Belt buffer for a product conveying device

Abstract

The invention relates to a belt buffer for a product conveying device which conveys products (13) from a production facility by means of conveyor belts (1, 2) to at least one further processing facility. The belt buffer has at least two buffer belts, which store products (13) and are arranged vertically one above the other. The buffer belts have, on the inlet side, a first vertically pivotable belt deflector (5) for optionally connecting to an inlet belt (3) and, on the outlet side, a second vertically pivotable belt deflector (6) for optionally connecting to an outlet belt (4). The belt buffer can convey the products (13) through the buffer in a first-in first-out process.

Description

[0001] Belt buffer for a product conveyor system

[0002] Technical field of the invention

[0003] The invention relates to a belt buffer for a product conveyor system, a product conveyor system with such a belt buffer, and a method for temporarily storing products using such a belt buffer. In particular, the invention relates to a belt buffer and a product conveyor system for piece goods from the food industry that are to be processed promptly.

[0004] State of the art

[0005] When manufacturing piece goods using production lines, it is common practice to use buffers to decouple processes and increase efficiency. Quality standards are particularly important in the food industry. In production lines, the piece goods produced in rows are taken from a production facility, such as a furnace or a casting machine, via a wide main conveyor and transported via a short route to a packaging facility. These include biscuits, chocolate bars, or chocolate tablets.

[0006] Depending on production output, several packaging lines are necessary to package a produced quantity with the lowest possible scrap rate. A packaging line consists of several packaging machines connected in series, such as a flow pack machine in the first position, a multipack machine in the second position, a cartoner in the third position and finally a palletizer. If one of the machines in this line stops due to a malfunction, the entire line is out of action. To ensure that there is no overflow during constant production, either an additional so-called standby packaging line must step in or a buffer must take over the surplus products, thus preventing an overflow of products (scrap). Belt buffers are known from the state of the art. These are located at the end of a feed line and can thus accommodate the overflow of product lines that cannot be allocated to the upstream packaging machines.An overflow of product rows can occur if the packaging lines being fed from the infeed line are stopped, and thus the incoming product rows cannot be allocated. State-of-the-art cross discharge stations are used to allocate the product rows. These stations can always remove the next product row from the continuously fed flow upon request from the respective packaging line. The product rows arriving on the main conveyors are conveyed to a cross discharge belt located below the conveyor level of the main conveyors.

[0007] This cross discharge belt is arranged transversely to the main conveying direction and conveys the product rows toward the packaging machines. To ensure a seamless, continuous product flow to the packaging machines, several short gap-closing belts are connected downstream of the cross discharge belt. The previously mentioned allocation of the product rows to the packaging lines in the cross discharge station is usually achieved by a combined lowering and retraction movement of the discharge-side belt nose of the main belt of the cross discharge station. A typical feed line comprises a line head station, subsequent cross discharge stations arranged in series, and a belt buffer at the line end to accommodate the overflow of product rows.

[0008] Here, the freshly produced product rows are received from the production line in a synchronized manner at the head of the line and separated from one another by short belts, transferring them into a regular, continuous product flow. Furthermore, the product rows are detected and inspected using sensors that measure their length, height, and distance from the adjacent product row. Furthermore, the product rows can be aligned and checked for metal contamination. Unacceptable rows are ejected via a retraction movement or a vertical pivoting movement of the outlet-side belt nose of a main belt at the head of the line onto an ejection belt located below and perpendicular to the main conveying direction. Any product rows that cannot then be allocated to the packaging machines by the downstream transverse discharge stations are then fed as overflow to the belt buffer located at the end of the line.

[0009] These state-of-the-art belt buffers operate according to the first-in, last-out (FiLo) principle. One such belt buffer is known, for example, from WO 2022 / 1 17606 A1. All buffer belts are reversible, meaning that when receiving product rows, the buffer belts run in the main conveying direction, and when discharging product rows, they run opposite (reverse) to the main conveying direction. In this case, receiving product rows means storing the product, and discharging product rows means removing it from the buffer. Furthermore, this means that the inlet and outlet of the belt buffer are located in the inlet area of ​​the belt buffer.

[0010] These belt buffers at the end of the feed line consist of single or multiple layers of stationary main belts stacked one above the other, which must be operated reversibly as buffer belts. These vertically stacked buffer belts are usually served by an upstream, vertically pivoting main belt and connected to the upstream feed system. This belt must also be able to be operated reversibly in the main conveying direction and against the main conveying direction. These buffer belts at the end of the line are typically arranged one above the other in a fan-shaped manner. Thus, the belts above the feed level have an upward gradient of up to 10°, and the belts below the feed level have a downward gradient of up to 10°.This means that the inlets of these buffer belts can be arranged with a small vertical distance from each other, so that the upstream pivoting main belt can then supply the various buffer levels with product rows with a short vertical stroke, even at high row outputs.

[0011] A key requirement for such a first-in, last-out belt buffer is the return of product rows during production, counter to the main conveyor direction, to the packaging lines directly upstream. The regular return of product rows from the belt buffer to the upstream packaging lines is referred to in technical jargon as "refeed." This refeed serves to empty the belt buffer. This can counteract the threat of overfilling as the belt buffer fill level increases.

[0012] Typically, the refeed rate is linked to the fill level of the belt buffer. The higher the fill level, the higher the refeed rate. For refeed, gaps must be systematically created in the incoming product flow, into which the refeed rows must then be allocated to the packaging line upstream of the belt buffer. Experience shows that a refeed rate of at least 20% is required to empty the belt buffer in a reasonable time. The refeed rate is the excess capacity of the installed packaging capacity relative to the production output. The installed packaging capacity is the sum of the output of all packaging lines.

[0013] A disadvantage of these belt buffers at the end of the line is their inherent operation according to the FiLo principle. This means that the first product rows stored are the last to be packaged again via the refeed process. In reality, this often means that the products remain unpackaged in the buffer for hours, which is detrimental to product quality and safety. Furthermore, the buffer belts for storing and retrieving must be operated intermittently and reversibly. Because the buffer belts are geometrically arranged at an angle, as described above, the product rows experience much less friction on the belt surface. In combination with the reversing cyclic operation of the buffer belts, the products can slip very easily. This, in turn, leads to subsequent malfunctions and product loss.

[0014] It is therefore the object of the present invention to provide a belt buffer for a product conveyor and a method for temporarily storing products during processing that ensure product quality and safety, enable timely processing of products, and permit a flexible design of the product conveyor. In particular, the belt buffer should be usable at the end of the line as well as at the beginning of the line of a product conveyor and be integrated into the product flow in such a way that the described disadvantages can be avoided. Summary of the Invention

[0015] According to the present invention, this object is achieved by a buffer according to claim 1, a product conveying device according to claim 11 and a method for temporarily storing products according to claim 14. Advantageous developments and different embodiments of the invention emerge from the subclaims.

[0016] A buffer belt according to the present invention, which is designed for a product conveying system that conveys products from a production line by means of conveyor belts to at least one further processing line, has at least two buffer belts for storing products. The products are present, for example, in the form of piece goods and are arranged, for example, in product rows that can be spaced apart from one another according to the requirements of the product conveying system and the further processing line. The buffer belts are particularly designed to store products that cannot be picked up by a further processing system. The at least two buffer belts are arranged vertically one above the other. Each of the buffer belts has a vertically pivotable belt deflection for optional connection to a conveyor belt in order to pick up products.According to the invention, the buffer belts each have a first vertically pivotable belt deflection on the inlet side for optionally connecting to an infeed belt and a second vertically pivotable belt deflection on the outlet side for optionally connecting to an outfeed belt. According to the invention, a buffer level is therefore provided by a single buffer belt. The buffer belt extends from the inlet to the outlet. Each of the buffer belts has a first vertically pivotable belt deflection on the inlet side for optionally connecting to the infeed belt and a second vertically pivotable belt deflection on the outlet side for optionally connecting to the outfeed belt. The belt deflections of the buffer belts are designed as flat wings which can be pivoted at one end about a horizontally running stationary pivot axis. The other end of the wings, or the belt deflections, is thus free and can be pivoted vertically up and down in order to connect to an infeed or outfeed belt.The infeed belt and the outfeed belt can serve as conveyor belts for transporting the products along a production line of the product conveying system, wherein the products are guided along the production line in a main transport direction from the production plant to a further processing plant, in particular to a packaging plant. Advantageously, the belt buffer itself can have an infeed belt and an outfeed belt, wherein the infeed belt is provided with the first vertically pivotable belt deflection and the outfeed belt is provided with the second vertically pivotable belt deflection.

[0017] The stacked buffer belts are essentially identical in design. They each have a horizontal, stationary conveyor chassis, on one side of which the inlet-side belt deflection and on the other side of which the outlet-side belt deflection are pivotally mounted. This arrangement enables the decoupling of the outflows at the inlet and outlet, even if the buffer levels consist of only one buffer belt. The inlet-side and outlet-side belt deflections are essentially identical in design, in particular, they are the same length. The buffer belts are advantageously mirror-symmetrical to a central axis of their conveyor chassis. The free ends of the belt deflections are designed in a known manner to facilitate product pickup and product discharge. The length of the conveyor chassis can be adapted to specified spaces or desired buffer capacities and dwell times.The length of the belt deflections can be adapted to specifications regarding a maximum permissible inclination of the buffer belts.

[0018] According to a method according to the invention for temporarily storing products during product conveyance by the product conveying device, a product infeed into the belt buffer and a product outfeed from the belt buffer take place at different buffer belts arranged vertically one above the other. This means that while products are fed from the infeed belt to a first belt buffer, products at the product outlet are discharged from a different, second belt buffer to the discharge belt. This creates a decoupling of the product infeed from the product outlet and allows maximum flexibility in the allocation of products delivered to buffer belts, independent of the discharge of products from the belt buffer. In principle, it is entirely conceivable that feeding and discharge could take place via the same buffer belt. In this case, the buffer belt is comparable to a conveyor belt for product transport.A certain buffer function can be achieved by shortening the product spacing on the buffer belt compared to the product spacing on the infeed belt. However, the buffer capacity is lower in this case. The selection of the supplied buffer belt and the discharge buffer belt can be carried out using a control system for the belt buffer or the product conveyor. The control system regulates the pivoting of the belt deflections and ensures that a free end of an infeed-side belt deflection is leveled with the infeed belt, and a free end of an outfeed-side belt deflection is leveled with the outfeed belt.

[0019] The belt buffer according to the invention makes it possible to feed stored products to a further processing plant according to the first-in, first-out (FIFO) principle. The belt buffer can be flexibly integrated into the product flow. It can be positioned at the beginning of the line, in the middle of the line, or at the end of the line. The proposed belt buffer concept is particularly advantageous at the end of the line in terms of product quality and safety, as well as product handling, due to the FIFO principle. Excessively long product dwell times in the belt buffer are avoided by the FIFO principle. The multi-layer design of the buffer belts and the integration of belt deflections at the inlet and outlet give the belt buffer a short overall length while maintaining a high buffer capacity.

[0020] Various designs of the belt buffer can be provided with varying numbers of buffer belts, depending on the required buffer capacity. The minimum design is two buffer belts. Four buffer belts are advantageously used to increase the storage capacity. However, more than four, for example, six, seven, or eight buffer belts, can also be integrated. It is important that the inclination of the buffer belts during the pick-up and delivery of products is not excessive, to prevent the products from slipping off the buffer belts.

[0021] Furthermore, the belt buffer can have two infeed belts and / or two outfeed belts, each arranged vertically one above the other, wherein each of the infeed belts and / or the outfeed belts can be connected to one of the infeed-side belt deflections or the outfeed-side belt deflections arranged one above the other. In this way, the belt buffer can, for example, store products from two different production plants or different production lines.

[0022] In an advantageous embodiment of the belt buffer according to the present invention, the inlet-side belt deflection and the outlet-side belt deflection can be controlled independently of one another. Accordingly, for example, only a storage operation can initially take place without the need for a simultaneous retrieval. Several buffer belts can first be filled before retrieval is initiated. Both storage and retrieval can also take place simultaneously. Furthermore, the speeds of the products on the buffer belts during storage and retrieval can be controlled independently, and the cycle interval of the products can be adapted to the requirements of the further processing system.

[0023] In a further embodiment of the belt buffer according to the invention, at least two belt deflections arranged vertically one above the other are coupled to one another. Therefore, the number of pivot drives for pivoting the belt deflections relative to one another and the control of the belt deflections can be reduced. The coupling can be implemented, for example, mechanically, for example by means of coupling struts which articulately connect the belt deflections arranged one above the other, or by means of an electronic coupling via the control system. Subgroups of belt deflections can also be coupled to one another on the inlet side and / or the outlet side. For example, in the case of four buffer belts, the upper two belt deflections and the lower two belt deflections can be coupled, whereby the upper belt deflection group can be independent of the lower belt deflection group. This allows for a flexible

[0024] Utilization of the belt buffer and efficient operation can be achieved.

[0025] In yet another embodiment of the belt buffer according to the invention, the infeed belt, the buffer belts, and the discharge belt are arranged in series, one behind the other. Advantageously, the infeed belt and the discharge belt are arranged on one level. The infeed belt, buffer belts, and discharge belt are thus aligned along a main transport direction of the product conveyor. The products can be delivered from the discharge belt to conveyor belts of the product conveyor in the same transport direction. Thus, an infeed conveyor direction from the production plant corresponds to an outfeed conveyor direction to the further processing plant. This creates a continuous product flow without the need to reverse the transport movement of the buffer belt, the discharge belt, or the subsequent conveyor belt. There is no need to store or retrieve products counter to the main transport direction.This variant is used, for example, when the belt buffer is positioned at the beginning or in the middle of a product line.

[0026] In another product conveying system, the belt buffer can be provided at the end of the conveyor line behind the production plant and behind product discharge stations that divert products from the conveyor line to a further processing plant. In this embodiment, an outfeed conveyor direction from the belt buffer is provided opposite to an infeed conveyor direction into the belt buffer. In this case, at least one of the buffer belts and the outfeed belt can be designed to be reversibly driven. Advantageously, the lowest buffer belt is designed to be reversible, whereby the reversed products can be discharged below the other buffer belts and below the infeed belt. However, any other of the existing buffer belts for returning products can also be designed to be reversible. This embodiment is used, for example,used when the belt buffer is positioned at the end of a product line and the products are to be fed back to conveyor belts in the opposite direction of transport to take the products to the further processing plants. In this case, the products are transferred from the infeed belt to one of the upper buffer belts in the main transport direction and then transported in the main transport direction over this buffer belt. As soon as this buffer belt is full and products are to be removed, products are transferred to the outfeed belt at the opposite end of the buffer belt. The outfeed belt initially runs in the main transport direction to pick up one or more rows of products. To return to the product line, the direction of movement of the outfeed belt reverses and the products can be transferred to the reversible bottom buffer belt. On the buffer belt, the products run in the opposite direction to the infeed belt.At the end of the buffer belt, the products can be transferred to a conveyor belt of the product conveying system, which, for example, belongs to a discharge station and carries the products from the production line to a further processing facility. The infeed belt can also be designed to be reversible. In this case, the products returned from the lowest buffer belt can be picked up by the infeed belt in their reversed direction of travel. They can then, for example, be fed to another buffer belt in the main transport direction, so that the product passes through the belt buffer again, or they can be transported to a further processing facility via a discharge station.

[0027] Due to the reversibility of at least the outlet belt and one of the buffer belts, the belt buffer can be positioned flexibly in the production line without having to forego the FIFO principle for product removal. Furthermore, constant reversing on the buffer belts to achieve a desired product cycle is avoided. Cycled reversing is reduced to the outlet belt and, if applicable, the infeed belt. However, since these belts are horizontal, the sudden reversing operation is not as critical as with the inclined belts of the belt deflections, as the adhesion of the products to the horizontal belts is maximum. This greatly reduces the potential for product slippage and thus increases the efficiency of the belt buffer.In an additional embodiment of the belt buffer according to the invention, pivotable sections of the buffer belts arranged below a level of the infeed belt and / or the outfeed belt are designed as autonomous, i.e., separate, conveyor belts. At least the pivotable sections of the belt deflections of these buffer belts are provided as pivotable conveyor belts. This can support the active conveyance of the products to an ascending belt deflection.

[0028] In one embodiment of the belt buffer according to the present invention, the inlet-side belt deflectors can pivot vertically above the inlet belt. Thus, none of the buffer belts are connected to the inlet belt, creating a gap between the end of the inlet belt and the ends of the buffer belts. Product waste or overproduction can be removed from the product line through this gap.

[0029] In summary, in the method for temporarily storing products during product conveyance by a product conveying device according to the present invention, products are fed into the belt buffer and discharged from the belt buffer by different buffer belts arranged vertically one above the other. Products can be fed into the belt buffer via the infeed belt in one conveying direction to an infeed-side belt deflection of a belt buffer, and products can be discharged from another buffer belt via the outfeed belt deflection of this other buffer belt in the same or opposite conveying direction. Storage into the belt buffer and discharge from the belt buffer can be controlled independently.

[0030] Short description of the characters

[0031] The invention is illustrated below with reference to the figures, which are for illustrative purposes only and are not to be interpreted in a restrictive manner. Features of the invention revealed by the figures, individually and in any combination, are to be considered as part of the disclosure of the invention. The drawings show:

[0032] Fig. 1 is a three-dimensional schematic representation of a first embodiment of a belt buffer according to the present invention,

[0033] Fig. 2 is a side view of the first embodiment of the belt buffer from Figure 1 ,

[0034] Fig. 3 is a detailed view of an inlet area of ​​the belt buffer from Figure 1,

[0035] Fig. 4 a detailed view of belt deflections arranged one above the other in the inlet area of ​​the belt buffer from Figure 1 ,

[0036] Fig. 5 is a side schematic view of a second embodiment of a belt buffer according to the present invention,

[0037] Fig. 6 is a schematic representation of a third embodiment of a tape buffer according to the present invention,

[0038] Fig. 7 is a side schematic view of a fourth embodiment of a belt buffer according to the present invention, and

[0039] Fig. 8 is a side schematic view of a fifth embodiment of a belt buffer according to the present invention.

[0040] Preferred embodiments of the invention

[0041] Figures 1 and 2 show a first embodiment of a belt buffer according to the present invention, which is designed for a product conveying device that conveys products along a conveyor line from a production plant by means of conveyor belts 1 and 2 to at least one further processing plant. In this embodiment, the belt buffer has an infeed belt 3, four buffer belts arranged vertically one above the other, which can store products from the conveyor line, and an outfeed belt 4. It is important to note that the belt buffer could also have no infeed belt 3 or outfeed belt 4. Each of the buffer belts has a first vertically pivotable belt deflection 5, 5', 5" or 5"' on the infeed side for optionally connecting to the infeed belt 3 and a second vertically pivotable belt deflection 6, 6', 6" or 6"' on the outfeed side for optionally connecting to the outfeed belt 3.The buffer belts each have a horizontal, stationary chassis 7, on which the belt deflectors are pivotably mounted at one end. A control unit 8 is mounted next to the buffer belts and serves to control and supply power to the belt buffer. The control unit 8 can be connected to a central control system of the product conveyor system. The inlet-side belt deflectors 5 and the outlet-side belt deflectors 6 can be controlled independently of each other.

[0042] As can be seen in Figure 3, an outfeed belt 9 is provided in the infeed area below the end of the infeed belt 3, which runs transversely to a main transport direction of the conveyor line according to arrow T. Products discharged from the infeed belt 3 that are not picked up by one of the infeed-side belt deflections 5 can be discharged by the outfeed belt 9. For this purpose, all four infeed-side belt deflections 5 are pivoted upwards above the plane of the infeed belt 3 so that none of the belt deflections are connected to the infeed belt, creating a gap 14 (see Figure 5).

[0043] Figure 4 shows a drive 10 and a coupling of the inlet-side belt deflections 5. In this embodiment of the belt buffer, the drive 10 is designed as a crank drive that drives the belt deflections via a lifting mechanism 11. The lifting mechanism comprises, for example, a drive shaft with a lever and crank rod, whereby the drive shaft can be driven by a geared motor. In principle, other drives for pivoting the belt deflections can also be used. The belt deflections are coupled to one another by means of coupling struts 12 so that all four inlet-side belt deflections 5 can be pivoted simultaneously. In a similar way, a drive 10' and coupling struts 12' are provided for the outlet-side belt deflections, which are designed essentially mirror-symmetrically to the drive 10 and the coupling struts 12.

[0044] As can be seen in Figure 1, the infeed belt 3, the buffer belts, and the outfeed belt 4 are arranged in series, one behind the other. The infeed belt 3 and the outfeed belt 4 are arranged on one level. Products 13 are guided in spaced-apart rows by means of the infeed belt in the transport direction T to the infeed-side belt deflections. In the illustrated operation of the belt buffer, the products 13 are presented to the second-highest infeed-side belt deflection 5' and transferred from there to the second-highest buffer belt. At the same time, products 13' that are temporarily stored on the topmost buffer belt are delivered from the topmost outlet-side belt deflection 6 to the outfeed belt 4 and conveyed in the main transport direction T by the conveyor belt 2 to a further processing plant. Thus, a product infeed into the belt buffer and a product outfeed from the belt buffer occur via different buffer belts arranged vertically one above the other.The products are thus conveyed through the belt buffer according to the FIFO principle.

[0045] Figure 5 shows a second embodiment of a belt buffer according to the invention, which, in contrast to the first embodiment, comprises only two buffer belts. The inlet-side belt deflections and the outlet-side belt deflections are each coupled to one another, as described in Figure 4 for the first embodiment. In the method step shown in Figure 5, the inlet-side belt deflections 5 are pivoted upward above the plane of the inlet belt 3, so that a gap 14 is created between the end of the inlet belt 3 and the inlet-side belt deflections 5. Products 13 conveyed by the inlet belt 3 fall downwards onto the discharge belt 9 and are discharged. A belt buffer with only two buffer belts is useful, for example, for small production quantities or slow production processes, since it has a simple structure.

[0046] Figure 6 shows a third embodiment of a belt buffer according to the invention, which has four buffer belts, two inlet belts 3 and 3' arranged one above the other, and one outlet belt 4. In contrast to the first embodiment, the inlet-side belt deflections 5 and the outlet-side belt deflections 6 are combined into subgroups with a common drive. The two lowest inlet-side belt deflections 5" and 5"' are combined by a drive 10. The two uppermost inlet-side belt deflections 5 and 5' are combined by a drive 10". The two lowest outlet-side belt deflections 6" and 6"' are combined by a drive 10'. And the two uppermost outlet-side belt deflections 6 and 6' are combined by a drive 10".

[0047] This embodiment of the belt buffer can advantageously be positioned at the end of a product line. The outlet belt 4, the lowermost buffer belt, and at least the lower infeed belt 3' can be designed to be reversible. Products delivered via the upper or lower infeed belt are preferably stored on one of the three upper buffer belts. As soon as one of these buffer belts is completely filled with products, they can be delivered to the outlet belt 4. As soon as a product formation of, for example, four product rows has been deposited on the outlet belt 4, the direction of the outlet belt 4 can be reversed, and the product formation can be delivered to the lowermost buffer belt, which conveys the product formation to the infeed area in the opposite direction to the main transport direction.There, the product formation can be delivered to the lower infeed belt 3', from which it is conveyed further to a further processing system or to another belt deflection 5, 5', or 5". In this embodiment, the products are also conveyed through the belt buffer according to the FIFO principle.

[0048] Figure 7 shows a fourth embodiment of a belt buffer according to the invention with four buffer belts, which are designed analogously to the third embodiment. Furthermore, an infeed belt 3 and two superimposed discharge belts 4 and 4' are provided. In this embodiment, products can be fed to two discharge belts simultaneously, whereby the belt buffer can be emptied more quickly. Figure 8 shows a fifth embodiment of a belt buffer with four buffer belts, which forms a combination of the third and fourth embodiments. Two superimposed infeed belts 3 and 3' and two superimposed discharge belts 4 and 4' are provided. This embodiment is suitable, for example, as a belt storage device for two connected production lines. For example, with this embodiment, product rows can be picked up from several infeed levels and delivered to several discharge levels simultaneously.

[0049] In summary, the belt buffer according to the present invention consists of at least two or more buffer belts arranged one above the other, whose inlet and outlet end deflections 5 and 6 are wing-shaped. Each wing is mounted in the respective stationary buffer belt chassis 7 and can thus pivot vertically about this bearing point. These wing-shaped belt deflections 5 and 6 are pivotally connected to one another by couplings 12 and are driven vertically pivotably, for example, via a crank mechanism 10, thus forming a belt switch with multiple levels at the inlet and outlet of the belt buffer.

[0050] If the lower buffer belt levels are located below the inlet / outlet level, the pivoting belt deflections 5 and 6 of these buffer belt levels at their inlet and outlet consist of autonomous conveyor belts. In longer belt buffer designs, an intermediate belt is arranged on these lower buffer belt levels.

[0051] At the inlet of the belt buffer, the pivoting belt deflectors of the buffer belts can be moved upwards far enough to create a gap 14 to the inlet level of the inlet belt 3, through which defective product rows can then be ejected downwards onto an outfeed belt 9 positioned perpendicular to the main conveying direction. This ejection function also comes into play when the belt buffer is full and the overflow needs to be ejected. If the belt buffer is positioned at the start of a product line or in the middle of the line, the product flow is moved through the buffer using the FIFO principle. The incoming product rows are fed via inlet belts 3, 3' and taken over by a buffer belt level. The product rows are synchronized at a definable distance from one another until a buffer belt level is completely filled and the outfeed process can begin.The switch at the inlet then switches to the next free buffer belt level, which can then receive the product rows coming from production. This decouples the inlet and outlet of the belt buffer, because both incoming and outgoing product rows are always handled by different buffer belt levels. This also makes it possible for Buffer Control 8 to increase the speed of the outgoing product rows, typical for dynamic buffers, depending on the buffer fill level.

[0052] If the belt buffer is positioned at the end of the line, it can also be operated according to the advantageous FIFO principle according to the invention. In this case, the belts located above the feed level serve as buffer belts, onto which the incoming product rows are cycled in the main transport direction. Once a buffer belt is full, the front first belt switch at the inlet switches to another empty buffer belt and can thus continue to accept the incoming product flow. During this time, the product rows on the already filled buffer belts can be transferred via the rear second belt switch and the downstream reversible outlet belt 4 to the lowest buffer belt level. Via this lowest belt level, the product rows return to the inlet and can be conveyed back to the upstream inlet belt by switching the inlet switch.The products are returned to the lowest buffer belt level against the main transport direction. The incoming product flow is thus buffered in the main transport direction on the buffer belts above the inlet level and then diverted via the rear second belt switch to the lowest buffer belt level, before returning to the inlet side against the main transport direction. This avoids constant reversing on the buffer belts and the product flow is guided through the belt buffer according to the FIFO principle. Reversing is reduced to belts 3 and 4 upstream and downstream of the belt buffer. However, because these belts are horizontal, reversing operation is not as critical as with inclined belts because the product adhesion to the horizontal belts is maximum. This greatly reduces the risk of product rows slipping and massively increases the efficiency of the belt buffer.

[0053] Reference numerals Conveyor belt Conveyor belt ,3' Inlet belt ,4' Outlet belt ,5', 5”, 5' ” Inlet-side belt deflections, 6', 6”, 6' ” Outlet-side belt deflections Chassis Control unit Outlet belt 0, 10', 10”, 10' ” Drive 1 Lifting mechanism 2, 12' Coupling struts 3, 13' Products 4 Gap Main transport direction

Claims

Patent claims 1. Belt buffer for a product conveying device that conveys products (13) from a production plant by means of conveyor belts (1, 2) to at least one further processing plant, wherein the belt buffer has at least two buffer belts that store products (13) and are arranged vertically one above the other, wherein the buffer belts each have a vertically pivotable belt deflection for optional connection to a conveyor belt, characterized in that the buffer belts each have a first vertically pivotable belt deflection (5) on the inlet side for optional connection to an inlet belt (3) and a second vertically pivotable belt deflection (6) on the outlet side for optional connection to an outlet belt (4), characterized in that the buffer belts each have a horizontal stationary conveyor chassis (7), on one side of which the inlet-side belt deflection (5) and on the other side of which the outlet-side belt deflection (6) are pivotally mounted.

2. Belt buffer according to claim 1 comprising an infeed belt (3) and an outfeed belt (4), wherein the infeed belt (3), the buffer belts and the outfeed belt (4) are arranged in series one behind the other.

3. Belt buffer according to claim 1 or 2, characterized in that the inlet-side belt deflection (5) and the outlet-side belt deflection (6) are independently controllable, in particular independently pivotable.

4. Belt buffer according to one of the preceding claims, characterized in that at least two belt deflectors (5, 5'; 6, 6') arranged vertically one above the other are coupled to one another.

5. Belt buffer according to one of the preceding claims, characterized in that the inlet belt (3) and the outlet belt (4) are arranged on one level.

6. Belt buffer according to one of the preceding claims, characterized in that pivotable regions of the buffer belts, which are arranged below a level of the inlet belt (3) and / or the outlet belt (4), are designed as autonomous conveyor belts.

7. Belt buffer according to one of the preceding claims, characterized in that at least the lowermost of the buffer belts and the outlet belt (4) are designed to be reversibly drivable.

8. Belt buffer according to one of the preceding claims, characterized in that the inlet-side belt deflections (5) can be pivoted vertically over the inlet belt.

9. Belt buffer according to one of the preceding claims, characterized in that two inlet belts (3, 3') and / or two outlet belts (4, 4') are each arranged vertically one above the other, wherein each of the inlet belts and / or the outlet belts can be connected to at least two inlet-side belt deflectors (5) or outlet-side belt deflectors (6) arranged one above the other.

10. Product conveying device which conveys products (13) from a production plant along a production line by means of conveyor belts (1, 2) to at least one further processing plant and has a belt buffer in the conveyor line for temporarily storing products (13) according to one of the preceding claims. 1 1. Product conveyor device according to claim 10, characterized in that the belt buffer is arranged between the production plant and the Further processing plant is provided and an inlet conveyor direction from the production plant corresponds to an outlet conveyor direction to the further processing plant.

12. Product conveying device according to claim 10, characterized in that the belt buffer is provided at the end of the conveyor line behind the production plant and behind product discharge stations which divert products from the conveyor line to a further processing plant, and that an outflow conveying direction from the belt buffer is opposite to an inflow conveying direction into the belt buffer.

13. A method for temporarily storing products (13) during product conveyance by a product conveying device according to one of claims 10 - 12, wherein a product inlet into the belt buffer and a product outlet from the belt buffer occur from different buffer belts arranged vertically one above the other.

14. A method for temporarily storing products according to claim 13, wherein products (13) are fed to the belt buffer via the infeed belt (3) in a conveying direction onto an infeed-side belt deflection (5) of a buffer belt, and products (13) are discharged from another buffer belt via the outfeed-side belt deflection (6) of the other buffer belt via the outfeed belt (4) in the same or opposite conveying direction.

15. A method for temporarily storing products according to claim 13 or 14, wherein storage into the belt buffer and removal from the belt buffer are controlled independently of one another.

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