GB2441519A

GB2441519A - Pivotable keel and rack arrangement for a sailboat

Info

Publication number: GB2441519A
Application number: GB0617396A
Authority: GB
Inventors: Philip Simon Gower
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-09-06
Filing date: 2006-09-06
Publication date: 2008-03-12
Also published as: GB0617396D0

Abstract

A sailboat keel, which in use is adapted for pivoting movement, is engageable with a rack 14 such that the keel rotates about said rack during said pivoting movement. The rack may have a curved surface with engagement means such as gear teeth 22 while the keel may include a complementary toothed cog 19. The keel may comprise a ballast bulb 2 linked to a foil (4, Fig 3) which in turn is linked to the toothed cog by a pivot bar 5, link arm 7 and link rod 8. The keel may in use be pivotably mounted to a base portion of a sailboat with the rack being mountable on a bulkhead 6 of the sailboat, or on a reinforced base frame of the sailboat.

Description

1 2441519 Device for Boat The invention relates to a ballast keel fbr a

boat, in particular a moveable keel for a pleasure or race boat.

Many types of boats have keels, which provide ballast for the boat to counter the capsize moment caused by the effect of the wind on the sails. Cniisers used for pleasure boating and racing sail boats both include keels, the keels comprising a weighted portion extending externally from the base of the boat in a downward direction, the weight of the keel generally depending on the size of the boat. The keel further comprises a portion which extends into the base of the boat, into the bilges.

Sailboats arc subject to a fluctuating directed force when the sails are out and the wind is up, and the keel provides a righting moment to counter the effects of the wind on the sails and thereby on the boat.

Moveable, or canting, keels are well known, and provide a counterbalance to the force of the wind on the sailboat. As the sail boat is subject to the force of the wind in a particular direction, the moveable or canting keel may be moved to balance the force and to keep the boat afloat and oriented safely on the surface of the water.

Conventionally the portion of the moveable keel in the bilge area is attached to the hull by a hydraulic rani, and the rain is powered by an electric motor or winch to move the keel The moveable keel is moved by a sailor in response to the wind on the sails. However the extent of the keel movement is restricted by the limitations of the rain. In addition theramisattachedtothehullandthehullissubjecttoatremendouspomtloadatthe point of attachment as this is the point at which the forces to move the ballast keel are concentrated. This places a great deal of strain at these points of attachment and while the hull is conventionally reinforced to accommodate this, such reinforcement can often fail with catastrophic results for the boat and potentially for the sailors.

spec 6 Sep 06.doc According to the present invention these problems are overcome by providing a greater arc for the moveable keel to swing through, in which movement of the keel is controllable by the sailor, and in which the forces from the keel are spread evenly across a bulkhead and then around the hull.

The present invention provides, according to a first aspect a device for a sailboat including a keel mountable on a boat; the keel including a rack, the rack co-operatively engaging with portions of said keel such that said keel rotates about a base of the boat.

Preferably the rack includes a curved surface.

Preferably the curved surface includes engagement means.

Preferably the engagement means comprise gears.

Preferably the keel comprises a ballast bulb linked to a foil, the foil linked to a pivot bar, thepivotbarlinkedto an ann andthe ann linkedto arod, therod including engagement means to engage with said gears.

Preferably the rod engagement means comprises a toothed cog.

Preferably the keel is pivotably mountable on the sailboat adjacent the base.

Preferably the rack is mountable on a bullthead of the boat.

Preferably the rack is mountable on a reinforced base frame of the boat.

spec 6 Sep (}6.doc Preferably the arrangement is such that the keel is rotatable about the base of the boat responsive to the cog moving along a geared surface of the rack.

The present invention provides, according to a second aspect a boat including the keel asdescribed,andfurther,touseofsuchakeelinaboat.

A preferred embodiment of the invention will now be described by way of example only and with reibrence to the accompanying drawings in which: FigurclshowsapriorartkeeL Fig 2 shows a perspective, angled view of a keel in accordance with a first embodiment of the present invention from a first direction, Figure 3 shows a further perspective angled view of the keel of Figure 2 from a second direction, Figure 4 shows a front view of the keel of Figure 2, and Figure 5 shows a perspective view of a keel in accordance with a first embodiment of the present invention with the keel at an extreme position.

Figure 1 shows a conventional canting keel with a ballast bulb 2 and foil 4, the keel rotatable about a pivot point 17 and moveable between a first and second position dependent on a hydraulic ram 40.

Figures 2, 3 and 4 show, from different angles, a keel 1 comprising a ballast bulb 2, Ibil 4, pivot barS, arm 7 and rodS, the foil 4 conventionally linking the ballast bulb 2 and barS. Each end of bar 5 includes a seal 10 for preventing water entering the bilge of the boat, and also includes a bearing portion 13 including bearings 11 at each end to assist in the movement of the keel. One end of pivot bar 5 is shown attached to and supported by a cross frame 16 of the hull at pivot point 17. The other end may be similarly supported (not shown). Foil 4 extends outwardly and away from the cross frame 16 and hull. BarS is further attached to an arm 7, which extends into the bilge spec6SepOó.doc of the boat, and is attached at the end remote bar 5 to a rod 8 at point intermediate the two ends of rod 8.

One end of rod 8 includes a cog 19 with geared teeth 20, which engage with a rack 14, the teeth 20 of the cog 19 engaging with teeth 22 on an upper surface of the rack 14 such that the rod 8 can move across the surface of the rack 14 causing the ballast bulb 2, foil 4, pivot bar 5 and arm 7 to rotate about the attachment points 17 of the rod 5 with cross frame 16, and thus the hull of the boat.

As can be seen from Figure 4 the rack 14 includes a first end 25 and a second end 26, the first end 25 adjacent the cross frame 16 and hull at a first side of the boat and the second end 26 adjacent cross frame 16 and the hull at a second side of the boat, a surface of the rack between the first 25 and second 26 ends following a curved path.

The cog 19 can move along this curved surface by engagement of the teeth 20 of the cog 19 with the geared teeth 22 on the curved surface of the rack 14. Components of the keel, such as the ballast bulb 2 and foil 4 follow a similar path to the cog, but in the opposite direction, responsive to movement of the cog across the curved surface of the rack 14.

The keel thus rotates about pivot point 17, and pivot bar 5, the pivot point 17 forming the centre of a circle, a circumference of which is followed by the curved surface of the rack 14. The ballast bulb 2 and foil 4 rotate through an angle about pivot bar 5, the angle being substantially the same as the angle of the segment of the circle of which the curved surface of the rack is the circumference and the pivot point 17 in the centre. The angle of the arrangement of the present invention provides for greater movement of the keel than that provided by prior art canting keels. The ballast bulb 2 and foil 4 Ibllow a curved path governed by the curved surface of the rack 14, and the path along which the keel can travel in the water is thus limited only by the length of the curved surface of rack 14.

spec 6 Sep 06.doc It is notable that the movement available to the keel of the present invention is greater than the movement available to conventional canting keels, limited as they are by present conventional moving means such as a hydraulic ram.

In the arrangement of prior art canting keels, seen in Figure 1, the hydraulic ram restricts the movement of the keel and has the further disadvantage that the hydraulic ram is anchored to the hull at specific points 3, the forces exerted on the hull by movement of the keel being directed at those specific points. The points 3 on the hull are reinforced but can fail for example if the forces on the boat are high, and such reinforcement affects the weight of a boat which might be significant, for example for a racing boat.

Figure 2 shows bolts 23 positioned on the rack 14, the bolts operative to attach the rack to a bulkhead of the boat. The bulkhead thereby bears the considerable forces exerted on the boat by movement of the keel, and the forces are spread over an area of the bulkhead rather than being located on a particular part of the base of the hull. This increases the robustness of the arrangement and increases the safety and security of the boat, in respect of prior art arrangements, as failure of the bulkhead to sustain the load will not necessarily rip a whole in the base of the boat, as failure in the prior art arrangements is inclined to.

The cog 19 can move across the surface of the rack, and according to one embodiment of the present invention is urged to do so by fbr example an hydraulic drive means (not shown) attached adjacent one end of the rod 8 upon which is mounted the cog 19.

The hydraulic drive means is conventional and can urge the cog to move in either direction, towards first end 25, or second end 26, of the rack 14. The drive means may include an eleciric motor (not shown) and may be operated by a member of the crew.

The cockpit of the boat may include, in addition to those features necessary to pilot the boat, a button to operate the hydraulic motor and cause the cog 19 to move to a spec6SepO6.doc desired position on the curved surface of the rack, thereby causing the ballast bulb 2 of the keel 1 to move to a desired position in the water. The arrangement may be such that the length of time the button is engaged directly affects the length of the path fbliowed by the cog on the rack and the ballast bulb of the keel in the water.

Figure 3 shows a view of the arrangement of Figure 2 from the opposite direction showing the cog 19 resting on the rack 14 and the teeth 20 of the cog 19 engaging with the teeth 22 of the rack. The cog can move across the surface of the rack via engagement of the teeth 20, 22, in response to which the ballast bulb 2 foil 4, ann 7 and rod 8 rotate about pivot bar 5 and the attachment point 17 of bar 5 to the cross frame 16 and hull.

Figure 4 shows a front view of the arrangement of Figures 2 and 3 with the cog 19 at a position approximately mid-way between the first 25 and second 26 ends of the rack 14. The cog can move along the suthce of the rack between the first and second positions, and during this motion the ballast bulb 2 of the keel moves between two positions, the range of movement being greater than is available in present, conventional keels.

Figure 5 shows the arrangement of Figure 4 with the cog 19 adjacent the first end 25 oftherackl4. A8canbeseen,withthecogl9adjacefltthisfirstefldthebase2is positioned at a first extreme position. With the cog 19 adjacent the second end 26 of the rack 14 the base 2 is positioned at a second extreme position.

The invention is not restricted to the details of the foregoing embodiment. For example, the Figures show a single cog 19 on rod 8 and a single rack 14, but it is contemplated that the rod 8 is not limited to engage with a single rod, for example the second end of the rod 8 may include a cog 19 with teeth 20 for engagement with a further rack 14 attached, for example by bolting with bolts, to a further bullthead. The bar 5 may include at least one additional arm 7 with a respective rod 8 engageable with a further rack 14 attached to a further bulkhead. The rack may not be bolted to a spee 6 Sep 06.doc bullthead but may be attached to a half bulkhead, this reinforced portion extending over the base of the hull adjacent the rack and not limited to the region in which the rack may attach to the hull; the teeth 20 on rack 14 may not necessarily be positioned on a top surface of the rack, but may be positioned elsewhere, the geared teeth arrangement may be replaced by an alternative arrangement for controlling the movement of the rod 8 across the rack 14.

spec 6 Sep 06.doc

Claims

I. A device for a sailboat including: a keel; a rack, wherein the rack is co-operatively engageable with said keel such that said keel rotates about said rack.
2. A device as claimed in claim 1 wherein said rack includes a curved surface.
3. A device as claimed in claim 2 wherein said curved surface includes engagement means. S. * S * S..

* :*
4. A device as claimed in claim 3 wherein said engagement means comprise gears.
5. A device as claimed in claim 4 wherein said keel includes means for engaging with said rack gears. *5 S * S

S

S.....

* 20
6. A device as claimed in claim 5 wherein said keel further comprises a ballast bulb linked to a foil, said foil linked to said keel engagement means.
7. A device as claimed in claim 6 wherein said keel further comprises a pivot bar linked to said foil, the pivot bar further linked to an arm linked to said keel engagement means.
8. A device as claimed in claim 7 wherein said keel further comprises an arm linked to said pivot bar, said arm further linked to a rod, including said engagement means.

Claims 9Mar07
9. A device as claimed in any one of claims 5 to 8 wherein said keel engagement means comprises a toothed cog.
10. A device according to any one of the preceding claims wherein the keel is pivotably mountable on a sailboat adjacent a base of said sailboat.
11. A device according to any one of the preceding claims wherein the rack is mountable on a bulkhead of a boat.
12. A device according to any one of the preceding claims wherein the rack is mountable on a reinforced base frame of a boat.
13. A device according to any one of the preceding claims, the arrangement being * * such that said keel is rotatable about said rack responsive to said cog moving along a surface of said rack. ** S * .
14. A boat including the keel of any one of the preceding claims. *5 *.
15. Use of a device as claimed in any one of the preceding claims.

55.5.. * 20
16. Use of a device as claimed in any one of the preceding claims in a sail boat.
17. Use of a device as claimed in any one of the preceding claims in a racing boat.
18. A device substantially as herein described with reference to the accompanying drawings.
19. A device substantially as herein described with reference to the accompanying

description.

Claims 9Mar07