US 3414919 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
Dec. 10, 1968 QA, @U51- 3,414,919
WATERCRAFT Filed Sept. 1966 5 Sheets-Sheet l FIG.5G
INVENTOR. j W BY j www Dec. 10, 1968 G, A, GUS-|- 3,414,919
l WATERGRAFT Filed Sept. 8, 1966 5 Sheets-Shee 2 NVENToR.
Dec. 1o, 196s G, A, @UST 3,414,919
WATERCRAFT Filed Sept. 8, 1966 5 Sheets-Sheet 5 INVENTOR.
BY my@ United States Patent O 3,414,919 WATERCRAFT George A. Gust, 909 Crestway Drive, Fort Wayne, Ind. 46809 Continuation-impart of application Ser. No. 522,095,
Jan. 21, 1966. This application Sept. 8, 1966, Ser.
3 Claims. (Cl. 9-310) ABSTRACT OF THE DISCLOSURE The invention is a paddleboard which includes an integrated, flexible assembly of a plastic body and aluminum tubes as reinforcement. The plastic is polystyrene foam of a density of about one (1) to three (3) pounds per cubic foot. Both the body and the reinforcing tubes have a degree of liexibility for the particular lengths thereof such that molding the tubes into the plastic body results in an integrated unit which itself is exibile. By reason of the tubes and body being conjointly flexible, relative movement therebetween is either minimized or eliminated whereby the reinforcing tubes are in effect looked to the body and under ordinary circumstances do not separate therefrom.
There results a paddleboard which is the ultimate in simplicity, is lightweight in construction, withstands rough handling and is of minimum expense.
This is a continuation-in-part of application Ser. No. 522,095, filed Jan. 21, 1966 now abandoned and bearing the title Watercraft The present invention relates to watercraft and more particularly to a watercraft conveniently useful in direct association with swimming and playing in the water.
The present invention resembles so-called paddleboards conventionally fabricated of hard, non-flexible materials such as wood, such paddleboards Ihaving a length approximating twelve (12) feet, a thickness approximating four (4) inches and a width of about two (2) feet. Paddleboards have found use as life-saving aids, oating objects used in direct connection with swimming, and a kayaklike watercraft which may be propelled either by using the hands as paddles or by using a kayak paddle having blades on opposite ends thereof. W'hile accomplishing all of the foregoing uses, and others in addition, the present invention is particularly signicant because of its substantially lighter weight, markedly greater degree of safety and expanded versatility and utility. All of this is explained in detail later on.
It is an object of this invention to provide a watercraft for carrying a human being, which is capable of being propelled similar to a kayak and which is safe, durable and strong as well as being substantially lighter in weight for a given size than prior devices of similar nature.
It is another object of this invention to provide a watercraft of the character 4hereinabove described uniquely designed so as to provide the necessary strength, flexibility and operating characteristics in a structure of minimal weight and maximal buoyancy.
The above-mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of an embodiment of the invention take-n in conjunction with the accompanying drawings, wherein:
FIG. 1 is a top plan view, partially broken away and sectioned for clarity, of one embodiment of this invention;
FIG. 2 is a side elevation thereof;
FIG. 3 is a stern view thereof;
FIG. 4 is a cross-section taken substantially along section line 4 4 of FIG. 1 in combination with a force diagram used in explaining certain of the principles of this invention;
FIGS. 5a and 5b are fragmentary longitudinal sections taken substantially along section line 5--5 of FIG. l, FIG. 5a being a section of the said portion and FIG. 5b being a section of the bow end;
FIG. 6 is an enlarged top plan View of a portion of the structure of FIG. 1 partially broken away and sectioned for clarity;
FIG. 7 is a side View of one of the devices of this invention as typically used in the water;
FIG. 8 is a side view illustrating certain characteristics of this invention;
FIG. 9 is a fragmentary longitudinal section similar to FIGS. 5a and 5b showing a slightly different embodiment of this invention;
FIG. 10 is a cross-section of another embodiment of this invention; and
FIG. 11 is a cross-section of still another embodiment of this invention.
Referring to the drawings, and more particularly to FIGS. l, 2 and 3, a watercraft constructed according to the principles of this invention is shown which is of elongated configuration and rectangular in cross-section as shown in FIGS. 3 and 4. This Watercraft may be considered as including a reinforced plastic body 15 solid and homogeneous throughout having upper and lower parallel surfaces 10 and 12 and bow and stern ends 14 and 16, respectively. The bow end 14 preferably is somewhat pointed or rounded as shown more clearly in FIG. 1. The stern 16 is substantially straight and normal to the longitudinal axis of the body.
The body 15, or hull as just described, is primarily composed of an expanded, buoyant plastic such as expanded polystyrene foam, this particular plastic being reforced by a series of longitudinally extending and elongated reinforcing members indicated by the numeral 18. In the embodiment shown, three such reinforcing members 18 are shown, these being parallel and spaced equallly apart. More particularly, these members may be formed of suitably rigid fiberglass reinforced plastic, paper tubing, wood, and the like, and in a preferred embodiment of this invention, these members 18 are in the form of aluminum tubes of particular size and stiffness characteristics. As shown in FIGS. 1 and 4, these tubes 18 are embedded in the plastic body 15 substantially midway between the upper and lower surfaces 10 and 12 and inset from the opposite lateral edges 20 and 2.2 by a distance approximating the thickness of the body 15. As shown in FIG. 4, the tubes 18 are spaced apart a 'distance greater than the thickness :of the body 15 and furthermore are of diameters which approximate one-fourth (1A) of the body thickness. As shown in FIG. 1, the center tube 18 is located midway between the edges 20 and 22 and extends from near the stern to a point near the bow 14. The two outer tubes 18 are located preferably about midway between the edges 20, 22 and the center tube 18. Also, these outer tubes 18 are somewhat shorter and terminate well Within the bow edge of the body as shown in FIG. 1.
The tubes 18 are embedded within the plastic body 15 to an extent which prevents dislodgement therefrom during even the most violent, normal usage of the device. In order to accomplish this, the tubes 18 must be of such size as compared to the thickness of the body 15 that they will not break through the plastic. Additionally, the opposite ends of the tubes 18 must be spaced inwardly from the adjacent ends of the body 15 which will prevent them from ramming through the body ends during violent llexure of the craft. Proper positioning and sizing of the tubes with respect to the plastic body enables the craft to be used with vigor and some violence without causing any breakage or weakening of the plastic material. This will be explained in more detail later on.
As shown more clearly in FIGS. 2 and 5b, the bottom surface 12 is angled at 24 adjacent to the bow 14 so as to provide a normal angle of attack between the bow end and Water through which it is being propelled. This surface 24 is angled such that the cross-section as shown in FIG. 5 b increases in thickness progressively in a direction extending rearwardly from the bow end 14. The central reinforcing tube 18 does not extend entirely to the point of the bow 14 or to the surface 24 but is spaced rearwardly therefrom. In one embodiment of this invention, the spacing from the bow point is approximately six (6) inches and about one and one-half (l1/2) inches from the surface 24.
Inasmuch as it is necessary to retain a sufficient thickness of plastic material between the reinforcing tube 18 and the various surfaces and edges of the body 15, it is preferred that the angulation of the surface 24 be kept as small as possible so as to maintain a relatively thick portion of plastic material between the tubes 18 and the surfaces 24. If an inadequate quantity of plastic material is provided between the right-hand end 26, for example, of the central tube 18 and the surface 24, a certain amount of llexure of the craft will result in the plastic breaking away and exposing and loosening the end 26. Thus, the thickness of the bow section should be as large as possible in order to avoid weakening the structure yet have some angulation to provide an angle of attack with the Water surface. As will become apparent from the explanations that follow, the particular construction of this invention permits even a greater angle 'of attack for the surface 24 than that provided by the angle of the surface 24 itself.
The plastic body must provide buoyancy adequate t0 support at least the weight of one, preferably two, adult persons. Many materials satisfy this buoyancy requirement for the dimensions given hereinafter for a typical embodiment of this invention; however, none of such materials alone without reinforcement are known to possess the necessary characteristics of strength, durability, flexibility and economy as are required in achieving the desired characteristics of this invention. These requirements will become more apparent from the description that follows which uses a basic size and design as a reference.
Suitable dimensions in a working embodiment of this invention involve a body length of from ten (10) to twelve (12) feet, a width of about two (2) feet, and a thickness of about four (4) inches. The tubes 18 are preferably seamless and of hard-drawn or tempered aluminum of approximately one and one-quarter (1%) inch outer diameter and one and one-eighth (1%) inch inner diameter, with the opposite ends thereof spaced inwardly from the opposite ends of the body about six (6) inches. The tubes 18 are spaced equally apart from each other as well as from the edges 20 and 22. The plastic body 15 is, in the preferred embodiment of this invention, expanded polystyrene foam of a density of about two (2) pounds per cubic foot.
In the fabrication of the craft, the plastic in the form of the usual polystyrene plastic beads is blown into a mold having the shape of the body 15 with the tubes 18 suspended or otherwise held in position in the mold cavity by means of suitable wires, pedestals or the like. When the cavity is filled with beads, steam is introduced into the cavity in the usual manner, causing expansion and fusion of the beads into a unitary mass. The tubes 18 are thereby molded within the unitary mass of plastic and are thereby tightly held in place. There is some degree of adhesion of this plastic mass to the tubes, which assists in the reinforcement and stilfening of the plastic.
As shown in FIG. 7, with an adult human being of normal size and weight sitting on the device floating in water at a position midway between the ends thereof, the device curves longitudinally such that the bow and stern ends thereof rise slightly. This obviously increases the angle of attack between the surface 14 and the surface 26 of the water. Thus, by providing a degree of flexibility in the craft to an extent which does not impair the strength thereof, the angle of the surface 24 need not be made as great as would be desirable if the craft were maintained stiff and straight under the conditions shown in FIG. 7. In a craft of this invention, the bow section can therefore be maintained thicker and lighter density plastic material for the body 15 used than would otherwise be possible, Ithereby maintaining the necessary strength, buoyancy and lightness in the entire body 15 as well as strength in the bow section. This is important, because known plastic materials inherently do not possess great strength and are subject to breaking when stressed or impacted by loads not normally regarded as being very great. Certainly, the use intended for the present invention is such that damaging loads are frequently encountered and these indeed would fracture or break off the bow end if the same were not provided with adequate strength. Maintaining a thickness dimension is part of the requirement in obtaining the necessary strength and angle of attack (due to flexibility of body 15) in the bow section.
Proper selection of sizes, materials and relative positioning thereof, as described hereinbefore, provides performance characteristics as illustrated in FIG. 8, wherein the craft is shown as floating on the surface of water having some wave action. The water surface 28 is shown as undulating or wavy, and the craft is shown as flexing to conform to these undulations. This degree of flexibility contributes to the durability of the craft inasmuch as the cross-sectional shearing stresses on the craft are almost non-existent, since the bottom 12 is directly supported on the water surface. If the craft were stiff and rigid, it will be noted that it would tend to be supported at the wave crests located approximately where the arrows 30 are shown. This would mean that the central or midportion of the craft would not be in as intimate engagement with the water, but instead would tend to be bridged between the two wave crests 30. The result would be to irnpart a shearing force to the midportion of the board, tending to break it transversely. However, by providing the flexibility as hereinabove explained, the damaging consequences of such shearing forces are minimized.
Keeping in mind the specic embodiment of the invention as given hereinabove, a further explanation of the design requirements of this invention will now be given. Assuming the same dimensions as given hereinbefore for the plastic body 15 and that this plastic body is polystyrene foam of about two (2) pounds density, if the tube 18 or other similar reinforcement is omitted, the resultant body no longer is adequate to serve the intended purposes. The body is weak and easily broken, and when loaded as shown in FIG. 7, the opposite ends curve upwardly by amounts approximating the body thickness.
If the body 15 is made sutllciently thick (no reinforcenient being present) to overcome this weakness problem, it acquires too much weight and bulkiness Iand furthermore possesses a degree of buoyancy many times greater than that which is needed. Thus, this excess material serves no useful purpose other than to interfere with the intended use and purpose of this invention while providing the strength required. Not only is this additional thickness objectionable from the standpoint of increasing the weight and expense of the craft, but it is additionally objectionable for the reason that it tends to render the craft laterally unstable and diflicult to maneuver. Therefore, it is desirable to maintain the thinness as shown in FIG. 4 without the buoyancy, strength and stability requirements being adversely affected. These design limitations arise in part from the requirement that the device be wide enough to accommodate an individual sitting thereon as well as to provide lateral stability. Thus, thewidth cannot be too narrow.
Ordinarily, reinforcing structures used in plastic bodies have been of substantial width, extending substantially throughout the cross-section of the plastic. In other words, as shown in FIG. 4, the reinforcement represented by the tubes 18 if flattened and laterally extended almost throughout the width of the body would be deemed conventional in design as reinforcement for plastic. However, in the present invention, it has been discovered that the unique combination of the plastic and tubing provides for the use of minimum quantities of both while at the same time accomplishing the necessary requirements of strength, durability, buoyancy and stability. It should be noted, as shown in FIG. 4, that the tubes 18 are spaced relatively far apart, providing for virgin plastic material only between these tubes. However, by reason of the reinforcing qualities imparted to the plastic by the tubes 18, as well as the normal strength characteristics of the plastic material itself, it has been found that no reinforcement is necessary transversely between the tubes 18. Experiments have proven that the most violent, normal usage of the craft made according to the specifications given hereinbefore will not result in breakage thereof, such usageincluding adults jumping up and down on the craft while the craft is floating in the water, jumping onto the craft feet-first from a dock elevated about two (2) feet above the water, towing the craft at speeds of about 30-miles-perhour behind a power boat and the like.
More or less tubes may be used as reinforcement without departing from the spirit and scope of this invention and different dimensions may be used so long as the requirements of stability and adequate width for a rider are not violated. Different densities for the polystyrene plastic may be used so long as the lightness, buoyancy and strength characteristics explained hereinbefore are preserved. Densities varying from one to three pounds per cubic foot have been found to give satisfactory results.
Greater stiffness for a given size tube may be imparted to the plastic 15 by following the design illustrated in FIG. 9 wherein Ia tube 18a like a tube 18 is provided on the ends thereof with radially outwardly extending flanges 30. This serves in holding the tube against relative longitudinal movement with respect to the plastic, thereby imparting greater stiffness to the plastic. This may be explained as follows. It will be observed that by bending the craft longitudinally, the tendency is for the bottom surface 12 to elongate and the upper surface 10 to shorten. The same is true of the aluminum tubes 18 embedded within the plastic. By reason of the soft nature of the polystyrene foam 15, repeated flexing of the craft can result in the tube 18 gouging or working a cavity in the plastic which is larger than the tube 18 itself. This impairs the reinforcement imparted to the plastic. Thus, it is important to provide la size and stiffness in the tubes 18 which will not permit the body to flex unduly but, on the other hand, to flex sufficiently to provide the improved results explained in detail hereinbefore. One method of imparting stiffness to the plastic body is that shown in FIG. 9. Another is to provide tubes 18 of suiciently large diameter and stiffness to insure against excessive bending under normal loads imparted to the craft.
Another embodiment of this invention is illustrated in FIG. 10, wherein the body 15 is identical to that previously described but has only a single reinforcing tube 18 in the central region thereof. This construction is identical to that disclosed in the preceding drawings except for the omission of the two outer reinforcing tubes 18. For additional reinforcement, however, without sacrificing the desirable characteristics of maintaining minimum weight as against maximum strength and durability, additional reinforcement is provided by means of a layer 34 of a stronger plastic material adhered by some suitable means to the bottom surface 12 of the body 15. This layer 34 extends from edge to edge and end to end of the body 15 and is adhered to the bottom surface by means of a suitably strong adhesive. The material of this l-ayer 34 may be of vinyl plastic thick enough to provide the reinforcing characteristics hereafter explained.
As shown in FIG. 7, when a weight is positioned on the craft between the ends thereof, the center part will tend to depress while the ends will rise. Thus, the bottom 12 of the craft will tend to elongate. By providing the layer 34 on the bottom surface 12 and suitably adhering it thereto, it is seen that the tensile strength and non-yielding character thereof against elongation will resist the bending of the body 15 and thereby reinforce the same. Therefore, maximum buoyancy for minimum weight in the craft may still be maintained without the necessity of sacrificing strength, durability or flexibility in the craft.
The layer 34 may be of any thickness or material as will provide for this result, an ordinary vinyl material of about 1/s to 1A inch thickness being satisfactory.
In FIG. 11 is illustrated another embodiment of this :invention in which the body 15 is shown encased in layers 36 and 38 which may be identical in composition and character to the layer 34.
The layers 36 and 38, in addition to being adhered to the upper land lower surfaces of the body 15, are intimately formed over the side edges as shown, with the meeting edges of the layers 36 and 38 being cemented together and covered by strip beading which extends around the perimeter of the craft. In a construction of this nature, the reinforcing tubes 18 may be omitted provided the material selected for the layers 36 and 38 has strength characteristics sufficient to resist bending of the body 15 as explained previously.
A craft made according to the preceding description is of optimum lightness, maximum buoyancy, adequate stability and substantial strength and is economical as well. It therefore possesses a maximum degree of safety for use as a water toy or swimming aid, and, furthermore, may be used with maximum comfort as a lounging pad which may either be floated on the water or laid on an uneven ground surface or deck of a swimming pool.
What is claimed is:
1. A watercraft comprising an elongated plastic body which is solid and homogeneous throughout and is of elongated cross-section; said plastic being polystyrene foam of a density of about one to three pounds per cubic foot, said body being wider than thick and longer than wide,
said body having flat top and bottom surfaces and opposite lateral edges, said width being at least of a dimension as will accommodate an adult sitting thereon, said body having bow and stern ends,
said bottom surface being flat and uninterrupted for the entire yarea thereof extending from the bow end to the stern,
at least one reinforcing member intimately attached to and embedded in said body intermediate said surfaces and ends thereof,
the opposite ends of said member terminating short of the ends of said body,
said member being straight and elongated and extending longitudinally of said body,
said member being of a material having a strength and density greater than said plastic,
said member being of a size, strength and flexibility which imparts longitudinal stiffness to said plastic to an extent whereby said member and said body will flex as a unit and said body ends will rise under the weight of an adult concentrated in the middle thereof thereby to increase the angle of attack at the bow end;
said member further being of a size and strength as to reinforce said plastic against breaking when subjected to said loading conditions, said member having a cross-sectional dimension less than the maximum thickness dimension of said body.
2. The watercraft of claim 1 in which said member extends substantially parallel to and coincident with the longitudinal axis of said body, two additional straight reinforcing members embedded in said body and disposed in parallel, spaced relationship with respect to and on opposite sides of the first-mentioned member, said rstmentioned member extending into said bow end for reinforcing the same, said two members terminating adjacent to said bow end such that said first-mentioned member constitutes the sole reinforcing member for said bow end.
3. The watercraft of claim 2 in which the bottom surface of said bow end is angled divergently from the forwardmost part thereof for a predetermined distance aft thereof, and said members are metallic tubes.
References Cited UNITED STATES PATENTS 2,999,041 9/1961 Lappala.
8 4/ 1962 Rosenthal. 11/1945 Howland 9-310 10/1966 Edwards 9-310 10/1966 Anderson 9-310 X 3/1966 Straub et al 9-11 X 3/1967 Lambach 9-310 8/1967 Ekstrom 9-310 FOREIGN PATENTS l/ 1963 Australia. 6/ 1964 Great Britain. 6/1952 France.
MILTON BUCHLER, Primary Examiner. 15 P. E. SAUBERER, Assisiam Examiner.