| CLAIMS 1) Device (100) for applying a liquid product (P) onto an element, comprising a supporting (1) element (50 lr) that supports two lateral containment elements (2) and a bottom element provided with a working edge, said lateral containment elements and said bottom element (3) defining a containment volume (V) for said liquid product (P) and means (5) for feeding said liquid product (P), characterized in that said feed means (5) are positioned inside said bottom element (3). 2) Device according to claim 1, characterized in that said lateral containment elements (2) are slidingly associated with said supporting element (1). 3) Device according to claims 1 or 2, characterized in that said feed means (5) comprise at least one duct (5c) provided on said bottom element (3), said duct (5c) comprising at least one outlet opening (5u) that places said duct in communication with said containment volume (V) and at least one inlet opening (5i) for said liquid product (P). 4) Device according to claim 3, characterized in that said at least one outlet opening (5u) is substantially arranged in an intermediate position with respect to the longitudinal development of said bottom element (3). 5) Device according to claims 3 or 4, characterized in that said outlet openings (5u) are more than two, uniformly distributed along the longitudinal development of said bottom element (3). 6) Device according to claims 3 or 4 or 5, characterized in that said at least one outlet opening (5u) is arranged in proximity to said working edge (3b). 7) Device according to any of the preceding claims, characterized in that it comprises means (8) suited to vary the distance of the working edge (3b) from said element (501rl) in order to vary the thickness of the product (P) deposited on said element (500rl). 8) Device according to claim 7, characterized in that said means (8) comprise at least one carriage (8c) integral with said bottom element (3) which is movable on a guide (8a) fixed to said supporting element (1). 9) Apparatus (500) for applying a liquid product onto a preferably laminate element, comprising a device (100) for applying said liquid product (P) onto an element (501rl) preferably constituted by a first roller positioned in contact with a second roller or rotating cylinder (501r2), on whose surface the bonding agent is deposited, characterized in that said device is constructed according to any of the preceding claims. 10) Apparatus according to claim 9, characterized in that a device (100) faces the surface (50 Iris) of said first cylinder or roller (501rl). 11) Apparatus according to claim 9, characterized in that said bottom element (3) is positioned obliquely with respect to the vertical plane (501rlp) on which the rotation axis (501rlr) of the first cylinder or roller (501rl) lies and its edge is suited to be arranged parallel to the rotation axis (501rlr) of the same cylinder or roller (501rl). |
FIELD OF APPLICATION OF THE INVENTION
The present invention concerns the technical field of laminate element processing, for example the paper-making and publishing sectors.
In greater detail, the present invention concerns the technical field of the equipment for applying a liquid product onto a laminate element by means of a roller or cylinder.
More particularly, the present invention can be used on apparatuses for applying or spreading a liquid product (for example, a liquid bonding agent) onto a laminate element (for example, a film or sheet, preferably made of paper) to be inserted in a production process for making bags to be obtained by folding and glueing the above mentioned laminate element.
More precisely, the invention concerns a device for applying a liquid product (for example, a liquid bonding agent) onto an element.
The invention also concerns an apparatus for applying or spreading a liquid product (bonding agent) onto a preferably laminate element (for example, a film or sheet, preferably made of paper) comprising a device of the type described above.
DESCRIPTION OF THE STATE OF THE ART
Apparatuses for applying or spreading a liquid product onto an element of the type described above by means of a roller or cylinder are known in the art. In particular, said apparatuses are used in the paper-making and publishing industry for applying the bonding agent onto a paper sheet intended to be used for making paper containers (for example, bags) to be obtained by properly folding and glueing parts of said sheet.
The roller apparatuses of known type (also called spreaders) comprise a device for applying the liquid product (bonding agent) onto an element that preferably consists of a first roller placed in contact with a second roller or rotating cylinder on the surface of which said bonding agent is deposited.
The surface of the second roller or cylinder is suited to be placed in contact with the paper sheet (or laminate element) in order to spread the bonding agent onto the sheet.
The device for applying the bonding agent comprises a supporting element (suited to be in its turn supported by a frame fixed to the structure of the spreader or suited to be rested on the ground) that supports two lateral containment elements and a bottom element consisting of a blade (also called doctor blade) whose working profile or edge is suited to face the surface of said first cylinder or roller.
More particularly, said blade (also called doctor blade) is arranged on an oblique plane (for example, on a plane parallel to a plane tangent to the surface of the cylinder) with respect to the vertical plane on which the rotation axis of the first cylinder or roller lies and its edge is suited to be arranged parallel to the rotation axis of the same cylinder or roller.
The blade or doctor blade, the lateral containment elements and the surface of the first roller or cylinder define a containment volume where the liquid bonding agent (liquid product) to be spread onto the surface of the first roller or rotating cylinder is placed.
According to the known art, there are also means suited to adjust the distance between the above mentioned working edge or profile and the surface of the roller or rotating cylinder.
Adjusting said distance means being able to check the quantity of liquid substance, that is, the thickness of the layer of bonding agent deposited on the surface of the first spread ng cylinder or roller, and therefore the quantity of bonding agent that is first deposited on the surface of the second cylinder or roller (also called spreading cylinder) during its rotation and then on the laminate element (paper sheet).
The device is supplied with the liquid product, that is, the liquid substance to be spread onto the laminate element, through feed means consisting of a pipe arranged above the doctor blade.
Always according to the known technique, the device is also provided with a sensor suited to measure the level of the substance present inside the containment volume. Said sensor is suited to signal when the liquid present inside the containment volume has reached a predefined minimum level. By warning the operator that there is a lack of bonding agent (that is, the liquid product), said means allow the operator to intervene and use the feed duct in order to feed the bonding agent into the containment volume. It should also be noted that in some solutions said rollers or cylinders have a considerable size and access to the containment volume, the bonding agent feed duct and the various parts of the device by the operator is guaranteed by the presence of a gangway arranged upstream of the first cylinder and beside the doctor blade. Said gangway develops at least for the whole length of the doctor blade.
Always according to the known technique, the device also comprises a collection tank arranged under the doctor blade and suited to collect any excess liquid substance (bonding agent) that may be present between the doctor blade and the first cylinder.
It should however be noted that the apparatuses of the type described above pose several problems; for example, it has been found that in the known apparatuses the operator does not have enough space to access the various parts of the apparatus and the device and to effectively carry out the necessary manual routine cleaning operations. It has been observed, in fact, that in order to carry out any type of operation on the device, for example to perform routine maintenance and/or feed the bonding agent and/or clean the doctor blade and/or clean the containment volume and/or check operation of the doctor blade and/or check operation of the level sensor and/or perform any maintenance operation, the operator must use the above mentioned gangway, which means having to face several obstacles. It should be observed, in particular, that the bonding agent feeding operations must take place even during operation of the apparatus. This means that in order to convey the bonding agent the operator must get on the gangway even when the rollers are rotating, which is obviously a risk for his/her health.
A further problem, typical of the known devices, is constituted by the fact that the residue collection tank is cumbersome and difficult to reach, in addition to being uncomfortable and difficult to remove.
A further drawback of the known solutions lies in that the sensor suited to detect the liquid or product level inside the doctor blade sometimes makes wrong readings of the level of liquid product present inside the spreading device. This is mainly due to the fact that during the reading process said sensor is disturbed by the presence of residues of product or dirt that have accumulated in the containment volume. This leads to a quite imprecise reading of the level of bonding agent present in the containment volume and makes it necessary to periodically remove the above mentioned residues and/or dirt. In addition to the above, said residue removal operations also affect the sensor, in fact the latter must be removed and/or disassembled with obvious risk of damage to or loss of some of its components.
A further drawback of the known solutions is represented by the fact that the known devices are particularly cumbersome.
A further drawback lies in that the feed duct, arranged above the containment volume, is quite bulky and hinders, in particular, all maintenance operations on the doctor blade and/or on the lateral containment elements, as well as the movement of the operator along the gangway.
It is therefore evident from the above that there is the need to identify alternative solutions which are more functional than the known solutions.
In view of the situation described above, it is desirable to provide a device for applying a liquid product onto an element that should be capable of eliminating or at least limiting the drawbacks posed by the known technique. It is therefore desirable to provide a device for applying a liquid product onto an element that should be capable of overcoming the drawbacks found in the device for applying a liquid product described above. Finally, it is also desirable to provide an apparatus for applying a liquid product onto a preferably laminate element comprising a device of the type described above and capable of overcoming the drawbacks posed by the apparatuses of known type.
The main object of the present invention is thus to solve or at least partially overcome the problems that characterize the solutions known in the state of the art.
In particular, it is one object of the present invention to provide a solution that makes it possible to facilitate cleaning and routine maintenance operations on both the device and the corresponding apparatus.
It is a further object of the present invention to provide a device and an apparatus that make it possible to simplify the removal of the tank for collection of the excess product present on the spreading cylinder or roller.
It is another object of the invention to provide a device that effectively and correctly detects the level of product (bonding agent) to apply (spread) present inside the containment volume.
It is a further object of the invention to provide a device in which to clean the detection means it is not necessary to remove part of the same detection means. It is another object of the invention to provide a device that is economical, easy to install and small-sized compared to known devices of a similar type.
A device and an apparatus in which the cleaning and maintenance operations to be carried out by the operator are easier than the operations required for the devices and apparatuses of known type.
It is another object of the invention to provide a device and an apparatus in which the above mentioned cleaning and routine maintenance operations require less time.
It is another object of the invention to provide a device that makes it possible to avoid any undesired outflow of bonding agent.
The invention also aims to propose a solution that makes it possible to provide a device that, though performing the same functions, has smaller minimum dimensions than the analogous devices of known type.
SUMMARY OF THE PRESENT INVENTION
The present invention is based on the general consideration that it is possible to obtain an application device of the type described above by decreasing the number of components of which it is made up.
A further general consideration on which the present invention is based is related to the fact that one or more of the elements making up the device carry out several functions.
Another consideration on which the present invention is based is related to the fact that by preparing special means for feeding the product it is possible to simplify the routine maintenance and cleaning operations and reduce any problems connected with them.
According to a first embodiment, the subject of the present invention is a device for applying a liquid product onto an element, comprising a supporting element that supports two lateral containment elements and a bottom element provided with a working edge, said lateral containment elements and said bottom element delimiting at least partially a containment volume for said liquid product, as well as means for feeding said liquid product, said feed means being arranged inside said bottom element.
The above thus shows that in the device that is the subject of the present invention the feed means are not bulky at all and thus ensure immediate and direct access to all the component parts of the device. This solution also makes it possible to produce devices and apparatuses with smaller minimum size than the devices and apparatuses of known type.
Further advantageous embodiments of the present invention are described in detail in the dependent claims. According to a further embodiment, the subject of the present invention is a device whose lateral containment elements are slidingly associated with said supporting element.
According to a further embodiment, the subject of the present invention is a device in which said feed means comprise at least one duct created in said bottom element, said duct comprising at least one outlet opening that places it in communication with said containment volume and at least one inlet opening for said liquid product.
According to a further embodiment, the subject of the present invention is a device wherein said at least one outlet duct is substantially arranged in an intermediate position with respect to the longitudinal development of said bottom element.
The above thus shows that the solution proposed according to the present invention advantageously makes it possible also to move the lateral containment elements mutually towards each other and towards the intermediate point of the bottom element, guaranteeing that the liquid product is always fed in the containment volume.
According to a further embodiment, the subject of the present invention is a device wherein said outlet openings are more than two and are uniformly distributed along the longitudinal development of said bottom element.
The above thus shows that the solution proposed according to the present invention also allows the product to flow on the whole longitudinal development of the bottom element at the same time and in a uniform manner.
According to a further embodiment, the subject of the present invention is a device in which said at least one outlet opening is arranged in proximity to said working edge, and more particularly always below the surface of the product present in the containment volume.
The above thus shows that the solution proposed according to the present invention advantageously makes it also possible to prevent the fed liquid product from coming into contact with the air. In fact, thanks to this solution the liquid product fed in the containment volume is always in contact with the liquid product already present in the containment volume.
According to a further embodiment, the subject of the present invention is a device that makes it possible to vary the distance between the working edge and the first roller or cylinder, and therefore to vary the thickness of the layer of product deposited on the cylinder or roller.
According to a further embodiment, the subject of the present invention is a device in which said means comprise at least one carriage integral with said bottom element, said carriage being movable on a guide fixed to said supporting element.
According to a further embodiment, the subject of the present invention is an apparatus provided with rollers for applying a liquid product onto a preferably laminate element, wherein said device is carried out according to any of the above solutions.
The above thus shows that the solution proposed according to the present invention also makes it possible to obtain an apparatus that offers all the advantages described with reference to the above mentioned device.
According to a further embodiment, the subject of the present invention is an apparatus in which the device is arranged so that it faces the surface of a first cylinder or roller preferably suited to be placed in contact with a second cylinder or roller.
More particularly, said device is arranged so that the bottom element is oblique with respect to the vertical plane on which the rotation axis of the first cylinder or roller lies and its edge is suited to be arranged parallel to the rotation axis of the same cylinder or roller.
Therefore, the above shows that the solution proposed according to the present invention advantageously makes it possible to achieve the set objects.
BRIEF DESCRIPTION OF THE DRAWINGS
Further advantages, objects and characteristics, as well as further embodiments of the present invention, are defined in the claims and will be illustrated in the following description, with reference to the enclosed drawings; in the drawings, corresponding or equivalent characteristics and/or components are identified by the same reference numbers. In particular:
- Figure 1 shows a partial section view of an apparatus for spreading a liquid product onto a laminate element, comprising a device for applying a liquid product onto a laminate element, both of them being the subjects of the present invention;
- Figure 2 shows a cross section view of the device for applying a liquid product onto an element and of the apparatus shown in Figure 1 ;
- Figure 3 shows an elevation view of the device and the apparatus of Figure 2 in a first operating position;
- Figure 4 shows an elevation view of the device and the apparatus of Figure 2 in a second operating position;
- Figure 5 shows another side section view of some elements shown in Figure 2; - Figure 6 shows a longitudinal section view of a member of the apparatus shown in Figure 1 ;
- Figure 7 shows a side view of an element of the apparatus shown in Figure 1 ;
- Figure 8 shows an elevation view of an element of the apparatus shown in Figure 1.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
By way of introduction, it is important to point out that corresponding components in different examples of embodiment are indicated by the same reference numbers.
In the case of a change in the position of the parts that make up the invention, the position indications given in the individual executive examples must be transferred, according to logic, to the new position.
It is also important to underline that, for a better understanding of the schematic diagrams attached, some parts of the non-limiting examples of embodiment shown have been represented using dotted lines.
While the following description, made with reference to the figures, illustrates some particular embodiments of the present invention, it is clear that the invention is not limited to said particular embodiments, rather, the individual embodiments described here below clarify different aspects of the present invention, the scope and purpose of which are defined in the claims.
According to a first embodiment, the subject of the present invention is a device for applying a liquid product onto an element.
An apparatus for spreading a liquid product onto a laminate element consisting for example of a sheet of paper S is schematically shown in Figure 1. The apparatus 500 comprises a device 100 for applying said liquid product P (comprising for example a liquid bonding agent) onto an element 501, preferably consisting of a first roller or cylinder 501rl that is placed in contact with a second roller or cylinder 501r2.
The bonding agent P is deposited, through the device 100, first on the surface 501rls of the first cylinder 501rl and then on the surface 501r2s of the second cylinder 50 lr2. The surface 501r2s is suited to be placed in contact with the sheet of paper (or laminate element) S so as to deposit the bonding agent P onto the sheet S, as shown in Figure 1.
It should be noted that the cylinders or rollers 501rl and 501r2 can be rotated on their own axes 501rlr, 501r2r, preferably in opposite directions, and that both of them can be motor driven or, alternatively, just one of them can be motor driven. The device for applying a liquid product onto an element is indicated as a whole by 100 in Figure 1 and is shown in greater detail in Figures from 2 to 5.
Said device 100 comprises a supporting element la that supports a bottom element 3 having a working edge 3b and a second supporting element lb that maintains in position two lateral containment elements 2.
It should be noted that the two supporting elements la and lb are in turn suited to be supported by means of a frame 500t fixed to the structure of the apparatus 500. Alternatively, the supports la and lb can be rested on the ground.
The lateral containment elements 2 and the bottom element 3 delimit a containment volume V for the liquid product P. The device 100 also comprises means 5 for feeding said liquid product P that are arranged inside the bottom element 3.
More particularly, in the preferred embodiments of the invention the feed means 5 comprise at least one duct 5c created in said bottom element 3, said duct 5c comprising at least one outlet opening 5u that places it in communication with said containment volume V and at least one inlet opening 5i for said liquid product P.
Said at least one outlet opening 5u is preferably arranged in a substantially intermediate position with respect to the longitudinal development of said bottom element 3, as can be seen in particular in Figures 3 and 4, and in proximity to said working edge 3b.
According to a further embodiment, the subject of the present invention is a device wherein said outlet openings 5u are more than two and are uniformly distributed along the longitudinal development of said bottom element 3.
It should also be noted that the bottom element 3 comprises a substantially flat surface 3s that is arranged obliquely with respect to the vertical plane 501rlp on which the rotation axis 50 r of the first cylinder or roller lies and its edge 3b is arranged parallel to the rotation axis 501rlr of the same cylinder or roller.
As previously explained, the surface 3 s of the bottom element 3, the inner surfaces of the lateral containment elements 2 and the surface 50 Iris of the first roller or cylinder 501rl define a containment volume V inside which the product P (in the example a liquid bonding agent) to be applied onto the surface of the laminate element S is placed.
Regarding the working profile or edge 3b, it is suited to face the surface 50 Iris of said first cylinder or roller 501rl .
The device also comprises means 8 suited to adjust the distance D between the above mentioned edge 3b and the surface 501rls of the cylinder 501rl. Adjusting said distance means being able to check the quantity of liquid substance, that is, the thickness W of the layer of bonding agent P deposited on the surface of the first spreading cylinder or roller, and therefore the quantity of bonding agent that is deposited first on the surface of the second cylinder or roller (also called spreading cylinder) during its rotation and then on the laminate element (paper sheet).
Said means 8 are arranged between the bottom element 3 and the supporting element 1 and comprise a worm screw 8a that fits into a threaded hole If made in the supporting element 1. The screw 8a is also coupled with a carriage 8c integral with the bottom element 3 that is movable on a guide fixed to the supporting element 1 constituted, in the preferred embodiment of the invention illustrated herein, by said screw 8a.
The device also comprises lifting means comprising a sensor 9 suited to detect the level of the substance present inside said containment volume. Said sensor 9 is suited to signal that the liquid present inside the containment volume has reached a minimum value with respect to a predefined value and to warn the operator that there is a lack of bonding agent P (that is, of liquid product) thus allowing the operator to intervene directly or to use an electronic control unit to activate a pump and/or automatically open a valve that allows the product P to be fed in the volume V via the above mentioned duct.
More particularly, the sensor 9 visible in particular in the Figures from 1 to 5 is supported by a bracket 9s connected to the second supporting element lb.
It should also be noted that the sensor 9 is installed directly on the doctor blade and rotating the device 100 means facilitating access to the sensor 9 (for example to perform routine checks and cleaning operations), with no need to remove it from the bracket and successively reinstall it and set it once again (as the distance of the sensor 9 from the bottom of the volume V could change). The device 100 also comprises a collection tank 15 arranged under the supporting element 3 and suited to collect any excess product P (bonding agent).
The lateral containment elements 2, one of which is shown in Figure 7, are slidingly associated with said second supporting element lb. This allows said containment elements 2 to move and reduce the area of the cylinder 50 lr affected by the deposit of product P, as shown in Figures 3 and 4.
More precisely, the lateral containment elements 2 are kept in position by means of two press members 2p slidingly fixed to the second support lb, as will be explained in greater detail below. More particularly, the two press members 2p, shown in detail in Figure 6, comprise a press element 2pe cooperating with elastic means preferably consisting of a helical spring 2pm having one end 2pm' that counteracts the second support lb through a containment element 2pc and the second end 2pm" that counteracts a preferably annular counteracting element 2pc that is integral with the press element 2pe.
As can be seen in Figure 9, each press element 2pe is slidingly coupled with a corresponding groove lbs made in the second supporting element lb shown in particular in Figure 8. Each press element is locked in the desired position by means of locking members preferably consisting of screws 2pv. In particular, Figures 3 and 4 show two of the possible positions that can be assumed by the lateral elements 2 (as can be observed, the mutual distance between the two elements can vary).
The possible movement of each lateral element is defined by the length of the corresponding groove.
The above clearly shows that the solution according to which the feed means of the product P are integrated in the bottom element 3 makes it possible to considerably reduce the complexity and the dimensions of the device 100 and the apparatus 500, ensuring easier installation and maintenance.
While the present invention has been described with reference to the particular embodiments shown in the figures, it should be noted that the present invention is not limited to the specific embodiments illustrated and described herein; on the contrary, further variants of the embodiments described herein fall within the scope of the present invention, scope which is defined in the claims.
Even though the invention has been described making reference to the attached drawings, in the construction stage changes can be made that shall all be considered protected by the present patent, provided that they fall within the scope of the inventive concept expressed in the following claims.
It is also worth noting that where the characteristics mentioned in the following claims are followed by reference signs, these are used merely to improve the comprehensibility of the claim itself and shall not be seen as limiting its interpretation in any way.
Without departing from the scope of the invention, the person skilled in the art can change and improve the subject of the invention as suggested by the natural evolution of the art.
It should also be underlined that all the parts can be replaced with other technically equivalent parts, that any material can be used, provided that it is compatible with the intended use, and that the various elements can have any size, depending on the needs.
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