The present invention relates to foam sports board for recreational use and, more particularly, to a laminated foam sports board with improved bottom surfacing characteristics.
Body boards for riding waves and other recreational sports board made of foam and other floatational material are known in the prior art. Ski boards and snow gliding boards made of hard plastic for use on snow are also known in the prior art.
For example, U.S. Pat. No. 5,328,200 discloses a ski or snow board with a scored plastic sole in which the scores are generally sinusoidal and have a width of 0.05 to 0.4 mm and a depth of 0.01 to 0.05 mm. The board disclosed in U.S. Pat. No. 5,328,200 is made from plastic and the longitudinal distance between the scores is not addressed other than to indicate that several tens of them may lie side by side over the width of the board. The scores are made either by grinding or milling.
U.S. Pat. No. 6,290,249 discloses a snow gliding apparatus with a number of channels cut into the bottom of the board. The channels do not appear to be closely spaced. The channels are cut into the bottom surface with a router or other cutting device.
However, it would beneficial to provide a foam core snow board with spaced grooves which can be cost effectively manufactured and which would have improved performance when in use.
With parenthetical reference to the corresponding parts, portions or surfaces of the disclosed embodiment, merely for the purposes of illustration and not by way of limitation, the present invention provides an improved sports board (15) comprising an expanded polymer foam core (16), an extruded thermoplastic polymer outer layer (20) having an inner surface (21) and an outer surface (22), an expanded polymer foam intermediate layer (19) between the core and the outer layer which is laminated to the inner surface of the outer layer, the outer surface of the outer layer being substantially planar and having at least one series (23) of longitudinally extending, parallel and alternating grooves (26) and ridges (27), the series having a width (28) and the grooves and ridges spaced across the width so as to provide from about ten to about eighty grooves per inch of the width. The grooves may be spaced so as to provide about forty-five grooves per inch of the width. The grooves may have a depth (33) of from about 0.05 mm to about 1 mm. The depth may be about 0.4 mm. The core may be polyurethane foam, polyethylene foam, polypropylene foam or polystyrene foam, the outer layer may be polyethylene or polypropylene, and the intermediate layer may be polyethylene foam or polypropylene foam. Each of the grooves may have a width (34) and the combined width of all the grooves in the series may be from about twenty percent to about eighty percent of the width of the entire series. The combined width of all the grooves in the series may be about fifty percent of the width of the series. The width of the grooves may be uniform. The core may comprise two polymer foam outer layers (51, 52), a polymer inner layer (53) between the two outer layers, the inner layer having a density greater than either of the two outer layers. The core inner layer and the two core outer layers may be polyethylene or polypropylene.
The present invention also provides an improved sports board comprising an expanded polymer foam core, an extruded thermoplastic polymer outer layer having an inner surface and an outer surface, an expanded polymer foam intermediate layer between the core and the outer layer which is laminated to the inner surface of the outer layer, the outer surface of the outer layer being substantially planar and having at least one series of longitudinally extending, parallel and alternating grooves and ridges, the series having a width and each of the grooves having a width, the combined width of all the grooves in the series being from about twenty percent to about eighty percent of the width of the series.
The present invention also provides an improved sports board comprising an expanded polymer foam core, an extruded thermoplastic polymer outer layer having an inner surface and an outer surface, an expanded polymer foam intermediate layer between the core and the outer layer which is laminated to the inner surface of the outer layer, the outer surface of the outer layer being substantially planar and having at least one series of longitudinally extending, parallel and alternating grooves and ridges, the grooves having a depth below the ridges of from about 0.05 mm to about 1 mm. The depth may be about 0.4 mm.
The present invention also provides an improved sports board (60) comprising an expanded polymer foam core (61), an extruded thermoplastic polymer outer layer (62) having an inner surface (63) and an outer surface (64), the inner surface laminated to the foam core, the outer surface of the outer layer being substantially planar and having at least one series of longitudinally extending, parallel and alternating grooves and ridges, the series having a width and the grooves and ridges spaced across the width so as to provide from about ten to about eighty grooves per inch of the width. The sports board may further comprise a second outer polymer layer (65) laminated to the foam core and the second outer layer may be polyethylene film or polypropylene film.
Accordingly, the general object of the presented invention is to provide an improved foam sports board having an extruded bottom surface with grooves that provide improved gliding properties.
Another object is to provide an improved foam based board in which the bottom surface can be formed with narrowly spaced small grooves.
Another object is to provide an improved foam board in which the bottom surface, having multiple grooves, may be laminated to one or more other foam layers of the board.
Another object is to provide a method of forming a sports board with a grooved bottom surface during extrusion.
At the outset, it should be clearly understood that like reference numerals are intended to identify the same structural elements, portions or surfaces, consistently throughout the several drawing figures, as such elements, portions or surfaces may be further described or explained by the entire written specification, of which this detailed description is an integral part. Unless otherwise indicated, the drawings are intended to be read (e.g., cross-hatching, arrangement of parts, proportion, degree, etc.) together with the specification, and are to be considered a portion of the entire written description of this invention. As used in the following description, the terms “horizontal”, “vertical”, “left”, “right”, “up” and “down”, as well as adjectival and adverbial derivatives thereof (e.g., “horizontally”, “rightwardly”, “upwardly”, etc.), simply refer to the orientation of the illustrated structure as the particular drawing figure faces the reader. Similarly, the terms “inwardly” and “outwardly” generally refer to the orientation of a surface relative to its axis of elongation, or axis of rotation, as appropriate.
Referring now to the drawings and, more particularly, to
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Core layer 16 is polyethylene foam. Layer 16 has a thickness of between about 0.5 inches and 2 inches, and preferably a thickness of 1 inch. Layer 16 has a density in the range of about 1.6 to 4 lbs/ft3, and preferably a density of about 2.2 lbs/ft3. Alternatively, core layer 16 is polypropylene foam having a density in the range of about 1.5 to 3.5 lbs/ft3, and preferably a density of about 1.9 lbs/ft3.
As another alternative, core 16 may be polyurethane foam having a thickness between about 0.2 inches and 1.5 inches, and preferably a thickness of about 1 inch, and a density in the range of about 35 to 95 lbs/ft, and preferably a density of about 65 lbs/ft3. In this embodiment, an additional layer 17 (not shown) is provided between intermediate layer 19 and the polyurethane core layer 16. This additional layer is a polyethylene foam layer that facilitates, as described later below, lamination of the polyurethane core to intermediate layer 19 and outer layer 20. Other expanded polymer foam cores, such as a polystyrene foam core, may also be employed.
Layer 19 is a polyethylene foam sheet. Intermediate layer 19 has a thickness of between about 1 mm and 5 mm, and preferably a thickness of about 3 mm. Layer 19 has a density in the range of about 4 to 8 lbs/ft3, and preferably a density of about 6 lbs/ft3. Alternatively, layer 19 may be polypropylene foam having a density in the range of about 2 to 6 lbs/ft3, and preferably a density of about 3 lbs/ft3.
Layer 20 is a polyethylene plastic sheet. Layer 20 has a thickness of between about 0.3 mm and 1.5 mm, and preferably a thickness of about 0.5 mm. Layer 20 has a density in the range of about 0.91 to 0.98 g/cm3, and preferably a density of about 0.95 g/cm3. Alternatively, layer 20 may be a polypropylene plastic sheet having a density in the range of about 0.86 to 0.94 g/cm3, and preferably a density of about 0.9 g/cm3.
The depth of grooves 26 may vary between about 0.05 and 1 mm, and preferably the depth 33 of each groove 26 is about 0.3 mm. Also, width 34 of each groove is between about twenty percent and eighty percent of the total width 39 of a groove 26 and an immediately adjacent ridge 27, and preferably the width 34 of groove 26 is about fifty percent of the total width 39. Thus, the preferred width 34 of groove 26 is the same as the width 35 of ridge 27. In the preferred embodiment, this width 34 and 35 is about 0.28 mm.
Layer 53 is laminated between layers 51 and 52. Layer 53 is a solid polyethylene sheet that stiffens the core. Layer 53 has a thickness of between about 0.4 mm and 2 mm, and preferably a thickness of about 1 mm. Layer 53 has a density in the range of about 0.91 to 0.98 g/cm3, and preferably has a density of about 0.95 g/cm3. Alternatively, layer 53 may be a polypropylene having a density in the range of about 0.86 to 0.94 g/cm3, and preferably a density of about 0.9 g/cm3.
Layers 54 and 55 are of the same structure and composition as layers 19 and 20, respectively, of the first embodiment 15.
Top layer 65 is polyethylene film. Layer 65 has a thickness of between about 0.02 mm and 0.15 mm, and preferably a thickness of about 0.07 mm. Layer 65 has a density in the range of about 0.91 to 0.98 g/cm3, and preferably a density of about 0.95 g/cm3. Alternatively, layer 65 may be polypropylene film having a density in the range of about 0.86 to 0.94 g/cm3, and preferably a density of about 0.90 g/cm3.
Bottom layer 62 is of the same structure and composition as layer 20 of the first embodiment 15.
Board 15 is formed in a series of steps using a specially configured roller 69, which forms the parallel and longitudinally extending grooves 26 and ridges 27 on surface 22 at the same time that layer 20 formed and laminated to intermediate layer 19. Thus, grooves 26 do not need to be ground, milled, routed or otherwise cut into the bottom surface 22. The grooves are provided in surface 22 of layer 20 as it is formed, and not in a separate stage after bottom layer 20 or board 15 is formed.
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Once formed, the resulting laminate 20/19 is then cut and configured to the desired shape. When using a thermoplastic polyethylene or polypropylene foam core 16, the remaining assembly is by conventional heat lamination. The remaining exposed surface of layer 19 is heat laminated to the bottom surface of layer 16 using a conventional heat lamination method. The resulting laminated foam board is then cut and configured to the desired shape and edge configuration. Finally, layer 18 is heat laminated to the top surface of layer 16, and then wrapped around to cover the sloped edge of core 16 and the straight edges of layers 19 and 20 to form a contoured side edge 37 to board 15.
If a thermoset polyurethane foam core is used with additional layer 17 employed between the polyurethane core layer 16 and intermediate layer 19, as described above, the remaining assembly is by compression molding. A compression mold having the desirable shape and contour of the foam board and having an upper portion and a lower portion is provided. Additional layer 17 is laid on the inner surface of the lower mold. Layer 18 is laid on the inner surface of the upper mold. Polyurethane resin is then injected into the mold cavity therebetween, where it reacts and foams to fill the mold cavity. With the mold cavity filled with polyurethane foam, the three layers conform to the shape of the mold. The heat generated by the chemical reaction of polyurethane foaming melts the inner surface of additional polymer foam layer 17 and foam layer 18, respectively, on contact with the hot polyurethane foam core, thereby forming a good heat bond between the core and outer layers. The molded foam laminate 17/16/18 is then trimmed for excess. The exposed surface of layer 19 of laminate 20/19 is then heat laminated to the bottom surface of layer 17 using a conventional heat lamination method to form the fully laminated foam board 15.
For board 50, layers 55 and 54 are formed and laminated using the same method used to form laminate 20/19 in board 15. The core of board 50 is formed by polymer extrusion and direct heat lamination. Hot thermoplastic polymer is extruded by a conventional polymer extruder to form polymer sheet layer 53. Polymer foam layers 51 and 52 are fed onto the top and bottom surfaces, respectively, of the hot polymer layer 53. The three layers 51, 53 and 52 are heat bonded together by passing them through a pair of nipping rollers to form core laminate 51/52/53 of board 50. The exposed surface of layer 52 is then heat laminated to the upper exposed surface of intermediate layer 54 by conventional heat lamination. The resulting laminated foam board 51/52/53/54/55 is then cut and configured to desirable board shape and edge configuration. Finally, layer 56 is heat laminated to the top exposed surface of layer 51 and then wrapped around to cover the sloped edge of core laminate 51/52/53 and the straight edges of layers 54 and 55 to form a contoured side to board 50.
With respect to board 60, top layer 65 is first heat laminated to core 61 using a conventional heat lamination method. Grooved layer 62 is then laminated to the exposed surface of core 61 of the resulting laminate 65/61 using the same process used to laminate grooved layer 20 and intermediate layer 19 for board 15, to form fully laminated board 60.
The present invention contemplates that many changes and modifications may be made. Therefore, the while the presently-preferred form of the improved sports board has been shown and described, and several modifications thereof discussed, persons skilled in this art will readily appreciate that various additional changes and modifications may be made without departing from the spirit of the invention, as defined and differentiated by the following claims.