Abstract:
A stop member ( 74; 174 ) is affixed to an elongated rudder blade ( 16 ) near its top and projects forward beyond the leading edge of the blade. A frame ( 62 ) in which the blade ( 16 ) is slidable lengthwise extends along a portion of the trailing edge of the blade and forward along the opposite sides. A separate mounting block ( 12 ) has a groove ( 48 ) receiving a portion of the leading edge of the blade ( 16 ). A pivot component ( 82 ) is mounted in the groove ( 48 ) for engagement against the underside ( 78 ) of the stop ( 74 ) when the blade ( 16 ) is in a normal upright steering position. A spring ( 52 ) is connected between the mounting block ( 12 ) and the frame ( 62 ) to bias the frame toward a position in which the blade ( 16 ) received therein extends in an upright steering position. From such position, the blade ( 16 ) can be swung upward and rearward, followed by forward translational movement through the frame ( 62 ) and along the mounting member ( 12 ).

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application is a continuation of International Application No. PCT/US2009/053149, filed Aug. 7, 2009, which claims the benefit of Provisional Application No. 61/087,069, filed Aug. 7, 2008, the entire disclosures of which are hereby incorporated by reference herein. 
     BACKGROUND 
     The present invention relates to a rudder assembly for a watercraft, particularly a personal watercraft, such as a kayak. 
     Known kayak rudders are almost always retractable. In the normal operating position, the rudder blade extends below the hull, at the stern, and is pivoted about an upright axis for steering control. For example, the rudder blade typically is carried by some type of mount that may have an upright stub shaft fitted in a bracket at the stern. The rotatable fit of the stub shaft in the bracket allows the rudder to be turned for steering the kayak. Typically, the rudder blade is pivoted to the mount for rotating upward about a horizontal axis so that it can be “retracted” out of the water. In some constructions, the arc or angle of retraction is 90 degrees, from a downward oriented, vertical position to an afterward oriented, horizontal position. In other constructions, the angle of retraction can be approximately 180 degrees, from a downward oriented, vertical position to an upward oriented, vertical position. In still other constructions, the angle of contraction is approximately 270 degrees, from a downward oriented, vertical position to a forward oriented, horizontal position (such as with the rudder blade resting on the stern portion of the watercraft). Another known construction is the so-called “Navigator Rudder System” described in an article from the December 2002 issue of  Sea Kayaker  magazine. In that system, a rudder blade is slidable in a sleeve, and it is the sleeve that is pivoted for swinging about a horizontal axis relative to a mount that, in turn, can be swung about a vertical axis. The blade can be retracted by sliding upward and forward through the sleeve as the sleeve rotates up, until the sleeve extends vertically and the rudder blade extends horizontally. 
     SUMMARY 
     This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
     This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
     The rudder assembly in accordance with the present invention is quickly and easily mountable on the stern of a personal watercraft such as a kayak. Such assembly includes an elongated blade that can be swung side to side by conventional steering control lines. In a preferred embodiment, a stop member is affixed to the blade near its top and projects forward from the leading edge of the blade. A frame in which the blade is slideable lengthwise extends along a portion of the trailing edge of the blade and forward along the opposite sides. A separate mounting block has a groove receiving a portion of the leading edge of the blade. A pivot component is mounted in the groove for engagement against the underside of the stop member when the blade in its normal upright steering position. A spring is connected between the mounting block and the frame to bias the frame toward a position in which the blade received therein extends in the upright steering position. From such position, the blade can be swung upward and rearward, followed by forward translational movement through the frame and along the mounting member. 
     The blade and stop member can be adapted for connection at different locations along the leading edge of the blade, such that the depth of the blade below the mounting block can be adjusted. The stop member and mounting block can have cooperating portions permitting limited relative movement if the blade encounters an obstacle as the watercraft is moving rearward, and enclosed areas are provided for connection of standard steering control lines to the mounting block. The blade is not mechanically attached to the frame, nor is it mechanically attached to the mounting block, and the only attachment of the frame to the mounting block is by way of the spring. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a top front perspective of a rudder assembly in accordance with the present invention; and 
         FIG. 2  is a top rear perspective of such rudder assembly with the stern portion of a personal watercraft shown in broken lines; 
         FIG. 3  is a fragmentary, enlarged, top rear perspective of such rudder assembly with parts shown in exploded relationship; 
         FIG. 4  is a corresponding top rear perspective of such rudder assembly with additional parts shown in exploded relationship; and 
         FIG. 5  is another corresponding top rear perspective of such rudder assembly with parts deleted and additional parts shown in exploded relationship; 
         FIG. 6  is a bottom front perspective of such rudder assembly with parts deleted and parts shown in exploded relationship; 
         FIG. 7  is an enlarged, fragmentary side elevation of such rudder assembly; 
         FIG. 8  is a section along line  8 - 8  of  FIG. 7 ; 
         FIG. 9  is a side elevation of such rudder assembly, corresponding to  FIG. 7 , but with parts broken away; 
         FIG. 10  is another corresponding side elevation of such rudder assembly with parts shown in different positions; and 
         FIG. 11  is another corresponding side elevation of such rudder assembly with parts shown in different positions; 
         FIG. 12  is a top rear perspective of such rudder assembly with a rudder blade shown partially retracted; and 
         FIG. 13  is a corresponding top rear perspective of such rudder assembly with the rudder blade shown further retracted; 
         FIG. 14  is a diagrammatic side elevation of such rudder assembly with different positions of the parts shown in broken lines; 
         FIG. 15  is a side elevation of such rudder assembly; 
         FIG. 16  is a corresponding side elevation of such rudder assembly with parts in different positions; and 
         FIG. 17  is another corresponding side elevation of such rudder assembly with parts shown in different positions; 
         FIG. 18  is a top rear perspective of modified parts of a rudder assembly in accordance with the present invention; 
         FIG. 19  is a corresponding top rear perspective with parts in different positions; 
         FIG. 20  is another corresponding top rear perspective with parts in different positions; and 
         FIG. 21  is another corresponding top rear perspective with parts in different positions. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a rudder assembly  10  in accordance with the present invention in assembled condition, ready for mounting on a personal watercraft such as a kayak. The assembly includes a mounting block or base  12  from which an upright pivot shaft  14  extends downward. Shaft  14  is received in a standard mount, such as a mounting bracket, at the stern of the watercraft. In the steering position shown, the rudder blade  16  is supported by the base  12  but is not mechanically connected to it. From the central position illustrated in  FIG. 1 , the blade  16  can be swung to one side or the other by manipulation of rudder control lines  18 . For example, in conventional kayaks it is common for such lines to be movable by operation of foot pedals or braces for steering the kayak. In general, in the construction of the present invention, the blade also can be swung upward about a transverse horizontal axis to an approximately horizontally-extending position by pulling on a rope or cable  20  that attaches to a mounting hole  22  at the top end portion of the blade  16 . From the upward-swung, horizontal position, additional pulling on the rope or cable  20  results in translating the rudder blade forward relative to the mounting base  12 . 
       FIG. 2  also shows all of the component parts of the rudder assembly  10  assembled and with the rudder blade  16  in its lowered, upright steering position. The stern position of a kayak K and the rudder mounting bracket B are shown diagrammatically in broken lines. The bracket has vertically aligned holes H that rotatably receive the shaft  14  so that the base  12  and rudder blade  16  can be swung side-to-side for steering. 
       FIGS. 3-6  show parts of the rudder assembly removed or broken away. The component parts are symmetrical about a central vertical plane, such that the starboard and port side parts are minor images of each other. 
     With reference to  FIG. 3 , a decorative and protective cap piece  24  is secured to the mounting base  12 , such as by a screw  26  that extends through an upright front flange  28  of the mounting base. For additional stability, another attachment screw can be used at the center or rear portion of the cap. In the illustrated embodiment, the inner edge of the top and rear walls of the cap  24  have short tongues  30  that mate with shallow grooves  32  in a central wall  34  of the mounting base  12 . Although a mating tongue-and-groove arrangement is illustrated, it is envisioned that pins and sockets could be used for the interfitting parts of the cap and central wall  34 . An integral triangular gusset  36  extends between the lower portions of the front flange  28  and wall  34 . The gusset carries a pair of clamp blocks  38 ,  40  that are connected by a screw  42 . The aft end portion of the steering cable is clamped between these blocks and, from the clamping point, extends outward to a hole  44  in the front flange  28 , and from there forward to the kayak steering mechanism. The cap and mounting block provide an enclosed area for connection of the steering control line. 
     More specifically, as seen in  FIG. 4 , the lower clamp block  38  can be secured on the gusset  36  by pins or screws  46 . The top clamp block  40  has a hole for the clamping screw  42  and can have an additional hole  44 ′ through which the end of the steering cable can be threaded. This allows for some adjustment in the steering cable and also convenient access for holding it in position as it is clamped between the blocks. 
     With reference to  FIG. 4  and  FIG. 5 , the central walls  34  of the mounting base  12  are spaced apart to form an upward-opening groove  48 . The groove is also open at the front and to the rear of the base  12 . Each wall  34  has a lateral cylindrical stub  50  for mounting of a helical torsion spring  52 . Mounting can be by a retainer washer  54  and screw  56  (the port spring  52  being shown in its mounted position in  FIG. 3 ). These parts (spring  52 , retainer  54 , and screw  56 ) are shown in exploded relationship at the port side in  FIG. 4  and at the starboard side in  FIG. 5 . Each torsion spring  52  has a downward extending spring arm  58  with an in-turned end  60  at the bottom and a horizontal spring arm  61  that extends forward. The forward spring arm engages against the gusset  36 , previously described. As described in more detail below, the biasing force of the downward-extending spring arm  58  is generally forward to urge a frame in which the rudder blade  16  is received toward the upright steering position for the rudder blade. 
     As seen in  FIG. 3  and  FIG. 4 , at the rear of the rudder assembly  10 , a pair of frame pieces  62  are connected together, such as by screws  64 . The frame pieces  62  have front extensions  66  that, in the orientation shown in  FIG. 3 , for example, extend below the corresponding torsion springs  52 . The in-turned end  60  of each spring is received in a hole  68  through the corresponding extension  66 . An alternative connection can be achieved by forming the bottom end of the spring into an eye and attaching the spring to the extension  66  by a screw. The springs are the only attachment of the frames  62  to the mounting base  12 . When the frames are joined together, they form a vertical slot receiving the upper rear portion of the rudder blade  16 . This slot is aligned with the slot  48  in the rear portion of the mounting base. 
     In  FIG. 4 , the frame members  62  are illustrated in an outward-shifted position to reveal a pair of rollers  70  that are fitted between the frame members with central grooves that ride along the rear edge of the rudder blade  16 . The rollers are coaxial with the frame screws  64 . 
     In  FIG. 5 , the rudder blade  16  has been moved rearward out of the groove  48  in the rear of the mounting base  12 . A stop block  74  is carried on the leading edge portion of the blade  16 . The stop block  74  can be attached by screws  75 , and a row of mounting holes  76  can be provided along the top portion of the blade such that the length of the blade below the block  74  can be adjusted by selecting the appropriate pair of mounting holes  76 . The stop block projects forward from the leading edge of the blade, which otherwise is straight. The underside of the block  74  has an arcuate cut-out  78 , preferably a quarter circle, i.e., approximately 90° and circular. 
       FIG. 6  shows the base  12  from below with the stub shaft  14  shifted down. When assembled, the upper end portion of the shaft is permanently fixed in a socket that extends up through the bottom of the mounting base  12 . For example, the upper end of the shaft can be received in a bushing that is overmolded in the base  12 , and then secured from the top by a screw. 
     Returning to  FIG. 5 , an internal part of the rudder assembly includes a horizontal shaft  80  and a central pivot member in the form of a roller or pulley  82 . Shaft  80  extends through the aligned stubs  50  and the roller  82  is received in the central portion of the groove  48  formed between the upright walls  34 . The curvature of the exterior of the roller or pulley  82  is approximately the same as the cut-out  78  of the stop  76  which is affixed to the rudder blade  16 . In normal use (i.e., the steering condition), the cut-out  78  of the stop  74  rests on the roller  82  as seen, for example, in the sectional, assembled view of  FIG. 8 . 
       FIGS. 7 ,  9 ,  10 , and  11  show the rudder assembly in elevation from the port side. In  FIG. 9 , the port cap piece is deleted to reveal the forward part of the central wall  34  at the port side and the downward-extending spring arm  58  connected to the lower front portion of the port frame piece  62 . The rear portion of the port wall  34  is broken away to reveal the rudder stop  74  on the central roller  82 . With the rear of the port frame piece  62  broken away, additional internal components can be seen, including the rear rollers  70  that are carried between the frame members  62 . Note that there is no mechanical connection of the rudder blade and stop to the remainder of the assembly, and that the only connection of the composite frame formed by pieces  62  is by way of the torsion spring. 
     In normal use, the rudder blade  16  is supported on the roller  82  by engagement of the stop block  74  against the roller. When it is desired to raise the rudder, pulling forward on the rope or cable connected at  22  will swing the rudder blade and rear frames counterclockwise to the horizontal orientation shown in  FIGS. 10 ,  12 , and  16 , against the biasing force of the torsion springs. Such biasing force is transmitted by way of the spring arms  58 . Additional pulling on the rope or cable connected at  22  will translate the rudder horizontally forward to the position of  FIGS. 11 ,  13 , and  17 . Since the back edge of the rudder blade is angled, i.e., the rudder increases in width from its top to its bottom, such forward translating shifts the rear frame pieces  62  upward. The rotation of the frame and the forward translation of the rudder blade are resisted by the force of the torsion spring on the frame pieces.  FIGS. 11 ,  13 , and  17  show the forward-most position contemplated with the base of the rudder almost fully retracted into the space between the frame members  62  and the frame members shifted upward to the maximum degree permitted by the torsion springs. The blade can be retained in the raised, forward-translated position by securing the control rope or cable in a cleat. Upon release of the control rope or cable the rudder automatically slides rearward and swings down to the upright steering position due to the force of the torsion springs. 
       FIG. 18  shows a modified mounting block or base that cooperates with a modified blade stop in an alternative embodiment of the present invention. Except for the modifications discussed herein, the alternative embodiment is identical to the embodiment previously described. The modified blade stop  174  attaches to the rudder blade  16  and has the same arcuate cut-out  78  as in the previous embodiment. Attachment of the stop  174  along the leading edge of the blade is by screws, and the depth of the blade is adjustable by selecting different mounting holes  76 . A new feature of the stop is an outward projecting, inclined flange  175  at each side of the stop. The flange is inclined upward and rearward at an angle of approximately 45°. 
     The modified base  112  is identical to the base previously described except for the provision of integral tail pieces  113  that project rearward at each side of the central slot  48 , at a location slightly below the roller on which the cut-out  78  rests; and in the provision of projecting portions  114  at the top of the mounting block base, above and to the rear of the roller location. Projecting portions  114  have inclined leading edges  115  which, like the stop flanges  175 , are angled upward and rearward at an angle of about 45°. 
     As shown in  FIG. 19 , when the parts are assembled, i.e., with the stop resting on the internal roller, the stop flanges  175  are immediately adjacent to the leading edges of the projecting portions  114 . These parts cooperate to provide an important safety feature that may protect the rudder blade or other parts of the assembly from damage if the blade contacts an obstacle while the watercraft is moving backwards. In that case, the bottom of the blade will be forced forward in the general direction of the arrow A in  FIG. 19 . The blade will try to rotate clockwise around the internal roller, which has the effect of tending to move the very top of the rudder rearward. Flanges  175  engage against the leading edges of the projections  114  and, with some inherent resistance, slide upward as seen in  FIG. 20 . In the position of  FIG. 20 , the stop and top of the rudder are raised as compared to the position shown in  FIG. 19 . The upward and counter-clockwise swinging motion is opposed somewhat by the torsion springs and also by the angling of the flanges  175  and cooperating leading edges of the projections  114 , but not so much as to prevent such movement if sufficient force is applied that damage to the assembly may occur.  FIG. 21  shows the positions of the parts as the top edge of the rudder is forced upward and rearward even more due to engagement of the bottom portion of the rudder with an obstacle. Ultimately, the flanges  175  slide completely over the projections  114 , whereupon the tendency is for the rudder to shift downward. At this point the bottom portion of the stop  174  engages the top edges of the tail pieces  113 . The first engagement is inside the central groove  48  where the bottom portion of the stop engages against inward projecting shoulders  116  of the tail pieces  113  (such shoulders  116  being visible in  FIG. 18 ). The torsion springs exert a fairly strong force tending to return the rudder blade to its normal vertical position and also limit how far rearward and upward the upper portion of the rudder can move. When the obstacle is past, the rudder automatically snaps back to its normal operating position. 
     If an obstacle is encountered while the kayak is moving forward, the rudder simply rotates upward out of the way, in the same manner as if it were retracted manually by pulling on the cord attached at  22 . The torsion springs will return the rudder to the normal operating position when the kayak passes over the obstacle. 
     Another convenient aspect of a rudder assembly in accordance with the present invention is that the rudder blade with its stop piece can be quickly and easily removed from the kayak. This is achieved by simply pulling back on the mounting frames and sliding the rudder blade upward until it is separated from the rest of the mounting assembly. The rudder blade then can be stowed inside the kayak or at any convenient location. 
     While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.