Abstract:
A cover assembly for covering an object subjected to an airstream due to transportation of the object in open air. The cover comprises a flexible cover adapted to fit over the object so as to conceal a portion of the object. An aperture is provided in the cover. A deflector is provided on an exterior surface of the cover and forward of the aperture with respect to a direction of transportation. The deflector is positioned such that a low pressure zone is created proximate to the aperture during transportation of the object in the direction by an airstream being deflected by the deflector, whereby air located between an interior of the cover and the object being transported exhausts through the aperture to an exterior of the cover to cause the cover to at least partially conform to the object.

Description:
[0001]    This application relates to and claims priority from United States Provisional Patent Application Serial No. 60/468,075, filed May 6, 2003, which is hereby incorporated by reference in its entirety. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention generally relates to a flexible cover for protecting an object subjected to an airstream in open-air transport and, more particularly, to a cover for personal watercraft, watercraft, snowmobiles and the like, that conforms closely to the object it protects by differential pressure.  
           [0004]    2. Background Art  
           [0005]    Flexible covers are widely used in open-air transport to protect objects exposed to an airstream when being towed by a vehicle. For instance, personal watercraft, watercraft and snowmobiles are partially covered during transport to be protected from the elements of weather and from windblown debris inherent to open-air transport.  
           [0006]    At highway speeds, looser portions of the protective cover have been known to whip and buffet. In addition to causing some noise, the whipping and buffeting may result in the cover being blown off by the airflow, or the cover being ripped open, thereby temporarily exposing the object being transported.  
           [0007]    U.S. Pat. No. 5,997,071, issued on Dec. 7, 1999 to Mazzarelli, discloses a protective cover secured to the object it protects by differential pressure, to overcome the above-cited problems. More precisely, the cover protects a substantial portion of an object, and exhaust apertures are defined in the cover. The exhaust apertures are each covered by a tear-shaped vent member having an open end. The open end of each vent member faces away from a direction of tow. The airstream that results from the tow circumvents the vent members, and the latter are shaped and positioned such that a pressure drop is created at the open end of the vent members. Therefore, as the vent members are each positioned over one exhaust aperture, air concealed between the cover and the object being transported moves out from under the cover through the exhaust apertures. This outflow of air will cause the flexible cover to mold or conform closely to the object that it protects.  
           [0008]    U.S. Patent Application Publication No. US 2002/0069947, published on Jun. 13, 2002, from Frechette et al., also describes a flexible protective cover secured to the object it protects by differential pressure. This publication discloses an alternative approach to creating the differential pressure between an interior of the cover and an exterior thereof. In this publication, exhaust apertures are provided in surfaces of the flexible protective cover that face away from the direction of transport. More specifically, two surfaces are identified as being disposed vertically in reference to the direction of travel, and as being disposed on the leeward side of the object. These surfaces are exposed to lower pressures and are hence provided with apertures through which air exhausts from the interior of the cover.  
           [0009]    A drawback of the prior art pressure differential systems is that they involve costly solutions. For instance, vent members must be formed of a material having sufficient structural integrity to withstand an airstream. Such vent members must therefore be manufactured according to more complex processes than that typically involved in fabricating covers, such as molding.  
           [0010]    Also, some types of pressure differential systems are not efficient on all types of covers. For instance, the pressure differential system of U.S. Patent Application Publication No. US 2002/0069947 requires a given geometry of the objects being covered, for natural low pressure zones providing sufficient suction to be formed. The geometry of some objects does not allow for suction of sufficient magnitude to be created.  
         SUMMARY OF INVENTION  
         [0011]    It is therefore an aim of an aspect of the present invention to provide a novel method of creating a pressure differential between an interior and exterior of a cover covering an object subjected to an airstream in open-air transport.  
           [0012]    It is a still further aim of an aspect of the present invention to provide a novel kit for creating a pressure differential between an interior and exterior of a cover covering an object subjected to an airstream in open-air transport.  
           [0013]    It is a still further aim of an aspect of the present invention to provide a novel cover that conforms to an object subjected to an airstream in open-air transport by differential pressure.  
           [0014]    Therefore, in accordance with the present invention, there is provided a method for creating a pressure differential between an interior and an exterior of a flexible cover covering at least partly an object being transported in open air to cause the cover to at least partially conform to the object, comprising the steps of: providing an aperture in the cover; providing a deflector on an exterior surface of the cover, forward of the aperture with respect to a direction of transportation of the object; and transporting the object in the direction whereby a low pressure zone is created proximate to the aperture by an airstream deflected by the deflector, whereby air located between the interior of the cover and the object being transported exhausts through the aperture to the exterior of the cover.  
           [0015]    Further in accordance with the present invention, there is provided a kit for creating a pressure differential between an interior and an exterior of a flexible cover concealing at least a portion of an object being transported in open air to cause the cover to substantially conform to the object by air, located between the interior of the cover and the object, exhausting through an aperture in the flexible cover, comprising: a flexible material tube adapted to be secured to the flexible cover forward of the aperture with respect to a direction of towing; and a reinforcement element adapted to be received in the flexible material tube to brace the cover around the aperture to maintain a shape integrity of the aperture; whereby a low pressure zone is created opposite the aperture during towing of the object in the direction by an airstream being deflected by the flexible material tube reinforced with the reinforcement element, whereby air located between the interior of the cover and the object exhausts toward the low pressure zone through the aperture to the exterior of the cover to create a pressure differential between the interior and the exterior of the flexible cover.  
           [0016]    Still further in accordance with the present invention, there is provided a cover assembly for covering an object subjected to an airstream due to transportation of the object in open air, the cover comprising: a flexible cover adapted to fit over the object so as to conceal at least a portion of the object; an aperture in the cover; and a deflector on an exterior surface of the cover and forward of the aperture with respect to a direction of transportation, the deflector being positioned such that a low pressure zone is created proximate to the aperture during transportation of the object in the direction by an airstream being deflected by the deflector, whereby air located between an interior of the cover and the object being transported exhausts through the aperture to an exterior of the cover to cause the cover to at least partially conform to the object.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    Having thus generally described the nature of the invention, reference will now be made to the accompanying drawings, showing by way of illustration a preferred embodiment thereof and in which:  
         [0018]    [0018]FIG. 1 is a port-side elevational view of a personal watercraft capable of being covered by a cover of the present invention;  
         [0019]    [0019]FIG. 2 is a starboard-side perspective view of the personal watercraft of FIG. 1 being protected by a cover in accordance with the present invention;  
         [0020]    [0020]FIG. 3 is an enlarged port-side elevational view of the personal watercraft protected by the cover of the present invention;  
         [0021]    [0021]FIG. 4 is an enlarged port-side elevational view of a differential pressure securing system of the present invention;  
         [0022]    [0022]FIG. 5 is an enlarged port-side perspective view of the differential pressure securing system;  
         [0023]    [0023]FIG. 6 is a cross-sectional schematic view of the differential pressure securing system of the present invention, with a screen thereof removed; and  
         [0024]    [0024]FIG. 7 is a port-side perspective view of a watercraft being protected by a cover in accordance with the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0025]    Referring to the drawings, and more particularly to FIG. 1, a personal watercraft, upon which a cover in accordance with the present invention will be fitted, is generally shown at  10 . The personal watercraft  10  includes a bow B, a stern S, a port P and a starboard (hidden in FIG. 1, but illustrated at “D” in FIG. 2). The personal watercraft  10  has two main parts, namely a hull  12  and a deck  14 . The hull  12  buoyantly supports the personal watercraft  10  in a body of water. The hull  12  and the deck  14  meet at bond line  16 . From bow B to stern S, the personal watercraft  10  has a hood  18 , a helm assembly  20  and a seating area  22 . The personal watercraft  10  is of conventional construction, the details of which are unimportant to the current invention.  
         [0026]    Referring to FIG. 2, the personal watercraft  10  is shown supporting a flexible cover  30  in accordance with the present invention. The cover  30  is of the type that is slipped onto the personal watercraft  10 , such that the personal watercraft  10  is fully covered at and above the bond line  16 . Moreover, a portion of the hull  12  is also covered by the cover  30 . The bottom open end  32  of the cover  30  includes a peripheral elastic member that will contract onto the convex body of the hull  12 , to provide some level of securement of the cover  30  on the personal watercraft  10  so as to be secured to the hull  12 . Various other fastening means (e.g., hooks, straps, zippered vent, etc.) can be used additionally or separately in order to secure the cover  30  to the personal watercraft  10 .  
         [0027]    The cover  30  is generally separated into two major portions. A skirt  34  covers the deck  14  and the bond line  16 , as well as the hood  18  and the seating area  22 , whereas a cap  36  conceals the helm assembly  20 . The skirt  34  is generally separated into a bow portion  34 B, a stern portion  34 S, and port and starboard portions  34 P (FIG. 3) and  34 D, respectively. Referring to FIGS. 1 and 2 simultaneously, the bow portion  34 B covers the hood  18 , the port and starboard portions  34 P (FIG. 3) and  34 D, respectively, generally cover the flanks of the deck  14 , and the stern portion  34 S covers an aft portion of the watercraft  10 , including a seating area  22 . It is pointed out that the cover  30  must be suited to generally cover a personal watercraft of typical construction, whereby the details of the cover are unimportant.  
         [0028]    The flexible protective cover  30  typically consists of an air- and water-impermeable material, such as a nylon or a polymeric material (e.g., polyester, polypropylene woven fabric with a polyurethane resin coating), for instance, on a cotton scrim. Once the cover  30  is slipped onto the personal watercraft  10 , air is maintained between an interior of the cover  30  and the personal watercraft  10 .  
         [0029]    In FIG. 2, a differential pressure securing system in accordance with the present invention is generally shown at  40 , as provided on the starboard portion  34 D of the skirt  34 . As shown in FIG. 3, another differential pressure securing system  40  is provided on the port portion  34 P of the cover  30 , such that both the starboard side D and the port side P have a securing system  40 . The differential pressure securing system  40  is shown in greater detail in FIG. 3, as provided on the port portion  34 P of the skirt  34 . The differential pressure securing system  40  has an exhaust aperture  42 . In FIG. 3, the exhaust aperture  42  has a rectangular shape and is provided with a screen  44 . A longitudinal dimension of the exhaust aperture  42  is generally perpendicular to the airstream direction over the port portion  34 P of the skirt  34 , as illustrated by vector V 1 . A deflector  46 , longitudinally parallel to the exhaust aperture  42 , is positioned fore of the exhaust aperture  42 , and is adjacent to a forward edge of the exhaust aperture  42 . The deflector  46  has an elongated quadrilateral shape. Referring to FIG. 5, it is seen that the deflector  46  disrupts the generally smooth surface of the port portion  34 P of the skirt  34 . Although they are illustrated having quadrilateral shapes, it is appreciated that the exhaust aperture  42  and the deflector  46  can have any other suitable shape to be operative according to the operation of the differential pressure securing system  40 , as set forth hereinbelow.  
         [0030]    In the preferred embodiment of the present invention as illustrated in FIG. 6, the deflector  46  consists of a flexible material (e.g., the same material as that of the cover  30 ), defining a tubular body such that a rigid or semirigid rod  48  is insertable thereinto. The rod  48  consists of a plastic, or of any other suitable material, such as wood, metal, or the like. The deflector  46  is secured (e.g., sewn, glued, fused, or the like) to the cover  30  at an edge thereof adjacent to the forward edge of the exhaust aperture  42 . Referring to FIG. 4, a top end  49  and a bottom end (shown at  47  in FIG. 3) of the deflector  46  are secured to the cover  30  in a width dimension of the deflector  46 .  
         [0031]    Now that the structure of the differential pressure securing system  40  have been illustrated, an operation thereof is described. Referring to FIG. 6, a cross-sectional view of the differential pressure securing system  40  is generally shown, with the screen having been removed from the exhaust aperture  42  for clarity purposes. The interior of the cover  30  is generally shown as “I”, whereas an exterior is generally shown as “X”. When the personal watercraft  10  is towed, a trajectory of an airstream over the differential pressure securing system  40  is generally shown as “V 2 ”. The airstream follows the surface of the cover  30 , and is deflected by the deflector  46 . The deflector  46 , being secured. to the cover  30  by an aft edge thereof, has a forward edge thereof lift from the cover  30 . The top end  49  (FIGS. 3 and 4) and bottom end  47  (FIG. 3) of the deflector  46  limit the rise of the forward edge of the deflector  46 . The trajectory V 2  of the airstream around the deflector  46  creates a low pressure zone, approximately shown as  50 . The low pressure zone  50  represents a zone where the pressure is below the ambient pressure at the exterior X of the cover  30 . Therefore, air lodged in the cover  30  will move toward the low pressure zone  50 , thereby escaping the interior I of the cover  30 . This will cause a pressure differential between the interior I and the exterior X of the cover  30 , whereby the cover  30 . will conform closely or adhere to the outer surface of the personal watercraft  10 . The “flap” configuration of the deflector  46  (i.e., with the forward edge rising from the cover  30 ) enhances the deflection of the airstream, thereby increasing the differential pressure at the low pressure zone  50 , as well as the size of the low pressure zone  50 .  
         [0032]    In order to optimize the adherence/conformance of the cover  30  to the body of the personal watercraft  10 , it is preferred that the exhaust aperture  42  be positioned opposite an air space between the cover  30  and the personal watercraft  10 . Accordingly, the air space defines a plenum that will be taken by air lodged between the cover  30  and the personal watercraft  10  and that will escape through the exhaust aperture  42 . Moreover, the cover  30  will adhere better to the personal watercraft  10  the better the sealing is between the interior I and the exterior X of the cover  30 , notwithstanding the exhaust aperture  42 .  
         [0033]    The absolute pressure in the low pressure zone  50  will be inversely proportional to the speed at which the personal watercraft  10  is being towed. Therefore, the higher the towing speed, the more effective the differential pressure securing system  40  will be.  
         [0034]    Although the differential pressure securing systems  40  are shown on the port and starboard portions  34 P and  34 D, respectively, of the skirt  34 , it is contemplated to position the differential pressure securing system  40  on other appropriate portions of the cover  30 . For instance, lateral portions of the stern portion  34 S can host the differential pressure securing system  40 . Moreover, as described and illustrated in the preferred embodiment, having a pair of differential pressure securing systems  40  on the port P and starboard D of the personal watercraft  10  enhances the efficiency of the securement.  
         [0035]    Referring to FIGS.  2  to  4 , the screen  44  prevents road debris (e.g., rocks) from entering the cover  30  through the exhaust apertures  42 . The rigid or semirigid rod  48  that is received in the tubular body of the deflector  46  ensures that the corresponding exhaust aperture  42  is not deformed. This reduces the risk of a deformation in one of the exhaust apertures  42 , due to the flexible nature of the cover  30 , allowing the airstream to enter the cover  30  through the exhaust aperture  42 , thereby impeding the pressure differential effect by which the cover  30  adheres onto the personal watercraft  10 . Moreover, the rod  48  adds structural integrity to the deflector  46 .  
         [0036]    Although the differential pressure securing system  40  has been operatively illustrated on the cover of a personal watercraft in FIGS.  1  to  5 , the differential pressure securing system  40  may also be used with protective covers of other objects to protect them in open-air transport, such as motorcycles, ATVs, snowmobiles, boats, bicycles. As an illustrative embodiment, a watercraft  110  is shown in FIG. 7, protected by a cover  130 . The cover  130  has been slipped onto the watercraft  110  such that only a portion of a hull  112  is exposed. A differential pressure securing system  140  is provided in the cover  130 , and its position corresponds to the cavity defined by the passenger receiving area of the watercraft  110 . This cavity defines the above-mentioned plenum.