Opening apparatus and method for opening gusseted tube fed from tube supply in folded state

Abstract

An opening apparatus for a gusseted tube which is fed in from a tube supply for the purpose of the later transfer to a device. The opening apparatus has at least two suction cheek arranged on each of two sides of the gusseted tube. Each suction cheek is arranged on one side of the gusseted tube and has a contact region which interacts with the gusseted tube and has a suction region with a protective device which lets an air flow through. The two suction cheeks lie opposite one another to be moved apart in a direction orthogonally with respect to the folded-together gusseted tube. An opening apparatus has both side cheeks of a pair arranged such that they can be moved along the outer face of the gusseted tube away from the other pair of suction cheeks to the outside.

Claims

1. A method for opening a folded gusseted tube fed from a tube supply in a longitudinal direction in a flatly folded state, the folded gusseted tube contains opposing sides with outer faces normal to the longitudinal direction, the method is carried out by an opening apparatus comprising two pairs of suction cheeks, each of the two pairs arranged on one of two opposing sides of the folded gusseted tube; the suction cheeks of each of the two pairs are arranged on the outer faces of the gusseted tube opposite in a transverse direction (9) of the folded gusseted tube orthogonal with respect to the longitudinal direction; the method comprising the steps of: smoothing the outer faces of the folded gusseted tube by moving at least one of the suction cheeks of at least one of the pairs along the outer face of the folded gusseted tube away from another pair in a direction parallel to the outer faces; thereafter attracting a region of the folded gusseted tube adjoining one of the suction cheeks by suction; and subsequently opening the folded gusseted tube at least partially by displacing the at least one of the suction cheeks of at least one of the pairs away from one another in the transverse direction of the folded gusseted tube.

2. The method according to claim 1, wherein, during the step of opening the folded gusseted tube, the gusseted tube is attracted by suction by both suction cheeks of the at least one pair.

3. The method according to claim 2, wherein the movement of at least one suction cheek of at least one pair in the longitudinal direction takes place before the step of opening the folded gusseted tube, and wherein the suction of at least one suction cheek of at least one pair in the longitudinal direction occurs after the movement to the of at least one suction cheek of the at least one pair in the longitudinal direction has finished or the suction already taking place at the beginning of the movement to the of at least one suction cheek in the direction parallel to the outer faces.

4. The method according to claim 2, wherein a throughput of at least one suction cheek changes during the movement thereof in the direction parallel to the outer faces.

5. The method according to claim 2, wherein the suction region is enlarged during the movement of at least one suction cheek in at least one of the direction parallel to the outer faces and the transverse direction.

6. The method according to claim 2, wherein the suction region is reduced during the acceptance of the gusseted tube by a pulling-over device following the step of opening the folded gusseted tube.

7. The method according to claim 2, wherein the suction cheeks of one pair are moved away from the suction cheeks of another pair in the direction parallel to the outer faces with a time delay with respect to one another or at a different speed.

8. The method according to claim 2, wherein at least one of the suction cheeks has a clamping device configured as a clamping finger, which fixes the folded gusseted tube in a clamping manner at least during the step of opening the folded gusseted tube, wherein the contact region of at least one of the suction cheeks has a recess on underside in a corner region of the at least one of the suction cheeks which faces away from the adjacent suction cheek arranged on the same side of the folded gusseted tube, wherein the recess of the at least one of the suction cheeks is provided with an additional element having an additional suction region, and wherein the additional element is displaceable between a first position which opens the recess and a second position which closes the recess at least partially.

9. The method according to claim 1, wherein the movement of at least one suction cheek of at least one pair in the longitudinal direction takes place before the step of opening the folded gusseted tube, and wherein the suction of at least one suction cheek of at least one pair in the longitudinal direction occurs after the movement to the of at least one suction cheek of the at least one pair in the longitudinal direction has finished or the suction already taking place at the beginning of the movement to the of at least one suction cheek in the direction parallel to the outer faces.

10. The method according to claim 9, wherein the suction cheeks of one pair are moved away from the suction cheeks of another pair in the direction parallel to the outer faces with a time delay with respect to one another or at a different speed.

11. The method according to claim 1, wherein the suction cheeks of one pair are moved away from the suction cheeks of another pair in the direction parallel to the outer faces with a time delay with respect to one another or at a different speed.

12. The method according to claim 1, wherein at least one of the suction cheeks has a clamping device configured as a clamping finger, which fixes the folded gusseted tube in a clamping manner at least during the step of opening the folded gusseted tube.

13. The method according to claim 1, wherein at least one of the suction cheeks has a clamping device configured as a clamping finger, which fixes the folded gusseted tube in a clamping manner at least during the step of opening the folded gusseted tube, and wherein the contact region of at least one of the suction cheeks has a recess on underside in a corner region of the at least one of the suction cheeks which faces away from the adjacent suction cheek arranged on the same side of the folded gusseted tube.

14. The method according to claim 1, wherein at least one of the suction cheeks has a clamping device configured as a clamping finger, which fixes the folded gusseted tube in a clamping manner at least during the step of opening the folded gusseted tube, wherein the contact region of at least one of the suction cheeks has a recess on underside in a corner region of the at least one of the suction cheeks which faces away from the adjacent suction cheek arranged on the same side of the folded gusseted tube, wherein the recess of the at least one of the suction cheeks is provided with an additional element having an additional suction region, and wherein the additional element is displaceable between a first position which opens the recess and a second position which closes the recess at least partially.

15. The method according to claim 1, wherein at least one of the suction cheeks has a clamping device configured as a clamping finger, which fixes the folded gusseted tube in a clamping manner at least during the step of opening the folded gusseted tube, wherein the contact region of at least one of the suction cheeks has a recess on underside in a corner region of the at least one of the suction cheeks which faces away from the adjacent suction cheek arranged on the same side of the folded gusseted tube, wherein the recess of the at least one of the suction cheeks is provided with an additional element having an additional suction region, wherein the additional element is displaceable between a first position which opens the recess and a second position which closes the recess at least partially, wherein the clamping device interacting with the additional element of the at least one of the suction cheeks has the clamping device, and wherein the clamping device is arranged on the additional element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the following text, exemplary embodiments of the invention will be explained which are shown in the drawings, in which:

(2) FIGS. 1-6 show illustrations of different positions of the suction cheeks for the purpose of spreading open a gusseted tube,

(3) FIGS. 7a and 7b show illustrations of different positions of the suction cheeks during the movement apart from one another,

(4) FIGS. 8a and 8b show oblique views of a suction cheek with a clamping finger in the release position and in the clamping position,

(5) FIGS. 9a and 9b show oblique views of an alternative refinement of a suction cheek with an additional element and with a clamping finger in the release position and in the clamping position, and

(6) FIGS. 10-13 show outline sketches for clarifying the spreading-open or opening operation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

(7) Consistent reference numerals are used for identical or similar components in all figures.

(8) FIGS. 1 to 6 show a side view of a gusseted tube 1 which is situated in an opening apparatus. As can be gathered, for example, from FIG. 13, the gusseted tube 1 has two outer faces 2, 3 and two side faces 4, 5 which are folded inwards in a V-shaped manner. Each side face 4, 5 consists of 2 equally long limbs 4, 4 and 5, 5, respectively. In FIG. 13, the gusseted tube 1 is already opened wide.

(9) In the exemplary embodiment which is shown, the opening apparatus has two suction cheeks 6 which are arranged on each of the two sides of the folded-together gusseted tube 1. In each case the suction cheek 6 which is arranged on one side of the gusseted tube 1 and the corresponding suction cheek 6 which is arranged on the other opposite side of the folded-together gusseted tube 1 form a pair. The opening apparatus which is shown therefore has two pairs of suction cheeks 6.

(10) The two suction cheeks 6 which lie on one side of the gusseted tube 1 are fixed on a common suction cheek carrier 7. Here, the suction cheeks 6 are mounted displaceably on the suction cheek carrier 7 for the purpose of the movement to the outside (arrow 8). To this end, a drive mechanism (not shown in greater detail) is provided which causes, during the movement to the outside (arrow 8), one suction cheek 6 to be displaced to one end of the suction cheek carrier 7 and the other suction cheek 6 to be displaced to the other end of the suction cheek carrier 7.

(11) Each suction cheek carrier 7 for its part is arranged on a crossmember 10 such that it can be displaced for the later movement apart from one another (arrow 9) for the purpose of opening the gusseted tube 1. To this end, a drive mechanism (not shown in greater detail) is provided which causes, during the movement apart from one another (arrow 9), one suction cheek carrier 7 to be displaced to one end of the crossmember 10 and the other suction cheek carrier 7 to be displaced to the other end of the crossmember 10. Furthermore, each suction cheek carrier 7 with the suction cheeks 6 fastened thereto can be tilted (arrow 12) by means of a hydraulic cylinder 11 in order to change its orientation.

(12) The suction cheeks 6 are shown in greater detail, for example, in FIGS. 8a and 8b. Each suction cheek 6 has a contact region which interacts with the gusseted tube 1 and has a suction region 13. For reasons of clarity, the suction region 13 is shown merely partially, but extends over the complete contact region.

(13) The suction region 13 has a protective device 14 which lets an air flow through and is configured as a grille in the exemplary embodiment which is shown. A fan 15 (not shown in greater detail) is situated behind the grille, with the result that a vacuum can be achieved in this way and the gusseted tube 1 can be attracted by suction in the region of the adjacent outer face 2 or 3.

(14) As can be gathered from FIGS. 8a and 8b, the contact region of each suction cheek 6 has a recess 16 of rectangular configuration in the form of a notch on the underside in the corner region which faces away from the adjacent suction cheek 6 which is arranged on the same side of the gusseted tube 1. In this way, the contact region is given the design approximately of an upside down L as viewed in plan view.

(15) A component, such as a clamping corner, of a device (not shown in greater detail) can be introduced into the said notched region for the later acceptance of the spread-open or opened gusseted tube 1.

(16) In addition, a clamping device 17 in the form of a clamping finger is provided, which clamping device 17 fixes the gusseted tube 1 in a clamping manner in the region of the outer edge at least during the movement apart from one another (arrow 9).

(17) As shown in FIG. 1, the gusseted tube 1 to be opened is first of all introduced between the two suction cheek carriers 7 as far as the lower edge of the folded-open suction cheeks 6. This is shown in FIGS. 1 and 10. The suction cheeks 6 are then folded against one another in the direction of the arrow 12 until they have assumed the position which is shown in FIG. 2 or FIG. 11.

(18) FIGS. 10 to 12 show all the faces, for example the outer faces 2, 3, at a small spacing merely for reasons of clarity. In practice, the gusseted tube 1 is not yet opened, for example, in FIGS. 10 to 12. To this extent, for example, the outer faces 2, 3 are in contact with one another in the regions, in which the limbs 4, 4 and 5, 5 of the side faces 4 and 5, respectively, no longer extend. In the situation which is shown in FIG. 11, the gusseted tube 1 is folded over in the region of the upper right-hand outer edge. In so far as it relates to the opening apparatus itself, only the suction cheeks 6 with the respective clamping device 17 are shown for the sake of simplicity.

(19) As can be gathered from FIGS. 10 and 11, each pair of suction cheeks 6 is situated at a spacing from the adjoining outer edge of the gusseted tube 1 at the beginning of the movement to the outside (arrow 8). Each pair of suction cheeks is then moved to the outside (arrow 8). Here, as indicated in FIG. 12, the outer faces 6 of the gusseted tube 1 are smoothed and the folded-over outer edge is also turned over. In the exemplary embodiment which is shown, the two suction cheeks 6 of each pair run synchronously. During the movement to the outside (arrow 8), the gusseted tube 1 is also attracted by suction by the respective suction cheek 6, with the result that, during the movement to the outside (arrow 8), the outer faces 2, 3 of the gusseted tube 1 are also tautened in addition to the smoothing.

(20) FIG. 12 shows the end position after the movement to the outside (arrow 8). In this position, the clamping fingers are already situated in their clamping position. The release position of each clamping finger which is configured as a clamping device 17 is shown in FIG. 8a and the clamping position is shown in FIG. 8b. The change takes place by way of a translational movement 18.

(21) Subsequently, as shown in FIGS. 5, 6 and 13, the suction cheeks 6 which are situated on one side of the gusseted tube 1 and the suction cheeks 6 which are situated on the other opposite side of the gusseted tube 1 are folded in the direction of the arrow 12 and are moved apart from one another in the direction of the arrow 9 for the purpose of opening the gusseted tube 1. After the opening, the clamping fingers can be released, with the result that the opened gusseted tube 1 can be accepted by a device.

(22) FIGS. 4 to 6 show the movement apart from one another (arrow 9) in greater detail. First of all, in FIG. 4, the suction cheek carriers 7 are folded over in the direction of the arrows 12 after the attraction by suction. Subsequently, the two suction cheek carriers 7 are moved apart from one another, with the result that the gusseted tube 1 is opened in this way.

(23) FIGS. 7a and 7b show the movement to the outside (arrow 8). The figures show the two suction cheeks 6 which are arranged on one side of the gusseted tube 1 on a common suction cheek carrier 7. During the movement to the outside (arrow 8), one suction cheek 6 is displaced to one end of the suction cheek carrier 7 and the other suction cheek 6 is displaced to the other end of the suction cheek carrier 7.

(24) FIG. 9 shows one exemplary embodiment, in which the recess 16 is assigned a displaceable, in this case pivotable, additional element 19 with an additional suction region 20. The shape and arrangement of the additional element 19 are configured in such a way that the said additional element 19 can be displaced by way of pivoting (arrow 21) between a first position which releases the recess 16 (FIG. 9b) and a second position which closes the recess 16 (FIG. 9a). In the second position, the entire suction region 13, 20 of the suction cheek 6 is enlarged, with the result that the gusseted tube 1 can be attracted by suction in a more optimum manner.

(25) After the opening of the gusseted tube 1, the additional element 19 is pivoted back into the first position which is shown in FIG. 9b. A component, such as a clamping corner, of a device (not shown in greater detail) can then be introduced into the notched region for the acceptance of the opened gusseted tube 1.

(26) A clamping device 17 is also provided in the exemplary embodiment according to FIG. 9, which clamping device 17 interacts with the additional element 19 in the exemplary embodiment which is shown and, moreover, is arranged on the additional element 19.