Note: Descriptions are shown in the official language in which they were submitted.
WO 94112320 PCT/N~Z;Y3/0~119
.. ~ :.:,.
'rhe Tool
~ ;2~28~3!313
This inven~ion relates to a tool.
For convenienca only lhe inven~;ion will predominantly be describc(l as~ool for tensionin~ wire to be joine(l, for which the inventit)n m~y 13~
particularly suitable. ~Iowever it is to l)e understood that it is not to be
limiled as such. Mor~over;because l;he invention may ~ave many olher .
applications, the prior art and possible applica~ions of the inven~ion
tliscusse(l below, are given by way Or example orlly.
There are a number Or known tools usetl for tensioning wire whcn the wirc
is l)eing joinell. For examplc, NZ I~atent l~pplication No. 240183 tliscluscs ~
tool which uses a single pivoted lever type mechanism w~lere;n one end of
~h~ wire to be joined is attached to a fitting on a ~Ixe(l membcr or the tool,
while the o~her end to ~e joined is grippetl by sliding eollets provi(lc~ on t,he
movable lever of the tool. The wire is thus able to bc drawn through n wire
re~aining ~le~ice by succcssive movemen& of the mo~a~lc lever, and ~hc cn(i
s~cured at th~ wire retaining devicc. With lhis t;ool, ~orce is applic(l to lhc
wire retaining device through a simple lever comprising a singlc pivot.
poinl;, with n movable n~ember pi~lol;ing about this poin~. The mecllanil:al
allvantage o~ such a tool is thus limited to that of a singlc pivo~ l~vcr
mechanislll. The tool may l;her~fore not be sui~al)lc f`or appl~ying D hi~ll
~ension to a wire, unless a sufficiently long arm is provi(led lo givc ~h~
reo,uire(l lever~ge. (~onsequently ~ comp;~cl desi~n mny no~ bc possil)le.
The tool of the prescnt inYention m~y ~)e sui~al)l~ ~or a numbcr ol
applications where a mechanical advantage greater thnn th~t Or ~ singrlc
lever mechanism is required. For cxample~ the principlc mny ~)e suil;l~)le
for use with tools such as tin snips, bolt cutters, hcavy (luty pop rivelor.s,
clamping pliers, and crimping tools.
51l~E~STITUT~ S~
~ Q ~4/12~0~ PCT/N~93/0011
Z~L2~3a~913
Conventional ~ools for these applications eithcr cvmprisc a somp~ical~e(l
linlcage mechanism to provide the required mechanical advantlg~, or u~se
a simple singlo lever mcch~lnism which re(~uires a su~fieicntly Is)n~ Icver
arm to obtain the required capacity. ~I~nce, with conventionlll syslems the
~ool is either expensive due to thc complcx linlcag~ me~h~nism, or in the
casc of a single lever mechanism, is either limit~d in c'apacity or rc(l~lires
a large lever arm.
The tool Or the present invention m~y also ~e suitabl~ for applic~tions
where amplification of movement is required with a negative mechanic.ll
advantage, that is, a mechanical advantage less than one.
Il is an object of the present invention to address the ~regoing prol)lem~s nr
at Icast to provide the pu~lic with a use~ul choicc.
Further a~pects and advantages of the present invention will ~)ccnme
apparent from ~he ensuing description which is given bv way o~ e~;~mple
only.
~ccording to one aspect of the presen~ invcntion there is providcd a tool
~omprising a i~xed meml)er,
a first movable member, said first movable meml)er being pi~otnll.~
connected to said fixed member by a first pivot me2ns provide(l ~)et~veen
sais~ f~xed meml)er and said first movable member~
a link means for linking between said fixed member and s.~id rlrst movnl)l~
member, said link means c~mprising at least;
a second movable member, said second moval)le member bein~ pivo~ally
connectcd to sai(l filxed mcmber by a secon(l pivot mcans, and
SUEISl'lTUTE SIIE~
, . .. . . . ... . .
wO ~4/12320 PC~Tn~z93/~O~l9
2~28~3~3
.... ~ ~...........
means for connec~ing bctwecn said first and secon(l movable mcmbcrs,
thc ~rr~ngcmcnt and cs)nslruction l)eing SUS~}l thslt pivotal movemcnt ol
saitl second moval)le member about said second pivot me~ns an(l s~ rst
movable member about sai(l first pivot means is communicate(l ~)etween
said first and second movable members by said linlc mea~ .
According to another aspect of the present invention there is provi(le(l ~
tool su~stantially as described ~bove, whercin saitl link mcsns compriscs
at least;
a sccon(l moval)lc member, said second movablc mernber bcing pivot~lly
conncctcd to said fi~ced member by ~ secon(l pivot me;~ns, an(l
mcans for connccting l~etwcen said first ar d second mo~able mem~)ers,
and
a ~hird movablc member, said third movable mem~er being pivotnily
connected to said fixed member by a third pivot means, and me~ns ~or
connecting between said second and third moval)le members,
t,he arrangement and construction being such that pivotal movemcn~ of
said thi~d movable member a~out said third pivot means an~l said ~ïr~t
n~ovable member about said first pivot means if communicat~d bet~v~cn
rirst an(l ~hird movahle members by sai~l link mcans.
According to another aspect of the present invention t}lere is provi(lcd ;
~ool substantially as tiescril~ed a~ove, whercin said link means comprises
mech:lnic~ll linkage.
~;UBST~UTE SHE
WO 94/12320 PCT/NZ~3/00119
38~93
l~ccor~ling to yet anoth~r aspcct of the prescnt invention thcre is provi(l~d .~too~ su~st~ntially as llescri~e(l al)ove, wherein s~id mech:lJIic.ll link.lgc
comprises a single pivo~ pin an(l/or pivotal surfacc.
~c~ording to even ycl another aspecl nf thc l~rc?sent invcnlinn l~)er(! i.s
provi(le(l a lool substanlially as (Icscri~e(l ~I)ovc, wllcrcj~sai(l I`irsl n~o-a~)lc
member is provide~l with an elongate~l apcriurc, and said ~econ(l pi~
means eomprises a pivot pin which is disposc(l in sai(l aperlur~?.
~ccording to even yet; anol.her aspect of thc present invention ther(~
provided a tool substantially as descri~e~ above, wherein saicl ~ccond
movable meml er is provided with an elongate(l aperture, an~l sai(l ~irst
pivot means comprises a pivot pin which is disposed in s~id aperture.
According to yet another a~3pect of tlle pre~ent invention there
i s provided a tool ~ubstant~ al ly as described above, where
said fir~t movable member i~ provided w1th apertures to
accoml~date pla~tic emhod1ments which axe di3p~;ed in said
aperture .
~ccording to another aspect of the present invention there is provided a
methr)rl of moving a movable mem~er o~a tool relative to a ~;~;e(t meml)er Or
~he ~ool, said movat)le member nn(l li.~;e(l Ineml)er ~ in~ pivt)l~ eotln(!cl~
l)y a pivot meml)er conlprising ~he stcl)s o~:
(i) providing a linlcage means ~)et~een sai~l fi:~l?cl and mov~l)le
members, and
(ii) moving a movable member of sai~l link means su as to cnllse sai(l
mo~able mem~er to pivot relative to said f`lxed member.
SUBST~T(JT~ SltlE'r
WO 94/12320 ;2~ 3 PCT/NZ9~/001,~9
!
According to yet another aspect of the prescnt invention there is provi~lc(l a
method of tensioning or joining wire using a tool substantially .u~
lescril)e(l abov~ comprising th~ s~eps of: -
(i) attaching a porlion of thc wire to ~ai~l fl~;cc~ nu~mber,
(ii) attaching the othcr en(! ~-1` thc wirc to ~.~i{t mnvat)~e mcm~ r
(iii) moving sai(l secon(l movable mcml~er relative to saict fixcd mcml~cr,
so tha~, said first mova~ule mem~er moves rcla~ive to sai(l fixed memL)cr, ~hc
ratio of angular movement of sai~l first mova~le mcmt~cr rel~l~ive lo thc
angular movement of said secon(l movable mcmt)cr, l~cin~ .
predetermined ratio less than one.
With the tool of the present invention as descril)ed above, the provision of
the linkage system enables an increase or decrcase in ~he mech.lnic.l:l
a(lvantage related to moving the mov~ble member r~lative to the fixesl
member, depending on the location of pivot points of thc pivot means tln(l
link means. Hence, in the case of arl increased rnechanical ad~anla~c
arr~ngement, a greatcr force m~y ~)e applie(l to o~)jccts conncc~ed l)y mc;~
Or the f~xed mennber and movai~le mem~)er, without the rc~uircmcnl l`or ~
large lever as would b~ the c~se with a single lever system, or wilhoul ~ilC
requirement for a complîc~te(l linlcage such as is usc~l with t()ol9 ~UCtl as
boil cu~l;crs and tho lilce. A relal ivcly low cosl compnct lool Inay lll~-s i
pro(luce(l .
Alternativcly, wi~h a decreascd mechanical advantage arrangemcnt ol' lhc
pivot points, amplifïcation of movement may be ob~,aincd.
With the above mechanism, lhe linlt means may comprisc any suital)lc
;UE~5TITUTE SHEIE~
WO 94/12320 PCT/I~I:Z93/00119
212~38~3
me~ns wherel~y a positiv~ or neg~tive mech~nic~ dv~nt~ nl~ly l-
~ol)tainecl. For example, tllis may involve ,~1 fluitl me~lium such 1s will~ :
hydraulic system, or may involve a mechanical sys~ern.
ln tlle case Or a niechazlical systcm, tllis may comprisc gear or cam
means, or a pin connection wi~h or wi~hout a linl~ rod, o,r-any com~)in:ltion
of ~hese.
Furt,hermore, any number of combinations of link mcans may be provi~lc~
to increase the positive or negative mechanical adv~ntage. That is to s~y, a
secon(l linl~ means may be provided between the second moval)~e mcml)cr
of a first linl~ means, and the fixe(l member. The second link me~ns may
opcrate on the same or a diffcrent principle to that of ~he first link means.
~lso, to obtain mechanisms having dif'ferent characteristics, linlc mean.
may be provided between any of the mova~le members that are ablc to move
relative to each other. For exampIe, a link means may be provided b~twec
th~ first movabIe member and second movable membcr,
In the case of a link rod, this may be connected between portions of the flrst
movable mem~er and the second mova~le memher l)y pivotal conncction
means ~uch as piYot pins or bearing sur~aces. Alternatively, the t,wo
movable members m~y be linlced togethcr by ~ singl~ pivot pin and/or
pivo~,al surface.
Wi~h thi~ arrangemenl, in order to ol)tain an incrcase in mcc}~anical
advantage, the second pivot means may be arran~ccl closer to thc single
pivot pin a;nd/or pivotal surfacc than is thc first pivol mcan~.
l~lternatively, to obtain a decrease in mechanical adv;~ntagc for si~uat,i()ll~swhcre the r~tio of angul~r movement of tl-e first mo~l)le mcm~)cr ~o t.l-e
second movable mernber relative to the fixe(l meml)er is grc~ r than nnc,
SUB8TlTgJTE 81tEET
WO 94/12320 2~ 3893 PCT/NZ93/00119
. ., ' '
~he first pivot means m~y bc arr~nged closer to the single pivoi ~n-(i/.nr
pivot~l surface than is the s~con(l pivot me~ns. O~`course, thc mech.lnic.ll
ad~rantage of the link means ~vill be %ero ir the pivot poin~s of thc r~r.sL .ln(l
secon(l pivot means coinci(le.
With the tool of the present invention, for use as .1 tcn;sionin~ dcvicc, ~hc
rotntion of thc ~lrst and secon(l pi~nt.~l mcml)ers is prc~`cr;ll)ly in lhe ~ llC
scnse relative to the fixed mcmbcr. IIencc, the second pivot rneans sh()ulcl
be positioned so that its disl~nce from the first pi~o~ means is less th~n ll-c
distance o~}le single piv()t pin and/or pivot~l surface from lhe ~rst pivot
means.
Furthermore, the second pivot means may pref`erably be provicle(l on thc
fixed member at a position relative to the first pivol, means such th~ ss~id
piYot pin and/or pivotal surface pa~se~ through a line through said lirst
ancl second pivot means during movement of said,flrs~ and secoald moval)le
members. With this arrangement, sliding motion on the pivotal surf~ce
may be kept ~o a minimum. The invenSion however is not limited tn this,
and with certain arrangements, it may be desirable to have a link menn~;
whereill movement of said second movable member relative to sai(~ ~irst
mo~rable mem~er involve~ significant sliding at said pivotal surlacc
therebetween. Such an arrangement mny involve n cam sur~lce.
In ~he c~se of the link mcans comprisin~ a coml)ination o~ linlc mcans,
thqse may be based on the same principle ancl may be 2~rrangcd witll
respective movable members rormecl as plate members which may be
stacked side by side, so that a compact design may l)e achiev~(l.
Fur~hermore, optional pivoS points m~y l)e provide~l on th~ rcspccti~c
movable members so that the mcchanical n~lvnnt~qge chnracteri~tic.s orthe
. 7
SUBSTITUTE 6HEel-
WO 94/12320 PCT/NZ93100119
Lz~3~393
linlc means may be varic(l as re(luire~l or desired.
In the case of a tool requiring l~rge mov~ment output for a small input
mov~ment (negative mechanical ~dvant~ge), this may be descrihed as ror n
positi~e mechanical aclv~ntnge tool by considering thc rirst mov.ql-lc
meml)er to l)e the inpu~ m~m~)er ~nd tl1e movahle member Or the linkn~o
mcans to be ~.he output meml)er.
W1 th the tool o~ the pre~3en~ lnvention, the movab~ e member~ may
be provided with an aperture or aper~ures to accomodate plastic
embodiments. which are disposed in said aperture to reduce the
frictinnal surface contact between the plates. The ~nvention
however ls not limited to this, it may be desirable to ha~e
plastl c em)~odiments ei ther slde of ~aid movable members .
. .. . .
Further aspects of the present invention vl,i]l becon1e apparent from ~he
ensuing description which is given by way of example only an~l with
reference to the accomp~nying dr~wings in which:
~: is a schematic diagrnm of a tool according to ~n emhotliment
of the present inv~ntion, and
E~r~: is a schematic dia~rnm ol another tool according ~o ~n
embodiment of the pr~sent invention, wherein the f ~rst
moval~le memher i8 the input mcml)er and the sccontl m(lvnblc
member is the ou~put memhcr, so th~t opcration of the tool
amplif~es the movcment of the first moYable rn~mi)er, nntl
~re 3: is a schematic di~gr~m n~ ~ tool ~ccording to ~nother
embodiment of the present invention showing a possiblc
coml)in~d linlc~ge mc~ns.
With respcct to figure 1 therc is pro~idc(i ~ tool gcnernlly indic~
SUE3STITUT SHE~ET
WO 94/12320 ~L2a89~ PCT/NZ93/00119
, . . .
arro~v 1. 'l`ile ~ool 1 com,)ris~s a fi~ emL)cl :~ a~ irs~ ms~v~ lc
mcmbcr 3. 'l`he f`irsl moval)le Illclnl)-!r 3 is pivolally co~lnec~c(i lo ~h~
mem~)er 2 by means of a pivot pin 4 fixedly ~ttache(l to lhe fi~;cd mcm~cr '~.
Tl~e tool 1 is f`urther l~rovide(~ wilh a linlcage f`ur conne~ling be~vccl- tllerixe~l mem~er ~ an~l the ~ïrst nlova~)le mcm~)er 3. rl`he linlcagc compriscs a
second pivot pin 5 rcmova~ly a~ached to t;he lixecl mc~ secon~
movable arm 6 which is pivol~l al~ou~ ~he pivo~ pin ~, and a connectin~ ~in
7 which provides a pivotal connection between the seeond mov~l~le mem~er
G ~nd the ;rst movable mem~)er 3. l'lle first moval)le mem~)er 3 is pro~ide(l
with an elongated aperture 5~ so ~hat it m~y pivot; aboui ~he pivol pi
wi~hou~ interferencc wi~h ~hc pivot pin 5 Fur~hcrmorc a holc 7a in ~h~
first movaL)le mem~er ;3, ~or a(:co~nmocl;lling t~c conncc~ing pin ' i~
slightly elongate~l to allow for the variation in distance between pivot pin 4t
and connecting pin 7, an~l between pivvt pin ~ ancl connecting pin 7 as l,hC
rlrst movable member 3 pivols al~out pivot pin 4. The hole 7a thus ac~s as a
pivv~al surrace which ~llows sli(ling an~l rolling pivo~l movemcnl.
With this arrangement, movemen~, of t~e secon~l mo~a~lc rllcm~cr (~
relat;ve to the fixed memL)er 2 causes the first mova~)le member 3 ~o pivol
al)uu~ ~he pivot pin 4 relalive ~o i;he f;xe~l melnl)er ~. The arr~ngc~ncn~ ol
~lle pivot pins 4, 3j and 7 is such t;hat with clockwise rota.lion of thc scculltl
,i
moval~le mem}~er 6 abou~, the ~ivoS pin 5, ~he l;rsl moval~lo mcm~Jcr 3 ;llso
turns clockvrise about the first pivo~, pin 4. Furt,heranorc, since the sccontl
pivo~, pin 6 is lucated closcr ~o lhc connecting pin 7 l~han is thc l;rst, pivo~ pil~
4, tlle ratiu o~ angular movemenl of` She firsl, mova~)le mcm~cr 3 ~boul tl~(?
fïxesl member 2 to ~he angular movement of ~he second mova~lc men~bcr (;
about ~hc ri~cd membcr 2 is lcss than 1. llcncc a mcchallic~l a(lv~nl.lgc i.s
obtained. As a result, compared to a single levcr device, l,he levcr ~rm
~ 9
$llBSTITUTE SHE!~E'r
WO 94/123~ ~ ~ '; PCTINZ93/00119
l~nglh Or llle seconcl moYal)le Illclnl)~r G m~y l~e shor~er to ob~:~in ~llc S~ C
rorcc at ~he tip of ~he moval)le/~ixe(l mem})ers.
~s shown in figure 1, ~hc tool is aàap~ed f`or use in lensionin~ an~l Sying
wirc. 'l`he fixed meml)er 2 is provided with a connector ri~ting 10 which
has a yoke(l end portion 11 sized to accommoda~e a urire ~onnecting tlcvicc
1~. The moval)le member 3 is provide~ wi~h a wire gripping device 15
which is fitte~l wit,h spring loa(le(l collets in a similar arrangemenl Lo
s~an~lard Pl) rivet grip.
Wh~n using lhc lool, one cll~l lG of ~ wirc is fixe(lly al~ cd lo ~le
conncc~or ~evice 1'~, while t.~lC o~her en(l 17 Or the wirc is lhrc~lc(l lhro~
~he connc~or d~vicc 1~, $hcn througll thc gripping (levice 1r). The mo~ l)lc
mcmbcr 3 is then moved aw~y from the fixcd mem~er ~ ~y oper~lin~ the
second movable mem~er 6, so that the wire is (lrawn ~hrough thc
connector deYice 12 ancl thereby tensioned. l~urin~ the tensioning
operation, the wire is grippe(l ~y a fitting 1~ which compriscs ~
1~ mechanism similar to that of ~he gripping device 1~, while the movable
~ member 3 is being moved towar~ls thc fixed mem~er 2. Whcn surricicn~teIlsion haæ been obta.ined, the end 17 is withdrawn from the gripping
deYice 15 and bent back on the tlevice 12 so a~ to ~;x the wire thcre~o.
~,
'l`he fixetl and mo~able mcmbers 2 an~l 3 Or the tol)l 1 may al50 ~e pr~vidc~l
with other suitable fittin~s. l~or examplc, these may comprise ~he jn~Y
elemexlts of a crimping tool, willl one jaw elcInent attachc(l to an CXlCllSil)ll
n~ the ~lxed mcm~r :~ which cxtcn(ls out ~o the other side of the moval)lc
member 3. With this arrangement, a crimping action mny ~e obtain~
between the mo~able members 3 an(l the jaw element with anti-clockwisc
movement of the secon~l mova~lle member ~.
~UBSTITlJT 8HIEEl-
WO 94/1~320 2~L:Z~38~3 PC~T/NZ93/~0119
Figur~ 2 shows anotllcr em~)ollimcnt Or tllc present invcnlion use~l t~)
provide an amplifisation of movemen~ (negative mechanical advantagc).
~ tool 100 comprises a rlxe(l memùer 20 an(l a first moval)le meml)el 3i).
The first movable mem~er 30 is pivotally connected to the ~ixed mem~er ~2()
by means o~ a pivo$ pin 40 rlxedly attache~l to the flxcd men~aber 20. The ~ool
100 is further prnvide~ with ~ linlcage for connecting between the ri~;e(l
m~m~er 20 ancl the rirst mov~ble mcml)er 3(). The linkage comprises ~
sccond pivot pin ~0 removably attacllecl ~o the fixe~l member 20, a secon~l
movable arm 60 which is pivotal a~out the pivot pin ~0, and a connec~ing
pin 70 which provislcs a pivotal connec~ion b~tween th~ seconcl mov;l~)lc
member 60 an(l the rirst moval)le member 3(). The second movablc
mcmber 60 is provi(lcd ~vith ~n clon~ated aperturc fi()a so thnt i~ m~y pi~ ol
about the piVQt pin 5() wililout inter~er~nce ~vitll thc pi~ot pin 4t).
Furthermore a hole 70a in l;he first movable member 60, for
accommodating the connecting pin 70 is slightly elongated to allow for thc
variation in distance between pivot pin 40, and connecting pin 70, an(l
bc~ween pivot pin ~0 and connecting pin 70 as the first movable rnemL~cr 3(~
pi~ots about pivot pin 40. 'l`he hole 70a l..hus acts as a pivotal surr~ce whiclallows sliding and rolling pivotal movement;.
With this arrangement, movement of t,he second movable mem~cr G()
relative to the fixed member '~0 causes the first mov~le membe~.3() ~o yivot
abou~ the pivot pin 40 relative t o the ~lxed member 20. The arrangemcnt of
the pivot pins 40, ~0 and 7() is such that with clockwise rotation of t,hc
second movable meml)er G0 a~out the pi~lOt pin ~0, the ~irst mov~l)lc
member 30 also turns clockwisc ~out thc first pivot pin 40. Furtllcrlllurc,
~ince ~he secon~l p;vot pin 50 is located further from the c~nnecting pin 7()
~han i~ the rirst pivot pin 40, the r~tio Or angular movcmcnt Or tllc lirst
11
SU~5TITUTE~ $H~El'
vvo ~4/~ Z~ 3 ; ~ PCT/NZ93/00119
moval)~e member ;~t~ about ~hc llxed mem~er ~(), to the angular movcr1 it
o~` the second movable mcn~l)er 60 abou~ the fixe(l rncmbcr :20 is grcatcr
~han 1. I~ence a negati~!e mechanical adYantage is obt~ined. Various
att;lchments may be fitte~l to the first mova~le mcmber 3V and thc f~xc(i
member 20, depending on the use which the tool 100 is to be put.
Figure 3 shows a tool generally indicated by arrow 2~ccording to a third
embodiment of the present invention. ln this figure, components hnYing
the same function as those of figure 1 are identified with the same
numerals and description is omitted for brevity. 'l'he linlcage ~or
connecting between the fixed member 2 and the first movable member 3
comprises the linkage of figure 1 with an ad(litional linkage for connecting
between the movable arm 6 and the fi~ced me~ber 2. The second linlc~c
comprises a third movable arm 160 which is pivotal about a pivot pin 1~0,
and a connecting pin 170 which pro~ des a pivotal connection between the
third movable member 160 and the second moYable member 6. The second
mo~rable mcmber 6 is provided with an elonga~ed ~perture 150a so ~hat it
may pivot about the pivot pin ~ without interrerence with the pivot pin 15().
I;'urthermore, ;a hole 1qOa provided in the second movable member G, ror
accommodatang the. connecting pin 170 is slightly elongated to allow for the
~ariation in distance b~tw~en pivot pin ~ and conne~tin~ pin 170 an(l
between pivot pin 150 and connecting pin 170 as the second movablc
member 6 pivots about pivoS pin 5. The hole 170a thus acts as a pivotal
surÇace which allows slid;ng an~ rolling pivotal movemerlts.
With this arranKement, movement of l,he third movable membcr 160
relative to the fixed member 2 causes the second movable member ~ to pivot
about the pivot pin 5 relative to the fixcd mcmber 2 which in turn causes
the filrst movable member to pivot ahout the piYot pin 4 relative to thc fiYed
rnember. 12
~;lJB~;TlTUTE~ SHEEl9
wo 94/~X320 ~ æ~3 ~CT/NZ93/00119
This embotliment shows llow lhc linlcage means o~ lhe present inven~ion
may l)e increase(l ~o provi~le ~n incrcase in positive or neg~tive mech~nic~l
a~lv~n~age.
I believe ~he advantages Or my inv~n~ion ~o l)e as rollows howe~ ~r it shoul(l
be appreciated that all such advantages m~y not b~alised Otl all
embodiments of the invention, and ~he following list is given by w~y of
example only as being indicative of potential advantages of the present
invention. Ii urthermore, it is not inten(lc~l ~hat the advanta~es of ~he
present invention be restricted to ~hose of the li~t wllich follows: -
1. The provision of a link mc~ns ~etwecn ~he mo~ablc meml~er .ln(l lilc~ixed memb~r enable~ t}le mcch~nic~ (lvant~ge of She ~inglc pivo~ io l)e
increased, ~r decreased9.depending on whether a higher load is to b~
applied to the movable mem~cr, or whether the mova~le mcm~cr i~
require~ to move through a greater angle l,han the movement of thc link
means le~er respectively.
2. The components of the tool may be designed so thal a simple three
plate type device is ol)tainell. This minimises the number of componcn~s,
making a more compact and lower priced device possible.
3. The design also ~acilitates the ad~lition of com~inations o~ linkages
between members moval)le relative to each other, since l,hese may ~)e
simply provi(lell in the ~`orm of flat plates stacke~l one beside the other, Witll
pi~ connections thorel~etween.
4. The principle Or the inventiorl may be equally applicd to a tlaol
whelein the rlrst moval)le ~nember is requircsl to move in an opposiSc scnsc
to movement of the s~cond movable mem~)er, by appropriate posilioning of
thc secon(l pivot relativc lo tlle rlrsS pivoS an(l linlcage pivol.
13
SlJE~STITa3TE S5HE~E~T
WO 94/1~320 PCT/NZ93/00119
,, ; ,
2~;~a~3~3
. The tool may be easily provided with a variety of attachments to
increase the versa~ility. For e~cample a combination of,~r ri~ret and wire
cutting attachments may be provided so that closing of the operating
member to~ards the fixed member may result in both a tensioning force
on the pop rivet and a compression force on the cutting attachment.
6. The tool may be used for work where amplification of movement is
required. For e~3:ample, the tool may be fitted with a mechanism which
enables a threaded nut to be rotated several turns for a small movement of
the operating handle. In this applic~tion, the tool may have facility ~or
varying the location of the pivot points so that a positive mechanic~l
advantage may be used to unload a nut. The pivot point loc~tions m~y
then be changed to give a negatiYe mechanical advaIltage (ie. a large
moveme~t for small movement of the operating handle).
Aspects of the present inveIltion have been described by way of e~;ample
only and it should be appreciated that modifications and additions may be
mad6e thereto without departing ~rom the spirit or scope thereof.
SllE3STITUTE StlelET
