EP1633633A1

EP1633633A1 - Machine for completing the upper closure of a flat-bottomed bag for small-sized products

Info

Publication number: EP1633633A1
Application number: EP04734684A
Authority: EP
Inventors: Paolo Vezzani
Original assignee: Altopack SpA
Current assignee: Altopack SpA
Priority date: 2003-05-30
Filing date: 2004-05-25
Publication date: 2006-03-15
Anticipated expiration: 2024-05-25
Also published as: ATE368617T1; ITMI20031088A0; EP1633633B1; WO2004106167A1; ITMI20031088A1; ES2291879T3; BRPI0411192B1; DE602004007918D1; BRPI0411192A

Abstract

The following inventions refers to a machine for completing the upper closure of a flat-bottomed bag for small size products. The machine comprises a conveying unit (1) of the bags (156) and a succession of stations (100, 200, 300 and 400) positioned along a substantially horizontal work path defined by said conveying unit (1). A first station (100) comprises means (45) for expelling air from inside the bag (156). A second station (200) comprises heat sealing means (90-91) to carry out the complete sealing of opposite flaps (138) of the top of the bag, cutting knife (102) for separating from the bag (156) an excess part of said flaps (138) above said sealing and collecting means (95-96) for carrying away said excess part. A third station (300) comprises folding means (136, 138, 141, 145, 150, 157) for folding sideways the sealed flaps (178) of the top of the bag. A fourth station (400) comprises means (173) for securing in position said folded flaps (178) (Fig. 1).

Description

"Machine for completing the upper closure of a flat-bottomed bag for small- sized products".

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DESCRIPTION The present invention refers to a machine for completing the upper closure of a flat-bottomed bag for small-sized products.

Packing machines are known that are used in particular in the food sector, and which enclose various small-sized products, such as short pasta, beans, chick peas, etc., inside a wrapping of flexible and transparent material, usually polypropylene.

It is also known that for an optimal presentation of the packs of pasta on shop shelves it is advisable that the bags have a flat bottom, and this shows various difficulties with the present machines.

In a pending patent application of the same Applicant, a packing machine for small-sized products is described, which enables flat-bottomed bag packs to be obtained.

This machine comprises a pair of heat sealing pincers fitted with cutting blade, that can be controlled to carry out a substantially D path in which, starting from a raised and shifted position, the pincers are transversally brought closer and engaged together to execute parallel horizontal lines of heat sealing of opposite flaps of a tubular wrapping which is made to descend vertically, then they are moved vertically, while still in the close position and mutually engaged position, for a section of the descent path of said tubular wrapping to carry out a double transversal sealing and an intermediate cutting of the tubular wrapping, and finally are brought back to said raised and shifted position.

The machine also comprises two pairs of lances which, moving toward each other in a perpendicular direction to said descent path of the tubular wrapping and to the path bringing the heat sealing pincers closer in synchronism with their movement, cause the formation of side pockets inside said wrapping just above and below said heat sealing lines.

Thus bag packs are produced in which, immediately above the lower sealing, two pockets or side recesses are present that permit the formation of a flat bottom suitable for the pack to be placed steadily on a shelf or on the shelf of a piece of furniture.

The bag leaves the above-mentioned machine with the bottom perfectly closed but with the top having an opening, which is then used to extract the air from inside the bag before finally closing it.

The object of the present invention is to produce a machine capable of expelling the air from inside the bag and then completing the closure.

In accordance with the invention said object is achieved with a machine comprising a bag conveying unit and a succession of stations placed along a substantially horizontal work path defined by said conveying unit, characterised in that a first station comprises means for expelling air from inside the bag, a second station comprises heat sealing means for carrying out the complete sealing of opposite flaps of the top of the bag, cutting means for separating from the bag an excess part of said flaps above said sealing and collecting means for carrying away said excess part, a third station comprises folding means for folding sideways the sealed flaps of the top of the bag and a fourth station comprises means for fastening said folded flaps in position.

A finished bag is thus obtained which is perfectly closed and ready for distribution.

An embodiment of the present invention is illustrated as non-limiting example in the enclosed drawings, in which:

Figure 1 shows an assembly representation in a frontal view of the conveying unit of a machine according to the present invention;

Figures 2 and 2a show respectively the plan of an assembly representation of the same conveying unit and one of its details enlarged; Figure 3 shows the plan of the enlarged detail of a mechanism for adjusting the distance between two conveyor chains of said conveying unit;

Figure 4 shows a side view from the right of the same conveying unit;

Figure 5 shows said conveying unit in transversal section according to the line V-V of Figure 1; Figure 6 shows a frontal view of the first station included in the work path defined by said conveying unit;

Figure 7 shows a part of Figure 6 in enlarged scale;

Figure 8 shows the plan of the same station from above in the rest position; Figure 9 is a similar view to that of Figure 8 with the station in working position,

Figure 10 shows a part of Figure 9 in enlarged scale;

Figure 11 shows the same station in transversal section according to the line XI-XI of Figure 6; Figure 12 shows a part of Figure 11 in enlarged scale;

Figure 13 shows a frontal view of the second station included in the work path defined by said conveying unit;

Figure 14 shows the same station in transversal section according to the line XIV-XIN of Figure 3; Figure 15 shows a part of Figure 14 in enlarged scale;

Figure 16 shows the plan of the second station from above;

Figure 17 shows apart of Figure 16 in enlarged scale;

Figure 18 shows a frontal view of the third station included in the work path defined by said conveying unit; Figure 19 shows a part of Figure 18 in enlarged scale;

Figure 20 shows in enlarged scale the same station in transversal section according to the line XX-XX of Figure 19;

Figure 21 shows in enlarged scale, from above, the plan of a part of the third station; Figure 22 shows a side view of the third station from the left in relation to Figure 18;

Figure 23 shows a part of Figure 22 in enlarged scale;

Figure 24 shows the left edge of a flap folding share of the third station; Figure 25 shows the right edge of the same flap folding share;

Figure 26 shows a frontal view of the fourth station included in the work path defined by said conveying unit;

Figure 27 shows an axonometry of the bag at the input of the machine;

Figure 28 shows an axonometry of the bag at the output of the second station;

Figure 29 shows an axonometry of the same bag at the output of the machine.

The complexity of the machine subject of the present invention requires a subdivision of the description in five parts: a) conveying unit 1; b) first station 100; c) second station 200; d) third station 300; e) fourth station 400; f) operation. a) Conveying unit 1 (Figures 1-5)

With reference to Figures 1 and 2, a conveying unit 1 is shown which provides for the continuous feeding of bags filled with product, with bottom completely closed, that leave a packing machine of the type described in the above-mentioned patent application. An example of bag, indicated overall with 156, is shown in Figure 27 where side pockets 163 and two partially sealed flaps 137 can be noted, between which there is an unsealed zone 162.

The conveying unit 1 comprises a base framework 2 that supports a surface 3 for the bags and a pair of conveyor chains 4 fitted with dowels 5 for the support of respective pushers 6. The surface 3 is supported by a mobile structure 14, which can be made to vibrate by a motor 38, that commands a plate 82, and can be adjusted in a vertical direction thanks to hoisting organs 7, controlled by a motor 8, which move the structure 14 upwards and downwards. A hoisting organ 7 is connected directly to the motor 8 while the other hoisting organ 7 is connected to the same motor 8 by means of a transmission shaft 9.

The chains 4 are extended between two cogwheels 12 held so that they revolve by support surfaces 13. The rotary movement of the cogwheels 12 is commanded by a motor 15 by means of a couple of transmissions 16 better shown in Figure 4. The transmissions 16 comprise rods 23 connected, by means of pin joints 24, above to supports 25 of the cogwheels 12, below to bevel gear pairs 73 that receive the motion from the motor 15 and are connected to each other by a transmission comprising cogwheels 27 and a chain 26. The distance between the two chains 4 can be adjusted by means of two mechanisms 10 and 11, the second of which is shown in Figure 3 and comprises support blocks 17 of the support surfaces 13 of the chains 4 that can be brought closer along a revolving bar 18, put into rotation by a motor 19 by means of a chain transmission 20 extended between cogwheels 77-78. Said revolving bar 18, having two inversely threaded portions 21, is held by a plate 22 fastened to the base framework 2.

A similar mechanism 10 is shown in turn in Figures 1 and 5, where a chain 28 can be seen that connects cogwheels 29-30. Said wheel 30 is splined on a revolving bar 31, having two inversely threaded portions 32, which enables support blocks 74 the same as the support blocks 17 of Figure

31 to be brought closer and to be moved away.

The mechanisms 10-11 are synchronised by means of the chain 28 that connects the cogwheels 30 and 78 to each other, enabling the rotation. The chain 28 runs longitudinally beside the shaft 9, as its path is imposed by service wheels 29 and 79-81 (Figure 1). It is also possible to adjust the phase shift of the support surfaces 13, and thus of the chains 4, thanks to the fact that, as shown in Figure 5, the support plates 74 are engaged with inversely threaded pins 75, on which cogwheels 34 are sp lined and whose rotary motion is induced by a motor 39 (Figure 1) by means of a transmission that comprises a shaft 41 that puts a cogwheel 35 (Figure 5) into rotation, which, by means of a chain 37, starts the motion of the wheels 33. Chains 36 connect the wheels 33 and 34. b) First station 100 (Figures 6-12)

A frame 42 supports a series of the mechanisms suited to imparting three basic movements for emptying the bag (intended as expulsion of the air inside it), whose partially sealed flaps 137 are held in position by straighteners 44 supported by manually adjustable bars 60 in one with said frame 42 (Figures 11 and 12).

A first movement is represented by a transversal motion of bag forming lances 55, that is induced by a motor 53 (Figures 8, 9 and 11) that puts a belt 56 extended between wheels 55 into movement. Mobile equipment 57, in one with said belt 56, runs along guides 58 transversally conveying a block 85 rigidly anchored to the same equipment 57 by means of plates 86-87. Said block 85 is connected to the bag forming lances 55 by means of arms 49 and support rods 47, so as to transmit to the lances themselves the motion imparted by the motor 53 and to determine their movement in a transversal direction in relation to that of feeding of the bags on the support surface 3. The block 85 supports a motor 51 that makes a belt 48 extended between wheels 50 move and which is rigidly anchored to mobile equipment

70, which pulls in an opposite motion the arms 49 in one with it.

Flap emptying blocks 45 are in turn movable in a transversal direction by means of mobile equipment 63 by means of arms 43 and plates 59. A motor 62 commands a belt 68 that is extended between wheels 65 and pulls said mobile equipment 63 along guides 64 (Figures 9-12) in an opposite motion.

There is also (Figure 11) a vertical movement of the whole frame 42, induced by a motor 71, by means of a conical transmission 84, that moves a rod 88 making use of a screw-lead screw coupling 72. A hinge 83 anchors said rod 88^"to the whole frame 42.

A guide 46 (Figures 6, 8 and 9) is placed finally in continuation of the straighteners 44. c) Second station 200 (Figures 13-17)

A frame 106 (Figure 14) supports a motor 93 (Figures 14 and 16) by means of a block 107, which commands the rotation of an eccentric cam 99, to which an end of a piston rod 110 is connected, whose other end is connected by pin joint to a block 111 that is supported so that it can slide by a block 101 and supports a rear pincer 91 with electrical resistance. Two holes 123 (Figures 16 and 17), made in a support block 103 in one with the block 101, act as ^"guides for the block 111 by means of bars 124 rigidly anchored to said block 111 by means of supports 125.

A further block 108 (Figure 16 e 17) is secured to the same block 101, and comprises a handle 98, securing levers 97, a front pincer 90 with electrical resistance and a hydraulic cylinder 92 which thanks to a piston 126 permits the transversal motion of a knife 102 inside the pincer 90.

A hydraulically commanded mechanism 109 (Figure 15) guarantees double movement to pins 95, supported by a plate 122: in a vertical direction by means of a piston 119 that slides in a hydraulic cylinder 89; - in a transversal direction by means of a piston 120 that moves in a second hydraulic cylinder 121.

Plates 104-105 connect the sealing/cutting zone with a suction hopper 96. As visible in Figure 17, the plate 104 provides for vertical cuts 112 in which the pins 95 can be inserted and can slide vertically. In Figure 14, to the lower left, and in Figure 13 a motor 94 can be seen that commands the rise/descent of the frame 106 by means of a conical transmission 127 that makes a rod 128 rise/descend by means of a screw- lead screw coupling 129. A hinge 130 transmits the vertical motion of said rod 128 to the frame 106. The height of the station 200 is defined by a millimetre ruler 95 (Figure 13). d) Third station 300 (Figures 18-25)

A frame 130 (Figures 18 and 22) supports a block 131 by means of a plate 132, that, by means of a plate 133, supports an arm 134 and a pair of hydraulic cylinders 135 and 158 (Figure 21) connected to each other by means of a prismatic block 159. A fold pressing bar 136 is secured to a plate

139 in one with the piston of the hydraulic cylinder 135 and faces an abutment 138 supported by said arm 134 (Figure 23).

The block 131 also supports a fold guide hydraulic cylinder 140 (Figures 19-20) that commands the descent/rise of a fold guide 141 by means of a plate 117. In Figure 20 a second hydraulic cylinder 142 can also be seen, rigidly anchored to the frame 131, which, by means of a piston 143, moves a blade holder block 144 which supports a folding blade 145, in front of which a flap draft is placed 157 (Figure 19).

Said block 131 finally supports a screw-lead screw mechanism 146 that can be manually commanded by means of steering wheel 147. Mobile equipment 148, that rises/descends along a threaded stem 149, adjusts the vertical position of a flap folding plate 150 secured to a plate 151. As shown in Figures 18, 21, 24 and 25, said share 150 presents a vertical entrance 160 (Figure 24) and a horizontal exit 161 (Figure 25) connected to each other by a fissure 162 that gradually descends and rotates from left to right, as shown in Figures 18 and 21.

A motor 152 (Figures 18 and 22) commands the vertical motion of the frame 130 by means of a rod 153, liinged to said frame 130, that rises/descends thanks to a screw-lead screw coupling 154 and to a conical transmission 155. e) Fourth station 400 (Figure 26)

A frame 170 supports a driven gear 171 that supports a reel 172 around which a tape 179 is wound that carries a succession of adhesive labels 173. A series of guide rollers 174 defines the path followed by said tape 179, which, once the labels have been removed, finishes its path winding onto a reel 175 in one with a driving wheel 176 supported by the frame 170. f) Operation

The machine described above is designated to carry out final sealing operations on bags 156 full of various sized products, that are presented as shown in Figure 27, which is completely closed at the bottom and presents in the upper part a pair of coinciding flaps 137 partially sealed to each other with an in-between unsealed zone 162. Two side pockets 163 are provided for below the sealed zones of the flaps 137. The various bags 156 are positioned in succession on the surface 3 between respective pairs of pushers 6 of the two chains 4 and are made advance by these intermittently from left to right looking at Figures 1 and 2 with the upper flaps 137 directed longitudinally.

The machine has been previously adapted to the dimensions of the bags adjusting the motor 8 to regulate the height of the surface 3, on the motor 19 to regulate the distance of the support surfaces 13 of the chains 4 and on the motor 39 to regulate the phase shift of the same support surfaces 13.

Advancing as described above, each bag 156 first enters the station 100 (Figures 6-12), whose vertical position is adjusted by the motor 71.

With the partially sealed flaps 137 guided by the straighteners 44 the bag forming lances 55, initially in the rest position (Figure 8), are, first of all, moved transversally towards the work zone, then they are longitudinally brought closer until they enter the side pockets 163 (Figure 9). The motors 53 and 62 command the above-mentioned transversal and longitudinal motion respectively. The air present in the upper part of the bag is forced out through the opening 162 by the flap emptying blocks 45 which, commanded by the motor 62, press the bag 156 in the above-mentioned upper part without product. When the operation has finished, the flap emptying blocks 45 move away again and the lances 55 return to the rest position to enable the bag 156 to leave the first station 100.

The chains 4 then convey the bag 156 with the flaps 137 in the guide 46 up to the second station 200 (Figures 13-17) where the pincers 90-91 (Figures 14-17) are made to press on a rectangular strip 178 of the upper part of the bag 156, below the partially sealed flaps 137. While the position of the pincer 90 is adjusted manually (una tantum) by means of the handle 98 and the securing levers 97, the pincer 91 moves transversally commanded by the motor 93. The strip 178 pressed by the pincers 90-91 is then sealed according to two longitudinal strips, one above and one below the cutting line of the knife 102 (figure 16-17), which comes out of the front pincer 90 moved by the hydraulic cylinder 92. The pins 95 (Figures 15 and 17), moving transversally thanks to the hydraulic cylinder 121, pierce the part of the cut bag, and, once the rear pincer 91 has moved away, pull said cut part upwards, moved by the hydraulic cylinder 89, and then again backwards, moved by the cylinder 121, so that the cut part of the bag comes up against the plate 104 which, by interference, causes it to be released. The suction hopper 96 eliminates the cut part.

Figure 28 shows the bag at the exit of the second station 200: the upper part of the bag comprising the partially sealed flaps 137 and the unsealed zone 162 has been removed, while a strip 178 below has been sealed.

When the operations of sealing and cutting have been completed, the bag 156 moves towards the third station 300. At the input (Figures 20 and 23) the combined action of the folding blade 145, of the flap draft 157, of the fold guide 141 and of the abutment 138 enable a corner of about 120° of - li ¬

the upper part 177 of the sealed fold 178 to be folded. Continuing along the station 300 (Figures 21-22), the above-mentioned upper part 177 of the flap 178 is pressed against the remaining part of the flap itself by the fold pressing bar 136 (Figure 23) pushed transversally by the hydraulic piston 135, so that the two parts of the flap 178 can enter the vertical input fissure

160 (Figure 24) of the share 150, suitably positioned thanks to the screw- lead screw mechanism 146 that positions it vertically. The progressive angular variation of the fissure 160 (Figures 18 and 21) in the direction of the movement of the bag 156 enables the flap 178 to be rotated a further 90° and to thus leave the station 300 in a horizontal position (Figure 25), ready to be labelled.

In the fourth station 400 (Figure 26) an adhesive label 173, co ing up against the folded top of the bags, leaves the tape 179 of the labelling machine and adheres to the top of the bag so as to guarantee that the flap 178 stays folded (Figure 29).

Figure 29 shows the bag 156 at the exit of the machine: it presents the sealed flap 178, folded and positioned horizontally, that is held in this position thanks to an adhesive label 173.

Claims

CLATMS 1. Machine comprising a conveying unit (1) of the bags (156) and a succession of stations (100, 200, 300 and 400) positioned along a substantially horizontal work path defined by said conveying unit (1), characterised in that a first station (100) comprises means (45) for expelling air from inside a bag (156) with upper flaps partially sealed (137), a second station (200) comprises heat sealing means (90-91) to carry out the complete sealing of opposite flaps (178) of the top of the bag, cutting means (102) for separating from the bag (156) an excess part of said flaps (178) above said sealing and collecting means (95-96) for carrying away said excess part, a third station (300) comprises folding means (136, 138, 141, 145, 150, 157) for folding sideways the sealed flaps (178) of the top of the bag and a fourth station (400) comprises means (173) for securing said folded flaps (178) in position.

2. Machine according to claim 1, characterised in that said conveying unit (1) comprises a supporting surface (3) for the bag (156) and a pair of chains (4) fitted with pushers (6) for the advancement of said bag (156) along said supporting surface (3).

3. Machine according to claim 2, characterised in that the chains (4) are supported by support surfaces (13) and move longitudinally commanded by a motor (15).

4. Machine according to claim 2, characterised in that said supporting surface (3) can be moved vertically thanks to a command motor (8).

5. Machine according to claim 3, characterised in that the support surfaces (13) can be moved transversally and longitudinally one in relation to the other by means of motors (19) and (39), respectively.

6. Machine according to claim 1, characterised in that the first station (100) comprises straighteners of flaps (44), bag forming lances (55) and flap emptying blocks (45).

7. Machine according to claim 6, characterised in that said bag - In ¬

forming lances (55) can be moved from a rest position to an operative position, and vice versa, thanks to a double movement, a transversal nearing movement commanded by a first motor (53) and a longitudinal work movement commanded by a second motor (51).

8. Machine according to claim 6, characterised in that the flap emptying blocks (45) can be moved transversally to said work path, commanded by a motor (62).

9. Machine according to claim 1, characterised in that the heat sealing means (90-91) of the second station (200) are constituted by pincers (90-91) with electrical resistance.

10. Machine according to claim 9, characterised in that a first pincer (90) is kept in a fixed adjustable position, while a second pincer (91) can be moved transversally commanded by the motor (93).

11. Machine according to claim 9 or 10, characterised in that the pincers (90-91) are brought to press on a rectangular strip (178) of the upper part of the bag (156), below the partially sealed flaps (137).

12. Machine according to claim 11, characterised in that one of said pincers (90-91) incorporates a mobile cutting knife (102) in relation to it to carry out an intermediate cut of said strip (178) and to separate from it said excess part of the sealed flaps of the bag.

13. Machine according to claim 1, characterised in that said collecting means (95, 96) of the second station (200) comprise pins (95) that can be engaged with said excess cut part of the bag (156).

14. Machine according to claim 13, characterised in that it comprises a mechanism (109) for moving said pins (95) from a rest position in which they do not interfere with the advance movement of the bag (156) to a succession of operative positions suitable for withdrawing said excess part offhe bag (156).

15. Machine according to claim 14, characterised in that said mechanism (109) comprises hydraulic cylinders (89 and 121) that command respectively a vertical movement and a transversal movement of said pins (95).

16. Machine according to one of the claims from 13 to 15, characterised in that said collecting means (95, 96) also comprise a suction hopper (96) positioned over said pins (95).

17. Machine according to claim 16, characterised in that said hopper (96) supports a plate (104) which, during the phase of rising and moving backwards of the pins (95), removes by interference said excess part, which is the sucked up by the hopper (96).

18. Machine according to claim 1, characterised in that said folding means (136, 138, 141, 145, 150, 157) of the third station (300) are made so as to provoke the progressive folding of the sealed flap (178) above the top offhe bag (156).

19. Machine according to claim 18, characterised in that said folding means (136, 138, 141, 145, 150, 157) comprise a folding blade (145), a fold guide (141) and an abutment (138) that carry out a first rotation of about 120° of the flap (178)

20. Machine according to claim 18 or 19, characterised in that said folding means (136, 138, 141, 145, 150, 157) also comprise a fold pressing bar (136) pushed transversally by a hydraulic piston (135), that presses the folded part of the sealed flap (178) against the remaining part of the flap itself.

21. Machine according to claim 20, characterised in that said folding means (136, 138, 141, 145, 150, 157) also comprise a share (150) provided with vertical fissure (160) for the input of the sealed and folded flap (178) and an internal passage (162) predefined in function of the folding required.

22. Machine accordmg to claim 21, characterised in that said passage of the share (150) varies in its angle in the direction of the movement of the bag (156) up to an output fissure (161) positioned horizontally at the right edge.

23. Machine according to claim 1, characterised in that said fourth station (400) comprises a frame (170) that supports a driven gear (171), a driving wheel (176) and a series of guide rollers (174) for the movement of a tape (178) that carries a succession of adhesive labels (173) that can be affixed on the upper folded flap (178) of the bag (156).

24. Machine according to claim 23, characterised in that the driven gear (171) supports a reel (172) from which said tape (178) is unwound.

25. Machine according to claim 24, characterised in that the series of guide rollers (174) defines the path followed by said tape (178) from said reel (172) of the driven gear to a reel (175) in one with the driving wheel

(176).

26. Machine according to claim 25, characterised in that said path of the tape (178) is made such that said labels (173) interfere with the movement of the top of the bag (156), leaving the tape (178) and adhering to the top of the bag (156) so as to guarantee that the flap (178) remains folded.