Device for attaching valve bags

Abstract

Device (10) for attaching valve bags (2), in particular for attaching valve bags (2) to a filling nozzle (27) of a packaging machine (1), with at least one attachment head (20) on which a pivotable gripper device (4) and an attachment device (5) are provided, wherein the gripper device (4) is provided and suitable for gripping and receiving a valve bag (2) from a bag bundle (3) arranged on a receiving surface (6) of a deposit table (7) in a first pivot position (8) and for transferring it to an attachment device (5) in a second pivot position (9), wherein the attachment device (5) is provided and suitable for opening the valve of a valve bag (2) and accelerating the valve bag (2) for attachment, wherein the attachment device (5) consists of at least two attachment parts (11, 12), of which at least one attachment part (11) is pivotably arranged, characterized in thatthat a common drive (14) is provided for pivoting the gripper device (4) and the pivotable plug-on part (11, 12), in that the gripper device (4) and the pivotable plug-on part (11, 12) are mechanically coupled via a coupling mechanism (15), wherein the coupling mechanism (15) comprises a toggle lever (16, 17).

Description

The invention relates to a device for placing valve bags and more particularly to a device for placing valve bags on a filler neck of a packing machine.Such devices or automatic mounting devices have become known in the prior art. For example, DE 35 25 348 C2 discloses a device for placing it on the filling spout or the filling spouts of a packaging machine, in which two suction strips are provided, which grip a single bag on both sides of the bag valve and open the bag valve. Subsequently, the sack with the sack valve open is accelerated by means of drive means and shot in the direction of the filling tube. In the known device, the gripper bars for opening the blind valve are arranged in a fixed position in the longitudinal direction, as is the drive means.Since the distance of the placing device from the packing machine is usually invariable and since different bag sizes can be moved on a packing machine, it has been found that errors in placing or in shooting the bags occur to an increased extent with smaller bag widths. It has been found that this is due to the greater distance between the end of the drive means of the automatic clip-on device and the beginning of the filler neck. Accordingly, it is desirable to have a device in which the distance between the end of the driving means and the filling nozzle is adjustable.Since the displacement of the entire automatic clip-on device is too complicated, a device was constructed in which the gripper bar for opening the blind valve is arranged in a fixed position in the transport direction of the blind, while the drive device is provided so as to be adjustable in the longitudinal direction. Thus, in the case of a stationary position of the valve bags, the gripper bar can always pick up the bags at the same point, while the drive means is adjusted in the longitudinal direction depending on the width of the bags in order always to maintain an optimum distance from the filling spout of the packaging machine, so that a substantially optimum placing result is respectively achieved.In this prior art, the gripper device for gripping the bags is now stationary, while the drive means is arranged so as to be displaceable in the longitudinal direction. Furthermore, the gripper is provided so as to be pivotable about a longitudinal axis, while the drive means comprises two pivotable components which, in the closed state, can accelerate the bag and fill it onto the filling spout.DE 37 40 995 A1 discloses a gripping device for an industrial robot arm. The gripping device has a suction tube with suction cups and pivotable gripping arms. The suction cups can pick up a valve bag from a stack. The gripping arms are pivotable by pneumatic cylinders and open the valve bag for being pushed on by the robot arm. The suction pipe can be arranged displaceably.DD 216 429 A1 discloses a method and an apparatus for placing open-top bags and valve bags on filling devices. The device comprises a horizontally arranged pivotable shaft, a straight guide arranged vertically thereon with suction cups and a suction bar. The device is arranged above a bag magazine. By the rectilinear guidance, an upper side of a bag is sucked directly out of the magazine. The shaft is then pivoted by a separate drive, so that the underside of the bag is guided over the suction strip. The bag is prepared for mounting. However, it has proven disadvantageous that the different movements of the drive means and the gripper device must be matched exactly to one another in terms of time. This is because safety times must be provided for this purpose, so that a considerable period of time must be provided for carrying out the various movements. This limits a possible increase in capacity.WO 97 / 22522 A1 also discloses a device for placing valve bags on a filler neck of a packaging machine. In this case, the blind valve of the uppermost valve bag is gripped by a stack of bags by means of a suction strip and the valve bag is introduced laterally into a receiving element of a storage or conveyor belt by a slide or by means of a pressed-on drive roller. The movements are positively coupled, so that a collision of the drive roller with the suction strip is not possible.A disadvantage here is that the speeds of movement of the suction bar and of the drive rollers are predetermined with respect to one another by the simple deflection mechanism. The placing time and thus the placing rate are determined by the handling step in the movement sequence at the lowest permissible speed in order to ensure sufficient operational reliability of the placing process. High clip-on rates cannot be achieved.It is therefore the object of the present invention to provide a device for plugging on valve bags which permits a high plug-on rate.This object is achieved by a device having the features of claim 1. Further features of the present invention are defined in the following description.The device according to the invention is provided for placing valve bags on one or more filling nozzles of a packaging machine. The apparatus according to the invention comprises at least one mounting head on which a pivotable gripper device and a mounting device are provided. The gripper device is provided and suitable for reaching and receiving a valve bag of a bag bundle arranged on a receiving surface of a storage table in a first pivoted position and transferring it to a placing device in a second pivoted position. The plug-on device is in turn provided and suitable for opening the valve of a valve bag and accelerating the valve bag for plug-on. According to the invention, the mounting device consists of at least two mounting parts, of which at least one mounting part is arranged, for example, pivotably, while the other mounting part cannot be provided pivotably or else pivotably. According to the invention, a common drive is provided for pivoting the gripper device and for pivoting the pivotable attachment part. For this purpose, the gripper device is mechanically coupled to the pivotable mounting part via a coupling mechanism. The coupling mechanism comprises a toggle lever.The invention has many advantages. It is particularly advantageous that only one common drive is required for pivoting with the gripper device and for pivoting the individual parts or components of the mounting device, since the individual components are connected via a coupling mechanism. The positively controlled mechanical coupling of the gripper device and the pivotable parts of the mounting device leads at any time to an exactly defined spatial position of the different parts with respect to one another, so that a collision of the individual parts with one another is in principle not possible. This eliminates a considerable portion of time, which must be taken into account in conventional solutions, since no safety times need to be observed between the individual movements. Rather, different movements can be started simultaneously in a coordinated manner.Preferably, the placing device is arranged adjustable in the longitudinal direction with respect to the gripper device in order to be able to compensate for different bag dimensions during placing. According to the invention, the coupling mechanism comprises a toggle lever. This is advantageous because a toggle lever allows a fast movement at one end to be transferred into a slow movement at the other end initially and vice versa.In a further preferred development of the invention, the toggle lever engages on a sliding rod and is fastened thereto so as to be displaceable in a longitudinal direction.Preferably, the coupling mechanism for the motion-coupled pivoting of the gripper device and of the pivotable attachment part has two toggle levers connected to one another in order to further reinforce the effect.This enables movement sequences that are exactly matched to one another, so that a very high working speed can be achieved. At the same time, the use of only one drive saves considerable technical and financial expenditure.In preferred refinements, the placing device is arranged displaceably along the sliding rod, so that with a fixed gripper device, a spatially variable placing device is made possible in order to be able to compensate for different bag dimensions during processing.In particular, the attachment device has two pivotable attachment parts and is composed overall of the two pivotable attachment parts. In this case, a plug-on part has, in particular, an opening element of an opening device in order to open the blind valve of a blind to be plugged on. Furthermore, the attachment device or each attachment part has an element of the acceleration device, so that when the two pivotable attachment parts are pivoted, an opening element and an acceleration element are pivoted in each case.In further developments, one and in particular exactly one attachment part is provided so as to be pivotable about the sliding rod or a rotating rod connected thereto in a rotationally fixed manner. Furthermore, it is possible that the gripper device is also provided to be pivotable about the rotary rod connected to the sliding rod in a rotationally fixed manner.In all embodiments, the gripper device preferably comprises a suction bar with a plurality of suction devices, wherein individual suction devices can preferably be switched off depending on the bag dimensions, so that the number of suction devices to which vacuum can be applied is variable.The attachment device preferably comprises a bag opening device, wherein the opening device preferably has an angled sheet metal on each of the two attachment parts. The two angled sheets in the position pivoted towards one another overall result in an approximately rectangular and in particular even almost square cross section, wherein one diagonal is oriented horizontally from corner to corner and the other diagonal is oriented approximately vertically from corner to corner. The length of the horizontal diagonal is smaller than the width of the blind valve, so that a blind valve held at the top in the middle automatically opens when the angled sheets are pivoted together.In particularly preferred refinements, the attachment device comprises an acceleration device which comprises a roller strip on an attachment part. Preferably, the acceleration device further comprises a belt drive on the other attachment part.Further advantages and possible applications of the present invention are evident from the exemplary embodiments which are described below with reference to the appended figures.Shown therein are: FIG. 1 is a schematic top view of a system with a packing machine and a device for placing valve bags; FIG. 2 is an overall view of the device according to the invention for placing valve bags; FIG. 3 shows a perspective view of the mounting head of the device according to FIG. 2 in a first position; FIG. 4 shows the mounting head of the device in a second position; FIG. 5 shows the mounting head of the device according to FIG. 2 in a third position; and FIG. 6 shows the mounting head of the device according to FIG. 2 in a fourth position.With reference to the figures, an exemplary embodiment of the device 10 according to the invention is now explained, which is designed as an automatic placing machine and serves for placing valve bags 2 on the filling nozzle or nozzles of a packaging machine 1.FIG. 1 shows a plant which has a packaging machine 1 for filling products into bags 2, an automatic placing machine 10 and a discharge belt 70 for transporting away the filled valve bags 2. The packaging machine 1 is designed here as a rotating filling system with a plurality of filling nozzles 27, onto which the valve bags 2 to be filled are plugged by means of the automatic plug-on device 10.The packing machine 1 rotates in the direction of rotation 48 while the attached valve bags 2 are being filled. The completely packed valve bags 2 are deposited on the discharge belt 70 and thus transported away.For example, such bags 2 are automatically filled with construction materials, such as cement, or with other pulverulent or granular materials. For this purpose, for example, the rotating packaging machine illustrated in FIG. 1 is used. It is also possible to use a row packer. In rotary packaging machines, the plurality of filling nozzles 27 are arranged symmetrically distributed over the circumference. The device 10 for placing the valve bags on, as shown in FIG. 2, is arranged at a predetermined angular position of the packaging machine 1.When a filling nozzle 27 of the packaging machine 1 is now in the placing position, an empty bag 2 is placed on the filling nozzle 27 with the aid of the placing head 20 using the placing machine 10.Modern packaging machines 1 with a number of eight or twelve or even sixteen filling nozzles have enormous throughput capacities, at which filling rates in the order of magnitude of 1 sack per second and more are possible. This means that about 3000 to 5000 bags are filled per hour, which represents an enormous logistic requirement.Automatic mounting machines have therefore become known for automatizing the mounting, in which an empty bag magazine 30 temporarily stores the bags for the automatic mounting machine.The operator then only has to insert bundles of bags 3 into the compartments 31 of the empty bag magazine 3. The bundles of bags are automatically fed to the depositing table 7 and are lifted individually from the receiving surface 6. Subsequently, the valve of the valve bag 2 is opened and the valve bag is fired onto the filling nozzle of the packaging machine 1.FIGS. 3 to 5 show an enlarged perspective illustration of the placing head 20 of the automatic placing machine 10 according to the invention in four different positions, wherein in the illustrations according to FIGS. 3 and 4 the placing head 20 is shown in the position for processing wide bags, while in the illustrations according to FIGS. 5 and 6 the placing head 20 is set for processing narrower bags.The mounting head 20 of the automatic mounting device 10 shown in enlarged form in the perspective illustration according to FIG. 3 comprises a housing 32 for storing and arranging the various components.The gripper device 4 is provided pivotably on the housing 32, which gripper device comprises a suction strip 19 which, in a first pivoting position 8, grasps the uppermost valve bag 2 of a bag bundle 3 consisting of valve bags 2 stacked flat one above the other. For this purpose, the suction strip 19 has a plurality of suction elements 33 spaced apart from one another in the longitudinal direction 13, which can preferably be individually switched on and off in order to adapt the active length of the suction strip to the current bag width 34.Furthermore, a mounting device 5 is arranged on the housing 32, which device here consists of two pivotable mounting parts 11 and 12 which pivot relative to one another during opening or closing.The attachment device 5 comprises the attachment parts 11 and 12, wherein an angled sheet metal 22 or 23 of a blind valve opening device 21 is provided on each attachment part. Furthermore, a roller strip 25 is provided on the attachment part 11 and a belt drive 26 is provided on the attachment part 12 which serves for driving and accelerating a bag arranged between the roller strip 25 and the belt drive 26.The roller strip 29 serves to guide the bag during the mounting and is opened only in the event of a malfunction. The pressure cylinder 49 presses the roller strip 29 uniformly against the belt drive 26.FIG. 3 shows the placing head 20 in a position in which the suction bar 19 is pivoted into the first pivot position in order to lift a new bag 2 from the bag bundle 3. In this case, the suction devices 33 of the suction strip 19 grip the bag in the bag valve region. At the same time, in the position according to FIG. 3, the mounting device 5 or its mounting parts 11 and 12 are shown in the pivoted, i.e. moved apart position. The movements of the attachment parts 11 and 12 and of the gripper device 4 with the suction bar 19 are mechanically positively coupled via the coupling mechanism 15, so that when the gripper device 4 is moved, the attachment device 5 also automatically moves. The movement is controlled by a drive 14, which is designed here as a piston-cylinder unit, whereby a fast and precise movement is possible even in dusting environments over long periods of time.The drive 14 acts directly on the pivot arm 37 of the gripper device 4 here, which transmits the torque via the pivot axis 41 to the lever 36, which in turn transmits the torque via the pivot point 42 to the lever 39 and finally to the lever 40. The two toggle levers 16 and 17 formed in this way control the movement sequence of the gripper device 4 and of the mounting device 5 in such a way that collisions are avoided, while at the same time a substantially maximum operating speed and operating reliability is achieved. This means here that, when the suction bar is transferred from the position shown in FIG. 3 into the position shown in FIG. 4, the suction bar is first pivoted upwards at a high speed, while the closing speed of the pivoting movement of the two attachment parts 11 and 12 remains virtually constant over the entire pivoting process, so that the risk of a collision is reliably avoided.At the same time, the positively controlled mechanical coupling of the two pivotable components, namely the gripper device and the mounting device, only requires one drive 14, which saves considerable additional effort.The transmission of the pivoting movement to the gripper device 4 is effected by the lever 40, which is pivoted about the pivot point 46 and thereby brings about a movement of the first coupling rod 44 and the second coupling rod 45 and of the lever 47. The second coupling rod 45 arranged parallel to the lever 47 forms a parallelogram guide which brings about a constant alignment of the suction strip, so that during the movement the position of the blind valve region 35 does not change with respect to the horizontal alignment.After the transfer from the position shown in FIG. 3 to the position shown in FIG. 4, the bag valve is opened by the closing operation of the angled sheets 22 and 23 of the bag opening device 21, while the bag extends downward between the roller strip and the belt drive 26. After the valve has been opened, the belt drive 26 is activated and the bag is fired in the longitudinal direction 13 onto a filling nozzle 27 of a packing machine or filling system 1.The states of the placing head 20 shown in FIGS. 5 and 6 correspond in principle to the states shown in FIGS. 3 and 4, but the placing head 20 is set for the processing of narrower bags 2.In order to keep the distance to be bridged from the end of the placing device 5 to the beginning of the filler neck at a constant and as small a measure as possible even in the case of narrower bags, the placing device 5 is moved in the longitudinal direction 13. As a result, a transfer from the state shown in FIG. 3 by longitudinal displacement results in the state shown in FIG. 5.At the same time, the gripper device 4 has kept its position stationary, since the support surface 6 of the depositing table 7 remains stationary. The coupling mechanism 15 here allows a very comfortable and reliable mode of operation of the automatic clip-on device 10, since the clip-on device 5 is mounted on the slide rod 18 such that it can be displaced with respect to the gripper device 4. The coupling mechanism 15, which engages on the slide rod 18, ensures that even in the position illustrated in FIG. 5 for narrower bags, the drive 14 causes reliably coordinated pivoting movements of the gripper device 4 and of the slip-on device 5.FIG. 6 shows the state with the placing device 5 closed, in which a bag valve of a bag, not shown, would be opened by the opening device 21, so that the bag could be fired onto a filling nozzle.List of reference numbers:1 Packaging machine 2 Valved bag 3 Bag bundle 4 Gripper device 5 Plug-on device 6 Receiving surface 7 Depositing table 8 1 Pivoted position 9 2 Pivoted position 10 Device, Automatic mounting mechanism 11 Mounting part 12 Mounting part 13 Longitudinal direction 14 Drive 15 Coupling mechanism 16 Toggle lever 17 Toggle lever 18 Slide rod 19 Suction bar 20 Mounting head 21 Bag opening device 22 Angled sheet metal 23 Angled sheet metal 24 Acceleration device 30 Empty bag magazine 31 Compartment 32 Housing 33 Suction device 34 Bag width 35 Bag valve region 36 Lever 37 Pivot arm 38 Lever 39 Lever 40 Lever 41 Pivot point 42 Pivot point 43 Pivot point 44 1 Coupling rod 45 2 Coupling rod 46 Pivot point 47 Lever 48 Direction of rotation 70 Discharge belt 25 Roller bar 26 Belt drive 27 Filling spout 28 Waiting surface 29 Roller bar

Claims

Device (10) for placing valve bags (2), in particular for placing valve bags (2) onto a filling spout (27) of a packaging machine (1), having at least one placing head (20) on which a pivotable gripper device (4) and a placing device (5) are provided, wherein the gripper device (4) is provided and suitable for gripping and receiving a valve bag (2) of a bag bundle (3) arranged on a receiving surface (6) of a placement table (7) in a first pivoted position (8) and for transferring it to a placing device (5) in a second pivoted position (9), wherein the placing device (5) is provided and suitable for opening the valve of a valve bag (2) and accelerating the valve bag (2) for placing on, wherein the mounting device (5) consists of at least two mounting parts (11, 12), of which at least one mounting part (11) is arranged pivotably, characterized in that a common drive (14) is provided for the pivoting of the gripper device (4) and the pivotable mounting part (11, 12), in that the gripper device (4) and the pivotable mounting part (11, 12) are mechanically coupled via a coupling mechanism (15), wherein the coupling mechanism (15) comprises a toggle lever (16, 17).The device (10) according to claim 1, wherein the mounting device (5) is arranged so as to be adjustable in the longitudinal direction (13) with respect to the gripper device (4) in order to be able to compensate for different bag dimensions.Device (10) according to the preceding claim, wherein the toggle lever (16) engages on a sliding rod (18) and is fastened thereto so as to be displaceable in the longitudinal direction (13).Device (10) according to one of the two preceding claims, wherein the coupling mechanism (15) comprises two toggle levers (16, 17) connected to one another for the movement-coupled pivoting of the gripper device (4) and of the pivotable attachment part (11, 12).Device (10) according to one of the preceding claims, wherein the attachment device (5) is displaceable along the sliding rod (18).Device (10) according to one of the preceding claims, wherein the attachment device (5) comprises two pivotable attachment parts (11, 12).Device (10) according to one of the preceding claims, wherein a plug-on part is provided so as to be pivotable about the sliding rod.Device (10) according to one of the preceding claims, wherein the gripper device (4) is provided so as to be pivotable about the sliding rod.Device (10) according to one of the preceding claims, wherein the gripper device (4) comprises a suction bar with a plurality of suction devices.The device (10) according to any one of the preceding claims, wherein the attachment device (5) comprises a bag opening device (21), which has angled sheet metal (22, 23) in each case on the two attachment parts (11, 12).The device (10) according to any one of the preceding claims, wherein the attachment device (5) comprises an acceleration device (24) comprising a roller strip (25) on an attachment part (11).The apparatus (10) according to the preceding claim, wherein the one acceleration device (24) comprises a belt drive (26) on the other attachment part (12).Device (10) according to the preceding claim, wherein the receiving surface (6) is preceded by a waiting surface (28), to which a new bag bundle can be transported while the current bag bundle arranged on the receiving surface is processed.Filling system (1) having at least one filling nozzle (34) for filling valve bags (2), comprising at least one device according to one of the preceding claims for placing the valve bags on the filling nozzle (34).

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