GB2165190A

GB2165190A - Boats and accessories

Info

Publication number: GB2165190A
Application number: GB08523321A
Authority: GB
Inventors: John David Britton
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-10-09
Filing date: 1985-09-20
Publication date: 1986-04-09
Also published as: GB8523321D0; GB8425515D0; GB2165190B

Abstract

An accessory for a boat, and a boat including two such accessories, for maintaining the boat in an upright condition as the surrounding water level falls. Each accessory comprises a mounting tube (17) in which an axially movable body (14) is axially slidable, a flange on the lower end of the tube being secured to the lower surface of the hull of the boat adjacent the stern thereof, with the tube extending upwardly within the hull. An operating mechanism (30) is provided for lowering and raising the body (14) so that a foot (15) on the lower end of the body can be engaged with the bed of the water in which the boat is floating. A resilient buffer arrangement (20, 24) allows limited vertical movement of at least the foot (15) to accommodate small movements of the boat, e.g. resulting from a swell on the water on which the boat is floating. <IMAGE>

Description

SPECIFICATION Boats and accessories The present invention relates to boats and to accessories for boats.

When a boat is moored or anchored in tidal waters, a problem often arises that some time after the mooring or anchoring, the tide goes out and the boat rests on the bed of the shore, river or estuary. While this is less of a difficulty with bilge keel boats, with conventional centre keel boats two particular problems arise. Firstly, as the boat subsides on the bed, there is a great danger that the propeller or propellers and/or the rudder can become damaged by fouling hard material, such as an anchor or rock, and can become severely damaged due to subsequent movement as the tide begins to rise. Secondly, if the boat in question still has people on board after mooring, it will be extremely uncomfortable for these people if the boat is pitched over at an angle.

In my British Patent specification 2086810A there is disclosed an accessory for a boat and a boat including two such accessories, in which the accessory comprises an elongate body, a foot on one end of the body, a mounting tube in which the body is axially slidable, a flange on the lower end of the tube for securing to the lower surface of the hull of the boat adjacent to the stern thereof, with the tube extending upwardly within the hull and operating mechanism for lowering and raising the body, so that the foot can be engaged with the bed of the water on which the boat is floating.

Such an arrangement is very satisfactory in many ways for removing the problem of damage to the rudder or screw(s) of the boat and for maintaining the boat in an upright condition even after the tide has gone out. However, it has been found that some difficulties do arise if there is a swell on the water because of the foot on the bottom of the boat being caused repeatedly to be lifted and lowered onto the bed of the estuary, river or the like.

It is now proposed, according to the present invention, to provide a resilient buffer arrangement allowing limited vertical movement to accommodate small movements of the boat. This may be achieved in a number of ways. For example there can be a coil compression spring mounted within the tube and bearing against the end of the body, on the one hand, and an end of an operating mechanism on the other hand. Alternatively a similar arrangement could be provided between the body and an extension portion thereof carrying the foot.

It is also contemplated that the resilient connection could be provided in the operating mechanism itself. For example the operating mechanism could include a vertically slidable bar and this could include a transversely extending member attached to a torsion bar, rotation of the torsion bar effecting pivoting of the transverse member and thereby vertical movement of the body. Once a particular position has been taken up, by the rotation of the torsion bar, the torsion bar can subsequently twist about its length, allowing the resilient movement of the body.

It is also contemplated that when a fluid pressure operated piston and cylinder arrangement is used to form the operating mechanism an expansion chamber could be provided associated with each slidable body to allow limited movement in a resilient fashion of the body.

Any of the above described arrangements, or further similar arrangements, prevent any undue shock being imparted to the hull of a boat, since the foot of the accessories will always be resiliently urged against the bed of the sea and thereby accommodate limited vertical movement of the hull of the boat due to a swell on the sea.

In order that the invention may more readily be understood, the following description is given, merely by way of example, reference being made to the accompanying drawing, in which the sole Figure is a schematic rear elevation of one embodiment of boat according to the present invention, provided with two different forms of accessory according to the invention.

Referring to the drawing, the hull 10 of the boat is shown as having a centre keel 11. Two accessories indicated by the general reference numerals 12 and 13 are mounted adjacent the stern of the boat and fitted into the hull of the body. The two accessories are generally similar, but include minor differences. With regard to the similarities, they each have an elongate body 14 having a foot 15 mounted at the lower end thereof, by means of a pivot ball joint 16. The body 14 is axially slidabie within the tube 17, having a transverse flange 18 on the lower end thereof. The upper part of each elongate body is associated with a hydraulic piston and cylinder arrangement of which only the cylinder 30 can be seen. The member 14 is connected to the piston rod of the piston and cylinder arrangement.Connected to each end of each piston are hydraulic lines 31 which in turn are connected to a control valve 32 fed by a hydraulic pump 33 from a reservoir 34. Actuation of the valve 32, therefore, can be arranged so that fluid under pressure is applied to the upper lines 31, so that the pistons are forced downwardly.

It will be noted that the lower surface of the flange 18 is provided with a recess 25 of a size to accommodate the foot 15. In use of this arrangement, if the boat is moored with the tide at least partly in, and the hydraulic cylinders are operated, the bodies 14 will become lowered until the feet touch the bed. However, in many instances, this will not be necessary and indeed the bed will be too far below the level of the portion of the feet for this to happen. Once the feet are sufficiently low down, however, as the tide goes out, there will be no chance of damage to the propeller or rudder (not shown). Furthermore, the boat will be kept in an upright condition assisting in the comfort of the crew on board the boat.

In order to overcome any difficulties arising if there is a swell on the water, which would result in the foot on the bottom of the boat being caused repeatedly to be lifted and lowered onto the bed of the estuary, river or the like, a resilient buffer arrangement is provided to allow at least limited movement of at least the feet 15.

The elongate body 14 associated with the accessory 12 includes a flange 19 against which is abutted a coil compression spring 20 telescopically mounted on the body 14 with a sleeve 21 carrying the pivotal ball joint 16 on which the foot is mounted. The other illustrated form of accessory 13 includes a tubular body 14 in which is telescoped an extension 22, the tubular body 14 having a flange 23 against which is engaged a coil compression spring 24, the extension 22 carrying the pivotal swivel joint 14 for the foot 15.

It will be appreciated that the spring 20 or the spring 24 allows limited resilient movement of the part 21 of the accessory 12 and of the foot 15 of the accessory 13. This limited resilient movement can accommodate any fluctuation in movement of the boat due to swell on the surface of the water and thereby can prevent the foot from becoming unduly embedded in the bed and also gives greater comfort for the occupants of the boat, when it is moored in tidal waters.

Claims

1. An accessory for maintaining a boat in an upright condition, as the surrounding water level falls, said accessory comprising an elongate body, a foot on one end of the body, a mounting tube in which the body is axially slideable, a flange on the lower end of the tube for securing to the lower surface of the hull of the boat adjacent the stern thereof, with the tube extending upwardly within the hull, an operating mechanism for lowering and raising the body, so that the foot can be engaged with the bed of the water on which the boat is floating and a resilient buffer arrangement allowing limited vertical movement of at least said foot to accommodate small movements of the boat.

2. An accessory according to claim 1, wherein the foot is pivotally mounted on the lower end of the body.

3. An accessory according to claim 1 or 2, wherein the flange includes an external recess shaped to accommodate, at least in part, the foot, so that the lower surface of the foot can be substantially flush with the lower surface of the hull.

4. An accessory according to any preceding claim, wherein the resilient buffer includes a coil compression spring mounted within the tube and bearing against the end of the body, on the one hand, and an end of an operating mechanism on the other hand.

5. An accessory according to any preceding claim, wherein the resilient buffer arrangement includes a coil compression spring between the body and an extension portion thereof carrying the foot.

6. An accessory according to claim 1, 2 or 3, wherein the resilient connection is provided in the operating mechanism itself.

7. An accessory according to claim 6, wherein the operating mechanism includes a vertically slideable bar having a transversely extending member attached to a torsion bar, the rotation of the torsion bar effecting pivoting of the transverse member and thereby vertical movement of the body, whereby, once a particular position has been taken up, by the rotation of the torsion bar, the torsion bar can subsequently twist about its length, allowing the resilient movement of the body.

8. An accessory according to claim 6, wherein a fluid pressure operated piston and cylinder arrangement is used to form the operating mechanism, and an expansion chamber is provided associated with each slidable body to allow limited movement in a resilient fashion of the body.

9. A boat comprising a hull, two mounting tubes secured to the hull adjacent the stern thereof, one arranged on each lateral side of the centre of the boat, a flange on the lower end of each tube secured to the lower surface of the hull, with each tube extending upwardly within the hull, an elongate body mounted in each mounting tube, a foot on the lower end of each body, an operating mechanism for lowering and raising each body, so that its foot can be engaged with the bed of the water on which the boat is floating, and a resilient buffer arrangement allowing limited vertical movement of at least each foot, to accommodate small movements of the boat.

10. A boat according to claim 9, wherein each foot is pivotally mounted on the lower end of its body.

11. A boat according to claim 9 or 10, wherein each flange includes an external recess shaped to accommodate, at least in part, its foot, so that the lower surface of the foot can be substantially flush with the lower surface of the hull.

12. A boat according to any one of claims 9, 10 or 11, wherein each resilient buffer includes a coil compression spring mounted within the tube and bearing against the end of the body, on the one hand, and an end of an operating mechanism on the other hand.

13. A boat according to any one of claims 9, 10, 11 or 12, wherein each resilient buffer arrangement includes a coil compression spring between the body and an extension portion thereof carrying the foot.

14. A boat according to claim 9, 10 or 11, wherein each resilient connection is provided in the operating mechanism itself.

15. A boat according to claim 14, wherein the operating mechanism includes a vertically slideable bar having a transversely extending member attached to a torsion bar, the rotation of the torsion bar effecting pivoting of the transverse member and thereby vertical movement of each body, whereby, once a particular position has been taken up, by the rotation of the torsion bar, the torsion bar can subsequently twist about its length, allowing the resilient movement of the body.

16. A boat according to claim 14, wherein a fluid pressure operated piston and cylinder arrangement is used to form the operating mechanism, and an expansion chamber is provided associated with each slidable body to allow limited movement in a resilient fashion of the body.

17. An accessory for a boat substantially as hereinbefore described, with reference to and as illustrated in the accompanying drawings.

18. A boat substantially as hereinbefore described, with reference to and as illustrated in the accompanying drawings.