Apparatus and method for reducing restoring forces of package sleeves in a filling machine

Abstract

A method for reducing restoring forces of package sleeves in a filling machine, where flat-folded package sleeves are removed from a magazine of the filling machine, erected to form a package sleeve forming a parallelogram in cross-section and then transferred to a transport device for transporting the upright package sleeve along a transport path. In order to enable a reduction in the restoring force adapted to the particular material of the package sleeve without increasing the cycle time for the removal and unfolding of the flat-folded package sleeve, the restoring force is reduced by temporarily increasing the internal angle between the package walls at the outer fold edges to more than 90 while the upright package sleeve is located on the transport path of the transport device. The reduction of the restoring force can be accomplished during the movement or during a standstill of the package sleeve on the transport path.

Claims

1. A method for reducing restoring forces of package sleeves in a filling machine, comprising the process steps: providing a magazine having flat-folded package sleeves, each of the flat-folded package sleeves comprises four parallel-running package walls separated from one another by folding edges, wherein the folding edges include outer fold edges and inner fold edges, and one acute internal angle at the outer fold edges is enclosed between the package walls, removing one of the flat-folded package sleeves from the magazine, unfolding the one of the flat-folded package sleeves to form an unfolded package sleeve forming a parallelogram in cross-section using a removal and unfolding apparatus, wherein the internal angle between the package walls at the outer fold edges is smaller than or equal to 90 during the step of unfolding, transferring the unfolded package sleeve using a transfer apparatus to a transport device downstream of the removal and unfolding apparatus and transporting the unfolded package sleeve along a transport path of the transport device, wherein at least one processing step is carried out on the unfolded package sleeve while the unfolded package sleeve is located on the transport path of the transport device, wherein the transport device is configured as a transport wheel with a plurality of radially outwardly extending receptacles, each of the receptacles configured for receiving one package sleeve and having a plurality of profiles at least one of at and adjacent to the folding edges of the package sleeve for contact therewith, and wherein the transport device has a drive for rotating the transport wheel about a rotational axis, and reducing the restoring force by temporarily increasing the internal angle between the package walls at the outer fold edges to more than 90 while the unfolded package sleeve is located on the transport wheel of the transport device, the transport device being operated in a stepwise manner, and the step of reducing the restoring force is accomplished during one of a standstill of the unfolded package sleeve on the transport path or during movement of the unfolded package sleeve along the transport path of the transport device.

2. The method according to claim 1, wherein the internal angle between the package walls at the outer fold edges is increased to more than 90 by moving the outer fold edges towards one another in the direction of a cross-sectional diagonal between the outer fold edges of the unfolded package sleeve during the step of reducing.

3. The method according to claim 1, wherein the internal angle between the package walls at the outer fold edges is increased to more than 90 by pivoting two opposite package walls parallel to one another in each case about one of the outer fold edges during the step of reducing.

4. The method according to claim 1, wherein the internal angle between the package walls at the outer fold edges is increased to an angle in the range between 120 to 180 during the step of reducing.

5. A filling machine for filling products into package containers, comprising: a magazine for receiving flat-folded package sleeves for producing the package containers, wherein each flat-folded package sleeve comprises four package walls separated from one another by outer fold edges and inner fold edges, with an acute internal angle at the outer fold edges enclosed between the package walls, a removing and unfolding apparatus for removing one of the flat-folded package sleeves from the magazine and unfolding the one of the flat-folded package sleeves to form an unfolded package sleeve forming a parallelogram in cross-section, wherein the internal angle between the package walls at the outer fold edges is smaller than or equal to 90 in the removing and unfolding apparatus, a transfer apparatus for transferring the unfolded package sleeve to a downstream transport device, the transport device transporting the unfolded package sleeve along a transport path, the transport device having a transport wheel with a plurality of radially outwardly extended receptacles for receiving the unfolded package sleeve, each of the receptacles having a plurality of profiles configured to be disposed at and/or adjacent to the inner fold edges of the unfolded package sleeve for contact therewith when the unfolded package sleeve is received in the each of the receptacles, and the transport device having a drive for turning the transport wheel about an axis of rotation, and means for reducing the restoring force of the unfolded package sleeve while the unfolded package sleeve is located on the transport wheel of the transport device.

6. The filling machine according to claim 5, wherein the drive is configured as a stepping drive configured to bring the receptacles for the package sleeves into a standstill position after turning the transport wheel by a step angle, the means for reducing the restoring force being activated while the transport wheel is at a standstill.

7. The filling machine according to claim 6, wherein each of the receptacles has at least one first profile that can be brought to rest against one of the outer fold edges of the package sleeve and the each of the receptacles has at least two second profiles that can be brought to rest against another of the outer folds edges of the package sleeve.

8. The filling machine according to claim 6, the each of the receptacles has two first holders which receive one of the outer fold edges and one of the inner fold edges of the package sleeve, two second holders which receive another of the outer fold edges and another of the inner fold edges of the package sleeve, the two first holders being disposed in a fixed position on the transport wheel and the second holders being disposed pivotably on the transport wheel so that due to the pivoting movement of the two holders, two opposite package walls are pivotable parallel to one another about one of the two outer fold edges.

9. The filling machine according to claim 8, wherein the means for reducing the restoring force comprises a cylinder cam mechanism with a cylindrical fixed cam body disposed coaxially to the axis of rotation of the transport wheel, a cylinder cam disposed in the cam body, a scanning element guided in the cylinder cam, and a linkage connected on one side to the scanning element and on the other side to the second pivotable holders.

10. The filling machine according to claim 9, wherein at least one section of the cylinder cam is disposed in a segment of the cam body displaceable in the direction of the axis of rotation.

11. The filling machine according to claim 6, wherein the means for reducing the restoring force comprises a push element that acts temporarily on at least one of the outer fold edges and is movable in the direction of a cross-sectional diagonal running between the outer fold edges of the upright unfolded package sleeve.

12. The filling machine according to claim 5, wherein the drive is configured as a stepping drive configured to bring the receptacles for the package sleeves into a standstill position after turning the transport wheel by a step angle, the means for reducing the restoring force being activated during the turning of the transport wheel.

13. The filling machine according to claim 12, the each of the receptacles has two first holders which receive one of the outer fold edges and one of the inner fold edges of the package sleeve, two second holders which receive another of the outer fold edges and another of the inner fold edges of the package sleeve, the two first holders being disposed in a fixed position on the transport wheel and the second holders being disposed pivotably on the transport wheel so that due to the pivoting movement of the two holders, two opposite package walls are pivotable parallel to one another about one of the outer fold edges.

14. The filling machine according to claim 13, wherein the means for reducing the restoring force comprises a cylinder cam mechanism with a cylindrical fixed cam body disposed coaxially to the axis of rotation of the transport wheel, a cylinder cam disposed in the cam body, a scanning element guided in the cylinder cam, and a linkage connected on one side to the scanning element and on the other side to the second pivotable holders.

15. The filling machine according to claim 14, wherein at least one section of the cylinder cam is disposed in a segment of the cam body displaceable in the direction of the axis of rotation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is explained in detail hereinafter with reference to the figures. In the figures:

(2) FIGS. 1a-d shows schematic views of a prior art filling machine to illustrate removal and unfolding of package sleeves from a magazine,

(3) FIG. 2 shows a schematic perspective partial view of a filling machine before activation of an apparatus for reducing the restoring force,

(4) FIG. 3 shows a partial view of the filling machine according to FIG. 2 during activation of the apparatus for reducing the restoring force,

(5) FIGS. 4a-d show schematic views to illustrate the removal and unfolding of package sleeves from a magazine of a filling machine according to FIGS. 2 and 3,

(6) FIGS. 5a-b show schematic views to illustrate the reduction of the restoring force in a filling machine according to FIGS. 2 and 3,

(7) FIG. 6 shows a schematic perspective partial view of a second exemplary embodiment of a filling machine during the reduction of the restoring force at a package sleeve and simultaneous transfer of another package sleeve to a transport device,

(8) FIG. 7 shows a partial view of the filling machine from FIG. 6 during the turning of the transport wheel,

(9) FIGS. 8a-d show schematic views to illustrate the reduction of the restoring force in a filling machine according to FIGS. 6 and 7,

(10) FIGS. 9a-f show schematic perspective partial views of a third exemplary embodiment of a filling machine in which the reduction of the restoring force takes place during a turning of the transport wheel and

(11) FIGS. 10a-c show schematic view to illustrate the reduction of the restoring force in a filling machine according to FIGS. 9a-f.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(12) Insofar as the filling machines according to the invention for filling liquid foodstuffs into packaging containers, shown in part in FIGS. 2-10, comprise the same components as the filling machine according to the prior art, shown in part in FIG. 1, the same reference numbers are used. In addition, reference is additionally made to the explanations for the filling machine shown in FIG. 1.

(13) The magazine (2) for receiving the flat-folded package sleeves (1) for producing the packaging containers is disposed on a frame (20) of the filling machine according to FIGS. 2-5 at the beginning of the conveyor line. The magazine (2) comprises retaining profiles (21a, b) which come to rest on the outer fold edges (3a, b) of the package sleeves (1). The removal side (7) of the magazine (2) exposes the two front package walls (5a, b) of the overall four package walls (5a, b, 6a, b) of the respectively front package sleeve (1). The removal and unfolding apparatus located downstream of the magazine (2) on the conveyor line of the filling machine comprises a suction gripper (9) having three pneumatic suckers for gripping the package wall (5a) exposed on the removal side (7). The suction gripper (9) is disposed displaceably along a rectilinear movement path (23) perpendicular to the exposed package wall (5a).

(14) The removal and unfolding apparatus furthermore has a flat guide surface (24) for the outer fold edge (3b) of the other of the two exposed package walls (5b) of the package sleeve (1). The flat guide surface (24) guides the outer fold edge (3b) in a sliding manner.

(15) Located after the flat guide surface (24) in the direction of the movement path (23) is a fixed retaining element (17) for receiving the outer fold edge (3a). The retaining element (25) for receiving the diametrically opposite outer fold edge (3b) can be moved to and fro by means of a linear drive between an initial position shown in FIGS. 4a-c and an end position shown in FIG. 4d. Both the fixed retaining element (17) and also the moveable retaining element (25) are configured as an angle profile. The two surfaces of the angle profiles disposed at an angle to one another come to rest against the package walls (5a, 6a or 5b, 6b) in the end position shown in FIG. 4d.

(16) As can be seen in particular from FIGS. 4a-d, the distance between the flat guide surface (24) and the movement path (23) of the suction gripper (9) decreases continuously in the direction from the magazine (2) to the retaining elements (17, 25).

(17) In order to transfer the package sleeve (1) completely erected by the retaining elements (17, 25), forming a square in cross-section, to a transport device (26) of the filling machine located downstream of the removal and unfolding apparatus, the suction gripper (9) can be moved vertically up and down by means of an actuator (22).

(18) The transport device (26) comprises a transport wheel (29) which is rotatable about an axis of rotation (28a) comprising four radially outwardly extending receptacles each having a first profile (30) and two second profiles (31). The first profile (30) is designed as an angular guide and can be brought to rest on the outer fold edge (3b). The two second profiles (31) are designed as rod profiles and can be brought to rest directly adjacent to the outer fold edge (3a). The first and second profiles (30, 31) form cells into which the unfolded package sleeves having rectangular cross-section can be inserted. The axis of rotation (28a) of the transport wheel (29) lies in a plane transverse to the conveyor line (23) of the filling machine. The transport wheel (29) is turned in a stepwise manner by 90 in each case about the axis of rotation (28a) by a drive not shown. From the transport wheel (29) shown, the unfolded package sleeves (1) are transferred to other transport devices not shown in the figures in order to perform further processing steps on the package sleeves.

(19) An apparatus (32) for reducing the restoring force is disposed on the transport device. The apparatus (32) for reducing the restoring force comprises a push element (33) that is connected via an arm (34) to a movement drive (35). The push element (33) designed as an angle profile extends parallel to the outer fold edge (3a) at which it can be temporarily brought to rest, where the fold edges (3a) rest against the edge (36) formed between the legs of the angle profile on the inner side thereof. The movement drive (35) is fastened to the frame (20) of the filling machine.

(20) The filling machine according to FIGS. 2, 3 operates as follows:

(21) After removing and unfolding the package sleeve (1), this is inserted into the downwardly pointing receptacle of the transport wheel (29). The transport wheel (29) is then turned in the anticlockwise direction (37) through a step angle of 90 with the aid of a drive not shown, so that the previously loaded receptacle comes into a horizontal, right-pointing standstill position. In this standstill position of the transport wheel (29), the movement drive (35) of the apparatus for reducing the restoring force is activated so that the push element (33) comes to rest on the outer fold edge (3a). In the course of the further movement of the push element (33), the package walls (5a, 6a) become detached from the rod-shaped second profiles (31) whilst the outer fold edges (3a, b) move towards one another in the direction of the cross-sectional diagonals (38). The internal angle (39) between the package walls (5a, 6a or 5b, 6b) at the outer fold edges (3a, b) is thereby increased to more than 90, as can be seen clearly from FIG. 5b. This enlargement of the internal angle (39) breaks the pre-tensioning force in the fold edges (3a, b) and the inner fold edges (4a, b). The push element (33) is then withdrawn into the initial position with the aid of the movement drive (35) so that the package sleeve (1) again has a rectangular cross-section but with reduced restoring force. The transport wheel (29) is then turned further through a step angle of 90 whereby the next package sleeve (1) received previously by the perpendicularly downwardly pointing receptacle comes into the horizontally right-pointing standstill position and a reduction in the restoring force is accomplished.

(22) The filling machine shown in part in FIGS. 6 and 7 differs from the filling machine shown in FIGS. 2 and 3 in that a package sleeve (1) which has not yet been completely erected to form a rectangle or square is transferred to the downward-pointing receptacle of the transport wheel (29). Furthermore the apparatus (32) for reducing the restoring force is constructed differently. Insofar as the filling machine shown in FIGS. 6 and 7 has the same components as the filling machine shown in part in FIGS. 2 and 3, the same reference numbers are used. In addition, reference is made to the explanations there to avoid repetitions.

(23) The transport wheel (29) also has four receptacles, where each receptacle comprises a first radially outwardly extending profile (40) that is disposed in a fixed position on the transport wheel (29). The first profile (40) is angled at the side edges. The angled profile regions form first holders (41) for receiving the outer fold edge (3a) and the inner fold edge (4a) of the package sleeve (1). A second profile (42) also extends radially outwards and is also angled in the edge regions. The angled regions form second holders (43) for receiving the other outer fold edge (3b) and the other inner fold edge (4b) of the package sleeve (1). The second profile (42) is designed as a coupler of a mechanical linkage having four articulations, that converts a rectilinear movement of a linkage (44) into an oscillating movement of the second profile (42). The mechanical linkage has two motion links (45) which are articulated at one end to side arms (46) disposed in extension of the second profile (42) and which are articulated at the other end in an articulated manner on the axle body (28b) of the transport wheel (29). The motion links (45) move parallel to the side walls (6a, 5b) of the package sleeve (1).

(24) The linkage (44) is designed in two parts. The linkage is divided into an angled part (44a) and a rectilinear part (44b). The angled part (44a) articulated to the underside of the second profile (42). At the opposite end the angled part (44a) is connected in an articulated manner to the rectilinear part (44b). The rectilinear part (44b) is connected to a scanning element (47) in the form of a cam roller at the end remote from the linkage. The rectilinear section (44b) is forcibly guided by a guide element (48) connected in a torque-proof manner to the axle body (28b) in the direction of the axis of rotation (28a) of the transport wheel (29). The scanning element (47) is part of a cylinder cam mechanism (49). The cylinder cam mechanism (49) comprises a cam body (50) disposed in a fixed position on the frame (20) coaxially to the axis of rotation (28a) of the transport wheel (29). A cylinder cam (51) in the form of a groove which guides the scanning element (47) is inserted in the cam body (50). A section (52) of the cylinder cam (51) is part of a segment (53) of the cam body (50) which is displaceable in the direction of the axis of rotation (28a). The segment (53) can be moved to and fro in a link (54) of the cam body (50) by means of an actuating member (55). The movement is accomplished with the aid of a drive not shown for the sake of clarity.

(25) The method for reducing restoring forces in package sleeves (1) in a filling machine according to FIGS. 6 and 7 is explained in detail hereinafter with reference to FIGS. 8a-d.

(26) FIG. 8a shows a view of the downwardly pointing receptacle of the transport wheel (29). In this position of the receptacle, the package sleeve (1) erected only partially to form a parallelogram is inserted into the receptacle. In the present exemplary embodiment the package sleeve (1) is erected to form a diamond which comprises approximately of the square cross-section of the completely erected package sleeve (1). The transport wheel (29) is then turned further in the clockwise direction (56) through a step angle of 90 so that the receptacle points horizontally left (cf. FIG. 6). During this turning through 90, the scanning element (47) is guided in the cylinder cam (51) inwards in the direction of the transport wheel (29), whereby the linkage (44) pivots the second profile (42) into the standstill position shown in FIG. 8b. In the standstill position of the receptacle shown in FIG. 8b, in which this points horizontally to the left, the package sleeve (1) is erected to form a square in cross-section. In order to now reduce the restoring forces caused by the fold edges (3a, b, 4a, b) in the package sleeve (1), the internal angle (39) between the package walls (5a, 6a or 5b, 6b) at the outer fold edges (3a or 3b) is increased to more than 90. In the horizontal left-pointing position of the receptacle shown in FIG. 8b, c, the scanning element (47) is located in the section (52) of the displaceably disposed segment (53) of the cam body (50). With the aid of the actuating member (55), the segment (53) is now displaced in the direction of the axis of rotation (28a) inwards in the direction of the transport wheel (29), whereby the second profile (42) swings into the opposite position to FIG. 8a), according to FIG. 8c). By this means the internal angle (39) is increased to a value of more than 90, in the exemplary embodiment shown of about 130. Then, during the standstill in the left-pointing position of the receptacle, the actuating member (55) is withdrawn until the section (52) is again in alignment with the remainder of the cylinder cam (51) as can be seen in FIG. 8d).

(27) Two further rotations of the transport wheel (29) through a step angle of 90 in each case now take place, where the package sleeve (1) which is completely upright and overstretched in its fold edges preserves its square cross-section. This is achieved by guiding the scanning element (47) during the subsequent two rotations through step angles of 90 in each case in an annular section (57) of the cylinder cam (51). As soon as the receptacle points horizontally to the right, the upright package sleeve is transferred with reduced restoring force to a following transport device not shown for the sake of clarity. During the subsequent rotation of the receptacle from this transfer position through 90 into this downward-pointing receiving position (FIG. 8a), the scanning element (47) is guided in the outwardly guided section (58) of the cylinder cam (51), whereby the pivotable second profile (42) again goes into the position shown in FIG. 8a for receiving another partially erected package sleeve (1).

(28) The filling machine according to the invention shown in part in FIGS. 9a-f largely corresponds to the filling machine according to FIGS. 6 and 7. Insofar as the filling machine has the same components, the same reference numbers are used. In addition, reference is additionally made to the explanations for the filling machine according to FIGS. 6, 7.

(29) The essential difference between the filling machine according to FIGS. 9a)-f) and the filling machine according to FIGS. 6 and 7 is that the reduction in the restoring force takes place exclusively during a movement of the upright package sleeve (1) along the transport path of the transport wheel (29) but not when the transport wheel is at a standstill, as in the exemplary embodiment of the filling machine according to FIG. 2 or 6 and 7. The receptacles of the transport wheel are configured in the same way as in the exemplary embodiment according to FIGS. 6 and 7 so that in this respect reference is made to the explanations there. The apparatus (32) for reducing the restoring force differs from that for the filling machine according to FIGS. 6 and 7 in that no section (52) of the cylinder cam (51) is disposed in a displaceable segment (53) of the cam body (50). A displaceable segment (53) can be dispensed with since the movement of the second profile (42) is brought about only by the movement of the scanning element (47) in the continuous cylinder cam (51) during the rotation of the transport wheel (29).

(30) The complete erection of the package sleeve and the subsequent overstretching of the package edges (3a, b, 4a, b) is explained in detail hereinafter:

(31) FIGS. 9a), 10a) show the transport wheel (29) with the downward-pointing receptacle in which the package sleeve (1) erected to form a non-square parallelogram in cross-section is received. The scanning element (47) is located in the cylinder cam (51) at the greatest possible distance from the transport wheel (29). During the subsequent turning of the transport wheel in the clockwise direction (56) through a step angle of 90, the scanning element (47) is guided on an inwardly guided section (59) of the cylinder cam (51) in the direction of the transport wheel (29), whereby the linkage (44) pivots the second profile (42) into the position shown in FIGS. 9c), 10b). In this position the two internal angles (39) between the package walls at the outer fold edges (3a, b) are increased to an angle of more than 90, in the exemplary embodiment shown, of more than 140 and the restoring forces emanating from the fold edges (3a, b, 4a, b) are thereby reduced.

(32) The transport wheel (29) is then rotated further through another step angle of 90, whereby the scanning element (47) runs through an outwardly guided section (58) of the cylinder cam (51). The second profile (42) is thereby pivoted by means of the linkage (44) into the position shown in FIGS. 10c), 9e), in which the package sleeve (1) has the desired square cross-section with reduced restoring forces. The receptacle points upwards. In this position a processing step can be performed on the completely upright package sleeve such as, for example, forming the package base.

(33) In the position rotated further through a step angle of 90 in the clockwise direction (56), in which the receptacle points horizontally to the right, the processed package sleeve (1) can be transferred to a downstream transport device. The turning movement between the position with upwardly pointing receptacle into the position with horizontally right-pointing receptacle is accomplished without further pivoting of the second profile. To this end, the scanning element (47) is guided in an annular section (57) of the cylinder cam (51) which can be seen from FIG. 10c).

(34) The previously described apparatus according to FIG. 9 is used in particular when the cardboard packagings processed in the filling machine have largely the same condition and the magnitude of the oscillation amplitude of the second profile (42) need not be varied for reducing the restoring force. The apparatus according to FIGS. 6, 7 is however used in particular in those filling machines in which package sleeves (1) having different cardboard conditions are processed. The amplitude of the oscillating motion of the second profile (42) can be adapted to the condition of the cardboard by means of the setting of the stroke of the displaceably guided segment (53).

(35) TABLE-US-00001 REFERENCE LIST No. Description 1 Package sleeve 2 Magazine 3a, b Outer fold edges 4a, b Inner fold edges 5a, b Package walls 6a, b Package walls 7 Removal side 8 Retaining elements 9 Suction gripper 10 Axis 11 Pivot arm 12 Guide surface 13 Guide elements 14 Movement path 15a, b Internal angle 16 Retaining elements 17 Retaining elements 18 19 20 Frame 21a, b Retaining profiles 22 Actuator 23 Movement path 24 Guide surface 25 Retaining element 26 Transport device 27 Sleeve slider 28a Axis of rotation 28b Axle body 29 Transport wheel 30 First profile (angle profile) 31 Second profile (rod profile) 32 Apparatus for reducing the restoring force 33 Push element 34 Arm 35 Movement drive 36 Edge (angle profile) 37 Anticlockwise direction 38 Cross-sectional diagonal 39 Internal angle 40 First profile 41 First holder 42 Second profile 43 Second holder 44 Linkage 45 Motion links 46 Side arms 47 Scanning element (cam roller) 48 Guide element 49 Cylinder cam mechanism 50 Cam body 51 Cylinder cam 52 Section 53 Segment 54 Link 55 Actuating member 56 Clockwise direction 57 Annular section 58 Outwardly guided section 59 Outwardly guided section