AU2005209611A1 - Device for manufacturing semi-finished products made of metal wire - Google Patents

Abstract

A device for the manufacture of semi-finished retention cages for bottles made of metal wire comprising a fixed support (8), a multiplicity of pincer assemblies (9) slidable on the fixed support (8) along respective first axes (A) converging in an origin (10) and having at least respective first and second pairs of jaws (15,15a) movable between a closed position and an open position and respective actuating members (28) for actuating the jaws (15;15a), a multiplicity of linear actuators (11) slidable on the fixed support (8) along respective second axes (B) positioned on the bisector of two adjacent lines of the first axes (A), and an actuating cam (50) rotatable around an axis (C) passing through the origin (10) to actuate respectively the pincer assemblies (9) and the actuating organs (28), in which said actuating cam (50) also actuates the linear actuators (11) and at least one of said actuating members (28) has a first command profile (34) actuating the first pair of jaws (15) according to a first law of motion and the other actuating members (28) have a second command profile (35) actuating the second pair of jaws (15a) according to a second law of motion.

Description

oD 1 (0 DEVICE FOR MANUFACTURING SEMI-FINISHED PRODUCTS MADE OF A METAL WIRE 00 o The present invention relates to a device for semifinished products made of metal wire, in particular for the manufacture of retention cages for bottles containing M sparkling drinks.

o Generally, retention cages comprise a reticular body ci positioned on a cap of the bottle and a circumferential retention ring connected to the reticular body to secure the reticular body to the bottle.

The cages are obtained by plastic deformation of a metal wire thanks to automated machines which comprise a first station for forming the reticular body and a second station for mounting the retention ring on the reticular body.

Machines commonly used to obtain the reticular bodies comprise in a same plane four pincers actuated by a first cam and slidable along a first pair of perpendicular axes and four linear actuators actuated by a second cam and slidable along a second pair of perpendicular axes having the same origin as the first pair of axes and angularly offset in phase by 45 degrees.

During an initial step of the productive process, the metal wire is automatically sheared and positioned at the pincers which close gripping it or retaining in an initial circular position so that respective ends are superposed and maintained tight by a single pincer.

Subsequently, the linear actuators and the pincers move towards the origin of the axes in co-ordinated way, obtaining a cross-shaped body that constitutes the starting semi-finished product for the manufacture of the reticular body.

oD 2 0 In the specification the term "comprising" shall be 0 understood to have a broad meaning similar to the term O "including" and will be understood to imply the inclusion 00 o of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. This definition also applies V.0 to variations on the term "comprising" such as "comprise" o and "comprises".

ci During the deformation step described above, breaks 10 occur in the metal wire, which may cause an interruption ci of the continuous production cycle, causing productivity losses.

In one aspect the present invention provides a device for the manufacture of semi-finished products made of metal wire that is free of the drawbacks described above.

In a further aspect the present invention is further to increase the production rate.

According to the present invention, a device for forming semi-finished products from metal wire, and comprising a fixed support, a multiplicity of pincer assemblies slidable on said fixed support along respective first axes equidistant and converging in an origin, said pincer assemblies comprising respective pairs of jaws movable between a closed position and an open position and respective actuating members for actuating said pairs of jaws, a multiplicity of linear actuators slidable on said fixed support along respective second axes positioned along the bisector of two adjacent lines of said first axes, and an axially symmetrical actuating cam rotatable around an axis passing through the origin and cooperating respectively with said pincer assemblies and said actuating members, characterised in that: oD 3 0- said actuating cam also actuates said linear actuators; at least a first one of said actuating members has O a first command profile actuating at least a first of 00 o said pairs of jaws according to a first law of motion and in that a second one of said actuating members has a second command profile actuating a second one of said ND pairs of jaws according to a second law of motion.

o For a better understanding of the present invention, ci IC) a preferred embodiment shall now be described purely by 0 S 10 way of non limiting example and with reference to the accompanying drawings, in which: Figure 1 is a partial front view of the device according to the present invention; Figure 2 is an axonometric view of a cage for closing a bottle containing sparkling drinks; Figure 3 is a partial section according to the line III-III of Figure 1; Figure 4 schematically shows a detail of the device of Figure 1 in a first and a second position; and Figures 5 and 6 respectively show enlarged details of the device of Figure 1; In Figure 1, the reference number 1 globally designates a device for the manufacture of semi-finished products made of metal wire, particularly for the manufacture of a reticular body 2 of a cage 3 further comprising a retention ring 4 connected to the reticular body 2 to close a cap of a body containing sparkling drinks.

In particular, the reticular body 2 (Figure 2) is obtained from a single segment of metal wire and comprises four equidistant uprights 5 obtained by twisting the metal wire and connected to each other by respective curvilinear segments 6 globally delimiting a oD 4 0- circular profile 7 closed substantially perpendicular to the uprights The reticular body 2 is obtained by means of the 00 o device 1, comprising a fixed support 8, four pincer assemblies 9 movable on the fixed support 8 along respective orthogonal axes A having an origin 10 and four IN tappet linear actuators 11 movable on the fixed support 8 o along respective axes B positioned coplanar to and along ci tfl the bisectors of the axes A.

S 10 Each pincer assembly 9 comprises a gearwheel element ci 12 rigidly connected to the fixed support 8, a slide 13 movable on the fixed support 8 along the axis A, a mandrel 14 supported rotatably around the axis A by the slide 13 and a pair of jaws of the type 15, 15a depending on whether the pincer assembly 9 respectively grips a single portion of metal wire or two ends of the segment.

Both types of jaws 15, 15a are hinged on the mandrel 14 towards the origin 10 and maintained in an open position by an annular spring 16.

In particular (Figure the gearwheel element 12 supports, freely rotatable around the axis A, a shaft 17 comprising at opposite ends a bevel pinion 18 and grooved portion 19 engaging in a corresponding coaxial grooved slot 20 borne by the mandrel 14 and open at the opposite part with respect to the jaws 15, Each pinion 18 is connected to the two pinions 18 of the adjacent pincer assemblies 9 thanks to respective transmission shafts 21 comprising a pair of end bevel gears 22 meshing with the related pinions 18 and globally forming a closed gear transmission 23 driven by an intermittent motor unit 24 connected to one of the transmission shafts 21 to command the simultaneous rotary motion of the jaws 15, SThe jaws 15, 15a are positioned symmetrically to the C respective axes A and comprise respective grip portions CC 25 oriented towards the origin 10 and actuating portions 00 o 26 positioned at the opposite part of the grip portions 25 relative to the hinge and superficially co-operating with an end shaped portion 27 connected in detachable way IND to a respective actuating tappet rod 28 movable along the o axis A and slidable in guide holes 29 having the axis A ci Vt and borne respectively by the mandrel 14 and by the shaft O 10 17.

ci Each actuating rod 28 is connected in freely rotatable way around the axis A on a slide support comprising a spring assembly 31 to dampen the impacts in a direction parallel to the axis A.

In particular (Figure each actuating portion 26 has an end projection 32 maintained in contact with the shaped portion 27 of the actuating rod 28 by the action of the annular spring 16 and a pair of planar surfaces 33 which convert towards the origin 10 starting from the end projection 32 and are made of wear-resistant material.

The shaped portion 27 (Figure 5) has a pair of planar guide surfaces 34 defining a respective angle a relative to the axis A to impose the law for opening and closing the jaws However, the shaped portion 27 of the pincer assembly 9 comprising the jaws 15a, i.e. the one which grips the ends of the segment of metal wire, has, at the guide surfaces, 34 a shaped profile 35 (Figure 6) having starting from an opposite end to the actuating rod 28, a first and a second rectilinear segment 36 inclined by the angle a relative to the axis A, a concave segment 37 intermediate between the rectilinear segments 36 and a last lateral segment 38 parallel to the axis A and oD 6 0- defining a lateral flank of the guide surface 34.

C The actuation of the movable members along the axes DO A and B, i.e. of the linear actuators 11, of the slides 00 o 13 and of the actuating rods 28 is achieved by means of a desmodromic cam device comprising a disk 50 (Figure 7) connected to the fixed support 8 slidably around an axis .D C passing through the origin 10 perpendicularly to the o axes A and B and having guide walls 51, 52 respectively ci V for the linear actuators 11 and the slides 13. The guide S 10 walls 51, 52 are closed and continuous, having respective ci pairs of rolling surfaces 60, 61 having generatrices parallel to the axis C and co-operate with respective multiplicities of pairs of rollers 53, 54a each borne by the respective linear actuators 11 and by the respective slides 13.

In particular, both the roller 53 and the rollers 54a are positioned at opposite parts of the respective guide walls 51, 52 co-operating with the respective rolling surfaces 60, 61 borne at radially opposite parts of the respective walls 51, 52.

Moreover, the disk 50 has a guide groove circumferentially obtained in the guide wall 52 and having a pair of rolling surfaces 62 facing each other and co-operating with four pairs of pulleys 14b having respective axes, parallel to each other and integral with the respective slide supports The guide walls 51, 52 and the guide grooves 55 are axially symmetrically having identical sectors every 90 and the slides 13 of the pincer assemblies 9 and the linear actuators 11 are positioned equidistant with respect to the axis C.

In particular, the rolling surfaces 61, 62 have profiles comprising a succession of ascending, descending and circumference arc segments following the teaching, G for example, of the patent IT 1264109. The rolling CO surface 60 is obtained similarly in relation to the 00 o surface 61 considering that, in the instants in which the linear actuators 11 move simultaneously with the slides 13, the segments of the rolling surfaces 60 must be IND offset in phase by 450 from the corresponding segments of o the rolling surfaces 61.

ci tfl The operation of the device 1 is as follows.

S 10 The disk 50 is driven by a motor member not shown herein, ci rotating at constant speed around the axis C and the guide walls and grooves 51, 52, 55 actuate in simultaneous and mutually identical way respectively the linear actuators 11 and the four slides 13 of the pincer assemblies 9 since they are axially symmetrical and have four identical angular sectors and the actuators 11 and the pincer assemblies 9 are angularly equidistant.

The cross-shaped body of the reticular body 2 is obtained starting from a step in which the rollers 53, 54a, 54b are in a radially extreme end stop position and the segment of metal wire is positioned in known way between the grip portions 25 according to a circular trace.

Subsequently, respective descending segments of the rolling surfaces 62 move the actuating rods 28 relative to the respective slides 13 towards the origin 10 closing the jaws 15, 15a on the wire and then advance integrally with the slides 13 travelling a shorter run than the linear actuators 11.

In this way the metal wire is bent forming the cross-shaped body in a plane that is perpendicular to the axis C after defining in continuous way a succession of closed intermediate geometric figures having rectilinear OD 8 0- sides and rounded bending vertices both at respective C junction portions between arched segments 6 and uprights CO 5 and at respective bending projections 56 exiting 00 o perpendicularly to the respective axis A from the grip portions 25 of the respective jaws 15, In particular, the vertices rounded at the jaws IND 15a are defined by portions of metal wire bend around the Sbending projections 56 and the perimeter of the ci V intermediate geometric figures can be calculated instant S 10 by instant based on the positions of the pincer ci assemblies 9 and of the linear actuators 11.

Consequently, the profiles of the rolling surfaces 61, 62 are radially and circumferentially dimensioned so the percent change in length of the perimeter of the two intermediate geometric figures remains unaltered or may vary within a margin that is smaller than the percentage of yielding or ultimate elongation of any metal wire suitable for working processes by plastic deformation.

Once the linear actuators 11 have reached a respective radial end stop towards the origin 10, damping heads 59 supported by the respective linear actuators 11 abut against a pivot 60 of axis C and the transmission 23 simultaneously actuates the four mandrels 14 which, rotating around the respective axes A, twist the wire obtaining the uprights Lastly, the jaws 15, 15a open freeing the crossshaped semi-finished product that continuous towards subsequent work processes and the pincer assemblies 9 and the actuators 11 move away from the axis C returning to the initial position.

The law of motion along the axes A, B of the slides 13 and of the linear actuators 11 is defined directly by the respective rollers 54a, 53 which roll on the C respective guide walls 52, 51 whilst the law of motion of O the opening and of the closing of the jaws 15, 15a is 00 o jointly defined by the law of motion defined by the guide groove 55 and by the law of motion defined by the guide surface 34 of the shaped portion 27 borne by the ID actuating rods 28.

o In particular, the rollers 54b impose point by point ci Vt to the respective actuating rods 28 the identical S 10 displacements defined by identical radial dimensions ci every 90 degrees on the rolling surfaces 62 actuating the jaws 15 together with the respective guide surfaces 34.

The jaws 15a, instead, co-operate with the shaped profile 35 integral with the respective actuating rod 28 and being positioned in the opening step along the concave segment 37, follow the entire concave segment 37 and then the rectilinear segment 36 until closing when they reach the rectilinear segment 38. Subsequently, the shaped portion 27 further advances until the rectilinear segments 36 impact with the planar surfaces 33 achieving the locking of the jaws 15a and actuating the spring assembly 31.

In particular, the concave segment 37 locally a slope relative to the upper axis A with respect to the angle a, allowing a shorter closing time of the jaws which close pressing on the end portions of the metal wire before the jaws The jaws 15 are actuated similarly to the manner described above, but following the guide surface 34 and during the closing phase the projection 56 is coupled with a conjugated seat borne by a grip portion opposite to the grip portion 25 having the projection 56 radially locking the segment in the radial direction.

in o 0 In this way, the jaws 15 close pressing on the metal C wire after the jaws 15a, but radially retain the wire O already when they are closing, whilst the jaws 15a retain 00 o the end portions of the wire only when the respective shaped portion 27 abuts against the actuating portions 26.

ID Moreover, the guide surface 34 and the shaped o profile 35 are therefore studied to convert the long and ci S relatively slow travel of the actuating rods 28 actuating 0 S 10 by the cam 50 into rapid and shorter displacements of the jaws 15, From an examination of the characteristics of the device according to the present invention, the advantages it allows to achieve are readily apparent.

In particular, the jaws 15a can be actuated independently from the jaws 15 to lock more rapidly the two ends which in case of excessively slow closure could escape, requiring the idling of the machine for maintenance purposes.

Moreover, the early closure of the jaws 15a stably secures the wire segment and makes more reliable the subsequent grip by the jaws 15, enhancing the precision of the subsequent work processes.

The use of a single disk cam 50 to actuate all members in alternating motion along the axes A and B allows to make very precise the phase offsets of the individual operations performed by the device 1 allowing to raise the production rate.

Use of a common cam 50 and the requirement for different laws of motion for the jaws 15 and 15a is possible thanks to the use of respective shaped portions 27 which are able to modify the common law of motion imposed by the disk cam 50 having respectively guide 0 0 ci

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Va 0 0 0 11 surfaces 34 and shaped profiles 35 differing from each other.

Moreover, both the guide surfaces 34 and the shaped profile 35 are dimensioned to obtain a rapid closure 5 reducing the slopes of the rolling surfaces 61, 62 and thus minimising wear.

The shaped portions 27 can be worked more easily and are less costly than the disk 50 and are easily replaceable enabling to correct any geometric 10 inaccuracies of the guide walls 52 by acting on the geometry of the profile, which can differ from the one described to obtain other laws of motion.

Moreover, the choice of appropriate geometry of the rolling surfaces 60, 61, 62 respectively of the guide walls and grooves 51, 52, 55 allows reliably to reach particularly low elongation values, enabling to use various types of metal wires suitable for plastic deformation work processes without breaks.

Moreover, it is clear that the device described and illustrated herein can be subject to modifications and variants without thereby departing from the scope of protection of the present invention, as defined in the accompanying claims.

Claims (6)

1. 2. Device as claimed in claim 1, characterised in that said actuating members are tappets and in that said first command profile comprises a rectilinear segment inclined by an angle relative to the respective said first axis and in that said second command profile comprises a curvilinear segment.
2. 3. Device as claimed in claim 2, characterised in that o) 13 0- said curvilinear segment is convex. c CC 4. Device as claimed in one of the claims 2 or 3, 00 o characterised in that in said open position said second pair of jaws co-operates with said curvilinear segment. Device as claimed in any of the previous claims, o characterised in that said pincer assemblies and said ci V linear actuators are movable towards said origin S 10 according to respective third and fourth law of motion ci combining which said metal wire is elongated within its ultimate elongation.
3. 6. Device as claimed in claim 5, characterised in that said metal wire is elongated within its yield elongation.
4. 7. A method for actuating a device for working semi- finished products made of metal wire as claimed in any of the previous claims, characterised in that it comprises the following steps: gripping said metal wire by a first pair of jaws; subsequent gripping said metal wire segment by at least a second pair of jaws.
5. 8. Method as claimed in claim 7, characterised in that said metal wire defines a closed geometric figure and in that said first pair of jaws grips respective ends of said metal wire.
6. 9. A method of forming semi-finished products made of metal wire, substantially as hereinbefore described with reference to the accompanying drawings. o 14 0i 10. A device for forming semi-finished products from Smetal wire, substantially as hereinbefore described with C) reference to the accompanying drawings. 00 \O ci ci