Abstract:
A rake system for removing underwater vegetation comprising a plate assembly, a handle assembly, and a line. The plate assembly comprises first and second engaging members each defining an engaging edge. The handle assembly is attached to the plate assembly. The line is attached to the handle assembly. During use, the user grips the handle assembly to toss the plate assembly to a first underwater location. The user then pulls the line to displace the plate assembly from the first underwater location along a harvest path. The engaging edges of the engaging members are adapted to engage the underwater vegetation to fix the underwater vegetation relative to the plate assembly such that continued pulling on the line removes the underwater vegetation in a harvest region defined by the harvest path.

Description:
TECHNICAL FIELD  
         [0001]    The present invention relates to systems and methods for removing underwater vegetation and, in particular, to hand tools that allow a user on the shore or in a boat to remove underwater vegetation.  
         BACKGROUND OF THE INVENTION  
         [0002]    Underwater vegetation is a problem in many bodies of water. For example, underwater vegetation can interfere with recreational activities such as swimming and boating. Some species of underwater vegetation, especially non-native species, can infest a body of water to a degree that interferes with wildlife and degrades water quality.  
           [0003]    Accordingly, numerous systems and methods have been developed to remove underwater vegetation. These systems range from relatively complicated under or in water harvesting activities to the use of hand tools such as garden rakes.  
           [0004]    The present invention relates to hand tools adapted to remove underwater vegetation from the bed of a body of water such as a pond or a lake.  
         RELATED ART  
         [0005]    A professional patentability search conducted on behalf of the applicant uncovered the following U.S. Patents:  
                                       U.S. Pat. No.   Inventor Name   Title                   5,152,126   Cousineau   SYSTEM FOR UPROOTING               AQUATIC PLANTS       5,079,905   Bergstrom   FLOATING WEED RAKE       4,774,804   Sands   SAND TRAP RAKE AND GOLF               BALL RETRIEVER AND METHOD       4,768,331   Jones   LAKE RAKE       2,961,817   Mitchell   DRAG RAKE FOR CUTTING AND               RAKING UNDERWATER GROWTH       1,723,616   Hawkins   BRUSH RAKE                  
 
           [0006]    The Jones, Bergstrom, and Mitchell patents all disclose mechanical rakes adapted to remove vegetation from ponds or lakes.  
           [0007]    The Jones patent employs teeth designed to present low resistance when pushed in an outward direction and which dig into the ground on the return, inward direction. The teeth are designed to break up the ground and remove the vegetation by the roots.  
           [0008]    The Mitchell patent is designed to cut underwater growth off immediately above the bottom of the water. To this end, the Mitchell device employs a curved plate having a sharpened inner edge that is pulled such that the sharpened edge moves along the lake bottom cutting the plants just above their roots. The Mitchell device is not intended to remove the plants by their roots. To the contrary, the Mitchell device is constructed to keep the parts thereof from digging into the ground and thereby loosening the roots.  
           [0009]    The Bergstrom device is designed to remove vegetation from the surface and thus employs a floating rig head. The Bergstrom device engages only the upper ends of the plants and would not be effective at removing the plants by their roots; plants engaged by the Bergstrom device may break anywhere between the upper portion of the plant and the root.  
           [0010]    The Cousineau patent is not a strictly mechanical device, but instead uses pressurized water to break up the ground in which the underwater vegetation is growing. The Cousineau device is not a rake in the traditional sense in that it is not intended to mechanically collect vegetation, although this may occur to a small degree. Instead, the purpose of this device appears to be to loosen the vegetation, which will then be removed by other means.  
           [0011]    The Sands patent discloses a device for removing a golf ball from the water. This device comprises a rigid piece having upper and lower vertical serrations. These serrations are not intended to remove vegetation. To the contrary, the device is also intended to function as a rake for maintaining sand traps. The serrations are primarily intended for sand trap maintenance, although the rake can also be used to remove golf balls from bodies of water.  
           [0012]    The Hawkins patent discloses a rake for brush that comprises a plurality of generally vertical plates that are serrated. This rake is intended for removing brush and not for underwater vegetation.  
           [0013]    From the foregoing, it can be seen that the need exists for improved rake systems and methods for removing underwater vegetation.  
         SUMMARY OF THE INVENTION  
         [0014]    The present invention may be embodied as a rake system for removing underwater vegetation comprising a plate assembly, a handle assembly, and a line. The plate assembly comprises first and second engaging members each defining an engaging edge. The handle assembly is attached to the plate assembly. The line is attached to the handle assembly. During use, the user grips the handle assembly to toss the plate assembly to a first underwater location. The user then pulls the line to displace the plate assembly from the first underwater location along a harvest path. The engaging edges of the engaging members are adapted to engage the underwater vegetation to fix the underwater vegetation relative to the plate assembly such that continued pulling on the line removes the underwater vegetation in a harvest region defined by the harvest path. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    [0015]FIG. 1 is a perspective view showing an exemplary water rake constructed in accordance with the principles of the present invention being used to remove underwater vegetation;  
         [0016]    [0016]FIG. 2 is a top plan view depicting the water rake of FIG. 1;  
         [0017]    [0017]FIG. 3 is a partial side elevation view depicting the angular relationship between a plate assembly and a handle assembly of the water rake of FIG. 1;  
         [0018]    [0018]FIG. 4 is an elevation view taken along one end of the plate assembly of the water rake of FIG. 1;  
         [0019]    [0019]FIG. 5 is front elevation view of the water rake of FIG. 1;  
         [0020]    [0020]FIG. 6 is a partial section view of the portion of the handle assembly circled in FIG. 1;  
         [0021]    [0021]FIG. 7 is a partial top plan view of upper plates of the plate assembly of the water rake of FIG. 1;  
         [0022]    [0022]FIG. 8 is a partial top plan view of a lower plate of the plate assembly of the water rake of FIG. 1;  
         [0023]    FIGS.  9 - 11  are top plan views of additional embodiments of the present invention showing alternative plate assembly profiles; and  
         [0024]    [0024]FIG. 12 is a partial, perspective, close-up view of the serrations on the engaging members of the exemplary water rake of FIG. 1.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0025]    Referring initially to FIG. 1 of the drawing, depicted at  20  therein is a rake system constructed in accordance with, and embodying, the principles of the present invention. In the following discussion, the basic construction and operation of the exemplary rake system  20  will first be described. After that the details of construction and operation of the system  20  will be described in further detail.  
         [0026]    I. Basic Operation of Preferred Embodiment  
         [0027]    [0027]FIG. 1 depicts the rake system  20  being used to remove underwater vegetation  22  from the bed  24  of a body of water  26 . The underwater vegetation  22  is typically a noxious or non-native species of plant that is disruptive of the ecosystem of the water  26 ; in other situations, the vegetation  22  may interfere with recreational activities or is simply undesirable for aesthetic reasons. Typically, such vegetation  22  has a root system in the bed  24  and extends up towards or to a surface  28  of the water  26 .  
         [0028]    The body of water  26  is typically a man-made or natural pond, lake, or the like. Such freshwater bodies are more susceptible to infestation by undesired underwater vegetation, but the rake system  20  may be used in other bodies of water as necessary.  
         [0029]    The exemplary rake system  20  comprises a plate assembly  30 , a handle assembly  32 , and a line  34 . The plate assembly  30  is connected to one end of the handle assembly  32 , and the line  34  is connected to the other end of the assembly  32 . The line  34  is or may be conventional and will not be described herein in detail.  
         [0030]    In the following discussion, the terms “front” or “forward” refer to the direction along the handle assembly  32  towards the plate assembly  30 , and the terms “back” or “rear” refer to the direction along the handle assembly  32  towards the line  34 . The rake system  20  may be oriented in any direction, and the terms “up” or “upper” and “down” or “lower” are used herein to refer to the system  20  during normal use. In addition, the term “harvest” simply refers to the gathering in of the underwater vegetation. Typically, the harvested vegetation is simply discarded. The vegetation may be consumed or otherwise further processed after removal. The use of the term “harvest” should not, however, be construed as requiring such consumption or other further processing.  
         [0031]    The rake system  20  is used basically as follows. The user may be standing on the shore adjacent to the body of water  26  or in a boat floating in the body of water  26 . The user secures a free end of the line  34  and grasps the handle assembly  32 . The user then tosses the handle assembly  32  and the plate assembly  30  in the forward direction into the water  26 . The assemblies  30  and  32  sink to the water bed  24  under their own weight. At this point, the line  34  extends between the user above the water surface  28  and the handle assembly  32  on the bed  24 .  
         [0032]    The user then pulls, or causes to be pulled, the end of the line  34  above the water surface  28  such that the plate assembly  30  is displaced rearward along a harvest path  36 . As the plate assembly  30  moves along the harvest path  36 , the plate assembly  30  engages the vegetation  22  and removes at least a portion of the vegetation  22  in a harvest region  38  defined by the harvest path  36 . Typically, the harvest region  38  extends equal distances on both sides of the harvest path  36 .  
         [0033]    This process is repeated for successive harvest paths  36  such that the harvest regions  38  overlap and the underwater vegetation  22  is removed from a larger area of the water bed  24 . When the user is standing on the shore, the successive harvest paths  36  may be arranged in parallel rows; when the user is in an anchored boat, the successive harvest paths may radially extend from the boat. A boat may also be moved to drag the plate assembly  30  along the harvest paths  36 . The exact pattern of the successive harvest paths  36  is not important as long as the paths result in removal of most or all of the underwater vegetation  22  in a larger area.  
         [0034]    As will be described in further detail below, the plate assembly  30  is not intended to cut the underwater vegetation  22 . Cutting the underwater vegetation  22  would leave the root system thereof intact, thereby allowing the underwater vegetation  22  quickly to reestablish itself in the harvest region. Instead, the rake system  20  is configured to engage the vegetation  22  such that the vegetation  22  is fixed relative to the plate assembly  30 . After it is fixed relative to the plate assembly  30 , pulling the line  34  causes at least a portion of the vegetation  22  engaged by the plate assembly  30  to be pulled out by its roots. The vegetation  22  may then be raised above the surface  28  and collected, usually for subsequent disposal. The rake system  20  thus removes the roots of the underwater vegetation  22  and thereby inhibits reestablishment of the vegetation  22  in the harvest region.  
         [0035]    With the foregoing basic understanding of the construction and operation of the present invention, the details of construction and operation of the exemplary rake system  20  will now be described in further detail.  
         [0036]    II. Plate Assembly  
         [0037]    Referring now to FIGS.  2 - 5 , it can be seen that the plate assembly  30  comprises a lower engaging member  40  and an upper engaging member  42 . The engaging members  40  and  42  define upper and lower engaging edges  44  and  46 , respectively. The exemplary plate assembly  30  further comprises a plurality of spacers  50  and plate bolt assemblies  52 . The bolt assemblies  52  each comprise a bolt  56  and a nut  58 . The plate assembly  30  is formed by extending each of the bolts  56  through an opening in the engaging members  40  and  42  and one of the spacers  50  and then threading the nuts  58  onto the bolts  56 . Structures other than the spacers  50  and the bolt assemblies  52  can be used to secure the engaging members  40  and  42  together.  
         [0038]    With the plate assembly  30  so assembled, the engaging edges  44  and  46  are adjacent to but offset slightly from each other and face the rear of the system  20 . As will be described in further detail below, the engaging edges  44  and  46  are adapted to bind or otherwise grip the underwater vegetation  22  extending from the bed  24  in the direction of the surface  28 as the plate assembly  30  moves to the rear.  
         [0039]    Accordingly, when the line  34  is pulled as described above, the engaging edges  44  and  46  engage the underwater vegetation  22 ; continued application of force to the line  34  will in most cases pull the vegetation  22  out by its roots. For the vegetation  22  to be pulled out by the roots, the stalk of the vegetation  22  must be strong enough transmit the pulling forces to the roots and the pulling forces must be sufficient to pull the roots from the bed  24 . Usually, the roots of underwater vegetation  22  are easily pulled from the bed.  
         [0040]    Less frequently, the roots are too strongly embedded to be pulled and the stalk of the plant may break. In rare cases, the roots are too strongly embedded to be pulled out and the stalk does not break; in these cases, the plate assembly  30  becomes snagged and special effort may be required to remove the system  20  from the snag.  
         [0041]    FIGS.  2 - 5  also show that the exemplary lower engaging member  40  comprises a single lower plate member  60  and the exemplary upper engaging member  42  comprises first and second upper plate members  62  and  64 . One half of the lower plate member  60  and the first upper plate member  62  define a first lateral portion  66  of the plate assembly  30 . The other half of the lower plate member  60  and the second upper plate member  62  define a second lateral portion  68  of the plate assembly  30 .  
         [0042]    An attachment structure  70  connects the handle assembly  32  to the plate assembly  30 . In particular, first and second head flanges  72  and  74  extend from the first and second upper plate members  62  and  64 , respectively. A plurality of attachment holes  76  are formed in the head flanges  72  and  74 . The attachment structure  70  further comprises handle bolt assemblies  78 . The handle bolt assemblies  78  comprise bolts  80  and nuts  82 . The bolts  80  extend through the attachment holes  76  and holes defined by the handle assembly  32 ; the nuts  82  are threaded onto the bolts  80  to form the connection between the plate assembly  30  and the handle assembly  32 .  
         [0043]    In the exemplary system  20 , a center attachment hole  76 a is formed in each of the flanges  72  and  74  and a plurality of peripheral attachment holes  76   b - d  are spaced along an arc centered about the center attachment hole  76   a.  One of the bolt assemblies  78   a  extends through the center attachment holes  76   a,  and another of the bolt assemblies  78   b  extends through one pair of the peripheral attachment holes  76   b - d.  This arrangement of attachment holes  76  and bolt assemblies  78  allows an angle at which the handle assembly  32  extends from the plate assembly  30  to be adjusted. The user may wish to adjust this angle depending upon the position from which the user is throwing the system  20 , the terrain defined by the bed  24 , the species of underwater vegetation  22  being removed, and other factors.  
         [0044]    The exemplary plate members  60 - 64  are made of flat stock metal that will sink when thrown in the water. As generally discussed above, the lower plate member  60  is a single piece of metal; the upper plate members  62  and  64  are symmetrical but mirror images of each other. The flanges  72  and  74  are integrally formed with the plate members  62  and  64  by bending portions of the plate members  62  and  64  at a right angle. When the plate assembly  30  is assembled, upper plate members  62  and  64  lie in substantially the same plane, and this plane is spaced from and parallel to the plane occupied by the lower plate member  60 . The flanges  72  and  74  are spaced from and parallel to each other when the plate assembly  30  is assembled.  
         [0045]    III. Handle Assembly  
         [0046]    As perhaps best shown in FIGS. 2 and 6, the exemplary handle assembly  32  comprises a handle member  90  and a line pin assembly  92 . The exemplary handle member  90  is a length of square tubing. As perhaps best shown in FIG. 5, the cross-sectional length of the sides of the tubing from which the handle member  90  is made is substantially the same as the distance between the flanges  72  and  74  of the plate members  62  and  64 . The bolts  80  of the handle bolt assemblies  78  extend through holes formed in the handle member  90  and the flanges  72  and  74  contact the handle member  90  to form a substantially rigid connection between the handle member  90  and the plate assembly  30 .  
         [0047]    In the exemplary rake system  20 , the line pin assembly  92  connects the handle assembly  32  to the line  34 . In particular, as shown in FIG. 6 the line pin assembly  92  comprises a line pin  94  and a retaining pin  96 . A line loop  98  is formed on the end of the line  34  to be connected to the handle assembly  32 . The line loop  98  is inserted into the hollow interior of the handle member  90 . The line pin  94  is then inserted through a hole in one side of the handle member  90 , through the line loop  98 , and through a hole in another side of the handle member  90 . The retaining pin  96  is then placed on the line pin  94  to prevent it from being withdrawn from the holes in the handle member  90 . The line pin  94  in turn prevents the line loop  98  from being withdrawn from the hollow interior of the handle member  90 , thereby securing the line  34  to the handle assembly  32 .  
         [0048]    IV. Engaging Edges  
         [0049]    Referring now to FIGS. 2, 4, and  8 - 12 , the exemplary engaging edges  44  and  46  will now be described in further detail. Several characteristics of the exemplary engaging edges  44  and  46  work together to increase the effectiveness rake system  20 . These characteristics will be referred to herein as engaging characteristics. The preferred embodiment uses all of the engaging characteristics described herein, but any one of these engaging characteristics may be used alone to enhance the ability of the rake system  20  to the remove underwater vegetation  22 . The present invention may thus be embodied using any one or any combination of the engaging characteristics.  
         [0050]    The spatial relationship between the engaging edges  44  and  46  also forms one or more of the engaging characteristic of these edges  44  and  46 . To help define the spatial relationships between the edges  44  and  46 , a number of reference axes will first be described relative to the system  20 . In particular, a system axis A and a lateral axis B are defined for the system  20  with reference to the plate assembly  30 . The system axis A extends through the plate assembly  20  in the front and back directions; the lateral axis B extends at a right angle to the system axis A from side to side relative to the plate assembly  20 .  
         [0051]    The handle member  90  defines a pull axis C along which the pulling forces are applied through the handle member  90  to the plate assembly  30 . The pull axis C can be aligned with the system axis A as shown by solid lines in FIG. 3 or extend at one or more angles with respect to the system axis A as shown by broken lines in FIG. 3.  
         [0052]    The plate assembly  30  further defines a plate axis D that extends at right angles to the system axis A and the lateral axis B. The first and second lateral portions  66  and  68  of the plate assembly  30  define first and second engaging axes E and F. The engaging axes E and F lie within the plane defined by the system and lateral axes A and B.  
         [0053]    The primary engaging characteristics of the exemplary engaging edges  44  and  46  will now each be described separately.  
         [0054]    A. Engaging Surfaces  
         [0055]    Referring for a moment to FIG. 12, depicted therein is a close-up view of any one of the exemplary engaging edges  44  or  46 . FIG. 12 shows that the plate members  60 - 64  define an upper surface  120  and a lower surface  122 . FIG. 12 further shows that the engaging edges  44  and  46  are defined by a plurality of first and second engaging surfaces  124  and  126 . The exemplary first engaging surfaces  124  are substantially parallel with each other, and the exemplary second engaging surfaces  126  are parallel with each other. The exemplary engaging surfaces  124  and  126  are both substantially perpendicular to the upper and lower surfaces  120  and  122 .  
         [0056]    The engaging surfaces  124  and  126  intersect at a first and second engaging angles α and β as shown in FIG. 12. In the exemplary system  20 , these angles α and β are substantially equal and are approximately sixty degrees. These angles α and β need not be equal, however, and are preferably within a range of twenty and one-hundred sixty degrees. The engaging angles α and β are not critical and will vary from one embodiment of the present invention to the another such embodiment.  
         [0057]    With the engaging edges  44  and  46  formed by the engaging surfaces  124  and  126  as just described, the edges  44  and  46  do not define sharp cutting surfaces perpendicular to vertically oriented fibers of vegetation  22  extending from the bed  24  to the surface  28 . The engaging edges  44  and  46  thus do not cut the vegetation  22 , as generally described above. To the contrary, the structure of the engaging edges  44  and  46  causes these edges  44  and  46  to mechanically engage the vegetation  22  such that forces applied along the pull axis C are transferred along the fibers of the vegetation  22 . The transfer of forces along these fibers enables the vegetation  22  to be pulled out of the bed  24  by the roots under many situations.  
         [0058]    The angles between engaging surfaces  124  and  126  form serrations or teeth on the engaging edges  44  and  46  that assist in binding or gripping the underwater vegetation  22 . In particular, as the engaging edges  44  and  46  move along the harvest path  36 , smaller diameter stalks of the vegetation  22  are forced into gaps  128  defined by the engaging surfaces  124  and  126 . The gaps are v-shaped, and the narrowing gaps  128  increase the friction between the engaging surfaces  124  and  126  and the stalks to apply the pulling forces to the roots of the vegetation.  
         [0059]    Larger diameter stalks may not fit entirely within the gaps  128 . Teeth points  128   a  defined by the intersection of the engaging surfaces  124  and  126  may slightly pierce such larger diameter stalks. For the most part, this piercing will be along the fibers of vegetation and will not cut through these fibers. The teeth points  128   a  will thus assist in transferring pulling forces to the vegetation  22 .  
         [0060]    The engaging surfaces  124  and  126  thus form an engaging characteristic that functions to enhance the transfer of pulling forces to the underwater vegetation  22  without cutting the vegetation  22  and leaving the roots.  
         [0061]    B. Edge Angles  
         [0062]    [0062]FIGS. 7 and 8 also show that the exemplary engaging edges  46  and  48  are arranged to define discrete sections. The lower plate member  60  defines a first inner section  130 , first and second outer sections  132  and  134 , and first and second intermediate sections  136  and  138 . The first upper plate member  62  defines a second inner section  140 , a third outer section  142 , and a third transition section  144 . The second upper plate member  64  similarly defines a third inner section  150 , a fourth outer section  152 , and a fourth transition section  154 . The use of the exemplary first and second upper plate members  62  and  64  results in a gap  160  between the second and third inner sections  140  and  150 .  
         [0063]    The inner sections  130 ,  140 , and  150  generally line on the lateral axis B. The first and third outer sections  132  and  142  are parallel to the first engaging axis E, while the second and fourth outer sections  134  and  152  are parallel to the second engaging axis F.  
         [0064]    In the exemplary rake system  20 , the first and second engaging axes E and F are angled with respect to the system axis A. Preferably, the angles between the axes E and F and the system axis A are equal and are approximately sixty degrees. These angles are typically in a first preferred range of substantially between forty-five and eight-five degrees to obtain the angled engaging edges  44  and  46  described in this subsection. In other embodiments of the present invention, these angles may be within a second preferred range of substantially between forty-five and one-hundred thirty-five degrees.  
         [0065]    With the angles in the first preferred range, a binding action is created on a large scale similar to that obtained by the v-shaped gaps  128  defined by the engaging surfaces  124  and  126 . In particular, after the gaps  128  are filled with vegetation  22 , subsequent stalks of the vegetation  22  will be directed towards the inner sections  130 ,  140 , and  150 , thereby increasing friction between the stalks already bound by the engaging members  40  and  42  and stalks that are subsequently encountered. Accordingly, even after the v-shaped gaps  128  are filled, the rake system  20  will continue to harvest the vegetation  22 .  
         [0066]    Referring now to FIGS.  9 - 11 , depicted therein are several exemplary angular profiles  170 ,  172 , and  174  that may be used to by a rake system of the present invention. The angular profile  170  depicted in FIG. 10 generally corresponds to the angular profile of the exemplary rake system  20  described in detail herein. The angular profile  172  of FIG. 9 is outside the first preferred range of angles set forth in this subsection but still within the second preferred range. The angular profile  174  of FIG. 10 employs a curved engaging edge. This curved engaging edge defines a continuously changing engaging axis, but the angle of the engaging axis defined at any point along the engaging edge of the profile  174  will be within the first preferred range defined above.  
         [0067]    C. Edge Spatial Relationships  
         [0068]    The exemplary rake system  20  of the preferred embodiment uses two engaging edges  44  and  46 . Some of the benefits of the present invention may be obtained by using a single engaging edge implementing the engaging characteristics defined in the previous subsection. The use of two engaging edges  44  and  46  is preferred, however.  
         [0069]    The two exemplary engaging edges  44  and  46  are generally aligned but are spaced from each as can best be seen in FIGS. 2 and 4. In particular, as shown in FIG. 2, these edges  44  and  46  are spaced from each other along the system axis A defined above. And as shown in FIG. 4, these edges  44  and  46  are spaced from each other along the plate axis D defined above. In particular, the lower engaging edge  44  is spaced forward and above the upper engaging edge  42 .  
         [0070]    Accordingly, when the pulling force is applied along the pull axis C, the lower engaging edge  44  first engages the vegetation  22 . The upper engaging edge  46  engages the vegetation  22  shortly thereafter when the vegetation  22  is deformed. The use of the upper engaging edge  46  thus increases the surface area of the engaging surfaces  124  and  126  that comes in contact with the vegetation  22  and thus the friction between the engaging members  40  and  42  and the vegetation  22 .  
         [0071]    V. Summary  
         [0072]    From the foregoing, it should be clear that the present invention may be embodied in forms other than those described above. A rake system constructed in accordance with the principles of the present invention may thus be embodied in one or more of a number configurations using any combination of the engaging characteristics described above. In addition, the construction of the plate assembly  30  and the handle assembly  32 , while preferred, is not critical to the principles of the present invention in its broadest form. The scope of the present invention should thus be defined by the claims allowed during prosecution of the present invention and not the foregoing detailed description of the present invention.