WO2011162664A1

WO2011162664A1 - Method and device for feeding wire to a binding machine

Info

Publication number: WO2011162664A1
Application number: PCT/SE2011/000117
Authority: WO
Inventors: Per-Olow Axner
Original assignee: MOWI - TEKNIK AB
Current assignee: MOWI - TEKNIK AB
Priority date: 2010-06-20
Filing date: 2011-06-19
Publication date: 2011-12-29
Anticipated expiration: 2012-12-20
Also published as: SE1000661A1

Abstract

Method for feeding wire (2) from a wire supply (3) to a feeder mechanism (9) in a binding machine (4), whose binding machine is intended to be used for binding at least one object (5), such as a pulp bale (6), with at least one revolution of wire (2). The present methods unique feature is that the feeding of wire (2) to the feeder mechanism (9) takes place by the wire (2) initially being fed by at least one feeding device (1) from the wire supply (3) to at least one wire compartment (intermediate storage) from which the binding machine's (4) feeder mechanism (9), during binding of the pulp bale (6), draws the necessary length of wire (2).

Description

Method and Device for Feeding Wire to a Binding Machine Field of the Invention

The present invention concerns a method and device for feeding (supplying) wire to a binding machine (wire binder), which for example is used to bind wire around pulp bales and the like, in accordance with the claims.

Background of the Invention and Prior Art

Equipment for binding together different types of objects with wire is used in several different areas. One such area is the binding of pulp bales and the like using some sort of binding equipment. Equipment for binding wire around pulp bales and the like are previously known from several different designs. Examples of such equipment are described in patents SE380496, SE509532 and SE509534. These patents describe binding machines for binding pulp bales with wire which include a feeder, a binding unit, a wire guide and a wire compartment. During binding of a pulp bale, a wire and the wire's loose end are fed forward by the feeder through the binding unit (with features and devices for cutting and twisting the wire) and then guided around the bale with the aid of a wire guide. The wire is fed at a cycle at speeds up to 5 m/s. When the wire's end for the second time reaches the device for cutting, feeding is stopped and the wire's end is gripped and held in place. The wire guide then releases the wire and the feeder is reversed to stretch the wire around the bale, after which the wire is cut and the ends are twisted into a knot. The returned wire is then used in the next binding. Stretching the wire provides a relatively large wire length that is taken up in the wire compartment. When using the devices in accordance with the patents, problems arise with the returned wire getting tangled in the wire compartment.

The worst problem with binding machines, such as those in the above mentioned patents, is when standstill occurs in the binding machine caused by so-called kink (wire kink) during feeding of wire from the wire supply to the feeder. The risk of kink occurring is dependent on the wire's feeding speed, acceleration of the wire and wire diameter. The risk of wire kinking occurring increases with feed rate speed and acceleration of the wire. Furthermore kink occurs more easily when using a wire of smaller dimensions than when using a relatively larger size. To reduce the risk of standstills, due to wire kink, the wire's cross-sectional area (diameter) relative to the size of wire needed to hold the bale together is oversized. Even with oversized wire, there is a significant risk of wire kink occurring with the sizes of wire that are currently used.

Improved binding machines have been developed to reduce problems with the returned wire tangling during stretching and returning. For example patent SE522986, by the applicant Metso Paper, describes an improved binding machine for binding pulp bales in which the returned wire is guided in an elongated wire compartment. The wire compartment which is formed by two walls that are bolted together with spacers, form an inner space with an essentially rectangular shape with a width that is slightly larger than the diameter of the wire. The design focuses on solving the problem of wire tangle in the wire compartment by the distance between the sides being adapted to the diameter of the wire so the wire can not fold double in the interior space. During feeding of wire into the wire compartment there is a problem with guiding the wire. The design according to this patent does not solve the problem of operation standstills caused by so-called kink during the feeding of wire from the wire supply to the binding device.

An automatic apparatus for feeding packaging strap is described in patent US03946921. This design includes a strap feeding mechanism having a pair of reversibly rotatable feed rolls for feeding and returning plastic strap and a detector for detecting the amount of strap fed and returned. Strap is fed to the feeding mechanism by a prefeeding device having

unidirectionally rotatable prefeed rolls and a detector for detecting the amount of strap that has been prefed. A control mechanism is also included that determines the difference between the amount of strap fed and returned by the feeding mechanism using photoelectric pulses and this is data is used to control the prefeeding mechanism to prefeed an amount of strap equal to that determined difference. This apparatus differs greatly from the present method and device. Firstly, this apparatus is designed for feeding strap not wire, which has many different presumptions. For example strap has completely different properties compared to wire which means that the problems associated with wire kink do not occur in the same way, thus making the strap feeding mechanism unusable for solving the problem of wire kink. Secondly, the present invention does not utilize pulses to determine the amount of wire to be fed from the wire supply or the wire compartment. Furthermore the present invention feeds wire in a continual operation and utilizes the time when the binding machine is occupied by the binding, cutting and twisting process to replenish the wire supply. The present invention accomplishes this unlike the mentioned apparatus by having a significantly lower feed rate of wire from the wire supply to the wire compartment, which basically eliminates the risk of the wire tangling or twisting itself in the wire supply. The so-called prefeeding process in the mentioned apparatus is a completely separate function unlike the present invention which has a continual prefeeding process during the entire binding cycle. The design for an automatic apparatus for feeding packaging strap described in patent US03946921 therefore differs substantially from the present invention's method and device.

When taking the above mentioned problems into consideration, there is a need for a significantly improved method and device for feeding wire into a binding machine.

Brief Description of the Invention Concept The main purpose of the present invention is to create a significantly improved method for feeding wire into a binding machine, as for example a binding machine for binding pulp bales. Another purpose of the present invention is to create a device for implementing the method. A further purpose of the present invention is to create a method by which the required diameter of the wire can be reduced. It is also a purpose of the present invention to substantially reduce the occurrence of so-called kink and thereby significantly improve the operational reliability of the binding machine. A yet further purpose of the present invention is to create a wire guide for the wire fed into the wire compartment.

Brief Description of the Drawings

In the following detailed description of the present invention, references to the following figures will occur. These are outlined in the following figure list. The exemplified embodiments in the figures do not limit the scope of protection of the present patent application. Note that the figures are schematic and details can thus be omitted in these.

Fig. 1 exemplifies a feeding device according to a first embodiment of the present invention.

Fig. 2 shows an alternative embodiment of a feeding device according to the present invention.

Fig. 3 shows a feeding device more in detail. The figure also shows a stretching device according to an alternative embodiment.

Fig. 4 to 6 show different lengths of wire in wire compartment 10 and wire compartment 13. Detailed Description of the Invention

With reference to the figures is show a feeding device 1 for feeding binding wire 2 from a wire supply 3 to a binding machine 4 which binds at least one object 5 such as a bale 6 of pulp material or the like with binding wire 2. The wire supply 3 ordinarily consists of, or includes, at least one spool 7 (coil) from which the wire 2 is unreeled from. Preferably, the wire 2 is drawn from the wire supply 3 to the feeding device 1 via one or more pulleys 8.

Preferably, the binding machine 4 consists of a previously known type of binding machine 4, or hereafter developed type of binding machine 4, which includes at least one feeder mechanism 9, at least one wire compartment (a first wire compartment) 10 and at least one twisting unit 11 for the wire 2. The twisting unit 11 may be of a previously known design such as a twining unit. Alternatively, the twisting unit 11 may consist of a joining device which connects wire ends with a different technology than twining, which is suitable for the purpose. It is for example conceivable that the joining of the wire ends is accomplished by welding or other suitable for this purpose joining technology. The feeding device 1 in accordance with the present patent application may consist of a separate unit which connects to an existing binding machine 4. Alternatively, the feeding device 1 may be integrated into a previously known type of binding machine 4 or into a new type of binding machine 4.

The feeding device 1 includes at least one feeder unit 12 for the wire 2. The feeder unit 12 feeds wire 2 from the wire supply 3 to at least one wire compartment. In the first embodiment of the present feeding device, which is shown in Fig. 1, the feeder unit 12 feeds wire 2 to a wire compartment 10 that is integrated in the binding machine 4. The feeding device 1 in this embodiment is essentially comprised of the feeder unit 12, with the accompanying drive unit, connected or integrated into the binding machine's wire compartment 10. Figure 2 shows a first alternative embodiment of the present feeding device 1. In this first alternative embodiment, the feeding device 1 includes at least one feeder unit 12 and at least one wire compartment (second wire compartment) 13.

In the first embodiment the feeder unit 12 feeds the wire 2 into wire compartment 10 and in the second embodiment into wire compartment 13. The feeding of wire into wire

compartment 10, or alternatively wire compartment 13, occurs at a lower and preferably a substantially lower maximum speed than the maximum speed at which the binding machine's 4 feeder mechanism 9 feeds wire 2 with during the binding of the pulp bale. If for example, the feeder mechanism 9 feeds the wire 2 at a speed of up to 5 m/s, the feeding of the wire 2 into wire compartment 10, or alternatively wire compartment 13, by the feeder unit 12, may for example occur at a rate of up to about 0.5 m/s. The lower feed rate of the wire 2 from wire supply 3 to wire compartment 10, or alternatively wire compartment 13, reduces the risk of the wire tangling or twisting itself in the wire supply 3. The risk of the wire 2 being pulled apart when fed to wire compartment 10, or alternatively wire compartment 13, is thereby reduced significantly. The difference in the feed rate between feeder mechanism 9, the binding machine 4, and feeder unit 12 in the feeding device 1 is controlled by the length of time between the binding machine's rebinding cycles. Feeder unit 12 must feed forward the equivalent length of wire which is required for each feeding cycle.

The feeding device 1 includes a detection of when a given length of wire, such as maximum wire length, is fed into wire compartment 10, or alternatively wire compartment 13. This detection function may also, in a stepless manner, detect the length of wire that is fed into wire compartment 10, or alternatively 13. The function of detecting wire length in wire compartment 10 or 13 may for example include one or more sensors.

The feeder unit 12 may consist of a feeder unit which is suitable for the purpose. Fig. 3 shows an exemplary form of feeder unit which includes at least one feed wheel 14 and one pinch wheel (or alternatively mating gear) 15. The feed wheel 14 is driven by at least one motor, not shown in the figures. This motor consists of a previously known type of motor, or hereafter developed motor, which is suitable for the purpose. Pinch wheel 15 is operated in the shown embodiment by at least one control device such as a clamp cylinder 16 or the like. During the feeding of the wire 2, the wire 2 is drawn between the feed wheel 14 and the pinch wheel 15. When feeding the wire the pinch wheel 15 is moved towards the feed wheel 14 by the clamping cylinder 16. During rotation (counterclockwise in the figures) of the feed wheel 14, the wire 2 is fed into wire compartment 10, or alternatively wire compartment 13. A sufficient friction between the feed wheel 14 and the wire 2 is required so that the wire 2 does not slip against the feed wheel 14. The required friction is achieved with previously known technology and is therefore not described in more detail in this patent application. In alternative embodiments the feeder unit may consist of another for the purpose suitable technology. Feed wheel 14 preferably includes a freewheel function, which for instance allows the wire 2 to be fed by feeder mechanism 9 from wire supply 3 if the feed wheel's drive motor develops operational problems. The feeding device includes a control system 17 which controls the feeding device's functions such as the feed wheel's rotational speed and other functions. This control (control system) can be done separately or included in the binding machine, line or other control systems.

Wire compartment 13, in the preferred embodiment contains at least the length of wire 2 which is required for binding one revolution around the bale 6. Wire compartment 13 may in alternative embodiments accommodate a wire length that is shorter than the wire length needed to bind the wire once around the bale 6. Wire compartment 13 can not however accommodate a shorter wire length than the binding length minus the wire length which is fed via the feed device 1 during the binding cycle and minus the returned length from the stretching of the wire 2 which is temporarily kept in the ordinary wire compartment 10 of the binding machine 4.

With reference to Fig. 4 to 6 are shown various lengths of wire 2, which are fed into wire compartment 10 and wire compartment 13, respectively. In Fig. 4, there is no extra temporarily stored wire length in wire compartment 10 and in wire compartment 13, respectively. In Fig. 5, the feed unit has fed the wire 2 into the wire compartment 13 to the point that at least one sensor has stopped the feeding of the wire into wire compartment 13.

In Fig. 6, the wire is fed by the feeder unit into wire compartment 13 to the point that at least one sensor has stopped the feeding of the wire into wire compartment 13. Furthermore, during stretching by the feeder mechanism 9, a returned strand of wire is fed into the wire compartment 10 of the binding machine 4.

During a binding cycle the feeder mechanism first feeds wire from the previous returned strand. After the returned strand is fed forward by the feeder mechanism, the feeder mechanism feeds the remaining required length of wire (for a binding cycle) from the wire that is fed and/or fed by the other feeder unit and temporarily stored in wire compartment 10. In the detailed description of the present invention, design details and subordinate parts of the method may have been omitted which are apparent to persons skilled in the field of the method and device. Such obvious design details and subordinate method parts are included to the extent necessary so that the proper and full performance of the present method and device is achieved. Even if certain preferred embodiments have been shown in more detail, variations and modifications within the scope of the method and device may become apparent for specialists in the field. All such variations and modifications are regarded as falling within the scope of the following claims. It is conceivable that the method and device in accordance with the present patent application may be used in another type of machine than a wire binding machine.

Claims

1. Method for feeding wire (2) from a wire supply (3) to a feeder mechanism (9) in a binding machine (4), whose binding machine is intended to be used for binding at least one object (5), such as a pulp bale (6), with at least one revolution of wire (2)

characterized by that the feeding of wire (2) to the feeder mechanism (9) takes place by the wire (2) initially being fed by at least one feeding device (1) from the wire supply (3) to at least one wire compartment (intermediate storage) from which the binding machine's (4) feeder mechanism (9), during binding of the pulp bale (6), takes (draws) the necessary length of wire (2) required for binding the pulp bale (6).

2. Method according to claim 1 characterized by that the feeding device (1) feeds wire (2) with a lower maximum feed rate to the wire compartment than the maximum speed that the feeder mechanism (9), included in the binding machine (4), feeds wire (2) from the wire compartment during binding of the pulp bale (6).

3. Method according to at least one of the previous claims characterized by that the feeder mechanism's (9) feeding of wire (2) during binding of the bale (6) takes place without the feeder mechanism's (9) feeding of wire substantially contributing to an acceleration (stretching) of the wire strand between the feeding device (1) and the wire supply (3).

4. Feeding device (1) for implementation of the method according to claims 1 to 3

characterized by that the feeding device (1) includes at least one feeder unit (12).

5. Feeding device (1) according to claim 1 characterized by that the feeder unit (12) includes at least one feed wheel (14) which is driven by at least one motor, at least one pinch wheel (15) and at least one control device such as a clamping cylinder (16).

6. Feeding device (1) according to claim 4 characterized by that the feeding device includes at least one wire compartment (13).

7. Feeding device (1) according to at least one of the previous claims characterized by that the feeding device includes a control system (17).