GB2452162A - Wire or Strip Cutting or Shearing - Google Patents

Abstract

Apparatus for cutting or shearing lengths of wire or strip from a source thereof, comprising supply means able to supply wire or strip to extend from holding means into a cutting or shearing member of cutting or shearing means arranged to cut or shear lengths of said wire or strip , the cutting or shearing means arranged to cut or shear lengths of said wire or strip,the cutting or shearing means comprising a plurality of spaced such cutting or shearing members and disposed to cut or shear a length of wire or strip by a displacement of the cutting or shearing means which positions another cutting or shearing member to receive a further length of wire or strip from the holding means. A method of cutting or shearing wire or strip is also disclosed.

Description

WIRE OR STRIP CUTTING OR SHEARING

Known wire straightening and cutting machines straighten wire delivered from a suitable source, such as from a loose coil, into straight lengths using a rotating spinner or rollers before the wire is delivered to a holder for cutting. The machine has a built in cutting system arranged to shear consecutive lengths of fed wire after straightening the wire and delivering a fixed length of wire to project beyond the cutting means.

In one of the known techniques, wire is fed from a coil to straightening means and then through holding means in the form of a fixed die to a moving shearing die as shown in Figure 1. The shearing die moves to shear the wire, but must return to its onginal pre-cutting position before it can effect the next and subsequent cut lengths of wire * I *,* In another known technique, wire is supplied from a similar coiled source and fed i through a similar fixed die to a moving sheanng blade as shown in Figure 2. The :*. shearing blade moves to shear the wire, but again must return (without cutting) to its original pre-cutting position before it can effect the next and subsequent cuts.

In these known wire cutting machines, both cutting means are subjected to linear reciprocation wherein a cut is effected during one stroke but not on the return stroke. It is this reciprocal motion of the cutting means coupled with availability of only one cutting member which limits the production of cut lengths of wire.

Other systems are known in which the wire or filament is fed either through a pair of wheels with cutters, or a rotating blade. In these systems, the wheels are approached end-on to the circumference with the wire or filament to be cut, and typically cut only into one fixed length of component. In another known wire cutting arrangement, a fixed speed continually rotating flywheel has cutters attached. The speed of the wire feed wheel and the cutting flywheel can be controlled to link the required matching speeds.

In that arrangement, the position of the flywheel and the attachments to the wheel determine the fixed length of wire to be cut and the flywheel does not stop.

It is an object of the present invention to devise a wire or strip cutting machine with improved productivity, i.e. a machine which can supply, straighten if needed, and then cut continuously fed wire at a faster rate than possible with the known illustrated machines. It is also an objective to devise such alternative embodiments of machine to feed, deliver and shear or cut material already in generally straightened strip form, such as lengths of metal strip, wire, filament, pin and/or needle but cut to any required and therefore variable length. * *. * * * * *.

*:. 15 According to one aspect of this invention, there is provided apparatus for cutting or shearing lengths of wire or strip from a source thereof, comprising supply means able :::; to supply wire or strip to extend from holding means into a cutting or shearing member of cutting or shearing means arranged to cut or shear lengths of said wire or strip, the cutting or shearing means comprising a plurality of spaced such cutting or shearing members and disposed to cut or shear a length of wire or strip by a displacement of the cutting or shearing means which positions another cutting or shearing member to receive a further length of wire or strip from the holding means.

According to another aspect of this invention there is provided a method of cutting or shearing wire or strip wherein a source of wire or strip is provided, the wire or strip is supplied to extend through holding means into the vicinity of a cutting member of cutting means adapted to cut lengths of said wire or strip, which cutting means comprises a plurality of spaced such cutting members and is disposed to cut a length of wire or strip, displacing the cutting means to another position in which another cutting member thereof becomes positioned to be capable of receiving a further length of wire or strip from the holding means and wherein said displacement effects a cut in the wire or strip.

In preferred embodiments of the present invention, use of a disc as the cutting means avoids problems associated with shearing dies or blades that have to reciprocate to an original or starling position before the next shearing cycle can begin. The preferred disc system with an array of multiple bores or slots needs only to move in one preferably rotary direction, retaining the wire for release and clearance from the disc bore or slot at a later stage. Such a bored disc can be indexed i.e. partly rotated by one rotary increment to shear the wire whilst simultaneously positioning the next bore *::: 15 or slot for further wire feed, as shown in Figure 3.

:. In order that the invention may be illustrated, more easily appreciated and readily carried into effect by those skilled in the art, embodiments thereof will now be described with reference to the accompanying drawings purely by way of non-limiting

example and wherein:

Figure 1 is a schematic illustration of the relevant components from a conventional wire straightening and cutting machine using a reciprocating collar die; Figure 2 is a schematic illustration of the relevant components from a conventional wire straightening and cutting machine using a reciprocating blade; Figure 3 is a schematic illustration of the relevant components of a wire straightening and cutting or shearing machine according to one embodiment of the invention; Figure 4 is a view corresponding generally with Figure 3, of a modified embodiment of the present wire straightening and cutting or shearing machine; Figure 5 is a view of a further preferred embodiment of the present wire straightening and cutting or shearing machine, and Figure 6 is a schematic illustration of an alternative embodiment of the principal working components of a wire cutting or shearing machine according to the invention based on a hardened cutting disc comprising a plurality of slots.

s Referring to the drawings, principal working components from a known cutting system : * are shown in Figure 1, based on a single fixed cylindrical collar die 1, to position the wire for co-operation with one linearly reciprocating shearing die 2.

As depicted in Figure 1, wire 3 which has already been straightened is fed from a loose unwound coil (not shown) in the direction of arrow A into the opening of an axial bore 5 at one face 4 of the fixed die 1. The fed wire passes through the fixed die 1 and projects from the other face (not shown) of the fixed die. The wire then passes into a similar axiai bore of a moving cyiindrical die 2, arranged to reciprocate in a generally vertical direction.

The length of wire 3a to be cut projects from beyond the far end 7 of the moving die at its furthermost face 6. Upon cutting by linear motion of the moving die 2 in one stroke of the reciprocation causes the wire to be cut. Wires (3b, 3c, 3d) which had already been cut are depicted as falling under gravity to a collector (not shown).

The Figure 2 arrangement shares some similarities with the known machine depicted in Figure 1, and to the extent practicable the same reference numerals have been deployed to identify the same components. Thus already straightened wire 3 is fed on a step-wise basis in the direction of arrow A to the axial bore 5 of fixed cylindrical die 1.

The length of wire 3a to be cut projects beyond the corresponding opening 76 of the fixed die. Cutting means incorporating a cutting blade 2a is positioned at the rear face of the fixed die and is mounted for linear reciprocation within the direction of arrow B. A cutting surface 7A is caused to engage the projecting wire during the downward stroke of reciprocal movement. After making the cut, the cutting blade returns to its original pre-cutting position on an upward stroke of reciprocal movement, during which *:*::* stroke there is no cutting of wire. Lengths of wire 3b, 3c and 3d which had already *. 15 been cut by the blade 2a are depicted as falling in the direction of arrow C under gravity alone into a collector (not shown).

Referring to Figure 3 depicting a preferred embodiment of the present invention, the principal distinction over the known arrangements resides in the construction and operation of the cutting or shearing means. Thus in Figure 3 wire 3 is fed from a loose coil (not shown) and straightened before being fed to the inlet 5 of a bore in a fixed cylindrical die 1 and projects as a length of wire 3a to be cut from the exit 7b of that bore. These parts of the Figure 3 arrangement generally correspond with the equivalent parts of the Figures 1 and 2 arrangements.

A hardened rotary cutting disc 8 is however used as the cutting means to effect sequential cuts to wire fed to it from the fixed die. This disc is mounted at axis 9 for rotation in the direction of arrow D. The disc incorporates an array of hollow bores 10 which extend through the disc, which extend in parallel with the axis of rotation of the cutting disc, The bores serve as cutting bores and cause the wire to be cut by incremental rotation of the disc, conveniently controlled by a stepper motor, servo motor, mechanical means or a combination of two or more of such control means (not shown). The length 3a of wire to be cut extends through and beyond bore 10 in the cutting disc. Wires 3b, 3c, and 3d which have already been cut are depicted as still projecting beyond the remote ends of such bores 10, and are at least temporarily retained in those bores until release therefrom The incremental rotation of the cutting disc is arranged such that the next succeeding bore is positioned to receive a subsequent length of wire to be cut, so that all bores in the cutting disc are or can be used at optional efficiency. * Sla * ** * S

The disc can be one piece or multi-piece construction. Cut lengths of wire can in some : arrangements be discharged from the disc by a jet of compressed air (not shown) wherein a nozzle of compressed air supply means (not shown) is maintained in alignment with successive bores as the disc incrementally rotates. Jets of air can be pulsed to discharge cut wires in unison with the feeding of fresh wire to be cut.

Alternatively cut lengths of wire can be mechanically discharged from the disc. Once released from the bores in the disc, the cut lengths of wire may simply descend by gravity into a suitable collector (not shown). Once cut wire has been ejected from the bore in the disc, that bore becomes available for re-use, so the cutting and ejection can operate in a continuous or step-wise cycle.

Referring to Figure 4, cut wire carriers in the form of a wire support drum can be added to the disc to enable long lengths to be processed. The support drum has longitudinal grooves 12 to support the longer cuts of wire. The wire lengths to be sheared by the disc can be determined by feeding a fixed length of wire through a bore in the disc.

Alternatively, the length of wire or strip to be cut may be determined by feeding the wire to a fixed mechanical stop (not shown) beyond the rearmost face of the disc or of the support drum, optionally with a detector (not shown) if required, to instigate the index motion, or the length to be cut may be determined by a combination of both such methods. The drum can be a multi-part assembly if required. Discharge by corn pressed air jet can still be effected.

Other operations can also be carried out on the wire whilst it is held in the disc and carriers, after the wire has been cut to the required length, such as, for example, the wires can be flattened or planished, formed or bent, chamfered or pointed The disc can be indexed mechanically or electrically or both, although the drawings being schematic and illustrative do not show full detail of such indexing, a suitable *l:. mechanism is described subsequently. I... * * * ***

The disc can be integrally formed to consist of one piece or it could comprise multiple *: sections, and either can contain individual cutting dies held in the disc or bores thereof, :*. 20 although not shown. S. * * S * * S.

The individual cutting dies if present within the disc, or the bores in the disc can be a predetermined cutting and/or retaining shape or section, not necessarily round. For example, the cross section could be triangular, rectangular, octagonal, diamond section or other geometric form.

The disc cutting system preferably consists of at least one disc including an array of a plurality of longitudinal bores parallel to and equidistantly spaced from its axis of rotation an end edge of the respective bores applying a shearing force on the wire, thereby cutting a predetermined length of wire. The cutting disc can be rotated by using a computer-controlled servo motor (not shown), for example an electric servo motor attached to the cutting disk can be indexed in increments and time as required by the computer-controlled servo drive. In this example, the servo drive is initiated by an electrical or electrical/mechanical wire length detector or by a time basis.

The electrical detector (not shown), that locates for the wire length is placed in a position on the machine at the required length to be cut which is beyond the cutting disc. Once the length of wire is located by the detector, the detector then sends an electrical signal to the servo drive, which in turn signals the servo motor to index the disc cutter to the next available bore/slot on the disc. The disc s then held fixed in this position whilst the next wire to be cut is fed through the bore/slot in the disc and the process is then repeated.

S 5*S

With the wire fed continuously into the disc assembly comprising a plurality of bores * acting as dies, a fixed stop can be used to give accuracy of lengths, with the detector :. 20 placed/arranged immediately before the fixed stop position. The stop holds the feed of * the wire temporarily whilst the disc is indexed by the servo motor to the next available bore/slot. The electrical detector to detect the wire is in this example an inductive proximity sensor. The sensor can operate by directly sensing the wire to be cut, or by a simple lever system, where the wire pushes a lever to a fixed stop. The movement of the lever is detected by the proximity sensor.

In a further preferred embodiment depicted in Figure 5, two or more wires can be simultaneously sheared using a two or multiple cutting disc arrangement, primary cuthng disc rotates incrementally in the direction of arrow E, whilst secondary adjacent but staggered cutting disc 8A rotates in the direction of arrow D. The wire shearing discs can be arranged to rotate independently or according to a predetermined relationship.

In an alternative arrangement, contemplated but not illustrated, the rotary disc could be replaced by a multiple bored magazine which is displaced linearly and presents a series of longitudinal bores as a single stack or column. A machine could be constructed in which such a magazine is indexed stepwise from one bore to the next until the end of the column where its direction may be reversed An alternative embodiment of the present wire straightening and cutting machine is depicted in Figure 6. In common with the known arrangements, and the embodiments thus far illustrated and described, the relevant principal components include means for feeding wire 3 that has already been straightened in the machine, using conventional rotating rollers (not shown). The supply of wire, typically from an uncoiled length (not shown) is fed in the direction of arrow A to the fixed position collar die 1, to be received :*. 20 at its inlet 5 in the front face of the fixed die, and to be passed through the exit bore * (not shown) of the fixed collar to project towards the cutting means.

in the Figure 6 arrangement, the means for cutting the wires is different from all of the cutting means thus far illustrated and described. The wire cutting means is still rotary, and mounted for rotation about an axis 9. The wire cutting means comprises a hardened cutting disc of suitable material (e.g. tool grade steel) into which are cut or formed a series of equidistantly spaced slots able to accommodate the widths of wires to be cut. The slots have opposing wali members which converge into an apex lOb into which the lengths of wire to be cut are inserted as shown. The slots are cut into or formed in the body of the cutting disc 8A at an acute angle relative to a notional radius extending from the centre of the cutting means to the opening of the slot in the s periphery of the cutting disc. This enables good seating of the wire lengths to be cut into the apex of the slots lOa such that a wall of the cut slot in the vicinity of the apex exerts a pressure on the wire and a twisting force helping to cut the wire length After the cut is effected, the wire may be retained in the slot or preferably discharged from the slot, under gravity optionally with some assisting force, and delivered to a suitable collection receptacle (not shown).

The advantages of the invention and of preferred embodiments thereof are manifold, but in particular include the following: I. In operation of preferred embodiments, the cutting disc is indexed, held in S...

that position whilst the wire (pin, needle or filament and the like) is fed through the bore to reach a stop beyond the cutting disc, and the disc is indexed again and the process repeated on a continuous basis. :. 20 * S..

2. Preferred embodiments of cutting or shearing machine according to the present invention support the wire (pin, needle, filament or the like) within the cutting disc, and that wire etc. is supported and sheared when the disc is indexed.

3. Using a wide rotary indexing disc with matching section bores increases disc life many times and gives better shearing ends of wire etc. compared to cutting blades or the conventional single die.

4. A plurality of bores instead of one bore in a cutting disc enables the cutting disc component to have a significantly increased wear life.

5. Cut wire, or strip if used, can be cleanly, horizontally sheared at its point of projection beyond the fixed holding die 6. Cut wire lengths can be contained within the rotary disc and drum enclosures thereto if present, and easily discharged therefrom into a collector.

7. The present invention of machine and method enable cutting, clearance and delivery of the cut wire etc. to be significantly quicker than the S...

above described known wire cutting devices and methods, thereby substantially improving productivity in terms of cut lengths of wire or strip etc. delivered per unit time. *. 20 * . a.e. * * a * .*

Claims (22)

1. Apparatus for cutting or shearing lengths of wire or strip from a source thereof, comprising supply means able to supply wire or strip to extend from holding means into a cutting or shearing member of cutting or shearing means arranged to cut or shear lengths of said wire or strip, the cutting or shearing means comprising a plurality of spaced such cutting or shearing members and disposed to cut or shear a length of wire or strip by a displacement of the cutting or shearing means which positions another cutting or shearing member to receive a further length of wire or strip from the holding means.

2. Apparatus as claimed in Claim 1, wherein the source comprises a supply of coiled wire, and the apparatus is constructed and arranged to feed straightened *:*::* wire or strip to the holding means. * I

3. Apparatus as claimed in either preceding Claim, wherein the holding means * comprises a fixed die. I.. I.

4. Apparatus as claimed in any preceding Claim, wherein the cutting or shearing means comprises rotary cutting or shearing means.

5. Apparatus as claimed in Claim 4, wherein the rotary cutting or shearing means comprises a disc with an array of radially spaced bores or slots at or in the vicinity of the periphery of the disc.

6. Apparatus as claimed in Claim 4 or 5, in which the cutting or shearing members comprise a plurality of bores extending in parallel to the axis of the rotary cutting means.

7. Apparatus as claimed in any preceding Claim, in which the cutting or shearing means is provided with cut wire or strip retention means.

8. Apparatus as claimed in Claim 7, in which the retention means comprises a support drum including means such as grooves for temporary retention of cut or sheared lengths of wire or strip.

9. Apparatus as claimed ri any preceding Claim, including stop means arranged to determine the length of wire or strip to be cut or sheared

10 Apparatus as claimed in Claim 9, in which the stop means are operative mechanically pneumatically, electrically, electronically or optically. * * ****

11. Apparatus as claimed in Claim 10, in which the stop means are operated by * optical and/or electronic sensor. *. 20 * * * ***

*:*.

12. Apparatus as claimed in any one of Claims 7 to 11, in which release means are provided to eject cut or sheared lengths of wire or strip from the said retention means.

13. Apparatus as claimed in Claim 12, in which the release means are operative mechanically and/or pneumatically.

14. Apparatus as claimed in Claim 13, including means to direct a jet of compressed air through a bore or slot of the cutting or shearing means, said jet aligned with a cut or sheared length of wire or strip present in the retention means.

15. Apparatus as claimed in any preceding Claim, substantially as herein described.

16. Apparatus as claimed in any one of Claims 1 to 14, substantially as herein exemplified.

17. Apparatus as claimed in any one of Claims 1 to 14, substantially as herein illustrated in any one of Figures 3 to 6 of the accompanying drawings.

18 A method of cutting or shearing wire or strip wherein a source of wire or strip is provided, the wire or strip is supplied to extend through holding means into the vicinity of a cutting member of cutting means adapted to cut lengths of said wire or strip, which cutting means comprises a plurality of spaced such cutting members and is disposed to cut a length of wire or strip, displacing the cutting means to another position in which another cutting member thereof becomes positioned to be capable of receiving a further length of wire or strip from the holding means and wherein said displacement effects a cut in the wire or strip. * * * *** S. * * S* * S*

19. A method of cutting or shearing wire or strip as claimed in Claim 18, using apparatus as claimed in any one of Claims Ito 17.

20. A method of cutting or shearing wire or strip as claimed in Claim 18 or 19, substantially as herein described.

21. A method of cutting or shearing wire or strip as claimed in Claim 18 or 19 substantially as herein exemplified.

22. A method of cutting or shearing wire or strip substantially as herein illustrated in any one of Figures 3 to 6 of the accompanying drawings. * ** * * * * a. a... * . S.. * S. * S * * *S * 5. * S * SSS S. S * *. a 55