KR100461214B1 - Device for opening tubular bag shapes - Google Patents

Abstract

The invention includes an apparatus for opening a tubular bag body that opens at least at one end, the apparatus comprising at least one slide that can be introduced into the open end of the bag between the bag walls to at least partially fold at least one end region of the bag wall Shaped back body opening device. According to the invention, at least one slide (3) can move along the predetermined path (8) and into and out of the bag end to be opened by at least one driven cam (9) engaging with the slide . The slide (3) usually has the shape of a circular path (4), the circular path comprising a section moving parallel to the bag conveying device. The conveying speed of the back body 2, 2a on the conveyor apparatus 1 and the speed of the slide 3 around the circular path are the same.

Description

{Device for opening tubular bag shapes}

Generally, the manufacture of a bag comprises the steps of providing a tubular material obtained by manufacturing a tubular material web or obtained by connecting the longitudinal edges of a flat material web in a tubular shape, and providing the tubular material with a bag body of an appropriate length And forming the bag floor by appropriately folding and closing one end of the bag body. A bag having a rectangular bottom fabricated in this manner is commonly referred to by a person skilled in the art as a box-shaped bag. In order to form the bottom of this box-type bag, the end portion of one of the two bag body walls, one of which is placed on the other, is folded along the transverse fold line with respect to the longitudinal axis of the back body, The end of the back body has a hexagonal folded configuration in which two parallel seams are opposed to each other and two pairs of parallel folding edges are opposed to each other. By folding the two seams toward each other and fixing the folded lobes, including the seams, to each other or to the cover sheet, the back body has a floor that becomes a rectangular shape when the finished bag is unfolded. It is also possible to apply the valve seat prior to folding the seam towards each other, which has a tube shape when folding the end of the back body into its final shape.

There are two known systems for folding the open end of a back body to form the bottom of a box-shaped bag today. Those skilled in the art will often refer to this as a folding-over "opening" of the back body.

The first known system includes a continuously movable spreading mechanism that is easily damaged and requires intensive adjustment and rework operations.

The second system includes an intermittently movable conveyor belt on which the longitudinal axis of the back body disposed transverse to the conveying direction is moved towards the opening station and the conveyor belt stops at this opening station. In the opening station, the shim of the back body end is pulled apart a little, the slider mounted so that lateral movement is possible but not movable in the other direction moves into the back body end and a part of the upper back body wall is folded back Which results in a hexagonal folded shape. The fold line along which the slider is folded when folding the back body wall is formed by a girder. The girder is disposed on the back body in the conveying direction and held on the back body when the belt is stopped, The slider in the back body moves across the girder. After the folding is completed, the slider is retracted, the girder is raised, and the conveyor belt continues its movement with the folded back body. The slider reciprocates in a horizontal plane corresponding to the plane of the back body on the conveyor belt by a pneumatic cylinder composed of a piston and a cylinder. The disadvantage of this assembly is that the back body must be kept stationary during the entire slide movement, so intermittent operation is required and this results in high wear and high energy consumption and limits production speed. This second known system will be described later in the description of the present invention.

Another prior art is German Patent No. 1 511 021, which discloses a method and apparatus for producing cross-bottoms of tubular material of various lengths to form a cross-bottom bag. The continuous action device includes a slide that is guided along an orbital path having some sections parallel to the direction of travel of the bag body, and the slide and the bag body move at the same speed. The slide is guided for at least a certain period of time along a path inclined with respect to the horizontal line so that the slide can be introduced into the open end of the back body and the path takes the form of a guide bar in which the slide is rolled off by the control roller .

The present invention relates to a device for opening tubular bag bodies that open at least at one end, wherein the bag body is introduced into one open end of the bag body between the walls of the bag body and extends over at least one end region of the bag body wall At least one slide that is at least partially foldable, the at least one slide being movable into the bag body to be opened out by means of reciprocating each slide.

The invention will now be illustrated by way of example with reference to the drawings.

Fig. 1 is a schematic side view of an embodiment of a tubular bag body opening device according to the present invention, and Fig. 2 is a schematic plan view of the device, in which a conveyor belt with a bag body is omitted.

The present invention provides a device of the kind that has the drawbacks of the prior art overcome, is robust, reliable and has little need to maintain, and has a manufacturing speed faster than ever before.

These advantages are achieved by means of an arrangement of the type comprising at least one driven cam, the means for reciprocating each slide being movable along a path and for coupling the slide to move back and forth. This structure according to the invention is suitable for the continuous operation, apart from the reciprocating motion of the slide, and the device mainly depends on the rotational motion, which is for example in the translational movement used in the device of German Patent No. 1 511 021 The abrasion is remarkably reduced and the driving energy is significantly reduced.

In a preferred embodiment of the invention, at least one cam is mounted on a driven chain or belt wrapped around a wheel or pulley, the wheels having a first orbital path section approaching the bag body and a second orbital path section Section, and a third orbital path section forming a cam return section. Optionally, a fourth orbital path section may be provided on the first and second orbital path sections having a substantially constant distance to the back body end to be opened. The cam moving in the first orbital path section moves the associated slide into the open end of each bag body while the cam retracts the slide when it reaches the second orbital path section. The fourth orbital path section serves to hold the slide in the rest position against the back body for a predetermined period while an additional processing step is performed on the back body.

In order to be able to change the sequence of motion of each slide, it is advantageous that the position of at least one of the wheels or pulleys of the means for reciprocating each slide can be adjusted.

Advantageous embodiments of the invention are characterized in that each slide has a guiding path for sliding engagement with the cam. The guide path of each slide for sliding engagement with the cam is usually a U-beam with an open end fixedly attached to the slide, the longitudinal axis of which is arranged at right angles to the reciprocating direction of the slide.

Although the slide is fixedly mounted to the work station, the full range of advantages of the present invention survive as long as the slide moves in line with the back body to be opened. The preferred embodiment therefore further provides a conveyor device for transporting the back body and a drive for moving the slide along the track path, the drive for moving the slide and the slide of the conveyor device along the track path, (Arrow A) of the back body is substantially synchronized with the speed of the slide (arrow C) along the trajectory on the conveyor apparatus.

In order to take advantage of the system, it is basically preferable to arrange at least two slides at equal intervals along the track path. Otherwise, a long distance must be maintained between each conveyed back body to give the slide enough time to return to its initial position in the orbital path. Providing multiple slides also makes it almost irrelevant how much time each slide requires to open the back body, which time should be divided by the total number of slides used and thus may be arbitrarily reduced Because.

The speed of the chain or belt is adjusted by the cam to be higher than the speed of the slide along the orbital path so that multiple moving slides equally spaced along the orbit along with the common cam drive can be used.

Advantageously, the drive for moving the slide along the orbital path includes a chain moving around the gear wheel or a belt moving about the pulley, the chain or belt being connected to the slide, and at least one of the gear wheel or the pulley Is driven by a motor.

The minimum energy consumption and minimum wear of the device according to the invention for opening the tubular back body is achieved by using the continuous operation drive as a drive for the slide to move along the track and as a drive for the conveyor device.

The track path of the slide is formed by rails mounted so that each slide can slide. The apparatus for slidably mounting a slide on said rail advantageously includes a bush and a shaft slidable therein, said bush or shaft being coupled to the rail by a roller and slide surface, .

In known systems, slides are typically made of plates that must be replaced wholly as the size of the back body changes, while another embodiment of the back body opening device in accordance with the present invention is able to adjust the cross beam and its mutual distance and length At least two slide fingers attached to the cross beam. Dependent on the predetermined dimensions, the bag bottom is adjusted according to its distance (thus forming the longitudinal edge of the bottom) and is adjusted according to its length (thus forming the width of the bottom with sliding movement). Therefore, when changing the size of the back body, it is not necessary to replace the slide.

As described above, the prior art provides the slide and the back body to be coplanar. This has the undesirable effect that when the back body is opened by the slide, up to four material layers are placed on top of each other while the back body is folded and only one layer is present in the other part. This difference in thickness creates a serious problem during continued processing of the back body. The present invention also provides a solution to this problem, wherein according to one embodiment, the back body is disposed transversely folded on the conveyor device for the back body, wherein the back body extends from the transverse fold line in the direction toward the slide Portion of the slide lies in a plane of reciprocation of the slide and the backbody portion extending from the transverse fold line in a direction away from the slide lies on a plane forming an angle, for example a right angle, with respect to the reciprocating plane of the slide . This action ensures that the two largest material layers of the backbody are folded and then placed on top of each other.

The following description will be made with reference to Figs. 1 and 2 at the same time. The illustrated tubular bag body opening device according to the invention comprises a conveyor belt 1 on which the back bodies 2, 2a are secured by suitable means such as vacuum. The conveyor belt moves continuously in the direction of the arrow A at a constant speed. The back body is disposed horizontally on the conveyor belt and its longitudinal axis is transversely with respect to the conveying direction A, except for the end region thereof which is to be formed as the back bottom. The end regions of each back body 2, 2a are folded vertically downward and suspended over one of six slides, designated by reference numeral 3 (only two slides are shown for clarity in Figure 1) .

The slide 3 is slidably mounted to a rail 4 having two opposite straight sections 4a and 4b interconnected at its ends by two semicircular sections 4c and 4d. The sliding connection of each slide 3 and the rail 4 is made by four rollers 31 and two of these rollers are respectively engaged with one of the two opposite longitudinal edges of the rail 4 . The roller 31 is rotatably attached to the front surface of the slide head 33, and the shaft 34 extends downward from the opposed surface thereof. On the shaft 34, a bush 35 is slidably mounted. The bushing 35 has a guiding path in the form of a horizontal U beam 38 and an open beam 39 with an open end from which the rectangular narrow plate slide fingers 36 and 37 are spaced apart Lt; / RTI > The slide finger may be adjustably attached to the cross beam (39). The U beam 38 and the cross beam 39 may also be formed as an integral unit.

Under the semicircular sections 4c and 4d of the rail 4, two wheels 5 and 6 having concentric vertical rotation axes 5a and 6a are arranged. At least one of the wheels is driven by a motor not shown. Both wheels 5, 6 are wound by a chain 7 which is moved in the direction of arrow C. The speed of the chain (7) is the same as that of the conveyor belt (1). The chain (7) is firmly interlocked with the projections (32) of each slide and pulls each slide (3) accordingly. The slides 3 are distributed equidistantly along the chain, i.e. along the rail 4, and the distance between the two slides is equal to the distance between the two back bodies on the conveyor belt. By appropriate control, each slide faces one back body on the conveyor belt 1 while moving along the section 4a of the rail 4.

A separate drive is provided to achieve movement of the bush 35 and slide fingers 36, 37 along the shaft 34. This drive consists of a chain 8 moving about four wheels 10, 11, 12, 13 with horizontal rotation axes. At least one of the four wheels is driven so that the chain 8 moves in the direction of the arrow B at a faster speed than the conveyor belt 1 and the chain 7. The four wheels 10, 11, 12, 13 and the chain 8 lie in a vertical plane below the longitudinal boundary 1a of the conveyor belt. The wheels 10,11,12,13 comprise a chain 8 surrounding them and having a first upwardly inclined section 8a, a second downwardly inclined section 8b and a longitudinal boundary of the conveyor belt 1 A third section 8c moving parallel to but opposite to the first section 1a and a fourth section 8d parallel to the third section and moving adjacent to the conveyor belt 1. The chain (8) has three cams (9) spaced apart at equal intervals.

Hereinafter, the operation of the apparatus will be described.

First, the motions of the conveyor belt 1 and the chains 7, 8 are set. On the conveyor belt, the back body is supplied at a predetermined interval, and in synchronism with this, the slide 3 moves horizontally around the rail 4. [ When the first slide reaches a position near the wheel 13, the cam 9 of the chain 8 engages the front open end of the U beam 38 of the slide. This occurs even if the absolute speed of the chain 8 is greater than the absolute speed of the chain 7 and the velocity component of the chain 8 parallel to the chain 7 in the inclined track section 8a is greater than the absolute speed of the chain 7 It is smaller than absolute speed. This means that the slide 3 catches and catches the cam 9 in the section 8a which raises the slide due to the upwardly inclined orientation of the track section 8a and at the same time, (38), and moves backward from the inside thereof. So that a plurality of slide fingers are associated with the open end of the back body facing these fingers and during this folding the wall of the back body which is visible in the figure in the drawing is connected to the longitudinal boundary 1a of the conveyor belt, (not shown) along the fold line defined by the ruler 15. The back wall of the back body is shown behind it in the figure and is sucked in completely or partially by the succeeding vacuum band so that it is not folded together with it.

The cam 9 reaches the wheel 10 before it leaves the U-beam 38 at its rear end and changes into movement along the section 8d. The slide fingers 36, 37 now reach their highest position and remain in that state as long as the cam 9 is in section 8d. The end portion of the back body has a hexagonal folded shape as shown in the back body 2a. In this state it is possible to bond or weld on the valve seat if necessary. In section 8d, which is parallel to the conveyor belt, the cam again has a higher speed than the orbital motion of the slide and therefore moves back in front of the U beam 38.

During the movement of the cam in the section 8d, the next slide already reaches the position of the boundary 1a and engages with the other cam 9 of the chain 8. The movement of this second slide and the entire additional slide takes place as described above and no further explanation is required.

The cam 9 reaches the wheel 11 before it leaves the U-beam of the slide at its front end and moves downwardly, i. E. In a direction away from the transport device for the back body, ) And also pulls the slide downward, and the slide finger finally disengages from the back body. The cam 9 finally leaves the U beam 38 via its rear open end and returns to the wheel 13 along the section 8c in a position where the chain 8 turns on the wheel 12. [ Where it is combined with the other slide (3). After being disengaged from the cam 9, the first slide 3 moves linearly by a certain distance and turns in the section 4c of the rail.

It is also possible to omit the track section 8d of the chain 8 and one of the two wheels 10 or 11 if it is determined that the slide finger is retracted immediately after reaching the maximum extended position without remaining in the extended position .

Claims (15)

An apparatus for opening a tubular bag body that opens at least at one end, May be introduced into one open end of the back body between the walls of the back body to at least partially fold over at least one end region of the back body wall and move into the back body end by means of reciprocating the slide to open A tubular bag body opening device comprising at least one slide that is moved outwardly, The means 8-13 for reciprocating the respective slide 3 comprise at least one drive cam 9 which can move along the path 8 and which can engage the slide 3 and move it back and forth, Wherein the tubular bag body opening device comprises: 2. A method according to claim 1, characterized in that said at least one cam (9) is mounted on a driven chain (8) or belt and moves around wheels (10, 11, 12, 13) or pulleys, And a third orbital path section (8c) forming a first orbital path section (8a), a second orbital path section (8b) away from the back body and a cam return section. . 3. A method according to claim 2, characterized in that a fourth orbital path section (8d) is provided between the first orbital path section (8a) and the second orbital path section (8b) Features a back body opening device. 4. A device according to claim 2 or 3, characterized in that the position of at least one of the pulleys or wheels (10, 11, 12, 13) in the device for reciprocating each slide is adjustable. Device. A device as claimed in any one of claims 1 to 3, characterized in that each slide has a guide path (38) for sliding engagement with the cam (9). 6. The method of claim 5, wherein the guide path of each slide for sliding engagement with the cam (9) takes the form of a U-beam (38) having an open end and attached to the slide, Wherein the first and second openings are disposed at right angles to each other. The conveyor device according to claim 2, further comprising a conveyor device (1) for conveying the back body and drives (5, 6, 7) for moving the slide (3) along an orbital path, 1) and the drive (5, 6, 7) for moving the slide along the track path are arranged such that the speed of conveyance of the back body (arrow A) (Arrow C). 8. A back body opening device according to claim 7, characterized in that the speed of the belt or chain (8) with said cam (9) is adjusted to be greater than the speed of the slide around the track path (4). 8. The apparatus of claim 7, wherein the drive for moving the slide along an orbital path includes a chain (7) moving around the gear wheels (5,6) or a belt moving about the pulley, Wherein at least one of the gear wheels or at least one of the pulleys is driven by a motor. 10. A device according to any one of claims 7 to 9, characterized in that the drives of the conveyor device (1) and the drives (5, 6, 7) for moving the slides along an orbital path are continuously actuated drives Back body opening device. 10. A device according to any one of the claims 7 to 9, characterized in that a plurality of slides (3) are distributed at equal intervals along the track path (4). 10. A back body opening device according to any one of claims 7 to 9, characterized in that the orbital path is formed by a rail (4) and each slide (3) is slidably mounted on the rail. 13. The apparatus of claim 12, wherein the means for slidingly mounting the slide on the rail (4) comprises a bush (35) and a shaft (34) slidable therein, one of the bush and the shaft Is coupled to the rail (4) by a sliding surface and the other is connected to a slide. 4. A method according to any one of the preceding claims, wherein each slide (3) comprises a cross beam (39) and at least two slide fingers (36, 37) attached to the cross beam ) Of the back body (10). 10. A method according to any one of claims 7 to 9, characterized in that the bag body is laterally folded on the conveyor device for the back body, the bag body portion extending from the transverse fold line in the direction toward the slide, Wherein the back body part disposed in the moving plane and extending from the transverse fold line in a direction away from the slide is disposed in a plane forming an arbitrary angle with respect to the reciprocating plane of the slide, Opening device.