Patent Publication Number: US-2010111613-A1

Title: Inflatable dock

Description:
RELATED APPLICATIONS 
     This application claims priority benefit of U.S. Ser. No. 61/018,345, filed Dec. 31, 2007. 
    
    
     BACKGROUND OF THE DISCLOSURE 
     a) Field of the Disclosure 
     The present invention relates to a floating inflatable dock. 
     b) Background Information 
     There are various applications where inflated members are used to support persons, cargo, equipment and other objects. There are certain advantages to having these inflatable members, such as in being able to insert them and remove them from a water environment, ship these to other locations for use, stow them in certain locations and then inflate them for temporary use. 
     However, one of the disadvantages of these can be stability. To stabilize various flotation members, or nautically related traveling equipment ballast is used in the form of various objects of higher density to add weight to the support portions of the inflatable apparatus, systems or objects. 
     It is toward these and other related problems which the embodiments of the present invention are directed. 
     SUMMARY OF THE DISCLOSURE 
     There is a dock assembly  10  which comprises a platform section having an inflatable chamber and also a counterweight section. The platform section comprises a main central panel section made of a drop-stitch panel, and also a side closure portion to provide its buoyancy. The counterweight section comprises flexible containing members that can be filled with water and positioned in or below water so that the weight of the mass of water has no affect while it is immersed in the water, but functions as a counter-balance if certain portions of the assembly are being lifted above the operating elevation. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side elevational view of an embodiment of a dock assembly of the present invention with the dock assembly having a square configuration; 
         FIG. 2  is a top plan view of the square shaped dock assembly shown in  FIG. 1 ; 
         FIG. 3  is a bottom view of the dock assembly shown in  FIGS. 1 and 2 ; 
         FIG. 4  is an isometric view showing three components which are formed into a sheet which is in turn used as part of a drop-stitch structure flotation platform section of the dock assembly; 
         FIG. 5  is an isometric view illustrating the basic structure of a drop-stitch panel section of the flotation platform section; 
         FIG. 6  is a cross-sectional view of the flotation platform section of the dock utilizing the structure of  FIG. 5 , and also its perimeter closure section; 
         FIG. 7  is a cross-sectional view similar to  FIG. 6 , but showing only one edge portion of the panel of  FIG. 6  drawn to an enlarged scale; 
         FIG. 8  is a side-elevational view of the dock assembly looking in a diagonal direction toward one of the four counterbalance members and toward the center of the dock assembly with a load being imposed at the center of the dock assembly; 
         FIG. 9  is a side-elevational view showing the dock assembly from the same location as in  FIG. 8 , but showing a load being imposed on a corner edge portion of the dock assembly and also illustrating the manner in which the several forces are imposed on the dock assembly; 
         FIG. 10  is a side-view similar to  FIG. 8 , except that the view is taken from a location looking toward one of the side edge portions of the dock assembly in a direction perpendicular to that side edge portion with a downward load being imposed at the center of the dock assembly; 
         FIG. 11  is a view similar to  FIG. 10 , showing the way force components would be imposed upon the dock assembly location of that side edge; 
         FIGS. 12A-12E  are four semi-schematic drawings illustrating various situations relating to the dock assembly; 
         FIG. 13  is an isometric view of a second embodiment; and 
         FIG. 14  is a sectional view taken at  14 - 14  of  FIG. 13 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference first to  FIGS. 1 ,  2 , and  3 , the dock assembly  10  of this first embodiment comprises a platform section  12  and a counterweight section  14 . The counterweight section  14  in turn comprises four counterweight members  15  at the corners of the platform section  12 . 
     The platform  12  comprises a main central panel section  16  having in plan view in this embodiment a rectangular shape (and in this embodiment a square shape). The panel section  16  is made as a drop-stitch panel  16 , and it has a perimeter closure section  18 . The panel section  16  and the perimeter closure section  18  together form the platform section  12  which can be considered to be a flotation platform section  12 , which has an inflatable pressure chamber  17 . 
     To describe in more detail the nature of the drop-sheet panel  16 , reference is now made  FIGS. 4 through 7 . 
     As indicated above, the drop-sheet panel section  16  has upper and lower sheets  19  and  20 . To make each of these sheets  19  and  20 , as shown in  FIG. 4 , there is first provided upper and lower thin polymer layers  22  and a middle layer of a tri-axial or bi-axial threads  23 , with these being laminated between the layers  22 . Thus, these two layers  22  and the core layer form a unitary sheet, and these are the sheets  19  and  20 . Then these two layers  19  and  20  are connected to one another by a large number of closely spaced threads  21  to form the panel as shown in  FIG. 5 . 
     The two sheets  19  and  20  are flexible, but they cannot be stretched. Also, the threads  21  are flexible, but these also cannot be stretched. Drop-stitch panels are commercially available with threads of various lengths. 
     With reference now to  FIGS. 6 and 7 , there is shown in cross-section the drop-stitch panel  16  with the perimeter closure section  18 . As can be seen in  FIG. 7 , the perimeter closure section  18  comprises outer perimeter edge portions  24  and  26  of the upper and lower sheets  19  and  20  extend a short distance beyond the perimeter edge of the threads  21 . There is a central main enclosing portion  28  of the perimeter closure section  18  and it has the configuration of an elongate thin sheet  28  which has edge portions  30  which overlap the outer perimeter portions  24  and  26  of the sheets  19  and  20 . These outer perimeter portions  24  and  26  and the edge portions  30  are bonded to one another to form an air-tight and water-tight perimeter for the panel  16  to form with the upper and lower sheets in the inflatable pressure chamber  17 . 
     With reference to  FIG. 1 , let us now turn our attention to the counterweight section  14  which in this embodiment comprises the four counterweight members  15 . Each of these four counterweight members  15  comprises a flexible water-containing configuration  36  which has the overall configuration of a rectangular prism. Each counterweight member  15  comprises four sidewalls  38  and a bottom floor member  40 . The sidewall members  38  have a moderate taper toward one another in a downward direction, so that each sidewall member has a slightly trapezoidal shape. 
     The upper edge portions of the four sidewalls  38  have a water-tight connection to the bottom sheet  20  so that each of these defines a water-tight chamber, which in this present embodiment is filled with water in its operating position in a body of water. Each of these counterweight members  15  has one or more valves shown schematically at  41  through which water can flow to fill the counterweight member  15  or to empty it. 
     These counterweight members  15  are made of a flexible material, so that when the dock is in its non-operating position, it can be folded up in a compact storage configuration. The platform section  12  has one or more air-inlet and outlet valves shown at  43  so that the platform section  12  can be inflated or deflated. 
     To describe now the operation of the present invention, reference will be made first to  FIGS. 8 and 9 . The dock assembly  10  is made substantially entirely of flexible material so that it can have an inflated operating configuration, and also a compact stowage configuration where the components are folded up into a storage configuration. 
     To place the dock assembly  10  in its operating condition, there are two major steps. One step is to inflate the platform section  12  to pressurize its interior to a relatively high pressure level (i.e. 5 to 10 PSI (pounds per square inch) or possibly more). 
     One of the characteristics of the drop-stitch configuration of an inflatable member is that when it is pressurized to a relatively high level, it is structurally substantially rigid. Thus, the platform section  12  maintains its configuration of having flat upper and lower surfaces  19  and  20  and a rounded perimeter closure section  18  which, in performing its functions, is able to withstand rather large forces applied to it and deviates from its regular configuration only slightly. Thus, for all practical purposes, the platform section  12  can be regarded as a relatively light-weight rigid panel, capable of maintaining its basic configuration and supporting rather substantial loads, but with a very small degree of bending under high loads. 
     The other step is to fill each of the four counterweight members  15  with water through one or more of the valves  41 . After each of these counterweight members  15  is filled with water, the valve(s)  41  is/are shut, and the water remains within the structure of the counterweight member  15 . 
       FIG. 8  illustrates the dock assembly  10  in its operating position on a water surface with the flotation platform section  12  inflated to a sufficiently high pressure and with each of the counterweight members  15  being filled to full capacity with water. The platform section  12  is the flotation member. With regard to the counterweight members  15 , the flexible water impervious material of which the counterweight section  14  is made has by itself very little weight. Thus, with each of the counterweight members  15  being filled with water, and being totally immersed in the water these counter-balance members  15  impose no loads on the floatation platform section  12 . 
     In  FIG. 8  there is shown a single force component  50  which represents the weight of a container or one or more persons imposed at the middle location of the flotation platform section  12 . Since this force  50  is at a central location on the platform section  12 , that force is distributed substantially equally throughout the entire platform section  12 . This would cause the platform section  12  to be positioned a short distance into the top surface portion of the water the water, and level is illustrated at  52 . 
     A typical small to medium square dock made as an embodiment of this invention could have dimensions, for example, of its four side portions being 8-feet in length. Thus, the area of the flotation platform section would be 8-feet squared, which would make this 64-square feet. With regard to the depth-dimension of the platform section  12 , in a typical embodiment, this depth-dimension which would be equal to the length of the threads  21  of the platform section  12  could be about 8-inches (i.e. two-thirds of a foot). 
     If we then calculate the volume of the inflated inside chamber or region of the platform section  12 , that would come out to approximately 43-cubic feet. If we now calculate the total force it would take to totally submerge the platform section  12 , assuming the weight of the water to be 62.5 pounds per cubic feet that would come out to over or about approximately 2,500-pounds of force. Now, however, if we assume that the applied force  50  is equal to, for example, 250-pounds, that would cause the platform section  12  to sink downwardly into the upper water surface portion by ten percent of the depth of the panel section  12 . In  FIG. 8  the upper surface of the water is indicated at  52 , but  FIG. 8  is not intended to be drawn to scale. 
     It is to be understood that the platform section could have other relative dimensions and shapes, such as an eight-foot by six-foot rectangle, etc. 
     In  FIG. 9  we look at a situation where the load  50  which is imposed on the center of the dock assembly  10  is moved to become the load  54  at the corner location  56  corner of the platform section  12 . We will assume that the magnitude of this force  54  of the load is enough so that it would cause the platform section  10  to tilt somewhat so that the one corner indicated at  56  would descend downwardly into the water, possibly as much as 6-inches or so. 
     The effect of this section  56  moving further into the water would result in an upward movement of the opposite corner of the dock assembly being lifted up from the water at the same time there is an upward force being applied against the bottom surface portion of the platform section  12  at the corner location. The pattern of this upward force of the displaced water is indicated by several arrows  58 , and this force indicated at  58  would decrease from left to right until it reaches a middle location of the platform section  12 , and this would cause the opposite end of the platform at  60  to move upwardly in a slant. The drawing of  FIG. 9  is not necessarily drawn to scale, but is presented to show the basic movements when this sort of force is applied at an off center location. 
     At this point, let us consider further various effects of having the four counterweight members  15 . As long as these counterweight members  15  are fully submersed in the water, there is no effect at all in the flotation characteristics of the platform section  12 . As indicated earlier, the material that makes up the walls of each of the four counterweight members  15  has little weight, and of course the water which is within the counterweight members  15  would exert no force at all, neither upward nor downward relative to the platform section  12 . 
     However, assuming that the load  54  of the weight that is imposed at an off center location upon the panel section  12  is great enough, then the oppositely positioned counterweight member indicated at  60   a  in  FIG. 9  would begin to rise upwardly from the water, and the amount of water in the member  60   a  which is above the actual water level would act as a counter-balancing weight that would limit the opposite end portion  61  of the platform section  12  from moving further downwardly. Thus, this would counteract the downward force  54  imposed at the opposite end of the flotation section  12 . 
     At this point, let us analyze the application of the forces shown in  FIG. 9 . If we look at the flotation force as indicated by the many small lines at  58 , we could resolve this into a single resultant force component which would be the summation of these, and that is numbered at  62 . Then the downward force of the weight of the water at  60   a  is indicated by the arrow  64 . The force component  62  is directed in an upward direction, while the two downward forces  54  and  64  are on opposite sides of the force  62 . Thus, for the vertical forces to balance, the sum of the forces  54  and  64  would have to be equal to the force  62 . 
     Also, to complete this analysis of the forces it is necessary to also resolve the force moments. We first look to the single upward force  62  as what we can term a “pivot location” about which the two forces at  54  and  64  must balance out. It can be seen that the moment arm extending between the two forces  62  and  64  is at least six-times as long as the moment arm from the forces  62  and  54 . Thus, the force  64  would be only about one-sixth of the downward force imposed at  54 . Thus, the downward load at  54  which is imposed on the platform section  12  could be six-times as great as the downward force  64  imposed by that portion of the counterweight member  14  that has the water-portion  60   a  above the level of the surrounding water. 
     With reference to  FIGS. 10 and 11 , let us now look at another situation where the load that is imposed on the platform section  12  is at a mid-location of edge portion of the dock assembly  10  which is located equally between two of the counterbalance members  14 , this force is indicated at  70  in  FIG. 11 . This has caused that whole edge portion of the platform section to be positioned more downwardly into water, and the resultant buoyancy force of the water is indicated at  72 . Again, we have the situation where the opposite side portion of the dock is raised out of the water, and the amount of water which is above the level of surrounding water is indicated at  74 . This results in a downward force at  76 . 
     We now have a similar situation to that of  FIGS. 8 and 9 , in that all of these forces need to balance out with regard to both the vertically applied forces, and also the force moments that are created. It can readily be seen that the platform section is able to carry a somewhat greater load about the edge portion, with the two opposite counter-balancing members  14  preventing further tipping of the platform section  12 . 
     It is believed that a better appreciation of characteristics of the present invention will be obtained by examining these in more detail. To accomplish this, reference is made to  FIGS. 12A through 12F . 
     In  FIG. 12A  the flotation platform section  12  is shown floating with the water line shown at  52 . The weight of the material of the platform section  12  is rather light, so there is shown a rather small force component  77  which would be, for example, the weight at possibly at 100 to 200 pounds. 
     Then in  FIG. 12B  there is shown a cargo container  78  that is placed along of the side edges of the platform section  12  to explore the effect of having off center loading. The effect of the weight of this cargo container is not shown in  FIG. 12A , but is shown in  FIG. 12B . 
     We will assume that the flotation platform section  12  has the chamber volume as discussed earlier in this text so that it would be about 25,000 cubic feet.  FIG. 12C  shows the same cargo container  78  in  FIG. 12A  with the weight of the cargo container having in effect a downward force component  80  which causes the container  78  to push the right hand side of the platform section down to the extent that the upper surface of the floating platform  12  is at the right side at the same level as the water line  52 . 
     In  FIG. 12C  the upward flotation force of the water acts against the entire bottom surface of the flotation platform  12 , so that this force extends across the entire bottom surface of the flotation platform  12 . The entire flotation force applied against the bottom of the flotation platform is indicated by a multiplicity of arrows  84 . 
     An inspection of  FIG. 12C  will reveal that the components are in an unstable position. It can be seen that on the right hand part of  FIG. 12C  there is the downward force component  80  which results from the weight of the cargo container, and there is also the upward flotation force which is shown by the many arrows  84  representing the upward pressure forces of the flotation platform  12 . Then in the left hand side of  FIG. 12C  there are the upward forces from the water pressing upwardly to raise the left hand side of the flotation platform  12 . However, there is no force component to counter the effect of the water force component  82  so that the applied force as shown in  FIG. 12C  would be cause upward movement of the left hand side of the flotation platform  12 , and would end up in the same situation shown in  FIG. 12E . 
     Reference is now made to  FIG. 12D  which shows one way by which this unstable situation of  12 C could be resolved. In  FIG. 12D  the instability of the situation of  FIG. 12C  is accomplished by placing another load in the form of a smaller cargo container  86  on the top left hand surface of the flotation platform  12 . Therefore, it can be seen in  FIG. 12D  that on the right hand side there is a rather substantial upward force of the water against the floating flotation platform  12  because of the greater depth of the right side of the platform  12 , and this matches the higher load capacity of the cargo container  78 . Then the smaller cargo container  86  has a matching downward force component. 
       FIG. 12E  illustrates a situation which could occur as soon as the full weight of the cargo container  78  is put in the position of  FIG. 12C . As indicated in  FIG. 12A , the physical components of the flotation platform  12  are quite light, as indicated by the force component  77 . Let us now look at  FIG. 12C  and we see the force component  82  which is something of a summation of the upward water forces that occur to the left of the location of the cargo container  78 . The effect of this is what we see in  FIG. 12E , which is the left hand part of the flotation platform  12  is being raised out of the water. At the same time the force  80  exerted by the weight of the cargo container  78  is sufficiently high so that it is beginning to rotate downwardly in a clockwise direction, and the entire left part of the flotation platform  12  is being raised out of the water. 
     If the cargo  78  is tied down to the floating platform  12  then the upward movement of the left part of the flotation section  12  and the downward rotation of the cargo container  76  continues. The cargo container  78  would continue its downward descent in the water. In the situation discussed thus far, the total interior volume of the flotation platform  12  is sufficiently great so that it would remain buoyant, and the left hand side of the flotation platform would have its left hand portion rising out of the water where it would be visible. 
     On the other hand, if the cargo container  18  was not secured to the upper surface of the flotation platform  12 , then the cargo container  78  would simply drop off from the platform  12  and likely go to the bottom of that body of water, and the flotation platform  12  would fall back to its level position above the water as shown in  FIG. 12A . 
     To close off this analysis, reference is now made to  FIG. 12F  which shows how the problems shown in  FIG. 12C  could be solved by the arrangement of the embodiments of the present invention. There is shown in  FIG. 12F  only one of the counter-balance members  15 , but in the arrangement of  FIG. 11  there would be two of the counter-balancing members  15  at opposite corners of the left side. So the result is as shown in  FIG. 12F , and the upward rotational movement of the left side of the flotation platform is diminished. Then, as more of the counter-balance  15  is out of the water the counter-balancing function increases. 
     The description of the platform sections  12  which is in the earlier part of this text shows the platform section in a rectangular configuration, and more specifically in a square configuration, and the four separate counterweight members  15  are at corner locations of the square rectangle. As a general comment, these counterweight members  15  are evenly spaced from one another to have the counter-balancing effect in a “broader territory”, and they are located at the corner portions of the platform section  12 . 
     This arrangement of the counter-balancing effects of the counterweight member  15  are distributed throughout the entire outer perimeter portions of the platform section  12 . Also, depending upon where the downward for and/or load is located, the counter-balancing function may be performed by a single counterweight member  15 , or a combination of two of the counterweight members  15 . 
     A second embodiment of the present invention will now be described with reference to  FIGS. 13 and 14 . Components of this second embodiment that are the same as, or similar to, components of the first embodiment will be like numerical designations, with an “a” suffix being used to distinguish those of the second embodiment. 
     With reference to  FIGS. 13 and 14 , there is shown a platform section  12 a which is, or may be, basically the same as in the first embodiment. However, instead of having a counterweight section  14  of a plurality of individual counterweight members  15 , there is one single continuous counter-balance member  14   a  located below the edge portion of the platform section  12   a.  As can be seen in  FIG. 14 , the counterweight section  14   a  has a cross-section substantially similar to the counter-balance members  15  of the first embodiment. 
     As an alternative, the counter-balance section  14   a  of the second embodiment could have the same basic configuration but would not have the continuous counter-balance member with the chamber extending throughout its length. Rather, there would be partitions such as shown at  92  between the two cross-members  94 , with each having their separate valve outlet/inlet to insert the counter-balancing water into the interior of that section  92 . 
     A benefit of this second embodiment is that the counter-balance member  90   a  extends for a much greater distance to provide more weight to the counter-balance members which in turn would permit these to be somewhat shallower in the depth dimension. Thus, when there is a tilting of the flotation platform  12 , there would be a much greater amount of total weight of the counter-balance member  90  for a given depth dimension so that it would permit even less upward counter balancing movement. Alternatively, the depth of the counter-balance section  90   a  could be made more shallow to position the center of gravity of the counter-balance at a higher level. 
     It is obvious that various modifications could be made to this embodiment without departing from the basic teachings of the present invention. 
     While the present invention is illustrated by description of several embodiments and while the illustrative embodiments are described in detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications within the scope of the appended claims will readily appear to those sufficed in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicants&#39; general concept.