HRP960586A2 - Apparatus for transferring valved bags to a filling machine - Google Patents

Abstract

An apparatus for automatically transferring valved bags (2) arranged in a stack (1) to a machine for filling the bags with a flowable material. The apparatus comprises means (3, 60) for picking up one bag (2) at a time from a stack (1); a conveyor (4) with a plurality of receivers (5) adapted to receive a bag (2) removed from the stack (1) by said picking means (3) and a first transfer device (6) and a second transfer device (7) for transferring the bag (2) to a filling machine with the proper orientation for being filled. The picking means (60) can comprise suction cup members (62) permanently communicating with a space (66) maintained at a pressure lower than the atmospheric pressure.

Description

The field of technology

The proposed invention relates to plants and machines adapted for filling sacks or bags with loose materials, especially powdery materials. More specifically, the invention relates to a device for delivering or supplying single valve bags to a filling or bagging machine.

It is known that so-called valve bags or bags are used for packing loose materials, i.e. bags equipped with a pair of flanges folded on the edge, one of the flanges has an opening or valve for introducing the material into the bag. A flange equipped with a vent is sometimes called a "valve" and both flanges can be rotated relative to the body of the bag.

In use, the bag being filled is carried towards the nozzle, from which the material exits, with the valve (flange) placed horizontally, and the body of the bag hanging vertically from that flange.

State of the art

As a general rule, insulting is very fast, so a supply device that can be adjusted to the speed of filling the insulting machine is highly desirable.

This is not possible if known devices are used, because the processes of lifting the bag, properly orienting the bag, placing the bag on the filling nozzle, opening the valve and filling the bag with the desired material are performed as mutually separate processes and therefore involve unused time and a long duration of the overall cycle .

Object of the invention

The aim of the proposed invention is to overcome the aforementioned disadvantages and limitations of the device according to the state of the art. In accordance with the invention, a device is provided that enables fast and continuous transfer of bags, especially without unused time. The invention relates to a device for automatic transfer of valve bags in accordance with patent claim 1.

In accordance with a further aspect of the invention, a device for lifting the bag using suction cups is provided.

Description of the invention

The invention will now be described in detail with reference to the accompanying drawings, which are by way of example and not limitation, and of which

Brief description of the drawing

figure 1 shows a side view of the device according to the invention;

Figures 2 and 3 show a top view and an end view of the device from Figure 1;

Figures 4 to 8 show some details of the delivery device;

figure 9 shows a side view of another embodiment of the device for lifting bags from a stack:

Figure 10 shows a section of the device shown in Figure 9 with some parts shown in two different operating positions.

In the drawings, the letters a and b are used to indicate the corresponding components of a pair of the same parts.

Description of preferred performance in detail

With reference to Figures 1 to 3, numeral 1 denotes a supply of folded valve bags which must be brought individually to the nozzle of the filling machine (not shown). Each bag or pouch 2 has two flanges or end portions 2a and 2b formed as meshes, and one of the flanges, i.e. flange 2a, is formed with an opening or "valve" for filling the bag.

The device for supplying bags to the filling machine mainly includes: a part 3, hereinafter referred to as a "selector", for picking up individual bags from a stack 1; a continuous bag conveyor 4 equipped with multiple elements 5, hereinafter referred to as "grippers", each of which is adapted to grasp and hold the bag first in position along the path of travel of the conveyor and carry it to the second position from where it will be transferred to the filling machine; the first transfer device 6 for moving the bags from the selector 3 to the conveyor 4, and the second transfer device 7 for moving the bags from the conveyor 4 to the filling machine. There is further provided a pressure part, such as a pressure roller or wheel 8, which ensures a supply of bags on the flanges 2b, which are further from the first transfer device 6 to prevent simultaneous lifting of two or more bags.

The conveyor 4 includes a belt 40 made of several plates, or something similar, which are connected to each other so that they can turn and move around two pulleys 41, 42. Transversely to the plates are fixed grippers 5, shaped as elongated parts similar to a box, which have a section shaped like the letter C, and are open at their ends.

In Figure 8, it is better to see how the longitudinal gap gives the catcher the shape of the letter C.

One of the pulleys, i.e. the pulley 42, is positioned so that, when the catcher 5 moves around it, it assumes a vertical configuration, the end opening of such catcher 5 facing the first transfer device 6. The position on the conveyor travel path in which the catcher assumes a vertical configuration corresponds to the first position mentioned above. However, the second position is located in the lower horizontal extension of the conveyor track. It is useful to choose another position before the middle of such a horizontal path.

The distance between the longitudinal axes of two consecutive grippers 5 depends on one transverse dimension (shorter), usually chosen for the vent (flange) in the bags intended for the given material, and preferably corresponds to the maximum possible size. By correctly choosing the shape of the catcher section, the latter will be able to accept a bag valve of any transverse size.

Selector 3 has a handle 9, in the form of a metal plate mostly bent at 90°, and located for example near the flange 2a, whereby the thickness of the handle will be slightly smaller than the thickness of the bags. The lever 9 has a horizontal part 9a and a vertical part 9b, the latter being secured to a support part 10, connected to a means (not shown) which allows the lever 9 to have a corresponding (vertically linear) longitudinal displacement, so that it is parallel to the surface of the stock 1, along the direction perpendicular to flanges 2a and 2b.

When the lever 9 moves towards the stock flange 2a, the free end of the horizontal part 9a is inserted between the flange 2a and the upper surface of the bag 2, thereby pushing the upper bag away from the roller 8 and releasing the other flange 2b from the roller 8. During this movement, the flange 2a rotates with with regard to the body of the bag with the handle 9 while the flange 2a stands vertically. This rotation of the flange 2a enables its engagement with the first transfer device.

Figure 4 shows better how the first transfer device 6 includes a pair of rollers or wheels 11, 12, which can rotate around vertical axes, one of the rollers being driven by the motor, while the other is a transfer roller. The rollers 11, 12 are located near the end of the stroke of the selector 3, so that the flange 2a in the direction of rotation can be inserted into the engagement between the pair of rollers 11, 12. One of the two rollers (roller 11 in the drawings) can be moved horizontally and pressed against the other roller to squeeze the bag's flanges between them. The surfaces of both rollers 11, 12 are machined for strong frictional engagement with the flange (they are, for example, toothed), so that the bag can be moved along the direction of the peripheral speed of the roller 11, and inserted into the vertically located catcher 5.

The side stop wall 13 (picture 2) exists on the opposite side from the one where the bags are introduced, to prevent the bags from coming out of the catcher. The second side wall 14, located between the device 6 and the belt 4, prevents the bag from coming out of the catcher on the opposite side.

It can be seen better in Figures 3, 5 and 6 that the second transfer device 7 is located on one side of the lower track of the conveyor 4, and consists of a part 15 that can be rotated around horizontal axes and is adapted to grip the flange 2a of the bag carried by the gripper 5 , in the same way as the first portable device. In the embodiment shown, part 15 includes a roller equipped with peripheral flanges of larger diameter, or a pair of small wheels on a common axle. The part 15 is carried on the lower end of the piston rod 16 mounted on the base 17 located under the upper horizontal track of the conveyor 4. In the extended position, the piston rod 16 presses the rotary roller 15 against the upper surface of the flange 2a of the bag, which is thus ejected from the catcher 5 due to frictional engagement with the rotary roller 15.

For this purpose, as shown in figures 7 and 8, the wall 50 of the catcher has a receiving gap 51, longer than the opposite continuous wall 52, thus forming a pair of protrusions 53 against which the part 15 presses the flange 2a of the bag. If desired, the transfer rollers, or wheels 18, may be placed in such protrusions as to oppose the force exerted by the part 15.

For the sake of simplification, parts for guiding and synchronizing the movement of some parts of the device are not shown in the drawing, as these components (eg computer) are well known in the art.

The operation of the device described above will be better evaluated from the following description.

By means of a suitable conveyor, which is not shown in the figure, the stack 1 of bags is delivered to a position adapted for their transfer to the conveyor 4. When the selector 3, previously brought close to the flanges 2b of the stack, moves towards the flanges 2a, so that the part 9a is inserted under the flange 2a of the bag lying on top of the pile, and that bag is moved from there under the roller 8. By continuing the sliding movement of the handle 9, the flange 2a turns around the selector 3 with respect to the body of the bag and is inserted into the space between the rollers 11, 12 of the device 6. When the flange 2a reaches the vertical position, the roller 11 presses against the roller 12 to grasp the bag and push it towards the side of the catcher 5, which at that moment is in a vertical position. The flange of the bag enters the catcher passing through the end opening and gap 51.

When the flange of the bag enters the catcher 5, the conveyor 4 moves on to bring the second catcher 5 into a vertical position, and then the above described procedures for lifting the bag 2 are repeated. As the conveyor belt advances, the bag 2 is lowered through the slot 51 into the catcher, where it remains supported with flange 2a on the wall 50 of the side wall of the gap 51.

When the gripper 5 with the captured bag reaches the right (i.e. second) position for transferring the bag to the filling machine, the piston rod 16 lowers and pushes the part 15 towards the upper part of the flange 2a, and the bag, (now in the right filling position) can taken out of the catcher 5 and transferred to the filling machine. The transmission is accompanied by the rotation of the part 15 which engages the flange 2a by friction. It is clear that in the device described above, the conveyor 4 can reach the transport speed, so that the idle times of the conventional devices are largely eliminated, and thus the full utilization of the working speed of the filling machine is achieved.

Of course, changes and modifications can be made to the device described above, which are within the scope of the invention. For example, the flange engaged with the gripper can be opposite to the one carrying the valve, i.e. flange 2b; the first transfer device may include two or more pairs of rollers, one of the pair of rollers being driven and the other being portable; the second transfer device may include more than one article 15 (and more than one pair of rollers 18); selector 3 can move fully rotary, etc.

Figures 9 and 10 show an alternative embodiment of a device for lifting one bag at a time from a stack 1. This lifting device is generally designated 60 and includes a frame 61 in which is mounted here a set of suction cups 62 for lifting the bags, these cups being able to be lifted vertically from the lower position in which they catch the bag, to the upper position, in which the bag can be dropped, and then go back to the lower position. As can be better seen in Fig. 10, each suction cup 62 acts together with a perforated plate 63 located below the cups, which causes a bag to be discharged from the cup 62 during the lifting of the cup, the number of which is sufficient to keep the flange 2a substantially horizontal during lifting.

The lifting device 60 further includes an endless belt 64, which can move at high speed around the pulleys 81, 82 (at least one of which is driven) to catch the bag dropped by the suction cup and transfer it to the conveyor 4 (not shown in Figures 9 and 10). As can be seen in Figure 10, this belt primarily includes two spaced rubber belts 64a and 64b that run side by side. Each belt 64a, 64b is adapted to grip the upper side of the flange 2a of the bag 2 and for this purpose the lower side of the belt is generally aligned with the perforated plate 63.

The lifting device 60 further includes a coupling assembly, hereinafter also referred to as an "alignment assembly", which includes handles for carrying bags gathered by a belt 64. In particular, the alignment assembly includes two couplings 65a and 65b, and since is their construction is identical, only one will be described in detail, with the other being mentioned in parentheses.The clutch 65a includes a shaft 71a (71b) carried by a support 72 (72b) which is alternately carried by a base 73a (73b) fixed to the frame 61 and connected with the crossbar 74a (74b) to the rod or tube 75 (see Figure 1) of the handle housing 76a (76b).

Each arm carries at the end a transfer roller 77a (77b) which has a base shaped so that when the bag is lifted, it is inserted between the valve (flange) and the bag body, and pushes the bag body down to facilitate its rotation in relation to the vent flange 2a.

The two couplings 65a, 65b are connected to the supporting frame 67, which can be moved vertically by means of a pneumatic cylinder 68 or another vertical actuator for raising and lowering the suction cups. In particular, the supporting frame 67 is guided by rods 69 fixed thereon, 1 can slide inside the bushing 70. The movement of the cylinder 68 is controlled in two directions by means of an electrovalve (not shown).

By rotating in relation to the supports 72a, 72b, each clutch 65a, 65b can move from a raised and passive position (right clutch 65b is shown in Figure 10) to a working position (left clutch 65b is shown in Figure 10) in which the rollers carried with the levers, they grasp the lower side of the flange 2a that carries the breather. This rotation is caused by the movement of a shaft above said support frame 67, to which a pair of rods 79a, 79b are secured so that they are alternately pivotally connected to a short lever arm 80a, 80b, rotationally secured to the shaft 71a, 71b.

The suction cups 62 are connected to a tube 66, in which a permanent vacuum is created by a suitable means such as a venturi tube. The tube 66 is fixed to the supporting frame 67.

The described lifting device works as follows. When the bags (for example stacked in a stack 1) are brought to a position where their flanges 2a, which carry the breather, are placed under the suction cups, the cylinder 68 is activated to lower the base 67. When the suction cup comes into contact with the breather flange of the first bag , the latter of the suction 1 adheres to the suction cups with a permanent vacuum created in the tube 66. In addition, the lowering of the structure 67 causes the joints 65a, 65b to break, and their handles 76a, 76b therefore move away from the belts 64a, 64b 1 from the bag 2.

Then the solenoid valve (not shown), which controls the cylinder 68, returns them, and during the lifting of the frame 67, the suction cups 62 hold the vented flange 2a in a horizontal position, while the flange is lifted from the body of the bag. At the same time, the couplings 65a, 65b move closer to each other and the base 78b of the right handle pushes down the body of the bag, thereby facilitating its rotation in relation to the vent 2a.

As soon as the suction cups 62 reach the level of the plate 63, the latter causes the raised bag to be discharged. Under these conditions, the arms 76a, 76b of the levers support from below the flange of the vent caught with the belts 64a, 64b and push it towards the conveyor 4. The passage of the cup through the cavities in the perforated plate 63 mainly defines the upper limit of the stroke of the piston, and a new cycle can begin.

Thanks to the permanent vacuum in the suction cups 62 and the mechanical discharge of the bags 2, the unused time that exists in known lifting devices is eliminated by the use of suction cups, because this unused time originates from the necessity of changing the pressure level in the suction cups.

It is clear that the embodiments described above only in illustration 1 do not limit the invention, and that the described components can be replaced with others that perform the same functions, even if they are arranged differently, they are within the scope of the invention.

The best way of industrial application

The invention can be applied in the field of filling valve bags with loose materials.

Claims (24)

1. Device for automatically transferring valve bags (2) stacked on a stack (1) to a machine for filling a bag with bulk material, where each bag (2) has a body and a pair of vent flanges (2a, 2b), one of which has a vent for charging, indicated by including - a device (3, 60) for lifting one bag (2) at a time from the aforementioned pile of bags (1); - a conveyor (4) which includes a plurality of grippers (5), each of which is adapted to grip in the first position of the conveyor's travel path the bag (2) taken from the stack (1) by means of the lifting means (3) and transports it to the second position on conveyor track to transfer it to the bag filling machine; - the first transfer device (6), located in the first position of the catcher and adapted to receive the bag (2) raised by the lifting means and its transfer to the catcher (5) while the latter is in the mentioned first position; and - a second transfer device (7) located in the second position of the gripper for extracting the bag (2) from the corresponding gripper (5) and transferring it to the said filling machine properly oriented so that it can be filled. 2. Device according to claim 1, characterized in that said lifting means (3) includes a lever (9) which can follow a reciprocating vertical movement or swinging movement in a plane parallel to the surface of the stack (1) and perpendicular to the two flanges (2a, 2b), whereby the movement of the lever (9) in one direction causes the lever (9) to be inserted between the first (2a) of the two flanges 1 of the bag body, to move the bag towards the first transfer device (6). 3. Device according to claim 2, characterized by the fact that the first flange (2a) is rotated during movement in one direction by means of the handle (9) until it reaches a plane perpendicular to the body of the bag. 4. Device according to claim 2 or 3, characterized in that the bag vent is located in the first flange (2). 5. Device according to any one of claims 1 to 4, characterized in that it contains a pressure means (8) that acts on the second flange (2b) to prevent the simultaneous taking of two or more bags. 6. A device according to any one of claims 1 to 5, characterized in that the grippers (5) are shaped as parts similar to elongated boxes, open at their ends, and have a longitudinal gap (51), which gives them a C-shaped section, and during the horizontal movement of the gripper from the first to the second position, the gap (51) with the adjacent parts of the box form abutment for the first flange (2a). 7. Device according to claim 6, characterized in that the distance between the longitudinal axes of two consecutive grippers (5) is generally equal to the longitudinal dimension of the first flange (2a) or the maximum transverse dimension of the relevant flange. 8. The device according to claim 6 or 7, characterized by the fact that in its first position the wall of the catcher (5), equipped with said gap (51), stands vertically, and the opening of the inner nest, formed by said catcher, faces the first portable device (6), while in the second position the respective wall is horizontal and facing downwards. 9. Device according to claim 8, characterized in that the length of the wall with the gap (51) is greater than the opposite wall, and protrudes over the opposite wall at the end opposite the one from where the bags (2) are to be inserted. 10. Device according to any one of claims 1 to 9, characterized in that the first transfer device (6) includes at least a pair of opposing articles (11, 12) which can be rotated about vertical axes, with a first flange (2a) inserted between them, at least one of these articles (11, 12) has a drive for rotation, and at least one of these articles (11, 12) can move towards the other article, for clamping the first flange (2a) between the respective articles (11, 12) and its transfer to the catcher nest (5) which is in the first position. 11. Device according to claim 10, characterized in that the same member of the pair, or each pair, is connected to a means that causes both its rotation and displacement parallel to its axis, while the other member is a transfer roller. 12. Device according to claim 10, characterized in that the first transfer device (6) includes at least two pairs of articles (11, 12) that can be rotated, part of each pair is connected to a means that causes its rotation, and the other part is connected to a means that causes its linear displacement. 13. Device according to any one of claims 6 to 12, characterized in that the conveyor (4) in the first position of the catcher is connected to the stopping means (13) located on the opposite side of the one on which the bag is introduced, to prevent the bag (2) from being exposed ) from the catcher. 14. Device according to any one of claims 1 to 13, characterized in that the second transfer device is adapted to eject the bag on the side of the conveyor opposite to the one on which the bag was introduced, and includes at least a part (15) that can be rotated about the horizontal axis and is adapted to grip the flange (2a) of the bag carried by the gripper (5) towards the wall of the gripper with the gap (51), the respective part (15) is further connected to the means for moving the article into engagement with the first flange (2a) when the gripper reaches second position, and for rotation of the article (15) to eject the bag (2) affected by friction from the catcher (5). 15. Device according to claim 14, in connection with claim 9, characterized in that the rotary part (15) is adapted to directly press the first flange (2a) of the bag against the prominent part of the catcher wall which has a gap (51). 16. Device according to claim 14, in connection with claim 3, characterized in that the rotary part (15) is adapted to press the first flange (2a) of the bag against the transfer rollers arranged on both sides of the prominent part (53) of the catcher wall which has a gap (51) . 17. Device according to claim 1, characterized in that the lifting means (60) includes parts with suction cups (62) that go from the place of lifting the bag to the place of dropping the bag, wherein these parts (62) are permanently in contact with the space (66) under a pressure lower than atmospheric pressure, and the means (63) for retaining the raised bags (2) works together with the parts with suction cups (62), whereby the retaining means (63), which is located at the place of discharge, is adapted so as to cause the discharge of the bag (2) from the parts with the suction cups (62) while the latter are kept connected to the space (66) at a pressure lower than the atmospheric pressure. 18. The device according to claim 17, characterized in that the lifting means (60) includes an endless belt (64) for transferring the lifted bags (2) to the conveyor (4)y and that the belt (64) extends along the length of its path in accordance with the position discharge of the bag, where it is gripped by friction on the vent side (2a) and transferred to the conveyor (4) by its rotation. 19. The device according to claim 17 or 18, characterized in that the lifting means (60) also has connecting joints (65a, 65b) that can swing behind and in front of the passive position into the working position, which joints (65a, 65b) have levers (76a, 76b) to grip that side of the vent (2b) which is opposite to the side gripped by the transfer belt (64). 20. Device according to claim 18 or 19, characterized in that the lifting means (60) includes a pair (63a, 63b) of belts and levers (65a, 65b) for each of the belts (63a, 63b), wherein the handles (76a) , 76b) levers adapted to grip the opposite edges of the vent with respect to the corresponding bag and press each of the edges against the corresponding belt (63a, 63b). 21. Device according to any one of claims 17 to 19, characterized in that said parts with suction cups (62) include a plurality of suction cups, the arrangement of which is such that the vent flange (2a) is held horizontally during the movement from the lifting position to the discharging position. 22. Device according to any one of claims 17 to 21, characterized in that the parts with suction cups (62) and the levers are mounted on a common base (67) connected to the means for commanding the reciprocating movement of the parts with suction cups (62) and the rocking movement lever parts, so that the latter reach their working position when the part with the suction cup reaches its discharge position. 23. Device according to any one of claims 17 to 22, characterized in that said mechanical means for separation include a plate (63) having multiple holes, the number and arrangement of which is equal to the number of parts with suction cups. 24. Device according to any one of claims 17 to 21, characterized in that each lever (76a, 76b) of the lever member carries at the end a transfer roller (77a, 77b) adapted to grip the exhaust flange (2a), wherein the rollers (77a) , 77b) mounted on a base designed to slide over the body of the bag during movement from the corresponding lever part to the working position.