CA2005108C - Very high speed flying shears - Google Patents

Abstract

Very high speed flying shears (10) which is suitable to shear rolled stock (18) travelling even at more than 100 metres per second and comprises two knives (14) with blades (17) able to contrarotate in relation to each other at a preset speed at least in the transient period of shearing and is equipped with a guide (11) able to move sideways (19-119) at a pre-set speed (V) and to position itself in a defined position in relation to the circumferential position of the blades (17), an inner dividing wall (27) being located downstream of the knives (14) in a conveyor channel (13), in which shears (10) during the transient period of shearing:
- the speeds (VR) of lateral movement of the guide (11) and of rotation of the knives (14) are correlated, and - the lateral position of the guide (11) and the circumferential position of the blades (17) of the knives (14) are strictly interdependent.

Description

'' i~005~08 1 ~VERY HIGH SPEED FLYING SHEARS"

2 **********

3 This invention concerns a very high .speed flying shears, 4 that is to say, a shear.s able to .shear to .size in a required .sequence the rolled stock travelling even at 100-120 metres 6 per .second.
7 Hi6h and very high speed flying xhear.s normally comprixf 8 contrarotating blades of a .start-.stop type or of a continuous-9 ly rotating type.
The invcntion can be applied to flying shearx having Il continuou.sly rotating blade.s or blade.s of a .start-.stop typc.
12 Thc description hereinafter will deal only with the ca.se of 13 a flyi.ng shearfi having contiriuou.sly rotating blades, but tnc 14 invcnt;ion cover.s a].s'o the case of flying shcar.s having b1ad of a xtart-stop type.
16 ~lany tria1x havc bcen conduct~d rcgarding flying xh(drx ancl 17 many pat~nts hcl-e becn fi1ed which tend to cnab1e rol1c~d xtoc~
18 to be xh~arcd when trav~11ing at high sp(ccl.~.
19 Thc prc.s~nt applicant too has designed, te.sted and cmbodied bcforc now devices whicn can pcrform shcaring at a high xpecd.
21 It hax already becn xhown that, if .shcaring ix to be 22 carried out at a high xpeed, an exact coordination bctwecn the 23 lateral position of thc rollcd stock and thc circumferential 24 position of the blade.s ix needed.
FR 666.433 di.scloscs a flying shearx linked i.n a coordi-I nated manner to a rolling ax.sembly which .shear.s the rolled 2 stock to size with bladex operated through a connecting rod.
3 To perform the shearing in thi~s patent, the r~lled .stock is 4 diverted momentarily along a loop. Even if the control and actuation .sy.~tem is updated, owing to the formation of this 6 loop thi.s invention can only proces.s rolled stock travelling 7 at up to medium speed.s. In fact, the lateral separation of 8 the two portions thus sheared becomes inaccurate as soon as 9 the spced of lengthwise feed of the rolled stock is increased.
DE 804.056 and GB 2,075,899 disclose the shearing of thc 11 head and tail of the rolled stock by a flying shears 12 cooperating with mechanical rotary means which traver.se the 13 rol1ed .stock laterally as it pas.sefi. The.se embodiment.s are 14 unacceptable for rolled xtock being fed at high and very high xpecdx and a1xo, more gcneral1y, in the case of any rol1ed 16 product having programmed .surface deformations such as round 17 bar.s for building work, for instance.
18 Moreover, the latera~ fieparation of the two portionx thux 19 sheared ix not clean and the propofied sy.stem does not permit the~ir accurate differentiation at high .shearing .speedx.
21 FR 1.578.587 di.~clo.se.s an updating of FR 666.433 with thc 22 provixion of xhearing of the head and tail. Thix ix obt.ained 23 with a mcchanical dixplac(ment of the inlet and outlet 24 cnanne1x. Thix embodimcnt involvex uxeful sugge.stic)n.~ but cannot b- emp1Oycd at high and very high spe{d~ xinc( 2~ coordination of the dixp1accmcntx and thc control of thc endx 27 of the xheared portions are xhown as being a .simplc mcchanical 28 link bctween the partx of which t.hc mechanixm conxixtx.
29 Thix is unacceptable where the small lengthx betwc~n xuch end.~ are dixplaced at high or very high speed.s and have to be 31 directed xeparately to differentiated lateral channel.s.
32 The problem to be overcome is therefore mainly connected to 33 the proper lateral or vcrtical fieparation of the head portion X005~0 1 from thc main body of the rolled product, or el.sc of thc main 2 body of the product from it.s tail portion, and also the 3 despatch of such two sheared element.s to different discharge 4 channel.s.
It should be noted that in the case of slender rolled .stock 6 a speed of 120 metres per second correspond.s to a speed of 7 more than 430 kilometre.s per hour, and this mean~ that minimum 8 di.stance.s between the front element and the rear one are 9 practically not noticed during the step of traditional mechanical deviation of the rolled stock.
11 It .should be borne in mind that in the ca.se of .small 12 fiection.s of about 4-8 mm. the high and very high .speed.s are 13 greater than 60-80 metres and normally reach 100 metre.s per 14 s(cond or more.
Even the larger ~ections wit'n a correlativc decrea.jc in 16 .~peed can be .sheared, according to the pre.sent invention 17 under examination, at speeds much higher than tho.~e which can 18 be reached with known sy~tem.~.
19 The pre.~cnt invention therefore tends to make po.ssible a correct, accurate separation and a correct, differentiated 2I delivcry of the front element in relation to the rcar elemcnt 22 as shcared without leading to problems of contact or wrong 23 delivcry of the matcrial or of abra.~ion of th~ rolLcd ~toc~
24 it.~lf.
2; Accordin~ to thc invcntion a .~pecific part.ition h'a~
26 arran~(d on the gcometrically dcfined l(ngthwi.~e axis of 27 shcaring.
2& Tlli.s partition coopcrate.~ by mcans of it.~ uppcr ridgc wit.h 29 thc head of thc succes~sive element in conveying .~uch succc.~.~ive element into a channcl different from the channel 31 of the pas.~age of thc preceding element.
32 ~'e mcntion here in a generic manncr a preceding clement and 33 a succes.sive element; the preceding elemcnt may be the head I port.ion or t.he central body, whilc the fiUCCCS~SiVe element may 2 be the central body or the tail portion, or may be pos.sible 3 shearcd ~seg~ent~s whcre continuou.s shearing to si~e is being 4 carried out.
S According to the invention the rolled stock is positioned, 6 at thc moment of .shearing, in a position which coincides 7 sub.stantially with the lengthwise shearing axis.
8 Acccording to the invention there is a rigid link, at least 9 during the transient period before the shearing moment, between the lateral position of the rolled stock, to which a Il lateral movement is also momentarily imparted, and the 12 circumfercntial position of the knive.s, which also are in 13 continuous movement during such transient period.
14 The outcome is that an instant before the shearing the rolled xtock is ~ituated, on the hori70ntal plane containing 16 the .shearing axis, at an angle, even though very xlightly, to 17 the shearing axis, and that an in.stant after the shearing the 18 succcs.sive clemcnt is also situated at an angle to the !9 xhearing axix but at an angle with another sign than the ~0 previous anglc.
21 Moreovcr, when the rolled fitock on arrival lies substant-22 ially on the xhearing axix, the knives lie subxtantially on 23 the vertical plane containing their axc.~ of rotat.ion; the 24 rolled xtock ix .~heared and the front clcment run.~ sub.~tant-ially along thc specific partition but i)arall~l to t.hc 26 stlearing axis.
27 According to the invention a .slight contact b~tween the 28 knivcx crlhances thix xituation by cauxing a xlight upward 29 bending of the arriving rolled xtock and by thux axsisting a transver.se ~urmounting of the partition owing to the lateral 31 and lengthwixc movcment of thc rolled stock itself.
32 This xurmounting enables the front and rear .sheared 33 elements to be corrcctly delivered into their .specific, 1 xeparate discharge channels.
2 According to a variant the guide ifi provided with vertical 3 adju.stment correlated, even only in steps, with the diameter 4 of the rolled .stock to be .sheared.
The invention therefore concerns a ve,ry high speed flying 6 .shears according to the feature.s of Claim 1, the dependent 7 claims dixclosing some variants.
8 The attached figure.s, which are given as a non-restrictive 9 example of the embodiment of the invention, show an embodimcnt of the invention.
11 Figs.1 to 5 give three-dimensional views of various 12 reciprocal positions of the knives and of the 13 laterally movable guide in which the rolled stock 14 r~ns;
Fig.s.Ia to Sa .show from above, thc xamc positionx as those 16 .shown in three dimen.sions in Figs.1 to 5;
17 Fig.6 xhows from above a high speed xhears;
18 Fig.7 gives a side view of the shearing moment;
19 Fig.s.8 and 9 give two preferred views of the phenomenon employed by the invention;
21 Fig.10 gives a pos.sible embodiment of a variant where the 22 xhear.s is use,d for largc xect,ions;
23 Figs.11 and 12 show in Carte~ian coordinat,cs the rclationxhip 24 of thc lateral dixplaecment xpeed to t,he poxition of t.hc guidc.
26 A flying .shears 10 comprisex two kni~e.~ 14 abIe to 27 contrarotatc in relation to each other and kinematically 28 connected together~ so that the pcripheraI xpeed of one knife 29 coincide.s exactly with the peripheral specd of the other.
Each knife 14 bears its respective blade 17 and their 31 direction of rotation 21 coincide.s with the direction of feed 32 22 of rolled stock 18.
33 Thc bladox 17 (.see Fig.7) comprixe advantageou.~ly a xlight ~oo6s1 I overlapping .segment at their point of cro.s.s-ovcr coinciding 2 with a plane 33 that contains the axe.s "Z" of rotation of the 3 knive~s 14.
4 The rolled .stock 18 i~s guided in a guid~ 11 ablc to move sidewayx in a required manner sub~stantially in a horizontal 6 plane (that i~s, parallel and intermediate to the plane.
7 containing the axe~s "Z") containing a .shearing axifi 20.
8 The guide 1I can move with a direction of movement 19 or 9 119, depending on the type of .shearing taking place, which in thi.s example i~s .shearing of the head or tail re~spectively.
I1 Lateral di.splacement of the guide 11 i.s governed in our 12 example by a gear wheel and threadcd shaft 40~ or another 13 known syfitem, actuated and controlled by a deviation motor 41, 14 the guide 1I being pivotable about a centre of rotation 37.
The .starting position of the guide I1, if the head of thc 16 rolled .stock i.s to be fiheared, a.s in Fig.6, i.~ poxition A; the 17 pofiition of arrival after the cycle of shearing the head i.s 18 pofiition B, wherea.s the coiling position i.s po.~ition C.
19 Po.sitionx B and C may coincide.
The cycle to shear the tail of thc rolled stock arranges 21 that the guide 11 xtart.s from po.~ition C,goe.s to po.sition B
22 and then move.~ from po.sition B to position A aftcr the 23 .shcaring of thc t,ail in a po.~ition coinciding with the 24 fihearing axi.s 20.
~he fihearing axix 2Q connuct,x .~uhxt,antially an intakc 26 entraining me~anx 35, the knive.~ 14 and an offtake entraining 27 mcanx 135.
28 The knives 14 arc xct and kept in rot,ation by a drive chain 29 driven by a motor 39 of the knivex.
A conveyor channel 13 i.~ included down.stream of the knive~
31 14 and may be immovablc or able to o.~cillate by a very .~mall 32 angle with itfi centre of rotation at 38, bcing moved by a jack 33 34.

I The conveyor channel 13 comprises an internal dividing wall 2 27, which extends frontally towards the knives 14 by means of 3 a specific partition 16, which approaches as closely as 4 po.s.sible the plane 33 containing the axes of rotation "Z" of the knives 14.
6 Thus, thc guide 1I starts from position A, reache.s a .spced 7 coordinated with the peripheral speed of the blades 17 of the 8 knive.s 14, performs the shearing operation, slows down until 9 it reaches po.sition B and then positions it.self at C for the coiling step.
Il The .speed of lateral traversing 19 or 119 of the guide 11 12 before the shearing opcration is such that the lateral 13 position of the guidc It is strictly correlated with the 14 angular position of the blade.s 17 of the knives 14.
The rcason for thi.s i.s that, at least at about thc shearing 16 moment, the guide 1I moves at each revolution of thc blades 17 17 by a determined fitep and, when the axis of thc guide 11 is 18 located on the .shearing axi.s 20, the blade.s 17 of the knives 19 14 lie on the plane 33 containing the axes of rotation "Z" of the knives 14 themselvefi.
21 Conveyor.s 42 arc positioncd downstream of the conveyor 22 channel 13 and cooperatc specifically with the offtake 23 entraining mcan.s 135 or with a scrap .shears 36.
24 The offtake entraining mcans 135 in turn coopcratcs with a coiling plant or anothcr plant suitable fc)r thc purposc.
26 ~ ~ According to thc invent.iorl thc guidc 11, as fihown in Fig.7, 27 ~ passe6 in its .sideways displaccmcnt in the immediate 28 neighbourhood of contact rollers 30 which enclo.sc the end 29 position of the blade.s 17 when rot.ating.
~, :: :
30~ The partition 16 too approaches a.s near as pos.~iblc to the 3I planc 33 containing the axe.s of rotation "Z" of the knives 14, 32- a.s is shown in Fig.7, but does .so without touching thc contact 33 rollers 30.

.,,:

I The distance L' of the frontal point of tho partition 16 2 from the plane 33 can be correlated with the diameter of the 3 rolled stock 18, fiO that the more that diameter increases, the 4 more the value of L' becomes.
S The partition 16 cooperates with a bottom 29 of the 6 conveyor channel 13, which in thi.s example i.s enclo.sed at itx 7 top by a cover 15 rotatable on hinges 23.
8 By lifting the cover it ifi therefore pos.sible to have 9 access to the in~side of the conveyor channel 13.
The initial segment of the partition 16 does not reach the I1 overall height of the conveyor channel 13.
12 The partition 16 is secured advantageously to the bottom 29 13 of the conveyor channel 13 by an anchorage pin and by a forked 14 portion, which engages the internal dividing wall 27 and keep.s the partition 16 in position.
16 Thi.~ solution, which may also be embodied with another 17 suitable solution, is such as to enable the partition 16 to be 18 readily replaced so that it can be adapted to the requirementx 19 of the various ranges of dimensions of the rolled stock 18.
The partition 16, as shown in Fig.7, comprise.s an upper 2I ridge 25 substantially parallel to the xhearing axi.s 20 and 22 vertically distant. from thc shearing axis 20 by a detcrmined 23 value 24.
24 This value 24 ix determined according to thc diamet.cr of 2~ the rolled stock 18 and thc type of tranxversc radiusing 26 forming the ridge 25 i.txclf.
27 The length L of the upper ridge 25 ix detcrmined ax a 2& function of the speed of lengthwixe feed 22 of t.hc rollcd 29 stock 18.
The speed of lcngthwisc feod 22 of the rolled xtock 18 3I conditions the spced of lateral displacement 19-119 of thc 32 guide 11 at least at about the transient period of shearing.
33 The partition 16 is adapted to the inner hcight of the ~005108 1 convcyor channe1 13 by a rounded spinc 26, which ~onnnct.s thl 2 ridge 25 to the upper part of the partition coopcr.~ting 3 ~substantial1y with the cover 15.
4 As we said earlier, the knive.s 14 rotatc continuously at lea.st during thc ~shearing cycle while the guide 15 mo~s from 6 po.sition A to pofiition C and vicever~sa, depending on the type 7 of shearing being carried out.
8 Fig.s.11 and 12 re.spectively show the cycle of .shearing the 9 head (Fig.ll) and the cycle of shearing the tail (Fig.12).
The lateral po.sition of the axi.s of the guide 11 i.s shown in 1l abscissae, whereas the speed "V" of displacement of the guide 12 11 is shown in ordinates.
13 A.s can be .seen in Fig.11, the guide 11 leaving position A
14 accelerate.s progre.s.sively until it reaches the .standard .speed "VR", which it maintain.s for a tract "LR" until the she~rinO
16 ha.s been performed; it then .slows down progre.ssively until 17 position B and then reache.s po.sition C, wherc it halts 18 finally. As we said earlier, position.s B and C may a1so 19 coincide.
In.stead, in Fig.12 the guide 11 .start.s from po.sition C, 21 accelerates progressively until it reaches the standard .ipced 22 "VR", maintainx that speed only along the tract "LR" to 23 perform shcar:ing on thc axis 20 and then .slows down progl~s.~-24 ively unti1 it halt.~ at position A.
2; During thn t;ract "IR", where thc guidc 11 tra~cl.i at. t.h~
2~ standard spccd "VR", the lateral posit.ion of the guide 11 is 27 strictly corrclated with the circumferential position of the 28 b1adex 17. Thc result of this i.s that, whcn the axis of the 29 guide 11 lies .substantially coaxially with the shearing a~is 20, the bladcs 17 of the knives 14 lie sub.stantia1ly on the 31 vertical plane 33 containing the axes of rotation "~" of the 32 knives 14 themselves.
33 The shearing cycle and the method on which the invention is Z0051(~8 -' -- 1 o 1 ba.sed are shown in Figx.1 to S.
2 ~ig.1 shows thc guidc 11 with th~ rolled .stock 18 just 3 emerging, the lateral po.sition of the guide 11 being 4 correlated with the circumferential position of the blades 17.
In Fig.2 the guide ]1 ha.s by now reached a lateral position 6 very near the blades 17 while continuing its lateral 7 displacement according to the arrow 19. As can be seen, the 8 blades 17 of the knives 14 in the po.sition of Fig.2 lie in a 9 xhearing po~sition, while thc rolled stock 18 pafi.ses lengthwixe 10 according to the arrow 22 outside the knives 14.
11 In Fig.3 the rolled .stock 18 has by now entered the zone of 12 contact with the knives 14 while it continues its lateral 13 travel according to the arrow 19 and its lengthwise travel 14 according to the arrow 22. In the position of Fig.3, which 15 coincides wit.h that, of Fig.8, the rolled stock runs very near 16 the partition 16 but still does not touch it substantially.
17 Fig.4, which coincides sub.stantially with Fig.7, show.s the 18 .situation at the end of shearing; here the axis of the guide 19 11 coincidex ~substantially with the shearing axis 20. In thix 20 situation the rolled stock 18 has been sheared into the 21 portions 118 and 218, while the blades 17 of the knivex 14 lie 22 substantially on the plane 33 containing the axes of rotat.ion 23 "Z" of t,he knive.~ 14 thcmsc1vcx. As can be .secn, t,he knivex 24 14 have t,h(~ir b1adex 17 coupled together and ha~e juxt 25 complet,ed th(~ h(aring.
26 In tne ,~ituat,ion of Fig.4 thc front portion 118 of tne 27 rollcd st,ock 18 i.~ .supported latera11y by the partition 16 and 28 continucs itx travel according to the arrow 22, while the 29 knivex 14 with their blades 17 determinc thc formation of a 3Q down~ardly curved rear end 31 of the front portion 118.
31 The rear portion 218 lies substantially on the shearing 32 axis 20 and, oncc again owing to the momentary rcciprocal 33 positions of thc blades 17 of the knivex 14, comprisex an I I

1 upwardly cur~ed front end 32.
2 Wherea~s the front portion 118 .~lide.~ on the .sidc wall of 3 the partition 16 and move~ no longer laterally but onl~
4 lengthwixc according to it.~ direction of feed 22, the rcar portion 218 continue.s it.~ .~idoway~s di.~placement according to 6 the arrow 19 owing to its own inertia and al.so owing to the 7 action of the guide 11.
8 The pre.sence of the upwardly curved front end 32 and the 9 action of lateral thrust enable the rolled fitock 18, being fed a.s .shown in Fig.9, to pa.s.~ ovcr (Figs.9 and 5) the upper ridge 11 25 of the partition 16 and thufi to make use also of its own 12 lengtnwise resiliencc. This enables the rear portion 218 to 13 pass laterally over the partition 16 and to position it.self 14 with ea.se on the other side of the internal dividing wall 27 while cont.inuing it~ lateral 16 and lengthwisc 22 travel.
16 Thi.s action of pas.~ing over the partition ix further 17 a.ssi.sted by the frontal conformation of the partition 16, 18 which comprises at it.s front end a rounded tongue 43, which 19 brings the upper ridge 25 downwards and makes it cooperate at lca.~t with the lcngthwi.~e shearing axis 20.
21 Thi.~ roundcd tongue 43 brings advantageously the forward 22 point 12 of the partition 16 below the lengthwise shearing 23 a~is 20 so as to a.~ t thc .surmounting action of th(~ curvcd 24 front end 3~ and the. momentary rc.~ilicnt bcnding act.ion of the rolIt~d stoc~ ]8.
26 ~hu.~, the coopcration bctwcen the reciproca1 po.~itions of 27 tne blade.~ Ij, the momentary position of tnc guide 11 and the 28 geometric conformation of the partition 16 mak~ po.~.~ible the 29 tranxver.~c surmounting of the partition 16 by the rear portion 218 in it.~ travel, thu.~ enab-ing a clean and definite 31 separation to bc obtaincd between the front portion 118 and 32 rear portion 218 ~heared by the shears 10.
33 When processing large sections, it may be found advant-200~

I ageou.s (Fig.~.6 and 10) to di.~place latcrally by mcLIn.~ of a 2 jack 34 the conveyor channcl 13, which in this casc will 3 rotate on the pivot 38. Such di.splacemlnt is very .small 4 (Fig.10) and .serves only to po.sition thc partition 16 better in relation to the lengthwi.se .shearing axi.~ 20, so that the 6 rolled stock 18 during the .shearing step will b~ po.sitioned 7 correctly.
8 Such displacement will be to the right or to the left of 9 the shearing axis, depending on thc specific shearing action to be performed.
Il According to a variant the partition 16 or the upper ridge 12 of the partition 16 may be adjustcd in height .so as to be 13 po.sitioned in the best po.sfiible po.sition in relation to the 14 diameter of the rolled .stock 18.

Claims (27)

1. Very high speed flying shears suitable for shearing rolling stock travelling even at a speed of more than one hundred meters per second, comprising:
two knives which counter-rotate relative to each other at a first predetermined speed at least during a shearing period and which define a shearing axis, each of said knives having a blade located at a circumferential position, each said blade extending substantially across the entire width of said knife;
a guide adapted to move essentially horizontally at a second predetermined speed to position the rolled stock at a desired lateral position relative to the shearing axis; and a conveyor channel located downstream of the knives and having an inner dividing wall;
means for moving the guide essentially horizontally during the shearing period with the second predetermined speed being correlated with the first predetermined speed, and the lateral position being correlated to the circumferential position of the blades so that the guide is substantially parallel to the shearing axis while the guide moves at said second predetermined speed and the blades cut the rolled stock;
said inner dividing wall comprising a partition, said partition having an end portion which has a transversely rounded upper surface, said upper surface being located a predetermined distanced above said shearing axis, said predetermined distance being related to the diameter of the rolled stock;
said rounded upper surface extending essentially parallel to said shearing axis, and said end portion further comprising a frontal rounded tongue which extends at an angle down from said rounded upper surface and which defines a frontal point.

2. The flying shears as claimed in claim 1, wherein said end portion has a length which is related to the axial speed of the rolled stock.

3. The flying shears as claimed in claim 1, wherein the axes of rotation of said knives define a vertical plane perpendicular to said shearing axis, and wherein the distance between the partition and the vertical plane is related to the diameter of the rolled stock.

4. The flying shears as claimed in claim 1, wherein the vertical position of said rounded upper surface can be varied according to the thickness of the rolled stock.

5. The flying shears as claimed in claim 1, wherein said frontal point is located in a horizontal plane which is near the shearing axis.

6. The flying shears as claimed in claim 5, wherein said horizontal plane is below the shearing axis.

7. The flying shears as claimed in claim 1, wherein, said partition defines a median vertical plane which substantially contains the shearing axis.

8. The flying shears as claimed in claim 1, wherein said partition defines a median vertical plane, said partition being movable so as to vary an angle between said median vertical plane and said shearing axis.

9. The flying shears as claimed in claim 1, wherein the axes of rotation of said knives define a vertical plane perpendicular to said shearing axis, and wherein the blades of said knives overlap each other when the blades are contained in said vertical plane.

10. The flying shears as claimed in claim 1, wherein the blades of said knives are shaped so as to create an upwardly curved front end in a rear sheared portion of the rolled stock.

11. The flying shears as claimed in claim 10, wherein said upwardly curved front end cooperates with the frontal rounded tongue and the rounded upper surface so as to pass laterally over the partition.

12. The flying shears as claimed in claim 1, wherein the blades of said knives are shaped so as to create a downwardly curved rear end in a front sheared portion of the rolled stock.

13. The flying shears as claimed in claim 12, wherein said partition defines a vertical flank portion, and wherein said downwardly curved rear end cooperates with said flank portion.

14. Very high speed flying shears suitable for shearing rolling stock travelling even at a speed of more than one hundred meters per second, comprising:
two knives which counter-rotate relative to each other at a first predetermined speed at least during a shearing period and which define a shearing axis, each of said knives having a blade located at a circumferential position, each said blade extending substantially across the entire width of said knife;
a guide moving means for moving a guide essentially horizontally at a second predetermined speed and positioning the rolled stock at a desired lateral position relative to the shearing axis; and a conveyor channel located downstream of the knives and having an inner dividing wall, said inner dividing wall comprising a partition which divides the conveyor channel into two compartments, said partition having an end portion which has two opposing side surfaces and a transversely rounded upper surface, said upper surface extending essentially parallel to said shearing axis, wherein during the shearing period, said knives cut the rolled stock into a front sheared portion and a rear sheared portion, and wherein the guide moves horizontally so as to cause said rear sheared portion to pass over said rounded upper surface from one of said compartments into the other of said compartments;
said end portion further comprising a frontal rounded tongue which extends at an angle down from said rounded upper surface and which defines a frontal point.

15. The flying shears as claimed in claim 14, wherein during the shearing period, the second predetermined speed is correlated with the first predetermined speed, and the lateral position is correlated to the circumferential position of the blades so that the guide is substantially parallel to the shearing axis while the guide moves at said second predetermined speed and the blades cut the rolled stock.

16. The flying shears as claimed in claim 14, wherein said rounded upper surface is located a predetermined distanced above said shearing axis, said predetermined distance being related to the diameter of the rolled stock.

17. The flying shears as claimed in claim 14, wherein said end portion has a length which is related to the axial speed of the rolled stock.

18. The flying shears as claimed in claim 14, wherein the axes of rotation of said knives define a vertical plane perpendicular to said shearing axis, and wherein the distance between the partition and the vertical plane is related to the diameter of the rolled stock.

19. The flying shears as claimed in claim 14, wherein the vertical position of said rounded upper surface can be varied according to the thickness of the rolled stock.

20. The flying shears as claimed in claim 14, wherein said frontal point is located in a horizontal plane which is near the shearing axis.

21. The flying shears as claimed in claim 20, wherein said horizontal plane is below the shearing axis.

22. The flying shears as claimed in claim 14, wherein said partition defines a median vertical plane which substantially contains the shearing axis.

23. The flying shears as claimed in claim 14, wherein said partition defines a median vertical plane, and wherein said partition is movable so as to vary an angle between said median vertical plane and said shearing axis.

24. The flying shears as claimed in claim 14, wherein the axes of rotation of said knives define a vertical plane perpendicular to said shearing axis, and wherein the blades of said knives overlap each other when the blades are contained in said vertical plane.

25. The flying shears as claimed in claim 14, wherein the blades of said knives are shaped so as to create an upwardly curved front end in said rear sheared portion of the rolled stock, and wherein said upwardly curved front end cooperates with the frontal rounded tongue and the rounded upper surface so as to pass laterally over the partition.

26. The flying shears as claimed in claim 14, wherein the blades of said knives are shaped so as to create a downwardly curved rear end in said front sheared portion of the rolled stock, and wherein said downwardly curved rear end cooperates with one of said opposing side surfaces.

27. Very high speed flying shears suitable for shearing rolling stock travelling even at a speed of more than one hundred meters per second, comprising:
two knives which counter-rotate relative to each other at a first predetermined speed at least during a shearing period and which define a shearing axis, each of said knives having a blade located at a circumferential position, each said blade extending substantially across the entire width of said knife;
a guide, upstream of said two knives, adapted to move essentially horizontally at a second predetermined speed to position the rolled stock at a desired lateral position relative to the shearing axis; and a conveyor channel located downstream of the knives and having an inner dividing wall;
means for moving the guide essentially horizontally during the shearing period with the second predetermined speed being correlated with the first predetermined speed, and the lateral position being correlated to the circumferential position of the blades so that the guide is substantially parallel to the shearing axis while the guide moves at said second predetermined speed and the blades cut the rolled stock;
wherein said inner dividing wall comprises a partition, said partition having an end portion which has a transversely rounded upper surface, said upper surface being located a predetermined distance above said shearing axis, said predetermined distance being related to the diameter of the rolled stock;
axes of rotation of said knives define a vertical plane perpendicular to said shearing axis;
the distance between the partition and vertical plane is related to the diameter of the rolled stock said partition defining a median vertical plane which substantially contains the shearing axis;
said rounded upper surface extends essentially parallel to said shearing axis, and said end portion further comprises a frontal rounded tongue which extends at an angle down from said rounded upper surface and which defines a frontal point;
the blades of said knives are shaped so as to create an upwardly curved front end in a rear sheared portion of the rolled stock;
said upwardly curved front end cooperates with the frontal rounded tongue and the rounded upper surface so as to pass laterally over the partition.