Paddleboard and process

A paddleboard (10) comprising a right board (12) slidingly connected to a left board (14). At least one interlocking sliding element is connected to the right board 12, and at least one interlocking sliding element is connected to the left board 14. Right board (12) and left board (14) are slidable longitudinally with respect to one another only within the plane of paddleboard (10), and parallel to the long axis of paddleboard (10). Utilizing a user's legs and feet to slide right board (12) and left board (14) longitudinally causes a propulsion system to propel paddleboard (10) over the water. A suitable propulsion system comprises pivoting paddles (16) or flaps (40) mounted under right board (12) and under left board (14).

BACKGROUND

1. Field of Invention

This invention relates to human powered watercraft, and more particularly, to surfboards, paddleboards.

2. Description of Prior Art

Currently paddleboards are propelled on flat water by use of a handheld paddle or by direct hand-paddling from a prone or kneeling position. They have a simple design, and are readily portable.

Lifeguards have recently come to consider the stand up paddleboard as one of their most critical pieces of equipment. A first reason is that the speed of a stand-up paddleboard is greater than hand-paddling prone or kneeling on a surfboard. A second reason is the ability to visually survey an area of water that is much greater from the standing position than from a prone position. On heavy surf days, lifeguards now frequently stay out on the water patrolling from the paddleboard. A third reason is that paddleboard portability and deployment speed is comparable to surfboards. If, however, paddleboards could be even greater speed, their utility would be further enhanced.

The art shows many human powered watercraft designs. However, no prior designs are as readily portable as a paddleboard. Portability is especially important for rescue response time, but is also important for any user. Prior designs are large and heavy. They have parts that move independently in multiple planes, and that cannot readily be locked to form a unitary object for transport or use. They also do not readily fit onto popular roof racks, as do paddleboards. These issues make them awkward and time-consuming to transport.

Prior designs are relatively complex. Many have an excessive number of parts, and are generally costly to manufacture. Further, some require user assembly prior to the first use. Some require assembly and disassembly for transportation.

With prior designs, the rider is unable to position the feet in a preferred or natural paddleboard stance. The watercraft has limitations as to the number of available positions and stances. This is limiting for the rider, and he/she cannot vary the stance in response to constantly changing water conditions. Prior designs also do not permit a rider to use uniform, directional cross-country skiing striding mechanics required for powerful, efficient strokes. Further, many actually require substantial shifting of body weight during strokes, such as shifting the weight from right to left, or from fore to aft.

Many designs specify retentive bindings or foot wells to retain the feet. This foot retention is required to counter instability on the water that is inherent with the design. Bindings or foot wells are inconvenient, and increase the chance of injury to the rider's foot, ankle, or leg when the rider looses balance.

Prior designs are difficult to remount in the event of the rider falling off or capsizing the watercraft. The right and left halves of the craft are relatively free to pitch, yaw, and roll independently of each other. The movement of the halves is not limited to movement that is only within the horizontal plane of the watercraft. Further, the movement of the halves is not restricted to movement that is only along the long axis of the watercraft. Remounting is difficult when the right and left halves of the watercraft are not securely connected together to limit movement. The leverage required to pull the rider's body onto a freely moveable half of the craft is unusually difficult. If the watercraft utilizes a foot well or bindings, then the rider insert his/her feet into the bindings while attempting to balance on the freely moving halves.

Most prior watercraft are inherently unstable on the water. Many have right and left halves that are free to move in two, or all three, planes. The right and left halves are generally free to independently pitch, yaw, and roll. Even on calm water, the rider's balance must be continually shifted to compensate for the independent movement of the parts. The balancing issue is exaggerated on rougher water.

This shifting requires continual and substantial balancing on the part of the rider. Attention, balance, and strength are required just to keep the right and left halves in proximity, and directed forward. Substantial concentration and coordination are required to use the craft. For the recreational rider, casual use of the craft feels more like work than play. The instability has the overall effect of detracts from permitting the rider to use smooth, powerful strides to propel the craft. The shifting of balance makes forward progress inefficient, and increases the chance falling.

Prior designs do not substantially glide over the water surface as quickly and easily as a paddleboard, but rather plow through the water generating greater water resistance. This greater water resistance, coupled with the inability to use a powerful striding motion, causes prior craft to move slowly through the water. The water speed of the craft is slow. It is nearly impossible to catch a wave with a cumbersome watercraft. A slowly moving watercraft is ineffective for rescue operations, and impedes athletic and recreational riders.

Prior designs are very specialized. They are for use in a very specific manner only, and lack functional flexibility. Generally they do not have alternate uses, and especially alternate and complimentary uses that are well established.

The above human-powered watercraft suffer from a number of disadvantages:(a) Paddleboard human propulsion comprises hand-paddling prone or using a handheld paddle(b) Restricts a rider's stance(c) Is unstable and requires substantial balancing(d) Requires substantial concentration and coordination to use(e) Riders have difficulty moving the halves with a full force stride(f) Plows through the water rather than gliding over the water(g) Does not have a rapid top water speed(h) Substantial difficulty surfing a wave with the craft(i) Difficulty remounting the craft(j) Manner of use is restricted, and lacks complimentary uses(k) Is heavy, large, or awkward in transport(l) Requires assembly for use

SUMMARY

The present invention is a paddleboard that comprises separated right and left halves called the right board and the left board. The right board is slidingly connected to a left board. The right and left boards are slidable longitudinally with respect to one another within the horizontal plane of the paddleboard. The right and left boards are always aligned in the plane of the paddleboard. Further, the boards move only in a direction that is parallel to the long axis of the paddleboard.

The lateral distance between the boards is minimal, and is fixed by the sliding connection. As such, when a rider standing on the board alternately moves his/her legs and feet fore and aft in a striding motion, the right and left boards are caused to likewise move fore and aft via the sliding connection. The right and left boards have a plurality of paddles connected to the bottom surface to function as a propulsion means. The paddles are hinge-mounted so they can pivot as the board moves fore or aft.

The hinges are configured so that moving a board aft over the water causes each paddle to move down and away from the board to a deployed position. The deployed position is approximately vertical, and perpendicular to the plane of the board. The rotation of each paddle is limited so that the paddle rotation is stopped when the paddle is vertical by a stop means. The deployed paddle causes substantial drag to the board moving aft. A multiplicity of deployed paddles maximizes water drag for the board as the board moves backward over the water.

Conversely, moving a board fore causes each paddle to readily rotate aft on the hinge to a non-deployed position. In the non-deployed position, the paddle is approximately horizontal and parallel to the plane of the board. As such, the board easily glides forward over the water surface with minimal drag.

When the rider uses an efficient striding motion similar to cross-country skiing, the right and left boards alternately resist moving aft over the water, then readily glide fore over the water. The legs and feet are the primary force of propulsion for the paddleboard. As such, the paddleboard makes rapid headway, gliding over the water.

In another aspect, the process of the present invention comprises the steps of: utilizing a rider's legs and feet to alternately move a slidingly connected right board and a left board fore and aft in a direction that is substantially parallel to the longitudinal axis of a paddleboard, wherein the right board and the left board move only within the plane of the paddleboard, wherein the distance between the right board and left board is minimal and fixed, and wherein the alternating fore and aft movements of the right board and the left board powers a water propulsion means to cause the paddleboard to efficiently and rapidly glide forward over the water.

OBJECTS AND ADVANTAGES

It is an object of the present invention to make a human-powered paddleboard that:(a) utilizes human propulsion means other than a handheld paddle or hand-paddling(b) utilizes a rider's feet and legs to move right and left halves of the paddleboard(c) glides over the water faster than standard paddleboards(d) is usable in the same manner as standard paddleboards(e) is useful for surfing(f) facilitates forward-directed, and full-force, striding(g) permits substantial range of stances(h) permits rapid variation of stance(i) is stable on the water(j) has ease of use(k) may be rapidly remounted(l) is fun for recreational users(m) has established alternative uses(n) is generally as portable as standard paddleboards(o) does not require assembly for use

Further objects and advantages are to provide a paddleboard that has improved water rescue capabilities when compared to standard paddleboards. Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings.

DESCRIPTION

According to one aspect, the invention provides a paddleboard that is longitudinally separated down the center to form a right board and a left board. The right and left boards are slidingly connected, wherein the right and left boards are slidable longitudinally with respect to one another within the plane of the paddleboard.

As such, when a rider standing on the board alternately moves his/her legs and feet fore and aft in a striding motion, the right and left boards are caused to move fore and aft with the feet via the sliding connection. Alternately sliding the right and left boards longitudinally causes a propulsion means to propel the paddleboard over the water.

FIG. 1shows a paddleboard10that is longitudinally separated down the center to form a right board12and a left board14. Right board12and left board14are slidingly connected, wherein right board12and left board14are slidable longitudinally with respect to one another within the horizontal plane of paddleboard10. However, the lateral distance between right board12and left board14in the horizontal plane of paddleboard10is fixed by the sliding connection.

It is preferred that the lateral fixed distance between right board12and left board14is minimal. As such, the proximal edges of right board12and left board14are parallel. Right board12and left board14have only a small gap between them over their entire lengths in order to permit sliding without increased friction. The lack of a larger gap maximizes the locations the rider may stand on the deck without inadvertently catching the feet between the sliding right board12and left board14. The term “deck” generally collectively includes the deck halves of the upper surfaces of right board12and left board14.

When a rider standing on paddleboard10alternately moves his/her legs and feet fore and aft in a striding motion, right board12and left board14are caused to alternately move fore and aft with the feet via the sliding connection. The striding motion is most similar to cross-country snow skiing. When right board12and left board14move alternately in a reciprocal manner, right board12is moving fore when left board14is moving aft. When the rider reaches the end of his/her stride, he/she reciprocably reverses stride so that right board12moves aft and left board14moves fore.

The sliding connection slides with minimal frictional resistance so as to minimize resistance to the rider's striding movements. Sliding right board12and left board14longitudinally causes a propulsion means to efficiently propel paddleboard10over the water. The force of leg movements is transferred to the propulsion means via right board12and left board14.

The sliding connection limits relative movement of right board12relative to left board14to movement in the horizontal plane. There is substantially no movement permitted in the vertical or transverse planes. Right board12and left board14are always aligned in the plane of the paddleboard. Further, the movement of right board12and left board14within the horizontal plane is limited to longitudinal movement substantially parallel with the longitudinal axis of paddleboard10. Changes in the small lateral separation of right board12and left board14is not permitted.

This ensures that the relative movement between right board12and left board14will be smooth and directional. Right board12and left board14are not free to pitch, yaw, or roll independently of one another. With right board12and left board14securely connected, the pitch, yaw, and roll exhibited by paddleboard10is minimized, and paddleboard10exhibits the same high level of stability as standard paddleboards. The limited, smooth, and directional movement of right board12and left board14is intended to improve the rider's stability and balance on paddleboard10.

While the stability of paddleboard10reduces the risk of capsizing, the directional movement of right board12and left board14also ensures that the rider is able to make smooth, deliberate, and powerful leg strokes. The rider is freed from using muscles and body mass for substantial balancing, and instead can dedicate the muscle activity to propulsion. The muscles are less distracted by balancing when the right board12and left board14are stabilized. The rider is able to focus weight and full muscle force is the forward direction. As such, paddleboard10facilitates forward-directed, and full-force, striding. The limited and directional movement of right board12and left board14improves the rider's stability and balance on paddleboard10, and therefore increases the speed of paddleboard10

On the top deck of paddleboard10, the rider is substantially free to select any stance at any time, and is able to vary the stance for the best advantage in striding power. The deck is generally flat, and permits any foot placement the rider chooses. The stance is not limited to preset locations on paddleboard10. Further, the rider can vary the stance instantly, and in rapid response to quickly changing conditions. The rider is therefore able to maximize balance and striding power by using an ideal and natural stance.

Maximizing striding balance and power ensures a faster response time in a rescue situation. It also ensures an effective workout for the exercising athlete, and ensures fun for the recreational rider.

The selectable stance combined with the overall configuration of paddleboard10also ensures that paddleboard10will possess the substantial stability of standard paddleboards.

The ability to vary the stance on the deck facilitates combining the water propulsion means of paddleboard10with the use of a handheld paddle. The rider can alternate striding with handheld paddling. This facilitates the rider's endurance and speed by alternately using the legs and arms for the primary propulsion. The rider may also handheld paddle while simultaneously striding. Blending handheld paddling with striding can increase the speed, endurance, and range for a rider.

A readily selectable stance also facilitates surfing with paddleboard10. Ocean rescuers routinely practice surfing on standard paddleboards, and are expected to be able handle the standard paddleboard in the waves as part of improving rescue response. Surfing generally requires that the rider is able to shift the feet rapidly to any position on the paddleboard10deck. The ability to select any stance on the fly is crucial to paddleboard10's viability as a surfing paddleboard.

It is preferred that the upper decks of right board12and left board14have foot-gripping, anti-slip, surface textures or materials. Such textures or materials further facilitate stable footing for the rider, similar to surfacing materials found on standard paddleboards.

Foot retention aids may be present on the deck of right board12and left board14. Foot retention aids may be comprised of small ridges, recesses, fore and aft blocks, open foot shells, and so on. Such aids may be secured to the deck in a range of locations that are entirely optional to the rider, such as with Velcro, or other securing means. Alternatively, the deck may be covered with Velcro, and the rider may wear booties or sandals having Velcro pads for engaging the deck. Further, standard foot bindings may be utilized. Foot retention is most appropriate for racers or other competitive riders.

A paddleboard ankle strap is connected to the aft end of right board12. Holes for housing a locking means are shown in the top surface of left board14, wherein the locking means can unlockingly prevent the relative movement of right board12with respect to left board14. A dent-resistant material may be used to surface the nose of right board12and left board14, to enhance collision durability.

Paddleboard10is able to substantially glide over the water surface, as do standard paddleboards of the art. Many other watercraft have substantial draw in the water, and therefore encounter substantial drag as the watercraft plows through the water. Paddleboards and larger surfboards draw minimal water due to a favorable high surface area to low weight ratio. The surface area to low weight ratio of paddleboard10is comparable to paddleboards of the art, and is considered to glide over the water with minimal water resistance. Paddleboard10does not have substantial water draw, and does not plow through the water in a manner that encounters high water resistance.

FIG. 2shows the bottom surface of paddleboard10. Paddles16line the bottom surface of right board12and left board14. Paddles16function as a water propulsion means.

Each paddle16is connected to a hinge18so it can pivot as right board12and left board14alternately move fore or aft. Each paddle16is oriented on the bottom surface of right board12and left board14so that the axis of hinge18is perpendicular to the longitudinal axis of paddleboard10.

Hinges18are configured so that moving right board12forward over the water causes each paddle16on right board12to readily rotate aft on hinge18to a non-deployed position, as shown inFIG. 2. The non-deployed position is approximately parallel to the plane of right board12. For example, the distal end of a first paddle16is rotated up near the proximal end of a second paddle16, and first and second paddles16are approximately horizontal.

Paddle16moves aft with minimal water resistance. In the non-deployed position, paddle16is approximately horizontal and parallel to the plane of right board12. As such, right board12easily glides forward over the water surface with minimal drag. The minimal drag position maximizes the distance right board12slides forward over the water when the rider's leg pushes right board12to fore during a glide stroke.

As right board12is moving fore over the water, left board14is moving aft over the water. As left board14moves aft over the water, the water causes each paddle16to move down and away from left board14to a deployed position, as shown inFIG. 2. As left board14moves backward over the water, the movement of the water against the trailing edges of each paddle16causes the edges to engage the water. When the water engages the trailing distal edge of a paddle16, the paddle16edge readily and automatically rotates the paddle16down and away from left board14, and into the deployed position. Gravity also assists in the deployment rotation of paddles16. The deployed position is approximately vertical, and perpendicular to the plane of left board14. The rotation of each paddle16is limited so that the paddle16rotation is stopped when the paddle16is vertical.

In the vertical position, paddle16is deployed. A deployed paddle16causes substantial drag to left board14moving aft over the water. A multiplicity of deployed paddles16maximize water drag for left board14as left board14moves aft over the water. The water drag minimizes the distance that left board14slides backward over the water when the rider's leg pushes left board14to aft, called the power stroke.

When the rider reaches the end of his/her stride, the rider reverses direction for both legs, and begins to move left board14forward again. Each paddle16drags in the water, but hinge18allows paddle16to readily and automatically rotate back to the non-deployed position approximately parallel with the bottom surface of left board14. Water drag is again minimized, and left board14glides freely over the water in a glide stroke. Simultaneously, the rider begins moving right board12aft in a power stroke. However, a manually operated linkage may be utilized to facilitate the movement of paddles16to the deployed and non-deployed positions.

The distance that right board12or left board14moves to aft over the water on the power stroke is substantially less than the distance that right board12or left board14moves to fore on the glide stroke. This is the case because paddleboard10is moving forward over the water.

During fore and aft movements of right board12and left board14, right board12and left board14each travel the same distance relative to one another, and relative to paddleboard10. However, the water resistance created by paddles16reduces the aft movement of right board12or left board14. Therefore the distance right board12or left board14moves aft over the water is less than the distance right board12or left board14moves relative to one another.

Similarly, during the actual time of a given stroke, the distance right board12or left board14moves fore over the water is less than the distance right board12or left board14moves relative to one another. For example, if right board12moves 1 meter relative to left board14, right board12will glide fore over the water less than 1 meter because left board14has move a small distance aft during the stroke.

When the rider uses a striding motion similar to cross-country skiing, right board12and left board14reciprocably drag aft over the water with high resistance on the power stroke, and easily glide fore over the water on the glide stroke with low water resistance. The striding motion has the overall result of moving paddleboard10efficiently over the water. The rider's legs and feet on the decks of right board12and left board14are the original or primary motive force for the propulsion of paddleboard10. The force of deployed paddles16against the water is a secondary motive force of paddleboard10propulsion.

The efficient propulsion provided by paddles16enable paddleboard10to move over the water at a high rate of speed. The efficient paddle16propulsion and the selectable stance combine to make paddleboard10faster and more efficient than prior paddleboards or other human-powered watercraft. The quickness of paddleboard10enhances performance for rescue, racing, exercise, and recreation.

The fast water speed of paddleboard10also improves the chances of riders catching and surfing waves. Surfers have considerable difficulty achieving sufficient water speed to catch waves. The larger the wave, the greater the difficulty. A rider may rapidly propel paddleboard10into a wave in order to catch the wave by striding on right board12and left board14, and also using a handheld paddle if preferred. The high water speed achievable on paddleboard10improves the chances of catching waves. Once the wave was caught, most riders would discontinue striding.

A further advantage for catching waves, riders can catch waves without having to jump up from a prone hand-paddling position to a standing position during the critical moments just prior to catching the wave. The rapid speed and selectable stance give paddleboard10ideal characteristics for paddleboard surfing. For the purposes of this discussion, a rider is considered to be a person who is actively propelling the paddleboard over the water utilizing a propulsion means such as paddles16, a handheld paddle, or is surfing on a wave with paddleboard10.

Paddles16shown in the non-deployed position are laying approximately parallel to the bottom surface of right board12. More precisely, paddles16lay with distal edges overlapping the adjacent paddle16slightly, similar to roof shingles. Slight overlapping of paddle16edges facilitates deployment of paddles16because the edges are more exposed to the flowing water. The exposed edges of the overlapping paddles16have sufficient drag against flowing water such that the will catch the edge and rotate paddle16into the deployed position when right board12or left board14moves aft.

Multiple paddles16may be tethered together at or near the distal edge, such that if one or more of the paddles fail to deploy during a power stroke, the tether will be pulled into deployment position via the edges of multiple paddles16that are deploying. When the tether is pulled into deployment position, it will tend to pull any occasional lagging paddles16into deployment.

Each paddle16is generally oriented on the bottom surface of right board12and left board14so that the axis of hinge18is perpendicular to the longitudinal axis of paddleboard10. However, it may be found that water flow dynamics permits greater overall water resistance when paddles16are oriented somewhat non-perpendicularly with respect to the longitudinal axis of paddleboard10. Similarly, there may be efficiently gains if any one paddle16in an array of paddles16is not parallel to an adjacent paddle16. Further, efficiency configurations of the paddles16edges may comprises a non-straight edge, or an edge that is curved in any plane.

InFIG. 2, near the stern, standard paddleboard fins protrude from the bottoms of right board12and left board14.

FIG. 3shows a paddle16and hinge18attached to the bottom surface of right board12. It is preferred that hinge18comprises a living hinge configuration, having a pinless flex hinge made from polyethylene or polypropylene. However, hinge18may comprise a knuckle and pin bearing configuration.

Hinge18is connected to a wing20. Wing20is connected to the bottom surface of right board12. It is preferred that wing20is glued to right board12. However, wing20may be glued to a liner that is glued to right board12, screwed into right board12directly; screwed or riveted into a liner that is connected to right board12, and so on.

The rotation of hinge18is limited by a stop22a. Stop22afunctions as a mechanical means to provide a moment opposite to the moment of the rotating paddle16. Stop22aprevents paddle16from rotating beyond the deployed position during a power stroke.

Stop22ashown comprises a cylinder connected to the surface of wing20. However, stop22acan comprise a raised edge of wing20that is proximal to hinge18. When paddle16is rotated to the deployed position, the edge of paddle16that is proximal to hinge18butts up against the proximal edge of wing20. The rotation of hinge18is stopped by contact between the respective edges of paddle16and wing20. The edge of wing20and the edge of paddle16have a configuration and adequate thickness to function as stop22a, and hold paddle16in the deployed position despite substantial water resistance forces.

Further, stop22amay comprise a protrusion extending from the bottom of right board12or left board14, a protrusion from the lower surface of wing20adjacent to hinge18, a rotation restriction associated with the knuckle of hinge18, anchored tethers attached to all paddles16on a board, and so on.

Alternatively, the proximal edge of paddle16may form the knuckle of a hinge18. Further, the proximal edge of paddle16may form the knuckle of a hinge18and a stop22a. Such a knuckle of hinge18may rotate about a pin connected to right board12or left board14, eliminating the need for wing20.

FIG. 4shows the aft edge of an interlocking sliding means, slider24inside a channel26. Channel26is shown in cross-section. Slider24is affixed to right board12by being partially embedded into right board12. Channel26is affixed to, and embedded within, left board14. Slider24is slidingly nested within channel26. Slider24is able to slide along a path within channel26that is parallel to the longitudinal axis of paddleboard10.

When slider24is slidingly nested in channel26, slider24is considered to slidingly connect right board12to left board14. As such, right board12and left board14may slide longitudinally with respect to one another within the plane of paddleboard10. When a rider standing on paddleboard10alternately moves his/her legs and feet fore and aft in a striding motion, right board12and left board14are caused to likewise move fore and aft via the sliding connection. Slider24slides within channel26with minimal resistance so as to minimize resistance to the rider's striding movements.

The sliding connection does not allow movement of right board12relative to left board14other than movement that is parallel to the longitudinal axis of paddleboard10. There is substantially no movement permitted within the vertical or transverse planes, and no lateral movement in the horizontal plane. This movement limitation improves the rider's stability and balance on paddleboard10.

It is preferred that slider24and channel26are comprised of high-strength, lightweight composite materials. It is further preferred that the contacting surfaces of slider24and channel26are comprised of low-friction materials so as to minimize resistance to the rider's striding movements. Suitable low-friction surfaces include Teflon®, nylon, polyoxymethylene, PVC, carbon fiber, and so on. However, slider24and channel26may be comprised of stainless steel, aluminum, and so on.

It is preferred that a torpedo28is connected to slider24for slidingly retaining slider24within channel26. Torpedo28is retentively nested within an enlarged inner portion of channel26such that slider24may move along the horizontal plane in a longitudinal direction only, but not in a lateral direction. Slider24is unable to move laterally to the right or left in the horizontal plane. As such, torpedo28affixes the lateral distance between right board12and left board14in the horizontal plain of paddleboard10, but permits longitudinal sliding. It is preferred that a fore torpedo28and an aft torpedo28are connected to slider24, and that each torpedo28is approximately 6 inches in length.

Slider24and channel26may be readily separated so that right board12and left board14may be separated for compact transportation and storage of paddleboard10. It is preferred that separation is possible via widened slots, or pullouts, at specific locations along the length of channel26. When torpedoes28are aligned with the pullouts, the torpedoes28readily slide out through the pullouts, and slider24is thereby released from channel26. Alternatively, channel26may be openable at the stern of left board14so that slider24and torpedoes28may be removed from channel26by sliding out the open stern end of channel26.

The separability of right board12from left board14for enhanced portability or storage is a valuable feature of paddleboard10. However, paddleboard10is substantially as compactly and conveniently portable and storable as paddleboards in the art when assembled, and without separation of right board12from left board14. An assembled paddleboard10is as easily transported and stored as paddleboards in the art.

Other known interlocking sliding means are also effective, such as ball-bearing races configured to permit longitudinal sliding while fixing the lateral distance between right board12and left board14, drawer slides, nesting rectangular tubes and channels, opposing channels, roller-coaster roller arrays, and so on.

A stringer30a, shown in cross-section, is connected to the medial surface of right board12, to increase the strength and flexural resistance of right board12. A stringer30bmay also be connected to the medial surface of left board14, to increase the strength and flexural resistance of left board14.

Stringers30aand30bare comprised of lightweight materials having sufficient strength to support right board12and left board14, such as nylon, balsa wood, PVC, Teflon, polyoxymethylene, carbon fiber, and so on. Stringer30bon left board14may comprise an extended flange associated with channel26. Stringer30aand stringer30bwould each have a slot to accommodate the fore and aft movement of slider24.

It is preferred that stringers30aand30balso provide protection for the respective interior opposing surfaces of right board12and left board14against bumping and chaffing that may occur during fore and aft movement due to the very close proximity of right board12and left board14. However, the opposing surfaces of stringers30aand30bmay be covered by resin, fiberglass, paint, and so on.

FIG. 5is a transparency view showing a slider24embedded within a transparent right board12. Paddleboard10is shown as it would appear if constructed from a transparent material. The embedded portion of slider24is durably anchored into right board12, such as by glue retention. It is also preferred that the embedded portion of slider24has surface retentive features to durably anchor slider24to right board12, such as divots, holes, tabs, and so on. A paddleboard ankle strap is connected to the aft end of right board12.

FIG. 5also shows a transparent channel26embedded in a transparent left board14. The left side of slider24is shown slidingly nested in channel26. Two torpedoes28are shown connected to the fore and aft ends of slider24.

Holes for a slider24locking means are shown in the top surface of left board14. Stringers30aand30bare shown connected to the medial surfaces of right board12and left board14, respectively.

FIG. 6Ashows a lock32penetrating through the deck of left board14, and through the upper half of channel26, where lock32is positioned in an unlocked position. When lock32is in the unlocked position, lock32is resting above, and slightly out of contact with, the upper surface of slider24. In this position, lock32does not drag on the surface of slider24, and thereby does not increase resistance to the sliding movement of slider24.

Lock32is connected to handle34. Handle34facilitates positioning the height of lock32relative to the surface of slider24. Handle34is shown protruding up from the upper deck of left board14when lock32is in the unlocked position. Handle34is configured so that the rider may push or pull on handle34in order to vertically reposition lock32.

Handle34is comprised of an elastomeric material. It is preferred that handle34is comprised of a buoyant elastomeric material, such that handle34and lock32could float on the surface of water.

Handle34is inserted into a cylindrical sleeve36, wherein sleeve36is able to retain handle34at a variety of vertical positions within sleeve36. The elastomeric material of handle34compresses when inserted into sleeve36, so that handle34may be frictionally repositioned in the same manner as a bottle cork. Sleeve36has finger access areas along the upper end to facilitate grasping handle34.

A hole38in slider24is shown unaligned with lock32, so that lock32is not insertable into hole38should the rider happen to push down on handle34.

It is preferred that handle34has a retentive feature to decrease the likelihood that handle34will inadvertently move upward and out of sleeve36. If handle34were to inadvertently move out of sleeve36, then lock32and handle34could fall out and be lost. A handle34retentive feature may comprise a ring of slightly greater diameter protruding from the lower end of handle34. A sleeve36retentive feature may comprise a circumferential recess in the wall of sleeve36which corresponds with, and can engage, the protruding ring of handle34. Other retentive features can include a spring-driven ball bearing lock, screw-threads, and so on.

It is preferred that a sleeve36recess is vertically located where it can engage the handle34ring when handle34is positioned in the unlocked position. The unlocked position is when lock32and handle34are at the greatest risk of loss.

FIG. 6Bshows hole38aligned with lock32, so that lock32is insertable into hole38. The rider has aligned right board12and left board14into a position where hole38is aligned with lock32, and has forcefully pushed down on handle34in order to push lock32down into hole38. The rider can push handle34into sleeve34using a foot or hand, and thereby push lock32into hole38.

Lock32is releasably engaged into slider24, such that slider24is unable to slide longitudinally in channel26. Lock32affixes slider24in channel26. When lock32is engaged in a locked position in slider24, then right board12is unable to slide longitudinally with respect to left board14. Handle34is frictionally compressed into sleeve36, such that handle34will not inadvertently slide upward to release lock32from slider24.

At least one hole38for locking with lock32is located on slider24in a location that corresponds with the bow and stern of right board12and left board14being evenly aligned. In the evenly-aligned locked position, paddleboard10is symmetrical, such that the overall appearance resembles a standard paddleboard. In the symmetrically locked position, paddleboard10is configured for standard rescue, exercise, and recreational uses, including surfing.

Additional holes38may be present to affix right board12at other selected positions relative to left board14. Lock32may also be used to prevent torpedoes28from inadvertently sliding into a channel26pullout slot, thereby preventing the inadvertent separation of right board12from left board14.

Other locking means for releasably affixing sliding right board12and left board14are also effective, including automatic spring-activated pins, cams, levered brake pads, and so on. For example, when the rider rotates a lock knob in advance, a spring-activated pin will automatically pop into a hole38as right board12and left board14are then moved to the desired alignment.

FIG. 7shows a plurality of alternative paddles, flaps40. A flap40is comprised of an elastomeric sheet. The sheet is connected to an anchoring material, flange42, and flange42is connected to the bottom of right board12or left board14. The portion of the flap40sheet that connects to flange42is comprised of a material that is homogenous with the material substantially comprising the remainder of flap40.

As such, flaps40functionally are living hinges, relying on the flexing of a portion of the elastomeric flap40material in order to permit rotation of flaps40. The flexing of the elastomeric material functions in a hinge-like manner to allow each flap40to alternately rotate between a deployed position and a non-deployed position.

A flap40may be formed by making cuts into a larger sheet, such as by making cuts on three sides of a rectangular shape. Similarly, a flap40may be formed by cutting a 180 degree curvature into a larger elastomeric sheet, thereby forming a D-shaped flap40.

Flange42comprises the remainder of the larger sheet from which flaps40are cut. Flange42surrounds an array of flaps40. The sheet of elastomeric material comprising flange42is homogenous with the material comprising flaps40. Flange42connects and anchors flaps40to the bottoms of right board12and left board14. Flange42thereby maintains the position and orientation of flaps40with respect to right board12and left board14. Flange42is anchored to the bottoms of right board12and left board14, such as by snaps, interlocking tabs, locks32, screws, pins, glue, and so on.

Flange42may be at least partly overlaid by a more rigid material that serves to anchor flaps40or flange42to right board12and left board14. The rigid overlay may serve to reduce flexing or stretching of flaps40or flange42. Flange42may be entirely connected to the bottoms of right board12and left board14via a connection to such an overlay, such as by snaps, interlocking tabs, locks32, screws, glue, and so on. For the purpose of this discussion, flange42, and any non-homogenous material overlaying flange42, will be considered to be a part of, and included in, flange42.

Flange42is configured to facilitate the water engaging the distal edges of flaps40to deploy flaps40during the power stroke. Flange42is configured to prevent flaps40from laying flush against the bottom of right board12or left board14, such as by inadvertently laying into recessed areas bounded by flange42, and from which flaps40were cut. If a flap40were to become inadvertently seated into the flange42recess, then the likelihood of the seated flap40engaging the water to deploy is greatly reduced.

For example, flange42may be reconfigured so that edges of flange42that are adjacent to flaps40are moved a small distance into the recesses so as to interfere with the distal edges of flaps40if they were tending to seat into the recesses. Further, flange42may be slit to facilitate moving a portion into the recesses to prevent seating of flaps40. Yet further, protrusions may be connected to flange42, connected to flaps40, or connected to the bottom of right board12or left board14, wherein the protrusions prevent flaps40from seating into the recesses of flange42.

The hinges of flaps40can be manufactured with an elastic position memory that tends to prevent the seating of flaps40into the flange42recesses. Further, as flaps40are used, being repeatedly and forcefully pushed aft to the deployed position, the elastic memory of the deployed position will tend to inhibit inadvertent seating of flaps40into the flange42recesses.

A semi-rigid stiffening border may also be connected to the rims of flaps40to inhibit flaps40from seating into the recess, and also to limit losses in flaps40water-resistance caused by excessive flexing of the edges of flaps40. The flexible material of flaps40may tend to flex too much at the edges, either at the distal edges, or along the lateral edges. This over-flexing can cause flaps40to partly loose valuable water resistance as the water slips too freely past the over-flexing edges. Materials added to reinforce the edges of flaps40can reduce such water-resistance losses, and increase the deployed paddling efficiency of flaps40.

When water resistance pushes flaps40into the deployed position, the elastic limits of the connection between flaps40and flange42is reached, and further rotation beyond the deployed position is substantially stopped. Flange42, and more specifically, the connection between flaps40and flange42, thereby limits the rotation of flaps40beyond the deployed position. As such, the elastic properties of the material from which flaps40and flange42are comprised are selected to permit rotation of flaps40only to the deployed position, but resisting rotation beyond the deployed position.

A frame44is shown anchoring the perimeter of flange42to the bottom of right board12or left board14. Frame44is connected to flange42and right board12or left board14, such as by bolts, screws, pins, and so on. Frame44inhibits flange42and flaps40from pulling away from the surface of right board12or left board14.

Frame44has struts crossing laterally over flange42between each flap40. The frame44struts further inhibit flange42and flaps40from pulling away from the surface of right board12or left board14. In addition, the struts are positioned to prevent flaps40from seating into the recesses of flange42, so that the water will catch and rotate flaps40for deployment.

Stops22bproject from the aft side of the frame44struts to limit the rotation of the flap40located aft of the strut. Stops22bshown are uniformly rigid, and the distal extensions of stops22bmake contact with elastomeric portion of flaps40. However, stops22bmay include semi-rigid distal extensions, including extensions that make contact with a rigid or semi-rigid stiffening border about the edges of flaps40. Stops22bmay also be hinged, elastomer coated, and so on. Alternatively, stops22bmay comprise anchored tethers connected to flaps40to limit the rotation.

In another variation, flaps40may be somewhat enclosed along their lateral sides, wherein such a laterally enclosed flap40forms a pouch. If flaps40are formed at least partly of an elastic material, the pouch may inflate somewhat with water during the power stroke, and deflate during the glide stroke.

The tendency of flaps40to stop rotation at the deployed position is influenced by multiple factors. A given degree of hinge rotation is dependent upon current hinge-area elasticity, the size and shape of the flaps40, and upon the variable amount of force that a given rider is able to exert upon right board12or left board14, and therefore on the amount of force exerted by the water against flaps40. As such, the degree of flaps40rotation may fluctuate between under-rotated relative to an ideal deployment rotation, and over-rotated. Both over-rotation and under-rotation will decrease the water-resistance efficiency of flaps40.

Further, the hinge-area elasticity is subject to change over time. A well-used flap40may increase elasticity such that it over-rotates at lower water forces than it did previously. An older, underused flap40may become stiff and oxidized, and may under-rotate. It is therefore preferred that an array of flaps40and flange42is conveniently rider replaceable. As such, a rider may quickly change flaps40and flange42to a greater or lesser elasticity that more exactly fits the rider's forceful exertion level. Further, a rider may quickly and conveniently replace an array of flaps40or flange42that has become worn or damaged, or otherwise is negatively affecting the performance of paddleboard10. Flaps40and flange42may be changed by disconnecting any snaps, interlocking tabs, locks32, screws, pins, and so on, that are connected to right board12or left board14.

FIG. 8shows a handheld paddle46. Handheld paddle46is a double-ended paddle, wherein the handle of handheld paddle46is bent such that the right paddle is oriented at approximately a right angle with respect to the left paddle. During use, the right and left paddles of handheld paddle46remain close to the water even when the opposite paddle is stroking in the water.

From the horizontal position, handheld paddle46is rotated approximately 15-20 degrees to dip the end paddle into the water. The total rotation from right to left during active paddling is therefore about 40 degrees.

Handheld paddle46facilitates coordinating paddle strokes with a rider's strides, and enhances a rider's balance and striding power on paddleboard10. With the paddle-to-water distance reduced, the rider stroke movement distance is reduced. Therefore, the time between paddle strokes is also reduced, and riders can easily increase their rate of paddle strokes. Handheld paddle46can thereby increase the overall water speed and stability of paddleboard10. Further, the angulation can improve the rider's leverage on the paddle handle.

Handheld paddle46is considered an integral part of paddleboard10because of the unusual rider balancing required during forceful striding. Handheld paddle46is important and necessary for enhancing rider stability.

Handheld paddle46improves the level of cardio exercise attainable with paddleboard10, or with other paddleboards. Further, handheld paddle46reduces the twisting and bending required by a rider for handheld paddling. Reduced twisting can increase rider endurance, and reduce muscle strain.

The handheld paddle46handle bend may comprise a single curvature or bend, or a plurality of alternating bends and straight portions. The total angle change of the bend may be somewhat more or less than 90 degrees. The center connector may provide a plurality of relative angles for the right and left paddles, so that the angulation of the right and left paddles may be lockingly selectable.

Alternatively, handheld paddle46may be constructed by attaching two standard handheld paddles to an angled center connector.

A flap40is shown deployed under paddleboard10.

From the description above, a number of advantages of paddleboard10become evident. Paddleboard10:(a) utilizes a rider's feet and legs to propel the paddleboard(b) glides over the water faster than standard paddleboards(c) is usable in the same manner as standard paddleboards(d) is useful for surfing(e) is useful for water rescue operations(f) has improved water rescue capabilities over standard paddleboards(g) facilitates forward-directed, and full-force, striding(h) permits substantial range of stances(i) permits rapid variation of stance(j) is stable on the water(k) has ease of use(l) is fun for recreational users(m) may be rapidly remounted(n) has established alternative uses(o) is generally as portable as standard paddleboards(p) does not require assembly for use
Operation

According to another aspect, the invention provides a process comprising the steps of: utilizing a rider's legs and feet to reciprocably move slidingly connected right board12and left board14fore and aft in a direction that is substantially parallel to the longitudinal axis of paddleboard10, wherein right board12and left board14move only within the plane of paddleboard10, wherein the distance between right board12and left board14is minimal and fixed, and wherein the alternating fore and aft movement of right board12and left board14powers a water propulsion means that propels paddleboard10efficiently and rapidly forward over the water.

The invention provides a preferred process comprising the steps of: utilizing a rider's legs and feet to alternately move slidingly connected right board12and left board14fore and aft in a direction that is substantially parallel to the longitudinal axis of paddleboard10, wherein right board12and left board14move only within the plane of paddleboard10, wherein the distance between right board12and left board14is minimal and fixed, and wherein moving right board12or left board14aft causes paddles16to rotate to a maximum water resistance position, and moving right board12or left board14fore on the water causes paddles16to rotate to a minimum water resistance position, thereby propelling paddleboard10to efficiently and rapidly glide forward over the water.

By using the paddleboard of the invention, it is now possible, surprisingly, for a standing rider to utilize leg and foot strength to achieve faster paddleboard speeds. The process offers the advantage that the user can now propel a paddleboard simply and rapidly using leg strength.

In a further embodiment of the invention, there are multiple applications of the method for propelling paddleboard10by forcefully sliding right board12and left board14in a reciprocating, striding motion.

A paddleboard10is garage-stored in a bag, and oriented so that paddles16tend to rest in the non-deployed position rotated against the bottom of right board12and left board14. When paddleboard10is standing on the stern, or lying flat with upper deck down, then gravity tends to rotate paddles16toward the non-deployed position.

One lock32is engaged in a hole38so that right board12and left board14are affixed to one another. As such, paddleboard10may be carried as a solid object. Paddleboard10is picked up by the rider and moved to a vehicle as easily as the other standard paddleboards commonly used by the rider.

The rider elects to remove paddleboard10from the bag for transportation, against manufacturer recommendations. Paddleboard10is strapped onto a car roof-rack so that the bow faces the front of the car, along with a handheld paddle46. As paddleboard10is driven to the water, the wind tends to push paddles16against the bottom surface of right board12and left board14so that they remain in a non-deployed position.

Upon arrival at a race location, the rider places paddleboard10on the water, and climbs onto the deck with handheld paddle46. The rider leaves lock32engaged in hole38so that slider24remains affixed to channel26, and paddleboard10thereby remains in a standard paddleboard configuration. As the starting gun sounds, the rider quickly outpaces the other racers by producing many more handheld paddle strokes with handheld paddle46than other racers using standard standup paddleboard paddles, or kayak paddles. Paddleboard10is as stable on the rough water as the other paddleboards in the race.

When the rider has progressed well in front of the other racers, and sufficiently out of range of their view, the rider grasps handle34with her fingers and lifts it up just sufficiently so that lock32is disengaged from hole38in slider24. However, handle34remains securely inserted into sleeve36. In the disengaged position, the distal end of lock32is suspended just above, and out of contact with, the upper surface of slider24. The proximal upper end of handle34protrudes somewhat above the surface of right board12. Slider24is thereby unlocked to slide freely in channel26.

The rider begins taking forceful and deliberate strides with her legs and feet. The force of the leg and feet movement is transferred to right board12and left board14. When right board12is moved aft on the power stroke, the water moving past the distal edges of paddles16engages paddles16and rotates them down into the deployed position. The rotation of each paddle16is interrupted by contact with a stop22when paddle16has a vertical orientation, perpendicular to the plane of paddleboard10. The deployed paddles16cause substantial resistance to further aft movement of right board12, and the aft movement of right board12slows substantially.

Simultaneously, left board14is moved fore, and paddles16are rotated up against the bottom surface of left board14. With this orientation of paddles16, left board14readily glides fore over the water with little resistance.

At the end of the rider's stride, the rider reverses the direction of the stride. Left board14begins to move aft, and paddles16under left board14deploy to the vertical position. The movement of left board14to aft immediately slows in the face of substantial water resistance against deployed paddles16. Right board12begins to move fore, and paddles16under right board12rotate back to a horizontal, non-deployed position. Right board12readily glides fore.

Whenever right board12or left board14moves aft, the movement is slowed by water resistance. Whenever right board12or left board14moves fore, the movement experiences minimal water resistance, and right board12or left board14moves fore easily and rapidly. The net result is that paddleboard10makes headway easily and rapidly.

Slider24readily slides through channel26, permitting right board12and left board14to slide fore and aft along the longitudinal axis of paddleboard10with little frictional resistance. Right board12and left board14are held in close proximity during sliding because torpedoes28prevent slider24from moving laterally within channel26. The plane of the upper decks of right board12and left board14respectively therefore do not change angulation, but rather remain at a fixed angle. The rider is presented with essentially a flat and solid deck similar to other paddleboards, with the exception of the fore and aft reciprocal sliding. The rider is able to remain standing on the stable, flat deck despite waves.

With an unusual wave, the rider is thrown into the water. She quickly regains the flat and stable deck, stands, places her feet in a comfortable stance, and begins striding again, loosing little time.

When the rider paddles with handheld paddle46while simultaneously striding on right board12and left board14, the speed of paddleboard10increases further. The rider arrives at the race finish in record time, and is declared the winner. However, after inspection of paddleboard10, an asterisk is placed in the record book by the rider's name, and a new classification is created for the organization's future paddleboard races.

At the end of the day, the rider's winning paddleboard10is still being viewed while the other race paddleboards are being been loaded into provided trucks. When organizers finally attempt to load paddleboard10, they discover that the last space remaining in the truck is too small. The rider elevates a lock32at the stern, and any other lock32, releasing slider24to move past the stern lock32. The rider separates right board12from left board14by sliding slider24aft out the stern end of channel26. Once separated, right board12and left board14fit together into the last remaining space on the truck for the ride back to the starting area.

A lifeguard is patrolling a beachfront area by standing on a paddleboard10out beyond a surf break. The stability of paddleboard10permits reliable and stable standing despite significant wave activity.

The lifeguard is moving paddleboard10over the water using a standard handheld paddle. He is simultaneously using a slow alternating leg striding motion to cause right board12and left board14to reciprocably slide fore and aft, thereby causing flaps40to propel paddleboard10forward over the water.

The lifeguard becomes aware of a potential rescue situation involving a swimmer down the beach, but nearer to the shore. He simultaneously increases the speed and force of the handheld paddling and the reciprocal sliding of right board12and left board14to accelerate paddleboard10to a high water speed. He directs paddleboard10diagonally toward the beach.

As paddleboard10moves over the water, the lifeguard watches incoming waves. At the right moment, powerful and directed striding movements power paddleboard10into an oncoming wave to catch the wave. As paddleboard10catches the wave, the lifeguard slides his foot over the top of handle34and uses his foot to push lock32down into light contact with slider24. Maintaining downward pressure on handle34, he slides right board12and left board14to bring their bow ends into even alignment until hole38is aligned with lock32. As soon as hole38is aligned with lock32, the downward pressure maintained on handle34pushes lock32into hole38, thereby affixing slider24in channel26. Right board12and left board14are lockingly affixed in side-by-side alignment so that paddleboard10has a non-sliding configuration that is similar to standard paddleboards.

The lifeguard rapidly surfs paddleboard10as close to the swimmer as possible, and then turns out of the wave. The lifeguard reaches down and pulls handle34up to the unlocked position. Immediately after unlocking slider24, he immediately resumes forceful striding and handheld paddling to close the remaining distance to the swimmer.

As paddleboard10approaches the distressed swimmer, the lifeguard again presses down on handle34, aligns the bows of right board12and left board14, and presses lock32into hole38to affix right board12to left board14. Paddleboard10is fixedly locked to enhance its stability while the lifeguard engages the swimmer.

After the rescue, with paddleboard10back at the lifeguard station, the rider determines that he needs a heavy-duty array of flaps40having a greater elastic resistance to deformation. He thinks this will better match his strength, and thereby provide additional water-speed. He selects two heavy-duty frames40that have greater resistance to deformation. He pulls the pins connecting the original frames40to right board12and left board14, and removes the two original frames40from paddleboard10. He secures the pins to connect a first heavy-duty flange42to right board12and a second heavy-duty flange42to left board14. During subsequent uses of paddleboard10, the rider achieves higher average water-speeds with the heavy-duty frames40connected.

Conclusion

In conclusion, paddleboard10is functionally flexible. Paddleboard10is ideal for established and popular uses of, and in the same manner as, paddleboards of the art for rescue, racing, surfing, paddling, exercising, and other recreation.

However, paddleboard10is also usable in manners unique to paddleboard10, such as rescue, racing, surfing, paddling, exercising, and other recreation at a uniquely high water speed. Paddleboard10's speed, striding motion, and stance facilitate an increased distance range and endurance for riders.

Paddleboard10also provides a uniquely high level of cardio-stimulation, endurance, and general performance achievable by a rider. A cross-country skiing motion, like that utilized on paddleboard10, is known to be a particularly effective exercise type. Paddleboard10is an ideal device for enhancing general athletic performance and balance.

The portability, simplicity, and low cost of paddleboard10make it a viable transportation means for people in remote areas, or for people with limited means. Paddleboard10may be used for personal transportation, for transporting limited goods onboard, or for towing goods, such as goods towed on a trailing board.

Overall, paddleboard10is a novel watercraft. Paddleboard10is fairly simple to manufacture, and can be sold at costs comparable to standard paddleboards. The use of paddleboard10is straightforward, making it useful for rescue, racing, exercise, or just for fun. These factors make paddleboard10economically viable.

Alternate propulsion means may be utilized in lieu of paddles16. For example, a rotating propeller could be powered via linkages connected to reciprocating right board12and left board14that converts the reciprocating movement to rotate a propeller axle. Other propulsion means includes linkage connected to a paddlewheel, a fish tale or whale tail stern paddle, lateral paddles, and so on.

Such configurations are considered to be within the scope of the invention. Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given.