LAYING HEAD

Abstract

A coil-forming head, defining a longitudinal axis, for forming coils of a substantially rectilinear metallic product, comprising a fixed supporting structure, a rotor, adapted to turn about said longitudinal axis and rotatably fixed to said supporting structure, wherein the rotor comprises a bell-shaped member, which expands outwards with respect to said axis and has an outer surface thereof provided with at least one spiral-shaped groove, dimensioned to convey and form coils of a metallic product having diameter from 5 to 8 mm, and comprises at least one spiral-shaped tube, arranged inside and integrally fixed to said bell-shaped member, and dimensioned to convey and form coils of a metallic product having a diameter from 8 to 25 mm, wherein feeding means are provided to feed the product to said at least one groove or to said at least one tube.

Claims

1. A coil-forming head, defining a longitudinal axis X, for forming coils of a substantially rectilinear metallic product, comprising a fixed supporting structure, a rotor, adapted to turn about said longitudinal axis X and rotatably associated to said supporting structure, wherein the rotor comprises a bell-shaped member, which expands outwards with respect to said longitudinal axis X and has an outer surface thereof provided with at least one spiral-shaped groove, dimensioned to convey and form coils of a metallic product having a first diameter, and at least one spiral-shaped tube, arranged inside and integrally fixed to said bell-shaped member, and dimensioned to convey and form coils of a metallic product having a second diameter greater than said first diameter, wherein there are provided feeding means to feed the metallic product to said at least one groove or to said at least one tube.

2. A coil-forming head according to claim 1, wherein said feeding means comprise a single selector device, provided with at least one first inner conduit for guiding the metallic product to the inlet of said at least one spiral-shaped tube, and with at least one second conduit for guiding said metallic product to the inlet of a respective spiral-shaped groove on the bell-shaped member, said single selector device being adapted to be rotated with respect to the bell-shaped member to guide said metallic product to the inlet of a respective spiral-shaped groove on the bell-shaped member or to the inlet of said at least one tube.

3. A coil-forming head according to claim 1, wherein the feeding means comprise a first selector device, provided with a first inner conduit to guide the metallic product to the inlet of a respective spiral-shaped groove on the bell-shaped member, and a second selector device, provided with a second inner conduit for guiding the metallic product to the inlet of said at least one spiral-shaped tube.

4. A coil-forming head according to claim 3, wherein said first selector device and said second selector device are alternatively arranged coaxially to the longitudinal axis X.

5. A coil-forming head according to claim 3, wherein when the first selector device is aligned with the longitudinal axis X, the inner conduit has an outlet stretch which diverges from the longitudinal axis X to guide the metallic product to the inlet of one of the spiral-shaped grooves of the bell-shaped member, whereas when the second selector device is aligned with the longitudinal axis X, the second inner conduit has a rectilinear axis coinciding with the longitudinal axis X.

6. A coil-forming head according to claim 4, wherein when the first selector device is aligned with the longitudinal axis X, the inner conduit has an outlet stretch which diverges from the longitudinal axis X to guide the metallic product to the inlet of one of the spiral-shaped grooves of the bell-shaped member, whereas when the second selector device is aligned with the longitudinal axis X, the second inner conduit has a rectilinear axis coinciding with the longitudinal axis X.

7. A coil-forming head according to claim 1, wherein said feeding means comprise a single selector device, provided with an inner conduit for guiding the metallic product and adapted to be inclined and possibly turned to guide said metallic product to an inlet of a respective spiral-shaped groove on the bell-shaped member or to an inlet of said at least one spiral-shaped tube.

8. A coil-forming head according to claim 1, wherein the bell-shaped member coaxially cooperates with a mandrel adapted to contain said feeding means within it.

9. A coil-forming head according to claim 1, wherein said bell-shaped member is substantially hollow truncated-cone-shaped and provided with a substantially cylindrical end stretch within which an end stretch of said spiral-shaped tube is arranged.

10. A coil-forming head according to claim 1, wherein said bell-shaped member is made of at least two stages arranged mutually in sequence along the longitudinal axis X so that outer surfaces of said stages, provided with spiral-shaped grooves, jointly define the outer surface of the bell-shaped member and can be arranged, by turning at least one stage about said longitudinal axis X, in at least one respectively relative angular position so as to define at least one continuous spiral-shaped path for said metallic product along the entire outer surface of the bell-shaped member.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0027] Further features and advantages of the present invention will be apparent in light of the detailed description of preferred, but not exclusive, embodiments, of a laying head illustrated by the way of non-limitative example, with reference to the accompanying drawings, in which:

[0028] FIG. 1 is a side view of a laying head according to the invention;

[0029] FIG. 2 is a front view of the laying head according to the invention;

[0030] FIG. 3 is a section view of a laying head, along section A-A of FIG. 2.

[0031] The same reference numbers and letters in the figures refer to the same elements or components.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

[0032] With reference to the figures, the laying head which is the object of the present invention is shown. In particular, in FIG. 3, the laying head is shown along a section plane A-A passing through longitudinal axis X.

[0033] The laying head comprises: [0034] a fixed supporting structure, for example a basement or a casing, [0035] and a rotor 1, adapted to turn about said longitudinal axis X and rotatably associated, for example by means of bearings, to said supporting structure.

[0036] The rotor 1 in turn comprises a mandrel and a substantially truncated-cone-shaped bell-shaped member 6, which expands outwards with respect to the longitudinal axis X and axially cooperates with the mandrel. The bell-shaped member 6 is provided with a plurality of substantially spiral-shaped grooves 8, 9, 10 (FIGS. 1 and 3) or channels on its outer surface to guide the metallic product for forming the coils.

[0037] The spiral-shaped grooves of the bell-shaped member 6 are advantageously dimensioned to convey and coil a metallic product having a first predetermined diameter, preferably comprised between 5 to 8 mm, e.g. a wire rod. Preferably, the radius of the grooves may vary from 8 to 20 mm.

[0038] The bell-shaped member 6 is substantially hollow truncated-cone-shaped and has a substantially cylindrical end stretch. In such an end stretch, the grooves form a single cochlea, the pitch of which is regulated by the number of grooves made on the bell itself.

[0039] In particular, the mandrel, preferably shaped as a hollow cylinder, is stably connected by means of mechanical coupling, to the bell-shaped member 6 according to axis X. The bell-shaped member 6 is inserted in the mandrel for an initial stretch and is inserted in a housing, the shape of which mates with that of said bell-shaped member 6. Preferably, the housing is truncated-cone-shaped. The housing is integral with the base or the casing of the laying head and is thus fixed, i.e. not rotatable. A small gap is left between the bell-shaped member 6 and the housing, e.g. at least 1 mm, which is in general sufficient to allow the relative rotation of the bell-shaped member 6 about axis X without causing interference or sliding against the housing. Preferably, such a clearance is smaller than the thickness of the metallic product to be coiled. The mandrel turns in the casing, fixed to the ground. The mandrel is rotationally associated to said casing by means of bearings. The casing may be entirely monolithic with the housing.

[0040] According to a preferred variant, the housing may be opened so as to allow access to the bell-shaped member 6.

[0041] According to another variant, the housing may be sliding along the axis X with respect to the bell-shaped member 6 to be able to vary the gap between the housing and the bell-shaped member itself.

[0042] The function of the housing is to contain the head and the tail of the piece of product to be coiled, which would otherwise tend to be ejected from the laying head by the centrifuge force. Thus, the housing acts as containing and protecting member. The fact of having a rotating bell with grooves open externally towards the housing has the advantage that the tail of the rolled product is braked, by the friction produced by the sliding against the inner surface of the housing, on the entire length of said housing. In this manner, when the tail arrives on the cochlea placed on the end of the bell-shaped member 6, the metallic product does not expand and is not thrown by a whiplash effect, so that perfect coils are obtained without defects. Furthermore, the presence of the housing makes it possible to obtain a better heat distribution of the head in the laying head. Indeed, the housing is uniformly heated on its entire surface by radiation by virtue of the combined action of the rotation of the rotor and the sliding of the rolled metallic product in the groove engaged each time. The bell-shaped member 6, instead, is subject to a non-symmetric heating by conduction of the rolled product which runs in the employed groove, but the radiation of the housing towards the inner bell-shaped member 6 makes it possible to decrease and compensate for such lack of heat uniformity. Furthermore, the reverberated heat of the coils unloaded onto the belt also contributes to a better uniformity of the temperature in the bell-shaped member 6. Thus, the heat deformations are uniformly and symmetrically distributed, with further benefits on the dynamic balancing of the laying head.

[0043] Advantageously, the mandrel contains inside feeding means of the metallic product to at least one of the grooves present on the bell-shaped member 6.

[0044] The rotor 1 of the laying head of the invention advantageously comprises at least one at least partially spiral-shaped tube 21 in the bell-shaped member 6.

[0045] Such tube 21 is integrally fixed to said bell-shaped member 6 and is advantageously dimensioned to convey and coil a metallic product, for example a rod, having a second predetermined diameter, preferably comprised between 8 and 25 mm, greater than said first predetermined diameter. Preferably, the inner diameter of the tube 21 may be comprised between 20 and 50 mm.

[0046] Supporting rings 22 are preferably envisaged, fixed to the inner surface of the bell-shaped member 6 and arranged coaxial to the axis X, for fixing the tube 21 to the bell-shaped member itself. The fixing means used to fix the tube 21 to the supporting rings 22, or directly to the inner surface of the bell-shaped member 6, are for example clamps 23. However, other suitable fixing means of the tube may be used.

[0047] The bell-shaped member 6 may be formed by two or three stages or parts. The end stage or part 10 comprises a substantially cylindrical end stretch of the bell-shaped member 6 in which a tube end stretch 21 is arranged, provided with the outlet section of the spiral-shaped metallic product. The outlet section of the end stretch of the tube 21 may be in the end stretch of the bell-shaped member 6 or external to said bell-shaped member 6.

[0048] The tube 21 has an inlet axis coaxial to the rolling line X and the outlet axis tangent to the nominal theoretical diameter of the coils which are formed in sequence.

[0049] A further supporting ring 24 is preferably provided, fixed inside the end opening of the bell-shaped member 6 and arranged coaxial to the axis X. The ring 24 is only used to block the end part of the tube 21 and is shaped to guarantee that the metallic product has an advancement movement.

[0050] A variant of the invention (FIGS. 1-3) envisages a single selector device 5 configured to be rotated about axis X. In particular, the selector device 5 is configured to be rotated with respect to the bell-shaped member 6. In other words there can be a relative rotation of the selector device 5 with the respect to the bell-shaped member 6. The selector device 5 is provided with at least one inner conduit 5 which can communicate with tube 21, and with at least one inner conduit 25 which can communicate with a groove of the bell-shaped member 6. Thereby, the selector device 5 can guide, by means of a respective inner conduit 25, the metallic product to the inlet of a respective groove on the bell-shaped member 6 or can guide, by means of a respective inner conduit 5, the metallic product to the inlet of said tube 21, according to the size of the product to be coiled. Preferably, a stretch of the inner conduit 5, which is distal from the bell-shaped member 6, lies on axis X and a stretch of the inner conduit 5, which is proximal to the bell-shaped member, is inclined with respect to axis X.

[0051] A main control is provided connected to the mandrel to feed the bell-shaped member 6 rotatably about axis X, e.g. by means of a reducer or equivalent means. The selector device turns always synchronously with the bell-shaped member 6 and the mandrel during the transit of the rolled product. The selector device may preferably receive the motion of the mandrel itself by means of a differential timing system, for example.

[0052] In this variant, two or more tubes 21 are present arranged symmetrically and radially in order to balance the centrifugal forces deriving from the rotation speed of the laying head in order to allow a rapid replacement of the worn tube.

[0053] Preferably, the bell-shaped member 6 is made in three substantially truncated-cone-shaped stages 8, 9, 10 arranged joined and mutually in succession along the longitudinal axis X so that their outer surfaces, provided with respective spiral-shaped grooves 8, 9, 10, jointly define the outer surface of the member 6. Furthermore, the greatest common divisor of the group of the number of spiral-shaped grooves of each stage is preferably equal to the number of spiral-shaped grooves 8, defined first number, of a first end stage 8 of the bell-shaped member 6, proximal to the feeding means 5, i.e. to the selector device 5.

[0054] A second end stage 10, distal from said feeding means 5, is provided with a second number of spiral-shaped grooves 10, which is either equal to or multiple of said first number of grooves 8, on an outer surface thereof. Said second end stage 10 of the bell-shaped member 6 has a substantially cylindrical end stretch, in which said second number of spiral-shaped grooves 10 may cover about a round angle, and in which the number of grooves 10 is preferably moderate, e.g. equal to or no more than double the number of grooves 8, because said grooves must preferably have a very small pitch.

[0055] As mentioned, one intermediate stage 9 is also envisaged, arranged between said first 8 and second 10 end stages and provided on its outer surface with a respective number of spiral-shaped grooves 9 which is advantageously a multiple of said first number of grooves 8.

[0056] The number of grooves of two adjacent stages may be advantageously different, in particular if it is geometrically feasible to make an adequate number of grooves on the two stages, or may be equally advantageously the same if, for example, the grooves of the two stages are subject to different wear, and thus have different durations, because of their position.

[0057] Angular positioning means are provided to adjust the angular position of one stage with respect to the next. In a possible variant, said angular positioning means are preferably at least one connection pin provided in at least one of two adjacent stages forming the bell-shaped member 6. Envisaging the bell-shaped member 6 in stages makes it also possible to facilitate the access to the at least one tube 21 in case of replacement of the tube, for example. According to another variant, such feeding means comprise, for example, a selector device arranged coaxially to the rotor and provided with an inner conduit for guiding the rolled metallic product to the inlet of a respective groove on the bell-shaped member. The inner conduit has an inlet stretch for receiving the metallic product, which enters into the head along the axis X. Such an inner conduit has an outlet stretch which diverges from the axis X to guide the rolled product to the inlet of one of the grooves on the bell-shaped member.

[0058] A main control is provided connected to the mandrel to feed the bell-shaped member rotatably about axis X, e.g. by means of a reducer or equivalent means. The selector device turns always synchronously with the bell-shaped member and the mandrel during the transit of the rolled product, so as to guarantee the continuous alignment between the outlet stretch of the inner conduit and one of the grooves on the bell-shaped member. The selector device may preferably receive the motion of the mandrel itself by means of a differential timing system, for example.

[0059] Further components and details of the laying head are omitted because they are not essential to illustrate the invention.

[0060] The rotor of the laying head of the invention advantageously comprises at least one at least partially spiral-shaped tube in the bell-shaped member.

[0061] Such tube is integrally fixed to said bell-shaped member and is advantageously dimensioned to convey and coil a metallic product, for example a rod, having a second predetermined diameter, preferably comprised between 8 and 25 mm, greater than said first predetermined diameter. Preferably, the inner diameter of the tube may be comprised between 20 and 50 mm.

[0062] Supporting rings are preferably envisaged, fixed to the inner surface of the bell-shaped member and arranged coaxial to the axis X, for fixing the tube to the bell-shaped member itself. The fixing means used to fix the tube to the supporting rings, or directly to the inner surface of the bell-shaped member, are for example clamps. However, other suitable fixing means of the tube may be used.

[0063] In this variant, the bell-shaped member may be formed by two or three stages or parts. The end stage or part comprises a substantially cylindrical end stretch of the bell-shaped member in which a tube end stretch is arranged, provided with the outlet section of the spiral-shaped metallic product. The outlet section of the end stretch of the tube may be in the end stretch of the bell-shaped member or external to said bell-shaped member.

[0064] The tube has an inlet axis coaxial to the rolling line X and the outlet axis tangent to the nominal theoretical diameter of the coils which are formed in sequence.

[0065] A further supporting ring is provided, fixed inside the end opening of the bell-shaped member and arranged coaxial to the axis X. The ring is only used to block the end part of the tube and is shaped to guarantee that the metallic product has an advancement movement.

[0066] In order to direct the metallic product in the tube, the feeding means comprise a further selector device, i.e. a second selector device, provided with a respective inner conduit for guiding the metallic product to the inlet of said tube.

[0067] The inner conduit has a rectilinear axis which coincides with the longitudinal axis X when the second selector device is aligned with the rotor. As the rectilinear axis of the inner conduit is in the working position aligned with the inlet of the tube, it may remain fixed and not turn about the axis X in integral manner to the rotor.

[0068] The first selector device and the second selector device are arranged alternatively coaxially to the longitudinal axis X. For example, for changing the production of coils from a metallic product with diameter from 5 to 8 mm to a metallic product with diameter from 8 to 25 mm, the first selector device is moved from the axis X and replaced with the second selector device, thus passing from a coiling performed by means of a groove of the bell-shaped member to a coiling by means of the tube in the bell-shaped member.

[0069] An advantageous variant of the invention envisages, instead, a single selector device (not shown), configured to be inclined with respect to the axis X and possibly also turned about its axis so as to guide, by means of a respective inner conduit, the metallic product to the inlet of a respective groove on the bell-shaped member or to the inlet of said tube, according to the size of the product to be coiled.

[0070] Variants of the invention (not shown) may be envisaged, in which two or more tubes are present arranged symmetrically and radially in order to balance the centrifugal forces deriving from the rotation speed of the laying head in order to allow a rapid replacement of the worn tube. The working tube change operation is carried out by means of a selector device arranged upstream of the radial arrangement which performs the function of leading in the metallic product and conveying it to one of the laying tubes of the radial arrangement. Such selector device has an inner conduit having an inlet stretch for receiving the metallic product which enters into the head in the coaxial direction of axis X. Such inner conduit has an outlet stretch which diverges from the axis X to guide the rolled product from the inlet direction in one of the shaped tubes.

[0071] In a further variant of the invention, the bell-shaped member is advantageously made in at least three substantially truncated-cone-shaped stages arranged joined and mutually in succession along the longitudinal axis X so that their outer surfaces, provided with spiral-shaped grooves, jointly define the outer surface of the member. Furthermore, the greatest common divisor of the group of the number of spiral-shaped grooves of each stage is advantageously equal to the number of spiral-shaped grooves, defined first number, of a first end stage of the bell-shaped member, proximal to the feeding means.

[0072] A second end stage, distal from said feeding means, is provided with a second number of spiral-shaped grooves, which is either equal to or multiple of said first number of grooves, on an outer surface thereof. Said second end stage of the bell-shaped member has a substantially cylindrical end stretch, in which said second number of spiral-shaped grooves may cover about a round angle, and in which the number of grooves is preferably moderate, e.g. equal to or no more than double the number of grooves, because said grooves must preferably have a very small pitch.

[0073] At least one intermediate stage is also envisaged, arranged between said first and second end stages and provided on its outer surface with a respective number of spiral-shaped grooves which is advantageously a multiple of said first number of grooves. By way of example, three intermediate stages are envisaged, provided with the respective grooves.

[0074] The number of grooves of two adjacent stages may be advantageously different, in particular if it is geometrically feasible to make an adequate number of grooves on the two stages, or may be equally advantageously the same if, for example, the grooves of the two stages are subject to different wear, and thus have different durations, because of their position.

[0075] Angular positioning means are envisaged to adjust the angular position of one stage with respect to the next. In a possible variant, said angular positioning means are at least one connection pin envisaged in at least one of two adjacent stages forming the bell-shaped member. Envisaging the bell-shaped member in stages makes it also possible to facilitate the access to the tube in case of replacement of the tube, for example.

[0076] The elements and features illustrated in the various embodiments may be combined without because of this departing from the scope of protection of the invention.