(19) Federal Republic of Germany

[emblem]

German Patent and Trademark Office

(10) DE 102 30 335 A1 2004.01.29

(12) Offenlegungsschrift

[= Published Patent Application]

(21) Application number: 102 30 335.5 (51) Int.Cl.⁷: B65G 47/69

(22) Filing date: July 5, 2002

(43) Disclosure date: January 29, 2004

(71) Applicant: KHS Maschinen- und Anlagenbau AG, 44143, Dortmund, DE

(72) Inventors: Backhaus, Martin, 44143 Dortmund, DE;

Smusch, Günther, 59368 Werne, DE;

Mundt, Georg, 59174 Kamen, DE;

Stienen, Thomas, 59425 Unna, DE

The following information was derived from the documents submitted by the applicant.

(54) Title: Low Pressure Collection and Accumulation Table for Containers and the Like

(57) Abstract: Proposed is a low pressure collection and accumulation table for containers and the like. There are at least three different types of belts, each of which can be driven at its own speed.

[see drawing]

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Specification

[0001] The individual production machines within an entire installation of the beverage industry are usually connected via container transport systems for transporting containers that are to be processed.

[0002] These container transport systems comprise not only their own transport components, which take over in essence only the transport of containers from one processing machine to the next, but also comprise components having more extensive tasks.

[0003] These components include system modules for accumulating containers. In the field these components are referred to as accumulators or also accumulation tables.

[0004] The main objective of these accumulation tables is to maintain the production sequence without any interruption even if consecutive processing machines exhibit widely varying or different working speeds.

[0005] Another objective is to compensate for short-term stoppages of the stream of containers, coming from the upstream processing machines, owing to the supply of containers, which have accumulated inside the accumulation table, and to guarantee a continuous feed to the downstream processing machines.

[0006] Over the course of time a plethora of proposals concerning the optimal design of such an accumulation table have been made. Therefore, a first step is to categorize them according to their operating or rather accumulation principle.

Background Art

[0007] First of all, one differentiates accumulation tables, which return again the containers that are received first as the last containers into the flow of production. Such accumulation tables are generally called FILO accumulators (first in, last out). Secondly one differentiates accumulation tables, which return again the containers that are received first as the first containers into the flow of production. Such accumulation tables are called FIFO accumulators (first in, first out).

[0008] FILO accumulators have the drawback that they are suited only to a limited degree for products, where the product quality depends on the amount of processing time, including transport and waiting periods. In order to avoid an unacceptably long residence time of the containers, it is necessary - even during the on-going operation of an installation - to empty periodically all of the FILO accumulators - a state that, on the one hand, increases the complexity of the control unit and, on the other hand, renders the method of carrying out the process of the entire installation unnecessarily difficult.

[0009] Since the FIFO accumulators do not exhibit the above described drawbacks, such accumulator systems are used preferably in the beverage and/or food industry.

[0010] One possible design of the FIFO accumulation tables is the one disclosed in the US 5,282, 525. The variant, described in this document, operates with only one conveyor belt. An inlet and an outlet of the accumulation table are arranged on the opposite sides of the accumulation table. The respective width of the inlet and the outlet is small, compared to the width of the accumulation table.

[0011] The outlet side has a guide, which is inclined in relation to the stream of containers and which guides the containers to the outlet. Since the device operates with only one conveyor belt, said belt is designed as a function of the width and covers the entire width of the accumulation table. In the field this conveyor belt is designed as a belt. In order to guarantee a constant flow of containers, this conveyor belt must be designed so as to be driven continuously. As a result, the frictional forces, which are inevitably generated between the container and the conveyor belt, cause the buildup of a permanent backup pressure between the containers. If this backup pressure exceeds a certain amount, damage may occur especially in the case of already labelled or painted containers - a feature that is undesired in the field.

[0012] Since the resultant backup pressure forces in such devices increase with the number of accumulated containers, the maximum size and, thus, also the accumulation capacity is very limited. This feature constitutes another serious drawback of such devices.

[0013] A similar device is also disclosed in the US 3,650,371.

[0014] In this device the inlet conveyor and the outlet conveyor are spaced apart so as to run parallel to each other, but are disposed at different height levels. Thus, the outlet conveyor is located below the inlet conveyor. Between the two conveyors are a plurality of tables. These tables exhibit a gradient in the direction of the outlet conveyor.

[0015] The containers are transported by the inlet conveyor in a straight line as far as the end of the accumulation table. At this point the containers impinge either on a guide, which is supposed to guide them to the outlet conveyor, or on other containers, which are stored temporarily in the accumulation table. In order to pass from the inlet conveyor to the outlet conveyor, the containers have to cross the tables, which are arranged between these two (inlet and outlet conveyor). Since these tables are in essence components without any drive units for the containers, the crossing of the tables can be achieved only by means of the backup pressure of the containers. As stated above, a container movement that is based in essence on the backup pressure is not desired.

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[0016] Thus, the inclined position of the tables, proposed in the US 3,650,371 in order to avoid the backup pressure, is unsatisfactory owing to the tilting edges, which are automatically the result of such an inclined position, and the level differences between the inlet conveyor and the outlet conveyor, which is also undesired in the field. Furthermore, the vibratory drive, which is also proposed for the tables, is not satisfactory in the field owing to the enhanced risk that the containers will tilt, thus resulting in the stoppage of the operation. Another drawback of such a device is that a totally automatic empty run of the accumulator is possible only to a limited degree. Furthermore, this device offers only negligible control and regulating options for the stream of containers and the accumulator behavior.

[0017] The US 4,401,207 also proposes a device, where the distinguishing feature is that the inlet conveyor and the outlet conveyor are formed by a conveyor belt that runs through the entire accumulation table. On both sides of this through-lane conveyor belt is at least one other conveyor belt, where the belts of one side are driven in the direction of the through-lane conveyor belt; and the belts of the other side are driven in the opposite direction. Above the conveyor belts, which convey in the direction of the inlet or the outlet of the accumulation table, guides are arranged just before the inlet or outlet in such a manner that the containers, conveyed in this direction, are fed again onto the through-lane inlet and outlet conveyor belt.

[0018] If in this device not all of the delivered containers are received by the conveyor downstream of the outlet, then these containers will accumulate in the area of the outlet. At this point, they will be pushed by the backup pressure among the containers onto the belts that feed in the direction of the inlet and will be carried away by said belts. In the area of the inlet the returned containers impinge on the newly delivered containers. At this location, too, the backup pressure builds up on account of the containers bumping into each other so that the containers are also pushed onto the additional conveyor belts that feed in the direction of the outlet. As a result of these mechanisms, there is a constant inventory of containers cycling between the inlet and the outlet when there is an insufficient decrease in the number of containers on the accumulation table.

[0019] In this case a major disadvantage is that the numerous overfeed movements are caused predominantly by the backup pressure between the containers.

[0020] Other significant drawbacks that must be mentioned constitute:

- the enhanced risk that the containers will tilt, since two conveyor belts, running in different directions, are mounted directly side by side. Therefore, the containers move past each other at a relatively high speed.

- poor utilization of the area of the accumulator, since the containers move predominantly to the edges of the accumulator during the accumulation process,

- the container stream stoppages, arising when the accumulator works under no load, since the containers circle over the entire area of the accumulator.

[0021] It also turns out that the control and regulating possibilities of the accumulator is unsatisfactory, since there is no possibility of adjusting or changing the speed and/or the feed direction of the conveyor belts.

[0022] Moreover, the WO 00/41955 also proposes a device.

[0023] In this device the surface of the accumulation table is made of a plurality of conveyor belts. In this case a distinction is made between the so-called conveyor belts and the accumulation belts. They are mounted side by side in such a manner that they alternate. The number of both the feed belts and conveyor belts may be greater than one. The WO 00/41955 also provides that all of the conveyor belts are moved at a first speed and all of the accumulation belts are moved at a second speed. Therefore, the speed of the conveyor belts is supposed to be the guide variable; and the speed of the accumulation belts is supposed to be a variable speed, which, however, is always less than that of the conveyor belts. During the normal course of operation, the containers are brought onto the accumulation table by means of a conveyor belt that extends into the accumulation table. If at this stage the outlet conveyor, which is also provided, does not decrease the number of containers by the necessary amount, the excess containers are pushed onto the accumulation belts by the conveyor belts due to the backup pressure that builds up. During the accumulation of containers, the accumulation belts stand still, according to the invention. This standstill of the accumulation belts is a major drawback of such a device, since the containers to be stored are unduly delayed at the transition point from the conveyor belts to the accumulation belts. Consequently containers with a comparatively high center of gravity and small base area are especially liable to tilt in an undesired manner and may eventually fall over.

[0024] Another significant disadvantage is the high relative speed between the accumulation belts, which are standing still in the normal case, and the conveyor belts, which run at a certain speed. Since both types of belts are loaded with containers, these containers are moved past each other at the resulting relative speed. The backup pressure in the mass of containers causes the containers, which are standing on different belts, to touch each other, thus generating a considerable amount of undesired noise.

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In the long run the constant contact of the containers with each other leads to damages and eventually to increased wear of the container material, a feature that is also undesired.

[0025] Another drawback of such a device is the sharply restricted control and regulating possibilities, because the accumulation belts, which are mounted on both sides of the conveyor belts, can be driven only at the same speed. Especially in the case of accumulation tables, where the outlet is not arranged in the center, but rather laterally on the accumulation table, the drawbacks of this limited control capacity become particularly apparent, since a targeted and especially gentle feed of the containers to the outlet of the accumulation table is not possible.

[0026] In order to de-accumulate the containers, it is provided that the accumulation belts are driven at a speed that is less than the speed of the conveyor belts.

Problem

[0027] The problem and object of the present invention is to provide a pressureless FIFO accumulation table, which avoids the above described drawbacks and which constitutes an improvement especially in terms of the control characteristics of the accumulation table. To this end, it is provided that in addition to the prior art conveyor belts and accumulation belts, another type of belt, which is driven at its own speed, is introduced. This new type of belt is mounted on one side of a conveyor belt; and the accumulation belts are mounted on the other side of a conveyor belt.

Embodiment

[0028] The present invention is explained in detail below with reference to one embodiment.

[0029] Figure 1 is a top view of a buffer table of the invention. Starting from the prior art, the pressureless accumulation table, which is presented here, also exhibits at least one inlet conveyor 1. Adjacent to this inlet conveyor 1, the containers are brought onto the accumulation table by means of one feed belt or a plurality of feed belts 2 on one end of the accumulation table 3. The feed belts 2 extend over the entire length of the accumulation table 3 and feed the containers to the opposite end of the accumulation table 3. At that point the containers are fed by means of a guide 5, which is disposed at this location, in the direction of the laterally arranged outlet 4. It may also be especially advantageous for the embodiments to exhibit a plurality of inlet conveyors, several groups of feed belts 2 and/or several outlet conveyors 4.

[0030] In addition to the feed belts 2, the invention provides dispensing belts 6 on one side. These dispensing belts 6 may consist of one-lane or also multi-lane conveyor belts of known design. In addition to the dispensing belts 6, there may also be the prior art accumulation belts 7. They, too, may consist of one-lane or multi-lane conveyor belts. The prior art accumulation belts 7 may be mounted on the side of the feed belts 2 that is located opposite the dispensing belts 6.

[0031] An accumulation table of the invention provides that in areas, which are used essentially for accumulating containers, a dispensing belt 6 is mounted next to the feed belt 2; and an accumulation belt 7 is mounted next to said dispensing belt. In another, especially advantageous embodiment of the present invention, any other combination of feed, dispensing and buffer belt may also be provided. For example, experience has shown that an arrangement, for example, feed belt 2, dispensing belt 6, accumulation belt 7, dispensing belt 6 and accumulation belt 7 is especially advantageous with respect to the accumulation area that is achieved in this manner and that is significantly enlarged.

[0032] The major distinction between the prior art - in particular, the WO 00/41955 - and the present invention lies in the feature that each type of belt is driven at its own speed and that this speed is variable in relation to each other as a function of the operating conditions.

[0033] Owing to these measures and the fact that the speed of the individual types of belts can be controlled over a wide range, the accumulation characteristic and the efficiency of the accumulation table within the entire installation are significantly improved.

[0034] The drive 8 of the belts can be carried out by means of any and all drive components that are known on the market and commercially available. Figure 1 depicts these drives 8 only in symbolic form. Examples of especially desirable drives are servomotors, frequency-controlled three phase motors, etc.

[0035] The invention provides that the belt speed complies with certain specifications depending on the operating state of the accumulation table and/or the entire installation.

[0036] In this respect the next step is to describe the normal operation, without any targeted increase or decrease in the amount of containers located on the accumulation table.

[0037] In this operating state the feed belts 2 move at a certain speed that is defined by the entire installation. The accumulation belts 7 move preferably at a low speed. The dispensing belts 6 move at a speed that ranges between the speed of the two other types of belts.

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[0038] The next operating state constitutes the accumulation of containers. In so doing, the containers that are fed in via the feed belts 2 accumulate, first of all, in the area of the outlet 4. As the backup pressure increases, the containers are pushed over then onto the dispensing belts 6 and the accumulation belts 7, which are mounted next to the feed belts 2. Then as the backup pressure continues to increase, said containers are pushed further by said dispensing and accumulation belts onto belts of various types that are mounted in turn next to them and where the actual accumulation ensues.

[0039] For the operating state "accumulation" the invention provides that the feed belts 2 are moved at a speed that is defined by the entire installation. In order to guarantee the largest accumulation volume possible, it has been demonstrated to be desirable not to move the accumulation belts 7 or to move said accumulation belts only at a very low speed. The speed of the dispensing belts 6 is supposed to be, according to the invention, between the speed of the two other types of belts.

[0040] For the operating state "de-accumulation" the following belt speeds are recommended.

[0041] The speed of the feed belts 2 is defined by the entire installation even during the de-accumulation process. The accumulation belts 7 and the dispensing belts 6 are driven at a speed that is greater than zero. Thus, in this case the two speeds can also exceed the speed of the feed belts 2.

[0042] Other desirable embodiments of the present invention may also provide still other types of belts. Thus, for example, the opportunity presents itself to provide another type of dispensing belt at its own speed in order to expand even further the control possibilities of such an accumulation table so that the processing of the containers can be designed so as to be even gentler and more preserving and in order to further improve the integration of an accumulation table into the entire installation.

[0043] However, even the implementation of embodiments comprising more than three different types of belts does not mean a departure from the path of the technical teaching disclosed in the present application.

[0044] As a function of the design of the entire installation, the properties of the raw materials of the containers, and other factors, which are not treated in detail at this point, - the belt speeds and/or combinations of the belt speeds of the individual types of belts that deviate from the speeds recommended in the above described applications may be advantageous. Even such cases do not mean that the scope of the present invention is abandoned.

[0045] In order to recognize which of the above described operating states of the inventive accumulation table should be implemented for the time being in a logical way, but also in order to adjust optimally the respective belt speeds, the accumulation table has sensors (not illustrated), which acquire all of the relevant parameters, such as the number of containers, the fill rate of the accumulation table, etc., and pass said parameters to a computer system, which is also not illustrated.

[0046] The computer system can evaluate this information for the purpose of determining the suitable preset values for the individual belt speeds.

Patent Claims

1. Low pressure collection and accumulation table for containers and the like, wherein the aforementioned table comprises the following features:

frame with a first end piece of the frame, a second end piece of the frame, and two opposite lateral sides; at least one inlet on the aforementioned first end piece of the frame, at least one outlet on the aforementioned second end of the frame, where the outlet can also be disposed laterally, at least one feed conveyor, which is mounted on the aforementioned frame in such a manner that it conveys products from the first end piece to the second end piece, characterized by at least three different types of belts, each of which can be driven at its own speed.

2. Low pressure collection and accumulation table, as claimed in claim 1, characterized in that the types of belts are at least feed belts (2), dispensing belts (6), and accumulation belts (7).

3. Low pressure collection and accumulation table, as claimed in any one or both of the claims 1 and 2, characterized in that the speed of the feed belts (2) is defined by the control of the entire installation and that the speed of the feed belts (2) is steplessly adjustable from zero to a maximum value.

4. Low pressure collection and accumulation table, as claimed in one or more of the claims 1 to 3, characterized in that the speed of the accumulation belts is adjustable from zero to a speed, which exceeds the speed of the feed belts (2).

5. Low pressure collection and accumulation table, as claimed in one or more of the claims 1 to 4, characterized in that the speed of the dispensing belts (6) is adjustable from zero to a speed, which exceeds the speed of the feed belts (2).

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6. Low pressure collection and accumulation table, as claimed in one or more of the claims 1 to 5, characterized in that it has sensors for acquiring relevant information for the control of the table.

7. Low pressure collection and accumulation table, as claimed in one or more of the claims 1 to 6, characterized in that the information, acquired by the sensors, is passed on to a computer system and can be used in said computer system for determining the control information, such as the optimal belt speed.

One sheet of drawings to follow.

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