EP0039469A1

EP0039469A1 - Apparatus for tying up packs of tiles

Info

Publication number: EP0039469A1
Application number: EP81103192A
Authority: EP
Inventors: Franco Tacchini
Original assignee: Officina Meccanica Sestese SpA
Current assignee: Officina Meccanica Sestese SpA
Priority date: 1980-05-07
Filing date: 1981-04-28
Publication date: 1981-11-11
Also published as: ES501898A0; PT72987B; IT1131447B; GR74894B; PT72987A; IT8021854A0; ES8300614A1

Abstract

A machine for packaging pieces such as tiles or bricks in general comprises an improved apparatus for tying up with wire already formed packs of said pieces. Said apparatus consists of means carrying out the feeding, the cutting and the positioning of a wire length - underneath the pack to be tied up und while the pack itself is being fed above - on two arms for winding said wire length around said pack, and it provides to wind said wire length around said pack through simultaneous rotation of said arms, immediately after the pack has been fed.

Description

The present invention relates to the systems for packaging even packs of pieces being fed irregularly, and especially packs of tiles or of bricks in general. More specifically, the present invention relates to an apparatus for tying up already formed packs of tiles, especially packs of tiles formed with the rotary vice object of the European patent application No. 80107255.4 in the name of the same Applicant. This tying up apparatus has been conceived with the object of allowing a machine for packaging the said pieces to make the most of the advantages provided by the said rotary vice.
The use of the vice according to the European patent application No. 30107255.4 allows in fact to operate at speeds for forming the packs of tiles which could never be obtained previously in this type of machines, wherein the need to improve also the devices - which, in the stages following that of forming the packs, provide for the tying up and the sorting out of said packs - appears besides evident. If, in fact, the tying up speed is not proportionate to the rythm at which the packs are formed, this will give rise to a choking in the system which undoes, in the tying up stage, the advantages obtained in the forming stage.
The devices used so far for tying up packs of bricks or of tiles in particular actually provide, in general, for three working stages: in the first stage, the wire for tying up the pack is prepared and positioned; in the second stage, the formed pack to be tied up is moved over the already prepared wire; in the third stage, the tying up is performed. Moreover, a subsequent intermediate stage is often required to allow the various parts of the tying up device to recover their initial position for the following cycle. This implicates quite a slow running of the packaging machine section dealing with the tying up of the packs.
In order to increase the speed of the tying up stage in the said packaging system, the present invention thus provides for an improved apparatus for the tying up of packs, wherein the feeding, the cutting and the appropriate positioning, under the pack, of the wire length for the tying up thereof, are carried out in a single working stage, while the pack itself is being fed above, whereupon, in a second stage, the pack is tied up with said wire length.
The apparatus according to the present invention is characterized by means for the feeding, the cutting and the positioning of the wire length, vhich comprise at least a wire feeding roller unit arranged at one end of the said apparatus, a carriage with wire drawing gripper apt to move in the longitudinal direction from said end of the apparatus to the opposite end thereof, shears arranged between said feeding unit and said carriage with drawing gripper, and a pair of nippers for positioning the wire length, apt to oscillate between a position in which they grasp the wire being fed from the carriage with drawing gripper and a position in which they present the wire to the means for winding said wire length around the pack to be tied up.
Preferably:

- the means for winding said wire length around the pack to be tied up comprise a pair of oscillating arms with end grippers, the first arm being mounted slidable onto an oscillating support to perform oscillations of about 180° around a pivot centre external thereto, while the second arm is pivoted at one of its ends to perform oscillations of about 90° around the same;
- the first winding arm is mounted slidable by means of rollers onto a support provided therefor, whereon it is subjected to the action of a spring, the said support carrying a retaining mechanism with contrast roller to balance the action of the spring alternatively with the tension of the wire grasped by the gripper of the arm itself;
- a pair of alternatively working feeding units are provided;
- the nippers for positioning the wire length are carried by end supports of a shaft being parallel to the path of the carriage with drawing gripper and being caused to oscillate by fluid pressure means;
- the winding arms are caused to oscillate simultaneously and in opposite directions by a single geared motor, through a cam, a rocking lever and suitable control leverages.

The invention will now be described in further detail, with reference to the accompanying drawings which represent, by mere way of example, a preferred embodiment thereof and in which:

Fig. 1 is a plan view of the tying up apparatus according to the invention;
Fig. 2 is a side view, with some parts removed, of the apparatus of figure 1, of which
Fig. 3 shows a head view, also with some parts removed; all the figures of these drawings being schematic.

The heretofore described apparatus for tying up packs of tiles or bricks is of the type wherein the tying up is carried out by means of a length of wire, usually iron wire, which is positioned from underneath between the two chains moving the pack forward, so as to be set with its terminals at 90° to each other in correspondence of one of the upper edges of the pack, such terminals being thus joined and twisted together by means of suitable nippers apt to fix the tying up.
With reference to the drawings, in the apparatus illustrated one notes first of all the presence of means for transporting the pack 1 to be tied up, said means consisting of a pair of longitudinal parallel transport chains 2 and of guiding supports 3. These means are housed in the upper part of the frame T of the apparatus and can be clearly seen in figures 2 and 3, while they are not shown in figure` 1.
Right beneath the pack transport means, at one end of the frame T, the apparatus according to the invention comprises means for feeding the iron wire 4 with which the tying up is carried out. Such means consist of a pair of side-by-side feeding units 5, each comprising a lower advancement roller 6 and an upper pressure roller 7 controlled by a fluid pressure cylinder 7¹. The two units 5 work alternatively, each fed by a different skein of wire 4, and they are brought in a working position through a transversal movement operated by a fluid pressure cylinder 17, each unit after running out of the skein feeding the other unit.
The wire feeding means 5 feed a wire drawing gripper 8 which is carried by a carriage 9, being movable from one end to the other of the frame T along a rail 9', under the control of a geared motor 10. With the wire drawing gripper 8 cooperate a pair of nippers 11 for positioning the wire, said nippers being carried by supports 12 which are keyed close to the ends of a longitudinal shaft 13 being parallel to the rail 9¹. The shaft 13, and with it the supports 12 and the nippers 11, can be caused to oscillate by a fluid pressure cylinder 14 acting onto a lever 15 fixed to the shaft 13. The wire drawing and positioning means are clearly illustrated in figures 1 and 3, but they are not shown in figure 2, which shows instead the wire feeding means, also shown in figure 1. To such means there are also associated shears 16 (figure 1) being interposed between the feeding units 5 and the gripper 8.
The apparatus is completed by means for winding the wire around the pack to be tied up, said means comprising a pair of oscillating arms 18 and 19 of different configuration carrying, at their ends close to the ends of the frame T, nippers 20 and 21 respectively, and having their oscillation centres in the central part of the machine, in 18 and 19' respectively. The means controlling the oscillation of the arms 18 and 19 comprise a geared motor 22, provided with a cam 23, and a connecting rod 24 which controls a rocking lever 25. This latter causes in turn the oscillation of the arm 18 - through a lever 25' with rack 26 meshing with a gearwheel 27 positioned in correspondence of the rotation centre of said arm 18 (said rotation centre being external to the arm 18, at the end of a support 28, onto the other end of which the arm 18 is slidably mounted) - and of the arm 19, directly through a connecting rod 25". The movement of the arm 18 in respect of its support 28 is guided by rollers 29 and it takes place thanks to the contrasting actions of a. return spring 30 and of the tension of the wire 4 being retained by the nippers 20 and 21 - when said wire is present - or - when the wire 4 is absent - of a retaining mechanism comprising a lever 31 fulcrumed on the support 28 and a lever 32 associated to the lever 31 and carrying a roller 32' apt to engage a fixed stop 33 of the frame T of the apparatus. The means for winding the wire around the pack to be tied up are placed in the upper part of the frame T and they can be seen in all three figures of the drawings, but particularly in figure 2.
In operation, the pack 1 to be tied up with the iron wire 4, is transported by the chains 2 in a tying up position (figure 2) and, at the same time, the length of wire 4, required for the tying up, is prepared and positioned beneath the pack 1 itself.
The preparing of the wire 4 starts by the feeding thereof on the part of the appropriate means 5: the wire, coming from a skein (not shown), is moved forward by means of the drawing roller 6 and of the pressure roller 7, up to being gripped by the drawing gripper 8 which is open in the position indicated by A in figure 1. Upon subsequent closing of the gripper 3, the roller 6 stops, the roller 7 is lifted by the cylinder 7' and the carriage 9 moves towards the opposite end of the frame T of the apparatus, thereby transporting the wire 4, clamped by the gripper 8, through the entire length of said apparatus. As seen, there are two feeding units 5, which are used alternatively under the control of the cylinder-piston 17, so as to prevent the apparatus from stopping each time the skein feeding the wire 4 in each unit has run out of wire. When the carriage 9 has reached the position indicated with B in figure 1, the nippers 11 for positioning the wire are caused to oscillate about the shaft 13 by the cylinder 14, up to moving into a suitable position for grasping the wire 4 (an intermediate position of the nippers 11 is shown in dashed lines in figure 3). The closing of such nippers then takes place and, straight after, the opening of the gripper 8 and the operation of the shears 16 which cut the wire 4 immediately downstream of its feeding means 5. Beneath the station at which the pack 1 must arrive, the wire length for its tying up is thus ready to accomplish its task. Such length must at this point be handled by the arms 18 and 19 which perform the actual tying up: for this purpose, the nippers 11 are again oscillated, in a direction opposite to the previous one, up to moving under the nippers 20 and 21 (position indicated in full lines in figure 3) which are placed at the ends of said arms 18 and 19, in respect of which they are offset in the longitudinal sense, just as it occurred between the nippers 11 and the gripper 8 in the previous stage. The wire can thus legrasped by the nippers 20 and 21, which close, while the opening of the nippers 11 takes place. At this point, the pack 1 has in the meantime reached its tying up station (figures 1 and 3). The geared motor 22 therefore starts to work and causes the arm 18 to oscillate by about 180° around the point 18', thanks to the movement which the rocking lever 25 imparts onto the rack 26 and to the rotation which this latter imparts onto the gearwheel 27. Simultaneously, the arm 19 is caused to oscillate by about 90° by the connecting rod 25" of the rocking lever 25. The two arms 18 and 19 then take up the position shown in dashed lines in figure 2. It is easy to see that, at this stage, the wire length 4 is positioned with its terminals facing each other at 90° in correspondence of an upper edge of the pack 1. Now the tying up with conventional methods may take place. It should be noted that the arm 18 is inclined, under the action of the spring 30, to keep permanently stretched the wire 4 grasped by the nippers 20 and 21, thereby allowing to easily compensate any differences in the size of the pack during tying up. The retaining mechanism 31, 32, 32', prevents on the other hand the arm 18 from moving under the action of the spring 30 during grasping of the wire length.
The skilled in the art will have already understood, from what has been said above, that the apparatus according to the present invention allows to considerably reduce the dead times which are normally present in the operations for tying up packs of tiles and the like when using the apparatuses of known technique. In fact, the two stages comprising the feeding of the pack and the wire positioning which - as mentioned hereabove - conventionally take place in succession, in the apparatus described take place simultaneously, and also simultaneous are the stages comprising the return of the winding arms 18 and 19 and the starting off or unloading of the tied up pack from the tying up station. This allows to obtain a particularly swift running of that part of the packaging machine concerned with the tying up of the pack, which is always of considerable interest, but which is particularly important hen the machine itself disposes of very fast means for forming the pack, such as for example the means described in the already cited European patent application No. 30107255.4 in the name of the same Applicant. It is in fact evident that an apparatus such as that described in this earlier application could not be rationally used, unless it were possible to carry out at an equally accelerated speed the tying up operations downstream of the same, as can actually be done with the apparatus according to the invention.
It is understood that the above description and drawings only illustrate by way of example the characteristics of the invention, and that other embodiments thereof may be possible and will appear evident to the technicians skilled in the art.
Also the specific details concerning the mechanical solutions to be adopted in the described apparatus which, to make the description simpler and clearer, it has been found preferable to illustrate in schematical terms, will appear quite evident to the skilled in the art.

Claims

1) Apparatus for tying up with wire already formed packs of pieces, especially tiles or bricks, characterized in that it comprises means for carrying out - in a single working stage - the feeding, the cutting and the proper positioning of the wire length required for the tying up, underneath the pack to be tied, while said pack is being fed above, and means for winding said wire length - immediately afterwards - around the pack to be tied up.

2) An apparatus as in claim 1, wherein said means for feeding, cutting and positioning said wire length comprise at least a wire feeding roller unit arranged at one end of said apparatus; a carriage with wire drawing gripper apt to move in the longitudinal direction from said end of the apparatus to the opposite end thereof; shears arranged between said feeding unit and said carriage with drawing gripper; and a pair of nippers for positioning the wire length, apt to oscillate between a position in which they grasp the wire being fed from the carriage with drawing gripper and a position in which they present the wire to the means for winding said wire length around the pack to be tied up.

3) An apparatus as in claim 1, wherein the means for winding said wire length around the pack to be tied up comprise a pair of oscillating arms with end nippers, the first arm being mounted slidable onto an oscillating support to perform oscillations of about 180° around a pivot centre external thereto, while the second arm is pivoted at one of its ends to perform oscillations of about 90° around said end.

4) An apparatus as in claims 1 to 3, wherein said first winding arm is mounted slidable onto its support by means of rollers and is subjected thereon to the action of a spring, the support carrying a retaining mechanism with contrast roller to balance the action of the spring alternatively with the tension of the wire being grasped by the nippers of said arm.

5) An apparatus as in claims 1 to 4, wherein a pair of alternatively working feeding units are provided.

6) An apparatus as in claims 1 to 5, wherein said feeding units are roller units.

7) An apparatus as in claims 1 to 6, wherein said nippers for positioning the wire length are carried by end supports of a shaft parallel to the path of the carriage with drawing gripper and being caused to oscillate by fluid pressure means.

8) An apparatus as in claims 1 to 7, wherein said winding arms are caused to oscillate simultaneously and in opposite directions by a single geared motor, through a cam, a rocking lever and suitable control leverages.