This application claims benefit of priority pursuant to 35 U.S.C. § 119(a) of European patent application no. 21170188.3 filed 23 Apr. 2021, which is hereby incorporated herein by reference in its entirety for all purposes.
The present invention relates to a device and a method for transporting ready-cut and filled hose pieces within a machine for producing bags filled with brewable material.
A generic device is known from EP 2 681 119 B1 and EP 3 733 384 A1. This device has a transport wheel, which comprises several bag receptacles distributed around its circumference.
In this previously known device, the cut-to-size and filled hose piece is inserted radially into the transport wheel to form a bag from the hose piece. In this process, the hose piece is formed in such a way that a chamber of a bag is produced which extends radially with respect to the transport wheel, wherein the bottom of the bag is located radially on the inside and the top of the bag is located radially on the outside. This station is also referred to as the insertion station in the scope of the description of the present invention. In this context, the cut-to-size and filled hose piece can also be formed as a single-chamber or double-chamber bag within the scope of the invention. In any case, downstream of the insertion station, the initially flat blank is formed in such a way that the chamber and thus the shape of the bag is essentially predetermined. The head is exposed in the region of the outer circumference of the transport wheel. In subsequent processing steps and while the transport wheel is rotating, a label is fed to the head of the bag according to the prior art and connected to the head of the bag.
The bag is then wrapped in an elongated piece of an envelope. This envelope is basically placed around the bag in a U-shape. The opposing edges of the envelope are then welded together to seal the bag completely in the envelope. The envelope is formed by a film through which the bag is packed inside the envelope in an aroma-tight manner. In the solution according to EP 2 681 119 B1, the bag is first removed from the transport wheel in the radial direction and inserted radially into the transport wheel with the bottom facing forward, as a result of which the envelope is wrapped around the bag. According to the solution described in EP 3 733 384 A1, the bag is swiveled in the transport wheel so that when the bag is removed from the transport wheel, the bag is removed from the transport wheel with the bottom facing forward and is thereby wrapped in the envelope.
Handling the thread inside the transport wheel is not entirely unproblematic. The transport wheel must rotate at a relatively high speed at high productivity. The transport wheel has a large number of clamps, edges, joints and the like on which the thread can get caught.
The present invention is based on the problem of providing a device and a method of the kind mentioned above, in which the thread is handled with greater safety in the region of the transport wheel.
In order to solve this problem with respect to the device, the present invention proposes a device with the feature of claim 1.
In a manner generally known, this device has a transport wheel which comprises a plurality of holders distributed around its circumference, each of which holds the bag. Associated with the transport wheel is an insertion station in which one of the hose pieces is inserted into the holder in a radial direction to form a bag with at least one chamber. This hose piece cut-to-size and filled with breable material is already connected to one end of the thread as the hose piece is inserted into the transport wheel. The chamber extends between a head and a bottom of the bag. In this process, the bottom of the bag is normally located radially inwards. The head of the bag is already located in the insertion station, preferably in the region of the outer circumference of the transport wheel. A label feeding station is also provided, in which a label is fed to the head. Furthermore, a connecting station is realized, in which a thread is connected to the label and/or the bag. Finally, in a manner known per se, a removing station is provided in which the bag is removed from the transport wheel. The aforementioned stations are usually provided distributed in the circumferential direction around the transport wheel. However, the label feeding station and the connecting station can be provided at a uniform position between the insertion station and the removing station. At the respective stations, there is an action on the bag to achieve the respective performance result in the respective station.
However, in the solution according to the invention, the bag can be moved past the respective stations and/or away from or towards the respective station continuously or intermittently by rotating the transport wheel.
According to the solution of the present invention with respect to the device, each holder is associated with a thread channel which can be connected to a vacuum source and a overpressure source. The thread channel is adapted to receive a thread. This is usually a piece of thread. Normally, the thread is already connected to the bag, i.e. to the hose piece circumferentially surrounding the bag, when it is received in the thread channel. Accordingly, the hose piece with the thread attached to it is already inserted into the transport wheel in the insertion station.
In the method according to the invention as claimed in claim 8, the thread is temporarily accommodated in the thread channel before the label and/or bag is connected to the thread and during the rotation of the transport wheel.
In this context, a vacuum threshold usually acts during the accommodation of the thread in the thread channel, by which the thread is not only sucked into the thread channel, but is also held within the thread channel during the rotation of the transport wheel. Only when the thread is connected to the label and/or the bag, the thread is blown out of the thread channel, so that it is available outside the thread channel for attachment to the label and/or the bag.
According to a preferred further development of the device according to the invention, the thread channel has a thread opening for inserting the thread. This is preferably located adjacent to a receptacle for the actual bag in the form of a holding shaft, for example. The thread channel has a remote air guide opening which, due to the rotation of the transport wheel, can be brought into operative connection with a vacuum opening or an overpressure opening. The thread channel then usually has only two openings. The thread is fed into the thread opening. The air guide opening conveys the pressure level acting in the thread channel.
The operative connection between the air guide opening and a usually stationary vacuum opening as well as a usually also stationary overpressure opening takes place due to the rotation of the transport wheel. Thus, the desired pressure level in the thread channel can be set by the rotation of the transport wheel depending on the respective station at which the respective holder is located. According to this, no complex valves or the like are necessary. The vacuum opening can have a constant vacuum in itself. The same applies to the overpressure at the overpressure opening. The desired pressures are inevitably set in the thread channel simply by passing the air guide opening past the vacuum opening or the overpressure opening. This results in directed flows in the thread channel through which the thread is laid, conveyed or held.
In view of this, the air guide opening is preferably recessed on a surface of the holder which extends radially with respect to the axis of rotation of the transport wheel. The vacuum opening or overpressure opening in operative connection with the air guide opening is provided opposite the air guide opening in each case. Thus, the vacuum opening and the overpressure opening are usually provided in a common plane and are exposed there, which extends parallel to the radial plane of the transport wheel.
With regard to a longer effectiveness of the vacuum, the vacuum opening is configured as an elongated open channel regularly as an annular segment. The air guide opening is preferably in operative connection with the vacuum opening during the rotation of the transport wheel from the insertion station to a position in front of the connecting station. As a result, the thread is effectively sucked into the thread channel during the rotation of the transport wheel via the acting vacuum and held there. This further development illustrates the concept of controlling the pressure conditions in the thread channel without the need for valves or the like. The pressure conditions in the thread channel desired for the treatment and processing of the thread on the transport wheel are set solely by the rotational movement of the transport wheel into the holding channel, in that its vacuum opening is brought into operative connection with the vacuum opening and/or the overpressure opening depending on the angular position of the transport wheel, or is arranged in such a way that no working pressure is set in the thread channel. This is superfluous, for example, after the thread has been connected to the bag and the label or has been fixed relative to the bag on the transport wheel. The same applies to angular positions of the transport wheel in which the holder is prepared, for example, to receive another bag after delivery to the removing station.
In order to attach the label with the aid of the thread, the thread channel in the connecting station is in operative connection with the overpressure opening. The connecting station has a thread guide which can be arranged opposite the thread opening of the thread channel with the label in between. This thread guide receives the thread blown out of the thread channel and deflects it. Due to the acting overpressure, the thread can be deflected several times and blown through the plane containing the label, so that the thread is guided past the label and/or through recesses within the label and knotted with the label in this way. Details of this can be found in EP 1 731 295 B1, the disclosure of which is incorporated by this reference into the disclosure of the present application. In any case, the previously discussed further development leads to a knot formed by an air guide through which the label is connected to the thread. In order to create a greater proximity between the label and the bag, at least the portion of the thread channel comprising the thread opening is movably provided in order to be brought closer to the head of the bag after insertion of the bag into the receptacle for attaching the thread to the label in the connecting station. This embodiment allows the label to be connected to the bag in closer proximity to the same, and consequently or in a subsequent station to be attached to the bag in such a way that the thread and the label can be handled as a unit at least until they are wrapped in the envelope in the course of a removal of the bag, thread and label. A section of the thread channel forming the thread opening can be pivotally arranged on the holder for this purpose.
According to a preferred further development of the present invention, the transport wheel has a bore for each holder. In this bore, an axle body carrying the holder is mounted so as to be pivotable about a pivot axis. Furthermore, a guide is provided which imprints an orientation on the holder with respect to the pivot axis during rotation of the transport wheel. This allows, for example, the holder as a whole to be pivoted as the transport wheel rotates, so that when the bag is inserted into the holder the bottom is at the front in the insertion direction, while at the removing station the bag is removed with the bottom at the front by a pivoting movement of the holder of substantially 180°. This allows the advantages according to EP 3 733 384 B3 to be achieved. However, the guide also effects that an air guide opening of the thread channel, which is arranged eccentrically to the pivot axis, is in operative connection with the vacuum opening in the insertion station and with the overpressure opening in the connecting station. The orientation of the holder in relation to the pivot axis can remain the same in the insertion station and in the connecting station. However, the vacuum opening can also be at a different radial distance from the axis of rotation of the transport wheel than the overpressure opening, so that by pivoting the holder about the pivot axis, the air guide opening can optionally be brought into operative connection with the vacuum opening or the overpressure opening.
In order to determine the position with respect to the pivot axis depending on the rotational movement of the transport wheel, the axle body preferably has at least one guide arm extending transversely to the pivot axis of the axle body, the free end of which is provided in a guide. For this purpose, the guide arm usually has a guide pin which is guided in a guide groove recessed in a disc provided on the side of the transport wheel opposite the holder. This guide disc forms the vacuum opening or the overpressure opening or carries means for forming the corresponding openings.
In accordance with its parallel aspect, the present invention proposes a holder for holding a bag filled with brewable material. This holder has a thread channel connectable to a pressure source. This implies that the holder has a first opening, typically provided adjacent to a receptacle of the holder for the bag, for the insertion of the thread connected at least to the label or the bag, and a second air guide opening, fluidly connectable to the pressure source, connected to this first opening via the thread channel. This means that the air guide opening can be connected to the pressure source in such a way that the pressure source influences the internal pressure in the thread channel to such an extent that a flow of the ambient air of the holder is generated in the thread channel, through which the thread is sucked into or blown out of the thread channel.
Preferably, this holder has an axle body which is mounted so that it can pivot about a pivot axis. This pivot axis is usually also the extension axis of the thread channel. Accordingly, the holder usually has an elongated axle body about which the receptacle for the bag, which can be formed by a holding shaft, for example, can be pivoted in order to pivot a usually head-side end of the bag and thus usually align it head-side so that the thread and/or the label can be connected to the bag in the desired orientation thereof.
The present invention furthermore provides a method for transporting ready-cut and filled hose pieces within a machine for producing bags filled with brewable material with a transport wheel, in which one of the hose pieces is inserted in a radial direction into a holder of the transport wheel (in an insertion station to form a bag with at least one chamber between a head (7) and a bottom of the bag, and the bag is removed from the transport wheel in a removing station, wherein between the insertion station and the removing station a label is fed to the transport wheel, which is connected to the bag by a thread. In the inventive method, the thread is accommodated in a thread channel prior to connecting for temporary accommodation during rotation of the transport wheel and is blown out of the thread channel for connecting to the label.
Preferable, the thread attached to the hose piece is sucked into the thread channel in the insertion station and is blown out of the thread channel to knot the label.
Further and according to a preferred embodiment of the inventive method the hose piece is inserted into the transport wheel with the thread attached to the hose piece.
Further details and advantages of the present invention will be apparent from the following description of an embodiment in connection with the drawing. Therein:
The envelope 4 comprises an elongated piece of aroma-tight film folded over a fold 14 to form two abutting legs 16, and sealed over two parallel longitudinal welds 18 and a transverse weld 20.
The completion of the bag 6 accommodated in the envelope 4 together with the label 10 takes place at the transport wheel described below with reference to
As
In
Adjacent to the insertion station 102 in the transport direction T, there is a label feeding station 112 in which a cut-to-size label 10 provided with a slot and holes for the thread 8 to pass through is fed to the head 7 of the bag 6. In this case, the holder 104 has a radial alignment unchanged with respect to the orientation in the insertion station 102. The same applies to a connecting station 114 following in transport direction T, in which in the embodiment the thread 8 is knotted to the label 10.
Following the connecting station 114, the holder 104 is pivoted so that this holder 104 is pivoted by 90° in the thread-securing station 116 characterized by reference sign 116 and accordingly extends tangentially relative to an axis of rotation D of the transport wheel 100. In this thread securing station 116, the thread 8 is inserted into the slot 12 of the label 10. In this way, the thread 8 is associated with the label 10 and thereafter with the bag 6 in order to prevent the thread from penetrating the sealing of the edges of the envelope material during the subsequent wrapping of the bag or even from catching on parts of the device during the further handling of the bag 4 together with the label 10 and the thread 8.
Reference sign 118 characterizes a removing station. In this removing station 118, the bag 6 is rotated by 180° relative to its alignment in the insertion station 102. While the bag 6 is inserted in the insertion station 102 with its bottom 9 forward into the holder 104, the bag 6 is pushed out with its bottom 9 forward when the bag 6 is pushed out radially in the removing station 118.
Between the removing station 118 and the inserting station 102, downstream in the transport direction of the removing station 118, there is a pivoting station 120 in which the holder 104 is pivoted by 180° so that it is appropriately aligned for receiving a new bag 6 in the insertion station 102.
As can be seen in
In
Each holder 104 has an axle body 150 which is freely rotatably held on the transport wheel 100 by a ball bearing 152 which is inserted in a bore 154 (cf.
An actuating arm 172, which is firmly connected to the actuating sleeve 158, projects radially from the actuating sleeve 158 and is provided with a cam follower 174 at its free end. This cam follower 74 interacts with the guide surfaces of the inner and outer opener cams 134, 136. This causes the bag clamp to pivot into the open position against the force of the clamp spring 160 and the hold-down spring 166. If there is no interaction between the cam follower 174 and the cam contour of the opener cam 134 or 136, the bag clamp 108 pivots into the closed position shown in
At the end of the axle body 150 opposite the holding shaft 106, two guide arms 176, 178 are provided which extend radially with respect to the central longitudinal axis of the axle body 150 and are projected in the axial direction by guide pins 180, 182, which each carry cam followers 184. The guide pin 182 has a greater axial extension than the guide pin 180.
Each guide pin 180, 182 engages in a respective guide groove which is recessed on a guide disc provided stationarily behind the transport wheel 100 in the top view according to
Due to the rotatable mounting of the axle body 150 via the ball bearing 152 with respect to the rotating transport wheel 100 and the two guide pins 180, 182 provided eccentrically with respect to the pivot axis of the holder 104, which is formed by the central longitudinal axis of the axle body 150, the pivoting movement of the holder 104 in the context of the rotational movement of the transport wheel 100 relative to the stationary guide disc can be generated and precisely specified.
The configuration with two guide pins 180, 182 permits close and precise positive guidance of the pivoting movement of the holder 104. As the top view according to
In the embodiment, the rotational movement of the transport wheel 100, together with the cyclic movement of the inner opener cam 134, induces the opening and closing of the bag clamp 108 in the region of the insertion station 102. In the removing station 118, the opening and closing of the bag clamp 108 is effected by pivoting the outer opener cam 136 while the transport wheel 100 is stationary. As shown in
Opening of the bag clamp 108 is effected via a cam 186 and abutment of this cam 186 against a free lever arm 188. The cam 186 is formed by a disc which is mounted pivotally about a pivot axis 189 via a ball bearing. Accordingly, actuation of the bag clamp 108 results from pivoting of the actuating sleeve 158 caused by the opener cams 134, 136.
The label 10 fed into the label feeding station 112 is applied against the outer surface of the air knot block 164 in a manner to be detailed below.
The suction channel 198 is formed between the insertion station 102 up to shortly in front of the connecting station 114. The blow opening 199 is located at the level of the connecting station 114.
As
In the insertion station, the pressure opening 206 is in operative connection with the suction channel 198 as an overpressure opening. Accordingly, a hose piece provided with the thread 8, which receives the tea dose of the filled bag therein, is not only introduced into the holding shaft 106 while forming the bottom 9 and the head 7 in the radial direction of the transport wheel 100. Rather, the thread 8 attached to the head 7 is also drawn into the thread channel 208 by the acting vacuum and through the thread opening 212. This holds the thread 8 in a predetermined position. There is no risk of the thread 8 getting caught on parts of the device during further processing of the bag 6. Due to the sustained suction pressure, the thread 8 is still in the thread channel 208 at the level of the label feeding station 112.
As
As can be readily imagined with reference to
Thereafter, the thread 8 is connected to the label 10 by means of a knot. A cutting knife 230 of a cutting device 232 provided in the connecting station 114 cuts off an end piece of the thread 8 projecting from the label 10 so that it ends substantially flush with the knot. The cut piece of thread is thereby captured via the suction opening 224 and conveyed out through the suction hose 226.
Number | Date | Country | Kind |
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21170188.3 | Apr 2021 | EP | regional |