GB2053804A - Apparatus for raising or lowering a drop keel of a boat - Google Patents

Abstract

Apparatus for raising or lowering a drop keel of a boat comprises a winch (27) carried on an elongate support post (26) removably mounted between upper (29) and lower (30) fixed supports attached to the boat; the support post also carries a sheave (25) at or adjacent its upper end over which passes the winch cable (24). A free end of the winch cable (24) is attachable to the keel by a snap release fastening so that the keel can be raised or lowered upon operation of the winch (27). <IMAGE>

Description

SPECIFICATION Apparatus for raising or lowering a drop keel of a boat The present invention relates to apparatus for raising and lowering a drop keel of a boat, and particularly to such apparatus which is adapted to be removable from its mounting on the boat to leave free space within the interior during periods of sailing when the keel is down.

The present invention finds particular utility in relation to drop keel sailing boats of a size sufficient to have a cabin. In such boats the available space is usually very restricted and the possibility of being able to raise and lower a drop keel without having the added restriction of the keel raising apparatus in the centre of the cabin constitutes a considerable advantage.

The present invention therefore, provides in one aspect, apparatus for raising and lowering the drop keel of a boat, comprising a winch carried on an elongate support post removably mountable between upper and lower fixed supports on the boats, the elongate support post carrying a sheave, at or adjacent its upper end, over which passes the winch cable a free end of which is attachable to the keel to effect raising or lowering thereof upon operation of the winch.

The apparatus is suitable for use with a "dagger" type keel which is raised and lowered in a straight line, and also with the pivoted type of drop keel; in the former case the winch cable will travel substantially vertically from the sheave to the attachment point with the keel, and in the latter case will travel at an angle to the vertical between these two points, in which case the sheave may require a pivoting bearing in orderto accommodate the changes in angle as they may not all be in the plane of the sheave.In either case it is important that the keel should be held against inadvertant dropping if the winch should be badly handled when either raising or lowering, and for this reason it is preferred that the winch is of the self-braking type, that is one which automatically resists the turning moment applied by the load when a controlling moment applied to an operating member is released. For manual operation the operating member of the winch would be a winch handle, whereas for powered operation the operating member of the winch would be a motor shaft.

In order to obtain the maximum benefit from the removability of the support post for the winch it must be possible for this to be disengaged easily from the fixed supports. Preferably, therefore, the fixed supports have sockets therein for receiving the ends of the winch support posts, and are fixedly attachable to fixed parts of the boat. In a preferred embodiment the said upper fixed support has a deeper socket than the lower fixed support. With such an arrangement the winch support post may be easily engaged and disengaged from the fixed supports simply by inserting the upper end of the post into the socket sufficiently far to raise the lower end of the post above the lower fixed support, aligning the bottom ends of the post with the socket in the lower fixed support and dropping the post into position.Of course, the upper and lower fixed supports must be spaced at the correct distance so that the upper end of the winch support post does not disengage from the socket in the upper fixed support when the lower end of the winch support post is dropped into the sockets in the lower fixed support.

Again, to make the best use of the removability of the keel raising apparatus it is preferred that the winch cable should be provided with means for making a readily releasable connection with a cooperating member of the keel. Such a readily releasable connection may be made, for example, by means of a snap shackle.

The present invention also comprehends a drop keel boat when fitted with apparatus for raising and lowering the keel thereof as defined herein above. In such a boat the fixed supports are preferably mounted on one side of the keel in a position such as to lie in a plane perpendicular to the length ofthe hull, including or at least approximately including the centre of gravity of the keel.

The keel is, for practical reasons, slidable in a keel case and there are preferably provided means for locking the keel in the lower position thereof, although the weight of the keel may well be sufficient to retain it in the lowered position without requiring such locking means.

Preferabiy the keel has a lower part of hydrofoil section and an upper part the shape of which corresponds with the shape of the interior of the keel case whereby to facilitate form locking engagement therewith when the keel is in the lowered position.

One embodiment of the present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which; Figure 1 is a front view of the embodiment; Figure 2 is a plan view from above of the embodiment illustrated in Figure 1; Figure 3 is a side view illustrating the range of movement of the keel.

Referring now to the drawings, Figure 1 is a cross sectional view through a boat in which the deck 11 and the lower part 12 of the hull can be seen in part, and in schematic form only. Attached to the lower part 12 of the hull is a keel case, generally indicated 13, having two main side walls 14. The bottom of the keel case 13 is substantially narrower than the main part thereof defined by the main walls 14 and is constituted buy a pair of walls 15 which define a narrow opening passing through the bottom of the hull 12. The two walls 15 defining the narrow bottom opening in the keel case 13 are linked to the main walls 14 by inclined shoulders 16.

Within the keel case 13 is a keel, generally indicated 17, comprising an upper portion 18 which is housed within the keel case 13 and a lower portion 19 of hydrofoil section. The upper portion 18 of the keel 17 has a form in cross section which corresponds substantially to the internal cross section of the keel case 13 and, in longitudinal section, has two upwardly projecting horns 22, 23 separated by a central recess 21.

The junction between the upper portion 18 and the lower portion 19 of the keel 7 is defined by a pair of inclined shoulders 20 the inclination of which to the general plane of the keel 17 corresponds substantially to that of the inclined shoulder 16 of the keel case 13 so that when the keel 17 is in the lowered position the upper portion 18 thereof fits firmly in the keel case, the horns 22,23 thereof resisting any turning moment applied by the keel 17.

Within the recess 21 is a connecting member in the form of an inset ring for receiving a snap shackle 30 attached to the free end of a winch cable 24 which passes over a sheave 25 carried by a winch support post 26 and is wound on a winch 27. The winch 27 has an operating handle 28 for manual operation, but could be motor driven.

Likewise, although a rotary winch 27 is illustrated, this could be in the form of a linear hydraulic actuator the stroke of which is sufficient to take up the cable 24 to raise the keel 17.

The winch support post 26 is carried in upper and lower fixed supports 29,30 secured to the deck and the hull of the boat respectively. Each of the fixed supports 29,30 is in the form of a securing block having socket-like recess therein for receiving an end of the winch support post 26. The socket recess in the upper fixed support 29 is deeper than the socket recess in the lower fixed support 30 and the spacing between the upper and lower fixed supports 29,30 is less than the length of the winch support post 26 so that this latter can be positioned by inserting the upper end into the socket recess of the fixed support 29, aligning its lower end with the socket recess in the lower fixed support 30 and lowering the post 26 into position.In this position it will be held against possible displacement, even if the boat is undergoing violent motion for example in a choppy sea, by the weight of the keel.

In normal sailing trim, however, the keel 17 once lowered will be held in position by separate keel retaining means (not shown) in the form of a transverse bar passing across the width of the keel case 13 and having a screw clamp by means of which the keel 17 can be held down with the shoulder 20 thereof pressed against the inclined shoulder 16 of the keel case. The snap shackle 30 can then be released and the winch support post 26 removed until it is required to raise the keel thereby freeing the space within the boat cabin, but nevertheless obtaining the advantages of a drop keel.

The horns 22, 23 fore and aft of the upper keel portion 18 enable form locking engagement to be made with the greatest leverage whilst still retaining the main mass of the keel 17 in the lowest possible position so that its centre of gravity is not unduly raised whilst at the same time obtaining a sufficient leverage about the opening 15 to resist turning moment applied by the keel 17 to the keel case 13.

Becasethe opening defined by the walls 15 is only larger than the lower portion 19 of the keel 17 by a small clearance the keel 17 is securely held in the boat under its own weight and should the cable 24 accidentally break while the keel 17 is in a raised or partly raised position any water in the keel case, which will have seeped in through the narrow clearance between the lower portion 19 of the keel and the opening defined by the walls 15, will provide a hydraulic damping effectto cushion the fall of the keel.

When fully raised the keel can be locked in place, for example by means of a bolt, in order to relieve the strain on the winch cable. Because the winch support post 26 is located to one side of the keel case 13 the cable 24 lies at an angle to the vertical (when viewed in a transverse plane as shown in Figure 1) and the keel is therefore held by its own weight against one side of the keel case 13 when in the raised position so that any tendancy to move about within the cabin is minimised.

Claims (17)

1. Apparatus for raising and lowering a drop keel of a boat, comprising a winch carried on an elongate support post removably mountable between upper and lower fixed supports on the boat, the elongate support post carrying a cable guide, at or adjacent its upper end, over which passes the winch cable a free end of which is attachable to the keel to effect raising or lowering thereof upon operation of the winch.

2. Apparatus as claimed in Claim 1, in which the winch is of the self-braking type, that is one which automatically resists the turning moment applied by the load when a controlling moment applied to an operating member is released.

3. Apparatus as claimed in Claim 1 or Claim 2 in which the said fixed supports have sockets therein for receiving the ends of the winch support post, and are fixedly attachable to fixed parts of the boat.

4. Apparatus as claimed in Claim 3, in which the said upper fixed support has a deeper socket than the lower fixed support.

5. Apparatus as claimed in any preceding claim, in which the said cable guide comprises a pulley or sheave over which the winch cable passes.

6. Apparatus as claimed in any preceding claim, in which the free end of the winch cable is provided with means for making a releasable connection with a cooperating engagement member of the keel.

7. Apparatus for raising or lowering a drop keel of a boat, substantially as hereinbefore described with reference to the accompanying drawings.

8. A drop keel boat when fitted with apparatus for raising and lowering the keel thereof, as claimed in any preceding claim.

9. A boat as claimed in Claim 8, in which the fixed supports are mounted to one side of the keel in a position such asto lie in a plane perpendicularto the length of the hull including or closely adjacent the centre of gravity of the keel when raised.

10. A boat as claimed in Claim 8 or Claim 9, in which the keel is slidable in a keel case and there are provided means for locking the keel in the lowered position thereof.

11. A boat as claimed in any of Claims 8 to 10, in which the keel has a lower part of hydrofoil section and an upper part the shape of which corresponds with the shape of the interior of the keel case, whereby to facilitate form locking engagement therewith when the keel is in the lowered position.

12. A boat as claimed in Claim 11, in which the upper part of the keel has fore and aft portions which project upwardly beyond a central portion which is provided with the said means for engagement with the connection means of the winch cable.

13. A boat as claimed in Claim 11 or Claim 12, in which the upper and lower parts of the keel are joined by a shoulder on each face of the keel.

14. A boat as claimed in Claim 13, in which the said shoulders lie at an angle in the region of 45" to the general plane of the keel.

15. A boat as claimed in any of Claims 11 to 14, in which the lower part of the keel passes through an opening in the lower part of the keel case which is smaller than the cross sectional area of the upper part of the keel such that the keel is retained in the lowered position by the engagement of the shoulder separating the upper and lower parts thereof engaging against the rim of the opening.

16. A boat as claimed in Claim 15 in which the said opening in the bottom of the keelcase has a narrow clearance with the lower part of the keel such that water can enter the keelcase therethrough.

17. A boat having apparatus for raising and lowering a drop keel thereof, substantially as described herein with reference to the accompanying drawings.