The invention at hand relates to a method for the conversion of a letter envelope production machine from a set-up mode to a normal production mode. Letter envelopes in the sense of the invention at hand are to be understood as letter wrappings or so-called shipping pouches.
In this context it has been known to extract, for quality control purposes, at such an extraction point of the letter envelope production machine letter envelope test samples on which as many letter envelope production steps as possible have been completed. In the case of the letter envelope production machine shown in
For an extraction of the letter envelope test samples in the case of the letter envelope production machine according to
As soon as the quality of the tested letter envelope test samples meets the quality requirements, the drive of the letter envelope production machine is stopped, the reject deflector is moved into its production position, the collection container is removed from the extraction point, and the closing flap adhesive coating station is swung into its production position. Subsequently, the machine drive is activated again and the machine can be moved up to production speed.
In the case of this known method for the conversion of the letter envelope production machine from set-up mode to production mode, a disadvantage is the fact that due to the stopping of the machine drive occurring following the set-up, product or, respectively, letter envelope cutting displacements frequently occur in the letter envelope production machine whereby previously obtained set-up results can no longer be achieved following the restart of the machine for production operation so that the quality of the letter envelopes produced during the production operation will be inferior to the quality determined within the framework of the quality control during the set-up mode. In these cases, an undesired fresh set-up of the letter envelope production machine will be necessary together with the corresponding expenditures.
One or more embodiments of the present invention provides a method for converting a letter envelope production machine from a set-up mode to a regular production mode that will assure that the quality of the letter envelope test samplings obtained in the set-up mode will also be obtained during the regular production operation without the necessity of carrying out the set-up mode multiple times.
In accordance with one or more embodiments of the invention, it is proposed to allow the letter envelope production machine to continue running at least at a base speed of greater than 0 m/s during the conversion from the set-up mode to the regular production mode so that the move of the work station from its extraction position to its production position occurs during the operation of the letter envelope production machine at this base speed. The set-up results obtained during the prior set-up mode can thereby be maintained for the regular production operation or, respectively, be carried over into the production operation without any loss of quality. Accordingly, only a one-time execution of the set-up mode will be required in a time, cost and resource-saving manner in order to take up the production operation under fulfillment of the preset quality requirements. In particular, the method in accordance with one or more embodiments of the invention will lead to a considerably lower generation of paper waste as compared with the state of the art.
In a manner that is known per se, a collection container to collect the extracted letter envelope test samples may be located at the extraction location in the set-up mode. According to one or more embodiments of the invention, the conversion of the letter envelope production machine from set-up mode to production mode also comprises, in addition to moving the work station into its production position, the removal of the collection container from the extraction point so that the removal of the collection container will also occur during the operation of the letter envelope production machine at base speed.
On the job safety of the operator of the letter envelope production machine is assured during the set-up mode by the fact that the collection container as well as, if necessary, other protective devices are designed in such a way that in the area of the extraction point the operator will not be able to come in contact with any movable parts of the letter envelope production machine. As an alternative to the collection container performing a safety function, it is conceivable to arrange in the area of the extraction point a safety-engineered barrier, for example in the form of a safety fence, in lieu of the collection container and to allow the extracted letter envelope test samples to drop to the ground.
During the set-up mode, the letter envelope production machine may be operated at a predetermined set-up speed that the operator can vary depending on the individual set-up requirements. In this case, the set-up speed may be moved up to the production speed of the regular production operation.
During the conversion in accordance with one or more embodiments of the invention of the letter envelope production machine from set-up mode into production mode, it will be run at a base speed of greater than 0 m/s, which is less than the regular production speed. This base speed is selected in such a way that the set-up results obtained during the prior set-up mode will be maintained completely or at least to the greatest extent for production operation. According to one or more embodiments of the invention, the base speed will be selected within a range from 5%-30% of the production speed. In most application cases, a base speed within the range from 10%-20% of the production speed has proved to be particularly advantageous.
According to one or more embodiments of the invention, for reasons of occupational safety, the run of the letter envelope production machine is stopped automatically if and when the conversion from set-up mode to production mode exceeds a predetermined time limit. In this context, the conversion process is automatically monitored by the machine control. To this end, for example, a safety-engineered barrier that is located at the extraction point and that actuates a safety switch or the like as long as it performs is securing function is monitored as to whether or not it is moved away from the extraction point and thus no longer performs its securing function. The point in time at which the safety-engineered barrier no longer performs its securing function is registered automatically by the machine control. If the machine control determines that the work station has not been moved into its production position within the predetermined time limit calculated from the registered point in time, it will immediately stop the drive of the letter envelope production machine. For reasons of occupational safety, the preset time limit after the expiration of which the drive will be stopped lies within a range of 10-50 s, for example at 20 s.
Alternatively, there is the possibility of not coupling the point in time at which the monitoring of the preset time limit begins with the deactivation of a safety-engineered barrier but with the activation of a separate safety button by the machine operator. In this variant, the point in time at which the machine operator activates the safety sensor will be automatically registered by the machine control. If and when the machine control determines that the work station has not been moved into its production position during the allotted time, it will immediately stop the drive of the letter envelope production machine. The safety-engineered barrier which prevents the operator from coming into contact with movable parts of the letter envelope production machine may be provided additionally in order to stop the drive of the letter envelope production machine immediately following its deactivation if the safety button was not activated by the operator beforehand.
The extraction point for the extraction of the letter envelope test samples for the execution of a quality control may be located at any arbitrary point of the letter envelope production machine as long as the corresponding work station can be moved back and forth at such a point in the required manner between an extraction position and a production position. Advantageously, the extraction point will be located where a multitude of the letter envelope production steps have already been carried out so that a corresponding number of production steps can be incorporated in the quality control. In this context it is particularly advantageous to extract the letter envelope test samples at an extraction point at which the letter envelope test samples are present in the form of incompletely finished letter envelope on which the letter envelope production steps of adhesive coating and of folding of the closing flap have not yet been performed. Since the aforementioned production steps are, as a rule, the final steps in the entire production process of a letter envelope, nearly finished letter envelopes will be present at this extraction point. In the case of this choice of the extraction point according to one or more embodiments of the invention, the work station movable between the extraction position and the production position is formed by the adhesive coating station for applying adhesive to the closing flap.
Exemplary embodiments of the invention will be described with reference to the accompanying figures. Like items in the figures are shown with the same reference numbers. In embodiments disclosed herein, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid obscuring the invention.
The paper web B fed from the right in
At the pre-creasing station 12, pre-creasing scores are embedded in the precut letter envelopes in preparation of later creasing processes. At the window cutting station 13, the address window is cut out of the precut letter envelope. By means of the downstream window gluing station 14, a piece of window material is glued into the previously cut out address window. Subsequently, the lateral flaps of the precut letter envelopes are folded at the lateral flap folding station 15. The previously folded lateral flaps are coated with adhesive at the lateral flap adhesive coating station 16, and at the bottom flap folding station 17, the bottom flap is folded onto the adhesive coated lateral flaps.
The letter envelopes that are almost finished after passing through the bottom flap folding station 17 and that have non-adhesive coated and open or, respectively, not folded closing flaps are then gathered into a so-called scaling flow at the scaling station 18. This scaling flow is guided through the closing flap adhesive coating station 3 in which the exposed closing flaps are coated with adhesive. In
For the purpose of implementing the set-up mode, the closing flap adhesive coating station 3 is swung into its extraction position shown in
The collection container 4 in its position shown in
As soon as the set-up mode of the letter envelope production machine 1 has been completed, i.e. as soon as the letter envelope test samples collected in the collection container 4 meet all quality requirements, the letter envelope production machine 1 can be converted to regular production operation. To this end, it is run at a base speed that is reduced relative to the production speed, and the reject deflector 6 is moved from its extraction position shown in
Subsequently, the collection container 4 including its safety cover 8 and the chute 5 are removed from the extraction point 2. Then the closing flap adhesive coating station 3 is swung from its extraction position shown in
After moving the reject deflector 6 into its production position and before swinging the closing flap adhesive coating station 3 into its production position, letter envelopes are produced at base speed that have no adhesive or insufficient adhesive on their closing flaps. These letter envelopes can be extracted from the product flow by means of an additional reject deflector downstream in production direction of the closing flap adhesive coating station 3. Since the period of time between the move of the reject deflector 6 into its production position and the swinging of the closing flap adhesive coating station 3 into its production position is relatively short, consequently only a minor amount of such waste will be generated.
In the case of the one or more embodiments being discussed here, a safety button not shown in the drawings is arranged in the area of the extraction point 2. As soon as the safety button is actuated by the operator of the machine, it will be registered by the machine control. A preset time limit is stored in the machine control within which it is expected that the closing flap adhesive coating station 3 will reach its production position represented in
As soon as the collection container 4 leaves its position shown in
In step 130, a query is made whether or not the collection container 4 designed, for example, as a crate has been moved from its position shown in
In step 140, a query is made whether or not the removal of the collection container 4 and the closing of the closing flap adhesive coating station 3 has occurred within the preset time limit of 20 s. If both actions have occurred within the 20 s, the program will end in step 150. The machine speed can subsequently be increased to production speed.
If the two actions mentioned in step 130 did not occur within the 20 s, the machine drive will be stopped immediately in accordance with step 160 and the fact of the machine stop is reported to the operator in accordance with step 170 by means of an optical display, for example a continuous light. Subsequently, the programs will end here, too, in accordance with step 150.
While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.
Number | Date | Country | Kind |
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10 2008 025 493.2 | May 2008 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2009/003434 | 5/14/2009 | WO | 00 | 11/29/2010 |