AU652484B2

AU652484B2 - Abrasion resistant means

Info

Publication number: AU652484B2
Application number: AU26234/92A
Authority: AU
Inventors: Ronald George Yates
Original assignee: Nortech Corp Pty Ltd
Current assignee: Nortech Corp Pty Ltd
Priority date: 1991-10-04
Filing date: 1992-10-07
Publication date: 1994-08-25
Anticipated expiration: 2012-10-07
Also published as: AU2623492A

Description

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AUSTRALIA

Patents Act 1990

ORIGINAL

COM4PLETE S FE CIFICATION STANDARD PATENT Invention Title ABRASION RESISTANT MEANS The following statement is a full description of this invention, including the best method of performing it know to me: This invention relates to abrasion resistant means and to the production thereof, and it refers particularly to a method of and means for extending the working life of equipment having wearing surfaces which, in use, are subjected to high abrasion and/or impact forces, such as pulverisers, scrapers, crnshers, dragline buckets, bucketwheel excavators, chutes, feeders, wear plates, bulldozers, graders, and other mining and earthmoving machinery.

It is known to provide hardened steel studs to be welded to the wearing surfaces of such equipment, such as the studs put out by Sherritt Gordon Mines Limited under its Australian Patent No. 542151, or those put out by Austuds, a Division of Laysand Pty. Ltd., and known by the trade mark AUSTUDS. It is believed such studs last, in use, somewhat longer than normal hard-facing materials, the time the equipment is out of operation during the installation of the studs is less than with other methods of applying abrasion resistant means, and that such studs are more effective than other abrasion resistant means.

This invention has been devised with the object of providing a method of and means for improving the effectiveness of such abrasion resistant means as hitherto known.

A further object is to extend the effective life of wear-resistant studs applied to those wearing surfaces, of equipment as mentioned above, which in use are subjected to abrasion forces.

Another object is to provide means for extending the effective life, or increasing the resistance to abrasion, of the wearing surfaces of mining, excavation, earth moving, and other equipment which, in use, are subjected -2to high impact loads and/or highly abrasive forces.

A further object is to provide abrasion resistant means which will be relatively easy to apply to the wearing surfaces of articles which, in use, are subjected to highly abrasive forces, as well as being relatively economical in application costs and in the life of such abrasion resistant means.

Yet another object is to provide a method of as well as means for incre.asing resistance to abrasion, and also to provide resistance to corrosion, wherein such means will not restrict the flow of material passing ovei it and will not cause bridging in chutes.

A still further object is to provide abrasion resistance means for the purposes indicated above which tay be designed and/or fabricated to suit the particular and/or individual requirements of the users of the equipment, and which will be relatively economical to provide, lightet than wear-plates of the same thickness as hitherto provided, and easy and rapid to install.

The invention devised with these and other objects in view provides the combination with a wearing surf ace, having thereon a number of abrasion and/or impact resistant studs or the like, of at least one layer of a relatively soft abrasion and/or impact resistant imaterial which covers the studs to a depth at least equal to the lengths of the studs extending beyond the wearing surface so that said studs do not project initially beyond the outer surface of the abrasion and/or impact resistant ra.tei al The invention also provides a method of increasing the resistance to abrasive wear, of surfaces which are subjected to abrasion action, which includes the step of applying, to a surface having thereon a numbele of weat resistant studs, at least one layer of a relatively soft abrasion and/oi impact resistant material in liquid form to a depth at least equal to tiilengths of the wear resistant studs extending beyond the wearing su:face so that the studs do not project initially beyond the outer surface of the abrasion and/or impact resistant material.

The relatively soft abrasion and/or impact resistant material may be a urethane manufactured with abrasion resistant qualities, such as urethane or a urethane known by the trade mark ADIPRENE for example, ADIPRENE L-100 or 93 DURO "Polyslip" impregnated with wear resistant "Teflon" wrli increased friction characteristics, or other abrasion resistant plastics material or synthetic rubbei. or a cerarmic nt.erial hereinaftel referl.' to generally as "relatively soft, abrasion and/oL impact iesistant material" The studs which do not form part of this invention may be of stainless 44 steel, such as those having a hardness of between 50 and 60 Rockwell C., -3or mild steel, or case hardened steel, or other material of suitable hard cess.

The studs may be fastened to a base plate as by welding such as by use or an arc welding gun providing a virtually smokeless welding operation and the relatively soft, abrasion and/or impact resistant material is preferably applied to the base plate, having the studs thereon, so as to cover the outer ends of the studs and thereby provide a cover over the ends of the studs as about 2mn to 6mrn, However, in some applications of the invention the relatively soft abrasion and/or impact resistant material may extend from the surface of the base plate the wearing surface only to the outer extremities of the studs so that the outer ends of the studs are flush with the outer surface of the relatively soft, abrasion and/or impact resistant material. The base plate may be provided, on its rear rU opposite surface, with one or more bolts, studs or other fastening means so as to enable it to be fastened to an article which is to be subjected to wear. Alternatively, the base plate may be provided with internally screw-threaded holes to receive bolts for fastening the plate in position, or with other suitable fast en. i. n- means. The bols t~i studs, 01 t .ew threaded holes, may be arranged so that a plate having the relatively soft, abrasion and/or impact resistant material on its outer surface may be rotated to provide for maximum usage of the wear resistant properties. For that purpose the fastening means are arranged in a pattern to enable the plate to be removed, turned, and replaced to fit in t he same place.

Accordingly, the plate may be made square in shape, or other even geometrical shape.

In an alternative form of the invention the wear-resistant studs and the layer or layers of relatively soft abrasion and/or impact resistant material are applied directly to the work surface, thereby eliminating thineed for the baseplates.

In a further alternative form of the invention the wear-i.esistant studs nay be formed integrally with that is, formed in the one piece, at the same time as the baseplate, as by casting, forging or pressing, and in one aspect of this form of the invention said studs may be formed with heads larger than the sterns or shanks as somewhat mushroom-shaped.

In the use of the baseplate with integral wear-resistant studs, when the relatively soft, abrasion and/or impact resistant material is applied to the composite plate the stud heads, if larger than the stems or shanks.

will tend to hold that relatively soft material in place and resist its separation from the baseplate. On the other hand, the baseplate with Sintegral wear-resistant studs may be used without the relatively sot, -4abrasion and/or impact resistant material as a means for reducing the time the equipment is out of operation when replacement of the said wearing surfaces is required.

In order that the invention may be clearly understood and readily put into practical form I shall now describe a preferred manner of carrying the invention into effect with reference to the accompanying drawings, whe rein: Fig. 1 is a perspective view of a composite plate with a number of wear -resistant studs fastened to it, showing a layer of relatively soft abrasion and/or impact resistant flexible plastics material applied to part of the plate; Fig. 2 is a cross-section on the line and in the direction of the arrows 2 2 of Fig. 1; and Fig. 3 shows an arrangement of several square plates attached to a base surface, as the blade of an earth-moving machine.

The composite plate illustrated in Figs. 1 and 2 has a baseplate 11 which, as shown in these Figures, is rectangular in shape. That baseplate 11 is of steel of a thickness preferably between 4rrm and 40mm, particularly and has fastened to its upper surface a suitable number of wear-resistant metal studs 12.

The number of such studs may vary according to the maximum diameter of said studs, the bond to be achieved between the abrasion and/or impact resistant flexible plastics material and the baseplate 11, the cost of the product, the strength and/or weight of the composite plate such as from 10 studs to 138 studs of 16rmm maximum diameter, and from 10 studs to 100 studs of maximum diameter, with a plate of 30cm square.

The studs 11 may be applied to the baseplate in even rows, as shown, or in staggered rows, and the composite plates may be square as depicted in Fig. 3 or rectangular as shown in Fig. 1 or other suitable shape.

The studs 12 may be of stainless steel, such as that having a hardness of between 50 and 60 Rockwell C, or of case-hardened steel, or mild steel, or other material of suitable hardness.

The baseplate 11 has on its under surface screw-threaded bolts or studs 14 by means of which the composite plate may be secured, as by nuts 15, to a work surface 16 provided with holes 17 for the reception of the bolts or studs 14, as shown in Fig. 2.

This invention provides a layer 21 of relatively soft, abrasion and/or impact resistant material such as Urethane 90, or 93 DURO "Polyslip" impregnated with wear resistant "Teflon" with increased friction characteristics, or any other urethane manufactured with abrasion resistant additions, applied to the baseplate 11 having thereon the wearresistant studs 12, so as to cover the wear-resistant studs 12 with a suitable amount of the relatively soft abrasion and/or impact resistant material as to a height of 4rrm. This layer 21 provides a padding of abrasion resistant material between the studs 12 as well as over the tops of the studs, and it is believed that layer of material 21 assists the studs in their pulverising and/or abrading action whilst reducing the amount of wear of the baseplate 11 and of the studs 12.

Although Fig.l shows the layer 21 extending over part only of the baseplate 11 it is to be understood that in use the layer 21 will cover the whole of the upper surface of the baseplate.

As an alternative form of the invention the wear-resistant studs 12 and the layer 21 are applied directly to the work surface, thereby eliminating the need for the baseplate 11, the wear-resistant studs being used in the same range of concentrations as set out abovt It is also believed that the wear-resistant studs may be formed integrally with the base plate as by casting or by forging and that the studs may be formed with enlarged heads somewhat mushroom shaped.

When a urethane is used to provide the layer 21 the plate 11 having the wear-resistant studs is first sandblasted and then is boxed with light timber (to provide a reservoir for the urethane) and heated to approximately 150 degrees centigrade. The urethane is mixed and also heated to approximately 150 degrees centigrade, and is then poured over the wear-resistant studs until said studs are covered by the urethane to a depth of approximately 4mm by the liquid urethane. The plate 11, with the urethane layer 21 over the studs 12, is then baked in an oven for twenty four hours at a temperature ofi/ 0 C removed, and when cooled slowly it may be applied to a work surface.

The urethane tends to contract at the location of the wear-resistant studs, providing indentations or "dimples" 22.

It is believed that a rubber may be found to be suitable and used instead of urethane, and then a sheet of the rubber may be applied to the top of the wear-resistant studs (as affixed to or incorporated in a base-plate) and the whole assembly is compressed in moulds to force the rubber to a bonding relationship with the wear-resistant studs and the baseplate.

As the problems associated with wear resistant products vary as the application of the product is varied it is clear that the composition of the layer 21, and the mode of its application, will need to be varied so as to suit the purposes for which the work surface is to be used.

This invention will be found to be of particular advantage when it is des irable Lo :educe thle eff ect of c logging of- the weaL s Luds, as by Llm application of the I ayet 21 to a chut-e for o1iveyinig wet, abrasive, rvttcria1 or in drag-liIne buckets or other equipment used or excavating hard, dry rocky material .Accordingly. al though in some usages Ithto application of the l ayer 21 will extend the life of thi, basep] ate and weat.

studs by as much as five tim'(es, or, so I beli eve., in otheL usages the iayei 21 may not extend the life of- the baseplate and weaL StudzL "to aM.' comnparabl e extent.

T I: is bel ieved that in some inistances i t mauy be of advantage to apply tht.

relatively soft. abrasion and/or, impact- resistant material in two ot l ay ers t o make uip the t otalI r equiredl.

The stud figuration illustrated in Figs. 1 anid 2 my be modified to suit particular arrangements or requiremenrs: it is believed such arrangeet.

will prevent the relatively soft abrasion and/or impact resistance material, Particularly urethane, from expanding or warping. It Is also bel ievedl it will assist the studs to absorb shock when the assemt -lv is subjected to impact loading. The cover of the layer 21 of- relat ively soft abrasi on anid!Or Limpact resi.start mnaterial May Wear away Lel alivel y quiickly.

and Once the outer enids fho usKctepart of t he sut at.'e th1ey comrbine with the urethane bet-W(een1 0Lherrif toc provide: tht-- pro avcLi on arnd abr-asion resistarice required.

The omposi2te a rr angotment. To y h-F abi i cated to arty tikmsandt- H'if ure--thane- may be applied by any suitable means and in any suit able maonner.

as3 'y S;PEaying dtii 'ect 'IV Ot to 111- o pj-0it 11 o tt- wokm t -Ug ol fct'": Oi i.

ma~cchinie t o be t reate(l It, will b e tnders tood thait the stutds 12 imy v b of any suitab.e shape or design, as tLhu- shap~e of the studs is not ortr of thi-s i i -\entj. on and the arrangement of tho0se- studs may be sel ected to SUitr par ticular requirements.

It is to be understood that the invention resides in the application of the JOW. relatively soft, abrasion and/or impact iresistan-t material. to a wearing sur face to a depth at least equal t Hie lenigth of the studs fastened to sochI wea r in g surf h-s $Ludsc~ ta ted above do niot f011 ot. pt f III( m tv Fcut ionII, but s i: vc- ty;. onet; of. -wiC1 is to provide meanis for hio]lding the relatively sof., i. ras ion, drid/OL ilmiPaC res1:istant itate ri a iiit position on the wearincg5iL~c' Such Studs mtay be of circuiai:shoc in) cross-section, as shown, or Of sCIuare shape, or all1.pticai. shape, Or rectangular shape, or i.n. form of r:ot:s or barsF extending :sribstani all -7 one end of the wearing surface to the other or froiim one side to Lhe other, or otherwise The term "studs" is to be deemed to include all such means as will function to hold the relatively soft abrasion and/or impact resistant Material in position on- the wearing surface.

All such mod if*L cat ionis aF; comne tini UiA I, voa I~~L sco pe o I' the e :i rin as set out ini the appended cl.!Is are 'to "be deeci,eo to be in-clu.ded in the ambi t. o4 the I nver:ti oni

Claims

1. The combination with a wearing surface having thereon a number of wear-resistant studs, of at least one layer of a relatively soft, abrasion and/or impact resistant material, characterised in that the depth of the at least one layer is at least equal to the lengths of the wear-resistant studs extending beyond the wearing surface so that said studs do not initially project beyond the outer surface of the abrasion and/or impact resis tant. material.

2. The combination as claimed in Claim 1 wherein the wearing surface is a plate capable of being fastened to that part of equipment which, in use, is subjected to abrasion and/or impact forces, said plate having the wear-resistant studs and the relatively soft, abras.uon and/or impact resistant material on one surface.

3. The combination as claimed in Claim 2 wherein the plate has orn its other surface a number of studs to permit the plate to be attached removably to the equipment with which it is to be used.

4. The combination as claimed in Claim 1 wherein the wearing surface is that part of working equipment which in use is subjected to abrasion and/or impact and the wear-resistant studs are fastened to it.

The combination as claimed in any one of the preceding claims wherein the relatively soft, abrasion and/or impact resistant meaterial covers the studs.

6. The combination as claimed in Claim 5 wherein the relatively soft, abrasion and/or impact resistant material covers the studs initially to a depth of between 2m and 6mn.

7. The combination as claimed in any one of the Claims 1 to 4 inclus'ive wherein the outer surface of the relatively soft, abrasior and/oi impact resistant material iis initially substantially flush w:ith the outer ends of the studs.

8. The combination as claimed in any one of the preceding claims wherein the relatively soft, abrasion and/or impact resistant material is a u rethan e.

9. The combination as claimed in any one of the preceding claims whoi ej.i the wearing surface and the wear-resistant studs are integral.

In the production of a wiar'- esis a nt surf-a incorporating a :umbeL of wear-resistant studs the s:tep of applying to the surface a quantity of a relatively soft, abrasion and/or impact resistant material, in liquid form, to a depth at least equal to the lengths of the wear-resistant studs extending beyond the wearing surface so that the studs do not project beyond the outer surface of the q abrasion and/or impact resistant material.

11. In the production of a wear-resistant surface incorporating a number of wear-resistant studs the step as claimed in Claim 10 wherein the relatively soft, abrasion and/or impact resistant material is made a thickness to cover the wear-resistant studs.

12. In the production of a wear-resistant surface incorporating a number of wear-resistant studs the step as claimed in Claim 10 or Claim 11 wherein the relatively soft, abrasion and/or impact resistant material is made a thickness to cover the wear-resistant studs by between 2m and 6mm.

13. In the production of a wear-resistant surface the steps of forming as an integral whole a wear-plate with a number of wear-resistant studs on one surface and then applying to the surface of the wear- plate at least one layer of a relatively soft, abrasion and/or impact resistant material so as to at least cover the wear-resistant studs.

14. In the production of a wear-resistant surface incorporating a number of wear-resistant studs the step as claimed in any one of Claims to 13, inclusive, wherein the relatively soft, abrasion and/or impact resistant material is a urethane.

In the production of a wear-resistant surface as claimed in any one of claims 10 to 14 inclusive the additional step of pre-heating the wearing surface to which the relatively soft, abrasion and/or impact resistant material is to be applied to a temperature of in excess of 1000 Centigrade.

16. In the production of a wear-resistant surface as claimed in any one of claims 10 to 15 inclusive the additional step of sand-blasting the wearing surface to which the relatively soft, abrasion and/or impact material is to be applied before the application of that material. RONALD GEORGE YATES Date: 21st January 1994 1'L .1 ABSTRACT The invention provides a method of and means for improving the resistance to abrasion and/or impact of the wearing surfaces of equipment which, in use, is subjected to high abrasion and/or impact forces, residing in the provision of at least one layer of relatively soft, abrasion and/or impact resistant material to said wearing surfaces, particularly such wearing surfaces incorporating wear-resistant studs or the like as hitherto known. Preferably, the relatively soft, abrasion and/or impact resistant material covers the studs, or the major part thereof.