EP3148788A1

EP3148788A1 - Device and method for forming a bottom opening on a bag body

Info

Publication number: EP3148788A1
Application number: EP15731827.0A
Authority: EP
Inventors: Hans Peter Gerber; Andreas KOHLFÜRST; Herwig Worff
Original assignee: Lohia Corp Ltd
Current assignee: Lohia Corp Ltd
Priority date: 2014-05-20
Filing date: 2015-05-20
Publication date: 2017-04-05
Anticipated expiration: 2035-05-20
Also published as: CN106660295A; TW201600325A; WO2015176094A1; EP3148788B1; CN106660295B; AT515831A1; BR112016026891B1; TWI640420B; AT515831B1

Abstract

The invention relates to a device and a method for forming a bottom opening (8) between bag sections (2', 2'') at the open end region (9) of a tubular bag body (2), comprising a transport device (3) for transporting the bag body (2) in a transport direction (5) transversely to its longitudinal extension (6), and an opening device (7) for forming the bottom opening (8) between the bag sections (2', 2'') at the open end region (9) of the tubular bag body (2). According to the invention, the opening device (7) comprises at least two spreading elements (10) in the form of wedge elements (12; 12', 12'', 12'''), which are successively arranged in the direction of transport (5) of the tubular bag body (2) and which are provided with edge surfaces (14; 14', 14'') rising counter to the rotational direction (13), by which the bag sections (2', 2'') can be spread apart at the open end region (9) of the tubular bag body (2) during the transport thereof on the transport device (3), wherein the wedge elements (12; 12', 12'', 12''') of successive spreading elements (10) have different wedge heights (h), which increase in the direction of transport (5) of the tubular bag body (2), preferably perpendicular to the support surface (4) for the tubular bag body (2) on the transport device (3).

Description

Apparatus and method for forming a bottom opening

a bag body

The invention relates to a device for forming a bottom opening between bag sections at the open end region of a tubular bag body, with a transport device for transporting the bag body in a transport direction transversely to its longitudinal extension, and with an opening device for forming the bottom opening between the bag sections at the open end portion of the tubular bag body wherein the opening means comprises at least one expansion element rotatable about an axis of rotation, which upon rotation between the sack sections at the open end region of the tubular

Sack body is insertable.

The invention further relates to a method for forming a bottom opening between bag sections at the open end region of a tubular bag body, wherein the bag body is transported transversely to its longitudinal extent in a transport direction and during transport a spreading element rotating about an axis of rotation between the bag sections at the open end region of the tubular bag body is introduced.

Systems for the production of sacks have long been known in the art. These systems include the provision of material hoses, obtained either by producing tubular webs or joining the longitudinal edges of flat webs into a tubular structure, cutting the hoses into tubular sacks of suitable length and forming a sack by opening, folding and closing an open sack End of the tubular bag body. To open the sack, various solutions have been proposed in the prior art.

From DE 640 287 C a device for mounting cross bottoms on a paper tube is known, wherein the two tube layers of a hose section with the aid of a

Separating fingers are separated from each other. As the hose moves on, a single expansion disc travels between the two tube layers, the sheath of which extends from one tip to the other widening wedge expands. Thus, the spreader penetrates deeper and deeper into the two wrapping layers of the tube during the rotation, whereby the tube bottom evenly

is spread apart.

However, the known design has the disadvantage that the

Spreading of the hose end takes place over a comparatively small distance over steep wedge surfaces. Thereby can

Malfunctions occur.

Furthermore, DE 1 611 701 discloses a device for opening the ends of transversely conveyed flat hose pieces in the manufacture of the cross bottoms of sacks and bags in soil making machines. In a variant embodiment for continuously operating machine maker bottom tube sections are passed by means of a circulating gripper chain in the lateral position on ver ^¬ various processing stations. To open the tube bottom a stationary suction box pair is provided, which has Sauglochreihen. The suction boxes are connected via pipes to a vacuum pump. The suction box are arranged diverging only a few millimeters in the transport direction. The known design is not intended and suitable to allow the penetration of a spreader or ^¬ same between the tube layers. In contrast, the support plate in the prior art on the one hand on a compressed air nozzle whose air flow is directed into the air gap between the two film layers. On the other hand, two

additional, counter-rotating Saugkastenpaare required with which the winding and laying of the crossbeam is completed.

From DE 912 045 a Bodenlegevorrichtung for Kreuzbodenbeutelmaschinen is known in which a sickle-like Bodenlegeorgan is provided, which can move into a pre-opened hose end. The sickle-like Bodenlegeorgan runs around an axis of rotation, which is rotatably mounted on a lever arm of a rotatably mounted double lever. Of the

Lever arm is controlled by a connecting rod provided at its ends with a connecting rod and a double lever with roller by an eccentric. By pivoting the axis of rotation of the Bodenlegeorgans around the fulcrum leads the Bodenlegeorgan except the circular motion caused by gears a pivotal movement.

However, this embodiment is disadvantageously unreliable, since the sickle-like Bodenlegeorgan can not always ensure a sufficient bottom opening. Therefore, malfunctions can occur in the prior art, which can lead to operational failures. In addition, the storage of Bodenlegeorgans is comparatively expensive.

In addition, in the prior art bottom opening ^¬ stations were used with rotating spreading tools with an upper part and a lower part, which are moved apart during the orbital movement of a mechanism. However, such multi-part spreading tools are disadvantageous

structurally complex and error-prone. In addition, extensive settings can be made on such spreader tools

to be required.

Other devices for opening hose trays are known, for example, from WO 2012/049040 or AT 406 755 B.

In contrast, the object of the present invention is to provide a device for forming a bottom opening, as stated at the outset, which the disadvantages of

The prior art alleviates or eliminates. Accordingly, the invention is the one hand to the goal of generating the bottom openings with high precision and reliability in continuous operation, the structural complexity of the device should be kept as low as possible. In addition, the maintenance effort should be reduced. Furthermore, a high speed Produktionsge ^¬ should be made possible.

This object is achieved by a device according to claim 1 and a method according to claim 19. Preferred execution ^¬ forms are given in the dependent claims.

According to the invention, the rotatable expansion element comprises a wedge element with at least one counter to the direction of rotation rising

Wedge surface on, with which the bag sections at the open

End portion of the tubular bag body during his Transports on the transport device are spread apart to form the bottom opening between the bag sections at the open end portion of the tubular bag body

To open the sack, a wedge-shaped expansion element is therefore used according to the invention, the wedge surface entgege the direction of rotation, i. from a front end region to a rear end region, for which the bag body rises on the transport device. When transporting the tubular

Sack body through the opening means, the rotating wedge member is inserted between the superposed bag portions at the open end portion of the tubular bag body, wherein the bag portions are pressed apart by the rearwardly rising wedge surface of the wedge member. Means of the wedge member, the opening width of the bottom opening of the tubular bag body is continuously increased. Favorable enough, therefore, the bottom opening at the open end portion of the tubular bag body can be made very reliable ^{¬ formed} . As a result, the service life of the opening device can be substantially increased. The wedge element preferably has a substantially vertical, ie perpendicular to the support surface for the bag body on the transport device extending axis of rotation, when the bag sections at the open end portion of the tubular bag body in a

horizontal position to be promoted by the opening device. In this embodiment, the rising wedge surface is disposed at an angle to the horizontal transport plane, wherein the wedge surface extends obliquely upwards or obliquely downward depending on the version from the front end to the rear end. Alternatively, the bag sections at the open end portion of the bag-shaped hose body, for example, be bent by 90 ° from the support surface on the transport device. In this embodiment, the wedge element can be arranged to rotate about a horizontal axis of rotation. In this case, the wedge surface of the wedge member is arranged rising in a horizontal plane counter to the direction of rotation. The circulation ^¬ movement of the wedge member is tuned with the Transportge ^¬ speed along the transport device, that the bottom opening is formed at the open end portion of the tubular bag body. Depending on the version you can at least one, in particular at both end portions of the tubular bag body (bottom) openings are formed. For this purpose, the system may have at least one wedge element on both sides in each case in order to form the bottom or upper-side opening. The inventive design is characterized by low structural complexity, which can be dispensed with a mechanism for extending a multi-part spreader. In addition, the pivot bearing of the spreading tool is particularly simple. Furthermore, it is advantageous that the wedge-shaped expansion element works reliably in continuous operation with high production speed.

Conveniently, the maintenance can be kept low.

In order to form the bottom opening at the open end region of the tubular bag body with the required opening width, the opening means in at least two transport ^¬ direction of the tubular pouch body on successive expansion elements. Preference is given to the preceding in the transport direction of the tubular bag body wedge element for producing a first, narrower opening width of

Floor opening and seen in the transport direction following

Wedge element for establishing a second, wider opening width of the bottom opening at the open end portion of the tubular bag body set.

For this purpose, the wedge elements of successive spreading elements have different, in the transport direction of the tubular bag body increasing wedge heights preferably perpendicular to the support surface for the tubular bag body on the transport device. Thus, the wedge height of the wedge member, i. the maximum extent of the wedge element perpendicular to the support surface for the bag body on the

Transport device, as seen in the transport direction of

Wedge element to wedge element too. Advantageously, the bottom opening is thereby formed stepwise with structurally simple means.

According to a particularly preferred disclosed embodiment

at least one expansion element, preferably each expansion element, an adjusting device for adjusting the wedge height of the

Spreading element on. In this version, the wedge height adjustable. Advantageously, such a

application-specific setting. The

For example, adjusting device can have a longitudinal guide extended in the vertical direction for adjusting two sections or parts of the spreading element relative to one another. Furthermore, locking means for locking the sections or parts of the expansion element in the set relative position

be provided to each other.

In order to spread apart the bag sections at the open end region of the bag body in opposite directions, it is favorable if the wedge element two in the transport direction

diverging wedge surfaces, preferably an upper one

Wedge surface and a lower wedge surface, wherein the upper wedge surface and the lower wedge surface preferably at an acute angle to the support surface for the tubular

Sack body are arranged on the transport device. In the opening device, therefore, preferably the upper bag portion of the tubular bag body is pushed upwards by means of the upper wedge surface of the wedge element, wherein the lower

Sack portion is pressed by means of the lower wedge surface of the wedge element down. As a result, the bottom opening on the tubular bag body can be made particularly reliable. Preferably, the upper wedge surface and the lower

Wedge surface with respect to the support surface for the tubular bag body arranged symmetrically on the conveyor. This allows the bag sections of the tubular

Sack body are pressed apart evenly around the center plane formed by the support surface on the conveyor to the bottom opening at the open end of the

form tubular bag body.

To ensure a continuous formation of the bottom opening on the

To allow tubular bag body, it is advantageous if the spreading elements during rotation in the transport direction of the tubular bag body overlapping wedge elements

have, wherein a wedge element preceding in the transport direction has a recess for the passage of a wedge element following in the transport ^¬ direction. In this embodiment, the wedge members are temporarily during the orbital movement arranged overlapping, wherein the front end portion of the following in the direction of transport wedge element passes through the recess of the preceding in the transport direction wedge element. Advantageously, therefore, the following in transport direction of the wedge element can already retract between the bag sections of the hose-shaped bag body ^¬ before the foregoing in the transport direction wedge element is still left the tubular bag body. Advantageously, malfunctions, in particular a jam of bag bodies in the opening device, are reliably avoided in this embodiment.

To open the bottom portion of conventional bag body, it has been found to be particularly advantageous if exactly three spreading elements are provided, which in the rotation in

Transport direction overlapping wedge elements for insertion between the bag sections at the open end of the

have tubular bag body. This execution

allows continuous shaping of the bottom opening, whereby malfunctions are largely avoided.

According to a particularly preferred embodiment, a wedge member at one respect to the rotation direction rear end portion to a holding portion for holding a relative rear of the transport ^¬ direction portion of the tubular pouch body during insertion of the wedge surface of the following in the transport direction the wedge member in a front portion of the tubular pouch body. Advantageously, so the tubular bag body in a part by means of a wedge element

opened state while the transport direction ^¬ subsequent wedge element for widening the bottom opening enters the open end of the tubular bag body.

In this embodiment, it is advantageous if the

Holding portion of the wedge member has a leading edge which is substantially at the same height as in

Direction of rotation seen rear end of the wedge surface is arranged. The height here refers to the distance of the

Lead edge of the support surface for the tubular bag body on the transport device. Due to the leading edge of the wedge element of the open end portion of the tubular Held bag body in a partially opened state when the following wedge member is immersed in the bottom portion of the tubular bag body to the opening width of

Gradually increase floor opening.

On the one hand to allow an overlapping arrangement of successive spreading and on the other hand holding the tubular bag body in the current, partially open state, it is advantageous if the wedge element between the wedge surface and the holding portion, the recess for

Having passage of the following in the direction of transport wedge element. Accordingly, the wedge member on the (seen in the direction of rotation) front end of the wedge surface and the rear end of the holding portion, wherein between the wedge surface and the

Holding section, the recess for the release of the

Rotary movement of the following wedge element is provided. The wedge elements are therefore also arranged partially overlapping by means of recesses in order to prevent the already partially opened end region of the tubular sack body from closing again.

In order to facilitate the insertion of the wedge element in the open end region of the tubular bag body, it is advantageous if the wedge element in the direction of rotation arcuate, in particular circular arc-shaped, curved. Accordingly, the wedge elements are formed arcuately with respect to the support surface for the tubular bag body on the transport device. As a result, the bottom opening can be formed particularly reliable.

In order to set the expansion element in rotary motion, it is advantageous if the wedge element is connected to a drive element coupled to a shaft element whose axis of rotation is preferably arranged substantially perpendicular to the support surface for the bag body on the transport device. Thus, the wedge member preferably has a substantially vertical, i. arranged perpendicular to the support surface in the transport device, axis of rotation.

With regard to a structurally simple, stable embodiment, it is favorable if the wedge element at least one preferably substantially perpendicular to the support surface for the bag body On the transport device arranged plate member which forms a wedge surface on one end face. Accordingly, the wedge surfaces are preferably formed on the upper or lower edge of a substantially perpendicular to the support surface in the transport device plate member.

For manufacturing reasons, it is preferably provided that the wedge element at least one preferably substantially parallel to the support surface for the bag body on the

Transport device arranged disc part which has at the outer edge region with the wedge surface

Plate part is connected.

In order to allow the expansion element to penetrate into the open end region of the tubular bag body, it is favorable if the opening device has a pre-opening station in the transport direction, with which the bag sections can be converted from a flat superimposed state into a spaced-apart state at the open end region of the tubular bag body are. In the pre-opening station, the bottom opening is released so far that the narrow end of the wedge element can enter between the bag sections at the open end region of the tubular bag body.

According to a preferred embodiment, the pre-opening station has at least one guide element with a guide surface inclined for the transport direction for one of the sack sections at the open end region of the tubular sack body, wherein the

Guide surface with a suction for sucking the

Sack section is connected to the guide surface. At the

Passing through the pre-opening station, the one bag section is conveyed along the open end region of the tubular bag body along the guide surface of the guide element, wherein the one bag section is held in contact with the guide surface by means of the suction element. Due to the inclined arrangement of the guide surface of the one bag section is removed during transport along the Voröffnungsstation of the other bag section, whereby the bag sections at the open end portion of the tubular bag body of the flat one above the other

lying state at the entrance of the Voröffnungsstation in the spaced apart, the bottom opening partially releasing state to be transferred.

A direct transfer of the bag body of the pre ^¬ opening station to the at least one spreading element for enabling ^¬ handy, it is advantageous if the overlapping with the at least one expansion element is arranged at least seen a guide element of the Voröffnungsstation in the transport direction. Accordingly, the wedge element between the bag sections of the blind ^¬ body intervenes as soon as the bag sections in the Voröffnungsstation in substantially the maximum opening width were apart ge ^¬ covered. Advantageously, therefore, a continuous transition between the Voröffnungsstation and the formation of the bottom opening can be achieved with the expansion element. Further opening means between the Voröffnungsstation with the inclined guide surface and the spreader are preferably not provided.

To release the bottom opening during transport of the tubular bag body, it is favorable if a drive element is provided for driving the guide element with the guide surface. When moving the guide element is the

Sack section held by the suction on the guide surface.

In this embodiment it is advantageous if the guide ^¬ element having an input connected to the drive member guide ^¬ belt, especially an endless belt, to which the guide surface for the bag sections open

End portion of the tubular bag body is formed. Accordingly, the suction port is entrained with the guide belt when the tubular bag body is transported through the pre-opening station. As a drive element can be provided in this embodiment, at least one drive roller on which the guide belt runs. Preferred are two

Drive rollers provided around which an endless belt is wrapped with the guide surface for the tubular bag body.

In order to produce the bottom opening uniformly at the open end region of the tubular bag body, it is advantageous if the Voröffnungsstation has two guide elements with diverging in transport ^¬ direction guide surfaces for the bag sections at the open end portion of the tubular bag body. In a preferred embodiment is an upper

Guide element provided with a transport direction in the upward rising upper guide surface and a lower guide element with a downwardly sloping in the transport direction lower guide surface. In an alternative embodiment, the tubular bag body is angled at the open end region at right angles to the transport plane. In this embodiment, the guide elements of the pre-opening station are arranged horizontally, wherein the distance between the guide surfaces increases in the transport direction increasingly.

In order to keep the bag section during transport through the Voröffnungsstation on the guide surface, it is advantageous if the

Suction element has at least one provided on the guide surface suction port for sucking one of the bag sections. The suction opening is connected to negative pressure generating means, with which the associated bag section is sucked to the guide surface.

According to a particularly preferred embodiment, exactly one suction opening is arranged on the guide surface. At this

Execution is the bag section during transport through the

Pre-opening station held by a single suction port on the respective guide surface. This design has surprisingly proved to be cheaper than the suction belt used in the prior art with regular Sauglochreihen, with which only a comparatively small

Opening angle could be achieved. This limitation of the prior art is due to the fact that the successive ^¬ suction openings when opening the bag body over low angles beyond would cause stresses in the bag body, which could solve the bag body of the guide surface. For this reason, the prior art in the transport direction after the suction belt further Voröffnungseinrichtungen, in particular a compressed air nozzle and counter-rotating suction ^¬ box pairs, provided to the unfolding of the bag bottom enable. In contrast, the arrangement of a single suction opening on the guide surface makes it possible for the bag body to be sucked onto the guide surface substantially at points. Thus, the guide surface can be comparatively large

Have angles of inclination relative to the transport plane, without causing tensions along the main extension of the bag section. Advantageously, the bag body is therefore reliably held on the guide surface. Due to the selective suction of the bag section this can be drawn on the one hand linear and on the other hand along a curve. Depending on the application, a vacuum chamber adjacent to the

Guide surface designed accordingly.

Furthermore, it is preferably provided that the endless belt forming the guide element has exactly two intake openings. In this embodiment, an endless belt is provided as a guide element, which is provided with exactly two suction openings. The distance between the two suction ports is preferably substantially equal to half the length (i.e., half the circumference) of the endless belt. When transporting the bag body through the Voröffnungsstation the one suction on the

Guide surface is arranged, is the other

Suction opening on the side facing away from the bag body side of the

Endless belt. As a result, one intake opening is active while the other intake opening is inactive. For a short period of time when circulating the endless belt, both intake ports may be inactive. This may be the case in particular when both intake openings are in the region of drive rollers

located, which drive the endless belt.

Particularly preferred is an embodiment in which the

Pre-opening station has at least one negative pressure generating unit with a vacuum chamber adjacent to the guide surface of the guide member with the suction port. The vacuum ^¬ chamber is preferably disposed in a housing within the guide ^¬ elements, which preferably has an endless belt. On the one hand, the vacuum chamber is connected via a suction line with the negative pressure generating means. On the other side of the vacuum chamber of the endless belt is passed, which has the suction port. This will the associated bag section applied to the guide surface of the endless belt.

The problem underlying the invention is also achieved by a method of the type mentioned, in which the rotatable expansion element has a wedge element with at least one counter to the direction of rotation rising wedge surface, with which the bag sections at the open end of the

tubular bag body be spread apart during its transport on the transport device to the

Form bottom opening between the bag sections at the open end portion of the tubular bag body.

The invention will be described below with reference to a preferred

Embodiment, to which it should not be limited, further explained. In the drawing show

Fig. La schematically a perspective view of a plant for the production of sacks, in which an inventive

Opening means is provided for opening the end portion of a bag body;

Fig. Lb schematically shows a part of a pre-opening station of the system according to Fig. La; and

Fig. 2 to 7 are schematic views of part of the

Opening device according to Fig. La in forming the

Sack opening by means of wedge-shaped spreading elements, which spread apart the stacked bag sections at the open end of the tubular bag body.

Fig. La shows a part of a plant 1 for the production of sacks, wherein a material web, in particular of a fabric ^¬ material, is processed in various stations to produce Kreuzbodenoder Kreuzbodenventilsäcken. The plant 1 has a (not shown) separating device to the

Material web to tubular bag bodies 2 to separate. The tubular bag body 2 consist of two stacked bag sections 2 ', 2'', wherein each bag section 2', 2 '' can be constructed of several layers of different material. The tubular bag bodies 2 are transferred to a transport device 3. In the transport device 3 the bag bodies 2 are successively conveyed on a substantially horizontal bearing surface 4 of the transport device 3 in a flat state in the transport direction 5 transversely to their longitudinal extension axis 6 shown schematically in FIG.

As shown in Fig. La, cf. 2 to 6, further seen, the transport device 3 with an opening device 7 for forming a bottom opening 8 between the bag sections 2 ', 2' 'at the open end portion 9 of the tubular bag body 2 is connected. The opening device 7 has a Voröffnungsstation 23, with which the bag sections 2 ', 2' 'at the open end portion 8 of the tubular bag body 9 from a flat superimposed state in a spaced-apart state can be transferred.

As can be seen from FIG. 1 a, the pre-opening station 23 has an upper guide element 24 with an upper guide surface 24 'rising upward in the transport direction 5 and a lower guide element 25 with a lower guide surface 25' sloping downward in the transport direction 5. As guide elements 24, 25 endless belts are provided in the embodiment shown, which are driven by drive rollers 24 '', 24 '''. The guide elements 24, 25 are each connected to a suction element 26 for sucking the associated bag section 2 ', 2''. The suction members 26 each have at least one suction ^¬ opening 26 'on the guide surface 24', 25 'of the endless belt. In the embodiment shown, each endless belt has exactly two intake openings 26 '(compare Fig. 1b).

As can be seen from FIG. 1b, the pre-opening station 23 has a vacuum-generating unit 27 for each guide element 24, 25. The negative pressure generating units 27 each have a negative pressure chamber 27 ', which adjacent to the

^{Guide surface} 24 ', 25' of the upper 24 and lower guide ^¬ elements 25 extends. The vacuum chamber 27 'is provided in a housing 27'', which is arranged within the guide element 24, 25. In order to apply a negative pressure to the suction opening 26 'of the guide element 24, 25, the

Low-pressure chamber 27 'via a suction line 27''' with (not shown) vacuum generating means, for example a Vacuum pump, connected. When the tubular bag body 2 is passed through the pre-opening station 23, the

Sack sections 2 ', 2' 'at the diverging in the transport direction 5 guide surfaces 24', 25 'of the guide elements 24, 25 applied. As a result, the bag sections 2 ', 2 "are continuously transferred from the flat superimposed state at the entrance of the pre-opening station 23 into the spaced apart, partially openable, bottom opening 8.

As can be seen from Fig. La further, the opening means 7 in the transport direction 5 after the Voröffnungsstation 23 a plurality of spreading elements 10 which are each rotatably mounted about a vertical axis of rotation 11. Through the Voröffnungsstation 23, the bottom opening 8 of the tubular bag body 2 is sufficiently open that the spreading elements 10 between the bag sections 2 ', 2' 'at the open end portion 9 of the tubular bag body 2 can penetrate. During the rotational movement, the spreading elements 10 travel between the bag sections 2 ', 2 "at the open end region 9 of the tubular bag body 2, wherein the bottom opening 8 is formed.

As can also be seen from FIG. 1a, the opening device 7 follows in the transporting direction 5 a bottom folding station 28, in which the geometry of the opening is brought into a correct, right-angled position with the aid of finger elements 29. Thereafter, the tubular bag body 2 can be processed in a conventional manner to the finished bags.

2 to 7, the spreading elements 10 are shown at various stages in the formation of the bottom opening 8. The tubular bag bodies 2 can in this case be conveyed through the opening device 7 in a state lying flat on one another in a horizontal plane, as shown in FIGS. 3 to 7. Alternatively, the floor area can be angled during transport through the opening device 7 (compare schematically Fig. 2).

According to Fig. 2, 3, the tubular bag body 2 is transported straight with partially released bottom opening 8 of the Voröffnungsstation 23 to the spreading elements 10. According to FIG. 3 to 7, the opening width of the bottom opening 8 is gradually increased, so that the bottom opening 8 is completely released after the expansion elements 10.

As can be seen in FIGS. 2 to 7, the rotatably mounted spreading elements 10 each have a wedge element 12, against which the direction of rotation 13, i. from the front end region to the rear end region, rising wedge surfaces 14 are formed. When transporting the tubular bag body 2 on the conveyor 3, the wedge elements 12 urge with the

Wedge surfaces 14, the opposite bag sections 2 ', 2' 'at the open end portion 9 of the tubular bag body 2 increasingly apart, whereby the bottom opening 8 between the bag sections 2', 2 '' at the open end portion 9 of the tubular bag body 2 is generated. Each wedge element 12 has an upper wedge surface 14 'for an upper sack section 2' and a lower wedge surface 14 '' for a lower sack section 2 ''. The wedge surfaces 14 ', 14' 'of the wedge elements 12 are each arranged at an acute angle to the horizontal support surface 4 for the tubular bag body 2 on the transport device 3.

As shown in Fig. 2 to 7 can be further seen, the wedge member 12 is vertical with a substantially, that is connected perpendicular to the supporting surface ^¬ 4 for the bag body 2 on the conveyor 3, arranged shaft member 15 with a

(not shown) drive is set in rotary motion. In the embodiment shown, the wedge surfaces 14 are formed on substantially perpendicular plate elements 16. The front wedge element 12 'seen in the transport direction 5 has a single plate element 16. The central wedge element 12 "seen in the transport direction 5 and the rear wedge element 12 '" in the transport direction 5 each have an upper plate part 16' which has the upper wedge surface 14 'on an upper end side and a lower plate part 16 ", which on a lower end face, the lower wedge surface 14 '', on. The plate elements 16; 16 ', 16' 'are in

Top view corresponding to the direction of rotation 13 arcuately curved. In addition, the wedge elements 12 in

Essentially in a horizontal plane Disk parts 17, which are coupled on the one hand with the shaft member 15 and on the other hand, at the outer edge regions, the plate parts 16 with the wedge surfaces 14; 14 ', 14''wear.

As can be seen from FIGS. 2 to 7, the opening ^device 7 in the embodiment shown has three spreading elements 10 which follow one another in the transport direction 5 of the tubular bag body 2. The individual spreading elements 10 have wedge elements 12, which different, in

Transport direction 5 of the tubular bag body second

have increasing wedge heights h. The wedge height h is measured here by the distance between the viewed in the direction of rotation 11 rear end of the wedge surface 14 and the support surface 4 for the tubular bag body 2 on the conveyor 3. As a result, the opening width b of the bottom opening 8 (see Fig. 6) of Wedge element 12 to wedge element 12 increases.

As can be seen further from FIGS. 2 to 7, the wedge elements 12, as seen in the direction of rotation in the transport direction 5, are partially overlapped by means of recesses 18 in order to achieve a continuous increase in the opening width b of the bottom opening 8. For this purpose, seen in the transport direction 5 front wedge element 12 'has a recess 18' for

Passage of the following in the direction of transport 5, middle

Wedge element 12 '' on. Accordingly, the middle

Wedge element 12 '' a recess 18 '' for the release of the

Rotational movement of the rear seen in the transport direction 5

Wedge element 12 '' 'on.

As is further apparent from FIGS. 2 to 7, the wedge element 12 has holding sections 19 at a rear end region with respect to the direction of rotation 13, with respect to which

Transport direction 5 rear portions 20 of the bag sections 2 ', 2' 'are held in the current opening state, while the wedge surface 14 of the following in the transport direction 5 wedge element 12 in front portions 21 of the bag sections 2', 2 '' of the same bag body 2 are introduced. For this purpose, the holding portions 19 of the wedge member 12 at least one

Leading edge 22, in the embodiment shown in each case an upper guide edge 22 'and a lower guide edge 22'', which at substantially the same height as that in the direction of rotation 13th seen rear end of the associated wedge surfaces 14 ', 14''of the respective wedge element 12 are arranged.

In the embodiment shown, comprises on the one hand as seen in the transport direction 5 ^¬ front wedge member 12 'retaining portions 19' on which the upper bag portion 2 'and the lower

Sack section 2 '' of the tubular bag body 2 are assigned. As a result, the assumption of the tubular bag body 2 from the front wedge element 12 'to the central wedge element 12' 'can be made reliable. On the other hand, as seen in the transport direction 5 mean wedge element 12 ''

corresponding holding portions 19 '' in order to accomplish a reliable transfer of the bag body 2 to the rear in the transport direction 5 seen wedge element 12 '' '.

The terms "bottom" and "top" for the arrangement

various components, such as the wedge members, are exemplified in the present disclosure for a preferred

Operating position used in which the bag sections 2 ', 2' 'are transported at the open end portion 9 of the tubular bag body 2 in a horizontal position.

Of course, however, an embodiment may be provided in which the bag sections 2 ', 2' 'are bent for example by 90 ° from the transport plane. In this embodiment, then the components of the system, such as the wedge elements 12, arranged tilted by a corresponding angle.

Claims

Claims:

1. A device for forming a bottom opening (8) between bag sections (2 ', 2' ') at the open end region (9) of a tubular bag body (2), with a transport device (3) for transporting the bag body (2) in one

Transport direction (5) transversely to its longitudinal extent (6), and with an opening device (7) for forming the bottom opening

(8) between the bag sections (2 ', 2' ') at the open end portion

(9) of the tubular bag body (2), wherein the

Opening device (7) at least one about an axis of rotation (11) rotatable expansion element (10), which during rotation between the bag sections (2 ', 2' ') at the open end portion (9) of the tubular bag body (2) is inserted, characterized characterized in that the opening device (7) has at least two spreading elements (10) which follow each other in the transport direction (5) of the tubular bag body (2), each rotatable spreading element (10) comprising a wedge element (12; 12 ', 12' ', 12' '). ') with at least one counter to the direction of rotation (13) rising wedge surface (14; 14', 14 ''), with which the bag sections (2 ', 2' ') at the open end region (9) of the tubular bag body (2) during its transport on the transport device (3) are spread apart to form the bottom opening (8) between the bag sections (2 ', 2' ') at the open end region (9) of the tubular bag body (2) and that the wedge elements (12; 12' , 12 '', 12 '' ') aufe in successive spreading elements (10) have different, in the transport direction (5) of the tubular bag body (2) increasing wedge heights (h).

2. Apparatus according to claim 1, characterized in that the wedge element (12) in the transport direction (5) diverging wedge surfaces, preferably an upper wedge surface (14 ') and a lower wedge surface (14''), wherein the upper wedge surface ( 14 ') and the lower wedge surface (14'') are preferably each arranged at an acute angle to the bearing surface (4) for the tubular bag body (2) on the transport device (3).

3. Apparatus according to claim 1 or 2, characterized in that the spreading elements (10) during rotation in

Transport direction (5) of the tubular bag body (2) overlapping wedge elements (12; 12 ', 12' ', 12' ''), wherein a preceding in the transport direction wedge element (12; 12 ', 12' ') has a recess (18) for the passage of an in

Transport direction (5) following wedge element (12, 12 '', 12 '' ').

4. Apparatus according to claim 3, characterized in that exactly three expansion elements (10) are provided, which during rotation in the transport direction (5) overlapping wedge elements (12; 12 ', 12' ', 12' '') for insertion between the Sack sections (2 ', 2' ') at the open end region (9) of the tubular bag body (2).

5. Device according to one of claims 1 to 4, characterized

in that a wedge element (12; 12 ', 12' ', 12' '') has, at a rear end region with respect to the direction of rotation (13), a holding section (19; 19 ', 19' ') for holding in relation to the transport direction (5 ) rear portion (20) of the

tubular bag body (2) during insertion of the wedge surface (14) in the transport direction (5) following wedge element (12; 12 '', 12 '' ') in a front region (21) of the tubular bag body (2).

6. The device according to claim 5, characterized in that the holding portion (19, 19 ', 19' ') of the wedge element (12, 12', 12 '', 12 '' ') has a guide edge (22), which substantially at the same height as in the direction of rotation (13) seen rear end of the wedge surface (14, 14 ', 14' ') is arranged.

7. Apparatus according to claim 5 or 6, characterized in that the wedge element (12; 12 ', 12' ', 12' '') between the

Wedge surface (14, 14 ', 14' ') and the holding portion (19, 19', 19 '') the recess (18) for the passage of in

Transport direction (5) following wedge element (12, 12 '', 12 '' ').

8. Device according to one of claims 1 to 7, characterized

in that the wedge element (12; 12 ', 12'',12''') is curved in the direction of rotation (13), in particular circular arc, is curved.

9. Device according to one of claims 1 to 8, characterized

characterized in that the wedge element (12; 12 ', 12' ', 12' '') is connected to a shaft element (15) coupled to a drive, the axis of rotation (11) of which is preferably substantially

perpendicular to the support surface (4) for the bag body (2) on the transport device (3) is arranged.

10. Device according to one of claims 1 to 9, characterized in that the wedge element (12; 12 ', 12' ', 12' '') at least one preferably substantially perpendicular to

Support surface (4) for the bag body (2) on the

Transport device (3) arranged plate part (16, 16 ', 16' '), which at one end face a wedge surface (14, 14', 14 '') is formed.

11. The device according to claim 10, characterized in that the wedge element (12; 12 ', 12' ', 12' '') at least one

Preferably, substantially parallel to the bearing surface (4) for the bag body (2) on the transport device (3) arranged disc part (17), which at the outer edge region with the wedge surface (14, 14 ', 14' ') having plate member (16 ) connected is.

12. Device according to one of claims 1 to 11, characterized in that the opening device (7) has a

Pre-opening station (23), with which the bag sections

(2 ', 2' ') at the open end region (9) of the tubular

Sack body (2) can be converted from a flat superimposed state in a spaced-apart state.

13. The apparatus according to claim 12, characterized in that the Voröffnungsstation (23) at least one guide element (24, 25) with a transport direction (5) inclined guide surface

(24 ', 25') for one of the bag sections (2 ', 2' ') at the open end region (9) of the tubular bag body (2), wherein the guide surface (24', 25 ') with a suction element (26) for Sucking the bag section (2 ', 2' ') against the guide surface

(24 ', 25') is connected.

14. The apparatus according to claim 13, characterized in that a drive element (24 '', 24 ''') for driving the

Guiding element (24, 25) with the guide surface (24 ', 25') is provided.

15. The apparatus according to claim 14, characterized in that the guide element (24, 25) one with the drive element

(24 '', 24 '' ') associated guide belt, in particular an endless belt, on which the guide surface (24', 25 ') for one of the bag sections (2', 2 '') at the open end portion (9) of the tubular Sack body (2) is formed.

16. Device according to one of claims 13 to 15, characterized in that the Voröffnungsstation (23) has two guide ^¬ elements (24, 25) in the transport direction (5) diverging guide surfaces (24 ', 25') for the bag sections (2 '. , 2 '') at the open end region (9) of the tubular bag body (2).

17. Device according to one of claims 13 to 16, characterized in that the suction element (26) at least one on the guide surface (24 ', 25') provided for suction opening (26 ') for sucking one of the bag sections (2', 2 '' ) having.

18. The apparatus according to claim 17, characterized in that the Voröffnungsstation (23) at least one

A negative pressure generating unit (27) having a negative pressure chamber (27 ') adjacent to the guide surface (24', 25 ') of the

Guide element (24, 25) with the suction port (26).

19. A method for forming a bottom opening (8) between bag sections (2 ', 2' ') at the open end region (9) of a tubular bag body (2), wherein the bag body (2) in a transport direction (5) transversely to its longitudinal extent ( 2a) is transported and during transport to a

Rotary axis (11) rotating spreading element (10) between the

Sack sections (2 ', 2' ') at the open end region (9) of

tubular bag body (2) is introduced, characterized in that the opening means (7) at least two in the transport direction (5) of the tubular bag body (2) successive expansion elements (10), wherein each rotatable expansion element (10) has a wedge element (12; ', 12'',12''') with at least one opposite to the direction of rotation (13) rising wedge surface (14; 14 ', 14''), wherein the wedge elements (12; 12', 12 '', 12 ''') successively

Spreading elements (10) have different, in the transport direction (5) of the tubular bag body (2) increasing wedge heights (h), wherein the bag sections (2 ', 2' ') at the open

End region (9) of the tubular bag body (2) during its transport on the transport device (3) with the

Wedge surfaces (14; 14 ', 14' ') of the wedge elements (12; 12', 12 '', 12 '' ') are spread apart to the bottom opening (8) between the bag sections (2', 2 '') on form open end region (9) of the tubular bag body (2).