Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~- 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
.,
- 2193875
. .
~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 .
.~ .
)
2193875
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'.-
2193875
~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
-- 8 --
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
2153875
~ 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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