CA2193875A1 - Lifter bar - Google Patents

Abstract

A lifter bar 10 for a grinding mill 12 provided with a rotatable shell 14 used for grinding ore, comprises an elongate member 16, typically made of metal or metal alloy, and having an upper portion 18 provided with a continuous surface 20. When the lifter bar 10 is installed in the grinding mill 12, the surface 20 is exposed to and contacted by the ore to he ground. Lower portion 22 of the lifter bar 10 lies adjacent inner surface 24 of shelf 14 when lifter bar 10 is installed in the grinding mill 12.
Fastening means 26 for releasably fastening the elongate member 16 to the shelf 14 is coupled at one end to the lower portion 22 and, is adapted for coupling at an opposite end to the shell 14.

The lifter bar 10 is provided with a slot 28 extending transversely through the lower portion 22 and a hole 30 extending through the lower portion 22 to the slot 28. The fastening means 26 comprises a nut 32 which is held within the slot 28, a sleeve 34 which is retained within the hole 30 and threadingly engages the nut 32, and a stud 36. The stud 36 is threaded at end 38 to also engage the nut 32.
Additionally, the stud 36 is threaded at opposite end 40 to allow bolt into the outside of the shell 14 .

Description

~- 219~875 L~T~R B~

The pre~ inveA~t iA~n rela1.es to a lif t~ }~a~- f~r ~.~rindiIlg lltill u~ed fo~ cJrin~i.rlg c~re.

~ rindin~ mJ.ll~ are u~ed for ~riIldi~Ag minex~l. hearirg c,r~
5 in~;o relatively ~m~ll part.i.cle~ .ich can th~n l~e s~lbse~uently proc~ssed rnr mineral e:;trac~t~ )n. A 5~in~.in~
mill t~ ally comprises ~A cyli.n(1rical ~shell ~rhic~ n it~
inner ~lrfac~ ed with ;~. plu~al.ity n~ ln~t~ .c ,r,l r~l~be~ li.ner~. Th~ liner~ protec~ the ir~Ae~ s~lrf~ce of t;he 10 ~hell f rom heinc~ worn a~a~ by the ore l~ein~ cl~ound . 'I'he liner~ ~re held in pl~ce by li.ft:er bars ~'7hl~h ar~ holted t.o th~ shel1 ~nd cl~mp ~po~ite Lon~i~ u(:31nal edgeEi c~ e~h litler to the inner ~ur fac:e o~ th~ dru~l~ The lifter h~
~ omp~ long~t~ members which c-xtend ~uh:~t~ntia:l Ly for 15 ~he le~g~h ~ he shell ~n-~ are cir~-lmfeAl.-e~tiaily sE~ e~d abou~ the inner ~l~rf~c~ of t:he ~hell . Irl ~)rde~ to f i~ he b~r~ to ~e shell, e~h li.f~;~t- }j~r is ~ro~ided ~ith ~
plurali.t~y o~ counte~-suAnk holes, whi- h ~xt~nd wl~olly through the h~r in the radial dir~tio~l o~ the shell.
20 Bolt~ are then pA#sed t:hrc~uyh the hol~s from the in~.ide c)f the shell and extend ~ rou~h hole~ ~rovidPd in t:he shell.
Each bolt iE~ ~rovided with a he~d ~haped ~o as to mate ~7ith th~ ~oun/:ex-slmk hol~.s in the lif ter bar . A nut ls th~n ~crewe~ vn to t~le ~pposit~ et~d of ~c h bol .. in ~rde:r to f i.x 25 t:he li~e3 ba~ and lin~r~ to the ~hell. When ~hc grin~
mill .i~ in use the ~hell i5 rotat;ed ~n~ th~3 lil~ter bars lift th~ ore and any grin~:linq balls t~ c~i nt wher~3 ~hey ~all l~y acti.on o~ gravi~:y, ther~?by J?rodl~c_ing a tul~ ling action whi~h has t:he effect of c~indi.ny thf3 ore.

31~ ~ifter ~rs Are made by casting, wi~h ~aviti~ f~ y ~orme~
durin~ tLe casting pxocess in oArd~r 1~o pr~vi.de the b~l I
holes. The~e c~ri~ 3s :Eorm we~k poi~t~ in the C~s~ d the correspondinfJ bolt hol~s provi~e zl :~ite f~r accel ~ra~ed wear of the lift~ b~r~ when i~ use. It .is ~olrun~ll to ., . .

~t.tempt ~c) st rengther! t;he lifte~ >ars by Frc:vJ.cliny pad~ o.r bulgers in the ~re~ c ~ th~ bolt h~:Le~ . ~iow~ r, thi~
increa~e~ the co.~t oi~ the li~ter hars ~nd in ~ny ~vellt.
c~nn~t~ ~ev~nt I he ac~c~.exate.d ~"e.~r in th~ ViCill.ity o~ th~
5 h-~lt h~le~.

Il: is aI~ obje~t~ E the prqseIlt inv~nti~n to E~r(~vi~le lifter bar whicl~ c~n he. ~astened to a grindiny mlll ~~Ji~hout the ~l~e of c~nvent~i~nal ~olt through-h(:~J e~ .

Acc~rding to a f~ aspe~t ~~ t.he presen~ in~.~en~ n thexe .J.(~ is provided a li~ter b~r for A yrinclill~ mill pr~vif.~ed wit~h a ~ t~ble ~hell, said lift:~r ]~a~ c~-.)mpri~:in~:
an ~lon~ate m~mber h~lng A~l Ur?~purtion pro~ided with ~ continuou~ u.rEa~ wl~i.ch ise:~p~sed l-.c~
material t.o be ~r~ounc~ by ~ mi l]. ~hen si~i.c~ t~er ~jar i~
~ tene~l to an in.ler ~rrfa~e o~ s~i.d ~he~Yld a lower portion ~dapted ~.o li.e ~dj~cent s,~id inrl~-?r surfA(~e of .~ai~
.~hell; and, a fa~tenin~ ln~An~ fo~ L-el e~sably f~steI~itlf~ ~ai.d ~Lon~a~3 men~er tfj S21Ld yrindilly mi:Ll, said ~st~inf~ m~ns 20 having one encl adapte~ for couplirl~ to s~id l.owe~ portion 0~ :~Ai(~l elonyate ~llember ~nd ~n c)pp~.site end af.~apt~ed ~or c~uplin~ t~o s~i~ ,sh~ll.

Prefera~ly s~id fasteninf~J means i~ ,f~l~3pt ec3L to er~gage ~ai~
lower ~ortion of ~id ~1 orlyate r.lem]~eJ; .

~5 ~referably said low~r portiorl is ~r.f~vidt~ with a r~t~ ess which ~~1it3! o~e end of sai~ stellin0 mean~ enga(~es.

P~t~er~bly said recess compri.~s a slot exl::endi~g tr~nsver.~ely through ~id :Lo~er po~tion of ~id e~.orlf~te member. The ~ l m~y p~ss ~it~er wholly ~r onl.y p~ Lally 3 0 through th~ ~longa~:~ m~ml;~er .

.~ .

) a Pre~erahl~, said l-:-we~ Ortic~l is l?rovi¢~ed wit~h A hol~
conununic~tin~ with .~aid ~lot a~A ~id ~aster.~iriy n-e~n~
extend~ throu~h ~aic~ h-~le .~ ; s~ r~posite er~d of sai.d fa~en~ng mea~s oa~l be connect~d to ~a~d ~l~ell.

Pref~rably said fas~enin~ means comEJr ises ~t said olle end f irs~ rt dispo~d in said sl~t allcl a .s~].e~ve cvn~l~ct~ble t o ~3ai d f .ir.~t par~ and ad~.pt~d ~:o ~ten-~ illtO ~.a~.d hol~ for re~aitling ~aid ~irst part i..n ea.id ~lot~

Prefer~bly .s~id .~:~ eev~ i.s formed wi th at) out;~r ~i~me~r 1~ less then the di.ame~e~ of ea.icl }~ole so ~hat. l;he ~ s1.ee~e ~r~d ~irst p~rt can move w.i.thirl said slot alld holc?
respectively.

P~eferabl~ sai ~ fas~eni.r~ means furt:h~r corllpri~es i3n elon~ate elernen~ di~ensioned so ~ to pass ~hrou~h s~id 15 .sleeve and h~vil~g ~ s~ end corlnect~ble to said ~irs~
p~rt and ~ 3~cc-ncl end ad~te~ for connee~tic~n 1:~ sa.id ~h~l.l, said second ~nd loc~a~ed at t~le ~ppositG end Rf ~aid ening mea~s.

Howe~.~er in an alt:ernate em}~oclimen~ the .~le~ve is not ~,0 re~[uired ~nd the elongate element }?as~es throu~h ~aid hole and has i.ts ~ t eJ~ onnecte~ to the ~irst par-t.

Pref~r~bly ~aid slot~ are ~o~itioned f~o tha~ when ~ liner is cla~lped to ~ai.d inne}A surface ~f s~id she~ll by ~ li.f trer bAr f~tesled ~o saicl ~hell, ~aid ~lc~ clispr~ed ben~ath 2.~ an e~cposed ~urface of ~,aid liner.

Pref~3rably said i~iLst p~r~. is ~ nut, and s~id ~:Longate eleme~ ;tud pro~ ded ~ h ~ .~cre~ thre~d ~t it~ ~lr~t and ~;~con~ ~ncls, .

f'.-~ccol~ding ~o ~ ~econcl ~sp~c~t of th~ prç~ell~ i.nverl~lon ther~
i~ providqd a li ~ter har fcr ~ grin~ling mill ~rovidefl w~t;~ i ro~tab~e shell, said lifte~ b.~ conpri~ing:
arl e1.~?n~ate member having an upper porti~r 5 prQvided wi th a c~ontir~u~-ls ,~wrfac~e whic~h i~ ex~osed t:c~
mate~ial tv be grouIld by said ~ 1 when ,s~i.d l i ~t?r ~a~
fe~steIled t.o ~Il inne~ ~ur fa.~e of .sai.c3 ~hell: ~n~1 a lo~ler portion ~d~pt~d to lie adja~eIlt ~aid irmer :~U~c~C-f~ of s~3id ~h~ l L;
10said lower por'ci-:)n provided wi.th ~n int egral and later~lly e.x.tendiny rnil;l. liIleX ac~apt ed 'cc) ~-erlie a por~:ior said ~otata~le shell: ~nd, a f~st ening me~tl.s fc~r rele~sabl-~ f~.st~rling :~.a.iA
elongat~e mf~mber ~rld mill l~ llçr to said grint~,in~ mill, SAi.d 15 ~a~tening me~ns havinS~ clne encl ~aptetl for couplirlg to .~Jaid l~er p ;;rtion of said c-lollg~te mem~er ~n~ an ~~pposite end adapl~ed for eou~lin~ tc ~aid shell.

In effect~ this $eco~ aspec~t of the inven~ion E~ro-~ide~ ~n it~te~ra~d lif~er b.lx and 11I1er~

In yeneral ~ll of the pr~exred and o~her op~ion~l ~eatur~G
of the firs~ asp~ct of the inven~ion can al~o be incoxporated i~ ~he a~ove second aspec~ of the inven~ion.

E~bo~iments of the pre~ent invention will now ~ de~crihed hy way of e~ample only, with xefer~ce ~o the accompanying dr~wirlys in which:

Figuxe l i~ a plan view from the ~ot~om of ~ fi~
~mbodiment ~f the l~fter bar;

Figu~e ~ i~ a v}ew o~ ~e~t:ion A-P, o~ th~ cex bar shown n Fi.gure l;

Figure 3 is ~ view of ~cti~n B-~ ~hr~ugh ~h~ lif~ bar shawn ln ~i~u~ 2;

- 6 - 2~93875 Fi~l1Le ~ is A ~ch~m.~ti.c vi.ew of a p~rtion of ~ c3r~.ndincT
mill hAVi 11~l installec~ ~herein the liftinc3 har ~s showll i.ri ~lgures J. - 3:

Fi~u~~e ~ ecti~>n vi~3w of a ~ecorl~. em].~odilrlent of l.:he lifter h~r;

F,igure ~ i~ a ~cherll~ti. ;; vi~w of ~ ~ortior~ o~ ~ g~in~ g mi~ 1 h~ving in.~Jt.~ ed t~erein a thir~ emb~in~ent c~f the li~t~er l~fl~r;

Fiyure 7 .i.s ~ cros~ ectic-rl vi.ew c~f ~ follrth ~nl~Jndime.nt o~
10 the li:~te~- b~x;

Fiyu~e ~ i~ a p~rtial. lon~itudinal view of ~he eln~:)odime shown i~ Fi~ure 7;

F~ gllre g i~ a par ti.al i,sorne.t~ view of a rif th ~mb~clim~nt of the li:Eter }~ar;

15 ~i.gu~e 1(:1 is ~ top view o~ ~ oorr.ponC~lt of th~; f.i~tl enlbodiment ~:hown irl Fi~u:r.e ~;

Figure llA i~ a lvngi~u~i.nal ~cti.oIl vi~w of a .~iY~th ~?m.~odiment ~f th~ er b~r; ~nd, Fis~ure llR is a vif~W of ~.e~tion B-B of th~ lifte~ r .~howr 20 in Piyur~. llA.

With r~e~el~ce ~ the a~ompa~yin~ clrawiny.~, it can be ~:~en ~h~t a lifter har ~0 f~r a griIlclin~ mill 12 ~rovided with ~
rot.~table shell 14 u~ed f~r ç~r~nding c~re, comprise~ an elong~te-l me~ber lt;, ~ypi~l;Ly made f~f a mel~~l or m~3t~
2~ ~lloy, havirly ~n uppe~ porl:i.on 18 providecl with a ~ontiIluou~ ~ur~ce 20 . ~hen ~he li~er ~r 10 i:~ in~llec~
in t~e ~rinding mill 1~ he SU~f~ACe :~0 iS e~?o~:ed to and c~ont~cte~ ~y the ore ~;fJ be gxo~n~t~ Low~r pc~rl;ion ~?. ~f l ;

,,;~ .

219387~ 1l r bar ~0 lie.~ adjac~.snt. i.nnP.~; s~ f~c~ 24 of :~he!.l 1 when lifter b~r 10 i~ st~ scl in th~3 grinding mil.~ 1~2.
Faste~ing me~ns 2~ f~r ~elea6~.)1y ~as~ eniIl~ t}.le ~3l0ngat~
member 16 to the ~heil :L4 ls co~pled ~ on~ end t.o the 5 l~wer portion 22 nnd, zLs .show~ m~t clear~.y in Fi~u~ , is adapte~ for c~ouplin~ ~ an oppo.~i te ent~ to ~.he sh~

The lif'ce~ h~r 10 i~ l~r~vi~ed wi.th thre~ ~eces~e~ in the f,~xm of slots ;~8 which extend tL-an~versely thl~~u~ low~:
poL tisn 2;2 . A ~e~r~t:e hole 30 extends thro~lgh th~ .I ower 10 portion ~z t.o each slvt ~8.

.
Fa~teIlin~ mean# ~6 compA;i.se~ ~hree rc~mponent~, a firs~ rt irl the form o~ a nut 3~, a ~;leev~ 3~1 ~nd a elon~e ~lem~llt in the .~onn or sl:ud 3~; which i~ thr~aded a~ fir~:t and ~econ~ erlds 38 antl 40. End 40 t;ermi.nates in ~A 'heX~lgO~
15 protrusi.~n 41 to ~rhi.ch a s}~anlle~ r~n be co1~p1ed i~o~-~c~ewiIl~ s tud 3 ~ into nut 3 ~ .

Nut 32 is provi~e~ with a hole havin~ ~n uppex ~hr~aded port1on 4~ for ~ngagin~ fir~t ~n~ 38 oi~ the stu~l 3~, and ~
concentl ic ~nd i~lcre~s~l diam~t~r 1~wer por~ion 44 provided 20 with a thread f~r thre~dillg1y engaying the sleeve 34. when assemb1i.n~ the 1i.fter bar 10, ~he nut 3~ i~ p~ssed t~XQU~h slot 28 ~nd 'che sleeve 34 ~ass~c~ ~hroll~h hole 30 and 'chreadi~gl~r en~aged with the 1Ower por~ion 44 of ~he nu~
32. Sleeve 34 i~ provid~d with an out6l~ dialnet~r smal.1er 25 th2~n ~he di~m~3te~A~ of hole 30 ~ ~As to al~ow movement of ~he sleeve 3~ within the ho1s ;30 and ~orrespolldin~ movemqn~ of t~e nut ~2 within s1Ot~ ~8. ~h~n conr~A~cted to the nut~
the s1eeve 34 ~xtend~ to ~.he end of ho:le 30. In ~his way, ~ e sleeve 3~ ef~ec,A~ 1y re~ains l:he nut 32 within t:he 1ift~r b~r 10 . Stud 36 is thell p~ssed ~hrou~h s] eeve 34 ~nd the f ir~t end 3 8 :Loo~ely ~c~r~weci ~nt:o the upper threaded portion 4~.

~, ' ' .~

21~3875 The elon~te rnem}~er ~ h att~h~ aster~in~ means 2~ is then pl~ed ir~side ;~lell lA a~ld di~pGsed betw~erl adja( ent .shell line~ 4~. The $iners ~re typically m~de from metal or rub~ and. are used to pl.nt~ect i~lner surface ~4 ~rom we~in~ Qw~y thro~l~h ~oIltac~: with t hC one bein~ cround .
IIoles (not shuwn~ ,~re ~oJ.-me~ the ~h~ll 14 t~r~u~h which ~he .~,econd end 40 of the ~tud 36 ~an pas~;. R washer 50 i5 pl.~ced ove~ end 40 ~nd nut 52 scr.~ed ontc) the .~ec~nd ~nd 4n to e~fectiv~ tt,~c~h the lifter ~ar lO to the in1,erio)-10 of the shell 14. LOWeL ~ortion ~ o~ each lifter har lOa~uts the longitudin~ g~ ot~ adja~ent. li~ler~l 46 so l;hat, when ~ .ened i~ pl~e, liftel~ b~rs lO ~ o ac~. t.o clan~p the lin~rs 4~ to ~heJ l l~ . r~e move~nt oi~ th~ nu~ 32 within slc~ 28 .~llowed by ~.he di~ere~ce .in diame~:~r .~f t he 15 sleeve 34 an~ hol~ 3n ~llow~ e~y alignment of st~s ~
~;ith the hole~ i.ri the ~hell 14. The bc?l tom ~lrf2lc~ oi~
member lfi io ~rovided ~ith a r~ce~ 47 ~.~r fit:tlns~ ~rer ~
portion oi~ adjacenl: :Liner~ 4~. The recess ~l is also em~loyed in the ~rlor- ~rt lii~ter h~r~ and doe.s not for-m 20 ~art of the in~ntion.

When the ~hell 14 is l~ade~ with ore ~nd rot;lte.d, ~!e lifter 1~2~r~ ~;si~t in pro-luc:in~ a ~umbling aCt-i.OJ1 o~ th~
ore ~sld In~tal ~rin~lin~ b~ or other grinding me~lia which ma~r be lo~ded in 1 he ~rixlding mill 12 ~o fac.ili.t.~t~
25 grin~ g of the ~ret Slot~ Z8 are lo~ate~l below t~e lev~l c~f upp2r (expo~ed) ~rfa~e 4d O~. the line.s 46 when t.}-le lifte~ bar 10 is f~terl~d in Iche ~,~rindin~ mill 1~.

~ eGond embodiment 10 ~ of t:he 1 if ter bar ifi illustratec~ i.n Fi,~ure 5. In thi.,~ ~mbodimet~t, ~.he ~ame referen~ numbers 30 are u~d ~co i,~dic~t~ identic~J. feature~ of th~ i~i.rst odiment ~nd ~ ime sym~~ol ( ~ used ~G i~ iCa~e fea~ures which have ~en modif:ied in thi.~, en~odimenl in c~om~ari~on to the Eirst ~3mbodimen~

... .. , . , , .. . . .. ~ , ..

2ts3s~s ~he m~.tn diffel.ences between ~he li~ r ha~ 10 ~ the ~irst embodiment and the lifter ~r 10' c)f t he second err,bc,dl.ment is thAt the slot ~8 ' exte~ ly p~ ~lly rAth~r tha ulholl~ throuyh ~he l.o~er p~rti~n ~;~' of ~h~ li~~r bar.
5 ~u~ther, the sleeve 34 of the rir~ embodiment h~ been ~i.sp~nsed with .~o that ~h~ ~astenin~3 me~ 6 ~ ~ompr i~es only the IlUt 3 ~ ~rld the threade~l stu~ ~6 . En~ 4~ the ~hreaded Gt~ld 36 is fa~4l elled 1~ th~ o~.lt~ifle of the ~hell 14 by way of a no~ lip nut .~2 ' . V~ sl?o,se~ between the nu~: 5~ ' 10 and the outside ~urf~Q ~f shell 14 i s a rec~s~ed wa~her 50~ and ~ sealing wa~heL 51' parti~lly re~ceiv~d withirl the ~ec~ ed ~JA~her ~Q ' . A p~ir ~f e~elet~c 62 aI~ also fc~rmed on ~pp~site sides o~ ~he s~rface ;20 of llft~r bar 1~'. The eyelet.s ~2 are prot~icled to ;ls~~ the lifting anrl 15 tr,~ port~n~ o~ the lif ter ~3a~s 1() In essenti~lly all le~pect~3, the ~.:~ ft~ bar 10~ f~ c~ti.ons in all lde.nti~a;L ma~Iler ~o li.. ter b~L 10. Hc~ever, ~le ~ifter bar 10 ' 1~ ~impl~r to irl~t~ll and In~nuf~c~ure a~ it doe~ not r~quir~ the s:Lee~e. 34 c~f t~le first embocliment and 20 th~ slots ~8 do n~ pas.s wholly ~hreu~h the lower pc)rtion 22 ~ of the li~tex bar 1~ ' . -furthe~: embod.iment; lV '; of the 1 i fl er bar is sh~wn irFigure ~ . The li~ter bar 10 ~ ~ in es~ence c omprises the corn~ination of the lifter ~r :1.0~ ~f ~ re 5 tog~ther with ~,5 a ll~.~ex 4~ ~orme,d irlteç~rally wi~h lo~r porti.orl 22~ of ~he lifter ~ar. The fa~tering me~n~ 26~ of the lifter bar 10'' i.s identical to thA~ 03~ the li~ter lO~ e lirler ~c)r~ion 4~ ~ ~ can talc~ any ~uit~.~ble ~hapa or cor~igurz~.ion.

~n a vari~tion of t~e lif~r }~r 1~ ho~,~ in Fi~ure 6, 30 the slot 2~ ' fo~ re~ei~ing ~h~ fa~terling me~n~ 2~ ' t~an in fa~t ~lternately h~ pl~cet~ in the line~; por tion 46 ~ ~ .
Howe~rer, 'chis 1.~ not prefo~ed ~s t3re~ter stre~~ses will then b~ pl~ed . ~ e thre~d~d stud ~6 due to the ~t~igllt ~i~;tribu~ion c?f the 1i~ter l~r lV'~.
. :

. .
:'1 ! ' j ~ o Further m~ification~: ~nd sr~ria'Ai.~ns of th~ 1 if ~c~r bar ;~r~
shown in Fig~lres 7 t:.o 10 On~ of th~ mo~ifi~ati.o~ h~wrl ~n l~igure 7 is the ~o~ n of an ov~rh~ny ~;4 o~re~ the o~enilly ~f .s;l.ot ~ in lifter 5 bar 10'''. q'he ~rer}lan~ fi4 as~ist~; in pr~vf~ntir~g de~ri.~
f~ro.n c].o~3ing the slot~ 2~ . Also, ~ mourltiTl~ pad 6k. i 5 prC)~idfcd ~Yithin S1-jt ~8' ' ' f~~r ~ atin~ th~ Xlllt 32. This i.s ~h~ mo~ det~i l in Fi~uî~ 8 . T~le pllr.po~ of the pad ~6 i:~i 'ccl prev~nt nut 3 1 from t.llrning wh~n the stud 3~ i~
1 O .~crewed in .

Ano~her w2ly o~. pr~ntirlg the rl~t 32 from t.urni.nS3 i ~ .shc~
in Fi~ure.~ ~ ~n~ 10. Her~ met~:L pl~te ~8 i~ provid~
with a hexagonal C!Ut-ClUt 70. 1~he :nul: .~2 ls pa.s.~ed part,i~lly thrvuyh the O'Ut-O~ 70 ~and fixed th~reto. This 15 çan be done by weldin~, a~e.~1~Jes, or fo~mi.ng a pres,s ~it.
The plate ~ di~ 3nsioned rel;3tive the slot 28''' st.~ th~t i~. cannot rot:ate wi~.hin ~he slo~ 28'' ' .

Yet a further v~riatior). ~ the lifte~ bar is shown in Figur~ 11. In t.his variation, the lifter ~al~ 10'''~ is :~ ~0 pl:o~rided wit:h a rece.~ fo~ openiJlg 2~' ' ' ' ~hich ~loe~ l~ot open zlt the ~ide of the 1 ifter ~t~r like slot~ ~8, ~' and bu~ ~ath~r opens on the bottom ~urface 71 of th~
li~te~ bar 10' ' ' thrc~ugh re~E:e~tive hcles 7a . The holes 72 extend vertically throu~h the lower portion 22. In u~e, ~5 nuts 3~ are ~a.~e~ through th~ hole~ 7~ o slo~ 28 ~
~hen pus~ed sideways to loca~e ever hole~ 30. ~ow the studs 36 ca~ }~e pu~hed u~ through hole~ 30 ancl ~cre-~recl intv the above-lyin~ nut:.f~ 32 50 ~S to bolt ~he li~te~ har~
10 ' r ~ / to the shell 14 . It will be ap~reciated t~ t in ~: 30 thi~ v~riat.i.on the 3lele~3 7~ z~n<l 3O ~nd thu~ :~ilots ~
will be su}~an~;ially se~.lefl frcrtl the in~ress of dehris a~:
. ,' ~hese holes ~re ~lam~?ed agaiIl.st the lin~r~ 46 andto~ ~hell . 14.

. . :
'~ '' .....

219387~ ' - ;Ll -Fr~:)m tl~e ab~ve clescriptiv;tl i~ wi l.~ be ap~Ient l~h~
odiments of; tl~ inverltion h~ve ~ulnerous ~dvant~s o~er the prior art. Significan~ly, the present ~mboc~iment do~
not recauil~e bol~ holes wllic~-l ext~ncl wholl.y thr~ h the 5 ~longate r,lember 1~ in t~e radi.~1 cl.il-action 1 n c~ler to allow ~ast:ening to t:he ~s~ll 14. Ther~fore tL~e ~rlher~n~
weAknes~es of ~le ~ri¢~r all lift~L' ~ar~ a~ e avoided l~y S~he E)~esent eml~odimen~ . Fl.lrther, ~s the llpper su~ ~ace continuous ~nd f~ee ~ ~ol~ oles ~.~s much ilnprcved we~r 10 ~ ara~teris~i.cs. In a~dltio~n, th~ slot~ ~.8 which the fastening m~an~ 26 engaye m~y be loc~ted be.lol,r tl~e l~vel o~
upper surface 4~ of li.t~er~ ~6 and ~herq~e ar-~ not ~cted UpOXl by the ~re b~ing ~r~und or ~rir~ding medi~.

It will b~ app~re~ to ~hc)se skille~ in t:he rnechan:Lcal ar~:
hat numerou.s modiflc~tions and v~ri~';.i~n~ may be mad~3 to the a~o~re-de~crlbe~ embodiment wi~hout departing froln the ba~ic inventive ~o~ept~. For e~arnple, t.he upper poI:tion 18 i.~ ~hown as ~ei.ng ~ub.stantlally rec~ang~ r (Ol~ ~nore - p~eçi,qely inyol:. ~hap~d) in cro~s-~e~tion. How~ver, ol:~ler 20 conf; ~tlrations are ~08~ 1e such as trian~ular ~ ~urther, ~lthough the~ .slot~ 2R els shown as ext~nding wholly through the lower part 22 they may he in the form of blinc~ holes.
In ~d~lition wh~?n. ~astening the lif~er har 10 to the inte~ of shell 14, rather thsn loo~ely ~C~win~ stu~ 3~
~5 onto nu~ 3~ pric;~ l~o p-L~cing the llftex ~r 14 into the .shell 14, the ~tu~ 36 can be screwed onto ml~ 32 fron~ the c~lt~ide of .~hell 14 . P~ uch mo~if i.cations and v~riat.ion~
are deRmed to be within the scope of ~he pre~n~ invention, the n~l:.ure t~f which i~3 to be ~etermined f rom the ~oregc:)ing 3 0 de~:cript:ion .

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Claims (14)

1. A lifter bar for a grinding mill provided with a rotatable shell, said lifter bar comprising:
an elongate member having an upper portion provided with a continuous surface which is exposed to material to be ground by said mill when said lifter bar is fastened to an inner surface of said shell: and a lower portion adapted to lie adjacent said inner surface of said shell and, a fastening means for releasably fastening said elongate member to said grinding mill, said fastening means having one end adapted for coupling to said lower portion of said elongate member and an opposite end adapted for coupling to said shell.

2. A lifter bar according to claim 1, wherein said fastening means is adapted to engage said lower portion of said elongate member.

3. A lifter bar according to claim 2, wherein said lower portion is provided with a recess which said one end of said fastening means engages .

4. A lifter bar according to claim 3, wherein said recess comprises a slot extending transversely thorough said lower portion of said elongate member.

5. A lifter bar according to claim 4, wherein said lower portion is provided with a hole communicating with said slot and said fastening means extends through said hole so that said opposite end of said fastening means can be connected to said shell.

6. A lifter bar according to claim 5, wherein said fastening means comprises at said one end a first part disposed in said slot and a sleeve connectable to said first part and adapted to extend into said hole for retaining said first part in said slot.

7. A lifter bar according to claim 6, wherein said sleeve is formed with an outer diameter less then the diameter of said hole so that the said sleeve and first part can move within said slot and hole respectively.

8. A lifter bar according to claim 7, wherein said fastening means further comprises an elongate element dimensioned so as to pass through said sleeve and having a first end connectable to said first part and a second end adapted for connection to said shell, said second end located at the opposite end of said fastening means.

9. A lifter bar according to claim 5 wherein said fastening means comprises a first part disposed in said slot and an elongate element dimensioned so as to pass through said hole and having a first end connectable to said first part and a second end adapted for connection to said shell,

10. A lifter bar according to claim 3, wherein said recess extends wholly though said lower portion.

11. A lifter bar according to claim 4, wherein said slot is positioned so that when a liner is clamped to said inner surface of said shell by a lifter bar fastened to said shell, said slot is disposed beneath an exposed surface of said liner.

12. A lifter bar according to claim 6, wherein said first part is a nut, and said elongate element is a stud provided with a screw thread at its first and second ends.

13 . A lifter bar according to claim 3 wherein said recess comprises a substantially horizontally disposed cavity formed in said lower portion and opening through a vertically extending hole on a bottom surface of the lower portion.

14. A lifter bar for a grinding mill provided with a rotatable shell, said lifter bar comprising:
an elongate member having an upper portion provided with a continuous surface which is exposed to material to be ground by said mill when said lifter bar is fastened to an inner surface of said shell; and a lower portion adapted to lie adjacent said inner surface of said shell;
said lower portion provided with an integral and laterally extending mill liner adapted to overlie a portion of said rotatable shell; and, a fastening means for releasably fastening said elongate member to said grinding mill, said fastening means having one end adapted for coupling to said lower portion of said elongate member and an opposite end adapted for coupling to said shell.