Patent Description:
Plants for uncoiling wire-rod coils have been known for some time. Such wire-rod coils generally belong to two types: for the vertical uncoiling and the horizontal uncoiling of the wire-rod coils. The former requires a certain height because they include vertical towers along which the wire rods uncoil, while the latter requires a certain length because the support for the wire-rod coils extends horizontally.

With reference to the vertical systems, a set of equipment extends along a deployment line comprising an uncoiling tower, a pair of vertical supports for the wire-rod coils to be uncoiled and a welding machine to weld the tail end of a first coil to the head of a second wire rod coil. Some more complex systems include at least a pair of trolleys on which are loaded coils of wire rods with a horizontal axis by means of a bridge crane with a hoisting hook or by means of lift trucks. The trolleys are then moved parallel to each other near a pair of uncoiling supports or fingers, each provided with a reclinable support base and a trestle fastened to the same.

The loading of wire-rod coils on the supports requires the horizontal positioning of the same supports by reclining their base so as to allow the carriage to run under the trestle and make it possible to fit the coil on the trestle. At this point, once the fastening bands of a first coil have been removed manually by an operator, one or more turns of the coils are unwound from the head and from the tail. Subsequently, the support base of the first coil is lifted vertically to allow the head of the wire rod of the first coil to pass through an uncoiling tower, positioned in line between the two bases of said supports, to then be connected to a pulling unit, while the tail is prepared to be welded to the head of a second coil. It should be noted that all these operations also require the manual intervention of an operator.

The pulling unit is then connected in turn to a straightening or stretching unit, for example to obtain straight bars to cut to length as demanded by specific requirements or preferences or for other processes on the wire rods that then can also be reassembled in coils.

In this configuration can start the unrolling of the first coil.

Further, a welding machine alongside the uncoiling line is activated by an operator to weld the tail end of the first coil to the head of the second coil. Afterward, the welded portion is left free on the ground. Sometimes, for more complex and costly systems, said welded portion is manually inserted into gripping pliers positioned between said two supports and in front in the direction of their loading with the coils.

At this point, the second coil can also be lifted vertically in the uncoiling position.

When the first coil is completely unwound, the operator generally follows manually the welded portion, which is dragged by the drag unit to allow the change of coil so as to obtain a continuous unwinding of the wire rods from a plurality of coils. Alternatively, this portion is released by the gripping pliers as a result of the dragging force of said pulling unit.

In particular, the operations of loading the coils on the respective supports, the vertical movement of the support bases and the passage from the uncoiling of an unwound coil to the next one occur in a single area.

This area is usually bordered by a protection grid open on the coil reception side. Thus, the operator has free access to the inside of this area to carry out all the required operations so that there can be a change of the coils in a continuous mode. However, in this manner the operator is xposed to the so-called "residual" risks of accidents that can also be serious, considering the material being handled and by the forces of the relative equipment involved.

Optical systems have also been proposed to verify the presence of persons near said equipment, but they have only partially solved the risks of accidents and, in any case, have the purpose of stopping production, with the necessity of restarting the machines and consequently slowing down production.

<CIT>, forming the basis for the preamble of claim <NUM>, discloses a welding unit comprising a wire feed tunnel defining a travel path through the welding unit for the first and second sources of wire. The welding unit further comprises a pair of wire feed ports disposed on opposite ends of the wire feed tunnel, and a wire joining zone disposed along a portion of the feed tunnel. The wire joining zone is configured to weld together an end of the first wore source to and end of the second wore source by applying weld heat to at least part of the respective ends of the first and second wire sources. The welding unit also comprises a switch configured to adjust the inner diameter of the wore feed tunnel until the inner diameter is substantially the same as the exterior diameter of the first and/or second sources of wire.

<CIT> discloses an apparatus for paying off wire from reels including a plurality of arbors for supporting reels of wire, guide means for guiding a wire being payed off from one of the reels, means for alternately shifting the guide means from one arbor to another arbor, and means for actuating the shifting means whenever a reel being unwound becomes exhausted.

<CIT> discloses a metal strip supply system wherein flux cored solder wire of a type readily available is continually payed off form large supply reels, through rolls which flatted it to the particular cross section desired as it is fed to the point of use.

<CIT> discloses a method and apparatus for cold forming wires, comprising unwinding a wire of a predetermined diameter, introducing the wire into at least one set of shaping rolls for reducing the cross section of the wire by at least <NUM>% while polygonally shaping the wire and repeatedly bending the wire to increase the elongation properties thereof.

<CIT> discloses a wire pulling output device which is pivotable with a rotary plate via a pivoting device into a lying loading position. It has upper and lateral wire guides for overhead and lateral pulling. The carrier is in the form of an output pin that can be pivoted into suitable positions for overhead or lateral pulling. The rotary plate is free to rotate for lateral wire pulling and is fixed by a locking device for overhead wire pulling.

Consequently, at present there is no system for controlling the processing steps that make it possible for to operator to work in complete safety while avoiding the necessity of stopping production.

The purpose of the present invention is therefore the design of an uncoiling and welding of wire rods continuous mode from coils that guarantees the highest possible level of safety.

Thus, a first objective of the invention is a system for uncoiling and welding wire rods from coils in continuously mode comprising a set of safety devices activated so as to guarantee maximum safety during all the steps of operation.

A second objective is a system for continuously uncoiling and welding wire rods from coils comprising a set of safety devices that guarantee an automatic change of wire-rod coils to allow an uncoiling of the same in a continuous mode.

A third objective is a process for uncoiling and welding wire-rod coils in a continuous mode comprising command and control steps that guarantee the greatest possible safety for the operator.

A further objective is a process for securing the change of wire-rod coils in an apparatus for the uncoiling and welding of wire rods in a continuous mode.

Advantages, characteristics and other objectives of the invention will become evident from the description which follows, given by way of non-limitative example, with reference to the enclosed figures, wherein:.

With reference to <FIG>, the plant according to the invention is indicated in general with reference numeral <NUM>. The plant includes at least one first support <NUM> for a first coil W1 of a wire-rod and a second support <NUM> for a second wire-rod coil W2, a vertical uncoiling tower <NUM> in line between said first and second supports, a welding machine <NUM> to weld the tail end of the first wire-rod coil in the uncoiling position with the head of the second wire-rod oil in the uncoiling waiting position, a holding gripper <NUM> of the welded portion of said coils positioned between said two supports and upstream with respect to the direction of their loading with the coils, a drag unit <NUM> downstream of the uncoiling tower for the first dragging of the wire rod. Afterward, the next dragging takes place in the dragging block (not shown but completely conventional) provided with a drum (capstan) on which the wire rod is wound to allow the speedy advancement through the various subsequent processing machines (rolling stands, stretching panels, etc.).

An enclosure <NUM> encloses on three sides the first and second supports, <NUM> and <NUM>, respectively, the uncoiling tower, the drag unit <NUM> and the holding gripper <NUM>, leaving one side open for loading the wire-rod coils on the respective supports.

It should be noted that the enclosure is effectively the only safety system presently put into effect to avoid the risk of accidents to the operators during the unwinding operations from the wire-rod coils. In fact, the access to the uncoiling area which includes the above-mentioned devices is possible only from the front, that is, from the loading position of the wire-rod coils, W1 and W2, respectively, on the respective first and second supports <NUM> and <NUM>, respectively or, in other words, upstream of the operations for preparing the coils to be uncoiled.

In particular, the enclosure <NUM> comprises four upright elements <NUM>, <NUM>, <NUM>, <NUM> between which are fastened protection metal grids (not shown in the figures) so as to surround a C-shaped space. Two front upright elements <NUM>, <NUM> form the free ends of the C-shaped space and identify the entrance side for the wire-rod coils to be loaded on the respective supports.

The supports <NUM> and <NUM> are conventional structures adapted to be loaded with a corresponding coil W1, W2 of wire rod to be uncoiled and include a trestle <NUM>, <NUM> that supports the coil during the uncoiling and a base <NUM>, <NUM> for supporting said coil. The base <NUM>, <NUM> of each support is provided with a lifting mechanism on the opposite side with respect to the side of reception of the coil in the enclosure <NUM> so as to bend the trestle horizontally in the position of reception of the coil itself (see <FIG>).

The uncoiling tower <NUM> is a prior art structure that rises vertically between said two supports <NUM>, <NUM> and includes a trestle <NUM> on top of which is installed a wire coil guide bell <NUM> followed by a return roller <NUM> for the downward movement of the wire coil toward the drag unit <NUM>.

The drag unit <NUM> is also entirely conventional and includes a set of rolls, one of which is powered so as to operate on the wire rod to drag it to the pulling monobloc.

The holding gripper <NUM> is positioned at the limit of the area defined by the enclosure <NUM> and is preferably installed on a wall <NUM> that extends longitudinally to the loading direction of the wire-rod coils W1, W2. The wall thus has a first end <NUM> bearing the gripping jaws of said gripper, which is turned toward the outside of the enclosure <NUM>, and an opposite second end <NUM>, which is thus turned toward the inside of the enclosure.

Advantageously, adjacent to the gripper <NUM> are positioned means <NUM> to delimit alternately the passage between the first support <NUM> of the first wire-rod coil W1 and the holding gripper <NUM>, and between the second support <NUM> of the second coil W2 and said gripper. Preferably, said means are door hinged close to the holding gripper <NUM>. According to a first variant embodiment, the door is hinged to said second end <NUM> so as to rotate alternately toward the first support <NUM> or the second support <NUM>. This movement will be provided for example by an electric motor controlled by a relative command and control unit, or more preferably by a pneumatic cylinder, solenoid valve and position sensors, as will be explained later in detail. Alternatively, the means can be an optical photocell or laser system.

Moreover, advantageously, the plant <NUM> includes perimetric sensors adapted to identify a first safety zone A barred during the uncoiling of the first coil W1 from the first support <NUM>, a second safety zone B barred during the uncoiling of the second coil W2 from the second support <NUM>. Preferably, the perimetric sensors are optical sensors, such as for example photocells or lasers. In particular, two first perimetric sensors include two units 10A, 10B, one of which 10A is installed near the end of the enclosure <NUM>, near a front upright element <NUM> and the other 10B on the wall <NUM> supporting the holding gripper <NUM>. Similarly, two second perimetric sensors comprise two units 11A, 11B, one of which 11A is installed near the end of the enclosure <NUM> in proximity of the other upright <NUM> and the other 11B on the wall <NUM> on the opposite side with respect to the other unit of the first sensors.

Advantageously, then, the space between the enclosure <NUM> and each of the two supports first <NUM> and second <NUM> is barred to the passage of persons or things. This passage is controlled by passage boundary means <NUM>, <NUM> that can be simply an enclosing section or additional perimetric sensors like those previously described. Therefore, they can be mechanical or optical means that delimit the passage.

A third perimetric sensor finally includes two optical units 14A, 14b, similar to the ones previously described, positioned in opposition to each other at a preset distance from the open side of the enclosure <NUM> so as to delimit a very large area that practically includes all the equipment and areas of movement of the wire rods, except for the welding machine <NUM>, as indicated by the strip S consisting of white and black bands in <FIG>.

In fact, the welding machine <NUM> is positioned not only outside the enclosure <NUM> but also externally to the wire-rod coils loading path. Alternatively, it could also be fixed centrally, with variations in the spaces available and in the presence if any of the loading trolleys, but still outside the area defined by the enclosure <NUM> and by the strip S.

According to a preferred variant embodiment, the equipment <NUM> also includes a pair of grippers <NUM>, <NUM> fixed to the ground. Preferably, these grippers are each fixed outside the enclosure <NUM>, to the side of the path for loading the wire-rod coils and generally in line with a front upright <NUM>, <NUM>. Said grippers have the purpose of temporarily locking the head end or tail end of coils before they are welded, in order to avoid accidental end sudden shifts or slips that could cause injuries to the operators.

In the case in which a system is provided for loading the wire-rod coils on the respective support by means of trolleys, two parallel loading paths <NUM>, <NUM> are provided in front of the open side of the enclosure <NUM>. Each path includes a track (not shown) for a trolley <NUM>, <NUM> carrying a wire-rod coil having a horizontal axis. Once a coil is loaded on a respective trolley, for example by means of a bridge crane provided with a pick-up hook from a storage area for wire-rod coils, the trolley is moved in front of the respective uncoiling support <NUM>, <NUM>. Once the coil has been unloaded from the trolley and loaded on the support, as explained below, the trolley is removed from the enclosure <NUM> to be loaded with a new wire-rod coil.

According to the present invention, the procedure for uncoiling and welding wire-rod coils in continuous mode is carried out by means of operating steps controlled in a safe manner to guarantee the safety of the operators. In fact, the process includes the steps of:.

wherein are advantageously performed the steps of:.

The step a) delimiting the operator safety area inside of which are carried out the automatic movements of wire-rod coils is achieved for example by building an enclosure as previously described. In place of the nets, it is possible to install panels of impact-resistant material, such as reinforced metal or plastic, possibly transparent so that all the components of the devices at work can be seen at all times.

Step b), in which the coils are loaded onto the supports is generally carried out by means of lifting hook of a bridge crane that brings the coils directly to the supports placed horizontally in the receiving position. Alternatively, a trolley like the one previously described runs up to the supports so as to fit the coil directly on the support trellis (<FIG>).

Normally, the coils reach the supports while still tied by metal or plastic bands. Thus, once they are fit onto the supports the operator can break these bands. In this manner, it is possible to unwind about two turns of the coil at the tail end to position it in the welding machine. At this point, the first support <NUM> of the first coil W1 is lifted in the vertical position and the head of the first coil W1 is fixed to the drag unit <NUM> after being passed through the uncoiling tower <NUM> in a completely conventional manner (<FIG>). Preferably, the tail end of the first wire-rod coil is engaged in the corresponding holding gripper <NUM> to be blocked for the greater safety of the operator.

At this point, the first safety zone A, where the first coil is unwound, is activated. Thus, the means that delimit the passage 10A, 10B and <NUM> will be activated. Preferably, the above first perimetric sensors 10A, 10B are activated to detect any wire rod going past the passage before the first support <NUM> between a front upright <NUM> and the wall <NUM> of the gripper <NUM>, and the door <NUM> closing the passage between the wall <NUM> and the gripper and the same second support <NUM> (<FIG>).

In this condition, the uncoiling of the first wire-rod coil W1 can begin in complete safety. In addition, advantageously, the detection of the preset end quantity of wire rod is activated. This detection can be either mechanical or electronic, and this can be based on an optical reading of the quantity of remaining turns.

Subsequently, the second wire-rod coil W2 can also be loaded on the corresponding second support <NUM> and its tail end can be unwound for about two turns and left on the ground. The head, instead, is brought to the welding machine <NUM> (<FIG>). In this manner, the operator is free to carry out the welding between the head of the second coil W2 and the tail end W1 of the first coil W1 (<FIG>).

It should said that, preferably, the tail end of the second coil W2 can be reversibly blocked on the corresponding gripper <NUM> for greater safety of the operator during the handling involved for welding (<FIG>).

Once welding is completed, the operator brings the welded portion to the holding gripper <NUM> (<FIG>). It should be said that such movement take place in complete safety because the operator remains outside said first safety zone A.

Now, the operator gets out not only of the area bordered by the enclosure <NUM> but also of the area in front of it and moves again to the welding machine <NUM>, thus also outside the coil loading path (<FIG>).

In this condition, can also be activated the second safety zone B, which consists in marking out all the area that is also in front of the holding gripper <NUM> and preferably is marked on the ground with the above-mentioned band S with white and black strips of <FIG>. Preferably, said zone is marked by the above third perimetric sensor 14A, 14B.

With the activation of said zone, the coil change can be carried out safely. The change, in particular, can take place only after the system has verified the conditions of:.

Once these conditions have been verified, the holding gripper <NUM> is automatically unlocked to release the welded portion and thus allow the completion of uncoiling the first coil and the start of the second coil. In particular, before the unlocking, when the end quantity of wire rod from the first coil is detected, the system slows down the uncoiling speed by acting on the rotation speed of the capstan or of the pull rollers of the corresponding unit. After the unlocking of the holding gripper, the uncoiling speed is again returned to the standard value. In addition, a system of verification of the end quantity of wire rod, also from the second coil W2, identical to the one of the above first coil W1, is activated.

When the first coil W1 is completely unwound, it is possible to move on with loading on the first support <NUM> a new wire-rod coil to begin a new continuous uncoiling cycle. For this purpose, the third safety zone C is activated to prevent access to the area before the second support <NUM> of the second wire-rod coil W2 through the activation of the second perimetric sensor 11A, 11B that marks the space immediately in front of the upright <NUM> of the enclosure proximal to said second support and to the wall <NUM> that supports the holding gripper <NUM>. The boundary between said wall <NUM> and the first support <NUM> of the first wire-rod coil W1 is also activated, preferably by moving the door <NUM> to block said passage. Finally, the prearrangement of the means that delimit the passage also prevents the passage between the first support <NUM> and the enclosure <NUM>.

In this condition, the first support <NUM> can be inclined by positioning the trestle <NUM> horizontally and allow the new loading cycle to begin in absolute safety. Obviously, in this case, the new coil on the first support <NUM> will have to weld its head to the tail end of the second coil W2.

From the description just given it is evident that the uncoiling and wire-rod welding process in the continuous mode and the relative plant are capable of guaranteeing a safety system that is highly effective in preventing accidents to the operators.

Thus, a further objective of the present invention is a process for securing the safety of the change of wire-rod coils in a plant for uncoiling and welding wire rods in a continuous mode, comprising the steps of:.

Preferably, the securing process is achieved in accordance with the steps previously described with reference to the continuous mode of uncoiling and welding the wire rods from wire-rod coils.

From what has been described to this point, it is evident that all the problems connected with the prior art uncoiling plants in terms of control and safety for the operators have been resolved. In fact, the division into differentiated safety zones controlled by delimitation devices have the great advantage of allowing the operator to access only non-dangerous zones in order to actuate all the operations necessary to allow the uncoiling in the continuous mode, that is, without interruptions of any kind.

Moreover, the systems of detecting trespasses in the safety areas are connected to each other and to a computer so as to verify at every instant every point of possible access to said areas. The activation of the systems, and therefore of the relative areas, takes place only after the verification of specific conditions that in turn if they are met allow the control of the devices.

It is thus evident that the plant and the relative process according to the present invention make it possible to achieve the highest standards demanded by the provisions in terms of safety.

Claim 1:
Plant (<NUM>) for continuously uncoiling and welding wire rods, comprising at least a first support (<NUM>) for a first wire-rod coil (W1) and a second support (<NUM>) for a second wire-rod coil (W2), an uncoiling vertical tower (<NUM>) in line between said first and second supports, a welding machine (<NUM>) for welding the tail of the first wire-rod coil in the uncoiling position with the head of the second wire-rod coil in a position for waiting for the uncoiling, a holding pliers (<NUM>) for the welding portion of said coils positioned between said supports and before their loading side of the coils, a drag unit (<NUM>) downstream the uncoiling tower, characterized by further comprising a fencing (<NUM>) enclosing on three sides the first (<NUM>) and second (<NUM>) supports, the tower (<NUM>) and the holding pliers (<NUM>), first means (<NUM>) for alternately delimiting the passage between the first support (<NUM>) and the pliers (<NUM>) and between the second support (<NUM>) and the pliers (<NUM>), second means (<NUM>;<NUM>) for delimiting the passage between the fencing (<NUM>) and the first support (<NUM>) and between the fencing and the second support (<NUM>), perimeter sensors (10A,10B;11A,11B; 14A,14B) adapted to, also cooperating with said first and second means (<NUM>, <NUM>, <NUM>), delimit a first safety zone
(A) baring the passage during the uncoiling of the first coil (W1), a second safety zone
(B) baring the passage during the change of uncoiling from the first (W1) to the second (W2) coils and a third safety zone (C) baring the passage during the uncoiling of the second coil (W2).