FR2557535A1 - System for the automatic sheathing of objects brought successively to the said system and installation comprising such a system - Google Patents

Abstract

System for the automatic sheathing of objects 34 and comprising a tubular casing 11 on the outer surface of which the said sheath 28 is coaxially stored, a tube 12 inside the said tubular casing 11 and capable of being driven with a reciprocating movement parallel to its axis which is parallel to the X-X axis of the said casing 11 and a device for cutting and closing 29 sections of the said sheath. According to the invention, this system is characterised in that the axis X-X of the said tubular casing 11 is inclined with respect to the vertical and in that the bottom part of the said internal tube 12 is shaped like a clamp 19, 20, pressed elastically in contraction and whose opening can be controlled. Such a system allows the orientation of the objects to be retained, provides a constant relative positioning of the closing clips with respect to the objects and a correct tension of the sheath, even for objects having different dimensions.

Description

The present invention relates to a system for the automatic sheathing of objects brought successively to said system, as well as an installation comprising such a system.

There is already known a system for placing objects in nets comprising a vertical tubular casing on the outer surface of which a coaxial mesh sheath 9 is stored, said casing and which can be unwound by a vertical downward pull, an inner tube at said envelope and capable of being animated by a vertical back-and-forth movement and a device for cutting and closing the ends of sections of said mesh sheath, arranged under said tubular envelope.

Thus, when objects, for example fruits or vegetables, are introduced through said inner tube and said tubular envelope, they fall and penetrate into the net sheath, the free end of which has been previously tightened by gathering and stapled by said device. cutting and sealing. Then the inner tube is moved, for example under the action of a jack, first downwards to unwind the desired length of mesh sheath and then upwards.

Finally, said cutting and closing device contracts said net sheath radially behind the objects, places two staples on the part thus tightened, and cuts said sheath between these two staples.

The system is then ready to receive and net one or more of the following objects.

Such a system works satisfactorily.

However, it has the disadvantage of not allowing an object put under a net to keep an orientation.

given to him during his drive to the system. Indeed, objects fall through the system and can therefore change their orientation; moreover, before cutting, the portion of mesh sheath containing one or more objects can rotate around the constricted part of the sheath.

However, in many cases, it is essential that the objects to be wrapped in a net keep a constant orientation all along a packaging line, in particular in order to allow a sequence of packaging operations based on a determined orientation. successive objects. This is for example the case for an automatic packaging installation for dressed dead poultry.

The main object of the present invention is a system for the automatic sheathing of objects, making it possible to respect and maintain the orientation that these have when they are brought to said system. In addition, the object of the invention is to allow fragile objects to be sheathed, by preventing them from falling vertically, which is always harmful.

For these purposes, according to the invention, the system intended for the automatic sheathing of objects and comprising a tubular envelope on the outer surface of which said sheath is coaxially stored, an inner tube to said envelope and capable of being brought a back-and-forth movement parallel to its axis which is parallel to that of said envelope and a device for cutting and closing sections of said sheath, is remarkable in that the axis of said tubular envelope is inclined with respect to the vertical and in that the lower part of said inner tube is conformed to clamp, -elastically pressed: at contraction and controllable at opening.

Thus, an object introduced into said inner tube can slide against the inner wall thereof, keeping its orientation until it gets stuck in said clamp which it partially spreads.

The opening of said clamp is controlled before the end of the advance movement of said inner tube, after the latter has drawn the quantity of sheath necessary for packaging the object. This is therefore maintained in the desired orientation during the sheathing.

In an advantageous embodiment, the lower part of said clamp is rigidly secured to said inner tube and forms a guide face, while the upper part of this clamp is articulated on the rest of said inner tube.

Preferably, a guide ramp is provided for introducing said objects into said inner tube, as well as a guide ramp for evacuating said objects from the system. Thus, it is certain that the orientation of the objects put under the net is identical to that of the objects brought to the system according to the invention.

 I1 is all the more so as said ramp for introducing objects penetrates into said inner tube until at least partially covering the lower part of the clamp, when said inner tube is in the high position, and that said ramp d 'evacuation is covered at least partially by said lower part of the clamp, when said inner tube is in the low position.

It will be noted that said elastic clamp forms a shock absorber for objects sliding inside said inner tube.

In known manner, said inner tube can be moved, relative to said tubular casing, by a jack. In this case, it is advantageous to provide a retractable stop mounted on a mobile part of said cylinder and mechanically connected to a mobile part of said clamp, this retractable stop being capable of cooperating with a fixed stop to open said clamp. Advantageously, the fixed stop is adjustable.

In particular when the dimensions of the objects can vary from one object to another, in order to obtain on each of said objects a correct tension of the sheath, it is made so that the downward stroke of said inner tube gives a length of sheath which is slightly too short to wrap each of said objects. The additional sheath length is unwound from the tubular casing by pushers mounted on the jaws of the cutting and closing device and intended to slightly advance each object before cutting and closing said sheath.

When, as is usual, each jaw of the cutting and sealing device is of complex structure and is actually composed of several jaws, one of which cooperates with the corresponding jaw of the other jaw to tighten and block the front sheath obturation and cutting thereof by other jaws of said jaws, it is advantageous that said jaws block said sheath, while said pushers have not yet finished pushing the product. Thus, we take advantage of the elasticity qualities inherent in the sheath used, to stretch it elastically just before sealing and cutting.

 The sheath is therefore perfectly stretched over the object, which further improves the presentation of the object under sheath.

The figures of the appended drawing will make it clear how the invention can be implemented. In these figures, identical references designate similar elements.

FIG. 1 is a perspective view of part of an installation for automatic mesh-filling of objects, such as poultry, at a work station comprising a system according to the invention.

Figure 2 is a schematic longitudinal sectional view of the system according to the invention, at rest.

Figure 3 is a schematic longitudinal sectional view of the system according to the invention, at the end of the advance movement of the inner tube and just before the withdrawal thereof and the intervention of the cutting and sealing device.

Figures 4, 5 and 6 illustrate the operating mode of pushers mounted on the jaws of the shutter and cutting device and intended to perfect the setting under net.

The installation according to the invention, shown diagrammatically in perspective in Figure 1, comprises a main conveyor 1 capable of supplying objects to be put under a net a plurality of work stations 2, only one of which is shown in said figure.

The net filling station 2 mounted in FIG. 1 comprises a conveyor 3, transverse to the conveyor 1 and able to be supplied with objects to be put under nets by a deflector 4, driven by a jack 5. When the jack 5 is actuated, the deflector 4 transfers, by pushing it, an object from the conveyor 1 onto the conveyor 3. Similarly, an object circulating on the conveyor 3 can be pushed towards a system 6 according to the invention, by a deflector 7, moved by a jack 8 .

The filleting system 6, according to the invention, is supported by a frame 9, on which is also mounted a control console 10.

As will be seen below, the system 6 comprises an outer tubular casing 11 and an inner tube 12, capable of being driven back and forth by a jack 13. A guide ramp 14, disposed opposite of the deflector 7 makes it possible to successively introduce, into the inner tube 12 of the system 6, the objects moved by the conveyor 3. At its lower part, the system 6 comprises a system 15 for adjusting the length of the thread and a ramp 16 for depositing the objects put under the net on an evacuation conveyor 17. The stroke of the inner tube 12, which, as will be seen below, determines the length of sheath 28 drawn, is chosen to be adjustable.

The axis X-X of the outer tubular casing 11 and that of the inner tube 12 are incined with respect to the vertical.

It is the same for the part 14a of the ramp 14 penetrating inside the tube 12 and the ramp 16 disposed at the outlet of the system 6. The inclination of the different elements 11, 12, 14a, 16 with respect to the vertical, is for example close to 450.

In FIGS. 2 and 3, the system 6 is shown more particularly, apart from most of the other elements shown in FIG. 1 and in particular of the frame 9, of which the outer tubular envelope 11 is integral. On the other hand, there a illustrates a certain number of elements not shown or not visible in FIG. 1.

Thus, in Figures 2 and 3, we can see that the system 6 has an introduction tube 18, which is integral with the casing it and is therefore fixed and which is located inside the tube movable interior 12.

The inclined part 14a of the ramp 14 penetrates inside the introduction tube 18.

At its lower part, the movable inner tube 12 is shaped as a clamp. The lower jaw 19 of this clamp is fixed and integral with the movable inner tube; it is shaped as a guide ramp approaching the axis of the casing 11 away from said movable inner tube 12. The upper jaw 20 has a semi-cylindrical shape and is articulated to the movable inner tube 12 about an axis 2Oatransveraal to this one. The concavity of the movable jaw 20 is directed towards the fixed jaw 19, and said movable jaw 20 is pressed elastically towards said fixed jaw 19 by a compression spring 21, bearing, on one side on the inner tube 12, of the other on the movable jaw 20. A system 22 makes it possible to adjust the force of the compression spring 21 and therefore the force which must be exerted on the movable jaw 20 to separate it from the fixed jaw 19.

In Figure 2, we can see that the cylinder 13 has two piston rods 23 and 24, aligned parallel to the axis X-X of the casing 11 but opposite.

The rod 23 rigidly connects the jack 13 to the movable inner tube 12.

On the rod 24 is articulated a pivoting stop 25, capable of cooperating with a fixed stop 26, arranged on the path it follows when the jack 13 moves the inner tube 12 downwards. A mechanical link 27 (target, rod, etc.) connects the pivoting stop 25 to the movable jaw 20 of the clamp 19, 20.

In FIGS. 2 and 3, for the sake of clarity of drawing, the mechanical connection 27 has been shown outside the envelope 11, but it goes without saying that this mechanical connection 27 could be housed between the envelope 11 and the inner tube 12, as shown for example for the system 21, 22 and for the cylinder rod 23. Furthermore, it goes without saying that the fixed stop 26, cooperating with the pivoting stop 25, can be chosen to be adjustable. or easily interchangeable (for example using a barrel having a plurality of stops 26 of different lengths), in order to allow the appropriate adjustment of the cooperation of said stops 25 and 26.

On the envelope 11 is stored a mesh sheath 28, capable of being unwound from said envelope by a pull exerted downwards. A device 30, of any known type, is provided below the lower opening 30 of the casing 11, for tightening the sheath 28 radially, for placing staples 31 for closing and for cutting it. The device 30 comprises two movable jaws 32 and 33, capable either of cooperating with each other to tighten, staple and cut said sheath 28, or of moving away to release the lower opening 30 from the envelope 11.

To explain the operation of the system 6, reference is made to FIGS. 2 and 3.

In FIG. 2, which illustrates the initial position for waiting for objects to be put under the net, the movable inner tube 12 is in its high position, the movable jaw 20 is pressed elastically towards the fixed jaw 19 by the action of the spring compression 21, the jaws 32 and 33 of the stapling device 29 are spaced from each other to clear the opening 30 of the casing 11 and the free end of the net sheath is tightened and kept closed by a staple 31 placed by the device 29 during a previous operation. Thus, the opening 30 is closed by the stapled end of the mesh sheath 28.

When an object 34 circulating on the conveyor 3 arrives opposite the deflector 7, the jack 8 is actuated and said object is pushed on the ramp ~ 14, until reaching the inclined part 14a thereof. The object 34 then enters the insertion tube 18 and the movable inner tube 12 by sliding, without changing the orientation which it has at the entrance to the ramp 14, first on the inclined part 14a of said ramp, then on the fixed jaw 19 of the clamp 19, 20. During this slide, the object 34 meets the upper jaw 20 which dampens its travel and which is partially spread by said object 34, to assume the position 20 'of intermediate opening. In this position 34 ′ of the object 34, the clamp 14, 20 resiliently holds said object.

The cylinder 13 is then actuated to drive the inner tube 12 downward, parallel to the axis X-X (see Figure 3). The object 34 comes into contact with the closed end of the sheath 28 and it is pushed, with the corresponding part of the sheath 28, beyond! of the stapling device 29.

If the downward movement of the inner tube 12 continues, the pivoting stop 25 meets the fixed stop 26, so that the stop 25 pulls on the mechanical link 27 and opens the movable jaw 20, which takes the open position 20 " The inner tube is then controlled on ascent by the jack 13 and the object 34 wrapped in sheath 28 is deposited on the outlet ramp 16. The flap 20 is kept open during the last part of the downward stroke and the object 34 comes gently into contact with the sheath 28.

 Dds that the clamp 19,20 (kept open for part of the ascent stroke to avoid reassembling the object 34) has crossed, going up, the jaws 19 and 20, the stapling device 29 is actuated to gather the sheath 28 transversely behind the object 34, then place two successive staples 31 there, between which it cuts said sheath.

The object 34 placed under the net can then slide on the evacuation conveyor 17 and the system 6 is found in the state illustrated by FIG. 2, orêt: for an next placing under the net of an object 34.

It is thus seen that thanks to the invention, the placing under an object 34 can be carried out without modification of the orientation of the latter and without risk of deterioration.

In order to perfect the appearance of an object 34 placed under a net, it may be advantageous for this net to appear as taut as possible. However, this presentation requirement is often difficult to satisfy, because said successive objects 34 can have different lengths, as is the case for poultry, for example.

To solve this problem, according to the invention, provision is made for the downward stroke of the inner tube 12 to give a length of thread 28 which is slightly too short to completely envelop each of said objects 34. In addition, on the jaws 32 and 33 of the device 29, pushers 36 and 37 are mounted capable, before closing said jaws, of slightly advancing each of said objects 34. Thus, the additional sheath length necessary for placing under the net is given by the traction exerted by said pushers on said sheath. The total length of unwound net therefore corresponds exactly to what is necessary to wrap the object 34.

We can further improve the presentation of the net on the objects 34 by playing on the inherent elasticity of a sheath such as the sheath 28 and by taking advantage of the fact that, by their known complex structure, the jaws 32 and 33 of the device. 29 comprise cooperating portions 35 which press and crumple the sheath 28 between them, before stapling and cutting. Indeed, the jaws 32 and 33 only shown schematically in the figures because known and not forming part of the present invention, in reality have a complex structure, each being composed of several moving parts which cooperate with the corresponding part of the another bit at different times.

Thus, in order to obtain a tension of the thread 28 on an object 34, it is provided that said cooperating portions 35 block said thread 28, while the pushers 36 and 37 have not yet completed their thrust in advance of the object 34. The portion of net placed on each object is therefore perfectly stretched.

 It goes without saying, although the description has taken for example a mesh sheath, that the present invention is not limited to this type of sheath and can be implemented with all kinds of sheaths and in particular transparent plastic sheaths.

Claims (10)

1 - System intended for the automatic sheathing of objects (34) and comprising a tubular envelope (11) on the outer surface of which said sheath (28) is stored coaxially, a tube (12) inside said tubular envelope ( 11) and capable of being moved back and forth parallel to its axis which is parallel to the axis (XX) of said envelope (11) and a cutting and closing device (29) sections of said sheath, characterized in that the axis (XX) of said tubular casing (11) is inclined relative to the vertical and in that the lower part of said inner tube (12) conforms to a clamp (19, 20), elastically pressed during contraction and controllable upon opening. 2 - System according to claim 1, characterized in that said clamp (19, 20) is controlled upon opening before the end of the downward movement of said inner tube (12) making it possible to draw the quantity of sheath (28) desired and just before the ascent of said tube (12). 3 - System according to one of claims 1 or 2, characterized in that the lower part (19) of said clamp is rigidly secured to said inner tube (12) and forms a guide face for the objects (34), while the upper part (20) of this clamp is articulated on the rest of said inner tube (12). 4 - System according to claim 3, characterized in that it comprises a guide ramp (14a) making it possible to introduce said objects (34) into the inner tube (12) and to guide them as far as the lower part (19) of said clamp, when said inner tube (12) is in its upper position. 5 - System according to claim 3, characterized in that it comprises a guide ramp (16) making it possible to evacuate said objects (34) and to keep the orientation of the latter and being partially located under the lower part ( 19) of said clamp, when said inner tube (12) is in its low position. 6 - System according to any one of claims 1 as, in which said inner tube (12) is moved relative to said tubular casing (11) by a jack (13), characterized in that it comprises a retractable stop ( 25) mounted on a mobile part (24) of said cylinder and mechanically connected to the mobile part (20) of said clamp, said retractable stop being capable of cooperating with a fixed stop (26) to open said clamp (19, 20). 7 - System according to claim 6, characterized in that said fixed stop (26) is adjustable. 8 - System according to any one of claims 1 to 7, wherein said device (29) for cutting and closing the sheath (28) comprises two cooperating jaws (32 and 33), characterized in that pushers ( 36, 37) are mounted on said jaws to slightly advance each object (34) and said sheath before cutting and closing of said sheath (28).  9 - System according to claim 8, wherein  said jaws (32 and 33) of the cutting device and  shutter comprises jaws (34 and 35) coop & rant to tighten and block the sheath before closing and cutting thereof, characterized in that said jaws (34 and 35) block said sheath, while said pushers  (36, 37) have not finished pushing ahead  on the object (34) being sheathed. 10 - Installation for automatic sheathing  of objects (34), characterized in that it comprises several systems  specified under any of claims 1 to  9 and supplied with objects (34) by conveyors  (1, 3, 17).