Patent Application
20100084080
The present invention relates to foam sports boards for recreational use and, more particularly, to bodyboards or snow sleds having a contoured surface profile for enhancing performance or providing features such as purchase enhancing region of a bodyboard, foot stopper or a seat retainer of a snow sled.
A variety of differently shaped bodyboards have specific features that improve handling and performance. A variety of fins attached to the bottom of the bodyboard are also known to provide steering and stability for both bodyboards and surfboards. A variety of decorative elements also appear on bodyboards. U.S. Pat. No. D345,000 to Foulke entitled Channel Rail Bodyboard shows a lower rail with a channel which is ornamental, and possibly also functional.
Also, a wide variety of patents show purchase enhancing features disposed or formed on the top of the board. For example, Brown U.S. Pat. No. 4,894,034 teaches a scoop on the top surface of the front nose end that has a concave section on the deck of the board for enhanced gripping of a rider's arm. U.S. Pat. No. 5,116,269 entitled Bodyboard With Side Grip Contour to Moran shows a pair of thumb grooves along two side edges of the top of the board. U.S. Pat. No. 5,273,470 to Sneddon entitled Bodyboard With Rider-Purchase Enhancing Regions shows elongated ridges extending diagonally across from one side edge of the top surface to the other edge of the top surface. U.S. Pat. No. 5,797,779 to Stewart entitled Bodyboard With Differentiated Topskin shows a bodyboard with top surface torso region of hourglass shape.
Enhancing purchase is a term that is used to describe improved support, position or holding of the board. The rider should have good stance, which is described as enhanced purchase.
The present invention provides a bodyboard with improved shape and purchase enhance features for improved manipulation in ocean surfing. The bodyboard supports a rider in ocean surf and includes an elongate bodyboard foam core having a top surface, a bottom surface, a nose surface, a nose, a tail surface, a tail and elongate laterally opposed sided edges having an upper and lower side rail surface. At least one top or bottom surface has a molded contour surface. A polyolefin foam skin layer has an outer surface and an inner surface. An adhesive resin layer bonds the inner surface of polyolefin foam skin layer to the molded contour surface of the molded foam core. The contour surface includes a variety of different shapes and construction features providing for purchase enhanced region and improved manipulation of the bodyboard in wave surfing. The bodyboard may include a bottom finger bulb with a shallow lengthwise bottom depression and shallow rear tail depressions.
The bodyboard has a pair of bottom finger bulbs with a shallow lengthwise bottom depression and a pair of shallow rear tail depressions. The process for producing the board requires removal of foam core material, or molding the foam core in a specific shape mold to provide the profile as shown in the figures. A polyethylene film/foam laminate is prepared by heat laminating a sheet of polyethylene film to a sheet of polyethylene foam. A layer of adhesive resin is applied to the foam side of the film/foam laminate. The adhesive resin coated side of the resulting film/foam laminate is then heat laminated to the contour surface of the foam core. The board 10 thus shows a bodyboard with contoured profile on the deck and a bottom slick skin with a concave depression extending substantially over the rear half of the bottom planning surface, two bottom finger bulbs at the corners of the nose and two channels near the tail.
The central lengthwise bottom depression is shallow and preferably extends across the rear half of the board to the tail of the board. However it should be understood by those skilled in the art that a bodyboard in accordance with the present invention might have the lengthwise bottom depression extending substantially over the entire bottom planning surface, or extending only in a selected region, for example extending on a region of about one third of the length of board from the tail end. The central lengthwise bottom depression provides improved handling and resistance to sideways board sliding allowing better control and steering of the board in fast and powerful waves. The depth of the depression is preferably between 3 mm and 15 mm deep. The depression preferably extends lengthwise across about third-quarter of the width of the board.
The bodyboard 10 has bottom finger bulbs with a shallow lengthwise bottom depression and shallow rear tail depressions. The features on the bottom of the board can be combined with features on the top of the board providing synergistic handling effect. For example, the top of the board may be generally flat merely having chamfered edge in its simplest form. Or the top may be contoured with various patterns of ridge and valley regions to form purchase enhance regions on the board.
Referring to
Accordingly, the general objective of the present invention is to provide an improved sports board in which different polyolefin materials may be used in the layers without loss of bond strength. Another objective is to provide an improved sports board with contoured surface with enhanced gripping and performance and can be fabricated using a less expensive laminating method at a higher production output. Another objective is to provide a method to adhere a foam skin to a preformed and preshaped foam core with distinct contour on at least one major surface of a foam board.
Bodyboards for riding waves and other recreational sports boards made of foam or other floatational material are known in the prior art. In general, such boards are composed of a number of polyethylene foam and polyethylene film layers that are laminated together by heating the layers as they are passed through nip rollers. The nip roller may be heated or unheated. This heating process causes adhesion by the localized collapse and bonding of the foam cells on the surface of the respective layers. The resulting laminate of the polyethylene foam and polyethylene film is then often heat laminated onto a standard foam core.
Because the standard foam core does not have a perfectly flat or planar surface, adhesive contact between the film and foam core is limited to the apexes of the cells on the surface of the foam core. Thus the point of contact is not uniform between the film and foam, but instead the film contacts the points of the outer surface of the core that protrude from the irregular cellular surface of the foam core.
Conventional film lamination methods typically use micro-cellular high-density foam sheets to improve the adhesion between the film and foam core. The micro-cellular foam sheet contains smaller peaks and valleys, with the peaks closer together. The surface area of contact between the sheet and foam is thereby increased. However, this kind of structure is still prone to delamination by mechanical contact forces and by the effect of heat and pressure when in use.
While it is known in the prior art that a thin layer of thermal plastic polyethylene film between a polyethylene foam sheet and a polyethylene film can be used to promote lamination, such thin layer of film is generally an unmodified low-density polyethylene with limited efficacy.
U.S. Pat. No. 5,647,784 to Moran describes making a typical composite bodyboard including an intermediate bonding film layer between a polypropylene foam core and at least one of upper and lower skin layers, which has different chemical composition from the foam core material. Preferably, the intermediate layer is a terpolymer based on polyethylene vinyl acetate and in the form of a thin, slit-film bonding adhesive. In the thermo lamination process, the film melts and acts as glue between the different materials of composite bodyboard.
U.S. Pat. No. 5,275,860 to D′Luzansky, et al. shows bodyboards and the like where the board comprises a closed cell foam core of polypropylene, a lower and upper skin of polyethylene and an intermediate layer heat bonded to each of the upper and lower skin. With the presence of intermediate layer which is a mixture of 65% polypropylene and 35% polyethylene, the peel strength between the foam core and each of upper and lower skin is improved. Multi-layered bodyboards and methods of manufacture are well known in the art and one of such boards is described in my application Ser. No. 10/797,995 titled “Multi-layered Sports Board” filed on Mar. 11, 2004 and is incorporated herein by reference.
Bodyboards and snow sleds made of foam material in general consist of a planar deck surface. It is obviously desirable to have contour profile built into the board at the opposite surface to the deck. It not only enhances the aesthetic appeal of the sports board, but also provides features such as purchase enhancing region of a bodyboard or a snow sled. Accordingly, there is need for adhesively bonded bodyboards with improved bonding between layers of different polymeric material having different surface contouring and cellular structure. Therefore, the primary object of the invention is to improve the performance, handling and construction of the body board.
Embodiments of the invention will now be described by way of example with reference to the accompanying drawings. Like reference numerals identify the same structural elements, portions or surfaces, consistently throughout several drawing figures. 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 read (e.g., cross-hatching, arrangement of parts, proportion, degree, etc.) together with the specification, and are a portion of the entire description of this invention.
The invention shows a new process of making a foam sports board such as a bodyboard for use in riding water waves, or a snow sled for use on snow slopes. The board may also be part of a sporting device such as a surfboard, snowboard, ski, gliding board or flotation device. Skilled artisans can readily expand this list to include other known foam applications.
The shallow bottom depression 15 preferably extends centrally lengthwise from about one half of the board length to the tail of the board. According to a first embodiment, the shallow depression preferably extends across at least one-third of the middle width of the board. The depth of the shallow depression is preferably between 3 mm and 15 mm and is preferably approximately 6 mm deep at the deep area that is in the middle of the width of the board. The shallow depression is preformed in the core of the board and a plastic bottom slick skin is then bonded to the core such as by an adhesive film layer.
As can be seen in
The tail depressions similarly provide stability for the board and are oriented outward such that the right tail depression is oriented diagonally to the right and the left tail depression is oriented diagonally to the left. As can be seen in
As can be seen in
Adhesive layer 201 is an ethylene and methyl acrylic copolymer. Adhesive layer 201 has a thickness of between 0.02 and 0.15 mm, and preferably a thickness of 0.07 mm. Adhesive layer 201 has a density in the range of 0.09 to 0.98 g/cm3, and preferably a density of 0.95 g/cm3. The ethylene methyl acrylate copolymer EMAC that can be obtained at Eastman Chemical Company of 100 North Eastman Road, Kingsport, Tenn. 37662 may be employed in the preferred embodiment of the present invention. Alternative adhesive resins, such as copolymer of ethylene with propylene, butene, hexene, octene, vinyl acetate, vinyl acetate and methyl acrylic, anhydride-modified polyolefin, including anhydride-modified ethylene vinyl acetate, anhydride-modified ethylene acrylate, anhydride-modified low-density polyethylene, and anhydride-modified linear low-density polyethylene, may be employed. The Bynel® adhesive resin, provided by Dupont Packaging, of 1007 Market Street, Wilmington, Del. 19898, may be employed in such an embodiment.
Foam core layer 88 is a molded foam. In the preferred embodiment, the foam core 88 is polystyrene foam. However, it is contemplated that other types of foam may be used, such as polyethylene, polypropylene foam, ethylene vinyl acetate foam, Arcel foam, polyvinylchloride foam and polyurethane foam. Layer 88 has a thickness of between 0.25 inch to 3 inch, and preferably a thickness of 1 inch to 2 inch. In the preferred embodiment, layer 88 is polystyrene foam and has a density in the range of 1.0 to 2.5 lbs/ft3, and preferably a density of 1.5 lbs/ft3 which is preferred for rigidity if the foam core thermoformed face operates as a mold die against a rigid forming mold. If polypropylene foam is used, layer 23 would have a density in the range of 1.5 to 3 lbs/ft3, and preferably a density of 1.9 lbs/ft3, which again is preferred for rigidity when the foam core thermoformed face operates as a mold die against a rigid forming mold. If polyethylene foam is used, layer 88 would have a density in the range of 1.6 to 4 lbs/ft3, and preferably a density of 2.2 lbs/ft3.
Bottom skin 70 comprises bottom polyolefin sheet layer 72, bottom polyolefin foam sheet 71 and adhesive layer 202. Bottom polyolefin sheet layer 72 is preferably a polyethylene sheet with a thickness of between 0.05 and 1.5 mm, and preferably a thickness of 0.45 mm and a density in the range of 0.91 to 0.98 g/cm3, and preferably a density of 0.95 g/cm3.
Bottom polyolefin foam sheet layer 71 is of the same structure and composition as layer 161.
Adhesive layer 202 is of the same structure and composition as layer 201.
A pair of side rail skin 20 comprise polyolefin foam sheet 21 and adhesive layer 203. Lower rail polyolefin foam sheet covers the lower rail surface of the board and is of the same structure and composition as layer 161. An adhesive layer 203 may also be applied to bond the lower rail polyolefin foam sheet 21 to the lower rail surface of the foam core 88.
It is desirable to improve the gripping property of the top foam sheet of the sports board. One method to achieve a higher coefficient of friction of the top foam sheet is by blending the polyethylene or polypropylene with some elastic polymer characterized with more flexible polymer chain structure such as ethylene vinyl acetate (EVA) and ethylene butyl acrylate (EBA). The addition of elastic polymer into polyolefin generally makes the foam sheet more resilient and softer to grasp.
Another method of increasing the coefficient of friction of the top foam sheet is to apply a film to the outer surface of the polyolefin foam sheet. The film has a higher coefficient of friction than the foam sheet. The film preferably has a thickness ranging from about 0.02 mm to about 0.4 mm, more preferably between about 0.07 mm and 0.15 mm. The film may comprise at least one member selected from ethylene/styrene interpolymer, ethylene/propylene rubber, homogeneous ethylene/alpha-olefin copolymer, ethylene/vinyl acetate copolymer and other thermoplastic elastomer, and blends of the foregoing. The film may be applied to foam sheet by any conventional processing technique known in the industry. The film may be extruded in a molten state onto a surface of the polyolefin foam sheet, whereon the film solidifies and adheres to the foam sheet surface. Such a process is typically known as extrusion coating.
The foam core 88 of the present foam sports board may take the form of any foam board known in the art such as molded expanded polystyrene (EPS) foam and expanded polyolefin foam and polyurethane foam. Polyolefin foams useful as the foam core include homopolymers and copolymers of ethylene, propylene and ethylene vinyl acetate as well as a wide variety of blends with one or more such homopolymers and copolymers. Expanded polystyrene (EPS) and expanded polypropylene (EPP) are particular preferable material for the foam core due to high rigidity to weight ratio. The foam core with the desirable contoured surface profile can be made by any conventional method known in the art. Useful fabrication methods include machining by hand or shaping equipments. More complicated profile shape may be applied to a foam plank by computerized shaping machine such as CNC programmed milling machine. Most preferably, the foam core is made by the conventional molding method of foam beads. The molded foam core has a thickness that is desirably from 0.25 inch to 3 inch, preferably form 1 inch to 2 inch.
The present invention is particularly useful with molded EPS foam core. Such foams are stiff and light weight and have relatively lower material cost. The EPS foam core substantially enhances the flexural strength of the sports board while the polyethylene foam skin provide a soft touch, resilient and comfortable riding deck surface.
In one embodiment, the foam skin is a polyolefin foam sheet. The polyolefin foam skin may be homopolymers and copolymers of polyethylene and polypropylene. The foam sheet may be a monolayer structure or a multilayer structure. In a multilayer structure, the foam sheet may be a laminate of two or more foam sheets.
In another embodiment, the foam skin is a laminate of polyolefin foam sheet and polyolefin film and the polyolefin film is the surface film. The polyolefin film preferably has the same polymer composition as the polyolefin foam sheet. The polyolefin foam sheet may be a monolayer structure or a multilayer structure. The film/foam laminate may be prepared via conventional film extrusion and the foam sheet is applied and heat bonded to the hot extrudate of film. The surface film may be in the form of a monolayer film, a multiple-layer film, or a co-extruded multilayer film. The monolayer film or multiple-layer film can be coated with a layer of adhesive resin to enhance the bonding between the film and the foam sheet layers. The surface film may also include a graphic image imprinted on it and the image is visible outside the board for decorating the board. Similar to the preparation of the top foam skin 60, an adhesive layer is applied to the polyolefin foam sheet surface of the polyolefin film/polyolefin foam laminate (72/71) to form the final bottom foam skin 70.
Sneddon in U.S. Pat. No. 5,273,470 incorporated herein by reference describes a bodyboard with rider purchase enhancing regions. The complex structure includes a purchase enhancing region including plural ridges extending diagonally across the region to improve rider stability. In the prior art, a surface pattern for gripping in bodyboard is generally first thermoformed on the top surface of a foam skin which is then heat laminated onto a foam core having a substantially planar receiving surface. For contoured deck bodyboard fabrication, desirable configuration of foam core is conventionally shaped or grinded by hand and machine out of a foam plank. Gripping features such as an elbow well that forms a depression below the level of planar deck surface of foam core requires removal of material. On the other hand, gripping features such as a gripping ridge that form a protrusion above the level of planar deck surface is typically made by laminate a foam piece on top of the foam plank in the required location and carefully shaped to the final configuration by detail hand shaping. A foam skin is then heat laminated to the resulting foam core with depressed or protruded gripping contour on the deck surface. Due to the non-planar nature of the contour deck surface, heat lamination process always requires hand pressing to bring the foam skin in immediate contact with the contoured foam core surface. Therefore it requires a lot of labor and handwork to make a contoured deck bodyboard.
In the present invention, the desirable contour of molded foam core can be formed by conventional foam beads molding techniques. Distinct depressions and raised areas can be made for enhancing performance or providing features such as purchase enhancing region of a bodyboard, foot stopper or a seat retainer of a snow sled. A foam skin is then heat laminated to the molded foam core. Intimate contact between the foam skin and the contoured surface of the foam core is facilitated by a elastic nip roller on the foam skin side so that the foam skin can be press fit into the depressed area and conform with the profile of the molded foam core. Therefore the present invention provides a system to fabricate contoured deck bodyboard at a lower production cost and a higher production output.
Suitable resilient materials for the nip roller include those rubber compounds known in the art. Illustrative rubber materials include neoprene, nitrile, EPDM, silicone, polyisoprene, polyurethane, viton, hypalon and blends of the foregoing. Other natural or synthetic rubber may also be used as long as the material has good flexibility and shape recovery properties. Preferably the resilient material is made of a blend of neoprene and nitrile rubber. More preferably the rubber material should be expanded to produce a lower density rubber foam which has the required properties of softness, resilience and quick recovery upon deformation. Such an expanded rubber materials are also called rubber sponge or cellular rubber.
An elastic nip roller can facilitate intimate contact between the top foam skin and the contoured foam core. Then the core can be reversed and the unlaminated side heated and a sheet of film/foam laminate is similarly laminated thereto and forms the slick bottom skin of the bodyboard. The bottom skin of the finished product usually comprises a low friction polyethylene film with backing foam sheet which is usually high density polyethylene foam. The slick bottom surface allows a user to glide over water or snow.
A press mold also called a compression press can be used.
A variety of body boards can be made using the above described processes. As seen in
Nose gripping nodes 121 is a pair of triangular protrusion on the top surface at two corners of the nose end and upper beveled edge to provide a handhold. Each gripping node is a triangular area defined by an edge of the upper rail surface, upper edge of the nose surface and a diagonally oriented line on the top surface. One surface of the node forms a continuation of the upper edge of the upper rail surface and another surface of the node forms a continuation of the upper edge of the nose surface, extending to the apex of the node which is above the top surface of the board at preferably between about 3 mm and about 12 mm.
The nose ridge 122 is a raised area adjacent to the nose preferably elongated and inhibiting the thumb from slipping toward the outside and off the nose edge when the nose ridge 122 is gripped. The nose ridge 122 is a wedge shaped ridge protrusion extending along selected regions of the nose end to provide a handhold, and one side of the ridge forms a continuation of the upper edge of the nose surface extending to the apex of the nose ridge which is above the top surface of the board at preferably between about 3 mm and about 12 mm.
Side grip ridge 123 is an elongated raised area adjacent to the upper side edge of the upper rail surface generally from the nose to one half the board length, wherein one side of the ridge forms a continuation of the upper side edge of the upper rail surface which extends to the apex of the ridge, the apex characterized by having a elongate flat surface having a width in the range of about 5 mm to about 50 mm and the apex extending above the level of the top surface of the board in the range of about 3 mm to about 12 mm.
Side gripping grooves 124 provide a handhold, each groove forming a depression below the level of the top surface of the board and sized to receive a rider's thumb, wherein each groove extends along selected regions of the top surface adjacent to the upper side edge of the upper rail surface from the nose to about one half the board length, wherein a depression depth of each groove is in the range of about 3 mm to about 12 mm, wherein the width of depression is in the range of about 20 mm to about 65 mm, wherein the bottom of depression is spaced from the side edge of the top surface in the range of about 18 mm to about 40 mm.
The hip lock ridges 125 prevent undesirable lateral movement of rider's lower torso and hip away from the board. Each hip lock ridge extending along selected regions of the top surface adjacent to the side edge of the top surface from the tail to about one half the board length, wherein one side of the ridge forms a continuation of the upper side edge of the upper rail surface which extends to the apex of the ridge, wherein the apex has an elongate flat surface having a width generally in the range of about 5 mm to about 50 mm and the apex extending above the level of the top surface of the board in the range of about 3 mm to about 12 mm.
Leg depressions 126 aid the withdraw of rider's legs when shifting from a prone to a dropknee riding position, wherein each leg depression of the pair of leg depressions extends from a deep portion at the tail of the board adjacent to a side edge and blends into the board at approximately one-quarter of the length of the board, wherein the deep portion is no more than 1 cm in depth.
The elbow retainer wells 127 enhance purchase of the rider's elbow, the elbow well being ergonomically contoured and sized to receive rider's elbow extending along selected regions of the top surface adjacent to the side edge of the top surface generally from the nose to one half the board length, characterized by a well of depressed area surrounded by perimetric region at a higher level than the well, depth of well relative to the perimetric region being in the ranges from 3 mm and 12 mm.
A pair of elbow pads 128 should be formed as two raised perimeter sections along the upper half portion of the riding surface adjacent opposite side edges of the bodyboard, extending from the nose to about half length of the board. The raised area of the pads may continue and connect with the side gripping ridge, nose ridge and the nose gripping nodes in the upper half of the board, or may continue and connect with the hip lock ridge in the lower half of the board. The recessed center area between the two pads may form an hourglass shape.
As seen in
As seen in
Turning to the concave depression on the slick bottom surface, the theory of operation is speculated as follows: when a rider surfs with a floating device, the friction on the planning surface is a function of the wetted surface area. The concave profile bottom captures air inside the large concave cavity and thus reduces the contact surface area with water. As a result, this reduces friction and increases speed. Therefore the bodyboarder can surf at a higher speed and deliver a longer projection. Prone riding is well known the most often used position to ride a bodyboard. One arm extending forwardly to grip the nose end of the board and the other arm extending along the rider's side to grip on of the board's side edges. When a rider need to make a turn, pushing or pulling against the board's nose end and/or side edges are performed to bend or twist the board. For example, pushing on one side edge will agitate a water flow from one side to the other side and a concave bottom reduces the water flow rate and therefore impedes sideward sliding. It has been found that a concave bottom provides the bodyboard with an incredible hold and reduces sideward sliding when a bodyboarder executes a turn by tilting the board laterally, especially in fast and powerful waves.
The boards in
The top foam skin or the bottom foam skin may be imprinted with graphic image for decoration. Printing ink may be applied to the outer surface of the polyolefin foam sheet (161, 71). Alternatively graphic image may be printed on a plastic film and the film is laminated to the outer surface of the polyolefin foam sheet. Additional backing film or foam layers may also be applied between the printed plastic film layer and the polyolefin foam sheet. Additional backing layers may be a plastic film or a binding layer such as adhesive resin layer. One possible printing method is described as follow. First, a polyethylene film layer is imprinted with the desired graphics using a conventional printing process. The polyethylene film layer can be fed from a top roll and polyethylene foam layer fed from a bottom roll. As the film layer and the foam layer are fed from the rolls, hot adhesive resin 201 is extruded, using a conventional extruder, between the film layer and the foam layer to form the laminate layers.
Alternatively, following the printing of the first polyethylene film, a second polyethylene film may be bonded to the graphics imprinted in the first polyethylene film by using conventional glue or adhesive so that the graphic is covered. The first polyethylene film has a thickness of between 0.02 mm and 0.15 mm, and the second polyethylene film has a thickness of between 0.01 mm and 0.15 mm. The resulting dual-layered graphic polyethylene film is similarly laminated to the polyethylene foam sheet by extruding an adhesive resin film layer in between.
The present invention contemplates that many changes and modifications may be made. Therefore, while the presently preferred forms of the improved bodyboard have 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. The following call out list of elements provides a reference for referencing the elements of the invention.
Side laminate layer, lower rail foam skin 20
This application is a continuation in part of Profile Bodyboard application Ser. No. 11/985,895 filed Nov. 19, 2007 by same inventor Wah Kan Cheung, which in turn claims priority from same inventor Wah Kan Cheung provisional application Ser. No. 60/860,535 filed Nov. 22, 2006.
| Number | Date | Country | |
|---|---|---|---|
| 60860535 | Nov 2006 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11985895 | Nov 2007 | US |
| Child | 12627195 | US |
