Abstract:
A system for launching or retrieving an auxiliary vessel, using at least one support frame, with a connected auxiliary vessel support platform, mounted for rotational and translational movement in Cartesian coordinate directions. The support platform may be inclined to proximate the water level to facilitate launch and retrieval operations.

Description:
FIELD OF THE INVENTION  
       [0001]     The related field are methods and systems for retrieving and lifting an auxiliary vessel from the water, into a storage and carrying position and for launching the vessel.  
       BACKGROUND OF THE INVENTION  
       [0002]     The world of watercraft may be separated into two general categories of ships and boats, boats being the smaller vessels, usually pleasure or recreational craft, or yachts. Boats may range in size from an auxiliary vessel, a dinghy for example, carried on with a larger boat, and used to ferry passengers from an anchorage to shore and back. The size of the auxiliary and of the main vessel, carrying the auxiliary dinghy may vary, depending on the application and need.  
         [0003]     As ships and boats may travel to destinations lacking embarking or disembarking facilities, for example, docks, wharfs, or slips, the auxiliary vessel is carried on the main vessel and launched when needed. When use is completed, the auxiliary vessel may be retrieved and stored in a suitable arrangement for travel with the main vessel.  
         [0004]     Auxiliary vessels, even though small, may present a challenge in launching and retrieving, considering the weight, shape, and distribution of its mass. For example, one popular type of auxiliary vessel is the inflatable generally U shaped pontoon boat which opens rearwardly and has a transom extending between the legs of the pontoons adjacent the rear free ends thereof. This transom is conventionally utilized for mounting a small outboard motor. Another type of auxiliary vessel is the personal water craft.  
         [0005]     Hauling an auxiliary vessel that is wide, bulky or heavy, for example, loaded or imbalanced with an attached outboard motor, on to the main vessel, for example one with a high freeboard relative to the length of the auxiliary vessel, makes impractical, sliding or pushing or dragging the auxiliary vessel on board. Usually required to lift and place the auxiliary vessel on board, is a lifting device with davits, or a cradle for holding the auxiliary vessel and lifting it from the water, and holding it in its lifted position, for swinging it out board of the main vessel, or swinging it on to the main vessel to a storage position.  
         [0006]     Many devices, for example the devices shown in issued U.S. Pat. Nos. 5,113,783, 5,018,473, and 4,864,951, disclose devices for holding, or lifting, an auxiliary vessel from its floating position, but none are able to accomplish the method of sliding or pushing or pulling, an auxiliary vessel onto or off, a storage platform and moving the storage platform from its retrieving position into its storage position in the process or retrieving the auxiliary vessel or moving the vessel from its storage position into its launch position, in the process of moving the auxiliary vessel off the storage platform and toward the water.  
       SUMMARY OF THE INVENTION  
       [0007]     Accordingly, it is an object of this invention to provide a method and system for easily retrieving an auxiliary vessel from its floating position, by sliding the auxiliary vessel on board onto a support platform or into the water, without the use of lifting davits or the use of other arrangements for elevating the auxiliary vessel from its floating position.  
         [0008]     It is another object of this invention to provide a method and system for transferring an auxiliary vessel from its floating position on to a storage or support platform, positioned in an inclined position with one end toward the open water, for easy movement of the auxiliary vessel onto the lower edge of the platform, and by sliding the auxiliary vessel onto the platform, toward its upper end or by sliding the auxiliary vessel toward the support platform lower end and into the water.  
         [0009]     It is another object of the invention, to move the support platform into a storage carry position which may be a horizontal storage position, under the force applied to move the auxiliary vessel on the platform or with the weight of the support platform or the auxiliary vessel, as it is moved or when it is moved, from its starting position at the lower end of the inclined platform, onto the platform and to the upper end of the platform.  
         [0010]     It is another object of the invention, to move the platform into a storage position by a complex rotational movement of a pivoted jointed polygon, for example a parallelogram, about one of its pivoting joints and translational movement of of the pivoting joints of the polygon.  
         [0011]     It is another object of this invention to provide a full or partial docking or locking system for holding the support platform in position when in its storage position and restraining it securely for transit and for limiting the travel of the support platform when it reaches its storage or launch positions.  
         [0012]     These and other objects of the invention will be apparent to those skilled in the art from the description of the invention in this Summary and in the Detailed Description. The invention, as shown in a preferred embodiment, uses the principles of an expanding/collapsing support, for example a scissors jack in the form of a polygon with rotating joints connecting its support legs, and for the example shown in a preferred embodiment, four supports, forming a four sided parallelogram polygon, with each support leg joined at the four respective ends for pivoting movement. The support frame or support frame, in a preferred embodiment, uses two parallel support frames or support frames connected by transverse supports to form a box for stability, with the two parallel support frames forming the sides of the expanding/collapsing support scissors jack.  
         [0013]     As shown in a preferred embodiment, the support frame or support frame jack or jack frame, as may be alternatively or interchangeably identified, is connected to a base platform, by a base pivoting joint mounted on a base platform. As shown in a preferred embodiment the base platform is mounted on a main or carrying vessel and proximate the water line to facilitate retrieving and launching an auxiliary vessel. As shown in a preferred embodiment, the supporting base is a platform attached to the transom of the carrying boat or vessel and with an end opposed to the open water. As would be apparent to those skilled in the art, the supporting base or the method or structure used to attach the support frame to the supporting base, may be varied without departing from the disclosed inventive principles.  
         [0014]     Mounted for pivoting movement on the support frames, at, or proximate, a support leg pivoting or pivot joint connecting adjacent support legs, shown for a preferred embodiment at the pivoting joint opposed to the base joint along an axis of the support frame, is a support launch/carrying platform. The platform may be mounted at an opposed pivoting joint or on an extension of one of the support frame supports or legs connected by the pivoting joint and extending outside the support frame or may be mounted on the support frame, between the pivoting joints, or by an extension of a support leg inside the support frame.  
         [0015]     According to the disclosed inventive principles as shown for a preferred embodiment, the support platform supported by the expanding/collapsing support, is translated by a physical displacement between a launch retrieve position and to a storage carrying position. In the launch retrieve position, the support launch/carrying platform is inclined with a first edge positioned proximate the water line and proximate the edge of the base support opposed to the open water, to facilitate launching and retrieval.  
         [0016]     In the storage carrying position, the support launch/carrying platform is translated from its inclined launch and retrieve position, to a carrying position, shown in a preferred embodiment as substantially horizontal.  
         [0017]     According to the disclosed inventive principles, as shown for a preferred embodiment, a support frame rotates about its respective base joint, while the respective support frame or support frame supports or legs, pivotly linked to each other, rotate about the pivot joints at their respective support leg ends to translate the support frame axes, passing through respective opposed corners of the support frame, from a parallelogram as shown in a preferred embodiment, through a square or rectangular position, depending on the relative lengths of the support frame legs and through a central position. In a preferred embodiment, where the support frame is a parallelogram with at least equal lengths for the opposed support legs, the support frame rotates about the base pivot joint while the axes of the parallelogram support frame rotate about a central point within the support frame and through a central position or center vertical position, as shown in a preferred embodiment, wherein the process, the shape of the support frame is translated to a square or rectangular to where the support frame axes are aligned in an opposite direction, for example relative to the vertical.  
         [0018]     In a preferred embodiment, the support frame may be used in its storage carry position or its launch support position, on one side of its central position, and without rotation through a center vertical or central position.  
         [0019]     The result of this complex movement, as shown and disclosed according to a preferred embodiment, is to move the support launch carrying platform from its carrying position on the main or carrying vessel to its launch position where the support launch carrying platform is translated proximate the open water with an inclined end, proximate and opposed to the open water and the open water end of the base platform, and then back to its storage carrying position.  
         [0020]     In the disclosed preferred embodiment, the base platform for the support is a platform extending from the transom of the main or carrying vessel and arranged with an end opposed to the open water. However, as would be understood by those skilled in the art, the invention as shown according to its disclosed inventive principles, may be placed on the port or starboard of a main or carrying vessel or in a forward position, without departing from the disclosed inventive principles.  
         [0021]     In operation, when the auxiliary vessel is launched, the support platform, is displaced toward its launch position, shifting the weight of the support platform and displacing its weight over the support frame central position, which may be the center vertical, where the rotational direction of the torque developed by the weight of the support platform is redirected in an opposite direction, from a direction toward the storage carrying position to the launch retrieval position.  
         [0022]     The reverse occurs when translating the support platform from its launch retrieval position to its storage carrying position. Retrieving the auxiliary vessel is the reverse process with the support frames being translated through over the support frame central position, which may be the center vertical position and with the weight of the support platform producing a torque rotating the support platform to its storage carrying position, upon passing through the support frame central or vertical center position.  
         [0023]     What is shown and described is a system for carrying an auxiliary vessel on a main vessel in a support carry position and for launching or retrieving an auxiliary vessel and for transferring the auxiliary vessel between the support carry position and the launch retrieve position, comprising, a) first means for a support platform for storing an auxiliary vessel in a storage carry position and for launching or retrieving said auxiliary vessel in a launch retrieval position; b) second means for supporting said first means and for displacing said first means by translational movement between said storage carry position and said launch support position.  
         [0024]     The system as described above, may be arranges so that c) said second means includes means for a support frame, including means for support legs and means for connecting said means for support legs for rotational movement, and means for connecting said support frame to a base for rotational movement of said support frame, or wherein, d) at least one said means for support legs includes means for supporting said first means for translating said first means from a substantially horizontal position to a substantially inclined position. These and other features of the disclosed inventive principles may be seen in the following detailed description.  
         [0025]     The invention disclosed, is described as a system for launching or retrieving an auxiliary vessel, comprising, at least one support frame, an auxiliary vessel support platform, said auxiliary vessel support platform connected to said at least one support frame for rotational movement, a base, said at least one support frame is mounted for pivoting movement about said base, said at least one support frame including support legs connected by pivoting joints for rotational movement, and interconnected in the form of a polygon or wherein said at least one support frame is a parallelogram and said support frame is mounted for translational movement, in response to said pivoting movement of said at least one support frame about said base, or wherein said parallelogram includes a major axis and a cross axis and said at least one support frame support legs are connected for contraction of said support frame along said major axis and rotation of said major axis, in response to said translational movement or wherein said at least one support frame is mounted for rotation about said base through a central or center vertical position.  
         [0026]     The disclosed invention is described as a method for carrying an auxiliary vessel on a main vessel in a support carry position and for launching or retrieving an auxiliary vessel and for transferring the auxiliary vessel between the support carry position and the launch retrieve position, comprising the steps of, a) mounting a support frame with pivoted connected support legs on a base for rotational movement about a base; b)mounting a support platform for rotational movement on said support frame; c) translationally displacing said support platform and said support frame between said support carry position and said launch support position, and inclining said support platform proximate the open water in said launch support position or rotating said support platform from said launch support position to said support carry position or including the step of displacing said support platform or said support frame through a central or center vertical position; or including the step developing a torque driving said support frame to said support carry position when relative to one side of said central or center vertical position or to said launch support position relative to the opposite side of said central or center vertical position. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0027]      FIG. 1  shows the expanding/collapsing support frame scissors jack in a view toward the port side of the main vessel and showing the port side support frame and the support platform in its storage carrying position.  
         [0028]      FIG. 1   a,  is a partial view of  FIG. 1  showing the support frame in a central or center vertical position where the rotational direction of the torque on the support frame under the weight of the support platform, can change from a direction toward the storage carrying position to the launch retrieval position.  
         [0029]      FIG. 2  shows the support frame as shown in  FIG. 1 , rotated from the storage carrying position or to the launch retrieval position, and in translation where the support frames may pass through a square or rectangle, shape.  
         [0030]      FIG. 3  shows the support frame, in a preferred embodiment of the invention, viewed from the port side, with the port support frame of  FIG. 1 , rotated to its launch retrieve position, and with the support platform inclined with a lower end proximate the open water and extending beyond the open end of the base platform.  
         [0031]      FIG. 3   a,  shows a variation of the support frame of  FIG. 3 , with an extension to one of the support frame support legs mounting the support platform on a pivoting support and outside the support frame, and with a stop for stopping the rotational movement of the support frame at its intended launch retrieve position.  
         [0032]      FIG. 4  shows in a front view, looking aft toward the open end of the base platform and toward the open water, two support frames, in the process of translational movement as shown in  FIG. 2 , and with the expanding/collapsing support frame scissors jack box frames connected with a cross member connecting port and starboard support frames, with the support platform mounted on the outside or exterior to the support box frame, and shown with the storage carry platform in the launch retrieve position.  
         [0033]      FIG. 5  is  FIG. 1  modified to show the port support frame of the support frame scissors jack in a storage position with the support frame axis on the launch retrieve side of the support frame central or center vertical position, as shown and described with reference to  FIG. 1 , and with limit and restraining stops, to stop the support frame and the support platform from over traveling its storage carrying position and with supports for holding the support platform in it storage position and against the torque produced by the support platform about the support frame pivot joint toward the launch retrieve position.  
         [0034]      FIG. 6  is  FIGS. 3 and 3   a,  modified to show the support platform mounted for pivoting movement on a support frame support leg extension and in its launch retrieval position, with limit stops to prevent the support frame from over-traveling its launch retrieval position. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0035]     A preferred embodiment of the invention is shown mounted in a fore and aft direction proximate the stern of a carrying or main vessel and with two parallel support frames connected to form a box with the support frames placed on the port and starboard sides, relative to the main vessel&#39;s fore and aft line. The same numerals are used in the Figures to show the same or similarly operating parts and particularly for the port and starboard support frames. “Pivoted,” as used means arranged for pivoting or rotational movement about an axis. The terms support frame or support frame or scissors jack, as used herein, refer to the support frame  21 , shown in the preferred embodiment in the form of a parallelogram scissors jack.  
         [0036]     The invention is shown in  FIG. 1 , and in a preferred embodiment, generally by numeral  11 , in its storage carry position, viewed from the port side of the main or carrying vessel  9 . The invention, according to its disclosed inventive principles is shown mounted on a base platform  13  attached to the transom  15  of a main or carrying vessel  9 , at location  15   a,  and proximate the water line  17 . The base  13  or base platform  13 , is shown as having an open end  19 , opposed to the open water, as indicated by arrow  20 .  
         [0037]     The disclosed invention as viewed from the port side of main vessel  9 , comprises a box frame, comprised of two scissors jack frames  21 , port and starboard, shown as  21   p  and  21   s  in for the forward aft arrangement of the invention, as shown in  FIG. 4 . The port and starboard jack frames are expanding/collapsing support scissors jack frames  21 , the port side jack frame shown in  FIG. 1 , for a preferred embodiment, with four legs connected as shown by pivoting or rotating connectors  21   a,    21   b,    21   c,  and  21   d.  Rotating pivot joint  21   d  is connected to the jack frame base  23 , which is mounted on the base platform or base  13 . Any suitable arrangement may be used to fix the expanding/collapsing support scissors jack frame  21  onto a suitable base  13  as would be known to those skilled in the art and these arrangements do not form part of the disclosed invention or would alter the disclosed inventive principles.  
         [0038]     As would be understood by those skilled in the art, the disclosure with regard to the port jack frame applies to the starboard jack frame, as shown in a preferred embodiment in  FIG. 4 .  
         [0039]     Attached to the support frame  21  at pivot joint  21   a  is support platform  31 . An auxiliary vessel  37  is shown supported by the support platform  31  in its storage carrying position. The support frame  21  axis  29 , through the center  22  of the parallelogram support frame  21 , not shown in  FIG. 1  and represented by parallel arrow  29 ′ relatively displaced from the support frame for purpose of explanation, at an angle with the vertical center  27 . The support frame  21  axis  29 , represented in  FIG. 1  by arrow  29 ′, in the direction of the storage carry position is under the effect of weight  33  of the support platform producing a torque driving the support platform toward the storage carrying position in the direction of arrow  28 .  
         [0040]      FIG. 1   a  shows the support frame  21  in a support frame central position or center vertical position for a preferred embodiment, over center with regard to the vertical  27  and the axis  29 ,  29 ′, of the support frame  21 .  
         [0041]     As would be understood by those skilled in the art, and as shown in  FIG. 1   a,  the term “over center,” is used for a preferred embodiment to show a point in the rotational travel of the support frame  21 , about rotational axis  21   d,  in the directions as shown by arrows  28  or  30 , toward the support carry or launch retrieve, position, where the weight of the platform  31 , with or without an auxiliary vessel  37 , through the pivoting joint  21   a,  on support frame  21 , develops no torque in the direction of arrow  28 , toward the support carry position as shown in  FIG. 1  or in the direction of arrow  30 , towards its launch retrieve position as shown in  FIG. 3 .  
         [0042]     As would be known to those skilled in the art, the central or center vertical position is used to illustrate a position in the travel of the support frame  21  where the torque on the support frame changes direction. As would be known to those skilled in the art, the central or vertical center, position of the support frame  21  where the torque changes direction may be varied by the size and shape of the support frames, the location of the support platform relative to the support frame  21  and the placement of the auxiliary vessel on the support platform  31 .  
         [0043]     In  FIG. 1   a,  the position of pivot joint  21   d  is shown on the base support  23  with respect to the view toward the port side of the main vessel.  
         [0044]     As shown for the preferred embodiment in  FIG. 1 , there is a docking fixture  41  with interlocking parts  41   a  and  41   b.  As shown in a preferred embodiment, the docking fixture uses a stud  41   b  aligned to fit into receptor  41   a.  Docking fixture  41  is intended to prevent the platform  31  from moving in the direction of bi-directional arrow  34 , past the intended storage carry position or towards the center and the launch positions, as shown in  FIG. 1   a  and  FIGS. 3 and 6 . Another docking fixture  45  may cooperate with transom  15  of the carrying vessel  9 , to prevent the support frame  21  and platform.  31  from moving under the weight  33  of the support platform  31  and the auxiliary vessel  37 , in the rotational direction as shown by arrow  28 , past its intended alignment position in the support carry position as shown by the alignment of the axis  29 ′, of the support frame  21 . The locking or docking devices  41  and  45  serve as limits to the travel of the support frame  21  and as restraining or retention devices to hold the support frame  21  and the support platform in position. As would be known to those skilled in the art, other suitable devises as now or hereafter known, may be used to hold the storage platform  31  in its store carry or launch retrieve, positions.  
         [0045]     As would be apparent to one skilled in the art, the various means or devices for docking and to hold the platform  31  and support frame  21 , aligned with its intended support carry position, may be varied and any suitable means may be used, without departing from the disclosed principles of the invention.  
         [0046]     Referring to  FIG. 2 , the support frame  21  is shown at a point in its physical displacement or translation to or from its support carry or launch retrieve, final position, as represented by directional arrows  28  and  30 . As may be seen from  FIGS. 1, 1   a,    2 , and  3 , the support platform  31  undergoes a translational movement as it is translated by a complex motion combining movement in a Cartesian coordinate direction, shown in a preferred embodiment in a substantially horizontal and vertical direction or, for example,in a direction from the support carry position to the launch retrieve position, and rotational movement about an axis, of the support frame  21 , as the support frame  21  contracts in going from one position, and expands along the main axis to the other position, going through a support frame central or center vertical position as shown for a preferred embodiment.  
         [0047]     In its translational movement, the parallelogram support frame  21 , as shown in a preferred embodiment, expands along its cross axis  29   a  and contracts along its main axis  29 , as the support frame is translated from its support carry position or launch retrieve positions, to where the support frame  21  may be a square or rectangle, as shown in  FIG. 2 , and then contracts along its cross axis  29   a,  and expands along its main axis  29 , as the support frame  21  rotates to final launch retrieve or support carry positions, respectively. Similarly, the support frame  21  would contract and then expand along its axis  29 , as the support frame  21  is displaced or passes through its central or center vertical position.  
         [0048]     The translational movement of the support frame  21  displaces the support frame by rotation about axis  21   d  in base  23  and displaces the support frame  21  and the support platform  31  in its Cartesian or linear directions, shown in the preferred embodiment, as approximate the horizontal with reference to the water line and the vertical with reference to arrow  27 , to extend the support platform  31  to the launch retrieve position or the support carry position.  
         [0049]     As would be apparent to one skilled in the art, the complex movement by rotation and in the Cartesian coordinate system, describing the translational movement of the support frame, reduces the displacement of the support platform  31 , mounted on the support frame  21 , in the vertical direction and horizontal direction, as compared to a displacement limited rotation only about a rotational axis, for example,  21   d  as shown in a preferred embodiment. The complex translational movement in the linear and rotational, directions raises and lowers the support platform  31  while displacing the support frame substantially in a direction along a Cartesian coordinate, or linear direction to extend the support platform  31  to its support carry or launch retrieve, positions while rotating the support platform through its central position.  
         [0050]     Referring to  FIG. 3  and  FIG. 3A , the platform  31  and the support frame  21  are shown for a preferred embodiment, in the launch retrieve position with the auxiliary vessel  37  in the water opposed to the open water end  19  of base  13 , and the inclined end  24  of the support platform  31 . The support  21  frame and platform  31 , are held in this position and prevented from movement toward the water by frame stop  62  shown mounted on support leg  21   g  on support frame  21  and in contact with an adjacent leg  21   f,  as shown in  FIG. 3A . As would be understood by those skilled in the art, the frame stop  62  is not limited to a stopping member extending from one leg of the support frame  21  to an adjoining member but may be used with any of the frame  21  support legs.  
         [0051]     Additionally, other suitable means may be used to stop the travel of the support frame  21 , whenin its storage carry position, as shown for a preferred embodiment, in  FIG. 5 . As shown in  FIG. 5 , the translational movement of support frame  21 , is limited to the quadrant on the launch retrieve side of the vertical center  27 , as shown in  FIG. 1   a,  and where the torque on the support frame  21  from the weight of the support platform  31  is in the direction of arrow  30 . In a preferred embodiment, suitable means like auxiliary support  92  cooperating with stop  94  on leg  21   g,  may be used to hold the support frame in position. The support  92  as shown in a preferred embodiment, may be mounted for rotational movement, in or out of operation with support frame  21 , by pivot joint  98  in auxiliary support base  96  on base  13 . Support frame  21  main axis  29 , is shown for purpose of explanation, parallel to but displaced from the center of the support frame  21 .  
         [0052]     Any suitable means may be used to dock or restrain movement of, the support platform  31  and the support frame  21 , at the intended limit of travel from one of its positions to another or at any between location, including electrical or mechanical limit switches and mechanically operated or electrically operated stops, as would be now or in the future, known to those skilled in the art.  
         [0053]      FIG. 4 , shows the support frame  21  and support platform  31  from the front looking aft and in the launch retrieve position. Pivot joint  21   a  is shown for explanation purpose, as it would appear in its position aft or behind pivot joint  21   c,  as may be seen in  FIG. 2 , to show the connection of the support frame to the support platform  31 . As may be seen in a preferred embodiment, as shown in  FIG. 4 , the support box frame  48  is formed by the connector  51 , connecting the port support frame and starboard support frame, respectively identified by  21   p  and  21   s  to distinguish their respective locations on the base platform  13 . The box frame  48 , is connected by the support frames  21   s  and  21   p,  to the respective support frame bases  23   s  and  23   p  at base pivot joints  21   d.  The support frame  31  is shown, in the position shown in  FIG. 2 , and in the launch retrieve position with end  24 , not shown behind the base  13 , shown in cross section, and opposed to the open water end  19  (not shown), of base  13 .  
         [0054]     The support frame  31  is shown in  FIG. 4 , mounted in outside the support support frames  21   p  and  21   s,  and as would be known to those skilled in the art, the support frame  31  may be mounted inside or outside the support box frame box,  48 , without departing from the disclosed inventive principles. Numerals  55  and  57  show the attached location of the port and starboard support frames  21   p  and  21   s,  to the base  13 .  
         [0055]      FIG. 5  shows a preferred embodiment of the invention with the support frame  21  and platform  31  in the support carry position. In  FIG. 5 , the support frame  21  is on the launch retrieve side of the vertical center, as shown in  FIG. 1   a,  and the weight  33  of the platform  31  drives the platform and its auxiliary vessel  37  into the engagement device  41 .  
         [0056]     Separately shown in  FIG. 5  is a support frame stop  58  mounted on a leg  21   h  and which rotates with leg  21   h  about support base pivot joint  21   d  to engage with base mounted stop  60  to prevent movement of the platform  31  and the support  21  past the limit of its support carry position. Other suitable stops may be used as would be known to those skilled in the art. The docking means  41  is shown in a preferred embodiment with a single cooperating stop  41   b  to limit movement of the storage platform  31  toward the launch retrieve position in the direction of arrow  30 . As would be known to those skilled in the art, other suitable locking or docking devices may be used.  
         [0057]      FIG. 6  shows in a preferred embodiment, the support  21  and platform  31  with leg  21   g  of the support  21  extending beyond pivot joint  21 , and supporting the platform  31  outside the support frame  21  by means of extension  66  on support frame leg  21   g.  As would be understood by those skilled in the art, the support platform  31  may be placed on a support leg within the support frame and between the support frame joints  21   d,    21   a,    21   b,    21   c,  without departing from the disclosed inventive principles.  
         [0058]      FIG. 6  shows the operation of the limit stop  62 , shown in a preferred embodiment mounted on frame support leg  21   g  and in contact with frame support leg  21   f,  preventing it movement toward support leg  21   g  and translation of the support frame  21  and the support platform beyond the intended stop launch retrieve stop position. As would be understood by those skilled in the art, the stop  62  may be placed on any of the other support legs and any other suitable stop may be used as would be known to those skilled in the art.  
         [0059]     As would be understood by those skilled in the art, the disclosed inventive principles may be varied as is now or hereafter known, without departing from the disclosed invention principles.