CA2940492C

CA2940492C - Sack feeding device for a sacking machine

Info

Publication number: CA2940492C
Application number: CA2940492A
Authority: CA
Inventors: Sergio Brioschi
Original assignee: FLSmidth AS
Current assignee: FLSmidth AS
Priority date: 2014-03-18
Filing date: 2015-03-04
Publication date: 2022-04-12
Anticipated expiration: 2035-03-04
Also published as: EP3119677B1; WO2015139705A1; CN106103289A; CN106103289B; RU2016140706A; RU2676962C2; RU2016140706A3; EP3119677A1; CA2940492A1

Abstract

A sack feeding device for a sacking machine comprising: means (21) for picking up one sack at a time from a stack of sacks arranged on a first plane (11); said sacks being elongated having two long sides (7, 9) and two short sides (6, 8), and at least one corner between a long and a short side comprising a valve (5), said long and a short side with a valve in between being referred to as a short valve side (6) and a long valve side (7); means (32, 34) for pushing one sack at a time so that said long valve side (7) is arranged on a second plane (40) and abuts against a retainer (41) and the long side (9) opposite to said long valve side (7) is contained by a vertical edge (36) opposite to said retainer (41), means (42) for pushing said short valve side (6) to a predetermined position on said second plane (40); means (46) for lifting said short valve side (6), away from said second plane (40).

Description

WO 2015/139705 PCT/D1(2015/050043 SACK FEEDING DEVICE FOR A SACKING MACHINE
Technical Field The present invention relates to an apparatus to insert a valve sack to a feeding tube of a sacking machine, in particular to a sack feeding device for a sacking machine. The sacks are made of paper or plastic, provided with a valve, glued, with or without a gusset, for powdery or granular materials such as concrete or other. The sacks have a rectangular shape with a valve arranged in a corner between a long side and a short .. side of the sack. The mouth of the valve is opened by spreading the sides and is introduced into a feeding tube of a sacking machine. A sacking machine comprises one or more feeding inlets that fill the sacks hanging thereto. The sacks are inserted manually or automatically in the feeding inlets.
Backoround Art Automatic machines are known for introducing sacks into the feeding inlets which take a sack at a time from lined-up stacks of sacks. By means of appropriate suction cups, the valve is opened and the sack is introduced into the feeding inlets of the sacking machine.
There are also rotary sacking machines which comprise a plurality of feeding inlets circularly arranged at predefined distances.
.. Machines for feeding sacks to a rotary sacking machine are much more complex since they must also satisfy the rotational movement of the inlet.
The task of providing sacks to a sacking machine in the case where the sacks have a constant size, or otherwise with small dimensional tolerances, is facilitated, but in some geographical areas the sacks are made by hand or with a low level of mechanization which implies employing sacks having wide tolerances also of 5% or more.
These drawbacks are increased, if the sacks are not sufficiently rigid, and therefore cannot be aligned in stacks.

2 Summary of the Invention Purpose of the present invention is to provide an apparatus for introducing a valve sack to a feeding tube of a sacking machine that is able to operate with valve sacks having dimensional tolerances not indifferent and obtained by sewing.
According to the present invention, these and other objects are achieved by a sack feeding device for a sacking machine comprising: means for picking up one sack at a time from a stack of sacks arranged on a first plane; said sacks being elongated having two long sides and two short sides, and at least one corner between a long and a short side comprising a valve, said long and a short side with a valve in between being referred to as a short valve side and a long valve side; means for pushing one sack at a time so that said long valve side is arranged on a second plane and abuts against a retainer and the long side opposite to said long valve side is contained by a vertical edge opposite to said retainer, means for pushing said short valve side to a predetermined position on said second plane; means for lifting said short valve side, away from said second plane.
According to another aspect of the present invention, there is provided a sack feeding device for introducing a valve sack to a feeding tube of a sacking machine comprising: means for picking up one sack at a time from a stack of sacks arranged on a first plane; said sacks being elongated having two long sides and two short sides, and at least one corner between a long and a short side comprising a valve, said long and a short side with a valve in between being referred to as a short valve side and a long valve side; means for pushing one sack at a time so that said long valve side is arranged on a second plane, means for lifting said short valve side to a predetermined position away from said second plane wherein said long valve side abuts against a retainer and the long side opposite to said long valve side is contained by a vertical edge opposite to said retainer, further wherein the sacking machine comprising: means for pushing said short valve side to a predetermined position on said second plane; means for retaining said short valve side by pressing the sack against the plane while said pushing means push said sack.
Date Recue/Date Received 2021-08-18 2a Further characteristics of the invention are described in the dependent claims.
The advantages of this solution compared to the solutions of the prior art are various. In particular, the device, according to the present invention, allows to manipulate the sacks individually due to their substantial dimensional tolerances and at the same time maintaining a high working speed.
Brief Description of Drawings The characteristics and advantages of the present invention will become apparent from the following detailed description of an embodiment thereof, that is illustrated by way of non-limiting example in the accompanying drawings, wherein:
Figure 1a shows an apparatus for introducing a valve sack into a feeding tube of a sacking machine, seen in perspective from the side in which the sacks are picked up, and figure lb a detail, according to the present invention;
Date Recue/Date Received 2021-08-18 WO 2015/139705 PCT/D1(2015/050043

3 Figure 2a shows an apparatus for introducing a valve sack to a feeding tube of a sacking machine, seen in perspective from the side in which the sacks are provided to the apparatus, and Figure 2b a detail, according to the present invention;
Figure 3 shows an apparatus for feeding a stack of sacks, for selecting them and feeding a valve sack to a feeding tube of a sacking machine, seen from above, according to the present invention;
Figure 4a shows an apparatus for feeding a stack of sacks, for selecting them and feeding one valve sack at a time to a feeding tube of a sacking machine, seen from one side, and Figure 4b a detail, according to the present invention;
Figure 5a shows an apparatus for feeding a stack of sacks, for selecting them and feeding one valve sack at a time to a feeding tube of a sacking machine, seen from the front in which the sacks are picked up, and figure 5b a detail, according to the present invention;
Figure 6 shows a schematically mage of a valve sack.
Detailed Description In the present invention, reference is made particularly to hand-sewn sacks typically made of thin plastic material and therefore scarcely rigid when flat so as not to withstand significant thrusts without bending and with non-constant dimensions between one sack and the other.
A valve sacks being elongated and having two long sides and two short sides, and at least one corner between a long and a short side comprising a valve 5.
A long and a short side of the sack with a valve in-between being referred to as a short valve side 6 and a long valve side 7. The long side opposite to the short valve side 6 has the reference number 8, and the short side opposite to the short valve side 7 has the reference number 9.
Referring to the attached figures, an apparatus for feeding a stack of sacks, for selecting them and feeding one valve sack to a feeding tube of a sacking machine, according to WO 2015/139705 PCT/D1(2015/050043

4 the present invention, comprises a support frame 10 which on one side supports a plane 11 for receiving a stack formed by a plurality of sacks.
The stack of sacks arranged on the plane 11 is pushed by a pair of vertical vanes 13, which move horizontally, and push the sacks against a retainer 14 transverse to the motion of the sacks themselves.
A lateral vane 15 movable transversely to the motion contains the stack of sacks along the short side 8 of the sack on the part opposite to the valve, against the opposing metal sheet 100.
The frame 16 of the machine supports the means 17 for moving individual sacks included in the stack.
The means 17 comprise a rod 20 transverse to the motion of the sacks which comprises 4 suction cups 21 connected by tubes to a vacuum system external to the machine.
The rod 20 has a vertical movement and a horizontal movement, so that the suction cups 21 come near to the long edge of the sack in proximity of the retainer 14, grasp it thanks to the activation of the vacuum and raise and move the sack.
The vertical movement of the rod 20 is given by a linear actuator 22, preferably pneumatic, fixed on a small side plate 23 which supports the rod 20.
An articulated quadrilateral allows horizontal movement of the rod 20.
The small side plate 23 is connected to a front rod 24 by means of a pin 25, and a rear rod 28 by means of another pin. The rods 24 and 28 are upperly fixed to the frame 16 by means of pins 26.
The horizontal movement of the rod 20 is given by a horizontal linear actuator 27, preferably pneumatic, permanently fixed to the upper part of the structure 16, and with the extendable arm connected to the rod 24.

5 PCT/D1(2015/050043 The machine comprises a cross member 30 connecting the two lateral supports 16. To the cross member 30 a lever 31 is pivoted which ends with a pair of free wheels 32. The lever 31 is perpendicular to the cross member 30.
5 The lever 31 can rotate, partly (by about 300), around the pins on the cross member 30, so as to give the wheels 32 a movement along an arc of circumference.
The movement is given by a linear actuator 33 upperly fixed on one side of the structure 16 and on the other side to the lever 31 in a position near the wheels 32.
The wheels 32 when lowered contrast a roller 34 rotating around its own axis driven by a motor.
The roller 34 is arranged slightly raised with respect to the plane 11 downstream from the retainer 14.
The frame 10 also supports a further plane 40 arranged downstream from the plane 11, along the direction of motion, and substantially at the same height. Said plane supports the sack when the suction cups 21 engage it.
Downstream of the roller 34 and parallel thereto a bar 35 is arranged which has a vertical edge 36 that faces the plane 40.
The sack arriving on the plane 40, in the way that will be later explained, abuts, with the long side 7 from the valve side, against a pair of retainers 41 transverse to the motion, arranged at the end of the plane 40, and the long side 9 opposite the valve 5 is in abutment against the vertical edge 36, also arranged transverse to the motion.
The width comprised between the retainers 41 and the edge 36 is just greater than the width of the sack.
A vane 42 has a transverse movement with respect to the motion of the sack that pushes it for a few centimetres and places it in a position predetermined by the end of stroke of the vane 42 itself. In this way, even if the sack is not properly arranged, the stroke of the vane 42 is sufficiently long to be able to always push the sack in the predetermined position.

WO 2015/139705 PCT/D1(2015/050043

6 The vane 42 also comprises means 38 for pressing the sack while pushing it to restrain and prevent it from being pushed too far. To maintain a high-speed processing of the sacks, the vane 42 pushes the sack with a speed that could push excessively (by inertia) the sack and incorrectly place it. For example a lever 38 is used, arranged in front of the vane 42 which by lowering presses the sack against the plane 40 (leaving it free to slide) while the vane 42 pushes it. In particular, the lever 38 has an opening in its central part where the vane protrudes 42, so that the two elements do not interfere with each other.
To allow the displacement of the sack on the plane 40 under the thrust of the vane 42 the two levers 38 rest slightly above the sack that must be moved by the vane itself so as to create a contrast friction that prevents the sack from moving by inertia beyond the stroke impressed by the vane 42.
The movement of the vane 42 takes place by means of a linear actuator 39.
The movement of the lever 38 takes place by means of a linear actuator 37.
Above the plane 40 a support 43 is provided, fixed to the frame 10, which reaches about half way of the plane 40, arranged transversely to the motion of the sacks, fixed to the frame 10 on the side opposite to the vane 42.
To the support 43 a rod 45 is pivoted, for picking up sacks, longitudinal to the motion of the sacks which comprises 4 suction cups 46 connected by tubes to a vacuum system external to the machine.
The rod 45 can rotate partially about the pins present on the support 43, so as to give a movement to the suction cups 46 over about a quarter of a circumference.
The movement is given by a linear actuator 47 fixed on one side to the support 43 and on the other side to the structure 44, in proximity of the suction cups 46.
On the support 43 also a bar 48 is arranged perpendicular to the support 43 and elongated along the motion direction of the sacks.
In order to speed up the loading of the next sack, on the support 43 in the rearmost position with respect to the suction cups 46 (from the short side 8 of the sack opposite the valve 5) another articulated quadrilateral is arranged.

WO 2015/139705 PCT/D1(2015/050043

7 A first rod 50, is fixed on one side to the frame 10, and pivoted on the other side to a second rod 51, at the end of which a small side plate 52 is pivoted. On this small side plate 52 a vertical linear actuator 53 is arranged which supports and moves vertically a pair of suction cups 54. An arm 55 is arranged in parallel to the second rod 51. The arm 55 is pivoted both to the small side plate 52 and to the first rod 50. A
further actuator 56 is arranged between the element 50 and an extension of the second rod 51.
The actuator 56 moves the second rod 51 so that the small side plate 52 and thus the suction cups 54 can follow about a quarter of a circumference, while the actuator 53 lowers and raises the suction cups 54.
Coupled to the frame 10 there are also means 60 for selecting the sack from the plane 40, for opening the valve 5 of the sack and then loading the sack on the feeding inlets of a sacking machine.
The means 60 comprise a vertical support structure 61 at the top of which an arm 62 rotating about the vertical axis of the structure 61 is arranged.
At the end of the arm 62 a guide 63 is arranged whereon a scaffold 64 which supports first pliers 65 formed by two arms with opposite suction cups 66 at the ends, and second pliers 67 without suction cups in a back position with respect to the first one 65.
The operation of the invention is apparent to the skilled in the art from what has been described and, in particular, is the following.
The sacks with the valve 5 oriented towards the machine are arranged one above the other on the plane 11.
The pair of vertical vanes 13, which in resting position are arranged on the outer side of 3 0 the plane 11 are actuated by appropriate belts and translated along guides so as to push the stack of sacks against the retainer 14.
The lateral vane 15 moves towards the stack of sacks containing and ensuring the position thereof.

WO 2015/139705 PCT/D1(2015/050043

8 The suction cups 21 are lowered due to the activation of the actuator 22, while the actuator 27 maintains the rod 24 drawn towards itself and the lowering of the suction cups 21 takes place along a vertical direction.
To the suction cups 21 a vacuum is applied to draw the long side 7 (the side of the valve 5) of a sack towards them.
The suction cups 21 are raised by the actuator 22, with the adjoining sack, and once raised, the actuator 27 pushes the rod 24 in the feeding direction of the sacks, and consequently the long side 7 edge of the sack is pushed forward again, and goes beyond the retainer 14, the roller 34 and the bar 35.
In this processing step the lever 31 and the wheels 32 are kept raised by the actuator 33.
The suction cups 21 pick up the sack at about 5-10 centimetres from the outer edge. The wheels 32 are lowered, by the actuation of the actuator 33 and push the portion of the sack which protrudes from the suction cups 21 against the roller 34, in motion. In any way the suction cups 21 and the wheels 32 are arranged alternately one with respect to the other so that they cannot interfere. The suction cups 21 release their grip, and the idler wheels 32 compress the sack against the roller 34 which by rotating, pushes the sack forward against the retainer 41, which stops between them and the vertical edge 36.
The wheels 32 and the suction cups 21 are returned to the previous position to select a new sack.
The sack is now with a long side 7 (the valve 5 side) against the retainer 41.
The vane 42 is actuated and pushes the sack, from the side of the short side 6 (the one with the valve 5), for a predetermined distance, holding it, at the same time, with the lever 38 to prevent it from being excessively launched and going beyond the predetermined position.
The sack remains well arranged in a predetermined position, i.e. with a long side 7 (the one with the valve 5) against the retainer 41 and with the short side 6 (the one with the valve 5) in a predetermined position determined by the end of stroke of the vane 42.

WO 2015/139705 PCT/D1(2015/050043

9 In particular, the valve 5 of the sack is arranged in a predetermined point delimited by two abutments i.e. by the end of stroke of the vane 42 and by the retainers 41.
At this point the suction cups 46 are lowered until coming into contact with the sack, by means of the linear actuator 47, the vacuum is activated and the suction cups take the sack along the short side 6 where the valve 5 is, and lift it. Advantageously, the rod 45 for supporting the suction cups 46 is not straight but is curved so that the sack is taken leaving a large free space close to the valve 5, i.e. the valve 5 is free for the next operations.
The sack at this point would be ready to be removed and inserted onto the feeding inlet of a sacking machine. But to speed up the handling of the sacks, the bottom of the sack is lifted so as to already place a new sack on the plane 40.
Then, simultaneously with the handling of the suction cups 46 also the suction cups 54 are moved, first by actuating the actuator 56 moving the suction cups as much as possible towards the bottom of the sack and then actuating the actuator 53 lowering them until reaching the sack. The vacuum is activated and the sack in taken.
The lifting of the suction cups 46 and of the suction cups 54 is done at the same time by lifting the sack taken by the two groups of suction cups arranged along the two short sides 6 and 8 of the sack.
While being raised, at about the middle of the sack the sack meets the bar 48.
It is thus raised from the plane 40 and folded in two.
The lifting and handling of the device is performed so that the rear side 8 of the sack, starting from about the middle of the sack, is arranged horizontally while the front part 6 of the sack, the one wherein the valve 5 is housed, is arranged vertically.
That is, the suction cups 46 perform a wider movement than the suction cups 54.
The sack is thus lifted with respect to the plane 40, so that the device, having in the meantime already taken in the initial position all the elements free to do so, may already carry and properly place the new sack.

WO 2015/139705 PC T/D1(2015/050043 The arm 62, with the adjoining open pliers, rotates towards the sack and position itself above the upper part of the sack (from the short side 6 of the one with the valve 5).
The pliers 65 and 67 close themselves onto the sack and a vacuum is actuated on the 5 suction cups 66. In particular, the pliers 65 with the suction cups 66 are arranged on the sides 6 and 7 of the sack valve, i.e. along the short side 6 and in the front part, while the pliers 67 are arranged in the back part of the same, always along the short side 8 of the sack.

10 The pliers 67 are kept closed while the pliers 65 are slightly opened so that the suction cups open the valve in order to fit it on the feeding inlet of the sacking machine.
Meanwhile, the arm 62 turns towards the sacking machine and the scaffold 64 slides along the guide 63 in order to correctly place the sack over the feeding inlet.
Other means for picking up the sack from the plane 40 alternative to the means 60 can be used.
The apparatus processes one sack at a time since the dimensional tolerances of the same are quite variable and do not allow the manipulation of stacks of aligned sacks. At the same time the apparatus has maintained a high processing speed.
The materials used, as well as the dimensions, may be any according to the requirements and the state of the art.
The apparatus thus conceived is susceptible of numerous modifications and variations, all within the scope of the inventive concept; moreover, all details are replaceable by technically equivalent elements.

Claims

CLAIMS:

1. A sack feeding device for introducing a valve sack to a feeding tube of a sacking machine comprising: means for picking up one sack at a time from a stack of sacks arranged on a first plane; said sacks being elongated having two long sides and two short sides, and at least one corner between a long and a short side comprising a valve, said long and a short side with a valve in between being referred to as a short valve side and a long valve side; means for pushing one sack at a time so that said long valve side is arranged on a second plane, means for lifting said short valve side to a predetermined position away from said second plane wherein said long valve side abuts against a retainer and the long side opposite to said long valve side is contained by a vertical edge opposite to said retainer, further wherein the sacking machine comprising: means for pushing said short valve side to a predetermined position on said second plane; means for retaining said short valve side by pressing the sack against the plane while said pushing means push said sack.

2. The device according to claim 1 further comprising means for picking up said sack with pliers along said short valve side; said means for picking up said sack comprise means adapted to open the valve.

3. The device according to claim 1 or claim 2 wherein said means for pushing one sack at a time are fed by said means for picking up one sack at a time, and comprise first suction cups for lifting said long valve side and means for moving said first suction cups along the movement direction of said sacks.

4. The device according to any one of claims 1 to 3 wherein said means for pushing one sack at a time comprise a rotating roller and a pair of wheels free to rotate; said wheels adapted to contrast said rotating roller.

5. The device according to any one of claims 1 to 4 wherein said means for pushing said short valve side comprise a vane which has a transverse movement with respect to the sack motion and pushes the same to a predetermined position.

6. The device according to any one of claims 1 to 5 wherein said means for retaining said short valve side, comprise a lever that, by lowering, presses the sack against said plane while said pushing means push said sack.

7. The device according to any one of claims 1 to 6 wherein said means for lifting from said second plane, said short valve side, comprise second suction cups.

8. The device according to any one of claims 1 to 7 further comprising means for lifting from said second plane said short side opposite to said short valve side in addition to said means for lifting from said second plane said short valve side.

9. The device according to any one of claims 1 to 8 further comprising a bar arranged along the motion direction of said sacks and arranged between said means for lifting from said second plane, said short side opposite to said short valve side, and said means for lifting from said second plane said short valve side.