GB2243895A

GB2243895A - Swivel Joint

Info

Publication number: GB2243895A
Application number: GB9010010A
Authority: GB
Inventors: David Gilmour
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-05-03
Filing date: 1990-05-03
Publication date: 1991-11-13
Anticipated expiration: 2010-05-03
Also published as: GB2243895B; GB9010010D0

Abstract

The invention relates to a swivel joint suitable for use in the mooring of water craft to minimise the problems caused by twisting of the anchor cable when the craft swings about the cable i.e. it "weathervanes". The joint comprises an annular housing (2) with a concave cavity (4) into which is received a semi-spherical head portion (10) of a rotatable member (8) so that a tail portion (12) projects from the rear of the housing. A head portion (22) of a closure member (16) is secured in the mouth of the cavity (4) to render the rotatable member (8) captive with respect to the cavity (4). Both members (8) and (16) are adapted to receive shackle pins or other linking means. <IMAGE>

Description

SWIVEL JOINT The invention is concerned with improvements in or relating to swivel joints particularly but not exclusively for use in the mooring of water craft.

Securing mooring for a craft at shelter conveniently involves the setting of a plurality of anchors, typically three, each secured to one end portion of an anchor cable, which may be chain or rope. The cable has at its opposite end portion a marker buoy intended to alert other craft of the presence of the anchor cable(s) and of the anchored craft which is secured by a mooring cable to the anchor cable adjacent the buoy.

In use, it will be found that the craft will tend to swing about the anchor cable, in a so-called "weathervaning" action. To prevent this action from twisting the anchor cable it is conventional to provide a swivel joint. However, such a joint needs to be of sound construction in order to remain servicable, since component failure will probably result in loss of or damage to the moored craft.

The invention provides a swivel joint adapted to maintain secure coupling between a cable and a securing point, comprising a housing including a cavity, a rotatable member having a contoured head portion adapted to be received in said cavity, a closure member adapted to be secured with respect to the mouth of the cavity so as to retain said head portion captive within the cavity, said closure portion and said rotatable member each comprising a tail portion, at least one 0-f said tail portions being adapted to be engaged by a shackle device.

Advantageously, the closure member may sealingly close the cavity and may be secured in fixed manner to the housing. Conveniently, the closed cavity may contain water resistant lubricant material, such as waterproof grease.

In use, one tail portion may be secured to a fixed mounting or each tail portion may be provided with a bore to receive a pin of a shackle device to which device one or more cables may be attached as required.

There will now be described with reference to the drawings, a swivel joint according to the invention. It will be understood that the description is given by way of example only and not by way of limitation.

In the drawings: Figure 1 is a side view partly in cross-section of a joint according to the invention; Figure 2 is a side view of the joint, having been turned through 90 , and Figure 3 is a diagrammatic representation of the swivel joint in a mooring location.

The joint as shown in Figures 1 and 2 comprises an annular housing 2 having a central cavity 4. The cavity 4 includes a concave annular surface 6. A rotatable member 8 is received in the cavity so that a part-spherical head portion 10 is received in the portion of the cavity defined by the surface 6. A tail portion 12 of the member 8 extends outwardly of the housing 2 and is provided with a through aperture 14 adapted to receive a shackle pin or other linking means.

A closure member 16 comprises a tail portion 18, also provided with a through aperture 20, and a head portion 22 which is received in the mouth of the cavity 4 so as to close the cavity and to retain the part-spherical head portion 10 captive but rotatable therewithin. A cross-aperture 24 extending transversely through the head portion 22 of the member 16 receives a pin 26, ends of which enter bores 28 formed in the housing 2 and are secured in place by welding at 30.

In order to facilitate free rotation of the head portion 10 in the cavity 4, waterproof grease may be injected at 32, a set screw 34 being used to close the inlet.

In Figure 3, the swivel joint of Figures 1 and 2 is shown in use, a cable 36 leading from a three-way anchor arrangement 38 (the anchors being indicated at A, A' and A") being connected to the tail portion 16 by a pin 40 of a shackle 42. A second shackle 44 is connected by its pin 46 to the tail portion 8. Cable B leads to a marker buoy (not shown) and cable Y to the craft, for example a yacht, which is therby enabled to ride at anchor.

Various modifications may be made within the scope of the invention.

Claims

CLAIMS:

1. A swivel joint adapted to maintain secure coupling between a cable and a securing point, comprising a housing including a cavity, a rotatable member having a contoured head portion adapted to be received in said cavity, a closure member adapted to be secured with respect to the mouth of the cavity so as to retain said head portion captive within the cavity, said closure portion and said rotatable member each comprising a tail portion, at least one of said tail portions being adapted to be engaged by a shackle device.

2. A joint as claimed in claim 1, wherein the cavity includes a concave annular portion, the head portion of the rotatable member being part-spherical so as to be received within said concave annular portion.

3. A joint as claimed in either one of claims 1 and 2 wherein said tail portions of the closure member and of the rotatable members are each provided with an aperture into which a shackle pin may be received.

Amendments to the claims have been filed as follows

4. A joint as claimed in any one of the preceding claims wherein said closure member is arranged sealingly to close the cavity.

5. A joint as claimed in claim 4 wherein the closure member is secured in a fixed manner to the housing.

6. A joint as claimed in claim 5 wherein apertures are formed in the housing at the region of the mouth of the cavity and an aperture is formed in the closure portion, a securing member being passed through said apertures in a aligned condition and fixed in place in a welding step.

7. A joint as claimed in any one of the preceding claims wherein the cavity is sealable to contain water-resistant lubricant material.

8. A swivel joint constructed and arranged substantially as hereinbefore described with reference to and as shown in the drawings.