US3433201A - Weight-steered water sled - Google Patents

Description

March 18, 1969 F. R. BROWN ETAL 3,433,201

WEIGHT-STEERED WATER SLED Filed Jan. 12, 1967 INVENTOR.

FLOYD R. anovm y ALTER L.FLOEl-IR WATTORNEY United States Patent 8 Claims ABSTRACT OF THE DISCLOSURE A self-propelled water sled driven by an outboard motor mounted against turning astern of a drivers position and steerable at any speed by the shifting of the weight of the driver without reliance upon either a rudder or directional surfaces on the hull.

The prior art While self-propelled water sleds steerable by shifting of the weight of the driver have heretofore been proposed, it has been assumed that in the absence of a rudder it was necessary to rely for turning either on side skidding or on the provision of directional surfaces on the underside of the hull which on tilting of the sled would produce a force for turning it in the direction of tilting. The first of these types not only is diflicult to keep on a straight course but slides oft" on turns, while the second requires a comparatively complex hull form. Too, as indicated by Sterling Patent No. 1,814,772, it appears not to have been appreciated that the position of the propeller lengthwise of the sled has any bearing upon its maneuverability.

Summary of the invention The improved self-propelled, weight-steered water sled of the present invention depends for maneuverability on neither skidding nor directional surfaces. Instead, it has its propellor or other propulsion means mounted to apply a pushing force substantially parallel to its longitudinal centerline, has longitudinally extending side keels on the underside of its hull at opposite sides of the centerline and makes use of relative drag on above and underwater parts of its hull for producing with the pushing force a turning force or moment in the direction toward it is tilted and of the keels for both maintaining it on a straight course when level and controlling its turns when tilted.

The preferred sled has a hull that is substantially flatbottomed and sided and has an upturned bow for better riding at low speeds. The simplicity of line readily adapts the hull for forming of fiber glass or other suitable material and, even with so simple a hull, the sled is easily maneuverable at low speeds and increases in maneuverability at higher speeds with increase in the water drag on the down-tilted side.

It therefore is an object of the present invention to provide a self-propelled water sled which, while turnable solely by weight-shifting, is uncomplicated in construction and readily maneuverable at any speed.

Other objects and advantages of the invention will appear hereinafter in the detailed description, be particularly pointed out in the appended claims, and be illustrated in accompanying drawings, in which:

Figure description FIGURE 1 is a plan view of one of the counterpart halves of a preferred embodiment of the improved water sled of the present invention;

FIGURE 2 is a side elevational view of the sled of FIGURE 1; and

FIGURE 3 is a front elevational view of the sled of the preceding figures.

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Detailed description Referring now in detail to the drawings in which like reference characters designate like parts, the improved self-propelled water sled of the present invention is comprised of a hull 1 made of suitable material. The preferred hull is both hollow and watertight and made of glass fiberreinforced epoxy or like plastic, commonly known as fiber glass. When made of fiber glass, the hull conveniently is formed of separately molded upper and lower parts 2 and 3, respectively, having a flanged joint at which they are bonded or otherwise suitably joined together, the illustrated joint extending around the hull below the gunwale 4 to form a projecting rub rail or bumper 5.

In shape the preferred hull 1 is generally square-ended and flat-bottomed, with an upand in-turned bow 6 for better riding at lower speeds. Making of the hull is facilitated and maneuverability of the sled improved, if the bottom or underside 7 and sides 8 of the hull are substantially fiat over most of the hulls length from a point forward of amidships to the preferred square stern 9. While exact flatness is permissible, the substantial flatness of the illustrated embodiment in which the bottom 7, longitudinally and laterally, and the sides 8, longitudinally, have a slight outward or convex curvature or rounding, is preferred for both increased strength and easier molding. Both convergence and extensive flairing, upwards, of the sides 8 will have an adverse effect upon the sleds maneuverability and for optimum performance the sides should be substantially vertical with any upward fiair slight.

For the sled to operate as intended, the hull 1 needs no center keel but must have side keels or fins 10 on its bottom 7 at opposite sides of its centerline. While there may be a plurality on each side, the illustrated pair of side keels 10, one to a side, will usually be adequate. Whatever the number, the keel or keels on each side should be sufficiently spaced or offset laterally from the centerline toward the adjoining side to be at least partly submerged at all speeds when the hull in turning is tilted toward that side and also should extend both fore and aft of the sleds center of gravity. The keels downstand vertically from the bottom 7 and are quite shallow, a depth on the order of that of the center keel of a power boat of comparable dimensions usually sufiicing. The width is unimportant except as necessary to resist the lateral forces encountered during turning. However, the keels, longitudinally, must be parallel to the hulls longitudinal centerline and should also be straight, if, as intended, one or the other is to enable a turn to be controlled and both are to cooperate in holding the sled when level on a substantially straight course. Too, by making their bottoms 11 flat and coplanar, the keels are enabled to act as skids on which the sled can be rested and slid when out of water. Even though shallow, to the extent of their depth the keels also increase the area of the hull exposed to drag during turning.

To shed water coming over the bow 6, the sled prefer ably has a turtle back or arcuately convex foredeok 12. A cowling 13, rising or upstanding from the rear or aft part of the foredeck 12, is useful for housing and shielding or protecting a gas tank 14 and, for engine starting, battery 15, which are held in place in seats 16, the latter in the case of the preferred fiber glass hull 1, conveniently being molded into the upper part 2. The main part of the hull, from a point forward of amidships to the stern 9, is decked or covered by a main deck 17, suitably flat, if as will usually be the case the sled is designed to be operated by a standing operator or driver. The main deck is protected at the sides by coamings 18 merging forwardly with the cowling 13 and extending aft therefrom to the stem 9. The roughly amidships forepart 3 of the main deck 17 is the platform or stand 19 on which the operator stands in operating or running the sled and at least this part of the main deck preferably is antiskidsunfaced.

For holding himself in position, the operator is provided with a hold bar or hand hold 20 extending laterally of and parallel to the main deck 17. Conveniently, the hold bar 20 is the cross-member of a handle 21 of inverted U-shape, the legs 22 of which, serving as the hold bars stanchions, are socketed or received at their lower ends in mounting brackets 23 fixed to the foredeck 12 at opposite sides of the cowling 13. As desired, the hold bar 20 may be fixed or adjustable in position, both fore and aft, any vertical adjustment to suit a particular operator readily being providable by mounting the legs 22 in the brackets 23 for fore and aft swinging to any of a plurality of positions with means (not shown) for locking them in selected positions.

As important to the maneuverability of the sled as the side keels is the location of the propeller or other propulsion element 24. In contrast with prior teachings, such as that of the Sterling patent, it is vital that the propeller have a fore and aft location aft of the sleds center of gravity, so as to push rather than pull the sled. The propeller is fixed against horizontal angling or turning relative to the hull 1 and, if the sled is to'turn equally well in both directions, also should be centered laterally on the hull. Most suitably, the sled is driven by an outboand motor 25 and the requirements for propeller location are met by mounting the motor in or at the stern either on the stern transom 26 or, as shown, in a rearwardly opening well 27 centered laterally on the hull and interrupting and projecting forwardly of the transom. The motor 25 may be clamped in the usual manner to the hull for rearward swinging to yield to an underwater obstruction, but, as opposed to the usual practice, will be locked or held, suitably by the usual inbuilt latch (not shown), against horizontal angling or turning relative to the hull in a center position in which the propeller is directed to apply its pushing force substantially parallel to the'hulls longitudinal centerline. While the longitudinal and lateral or transverse location or position of the propeller 24 relative to the sleds center of gravity is all important, it also is important that the propeller be so located vertically relative to the center of gravity as neither to drive the bow 6 down nor to tend toflip the sled over on its back.

Control of the action of the motor 25 is exercisable by the operator from a standing position on the platform 19 by mounting on a panel 28 on the handle 21 below the hold bar 20 one or more control levers suitably connected to the motor. In the illustrated embodiment a single control lever or bar 29 serves to control all of the actions, the lever Ibeing rotata ble in opposite directions for forward and reverse and swingable vertically for controlling speed. As an operator who fell off the sled could well be injured if the motor thereafter continued to run, the control lever 29 also serves as a deadman lever by being springloaded to swing to a down position in which it shorts the motor the moment it is released by the operator.

The buoyancy of the hull 1 will depend on the size of the motor and number of occupants for which the particular sled is designed. In any case, for low speed maneuvering, the hulls buoyancy should be such as to support the load for which it is designed with the main deck 17 above water level or not awash. This dependency for floatation upon hull buoyancy will decrease with increase in speed, at which time the higher propulsive force of the propeller 24 will cause the hull to plane on its substantially flat bottom 7 with its bow 6 lifted above water.

The drag of water on the submerged or underwater part of the hull relative to that of air on both the abovewater part of the hull and the operator, will increase with increase in speed. The propeller 24 because of its location applying a pushing force at least aft of and preferably also in substantial longitudinal alignment with the center of gravity, and the main reactant to that (force, the drag of water on the submerged part of the hull, progressively shifting with increase in tilt away from the center of gravity toward the down-tilted side, the sharpness of a turn at any speed will be determined by the degree of tilt. Moreover, as the water drag increases more rapidly than the speed and this disproportionate increase is only partly compensated by planing, the sensitivity of the sled to weight-shifting by the operator and its response thereto in turning or maneuvering will increase with increase in speed. However, while it is the eccentricity of the applied and main reactant forces that produces the turning force, if only the latter were involved, the tendency of the sled would he to spin or side slip rather than turn and this tendency would increase with increase in speed. This tendency must be resisted if the sled is to be maneuverable or controllable in its turns and it is this function that is performed in a turn by one or other of the side keels 10. Partly or fully submerged, depending upon the extent of planing, the side keel on the down-tilted side tends, because of its straightness and longitudinal disposition relative to the hull, to hold the sled upon a straight course in opposition to the turning force and makes it possible for an operator readily both to turn the sled at will and control the extent of the turning.

From the above detailed description it will be apparent that there has been provided an improved self-propelled water sled which is readily maneuverable at any speed simply by weight-shifting. It should be understood that the described and disclosedembodiment is merely exemplary of the invention and that all modifications are intended to be included that do not depart from the spirit of the invention.

Having now described our invention, we claim:

1. A self-propelled water sled, rudderless and maneuverable by Weight-shifting, comprising a single hull on which the sled entirely depends for buoyancy, propulsion means mounted on and fixed against horizontal angling relative to said hull and located aft of a center of gravity of said sled, straight side keel means on an underside and extending longitudinally of said hull at opposite sides and parallel to a longitudinal centerline thereof andv fore and aft of said center of gravity, said side keel means on each side of said centerline being so spaced laterally therefrom as to be at least partly submerged on downtilting of said hull toward said side, a deck at least partly covering a top of said hull and longitudinally overlapping and extending laterally between said side keel means, and means projecting above said deck for enabling an operator to support himself in standing position thereon, said sled depending for controlled turning on the cooperative action of the side keel means and relatively greater frictional drag on the down-tilted side of said hull under the force applied by said propulsion means.

2. A water sled according to claim 1, wherein the hull aft of a bow thereof has a substantially flat bottom and the side keel means are fixed to and downstand from said bottom toward opposite sides thereof.

3. A water sled according to claim 2, wherein the propulsion means are propeller means of outboard motor means.

4. A water sled according to claim 3, wherein the motor means is a stern-mounted outboard motor centered laterally on the hull.

5. A water sled according to claim 1, wherein the side keel means are a pair of side keels fixed to the hull at opposite sides of the longitudinal centerline thereof.

6. A water sled according to claim 5, wherein the side keels have flat coplanar bottoms.

7. A water sled according to claim 4, wherein the motor is mounted in a rearwardly opening well in and centered laterally on a stern of the hull.

8. A water sled according to claim 1, wherein the hull is formed of separately molded upper and lower glass 5 6 fiber-reinforced plastic parts and the parts have a flanged 3,213,822 10/ 1965 Sawchuk 11570 joint forming a rub rail around the hull. 3,340,845 9/1967 Tyrack 11570 References Cited FOREIGN PATENTS UNITED STATES PATENTS 5 795,194 5/1958 Great Britain. 2,744,267 5/1956 Roby 115-70 X 2,828,491 4/ 1958 Turgeon 11570 TRYGVE M. BLIX, 'Primary Examiner.

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