Priority is claimed to Swiss Patent Application No. CH 00676/16, filed on May 26, 2016, the entire disclosure of which is hereby incorporated by reference herein.
The invention relates to a glue application roller for use in a gluing assembly equipped with at least one scooping roller, whereby the glue application roller consists of a glue roller body that is provided with a central hole to receive a drive shaft. Moreover, the invention relates to a method for the operation of a gluing assembly using the glue application roller.
During bookbinding, the book blocks that have not yet been provided with a cover are transported by means of a transport device, while an application roller that cooperates with a scooping roller is rolled along the spine of the book block, thereby applying adhesive to the spine.
The contour of the spine of the book block can be straight or else round as well as quasi-round, which is why a correspondingly shaped application roller is used. Prior-art application rollers have, for example, a flat or profiled configuration.
These and similar methods and devices can be found in European patent application EP 0873882 A1, in German patent DE 3502733 C1 or in German patent application DE 4332069 A1.
The prior-art methods and devices call for a manual replacement of the application roller.
Whenever a new production order is received, the bookbinding line has to be brought to a standstill for safety reasons since the application roller can only be removed or installed when the housing is open. Consequently, after adhesive has been applied to the spine of the last book block belonging to the preceding production order, the machine first has to be brought to a standstill. After the housing is opened, the application roller that is currently present is removed and an application roller that is suited for the new production order is installed. In the ideal case, before the application roller that is currently present is removed, the application of glue onto the glue scooping roller is set to almost zero and consequently, the glue film thickness on the application roller is also set to the minimum thickness, so that the application roller can be removed with virtually no dripping. In order to remove the application roller, at least the side scraper, which is installed in the dismantling direction, has to be pivoted out of the way. Then the application roller is manually moved away from the glue scooping roller by means of a positioning unit and removed by hand. Subsequently, the new application roller is slid back onto the drive shaft and locked in place, and then moved towards the scooping roller by means of the positioning unit. Then the one scraper has to be pivoted back in place and both scrapers have to be adjusted to the thickness and diameter of the new glue application roller, and the glue film thickness on the glue scooping roller has to be set manually once again. Once the housing has been closed, the production can be started up again and the new production order can be processed.
The prior-art methods and devices are thus relatively time-consuming and also require manual intervention on the part of the operating personnel. As a result, especially in cases of small print runs, this translates into retooling that requires a relatively long time.
Moreover, European patent specification EP 2634007 B1 discloses a device consisting of at least two application rollers that are spaced axially relative to each other as well as a replacement apparatus for the application rollers. Each of the application rollers is oriented so as to be flush with the scooping roller. The replacement apparatus is configured in such a way that a first application roller that is oriented so as to be flush with the scooping roller can be replaced by a second application roller.
Owing to this configuration of the device and to the corresponding process sequence, the replacement of the application rollers arranged in the device can be carried out without manual intervention and independently of the size of the print run of a given production order.
However, such a solution encounters difficulties if glue residues harden on the disengaged glue application roller, since these glue residues then cause malfunctions during the subsequent use if they are not specifically removed or dissolved beforehand. These malfunctions are no longer so critical in the case of self-dissolving glue residues, if such types of glue are used.
European patent specification EP 2634008 B1 proposes using a certain automatic approach in a gluing assembly in order to switch over from one application roller to another. An installed application roller is dismantled in that, together with its rotating shaft, it is pivoted away from the glue scooping roller by using a pneumatic drive in such a way that this application roller can be swung out without touching the glue scooping roller.
The new application roller can be manually or automatically slid onto the rotating shaft, and then the above-mentioned pneumatic drive can bring this application roller back into position relative to the glue scooping roller. Because of the different round or straight contours of the application rollers, the distance has to be readjusted between the glue scooping roller and the rotating shaft—and thus the application roller.
In an embodiment, the present invention provides a glue application roller for use in a gluing assembly equipped with at least one scooping roller. The glue application roller includes a glue roller body that is provided with a central hole to receive a drive shaft. The glue roller body has at least two parts including a base and an outer ring. The base is operatively connected to the drive shaft by a non-positive fit. The outer ring is configured with at least one cavity. The base and the outer ring are coupled to each other non-positively via at least one first means. On at least one side of the glue roller body, there are second means that ensure that compressed air and/or another gaseous or liquid medium is fed into or discharged from the cavity so as to effectuate a change in a circumferential contour of the cavity.
The present invention will be described in even greater detail below based on the exemplary figures. The invention is not limited to the exemplary embodiments. All features described and/or illustrated herein can be used alone or combined in different combinations in embodiments of the invention. The features and advantages of various embodiments of the present invention will become apparent by reading the following detailed description with reference to the attached drawings which illustrate the following:
In an embodiment, the invention provides a remedy to the entire situation discussed above by a device and a method with which adhesive is transferred by a glue application roller onto the book spine of a book block without any manual intervention. This should be possible independently of the spine shape of the textblockbook block that is to be processed, that is to say, either with a straight and/or a round spine.
In particular, this should be possible within the scope of small print runs with varying spine shapes and especially if only one book is to be produced.
According to an embodiment of the invention, the device has a glue application roller as well as an air feed unit by means of which compressed air is fed into a glue application roller that is configured with a cavity. Instead of using compressed air, it is also fundamentally possible to use another gaseous or liquid medium.
For the sake of simplicity, the term compressed air will be used below, but without intending to exclude the use of the other above-mentioned and operatively conceivable media.
The contour of the round-spine glue roller can be changed into the straight-spine glue roller by increasing the pressure of the compressed air that is fed in. A proportional valve is used to set the pressure in accordance with the desired spine shape, thus rendering it unnecessary to replace a glue roller.
When it comes to the material of the pressure-active cavity portion of the glue application roller, it can be such that the increase in the internal pressure of the round shape (concave in the overall view) all the way to the straight contour does not end but rather can be continued until an upward curved (convex) contour is created, which is used for special textblock spines.
As a result, any glue scrapers that might be used on the outer contour of the glue application roller are not affected by the contour change and they can remain at their place of use.
In general, it applies that the internal pressure (pR) in the glue application rollerRound is less than the internal pressure (pF) of the glue application rollerFlat.
When the convex circumferential contour is created, the internal pressure (pF) of the glue application rollerFlat is smaller than the desired internal pressure (pC) of the glue application rollerConvex.
Below, the main focus will be on the change of a round-spine glue roller contour into a straight-spine glue roller contour: as a result of the change from the round-spine glue roller contour into the straight-spine glue roller contour, the effective diameters of the glue application roller and thus also its circumferential speed are changed. This change is adjusted or controlled by the drive of the gluing assembly as a function of the diameter difference.
For this purpose, according to an embodiment of the invention, the rotational speed of the drive is individually set by a frequency converter. Consequently, via a gear system, a predefined rotational speed is generated on the drive shaft on which the glue application roller is mounted. On the basis of a specially drawn-up table, a given air pressure in the glue application roller is associated with each book block as a function of its thickness and spine shape. Based on the air pressure in the application roller, specially undertaken test series were able to determine the effective diameter of the glue application roller and thus also the concave shape of the glue application roller. The effective diameter describes the apex of the roller contour that is in contact with the apex of the rounding of the book block, for example, in the case of a rounded and compressed book block.
Depending on the production speed of the bookbinding line, the book block is moved underneath the glue application roller at a defined transport speed in the transport direction of the book block. The glue application roller is wetted by the glue scooping roller at a defined glue film thickness and the glue application roller transfers this picked-up glue onto the spine of the book block. During this transfer of the glue, approximately the same speeds should prevail at the contact points of the glue application roller with the spine of the book block. Since the speed of the book block is not dependent on the book block format, but rather, is oriented towards the production speed of the bookbinding line, the speed of the glue application roller has to be adjusted here accordingly in that the rotational speed of the drive shaft is changed.
For this purpose, if all of the embodiments according to the invention are to be encompassed, the effective glue-transferring circumferential surface of the glue application roller has to have a high flexibility relative to the contour of the glue application roller that has to be wetted.
According to an embodiment of the invention, in order to avoid contamination with glue at the head or foot of the book block during the application of glue, the speed of the glue application roller can be increased or decreased in these areas and a pneumatic lifting unit can lift the entire gluing assembly off of the book block.
Improvements can be made by changing the air pressure in the glue application roller so as to avoid contamination with glue at the head or foot of the book block. During the gluing of the book block, the air pressure in the area of the head and/or foot can differ from that in the middle section of the book block. In the case of a single print run, an air pressure that is optimal for this process and that differs from that used for book block gluing can be employed to transfer the glue film from the glue scooping roller to the glue application roller, and then it is possible to switch over to the air pressure that is optimal for this book block when the book block moves past in order to have glued applied onto it.
The height difference between the glue application roller and the spine of the book block resulting from the change in the effective diameter is adjusted as a function of the difference between the radiusRound and the radiusFlat or vice versa by means of an additional height adjustment mechanism, so that the switch-over from flat spines to round spines takes place automatically.
For this purpose, an automatic height adjustment mechanism is installed on the gluing assembly. With this solution according to an embodiment of the invention, two track rollers, which are installed on the outer points of the axis of rotation of the gluing assembly, move the gluing assembly in the transport direction of the book block as a function of the book block format. The height adjustment mechanism described here is only put forward by way of example. Other solutions are also possible in which a height change from flat to round is carried out by a cylinder with a fixed stroke. The spindle has a handwheel for purposes of fine adjustment and the rocker is turned by a switchable spline.
Via a rocker to which a track roller is attached, the gluing assembly rests on a rigid support. This support is connected to the back-gluing station so that, when the height of the back-gluing station is adjusted, the height of the gluing assembly is automatically adjusted along with it when the entire gluing assembly is turned around its axis of rotation. In this process, the glue application roller executes the same height adjustment as the back-gluing station.
Owing to the automatic height adjustment mechanism according to an embodiment of the invention, it is possible to effectuate different diameters of the glue application roller. A drive serves to drive a spindle that is connected to the rocker via a pivot joint, and it rotates the rocker around its axis of rotation. Since the track roller that is attached to the rocker rests on the support, the height of the axis of rotation of the rocker is adjusted, thereby pivoting the entire gluing assembly around its axis of rotation.
The compressed air can be fed into the glue roller either centrally via a hole in the drive shaft or else via a cap that is installed on the glue application roller. In both cases, compressed air is fed into the rotating glue application roller via a revolving air distributor and it is regulated by means of a proportional valve as a function of the desired contour.
This also has the advantage that this allows the air pressure to be set very precisely. Thus, in these gluing assemblies, a variety of hot glues can be used so that the temperature of the glues during the processing can differ up to a temperature of 100° C. The proportional valve can counter a heating up of the glue application roller, thereby also countering an unwanted pressure increase in the glue application roller, so that a desired pressure can be maintained in a controlled manner.
Of course, as already mentioned above, instead of using compressed air, it is also fundamentally possible to use another gaseous medium that then behaves physically similar to air under the pressure increases that occur.
For this purpose, the glue application roller is configured for use in a gluing assembly equipped with at least one scooping roller. This glue application roller comprises a glue roller body with a central hole to receive a drive shaft.
The glue roller body consists of at least two parts, whereby, on the one hand, it comprises a base that is operatively connected to the drive shaft directly by means of a non-positive fit, and on the other hand, it comprises an outer ring that is configured with at least one cavity. The base and the outer ring are coupled to each other non-positively via at least one means, whereby, on at least one side of the glue roller body, the drive shaft is provided with central or quasi-central means via which compressed air can be fed in or discharged in order to effectuate a contour change of the outer circumference of the cavity of the outer ring of the glue roller body.
Moreover, the gluing assembly is operated making use of the glue application roller, and it entails at least the following main process steps:
This cavity, however, can also be augmented by a number of radially positioned membranes that divide the cavity into sectors, whereby these sectors are individually charged with compressed air and are configured so as to be air-tight relative to each other or else, via openings that interact, these sectors form a communicating system over the entire cavity.
According to
This pressure differential changes an outer round contour 119 of the glue roller body into a flat contour 120, as a result of which both book block spine shapes (round/flat) can be processed alternately, which can be done without replacing the glue roller bodies. The same approach in the reverse order also applies when pressure in the glue roller body has to be relieved so that the circumferential flat contour 120 of the glue roller body can be changed back into the (original) circumferential round contour. Gaskets 121 arranged on both sides ensure proper sealing of the transition of the hole 118 that conveys compressed air and that extends in the radial direction between the outer circumference of the drive shaft and the inner circumference of the base of the glue roller body.
This axially or quasi-axially oriented hole 204 passes through a bolt 206 which serves as a connection between the cap 201 and the base 104, and the bolt 206 that is screwed into the base 104 is sealed off vis-à-vis the cap 201 by means of a gasket 207.
Accordingly, in
This is thus an embodiment variant in which the air is fed into the cavity 106, without involving the drive shaft 103a.
In summary, it can be said that the compressed air is fed into the glue roller either centrally via a hole in the drive shaft (see
Consequently, it can be seen from the description of
By changing the round-spine contour into the straight-spine contour, the effective diameter of the glue application roller and thus also its rotational speed change. This change is adjusted or regulated accordingly by the drive of the gluing assembly 300 as a function of the diameter difference.
For this purpose, according to
Since the speed of the book block 305 is not dependent on the book block format, but rather, it is based on the production speed of the bookbinding line, the speed of the glue application roller has to be adjusted accordingly here by changing the rotational speed of the drive shaft 306. In order to avoid contamination with glue at the head or foot of the book block during the application of glue, the speed of the glue application roller can be increased or decreased in these areas and a pneumatic lifting unit can lift the entire gluing assembly off of the book block. Of course, improvements can be made by changing the air pressure in the glue application roller so as to avoid contamination with glue at the head or foot of the book block. Thus, during the gluing of the book block, the air pressure in the area of the head and/or foot can differ from that in the middle section of the book block. In the case of a single print run, an air pressure that is optimal for this process and that differs from that used for book block gluing can be employed to transfer the glue film from the glue scooping roller 303 to the glue application roller, and then it is possible to switch over to the air pressure that is optimal for this book block when the book block moves past (see item 307) in order to be glued.
The height difference between the glue application roller and the spine of the book block resulting from the change in the effective diameter is adjusted as a function of the difference between the radiusRound and the radiusFlat or vice versa, so that the switch-over from flat spines to round spines takes place automatically.
For this purpose, according to
Owing to the automatic height adjustment mechanism 308, it is possible to operate with different diameters of the glue application roller. A drive motor serves to drive a spindle 312 that is connected to the rocker 310 via a pivot joint 313, and it rotates the rocker around its axis of rotation. Since the track roller 309, which is attached to the rocker, rests on the support 311, the height of the axis of rotation of the rocker is adjusted, thereby pivoting the entire gluing assembly around the axis of rotation. The arrow 317 drawn on the glue application body 101 designates the rotational speed of the total rotational speed prescribed by the drive shaft 306.
This also has the advantage that this allows the air pressure to be set very precisely. Thus, in these gluing assemblies, a variety of hot glues can be used so that the temperature of the glues during the processing can differ up to a temperature of 100° C. The proportional valve can counter a heating up of the glue application roller, thereby also countering any unwanted pressure increase in the glue application roller, so that a desired pressure can be maintained in a controlled manner.
While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. It will be understood that changes and modifications may be made by those of ordinary skill within the scope of the following claims. In particular, the present invention covers further embodiments with any combination of features from different embodiments described above and below. Additionally, statements made herein characterizing the invention refer to an embodiment of the invention and not necessarily all embodiments.
The terms used in the claims should be construed to have the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article “a” or “the” in introducing an element should not be interpreted as being exclusive of a plurality of elements. Likewise, the recitation of “or” should be interpreted as being inclusive, such that the recitation of “A or B” is not exclusive of “A and B,” unless it is clear from the context or the foregoing description that only one of A and B is intended. Further, the recitation of “at least one of A, B and C” should be interpreted as one or more of a group of elements consisting of A, B and C, and should not be interpreted as requiring at least one of each of the listed elements A, B and C, regardless of whether A, B and C are related as categories or otherwise. Moreover, the recitation of “A, B and/or C” or “at least one of A, B or C” should be interpreted as including any singular entity from the listed elements, e.g., A, any subset from the listed elements, e.g., A and B, or the entire list of elements A, B and C.
Number | Date | Country | Kind |
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0676/16 | May 2016 | CH | national |
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Number | Date | Country | |
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20170341101 A1 | Nov 2017 | US |