Ships – Boats – boat component – or attachment – Collapsible
Reexamination Certificate
2002-04-01
2004-05-04
Swinehart, Edwin (Department: 3617)
Ships
Boats, boat component, or attachment
Collapsible
Reexamination Certificate
active
06729260
ABSTRACT:
FIELD OF THE INVENTION
The present invention is for a collapsible boat which is extremely lightweight and easy to assemble. The collapsible boat has particular utility for use as a kayak.
BACKGROUND OF THE INVENTION
Collapsible boats such as canoes and kayaks have classically had a frame which supports a skin which forms the hull of the boat. The skin is frequently loosely fitted over the frame, and then tensioned over the frame by inflatable chambers either contained in the skin or positioned between the skin and the frame. When the chambers are inflated by the user, the skin is tightened over the frame to provide rigidity to the resulting boat.
In the case of folding kayaks, the skin is formed with a deck which limits the ability to fit the skin over the frame, since the skin completely surrounds the frame at the ends. In such case, the frame is typically formed in two halves which are inserted into the skin and then assembled together. In some designs, the connection of the frame halves together also serves to expand the frame longitudinally, providing some degree of tension against the skin.
The use of an independent, free-standing frame complicates the structure of the boat and increases weight. In the case of canoes, which typically lack decks, it has been found advantageous to employ the tension of the skin to secure the frame elements together. Such boats are taught in U.S. Pat. Nos. 5,915,327 and 6,314,904, by the inventor of the present invention. These boats employ a frame having a telescoping keel stringer, and the frame is expanded longitudinally by the action of supplemental stringers. The supplemental stringers forcibly engage the telescoping keel stringer at each end and increase the effective length of the telescoping keel stringer as the supplemental stringers are fitted into position with respect to the other elements of the frame. The increased length of the telescoping keel stringer acts to tension the frame against the skin longitudinally. Further tensioning of the skin over the frame is provided by inflatable compartments. While such boats have achieved significant reductions in weight, further simplification of the frame structure would be advantageous to further reduce weight and to facilitate fabrication. Additionally, the end structure employed in these boats limits the shape of the ends to a relatively broad curve, limiting the visual appearance of the resulting boat and making fitting a deck to the boat for use as a kayak problematic.
Thus, there is a need for a collapsible boat having reduced weight and a simplified structure. There is also a need for a lightweight collapsible boat which is suitable for use as a kayak.
SUMMARY OF THE INVENTION
The collapsible boat of the present invention has a frame which is covered by a hull skin. The frame includes a pair of gunwales, each having a gunwale first end and a gunwale second end, and a series of ribs, each of which is attached to the gunwales by gunwale-engaging clips. The frame also includes a keel stringer, which terminates at a first stem element and a second stem element. The first stem element terminates at a first stem element end, while the second stem element terminates at a second stem element end.
Preferably, the gunwales and the keel stringer are each formed of multiple pieces of tubing, slidably connectable and maintained together with shock cord in the manner known in the art for forming collapsible tubular members. The ribs are preferably each formed of a single piece of tubing. The keel stringer has rib-engaging clips affixed thereto, to which a central portion of each of the ribs can be lockably engaged. Preferably, each rib has a clip-engaging attachment designed to lockably mate with one of the rib-engaging clips of the keel stringer. Such rib-engaging clips and clip-engaging attachments are described in U.S. Pat. No. 6,314,904 of the present inventor, incorporated herein by reference.
Means are provided for securing the gunwale first ends with respect to the first stem element end and for securing the gunwale second ends with respect to the second stem element end. These means complete the formation of the frame and, when longitudinal tension of the frame against the hull skin is provided, these means allow such longitudinal tension to secure the various elements of the frame together.
One aspect of the present invention resides in a preferred structure for securing the gunwale first ends with respect to the first stem element end. With this preferred structure, each of the gunwale first ends has a first end connector which is connectable to the first stem element end. Preferably, the first end connectors are freely movable into engagement with the first stem element end from above, and the first stem element end supportably engages the first end connectors to prevent further upwards motion of the first stem element with respect to the gunwale first ends.
The connection of the gunwale first ends to the first stem element end can be facilitated by the use of a first bracket attached to the first stem element end, in which case the first end connectors are designed to be connectable with the first bracket. In a preferred embodiment, the first bracket has a pair of upwardly-opening slots and the first end connectors are formed by bolts with shanks sized to slidably engage each of the slots, while the heads of the bolts are sized to retain the bolts in the slots.
Alternatively, the first stem element end can be directly engaged by the first end connectors on the gunwale first ends. In one preferred embodiment, the first stem element end has an opening, and the first end connectors are formed with pins which are insertable into the opening.
A similar structure can be employed for securing the gunwale second ends with respect to the second stem element end, in which case the gunwale second ends each have a second end connector thereon which is connectable to the second stem element end.
The hull skin of the collapsible boat has a pair of gunwale sleeves which slidably engage the gunwales of the frame. The hull skin also has a pair of side panels attached to the gunwale sleeves, and a bottom panel attached to the side panels. The side panels and the bottom panel are configured to secure the side panels to each other at the ends of the boat. Preferably, the bottom panel has bottom panel extensions at each end to which the side panels are attached, the bottom panel extensions forming the regions of the hull skin which overlie the first and second stem elements.
Another aspect of the present invention resides in the optional use of the hull skin to secure the gunwale ends to the corresponding stem element end at one or both ends of the collapsible boat, this option being discussed hereinafter in terms of the gunwale second ends and the second stem element end. When this option is employed, the means for securing the gunwale second ends is provided by closed sleeve ends on the gunwale sleeves in combination with means associated with the hull skin for securing the gunwale second ends together and preventing upwards motion of the second stem element end. The closed sleeve ends of the gunwale sleeves limit the longitudinal position of the gunwales with respect the gunwale sleeves by blocking motion of the gunwales when the gunwale second ends are engaged with the closed sleeve ends. Preferably, the gunwale second ends are engaged by the closed ends when at a position where they reside in close proximity to the second stem element end after the frame is assembled. The means for securing the gunwale second ends together and for preventing upwards motion of the second stem element end act both to maintain the gunwale second ends in close proximity to each other and to limit any upward motion of the second stem element end. The use of the closed sleeve ends serves to provide greater accuracy in alignment between the frame and the hull skin, and can be employed in collapsible boats having various means for securing the gunwale first ends with respect to the first stem element end.
The closed ends
Semprebon Jeffrey E.
Swinehart Edwin
Weins Michael J.
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