FIELD OF THE INVENTION The present invention relates to access openings and ramps for entering and exiting boats and more particularly, although not necessarily exclusively, to so-called "diver's, "or similar, doors for boats having inflatable or foam components.

BACKGROUND OF THE INVENTION U. S. Patent No. 5,579, 714 to Hemphill, incorporated herein in its entirety by this reference, discloses a diver's door for inflatable boats. As noted in the Hemphill '714 patent, the door comprises a removable support section including a means for releasably attaching the support section to the deck of a boat and an inflatable support element attached to the support section such that the tube element and the removable support section are removable as a single unit from the deck of a boat.

See Hemphill'714, col. 2,11. 38-43. When at least partially deflated, the inflatable tube may be fitted between the main inflatable elements of the boat, attached to the boat deck, and then fully inflated to form (together with the main inflatable elements) a continuous sidewall for the boat. By contrast, partially or wholly deflating the tube and releasing its attachment to the deck allows removal of the tube, thus forming an entry or exit way onto the deck. See id. , col. 4,11. 33-53.

U. S. Patent No. 5,832, 864 to Hemphill, also incorporated herein in its entirety by this reference, discloses alternative diver's doors for inflatable boats. In these alternative versions, the inflatable tube may include a flange adapted to be received by a slot in the hull of the boat. According to the Hemphill'864 patent, engagement of the flange and slot inhibits water from entering into the boat when the inflatable tube is positioned between the main inflatable elements. The flange preferably is flexible, further, "to facilitate insertion of the diver ['s] door into position between [the main]

inflatable tube elements"of the boat. See Hemphill'864, col. 3,11. 63-64 (numerals omitted).

Detailed in U. S. Patent No. 6,371, 040 to Hemphill, et al. , incorporated herein in its entirety by this reference, are collar assemblies for watercraft including boats.

Embodiments of the assemblies may include tubes having inflatable bladders wholly- or partially-surrounded by foam material. In some situations, incorporating both inflatable bladders and foam material into the assemblies allows them to be more durable than purely inflatable tubes, as they are less subject to deflation because of, for example, punctures.

U. S. Patent No. 5,878, 685 to Hemphill, et al. describes yet another foam collar system for boats. Acting as a fender, the system is formed from a molded polymeric foam material with reinforcing and surface coatings. Like the previously-discussed patents, the Hemphill'685 patent likewise is incorporated herein in its entirety by reference.

SUMMARY OF THE INVENTION The present invention provides alternative access openings for boats having collars or similar assemblies or for boats having vertical sidewalls. The invention also provides ramps extending from the access openings. By supplying both access openings and ramps, the components of the invention facilitate persons entering and exiting the corresponding boats.

In some embodiments of the invention, the collar assembly includes a segment that is split in one or more ways and adapted to unfold, or otherwise open, along the splits to form a ramp extending outward from the hull of the associated boat. If desired, a step may be attached to the portion of the segment farthest from the hull when unfolded. The step advantageously may function as a latch when stowed, although such functioning is not mandatory. Handles may be included adjacent the edges of the segment so as to be exposed, and thus useful, when the segment is unfolded. Alternatively or additionally, handles may be incorporated onto any lateral or other surface exposed in use.

Because any unfolded portion of the segment remains in place along the hull, the corresponding area is not completely open to the water. This reduces the possibility that the vessel might flood when the ramp is deployed. Employing a ramp facilitates entry onto and exiting from the boat and may assist a crewmember sliding

or dragging a person or object from the water into the boat. Indeed, deploying the ramp may, in some instances, provide an area bounded by the ramp and hull in which a person or object may be corralled, or captured, temporarily, which could be valuable to a lone crewmember on a boat tasked both with maneuvering the boat and rescuing, or retrieving, the person or object from the water.

In other embodiments of the invention, part of the segment is removable from the remainder so as to reduce the height of the collar assembly in the area of the segment. Typically the removable portion will be made of foam. However, it could be inflatable as long as its removal does not preclude its re-inflation thereafter.

Yet other embodiments of the invention are especially useful with the fenders illustrated in the Hemphill'685 patent when used with rigid-hulled boats. Such boats may include a hinged segment of the hull and fender that opens both to expose an access opening into the boat and to create a ramp. A latch mechanism may be used to maintain the segment in place when not in use as a ramp. Embodiments of the innovative assemblies further may be self-contained if desired and fitted (even retroactively) into openings made into sides of any boats with sufficiently low freeboard.

It thus is an optional, non-exclusive object of the present invention to provide access openings for boats.

It is another optional, non-exclusive object of the present invention to provide ramps for boats.

It also is an optional, non-exclusive object of the present invention to provide collar assemblies having segments adapted to unfold, or otherwise open, to provide both the access openings and ramps.

It is a further optional, non-exclusive object of the present invention to provide ramps that, when not in use, may function as portions of the side walls of boats.

It is, moreover, an optional, non-exclusive object of the present invention to provide steps that may be connected to the ramps, with such steps advantageously (although not necessarily) also functioning as part of latching mechanisms designed to maintain the ramps in place when not in use.

Other objects, features, and advantages of the present invention will be apparent with reference to the remaining text and the drawings of this application.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A-D illustrate an exemplary collar segment of the present invention attached to a boat.

FIGS 2-5 illustrate aspects of a rigid-hulled boat having a hinged segment of the hull and fender, with the hinged section adapted to open to form an access opening and ramp.

DETAILED DESCRIPTION FIG. 1A depicts, in cross-section, part of a collar assembly 10 of the present invention. Assembly 10 may be mounted, or otherwise appropriately attached, to hull H or other structure of boat B and include a segment 14 of one or more buoyancy elements. Although FIG. 1A shows segment 14 as being tubular, with circular cross- section, the segment 14 need not be so configured. Segment 14, further, typically is made, at least in part, of foam material, although this too is not mandatory. Instead, for example, segment 14 may comprise one or more inflatable bladders or similar components. Segment 14 could comprise both foam and inflatable materials in certain instances.

Regardless of composition, the segment 14 of FIG. 1A is illustrated as having two portions, upper portion 18 and lower portion 22, with the terms"upper"and "lower"being with respect to a static water line when segment 14 is in the position of FIG. 1A. In this embodiment of segment 14, portions 18 and 22 are connected (as, for example, by hinges) along axis 24, a point of which is shown in FIG. 1A, so that surface 26 of portion 18 abuts surface 30 of portion 22. Hence, with segment 14 in the"closed, "or"folded"position of FIG. 1A, it may function as a contiguous part of the buoyancy elements of boat B.

FIG. 1B details segment 14 in the"open, "or"unfolded,"position, with surfaces 26 and 30 exposed. In this position, segment 14 provides an area of decreased height of the buoyancy elements, thus supplying an access opening into boat B. Because upper portion 18 rotates partially below lower portion 22, segment 14 additionally provides a ramp sloping upward from the water line toward the access opening. Indeed, if desired handles 34 may be provided on either or both of surfaces 26 and 30, as shown in FIGS. 1C-D, to facilitate use of the unfolded segment 14 as a

ramp. Likewise, in some cases exterior surface 36 of portion 18 may abut and bear against hull H for support when segment 14 is deployed as a ramp.

Step 38 optionally may be included as part of assembly 10. If present, step 38 preferably is weighted and attached to portion 18 so that it depends therefrom toward the water line when segment 14 is unfolded. If appropriately configured, further, step 38 may also function as a latch if desired, assisting attachment of assembly 10 to hull B when segment 14 is closed.

Hence, to open segment 14 when it is closed (as in FIG. 1A), one need merely unlatch portion 18 and rotate it about axis 24 in the direction of arrow A until exterior surface 36 abuts hull H (as in FIG. 1B) or surfaces 26 and 30 otherwise are adequately exposed for use. Thereafter to close segment 14, portion 18 need merely be rotated in the opposite direction, as denoted by arrow B, and relatched to hull H. Assembly 10 thus provides a device useful not only as a buoyancy element, but also as a ramp and access opening for boat B. Those skilled in the art will recognize that assembly 10 may be structured differently than depicted in FIGS. 1A-D and that, for example, segment 14 possibly could be configured so that its opening occurs through rotation of portion 14 rather than portion 18. As yet another alternative, segment 14 could open as a result of portion 18 translating (rather than rotating) or otherwise moving relative to portion 22.

FIGS. 2-5 illustrate an analogous assembly 100 for use with a rigid-hulled boat B'or a rigid-inflatable boat ("RIB"). Boat B'may include rigid sidewalls 104 to which foam (or other) material 108 may be mounted as fenders. In this version of the invention, either or both sides 104 may include segment 112 moveable with respect to the remainder of the side 104. Segment 112 additionally may be hinged or otherwise connected to hull H'of boat B'so that it may pivot toward the water line. When segment 112 is closed, as in FIGS. 2-3, it may function as a contiguous portion of assembly 100. When segment 112 is pivoted (and thus is open) in the manner depicted in FIG. 4, by contrast, it may function as a ramp to facilitate entry onto and exit from boat B', particularly for persons entering from or exiting to the water. Such persons enter and exit from access opening 116, the space present in assembly 100 when segment 112 is open.

Shown in FIGS. 2-4 is optional step 120, which if desired may be incorporated onto the side of segment 112 opposite the axis about which it pivots. When segment 114 is open, step 120 may be used to support a person commencing use of the

segment 114 as a ramp. When segment 112 is closed, step 120 may perform instead as a hand rail for persons within boat B'. FIG. 3 additionally details an exemplary mechanism 124 for latching segment 112 in the closed position from within boat B', although those skilled in the relevant art will recognize that any suitable mechanism may be used instead.

The foregoing is provided for purposes of illustrating, explaining, and describing exemplary embodiments and certain benefits of the present invention.

Modifications and adaptations to the illustrated and described embodiments will be apparent to those skilled in the relevant art and may be made without departing from the scope or spirit of the invention. As non-limiting examples of such modifications, segment 14 or 112 could be completely separable from the surrounding elements or wall, respectively, or portion 18 of segment 14 could be separable from portion 22 (in which event it would be connected directly to hull H rather than indirectly via portion 22 when segment 14 is deployed as a ramp).