Inflatable hull structures and demountable joint between elongated structural elements

Claim 2

An inflatable hull structure for a multihull boat, comprising an elongate inflatable hull tube, a rigid tubular hull beam, said hull beam being substantially coextensive in length with said inflatable hull tube, said inflatable hull tube being demountably anchored to said hull beam, a forward end member at the tip of said inflatable hull tube, the forward end of said inflatable hull tube tapering down to said forward end member, and a bow member, said bow member being formed with bow cheeks meeting at a bow stem, said bow member having a socket engaged upon the forward end of said hull beam in a manner resisting rotation, said inflatable hull tube forward end member and said bow member having interfitting conformations, and releasable securing means holding said bow member and said forward end member of said inflatable hull tube in engagement.

Claim 3

The structure according to claim 1, in which said forward end member is a dished plate spaced below said hull beam and having a central depression which snugly engages on a circular boss on the bow member, said boss being surrounded by a shallow angular depression receiving the outer portion of said dished plate to ensure positive location of the forward end of the hull in all radial directions with respect to said bow member, said releasable securing means comprising a length of cord secured to the hull tube and passing through the eye of a nylon slider slidably secured in a short vertical track fixed to the aft face of the bow member, and a cloth piece having a fold adjacent to the underside of said hull beam and extending downward into bonded engagement with the forward portion of the hull tube adjacent and between the bow cheeks of the bow member.

Claim 4

In a multihull boat comprising a plurality of hulls each having a hull beam and a cross beam for connecting said hulls, the improvement comprising a demountable joint between a first said beam and a second said beam, said first beam having first and second sheet metal brackets on opposite lateral face portions thereof, the brackets extending laterally of the first beam and each having an aperture receiving a respective fastening element, both brackets being secured by said fastening elements to the second beam at positions spaced apart along the latter, the first bracket having an extension forming a bridge across the first beam and a registration portion extending from said bridge and secured to the apertured part of the second bracket.

Claim 5

In a multihull boat comprising a plurality of hulls each having a hull beam and a cross beam for connecting said hulls, the improvement comprising a demountable joint between a first said beam and a second said beam, said first beam having first and second sheet metal brackets on opposite lateral face portions thereof, the brackets extending laterally of the first beam and each having an aperture receiving a respective fastening element, both brackets being secured by said fastening elements to the second beam at positions spaced apart along the latter, the first bracket having an extension forming a bridge across the first beam and a registration portion extending from said bridge and secured to the apertured part of the second bracket.

Claim 6

The structure defined in claim 3, wherein the said registration portion is formed with an aperture which is aligned with the aperture in the second bracket and a bush extends through these two aligned apertures to secure the registration portion of the first bracket to the second bracket and to form the aperture for the relevant fastening element.

Claim 7

The structure defined in claim 4, wherein the arrangement of first and second brackets is repeated on the first beam in a position where they will be on the opposite side of the second beam, with the bushes of the two brackets aligned.

Claim 8

The structure defined in claim 5, wherein said two first brackets and a spacing portion therebetween are formed from a single piece of sheet metal.

Claim 9

A rudder assembly comprising a rudder stock for pivotal mounting on the stern of a hull structure, a rudder blade pivoted adjacent its upper end to the rudder stock about a horizontal axis, said rudder blade having alternate operative and raised positions achieved by pivoting thereof about said axis, a hinged linkage comprising a lower link hinged to a point on the rudder blade, which point is below the pivot of the rudder blade with the rudder blade in its operative position, said lower link being hinged at its upper end to a lower end of an upper link hinged at its upper end to a first point on the rudder stock above said rudder blade pivot, elastic means acting between the hinge point of the hinged linkage and a second point on the rudder stock, the line of action of the elastic means lying below said first point with the rudder in its operative position.

Claim 10

A rudder assembly comprising a rudder stock for pivotal mounting on the stern of a hull structure, a rudder blade pivoted adjacent its upper end to the rudder stock about a horizontal axis, said rudder blade having alternate operative and raised positions achieved by pivoting thereof about said axis, a hinged linkage comprising a lower link hinged to a point on the rudder blade, which point is below the pivot of the rudder blade with the rudder blade in its operative position, said lower link being hinged at its upper end to a lower end of an upper link hinged at its upper end to a first point on the rudder stock above said rudder blade pivot, elastic means acting between the hinge point of the hinged linkage and a second point on the rudder stock, the line of action of the elastic means lying below said first point with the rudder in its operative position.

Claim 11

A rudder assembly according to claim 7, wherein a tiller arm is secured to the rudder stock, a substantially inextensible and flexible member connects a leading part of the tiller to an upward extension of said upper link so that the rudder blade can be swung to its upper position by pulling on the flexible member.

Claim 12

A rudder assembly according to claim 8, wherein said line of action of said elastic means is substantially parallel to said tiller arm.