GB2162131A

GB2162131A - Improvements in or relating to buoyancy tubes

Info

Publication number: GB2162131A
Application number: GB08515803A
Authority: GB
Inventors: Peter Cronin Gordon
Original assignee: Lifeguard Equipment Ltd
Current assignee: Lifeguard Equipment Ltd
Priority date: 1984-07-04
Filing date: 1985-06-21
Publication date: 1986-01-29
Also published as: GB8515803D0

Abstract

A buoyancy tube (10) is secured to a rigid hull of a boat by means of attachment comprising channels (20, 21) in which are received stiff reinforcing members (18,19) secured to the buoyancy tube (10) by securing strips (17). A sealing strip (50) is positioned between the tube (10) and a support portion (15) of the hull. When the tube (10) is inflated, a pull is exerted by the securing strips (17) on the reinforcing members (18, 19) which are thereby held in a position at which they cannot be released from the channel members. When the tube (10) is deflated, the pull is removed so that the reinforcing members (18, 19) can drop down to a position at which they can be removed from the channels (20, 21) in a lateral direction. <IMAGE>

Description

SPECIFICATION Improvements in or relating to buoyancy tubes This invention relates to buoyancy tubes and is particularly concerned with the attachment of an inflatable buoyancy tube to a boat having a rigid hull.

Normally, such a buoyancy tube, when attached to a rigid hull, extends along both sides of the hull from the bow to the stern. Normally also, the tube is permanently attached to the hull. If, however, the tube is fitted with a detachable system of attachment, then the tube carries at least one securing strip usually running substantially the full length of the tube and having a rope -known as a "bolt-rope" - stitched into the free edge of the strip. The rope enclosed by the strip is positioned in a retaining channel in or on the hull, whereby the tube is attached to the hull. The bolt rope is slidably engaged in the channel and therefore, in order to detach the buoyancy tube from the hull, the tube needs to be drawn off from the bow or stern and space is needed around the boat to enable the tube to be drawn off. Sometimes a considerable pulling force is needed.For these reasons, it is usually necessary to have the boat out of the water to detach the buoyancy tube. Moreover, the "bolt-rope" arrangement suffers from the problem that only a minor knock on the hull can distort the retaining channel and jam the "bolt-rope", thus causing considerably problems in removal of the tube.

An object of the invention is to provide an improved way of attaching a buoyancy tube to a rigid hull.

According to a first form of the present invention, there is provided a buoyancy tube attachment assembly comprising a rigid hull, a buoyancy tube extending along the side of the hull, at least one securing strip attached longitudinally to the buoyancy tube, a reinforcement member secured along the free edge of the (or each) securing strip, and a retaining channel for the (or each) securing strip longitudinally disposed in or on the side of the hull, the reinforcement member being engaged in the retaining channel of the hull and there being sufficient space within the channel to permit the reinforcement member to be moved within the channel between two positions, into a first of which the reinforcement member may be inserted and from a first of which the reinforcement member may be withdrawn, in each case in a direction transverse to the axis of the channel, and in a second of which the reinforcement member is retained by the channel against withdrawal therefrom, the reinforcement being retained in the second position as a result of a pull exerted by the securing strip on the reinforcement member.

In a second (alternaitve) form of the invention, which may be preferred, the reinforcement member is engaged in the retaining channel of the hull by sliding it axially into the channel rather than inserting it into the channel in a direction transverse to the axis of the channel and there is insufficient space within the channel to permit the reinforcement member to be inserted in or withdrawn from the channel in the direction transverse to the channel axis, i.e. the reinforcement member can only be inserted into or withdrawn from the channel by sliding it axially into or out of the channel.

The invention includes the buoyancy tube with attached securing strip(s) and reinforcement member(s) as already described for securing to the rigid hull. The invention further includes a method of attaching the buoyancy tube to the rigid hull by engaging the reinforcement member(s) in the retaining channel(s) in the manner already described.

The preferred buoyancy tube is an inflatable tube which, when inflated, provides the desired pull exerted by the securing strip on the reinforcement member to retain that member in the channel and, when deflated, allows the reinforcement member to be readily inserted in or withdrawn from the retaining channel in either the first or second form of the invention. The reinforcement member may be of any suitable form, for example, it may itself be a strip of reinforcing material enclosed within the edge portion of the securing strip, or it may be a moulded or extruded section which is attached directly to the tube or to the securing strip.In the first form of the invention, the reinforcing material is preferably such that the reinforcing strip is essentially rigid transversely to prevent its withdrawl from the retaining channel when the strip is in its second position but is sufficiently resilient longitudinally to allow the strip to conform to the longitudinal contour of the rigid hull, or it may be in multiple sections, thus allowing the deflated tube to be packed for storage when not in use.

In a second form of the invention the reinforcing strip has a degree of rigidity such that it will slide freely in the channel when the tube is deflated and is preferably in multiple sections. This second form of the invention has an advantage over the conventional "bolt-rope" arrangement which tends to jam because of the lack of rigidity of the rope.

In addition to the retaining channel(s), the rigid hull preferably includes support means for the buoyancy tube. These support means provide an abutment against which the inflated tube can press in order to provide the desired pull exerted by the securing strip on the reinforcement member. It is preferred that, where possible, a retaining channel is provided in the hull on each side of the support means and the buoyancy tube is provided with two securing strips, the reinforcement members of which engage in the channels on opposite sides (e.g. inboard and outboard sides) of the support means for the tube. At the transom of the hull, this arrangement may be reduced to only a single channel (on each side of the transom) in which the reinforcement member of the outboard securing strip on the buoyancy tube engages.The inboard securing strip and channel may thus terminate short of the transom. At the transom, support means for the buoyancy tube may also be provided.

The securing strips preferably run the full length of the buoyancy tube and rigid hull. In addition, securing straps may be provided at intervals along the length of the hull and at the transom to provide additional attachment of the buoyancy tube to the hull. Each strap may pass round a major portion of the tube and be detachably connected at its ends to the hull, for example by buckle fastenings.

Leakage of water into the interior of the hull of a boat of the kind having a rigid hull and an inflatable buoyancy tube releasably attached to the hull, is undesirable.

According to another aspect of the present invention, a boat comprises a rigid hull and a buoyancy tube adapted to be releasably attached to the hull so as to extend along the sides thereof, a sealing strip being provided between the hull and the buoyancy tube separately from the means for attachment The sealing strip may be attached either to the hull or the the buoyancy tube but is preferably bonded to the latter.

Where a transom is provided at the stern of the boat, a sealing strip is preferably also provided between the buoyancy tube and the transom.

The sealing strip is advantageously of a resilient foamed rubber or plastics material and may be pre-coated on one side with a self-adhesive layer.

The means for attaching the buoyancy tube to the hull may be the conventional "bolt-rope" as described above, or a securing strip having a reinforcement member and co-operating with a retaining channel, also as described above.

The invention will now be further described by way of example, with reference to the accompanying drawings, in which, briefly, Figure 1 is a plan view of a rigid hull fitted with a buoyancy tube, Figure 2 is a side elevation of the hull and tube shown in Fig.1, Figure 3 is a fragmentary transverse sectional view on a larger scale of part of the hull and tube showing the attachment of the tube to the hull by securing strips, the tube being inflated, Figure 4 is a section similar to that of Fig.3 but taken at a position where the securing straps are also present, Figure 5 is a rear elevation of the hull and tube shown in Figs. 1 and 2, and showing the transom, Figures 6 and 7 are fragmentary views on a larger scale of parts of the transom and buoyancy tube shown in Fig.5, Figure 8 is a fragmentary perspective view on a larger scale of the transom and buoyancy tube shown in Fig.5, Figure 9 is a fragmentary view corresponding to Fig.3 but showing the buoyancy tube in a collapsed state, Figure 10 is a sectional detail on line X-X of Fig.8, and Figure 11 is also a fragmentary view corresponding to Fig.3 but showing a modification of the arrangement shown in Fig.9.

Referring to the drawings in more detail, Figs. 1 and 2 show an inflatable buoyancy tube 10 attached to the sides of a rigid hull 11 (provided with a transom 12) by means described more fully below in connection with Figs. 3, 4, 6, 7 and 8. However, the positions of the securing straps 13 (see also Figs. 4, 6, 7 and 8) have been indicated in Figs. 1 and 2.

The means of attachment shown in Fig.3 extend along substantially the full length of the tube. A side portion 14 of the rigid hull, which is made of glass reinforced plastics material (GRP), includes a tube support portion 15 for the buoyancy tube 10, to which are attached fabric securing strips 16, 17 running the length of the tube. Reinforcement strips 18, 19 are enclosed in the free edges of the strips 16, 17 respectively and engage in channels in extruded aluminium channel forming members 20, 21 secured by stainless steel screws 22 to stainless steel strips 23 bonded into the GRP. The inflated tube 10 on its support 15 exerts a pull on the strips 16, 17 which holds the reinforcement strips 18, 19 in the recesses of the channel members 20, 21 in abutment with the lips 24, 25 of the channel members, whereby the buoyancy tube is attached to the rigid hull.

To avoid repetition, Fig.4 uses where possible the same numbers as in Fig.3 to identify the parts of the tube-to-hull attachment, but in addition Fig.4 includes a section through a securing strap 13, such straps being attached at evenly spaced distances along the tube length. Brackets 26, 27 of stainless steel plate are fixed to the hull portion 14 by a stainless steel bolt 28 (with associated locknut and washer). The strap 13, of nylon webbing, passes round the tube 10 and is secured at its ends to the brackets. The ends of the straps pass through slots 29 in the brackets 26, 27 and each end is permanently stitched at 13A to the centre bar of a three bar black nylon buckle 30 in contact with the bracket.As shown in Fig.4, the inflated tube 10 exerts a pull on the strap 13, which passes round it, and this pull holds the buckles 30 in contact with the brackets 26,27, whereby the strap secures the tube to the hull. When the tube is deflated, the buckles may be passed through the slots 29 into the position shown in Fig.4 (or may be withdrawn from that position through the slots).

The three bar buckle is wider than the slot whereby it cannot accidentally be withdrawn through the slot when the tube is inflated. To pass the buckle through the slot, the buckle needs to be positioned diagonally to the slot for insertion or withdrawal and this is possible due to the flexible nature of the webbing strap. A cover patch 31 covers the strap 13 where it passes around the tube 10.

To prevent water from leaking into the interior of the boat through the means 18,20 for attachment, between the tube support portion 15 and the tube 10 and through the means 19,21 for attachment, a sealing strip 50 is disposed between the support portion 15 and the tube 10. This sealing strip 50 extends throughout the length of the tube 10, as shown in Fig.1 by dotted lines. The sealing strip 50 is attached either to the tube 10 or to the support portion 15 and is preferably bonded to the tube so as to engage the support portion 15 approximately midway along its arcuate upper surface, as shown in Figs. 3 and 4. The sealing strip 50 may be of foam rubber or foam plastics. When the tube 10 is inflated, the sealing strip 50 is compressed from its shape shown in Fig. 9 to that of Figs. 3 and 4.

Referring now to Figs. 5 to 8 and 10, the inflated tube 10 and the rear of the transom 12 are indicated on each figure. In Fig.5, the location of the details shown in Figs. 6 and 7 is indicated generally by reference numbers 32 and 33 respectively.

Each end of the top edge of the transom carries a stainless steel bracket 34 (Figs. 6 and 8) bolted thereto. One end of a nylon webbing strap 13 is attached to the bracket 34 using a three bar nylon buckle 35 in the manner of Fig.4. The hull 11 below the transom 12 (Fig.7) extends as a support member 36 for the tube 10 and also carries an aluminium bracket 37 which is screwed to a tapping plate 38 bonded into the GRP hull. The other end of the nylon webbing strap 13 (which passes around the tube 10) is attached to the bracket 37 using another buckle 35. As may be seen from Figs.8 and 10, the end of the transom extends in flanges 39 which provide additional support for the tube 10. The flanges are flanked by rubber extrusions 40 attached with adhesive to the buoyancy tube 10.

Transom covers 41 are attached with adhesive to the buoyancy tube and rubber extrusions. A cover patch 42 for the strap 13 is also provided where the strap passes around the tube (Figs. 6 and 7).

The support member 36 (Fig.7) carries an aluminium channel forming member 20 which retains the reinforcement member 18 of the securing strip 16 attached to the tube 10, the arrangement being in the manner of Fig.3.

Resilient sealing strips 51 are arranged between the tube 10 and the ends of the transom 12, as shown in Figs. 6, 7 and 10. These strips 51 join on to the ends of the strip 50 and, like the strip 50, are preferably bonded to the tube 10 and made of foam rubber or plastics material. The strips 51 prevent water leakage between the tube 10 and the transom.

In Fig.9, the same reference numerals are used as in Fig.3, but the tube 10 is in a collapsed condition and the reinforcement member 18 of the strip 16 is shown in its first position into which it may be readily inserted and from which it may be readily withdrawn when the tube is collapsed. In Figs.

3, 4 and 7, the tube is shown in its inflated condition and the reinforcement member is shown in its second position in which it is retained by the channel forming member.

Figs. 3, 4, 7, 9 and 10 relate to the first form of the invention where the reinforcement member 18 may be inserted into or withdrawn from the channel in a transverse direction. In Fig.11 the two parts of the channel forming member 20 are closer together than in Fig.9 and the reinforcement member 18 can only be inserted into or withdrawn from the channel by sliding the member axially into or from the channel when the tube is collapsed as in the second form of the invention. The member 18 cannot be inserted into or withdrawn from the channel in a direction transverse to the channel axis.

The invention as illustrated above in the drawings has a number of advantages.

1. The tube can be readily removed from the hull without the need for special tools or other equipment, so that if damaged and requiring repairs, these can be effected at a service station without requiring the entire boat. A replacement can be then easily fitted whilst such service is being undertaken.

2. The tube can be replaced on the hull with the boat still afloat, given reasonable sea conditions.

This is in contrast to the "bolt-rope" arrangement described earlier.

3. The tube is held tightly against the hull and transom by means of the securing strips. The additional securing straps also give considerable strength to the attachment.

4. The mechanical attachment system has been shown to be stronger than the tube fabric.

5. The additional retaining straps allow rapid removal of the buoyancy tube from the hull utilising an interlocking stainless steel bracket and nylon webbing buckle.

6. The resilient sealing strips minimize leakage into the boat, despite the buoyancy tube being removably attached to the hull.

The removal of the tube from the hull requires that the tube be deflated first, when the retaining strap's buckles can be unlinked, followed by removal of the securing strips from the channels on the hull. It should, however, be noted that the tube cannot inadvertently be detached if it is deflated. It requires a positive action, as well as deflation to remove the tube.

Although no special tools are needed to remove the tube from the hull, removal of the tube can be facilitated by providing holes in the securing strip at intervals along its length, for example, approximately every 250 mm, so that a screwdriver can be inserted in the holes to disengage the reinforcement strip from the retaining channel in the hull when the tube is deflated. The channel-forming member may also be recessed at positions corresponding to the holes so that pressure can be applied from behind the securing strip.

Claims

1. A boat comprising a rigid hull and a buoyancy tube adapted to be releasably attached to the hull so as to extend along the sides thereof, a sealing strip being provided between the hull and the buoyancy tube separately from the means for attachment.

2. A boat as claimed in claim 1, in which the sealing strip is attached to the buoyancy tube.

3. A boat as claimed in claim 2, in which the sealing strip is bonded to the buoyancy tube.

4. A boat as claimed in any preceding claim, in which the hull includes support means for the buoyancy tube to provide an abutment against which the inflated tube can press to provide a reaction whereby a pull is exerted in the securing strip.

5. A boat as claimed in claim 4, in which a sim ilar means of attachment is provided at each side of said support means.

6. A boat as claimed in claim 4 or 5, in which said sealing strip is disposed between said support means and said tube.

7. A boat as claimed in any preceding claim, in which the means for attachment comprise a retaining channel longitudinally disposed in or on the side of the hull, an elongate reinforcement member receivable inside the retaining channel and a securing strip by which the reinforcement member is secured to the buoyancy tube.

8. A boat as claimed in claim 7, in which the reinforcement member is relatively stiff.

9. A boat as claimed in claim 7 or 8, in which there is sufficient space within the channel to permit the reinforcement member to be moved laterally within the channel between two positions, at a first of which the reinforcement member may be withdrawn and inserted, in each case in a direction transverse to the channel, and at a second of which the reinforcement member is retained in the channel against withdrawl therefrom in the said direction, the reinforcement member being held in the second position under the pull exerted by the securing strip.

10. A boat as claimed in claim 7, in which the relatively stiff reinforcement member is engaged in the retaining channel by sliding it longitudinally into the channel and cannot be removed from the retaining channel except by sliding it longitudinally.

11. A boat as claimed in claim 9, in which the inflatable tube, when inflated, exerts the said pull on the securing strip and, when deflated, allows the reinforcement member to be moved between the said positions.

12. A boat as claimed in any of claims 7 to 11, in which the reinforcement member comprises a strip of reinforcing material enclosed within the edge portion of the securing strip.

13. A boat as claimed in any of claims 7 to 11, in which the reinforcement strip comprises a moulded or extruded section integral with or attached to the securing strip.

14. A buoyancy tube attachment assembly comprising a rigid hull, a buoyancy tube extending along the side of the hull, at least one securing strip attached longitudinally to the buoyancy tube, an elongate reinforcement member secured along the free edge of the (or each) securing strip, and a retaining channel for the (or each) securing strip longitudinally disposed in or on the side of the hull, the reinforcement member being engaged in the retaining channel of the hull and there being sufficient space within the channel to permit the reinforcement member to be moved laterally within the channel between two positions, at a first of which the reinforcement member may be withdrawn and inserted in each case in a direction transverse to the channel, and at a second of which the reinforcement member is retained by the channel against withdrawal therefrom, the reinforcement being retained in the second position as a result of a pull exerted by the securing strip on the reinforcement member.

15. A modification to the attachment assembly claimed in claim 14, in which the reinforcement member is engaged in the retaining channel of the hull by sliding it longitudinally into the channel rather than inserting it into the channel in a direction transverse to the channel and there is insufficient space within the channel to permit the reinforcement member to be inserted in or withdrawn from the channel in the direction transverse to the channel, i.e. the reinforcement member can only be inserted into or withdrawn from the channel by sliding it longitudinally into or out of the channel.

16. An attachment assembly as claimed in claim 15, in which the buoyancy tube is an inflatable tube which, when inflated, provides the desired pull exerted by the securing strip on the reinforcement member to retain that member in the channel and, when deflated, allows the reinforcement member to be readily inserted in or withdrawn from the retaining channel in either the first or second form of the invention.

17. An attachment assembly as claimed in claim 14, 15 or 16, in which the reinforcement member is itself a strip of reinforcing material enclosed within the edge portion of the securing strip.

18. An attachment assembly as claimed in claim 14, 15 or 16, in which the reinforcement member is a moulded or extruded section which is attached directly to the tube or to the securing strip.

19. An attachment assembly as climaed in claim 14, in which the reinforcing strip is essentially rigid transversely to prevent its withdrawal from the retaining channel when the strip is in its second position but is sufficiently resilient longitudinally to allow the strip to conform to the longitudinal contour of the rigid hull, but may be in multiple sections, thus allowing the deflated tube to be packed for storage when not in use.

20. An attachment assembly as claimed in claim 15, in which the reinforcing member has a degree of rigidity such that it will slide freely in the channel when the tube is deflated.

21. A boat constructed substantially as herein described with reference to and as illustrated in the accompanying drawings.