Abstract:
A tether device includes a magnetic base; a pole having a first end attached to the magnetic base; and a connector or clip attached at a second end of the pole, for removably connecting the tethering device to a user. Also, a method for tethering a user to a hull of a vessel including the steps of providing a tether device having a magnetic base, a pole having a first end attached to the magnetic base, and a connector or clip attached at a second end of the pole; connecting the connector or clip to the user; and engaging the magnetic base with the hull of the vessel.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a division of application Ser. No. 12/402,002 filed Mar. 11, 2009, issuing as U.S. Pat. No. 8,556,031 on Oct. 15, 2013, which is a continuation-in-part of application Ser. No. 12/335,958 filed Dec. 16, 2008, now abandoned, both of which are incorporated by reference herein in their entireties for all purposes. 
    
    
     GOVERNMENTAL INTEREST 
     This invention was made with Government support under Contract No. N00024-03-C-5115 awarded by the Department of the Navy. The Government has certain rights in this invention. 
    
    
     FIELD OF INVENTION 
     The present invention relates to a tether device. More particularly, the present invention relates to a tether device and method for tethering a user to a hull of a vessel to enable a user to draw him- or herself toward the inward sloping portions of the vessel&#39;s hull to perform painting and other maintenance and repair tasks. 
     BACKGROUND OF THE INVENTION 
     When ships and other vessels are floating in water and the hull of the vessel requires painting and/or other maintenance and repairs, a maintenance person must be lowered over the side of the vessel in a support harness to access the exterior side surface of the hull to perform the service. Some portions of the hull slope inward from the point of suspension. To reach these areas, a secondary support must be used to draw the maintenance person close enough to the inward sloping portions of the hull to perform the task. 
     Permanently welded clips are provided on the hulls of vessels where tethering is required to perform painting and/or other hull maintenance and repairs. The clips are accessed by the maintenance person using a grappling hook. The person then sequentially hooks on and off the clips to move along the hull. This requires a great deal of manual dexterity and increases safety risk during these maneuvers. 
     The use of welded clips has several disadvantages. The vessel&#39;s hull is weakened by the clip welding process due to heating. The discontinuities on the exterior surface of the hull promote corrosion because the paint film is less durable in these areas. Many ships and vessels have in excess of 100 clips welded to the exterior surface of the hull. 
     Accordingly, a device and/or method is needed that allows the elimination of the welded clips. 
     SUMMARY 
     Disclosed herein is a tether device comprising: a magnetic base; a pole having a first end attached to the magnetic base; and a connector or clip attached at a second end of the pole, the connector or clip for removably connecting the tethering device to a user. 
     Also disclosed herein is a method for tethering a user to a hull of a vessel. The method comprises the steps of: providing a tether device comprising a magnetic base, a pole having a first end attached to the magnetic base, and a connector or clip attached at a second end of the pole; connecting the connector or clip to the user; and engaging the magnetic base with the hull of the vessel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a perspective view of an embodiment of a tether device. 
         FIG. 2  shows a cut away view of the magnetic base of the tether device. 
         FIG. 3  shows a pictorial representation of the tether device in operation for tethering a user to a hull of a vessel. 
         FIG. 4  is a pictorial representation of an embodiment of a tether device according to the application in operation for tethering a person to the hull of a vessel. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a perspective view of an embodiment of a tether device  10  for tethering a maintenance person or other user to a hull  110  of a vessel  100 . The tether device  10  enables the user to draw him- or herself toward the inward sloping portions of the vessel&#39;s hull  110  to perform painting and other maintenance and repair tasks while the vessel  100  is floating on water. In addition, the hull clips which negatively impact the hull of the vessel over the lifecycle of the vessel, may be deleted when the tether device  10  is utilized. The tether device  10  generally comprises a magnetic base  20 , a lightweight, elongated tethering pole  30  extending away from the base  20 , and a connector or clip  40  disposed at a free end of the pole  30 . The magnetic base  20  of the tether device  10  allows it to be magnetically attached to the hull  110  of the floating vessel  100  ( FIG. 3 ). The vessel  100  may include, without limitation, a naval ship, a tanker, a bulk carrier, a container ship as well as a towed or pushed barge. 
     In one embodiment, as shown in  FIG. 2 , the magnetic base  20  comprises a housing  21  and one or more electromagnets  23  disposed within the housing  21 . The housing  21  includes a top wall  21   t,  at least one side wall  21   s  depending from the top wall, and a bottom wall  21   b.  The top and side walls  21   t,    21   s  of the housing  21  form an internal compartment  22  for containing the one or more electromagnets  23 . The electromagnets  23  are powered by a power source. In one embodiment, the power source may comprise a battery  24  disposed in the internal compartment of the housing  21  with the electromagnets  23 . In an alternative embodiment, the power source may comprise an alternating current source. The current source may be obtained from the vessel with suitable electrical power isolation to preclude a shock hazard. A switch arrangement  25  may be provided for allowing a user to selectively connect and disconnect the power source to and from the electromagnets  23  to respectively activate and deactivate of the magnetic base  20 . A protective covering  26  may be disposed on the bottom wall  21   b  to protect the exterior surface of the vessel&#39;s hull from damage when the tether device  10 , is placed thereon. The protective covering  26  may be of any suitable material for preventing marring of a hull&#39;s exterior surface. Examples of such materials include, without limitation, felt or other fabrics, plastic, natural or synthetic rubbers, and polymeric foams. In a preferred embodiment, the protective covering  26  comprises the natural or synthetic rubber mentioned earlier because it provides a high degree of friction to prevent sliding. 
     When activated by the switch arrangement  25 , the one or more electromagnets  23  should have sufficient magnetic strength to retain the tether device  10  to the hull  110  of the floating vessel  100 , when tethering the user thereto. 
     Referring again to  FIG. 1 , the tethering pole  30  is capable of being telescopically extended and collapsed to provide a variably adjustable length to suit stand off distance requirements. In one embodiment, the telescopically adjustable tethering pole  30  comprises a mount  31  fixedly attached (e.g., welded, riveted, screw-fastened, etc.) to the top wall  21   t  of the magnetic base housing  21 , two or more telescopically engaged tubes  32   o  and  32   i,  the outer tube  32   o  of which is fixedly connected or pivotally connected (e.g., a ball and socket or like arrangement  150  as shown in  FIG. 4 ) to the mount  31 , and a solid rod  33  telescopically disposed within the inner tube  32   i.  The pole  30  may be adapted and dimensioned to provide friction between the outer and inner tubes  32   o  and  32   i  and between the solid rod  33  and inner tube  32   i  to maintain the length of the pole  30 , once it has been extended or collapsed to a desired length. Alternatively, the pole  30  may include internal locking rings such as those found on photographic tripods, to maintain the length of the pole  30 , once it has been extended or collapsed to a desired length. The outer tube  32   o  may be fixedly connected to the mount  31  using any suitable method. For example, one or more set screws may be used for fixedly connecting the outer tube  32   o  to the mount  31 , or the outer tube  32   o  may be threaded into the mount  31 . The outer tube  32   o  may also be pivotally connected to the mount  31  using any suitable method. For example, a ball and socket (ball-joint) arrangement ( 150 , shown in  FIG. 4 ) may be used for pivotally connecting the outer tube  32   o  to the mount  31 . The connector or clip  40  may be fixedly attached to a free end portion of the rod  33 . The connector or clip may comprise a quick release hook or, in another embodiment, a solid loop and a carabiner to allow for attachment and release. 
     As shown in  FIG. 3 , the tether device  10  allows a user  120  to draw him- or herself toward the inward sloping portions  111  of the vessel&#39;s hull  110  to perform painting and other maintenance and repair tasks while the vessel  100  is floating on water  130 . The tether device  10  may also be used to work on non-sloped sections of the vessel&#39;s hull  110 . In one embodiment, the user  120  attaches the connector or clip  40  of the tether device  10  to the user&#39;s suspension harness, clothing, footwear, helmet, belt, and other articles worn (denoted generally by reference numeral  140 ) by the user  120 . After the connector or clip  40  has been attached to the user  120 , the user  120  is lowered over the side of the floating vessel  100 , adjacent to a sloped section  111  of the hull  110  of the floating vessel  100 . The user  120  then activates the electromagnets  23  of the magnetic base  20 , by way of the switch arrangement  25 , and extends the tethering pole  30 , to attach the tether device  10 , via the magnetic base  20  to the sloped section  111  of the hull  110  at a selected location thereof, and pulls himself or herself toward the hull  110  of the vessel  100  by collapsing the tethering pole  30  and locking the pole  30  to the desired length. Once the tether pole  30  is collapsed, the user  120  may attach a strap ( 160 , shown in  FIG. 4 ) to the magnetic base  20  and disconnect the tethering pole  30  to allow for greater freedom of movement while performing tasks. 
     When work at that location of the vessel  100  is completed, the user deactivates the electromagnets  23  of the base  20 , via the switch arrangement  25 , thereby releasing the magnetic base  20  and thus the tether device  10  from the hull  110  of the vessel  100 . If desired, the user  120  can then relocate the magnetic base  20  of the tether device  10  to another location of the hull  110  and repeat the procedure described immediately above. Once work on the vessel  100  has been completed and the user  120  is back on the vessel  100  or dock, the connector or clip  40  may be disconnected from the user&#39;s suspension harness, clothing, belt, footwear, helmet, and other worn article  140 . 
     In an alternate embodiment, the electro-magnets may be replaced by one or more permanent magnets. As in the previous embodiment, the one or more permanent magnets should have sufficient magnetic strength to retain the tether device on the hull of the floating vessel, when tethering the user thereto. In this embodiment, magnetic base of the tethering device may be attached and released from the hull of the floating vessel thru mechanical leverage. 
     In another alternate embodiment, the tethering pole may comprise a single tube instead of the two or more telescopically engaged tubes as previously described. The single tube may be fixedly or pivotally connected to the mount, and a solid rod with a connector or clip fixedly attached to a free end portion thereof, may be telescopically disposed within the tube. 
     The tethering pole, in still another alternate embodiment, may comprise a fixed length, solid shaft. A first end of the shaft may be fixedly or pivotally connected to the top wall of the magnetic base housing. The connector or clip may be fixedly attached to the free end portion of the rod. 
     While the foregoing invention has been described with reference to the above, various modifications and changes can be made without departing from the spirit of the invention. Accordingly, all such modifications and changes are considered to be within the scope of the appended claims.