Abstract:
The method of the invention comprises immobilizing the queue on its entire length using flaps ( 10, 11 ) for creating a gap between two consecutive objects and for isolating downstream from said gap a group of objects defining the batch; inserting into the gap thus created a first cleat ( 39 ) having a longitudinal advance speed Vt lower than the running speed Va of the conveyor belt ( 3 ); releasing said immobilized queue and making the cleat in charge of it; starting a new temporary immobilization of said queue; and so on. The device for implementing the method comprises: on the one hand, means in the form of flaps ( 10, 11 ) for immobilizing the queue on the length thereof by clamping in order to define a gap between two consecutive objects in said queue, and on the other hand, a means in the form of cleats ( 39 ) that can be inserted in and take in charge the immobilized queue. Each cleat ( 39 ) is associated with a roller-shaped member ( 38 ) for maneuvering the flap ( 10 ). The reactive flap ( 11 ) is submitted to the action of spring means ( 16 ) for automatically returning the flap ( 10 ) into place.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a National Stage of International Application No. PCT/FR2008/051335 filed Jul. 17, 2008, claiming priority based on French Patent Application No. 0705549, filed Jul. 30, 2007, the contents of all of which are incorporated herein by reference in their entirety. 
     FIELD OF THE INVENTION 
     The present invention relates to a method for forming batches of substantially parallelepiped objects moving continuously on a conveyor belt to feed, for example, a tight packing machine; it also relates to the device for the implementation of said method. 
     DESCRIPTION OF THE PRIOR ART 
     More specifically, the invention relates to the formation of batches of substantially parallelepiped objects, such as cartons of milk or fruit juice, with a view to the packaging thereof by a tight packing machine of the type described in document FR 2847242, for example. 
     This tight packing machine must be fed with extreme, faultless precision, since, after this packaging, the packages are palletized and routed to the point of sale thereof. The slightest incident may have repercussions on a large proportion of the batches or even the pallet. 
     However, products such as fruit juice or other cartons are relatively difficult to handle, particularly as, in some cases, they may comprise a straw which is attached directly on a side face of the product. 
     In this field relating to the splitting of a product queue, the document DE 3825069 describes a conveying device for separating trays in single file, one behind the other. 
     This separation device comprises a passage formed from two flaps which are hinged to create a temporary diversion of the passing tray and to guide same to an abutment arranged on the side of the conveying track, said abutment immobilizing the tray in question for a sufficient time to create a gap between the immobilized tray and the previous tray. 
     Such a device may operate at relatively high outputs for separating trays but it is not suitable for forming, at high outputs, batches consisting of products such as cartons. 
     The document EP 1717170 describes a palletizing installation comprising a device for preparing batches with packages arriving in single file. 
     The front of the queue is taken in charge by an abutment and, once the number of packages forming the batch has been reached, the queue is stopped by a gripper system. While the queue is stopped, the batch is moved transversally to a palletizing table. 
     The sequential nature of this type of device is not suitable for very fast outputs such as those encountered in installations for preparing batches consisting of carton type products. 
     SUMMARY OF THE INVENTION 
     The present invention proposes to solve the problems of packaging these substantially parallelepiped milk, fruit juice or other carton type objects in batches; it proposes a method and a device for the implementation thereof making it possible to operate at high outputs with maximum safety and efficiency. 
     In this way, according to a first of the aspects thereof, the present invention relates to a method for forming batches of substantially parallelepiped objects moving aligned and adjacent to each other, in single file, said objects, having a length l, being conveyed by a conveyor belt advancing at a longitudinal speed Va, said method consisting of:
         immobilizing said queue, on the entire length thereof, in a passage, using stopping means which act sequentially, to create a gap between two consecutive objects and to isolate, downstream from said gap, a group of objects defining the batch with the programmed number of objects thereof,   inserting into the gap thus created a first cleat having a longitudinal advance speed Vt lower than Va,   releasing said immobilized queue and having said first cleat handle same, at the leading object thereof,   starting a new temporary immobilization of said queue, with a view to inserting a second cleat in the new gap thus created, when the distance covered by the first cleat, measured from the end of said stopping means, is equivalent to at least the length L of the batch of objects,   releasing the queue retained by said stopping means to have same handled by said second cleat,   releasing the batch retained by said first cleat and so on, starting another stoppage of the queue, etc.       

     Again according to the invention, the method for immobilizing the queue consists of:
         deforming the passage so as to reduce the entry cross-section thereof to immobilize the queue by blocking the object(s) in said entry,   applying, on the side faces of said objects which are in said passage, a pressure wherein the intensity decreases between said entry of said passage and the downstream end thereof to reduce the contact pressure between said objects,   placing, at the end of said passage, a safety stop in the form of an abutment to hold the downstream object at the front of the queue. This specific feature makes it possible to prevent the blockage of the downstream object, forming the front of the queue, against the safety abutment and also enables the use of simple means, detailed hereinafter, to deform the passage wherein the objects are moving.       

     According to a preferential arrangement of the invention, the gap created between consecutive objects, when the queue is stopped, has a length which is the order of half the length l of said objects. 
     Again according to the invention, the difference in speed between the object conveyor belt and the cleats for handling the various batches of objects is of the order of 10 to 15% with a lower speed for said cleats so as to create a gap between the batches before presenting same to the tight packaging machine, for example. 
     According to a further arrangement of the invention, the cleats handle and guide the batch of objects over a distance of the order of 1.5 times the length L of said batch of objects. 
     The invention also relates to a device for the implementation of the method for forming batches using objects moving in single file, adjacent to each other, conveyed by the endless belt of a conveyor, said device comprising:
         means for immobilizing the queue on the entire length thereof so as to create a gap E between two consecutive objects of said queue and,   means in the form of cleats, suitable for being inserted in the gap thus created, for, in particular, handling the front of the immobilized queue,       

     said immobilization means and said cleats operating in a coordinated manner to start the immobilization of the queue when the cleat for handling the queue, after said queue has been released, has covered a distance which, measured from the end of said immobilization means, is equivalent at least to the length L of the batch to be prepared. 
     According to a preferential arrangement of the invention, the means for immobilizing the queue consist of:
         flaps arranged facing each other forming a passage wherein the objects pass: —one deflecting flap and—one reactive flap, each flap being movable about a vertical axis situated at the upstream portion thereof, respectively,   means for pivoting said deflecting flap in the direction of the other flap so as to deform said passage,   means for impeding the reaction movement of the reactive flap when it is pushed, by means of the objects, by the deflecting flap, said means being used to carry out rapid and effective tightening or clamping of the queue for almost instantaneous immobilization.       

     Again according to the invention, the axes of the flaps are offset longitudinally: the axis of the reactive flap being situated downstream from the axis of the deflecting flap, at a distance between the length l and half this length of the objects, said distance being measured on the longitudinal feed axis of the objects. 
     This structural arrangement makes it possible to deform the passage by reducing the width of the entry thereof and this deformation is performed a relatively moderate force by means of the lever effect given to said deflecting flap by the position of the hinge axis thereof. 
     The deformation of the passage forms a type of bottleneck and makes it possible to block the queue not at the end thereof, as is generally the case, but considerably upstream from the front of the queue; for this reason, the contact pressure between the objects is released and the leading object may even be practically free. 
     According to a further arrangement of the invention, the reactive flap is retracted, under the effect of the deflecting flap, via the objects arranged between same, said reactive flap, by retracting, releasing a safety stop in the form of an abutment capable of temporarily holding the upstream object forming the front of the queue. 
     Again according to the invention, the cleats are regularly distributed and carried by a motor-driven endless chain wherein the active side is parallel with the object feed direction and arranged downstream from the deflecting flap, said cleats being spaced by a pitch P which is substantially greater than the length L of the batch of objects, of the order of a few millimeters, between 1 and 5 mm depending on the type of objects. 
     According to a preferential arrangement of the invention, the cleat is associated, on the endless chain, with a member for maneuvering the deflecting flap, said maneuvering member engaging with a cam-shaped fitting arranged on said deflecting flap so as to pivot same as the cleat approaches same, the assembly formed by the roller and the cam making it possible to coordinate the stoppage of the queue and the passage of the cleat for the insertion of said cleat in the gap created between two objects by the immobilization of said queue. 
     Again according to the invention, the reactive flap is impeded by spring type means, said reactive flap performing the automatic repositioning of the deflecting flap, by means of said spring, via the objects moving between same, when the roller leaves the cam of said deflecting flap. 
     According to a further arrangement of the invention, the length of the deflecting flap is, for example, of the order of the length of three to five objects. 
     Again according to the invention, the deflecting and reactive flaps and the downstream abutment are arranged on the same structure wherein the position is longitudinally adjustable in relation to the general frame to adapt to changes in the formats of the objects and/or the batches to be formed, said structure being adjusted longitudinally in relation to the position of the upstream guiding wheel of the endless chain comprising the rollers and the cleats, said position of said upstream wheel being in turn longitudinally adjustable to accommodate different chain models wherein said cleats and rollers are distributed according to a pitch suited to the length L of said batches to be prepared. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is now described using a merely illustrative and in no way limitative example of the scope of the present invention, using the following illustrations, wherein: 
         FIG. 1  is a perspective view of the device according to the invention for the formation of batches of objects moving continuously against each other on a conveyor belt; 
         FIGS. 2 and 3  are two partial enlarged views of the support assembly of the passage of the objects at the exit whereof the batches of objects are formed; 
         FIGS. 4 and 5  are two top views respectively illustrating the device according to the invention in an idle position and in a stopping position of the object flow for forming a batch of objects; 
         FIG. 6  is a perspective bottom view of the endless chain assembly of the device according to the invention, 
         FIG. 7  represents, in the form of a functional diagram, the essential components of the batch preparation device, 
         FIGS. 8 to 12  show various steps of batch preparation according to the method according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  represents a perspective view of the device  1  according to the invention for forming batches of objects  2  moving continuously in line against each other, in single file, on a conveyor belt  3 . The objects  2  are thus supplied, by means of the type known per se, upstream on the conveyor belt  3  continuously and adjacent to each other, in single file. 
     The objects  2  to be formed in batches, of the food carton type, have a parallelepiped shape; these objects  2  have a length l, as illustrated in  FIG. 8 , and the batch formed from these objects  2  has a length L, as illustrated in  FIG. 11 . 
     The device  1  according to the invention comprises—a support assembly  4  wherein a passage  5  is formed for the objects  2  and—an endless chain assembly  6 , the function of which will be explained hereinafter. 
     The support assembly  4  consists of a first wall  7  and a second wall  8 , parallel with each other, arranged on either side of the conveyor belt  3  and interconnected by a plurality of crosspieces  9 , provided to be substantially transverse to the feed direction of the conveyor belt  3  and corresponding to the direction of the arrow F as illustrated in  FIG. 1 . 
     On the inner face of the wall  7 , a side plate in the form of a pivoting flap  10  (or side leaf) is attached, wherein the pivoting is controlled by the endless chain assembly  6 , whereas on the inner face of the wall  8 , facing the flap  10 , a side plate in the form of a flap  11  preferentially also provided as pivoting is also attached. 
     More specifically, to enable the blockage of the continuous flow of the objects  2  moving on the conveyor belt  3  and in the passage  5 , said passage  5  is deformed by movement, preferentially by pivoting the pivoting side flap  10  attached on the first wall  7 , which activates the movement of the objects on the conveyor belt  3  which then press against the side flap  11  of the second wall  8 , thus causing the blockage of the objects housed between the two side flaps  10 ,  11 . 
     The flap  10  forms the deflecting flap, i.e. the flap separating the objects  2  transversally, and the flap  11  forms the reactive flap in that it is maneuvered by said deflecting flap by means of said objects  2  and that, as detailed hereinafter, the reactive flap  11  returns said deflecting flap  10  to the idle position. 
     Each side flap  10 ,  11  is attached on the inner surface of the respective wall  7 ,  8  via attachment means consisting of axes  12 ,  13 , respectively. These axes  12 ,  13 , are positioned upstream from the flaps  10 ,  11 , respectively, said flaps pivoting transversally in relation to the feed direction F of the objects  2  on the conveyor belt  3 . 
     In order to facilitate the blockage of the queue, the entry of the passage  5  undergoes retraction, i.e. a reduction of the width thereof by moving both side flaps  10 ,  11  closer together during the pivoting thereof. This retraction is obtained by offsetting the pivoting axes  12 ,  13  of both side flaps  10 ,  11  in relation to each other in the feed direction F of the objects  2  on the conveyor belt  3 , i.e. both pivoting axes do not belong to the same plane which is transverse to the feed direction F. 
     The axis  12  of the deflecting flap  10  is situated upstream from the axis  13  of the reactive flap  11 , at a distance which is, for example, between the length l and half of said length l of the objects  2 , said distance being measured on the longitudinal feed axis of said objects. This structural arrangement enables, with a relatively moderate force applied on the deflecting flap  10 , the application of strong pressure on the object(s)  2  arranged at the entry of both flaps  10 ,  11 , due to the lever effect provided by said deflecting flap  10  due to the position of the hinge axis  12  thereof. 
     In order to activate the pivoting of the deflecting flap  10 , a cam  14  for controlling the pivoting of said flap  10  is provided, which is attached on the outer surface  10   a  thereof (see  FIG. 2 ), i.e. on the surface opposite the surface suitable for coming into contact with the objects  2  moving on the conveyor belt  3 . 
     The idle position of the deflecting flap  10  is established by an abutment  15  which is attached on the wall  7  as represented in  FIGS. 2 to 5 . When the cam  14  is not controlled and a flow of objects  2  is fed on the conveyor belt  3 , the flap  10  is then substantially parallel to the feed direction F of the objects  2 , said objects  2  when passing the passage  5  tending to push the side flaps  10 ,  11  outwards and thus press said flap  10  against the abutment  15 . 
     The abutment  15  is made of a plastic or rubber material, whereon the deflecting flap  10  rests. 
     The reactive flap  11  attached on the second wall  8  of the support assembly  4  rests against spring means  16  suitable for applying a thrust force continuously on said flap  11 , i.e. suitable for applying a thrust force substantially transverse to the feed direction F of the objects  2  and tending to press said flap  11  against the objects  2  moving on the conveyor belt  3 . 
     In this way, in the embodiment illustrated in the various figures, the cam  14  tends to actuate the pivoting of the deflecting flap  10  in the anti-clockwise direction, whereas the spring means  16  tend to actuate the pivoting of the reactive flap  11  in the clockwise direction, the cam  14  and the spring means  16  being respectively provided downstream from the pivoting axes of the two flaps  10 ,  11  attached respectively on the walls  7 ,  8  of the support assembly  4 . 
     Hereinafter in the description, the term “upstream” member refers to a member situated or moving upstream from the conveyor belt  3  and the term “downstream” member refers to a member situated or moving downstream from the conveyor belt  3 . In other words, the conveyor belt  3  moves from an “upstream” member to a “downstream” member. 
     Additionally, the device  1  according to the invention may comprise a member  17  for holding the flow of objects  2 , acting as an abutment, against which the object  2   a  at the front of the queue is liable to rest, as represented in  FIG. 5 . 
     Preferentially, the member  17  for holding the flow of objects  2  blocked between the flaps  10 ,  11 , is attached to the same wall  8  as the flap  11  subject to the thrust force of the spring means  16 . 
     Preferentially, the flaps  10 ,  11  block the flow of objects  2  in the passage  5  without the object  2   a  blocked most downstream abutting against the member  17  for holding the flow; the flaps  10 ,  11  block the queue at the entry of the passage  5  by restricting the width of said entry. 
     However, in the event of the failure of the clamping of the objects  2  in the passage  5 , due, for example, to a dimensional variation of the object, the most downstream object  2   a  may not be sufficiently clamped between the two flaps  10 ,  11  and continue to move due to the feed movement of the conveyor belt  3  to the holding member  17 . 
     Furthermore, in order to facilitate the return to the conveyor belt  3  of the downstream object abutting on the holding member  17 , it is provided that the flap  11  comprises at the downstream end thereof at least one tooth  18 ,  19 , as represented in  FIG. 2 , suitable for passing through the openings  20 ,  21  formed in the holding member  17  and moving the most downstream object  2   a  abutting against the member  17  for holding the flow. 
     More specifically, the holding member  17  is in the form of a U-shaped caisson consisting of two walls  23 ,  24 , i.e. one upstream transverse wall  23  and one downstream transverse wall  24  preferentially attached by the free end thereof on the second wall  8  of the support assembly  4 , and a rear wall  25 , provided substantially parallel to the feed direction F. Objects  2  not blocked by the flaps  10 ,  11 , but deflected anyway, abut against one of the two transverse walls  23 ,  24  (see  FIG. 5 ). 
     The openings  20 ,  21  provided in the caisson  22  are advantageously formed in the upstream transverse wall  23 , against which an object  2  is liable to abut, and in the wall  25  so that the teeth  18 ,  19  are substantially in the same plane as said wall  25 . During the pivoting of the flaps  10 ,  11 , the teeth  18 ,  19  move in the portion of the opening  20 ,  21  formed in the upstream transverse wall  23 . 
     A possible embodiment of the spring means  16  is illustrated in  FIG. 3 . 
     The spring means  16  consist of a rod  26  passing through the wall  8  and a caisson  27 , also attached on the outer face of said wall  8  (i.e. the face not facing the flow of objects  2  moving on the conveyor belt  3 ), the caisson  27  having an overall U-shape, with two walls  28 ,  29  forming the vertical arms of the U and wherein the ends are attached directly on the outer surface of the wall  8  and a rear wall  30  through which the rod  26  also passes. 
     The rod  26  comprises a first support end  31  suitable for coming into contact and pushing against the outer surface of the flap  11  attached on the wall  8 . 
     A spring  32  is provided wound about the rod  26 ; this spring  32  rests, on one side, on a ring  33  which is arranged at the end  31  of the rod  26  and, on the other side, on a washer  34  which is attached on the inner surface  30   a  of the rear wall  30  of the caisson  27 . This rod  26  passes through the wall  30  in the middle of the support washer  34  and a ring  35 , acting as an abutment, is attached on the end of the rod  26 ; this ring  35  abuts on the outer surface  30   b  of the rear wall  30 , when the flap  11  is substantially parallel to the feed direction F of the conveyor belt  3  and deviates therefrom when said flap  11  is pivoted to block the queue of objects  2 . 
     Due to this embodiment of the spring means  16 , the rod  26  is constantly subject to tension tending to increase the separation between the rear wall  30  and the end of the rod  26  resting against the flap  11 . The spring  32  is contracted when said flap  11  is moved due to the pivoting of the deflecting flap  10  via the objects  2  positioned between same. The return movement of the flap  10  is actuated by the release of the spring  32  which pushes the flap  11  and, via the objects  2 , said flap  10 . 
     In order to control the pivoting of the deflecting flap  10  via the cam  14  attached on top, an endless chain assembly  6  is provided, preferentially provided to be removable and movable as for the support assembly  4 . This assembly  6  comprises an endless chain  37  whereon at least one bearing roller  38  suitable for engaging on the cam groove formed by the cam  14  attached on the flap  10  is attached, along with a cleat  39 , said cleat, for example in the form of an insert, is suitable for inserting in the gap between two objects  2  moving on the conveyor belt  3  at the exit of the passage  5  formed by the two flaps  10 ,  11 . When it is inserted in the gap E formed between two objects, the cleat  39  is suitable for serving as a support for the most downstream object  2   a  of the flow of objects  2  blocked by the flaps  10 ,  11  in the pivoted position thereof (see  FIG. 5 ). 
     The endless chain  37  is engaged on two toothed wheels  40 ,  41 ; at least one of the two wheels  40 ,  41  is suitable for moving along a direction substantially parallel to the feed direction F of the objects  2  on the conveyor belt  3 . 
     This endless chain  37  is positioned laterally in relation to the conveyor belt  3  so as to enable the insertion of the cleats  39 , attached on the chain  37 , downstream from the most downstream object  2   a  of the flow of objects  2  which is blocked by the flaps  10 ,  11 , when these objects  2 ,  2   a  return to the conveyor belt  3 . 
     More specifically, in order to form batches of objects  2  at intervals from a continuous flow of objects  2  adjacent to each other moving on a conveyor belt  3  at continuous speed, the objects  2  firstly passes in the passage  5  at the exit wherefrom the batches of objects  2  are formed. 
     When the objects  2  pass in the passage  5  at least one flap  10  is then moved, preferentially by pivoting, in the direction of the flow of objects  2  moving on the conveyor belt  3  and in the direction of the other flap  11 . Preferentially, since both flaps  10 ,  11  are provided pivoting, but with pivoting axes transversally offset in relation to each other, the pivoting of the flap  10  in the direction of the other flap  11  actuates the transversal deflection of the flow of objects  2  in relation to the feed direction F and, by reaction, the pivoting of said flap  11 , via said objects  2 . 
     Due to the transverse offset of the pivoting axes, the flaps  10 ,  11  no longer remain parallel with each other during this pivoting movement and tend to move closer together and apply a pressure force on either end of the objects  2  which holds and blocks these objects  2  between the flaps  10 ,  11 , despite the feed movement of the conveyor belt  3 . 
     The flap  10 , by moving closer to the flap  11 , also moves closer to the axis  13  thereof, which causes a retraction at the entry of the passage  5  formed by both flaps  10  and  11 . 
     This closure at the entry of the passage  5  makes it possible to modify the pressure normally applied between the various objects  2  in single file; blocking the queue at the entry of the passage  5  makes it possible to release the pressure between the objects in said passage. For this purpose, the object  2   a  at the front in the passage  5 , is not pressed between the abutment  17  by the other objects such that, when the flaps  10  and  11  return to the idle position, under the effect of the spring means  16 , the object  2   a  is repositioned without any difficulty on the longitudinal conveying path. 
     During the blockage of the flow of objects  2 , it is possible to insert a cleat  39  on the feed trajectory of the objects  2  on the conveyor belt  3  at the exit of the passage  5 , said cleat  39  being inserted downstream from the most downstream object  2   a  of the objects  2  blocked by the flaps  10 ,  11  in the passage  5 . 
     Given that the conveyed objects  2  are preferentially parallelepiped, it is indeed necessary to provide gaps in the continuous flow of objects  2  to enable the insertion of such a cleat  39  and, consequently, enable the formation of batches of objects, each batch consisting of the number of objects  2  positioned between two cleats  39  which are inserted successively in the flow of objects  2  at the exit of the passage  5 . The cleats  39  are spaced by a pitch P which is substantially greater than the length L of the batch of objects, of the order of a few millimeters, between 1 and 5 mm depending on the nature of the objects. 
     In order to enable the release of the objects  2  blocked between the two flaps  10 ,  11 , the pivoted flap  10  then returns to the initial position thereof, i.e. in a position substantially parallel with the feed direction of the conveyor belt  3 . If two flaps  10 ,  11  are provided pivoting, the spring means  16  facilitate the return of said flaps  10 ,  11  to the position thereof, said spring means  16  applying a thrust force substantially directed towards the other of the two flaps  10 ,  11  and towards the conveyed objects  2 . 
     Due to the return of the flaps  10 ,  11  to a non-pivoted position (said flaps both being substantially parallel to the feed direction F and having no influence on the feed of the flow of objects  2  on the conveyor belt  3 ), the objects  2  released on the conveyor belt  3  move until coming into contact with the most downstream object  2   a  of the objects  2  released on the cleat  39 . 
     To enable the formation of a batch of objects  2  abutting on the cleat  39 , the cleat  39  advances in a longitudinal direction, merged with the feed direction F of the objects  2 . 
     Subsequently, as detailed hereinafter in relation to  FIGS. 8 to 12 , at the exit of the passage  5 , a number of objects  2  corresponding to the number of objects  2  to form the batch of objects  2  to be formed is released, the most downstream object  2   a  of the flow remaining abutting against the cleat  39  and the other upstream objects  2  abutting against same in succession. 
     The advance speed Vt of the cleat  39  is, for this purpose, slightly less than the feed speed Va of the conveyor belt  3 . 
     When the distance between the cleat  39  and the end of the flap  10  is equivalent to the length L of the batch of objects  2  provided, the roller  39 , which is associated with the following cleat  39 , comes into contact with the cam  14  of the deflecting flap  10  to stop the queue of objects  2  a second time. 
     The cycle is resumed sequentially; again, the deflecting flap  10  pivots, making it possible to form a further batch of objects  2  in turn held by the cleat  39 , said batch comprising a number of objects  2  corresponding to the number of objects released on the conveyor belt  3  between two successive queue blocking steps by the flaps  10 ,  11 . 
     Preferentially, the movement step preferentially by pivoting the deflecting step  10  arises from the roller  38  coming into contact on the cam  14  attached to the deflecting flap  10  and, more specifically, the step for placing the roller  38  in contact and the step for inserting a cleat  39  on the feed trajectory F of the objects  2 , at the exit of the passage  5 , are carried out using a step for feeding the endless chain  37  whereon said roller  38  and said cleat  39  are attached. 
     Furthermore, as represented more specifically in a perspective bottom view in  FIG. 6 , the endless chain  37  assembly  6  is fitted on a frame  50  which is in turn rigidly connected to the general frame  51  of the conveyor, said frame  51  actually consisting of the sides of said conveyor. 
     It can thus be noted that the toothed wheel  41  is rotated using a driving shaft  42  connected to driving means, of the type known per se and not shown in  FIG. 6 , whereas the other toothed wheel  40  is provided to be movable to accommodate a plurality of chain  37  models, each chain being adapted to the dimension of the objects  2  and to the length of the batches to be formed. The position of the wheel  41  is fixed as it is related to the grouping means of the tight packaging machine located immediately downstream, as explained above. 
     The wheel  40  is mounted on a shaft  43  which is vertical and suitable for moving in a longitudinal groove  44  formed in the frame  50 ; the position thereof is lockable by clamping by means of the handle  52 . The tension of the chain  37  is adjusted by means of a gas type cylinder  45 , before the immobilization of the shaft  43  by the handle  52 . 
     Additionally, to ensure improved guidance of the objects in the passage and at the exit of the passage, guide rails  46 ,  47  are provided attached to the walls  7 ,  8  suitable for guiding the objects  2  on the conveyor belt  3  both at the entry and exit of the passage  5 . 
     When the format of the objects changes, along with the length of the batch, it is also necessary to adjust the position of the assembly  4 , supporting the flaps  10  and  11 , in relation to the endless chain assembly  6 . To facilitate this adjustment of the position of the support assembly  4  in relation to the endless chain assembly  6 , a positioning member  48  is provided, attached on the support assembly  4 , for adjusting the distance between the support assembly  4  and the endless chain assembly  6 . 
     For example, as represented in  FIGS. 1 and 2 , the positioning member  48  is an elongated rod wherein the end, at right angles, serves as a reference point and engages with the roller  38  to position the support assembly  4  in relation to the endless chain assembly  6 . 
       FIG. 7  illustrates, in the form of a simple functional diagram, the essential members of the device according to the invention. The frame  51  of the conveyor comprises: the support assembly  4  which is positioned longitudinally on the belt  3  of said conveyor and the endless chain assembly  6  which is positioned laterally in relation to said belt  3 , substantially downstream from said assembly  4 . 
     As explained above, the assembly  4  is movable longitudinally in relation to the frame  51 , guided by means of grooves or slides  53 , to adapt the position of the cam  14  of the deflecting flap  10  in relation to the position of the rollers  38 , said position of the rollers  38  and the cleats  39  being dependent on the type of objects  2  to be formed in batches and is also dependent on the size of the batch of objects. 
     The assembly  4  serves as a support for both flaps  10  and  11  defining the passage  5  wherein the queue of objects  2  is blocked. The deflecting flap  10  is hinged at the upstream portion thereof by means of an axis  12  and the reactive flap  11  is hinged about an axis  13  which is also situated at the upstream portion thereof, i.e. at the entry of the passage  5 . Both axes  12  and  13  are offset longitudinally as specified above, by a distance d which is, for example, between l, and ½ l, where l, is the length of the objects  2 . Preferably, this distance d is approximately ½ l. 
     The downstream end  55  of the flap  10  is slightly offset, in the longitudinal direction, in relation to the abutment  17 ; it is situated upstream from said abutment  17  to enable an anticipation of the movement of said flap  10  during the lateral offset of the front of the queue of objects  2  and to avoid knocking the last object of the batch being prepared. The distance a separating the downstream end  55  of the flap  10  and abutment  17  is between ½ and ¼ l. 
     The activation of the movement of the flap  10  results from the contact between the roller  38  and the cam  14  of said flap; said cam  14  is raised when the distance L′ between the cleat  39  and the end  55  of the flap  10  corresponds substantially to the length L of the batch of objects to be formed. 
       FIGS. 8 to 12  below show the sequence of movements to create a gap in the queue, between two consecutive objects, and to form a batch of objects and guide same to the tight packaging machine, for example. 
       FIG. 8  shows the queue of objects  2  advancing with the conveyor belt  3  at a speed Va, held by the cleat  39 ( 1 ) which is inserted between the object  2   a ( 1 ) at the front of the queue and the last object  2  of the batch prepared. In  FIG. 8 , the cleat  39 ( 1 ) is situated at a distance L′ from the downstream end  55  of the flap  10 , said distance being equivalent to the length L of the batch of objects to be prepared. 
     When the cleat  39 ( 1 ) reaches this distance L′, the roller  38 ( 2 ) comes into contact with the cam  14  of the deflecting flap  10  and pivots same very rapidly. This pivoting of the flap in  FIG. 9  deflects the objects  2  in the passage  5  defined by said flap  10  and the flap  11 , on the side thereof, and places the object  2   a ( 2 ) at the front of the queue facing the abutment  17 . 
     The pivoting of the flap  10  also restricts the width of the entry of the passage  5  and blocks the queue upstream from said entry. 
     The queue is blocked and stopped almost instantaneously at the entry of the passage  5  and some relaxation of the products in said passage  5  due to the distance a separating the end  55  of the flap  10  and the abutment  17 . This distance a enables the objects in the passage  5  clamped between the flaps  10  and  11  to decelerate and stop. 
     The blockage of the queue at the entry of the passage  5  makes it possible to release the contact pressure between the objects  2  in said passage  5  and, in particular, prevent the leading object  2   a ( 2 ) from applying a strong pressure against the abutment  17 . Excessive pressure between the object  2   a ( 2 ) and the abutment could introduce excessive friction between the two with possible degradation of said objects and require a significant effort to reposition the deflected objects on the longitudinal axis of the conveyor belt  3 . The flaps  10  and  11  are returned to the idle position by the spring means  16 , as detailed hereinafter. 
     The pivoting of the flap  10  also enables the cleat  38 ( 2 ) to pass in front of said flap  10  and, as can be seen in  FIG. 10  hereinafter, it enables the positioning thereof behind the batch previously prepared, prior to insertion between the object  2   a ( 2 ) and the last object  2   c ( 1 ) of the previous batch. 
     During the blockage of the queue, the conveyor belt  3  continues to advance at a speed Va and it conveys the batch of three objects which are upstream from the abutment  17 ,  FIG. 10 . This new batch is handled by the cleat  38 ( 1 ) wherein the longitudinal running speed Vt is substantially less than Va, of the order of the 10 to 15%, for example. 
     The cleat  39 ( 1 ) continues to advance while controlling the movement of the prepared batch and the gap E between the objects  2   c ( 1 ) and  2   a ( 2 ) becomes sufficient,  FIG. 11 , for the safe insertion of the next cleat  39 ( 2 ) in said gap. This gap E has a value of the order of ½ to ¼ l. At the same time, the roller  38 ( 2 ) leaves the cam  14  and the flap  10  returns to the idle position resting on the abutment  15 ′ as illustrated in  FIG. 7 . The flap  10  is returned automatically under the effect of the pressure applied via the objects  2  in the passage, which are realigned by the flap  11 , in turn actuated by the spring means  16 ,  FIG. 12 . 
     The newly prepared batch is bordered by the cleats  39 ( 1 ) and  39 ( 2 ) and is maintained at the feed speed Vt of said cleats, making it possible to increase the distance between two successive batches by means of the difference in speed between the conveyor belt  3  and the chain  37  supporting said cleats. The cleats guide the batch prepared over a distance of the order of 1.5 times the length L of said batch, for example. 
     When the flaps  10  and  11  have returned to the idle position, the queue is released and the leading objects  2   a ( 2 ) thereof gains on the cleat  39 ( 2 ) which is inserted, and the cycle is resumed as described above, from  FIG. 8 .