GB2469330A - A hand tool with a cutter and a scorer - Google Patents

Abstract

A hand tool 10 suitable for cutting rigid sheet material such as plasterboard comprises a first end having a scorer 30 and a second end having a first cutter 40. The scorer comprises a perforating wheel 32 with a plurality of projections 38 around its circumference, its axial width preferably being greater than that of the projections, or a cutting wheel with an annular cutting disc of smaller axial width than the wheel. The first cutter may comprise a concave first blade and may be pivotally moveable between a stowed and an extended position. When the first cutter is extended its blade preferably forms an obtuse angle with the axis of the tool. A second cutter 50 may comprise a serrated second blade that may be pivotally moveable between a stowed and an extended position. When the second cutter is extended its blade preferably extends substantially along the axis of the tool. The tool may also have two shielding discs concentrically mounted on a respective side of the cutting wheel, each disc having a diameter larger than that of the wheel. Material is scored on one surface, broken and then cut on the opposite surface.

Description

HAND TOOL

ih nvenuon rejates to a hand toot and fluiariy, but not ax sveh, to a hand tom for outflnp arfitd s materiaL Rmd sMote are sr,rd a tenaiv&y n the oufldinp end nonstruction ndusme..s to oroykie smooth. flat surfaces to the interior sorfaces of waiis, rxoo and other intemai bukino festhres flrior to a firflshino rnetenai bang appfled.

lb Snr.:h noid sheet materials otter'. cornorise coIl osite 000structons An exampie of a ripci sheet a a nasno a cornoosite construction which is comntoniv used in bufldinc and construction app osbons a piasferboard. Hasterooarrt is sian c.orimlorfly k:nown as Yweii, 0 sum board or wittoard, t5 Piastertard 5 typkiathy made of a tayer of gypsum piaster pressed t.'tweefl two sheets of paper. the composite sheef then hemp kkn dhed, it a snown to cut pasterboard to size by scoring the paper on the front side with a biaded utiity knife, breaking the sheet core ob the cut, scorn the paper beefring again using the uflfltv finite, anti inaky brer$dng the. sheet n tne o osce drtebon.

rne features such as hoies for eieotricai power Otttets end iight awitohes are usueiiv cut using a utitty knife, Ke'jhoie saw or a smaH hqfesoeed bit in a rotary toot :25 A Orobme.m wth the known method tbr ou'tting iesterttoerd described above is that it either repuoes�= two peopie. one person workino on each side the fiat board, or one person must work sac.uentiaiiy from first the front she and then the back side. since the most common size for iasterboard sheets is I.2rn b 2. $rn, a singie use.r often finds suoh cutbno operations dhfiouit and time.consum,ino.

Ths known methoot then reties uoon tne use of a sharp baded utitty knife wh,ich raises m.anv safef.y coucerrs, tjtiity krives are the cause c mnsn:y worik iace irfiurws.

Knows can pose ermk both to users and to feiiow workers for severei reasors. as

tn order to he ebie to cut end score eiteotvay. knife bLades s'houid be sharp. However.

this makes them more dancerous since they can cut more oasis.

On the other hand. if a Knife Made Fs Munt it can then be dannerous because the user may Strom tome to Overcame the tuntness. This nan sonificantis increase the heit nt inadvertent inury shouth the knfe siir from us iniended path.

There are moeasnpiy stnnoent heetth and safety re:ouiatinns sunTnundino The use of abUt knives m the buUthno and construction nctutr.u. Men workpiac.es have proratyted The use of such itrUves where aiiernatiye. cutUng methods are evaUshie, lb fri overcome these sefet concerns 5u OUndnO The use cu utbity itrmtes a s itnown to use knraes hacac retractathe. biedes, An ext noie of auth a uNit knife ra described in tnoari patent epphcavon nunseer CA $ 506 eet W'nust this soiution can provide a safet benefit, it aLso requires the user tn positwety tt; retract the Made when the korfe i no tanner in use. Faiiino to retract the biade can totaUy negate The aseocet,sxi safety benefk, Anot.ner uNit knife which addresses these safety cncerns comnoses a biade which is spring toaded n a retracted postUon and must be positiusty heid in the extended caNon ti) by a user: ?&raves of the desiqn can be difficuif and noonvenient 10 L55, None of the kn,ives described above however, nrovktea hand toni which can Paused dv a smote user to cut a ripid matehai such as r�=iasterdoard without raquinnp access to both sides cite ethel meteriai.

Furthern'iore. none of the sciutiona nrovide a hand toni whIch can be used by a aingie user to cat a npid matehai such as plasterboard without the use of a sharp edged biade i\c.cord?no'to a first sr.Iect of the Invenbrin there iS provided a hand tool. comcrisinp a Sri scorer and a first cutter Vbean the tool is used to er r'ctid sheet materiaL the scorer atlows a tiser tosoore a front face of the material prior to brealunq the note of the meteriai aionp the scored iine.

Sf5 After breaknc the sheet core, the first cutter can be empioed: to out a ioyer en the back face of The rneiariai from the frcat face.

thus. by tr inn a sc:ore.r and a cuuer flxi a hnqe hand tooL a user may cu hems, such as rkecf sheet mateeLa, whhout rem nno aocese to both ethes of The matenat N \N" NON \ N,, \ core unbon task's sfrnper arTh cc suer to uneneke, Furthermore, the hand tno russ be used to cut mareha th seuatThns where S u: not P0555th: to gThn ace: to both hdes of the n:yrfr, Thfe metres the hanc toot of the roenuon more fle>cbte and useftd than oonsntona cuthng toots, C)pt':onaftv, the hand too oornprtsea a first end and a second end, the soccer beino coated at the t end, and The first,ther ocated at the second end.

When the neno Sno s to be used to snore a surface, S s hehi tn a user's hat-cd such that iS tue fret ace fs the Theta and, owe, when the hand toot Th to be i.,sed to cut a surface. is hetd tn a user's hand such that the second end te the dtstat end, Optioriahy, the scorer ocirund see rotatarde pertoratinu wheeL true perforatinc whee \ N N,. .N. " N,, SC? Wt) the use or a perforaSno wheet to score the surtace of the front tans of the sheet ern?nares the need for the scorer to be in tue form of a sharp edped bade. Tub ?n'?proyee the safety of the tooL Th contrast to a units wh?ch woud cut the surface chthematerrai, the perforating wheet creates a series of uertorations n the face or the sheet malaria, These perforat?ons eat to muSts a tine of weauness atcw which the core of the rnetehat may us broken, the cadia ienpth o the p Oe'ctone on the cerforeting wheat 9 preferabty in the canoe of trim to tumm, and more pretarauty between 2mm end 3mm, if rh-a red?at enqth of the ororectton.s, is tess than 1mm. the pertorefions, formed by the prcmectic:ns wh nor to suthcientiy deers to produce a me of weaKness in the core of the S'S matensi, resuitino m an ?rr oar rea urir?cf of the core materhd, C: h the rad& kecth of the grojectiori on the mrtbre'tfr;o wheei s ctr ater than 4mm. the orc)er;scns w esr the core mateha end wW thus be ur�^et'$e to form a sakes of S OohoraUy, the sxa ddth Ot the ç foratno whee e oreater than the ake wh'ith of each _t- *-c \%?\-. Uu t"

Ar; acscntana o the avte wettn of the penoret}ng whee beke oreater than the ake 5h of the proeckms e that;n use the hertphere edge ot the gerthrkeno whee ecte as a moo to the pake of nroethone. W'nen ores nra k apthed th the. hanct toO as.

contacts a rnatenat the oroectmns ne rate the surface of the roaterke unth the pertoheret edge of the perforathrg whee' mao contacts the surthca of the materiaL Thus.

the enoheri shoe otthe gerforeting wheei orevents: the omieotmns from over penetrating the surfase th the materiaL Ootonshv, the scorer comprises a rotatake cutting wheeJ, the cutt;ng wheei compnainçt an sonniat cuttnO diac The cketing disc scores the surface of the matarisi resuiting in a scored groove.. This scored groove then provides a hne. of eakness siong whioh the core of the mateha may be broken Optionav. the amai width of the rotetahie cumog wheei greeter San the axiai width of >t; ; ;uc; An adsante e of the axisi w;dth of the rotetabie c.ctting wheei being rester tnan tneaxmi wthth of the ennuier cutting disc is that in use the psnphend euce ci the rotatahie cuttsn k" +k..

\ \ � \. � � " tom as it contacis a roaterisi, the: areiumr outtino disc oenetrsdes the surface of the ta maixsnei untt the penpherai eckfe of the rotatebie coten5 shee &ao coniects the surface of the maieriei. Thus, the oeripherai edge of the motetabie cutttigwheei orevente. the annuier cutting disc born over genetrabno the surface of the metenei.

Optior;eii, the Inst cutter comprises a first oieoie having a concave orofiie, The first hiarte can be extended through the broken cone of the rne<tenai in order to cut the iayer on the hack face of the materiai. By having e concarve viade prof;ie. fhe firsi biade outs the thyer or the back face ot the anterm as the hand tcc s brawn mwards the user i.e. on a downward Out snoke) By ontincl the beer on the back face of the. mareriai on the nut stroke, the rnateriai core ttrovdas soooon' to the beer whkth prevents the iayer on the back face from te:arirq.

Furthermore, time enebies the bet hiSs to cut the materab without reouir)n a sharo Thu this feature enSes the hand toot to be used to cut a Layer or' the back face of the mawriey iti'tt renuirino access to the oacr of the materiaL Optionatiy. the tIrst cuber is tckotatiy mounted on the hand tom and s moveabte between a first ocaition in which the first cutter is bewed m cavity in the hand tooi and a second position in wnioh the first cutter extenots from ide hand tooi.

Ths. teature makes the hand toot convenient louse by enabtino the first cutter to be stowed in tee body yI henc loot when not in use.

tnt an attemefive embodiment, The frst cutter may etde exiety out from, its stowed nosinon in the body of the hand toot, before pivotino into the second position *,...\. N *t,' ...,,,4tL \ . " \ \ V,,. \. " 0 en obtuse enpie with the axis of the hand tent.

Ths makes the first cutter easier and more concenient to use when cutfno the iayen on the heck face of the sheet matedei, Optionatty. the hand tom further comprises a second cuber oomonsino a second bLade, the second Liiabe havino a serrated nrofiie.

The second cutter can be used for outfinq and shapint'. features on the shee n";ateriai, such as apertures to acwapt eiectrioat sockets and bnht switches, or irreguiariy shaped features, Options, the second cutter is pivotait mounted on the hand toot an s rnoyeabie between a first poston in wh,rrh the second cutter is. stowed n a cavity in Iris fiend toot and a second position in which the second cutter extends from the hand tooi, Thm taaWrs makes the hand toot. convement to usa h enabUnr the aecono cutter to be isd n tha body of the hand toc when not tn use.

anaherr:attve embodwnenf the second on may tThde wdauy out from tts stowed poaWon m The body of the hand tov4, betore vottr' frtto the second poaWon.

Ophonaity. When tne court cutter a to the second postttcn. the. btada ot the secooct cutter extends substanhay atono the ads of the neon: fy't.

rt5 makes toe second cutter easter ano mote cooyenjent when outhr:c' and ct'.c.ct n*.fl& ...... ..4..

OcttoriatN. the first arid soortoutters are toteorahy formed, Thie feature ahowa for a orphe somposde cutter hadrut both a first cutter and a second cutter extendno atonci axiat edpea Opttonettv. the secono cotter has protriston which Q&5terds Thom the second anti of the hand toot when the second outiter is n os first cotxcn the protruatori s used to puncture the sheet marterm and cream a Otiot hote to attow W55?er and more convenient use of the second cutter for cutting arid snaidog features, 55 apertures on the sheet materiat Opttoriafly, the hody has a recess adapted to aocornmodate so end of a mea crino tape.

This feature aitows the. user to hoTh a fret end ot a measuring taco to the recess of the hand toot whhst the hand tooHs irt use.

The recess may be toosted on a dde of the haoc toot. Atteroativety, the recess rises be tocated substaof.ietiv on the centre hoe of the hand toot.

in an arrenoe.ment it'; which the recess. te substaotiaflv on the centre hoe of the: hand toot xc the recess ma edo inciude a means for cetaiorno the sort of the n:ie:asudr'w taco, frp examie a retairdno oh or a haotr. to thia way the. user does not have to both. the end of the. measurir;c taco to the recess, makoo the hanu toot more convenient to use. E' Th

tO a second sspset 01 the vndon there s provided a rn thod of cuttinç a tOtsr SIP a rc cc cc crisinp a er and a first c:Hter tltrnethn:1 ccmpdsin the 5t50S p1: C' et brealono a core aver of the materiaL and cnttlrm an opposIte aurface layer of a matefial, The scprr Is used to score the surface ot the materIal. thus orovdino a ne of eaKnes atonq widch the matenal is to oe cut. The core Layer of the to ter1 can then be broken IC by bendinp the material across the plane of the scored llr'e. Fhnallv, the opposIte surface layer can ne out so as to sewer the two peces of the matesial, Optionally, the hand tool further comprIses a fIrst ry,i the scorer bei'nct ttatabl mounteo at the first end, the method compronno the further initial steps of: roldinp the hand tool such that the fIrst end a a thstal end and an sos alono the hand toot forms an acute angto with a surface of the materiaL ann pressn, the hand tool aoainst the rface of the rnatenal whUst moving the hand tool aLcog the surface ot the rnatehal n a predetern'fine,:i deectlon, c Clpttorml, the scorer comprises a rotatable cuttino wheel, the hand tool further comprisIng bVO sheidriq discs. each a elowig dm0 being ooncentrlcalhy mounted on a respecttve thde of the rotatable cualno wheel. the diameter of each shieidmg disc being larger than the diameter or the rotatable cutting wheel :2's Oobonay. the hand tool further c mpr?sea a second end end the fIrst cutler hemp located at the second end, the method compnsmq the further steps of: aftet breaking the core of the materiel pcsltlomn the lirst cutter such that t forms en obtuse angie. with sri axis elono the hand tool: holdtno the. hand tool such that the second end s a ciht& end and an exts along the hand tool farms an acute angle with the surface of the materiel, extencilno the first cutter through the broken core of the rnetenal and applying a sewing action to the material.

Optionally, the hand tool furthw composes a recess, the hand tool betnoused. in corfiunctiori wIth a measuring tsoe havno a first end, the method comprising the further stess Ca, b sejrno a first coo o a rneasudrio tame n the rer;aaac rokimq a onadeterroined pont Soc the meaaurinc ta>e ad a free edge of the miteha!; h oreoe termined pomt wonç! the rise edge of the roaterad n %C% rkcth the noveciem of the h5:na too!.

This owa the user to out mecca of metera! hathrç a constani d!menson. thua making the hand too! more f!ex!the and usefui, ow!b!!ows a descr!0000nf an embod!mem of theirmebeort, dv way of nom hrrnr!no awanatit nab ralerence danomede. to the e000 to ntfino drawinos n wtoh: Figure 1 s a side view of a hand too! aocordthq to a first embodiment of the invention showing the comoosite cutter m a hrst ocaftion. stowed in the hand too!.

$ a an end view of the fIrst end of the hand toot of gure I ahow!nc the pertoianr':g; wheeL a mdc wew of the r'and too! of:gure f showmo the oomoos!te cutter in a second r.os!ton, evteno;ed from the hand tooL Ptgure $ is a side wew of the hand toot of Fioure. I showmo tue rvyuoosfts orxterin, a thfrd nosifofo, extended born the hand tooL Ficure 5 is a then view of the hand too! of Flours 1 shownr) the ehpr'!nnent of the scorer reiatve to the hand too!.

Fiture 6 is a perspectve vew ot the hand too! of Figure 1 being used to score the front feoe of a: meteria!.

Figure 3 n oereohv vewof the hand. too! of Folure I with the oompomte cutter m the second position bang used to cut aiayer one beck face of the matehai.

Fklure 8 a a oerspective view of the hand too$ of Figure I toth the ooni'mebe cutter in as the third positmo, eang used to:3rfle a shaped aperture n the. meteria!.

lOgure 0 s a iew o the brat end of a second entbodenern' of the nvendon snownc the cuthno wheei end ehwldno dsce Pure IC) is a vew of the lOst eon nO the hand too of fhoure 9 showno the dethomation a 0 the sheklinp dwcs Wren the hand tool is in use.

Referhno to Figures 1 to S.a hand tool accordino to a lirat enrbothment nO the invention is designated qeneraUy by the reference numeral 10. The hand tool lOcornorises a scorer a brat cuttet $Q and a second cutter 50. in Pus ernbothment the first cuber $0 ann the second cutter 50 are intep:raby torrned as a c;ornposite cutter 00, r foot 10 has a fIrst end 22 and a secono end 2$ ann: a adapted to be held in the hand ci a user.

In other embodiments the audac.e of the hand tool 10 may be ndaed, prorated or knurled to provine mprcved grip to the user. JternaOvety, the surface of the hand tool 10 may beprovidert with a soft grip surface. ooverino which makes the hand tool 10 easier anu more con'Uortaow to use.

The scorer 3(1 oornohses a perfaratinq wheel 32 i'showr in Fipure 2) which is rotatably connected to the brat end $2 of the henri tool 10 n a pivot pin 36 The pivot pin 36 a secured to the Scat end 22of the hand toot 10 and passes throuqh the perlorattno Wheei 32, the perk aPug wheel 32 rotating about the pwot pin 30.

Ott The pert raotnr wheel 32 comprises a disc haytno a okraiity of proieotions 3$ formed ciroumferentheiv around its oenpherv, The prcections 3$ protrude radially from the r:senoherv of the. wheeL in the brat embodiment of the invention, each of the pm actions 3$ is rectanclular m cross :3 sechon, in other ernbodintents the protec32rs 3$ may have a dilterent cross vectiorta profile, such as owouiar, sQuare, etc. The ocmooaha cutter 00s pivotaiiy located at the second end 2$ of the hand tool 10 by a QivOt pin 4$. The composite cutter $0 pivots about pin 4$ at the second end 24 of the Os han�^d tool 10 and is moveabie between a first position in which it cs stowed n a cavity $8 in the hard toottd, and a second position n which it extends front the second end 2$ of the hano: toco 10.

One edge of the firs cutter dlii a torrneci as a first biade 4$. The first bisdEt $2 is concave.

in nrofiie. P farsbiv, the first biade $2 dn not inriude a 5arp edge.

it Figure 1 snows the rnperte cutter $0 in its fird position. wed in a cavity 2$ m the When the first cutter $0 i5 use, as shown in Fiours 0, it extends from the second end 24 ot the hand foci 10 with the first biade 42thrminc an obtuse angie wtth an axis thong \, ,.

When the corn ease cutter (10 is in Os first sosition, a portion of the cornposfte cuitter $0 e.'xtends frnrn the second end 24 of the hand tooi 10 forn'iinp a orotrusion 70.

0' One edge cO the second cutter 50 is formed as a second biade 52. The second biade 52 has a serraiad profits, When the second cutter 50 s in use ii extends from the second end 2$ or the hand tooi 10, with the second biade 52 extendinp sucsta,ntiarn; sirsnq the axis of tn hand toot 10, Ficore 4 shows the coniecede cutter 60 in its third oositlon extending subsrantlaUv thong the suns 01 the hand toot 10.

in the first embedment, the first cutler 40 and the second cutter 50 are ntegrag formed ""t as comnoosde cutler 60 However, in other embodiments the first cutter $0 and the second cutter 50 may be formed as separate features, each being iocated at the second end 2$ ci' the hand tooi The hand toot 10 has a recess $0 which is sized to accept a first snd of a measuring taos (not shown. The first end of the oteasunno tape may be secured to the hand toci 1,0 by the user's hanc.

:tf in the diustrated err odment the recess $0 is iccated on a mdc. of the hand leoi 10.

AJternave the rcess: ff0 may be faceted substartlaLfa on the centre ne cit the hand tofa 1 fa another embothment the recess 80 mn indude a gnat wttcn s used to rsunncitapehavin9an use. as shown in Fqure 6. the hand too 10 is first heid nauser's hand such that the in.f and 22 is the distai ann with the scorer 30 in contact wth the front face of the mateniai ro ca cut, and an axis aion. the. hand tocd 10 forms an acute enr$e wild the surlack. cfl the materiaL Pressure is apo0ed to the hand tool 10 by the user so as to force the projections 3$ of the scorer 30 to e.ftorate the surface of the front face of the iNs hand tool 10 s then drawn afar the surface of the mlderlai siorici the line amross which the material is to be cut. Thw action creates a series of closely spaced cerforations which act as a hne of weakness in the metedaL When the desired cuttino hne has bear: scored into the surface; of the n'mtedaL the core of the material can be broken aicng the scored faa, Ths can e a tleved by bendico on the materiel across the obne exterithno throutjh the scored line, Since the scored line produces a hne of weakness in the materhai, the core 01 the ",iw."',,4i,,", , ""," ."b";'.

C C:\"U C: z,iLC: C:4 U:V no nano tool 10 may now be reoosuonec; in Uris users nar':o: m:s shown in hgure c) such tn41 tflf.i seconcJ suu4 n: the dIstal end and with the ffrsl cutter 41) in ts extended osition, such that It forms an obtuse. anpie with en axIs aionp Free hand tool 10 The hand tool ID is positioned such that an axis along the hand tool 10 forms an acute anoN with the surface of the rnatenai The fIrst blade 42 can then be. pushec: through the broken core of the rnatehai and throuph the Layer on the back face of the rnstenai. By emtopin a sawinc action the.

concave profile of the fIrst blade 42 can be used to out the eyer on the beck face of the malenaL. Ths cutting action s carried, out as the hand tool 10 is drawn towards the user (i,e or a oownwaro ou'ii strokey thst was, the rnatena oan us out aonp a paritcuLar ne w$hout the user requrnt access o the bac:k face of the metedaf Tue havi too 10 can wSO 05 ueu to create shaped apertures n a ruatehaL as r' . Thk a aoheved ha brat hokflnq the hand too tO tn a users hand sech that the aeoond <j s4 ts the dktat and, and wed fee seoono: cutter 50 tn Os stowed ptefon The protrureon 70 a then used to ounoture3 the surface of the maten'at atoep an edate of the hI aperture to be cut.

1h hand toot 10 a then enositoned n the needs hancf stilt wed the second end 24 sc: the dktat end, but now wed the second cutter 50 tn its extended posOton, such that 0 exrends substarittaile atone the axis of the hand toot 10. The hand too 10 ts *csttoned t. such that an s>ils atonal the hand toot 10 5 substanhetty nornaat to the surfaoe of the t" .... ".*c' The tip of the second btade 52 a then pushed through the matertat arid the serrated edge of the second btade 52 used io oui atonçt the edge of the desired aoerture.

The recess $0 can be usea in seniunotton wed a rneasuhnp tape r':ot shown to cut pieces of matertat failng a constant du'renton from a free edoe.

5: a,cnevad by securtnq a ftrst end of the measunnp tape tn the recess 80 of the as hand toot tO. A peadse nitned potnt atong the naeasunn tape can then us hetd at a tree cope of the matenat. from whtoh it ta destred to have a constant dtmeriston.

toe herid toot 10 ta then used to score the surface ot the matehat as outilneal above. As the hand toot 10 ts drawn atono One surface of the materiaL the oredetarmtned point atOng tn measunn tape is moved atong the free edge of the rriatertat at the. sante rate.

The recess Sf) max atso be used. to score a One. having a constant radtus. This can be achieved by secunnp a flrst end of the measurin tape in the recess 80. and then fi,xin a predetermined pont atonci the measunne tane at a point on the materiaL As the hand as toot 10 is drawn atong the surface nO the mnatenat, it wilt Score a tete having a constant radius'.

Fig rs P end 10 shtrws a hard icci accordinci to a second embodiment of the inven1ion wmcn s deannatad qeneray 34 the retemrice numersi 100. Pans ci the hand tooi 100 that corresoonci ix; parts ci hand tool 10 have been given corre onthng reference numaras for ease reisrerice.

in the second embodiment Oi the hand toci 100, the scorer 30 oornpilses a rotatabie cutun wriesi <sO.

A air of circuiar shthidinci thecs 110 is mounted ccn:centricaiiv with the rotatabie cutiinp wheai 3$ with each shemnt disc 110 beinc iccated on a resoec.tive side 01' the cuttirin wneei 34.

Each of the shteidinc discs 110 has an outhr diameter which s graaier than the oatS diameter of the cuthno wThe1 34.

in this embcvlhmarn, the shiektno discs 110 are made from a rubber mstenai However.

in other emboniments of the uwenbon the shieidinq discs I 1,0 may be formed from other r'esthent mamertais The hand tooi 100, accorthno to a sex;cnd embodiment of the nvenbon is used ri the sanernarner as the hand tcoi 10. As the hand tooi 100 s pressed aqainst the surface of the rnatenaL the shiaithno r3sc$ ItO) on ethar sate of the cuttinp wheai 34 detorni, aiiowinc the cottinrl wheei 3$ to coniact the surface 01 the matenai, as shown n Ficiura 10. The hand tooi 100 may then be drawn aicno the surface of the maienai aicnp tha Sri bne across which the mate*nai e 34 cot to oreatee slrocve. which acts as a hoe of weat,ness in the rn&ertai.

When the hand atci 100 ieaves the surface ci the materiaL the shwidinp dkcs sprinci bach into their oricdna shape and cuard the cuttinu wheei.