CA1066690A - Tool for moving a long flexible leading wire through hollow passages - Google Patents

Abstract

A B S T R A C T O F T H E D I S C L O S U R E

This invention relates to a tool for moving a long flexible wire through hollow passages of different kinds. Such tools may be used in connection with the drawing of electric cables in conduits, but also in connection with cleaning or other treatment of conduits having so small dimensions that they are not accessible in another way than by such a wire. The tool comprises two tubes being telescopically movable in relation to each other in order to feed the leading wire. The improvement according to the invention consists in a retaining mechanism designed in such a manner that the tool is capable of feeding the leading wire into as well as out of conduits or the like.

Description

Thls lnvention relate~ to a tool ~or moving 8 long flexible wire through hollow pasRages of dif~erent kinds. Such tools ma~ be used in connection with the drawing Or electric cables in hidden conduits, but also in connection ~ith cleaning or other treatment of conduits ha~ing 80 small dimensions that they are not accessible ln another way than by such a wire.
~ 0018 for the above purpose are previously kno~n. For instan-ce, the S~edish patent specification 140 707 dlscloses a tool comp-rising two tube~ being telescopically movable in relation to each other and denominated feed tube and guide tube respectlvely, the reea tube being associated with a retaininB mechanism ~hlch, on one hand, is arranged to seize the wlre and firmly connect the ~ame to the ~eed tube during the displacement thereo~ in a rirst direc-tion in relation to the guide tube, but on the other hand, on dis-placement Or the feed tube in an opposite second dlrection, leavethe hold o~ the wlre 80 as to allow the last-mentloned aisplacement ~lthout conveylng the wire. ~hough this tool permlts a more e~lci-ent method of working than a slmple manual lnsertion Or the ~ire into the condult, the same i8, however, concomltant wlth a plu-rallty Or disadvantages. I.a. the retaining mechanism thereoi~ merelypermlts ~eealng o~ the ~lre in one direction through the tool, i.e. 1.
lnto the ¢onduit or passage, the extraction o~ the ~lre ~rom the passage ¢ompulsorily having to be done by hand without tbe assls-tan¢e Or the tool. This is often laborlous to perrorm because tho ~lre is usually dlf~icult to seize by the hand. Thus, the ~ire 18 comparatively thln and ~uitably it has a slippery sur~a¢e in order to facllltate as far as possible the conveylng of the wire ln the passa~e. Purther, the tool relies upon the operator holdlng the ~lre ~ith one Or his rlngers during the return oi the wire between t~o roeding movements. ~his manual holding Or the wlre may on one hand - : . ~ . . . . . . . . . - . j : :- , ~
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~.06669o be troublesome to perform appropriately at all timesand on the other hand cause physiological disabilities to the opera-tor.
The present invention aims at eliminati~g the above S disadvantages and to this end it relates to a tool being cha-racterized by the fact that the retaining means comprises at least one locking body in said feed tube and having two spa-ced apart wire locking areas and being adjustable into two different working positions or ranges, said locking body, on one hand, in a first working position, being in a position for the conveyance of the wire on displacement of the feed tube in the first direction in relation to the guide tube and the release of the wire from the engagement with the feed tube on the displacement thereof in the opposite direction in re-lation to the guide tube, and on the other hand, in a second working position, being in a position for the conveyance of the wire on displacement of the feed tube in said second di-rection in relation to the guide tube and release of the wire from the engagement with the feed tube on displacement there-of in said first direction in relation to the guide tube.
Thereby the tool can feed the wire into as well as out of the passage in question.
When a wire has been mentioned here, this concep-tion is used in the form that has gained a standing in the practical field of the art. In order to attain a more logi-cal lucidity, the object in question will hereinafter be de-nominated leading wire due to the leading or guiding nature C

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-~06669o thereof. The leading wire may in its practical realiza-tion consist of any arbitrary - 3A - ~
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~OG6690 element being long and flexible, though it has to have suffi-cient stiffness for being capable of being pushed through pas-sages of different kinds. Thus, the conception leading wire should be taken in its broadest sense.
With reference to the attached drawings, a closer description of two embodiments of the invention will follow below.
IN THE ~RAWINGS: -Figure 1 is a side elevation mainly sectioned and partially cut illustrating a first embodiment of the tool ac-cording to the invention during a first working phase;
Figure 2 is a similar elevation during a second work-ing phase;
Figure 3 is a side elevation of the same tool during a third working phase and Figure 4 is a similar elevation of the tool during a fourth working phase;
Figure 5 is an enlarged sectioned side elevation ~howing the retaining mechanism according to the invention;
Figure 6 is a side elevation of the rear part of the tool illustrating how the retaining mechanism has been adjust-ed into a second working range or position diverging from the position shown in Figures 1 - 5;
Figure 7 is a partially sectioned elevation from .
above showing the front part of the tool;
Figure 8 is a cross section in Figure 7;

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~066690 Figure 9 is a section through a passage illustrating how the tool is used for drawing cables;
Figure 10 is a partially sectioned side elevation illustrating an alternative embodiment of the tool having two locking bodies;
Figure 11 is an enlarged side elevation of the rear part of the tool according to Figure 10 with the locking bodies in a first working position; and Figure 12 is a section through the retaining mechan-ism with the locking bodies in a second working position.
The tool according to the invention (see Figures 1 to 5) comprises two tubes 1, 2 being telescopically movable rela-tive to each other and denominated feed tube and guide tube re-spectively. The feed tube 1 is arranged exteriorly of the guide tube 2 and presents at the rear end thereof a flattened portion 1'. A leading wire 3 runs through the two tubes, the frontal extremity of said wire in this case presenting a claw 4, to which the frontal extremity of a cable to be drawn can be hooked or attached. Advantageously, the leading wire 3 may consist of a plastic element having a circular cross section and a cross sectional diameter of 1 to 5 mm and a length adapt-ed for the purpose. In practice, the length of the plastic element 3 may amount to 5 to 25 m.
Instead of a leading wire having a circular cross section, it is however also possible to use a wire having a different cross section shape, for instance a flattened, oval B

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or rectangular shape.
A retaining mechanism generally designated S (see Figure 51 is associated with the feed tube 1, the main part of said mechanism consisting of a locking body 6 provided with two spaced apart seizing or wire locking areas 7 and 8. The locking body 6 is pivotally mounted on a shaft or pivot pin 9 supported by the two opposite walls of the flattened end por-tion 1' of the feed tube. The two seizing areas 7, 8 can co-operate with an abutment 10 which in this case consists of the inner wall of the feed tube. Between the two seizing areas 7, 8 there is a linear portion 11 of the very locking body 6, said portion allowing the leading wire 3 to pass freely between the locking body and the abutment when the locking body is in a position perpendicularly to the abutment. The two seizing areas 7, 8 advantageously consisting of toothings or knurlings have a curved profile shape.

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:- . - , . . . : :- -- -, In the ~icinity o~ its lower extremity, the locking body 6 i8, by a guide pin 12, hingedly connected to an arm 13 pro~ecting obliquely rearwardly and downwardly from a sleeve 14 (see ~igq. 1 and 2), which i8 displaceable a defined di~tance to and fro along the feed tube 1. On the sleeve 14 there i8 fixed a handle 15 prere-rably made Or rubber. The movement o~ the sleeve and the handle in the direction iorwardly along the feed tube 1 iq limited by the lea-dlng ~ire 3 belng clamped by the locking body 6. Thus, when the handle 15 i8 mo~ed for~ardly the seizing area 7 of the locking body 18 pivoted against the leading wire while contlnuously increaslng the clamping thereof until it finally no longer will be possible to i'urther mo~e the handle forwardly. A holder or ring 16 made oi' plastlc or hard rubber is fixed on the feed tube 1. This ring 16 has the purpose o~ ~acilitating, when required, a holding Or the locklng body ln the position in whi¢h the leading ~lre 18 locked by co-ope-ration with a slmllar ring portion on the handle. In practice, this is performed by the operator pressing with his finger3 the rlng portlon oi' the handle towards the ring 16. It 18 obvlous that the locklng body 6 as lllustrated ln Fig. 5 ls ln a flrst selzlng posl-tlon when the handle 15 is in the operatlng position show~ ln ~ig.
1, namely moved towards the ring 16, and that the same locking body a~ ~hown ln Flg. 2 is in a neutral posltion when the handle t5 is in the operatlng posltion illustrated in Fig. 2, namely displacea a dlstan¢e i~rom the rlng 16.
For read~ustlng the lo¢klng body 6 i'rom one worklng posltlon to another, a reverslng means 17 18 provided conslstlng oi' a plate having a holdlng i'lange 18, said plate belng pi~oted on a shaft 19 at the end portion 1' o~ the feed tube. A slot generally designated 20 18 recessed ln the plate 17, a pro~e¢tion associated wlth the locklng body 6 engaging said slot. This pro~ection sultably consists o~ the guide pin 12 previously mentioned.

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1C~66~9 The slot 20 ha9 three branche~ or portlons 21, 22 and 23, the two first mentioned of which extend in certain sngle~ out ~rom the intermediate branch 2~ interconnecting the t~o branches 21 and 22. ~he exten~ion of the intermediate ~lot branch 23 substantially ooincides with an arc llne having a radius equal to the distance between the guide pin 12 and the pivot axis t9 of the revorsing plate when the guide pin i8 in the neutral position o~ the locklng ; body, ~hen the guide pin engages the slot branch 21 the reverslng plate 17 and accordingly also the locking body are read~usted for tO feeding the wire 3 rorwardly as indicated by the arro~ 24, Inver-sely, the re~ersing plate 17 (and of course the locking body 6) is read~usted for feedlng the w~re 3 rearwardly as indicated by the arrow 25 when the guide pin 12 engages the slot branch 22, On the ~eed tube 1 a pressure sprlng 26 i9 provided in the form o~ a plate spring engaging transverse recesses or indents 27 in the envelope sur~ace of the guide tube 2 with an easy contact pressure, The aim o~ thls spring engagement between the reed tube and the guide tube is to make the resistance to dlsplacement of the feed tube in relation to th~ guide tube greater than the resistance to displacement o~ the sleeve 14 in relation to the reed tube, thereby en9ur$ng that the handle 15 and the sleeve 14 are brought to a oorrect operating posltlon before the displacement of the feed tubs in relation to the gulde tube is initiated. ~hough a spring and ¢o-operating indents have been provided in the embodiment shown, other means are also conceivable ln order to per~orm the same ~unc-tlon; ror in~tance a frictlonal engaBement between the feed tube and the guide tube.

,,, . ` ~ ~-~' ~066690 In the vicinity of it~ frontal extremity, the guide tube 2 has a collar 28 serving in practice as a front stop for the feed tube 1 as ~ell as a grip portion for one of the operator's hands (for right-handed perRons the leit hand grips the collar 28 while the rlght hand grips the handle 15). The collar 28 ad~antageously conYlsts Or an annular body.
The guide tube 2 has a curved or bent frontal extremity 29 in order to provide at least a slight friction between the guide ; tube and the leading wire passine therethrough. Thereby lt is en-sured that the leading wlre 18 not unlntentionally moved on the return movement Or the feed tube after a feeding movement. Thls rrlctlon-increasing effect ma~ be further enhanced by providing at least the frontal extremlty of the guide tube with a ~riction-in-creasing llnlng 30 on the inner side of the tube. ~he lining 30 may ror example consist of glass fibre, te~tile or the like.
In order to facllitate the insertion of the leadlng wlre 3 lnto and through the gulde tube 2, the rearward mouth Or the gulde tube may be ~a~hioned ~ith a conical entranoe surrace 31.
In Flgs. 7 and 8, a preferred embodlment ior drawlng a oablo deslgnated 32 18 lllustrated. In this embodiment, a plpe 34 le oonneoted to a slde aperture 33 ln the frontal extremlt~ Or the gulde tube, sald plpe extendln~ from the aperture to the oollar 28 Or the gulde tube, said oollar being cut through by the plpe ao that it will open on the back Or the collar. On the back oi' the collar a outting means 35 for cuttlng Orr the oable 32 ia arran-ged, sald means belng created in a suitable manner. Ad~antageously, the oable 32 may be wound onto a storage bobln (not shown) dlsposed ror instance underneath the guide tube. In a simllar manner lt 18 also posslble to arrange the leeding wlre 3 on a storage bobln con-~0 ne¢ted to the feed tube.
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. - , ., -~. 1066690 ~ hough lt is preferred to carry the cable 32 through a pipe 34 in the manner described, it is per æe conce$vable to pass in the cable directly through the aperture 33 or to connect the cable di-rectly to the claw 4 o~ the leading wire without passing the cable through the orifice Or the guide tube.
The tool described operates in the following manner.
; It i~ assumed that the leading wire 3 is to be fed in a flrst direction from behlnd snd forwardly through the tool, i.e.
into the passa~e or condult in which a cable shall be dra~n. In 10 Flg. 1 the tool is shown ln a phase when the reed tube 1 1B pushed forwardly as ~ar as pos~ible towards the collar 28 and the handle 15 as well as the sleeve 14 thereof are pushed rorwardly towards the rlng 16. In this position, the looking body 6 is in a seizing position pro~iding an engagement between the leading wire 3 and the ~eed tube 1 (cf. Fig. 5). In order to attend to the feeding Or the leading wire 3 one step forward the feed tube 1 now has to be re-turned to a position drawn away ~rom the collar 28. As shown ln Fig. 2, this is performed by moving the handle 15 rearwardly rrom the rlng 16, whereby the handle via the sleeve 14, the arm 13 and the gulde pln 12 causes the locking body 6 to pi~ot to the neutral positlon shown ln Flg, 2 ln whlch the engagement between the loc~ing body and the leading wire ¢eases. On continued drawing Or the handle 15 rearwardly away from the collar 28, the feed tube 1 ~ollows to the posltion shown in Fig. 3. This conveyanoe Or the ~oed tube is attended to by the sleeve 14 being ~topped in its mo~ement ln rela-tion to the feed tube by means of the pin 12, which has been mo~ed to the end Or the fir~t slot branch 21, the reversing plate 17 then servlng as a stop for the movement of the sleeve 14 ln relation to the ~eed tube. It is apparent that the return of the ~eed tube 1 from the collar 28 is done wlthout conveying the leadlng wire.

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When the feed tube ha~ reached lts end poaition (which 1a decided by the operator) the handle 15 i~ displaced in the opposite direc-tion. ~ereupon the locking body 6 i~, a~ illu~trated in Fig. 4, brought to its seizing position in which the leading wlre 3 i8 held in relation to the feed tube. On continued displacement o~ the handle towards the collar 28, the feed tube 1 ~ollows and a leaaing wlre part corresponding to the tra~el performed 18 fed out of the orifice o~ the guide tube 2 as shown in Fig. 4.
It should be noted that the 3pring 26 always ensures that the handle 15 assumes the correct operatlng position be~ore the relative ~ -movement between the feed tube and the gulde tube is initiated.
In Fig. 6 it is shown how the reversing plate 17 has been readJusted in order to get the locking boay 6 to work in the se-cond working range thereof. In this case the revereing plate ha~
been pi~oted upwardly about the shaft 19 thereor 80 as to locate the guide pin 12 to the second slot branch 22. In this positlon, a withdrawal o~ the handle 15 ~rom the collar 28 means that the locking body will engage the leading wire 3 80 that this can ~ollo~
the i~eed tube in the mo~ement thereo~ rearwardly from the collar 28.
Inversely, the locking body 6 will return to the neutral posltlon as ~oon as the handle i8 moved forwardly in relatlon to the reed tube 80 that the leading wlre 3 run~ ~ree of the locking body on mo~ement o~ the ieed tube towards the collar 28. Hence tho leading wlre 3 can posltively be fed back through the tool.
Flg. 9 illustrates the use of the tool accordlng to the ln-vention ln conneotlon with drawing a cable 32 through a conduit 36 irom a box 37 tdlsposed ~or inYtance ln a wall o~ a room ln a bull-ding) to an oriflce 38 (in another room of the building). ~he con-duit 36 can run ln many curve~. ~he cable 32 i9 pro~ided wlth a _ 10 --.

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loop 39 which i9 hooked onto the ~ront claw 4 of the leadlng wlre 3. The leading wire ~8 fed in a manner previously descrlbed from the box 37 to the orifice 38, where the cable automatlcally leaves its engagement with the leading wire since the leading ~irb is bent back as illustrated in the dra~ing so that the cla~ is turned back-~ards and the loop 18 released. This means that the cable is passed through the conduit at the same time as the leading ~ire and that the leading wire can be returned tc thc box 37 without making lt necessary for the operator to move between the dlrferent rooms in order to tamper with the cable. Thu~, ~rom one single place, the operator can attend to the passing of the cable through the condult to the place intended.
In practlce the leading wire can be fed and returned rospec-tl~ely with a speed amounting to several meters per minute.
Reference is now made to Figs. 10 to 12 illustrating an al-ternati~e embodlment Or the in~ention. In this case, the re~ersing means consists Or a slee~e 17' whlch is rotatable to and rro rela-tl~e to the reed tube ln, Two opposite locking bodles 6' are asso-olatea with thls re~erslng means, said locking body belng arranged to selze and hold the leadlng wire 3' between each other. Similar-ly to the looklng body 6 previously described, each Or these lock-lng bodies has a linear portlon 11' and two seizlng areas 7', 8' on each slde Or this portion. ~lkew$se, the locking boales are pl~o-tlng on sharts 9' and by plns 12' they are pl~otably connected to arms 13' pro~ectlng rearwardl~ rrom tha handle 15'.
As best shown in Fig, 12, the sleeve 17' is rotatablg arranged esterlorl~ Or a core-llke part 40 rigidly attached to the e~tre~lty o~ the reed tube ln, ~or instance b~ a screw connectlon. In the core part 40, there 18 a central slit 41 housing the locking bodies .. . ............................. .

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6', the shaft 9' extending between the two opposite walls of the core part defining the slit 41. ~he core part has a threaded exten-sion 42 on which a locking nut 43 i9 secured. Between the locking nut and the very core part 40, a flange 44 extending across the length of the ~leeve 17' is held. Hence also the sleeve itself i8 held on the core part. On the ~lee~e, there is a knurled surface 45 lntended to facilltate the holding of the sleeve on rotating the same.
In the slee~e 17',two slots 20' analogous to the slot 20 pre~iously described are recessed, each Or said slots having three branches, namely a first branch 21' (see Pig. 11) extending parallel to the longtudinal direction of the leadlng wlre and intended for reeding the leadlng wire forwardly, a second branch 22' (see Flg.
10) likewise extending parallel to the leading wire and intended for feeding the leading wire rearwardly and a third transverse branch (Fig. 11) interconnectlng the two branches 21' and 22'. ~hen the sleeve 17' i8 ad~usted ln the position sho~n in Figs. 10 and 12 with the locking bodies 6' engaglng the first branches 21' of the slots 20', lt is e~ident that the leading wire 3' can be fed forward-ly as lndl¢ated by the arrow 24' ln Fig. 10. A read~ustment o~ thefeed directlon lB slmply performed by rotating the slee~e 80 that the locking bodies wlll engage the second branches 22' o~ the slot~
20' as indicatea by the arrow 25' in Fig. 11.
It 6hould be observed that the pro~ectlon in the ~orm o~ the guide pin 12 engaging the slot 20 in the embodlment shown ln Plgs.
t to 5 corresponds to the elongated portion 6" Or the ~ery locking body 6' pro~ectlng away from the areas 7', 8' and 11' in the embodi-ment shown in Flgs. 10 to 12.

, ~ . . . -- - . - ~ . . . ~ , - - , 1(~66690 In order to make certain that the sleeve 17' i8 held in the posltion intended, a spring-loaded ball 46 may ad~antageously be provided as indicated by the dotted lines in Fig. 12, said ball engaging either Or two qeat~ 47 receq~ed in the nange 44, said seats derining the ad~ustment positions.
The embodiment shown in Figs. 10 to 12 is additionally modi-fled in co~parison with the embodiment shown in Flgs. 1 to 5 inas-much as the means for making the resistance to aisplacement Or the feed tube in relation to the guide tube greater than the re3istance to displacement Or the handle 15 in relation to the ~eed tube has been given a different desig~. Thus, in th~s ca3e the guide tube 2' has a completely smooth envelope surface, while the reed tube 1 n at the rront is provlded with a bushing 48 having an internal annu-lar groove 49. An endless elastlc ring 50, preierably made Or rub-ber, is inserted into the groo~e 49, said ring having a smallarwidth than the groove 49. As long as this ring is anywhere between the t~o ends of the groove it wlll, by pressing between the outer surface Or the guide tube and the inner surface Or the groove, pro-vide a slight locking of the feed tube in relation to the guide tube, but as soon as the ring i8 bxought to one or the other Or the two ends o~ the groove, the locking efrect will oea~e and the feod tube can be moved ln relation to the guide tube wlth a rather slight errort.
The ad~antages Or the inrention are e~ident lnas~uch as tho leaalng wlre can be qui¢kly and efficiently movea iorwardly as well as rearwardly.
Of oourse the invention i8 not limited merely to the embodi-ments described above and ~ho~n in the drawings. ~hus, lt i8 con-ceivable to use the tool for other purposes than Just leading lOG669V
cables. The tool may for ln~tance be u~ed for cleanlng condults of d$fferent klnds, a suitable oleaning member, e,g, a brush or the llke, being used lnstead of an attachment claw. A180 other modifioations of the invention are concei~able within the soope ~.
of the follo~ing clalms.

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Claims

WHAT I CLAIM AS MY INVENTION IS:
(1) A tool for moving a long flexible leading wire through hollow passages, for example in order to draw electric cables through inaccessible conduits or the like, comprising two tubes being telescopically movable in rela-tion to each other for displacement one relative to the other in a first direction and a second direction and de-nominated a feed tube and a guide tube respectively, the feed tube being operatively connected to retaining means which, on one hand, detachably secures the leading wire to the feed tube during the displacement thereof in a first direction in relation to the guide tube, but on the other hand, on displacement of the feed tube in an opposite se-cond direction, releases the leading wire therefrom so as to allow the last mentioned displacement without conveying the leading wire, characterized in that the retaining means comprises at least one locking body in said feed tube and having two spaced apart wire locking areas and being ad-justable into either one of two different working positions, said locking body, on one hand, in a first working position being in a position for the conveyance of the leading wire on displacement of the feed tube in the first direction in relation to the guide tube and the release of the leading wire from the engagement with the feed tube on the displace-ment thereof in the opposite second direction in relation to the guide tube, and on the other hand, in a second work-ing position being in a position for the conveyance of the leading wire on displacement of the feed tube in said second direction in relation to the guide tube and re-lease of the leading wire from the engagement with the feed tube on displacement thereof in said first direction in relation to the guide tube, whereby the tool can feed the leading wire into as well as out of said passage.
(2) The tool according to Claim 1, wherein said lock-ing body is pivotally mounted in said feed tube about an axis extending transversely of the feed direction of the leading wire, an abutment in said feed tube, said locking body co-opera-ting with said abutment in order to, on one hand, allow free relative movement of the leading wire between the locking body and the abutment when the locking body assumes a neutral posi-tion of pivoting, in which the two wire locking areas of the body are located at approximately equal distances from the abutment, and on the other hand to clamp the leading wire be-tween the abutment and either of the wire locking areas of said body by the locking body being pivoted about its axis from said neutral position to a wire locking position.
(3) The tool according to Claim 2, wherein the abut-ment consists of the inside wall of the feed tube.
(4) The tool according to Claim 2, wherein the lock-ing body is pivotal between the neutral position and either of said wire locking positions by means of a suitable sleeve-shap-ed handle which is movable on the feed tube between two spaced apart positions of operation and hingedly connected to the lock-ing body by a guide pin located at a distance from the pivot axis of the body.

(5) The tool according to Claim 1, wherein the feed tube is arranged exteriorly of the guide tube.
(6) The tool according to Claim 2, wherein a rever-sing means is mounted on the feed tube for adjusting the lock-ing body from one working position to another, said reversing means being movable in relation to the feed tube and having a slot formed therein, said slot having three portions, said slot including a central portion and an end portion extending from each end of said central portion, the axis of said end por-tions being at an angle to the axis of said central portion, projection means extending from said locking body and engaging said slot, said locking body being adjusted in a frist working position when said projection means is in one of said end por-tions of said slot, in a second working position when the pro-jection means is in the other end portion of said slot and in its neutral position when said projection means is in the cen-tral portion of said slot.
(7) The tool according to Claim 6, which includes a handle, a guide pin between said handle and said locking body, wherein said reversing means consists of a plate being pivot-able about a shaft in relation to the feed tube and said pro-jection means comprises a portion of said guide pin, one of said end slot portions substantially coinciding with an arc line having a radius equal to the distance between the pivot axis of the reversing plate and guide pin when the latter is in the neutral position of the locking body.

(8) The tool according to Claim 6, wherein the reversing means consists of a sleeve being movable to and fro relative to the feed tube, the slot being recessed in said sleeve, and that the projection of the locking body engaging the slot consists of an extension of the locking body.
(9) The tool according to Claim 8, which inclu-des a pair of opposite locking bodies, said bodies coopera-ting in order to detachably secure the leading wire.
(10) The tool according to Claim 9, wherein the sleeve is rotatably arranged exteriorly of a core-like part attached to an extremity of the feed tube and presenting a central slit in which the locking bodies are housed, the end portions of said slot extending substantially parallel to the longitudinal direction of the feed tube and the central portion of said slot extending across the longitudinal di-rection of the end portion of said slots.
(11) The tool according to Claim 10, which inclu-des a flange on said sleeve extending transversely of the longitudinal axis of said sleeve, said flange being situated between the said core-like part, and a locking nut applied to a threaded extension of said core-like part.
(12) The tool according to Claim 4, which inclu-des a holder on said feed tube operatively connected to said handle, when said handle is moved towards said holder in or-der to hold the locking body in a position in which the leading wire is locked.

(13) The tool according to Claim 4, which includes resistance to displacement of the feed tube in relation to said guide tube, and resistance to displacement of said handle relative to said feed tube, and means for making the resis-tance to displacement of the feed tube in relation to the guide tube, greater than the resistance to displacement of the handle relative to the feed tube, thereby ensuring that the handle and accordingly also the locking body, assume the correct operat-ing position before the displacement of the feed tube relative to the guide tube is initiated.
(14) The tool according to Claim 13, wherein said means comprises at least one spring attached to the feed tube and engaging transverse recesses in the envelope surface of the guide tube with relatively low contact pressure.
(15) The tool according to Claim 13, wherein said means comprises an endless elastic ring disposed in an annular notch in the inside of the feed tube, said notch having a greater width than the elastic ring.
(16) The tool according to Claim 1, which includes a curved extremity formed on the front end of said guide tube to provide at least a slight friction between the guide tube and the leading wire passing therethrough, thereby ensuring that the leading wire is not unintentionally moved on the re-turn movement of the feed tube after a feeding movement.
(17) The tool according to Claim 16, wherein at least the curved frontal extremity of the guide tube is provid-ed with a friction increasing lining on the inner side thereof.
(18) The tool according to Claim 1 which inclu-des a curved frontal extremity on said guide tube, and a collar adjacent said curved frontal extremity serving as a front stop for the feed tube and suitable also as a grip portion for one of the operator's hands.
(19) The tool according to Claim 1, wherein the guide tube has a collar, an output orifice and an aperture in the tube wall for the insertion of at least one cable into the guide tube for simultaneous feeding of the lead-ing wire and the cable out of the output orifice of the guide tube.
(20) The tool according to Claim 19, wherein a pipe is connected to the aperture, said pipe extending from said aperture to the collar of the guide tube.
(21) The tool according to Claim 20, which inclu-des cutting means operatively connected with the collar for cutting off the cable inserted in the guide tube.
(22) The tool according to Claim 1, which inclu-des a curved extremity on said leading wire and a claw on said curved extremity for receiving a loop of the front part of the cable to be drawn.