Patent Publication Number: US-7895964-B2

Title: Retractable boat top with arched canopy

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation-in-part of application Ser. No. 11/487,287 filed Jul. 15, 2006 now U.S. Pat. No. 7,571,691 for Retractable Bimini Top Device. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to convertible top covers for boats, commonly called bimini tops, and more particularly to an improved retractable boat top device having an arched canopy assembled for operative attachment to a radar arch or like structure upon the boat deck that is automated in its operation and adapted to maintain an arched configuration during deployment. 
     In recreational boating, the so-called “bimini top” is a convertible cover erected upon the deck of the boat and made to be deployed at an elevation comfortably above the heads of the passengers. Drawing its name from the Bimini islands in the Bahamas where it was first employed by boaters to provide desired shade from the strong rays of the tropical sun, the standard type of bimini top and those convertible boat covers of the same nature generally comprise a flexible canvas material secured to a foldable support frame that is erected across the deck and pivotally attached thereto. These standard types of foldable bimini tops can be raised when needed or lowered into a substantially flat position upon the deck when not in use or when an overhead obstruction may otherwise require its lowering. Deployment of these foldable bimini tops is often done manually but has been designed to be power driven, such as those described in U.S. Pat. Nos. 6,209,477 to Briedenweg and 6,983,716 to Ankney et al. Regardless of their specific foldable structure or method of operational deployment, the installation and utilization of bimini tops have become increasingly important for the protection of passengers and crew on board boats against excessive sun exposure and the evident risks of skin cancer caused thereby. 
     Existing framework generally used to construct present bimini top installations includes a system of poles or like rigid members mounted to the port and starboard sides of the boat and made to extend across the deck at a sufficient height level to support the canvas top overhead the occupants. As currently arranged and implemented, these pole systems typically have separate front and rear pole members over which the canvas top is extended and, depending upon the length of the top from fore to aft, one or more additional pole members are needed and disposed between the front and rear poles to firmly support the intermediate section of the top. Although these pole systems may be pivotally mounted to the boat deck so that they can be folded down and lowered out of the way when the bimini top is not needed, the pole members still obstruct a person on board from reaching out over the side of the boat when fishing, docking or mooring the boat and further present an obstacle in boarding and loading equipment onto the deck. While these and other similarly devised implementations of convertible bimini tops have been effective in providing suitable shade protection from the sun when needed, they have not satisfactorily resolved the problems of obstructions and obstacles caused in and around the boat deck by their supporting framework nor have they provided a completely hands free system of operation both in extended deployment and retracted storage of the bimini top. 
     Furthermore, in implementing a retractable canopy system, particularly one deployed upon a recreational boat, rain water accumulating upon the extended canopy needs to be continually drained off the extended canopy surface, preferably away from the boat deck in a flow direction that will not affect the passengers. Existing prior art retractable canopy systems heretofore adapted to boat operations, while being effective in their deployments, have not satisfactorily addressed this drainage requirement without reducing headroom on board the deck and limiting visibility for driving the boat forward or in reverse during docking. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is a general purpose and object of the present invention to provide an improved retractable canopy top for recreational boats that is fully automated and capable of operative attachment to existing overhead structure on the boat without causing obstructions upon the deck. 
     A more particular object of the present invention is to provide an improved automated retractable canopy top capable of deployment upon the existing radar arch structure of a recreational boat that effectively shades those on board from the sun and drains any accumulating rain water away from the deck of the boat without adversely affecting headroom of the passengers or visibility of the driver. 
     Another object of the present invention is to provide an automated retractable canopy top for recreational boats that is capable of providing effective sunshade protection to persons on board the boat without presenting obstructions to their movement or performance of tasks on or around the deck. 
     Still another object of the present invention is to provide an improved automated retractable canopy device that is particularly suitable for use upon a sport fishing boat to provide fishermen with needed shade protection even while game fishing and without hindering their performance. 
     A further object of the present invention is to provide an automated retractable boat top device that is capable of hands free operation between an extended deployment and retracted state with protection of the retracted top while in storage. 
     A still further object of the present invention is to provide an automated retractable boat top device that is relatively inexpensive to manufacture, easy to assemble and install upon existing boat structure, and capable of improving the functionality and appearance of the boat upon which it is installed. 
     Briefly, these and other objects of the present invention are accomplished by an improved retractable boat top device having an arched canopy assembly operatively deployed in mounted attachment upon a conventional radar arch or like elevated structure on the deck of a boat. The arched canopy assembly includes a stationery roof section formed having a curved planar surface transversely mounted within the radar arch, a pair of telescoping extension arms mounted on opposite sides of the roof section, and an arched roller assembled to hold a flexible canopy material thereon and operatively connected between the outer ends of the extension arms so that the flexible canopy material may be extended and retracted relative to the stationery roof section in an arched configuration substantially in the same plane as the roof section. The arched roller includes a curved roller bar supported coaxially within the bore of a flexible hose member that supports the canopy material in a rolled-up state and further includes torsion spring members mounted along opposite sides of the roller bar to maintain tension upon the canopy material during roll-out and retraction. 
     For a better understanding of these and other aspects of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings in which like reference numerals and character designate like parts throughout the figures thereof. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a fuller understanding of the nature and objects of the present invention, references in the detailed description set forth below shall be made to the accompanying drawings in which: 
         FIG. 1  is a perspective view of a recreational boat equipped with a retractable bimini top device made in accordance with the present invention and shown in extended deployment from rooftop structure on the boat; 
         FIG. 2  is a plan view of the retractable bimini top device of  FIG. 1  shown in mounted attachment beneath the rooftop structure of the boat; 
         FIG. 3  is a side elevation view of the retractable bimini top device shown in  FIG. 2 ; 
         FIG. 4  is an enlarged plan view from below of the retractable bimini top device of  FIG. 3  including a partial cross-section taken along the line  4 - 4  therein; 
         FIG. 5  is a plan view of the retractable bimini top device according to the present invention shown in its retracted position mounted beneath the rooftop structure of the boat; 
         FIG. 6  is a side elevation view of the present retractable bimini top shown in  FIG. 5 ; 
         FIG. 7  is an enlarged plan view from below of the retractable bimini top device of  FIG. 6  including a partial cross-section taken along the line  7 - 7  therein; 
         FIG. 8  is a schematic plan view sectioned in part of an alternate embodiment of the retractable bimini top device according to the present invention; 
         FIG. 9  is a schematic plan view sectioned in part of another alternate embodiment of the present retractable bimini top device; 
         FIG. 10  is a schematic plan view sectioned in part of a further alternate embodiment of the retractable bimini top device according to the present invention; 
         FIG. 11  is a schematic plan view sectioned in part of a still further alternate embodiment of the present retractable bimini top device; 
         FIG. 12  is a perspective view of a modified version of the retractable bimini top device having an arched canopy configuration and mounted to a conventional radar arch of a boat; 
         FIG. 13  is a further prospective view of the modified retractable top device of  FIG. 12  shown mounted on the radar arch with a section of the canopy removed; 
         FIG. 14  is a longitudinal cross-section of the arched roller assembly employed in the modified retractable top device of  FIG. 12  in accordance with the present invention; 
         FIG. 15  is a perspective illustration of a recreational boat equipped with the modified retractable canopy top device of  FIG. 12  shown in a retracted position; and 
         FIG. 16  is a perspective illustration of a recreational boat equipped with the modified retractable canopy top device of  FIG. 12  shown in an extended position. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following is a detailed description of a preferred embodiment of the present invention and the best presently contemplated mode of its production and practice. This description is further made for the purpose of illustrating the general principles of the invention but should not be taken in a limiting sense, the scope of the invention being best determined by reference to the appended claims. 
     Referring now to  FIG. 1 , a preferred embodiment of the present retractable bimini top device, generally designated  10 , is depicted in mounted attachment to and extended deployment from just beneath a rigid canopy or similar rooftop member T set above the deck of a recreational boat B. Designed for automated operation, as described below in greater detail, to provide additional sunshade protection for those on board the boat B, the present retractable bimini top device  10  includes a canvas cover  12  or similar flexible fabric material of an opaque nature that is stored in a rolled-up state and attached at one outer end thereof to a moveable support frame  14  that is disposed for substantially horizontal movement and driven in alternate linear directions through a pair of housing tubes  20  mounted beneath the rooftop member T. 
     Referring now to  FIGS. 2-4  in conjunction with  FIG. 1 , the support frame  14  is rigid U-shaped member, preferably tubular in construction, having a pair of substantially parallel legs  14   a  and  14   b  extending longitudinally from a transverse piece  14   c  that is preferably curved in form. The canvas cover  12  is formed and finished in a substantially rectangular configuration, the width thereof being sufficient in size to substantially span the dimension between the legs  14   a  and  14   b  of the support frame. The length of the canvas cover  12  will vary based upon the desired extension of the bimini top device  10 . The outer end of the canvas cover  12  is wrapped around the transverse piece  14   c  of the support frame  14  and secured in place, preferably by conventional stitching of the canvas material. The opposite end of the canvas cover  12  is attached along the entire width thereof to the hub interior of a spring-loaded roller  16  of the type commercially available and conventionally used for stored support of retractable awnings. From the interior hub attachment, the canvas cover  12  is wrapped circumferentially in layers around the body of the roller  16  to form the rolled-up state in which the canvas cover is stored in the present bimini top device  10 . In its rolled-up state upon spring roller  16 , the canvas cover  12  is positioned so as to feed the outer edge of the cover in the direction of the support frame  14  and its attachment to the transverse piece  14   c , the direction of feed being in opposition to the internal spring force applied and exerted through the spring roller. This internal force is generally established for each spring roller  16  and may be adjusted, typically by turning the roller in place on its end pins. The internal spring force generated by the spring roller  16 , adjusted as necessary, assists in the retraction of the canvas cover  12  upon the support frame  14  and further maintains the canvas cover in a relatively taut condition when in extended deployment. A pair of projection brackets  18  of the type conventionally used with standard spring-loaded rollers are positioned to engage opposite ends of spring roller  16  and are attached to the bottom surface of the rooftop member T using conventional hardware to position the roller transversely between the legs  14   a  and  14   b  of the support frame  14  and allow the roller to rotate freely in both directions so that the canvas cover  12  may unroll and retract in a straight path aligned between the opposite legs of the support frame. 
     The housing tubes  20  used to convey the support frame  14  are cylindrical in form and made in lengths sufficient to contain longitudinally therein substantially all of the respective lengths of the legs  14   a  and  14   b  of the support frame. The housing tubes  20  are spaced apart and disposed in parallel, their separation being established by the transverse dimension between the legs  14   a  and  14   b  of the support frame  14 . Positioned in parallel upon the bottom surface of the rooftop T with the spring roller  16  mounted transversely therebetween, the housing tubes  20  are each mounted to the rooftop member via mounting blocks or clamps  22 , preferably in pairs along the respective tube lengths, as seen in  FIG. 3 . Attached to the bottom surface of the rooftop member T using conventional hardware, the mounting blocks  22  are each formed with an aperture therethrough that is made to fit over and engage the outside surface of the housing tubes  20  and together secure the housing tubes in place just beneath the rooftop surface. 
     A separate pair of reversible electronic motors  24  is used in this preferred embodiment of the present retractable bimini top device  10  to drive the support frame  14  in alternate linear directions through the housing tubes  20  and carrying the attached canvas cover  12 . Mounted at the end of each housing tube  20  opposite of the support frame  14 , the reversible motors  24  are conventional electronic devices commercially available in a variety of forms and sizes designed to produce a steady level of torque along a drive shaft at predetermined rates of rotation and in opposite directions. In the present embodiment, the drive shaft of each reversible motor  24  is adapted and formed as a lead screw  26 , best seen in  FIG. 4 , having an extended threaded length coaxially disposed through the respective housing tube  20 . Each reversible motor  24  is fixed in position at the end of the respective housing tube  20  and mounted to the bottom surface of the rooftop T using a mounting bracket  28  or like form of clamp that holds the body of the motor firmly in place and attaches to the rooftop surface with conventional hardware. The reversible motors  24  are electrically powered and preferably connected to the available power supply on board the boat B with the proper operating voltage being provided using conventional inverters and/or regulators as necessary. Synchronized control of the operation of the reversible motors  24  in both directions is provided by conventional electrical switching, preferably activated by remote-control means, with limit-switching capabilities to limit the revolutions of the lead screw  26  and the corresponding movements of the support frame  14  in both directions. 
     As best viewed in  FIG. 4 , the separate legs  14   a  and  14   b  of the support frame  14  each slidingly engage the outer end of the respective housing tube  20  through a bearing fitting  30  affixed to the outer end of each tube. Each end fitting  30  is a ring-like member having a smooth outer surface sized to conform with the inner diameter of the housing tube  20  and an inner bearing surface established by a circular set of ball bearing members, the effective inner diameter of which conforms with the outer surface diameter of the support frame legs  14   a  and  14   b . Inside each housing tube  20 , a moveable bearing fitting  32  is coaxially disposed and further joined and connected to the end of each respective support frame legs  14   a  and  14   b . Each interior bearing fitting  32  is similarly, like end fittings  30 , a ring-like member, but unlike the end fittings, the interior bearing fittings have an outer bearing surface established by a circular set of ball bearing members with the effective outer diameter conforming with the inner surface diameter of the housing tubes  20 . The inner surface of each interior bearing fitting  32  is threaded to conform with and engage the threaded surface of each lead screw  26 . The inner threading of the interior bearing fittings  32  may be formed integrally upon the surface of the fitting or more preferably, be provided by a threaded insert or nut  34  coaxially fixed therein. As a result of this combination of bearing fittings  30  and  32  and their respective engagements with housing tubes  20  and support frame legs  14   a  and  14   b , rotational movements of the lead screws  26 , concurrently produced under the drive of their respective motor  24 , will move the support frame  14  outbound into extended position, as shown particularly in  FIG. 4 , with the canvas cover  12  fully deployed thereon. 
     Referring now to  FIGS. 5-7  wherein the present bimini top device  10  is shown in its retracted position, the legs  14   a  and  14   b  of support frame  12  are retracted and drawn together into and substantially through the complete length of each housing tube  20 . The support frame legs  14   a  and  14   b  are drawn in unison into such retracted position driven upon the reverse revolutions of lead screws  26  generated by each associated motor  24 , the lead screws acting directly through its threaded engagement with the movable inner bearing fitting  32  and its threaded insert  34 . While the support frame legs  14   a  and  14   b  are drawn into this retracted position, the movement of the support frame  14  and each of its respective legs is guided and facilitated by the sliding engagement of the support frame legs with the bearing fittings  30  at respective outer ends of the housing tube  20 . At the same time the support frame  12  is drawn into the housing tube  20 , the extended section of the canvas cover  12  attached to transverse piece  14   c  is drawn onto the spring roller  16  under the influence of its internal spring-loaded force so that upon full retraction of the support frame  14 , the transverse piece  14   c  of the support frame is disposed in a position proximate to the edge of the rooftop member T with substantially all of the canvas cover  12  rolled-up onto and stored upon the spring roller  16  just beneath the rooftop member. 
     Referring now to  FIGS. 8-11 , several alternate embodiments of the present retractable bimini top device  10  are illustrated and described here, particularly as to variations in the automated manner used to drive the reversible movement of support frame  14 . It is noted with respect to these alternate embodiments that for the most part, the fitted arrangement of the support frame  14  and housing tube  20  together with the attachment and spring-loaded coupling of the canvas cover  12  are substantially the same as described in the preferred embodiment described above. In the embodiment of  FIG. 8 , one most similar to that described above with respect to  FIGS. 1-7 , a single reversible motor  40 , like that of motors  24 , is employed with an associated drive shaft  42  mounted upon the bottom surface of the rooftop member T transversely to the housing tubes  20  using a pair of mounting brackets  46 . A pair of worm gears  44  or like rotational converters are coupled to the drive shaft  42  at positions proximate to the ends of the housing tubes  20  and in turn, coupled to a respective lead screw  26  coaxially directed into the housing tube. 
     In both  FIGS. 9 and 10 , a compression spring  56 , typically in a helical coil form, is sized to fit and mounted within each of the respective housing tubes  20  at the inner end thereof opposite to the outer end where the bearing fitting  30  engages the support frame  14 . In this mounted position within housing tube  20 , each compression spring  56  is made to urge upon inner bearing fittings  32  and the respective support frame legs  14   a  and  14   b  attached thereto thereby providing an outward biasing force upon the support frame  14  in the direction of its extended position. In  FIG. 9 , opposed drawing forces upon the respective support frame legs  14   a  and  14   b  are equally applied by a pair of unidirectional motors  50  each mounted in proximity to the inner end of a respective housing tube  20  together with an associated pulley member  52  that is coupled to the drive shaft of the motor by means of a conventional clutch. A length of cable  54  is attached at one of its ends to the inner bearing fitting  32  and routed through the compression spring  56  to the pulley member  52  upon which the remaining cable is wound and connected. Under the outward bias forces exerted by the compression spring  56  upon the support frame legs  14   a  and  14 , the support frame  14  with the canvas cover  12  attached thereto is pushed forward and outward of the housing tubes  20  to a fully extended position, the clutch coupling of the pulley  52  allowing the length of cable  54  to fully extend. To retract the support frame  14  in this case, the motors  50  are activated and under synchronized control made to pull the length of cable  54  back onto the pulley member  52  and thereby draw the respective support frame legs  14   a  and  14   b  back into the respective housing tubes  20 , this while the canvas cover  12  is drawn back onto spring roller  16 . In  FIG. 10 , a similar implementation of an outbound spring force applied to the respective support frame legs  14   a  and  14   b  is accomplished by a pair of compression springs  66  mounted with housing tubes  20  and a drawing force opposed to the spring force is applied using a cable  63  wound upon a pair of motor-driven pulleys  62 . In the embodiment of  FIG. 10 , however, a single unidirectional motor  60  is employed with an extended drive shaft  65  mounted and connected between the separate pulleys. 
     In the embodiment of  FIG. 11 , a hydraulic version of the automated drive means for reversible movement of the support frame  14  is disclosed. A conventional hydraulic motor pump  70  mounted to the roof-top member T generates fluid under pressure and is controlled to feed the fluid through either a pair of rear fluid lines  76  connected to the back end of the respective housing tubes  80  or a pair of forward fluid lines  78  connected to the front end of the housing tubes. The housing tubes  80  in this case are modified versions of the aforedescribed housing tubes  20  in order to both accept the fluid lines  76  and  78  and to provide adequate sealing of the housing chamber. In this latter regard, the back end of housing tube  80  is closed and additional seals  72  and  74  are provided in connection with bearing fittings  30  and  32 . To extend the support frame  14  in this case, controlled fluid pressure is fed from the motor pump  70  to the back ends of the respective housing tubes  80  via fluid lines  76  thereby pushing the respective support frame legs  14   a  and  14   b  forward and outward from the housing tubes. To reverse this movement and retract the support frame  14 , rear fluid is released from the back of the chamber of the housing tube  80  and forward fluid fed to the front of the chamber via lines  78 . 
     Referring now to  FIG. 12 , a modified retractable boat top device, generally designated as  70 , is shown in an extended deployment upon a conventional radar arch structure R typically erected on recreational boats, the retractable boat top device  70  here providing a distinctive arched configuration in its deployment in accordance with the present invention. The present retractable boat top device  70  comprises an arched canopy assembly  72  that includes a stationery roof section  74  transversely mounted in a substantially horizontal plane within the radar arch R, a pair of telescoping extension arms  76  mounted in parallel alignment on opposite sides of the roof section, and an arched roller assembly  80  adapted to carry an extended length of a flexible canopy material  82  wrapped thereon and driven to move upon the extension arms in reversible directions substantially in the same plane as the stationery roof section. The stationery roof section  74  is formed having an arched surface that is convex in its mounted profile across the width thereof, and has an effective width substantially equal to the transverse opening within the radar arch R. The overall length of the roof section  74  may vary based upon the size and shape of the boat intended for deployment, with the length typically being sufficient to provide equidistant projections fore and aft of the radar arch structure R. A mounting bracket  78 , better viewed in  FIG. 13 , is attached to the interior side walls of the radar arch structure R using conventional fasteners and is used to hold and support the roof section  74  on opposite sides thereof, maintaining the roof section in its stationery position transversely mounted within the radar arch. 
     Referring to both  FIGS. 12 and 13 , the telescoping extension arms  76  are cylindrically-formed longitudinal members comprising a series of tubular segments fitted together and adapted to move coaxially in reversible directions. In similar fashion to the operative combination of housing tubes  20  and legs  14   a ,  14   b  of support frame  14  described above and shown in  FIGS. 4-7 , the telescoping extension arms  76  of retractable boat top device  70  are mounted in parallel alignment and made to move axially and in unison to deploy flexible canopy material  82 , here in the present device conveyed upon arched roller assembly  80 . Each of the telescoping extension arms  76  is secured in place upon the radar arch R along opposite sides the roof section  74  using mounting brackets  78 . A pair of reversible electronic motor  77 , similar to those motors  24  described above with respect to  FIGS. 4-7 , are mounted separately at each forward most end of the telescoping extension arms  76  and used to drive the movement of the arms and their telescoping segments in alternate linear directions. As in the case of the embodiment shown in  FIG. 4 , the drive shaft of each reversible motor  77  is adapted and formed as a lead screw having an extended threaded length coaxially disposed through the segments of the telescoping extension arms  76 . Similarly to motor units  24 , reversible motors  77  are electrically powered and preferably connected to the available power supply on board the boat with the proper operating voltage being provided using conventional inverters and/or regulators as necessary. Synchronized control of the operation of the reversible motors  77  in both directions may also be provided by conventional electrical switching, preferably activated by remote-control means, with limit-switching capabilities to limit the revolutions of the lead screw and the corresponding travel of the telescoping segments of the extension arms  76 . The outer ends of the telescoping extension arms  76  rearward on the inner most tubular segments thereof are linked to the arched roller assembly  80  on each side to convey the roller assembly and the flexible canopy material  82  thereon back and forth relative to the stationery roof section  74  in an arched configuration substantially conforming to that of the roof section. An intermediate support frame member  84  formed having a similar arched profile is secured transversely between the extension arms  76  upon corresponding tubular segments intermediately located on each side and routed beneath the flexible canopy material  82  to help maintain the arched configuration of the canopy material  82  during deployment and in the extended state as shown in  FIG. 12 . A transverse end support member  85  similarly curved in its form may be attached across the outermost ends of the telescoping extension arms  76  and beneath the arched roller assembly  80  to provide support for the roller assembly in its deployed position and help maintain the horizontal level of its movement upon the extension arms. 
     Referring now to  FIG. 14  in conjunction with  FIGS. 12 and 13 , the arched roller assembly  80  for deploying the flexible canopy material  82  in the present retractable boat top device  70  includes a curved roller bar  86  coaxially disposed and supported within the bore of flexible hose member  88  with a pair of elongated torsion springs  94  operatively mounted along the roller bar and secured at the opposite ends of the hose member for rotational deployment of the canopy material in an arched configuration. The curved roller bar  86  is preferably made from a high-strength, corrosion resistant material, such as stainless steel, formed having a common radius of curvature across the length thereof to provide a substantially uniform rounded profile from one end of the bar to the other. The flexible hose member  88  is cylindrical in its fabricated form and made from a strong, durable material, such as rubber or plastic, capable of conforming to the curvature of the roller bar member  86 . The curved roller bar  86  is coaxially supported within the conforming hose member  88  by a roller support member  90  and a pair of collar supports  92  positioned together in the middle of the hose member as well as by a pair of end caps  98 , one secured in each end of the hose member, to coaxially engage the ends of the roller bar with a bearing support. The roller support member  90  is ring-like in form having an inner diameter sized in excess of the diameter of the curved roller bar  86  to permit its passage therethrough and relative rotational movement therein and an outer diameter sized to fit the bore diameter of the hose member  88  so that the roller support member may be pressed into the bore and secured in place in the middle of the hose member. A set screw (not shown) or the like may be used to engage the outer rim of the roller support member  90  through the wall of hose member  88  to hold the roller support member in place and secure it to the hose member. The collar supports  92 , also ring-like in form having an inner diameter sized to fit the roller bar  86  axially therethrough and an outer diameter lesser than that of the bore diameter of hose member  88 , are each further adapted to be set upon the roller bar and secured thereto in a position closely bordering opposite sides of the roller support  90  to maintain the central position of the roller support within the hose member. 
     The elongated torsion springs  94  are assembled over and upon the roller bar  86  within the hose member  88 , one torsion spring being disposed on either side of the curved length of the roller bar. Each of the torsion springs  94  is set in position and attached inwardly upon the roller bar  86  by a spring guide  96  cylindrical and slotted in form that is partially inserted upon and connected to the inward end of the torsion spring and secured in place upon the roller bar by a set screw or the like. The outward ends of each torsion spring  94  are adapted to engage upon and secure to the end caps  98  attached at either end of the hose member  88  and thus provide a resistant torque to the rotational movement of the hose member  88  about the curved roller bar  86  during the deployment of the arched roller assembly  80  upon extension arms  76  that serves to maintain needed tension in the roll-out and retraction of the flexible canopy material  82  in its arched configuration. 
     In the operative implementation of the arched roller assembly  80  of the present retractable boat top device  70 , an inward end of the length of canopy material  82  is fastened upon and secured to the surface of the flexible hose member  88  so that the canopy material can be wrapped in continuous layers about the hose member with the opposite or outward end of the canopy material being extended from the roller assembly and coupled to or directly connected upon the rear surface of the stationery roof section  74 . In accordance with this implementation of the arched roller assembly  80 , the movement of the telescoping extension arms  76  back and forth relative to the stationery roof section  74  produces an associated rotation of the conforming hose member  88  about the curved roller bar  86  and resulting deployment of the canopy material  76  relative to the stationery roof section in an arched configuration that is maintained during roll-out and retraction by resistant torque applied to the rotating hose member in the roller assembly via the torsion springs  94  mounted therein. 
     In a normal, retracted state depicted in  FIG. 15 , the present boat top device  70  is mounted transversely to the radar arch structure R of the recreational boat B with the arched canopy assembly  72  and the arched roller assembly  80  thereof fully retracted against the rearward edge of the stationery roof section  74 . When operationally deployed as depicted in  FIG. 16 , the arched canopy assembly  72  is driven rearward from the stationery roof section  74  in a substantially horizontal plane upon the pair of telescoping extension arms  76  mounted in parallel alignment on opposite sides of the roof section. The arched roller assembly  80  is moved directly upon the extension arms  76  rolling out the flexible canopy material  82  wrapped thereon about the hose member  88  in a continuous extension from the stationery roof section  74  and an arched configuration that is maintained substantially over and across the width of the deck. 
     Therefore, it is apparent that the described invention provides an improved retractable canopy top for recreational boats that is fully automated and capable of operative attachment to existing overhead structure on the boat without causing obstructions upon the deck. More particularly, the disclosed inventive device provides an improved automated retractable canopy top capable of deployment upon the existing radar arch structure of a recreational boat that effectively shades those on board from the sun and drains any accumulating rain water away from the deck of the boat without adversely affecting headroom of the passengers or visibility of the driver. In its disclosed operative attachment, the present automated retractable canopy top device is capable of providing effective sunshade protection to persons on board a recreational boat without presenting obstacles to their movement or obstructions to their performance of tasks on or around the deck. The disclosed invention is particularly suitable for use upon a sport fishing boat to provide fishermen with needed shade protection even while game fishing and without hindering their performance. In addition, the present inventive device is capable of hands free operation between an extended deployment and retracted state with protection of the retracted top while in storage. Furthermore, the disclosed device is relatively inexpensive to manufacture, easy to assemble and install upon existing boat structure, and capable of improving the functionality and appearance of the boat upon which it is installed. 
     Obviously, other embodiments and modifications of the present invention will readily come to those of ordinary skill in the art having the benefit of the teachings presented in the foregoing description and drawings. Alternate embodiments of different shapes and sizes, as well as substitution of known materials or those materials which may be developed at a future time to perform the same function as the present described embodiment are therefore considered to be part of the present invention. For example, an adaptation of the described retractable boat top device, particularly including the operative combination of the arched roller assembly  80 , flexible canopy material  82  and telescoping extension arms  76 , can be assembled to and fitted upon the stationery surface of a building or other structure so that the canopy material may be deployed from the stationery building surface in the same arched configuration that is provided and maintained by the present invention described herein. Accordingly, it is understood that this invention is not limited to the particular embodiment described, but rather is intended to cover modifications within the spirit and scope of the present invention as expressed in the appended claims.