EP0003724A1 - Machine for mechanically opening and emptying bags that may contain a toxic product - Google Patents

Abstract

Mechanical opening and emptying machine for bags that may contain a toxic product. Including a conveyor (1) intended to bring each bag (7) to a product hopper (3), cutting means (2, 2 ') capable of cutting three sides of the bag during the advancement of the latter and an assembly gripper (4) capable of gripping the cut bag to move it, emptying it into the hopper (3) and bringing it to an evacuation location (6), the machine being able to be equipped with means suitable for automatically controlling the conveyor, the cutting means and the gripping assembly according to a predetermined cycle of operations. The machine according to the invention makes it possible to open and empty bags which may contain powdery or fibrous products which can be toxic or corrosive, such as asbestos, without affecting the health of the workforce, by opening and emptying the bags mechanically near the product use station.

Description

The subject of the invention is a machine for mechanical opening and emptying of bags which may contain a toxic product.

We know that some industries use products delivered in bags that are generally opened by hand to bring their content to the appropriate position in a production cycle, which can mobilize a large and therefore expensive workforce, if you want a high production rate.

Sometimes the contents of the bags can be harmful to health either because it is dangerous to touch, absorb or breathe, or because its fumes or radiation attack human tissue. This is particularly the case with corrosive products, or powdery or fibrous products, such as asbestos, for example, the dust of which can cause lung cancer.

Staff protection measures must therefore be provided to open the bags, but these precautions, which inevitably add to the cost of production, are not always effective and generally limit industrial output.

The invention aims to obtain a good production rate with reduced labor without affecting health even if the contents of the bags are toxic, by opening and emptying the bags mechanically near the station of use of the product.

The invention therefore relates to a machine for mechanical opening and emptying of bags which may contain a product. toxic.

It comprises a conveyor intended to bring each bag to a product hopper, cutting means capable of cutting three sides of the bag during the advancement of the latter and a gripping assembly capable of gripping the cut bag, moving it, empty it into the hopper and bring it to an evacuation location, the machine being able to be equipped with means suitable for automatically controlling the conveyor, the cutting means and the gripping assembly according to a predetermined cycle of operations.

The machine may further include a means for driving empty bags.

The machine can be housed in an enclosure and this can be put under vacuum.

The cutting means capable of cutting three sides of a bag are two cutting elements with a vertical axis each carried at one end of an arm, the other end of which is articulated on a constraint system capable of constantly bringing the cutting element towards the axis of the conveyor, the elements of the restraint system being fixed respectively to the left and to the right of the conveyor, so that the first cutting element, which encounters a bag, cuts in a single stroke part of the front face of the bag and a side face, the second cutting element then cutting the rest of the front face and the other side face.

The cutting elements are advantageously rotary discs; they can also be fixed knives or any other equivalent means.

The gripping assembly comprises a movable support and a gripping means chosen from those which act by hooking, suction and pinching and, the cut bag being fixed to said means, the movement of the support causes the bag to deploy over its length twice above the product hopper. The gripping assembly can be movable in a horizontal plane.

Advantageously, the gripping assembly is movable in a vertical plane. This set is made up by a box which carries rotary hooking hooks and is secured to two arms capable of pivoting about an axis so that, the hooks having been inserted in the upper part of a cut bag, the rotation of the arms makes it possible to deploy it above the hopper to empty it and direct the emptied bag to its disposal location.

The machine according to the invention advantageously comprises, in order to prevent accidental falling into the hopper of bags and parts of cut bags, in addition to a conveyor, two cutting means and a gripping assembly of the mobile type, a drive means, mounted in the path of the path of the emptied bag and suspended from the box of the gripping assembly, which comprises two rollers arranged in a V shape able to approach each other and to rotate so as to pinch the emptied bag and to drive it towards the evacuation location, in particular when the emptied bag is released from the gripping assembly.

• - les figures 1 et 2 sont des vues en élévation et en plan de l'ensemble de la machine ;
• - les figures 3 à 9 illustrent le fonctionnement des moyens de coupe ;
• - les figures 10 et 11 illustrent respectivement le fonctionnement de l'ensemble de préhension et un détail dudit ensemble de préhension et
• - la figure 12 montre le montage des parties du moyen d'entraînement de sacs vidés.

The accompanying drawings show by way of example an embodiment of the invention in which:

• - Figures 1 and 2 are elevational and plan views of the entire machine;
• - Figures 3 to 9 illustrate the operation of the cutting means;
• FIGS. 10 and 11 respectively illustrate the operation of the gripping assembly and a detail of said gripping assembly and
• - Figure 12 shows the mounting of the parts of the drive means of empty bags.

The bag opening and emptying machine according to the invention comprises a carrier 1 for bags, two cutting means 2, 2 'for bags, a product hopper 3, a gripping assembly 4 for cut bags, a means for drive 5 of cut bags and an evacuation location 6 of empty bags. The machine further comprises means suitable for automatically controlling the parts. mobile of the machine according to a predetermined cycle of operations, these means not being shown in the accompanying drawings.

The closed bags 7, filled with a product to be poured into the hopper, are designated by 7 and any means intended to convey the bags to the machine; this means can be a conventional transporter. 9 indicates an enclosure which surrounds the machine; the enclosure can possibly be placed under vacuum to avoid the dispersion of dust outside. It should be noted, however, that the machine must not be housed in an enclosure if one can work in the open air, and that it suffices to provide a suction device if the opening and emptying of the bags give off dust.

There is shown schematically the conveyor 1 (Figures 1, 2) intended to smoothly drive the bags 7 in the direction of the arrow 10 between two drums 11 (inlet of the enclosure 9) and 12 (hopper 3 to product) one of which can be rotated.

Each cutting means 2, 2 ^t comprises a movable cutting element above the conveyor 1, and a constraint system intended to constantly bring the cutting element towards the axis 14 of the conveyor.

Each cutting element is a disc 20, 20 'with vertical axis 21, 21', which can be rotated by a belt 22, 22 'mounted on the axis of a motor 23, 23'. The vertical axis 21, 21 'is carried by a pivoting arm 24, 24', articulated around a fixed axis 25, 25 'which also carries a link 26, 26' articulated at the free end of the rod 27 , 27 'of an advantageously pneumatic cylinder 28, 28'. In the embodiment shown, the fixed axis 25, 25 'of pivoting of the arm 24, 24' is located in the axis of the motor 23, 23 '.

The cylinders are mounted respectively, one to the left, the other to the right of the conveyor.

The cylinders being deployed, the rotary discs 20, 20 'are therefore one behind the other at right of said axis; the height of the discs is adjusted so that they are exactly at the same level. The constraint device is also adjusted so that the force (arrow 29.29 ′) which it develops is less than the longitudinal force or the sliding force of the bag sliding on the conveyor.

Carried by the conveyor 1, a first bag 7 comes into contact with the first rotary disc 20 towards the middle of the front face 70 of the bag, the thrust exerted by the bag on the disc maintaining the contact permanently (Figures 3, 4 ' ). The bag continuing to advance, the rotating disc causes a cutout 71 in said face 70 (Figure 4). During the conveyor advance, the bag repelling the disc and the latter resisting the thrust under the effect of the constraint system, the arm 24 is forced to pivot towards the edge of the conveyor, while maintaining contact with the bag, the disc 20 now attacks the lateral face 72 and makes a cutout 73 therein. When the disc ceases to be in contact with the bag due to the advancement of the latter, it returns to its initial position at the right of axis 14 of the transporter to allow the next bag to be cut.

The cylinder 28 ′ of the cutting means 2 ^t was fixed to the other bank of the conveyor relative to the cylinder 28 of the cutting means 2 at a distance such that the rotating disc 20 ′ attacks the front face 70 of the bag 7 at the time where the disc 20 begins the cutting of the lateral face 72. (Figure 4). The disc 20 ', engaged in the beginning of the slot resulting from the cut 71 previously operated by the disc 20 now performs a cut 74 so that the front face 70 is completely notched (Figure 4.).

As the conveyor advances, the arm 24 ′ pivots around the bag (FIG. 8) attacks the other lateral face 75 and cuts there 76, so that three sides of the bag have been cut when the contact between the bag and the discs will have been ruptured (Figure 9); a bag thus cut will be designated by 77 (FIG. 10).

The pneumatic cylinders 28, 28 'are connected to a compressed air supply, not shown, which provides the bodies of said cylinders 28, 28' with a set pressure.

Thanks to a control device, it is possible to stop the advancement of the conveyor 1 when the front of a cut bag 77 is located in line with the drum 12 (FIG. 10) in front of the opening of the hopper 3, and to implement the gripping assembly 4 of the machine.

This comprises two parallel arms 40 in L (Figures 1, 2, 10) whose branches 41 and 42 are articulated around an axis 43 fixed to the enclosure 9; the upper branches 42 carry at their end two beams 44 which support a box 45 crossed by a shaft 46 provided with rotary hooks 47 intended to grip the cut bags. The shaft 46 is connected by a link 48 to the rod of a jack 49, advantageously pneumatic, fixed to one of the uprights 44, and openings 400 and 401 are provided at the base of the box 45 (FIG. 11) in the course of the rotary hooks. When the jack 49 is retracted, the hooks 47 are retracted, that is to say that their points 402 are located in the box.

If the box is placed towards the downstream end of a cut bag 77 and if the jack 49 is deployed, the link 48, articulated around the shaft 46, rotates the latter in the direction of clockwise, so that the tips 402 exit through the openings 400, pass through the bag 77 a first time at this location, then a second time at the opening 401, to return to the box. For the same hook, the bag is therefore pierced twice and this safety grip prevents any unhooking of the bag during its movement towards the outlet 6, the bag being emptied into the hopper 3 during this operation.

Outside the enclosure 9 (FIGS. 1, 2, 10), there is also provided, on each side, a jack 403, advantageously pneumatic, the bottom of which is attached to a fixed suspension point 90 and of which the rod 404 is integral with a lever 405 articulated around the axis 43 to which the arms 40 in L are linked, the actuation of the jacks 403 having to allow the gripping assembly 4 to travel in substance a quarter of a circle above the hopper 3.

There is also provided a drive means 5 (Figures 1, 2, 10, 12) intended to participate in the routing of the cut bags to the evacuation 6 of empty bags and especially to prevent the accidental fall of bags and parts of bags in the hopper.

This means, which is attached to fixed vertical uprights 91, comprises on the one hand, two rollers 51 and 52, one of which can rotate continuously under the action of an electric motor 53 and, on the other hand, two cylinders 54, advantageously pneumatic, each of which is suspended from the bottom to a fixed support 92 integral with the upright 91 and the rod 55 of which acts by a hinge 56 and a pivot point 57 of a bent lever 58-59 itself integral one of the rollers 51 or 52, the pivot point 57 of each of the bent levers being mounted on a cross member 93 fixed between the vertical uprights 91; the drive means further comprises two free rollers 500 parallel to the support 93.

In the deployed position of the jacks 54 shown in the drawings (Figure 10), the axes of the rollers 51, 52 form an angle V in a vertical plane; by retracting the jacks, on the contrary, the links 58 are removed, so that the arrangement 51 ′, 52 ′ is finally obtained, where the rollers tend to touch, the roller 51 ′ already in rotation driving the roller 52 ′ in the opposite direction.

As has been said, the arrival of the front of a cut bag 77 in line with the drum 12 (FIG. 10) causes the transporter 1 to stop. At this precise moment, the rollers 51, 52 of the means drive 5 are spaced apart in V and the gripping assembly 4 is stopped in a vertical position above the evacuation location 6, the hooks 47 are retracted in the box 45.

The stop of the conveyor 1 triggers the expansion of the jacks 403 (FIG. 10); grip set 4 performs its trajectory in the opposite direction to that of the curved arrows 406 and places the box 45 on the cut bag 77 stopped on the conveyor.

The stop of the jacks 403 controls the expansion of the jack 49 so that the hooks 47; advantageously 3 to 5 in number, exit through the openings 400 and return to the box through the openings 401 after having twice pierced the upper part of the bag 77 (FIGS. 10 and 11). The complete expansion of the jack 49, which has enabled gripping, in turn triggers the reaction of the jacks 403 and, simultaneously or almost, the restarting of the conveyor 1.

It follows that the gripping assembly 4 lifts the bag 77 by the hooks 47 while the bag is brought towards the opening of the hopper 3. The emptying of the bag therefore begins, and it is completed when the bag is developed on twice its length during rotation.

During the movement, the emptied bag passes between the drive rollers which close when the bag is sufficiently engaged (Figures 10,12), the retraction of the jacks 54 being effected under the impulse of an end device. race not shown; at this time, the hooks 47 retract inside the box, thus releasing the bag 77.

The rollers 51 ′, 52 ′ having tightened on the emptied bag drive it towards the discharge opening 6; the free rollers 500, mounted respectively in front of and behind the rollers 51 ', 52', favor the passage. When the emptied bag falls through the opening 6, the rollers 51 ', 52' move apart and the whole machine is ready to empty the next bag.

At the stage of emptying the cut bags, one can consider, taking into account the type of product, a brush or shaking system.

In addition, we can also consider a product scraping system to direct towards the hopper 3 the product which would have escaped from bags 7 during their transfer from the external transporter 8 to the transporter 1.

Of course, the invention is not limited to the embodiment which has been described and shown by way of example and it would not be departing from its scope by making modifications to it. Thus, to ensure the continuity of the successive movements of the machine, it is possible to use detection and control means, such as feelers, photoelectric and infrared cells, limit switches, scales, shutters, etc., and it It goes without saying that the machine can also be controlled manually. Finally, the invention obviously does not relate to the application of pneumatic cylinders and they can be replaced by mechanical, hydraulic or other means.

Claims (11)

1. Machine for opening and emptying mechanical bags which may contain a toxic product, characterized in that it comprises a conveyor intended to bring each bag to a product hopper, cutting means capable of cutting three sides of the bag during the advancement of the conveyor and a gripping assembly capable of gripping the cut bag, moving it, emptying it into the hopper and bringing it to an evacuation location, the machine being able to be equipped with means suitable for controlling automatically the moving parts of the machine according to a predetermined cycle of operations. 2. Machine according to claim 1, characterized in that it may further comprise means for driving cut bags. 3. Machine according to claim 1 or 2, characterized in that it can be housed in an enclosure. 4. Machine according to claim 3, characterized in that the enclosure can be placed under vacuum. 5. Machine according to claim 1, characterized in that the cutting means capable of cutting three sides of a bag are two cutting elements with a vertical axis each carried at one end of an arm whose other end is articulated on a restraint system capable of constantly bringing the cutting element towards the axis of the conveyor, the restraining elements being fixed respectively to the left and to the right of the conveyor, so that the first cutting element which encounters a bag cuts in a single stroke a part of the front face of the bag and a side face, the second cutting element then cutting into the rest of the front face and the other side face. 6. Machine according to claim 5, characterized in that the cutting elements are rotary discs. 7. Machine according to claim 5, characterized in that the cutting elements are fixed knives. 8. Machine according to claim 1, character sée in that the gripping assembly comprises a movable support and a gripping means chosen from those which act by hooking, suction and pinching and, the cut bag being fixed to said means, the movement of the support causes the bag to deploy twice its length above the hopper. 9. Machine according to claim 8, characterized in that the gripping assembly is movable in a horizontal plane. 10. Machine according to claim 8, characterized in that the gripping assembly is movable in a vertical plane and is constituted by a box which carries rotary hooking hooks and is secured to two arms capable of pivoting around a axis so that, the hooks having been inserted in the upper part of a cut bag, the rotation of the arms makes it possible to deploy it above the hopper to empty it, and to direct the emptied bag towards its evacuation location . 11. Machine according to claims 2 and 10, characterized in that it advantageously comprises, in order to prevent the accidental fall into the hopper of bags and parts of cut bags, in addition to a conveyor, two cutting means and a gripping assembly of the type mobile, a drive means, mounted in the path of the path of the emptied bag and suspended from the box of the gripping assembly, which comprises two rollers arranged in a V shape able to approach each other and to rotate so as to pinch the emptied bag and drive it towards the evacuation location, in particular when the emptied bag is released from the gripping assembly.

Images