CA2060497C - Zoom stripper - Google Patents

Abstract

A "Zoom Stripper" which enables the user to strip insulation off any electrical wire of any size in range from AWG #8 to 2000 MCM.
The tool is single hand operable and may be used in stripping insulation off any kind of electrical wire, stranded or solid type.

Description

Zt~OM STRIPPER ~ 4 ~ 7 BACKGROUND OF l~IE INVENTION
The presen~ invention relates to a mAml~lly operabie tool fior ~L~ippi~ insulation from elPctrir~l wires. It all~ws the user to strip any size of elec~ical wire from AWG #8 to ~2,0()0 MCM.
It is common in all tools for ~Il,ppi~ in~ulation off ele~ es to cut ~e insulation across around the con~lc~t- r? and then pull offthe ~ut insulation. However, this procedu~e is inPffi~.ient for ~ pi~p insulation off electrical wires thicke~ than AWG ~.
o This is a consequence of the fact th~t such elc~ l conductors are alm~st always mAmlf:~hlred from stranded wire; the iniulAtin~ m~t~riAl melts among the str~ds of wire, it difficult to puli off the insuiation. I found that this disadvanta~e mA~ be o~ come by cutting ~e insulatiGn both ac~vAss and alon~ t~e l~th of tlhe wire, then pull offthe cut insulation. Although the lf~ngitufiinAl cut is emploYed in several stripping tools~
~e method in Yvhich the across and along cuts are colllb~e~ in the present invention is thought to be ~i~inAI
A search of the prior art has revealed a wealth of pate~ts relating to the art. Ihe following seven patents are deemed to be l~rt;sellLative of the present state of the art.
Therefore they shall be taken for c~A,mp:lri.~on to show the f1i~tin~tiQn be~ween them and my 20 new idea. All patents pl~sented below are registered with the US Patent Office.
Most wire ~ per~ operate by p~l~vrl,ling a transversal ~across) cut around the conductor? and pulling the insulation offthe wire by pulling on the confiuctor against the f f.lhle ~ gf.tl~ r~ e gvtr~.e tool~ do ll"e a lv~5itu~;~1 cl. t ~guch ~ f.~~lg uged .

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2 ~ 6 ~ ~ 9 7 t~ de-in~cll~te P~me~- ~r coaxial-~pe ca~le~ to ease t~e de~in~ul~ti~n process, v~xy few tools allow t~e user to perform ~e de-insulation process in one step. Of the strippers Ul the latter categors~, most are r~sftict~ to specific types of ca~les and ins~ ti~ ng ~urthermore, most of these strippers operate over a very limited range of wire diameters.
Finally, their design is overly cQmple~. H is desirable to have a t~l that perfolms both the across and along cuts in one continuous motion (i.e. without ha~/ing to remove the wire .firQm the tQQl, Qr Q~l~ing the toQl and moving ~e wLre inta a d,~ent channel), operates across a wide range of elecirical wire sizes, a wide ran~e Qf insulatin~ m~t~i.qT~, and is easy and safe to use.
It should also be noted tha~ some hand operated wire ~ilil)p~l~ operate by notchin~
the insulation ~t two or four locations, corresponding to the places where the ~V- or similarly shaped~ blades come into contact with the eie~r r~T wire. l~e insuiation is removed by pulli~ on the wire against the body of the stripper. ~ ile this method is effective for small diameter wires, it is inefficient fior lar~er ones, because most of the insulation rtalldins uncut and thus offers greater re~i~t~nce w~en pulled. It isadvantageous then, to have a tool which p~,ru~ s a cut across the electricai conductor.
Now con~ t r a~ electncAl cnml~1c10r nt~mlf:lrtllred fiom sttYInf?Pd ~rires (i.e. w~es twisted to~ether, as in a rope). Du~ing th~ insulation process7 insulating m~f~ l is for~d between t~le outer strand of u~re. Thus7 even when the insulation is cut around the c~n~ t~-r the l~n~Ainill~ amount of insulation causes the ~Lppi~g process to be inefficient Ihis may be overcome by cutting the insulation along the con~ tor, from the transversal cut to the free end of the ca~le.

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p~ 2 c~f ln 2 ~ 6 ~ ~ ~ 7 Cleally, a '.ool capable of pelf~ i~ such a cut would be preferable. ~ext we discuss the main dil~t;r~llces between the prior art an~ the invention presented herein.
U. S. Patent No. 5,131,2~9 to Krampe (correiponding to Eur~pean PuUished Application 417,22~) discloses a tool for ~LIipping e1~,tri~Al wires. ~he Krampe stripper 50 does not perfo~n a l~itll-1in:l1 cut. The tool might appear similar to the present invention because ofthe ap~nt ~imil~r~ties in collstruction (i.e., the bodies are simil~r3. However, the mobile blade carrier carries a blade perpendicular to tbe axis of the wire to be de-insulated. An across cut is made, the blades r~...~il,i~ in contact with the uire. The mobile blade carrier i~OE,~her with its arm are moved back with respeet to the otller arm, a motion which forceslpushes the cut in~ tinn off. As a consequence. the operation of the Krampe tool is wholly different fi~m that of the present iz~vention, as will be seen later.
I ~. S. Patent ~o. 5,00~,006 to Sawyer et al. discloses a tooi for de-insulating RQmex-type ca~les. The tool is prov~ded with lon~ in~1 rh~nnel~7 speeifically de~
to fit Romex-type cables; as such, this tool can not be used successfully to de-insulate ~o round electri~l cf~n~ ct.~rs of (relatively~ large ~i~m~t~r Althoug_ this stlipper does p~lr~ ~vt;l~al and lof~ihldin~l cuts, these cuts are p~lÇvlllled in a fashion largely t from th~t used by the present invention. The transversal cuts c~nsist of two n otches on directly opposites sides of the cable. The l~n~tuf lin~l cuts a~e perfo med by two blades fixed in the l~ngitl~lin~l ch~nnP1~ of the Y;ll;pp~l'S arms, by pulling the strippe~
down the length of the cable.
U. S. P~te~t No. 4,799,40~ to D~z-De-Gue~u ~iscloses a tool fo~ ~L;ppiL~
armored, waterproof, or coaxial cables. This tool also performs transve ~al afld ~ ~V~ a. llV~ L ~ ,a ~ v V~~ a ~v ~ -lL a~LL -~ ~.V~L-~-Vl. l~L~l p 0.. ~ ,,f 1"

t~e t~ar~sT~e~al cl..t is per.F~ d, ~e to~l must be opened, the wire positioned in a dilT~ t 70 groove, and the cut is fin~lly p~lrurllled. Note that as in the previous patent, the lon~ 1in:l1 cut is p~rOlll .ed ~y slidiD~ the tool the length of the wire.
U. S. Patent No. 4,768,404 to Bie~n~l~i refers to a piiers-like ~hippin~ tooi. The operation of this tool is sol~wl~t similar to that of the ~r~m~ tool. Initially, the tool pelr~ s a h~sv~l~al by means of blades mounted on mobile inner jaws. The blades then remain in contact with the conductor, while the inner jaws a~e pulled back relative to the outer jaws {and the entire tool), the outer jaws glippi~ the c~n~lllct-~r throu~hout the op~r~ti- n The m~en~l,l of the inner jaws forces the cut insulatio~ off, in a Ll~ler similar to that of the Krampe tool. Note that the transversal cut does not reach around the cl-n-luctt-t; thus, the tool would pe~form poorly on lar~er ~ mPt~r wires. Finally, the ~o sflipper is not pro-vided with any means for makin~ ion~itu-iin~l cuts.
U. S. Patent No. 4,577,405 to Butler refers to a blade which m~y be used ~
~llippel~ to pel~ullll transversal cuts. As such, it can not ~e s~o~ d to a stripper. H
should be n PntiQr~l that such blades may replace the V-shaped blades presently used in the invention to i~ lvve its p~
U. S. Patent No. 4,477,949 to Kane discloses a tool for sll;pp~ plastic sheath f~vm el~fric~l cables. This t~l is similslr in its operation to the Sawyer et. al stripp~
(in~ f~11y7 it is also int~1~1 for use on Romex-type cables). H also performs transversal a~d IQn~itoflin~l cuts. As the ~llipp~r~ are closed on the conductor, the transversal blades notch the insulation on opposite blades. The lc~n~itll-lin~l blades, fixed ~o to the a~ms of the stripper, also cut into the insulation. To complete the stripping ,~"~,f,j~t. th~ t,Wl i~ V~l~l th~ l~ ;ft~ f f~h,~ ~,Ot~ ,t,&l. T,h.i,, ~ t~1;v~ L~ v lfvr~ th~
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trsnsversal blades away from the cl-m11lr.tor, i.e., the transversal blades are pivotally mounted. It should be noted that this stnpper p~onns best for fiat cc-n-luctQri, since the afms of the stripper are ~vided with I~ts~ hAnnP~ ust as the Sswyer et. al tool~
this stripper is P~ec~e~l that this tool would perform po~rly on roulld conductors of relatively large ~ mPtPr U. S. Patent No. 4,366,730 to Casadio describes a ~L~ippi~g tool similar to the K~m~ and R~iPg~n~ I.ippe,~. The Casadio stripper operates in a fashion highly similAf to that ofthe T3i~n~ki tool. Two sets of jaws ~rasp the electrical cnn-hl~f~r, with the 100 imler jaws making the transversal cut. Next, the inner ja~,vs are pulled back relative to the outer jaws. which m~in1~in their grip on the cnn~ r.~f~r th~u~hout the operation. This motion forces the cut insulation off the conductor, cQr,.pl~ g the sLlppiug operation.
Note that this tool is not provided with any means for perfiofmin~ n~itu~lin~l cuts.
By an~lysis of all the presented patents, it fesults that they work on common small size of electrical wires up to AWG~ 10 size or maybe AWG#8 in the best ~itu~,ti~n ~UMMARY OF THE INVENT~O~
The object of the present invention is to solve s~me of the problems encounte~ed in the operation of the sl~ mentioned above, by providing a ~nd opera~le tool of simple ll0 construction. This tool is easily handled, performs well in tight places. and operates i~f~ctQri1y over a wide range of cQn~iuctnr sizes and insulatin~ m~f~ri~1i I~e tool in~h1des a body and a first arm hinged to~ofh~ at one end and outwardl~
biased by a sprin~. The opposite end of one of the hsntll~ is provided with a V-s_aped h~U~ h~ h ~ "~ u~ A tv ~ ~~l ;P~ ii~ A ~~ r-'~lh~

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blade is mounted in ~ont of the housing, opening in the same direction as the housin~
operation, when the h~n~ s are squeezed togethpr~ the cable is forced against the blade and the in~ tion is cut. Tuming the stnpper a 1/4 of a turn in the clock- and counter~
clockwise directions completes the transversal cut. After the transversal cut has been performed the handles are relaxed somewhat and a second arm ca~ g a lf~n~itu-lit-~l 120 blade is pulled into the cutting position. ll~e h~n~ s are once again pulled together, with the l~ngihl-1in~l blade effecting an along cut The strip~e~ may be turned slightly to either side to loosen the insulation. Finally~ the operation may ~e completed by pulling on the cut insulation with the stripper, or ~y removirlg the insulation by hal~d after the stripper is taken away.

BRIEF DESCRIPTION OF THE DRAWlNGS
In the drawings which illustrate em~lin~nt~ of the inveq~on, Figure l is a side view of the Zoom Stripper, and Figure 2 is a ~nt view of the Zoom Stripper.

DESCRIPTION OF THE PREFERRED EMBODIMENT
The ~oom Strip~ illll~tr~f~1 in the above mentionecl draw~n~s inc~ a pistol-shaped body 1 and a ~st ~obile arm 2 of simil~r size The body 1 and the mobile a~ 2 are joined to~ether by means of a holding pin 3 placed in the elbow of the body 1 Below the elbow to the end of the handle, the fi~st mobile arm 2 and the ~dy 1 ~e pa~allel an~
~ehave like a pliers h~ndle. A sprin~ 10 installed the ~odv 1 biases the body 1 and the ~at a~ 2 Q~LtL~d1ly ~T~u~ ~L~ dei t.~ . elb~, t~ s fil~t r~.~vbi'~ ~- 2 i~ ~ap1L~.t i.~ ~v~ ~idel"

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tumed toward the back ~û de~rees each side, en.~ciQg the stripper body l, at holding pin 3. A~er passing the elbow at the holding pin 3, both sides of ~le first mobile a~m 2 are 140 b~ou~ht tu~ether ~boYe the top of ~e ~dy l, ~nd m~ parallel to the f~ont end of it. The two sides of first mobile aml 2 are welded together at the fiont end? d~ in~ a thin space between them? up to the fiont end. I~e ~ont end of the first mobile arm 7 iS rounded open on the side facin~ the bo~r 1 about 3116 inches ~5 mm) to each side. This shape allows the head of the first mobile alm 2 to slide e~sily around the insulation of the Pl~f, ic~l wi~e while the L~v~r~al cut is p~. ~o...~ Thus, when viewed from above, the first mobile aIm 2 appears as a letter Y w~se hase is ~riented toward the front of stripper, and whose arms emhM~ the stripper ~r, then tum downward ~0 de~,rees? and finally join to~ether on the underside of the stripper bociy. In other words, the upper n~enlber of the frst mobile arm 2 is Y-shaped, with the base of the Y pointing forward and the arms f~~n~ling back 150 and down.
The front end of the body 1 contains a V-shaped housing 4. The allgle between the housing's walls is 60 degree~ ~i.e., thirl~r degrees to eithe~ side ~om a vertical c~nterline~, and its vertex is rounded so as to accommodate the ~xt~n:~l (liAm~t~ of the smallest insulated wire to be stripped, i.e., the ~Ai~m~ter of an insulated AWG ~8 elecfric~l wire.
The opel~ing of the housing 4 should be large enough to accommodate the lar~est insulated wire to be ~Lipped, i.e.; ~n insulated AWG #410 el~l. ;~Al wire. The length of the housing 4 shall be such that the housing can accommodate any length of conductor w~ich may ~e desired to be ~ilipped, or at least 1 inch (~2.~ cm).
An across cut blade ~ is placed at the front end of the housing 4 . The across cut 15u L,ll.~.e 5 ig V=g~L~ c~g ~e~l? r~Lii tg ve,.ex .~d~,d. T.~ ,et~, ~f tLIh1e ~J~V ~ e iC<
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r~ o~ 7 ~nf 1 n 2 0 ~ 7 sl,ch tLt ~e ~m ll~t s~e of uire to be str~ppe~, i.e., ~WG #~, is accommodated withQut touching the electrical conductor. At the e~lreqne points. the across cut blade ~ is wide enough to accommodate the large~t size of wire to be strippe~l7 i.e., AWG ~4/07 again without touching the elecfti~l conductor. Thus7 the angle between the edges of the across cut blade 5 is the same as the angle between the walls of the V-shaped housin~ 4. The across cut blade 5 is installed such that its cutting edge is raised from the walls of the housing 4, so that it may score the insulation of the el~l.;r~l cQn~ r.tf~r when the c~n~luctor is placed in the housing. The amount of offset between the edges of the a~ross cut blade ~ and the walls of the housing 4 is the same as the 11.icl~ s of the in~ ti~n of 70 the cQn-l~c1nr to be stripped. A blade m~mlf~ctured atld installed as specified above minimi7P~ the risk that the e~ 1 c~n-11lr~tr~ will be tlA..~ dur~ the de-insulation process. Finally, the across cut blade 5 is f~t~nP~ in position by tWQ screws 11.
ln anQther aspect of the inve~tiQIl, a h~ngifll~lin~l cut blade 6 is embedded itl th~
front end of the said first mobile a~m 2. More precisely~ it is housed in the space d~.limif~d by the two sides of the first mobile ann 2 above the body 1. The said longifllflin~l cut blade 6 is free to move in the axialll~n~itu~lin~1 di~ection and is held to its path bs~ two guiding pins 7, said pins being f~t~n~l to the blade's body. Each of the two guidin~ pins 7 has an adequate channel in the sides of the ~rst mobile arm, such that when the 1t3n~it11flin~1 cut blade 6 is activated, the bl~de 6 is guided forward and down, deep enough to penetrate l~n~itll-lin~lly any thil kn~ of insulation. In this position, foIward end of the 1c~ngitl1-1in~1 cut blade 6 is ali~ed with the said across-cut blade 5. This ensures that the k~n~ituAin~1 and transversal cuts meet, m3king the process of remo~in8 the cut insulation .,,~
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as easy as possible. Lastly, the le~th of the said l~t~itu~lin~l cut blade 6 shall be equal to the len~th of the housing 4.
T~ y~t ~th~ asp~t ~t~e ~v~ii~ seeof~d mobile ann B is us~ to activate the l~itu lin~l cut blade 6. The second mobile aIm ~ is embedded in an opening made on the l~ngit~l-lin~l central axis of the body 1, forward of the body's elbow. I~he second mobile aIm 8 is placed forward enough such as not to interfere with the first mobile arm 2.
however, the second mobile ann 8 should be placed such that it is within easy reach of the o index finger of the operator to allow for efficiPnt use of the tool. ~e second mobile arm ~
is joined to the body 1 by means of a holding pin ~ fastened in the said stripper ~dy 1, about which it is free to pivot. A SpIi~ 12 pulls the longitll~in~l cut blade 6 in its rest position while the blade is not engaged.
We nQw illustrate the operation of the Zoom Striy pe~. The user may hold the tool in one hand in the open position (at rest~. With the other hand7 the user may hold the electrical wire to be ~llipped.
Insert the electrical wire tu be ~l,;pped into the housi11g 4 to the desired length.
Close the stripper by pullin~ on the first mobile aIm 2 so that the wire is forced against the across cut blade 5 thus cuttin~ the insulation. Note that pUIlitlg too ha~d on the 200 first mobile arm ~ ~uses the fiont end of the ~n to pe~ e into the iIlsulation, thus intPrfe~ing with the ~ ti-~n of the Zoom Stripper. Howeve~, not pull~g ~rd enough results in the across cut blade 5 not cutting the insuiation.
T~n the ~tripper clock- and counter-clockwise twice in e~ch direction7 ~t least ~0 degrees (1i4 of a tum). I~is operation cuts the insulation transversally.

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2 0 ~ ~ 4 9 7 ~ h ~$ 7 Rel~x the first mokile a~n ~, and using ~e index finger pull the second _obile arm 8 until the l~ngitu-lin.ql cut blade 6 is in the front, advanced positio~
Pull once again on first mohile ~m 2 with enough force that the k~ngit~ it ~l cut blade 6 cuts the insulation along the electrical conductor. Once the insulation is cut, stop pulling on first mo~ile arm 2, without letting it oper~ tum the stripper 20-30 degrees ~l/12 210 of a tum~, clock- and counter-clockwise. By turning the stripper, the cut insulation will rotate with it, free from the eleclllcal conductor. Pull out the cut insulation. The process of stripping the insulation offthe electrical cl~nflllc~.t~ is c- mplete ~-G

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Claims (6)

1. A hand tool for stripping insulation from electrical wires, comprising a stripper body shaped as a pistol whose upper member contains a V-shaped housing for the purpose of adapting the electrical wire to be stripped;
a first mobile arm hinged to the stripper body at its elbow, said mobile arm being free to pivot about the hinge point, for the purpose of aiding in gripping the electrical wire;
a longitudinal cut blade housed in the first mobile arm, above the V-shaped housing in the stripper body, said blade allowing the user to perform a longitudinal cut in the insulation of the electrical wire to be stripped;
a V-shaped blade mounted to the forward extremity of the upper member of the stripper body for the purpose of effecting an across cut in the insulation of the electrical wire to be stripped;
a secondary mobile arm also hinged to the stripper body, said arm being used to move the longitudinal cut blade into a forward position;
a spring for moving said longitudinal cut blade into a backward position; and another spring for biasing the first mobile blade outwardly from the stripper body.

2. A wire stripper as claimed in claim 1, wherein the upper member of the stripper body contains a V-shaped groove extending from its tip to a third of the length of the member.

3. A wire stripper as claimed in claim 1, wherein the arm embracing the stripper body has a Y-shaped upper member, the base of the Y forming a slot extending above and along the V-shaped groove of the body, the arm being free to pivot about a holding pin mounted on the elbow of the body, the arms of the Y joining together on the underside of the stripper body.

4. A wire stripper as claimed in claim 1, wherein a V-shaped blade is mounted to the front of the stripper, the angle between the edges of the blade being the same as the angle of the walls of the groove, the edges of the blade being raised with respect to the walls of the groove.

5. A wire stripper as claimed in claims 1, 2 or 3, wherein the slot of the mobile arm embracing the stripper body houses a mobile blade, the mobile blade being equal in length to the V-shaped groove in the stripper's upper member, the mobile blade being free to slide back and forth, being guided by guiding pins mounted on the blade, said guiding pins being free to slide in channels in the mobile arm.

6. A wire stripper as claimed in claim 1, wherein a second arm is installed through a central slot in the upper member of the stripper body, the second arm being free to pivot about its holding pin, the arm being able to push forward the mobile blade housed by the first arm.