US20010042498A1

US20010042498A1 - Drive and control system for watercraft

Info

Publication number: US20010042498A1
Application number: US09/756,986
Authority: US
Inventors: Daniel Burnham
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-01-10
Filing date: 2001-01-09
Publication date: 2001-11-22

Abstract

A surfboard-based powered water craft is propelled by gas or electric power plant. A water jet pump supplies water under pressure, which is exhausted through a steering nozzle. A steering shaft, carried by the surfboard-based body, pivots in response to movement of a steering arm. The steering arm pivots about a vertical axis and a horizontal axis. The weight of the power plant is carried forward the center, whereby a rider on top of the surfboard based body tends to balance the weight of the power plant.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable.[0001]

BACKGROUND—FIELD OF INVENTION

This invention relates to powered personal watercraft, specifically to an improved drive and control system typically for surfboard-based watercraft.

BACKGROUND—DESCRIPTION OF PRIOR ART

Surfboard-based powered personal watercraft have been developed and refined for over three decades. Today these watercraft are of increasing use, but an ideal drive and control system for same has not yet been provided. U.S. Pat. No. 4,274,347 to Dawson (1981) discloses a power operated surfboard with a gasoline engine and drive system mounted to the rear of the craft. A watercraft based on Dawson's design, tradename Surrlet, has been commercially produced and available for many years. The Surflet craft is considered a benchmark craft in the field and realized many inherent advantages to the surfboard-based powered watercraft. A refined Surftet craft is still commercially available, but it's design and function have kept it obscure relative to the personal watercraft market.

U.S. Pat. No. 5,582,529 to Montgomery (1996) discloses a high performance motorized water ski and a craft based on this design, tradename Powerski Jetboard, is soon to be commercially available. Montgomery's design realized many improvements on the Surfjet design and is considered the current benchmark in the field. The PowerSki Jetboard provides a relatively beautiful, high performance, high utility surfboard-based watercraft and the craft's improvements on the SurfJet are well documented and obvious. Montgomery's design still fails to realize many of the handling and overall performance advantages inherent to the surfboard-based hull it utilizes.

Both the SurfJet and the PowerSki Jetboard designs utilize a drive design with the power-plant and drive located to the rear of their hull longitudinal center. This results in a watercraft with an unladen center of gravity that is also behind the hull longitudinal center. Relative to intended and true craft use, these rearward center of gravity designs are inherently unstable and performance limited and also interfere with rider/craft/water interface. This weight rear design also harms the the overall effciency and planing ability, or rising partially out of and gliding across the water ability, of these craft when ridden.

The inherent instability of both the SurfJet and the PowerSki Jetboard is best demonstrated as these watercraft become airborne off a jump or wave on the surface of the water. Such jumping is a much desired aspect of many water sports including windsurfing, surfing, wakeboarding, and personal watercraft riding, often called Jet skiing. Both prior art craft provide a relatively light weight-loading, or ratio of craft relative lower surface area to net craft weight. Both craft provide a lighter loading, or more area-less weight, than a comparisson JetSki type watercraft. This lighter weight-loading provides for a craft with potentially higher overall efficiency and with the ability to jump higher off an equal wave, with other relevant factors being equal, than many typical powered personal watercraft. However due to their rearward weight bias, when the SurfJet and the PowerSki Jetboard are typically launched off a jump of more than a few feet, the rear of the craft will fall away and separate from the rider. It has been demonstrated that when jumped to sufficent height both craft will typically completely seperate from their rider and actually land into the water rear first. These prior art craft cannot provide for rider controlled landings of the higher jumps of which they are capable.

In the sport of both wavesurfing and windsurfing a rider typically rides and maneuvers the craft while on the relatively flat upper surface, or deck, of the hull. In both sports said rider is most typically positioned towards the rear of the craft on the deck for optimal manuverability and control. This is illustrated in placement of mats, bindings, and other control enhancement devices on this rear deck area of both surfboards and windsurfboards. The Dawson and Montgomery designs both place the craft engine within the rear longitudinal half of their hulls. This arrangement does not provide for a rear deck as relatively flat as possible, nor a craft cross- section at the rear as relatively thin as possible, both critical to optimal rider/craft/water interface.

Virtually all floating boat, surfboard, and personal watercraft hulls plane across and move thru the water most efficently when relatively flat or parallel to the water surface. The SurfJet and the Powerski Jetboard are sensitive to rider weight distribution due to their relative small size and water displacement. Both of these craft, as in surfboards, provide approximately equal shape, upper and lower hull surface area, and displacement of their hulls relative to their front and rear halves. The SurfJet and PowerSki Jetboard designs create a preponderance of weight at the crafts rear by placing the weight of both engine and drive, and typical rider to the rear. This preponderance of weight to the rear tends to tip these craft up in the front and push the rear down when they are floating in water. This tendancy away from the optimal flat and parellel hull to water surface relation introduces drag and decreases overall efficiency. The SurfJet and PowerSki Jetboard do not provide optimal weight distribution across their hulls for craft planing, overall efficiency, or overall effectiveness.

The SurfJet and PowerSki Jetboard designs do not provide a mechanical means to steer the craft and are designed to turn via rider weight change only, as in surfing and windsurfing. This is impracticable in a powered personal watercraft due to the weight and size of a craft necessary to carry a typical rider. Both the SurfJet and Powerski Jetboard provide a fixed water jet at their rear which sends a high velocity stream of water from the rear of the craft. This high velocity stream provides not only thrust, but also directional stability to the craft. Only when in the water can this directional stability overcome the instability inherent in the SurfJet and PowerSki Jetboard rearward center of gravity designs. The high directional stability of these designs when underway in the water, combined with the extra weight necessary to power the craft equals a craft that cannot be effectively maneuvered or ridden in a way that emulates surfing or even Jet Skiing. This creates a ride that is in effect too stable and not challenging. To a proficent rider, the SurfJet and moreso the PowerSki Jetboard can offer a ride that is exciting based on speed only and, without benefit of a mechanical steering system, neither can fully utilize the high performance handling characteristics of the surfboard-based hulls they utilize. The limited performance generally, and the unusually high rider effort required for high craft performance specifically, have kept these watercraft from widespread use. These two prior art surfboard-based watercraft cannot provide an optimal surfboard-like ride or handling.

SUMMARY

In accordance with the present invention a drive and control system for watercraft comprises a framework, typically integrated into a surfboard-based hull,that supports a powerplant and water jet drive systems in watertight compartments as needed. This drive and control system features a steering arm mounted pivotally on a vertical axis steering shaft, to control steering input, and horizontally hinged at it's base to allow said arm to adjust to position of rider. This steering arm is also provided with two handles and means to control powerplant and waterjet systems at the arms upper end.

Objects and Advantages Accordingly, besides the objects and advantages of the prior art craft described in the above patents, several objects and advantages of the present invention are;

(a) to provide a watercraft of highest possible performance, overall efficiency, and overall utility;

(b) to provide a watercraft which operates cleanly and quietly, with least possible vehicle emissions;

(c) to provide a watercraft which is exciting, challenging, and requiring skill to ride and operate;

(d) to provide a watercraft that is relatively stable and easy for beginning riders to learn to ride and operate;

(e) to provide a watercraft which is capable of levels of performance and handling revolutionary to prior art craft of the field;

(f) to provide a watercraft whose unladen center of gravity is located forward of craft longitudinal center;

(g) to provide a watercraft which features a mechanical steering system designed for use by rider typically standing side stance to longitudinal axis of craft on the rear deck section;

(h) to provide a watercraft which provides a means to control all pertinent drive and control systems from the upper steering arm, near steering arm handles;

(i) to provide a watercraft whose integrated drive and control system, with minimal modification, is adaptable to the widest variety of watercraft hull types, including existing surfboard and windsurfboard hulls;

(j) to provide a watercraft which utilizes many 'off the shelf or commercially produced and available parts and assemblies;

(k) to provide a watercraft which can utilize the greatest amount of specialty performance or aftermarket parts for the craft's systems;

(l) to provide a watercraft whose electric power system utilizes existing parts and technology, yet remains adapable to improved parts and technology;

(m) to provide a watercraft whose additional embodiment internal combustion enginepower system utilizes existing parts and technology, yet remains adaptable to improved parts and technology;

(n) to provide a watercraft which utilizes standard ‘JetSki’ watercraft type water jet pump and associated drive and control systems;

(o) to provide a watercraft whose overall weight is as low as possible;

(p) to provide a watercraft which operates as reliably as possible;

(q) to provide a watercraft which is well suited for both private ownership and pleasure craft rental markets;

(r) to provide a watercraft whose electric power system features a quick change battery pack exchange system;

(s) to provide a watercraft whose additional embodiment internal combustion engine power system features electric start and other features common to powered personal watercraft.

Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings. [0030]

DRAWING FIGURES

FIG. 1 shows a side view of the drive and control system for watercraft in accordance with the present invention illustrating the manner in which the craft is used or ridden. [0031]
FIG. 2 shows a top view of the basic framework of the drive and control system. [0032]
FIG. 3 shows a bottom view of the basic framework of the drive and control system. [0033]
FIG. 4 shows a side view of the basic framework of the drive and control system. [0034]
FIG. 5 shows a top view of drive and control system integrated into a surfboard-based hull and executing a left turn. [0035]
FIG. 6 shows a top view of drive and control system integrated into a surfboard-based hull and executing a right turn. [0036]
FIG [0037] 7 shows a side view of a general representation of drive and control system illustrating relative center of gravity.
FIG [0038] 8 shows a bottom view of a general representation of drive and control system illustrating water jet pump and controls.
FIG [0039] 9 shows a top view of preferred embodiment of the present invention.
FIG [0040] 10 shows a side view of the preferred embodiment of the present invention.
FIG [0041] 11 shows a bottom view of the preferred embodiment of the present invention.
FIG [0042] 12 shows a top view of the framework of additional embodiment of the present invention.
FIG [0043] 13 shows a bottom view of the framework of additional embodiment of the present
FIG [0044] 14 shows a top view of additional embodiment of the present invention.
FIG [0045] 15 shows a side view of additional embodiment of the present invention.

FIG 16 shows a bottom view of additonal embodiment of the present invention.



Reference Numerals In Drawings

	20 framework	28 main cover hinges
	21 fasteners	29 main compartment
	22 front compartment	30 main compartment cover
	23 front compartment cover	31 main cover latches
	24 steering reinforcement	32 middle compartment
	25 steering mounts	33 middle compartment cover
	26 steering system passage	34 filled section
	27 control line passage	35 motor mount bulkhead
	36 rear compartment	68 pump driveshaft bearing
	37 rear compartment cover	69 pump driveshaft
	38 bearing mount bulkhead	70 driveshaft waterseal
	39 waterseal mount bulkhead	71 nozzle trim
	40 driveshaft passage	72 nozzle trim pivot
	41 bottom hollow section	73 main shut-off contactor
	42 grate mounts	74 shut-off knob
	43 pump reinforcement	75 shut-off key
	44 pump mounts	76 shut-off actuator seal
	45 steering shaft	77 shut-off actuator
	46 steering base	78 throttle potbox compartment
	47 steering head unit	79 potbox compartment cover
	48 lower steering arm	80 throttle potbox
	49 steering arm hinge	81 potbox linkage
	50 upper steering arm	82 throttle linkage passage
	51 lower handle	83 battery tray
	52 upper handle	84 battery
	53 pump over	85 tray handle
	54 intake grate	86 multi-function area
	55 surfboard-based hull	87 cooling water outlet
	56 steering linkage	88 cooling aparatus
	57 water jet pump	89 motor controller
	58 steering nozzle pivot	90 motor
	59 steering nozzle	91 bilge pickup
	60 speed control linkage	92 contactor support
	61 trigger speed control	93 control line seal
	62 trim control	94 throttle potbox wires
	63 trim linkage	95 bilge line
	64 general powerplant	96 cooling water line
	65 general output shaft	97 pump cooling water outlet
	66 coupling hub	98 pump bilge line inlet
	67 flexible coupling	99 engine-powered framework
	100 reserve fuel cell	116 engine
	101 fuel cell filler cap	117 exhaust manifold
	102 reserve cell rear bulkhead	118 waste water line
	103 fuel valve	119 exhaust coupling
	104 cell main connector	120 engine output hub
	105 vent main connector	121 upper driveshaft
	106 air intake	122 upper driveshaft bearing
	107 exhaust pipe	123 starter battery
	108 exhaust pipe jacket	124 electric starter motor
	109 fuel feed	125 starter control lines
	110 main cell front bulkhead	126 carburetor
	111 main fuel cell	127 engine kill lines
	112 tank pickup	128 throttle linkage
	113 upper dnveshaft passage	129 starter switch
	114 main cell rear bulkhead	130 dead-man kill switch
	115 cooling manifold	131 kill switch wrist lanyard

DESCRIPTION

FIGS. 1-11—Preferred Embodiment

A preferred embodiment of the drive and control system for watercraft of the present invention is illustrated in FIG. 1 (side view) as it may be used by a rear positioned standing rider. Refering to FIG. 1, the drive and control system is integrated into a surfboard-based [0047] hull 55 and the operator is holding handle 52 provided on steering arm 50. The placement of system controls, typically at craft operator handle(s), as well as basic craft operation are well known to prior art craft of the field and will therefore not be discussed in detail here.
Referring now to FIGS. [0048] 2-4 a framework of the preferred embodiment of the present invention 20 is shown in top, bottom, and side views. This framework provides a means of structual support for the drive and control system components and can be built into the hull of a craft specifically designed for this drive and control system. This framework can also be adapted to many existing watercraft hulls with minimal framework and watercraft modification. This framework is intended to be made as relatively small and light as possible, to allow its integration into a wide variety of watercraft types, yet still allow enough room to comfortably mount and house system components. This framework can be easily constructed of thin wood, epoxy-type glues, and fiberglass cloth. This framework can be constructed on its own and ‘dropped-in’ to an existing watercraft hull, or built into a hull constructed around the basic framework. Additionally this framework can be easily integrated into more advanced and easily mass-produced hollow shell hull designs and materials used extensively in JetSki type watercraft.
[0049] Cover fasteners 21 are typically of screw-down or turn and lock type and provided at the corners of the covers. These fasteners are to be marine appropriate and made unobtrusive to the upper deck surface of the craft. Waterproof front compartment 22 is covered with front compartment cover 23 to provide watersealing at the top of the front compartment. Cover 23, as with all compartment covers described below, allows service access to compartments and also serves as the upper deck surface of the craft which typically supports a standing operator. To provide high strength and thinness in this part, the covers are typically constructed primarily of fiberglass. A steering reinforcement 24 is provided which typically spans the longitudinal framework members near the top of the framework This reinforcement provides a reinforced mounting or support for the systems steering mechanism. Steering mounts 25 are provided in the steering reinforcement and are typically permanently mounted nut type and placed around steering system passage 26. A control line passage 27 is provided to the rear of the steering system passage and these passages allow a waterproof passage of craft control lines and steering shaft from outside the hull to inside the waterproof compartments of the framework.
Main cover hinges [0050] 28 typically consist of a female receptor in the framework at the top front of main compartment 29 and a male post or lip on the front of main compartment cover 30 The main cover hinges, together with the rear positioned main cover latches 31, provide a means to quickly and repeatedly open and remove, and replace and re-waterseal the main compartment cover. As with cover fasteners, the cover hinges and latches are typically countersunk into the framework to not obtrude on the upper deck surface. Main compartment 29 is forward of typical craft hull longitudinal center to provide a unladen craft center of gravity also forward of craft longitudinal center. It is an object of the present invention that drive and control system components be placed so as to provide an optimal craft center of gravity placement within the front half of the craft. A middle compartment 32 is covered by middle compartment cover 33 and defined at the front by the main compartment. A filled section 34 provides an area for components and component lines to run from the waterproof compartments of the framework to the rear pump area. This filled area is typically filled with lightweight closed cell foam to permanently locate the component and component lines that are within this area.
A [0051] motor mount bulkhead 35 divides middle compartment 32 and, rear compartment 36, which is covered with rear compartment cover 37. A bearing mount 38 is provided within the rear compartment and waterseal mount bulkhead 39 defines the rear of the compartment. Hatching is used in these drawings to illustrate hollow sections of the top and bottom of the framework. Driveshaft passage 40 connects the rear compartment to the bottom hollow section 41 and to the front of this section are intake mounts 42. The pump reinforcement 43 spans the longitudinal framework and provides pump mounts 44 and typically defines a top-rear section of the bottom hollow section.
A steering [0052] shaft 45 is held in steering base 46 which serves as both bearing and mounting for the shaft. A steering head unit 47 is connected to the top of the shaft and lower steering arm 48 to the bottom of the shaft. The steering head unit provides for steering arm hinge 49 which connects upper steering arm 50 to the head unit. Lower handle 51 and upper handle 52 are at the upper end of the upper steering arm. A pump cover 53 and integrated intake grate 54 effectively cover bottom hollow section 41. The pump cover and intake grate, and many more parts, are easily adaptable from similar parts common to JetSki type watercraft.
FIGS. [0053] 5-8 show a simple and basic illustration of the present invention to better illustrate the major functions of the invention. A surfboard-based hull 55 is typically constructed of fiber-glass over a foam core. The large displacement and size as well as the handling characteristics and refined hydrodynamics of windsurfboard hulls make them well suited for integration with the drive and control system of the present invention. Steering linkage 56 links lower steering arm 48 to water jet pump 57, specifically to steering nozzle 59 which pivots on steering nozzle pivot 58. FIGS. 5 and 6 illustrate the different positions of the upper and lower steering arms, steering linkage, and steering nozzle when executing a left and right turn respectively. The pivoting steering arm allows a rider to effectively control the steering of the craft while in a side stance at the rear of the craft, the most natural surfing position. The crafts two handles also provide easy two handed opperation and primary and secondary placement of drive and control system controls. Referring to FIG. 7, a speed control linkage 60 links trigger speed control 61 to general powerplant 64 to provide a means to control craft speed from upper handle 52. A trim control 62 typically of locking twist-grip type connects to trim linkage 63 and provides a means to control craft trim from lower handle 51. A general output shaft 65 transfers drive power to a flexible coupling 67 via coupling hub 66 and on to pump driveshaft 69. The pump driveshaft is supported by support bearing 68 and runs through driveshaft waterseal 70. The driveshaft waterseal mounts to waterseal bulkhead 39 and water seals the waterproof component compartments of the framework from the flooded driveshaft passage 40 and bottom hollow section 41 as the spinning driveshaft passes through these areas. A nozzle trim 71 pivots on nozzle trim pivot 72 and is actuated by trim control 62 via trim linkage 63. A water jet trim control system is provided on many current JetSki watercraft but neither prior art craft of the field described above utilize this advantageous system. FIG. 7 also illustrates the crafts forward of longitudinal center center of gravity and the movement of upper steering arm 50 to adjust to rider position. FIG. 8 shows a bottom view of the basic water jet pump drive and controls
FIGS. 9, 10, and [0054] 11 show a top, side, and bottom view respectively of the prefered electric motor-based embodiment of the present invention. This electric motor-based power system realizes many advantages including no vehicle emmissons, almost silent craft operation, use of existing technology, added safety, and high performance. This power system is used extensively in the relatively new field of high performance electric go-karts. These systems are designed for high proformance, ease of use, reliability, cost effectiveness etc., and are well suited for use in the drive and control system of the present invention. Because both the electric motor-based power system shown here and the engine-based power system of the additional embodiment are common, many of the working components of each have been ommited for clarity. A main shut-off contactor 73 disconnects main power when shut-off knob 74 is depressed. Shut-off key 75 provides a means to lockout system power. Front compartment cover 23 provides shut-off actuator seal 76 which supports and seals shut-off actuator 77. When the cover is in place this actuator provides a waterproof and unobtrusive to the upper deck means to actuate shut-off contactor 73. A throttle potbox compartment 78 is provided in upper steering arm 50 and covered with potbox compartment cover 79. This compartment provides a waterproof housing for throttle potbox 80, or potentiometer, which is actuated by trigger speed control 61 via throttle potbox linkage 81 which utilizes throttle linkage passage 82. A battery tray 83 holds three battery 84 sets and is provided with tray handle 85 to allow easy removal and replacement of battery sets. Battery 84 is shown as small size sealed deep cycle 12 volt battery for a high performance system but system voltages, battery size, capacity, output, and battery sets can be varied to meet a wide variety of performance parameters. A multi-function area 86 is provided between the illustrated battery trays and serves as control line and power line passage as well as battery quick disconnect plug (not shown) storage. A water cooling outlet 87 is provided for expelling spent cooling water from cooling apparatus 88 from the craft hull. The cooling apparatus is a means to cool heat sensitive electrical and mechanical components including motor controller 89, motor 90, and support bearing 68, although for clarity only the motor controller is shown as serviced by cooling aparatus. A bilge pickup 91 is provided with a one-way flow control valve and is typically located within rear compartment 36 and picks up unwanted water that penetrates the waterproof compartments of the framework. The separate compartments are provided with a means to drain unwanted water towards the bilge pickup for expullsion from the hull.
Referring now to FIG. 10 [0055] contactor support 92 locates the main shut-off contactor 73 in front compartment 22. A control line seal 93 waterseals lines from the upper steering arm 50, including throttle potbox wires 94, as they pass into front compartment 22. Bilge line 95 feeds water from bilge pickup 91 to pump bilge line inlet 98. Cooling line 96 feeds water from pump cooling water outlet 97 to cooling aparatus 88. Both bilge line 95 and cooling water line 96 are typically built permanently into the framework to provide line outlet fittings close to the component the line serves. A section of flexible removable hose can connect these outlet fittings to the components served allowing easy component service.

FIGS. 12-16—Additional Embodiment

FIGS. 12 and 13 show a top and side view, respectively, of the basic framework of an additional internal combustion engine-based power system embodiment of the drive and control system of the present invention. FIG. 12 shows an engine powered [0056] framework 99 very similar to the preferred embodiment electric drive-based framework. A reserve fuel cell 100 is typically constructed of fiberglass and built into a section of front compartment 22 and capped with fuel cell filler cap 101. The reserve tank is defined at its rear by reserve cell rear bulkhead 102. A fuel valve 103 is typically provided on reinforcement 24 and controls fuel flow through cell main connector line 104. A cell vent connector 105 connects to the top of reserve fuel cell 100. Air intake 106 is typically provided on main compartment cover 30 and provides waterproof combustion air intake. Exhaust pipe 107 and exhaust jacket 108 are built into the framework and typically run from main compartment 29 to bottom hollow section 41. The exhaust pipe provides a one-way flow valve to prevent water intake, and the exhaust jacket serves as heat insulation for the exhaust pipe as the pipe passes through the framework The exhaust jacket may be constructed of insulating material or designed as a water fed cooling jacket as illustrated.
A [0057] fuel feed 109 fitting is provided on main cell front bulkhead 110 which defines the front of main fuel cell 111. The main fuel cell is of similar construction to reserve fuel cell 100 and features a tank pickup 112 which is flexible, serviceable, and provides for a fuel filter. The main fuel cell is designed to place the majority of fuel weight, which can vary as fuel is burned, to a central rearward position most neutral to craft handling. A upper driveshaft passage 113 is provided through the main fuel cell which is defined at the rear by main cell rear bulkhead 114. Referring now to FIGS. 14, 15, and 16 which show a top, side, and bottom view, respectively, of engine-based additional embodiment of the drive and control system of the present invention integrated into a surfboard-based hull 55. A cooling manifold 115 distributes cooling water from pump cooling water outlet 97 to engine 116. The engine is shown as a horizontally opposed four cylinder four-stroke engine with dual exhaust as this design is well suited for use in the drive and control system of the present invention. Many exsisting engine types are easily adapted to this drive and control system by modifing size and shape of waterproof component compartments, deleting one exhaust pipe, providing for an engine pull-starter, etc.. It is an object of the present invention to provide a high performance gasoline engine power system that is as relatively clean, quiet, and efficient in operation as possible. An exhaust manifold 117 gathers engine exhaust and is linked to exhaust pipe 107 with a flexible exhaust coupling 119. This coupling allows for engine vibration and is common to JetSki type watercraft and may be water cooled by engine waste water line 118. The waste water line can also feed cooling water to the exhaust pipe jacket 108 and other heat sensitive parts and systems. An engine output hub 120 is typically splined to accecpt a ‘floating’ upper driveshaft 121 which transfers power to flexible coupling 67 which sends it to pump driveshaft 69 and ultimately to the water jet pump 57 impeller to produce thrust. An upper driveshaft bearing 122 is mounted to main cell rear bulkhead 114 and supports the upper driveshaft. Referring now to FIG. 15 a engine starter battery 123 is provided to power electric starter motor 124 whose starter control lines 125 typically run to upper steering arm 50 and to starter switch 129 to operator to start the craft's engine from the upper steering arm near handle 51. A carburetor 126 is shown as actuated by trigger speed control 61 via throttle linkage 128 to provide engine speed control. Engine kill lines 127 typically run from engine ignition to dead-man kill switch 130 which disables the ignition in the absence of kill switch wrist lanyard 131 or by push-button on the switch. FIG. 16 shows a bottom view of the above additional embodiment of the present invention. For clarity, FIGS. 12-16 omit working parts of the drive and control system that are common and well-known such as fuel lines, vibration isolating engine mounts, and engine electrical systems.

Advantages

From the description above, a number of advantages of my drive and control system for watercraft become evident; [0058]
(a) A unique steering system allows an operator to effectively steer the craft while remaining balanced in a natural surfing, skateboarding, snowboarding, and wakeboarding sideways stance. [0059]
(b) A forward of craft longitudinal center craft center of gravity provides a craft that is inherently stabe in water and when airborne. [0060]
(c) Because the majority of the craft unladed weight is toward the front of the craft, the rear mounted water jet pump, through its steering nozzle, effectively steers or pushes this weight when turning which provides for a light craft ‘feel’ not provided by prior art craft of the field. [0061]
(d) The steering systems rear mounted directional thrust water jet steering system provides unprecedented levels of craft performance and handling to prior art craft of the field. [0062]
(e) The steering systems allow a rider to ‘snap’ or ‘whip’ the rear of the craft around in a turn, a ‘move’ or manuevuer common to the sports of surfing and JetSkiing but not provided by prior art craft of the field. [0063]
(f) The drive and control system realizes numerous objects and advantages of prior art craft of the field including overall efficiency, ease of use and operation, and utility. [0064]
(g) The intensive commercial promotions of the above described prior art craft of the field suggests a widespread market and use of a high performance craft of this type. [0065]
(h) The use of many proven, refined, and commercially avalilable parts and systems provide reliability, performance, and manufacturing advantages. [0066]
(i) The use of a typical JetSki water jet pump provides a refined and high efficiency water drive system which is critical to craft performance. [0067]
(j) The JetSki water jet pump provides steering and trim controls and water outlet and intake lines. [0068]
(k) The drive and control system of the present invention provides functional systems for all controls and systems of the typical JetSki water jet pump. [0069]
(l) The preferred and additional embodiment of the present invention allow a proficent operator to ‘slide’ the craft across the water, often sideways to the direction of travel, a manuever common to high performance JetSkiing. [0070]
(m) The natural balance of craft and rider center of gravity provides for manuevers such as ‘ollies’ or rider induced jumping of the craft above the surface of flat water through ‘weighting’ and ‘un-weighting’ of the standing rider. [0071]
(n) The drive and control systems weight forward design provides controlled and gentle landings of relatively very high and far craft jumps. [0072]
(o) The revolutionary advances in craft performance and handling provided by the drive and control system allow a new performance envelope, similar to surfing and JetSkiing, to be explored by the rider of a craft based on this design. [0073]
(p) The preferred electric motor-based embodiment of the present invention provides a craft that is virtually silent and non-polluting in operation. [0074]
(q) The preferred electric motor-based embodiment of the present invention provides a craft that can be utilized in many eco-sensitive environments where the use of engine-based craft are increasingly restricted. [0075]

Operation—FIG. 1

The basic operation of the preferred and additional embodiment of the drive and control system of the present invention is similar to the operation of the prior art craft of the field, the SurfJet and the PowerSki Jetboard. The flexible cable or rope style handles of these craft are replaced with a piviotally mounted and hinged rigid [0076] upper steering arm 50 of the present invention. The steering arm 50 of the present invention is provided with two handles and the upper handle 52 is the primary operator handle and similar in function to the handle systems of the Surrlet and PowerSki Jetboard. As in the Surfjet and PowerSki Jetboard, an operator of the present invention controls speed and engine kill function from this upper handle. The present invention additionally provides steering control through side to side movement of the upper handle 52, and water jet pump trim control 62 on the secondary lower handle 51. The additional engine-based embodiment of the present invention also provides engine starter switch 129 near lower handle 51 and dead-man kill switch 130 near upper handle 52. Kill switch wrist lanyard 131 is common to JetSki watercraft and actuates kill switch 130 when the craft and operator separate. The drive and control system for watercraft of the present invention is designed to be a self-contained unit adaptable to many watercraft hull types. FIG. 1 illustrates the additional engine-based embodiment of the present invention integrated into a surfboard-based hull 55 as it may be typically used or ridden. To steer the craft the rider typically moves upper handle 52 and/or lower handle 51 to the left to execute a right turn shown in FIG. 6, and to the right to execute a left turn shown in FIG. 5. The rider typically moves upper handle 52 with one forward hand while standing side-stance on the rear deck of the craft shown in FIG. 1.
FIG. 7 shows how the [0077] upper steering arm 50 pivots on steering arm hinge 49 to allow the rider to swing the arm and handles from off the deck to past the hinge and toward the front of the craft. The function and use of the majority of the parts and systems of the drive and power systems of the present invention are common and well-known and will not be discussed in detail here.

Conclusion, Ramifications, and Scope

Accordingly, the reader will see that the drive and control system for watercraft of this invention can be used to closely approximate the performance and handling of surfboard-based craft powered, by waves and wind, in a self-powered watercraft. In addition, the electric motor-based embodiment of this invention provides a high performance craft that is clean, quiet, reliable, and easy to use and manufacture. The additional engine-based embodiment provides a craft of highest proformance, ease of use, and utilization of existing technology and parts. Furthermore, the drive and control system for watercraft has the additional advantages in that [0078]
it permits for both an electric-motor based and a engine-based embodiment of the drive and control system which predominantly use existing technology and parts; [0079]
it permits a self-contained and waterproof drive and control system easily adapted to a wide variety of existing as well as specificity designed watercraft hull types; [0080]
it allows for a surfboard-based craft with a steering system designed for use by a rider in the natural surfing side stance and typical rear standing position on the craft; [0081]
it provides a craft that is safe to both rider(s), and swimmers or bathers; [0082]
it provides a craft more efficient and easier to transport and use than the majority of personal watercraft currently available; [0083]
it provides a craft capable of performance, handling, and enjoyment by both rider and spectator that is revolutionary to the field of personal watercraft. [0084]
it provides a craft whose revolutionary capabilities allow it to gain the wide-spread use and manufacture not provided by prior art surfboard-based powered watercraft of the field. [0085]
While my above description contains many specificities, these should not be construed as limitations on the scope of the invention, but rather as an exemplification of a preferred and additional embodiment thereof. Many other variations based on this invention are possible. For example, the drive and control system can be integrated into a variety of watercraft hulls including canoes, lightweight inflatable pontoon boat with seat(s), or ‘catarafts’, inflatable and standard construction boat hulls, JetSki type watercraft, etc. [0086]
Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the following claims and their legal equivalents. Additionally, this document is in reference to U.S. Patent and Trademark Disclosure Documents 364072 to Burnham ( 1994 ), 413979 to Burnham ( 1997 ), and 445466 to Burnham ( 1998 ). [0087]

Claims

1. A watercraft, comprising:

(A) a surfboard-based hull;

(B) a water jet pump in communication with a pivoting steering nozzle;

(C) a steering shaft carried by the surfboard-based body, the steering shaft linked to the steering nozzle by a steering linkage, whereby rotation of the steering shaft pivots the steering nozzle; and

(D) a steering arm, having a lower portion in communication with the steering shaft and an upper portion connected to at least one handle.