APPARATUS, MACHINE AND METHOD FOR DEFORMING THE OPPOSITE ENDS OF A PIECE OF WIRE

Abstract

 Apparatus for deforming two opposite ends (1a,1b) of a piece of wire (1) extending in a longitudinal direction (X-X), comprising a first device (1000) for forming the first end (1a) of the piece of wire (1), configured to form the first end (1a) by means of cold-deformation, such as to produce a cross-section of the first end with an area greater than the cross-section of the initial piece of wire; and a second device (2000) for forming the second end (1b) of the same piece of wire (1), configured to perform forming of the second end (1b) by means of cold-deformation such as to produce a cross-section of the formed second end greater than the cross-section of the initial piece of wire.

Description

[0001] The present invention relates to:

• a forming apparatus, in particular for cold-moulding or upsetting, the two opposite ends of a piece of wire;
• a machine for forming the two opposite ends of a piece of wire, comprising said apparatus;
• a method for forming the two opposite ends of a piece of wire.

[0002] It is known in the technical sector relating to the machining of materials that there exists the need to form, from a wire-like material, bodies, such as tools, which have at least one end with a diameter greater than the diameter of the body obtained from an initial wire; an example of such a need consists in spanners with a shaped double end having a specific form, for example a hexagonal or male star-like form, used to operate corresponding parts with a female hexagonal form (socket-head screw) or star-like form and the like.

[0003] Also known are forming/bending machines designed to machine sections of wire having a predefined length so as to deform the opposite ends thereof; said machines however have a number of drawbacks including the fact that it is not possible to shape both ends since double deformation with upsetting and enlargement of the two ends would result in the formation of undercuts which would prevent the extraction of the machined piece.

[0004] The known machines therefore envisage the formation of a first end with a diameter greater than that of the initial wire by means of a first cold-moulding upsetting operation so as to obtain the necessary increased diameter and a subsequent extrusion operation in order to obtain the final desired (for example hexagonal) form; and the formation of the second end with a diameter smaller than that of the wire by means of a corresponding extrusion operation which also defines the final form of the spanner.

[0005] Machines of this type are for example known from EP 1 018 406 B1 in the name of the same present Applicant.

[0006] These machines have limitations arising from the fact that, in order to obtain the form and the cross-sectional area of the two ends, it is necessary to extrude a wire which has a cross-sectional area appropriate for the cross-sectional area to be obtained; this involves, in order to obtain the desired characteristics of mechanical resistance, in particular to twisting and/or bending, the need to perform machining operations which start from very large diameters of the wires, with a consequent waste of material and increase in the cost of the finished product. At least three machining passes are required.

[0007] The technical problem which is posed, therefore, is to provide an apparatus which is able to machine portions of wire-shaped material in order to obtain operating spanners having both ends shaped, for example in the manner of hexagons or the like, with a cross-sectional area greater than that of the initial wire, achieving a significant reduction in the amount of initial material required and at the same time resulting in spanners which have a high mechanical resistance in particular to bending.

[0008] In connection with this problem, it is also required that this apparatus should have small dimensions, be easy and inexpensive to produce and assemble and be able to be easily installed at any user location using normal standardized connection means.

[0009] These results are obtained according to the present invention by an apparatus for forming the opposite ends of a piece of wire extending in a longitudinal direction according to the characteristic features of Claim 1.

[0010] According to a first aspect, the invention therefore relates to an apparatus for deforming opposite first and second ends of a piece of wire extending in a longitudinal direction, comprising a first device for forming the first end of the piece of wire, configured to form the first end by means of cold-deformation, such as to produce a cross-section of the first end greater than the cross-section of the initial piece of wire; and a second device for forming the second end of the same piece of wire, configured to form the second end by means of cold-deformation such as to produce a cross-section of the formed second end greater than the cross-section of the initial piece of wire.

[0011] Advantageously, the apparatus is therefore able to form the two ends with the desired final form employing only two forming steps/devices, being moreover compact and simpler and resulting in less wastage of material.

[0012] In a particularly advantageous arrangement, said first device for forming the first end and second device for forming the opposite end may be arranged alongside each other in a transverse direction perpendicular to the longitudinal direction. According to preferred embodiments, the first device for forming the first end and the second device for forming the second end each comprise a fixed die assembly and a finishing assembly which is coaxially movable in the longitudinal direction from/towards the associated die assembly from a distanced position into a position in contact with the latter.

[0013] Preferably, the first end is deformed inside the first movable finishing assembly with the finishing assembly in the position in contact with the first die assembly and the second end is deformed inside the second fixed die assembly with the first end housed inside the second movable finishing assembly which is in the position where it is in contact with the second die assembly.

[0014] Therefore, the two opposite ends may be formed by moving only the two finishing assemblies and preferably without having to adjust the orientation of the piece of wire.

[0015] By forming the first and/or the second end with the respective finishing assembly in the position in contact with the die assembly, the result is achieved that, in order to form either end, the piece of wire is contained entirely inside the finishing-die ensemble, being therefore more stable and centred during forming with a consequent smaller risk of deformations and greater machining precision. Therefore, it is possible to machine pieces with a smaller cross-section, achieve a better quality of the finished product and reduce the amount of wasted material. In particularly preferred embodiments, the second finishing assembly comprises a housing mould for housing the already formed first end of the piece of wire and a clamp arranged in front of the housing mould, the clamp being operable to close/open so as to grip the body of the piece of wire. The second die assembly comprises in turn a mould for forming the second end of the piece of wire and a die clamp, axially arranged between an inlet for the piece of wire and the die mould, which can be operated so as to close around the piece of wire. Advantageously, in the position where the second finishing assembly is in contact with the second die assembly for forming the second end of the piece of wire inside the mould of the second die assembly, the clamp of the second finisher and the die clamp are preferably in contact with each other, with the clamp of the second finisher partially inserted inside the second die assembly.

[0016] Therefore, the piece of wire is firmly retained and correctly positioned during forming of the second end, reducing further the risk of deformations and improving the machining precision and therefore the quality of the finished product.

[0017] Further preferred embodiments of the first and second devices are described in Claims 3 to 18, which are herein incorporated by reference.

[0018] The present invention relates furthermore to a forming machine according to Claim 19 and a forming method according to Claim 21.

[0019] According to a preferred embodiment of the method, the step for forming the first end comprises:

• transporting, preferably with a rectilinear translational movement in the transverse direction, a piece of wire to a coaxial position between the first finisher and the first die;
• actuating the first finisher in the longitudinal direction so as to cause the insertion in succession of the first end and of the second end of the piece inside the first finisher and the first die respectively, and the formation of the first end inside the first finisher;
• extracting the piece from the first device.

[0020] According to a preferred embodiment of the method, the step for forming the second end comprises:

• transferring - preferably with a rectilinear translational movement in a transverse direction perpendicular to the longitudinal direction - the piece to the second forming device in a coaxial position between the second finisher and the second die;
• actuating the second finisher in the longitudinal direction so as to cause the insertion in succession of the first end and of the second end of the piece respectively inside the second finisher and the second die and the forming of the second end by means of cold-deformation thereof inside a mould of the second die;
• extracting the piece with both ends formed from the second forming device. Preferably the step for forming the first end comprises:
• initial displacement of the first finisher in the longitudinal direction towards the first die with insertion of the first end 1a of the piece inside the mould of the first finisher;
• completion of the displacement of the first finisher towards the first die with entry of the second end into the first die until the mould of the first finisher comes into contact against the first die in order to define the deformation volume of the first end of the piece; and
• further displacement of the casing and the punch with respect to the mould towards the first die, operated by the actuator element, so as to cause the upsetting of the first end of the piece inside the mould by the punch and the compression of a spring arranged between the mould and a shoulder inside the casing and axially opposite to the mould;
• return of the first finisher into the initial position with the consequent movement of the casing and the mould away from the die and thrusting force in the opposite direction against the piece exerted by the punch displaced with respect to the casing and the mould by means of a pusher so as to cause the extraction of the piece from the first finisher;
• displacement of a pin of the first die towards the first finisher so as to cause the extraction of the piece from the first die, with gripping of the piece by retaining and transporting means.

[0021] According to a preferred aspect the step for forming the second end may comprise:

• transporting the piece extracted from the first forming device and positioning it in a coaxial position situated between the second finisher and the second die;
• initial displacement of the second finisher towards the second die, with insertion of the first end of the piece inside the mould of the second finisher and the second end of the piece inside the second die;
• completion of displacement of the second finisher until it comes into contact with the second die, with subsequent closing of the clamp of the second finisher and the clamp of the second die around the piece of wire;
• forming of the second end of the piece of wire inside the mould of the second die, by means of cold-deformation performed by the further displacement of the clamp of the second finisher and the clamp of the second die which axially push the piece of wire against a fixed pin, forcing the material of the second end to be deformed inside the end of the mould and to assume the corresponding desired final shape.

[0022] In the various embodiments of the invention, the cold-deformation may be in particular an upsetting operation.

[0023] Further details may be obtained from the following description of a non-limiting example of embodiment of the subject of the present invention provided with reference to the attached drawings in which:

Figure 1: shows a view cross-sectioned along a vertical plane of a first finishing assembly for forming a first end of a piece of wire;

Figure 2: shows a cross-section along a vertical plane of an auxiliary die assembly of the first assembly according to Fig. 1 for forming a first end of a piece of wire;

Figure 3: shows a cross-section along a vertical plane of a second auxiliary finishing assembly for forming a second end, opposite to the already formed end, of a piece of wire;

Figure 4: shows a cross-section along a vertical plane of a die assembly for forming the second end, opposite to the already formed end, of a piece of wire;

Figure 5: shows a cross-section along a vertical plane of two assemblies for initial forming of the first end, aligned and ready for starting the forming of the first end;

Figure 6: shows a cross-section along a vertical plane of the two assemblies for forming the second end, aligned and ready for starting the forming of the second end of the piece of wire;

Figure 7: shows a cross-section along the plane indicated by VII-VII in Fig. 2;

Figures 8a-8b: show schematic cross-sections of the clamp assembly of the second finisher, during two different actuating operations;

Figures 9a-9b: show cross-sections along a vertical plane of the assemblies according to Fig. 5, during the various steps for forming the first end of the piece of wire;

Figures 10a-10m: show cross-sections along a vertical plane of the assemblies according to Fig. 6, during the various steps for forming the second end of the same piece of wire;

Figure 11: shows a schematic cross-section of a vertically extending forming machine according to the present invention; and

Figure 12: shows a schematic cross-section of a horizontally extending forming machine according to the present invention.

[0024] As shown in Fig. 1, a longitudinal reference axis X-X, corresponding to the greater dimension of the piece of wire 1 whose opposite ends 1a,1b are to be formed, as well as a radial/transverse direction Y-Y perpendicular to the preceding direction, are assumed solely for easier description and without a limiting meaning; below adjectives such as "lower" (or "bottom") and "upper" (or "top") and will be used to identify relative positions of components of the assemblies with reference to the vertical orientations shown in the figures; it is understood that these adjectives may be modified for example with reference to a horizontal orientation as shown by way of example in Figs. 11,12.

[0025] The apparatus according to the invention comprises a first device 1000 for forming the first end 1a of a piece of wire 1, and a second device 2000 for forming the second end 1b of the same piece 1 of wire.

[0026] In detail the first device 1000 comprises:

• a first finishing assembly 1100 (below abbreviated also "first finisher") which is displaceable in the longitudinal direction X-X and designed to form the first end 1a of the piece of wire 1;
• a first assembly 1200 (below abbreviated also "first die") which is an auxiliary to the first assembly 1100 and aligned with the latter along the longitudinal axis X-X (Fig. 5) and integrally fixed to the structure of the machine.

[0027] In greater detail, the first finisher 1100 is movable in the axial/longitudinal direction X-X from a position distanced from the first die 1200, said position allowing the positioning of the piece of wire 1 between the two assemblies where it is arranged coaxially therewith, a position close to the first die 1200 where the subsequent movements for forming the first end 1a of the wire will be performed. According to the preferred example shown, the first finishing assembly 1100 comprises:

• a casing 1101 displaceable in both senses of the longitudinal direction X-X between a position distanced from the die 1200 and a position close to the latter;
  displacement of the casing may be performed by an actuator element known in the sector by the term "ram", schematically indicated by 1150 and acting on the casing 1101 by means of a coaxial plug 1160, arranged between the ram 1150 and the casing 1101 and displaceably integral with the ram 1150 and casing 1101.

[0028] The ram 1150 may in turn be moved by actuating means conventional per se and only schematically illustrated in Figs. 11 and 12.

[0029] Inside the casing in particular the following are coaxially arranged:

• a (finishing) mould 1110, projecting along the longitudinal axis X-X through an opening 1101a of the casing 1101. A free end 1111a of the mould, directed during use towards the first die 1200, is shaped with the final form - for example hexagonal form - which the first end 1a of the piece of wire must assume;
• a coaxial punch 1112, inserted inside the casing 1101 and through the mould 1110, displaceable along the longitudinal axis X-X with respect to the casing and the mould, between an extracted position and a position retracted with respect to the casing 1101;
• a piston 1130 integral with the punch 1112 and, on the opposite side to the punch 1112, with a rod 1130a.

[0030] The piston 1130 is coaxially arranged inside the casing and displaceable in both senses of the longitudinal direction X-X between a positioned distanced from the plug 1160, corresponding to the position where the punch 1112 is extracted from the casing 1101 and a position of bearing contact against the plug 1160, corresponding to the retracted position of the punch.

[0031] As will emerge more clearly below, the piston 1130 is in particular movable together with the casing so as to push against the punch 1112 during forming and in the opposite sense to the casing so as to allow the punch 1112 to return into the position extracted from the casing, following the return movement of the casing.

[0032] A spring 1140 is arranged between the mould 1110 and a shoulder 1102, inside the casing and axially opposite the mould, said spring, as will become clearer below, being designed to be compressed by a movement of the casing with respect to the mould 1111 towards the first die, when the mould is stably resting against the die 1200 during the forming step.

[0033] The ram 1150 is crossed by a through-duct 1150a which is designed to allow the coaxial insertion of a pusher 1131, movable in the longitudinal direction X-X with respect to the ram 1150 so as to act on the rod 1130a of the piston 1130 and displace it coaxially with respect to the casing 1101.

[0034] In greater detail, in the preferred embodiment shown, the plug 1160 of the casing 1101 has a through-hole such as to allow the insertion of the rod 1130a, but not the passage of the piston 1130; with this configuration, when the casing is displaced towards the first die of the ram 1150, the piston 1130 comes into bearing contact with the plug 1160 and becomes displaceably integral with the casing 1101 for the forming of the first end.

[0035] During the return of the casing into the initial position, the pusher 1132 acts against the rod 1130a of the piston, causing the relative movement thereof with respect to the casing, as far as the position distanced from the plug 1160, corresponding to the position where the punch 1112 is extracted from the casing 1101.

[0036] As shown in Fig. 2, an example of the first auxiliary assembly or first fixed die 1200 comprises:

• an outer cylinder 1201, the part of which proximal to the first finisher (at the bottom according to the orientation of the figures) houses a cylinder body 102 which is axially crossed by a coaxial through-hole 1202a with an internal diameter slightly bigger than the outer diameter of the piece 1 of wire;
• an upper sleeve 1203 (distal from the first finisher), which is axially constrained to the cylinder 1201 and which has formed inside it a coaxial duct 1203a inside which there is axially inserted a pusher 1205 prolonged by a pin 1205a extending inside the coaxial hole 1202a and coaxially movable in the longitudinal direction X-X from a position extracted at the top into a position inserted axially (Fig. 2) as far as an end-of-travel stop 1204a; as will become clear below, the extracted position of the spindle allows the coaxial insertion of the piece 1 inside the die 1200 during the forming of the first end of the piece, while the inserted end-of-travel position allows, by means of the pin 1205s, the piece 1 to be pushed out from the die 1200 by way of completion of the step for forming the first end; Preferably, the pusher 1205 has (Fig. 7) a hollow-lobe cross-section inside which axial pins 1206 are axially inserted, said pins being arranged at a uniform angular distance and being designed to keep the pin 1205a centred so as to prevent deviations due to the peak load applied during forming of the end of the wire. The pusher 1205 is displaced by an extractor 1207 which coaxially acts against the pusher 1205 on the opposite side to the pin 1205a and has a dual function: during forming it supports the axial thrust applied to the pin 1205a, keeping it fixed, while during extraction of the piece 1 it pushes against the pin 1205a so as to cause the piece to come out of the die.

[0037] As shown in Figs. 3 and 4, a preferred example of a second forming device 2000 designed to form the second end 1b of the piece of wire 1 comprises:

• a second finishing assembly 2100 - referred to below in short also as "second finisher" (Fig. 3) - for gripping the first end 1a, already formed, of the piece of wire 1, displaceable in both senses of the longitudinal direction X-X;
• a second assembly 2200 (Fig. 4) (indicated below in short also as "second die") for cold-forming the second end 1b of the piece 1, coaxially aligned with the second finisher along the longitudinal axis X-X (Fig. 6) and fixed in position integrally with the structure of the machine (Figs. 11,12).

[0038] In greater detail, the second finisher 2100 is movable from a first position coaxially spaced from the second die 2200 and designed to allow the positioning, in the transverse direction, of the piece of wire 1 between the two assemblies, into a position coaxially in contact with the second die, where insertion of the second end 1b of the piece inside the second die 2000 and the movements for forming the second end 1b of the piece 1 inside the second die 2000 will be performed.

[0039] According to a preferred embodiment of the invention, the second finisher 2100 comprises a sleeve 2101, extending coaxially between a free end directed towards the second die and a rear end which is rigidly connected to a plug 2160 for connection to the ram 2150 for performing displacement.

[0040] The sleeve 2101 has, coaxially arranged inside it, a mould 2111 inserted along the longitudinal axis X-X, a bottom part 2111b of which (distal from the second die) has a circular profile corresponding to the cross-section of a coaxial punch spindle 2120 and the free end 2111a of which (proximal to the second die) is shaped with the form - for example hexagonal form - of the first already formed end 1a which must be inserted inside the mould during forming of the second end 1b of the wire.

[0041] A clamp 2112 is coaxially arranged at the top of the mould 2110 and is inserted inside the free end (top end in the example shown) of the sleeve 2101, the jaws thereof being able to be operated so as to open/close in the radial/transverse direction Y-Y so as to clamp the cylindrical body of the piece of wire 1. In particular, the opening/closing of the clamp 2112 is controlled by means of a coaxial counter-wedge 2113, a free end of which (directed towards the second die) contains and operates said jaws and an opposite (rear) end of which is displaceably integral with the plug 2160 and therefore with the actuating ram 2150 and the sleeve 2101.

[0042] According to a preferred embodiment, the clamp 2112 is of the type with four segments 2112a (Figs. 8a, 8b) in the form of an overturned truncated cone with an inclined outer side; the segments are closed (Fig. 8a) in the radial direction by the counter-wedge 2113.

[0043] The counter-wedge 2113, in particular, moves axially towards the second die 2200 together with the clamp 2112, pushed by the ram 2150; when the counter-wedge 2113 reaches and bears against the second die, the clamp 2112 is forced to move coaxially with respect to the counter-wedge 2113 against the action of springs 2115, causing the closing of the segments which form the jaws 2112a; the reverse opening movement (Fig. 8b) of the segments is instead produced by the action of the springs 2115 which, compressed during clamping, return into the initial position following retraction of the ram and therefore the counter-wedge with respect to the open position of the jaws 2112a.

[0044] A longitudinal spindle 2120, which is coaxially inserted inside the sleeve 2101 through the clamp 2112 and the mould 2111, is movable axially with respect to the mould 2111 between a forming position, in which it is designed to form a longitudinal positioning stop for the first end 1a of the wire inside the second finisher, in particular inside the free end 2111a of the mould 2111 designed to receive the already formed first end 1a of the piece of wire 1, and an extraction position, in which it projects from the mould 2111.

[0045] A plunger 2131 coaxial with the spindle 2120 is arranged below the latter, having one end 2131a placed in contact with the spindle 2120.

[0046] The other end 2131b of the plunger is situated opposite a coaxial piston 2130, which can be operated in both senses of the longitudinal direction X-X, between a forming position where it is fixed with respect to the sleeve 2101, in particular bearing against the plunger 2160 and therefore rigidly connected to the ram 2150, so as to push against the plunger 2131 and therefore the spindle 2120 when the finisher moves towards the die during the forming step, and an extraction position, in which it is displaced towards the second die with respect to the sleeve 2101 and the ram 2150, so as to allow the return movement of the spindle 2120 into the extraction position for extraction of the piece 1 once forming has been completed.

[0047] The return movement of the piston 2130 may be produced by the movement of the sleeve 2201 away from the die 220, in cooperation with a pusher 2132 which is inserted coaxially inside a through-duct which passes through the ram 2150 so as to act on the piston 2130 and displace it coaxially with respect to the sleeve 2101 and the ram 2150.

[0048] As shown in Fig. 4, the second assembly or second, fixed, die 2200 for forming the second end 1b of the wire 1 comprises:

• a hollow cylinder 2201 which has, arranged inside it, in a position proximal to the point where the wire 1 enters into the die:
• a die clamp 2122, comprising jaws 2212a with a frustoconical profile, movable in both senses of the radial/transverse direction Y-Y and coaxially inserted inside a counter-wedge 2213 with which they cooperate by means of a relative coaxial displacement which causes closing/opening of the clamp; as will become clear below, the movements of the die jaws are produced by the finisher which is moved against the die;
• a mould 2211 for forming the second end 1b of the piece 1, a bottom part 2211a of which has a form (in the example hexagonal form) corresponding to that desired for the end to be formed, while the top part 2211c has a cylindrical hole designed to allow the sliding of a pin 2205a;
• the cylinder 2201, the mould 221 and the clamp 2212 are crossed by an axial duct 2201a which has a diameter and axial length such as to allow the entry of the piece 1 until the end 1b to be formed is arranged inside the mould 2211a.

[0049] As shown in Figs. 10c-10f, in the position where the second finishing assembly is in contact with the second die assembly, the clamp 2112 of the second finishing assembly and the die clamp 2212 are in contact with each other, with the clamp of the second finisher which is advanced so as to be partially inserted inside the second die, causing the closing of the jaws of the die clamp around the piece of wire 1, the closing of the jaws of the finisher clamp around the piece of wire 1 inside the second finisher and the displacement of the finisher-die jaws pack towards the inside of the die for forming the second end 1b of the piece of wire inside the mould 2211a of the second die assembly.

[0050] In the preferred embodiment shown, the second die assembly further comprises: an upper spacer 2203, which is axially constrained to the base of the machine and inside which a coaxial duct 2204 is formed, inside said duct there being axially slidable a pusher 2205 movable in the longitudinal direction X-X upon operation of an extractor 2204b in turn moved by external synchronized actuating mechanisms (not shown), from a position extracted at the top (not shown in the figures) into a position (Fig. 4) axially inserted as far an end-of-travel position determined by the rod 2204b by means of mechanisms of the machine (not shown). The pusher 2205 is coaxially prolonged towards the second finisher by the pin 2205a inserted and slidable inside the duct 2201a, as will become clear below, the extracted position of the pin allowing the coaxial insertion of the piece 1 inside the die and acting as a reaction stop for the forming of the second end 1b of the piece, while the inserted end-of-travel position allows the piece 1 to be pushed out of the die by way of completion of the step for forming the second end.

[0051] In the preferred embodiment described, the pusher 2205 has a cross-section with hollow lobes 2205a inside which axial pins 2206 are axially inserted, said pins being arranged at a uniform axial distance and being designed to keep the punch centred so as to avoid deformations due to the peak load applied during the forming of the end, the pusher therefore has the same configuration shown in Fig. 7.

[0052] With the configuration of the two forming devices described above it is possible to obtain the forming of the two opposite ends 1a, 1b of a piece of wire 1 according to the method which comprises the steps of:

Forming of the first end:

[0053] 

• transporting in the transverse direction a piece of wire 1, for example cut beforehand from a continuous wire, into a coaxial position situated between the first finisher 1100 and the first die 1200 (Fig. 9a), preferably with a rectilinear translational movement performed by gripping and transport devices (not shown);
• inserting in succession the first end 1a and second end 1b of the piece 1 inside the first finisher 100 and inside the first die 1200 respectively;
• forming the first end 1a inside the first finisher 1100;
• extracting the piece 1 from the first device.

Forming of the second end:

[0054] 

• transferring - preferably with a rectilinear translational movement performed by gripping and transport means (not shown) - the piece 1 to the second forming device into a coaxial position between the second finisher 2100 and the second die 2200;
• inserting in succession the piece 1 into the second finisher 2100 and into the second die 2200;
• cold-forming the second end 1b, preferably by means of upsetting of the same, inside the mould 2211 of the second die 2200;
• extraction and release of the piece 1 with both ends formed.

[0055] In detail:

STEP 1

[0056] 

1.1

transporting (Fig. 9a) a piece of wire 1 into the coaxial position between the first finisher 1110 and the first die 1200;

1.2

initial displacement (Fig. 9a) of the first finisher 1100 in the longitudinal direction X-X towards the first die and insertion of the first end 1a of the piece 1 inside the mould 1111a of the first finisher;

1.3

completion (Fig. 9c) of the displacement of the first finisher 1100 towards the first die 1220 with entry of the second end 1b into the first die until the mould 1111,1111 a of the first finisher is closed in the longitudinal direction against the first die (Fig. 9c) in order to define the deformation volume of the first end 1a of the piece 1;

1.4

further displacement of the casing 1101 with respect to the mould 1111 towards the first die 1200, with operation of the punch 1112 by means of the piston 1130 in turn pushed by the ram 1150 - plug 1160 chain so as to perform upsetting of the first end 1a of the piece (Fig. 9a) inside the mould 1111 and compression of the spring 1140;

1.6

return of the first finisher 1100 (Fig. 9e) into the initial position with the consequent movement of the casing 1101 and the mould 111 away from the die 1200 and the pushing force against the piece 1 exerted by the punch 1112 in turn moved with respect to the casing and the mould by the piston 1130 pushed by the pusher 1132;

1.7

displacement of the pusher 1205 and the pin 1205a of the first die towards the first finisher 1100 and the start of extraction of the piece 1 from the first die 1200 with gripping of the piece by retaining means (not shown) designed to prevent it from falling;

1.8

completion of the displacement of the pusher 1205 as far as the end-of-travel stop 1204a and complete extraction of the piece 1 from the die 1200;

STEP 2

[0057] 

2.1

arrival inside the second forming assembly (Fig. 10a) of the piece 1 exiting the first forming assembly and positioning of the piece in a coaxial position between the second finisher 2100 and the second die 2200;

2.2

start of displacement (Fig. 10b) of the second finisher 2100 towards the second die 2200, with insertion of the first end 1a of the piece 1 inside the mould 2111a of the second finisher;

2.3

displacement of the second finisher until it comes into contact with the second die 2200, with closing of the clamp 2112 (Fig. 10c) of the second finisher and of the clamp 2212 of the second die around the piece of wire and cold-forming of the second end 1b of the piece of wire inside the mould of the second die 2200. In detail:
during the displacement of the finisher towards the die 2200, the clamp of the finisher enters inside the second die; in particular, the top end of the counter-wedge 2113 enters coaxially into the rear end of the sleeve 2202 and the top end of the finisher clamp enters coaxially into the rear end of the sleeve 2201 until it comes into contact with the clamp of the die; when the jaws of the finisher clamp come into contact with the jaws of the die clamp, the advancing movement of the finisher towards the inside of the die causes:

• pushing of the finisher clamp jaws against the jaws of the die clamp, which are moved axially inside the counter-wedge 2213, causing the jaws of the die clamp to close around the piece of wire 1;
• at the same time, owing to the reaction effect, the jaws of the finisher are pushed inside the associated counter-wedge 2113, which results in closing of the jaws around the piece of wire 1 inside the second finisher;
• when the jaws of the finisher clamp reach the bottom of the associated counter-wedge, the relative travel of the clamp with respect to the counter-wedge is stopped in the clamping position of the jaws;
• when the jaws of the die reach the bottom of the associated counter-wedge 2213, the finisher continues its travel towards the inside of the die, causing the displacement of the closed jaws, together with the said counter-wedge 2213, with consequent compression of the spring 2215;

2.4

the displacement of the finisher/die jaws assembly, closed inside the respective counter-wedges, towards the inside of the die, transports the piece 1 towards the pin 2205a, which has a fixed position, since it rests on the pusher 2205 in turn resting on the extractor 2204b, in the extracted forming position;

2.5

when the end 1b of the piece comes to rest against the fixed pin 2205a, while the piece continues to advance, the material of the end 1b, which is situated inside the end of the mould 2211a with the desired final form, is forced to deform so as to occupy the entire empty volume available, assuming the desired final form;
continuing its axial pushing action, the finisher forces the clamp to move the counter-wedge along with it, against the thrusting action of the spring 2215, forcing also the mould 221 to be displaced, against the thrusting action of a second concentric spring 2211b, which ensures the contact between mould and jaws 2212a of the clamp;

2.6

the actions described allow therefore the axial upsetting thrust be exerted on the wire 1, causing the movement of material which is forced to fill the mould 2211a of the second die with consequent deformation of the end 1b which assumes the desired final form (e.g. hexagonal form);

2.7

once the upsetting operation has been completed, the second finisher starts to return into the initial position, distanced from the second die, causing the die counter-wedge to return into the initial position with freeing of the jaws of the clamp 2212 which are pushed by the spring 2215 so as to open again, resuming the initial position;

2.8

the return of the second finisher 2100 (Fig. 10i) into the initial position also causes the opening of the clamp 2112 of the second finisher and the separation of the finisher from the wire 1;

2.9

completion of the return movement of the second finisher into the initial position (Fig. 10i) and gripping by the means (not shown) for transporting the section of the piece 1 projecting from the second die in order to prevent the uncontrolled falling thereof;

2.10

pushing of the extractor 2204 against the pusher 2205 (Fig. 10m) as far as the end-of-travel stop 2204a and completion of extraction of the piece 1 from the die 2200 retained by the said gripping means;

2.11

extraction of the piece 1 and transfer thereof to the following machining stages.

[0058] With the configuration described above of the two devices 1000 and 2000 for forming the opposite ends 1a, 1b of a piece of wire 1 and respectively comprising a first finisher 1100 and a first die 1200 and a second finisher 2100 and a second die 2200, it is possible to realize a rectilinear machine (Figs. 11,12) inside which it is possible to perform the two forming steps in succession, with transfer of the piece 1 from the first device 1000 to the second device 2000 by means of gripping and transport means, conventional per se and not shown, which may also be configured to release the piece of wire following the initial insertion into the finisher and into the die and free the area between finisher and die, in order to allow contact between them for forming.

[0059] It is therefore clear how the apparatus and the machine according to the invention are suitable for the production, with a small number of forming steps, of tools from a piece of wire, the two opposite ends of which have a cross-sectional area greater than the cross-sectional area of the initial wire, said area being able to be kept at a minimum value in relation to the forces, in particular flexing and/or twisting forces, which the finished tool must withstand during use.

[0060] All of this favours a reduction in the amount of wasted material and the final production costs.

[0061] Although described in connection with a number of embodiments and a number of preferred examples of implementation of the invention, it is understood that the scope of protection of the present patent is determined solely by the claims below.

Claims

1. Apparatus for deforming two opposite ends (1a,1b) of a piece of wire (1) extending in a longitudinal direction (X-X), comprising a first forming device (1000) for forming the first end (1a) of the piece of wire (1), configured to form the first end (1a) by means of cold-deformation such as to produce a cross-section of the first end with an area greater than the cross-section of the initial piece of wire; and a second forming device (2000) for forming the second end (1b) of the same piece of wire (1), configured to perform forming of the second end (1b) by means of cold-deformation such as to produce a cross-section of the formed second end greater than the cross-section of the initial piece of wire.

2. Apparatus according to Claim 1, characterized in that said first forming device (1000) for forming the first end (1a) and second forming device (2000) for forming the opposite end (1b) are arranged side-by-side in a transverse direction perpendicular to the longitudinal direction (X-X) of extension of the piece (1).

3. Apparatus according to Claim 1 or 2, characterized in that said first device (1000) for forming the first end (1a) and second device (2000) for forming the second end (1b) each comprise a fixed die assembly (1200,2200) and a finishing assembly (1100;2100), each finishing assembly being coaxially movable in the longitudinal direction from/towards the associated die assembly from a distanced position into a position in contact with the latter.

4. Apparatus according to Claim 3, characterized in that said first finishing assembly (1100) comprises:

a casing (1101) displaceable in both senses of the longitudinal direction (X-X) between a position distanced from the die (1200) and a position close to the latter;

inside the casing there being arranged a mould (1110) for forming the first end (1a) of the piece of wire, a free end (111a) of which, arranged for contact with the first die (1200), is shaped with a desired final form for the first end (1a) of the wire.

5. Apparatus according to the preceding claim, wherein the following are arranged inside the casing and coaxially with the mould (1110) for forming the first end:

- a coaxial punch (1112), inserted inside the casing (1101) and through the mould (1110), displaceable along the longitudinal axis (X-X) with respect to the casing and the mould, between an extracted position and a retracted position relative to the casing (1101);

- a piston (1130) displaceably integral with the punch (1112) and, on the opposite side to the punch (1112), with a rod (1130a); the piston (1130) is arranged and configured to be displaced in the longitudinal direction (X-X) with the casing so as to push against the punch (1112) during forming of the first end (1a), and so as to move in the opposite sense to the casing in order to allow the return movement of the punch (1112) to the extracted position relative to the casing, following a return movement of the casing.

6. Apparatus according to Claim 3, 4 or 5, comprising:

- a spring (1140) designed to be compressed by the movement of the casing of the first finishing assembly relative to the mould (1111) towards the first die (1200) and arranged between the mould (1110) and a shoulder (1102) situated inside the casing and axially opposite to the mould;

and/or

- an actuator element (1150) for displaceably actuating the casing (1101), preferably comprising a ram acting on the casing (1101) by means of a coaxial plug (1160), arranged between the ram (1150) and the casing (1101) and displaceably integral with the ram (1150) and the casing (1101), wherein optionally the piston (1130) is displaceable in both senses of the longitudinal direction (X-X) between a position distanced from the plug (1160), corresponding to the position where the punch (1112) is extracted from the casing (1101), and a position where it bears against the plug (1160), corresponding to the retracted position of the punch;

wherein, optionally, the first finisher comprises a pusher (1131), movable coaxially in the longitudinal direction (X-X) with respect to the casing (1101) so as to act on the rod (1130a) of the piston (1130) in order to displace it coaxially with respect to the casing (1101); the pusher being preferably coaxially insertable inside a through-duct (1150a) passing through the actuator element for actuating the casing, in particular through the ram (1150) and the plug (1160).

7. Apparatus according to one of Claims 3-6, characterized in that said first die assembly comprises:

- an outer cylinder (1201) with a part proximal to the first finisher, inside which there is housed a cylindrical body (1201) axially crossed by a coaxial hole (1202a) for insertion of the piece of wire (1);

- a sleeve (1203), distal from the first finisher and axially constrained to the outer cylinder (1201), which has formed inside it a coaxial duct (1203a) inside which there is axially inserted a pusher (1205) prolonged by a pin (1205a) extending inside the hole (1201a) and coaxially movable in the longitudinal direction (X-X) from an extracted position into a position inserted axially as far as an end-of-travel stop (1204a).

8. Apparatus according to Claim 7, characterized in that the pusher (1205) has a cross-section with hollow lobes (1203a) which have, axially inserted inside them, axial pins (1206) which are arranged at a uniform angular distance and are designed to keep the pin (1052) centred during forming of the wire end.

9. Apparatus according to one of Claims 3-8, characterized in that said second finishing assembly (2100) comprises:

-- a mould (2111) for housing the first end (1a) of the piece of wire, a front end (2111a) of which directed towards the second die is shaped with the final form of the already formed first end (1a);

-- a clamp (2112) arranged in front of the mould (2111), with jaws which can be operated so as to open/close in order to grip the cylindrical body of the piece of wire (1).

10. Apparatus according to the preceding claim, characterized in that said second finishing assembly (2100) comprises a sleeve (2101) extending coaxially between a free end directed towards the second die and a rear end which is displaceably integral with an actuator element for displaceably actuating the sleeve (2101), in particular rigidly connected to a plug (2160) connected to a ram (2150),
wherein the following are coaxially arranged inside the sleeve (2101):

-- the mould (2111) housing the first end (1a) of the piece of wire, and

-- the clamp (2112) arranged at the top in front of the mould (2110) and inserted inside the free end of the sleeve (2101).

11. Apparatus according to the preceding claim, characterized in that said second finishing assembly (2100) comprises a longitudinal spindle (2120), coaxially inserted inside the sleeve (2101) through the clamp (2112) and the mould (2111) and movable axially with respect to the mould (2111) between a forming position, in which it is designed to form a longitudinal positioning stop for the first end (1a) of the wire (1) inside the mould (2111), and an extraction position, in which it projects from the mould (2111).

12. Apparatus according to the preceding claim, wherein the second finisher also comprises a plunger (2131) coaxial with the spindle (2120), with a first end (2131a) making contact with the spindle (2120) and a second end (2131b) situated opposite a coaxial piston (2130), which can be operated in both senses of the longitudinal direction (X-X) between: a forming position in which it is displaceably fixed with respect to the sleeve (2101) and the actuator element, in particular bearing against the plug (2160) and therefore rigidly connected to the ram (2150), so as to press against the plunger (2131) and therefore the spindle (2120) when the finisher moves towards the die during the forming step; and an extraction position, in which it is displaced towards the second die with respect to the sleeve (2101), so as to move the spindle (2120) into the extraction position when the sleeve (2101) moves away from the die (2200) once forming has been completed;
and wherein, optionally, the second finisher also comprises a pusher (2132) which is coaxially inserted inside a through-duct which crosses the actuator element (2150) so as to act on the piston (2130) in order to displace it coaxially with respect to the sleeve (2101) and the actuator element (2150).

13. Apparatus according to one of Claims 9-12, characterized in that the clamp (2112) of the second finishing assembly (2100) is operable so as to open/close by a coaxial counter-wedge (2113), a free end of which directed towards the second die contains and operates the jaws of the clamp (2112) and an opposite end of which is displaceably integral with the actuator element (2150;2160) for displaceably actuating the sleeve (2101);
wherein, optionally, the jaws of the clamp (2112) are formed by four segments (2112a) in the form of an overturned truncated cone with inclined outer side, the segments being able to be closed in the radial direction by a displacement of the clamp (2112) with respect to the counter-wedge (2113) against the action of springs (2115); wherein the opening movement of the segments is caused by the action of the springs which, compressed during clamping, return into the initial position following displacement of the counter-wedge (2113) with respect to the clamp (2112) in the opposite direction to the closing direction.

14. Apparatus according to one of Claims 3-13, characterized in that said second die assembly comprises:

-- an inlet for the piece of wire (1);

-- a mould (2211) for forming the second end (1b) of the piece of wire (1), having a part (2211a) proximal to the inlet which has a form corresponding to the final form required for the second end to be formed;

-- a die clamp (2212), axially arranged between the inlet for the piece of wire and the mould (2211) and the mould (2211) and operable so as to close around the piece of wire;

-- a coaxial duct (2201a) which crosses the mould (2211) and the clamp (2212) and has a diameter and axial length such as to allow entry of the piece (1) until the second end (1b) to be formed is arranged inside the mould (2211).

15. Apparatus according to the preceding claim, when dependent on one of Claims 9-13, wherein in the position where the second finishing assembly is in contact with the second die assembly for forming the second end (1b) of the piece of wire (1) inside the mould (2211) of the second die assembly, the clamp (2112) of the second finishing assembly (2112) and the die clamp (2212) are in contact with each other, with the clamp of the second finishing assembly partially inserted inside the second die assembly.

16. Apparatus according to Claim 14 or 15, characterized in that said second die assembly further comprises:

-- a hollow cylinder (2201) inside which the following are arranged:

-- the die clamp (2212);

-- the mould (2211) for forming the second end (1b) of the piece (1) of wire, a part (2211c) of which distal from the inlet has a cylindrical hole suitable for slidably receiving a pin (2205a);

-- the coaxial duct (2201a) which crosses the cylinder (2201), the mould (2211) and the clamp (2212);

-- an axially stationary top spacer (2203) which has, formed inside it, a further coaxial duct (2204) inside which there is axially slidable a pusher (2205) movable in the longitudinal direction (X-X) upon operation of an extractor (2204b) from an axially extracted position into an axially inserted position; the pusher (2205) is coaxially prolonged towards the second finisher by a pin (2205a) inserted and slidable inside the coaxial duct (2201a) from an extracted position designed to allow the coaxial insertion of the piece (1) inside the die (2200) and act as a reaction stop for the formation of the second end (1b) of the piece, into an end-of-travel inserted position designed to push the piece (1) out of the die by way of completion of the end forming step.

17. Apparatus according to one of Claims 14-16, wherein the die clamp (2212) comprises jaws (2212a) movable in both senses of a radial/transverse direction (Y-Y) for closing the clamp onto the piece of wire, the jaws (2212a) having preferably a frustoconical profile and being coaxially inserted inside a counter-wedge (2213) with which they cooperate in order to close the clamp.

18. Apparatus according to one of Claims 16-17, wherein the pusher (2205) has a cross-section with hollow lobes which have, axially inserted inside them, axial pins (2206) which are arranged at a uniform angular distance and are designed to keep the pin (2205a) centred during forming of the second end (1b).

19. Machine for forming the two opposite ends (1a,1b) of a piece of wire (1), characterized in that it comprises a deformation apparatus according to one of the preceding claims.

20. Machine according to the preceding claim, characterized in that it comprises means (1150) for actuating the first and second finishers acting on an actuator element (1150;2150) for displaceably actuating each finisher.

21. Method for forming the two opposite ends (1a,1b) of a piece of wire (1) extending in a longitudinal direction, by means of a machine according to Claim 19 or 20 comprising the following steps:

- forming, by means of cold-deformation, in particular upsetting, a first end (1a) of the piece of wire (1), by means of the first forming device (1000) which performs a cold-deformation of the first end (1a) such as to produce a cross-section of the first end with an area greater than the cross-section of the initial piece of wire; and

- forming, by means of cold-deformation, in particular upsetting, the second end (1b) of the piece of wire (1), by means of the second forming device (2000) which performs cold-deformation of the second end (1b) so as to produce a cross-section of the formed second end which is greater than the cross-section of the initial piece of wire.

22. Forming method according to the preceding claim, wherein the machine comprises an apparatus according to one of Claims 3-18 and wherein:

the step for forming the first end comprises:

- transporting, preferably with a rectilinear translational movement in the transverse direction, a piece of wire (1) into a coaxial position situated between the first finisher (1100) and the first die (1200);

- actuating the first finisher in the longitudinal direction (X-X) so as to cause the insertion in succession of the first end (1a) and the second end (1b) of the piece (1) inside the first finisher (1100) and inside the first die (1200), respectively, and the forming of the first end (1a) inside the first finisher;

- extracting the piece (1) from the first device (1000); and/or

the step for forming the second end comprises:

- transferring - preferably with a rectilinear translational movement in a transverse direction perpendicular to the longitudinal direction (X-X) - the piece (1) to the second forming device (2000) in a coaxial position between the second finisher (2100) and the second die (2200);

- actuating the second finisher in the longitudinal direction so as to cause the insertion in succession of the first end (1a) and the second end (1b) of the piece (1) inside the second finisher (2100) and the second die (2200), respectively, and the formation of the second end (1b) by means of cold-deformation thereof inside a mould (2211) of the second die (2200);

- extracting the piece (1) with both ends formed from the second forming device.

23. Method according to Claim 21 or 22, characterized in that the first end of the piece of wire is deformed inside the first finishing assembly, with the finishing assembly in the position in contact with the first die assembly, and the second end is deformed inside the second fixed die assembly, with the first end housed inside the second movable finishing assembly which is in the position in contact with the second die assembly.

24. Method according to Claim 22 or 23, characterized in that the step for forming the first end (1a) comprises:

- initial displacement of the first finisher (1100) in the longitudinal direction (X-X) towards the first die with insertion of the first end (1a) of the piece (1) inside the mould (1111a) of the first finisher;

- completion of displacement of the first finisher (1100) towards the first die (1200) with entry of the second end (1b) into the first die until the mould (1111,1111a) of the first finisher comes into contact against the first die in order to define the deformation volume of the first end (1a) of the piece (1);

- further displacement of the casing (1101) and the punch (1112) with respect to the mould (1111) towards the first die (1200), operated by the actuator element (1150;1160), so as to perform the upsetting of the first end (1a) of the piece inside the mould (1111) by the punch (1112) and the compression of a spring (1140) arranged between the mould (1111) and a shoulder (1102) inside the casing and axially opposite to the mould;

- return of the first finisher (1100) into the initial position with the consequent movement of the casing (1101) and the mould (1111) away from the die (1200) and a pushing force in the opposite direction against the piece (1) exerted by the punch (1112) displaced with respect to the casing and the mould by means of a pusher (1132) so as to cause the extraction of the piece from the first finisher (1100).

- displacement of a pin (1205a) of the first die towards the first finisher (1100) so as to perform the extraction of the piece (1) from the first die (1200), with gripping of the piece by retaining and transporting means; and/or in that the step of forming the second end (1a) comprises:

- transporting the piece (1) extracted from the first forming assembly and positioning it in a coaxial position situated between the second finisher (2100) and the second die (2200);

- initial displacement of the second finisher (2100) towards the second die (2200), with insertion of the first end (1a) of the piece (1) inside a mould (2111a) of the second finisher and insertion of the second end (1b) of the piece inside the second die (2200);

- completion of displacement of the second finisher until it comes into contact with the second die (2200), with subsequent closing of a clamp (2112) of the second finisher and a clamp (2212) of the second die onto the piece of wire (1);

- forming of the second end (1b) of the piece of wire inside the mould (2211) of the second die (2200), by means of cold-deformation performed by the further displacement of the clamp (2112) of the second finisher and the clamp (2212) of the second die which axially push the piece of wire (1) against a fixed pin (2205a), forcing the material of the second end (1b) to be deformed inside the end of the mould (2211a) and assume the corresponding desired final shape.

Drawing