[0001] The present invention relates to a twin-wire straightener for metallic materials
in wire form and the like.
[0002] In the field of the treatment of metallic materials in wire form, profiles and the
like, machines are conventionally employed which are equipped with suitable straightening
elements. In particular, in the field of machines for treating iron rods for reinforced
concrete, said machines generally have at least one straightener provided with a plurality
of mutually opposite straightening elements constituted by contrarotating wheels;
the materials being treated, which arrive from bars and from rolls or reels, are inserted
between said wheels along a preset longitudinal advancement axis.
[0003] Said machines often have two straighteners arranged in series, in which one has wheels
provided with vertical axes and the other one has wheels provided with horizontal
axes, said straighteners being meant to correct a corresponding Cartesian component
of the curvature.
[0004] In particular, twin-wire machines are known which allow to simultaneously treat two
wires, which are arranged longitudinally side by side along said advancement axis.
In these machines, the straighteners are provided with straightening elements which
are peripherally provided with a twin groove meant to be engaged by the two wires
to be straightened.
[0005] In twin-wire machines the problem is therefore felt of tilting the plane of arrangement
of the wires to be straightened during transfer from the first straightener to the
second straightener. In the first straightener, the two wires are in fact superimposed
on a vertical plane, whilst in the second straightener they are arranged side by side
on a horizontal plane.
[0006] Tilting devices are currently known for this purpose which are substantially constituted
by a tubular cam provided with a helical profile and are arranged in an intermediate
position between the two straighteners.
[0007] Said devices, in addition to being relatively expensive, can also cause considerable
wear of the surface of the wires being treated and can also negatively affect the
straightening of the wires.
[0008] The aim of the present invention is to solve the above problem, by providing a twin-wire
straightener that allows to tilt the plane of arrangement of the wires that leave
said straightener without causing wear and without compromising the correct straightening
of said wires.
[0009] Within the scope of this aim, an object of the present invention is to provide a
twin-wire straightener which is simple in concept, safely reliable in operation, versatile
in use and has a relatively low cost.
[0010] This aim and this object are both achieved, according to the present invention, by
the present twin-wire straightener for metallic materials in wire form and the like,
of the type comprising a double set of straightening elements which are supported
so that they rotate in mutually opposite directions along parallel axes and between
which two wires to be straightened are suitable to be inserted along a preset longitudinal
advancement axis, said wires being arranged side by side on a plane of arrangement
which is parallel to said axes of the straightening elements, said straightening elements
being peripherally provided with a twin groove meant to be engaged by said wires to
be straightened, said straightener being characterized in that it comprises a device
for tilting the plane of arrangement of said wires, said device having a first and
a second conical rollers which are supported so that they can rotate freely, about
axes which are parallel to the axes of said straightening elements, downstream of
said straightening elements along said longitudinal advancement axis, and are arranged
so that they are mutually spaced and have mutually opposite tapers, so as to act respectively
on said wires with mutually opposite thrust components which are oblique with respect
to said plane that is parallel to the axes of said straightening elements.
[0011] The details of the invention will become apparent from the detailed description of
a preferred embodiment of the twin-wire straightener, illustrated only by way of non-limitative
example in the accompanying drawings, wherein:
figure 1 is a partially sectional view, taken along a longitudinal plane, of the twin-wire
straightener according to the invention;
figure 2 is a transverse sectional view thereof, taken along the plane II-II of figure
1, at said tilting device;
figure 3 is a corresponding front view of a detail of said device;
figures 4, 5, and 6 are further sectional views of the straightener, taken respectively
along the planes IV-IV, V-V, and VI-VI of figure 1;
figure 7 is a transverse sectional view of a different embodiment of said tilting
device;
figure 8 is a corresponding plan view of said tilting device.
[0012] With particular reference to the above figures, the reference numeral 1 generally
designates the twin-wire straightener for metallic materials 2 in wire form and the
like, for example iron rods for reinforced concrete. Hereinafter, for the sake of
simplicity, said metallic materials are generally termed wires.
[0013] The straightener 1 has, in a per se known manner, a double set of straightening elements
3 and 4, which are supported so that they rotate in mutually opposite directions by
a frame 5 about vertically parallel axes; two wires 2 to be straightened are suitable
to be inserted between the straightening elements 3 and 4, along a preset longitudinal
advancement axis; said wires are mutually superimposed on a vertical plane of arrangement
which is parallel to the axes of said straightening elements 3 and 4.
[0014] The wires 2 to be straightened are inserted between the straightening elements 3
and 4 by means of a tubular inlet wire guide 6, which is fixed to the frame 5 of the
straightener.
[0015] The straightening elements 3 and 4 are conveniently constituted by pairs of mutually
opposite wheels, which are peripherally provided with a twin groove 3a, 4a meant to
be engaged by said wires 2 to be straightened.
[0016] More particularly, on one side with respect to said advancement axis of the wires
2 straightening wheels 3 are fixed, which are supported so that they can rotate on
respective pivots 7, while on the opposite side there are provided moving straightening
wheels 4, which are rotatably supported on corresponding pivots 8. The position of
the fixed wheels 3 can be adjusted individually in a direction which lies transversely
to said advancement axis by means of screw elements 9 at respective slots 10 formed
in the frame 5 (reference should be made in particular to figure 5).
[0017] The pivots 8 of the moving rollers 4 have an eccentric shape and are rigidly coupled
to respective levers 11 which are suitable to be rotated through an angle and synchronously
on a horizontal plane by means of a connecting rod 12, to which they are pivoted at
additional vertical pivots 13. The connecting rod 12 is in turn pivoted to a rocker
14, which is pivoted on a vertical axis to the frame 5 and is meant to be actuated
by an actuator 15, for example a pneumatic cylinder.
[0018] The straightener 1 is provided with a device for tilting the plane of arrangement
of the wires 2, which is generally designated by the reference numeral 20 and is arranged
downstream of the straightening elements 3, 4 along said longitudinal advancement
axis.
[0019] The tilting device 20 is provided with a first conical roller 21 and with a second
conical roller 22, which are supported, so that they can rotate freely about vertical
axes which are parallel to the axes of the straightening elements 3 and 4, on opposite
sides with respect to said advancement axis of the wires 2, and are arranged at an
appropriate distance from each other with mutually opposite tapers, so as to act respectively
on said wires 2 with mutually opposite thrust components which are oblique with respect
to said plane that is parallel to the axes of the straightening elements 3 and 4.
[0020] More particularly, by way of non-limitative example, the taper of the first conical
roller 21 is directed upward, while the second conical roller 22 is arranged outside
the first roller 21, i.e., in a vertically raised position, and its taper is directed
downward (see figure 2 in particular).
[0021] The conical rollers 21 and 22 are supported, so that they can rotate freely by means
of rolling bearings 23 and 24, on respective pivots 25 and 26 which are mounted vertically
on the frame 5; the pivots 25 and 26 have, for mounting on the frame 5, respective
eccentric portions 25a, 26a which allow to adjust the mutual distance of the conical
rollers 21 and 22. The pivots 25, 26 are locked in the active position by corresponding
screw means 27, 28.
[0022] It should be noted that the conical rollers 21, 22 are arranged on slightly offset
vertical planes. In particular, in this example,the first conical roller 21 is arranged
on a plane which is shifted slightly backward with respect to the second roller 22
for overall dimension reasons.
[0023] Downstream of the conical rollers 21, 22, along the direction of advancement of the
wires 2, there is provided a tubular outlet wire guide 30 which is stably fixed to
the frame 5. Said outlet wire guide 30 is internally provided with a through cavity
31 which has a converging shape and is contoured so as to form an outlet 32 which
is elongated on a plane which lies obliquely with respect to the vertical plane that
lies longitudinally to the straightener (see also figure 3).
[0024] Finally, the straightener has, upstream of the tilting device 20, an additional straightening
element 16 which is aligned with the fixed wheels 3, as shown in detail in figure
6. Said additional straightening element 16 is substantially constituted by a split
roller, i.e., a roller formed by two side by side rollers 17 which are peripherally
provided with a corresponding groove 17a and are rotatably supported by respective
pivots 18. The pivots 18 can be adjusted independently by means of corresponding screw
elements 19.
[0025] In practice, the additional straightening element 16 allows to independently perform
different straightenings of the wires 2 that enter the tilting device 20.
[0026] Operation of the twin-wire straightener is easily understandable from the above description.
[0027] The wires 2 to be straightened are inserted, by means of the inlet wire guide 6,
between the straightening elements 3 and 4, which rotate in mutually opposite directions,
and advance along the preset longitudinal axis, so that they are superimposed along
a vertical plane of arrangement, engaging the peripheral grooves 3a, 4a of said straightening
elements 3 and 4.
[0028] When they exit the straightening elements 3 and 4, the wires 2 engage the conical
rollers 21, 22 of the tilting device 20. Said conical rollers 21 and 22, provided
with opposite tapers, act respectively on the wires 2 with mutually opposite thrust
components which are oblique with respect to the vertical advancement plane, causing
an opposite lateral movement of said wires.
[0029] In practice, the wires 2 are arranged, by means of the thrust of the conical rollers
21 and 22, on a plane which is oblique with respect to the vertical plane that lies
longitudinally to the straightener.
[0030] The wires 2 then pass through the outlet wire guide 30, provided with an outlet 32
which is elongated on a plane which is likewise oblique with respect to said longitudinal
vertical plane, so as to be preset for entering a subsequent straightener provided
with straightening rollers having horizontal axes.
[0031] The described twin-wire straightener therefore achieves the aim of tilting the plane
of arrangement of the wires that exit from said straightener without causing wear
and without compromising the correct straightening of said wires. The plane of arrangement
of the wires is in fact tilted without friction by means of the pair of freely rotating
conical rollers 21 and 22.
[0032] The fact should also be noted that the described tilting device is very simple from
the constructive and functional point of view and has low costs with respect to conventional
devices in addition to being adjustable for the various wire diameters that can be
treated.
[0033] Figures 7 and 8 illustrate a different embodiment of said device for tilting the
plane of arrangement of the wires, which is provided with a first conical roller and
with a second conical roller, designated again by the reference numerals 21 and 22
for the sake of clarity, which are arranged so as to have mutually opposite tapers.
The conical rollers 21 and 22 are supported so that they can rotate freely, by means
of the corresponding rolling bearings 23 and 24, on the respective pivots 25 and 26,
which are mounted vertically on the frame 5.
[0034] According to the illustrated embodiment, the pivot 25 of the first conical roller
21 has a fixed axis on the frame 5, while the pivot 26 of the second conical roller
22 is guided so that it can slide, by means of a bush 29, in a slot 40 formed on the
frame 5; the slot 40 is arranged transversely to the wire advancement direction, substantially
on the vertical plane of arrangement of the axes of the conical rollers 21 and 22.
[0035] A helical spring 41 is suitable to act elastically on the bush 29 of said pivot 26
and is accommodated in a corresponding seat 42, which is formed on the frame 5 and
is aligned with the slot 40. The spring 41 applies a pressure which is appropriately
adjustable by means of an adjustment screw 43, which is locked in the active position
by means of a nut 44.
[0036] The spring 41 pushes the movable conical roller 22 toward the fixed-axis conical
roller 21, so as to elastically clamp the wires to be straightened between said rollers
21 and 22. In this manner, correct clamping pressure of the wires on the part of the
rollers 21 and 22 is ensured. In particular, said clamping pressure of the rollers
21 and 22 adapts spontaneously to the different dimensions of the rods being treated,
without requiring any adjustment.
[0037] It is of course possible to provide both conical rollers 21 and 22 so that they can
move in the above-described manner and be actuated by respective springs, mounted
in mutually opposite positions, for clamping the wires being processed.
[0038] Moreover, as shown in said figures 7 and 8, the conical rollers 21 and 22 may be
peripherally provided with a respective pair of grooves 21a, 22a which are shaped
for example so as to have a circular profile, in order to guide in an optimum manner
the wires 2 in the rotation which is required to pass from the straightening elements
which have horizontal axes to those which have vertical axes.
[0039] It is also possible to subject only one or both of the conical rollers 21 and 22
to actuation means, not shown, which are meant to positively and/or negatively move
said rollers 21, 22 transversely to the wire advancement axis, along a corresponding
slot 40. In particular, said actuators can cooperate with said spring 41, which is
meant to provide a controlled force for the elastic clamping of the wires.
[0040] In this manner, the conical rollers 21, 22 can be kept in contact with the wires
being treated only during a suitable insertion step and, viceversa, moved away from
contact once wire insertion has been completed.
[0041] Accordingly, the conical rollers 21, 22 are prevented from being uselessly subjected
to wear during normal operation, when their intervention is not required.
[0042] Said actuators can of course actuate both the approach of the conical rollers to
the active position and their spacing into a disengagement position.
[0043] In the practical embodiment of the invention, the materials used, as well as the
shape and the dimensions, may be any according to requirements.
[0044] Where technical features mentioned in any claim are followed by reference signs,
those reference signs have been included for the sole purpose of increasing the intelligibility
of the claims and accordingly, such reference signs do not have any limiting effect
on the interpretation of each element identified by way of example by such reference
signs.
1. A twin-wire straightener for metallic materials in wire form and the like, of the
type comprising a double set of straightening elements which are supported so that
they rotate in mutually opposite directions along parallel axes and between which
two wires to be straightened are suitable to be inserted along a preset longitudinal
advancement axis, said wires being arranged side by side on a plane of arrangement
which is parallel to said axes of the straightening elements, said straightening elements
being peripherally provided with a twin groove meant to be engaged by said wires to
be straightened, said straightener being characterized in that it comprises a device
for tilting the plane of arrangement of said wires, said device having a first and
a second conical rollers which are supported so that they can rotate freely, about
axes which are parallel to the axes of said straightening elements, downstream of
said straightening elements along said longitudinal advancement axis, and are arranged
so that they are mutually spaced and have mutually opposite tapers, so as to act respectively
on said wires with mutually opposite thrust components which are oblique with respect
to said plane that is parallel to the axes of said straightening elements.
2. A straightener according to claim 1, characterized in that said conical rollers are
rotatably supported by respective pivots provided with a corresponding eccentric portion
which allows to adjust the mutual distance of said conical rollers.
3. A straightener according to claim 1, characterized in that downstream of said conical
rollers there is provided a tubular outlet wire guide, which is internally provided
with a through cavity which converges in the advancement direction of said wires and
is shaped so as to form an outlet which is elongated on a plane which lies obliquely
to said plane that is parallel to the axes of said straightening elements.
4. A straightener according to claim 1, characterized in that it has, upstream of said
tilting device, an additional straightener which is aligned with a plurality of said
straightening elements and is provided with a pair of side by side rollers, which
are suitable to peripherally engage said pair of wires and are supported rotatably
by respective pivots which can be adjusted independently by means of corresponding
screw elements.
5. A straightener according to claim 1, characterized in that at least one of said conical
rollers is rotatably supported by a pivot which can move at a slot which lies transversely
to said longitudinal advancement axis of said wires to be straightened, in order to
adjust the mutual distance of said conical rollers.
6. A straightener according to claim 5, characterized in that said moving conical roller
is suitable to be actuated by elastic means which act in a direction which is aligned
with said slot and are suitable to provide an adjustable elastic pressure for clamping
said wires.
7. A straightener according to claim 1, characterized in that at least one of said conical
rollers is subjected to actuator means which are meant to positively and/or negatively
move said roller transversely to said longitudinal advancement axis of said wires
to be straightened, so as to keep said conical rollers in contact with said wires
during a controlled treatment step.
8. A straightener according to claim 1, characterized in that said conical rollers are
peripherally provided with a respective pair of grooves suitable to guide said wires
to be straightened.