EP0194478B1

EP0194478B1 - Device for straightening rods or wire without relative rotation of succeeding elements of material about the longitudinal axis

Info

Publication number: EP0194478B1
Application number: EP19860102121
Authority: EP
Inventors: Giorgio Del Fabro; Marcello Del Fabro
Original assignee: MEP Macchine Elettroniche Piegatrici SpA
Current assignee: MEP Macchine Elettroniche Piegatrici SpA
Priority date: 1985-03-08
Filing date: 1986-02-19
Publication date: 1989-12-06
Also published as: EP0194478A2; DE3667255D1; ES552751A0; JPS61269945A; JPH0761517B2; ES8704363A1; EP0194478A3

Description

This invention relates to a device preventing the rotation of longitudinal advancing rods particularly for straightening and bending machines.
At the present state of the art straightening and/or stirrup machines, that bend and shear steel rods or straighten and shear coil fed rod or wire automatically are well known.
In this prior art, straightening/bending machines, the second one e.g. called stirrup machines, work continuous feeding rods or bars or wire, by using straightening and roll advancing means, and bend and shear the advancing material into stirrups, (Italian Patent No. 1 024 224 in the name of Del Fabro). Other machines are realized not for bending the raw material but only for straightening and shearing into stock.
It is well known that raw material continuous feeding rolling means, particularly if the raw material to be worked is hot milled rod, causes an uncontrolled rotation for different reasons e.g.:

-the anisotropy of the material, a section not perfectly round, superficial imperfections, residual stresses, etc.

Consequently, twisted stirrups are the main disadvantage of automatically fed stirrup machines.
Many efforts have been made to eliminate this drawback but they have not been sufficiently positive.
Other efforts have been made with straightening devices that have a series of rolls and counter rolls means, either free or motorized (driven function), that oblige the raw material to advance in deviated pathway in different planes. (US-A-2 517 309 "HELLER", FR-A-2 138 615 "KIESERLING", DE-C-230 468 "RINNE"). These device are principally used as a straightening means that eventually draws or advances the raw material, but in any case they are unable to completely prevent the uncontrolled rod rotation.
In particular FR-A-2138 615 which discloses the features of the pre-characterizing part of claim 1 utilizes straightening means structure rotating around the deviated raw material, so it is practically impossible to keep the advancing bar from rotating. Slightly uncontrolled rotation, by twisting action, caused by said rotation of the complete structure around the raw material, cannot be avoided.
On the other hand, slight rotation in this solution does not cause any inconveience, the main scope being to realize the straightening of very long bars or tubes.
It is accordingly an object of the present invention to overcome these drawbacks and perform an improved straightening operation eliminating any rotation whatsoever of the row material to allow realization, after straightening, of untwisted stirrups.
According to the invention this problem is solved by providing a device for straightening rods or wire without relative rotation of succeeding elements of material about the longitudinal axis, said device comprising:

a plurality of longitudinally spaced groups of guide rolls, whereby each group of rolls is arranged such that it is offset with respect of the previous groups of rolls, such that the material is deviated from a linear path, and that at least one group of rolls lies in a different plane to the remaining groups, characterized in that
- -said groups of guide rolls each comprise a set of opposed, staggered straightening rolls arranged in a straight line such as to make the material take a serpentine path, before being deviated by a successive group of straightening means;
- -at least one set of opposed staggered rolls comprises means for adjusting the roll separation between opposed rolls to change the pressure applied to the material; and that the guide rolls are free too rotate solely about their own axes.
The advantages offered by the invention are mainly that the material is not only held in position continuously by use of said group of guide rolls, but also straightened being also possible to adjust the "hold" of these "groups of guide rolls", increasing or decreasing the pressure according to the characteristics of the material.

In a preferred embodiment the device further consists of:

-on a first working plane, a first group of guide rolls followed by a second group of guide rolls, realizing a pathway deviation angle, comprised between 10° and 90°,
-between said first and second groups an intermediate group of opposed advancing rolls means and
downstream from the second group of guide rolls, reangling means comprising an adjustable counter-roll, that counter-bends the material against and between two anvil rolls, one of said anvil rolls being part of said second group of guide rolls;
-on a second working plane parallel to the advancing and working line pathway, orthogonal and placed downstream from the first one, a further group of guide rolls is placed, followed by a second reangling means similar to the previous one, which brings the material back to the advancing working line.

With this solution uncontrolled flection is prevented to the advancing rod by said deviated pathway sides, being "continuously held" by the respective group of rolls, and controlled by the reangling means.
In a further embodiment, the opposed rolls are "V" guttered.
With this solution the material is "held" in lateral deviations, and the device can work different rod diameters.
Some ways of carrying out the invention are described in detail below with reference to drawings which illustrate some specific embodiments.
Figure 1 is a schematic view of the traditional stirrup operating devices; Figure 2 is a side view of the twisting of a traditional stirrup; Figure 3 is a perspective view of a twisted stirrup; Figure 4 is a well known curved deformation (in exaggerated continuous bending) of the raw material/rod/wire in drawing condition; Figure 5 is an orthogonal view of the rod between two rolls to show one of the causes of its rotation during advancing; Figure 6 represents schematically the continuous arm lever applied on the advancing rod by a not represented straightening means; Figures 7-10 are other various disclosed solutions without respective straightening means between the deviating points; Figure 11 is a schematic perspective view of the device embodying the invention, that can be placed between the uncoiler and a bending device in stirrup machine (not shown); Fig. 12 is a transversal schematic section of an advancing rod corresponding to one of the two opposite guttered roll guide means.
Figure 1 shows that in prior art, a stirrup machine generally consists of: a rod coil feeder (A), a horizontal rolling straightener means, one in horizontal plane (B and the other in vertical plane (B'); a pair of roll advancing means (C), a shear means (D); a bending means (E) with guiding fork (f) and bending nib (n) that rotates to bend the rod (b) into a stirrup (s).
As represented in Figure 2 and 3, in prior art, the obtained stirrup is twisted because the advancing or straightening roll means cannot hold against rotation the bar because the rod is out of round and thrusted by the respective opposed rolls (r) which tend to rotate towards the thrust (Fig. 5). Uncontrollable rotation of the advancing bar is verified also in the use of large advancing rolls (r) with staggered counter rolls (r) that give a curve to the advancing rod ex. smaller ones (r') to realize e serpentine path, thus resulting in a twisted stirrup (s).
The invention utilizes the system of deviating roll means (R) with an inclined continuous arm guide lever (L-p Fig. 6) comprising at least one deviation roll (1) the continous arm lever (p) being placed upwards or downwards of said deviating roll (1) on the advancing rod (b) (Fig. 6 to 10).
This solution to utlize an inclined continuous arm guide lever means has the scope to increase the length of the respective arm lever (L) as represented in Fig. 6. The angle of deviation (i) of the rod (b) can be realized between 10° and 90°. To maintain the same direction of the advancing rod (b), two deviation rolls (1) may be used as in Fig. 7 and with auxiliary use of counter rolls (1'), more deviation rolls can be used (1) and respective counter rolls (1') as indicated in Fig. 8-10. The advancing rod can be deviated to "Z" shape (Fig. 7, 8), or loops or other combined shapes.
Deviation devices for each angle deviation (R, R') form individual deviation units (F) for the advancing rod.
Less preferably, in working line straightening devices (B, B') can be placed upwards and downwards of the deviation units (F) as represented in Fig. 8.
To prevent curving effect from the respective deviation devices (R), at least one straightening roll adjustable in position (2) in order to "straighten" the rod is utilized downstream of the deviation device (R).
In the usual solutions deviation units can work in couples (F), one in horizontal plane (F) and one in vertical plane (F') as represented in Fig. 10.
As per the present invention, between one deviation device (R) and the other, a guide bar unit (3) can be placed in order to avoid flection of the advancing bar (b), reinforcing the adjacent continuous arm lever (L), said guide bar being straightening means in the feature of groups of guide rolls as represented with (c, c', c") in Fig. 11.
The first deviation device (R'%@be movable as represented in Fig. 10 to vary the angle of deviation in association with straightening means (3), depending from the left or right coil developing and in compliance to the utilization of one or two rods.
In a preferred embodiment of the invention are represented in Fig. 11, the device comprises:

-on a first working plane (A) a first group of guide rolls (c) and a second one (c') realizing a pathway deviation angle, preferably comprised between 10° and 90°. Each one being realized by two opposed parallel staggered straightening rolls arranged in straight lines (2, 3), being in the apex between the said groups of guide rolls (c, c'), placed a roll advancing means (d) to advance the rod and, downwards from the second group (c'), placed reangling means (e), to realign the advancing rod on the advancing working line parallel to said plane;
-on a second working plane (B) parallel to the advancing and working pathway line, orthogonal and downstream placed from the first (A): a further inclined group of guide rolls (C") is placed between two respective deviation angles, in respect to said rod pathway working line and downstream from this one, a reangling means (e') to realign the advancing rod on the advancing working line parallel to said plane, are further placed;
downstream from said reangling means (e'), an adjustable opposed rolls guide means is utilized to realign definitely the rod in its said working pathway line (f).

The first working plane (A) is horizontal or approximately horizontal and the second (B) is vertical or approximately vertical.
The first roll straightening arm means (c) placed between the deviating angles, is adjustable in its inclination to vary the rod deviation angle up to 90°.
The series of upper rolls (3) of each group of guide rolls (c, c', c"), are adjustable in pressure by manually controlled means (4), against the opposing rolls (2), being staggered not aligned.
The opposed rolls (2, 3) of each group of guide rolls (c, c', c") and the opposed rolls of said realigning and guide means (e, e', f) have V-shaped rims for the advancing rod (1), in order to allow the working of a range of rod diameters (1).
The advancing means (d) is realized by a single pair of opposed rolls (5, 6) being at least one (6) adjustable in pressure against the opposed one (5).
The couples of advancing rolls can be adjusted in order to apply less pressure on the rod.
Said rod roll reangling means (e, e') comprise a couple of inside apex angle anvil rolls (8, 8') and an adjustable opposed pressure roll (7).
One of said anvil rolls (8') is enclosed upwards the second and the third group of guide rolls (c', c").

Claims

1. A device for straightening rods or wire without relative rotation of succeeding elements of material about the longitudinal axis, said device comprising:

a plurality of longitudinally spaced groups of guide rolls, whereby each group of rolls is arranged such that it is offset with respect of the previous groups of rolls, such that the material is deviated from a linear path, and that at least one groups of rolls lies in a different plane to the remaining groups, characterized in that

-said groups of guide rolls (c, c', c") each comprise a set of opposed, staggered straightening rolls (2, 3) arranged in a straight line such as to make the material take a serpentine path, before being deviated by a successive group of straightening means (c, c', c");

-at least one set of opposed staggered rolls (2, 3) comprises means for adjusting the roll separation (4) between opposed rolls (2, 3) to change the pressure applied to the material; and that the guide rolls are free to rotate solely about their own axes.

2. A device as claimed in claim 1, characterised in that further comprises:

-on a working plane (A), a first group of guide rolls (c) followed by a second group of guide rolls (c'), realizing a pathway deviation angle, comprised between 10° and 90°,

-between said first and second groups an intermediate group of opposed advancing roll means (5, 6) and

-downstream from the second group of guide rolls (c'), reangling means (e) comprising an adjustable counter-roll (7), that counter-bends the material against and between two anvil rolls (8, 8'), one of said anvil rolls (8') being part of said second group of guide rolls (c');

-on a second working plane (B) parallel to the advancing and working line pathway, orthogonal and placed downstream from the first one (A), a further group of guide rolls (c") is placed, followed by a second reangling means (e') similar to the previous one (e), which brings the material back to the advancing working line.

3. A device as claimed in claim 2, wherein said first working plane (A) is horizontal.

4. Device as claimed in claim 1, wherein said first group of guide rolls (c) is adjustable in its inclination to vary the deviation angle.

5. A device as claimed in claim 2, characterised in that it comprises downstream of the respective second reangling means (e'), a pressure adjustable opposed roll means (f) similar to the previous reangling means (e, e').

6. A device as claimed in claim 1, characterised in that said opposed rolls (2, 3) have V-shaped rims.