Apparatus for the groupwise packaging of bags

Abstract

To an apparatus for the groupwise packing of bags, the bags are fed in an interconnected longitudinal series forming a bag band having successive rows formed of a single bag or a plurality of tranversally adjoining, interconnected bags. The apparatus includes a mechanism for imparting to the leading bag row of the advancing bag band a velocity that is greater than the advancing speed of the bag band. As a result, the leading bag row is, along a weakening line, torn off the bag band.

Description

BACKGROUND OF THE INVENTION

This invention relates to an apparatus for the groupwise packing of bags which are fed to the apparatus in a longitudinally interconnected condition to form a bag band. In the transversal direction the band may have a single bag, or a plurality of interconnected bags.

U.S. Pat. No. 3,631,651 discloses an apparatus of the aboveoutlined type in which the bags are fed as an interconnected band directly up to the grouping station which includes a mechanism for severing at least one transversal row as a whole or at least one individual bag, as the case may be, and for conveying the thus severed bags to a packaging container or box. The embodiment described in U.S. Pat. No. 3,631,651 includes a presser member which executes vertical strokes and which cooperates with a lowerable plate for separating, along weakened lines, the bags received on the plate. There are further provided periodically moved suction heads for introducing the separated bags into the box.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an improved apparatus of the aforeoutlined type in which the introduction of the separated bags into the box is effected by simplified means and which ensures a substantially increased productivity compared to apparatuses operating with conventional separating means.

This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, there is provided a mechanism which imparts to a leading, or first transveral row of bags of the bag band a velocity which is greater than that of a successive second transversal row of bags in the band, so that the bag band breaks along a weakened line provided between the two transversal rows and thus the first transversal row of bags is separated from the remainder of the bag band.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic sectional side elevational view of a preferred embodiment of the invention taken along line I--I of FIG. 2.

FIG. 2 is a top plan view of the same embodiment.

FIG. 3 is a partial sectional view of the same embodiment taken along line III--III of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Turning now to FIGS. 1 and 2, the preferred embodiment illustrated therein includes an endless conveyor belt 1 which serves for the transport of a series of bags 2 which form an interconnected bag band and which, for example, may be filled with tea. In this example the bag band has transversal rows of two bags each. In the bag band between the bags there are provided transversally extending weakening lines 3 as well as a longitudinally extending weakening line 4. In order to prevent a sagging of the bag band-carrying upper reach of the conveyor belt 1, there is provided a backup plate 5 in contact with the underside of the upper reach. Downstream of and adjacent to the discharge end of the conveyor belt 1 there is arranged a table 6 which has an inlet portion 6a of wedge shaped section provided with three cutouts 7. Into each cutout 7 there projects, from below, a pinch roller 8 which is urged upwardly by means of a spring 9 into engagement with an associated pinch roller 10, one disposed above each roller 8. The three rollers 10 are mounted on a common shaft 11 which is movable vertically in the direction of the double-headed arrow 12. For permitting such a vertical movement, the shaft 11 is supported at its ends by vertically guided carriers 13 (only one shown in FIG. 1). Each carrier 13 is provided at its upper portion with a horizontal arm 14. At their free end the latter freely rotatably support a shaft 15 on which there are mounted three clamping rollers 16 disposed upstream of the pinch rollers 8, 10 when viewed in the direction of bag transport.

Above a reversing roller 17 of the conveyor belt 1 at the discharge end thereof, there is provided a reversing roller 18 which is driven through a spur gear pair 19, 20 by the reversing roller 17. The reversing roller 18, in turn, drives the shaft 11 by means of two endless drive belts 21 and associated drive pulleys 22 affixed to the shaft 11. The driving connection between the reversing roller 17 and the shaft 11 of the pinch roller 10 is so designed that the peripheral velocity of the pinch rollers 8, 10 forming a pinch roller pair is greater than the peripheral velocity of the reversing roller 17 of the conveyor 1. The purpose of this velocity difference will become apparent as the specification progresses. The reversing roller 18 further drives two pairs of endless belts 23 which are trained about two pairs of reversing rollers 24. The axle 25 of each pair of reversing rollers 24 is supported by separate arms 26 (only partially shown in FIG. 2) secured to the machine frame.

Downstream of and adjacent to the discharge end of the table 6, there is provided a slide 27 which is horizontally reciprocable in the longitudinal direction of the belt 23 and which forms three parallel arms 29 extending from the slide body 27a in the longitudinal direction away from the table 6. In FIGS. 1 and 2 the slide 27 is shown in its most advanced extreme position (farthest from the table 6), whereas in FIG. 1 its rearmost extreme position is shown in phantom lines at 27'. The table 6 includes two projecting bridging members 28 which are dimensioned in such a manner that they overlap the slide body 27a even if the latter is in its farthest position from the table 6. The arms 29 have, as illustrated in FIG. 3, a T-shaped cross section so that each arm 29 forms a rib 30 extending in a vertical plane and two horizontal ledges 31. The slide 27 further has an arm 32 which is engaged by a mechanism, not shown, for the purpose of displacing the slide 27 into its one and the other extreme positions.

Between any two arms 29 there are provided two vertically reciprocable strippers 33 which move adjacent the ledges 31 and which are attached to the lower terminus of two vertically guided carriers 34. Below the slide 27 there is positioned a box 35 in which the separated bags are to be deposited and packed.

It is to be understood that the bag band may have transversal rows of more than two bags. It is apparent that, for handling such bag bands, the number of components, such as parts 7, 8, 10, 16, 21-26, 28, 29 are duplicated, as needed, in the transversal direction.

The above-described apparatus operates in the following manner:

When the carriers 13 are moved downwardly, the bag band, in the zone of the second bag row 2.sub.1, is pressed by the clamping rollers 16 against the conveyor belt 1 which moves with a velocity v.sub.1. The peripheral velocity of the clamping rollers 16 is also v.sub.1. Simultaneously, the bag band is, in the zone of the first, leading bag row 2.sub.2 pinched between the three rollers 10 and the three rollers 8, so that there is imparted to the bags of the bag row 2.sub.2 the peripheral velocity v.sub.2 of the pinch rollers 10. The velocity v.sub.2 is greater than the velocity v.sub.1 of the bags in bag row 2.sub.1. As a result of this velocity difference, the bag band tears along the transversal weakening line 3.sub.1 extending between the bag rows 2.sub.1 and 2.sub.2. The two connected bags forming the bag row 2.sub.2 are forwarded then by the endless belt 23 by friction over the table 6, the bridging member 28 and the slide 27, until they reach the ribs 30 which, at their input side, have a wedge-like, raised part 36 functioning as a cutter and arranged upstream of the ledges 31.

Then the longitudinal weakening line 4 which is oriented in alignment with the cutter 36 arrives into engagement with the latter on the middle rib 30 and is slit thereby. As a result, the two bags of the bag row 2.sub.2 are severed from one another and each bag 2.sub.3 is now, as shown in FIG. 3, laterally supported underneath the longitudinally extending opposed bag seams soley by two ledges 31 oriented to one another. Thereafter, the strippers 33 are moved downwardly by means of their carriers 3 for pushing the bags 2.sub.3 downwardly off the ledges 31 and thus causing them to fall into the box 35. The stripping speed is preferably greater than the speed which the bags would assume in case of a free fall to the bottom of the box 35 in order to achieve a rapid uniform stacking. When the slide 27 is in its most advanced position shown in solid lines, the bags in the box 35 assume a stacking position 2.sub.4 and when the slide 27 is withdrawn into its position 27' shown in broken lines in FIG. 1, the bags in the box 35 assume a stacking position 2.sub.5. The slide 27 is, after each stripping operation, displaced into its other terminal position; the distance between the two terminal positions is selected in such a manner that the bags of the two stacks 2.sub.4 and 2.sub.5 formed in the box 35 slightly overlap at their edges. It is to be understood that more than two stacks may be formed in the box 35, in which case the slide 27 has one or more intermediate positions between its two extreme positions. If, on the other hand, the user of the apparatus according to the invention finds a single stack of bags in the box 35 sufficient and there is no need for longitudinal slitting (either because each row of the bag band contains only a sole bag or because a packing of the bags in their transversally attached condition is deemed satisfactory), then the slide 27 may be omitted altogether.

The apparatus according to the invention is simpler and operationally safer than devices known heretofore and also, it has a substantially greater productivity.

It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.

Claims

I claim:

1. In an apparatus for the groupwise packing of bags, the apparatus including a conveyor for transporting a coherent bag band of indefinite length, the bag band being formed of interconnected bags arranged in succession along the direction of transport, and further arranged in rows extending transversally to the direction of transport, each bag row containing a plurality of bags connected to one another by a longitudinal weakened portion extending in the direction of transport, each bag row being connected to the adjoining bag row by means of a transversally extending weakened portion, the bag band including, when viewed in the direction of transport, a leading or first bag row and an adjoining or second bag row, the improvement comprising separating means for separating said first bag row from said bag band along the weakened portion between said first and said second bag rows; a slide extending downstream of said conveyor and said separating means for receiving said first bag row separated from said bag band; endless belt means extending immediately adjacent and substantially parallel to said slide for engaging said first bag row and moving it on and along said slide; cutting means affixed to said slide and oriented in alignment with each said longitudinally weakened portions for separating the bags of the first bag row from one another during their movement on said slide by virtue of said second conveyor; ledge means forming part of said slide and disposed downstream of said cutting means for receiving the individual separated bags of said first bag row, said ledge means constituting the sole support of said individual bags by engaging longitudinal edge portions thereof; and stripper means arranged for movement adjacent said ledge means for pushing said individual bags off said ledge means to cause them to fall onto a predetermined location, whereby at least one bag stack is formed during continuing operation of said apparatus.

2. In an apparatus for the groupwise packing of bags, the apparatus including a conveyor for transporting, with a first velocity, a coherent bag band of indefinite length, the bag band being formed of interconnected bags arranged in succession along the direction of transport, and further arranged in rows extending transversally to the direction of transport, each bag row containing a plurality of bags connected to one another by longitudinal weakened portion extending in the direction of transport, each bag row being connected to the adjoining bag row by means of a transversally extending weakened portion, the bag band including, when viewed in the direction of transport, a leading or first bag row and an adjoining or second bag row, the improvement comprising separating means for imparting to said first bag row a second velocity that is greater than said first velocity, whereby said first bag row is separated from said bag band by rupture along the weakened portion between said first and said second bag rows; a slide extending downstream of said conveyor and said pinch rollers for receiving said first bag row separated from said bag band; endless belt means extending immediately adjacent and substantially parallel to said slide for engaging said first bag row and moving it on and along said slide; cutting means affixed to said slide and oriented in alignment with each said longitudinally weakened of location, portions for separating the bags of the first bag row from one another during their movement on said slide by virtue of said second conveyor; ledge means forming part of said slide and disposed downstream off said cutting means for receiving the individual separated bags of said first bag row, said ledge means constituting the sole support of said individual bags by engaging longitudinal edge portions thereof; and stripper means arranged for movement adjacent said ledge means for pushing said individual bags off said ledge means to cause them to fall onto a predetermined locations, whereby at least one bag stack is formed during continuing operation of said apparatus.

3. An apparatus as defined in claim 2, said separating means including at least one pair of pinch rollers arranged to frictionally engage said first bag row at both sides thereof and means for imparting to said pinch rollers a peripheral velocity that is identical to said second velocity.

4. An apparatus as defined in claim 3, including at least one clamping roller arranged upstream of said pinch rollers with respect to said direction of transport, said clamping roller being arranged for pressing said second bag row against said conveyor during the frictional engagement of said first bag row by said pinch rollers.

5. An apparatus as defined in claim 1, including means for displacing said slide into one of a plurality of horizontally spaced positions for forming a plurality of said bag stacks; a table extending between said conveyor and said slide for receiving said first bag row from said separating means, said table having bridge members extending from said table and overlapping said slide in any position thereof for providing a transfer surface between said table and said slide, said endless belt means extending immediately adjacent and substantially parallel to said table for engaging said first bag row and moving it on and along said table and said bridge members.

6. An apparatus as defined in claim 3, including a shaft supporting one pinch roller of the pinch roller pair; means providing for a vertical movement of said first shaft; and spring means urging the other pinch roller of the pinch roller pair into contact with said one pinch roller.

7. An apparatus as defined in claim 4, including a first shaft supporting one pinch roller of the pinch roller pair; spring means urging the other pinch roller of the pinch roller pair into contact with said one pinch roller; a second shaft supporting said clamping roller; movable holder means supporting said first and second shafts; and means supporting said holder means for vertical reciprocation to provide for a vertical movement of said first and second shafts.