NZ330979A - Floatation device using non-inflatable parts - Google Patents

Description

Patents Form No. 5 No.330979 Date:13th July 1998 Patents Act 1953 COMPLETE SPECIFICATION AN IMPROVED FLOTATION DEVICE I, GRAEME JAMES BODDY of 77 Eastern Terrace, Christchurch, NEW ZEALAND a New Zealand citizen, hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: TITLE:- AN IMPROVED FLOTATION DEVICE Technical Field The present invention relates to a modification of the floatation device described in New Zealand specification No. 299373.

New Zealand specification No. 299373 discloses an improved floatation device for aquatic use, comprised of at least one inflatable float. An inflatable construction aids the transport and storage of the device when not in use by enabling the volume of the device to be greatly reduced by the deflation of the inflatable float(s).

However, commercial rafting companies often prefer to avoid the time and inconvenience involved in inflating/deflating each craft for each trip. Instead, the crafts normally remain in a permanently inflated state and are transported to the launch site stacked on and secured to a trailer. Although the floatation device described in New Zealand Patent No 299373 (hereinafter referred to as the 'inflatable chair') requires substantially less inflation than a typical commercial raft, nevertheless some commercial operators would still prefer to maintain the floatation devices in a permanently ready-to-use condition. Therefore, to meet such a need, the present invention seeks to retain the advantages and characteristics of the said floatation device when in use, whilst replacing the inflatable construction of at least the float(s) with a semi-rigid or rigid construction.

The present invention would also be applicable to individual users unconcerned with the space-saving advantages of inflatable construction and desiring a cheaper but still robust embodiment of the said inflatable chair. Utilising a semi-rigid/rigid construction enables a variety of float shapes to be readily implemented which would be too difficult and/or expensive to be practically produced with an inflatable construction. It further enables the whole craft to be produced as a single semi-rigid/rigid unit, thus obviating the construction and manufacture costs of the component elements required to make the inflatable chair. A simplified versions of such a craft may be employed as a pool toy or for similar amusement purposes.

Disclosure of Invention It is an object of the present invention to provide a float with a hydrodynamically efficient underwater profile, capable of efficient human propulsion, using hands and/or legs, which secures the user in a semi-reclining position and which is sufficiently manoeuvrable, in both forward and reverse direction, to enable the user to engage in white-water river use whilst protecting the user's body and minimising the risk of snagging the lower surface on under water hazards.

The dimensions and proportions of the float are chosen with the object of providing high longitudinal stability in turbulent water.

It is a further object of the present invention, to engender in the user a feeling of close, direct involvement with the environment, by virtue of close proximity of the seating position to the water.

The present invention provides a chair configured to be primarily propelled by a user's hands and feet, comprising:- - a hull which is substantially U-shaped in plan view, wherein the opposing sides of the U-shape are formed by one or more streamlined, rigid or semi-rigid float(s); - a central rigid or semi-rigid section filling the area between the sides of the U-shape from the apex (hereinafter referred to as the bow) towards the free ends of the U-shape (hereinafter referred to as the stern); wherein the hull displays a degree of rocker approaching the bow; the lower surface of the central section is a hydrodynamically-efficient shape, describing a smooth, continuous curve from the bow towards the stern and extending to or below the waterline when in use; the upper surface of said central section providing lower and upper-body support for a user, in the form of a seat base between said opposing floats and a seat back adjacent said seat base, said seat back being located between said seat base and the bow; the overall length of the hull being substantially greater than that of the seat base; said hull, said seat base and said seat back being proportioned and dimensioned such that a user sitting on said seat base between the said floats with the user's back against the said seat back may simultaneously immerse his/her lower legs and hands into the water for propulsion and maneuvering.

Preferably, the or each float extends upwards from the upper surface of the central section to a level at or near the upper surface of user's legs/lower-body in use.

Preferably, the underside of the centre section rises towards the stern to a point at or near the waterline of the chair when in use.

Preferably, the hull also displays a degree of rocker at the stern.

Preferably, said floats extend beyond the stern-most edge of the centre section for a distance greater than 50% of the length of the seat-base.

Preferably, the aspect ratio of the overall length to the width is approximately 1.7-3:1.

Preferably, the overall length of the chair is approximately equal to the face/head height of the typical user (e.g. 1.6-1.8 metres for 1.8-2 metre person).

Preferably, the underside of said floats and said central section is configured to permit surfing or planing.

Preferably, said seat back is upwardly inclined from the said seat base towards the bow.

In one embodiment, both sides of the U-shape may be formed from a single continuous float. The said floats and at least part of the central section may be formed as a single continuous item. Said central section may be made of any suitable semi-rigid or rigid material or combination of same.

In a further embodiment, each opposing side of the U-shape is formed by a single separate float extending substantially parallel to the longitudinal axis of the chair.

Preferably, a releasable restraining means is provided to secure the user to the craft around the user's waist and/or upper thigh area.

Said releasable restraining means may comprise a strap releasably securable across the upper thigh/hip area of each of the user's legs to one or more securing means.

Alternatively, said releasable restraining means may comprise a waist strap and releasable securing means.

Preferably, said floats are proportioned and configured to be stackable or nestable.

In one embodiment, said upper-body support comprises an adjustable seat-back releasably securable to said central section and/or the floats. An inflatable buoyancy means may be provided between the seat-back and the bow.

Preferably, a major portion of the lower surface of the centre section forms a smooth continuous surface with the underside of the floats. Alternatively, the underside of the central portion may be recessed upward relative to the underside of said floats.

In a low buoyancy embodiment, the overall buoyancy of the craft may be reduced such that the weight of water displaced if fully submerged is less than approximately 200% of the user's body weight and/or the buoyancy of each opposing side of the U-shape formed by a single separate float is such that the weight of water displaced if the said float is fully submerged is less than approximately 60% of the user's body weight.

As used herein: i) The term "U-shaped" is defined as encompassing arch-shaped, V-shaped and any shape including substantially straight, curved, parallel and/or diverging opposing symmetrical limbs or legs and a curved, pointed, or straight transverse connection at one end of the opposing limbs of the U-shape. ii) The term "rocker" is defined as the upwards curvature or inclination, in a longitudinal direction, of the underside of the craft's hull. iii) A "semi-rigid or rigid section" is defined as including, foam, solid-skinned or wholly or partially solid section, or any combination of these formed from any suitable material but excluding inflatable construction (except where specifically stated to the contrary).

Brief Description of the Drawinas:- By way of example only, a preferred embodiment of the present invention is described in detail with reference to the accompanying drawings, in which:- Fig. 1 is a perspective view from above of a first preferred embodiment of the present invention, Fig. 2 is a perspective view from below of embodiment of the present invention shown in fig 2, Fig. 3 is a section through line A-B of Fig. 2 (shown inverted) with a human user shown in phantom; Fig. 4 is a further perspective view of an embodiment showing only the seat-base and bow-hull floor sections; an alternative embodiment is shown in broken lines, Fig. 5 shows a section through line C-D of Fig. 2, Fig. 6 shows a corresponding view to Fig. 5 of a further preferred embodiment, Fig. 7 shows a plan view of the preferred embodiment shown in Fig. 1, with a further preferred embodiment represented by a dotted line; and Fig. 8 shows a corresponding view to Fig. 3 of a further preferred embodiment.

Best Modes For Carrying Out the Invention Referring to drawings 1- 5, an embodiment of the substantially U-shaped chair is shown, comprised of two rigid/semi-rigid floats (2, 3), a seat base (4), a seat-back (8), a bow hull floor section (12) and a hull skin section (15a) which is substantially equivalent in exterior shape to the first preferred embodiment disclosed in NZ Patent No. 299373, with the exception that the floats (2, 3) are either rigid or semi-rigid in construction and not inflatable and that the inflatable buoyancy bag and waterproof covering is replaced by a rigid waterproof enclosure with a releasable access hatch/cover (in the area indicated by arrow (7a)). Rigid floats (2, 3) could be produced from a thermoplastic material by roto-moulding or similar means, whereas semi-rigid floats (2, 3) may be formed as semi-flexible tubes filled with a closed-cell foam (e.g. polyolefin). This structure provides the required degree of rigidity whilst still maintaining a resilient outer surface, thus dampening the shock of any impact with a rock or similar when in use. Furthermore, the craft would remain buoyant, despite any penetration of the outer skin.

The two floats (2, 3) are shown as being circular in cross-section and tapering at both ends to conical points (10, 11) at the stern and (13, 14) at the bow, though it will be appreciated that any cross-sectional/longitudinal shape is possible with a rigid/semi-rigid construction. Once freed from the shape constraints imposed by an inflatable construction, any chosen shape may be readily reproduced from a suitable mould. The longitudinal axes of the float tubes (2, 3) are orientated to converge towards the bow (6), (although they do not meet in this preferred embodiment) and are substantially parallel towards the stern.

In the embodiment shown in figs. 1-5, the hull skin section (15a), the seat-base (4) and the bow hull floor section (12) (as employed in the first preferred embodiment of the said inflatable chair in New Zealand Patent No. 299373) are preferably formed as a single continuous moulding together with floats (2, 3). In the case of a rigid construction, the upper surface of the seat-base (4) could be covered with a semi-rigid layer of padding such as a foam rubber. Similarly, the sides of the floats (2, 3) adjacent to the user's upper legs/lower torso could be padded in a corresponding manner. Figures 5 and 6 shows respectively, a comparison between the lateral cross section (taken through the seat-base (4) along line C-D shown in fig 2) of the aforesaid embodiment with a separate seat-base (4) (fig. 5) and the preferred embodiment with a continuous integrally-moulded seat-base/floats assembly (2a, 3a, 4a). Alternatively, it would be possible to form the seat base (4) itself from an inflatable construction.

The underwater profile of the central section (15) may be formed with an even more streamlined shape and finish than is possible for the said inflatable chair.

A central section (15) formed the lower surface of the combined seat-base/bow hull floor section, hull skin section (4, 12, 15a), delineates a smooth curve from the bow (6) extending below the water surface and rising to the edge of the seat base (5) which is approximately level with the water-line of the chair when in use. The underwater surface of both the floats (2, 3) and the central section (15) is free from any protuberance or distortion and is conducive to maximising the hydrodynamic efficiency and performance criteria required of the chair.

In the preferred form of this embodiment, the seat-back (8) is also integrally moulded with the floats/central section assembly (2a, 3a, 15) and is comprised of a near-rectangular section contoured to the shape of a user's back and upwardly inclined towards the bow from the intersection (9) with the seat-base (4).

In an alternative (though more expensive) embodiment, shown in fig 3., the seat-back (8) may be formed as a distinct, adjustable, semi-rigid foam seat-back, which is zipped to the intersection (9) (as disclosed in New Zealand Patent No 299373), wherein the volume between the seat back (8) and the bow-hull floor section (12) is filled by a removable, inflatable buoyancy bag (16) and/or cargo. After inflation, the bag completely fills the space (excluding that taken up by any cargo) behind the seat back (8), displacing any water that might otherwise settle there. This prevents any water splashing into the chair from being retained, as the buoyancy bag and the user's body fills all the available cavities/apertures and thus the float is in effect self-draining. The angle of inclination of the seat-back may be varied by adjusting straps (20, 21) fixed from the side of the seat-back (8) to the floats (2, 3) and/or adjusting the volume of an inflatable buoyancy bag (16) placed between the seat-back (8) and the bow hull floor section (12). An elastic-edged covering flap (7) (replacing the hatch cover (7a)) is attached to the top of the seat-back (8) and stretches over the adjustable buoyancy bag (16) to the bow (6) where it is attached by an adjustable strap (19) or similar fastening. Alternatively the seat-back (8) may be adjustably secured to the seat-base/bow hull floor section (4, 12) or to the sides of the floats (2, 3) to enable its longitudinal position to be adjusted. This permits users of differing physical stature to use the float.

Preferably, for all embodiments, the user's knee will extend to a point just past the seat-base edge (5) enabling the portion of the legs below the knee to kick or float in the water. The floats (2, 3) extend rearwards beyond the seat-base edge (5) for a distance greater than 50% of the length of the seat base 4, and preferably between 50% and 80% of said length. This distance is approximately equal to the position of the ankles of the extended leg of the seated user. This enables the float to provide sufficient buoyancy in the stern (preventing/minimising the likelihood of pitch-poling) whilst not hindering the use of the feet for kicking (with fins) or for fending-off boulders, rocks and similar obstacles.

The length to width aspect ratio is a critical design consideration which has been found to have an optimum value of approximately 1.7-3:1. The overall length itself is also an important parameter and should ideally be approximately equal to the height of the user's face (e.g. approximately 1.6 meters of a typical 1.8 meter user). These values will naturally alter with users of different stature, requiring chairs of different sizes to be produced for optimum performance.

The combination of the relatively long overall length together with extension of the floats (2, 3) past the seat-base edge (5) provides a stable platform for the user to climb into the seat from the water without the chair tipping or flipping over.

The semi-reclining seat configuration and rigid or semi-rigid centre section provide the following advantages:- (i) Support, stability and comfort, enabling practical use for extended periods. (ii) Places the user's legs in the optimum position for kicking, floating on the water surface, minimising drag, avoiding submerged hazards and for fending off rocks, boulders etc. (iii) Efficient use of the user's arms for paddling - both forwards and reverse, enhanced by their economically efficient position and close proximity to the water surface aided by the relatively narrow diameter of the tubes allowing the user to easily reach over the sides. (iv) Minimises transom drag. (v) A low centre of gravity, thus increasing stability. (vi) Decreasing any tendency of the user to slide out of the open stern in turbulent water. (vii) Lateral stiffness, preventing the floats (2, 3) collapsing towards each other under the weight of the user and enhancing the overall structural integrity of the float. (viii) The curved underwater profile prevents rocks/obstructions snagging and minimises the likelihood of damage, in both directions of travel. (ix) Absorbs shock and protects the user's body between the midriff and the knees from any underwater collisions. (x) The user is able to pivot (with the assistance of waist and legs straps) and also has the freedom to move the upper body fore and aft to balance and tilt the chair longitudinally The user may be secured to the chair by means of quick-release straps (22, 23) or other suitable means. This enables the user to perform a variety of vigorous manoeuvres without becoming detached from the chair.

A number of handles (not shown) can be located along the upper surface of the floats (2, 3) for use in turbulent waters by users not secured to the chair by said straps (22, 23) or similar means. Handles located near the ends (10, 11) and middle of floats (2, 3) aid reentry of the chair by a person in the water. All handles improve the general handling and transportation of the chair out of the water.

It will be appreciated that by varying the cross-sectional area of the floats (2, 3) and 9 therefore varying their buoyancy, the performance and response characteristics of the float can be altered.

Increasing the cross-sectional area of the floats (2, 3) increases the overall stability and buoyancy of the float, minimising the risk of inversion. This would be desirable for heavier or less experienced/able users.

Decreasing the cross-sectional area (particularly by reducing the width) of the floats reduces the overall stability and buoyancy, most notably the lateral stability, whilst increasing the ability to bank and roll the chair. This enables experienced users to perform more advanced manoeuvres such as hand-rolling.

It has been found in practice that a reduced buoyancy embodiment provides the more ambitious/experienced user with a range of dynamic manoeuvres that would be difficult with a more stable buoyant chair. The ability to hand-roll the chair is particularly important as it enables the user to safely remain in the chair, despite a capsize. Naturally, the ability to execute such a manoeuvre is enhanced by securing the user to the chair in some way.

Whilst the simple quick release straps (22, 23) located across the user's waist are sufficient (and indeed optional) for a stable high buoyancy embodiment of the chair, a more secure means of restraint is required for a low buoyancy embodiment. This is provided by a releasable restraining means (24) which take any suitable form. In one embodiment, the releasable restraining means (24) comprises a strap (28) (as shown in fig. 3) releasably securable to one or more securing means (29) across the upper thigh/hip area of each of the user's legs. The securing means (29) can take any convenient form such as a single clasp, buckle, or of the like, able to simultaneously release both the legs straps (28), or individual buckles or similar requiring independent release of each legs straps (28). It will be appreciated that the quick release nature of the restraining means is paramount given that the user may well be inverted underwater attempting to release themselves from the chair.

In general terms, hand rolling of the chair may only be reliably achieved below a certain degree of buoyancy. Whilst differing ability and experience of the user is obviously an important factor, two approximate indications of the ability to hand-roll are; - when the weight of water displaced by the whole chair if fully submerged is less than approximately 200% of the user's body weight and - when the buoyancy of each opposing side of the U-shape formed by a single separate float (2, 3) is such that the weight of water displaced if the said float is fully submerged is less than approximately 60% of the user's body weight.

The above comments assume the use of webbed gloves by the user, without which hand rolling would be far more difficult. The reduced cross-sectional area (and consequently a reduced width) of the floats (2,3) (as shown in Fig. 6) of a low buoyancy non-inflatable embodiment would produce a substantially parallel sided U-shaped hull (in plan view) from the stern to the region adjacent the user's chest/shoulders. Figure 7 shows a plan view of the first preferred embodiment with the periphery of the low buoyancy embodiment denoted by a dotted line (30). Provided the bow hull floor section (12) still maintained a hydrodynamically efficient side profile, a substantially straight, blunt-ended parallel-sided U-shape (as shown in Fig. 7) would be possible. However, the requirement would still exist for the user to be able to immerse (for paddling) their hands/lower arms whilst reclining on the seat back (8).

Any of the above embodiments (particularly the low buoyancy embodiment) may be used in an indoor swimming pool or similar for games such as an adaption of water-polo.

In a further preferred embodiment, (as shown in Fig 8) the chair is optimised for use on snow or for towing across water. In this embodiment, the chair is configured such that the underside of the seat-base (4) is ideally raised slightly from a line drawn tangentially between floats (2, 3), wherein said floats maintain a flat hull profile, aft of the seat base/seat back intersection (9), i.e. no rocker in the stern. The floats (2,3) would thus act as 'rails' in this embodiment.

This may be achieved by replacing the curved seat-base (4), with a flat base or by the use of suitable adjustable fastening means on floats (2, 3), altering the angle of seat-base (4) between positions E (raised towards the stern) or F (parallel to the water's surface). The characteristic features of the fourth preferred embodiment in comparison to the above described embodiments are; - no rocker at the stern, - a slightly raised centre section (25) with respect to the bottom of floats (2, 3), 11 - a longitudinal ridge (26) for directional stability on each float (2, 3) and a simplified cushion/support pillow (27) replacing the seat back/buoyancy bag (8,16) assembly.

This configuration would also enable the user to adopt a prone position facing the bow.

It will be further appreciated that there are a variety of different configurations possible for all the embodiments by altering the geometry of the floats, the size and arrangement of the chair elements and the construction means/materials. The angular relation of the centre line of the legs of the U-shaped hull can range from being substantially parallel to converging at either bow or stern or both.

In practice it has been found that on flat and/or slow moving water, the chair is paddled by the hands and/or feet in a bow-first direction. In fast flowing/white-water, the user faces downstream (i.e. stern first) being carried by the current, and propels himself (using his legs and/or hands) at an angle against the current (ferry glide) as a means to navigate left or right to avoid hazards.

All the embodiments of the chair can also be used in a similar fashion to a body-board, with the user adopting a prone position facing the bow. Straps (20) or handles (not shown) located adjacent to strap (20) can be used by the user as a secure hand-hold in this body position.

The shape of the float under-side, particularly at the bow, promotes the ability to surf/plane on waves, especially the type of standing waves produced in some white-water and/or rapid rivers.

It will be appreciated that it is desirable for storage and/or transport that the chair be stackable or nestable and thus occupying a reduced volume. Both the inflatable and non-inflatable versions may be stacked by reversing alternate chairs such the seat-back (8) of one chair may be inserted between the free ends of the floats (2,3) at the stern of another chair. Due to the greater variety of shapes and configurations possible, the non-inflatable chair may be more readily adapted to form a more intimate stacking than the inflatable version. 12

Claims (26)

1. A chair configured to be primarily propelled by a user's hands and feet, comprising:- - a hull which is U-shaped in plan view, wherein the opposing sides of the U-shape are formed by one or more streamlined, rigid or semi-rigid float(s); - a central rigid or semi-rigid section filling the area between the sides of the U-shape from the apex (hereinafter referred to as the bow) towards the free ends of the U-shape (hereinafter referred to as the stern); wherein the hull displays a degree of rocker approaching the bow; the lower surface of the central section is a hydrodynamically-efficient shape, describing a smooth, continuous curve from the bow towards the stern and extending to or below the waterline when in use; the upper surface of said central section providing lower and upper-body support for a user, in the form of a seat base between said opposing floats and a seat back adjacent said seat base, said seat back being located between said seat base and the bow; the overall length of the hull being substantially greater than that of the seat base; said hull, said seat base and said seat back being proportioned and dimensioned such that a user sitting on said seat base between the said floats with the user's back against the said seat back may simultaneously immerse his/her lower legs and hands into the water for propulsion and maneuvering.
2. A chair as claimed in claim 1, wherein the or each float extends upwards from the upper surface of the central section to a level at or near the upper surface of user's legs/lower-body in use.
3. A chair as claimed in claim 1 or 2, wherein the underside of the centre section rises towards the stern to a point at or near the waterline of the chair when in use.
4. A chair as claimed in any one of claims 1-3, wherein the hull also displays a degree of rocker at the stern.
5. A chair as claimed in any one of claims 1-4, wherein said floats extend beyond the stern-most edge of the centre section for a distance greater than 50% of the length of the seat-base.
6. 6. A chair as claimed in any one of claims 1 -5, wherein the aspect ratio of the overall length to the width is approximately 1.7-3:1.
7. 7. A chair as claimed in any one of claims 1-6, wherein the overall length of the chair is approximately equal to the face/head height of the typical user.
8. 8. A chair as claimed in any one of claims 1 -7, wherein the underside of said floats and said central section is configured to permit surfing or planing.
9. 9. A chair as claimed in any one of claims 1-8, wherein said seat back is upwardly inclined from the said seat base towards the bow.
10. 10. A chair as claimed in any one of claims 1-9, wherein both sides of the U-shape may be formed from a single continuous float.
11. 11. A chair as claimed in any one of claims 1 -10, wherein said floats and at least part of the central section are formed as a single continuous item
12. 12. A chair as claimed in any one of claims 1-9, wherein each opposing side of the U-shape is formed by a single separate float.
13. 13. A chair as claimed in claim 12, wherein the buoyancy of a single said float is such that the weight of water displaced if the said float is fully submerged is less than approximately 60% of the user's body weight.
14. 14. A chair as claimed in any one of claims 1 -13, wherein the overall buoyancy of the chair is such that the weight of water displaced if the chair is fully submerged is less than approximately 200% of the user's body weight.
15. 15. A chair as claimed in any one of claims 1 -14, wherein at least part of said central section is inflatable.
16. 16. A chair as claimed in any one of Claims 1-15, wherein at least part of said central section is made of foam material.
17. 17. A chair as claimed in any one of Claims 1-16, wherein at least part of said central section is made of a plastics material.
18. 18. A chair as claimed in any one of claims 1-17, wherein a releasable restraining means is provided to secure the user to the craft around the user's waist and/or 14 upper thigh area.
19. 19. A chair as claimed in claim 18, wherein said releasable restraining means comprises a strap, releasably securable across the upper thigh/hip area of each of the user's legs to one or more securing means.
20. 20. A chair as claimed in claim 18, wherein said releasable restraining means comprises a waist strap and releasable securing means.
21. 21. A chair as claimed in any one of claims 1-20, proportioned and configured such that a plurality of chairs are stackable or nestable.
22. 22. A chair as claimed in any one of claims 1 -21, wherein said upper-body support comprises an adjustable seat-back releasably securable to said central section and/or the floats
23. 23. A chair as claimed in any one of claims 1-22, wherein an inflatable buoyancy means is provided between the seat-back and the bow.
24. 24. A chair as claimed in any one of claims 1-23, wherein a major portion of the lower surface of the centre section forms a smooth continuous surface with the underside of the floats.
25. 25. A chair as claimed in any one of claims 1-23, wherein the underside of the central portion may be recessed upwards relative to the underside of said floats.
26. 26. A chair substantially as hereinbefore described, with reference to and as shown in figures 1 -5, or 6, or 7 or 8. aim INTELLECTUAL PROPERTY Urfio- | OF N.Z. 1 3 JUL 19S9 RECEIVED