The present invention is related generally to personal watercraft. More specifically, the present invention is related to rub rails on personal watercraft.
Personal watercraft (PWC) have become increasingly popular in recent years. A personal watercraft, also known as a “jet ski” typically has a bottom hull, handle bars for steering, a tunnel within the bottom hull, a jet pump located within the bottom tunnel, and an engine within the hull under the top deck for driving the jet pump. The jet pump typically pulls in water from the front of the tunnel under the boat, and discharges the water at high velocity through a steerable nozzle at the rear of the boat. The handlebars are typically coupled to the nozzle, which is the steering mechanism for the personal watercraft. The watercraft commonly has a straddle-type seat and foot wells disposed on either side of the seat.
Personal watercraft typically have a top deck affixed to a bottom hull. The PWC has a shroud mounted in front of the driver on top of the top deck to house the steering column and some instruments. A front portion of the top deck includes a hinged cover or “hood.” The underside of the hood can include a gasket or a grommet that attempts to provide a watertight seal between the hood and the top deck. The hood typically covers either a storage bin or an engine access port.
Personal watercraft often have a “rub rail” that can serve as a bumper around the boat. The rub rail can be wrapped around the outer extent of the top deck, to protect the top deck from damage from other boats or docks alongside. Rub rails ideally have some give or resiliency. This resiliency can be provided with a complex lateral or transverse profile. Some such rub rails have an outer wall over a central channel, or a pair of cantilevered wings that provide the resiliency. Rub rails are generally formed using one of two methods. Extrusion can be used to form straight sections of rub rail. A die for the extrusion process can cost on the order of 10,000 dollars, or less. Where straight sections of rub rail are not appropriate, injection molding can be used to form complex curves and rear corner pieces. Injection molds can cost on the order of 100,000 or 200,000 dollars, depending on the complexity. Injection molds cannot easily be used to form certain lateral or transverse shapes. In particular, injection molding cannot easily be used to form a profile that cannot be pulled from the mold, for example, profiles having a central channel or converging cantilevered wings.
Personal watercraft typically have an outer periphery or bow line. This periphery can be formed by the coming together and bonding of the bottom hull to the top deck. Some personal watercraft have a “horizontal bond line”, resulting from the top deck and bottom hull extending horizontally and outwardly together over a horizontal segment in which the top deck and bottom hull are bonded together. A rub rail to protect and cover this horizontal bond line can function as a cap, having an upper lip extending over the top deck to support the rub rail and hold it in place. Such a rub rail can have a bottom lip extending under the bottom hull segment as well.
Other watercraft have a “vertical bond line”, resulting from the top deck extending downward to terminate in a vertically downward segment. The bottom hull can extend upward to form the hull along the waterline, then extend further upward, then outward in an upside down “U” shape, then downward to terminate in a vertically downward segment alongside and inside of the outer top deck vertically downward segment. The vertically downward segments of the top deck and bottom hull are said to form the vertical bond line.
The vertical bond line typically has a top deck outer vertical surface on which to mount the rub rail. Most vertical bond lines do not provide an upper ridge on which to hang or support the rub rail. The rub rail is typically secured with fasteners of some sort. Rub rails secured to vertical bond flanges are usually, if not always, formed of a rigid material. Forming such a rub rail out of a flexible or even a semi-rigid material can lead to a very soft rub rail after the rub rail has been in direct sunlight for a period of time. If hot and soft enough, the rub rail can even be pulled from and over the fasteners, away from the watercraft. For this reason, rub rails for vertical bond flanges are typically made from rigid polymers, to avoid this tearing and to avoid sagging of the rub rail.
Rigid rub rails can present a problem in that they do not conform to complex surface geometries as easily as semi-rigid or flexible. In particular, vertically curved or bow lines have been difficult to protect with rigid rub rails. Also, rear corners have been difficult to protect with rigid rub rails. One solution has been to make the rub rails for complex curves or corner pieces using injection molding. Injection molding suffers from the cost disadvantage discussed above. Injection molding also can limit the rub rail to shapes that have limited resiliency. Finally, the discrete rear corner pieces formed by injection molding can form a gap or discontinuity where they meet the side rub rail pieces and can be snagged as the discontinuity catches on docks, even pulling the rub rail away from the watercraft. A continuous extrusion could be used that wraps around the rear corners, but current rub rails, if flexible enough to wrap around the rear corners, tend to both wrinkle and to sag on the vertical bond flange.
What would be desirable are watercraft designs that do not require separate rear corner pieces. What would also be desirable are rub rails that are rigid enough to be used on vertical bond flanges without sagging, can be formed using extrusion, and can wrap around rear corners and protect personal watercraft hulls over vertical curves.
The present invention provides a jet propelled personal watercraft including a hull, the hull having a bottom hull and a top deck secured over the bottom hull, the hull defining an engine compartment sized to contain an internal combustion engine for powering a jet propulsion unit. The personal watercraft also includes a jet propulsion unit including a steerable water discharge nozzle. The top deck can have a raised, longitudinally extending seat adapted to accommodate an operator in straddle fashion. The top deck can have a downwardly extending portion about the watercraft periphery terminating in a bottom edge.
A polymeric rub rail including a vertical portion can be secured to the top deck downwardly extending portion and have an inwardly extending lip disposed beneath the top deck bottom edge, and further have a bottom lip curved upward and inward from the rub rail toward the bottom hull. Some rub rails have a first wing extending downwardly from the rub rail vertical portion and a second wing extending upwardly from the rub rail vertical portion to form an open channel between the wings and the vertical portion. The converging wings can provide resiliency to the rub rail. In some watercraft, the rub rail is formed of a polymeric material having a Shore A hardness of at least about 90. In other watercraft, the rub rail is formed of a polymeric material having a Shore A hardness of at least about 95. The rub rail can be secured to the top deck over a region having a vertical radius of curvature of less than about 20, 15, or 10 inches, depending on the embodiment.
Some personal watercraft have two, opposite rear corners, wherein the rub rail wraps continuously around at least one of the corners. The rub rail wraps continuously around both rear corners in other personal watercraft, and includes a first corner piece wrapping continuously around a first corner and a second corner piece wrapping continuously around the second corner in still other personal watercraft. The corners can have a radius of curvature of less than 2 feet or 1 foot, in various embodiments. Some watercraft have a rub rail with a vertically curved region. The vertical curve can have a radius of curvature of less then about 20 inches, or even less than 10 inches.
The invention includes methods for securing a polymeric rub rail about a personal watercraft top deck periphery. One method includes providing the personal watercraft, the watercraft having a vertically curved portion of a top deck periphery having a substantially downwardly oriented outer face, and also providing the rub rail, the rub rail having a vertical region for securing to the top deck downwardly oriented outer face. A forming jig can be provided, the jig including substantially the same geometry as the vertically curved personal watercraft top deck section. The rub rail can be heated, then forced to conform to the jig, then allowed to cool, and freed from the jig. The pre-formed rub rail can be secured to the watercraft top deck downwardly extending face. The rub rail can be formed from a rigid material, having a Shore A hardness of at least about 90 or 95, and/or a tensile modulus of at least about 2 GPa.
In some methods, the rub rail has a pair of substantially opposed wings extending outwardly from the rub vertical region and toward each other to form an open channel between the wings and the vertical region. The method can further include inserting a mandrel into the cavity between the wings and the vertical region such that the cavity does not become closed during heating. The heating can be to a temperature of about or above the heat deflection temperature of the polymer in some methods.
The invention can include a rub rail for use on a personal watercraft, the rub rail having a longitudinal dimension, a vertical dimension, and a lateral dimension transverse to the longitudinal and vertical dimensions. The rub rail can have an inward lateral direction to be disposed toward the watercraft and an outward lateral direction to be disposed away from the watercraft. The rub rail can further include a vertical section including an inwardly facing surface for disposition against a personal watercraft peripheral surface, the vertical section having a longitudinally extending mid-region dividing the rub rail into a top region and a bottom region. A first wing can extend outwardly and vertically from the rub rail vertical section. The rub rail can be an extruded rub rail having a Shore A hardness of at least about 90 or 95 and can have a curve along the longitudinal dimension. The curve along the longitudinal dimension can include a vertical curve, a horizontal curve, or a simultaneous vertical and horizontal curve.
The rub rail first wing can extend outwardly and downwardly from the vertical section, and the rub rail can further have a second wing extending outwardly and upwardly from the rub rail vertical section. The rub rail can also have a first lip extending inwardly from the vertical section and a second lip curving upwardly and inwardly from the vertical section.
The present invention includes another rub rail for mounting on a personal watercraft, the rub rail having a longitudinal dimension, a vertical dimension, a lateral dimension transverse to the longitudinal and vertical dimensions, an inward lateral direction to be toward the watercraft, and an outward lateral direction to be away from the watercraft. The rub rail can have a transverse, cross-sectional profile that cannot be made using injection molding, with the rub rail being formed from a rigid material having a tensile modulus of at least about 2.5 GPa and a curve along the longitudinal dimension. The curve can include a vertical curve, a horizontal curve, or both a vertical and horizontal curve.
The present invention provides a method for attaching a rub rail to a personal watercraft, the method including providing a rub rail formed from a rigid material having a tensile modulus of at least about 2.5 GPa and having a transverse profile that cannot be made using injection molding, and also providing a personal watercraft having a substantially vertical peripheral curved surface. The rub rail can be formed to have a rub rail curve substantially matching the watercraft surface curve, such that the rub rail maintains the curve when unconstrained. The pre-formed rub rail can be secured to the watercraft surface. The method can use a rub rail made by extrusion. The method can include providing a forming jig having a jig surface substantially matching the personal watercraft curved surface, wherein the forming includes heating the rub rail, then forcing the rub rail against the jig surface, then cooling the rub rail.
The following detailed description should be read with reference to the drawings, in which like elements in different drawings are numbered identically. The drawings, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the invention. Several forms of invention will be shown and described, and other forms will now be apparent to those skilled in art. It will be understood that the embodiments shown in the drawings and described below are merely for illustrative purposes, and are not intended to limit the scope of the invention as defined in the claims that follow.
A single, rigid, rear center bumper 106 can extend between rub rail corner portions 104 and 105. The horizontal radius of curvature in the watercraft rear is indicated at 112. As can be seen from inspection of
Top deck 122 includes an outwardly facing surface or face 124, an inwardly facing surface or face 126, and a downwardly facing surface or edge 128. Inwardly facing and outwardly facing surfaces 124 and 126 are substantially downwardly extending, as can be seen from inspection of FIG. 6. Bottom hull 130 includes an outwardly facing surface or face 132, an inwardly facing surface or face 134, and a downwardly facing surface, face, or edge 136. Top deck 122 may be seen to terminate downwardly in bottom edge 128. Rub rail 120 may be seen to have an inwardly extending lower lip 152 extending inwardly from rub rail vertical portion 142. Inwardly extending lip 152 has an upper surface that, in some embodiments, can fit closely to top deck downwardly facing edge 128. Rub rail 120 may also be seen to have a center longitudinal strip portion 121 that can be used to secure rub rail 120 to top deck 122 using fasteners. Center strip portion 121 can effectively divide rub rail 120 into a top longitudinal region and a bottom longitudinal region.
Rub rail 120 may also be seen to have a bottom, inwardly and upwardly curved lip 154. Lip 154 terminates in an upwardly and inwardly extending, terminating ridge 156. An inwardly facing channel 158 may be seen formed between upwardly and inwardly curved or curled section 154 and inwardly extending rib 152. Applicants were surprised to discover that the inwardly and upwardly curved rib 154 provided an increased ability for rub rail 120 to hug top deck 122 around sharp corners. In particular, bottom curled rib 154 allowed rub rail 120 to hug top deck 122 around the rather sharp turning rear corners without wrinkling the major outward surfaces of the rub rail. Any wrinkling is forced toward lip 154. It may be seen from inspection of
Rub rail 32 also includes a vertically level rear region 227 proceeding forward to a vertically curved region 223 having a vertical radius of curvature as indicated at 225. In various embodiments, vertically curved region 223 has a vertical radius of curvature of less than 20, 15, and 10 inches, respectively.
The rub rail can be made of any suitable polymeric material, for example, a rigid vinyl or PVC. In various embodiments, the PVC has a Shore A hardness of at least about 90 and/or has a tensile modulus of at least about 2.5 GPa. Some rub rails have a tensile modulus of at least about 0.5 GPa or between about 2.5 and 3 GPa. Other rub rails have a Shore A hardness of at least about 95 and/or a tensile modulus of at least about 1. The rub rail can be manufactured using any well known suitable extrusion technique. The rub rail can be any suitable height and thickness, depending on the watercraft. Some rub rails are about 2 inches in height, having a wall thickness of between about ⅛ and ½ inch.
In preferred embodiments, the rub rails are preformed to match the desired geometry of the watercraft. The rub rail can be formed using an extrusion method to create the desired profile, for example, the cross-section as seen in
Inspection of
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