GB2242499A - Chain cable stud - Google Patents

Abstract

Replacement stud for chain cable, comprises body elements 14, 16 having saddle ends 18, 20 to seat against the opposing inner faces across the link 12; one element having a threaded spigot 22 received in a socket 24 of the other element to align them axially, and a jacking nut 26 on the spigot being used to spread the stud into tight engagement in the link. A spacer 28 may be fitted to fill the gap between nut 28 and the main pan of element 14. The stud enables repairs to be made on site without unrigging the cable. <IMAGE>

Description

CHAIN CABLE STUD This invention relates to chain cable of the well known stud link type, particularly large size heavy duty cable such as anchor cables of ships and other vessels or floating or other structures such as oil rigs, piers and harbour installations, and the like.

Such cables are subjected to heavy wear under adverse conditions which often causes the transverse studs of the links to become loosened eg by fracture of a welded juncture between the end of the stud and the inner periphery of the link. Occassionally a tud may be completely displaced and lost.

In many situations taking a defective cable out of sefvice for off-site repair is very inconvenient and uneconomic and users have been faced with the dile@@e c having to replace ar entire cable particularly where exacting standards of safety and reliability apply er making a compromise repair by removing defective links ano replacinr them with connecting shackles. The latter form of repair may only be acceptable as a temporary expedient and is not always possible or practicable.

The object of the invention ist to provide means for effectin the repair of suoh defect in a particulary econorical effective and safe manner, on-site and in many cases without having to un-rig the cable or remove it from service and without disturbin3 the. integrity of the links themselves, the repair so effected beino substantially equal in durability and reliability t the stud lin as originally manufactured.

According to one aspect of the invention there is provided a replacement stud for insertion into an already formed lin of a stud link chain cable comprising first and second body elements operatively located in aligned relationship to constitute an expandable stud body by screw jacking means of the stud acting between said elements, oppositely directed outer end faces of th elements being shaped to seat against opposing inwardly facing portions of the link against which they are urged by operation of the jacking means in use to secure the stud in the link.

Conveniently the inner end of the first body element is shaped to provide an externally threaded axially projecting spigot and the inner end of the second body element is shaped to provide a co-axial socket for sliding engagement with said spigot, the jacking means being constituted by said spigot and a nut in threaded engagement therewith operatively abutting the inner end of the second element.

With the latter arrangement the stud may further comprise one or more spacers to be dimensioned to fill the gap between the main part of the first element and the nut when the desired adjustement has been made.

The invention further resides in a method of repairing a lin' of a stud linked chain cable includin the steps of removing any defective stud or portion thereof remaining in the link effecting any necessar fettling or cleaning up of those opposing inwardly fin portions of the link against which its stud seats i if and as necessary, providing a replacement stud as define by any one of the preceding paragraphe, locating said stud transversaly weithin the link in the appropriate position, operating the screw jacking means to urge thu ester and faces of the body elements into tight abutment with said link portions, and, preferably but not essentially, dimensioning, fitting and securing any spacers as referred to above if such are required.

Said method may further include the step of sealing or bonding the interfaces between the outer ends cf the body elements and the said link portions with a metalbased or other compound for most effective seating and/or securing and/or protection against ingress of water or corrosion.

ror added security and permanence the screw jacking means, once adjusted, and/or any spacers once assembled, and/or possibly the abutment of the stud with the link, may be additionally secured by welding.

Finally the assembled link and replacement stud ray be coated with an anti-corrosive paint or other compound.

An example of the invention is now more particularly described with reference to the accompanying drawings wherein Figure 1 is a part sectional view of a replacement stud assembled in a cable link.

Figure 2 is a side-elevation of the stud alone turned 90 about its axis from th Fl igure 1 position an- Figure 3 is an end-view of a spacer ring of the stud.

Th replacement stud 1 is shoun in Figure 1 In its assembled condition as secured in a link 12 (part only shown in broken lines) Stud 10 comprises first and second body elements 14,1S each havin outer end portion 15,20 shaped as a saddle providing outer end faces which seat securely against opposing inwardly facing portions of tne lin: 12 with stud 10 positioned transversaly of the latter.

Elements 14,16 are forced or otherwise shaped to also provide matins formations aligning them co-axially when assembled. Fore specifically the inner end of element 14 includes am axially projecting spigot 22 which is externally threaded, and the inner end of element 20 includes a socket 24 within which spigot 22 is received for free sliding engagement.

A jacking nut 26 is threadedly engaged on spigot 22 for abutment with the inner end face of element 16 thus the effective overall length of the assembled stud 1C can be seiectively adjusted by operation of the screw jacking means constituted by nut 26 arid spigot 22, in particular by screwing nut 26 to the right as viewed in Figure 1 the elements will be urged apart into tight engagement with opposing portions of link 12.

Tn utilising the invention to replace a missing or demaged stud of link 12 the defective stud (if still present) will be removed eg by 'burning' it out and the portions of the link against which the replacement stud is to seat are cleaned up as necessary, for example by grinding and/or shotblasting to remove any remnants of welding which secured the original stud, and scale or corrosion.

The replacement stud 10 is then assembled with nut 26 slacked off so that it can positioned within the link.

A plastic steel compound or other sealing or bonding compound is preferably first applied to the outer end faces of the stud and/or to the associated parts of the 1ink t ensure full seating any provide resistance ±- Ingress of water and corrcsion at the joints between the stud and the link. Nut 28 is then tightenec so that the stud is secured in place in compression.

There will then be a gap between the free face of nut 2, and the annular face t the junction of spigot 22 with the main part of elements 14. This is filled by spacer ring 2 which, as shown in Figure 3, , is slit diametrically into two halves 28a,28b so that it can @@ positioned about the exposed portion of spigot 22. in 26 will be oround or otherwise sized on site so that its axial width corresponds to said gap and it. and/or the associated faces of the nut 26 and/or element 14 ray be forme with a slight taper cr chamfer so that the spacer 26 can be positively retained by slightly over-tightening nut 26, springing link 12 open a little, inserting the spacer, and then slacking the nut back by a small decree to capture the spacer.

The assembly may additionally be secured by welding eg spot welding to prevent any possible rotation of nut 28 and to further secure spacer 28 in place. For some applications it may also be permissable or desirable to weld the junction between the outer ends of the stud 10 and link 12.

Finally the whole repair will normally be coated with anti-corrosive paint.

The whole process described can be carried out on site using tools and equipment normally readily available or easily transported to the job and the repair can be effected without any need to remove the chain cable from its operative position or disconnect it, indeed it may even be possible to effect such a repair while the cable still carries its working load.

A further advantage of the invention is that if the replacement stud should itself become loosened in service the screw jacking means can be further tightened to secure the stud once more.

While the screw jacking means constituted by nut 26 and spigot 22 is preferred as providing a particularly siren, joint between the two body elements of tl- s and as being economical to manufacture with a minimum of components other forms of screw jacking means are contemplated within the invention.

or example both body elements might be provided with sockets at their inner ends to receive separet externally screwed jacking bar, with this arrangement one said socket could be internally threaded for screu engagement with the bar, the latter being rotated by an integral nut formation intermediate its ends or possibly a transverse through aperture to receive a tommy bar or both sockets could be internally threaded, the ends o the jacking screw being provided with opposite hander screwthreads for shifting both elements in opposite senses as the bar rotates. In another construction a threaded bar could be received in sliding non-threaded engagement in co-axial sockets of both elements, the latter being forced apart by a co-acting nut or nuts in threaded engagement with an intermediate part of the bar.

Claims (10)

1. A replacement stud for insertion into an already formed link of a stud link chain cable comprising first and second body elements operatively located in aligned relationship to constitute an expandable stud body by screw jacking means of the stud acting between said elements, oppositely directed outer end faces of the elements being shaped to seat against opposing inwardly facing portions of the link against which they are urged by operation of the jacking means in use to secure the stud in the link.

2. A stud as in Claim 1 wherein the inner end of the first body element is shaped to provide an externally threaded axially projecting spigot and the inner end of the second body element is shaped to provide a co-axial socket for sliding engagement with said spigot, the jacking means being constituted by said spigot and a nut in threaded engagement therewith operatively abutting the inner end of the second element.

3. A stud as in Claim 2 further comprising one or more spacers to be dimensioned to fill the gap between the main part of the first element and the nut when the desired adjustment has been made.

4. A replacement stud substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

5. A method of repairing a link of a stud linked chain cable including the steps of removing any defective stud or portion thereof remaining in the link, effecting any necessary fettling or cleaning up of those opposing inwardly facing portions of the link against which its stud seats if and as necessary, providing a replacement stud as defined by any one of the preceding claims, locating said stud transversely within the link in the appropriate position, and operating the screw jacking means to urge the outer end faces of the body elements into tight abutment with said link portions.

6. A method as in Claim 5 including the step of sealing or bonding the interfaces between the outer ends of the body elements and the said link portions with a metalbased or other compound.

7. A method as in Claim 5 or 6 including the step of additionally securing the stud to the link or components of the stud to each other once assembled and adjusted by welding.

8. A method as in Claim 5, 6 or 7 including the step of coating the assembled link and stud with anti-corrosion paint or other compound.

9. A method of repairing a link of a stud linked chain cable substantially as herein before described with reference to the accompanying drawings.

10. A stud linked chain cable or a link thereof when repaired by the method of any one of claims 5 to 9 or including a stud as in any one of Claims 1 to 4.