. 2 ; 
         FIG. 4  is a top view of a walkway module shown in  FIG. 3 ; 
         FIG. 5  is a face view of a walkway module shown in  FIG. 3 ; 
         FIG. 6  is a perspective view of a vertical side module shown in  FIG. 2 ; 
         FIG. 7  is a side view of the vertical side module shown in  FIG. 6 ; 
         FIG. 8  is an end view of the vertical side module shown in  FIG. 6 ; 
         FIG. 9  is a perspective view of a single rear tube coupler that may be used with the dock structure module shown in  FIG. 2 ; 
         FIG. 10  is a perspective view of a single front tube coupler hat may be used with the dock structure module shown in  FIG. 2 ; 
         FIG. 11  is a perspective view of a double rear tube coupler that may be used with the dock structure module shown in  FIG. 2 ; 
         FIG. 12  is a perspective view of a double front tube coupler that may be used with the dock structure module shown in  FIG. 2 ; 
         FIG. 13  is a perspective view of a single rear tube coupler shown in  FIG. 9  coupled with an upper cross member and upper side member as shown in  FIG. 2 ; 
         FIG. 14  is a perspective view of a single front tube coupler shown in  FIG. 10  coupled with an upper cross member and upper side member as shown in  FIG. 2 ; 
         FIG. 15  is a perspective view of a double rear tube coupler shown in  FIG. 11  coupled with adjacent upper cross members and upper side member as shown in  FIG. 2 ; 
         FIG. 16  is a perspective view of a double front tube coupler shown in  FIG. 12  coupled with adjacent upper cross members and upper side member as shown in  FIG. 2 ; 
         FIG. 17  is a perspective view of a single rear tube coupler which illustrates the joining of a coupler to an upper cross tube member, an upper side member, and an upper linking member; 
         FIG. 18  is a pictorial view of a modular dock structure comprised of two dock structure modules illustrating the use of a movable boat hoist in each dock structure module and lagging atop each walkway module; 
         FIG. 19  is a perspective view of an angle iron track for use with a movable boat hoist that may be used with the dock structure module shown in  FIG. 2 ; 
         FIG. 20  is a pictorial view of a modular dock structure comprised of a plurality of dock structure modules illustrating the flexibility of configuration of a plurality of the components of the improved modular dock structure; and, 
         FIG. 21  is a perspective view of a piling end cap that may be used with the dock structure module shown in  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following description, to the extent possible for clear description, elements that appear in different figures will bear the same reference numerals. 
       FIG. 1  is a perspective view of the modular dock structure. 
     A modular dock structure  10  is comprised of one or more dock structure modules  20 . The walkway modules  30  of a dock structure module  20  are affixed to vertical piling  12  driven into the bed of a body of water. The vertical piling  12  support the dock structure module  20 . The vertical piling  12  are not a pre-fabricated part of the modular dock structure  10 , but provide the foundation upon which the modular dock structure  10  is constructed. The vertical piling  12  to support the modular dock structure  10  are driven into the bed of a body of water at pre-determined locations and a dock structure module  20  is then affixed atop the vertical piling  12 . 
     In the preferred embodiment, the vertical piling  12  are steel pipes with 7″ outside diameter and ⅜″ thickness and are affixed at a plurality of locations on each walkway module  30  by inserting the vertical piling through the lower surface  33  of the walkway module  30  and affixing by mechanical affixing means. In the preferred embodiment, the vertical piling  12  is capped with a piling end cap  14  which is inserted into the walkway module  30  to provide a rigid structure. The vertical piling  12  and piling end cap  14  are not powder coated. The piling end cap  14  is welded to the vertical piling  12  and the walkway module  30 . In the preferred embodiment, the piling end cap  14  is welded at an appropriate location to support each walkway module  30 . The landward side of a modular dock structure may be affixed to vertical piling  12  or may be affixed to a shore wall or other structure sufficient to support the modular dock structure  10 . Such vertical piling  12 , shore walls or other foundation for the modular dock structure  10  are permanently affixed to the landward side of the walkway module  30  by mechanical affixing means which can be welding. A series of dock structure modules  20  can be stacked adjacent to each other laterally and can be connected to create multiple bays for the stationing of multiple watercraft. Each bay may employ a boat hoist  160  which can be employed to remove a watercraft stationed in the associated bay from the body of water for cleaning, access to the hull and for storage. In the preferred embodiment, a boat hoist  160  is constructed to be slidably retained by opposing upper side members  54  with engagement of the boat hoist being accomplished by the upper and lower flange surfaces of the I-beam  57  and  59  of the opposing upper side members  54 . In an alternative embodiment where a boat hoist  160  would be employed within a given dock structure module  20 , a pair of angle iron tracks  170  creating a retaining channel for the boat hoist  160  are permanently affixed to the opposing upper side members  54  of an associated dock structure module  20 . A modular dock structure  10  can be built in a variety of configurations depending upon the orientation of the dock structure modules  20  and the number of dock structure modules  20  desirable to be used. 
       FIG. 2  is a perspective view of a dock structure module and illustrates configuration in its simplest form. 
     A dock structure module  20  is comprised of a pair of horizontal opposing walkway modules  30  which each support a pair of opposing vertical side modules  50  which are joined by a pair of transverse upper cross members  58 . The dock structure module  20  defines a bay or a empty space  22  between the opposing walkway modules  30  which are spaced sufficiently to define a bay or empty space  22  to enable a watercraft of the appropriate size to travel linearly between the innermost face member  32  of each walkway module  30  without the watercraft contacting the innermost face of the face member  32 . In the preferred embodiment, the distance between the innermost face member  32  of each walkway module  30  is 120″, but there may be other embodiments of smaller or larger dimension to accommodate varying sizes of watercraft. 
     The opposing vertical side modules  50  are comprised of a plurality of vertical support members  52  which elevate upper side members  54  perpendicular to the walkway module  30 . The upper side members  54  receive a pair of couplers at each end. Such end couplers are received by an upper cross member  58  which is connected to and received at both ends by the opposing couplers at the same end of opposing upper side members  54 , defining a rectangular frame upon which a roof can be supported. 
     The preferred embodiment uses a steel I-beam for the upper side members  54  and steel square tubing for the vertical support members  52  and upper cross members  58 . The ends of upper cross members  58  and upper side members  54  may be joined with single front tube couplers  90  on the waterward side of a body of water and single rear tube couplers  80  on the landward side of a body of water when the modular dock structure  10  consists of one dock structure module  20 . When a modular dock structure  10  consists of more than one dock structure module  20 , a double front tube coupler  100  is used to join upper side members  54  and upper cross members  58  on the waterward side where an interior vertical side module  50  is used. Likewise, in such applications where a plurality of dock structure modules  20  are used, a double rear tube connector  110  is used on the landward side of the body of water to connect upper side members  54  to upper cross members  58  above an interior walkway module  30 . 
     In the preferred embodiment, all walkway modules  30  is powder coated, each upper side member  54  is powder coated, each vertical support member  52  is powder coated, each upper cross member  58  is powder coated, and all single rear tube couplers  80 , all single front tube couplers  90 , all double rear tube couplers  110 , and all double front tube couplers  100  are powder coated before installation and assembly of a dock structure module  20  to dramatically increase the lifespan of the dock structure module  20  and dramatically slow the deterioration due to oxidation and other deleterious processes of weather and other impact damage. In the preferred embodiment, the upper side members  54  and upper cross members  58  are elevated 96″ above the top most surface of a walkway module  30 , enabling all but the very largest of human beings to traverse the top of a walkway module&#39;s  30  surface without impacting its head upon the upper side members  54  or upper cross members  58 . Other embodiments may vary the 96 inch height to a variety of other specific dimensions depending upon the application. 
       FIG. 3  is a perspective view of the walkway module shown in  FIG. 2 . 
     This figure illustrates the design of the walkway module  30  portion of the dock structure module  20 . The walkway module  30  is comprised of a pair of opposing side members  32  and  34  and a pair of opposing end members  36  and  38 . A plurality of spaced decking support members  35  are arranged perpendicular to the opposing side members  32  and  34  with the ends of the decking support members  35  affixed to the interior of the opposing side members  32  and  34 . The decking support members  35  are spaced to create a plurality of receiving cavities  47 ,  48  and  49  into which the lower end of each vertical support member  52  is inserted and affixed such that each vertical support member  52  is supported by its associated walkway module  30 . 
     Each decking support member  35  is recessed below the top most surface of the side members  32  and  34  and the end members  36  and  38 . In the negative space created by the recession of each decking support member  35 , a plurality of top support members  42 ,  44  and  46  lay perpendicular to and across the decking support members  35  with the lower most surface of each top support member  42 ,  44  and  46  affixed to each deck support member  35  it crosses at the location of the intersection. The exterior most top support members  42 ,  44  and  46  are placed in such a way that they do not cover the receiving cavities  47 ,  48  and  49  created by adjacent decking support members  35 . 
     The side members  32  and  34  and the end members  36  and  38  and the decking support members  35  and the top support members  42 ,  44  and  46  all have top most surfaces which support decking. In the preferred embodiment there are eight decking support members  35  and four of those decking support members  35  are evenly spaced between the end members  36  and  38 , while another decking support member  35  is placed immediately adjacent to each end member  36  and  38  to create a receiving cavities  47  and  49  sufficient to receive the lower most end of a vertical support member  52 , with the remaining decking support members  35  placed on either side of the mid-point of each side member  32  and  34  to likewise define a receiving cavity  48  for the lower most end of a vertical support member  52 . In the preferred embodiment, the area of the top surface of a walkway module  30  is eighty square feet defined by side members  32  and  34  that are 240″ long and end members  36  and  38  that are 48″ wide. In the preferred embodiment, the vertical support members  52  are made from steel square tubing of 6″×6″ or 8″×8″ and are positioned 14″ to the left of the right most edge of the right most side member  32  for steel square tubing of 6″×6″ and 13″ to the left of the right most edge of the right most side member  32  for steel square tubing of 8″×8″ when viewed from the waterward side of the dock structure module  20 . 
       FIG. 4  is a top view of a walkway module shown in  FIG. 3 . 
     This view illustrates the configuration of the side members  32  and  34 , end members  36  and  38 , decking support members  35  and top support members  42 ,  44  and  46  as viewed from the top, showing the defined receiving cavities  47 ,  48  and  49  in which the lower most ends of the vertical support members  52  are received. 
       FIG. 5  is a face view of a walkway module shown in  FIG. 3 . 
     A walkway module  30  has an upper surface  31  and a lower surface  33 . The upper surface  31  is comprised of side members  32  and  34  and end members  36  and  38 , decking support members  35  and top support members  42 ,  44  and  46  which provide support and strength for placing decking on the upper surface  31  of a walkway module  30 . Decking can be acquired in a variety of formats, including pre-fabricated concrete, wood products, tile products, and other suitable substances upon which human beings can traverse a walkway module  30 . Such decking is affixed to the walkway module  30  by affixing means to form a continuous surface on the upper surface  31  of the walkway module  30 . In the preferred embodiment, the walkway module  30  is powder coated before it is joined or affixed to vertical support members  52 . After powder coating, vertical support members  52  can be joined with an associated walkway module  30  during installation and assembly. A walkway module  30  can be joined or affixed to vertical support members  52  after the walkway module  30  and vertical support members  52  have been powder coated. In that circumstance, the powder coating at the location of the weld will be disrupted. However, the location of the weld will be beneath the surface of the decking placed on the upper surface  31  of the walkway module  30  so that any such weldment will be concealed from view and not disrupt the visible portion of the powder coating. 
       FIG. 6  is a perspective view of a vertical side module shown in  FIG. 2 . 
     The vertical side module  50  is comprised of an upper side member  54  and a plurality of vertical support members  52  which are affixed at their upper most end and spaced apart along the underside of the upper side members  54 . The upper side members  54  have receiving cavities  53  and  55  at each end for a coupler to enable the upper side member  54  to be fixed and connected to upper cross members  58 . A variety of couplers can be used to affix and connect an upper side member  54  to an upper cross member  58  depending upon whether there will be one dock structure module  20  in the ultimate modular dock structure  10  or a plurality of dock structure modules  20  in the modular dock structure  10 . In the preferred embodiment, the upper side member  54  is a steel I-beam 288″ in length with the flange surfaces of the I-beam  57  and  59  oriented so they are horizontal. The lower flange of the I-beam  59  is affixed to the uppermost end of each vertical support member  52 . There are three vertical support members  52  in the preferred embodiment and in the preferred embodiment the vertical support members  52  are made from steel square tubing, 6″×6″ or 8″×8″ dimension, with the waterward most face of the vertical support member  52  located 50″ from the waterward most end of the upper side member  54 , the interior vertical support member  52  located 109″ from the landward face of the waterward most vertical support member  52  and the waterward face of the most landward vertical support member  52  located 109″ landward of the landward face of the interior vertical support member  52 . 
     The lower most end of the vertical support members  52  are received by the receiving cavities  47 ,  48  and  49  of a walkway module  30  and are affixed between adjacent, associated decking support members  35 . In the preferred embodiment, the uppermost end of the vertical support members  52  are affixed to the upper side members  54  by welding the vertical support members  52  to the upper side members  54 . These welds are made prior to powder coating. After the vertical support members  52  have been welded to the upper side members  54 , the couplers that will be used to attach upper cross members  58  are welded to the upper side members  54  and then the vertical side module  50  is powder coated. 
     In the preferred embodiment, there is a dock structure module  20  defined by a pair of walkway modules  30  that each have an associated vertical side module  50  extending above them. Each vertical side module  50  is connected to the other by use of an upper cross member  58  at each end of the vertical side module  50  to define a rectangular structure which is supported above the opposing walkway modules  30 . In the preferred embodiment, a roof structure which can be of varied design, is placed upon the elevated rectangular area defined by the upper side members  54  and upper cross members  58  in order to protect persons on the walkway module  30  and items on the walkway module  30  from exposure to the elements, falling rain, avian species in flight overhead, the harmful rays of the sun, etc. 
       FIG. 7  is a side view of the vertical side module shown in  FIG. 6 . 
     This figure shows the orientation of vertical support members  52  and their associated upper side members  54  as well as the receiving cavities  53  and  55  on each end of the upper side member  54 . 
       FIG. 8  is an end view of the vertical side module shown in  FIG. 6 . 
     This figure illustrates the receiving cavity  53  on the waterward side of a vertical side module  50 . The waterward receiving cavity receives and accepts the insertion of a single front tube coupler  90  or a double front tube coupler  100  to enable the waterward side of an upper side member  54  to be connected to an associated upper cross member  58 . The single front tube coupler  90  is used in applications where the vertical side module  50  forms the outermost edge of the frame of a dock structure module  20 , while a double front tube coupler  100  is used to join an interior upper side member  54  to two associated upper cross members  58  for applications for which there is more than one dock structure module  20  in a given modular dock structure  10 . 
     While the use of weldments to join metallic and steel members or elements is a useful process, in general, it is destructive to the powder coating applied to the elements or members of the dock structure module  20  and thus undesirable as a means for joining the elements or members of the completed assembly. To avoid and limit the use of weldments in the completed assembly four novel couplers have been designed to couple the elements and members of the dock structure module  20  to each other. Said couplers are discussed and described in more detail below. In the preferred embodiment, all of said couplers are either welded to their associated members or elements and then powder coated after the weldments are made or are coupled to their associated members or elements by the use of standard fasteners which do not damage the powder coating applied to the couplers at the time of assembly. 
       FIG. 9  is a perspective view of a single rear tube coupler that may be used with the dock structure module shown in  FIG. 2 . 
     The single rear tube coupler  80  joins an upper side member  54  to an associated upper cross member  58  on the landward side of a dock structure module  20 . The single rear tube coupler  80  enables two adjacent vertical side modules  50  to be joined by an upper cross member  58 . A single rear tube coupler  80  is comprised of six connector plates  81 , one inner connector plate  91 , and one single end connector plate  101 . Each connector plate  81  has a leading edge  86 , a trailing edge  87 , and a pair of opposing side edges  88 . Each inner connector plate  91  has a leading edge  96 , a trailing edge  97  and opposing perpendicular side edges  98 . Each single end connector plate  101  has a leading edge  106 , a trailing edge  107  and opposing perpendicular side edges  108 . The single rear tube coupler  80  is constructed by welding the side edge  88  of a connector plate  81  to the side edge  88  of a second connector plate  81 , longitudinally, so that the leading edges  86  form a right angle and so that said leading edges  86  are planar with one another. A third connector plate  81  is then welded longitudinally along its side edge  88  to the side edge  88  of a connector plate  81  at the side edge  88  opposite where the weld between the first two connector plates  81  was made so its leading edge  86  forms a right angle with the connector plate  81  to which it is welded and is planar with the leading edges  86  of the other two welded connector plates  81  such that its unwelded side edge  88  is planar with the unwelded side edge  88  of the first connector plate  81 . A fourth connector plate  81  is then welded on each side edge  88  to the receiving unwelded side edges  88  of the other two connector plates  81  so that it forms a right angle with both connector plates  81 , forming a square male insertion adapter  120 . 
     The single rear tube coupler  80  is comprised of a male insertion adapter  120  that can be inserted into and received by the receiving cavity of the upper cross member  58 , a male insertion adapter  120  that can be inserted into and received by the receiving cavity of an upper side member  54 , and a female receiving adapter  130  which can receive the receiving cavity of an upper side member  54  that is longitudinally centric and planar with an associated upper side member  54  and having both male insertion adapters  120  longitudinal with the female receiving adapter  130  and both male insertion adapters  120  simultaneously perpendicular to each other and with each male insertion adapter  120  having means of mechanically connecting it to an upper cross member  58  through the use of standard style fasteners, such as nuts and bolts, that hold each male insertion adapter  120  inside the receiving cavity of an upper cross member  58  by means of a nut and bolt or other similar fastener which engages the receiving cavity of the upper side member  54  or upper cross member  58  and male insertion adapter  120  simultaneously so as to prevent disengagement by traction, and simultaneously having means of engaging the female receiving adapter  130  by use of a weldment or other mechanical means. 
     In the preferred embodiment, the female receiving adapter  130  is welded to an upper side member  54  which is a steel I-beam. 
     The single rear tube coupler permits, in the preferred embodiment, the upper cross member  58  and upper side member  54  of the dock structure module  20  to be joined as depicted in  FIG. 13  as described and illustrated below. 
       FIG. 10  is a perspective view of a single front tube coupler that may be used with the dock structure module shown in  FIG. 2 . 
     A single front tube coupler  90  is comprised of a male insertion adapter  120  and a female receiving adapter  130  wherein the male insertion adapter  120  and female receiving adapter  130  are longitudinally aligned and planar with each other. The male insertion adapter  120  is designed to be inserted into the end of an upper cross member  58  and to be received by the receiving cavity of an upper cross member  58  and the female receiving adapter  130  is designed to be affixed to an upper side member  54  by mechanical affixing means, which is affixed by welding in the preferred embodiment. 
     In the preferred embodiment, the single front tube coupler  90  is made of steel and is comprised of two connector plates  81 , an inner connector plate  91  and a single end connector plate  101 . The single front tube coupler is constructed by welding the side edge  88  of a connector plate  81  to the side edge  98  of an inner connector plate  91 , longitudinally, so that the leading edges  86  and  96  form a right angle and so that said leading edges  86  and  96  are planar with one another. A second connector plate  81  is then welded longitudinally along its side edge  88  to the unwelded side edge  98  of the inner connector plate  91  at the side edge opposite where the weld between the connector plate  81  and inner connector plate  91  was made so that its leading edge  86  forms a right angle with the inner connector plate  91  to which it is welded and is planar with the leading edges  86  and  96  of the previously welded connector plate  81  and inner connector plate  91  and such that is unwelded side edge  88  is planar with the unwelded side edge  88  of the first connector plate  81 . A single end connector plate  101  is then welded on each side edge  108  to the remaining unwelded side edges  88  of the two connector plates  81  so it forms a right angle with both connector plates  81 , forming a square male insertion adapter  120 . 
     The single front tube coupler  90  is used to join the upper cross member  58  and upper side member  54  of the dock structure module  20  at a right angle on the waterward side of the dock structure module  20  for applications in which there is only one upper cross member  58  being connected to the associated upper side member  54  which will always be the case in the construction of a modular dock structure  10  containing only one dock structure module  20 . The single front tube coupler  90  is always used on the waterward end of an upper side member  54  which forms the side most edge of the dock structure module  20  of which there will always be at least two. 
     The single front tube coupler  90  permits, in the preferred embodiment, the upper cross member  58  and upper side member  54  of the dock structure module  20  to be joined as depicted in  FIG. 14  as described and illustrated below. 
       FIG. 11  is a perspective view of a double rear tube coupler that may be used with the dock structure module shown in  FIG. 2 . 
     The double rear tube coupler  110  joins the receiving end of an upper side member  54  to the receiving end of an associated upper cross member  58  on the landward side of a dock structure module  20 . The double rear tube coupler  110  enables an interior vertical side module  50  adjacent to two other vertical side modules  50  on each side of said interior vertical side module  50  to be joined by an upper cross member  58  on each side of the interior vertical side module  50  in an application where more than one dock structure module  20  is used in creating a modular dock structure  10 . 
     A double rear tube coupler  110  is comprised of three male insertion adapters  120 , having two of the adapters oriented opposing one another on a longitudinal axis and one male insertion adapter  120  centrally located and perpendicular to the longitudinal axis upon which the other two male insertion adapters  120  are aligned. The double rear tube coupler  110  is designed and used for joining the ends of two opposing upper cross members  58  to the landward receiving cavity of an upper side member  54  in applications where an interior vertical side module  50  is used in order to create a modular dock structure  10  that has more than one dock structure module  20 . 
     In the preferred embodiment, the female receiving adapter  130  is welded to an upper side member  54  which is a steel I-beam. 
     The double rear tube coupler  110  permits, in the preferred embodiment the receiving ends of two upper cross members  58  and the receiving end of one upper side member  54  of the dock structure module  20  to be joined on the landward side as depicted in  FIG. 15  as described and illustrated below. 
     In the preferred embodiment, a double rear tube coupler  110  is comprised of eight connector plates  81 , two inner connector plates  91 , and one double end connector plate  111 , having two opposing leading edges  116  and two opposing side edges  118 . The double front tube coupler  110  is constructed by welding the side edge of a connector plate  81  to the side edge  88  of a second connector plate  81 , longitudinally, so that the leading edges  86  form a right angle and so that said leading edges  86  are planar with one another. A third connector plate  81  is then welded longitudinally along its side edge  88  to the side edge  88  of a connector plate  81  at the side edge  88  opposite where the weld between the first two connector plates  81  was made so that its leading edge  86  forms a right angle with the connector plate  81  to which it is welded and is planar with the leading edges  86  of the other two welded connector plates  81  such that is unwelded side edge  88  is planar with the unwelded side edge  88  of the first connector plate  81 . A fourth connector plate  81  is then welded on each side edge  88  to the receiving unwelded side edges  88  of the other two connector plates  81  so that it forms a right angle with both connector plates  81 , forming a square male insertion adapter  120 . This square male insertion adapter  120  is then welded along the trailing edge  87  of each connector plate  81  to a double front tube coupler  100  such that the trailing edges  86  of two opposing connector plates  81  are welded longitudinally along both side edges  118  of the double front tube coupler&#39;s  100  double end connector plate  111  along the side edges  118  of the double end connector plate  111  at the location where the side edges  118  of the double end connector plate  111  are unwelded and such that the trailing edge of the connector plates  81  is affixed to the exterior surface of the double front tube coupler  100 . 
       FIG. 12  is a perspective view of a double front tube coupler that may be used with the dock structure module shown in  FIG. 2 . 
     The double front tube coupler  100  joins an upper side member  54  to an associated upper cross member  58  on the waterward side of a dock structure module  20 . The double front tube coupler  100  enables an interior vertical side module  50  adjacent to two other vertical side modules  50  on each side of said interior vertical side module  50  to be joined by an upper cross member  58  on each side of the interior vertical side module  50  in applications where more than one dock structure module  20  is used in creating a modular dock structure  10 . 
     The double front tube coupler  100  is comprised of a male insertion adapter  120  that can be inserted into and received by the receiving cavity of an upper cross member  58 , an opposing male insertion adapter  120  that can be inserted into and received by an upper side member  54 , and a female receiving adapter  130  which can receive the receiving cavity of an upper side member  54  with the said male insertion adapters  120 , opposing male insertion adapter  120 , and female receiving adapter  130  longitudinally centric and planar with an associated upper side member  54  and having both male insertion adapters  120  longitudinal with the female receiving adapter  130  and both male insertion adapters  120  simultaneously longitudinally centric with each other and with each male insertion adapter  120  having means of mechanically connecting it to an upper cross member  58  through the use of standard style fasteners, such as nuts and bolts that hold each male insertion adapter  120  inside the receiving end of an upper side member  54  by means of a nut and bolt or other similar fastener which engages the receiving end of the upper cross member  58  and male insertion adapter  120  simultaneously so as to prevent disengagement by traction. 
     In the preferred embodiment, the female receiving adapter  130  is welded to an upper side member  54  which is a steel I-beam. 
     The double front tube coupler  100  permits, in the preferred embodiment, the receiving ends of two upper cross members  58  and the receiving end of an upper side member  54  of the dock structure module  20  to be joined as depicted in  FIG. 16  as described and illustrated below. 
     In the preferred embodiment, a double front tube coupler  100  is comprised of four connector plates  81 , two inner connector plates  91 , and one double end connector plate  111 . The double front tube coupler  100  is constructed by welding the side edge  88  of a connector plate  81  to the side edge  118  of a double end connector plate  111 , longitudinally, so that the leading edges  86  and  116  form a right angle and so that said leading edges  86  and  116  are planar with one another. A second connector plate  81  is then welded longitudinally along its side edge  88  to the side edge  118  of the double end connector plate  111  at the side edge  118  opposite where the weld between the first connector plate  81  and double end connector plate  111  was made so its leading edge  86  forms a right angle with the double end connector plate  111  to which it is welded and it is planar with the leading edges  86  and  116  of the welded connector plate  81  and double end connector plate  111  such that its unwelded side edge  88  is planar with the unwelded side edge  88  of the first connector plate  81 . An inner connector plate  91  is then welded on each side edge  98  to the unwelded side edges of the remaining unwelded side edges  88  of the other two connector plates  81  so it forms a right angle with both connector plates  81 , forming a square male insertion adapter  120 . Then, a third connector plate  81  is welded longitudinally along its side edge  88  to the side edge  98  of an inner connector plate  91 , longitudinally, so that the leading edges  86  and  96  form a right angle and so that said leading edges  86  and  96  are planar with one another. A fourth connector plate  81  is then welded longitudinally along its side edge  88  to the unwelded side edge  98  of the inner connector plate  91  at the side edge  98  opposite where the weld between the connector plate and inner connector plate was made so its leading edge  86  forms a right angle with the connector plate  81  to which it is welded and is planar with the leading edges of the welded connector plate  81  and inner connector plate  91  such that its unwelded side edge  88  is planar with the unwelded side edge  88  of the third connector plate  81 . The unwelded end of the double end connector plate  111  is then welded on each side edge  118  to the remaining unwelded side edges  88  of the third and fourth connector plates  81  so it forms a right angle with both connector plates  81 , forming an opposing square male insertion adapter  120 . 
       FIG. 13  is a perspective view of a single rear tube coupler shown in  FIG. 9  coupled with an upper cross member and upper side member as shown in  FIG. 2 . 
     A single rear tube coupler  80  is used to join an associated upper side member  54  to an associated upper cross member  58  on the landward side of the dock structure module  20 .  FIG. 13  demonstrates the connection that is made in that circumstance. After the connection is made, there is an exposed male insertion adapter  120  which may be coupled to an upper linking member  70  to enable either two dock structure modules  20  to be positioned with their inward most faces parallel to one another or to affix the upper linking member  70  to a permanent structure, such as a roof, on the landward side of the dock structure module  20  by affixing means. The engagement between the single rear tube coupler  80  and each upper side member  54 , upper cross member  58  and upper linking member  70  are made as described in more detail below and as depicted in  FIG. 17 . 
       FIG. 14  is a perspective view of a single front tube coupler shown in  FIG. 10  coupled with an upper cross member and upper side member as shown in  FIG. 2 . 
     A single front tube coupler  90  is used to join an associated upper side member  54  to an associated upper cross member  58  on the waterward side of the dock structure module  20 .  FIG. 14  demonstrates the connection that is made in that circumstance. The engagement between single front tube coupler  90  and each upper side member  54  and upper cross member  58  are made as described in more detail below as depicted in  FIG. 17 . 
       FIG. 15  is a perspective view of a double rear tube coupler shown in  FIG. 11  coupled with adjacent upper cross members and upper side member as shown in  FIG. 2 . 
     A double rear tube coupler  110  is used to join an associated upper side member  54  to two associated upper cross members  58  on the landward side of the dock structure module  20 .  FIG. 15  demonstrates the connection that is made in that circumstance. After the connection is made, there is an exposed male insertion adapter  120  which may be coupled to an upper linking member  70  to enable either two dock structure modules  20  to be positioned with their inward most faces parallel to one another or to affix the upper linking member  70  to a permanent structure, such as a roof, on the landward side of the dock module structure  20  by affixing means. The engagement between the double rear tube coupler  110  and each upper side member  54 , two upper cross member  58 , and upper linking member  70  are made as described in more detail below and as depicted in  FIG. 17   
       FIG. 16  is a perspective view of a double front tube coupler shown in  FIG. 12  coupled with adjacent upper cross members and upper side member as shown in  FIG. 2 . 
     A double front tube coupler  100  is used to join an associated upper side member  54  to two associated upper cross members  58  on the waterward side of the dock structure module  20 .  FIG. 16  demonstrates the connection that is made in that circumstance. The engagement between the double front tube coupler  100  and the upper side member  54 , two upper cross members  58  and upper linking member  70  are made as described in more detail below and as depicted in  FIG. 17 . 
       FIG. 17  is a perspective view of a single rear tube coupler which illustrates the joining of a coupler to an upper cross tube member, an upper side member, and an upper linking member. 
     Similar to what is shown in  FIG. 13 ,  FIG. 17  depicts a single rear tube coupler  80  with its female receiving adapter  130  connected to an upper side member  54 . After the connection between the female receiving adapter  130  and the upper side member  54  is made, there are two exposed male insertion adapters  120 . The connection between the female receiving adapter  130  and the upper side member  54  is made by welding the female receiving adapter  130  into the receiving cavity  55  of the associated upper side member. In applications that utilize double rear tube couplers  110 , the female receiving adapter  130  of the double rear tube coupler  110  is welded into the receiving cavity  55  of the upper side member  54 . In applications where a single front tube coupler  90  or a double front tube coupler  100  are used, the female receiving adapters  130  of the said couplers are welded into the receiving cavity  55  of the associated upper side member  54 . Whichever fashion of coupler is used, be it single rear tube coupler  80 , single front tube coupler  90 , double rear tube coupler  110  or double front tube coupler  100 , the female receiving adapter  130  of that fashion of coupler is welded into its associated receiving cavity  53  or  55  before powder coating of the vertical side module  50  occurs so that the welding process does not damage the powder coating. The male insertion adapter  120  that is perpendicular to the upper side member  54  is then inserted into the receiving cavity of an upper cross member  58  and is engaged with the upper cross member  58  by the use of a plurality of standard fasteners sufficient to prevent disengagement by traction. In the preferred embodiment, hex nuts  74  are used to retain hex bolts  72  on all four planar surfaces of the male insertion adapter  120 . In the preferred embodiment, two hex nuts  74  and two hex bolts  72  are used on each of the four faces of the male insertion adapter to engage the male insertion adapter  120  with the upper cross member  58 . In the preferred embodiment, the hex nuts  74  are welded into the receiving cavity of the coupler being used, whether it be a single rear tube coupler  80 , a single front tube coupler  90 , a double rear tube coupler  110  or a double front tube coupler  100 , because the interior of the coupler is not accessible after assembly. Powder coating is undertaken after the hex nuts  74  have been welded into the couplers. Similarly, the upper linking member  70  is engaged with the male insertion adapter  120  that is collinear with the upper side member  54  using the same mechanism of engagement through the use of hex nut  74  and hex bolt  72  that is used to engage an upper cross member  58 . 
     In the preferred embodiment, the single rear tube coupler  80 , upper side member  54 , upper cross member  58  and upper linking member  70  are all powder coated before assembly of each of those modular elements so that no weldments are required to be made in order to join the modular elements after powder coating. The design thus results in no damage to the powder coating at the time of engagement of the modular elements thereby significantly extending the expected life of the joint and connection made between the single rear tube coupler  80 , upper side member  54 , upper cross member  58  and upper linking member  70 , and providing a pleasing, finished appearance without need for regular maintenance. 
       FIG. 18  is a pictorial view of an improved modular dock structure comprised of two dock structure modules illustrating the use of a movable boat hoist in each dock structure module and lagging atop each walkway module. 
     It is desirable to use a boat hoist in conjunction with modular dock structures  10 , in general. Each dock structure module  20  of a modular dock structure  10  in the current design is capable of having a boat hoist  160  retained between its opposing upper side members  54 . Boat hoists  160  can take on a variety of configurations and are beyond the scope of this invention, but  FIG. 18  is illustrative of the environment in which a boat hoist  160  such as that shown can be accommodated. In such applications, the boat hoist  160  will be constructed to be slidably retained by opposing upper side members  54  with engagement of the boat hoist being enabled by the upper and lower flange surfaces of the I-beam  57  and  59  of the opposing upper side members  54 . In such applications, the longitudinal location of such boat hoist  160  can be varied by its longitudinal placement along the channel created by the inner lower flange  59  and upper flange  57  of the upper side member  54  where the upper side member  54  is a steel I-beam. In such applications, a boat hoist  160  could be welded or connected with standard fasteners to the opposing upper side members  54  in order to create a secure attachment or could otherwise be joined with the upper side members  54  by other affixing means. Walkway modules  130  can be covered by a variety of materials, as mentioned above, including pre-fabricated concrete lagging  164 . Such lagging or other surface may be installed at the time of installation, on site, or before a given walkway module  30  is transported to the construction site. 
       FIG. 19  is a perspective view of an angle iron track for use with a movable boat hoist that may be used with the dock structure module shown in  FIG. 2 . 
     In another embodiment of the disclosed invention, the upper side member  54  is constructed of steel square tubing instead of a steel I-beam. In such applications, an angle iron track  170  is welded to the interior face of each opposing upper side member  54  to create a track upon which a boat hoist  160  can be slidably retained in the manner discussed above in regard to  FIG. 18 . In such applications, the angle iron track  170  is welded to the upper side member  54  before powder coating occurs, so that it becomes part of the vertical side module  50 . 
       FIG. 20  is a pictorial view of an improved modular dock structure comprised of a plurality of dock structure modules illustrating the flexibility of configuration of a plurality of the components of the improved modular dock structure. 
     In the pictorial representation, an ideal modular dock structure  10  is depicted containing a plurality of dock structure modules  184 . In the pictorial representation, the landmass  180  from which the modular dock structure extends is shown. The modular dock structure extends over a body of water  190  and creates a plurality of bays or empty spaces  182  where watercraft can be stationed. The pictorial representation depicts a series of walkway modules  186  that travel perpendicular to the walkway modules of each dock structure module  184  and can be supported by piling driven into the bed of the lake or secured to the opposing walkway modules of each dock structure module  184 . 
       FIG. 21  is a perspective view of a piling end cap that may be used with the dock structure module shown in  FIG. 2 . 
     The piling end cap  14  is comprised of a top plate cap  16  and two vertical side retainers  18 . The piling end cap  14 , in the preferred embodiment, is welded to the vertical piling  12 . The top most end of the vertical piling  12  is slotted between the vertical side retainers  18  so that the top most end of the vertical piling  12  fits snugly between the vertical side retainers  18 . The top plate cap  16  is flush with the top most end of the vertical piling  12 . The piling end cap  14  is then appropriately welded to the vertical piling  12 . 
     The piling end cap  14  is not powder coated. In the preferred embodiment, walkway modules  30  are supported by a plurality of vertical piling  12  which have each been topped with a piling end cap  14 . The piling end cap  12  of each vertical piling associated with a particular walkway module  30  are then each welded to the particular walkway module  30  to appropriately support the walkway module  30 . The welds made at this location are ultimately covered by decking or lagging panels  164  obscuring the visibility of the welds. In the preferred embodiment, the vertical piling  12 , the piling end caps  14  and walkway modules  30  are constructed of steel members thick enough to withstand oxidation and corrosion over the expected life of the dock structure module  20  and modular dock structure  10  so that any damage to the powder coating on the walkway modules  30  is obscured by lagging or other decking atop the walkway modules  30  and is thus not visible to users of the subject modular dock structure  10 , while being made of steel of sufficient thickness to outlast the expected lifespan of the modular dock structure  10  in the event of oxidation or corrosion. 
     As depicted, there are a variety of configurations in which the modular dock structure can be oriented by repetition of the use of a dock structure module  20 , such that modular dock structures of virtually unlimited size and orientation can be created such as in the setting of a marina. Likewise, it is evident that the walkway modules can be lined with impact resistant materials (such as a bumper) in order to prevent damage to watercraft coming into contact with the walkway structures and a variety of fixtures, such as anchoring cleats, rings, etc. can be affixed to the walkway modules to enable watercraft to be tied off or otherwise anchored to a walkway module. 
     The description of the invention is given in its best mode with the presentation of drawings depicting the preferred embodiment of the modular dock structure invention and its basic dock structure module. The invention can be variously arranged to have a variety of embodiments and modes of operation, within the ability of those skilled in the art and without the need of further invention.