Patent Application
20050000417
The present invention relates to a curling—sealing compound lining machine for non-circular metal lids of containers, from among the various machines intended for this type of construction of said container components, whether these are bases or lids of any non-circular shape, in rectangular, oval, square, triangular and other configurations.
This invention is characterised by a special construction of the machine that allows a simultaneous curling and sealing compound lining of the lid, improving its finish, increasing production and facilitating access of the lids to the sealing compound-drying oven, all of this by a rotary construction of the machine, with several consecutive, complementary working positions for the curling devices and the sealing compound lining devices, that are movable and opposite each other in every position.
For this purpose, it is provided with a new and simpler construction of the curling device, with an inclined gun focussing the sealing compound stream to the inside of the lid edge, which is made possible by an improved finish of the curling that later will also facilitate the final closure of the container.
Feeding is performed continuously, that is, without any stoppages of the main platen, as well as improving the deposition of the lid, which is carried out in the core gradually and without errors.
The discharge is also continuous and synchronised, by simultaneously providing two different speeds for the lid-conveying means.
Finally, the machine allows a simple exchange of the lid-carrying plates, the copying cam, when the implementation is by a mechanical cam, while when using an electronic cam it is enough to reprogram the servomotor set, naturally replacing the down-stacker with another suitable for the new configuration, all of this enabling a simple adaptation to any lid shape.
The earliest known antecedents for curlers of non-circular lids are those employing a press, with the disadvantage of the low production speed and the foreseeable imperfect finish resulting when the container is closed due to the need to allow exit of the lid core.
Later were implemented roller curlers, which generally used two complementary curling rollers with an incomplete finishing that resulted in a complicated closure of the container. These curling defects also cause a sealing compound fillet in a critical position, as the sealing compound wets the corners more than would be desirable.
As regards sealing compound lining machines, tampon systems are known that use a sealing compound arc with a capacity on the order of 100 lids/min. that cannot provide sealing compound to the lid flange. Equally imperfect is sealing compound showering, also using a non-revolving method, in which a mask leaves open a projection of a multiplicity of small sealing compound droplets that together form a set of aligned points that replaces the sealing compound band, naturally also used for central application of sealing compound and not under the lid curl, although it is three times faster than the immediately preceding system.
Sealing compound lining machines with a discontinuous feed using belts with an indexed (start and stop) motion, with discontinuous lid feeding, have a seriously limited speed even in the only known case where the feed and discharge lines are duplicated as well as duplicating the feed of each one, and struggle to reach 400 lids/min.
In this unique machine a lid is deposited during the stop of the belt and another during its motion, with these lids being sent to corresponding sealing compound lining stations. In these stations and during the stops of the conveyor belt the lid rotates about its axis and the sealing compound, provided with servomechanisms that can only make it rotate about its vertical axis, applies the sealing compound in different angles of inclination resulting in a sealing compound lining band that does not maintain its distance from the lid edge, despite the cost of installing the electronic control servomechanisms for the guns; in addition, the type of lid to which the sealing compound lining is applied cannot be changed as it can only be positioned by gravity, the lids are not discharged with accurate regularity, and the machine cannot operate with any conventional drying oven, nor with two independent ovens or with an oven having two scoop towers.
As regards the lid-feeding device, in the cases described heretofore, with the exception of the aforementioned double feeding system, this is performed with the belt or the rotary base stopped, and under gravity.
One known system involves a lid held in a lower, displaceable base provided with an orifice to allow the lid to fall, together with jack-knife clips that hold the pile of remaining lids placed on top of the lowermost one, until the platform returns and the clips let the lids fall on the un-perforated area of said platform.
Another better-known system is the worm gear, with generally two opposite ones used that feed each lid to a lower platen provided with satellite platens in charge of feeding the lid tangentially and with the lid support stopped.
Finally, as regards discharge devices for curing or sealing compound lining machines, the initial system involved parallel tilt bars that guided the lid and released it after raising it.
This has subsequently been changed by a faster but less efficient system that is effected in an unsynchronised manner, as the lid slides when there is dust on the belt or due to the natural asynchrony from constant use or machine vibrations.
The applicant is not aware of any curling—sealing compound lining machine for non-circular container lids that has the simplicity, speed and is as free of errors and failures in the handling of lids as the one described hereunder.
The present invention relates to a curling—sealing compound lining machine for non-circular container lids from among the various machines intended for this type of construction of the said components of containers, whether they are bases or lids of any non-circular shape.
It is important to perform the lid curling and sealing simultaneously due to the time gained in the process and the reduced energy consumption and manufacturing space, as well as the reduced costs, and further making unnecessary the intermediate storage between the stages of the process. On top of this there is the added advantage of perfected finish of the lid, eliminating rejections, as the finish of the lid edge is improved; furthermore, the contained closure is therefore improved thereby increasing the production of packaged products. The ordered and synchronised access of the lids to the sealing compound-drying oven is also facilitated.
All of this is achieved by a machine comprised of a single unit, with a prismatic construction and a body provided with common driving means, as well as an upper base having a rotary platen, that performs both the curling and sealing compound lining operations simultaneously at a high speed, rotating the lid and attaining productions of 800 lids/min.
The platen has a number of different working positions or stations that are equidistant and have a complementary consecutive action, both for the curling and the sealing compound lining devices. Both types of device are set opposite each other in each workstation, and are movable such that along a theoretical arc of almost 90° that matches the closest position of said curling and sealing compound lining devices, both the curling and sealing compound lining means are distanced from their usual working positions.
Along said theoretical arc of almost 90°, in which the run of the lids in the machine starts and finishes, the lid does not rotate about its axis; however, if the number of stations were changed if the machine were gradually increased or reduced in size or if the distance between said workstations were changed, it may be that the lid would rotate a fraction of a revolution in the first station, in the last or in both.
The three remaining theoretical 90° arcs are used for performing at most three full revolutions of the lid, so that all are used for curling and only two at most for sealing compound lining, remarking that during sealing compound lining a slight sealing compound overlapping is recommendable between the sealing compound lining end point of the first revolution and the sealing compound lining end point of the process, which leads to a slight increase in the run of the gun.
Notwithstanding the above, the possibility is not ruled out of performing the curling in two stages, and even of performing the sealing compound lining in a single theoretical arc of 90° with the aforementioned consideration of having an overlap between the initial and final ends of the sealing compound band in the case of two sealing compound lining revolutions.
This difference of action of the two devices implies a separation between the curling and sealing compound lining operations to serve as a cushion between the initial and final parts of this theoretical case, i.e. between the central, preferably sealing compound lining, arc of somewhat more than 180° when including the sealing compound overlap, and the maximum revolutions curling arc of about 270°, equivalent to three curling revolutions, with the last revolution preferably used for fine adjustment of the lid edge.
In the remaining theoretical 90° the lid-carrying platen does not turn about its axis to facilitate feeding and discharge of the lid; it is possible to reduce said theoretical or to increase the number of devices for discharge or feeding.
The construction of the sealing compound lining device allows a completely accurate inclination of the gun in any desired angle on the plane internally tangent to the edge of the lid flange, so that the width of the sealing compound stream allows to focus it not only on the inside face of the lid but also on the inner segment of the flange rounding, and by centrifugal force to a considerable extent of the flange, this being a clear advantage over the gun balancing system that in an extreme position brings the sealing compound unnecessarily close to the same edge and, alternatively, at the opposite extreme position displaces the sealing compound towards the inside of the lid, where it is not useful.
All of this is made possible by an improved finish of the curling that always precedes the sealing compound lining and that, in the curved transition areas of the lid profile, is particularly noticeable as no sealing compound overflows and is spilled outside.
In addition to this improved finish, the final closure of the container is also facilitated by a later fine adjustment of the edge line of the lid or the base in its last turn in the core.
The new feeding device, with a single spindle attacking the base of the lid deposit, allows feeding to be performed continuously for all lids, without any stoppages, improving the depositing of the lid on the lid-bearing platen, which is performed gradually and without errors by first resting a long side of the lid on the protrusion of the lid bearing core, while the worm gear maintains the lid held on the opposite side and lets it enter this protrusion gradually by pulling on the edges of the core until the lid is fully inserted in the core, with the aid in the case of ferromagnetic lids of the magnetic field created inside the core, or alternatively, of the suction force exerted by conventional vacuum means in the case of aluminium and other non-ferromagnetic lids. In turn, and in order to prevent the lid from moving from its position with respect to the lid carrying platen in any case, a top ring can be provided to guide the top central part of the lid. This ring will have a break in the lid discharge and feed area.
After the lid has been deposited in the station the curling arm will approach, followed by the sealing compound lining arm, which had both retracted previously to discharge the lid, which lid has in turn completed the full revolution of 360° for curling and sealing compound lining in the machine. The arms are also retracted to prevent collisions with the feed tower.
The discharge device allows a synchronised exit of the lids and bases by having a conveyor belt provided with either a magnetic element of greater strength than that of the core, or a lid suction power greater than that of the vacuum that held it to the core, or a combination of the two depending on each case.
After this the lid falls on a miniature conveying system with two different speeds, with the belt speed faster than the synchronism chain speed. The latter has flanges so that when acting simultaneously they allow a continuous and synchronised conveying of the lids to the drying oven.
Finally, compared to conventional machines, most of which were designed for a single type of lid for each activity, curling or sealing compound lining, this machine in addition to curling and sealing compound lining simultaneously allows operating with any type of lid shape by simply resorting to an easy and quick exchange of the down-stacker, the lid-bearing platens and the copying cam, in the simplest and cheapest case of using a mechanical cam, while in the alternative case of using an electronic cam, when the user wishes to do so for whichever reason, such as when launching short series of different lid formats and wishing to minimise the time of replacing components, no mechanical device need be replaced as it is sufficient to reprogram the servomotors, allowing a simple adaptation to all lid shapes.
The present descriptive memory is accompanied by a set of drawings that illustrate a preferred and not limiting example of the invention.
a and 7b are respectively a plan and elevation schematic view of the lid discharge device placed on a section of the machine, showing the discharge synchronisation means.
In view of the above, the present invention relates to a curling—sealing compound lining machine for non-circular container lids characterised by being comprised of a single unit, with a prismatic construction and a body provided with common driving means, as well as an upper base having a rotary platen (1), that in addition to performing both the curling and sealing compound lining operations simultaneously and at a high speed, allows operation with any type of profile of the lid (2) or base, adapting to any shape of these, for which is performed a simple and quick exchange of the lid-carrying platens (3), the copying cam (1.2) and the down-stacker (8.1); the machine (4) operates by rotating the lids among a number of workstations (5), preferably equidistant, provided with curling (6) and sealing compound lining (7) devices that are placed diametrically opposite each other in each station and are capable of moving from their usual working positions along an arc that matches the consecutive location of the feeding (8) and discharge (9) devices.
In this arc of the rotary platen (1) the lid (2) does not revolve at all, while in the arc remaining to complete the circle or to reach the following area of location of further feeding (8) and discharge (9) devices the lid (2) turns one or more full revolutions in each station (5) for curling and sealing compound lining, with the latter process preferably including a small overlap (10.1) of the continuous sealing compound band (10).
In this preferred example with a single unit of feeding (8) and discharge (9) devices, the revolution-free arc of the lid-carrier is a 90° arc, with three full revolutions performed in the following 270°, in which already act the corresponding curling (6) and sealing compound lining (7) devices that act in this single set of devices, completing the operation with the lid (2).
The curling device (6) is provided with a curling roller (6.1) held by a rod (11) and attached to a follower arm (12) that follows the path of the bottom face (1.3.1) of the copying cam (1.3), with the cams remaining fixed in place and with the assembly formed by the platen (1) and the supporting arm (1.2) of the shafts (3.1) turning about it. Said support arm (1.2) of the shafts (3.1) is in charge of providing the rotation of the lid-carrying platen (3) about its shaft (3.1) by a conventional cam-follower system.
The sealing compound lining device (7) inclines the gun (7.1) with full accuracy, following the upper profile (1.3.2) of the copying cam (1.3) by means of the follower arm (13) in any angle desired with respect to the plane of attachment to the arm (7.2) set for each type of lid, and focusing the sealing compound stream (7.3) to the base (2.1) of the lid (2), and by centrifugal force to the inner face of the flange (2.2) and to a considerable extent of the inner rounded segment (2.3) of said face, as the curling precedes the sealing compound lining and there is no external overflow whatsoever of the sealing compound, with the final closure of the lid favoured by the fine adjustment of the edge line of the lid (2).
The feeding device (8) is provided with a single spindle (8.1) and deposits continuously the lids (2) without stops or errors, first holding a long side (2.1) of the bottom lid (2) of the lid deposit (8.2) in the core (3.1) of the lid carrier (3) and then gradually resting it on the core protrusion (3.1), with the lid held by the worm gear (8.1) and on its opposite side (2.2) by the deposit (8.2), which is suitably inclined for this purpose and also to facilitate the introduction of the spindle through the end of its uppermost base (8.2.1) until it is fully inserted in the core (3.1), in which operation participate, either alternatively or complementarily, magnets (3.2) inserted in the core (3.1) or conventional vacuum means.
Afterwards the curling device (6) approaches first, and after it the sealing compound lining device (7), which had been retracted earlier by the discharge device (9) of the last finished lid (2) in order to free space for passage of the feeding tower (8.2).
The discharge device (9) is provided with a conveyor belt (9.1) having a magnetic element (9.2), that is more powerful than the magnets (3.2) of the core (3.1), and/or vacuum means that are stronger than the vacuum used to hold the lid (2) in its circular path, such that latter may remain or be eliminated when not required, then stopping the action of either of the means for absorbing the lid (2), which will fall on a mini-conveyor (9.3) provided with a belt (9.4) and a synchronism chain (9.5) that move at different speeds as they are arranged with different diameters of the main pinion (9.6), with that of the belt (9.4) greater than that of the chain (9.5), and the latter having flanges (9.7) for holding the extracted lid (2), synchronising the continuous conveying of the lids (2) to the drying oven.
Complementarily it is possible to install a top guide ring for the upper central part of the lid (2) that will be open at the segment of the platen (1) located between lid discharge and feeding.
The machine (4) may incorporate different numbers of workstations (5) in either odd or even numbers if, in order to optimise the ratio between the revolutions of the platen (1) and the revolutions of the lid-carrying platens (3) it is preferable to have machines with 4, 6, 8, 10 or 12 workstations (5), although greater numbers are not advisable as the size of the machine would interfere with the production line.
When more than one set of feeding (8) and discharge (9) devices is provided in the machine, an equal number of revolution-free arcs of the lid carrier (3) are installed with a coverage angle appropriate for the stations (5), so that the two are separated and arranged according to the corresponding revolution sector, while the curling and sealing compound lining devices (6) and (7) that operate with each set of arcs complete their action with the lid (2) before arriving at the following arc, that begins at the location of the new discharge device (9) of the curled and sealing-compound lined lid (2) and ends at the feeding device (8) that initiates the following operation on the lid (2).
In the case of machines (4) with an even number of stations (5) the feeding and discharge devices (8) and (9) can be arranged in double sets, so that a set of feeding and discharge devices (8) and (9) acts with even positions of the stations (5) and another set accts with the odd positions. These odd or even positions can incorporate lids (2) that are identical or different from each other.
When an electronic cam is provided it is sufficient to reprogram the servomotor assembly and to simply replace the down-stacker (8.1) and the lid-carrying platens (3), thus not having to replace the two internal mechanical devices, the lid-carrying platens (3) and the copying cam (1.3), as it is sufficient to reprogram the servomotor assembly.
Thus, the curling and sealing compound lining operations in the corresponding arc and with the appropriate number of revolutions, depending on the curling and sealing compound lining arcs and the stoppage arcs, as designed for each case, can be effected by a specific design of the copying cam (1.3) and the support arm (1.2) of the shafts (3.1) or, when implementing an electronic cam, by reprogramming the servomotor assembly.
Lastly, in industries requiring curling units the high productivity and low cost of this machine as compared to market-available sealing compound liners allows its application exclusively for sealing compound lining operations, for which it is only necessary to remove the curling devices (6), the rod (11) and the follower arm (12) from the various stations (5).
The essence of this invention is not affected by changes in the shape, size and arrangement of the component elements, which are described in a non-limiting manner that should allow its reproduction by an expert.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/ES02/00271 | 6/5/2002 | WO |
