1. Field of the Invention
The present invention concerns a folding station of a folding box gluing machine for processing a blank delivered along a conveying section with a controllable delivery speed, wherein the blank has a middle piece on which side pieces are attached at the sides of the middle piece, which are folded inward along folding grooves between the middle piece and the side pieces, across a folding line toward the lengthwise middle of the blank and then folded up in order to produce the folded boxes, with a folding strap that folds the side pieces upward, being guided by a folding shunt, a positioning roller, and one or more deflection and pressure rollers.
2. Description of the Related Art
A known folding box machine used to transform blanks into folded box tubes is disclosed in DE 102 41 448. The blanks correspond to a view of a ready-to-produce folding box. The folding must be performed with precision, since the folding will determine the angle trueness of the finished folded box.
In order to produce the folded box tube, folding straps or folding bands are used and arranged to lie against portions of the blank being folded up, or the side pieces of the folding box blank, and maintain the folding along the folding line. The folding straps are arranged so as to have a helical shape and are arranged to operate on the portions being folded. To effectively perform the folding operation, the folding straps travel at a speed corresponding to the speed of the blank. In order to ensure the angle trueness of the finished folded box, a plurality of loosely turning disks are arranged in the folding line, and make contact with the folding box blank in the vicinity of the folding lines.
Another known folding station for folding blanks is disclosed in DE 44 39 198 A1. Folding is performed using folding straps, which engage the side flaps of a blank from underneath. The folding straps thus travel from a plane underneath the blank to a plane above the middle piece of the blank. The axes of the folding straps are twisted relative to each other so that the surface of the folding strap facing the blank rotates by a total of about 180 degrees along the delivery path of the blank. In order to maintain close tolerances during the folding of the blanks, an edging device is arranged in the region of the folding lines of the blanks in the forward region of the delivery path.
It is evident from the described state of the art that exact folding along the folding lines and maintaining angle trueness of the blanks after folding present problems with the conventional folding process.
To overcome the problems described above, preferred embodiments of the invention provide a folding box gluing machine which provides precise folding with minimal additional parts, and which enables adjustment of the folding station to accommodate diverse blanks in a flexible manner and with minimal expense.
A preferred embodiment of the present invention provides a folding box gluing machine in which the distance from the folding strap to the folding line of the blank is adjustable, such that the folding strap constantly works on an outer region of the side piece. Preferred embodiments of the present invention make it possible to grasp even the most diverse blanks in the region of the side pieces that is most favorable for folding to thereby assure precise folding. The adjustability of the folding strap relative to the folding line and thus to the particular length of the side piece of the blank, enables the optimal folding moment to be exerted on the blanks. The use of an adjustable modular suspension facilitates horizontal and vertical adjustment of the folding strap with respect to the direction of transport of the blanks.
Other features, elements, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments with reference to the attached drawings.
In the delivery direction, which runs from right to left in
Immediately next to the folding station 3 is the transfer station 5. The transfer station 5 feeds the folded boxes having not-yet-hardened glue seams to a collecting and pressing station 6. A stream of folded boxes is produced as they pass from the transfer station 5 to the collecting and pressing station 6. Therefore, the collecting and pressing station 6 includes pressing bands, by which the glue seams are maintained under pressure until the adhesive is securely set.
In the first region 12, the side piece of the blank, lying flat on the folding strap 8 at the beginning of the folding station, is rotated through about 90 degrees to a perpendicular position. The perpendicular position, also designated below as the vertical direction, is relative to the transport direction of the blanks, from the start of the folding station at the deflection roller 11 to the end of the third region 15.
In the first region 12, the folding strap 8 is deflected through about 90 degrees by a folding shunt 16. The deflection of the folding strap 8 pushes up the side piece of the blank by about 90 degrees. Thus, the side piece is situated at a right angle to the plane of the transport direction and is perpendicular to the middle piece of the blank. The middle region 13 follows the first region 12, and includes three deflection rollers defined by triple roller 13′ (see
According to the preferred embodiment of the present invention, the folding strap 8 is configured to be adjustable with respect to the folding line. For this, folding shunt 16, triple roller 13′ and the pressure rollers 14 are mounted on a linear guide 17 by adjustment devices 18. The adjustment devices 18 enables horizontal and vertical adjustment of the folding shunt 16, the triple roller 13′ and the pressure rollers 14. The adjustment devices 18 are freely adjustable in the preferred embodiment, and include screws 20 arranged in slots 19, see
To ensure that the folding strap 8 optimally engages with the side pieces of the blanks in the entry zone of the blanks, the location of the positioning roller 10 is also adjustable. The folding strap 8 is fed over the deflection roller 9 to the positioning roller 10. The location of the positioning roller 10 can be changed by a spindle drive with a set screw 22, which turns in the direction of the arrow P. The adjustment will be explained using
Adjustment of the folding strap 8 provides the advantage of optimal folding of the boxes in the region of the finished folding station 3. It is always preferable to apply the folding strap 8 as far away from the folding line or groove line as possible, in order to minimize deviations from the angle-true folding, also known as fish-tailing, and to provide an optimal operating location. In all known folding box gluing machines, the operating location of the folding strap always lies in the immediate vicinity of and directly on the groove line of the bend. The present invention provides for adjustment of the folding strap 8 sideways in the forward starting region 12. In the following folding shunt 16, where the folding strap 8 is twisted from about 0 degrees to about 90 degrees, the folding shunt 16 is secured to the side in the forward region and adjustable in height in the rear region.
While the present invention has been described with respect to preferred embodiments, it will be apparent to those skilled in the art that the disclosed invention may be modified in numerous ways and may assume many embodiments other than those specifically set out and described above. Accordingly, it is intended by the appended claims to cover all modifications of the invention which fall within the true spirit and scope of the invention.
Number | Date | Country | Kind |
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10 2004 022 342.4 | Apr 2004 | DE | national |