Patent Publication Number: US-2020299072-A1

Title: Method and Device for the Hydraulic Forced-Supply Filling of Cases with Floating Objects

Description:
The invention relates to a method and a device for the hydraulic filling of cases—in particular cases which are water-permeable but are able to contain objects, such as open crates and/or box pallets, generally known under the name palox—for storing or transporting large amounts (typically several hundred kilos) of fruit or vegetables or other floating objects. 
     There are already known (FR1485753, FR2036095, U.S. Pat. Nos. 5,242,250, 7,159,373 . . . ) devices for filling cases with floating objects such as fruit or vegetables, for example apples. Such a device comprises a tank for receiving a case to be filled, a device for loading/unloading a case into/from the tank and a channel for supplying a hydraulic stream in the upper part of the tank. A pump is provided to suck in the liquid stream drawn from the bottom of the tank and to recycle it upstream of the supply channel, and thereby ensure a flow through the tank so as to fill the case with objects floating in the stream entering the supply channel. 
     The problem which has arisen for a long time with these devices in which the operation is, by design, discontinuous, is that of the productivity of the method for filling the cases, i.e. optimising the overall rate of filling of the cases with objects. In fact, such a filling device generally located in the downstream portion of a device for sorting floating objects, e.g. a device for calibrating fruit, is the factor limiting the overall rate and general productivity of this sorting device. This problem is more and more acute as modern devices for calibrating or pre-calibrating fruit are constantly being improved and have higher and high operating rates and speeds. 
     For this purpose, FR1485753 provides a rounded overflow-chute forming a cross-section restriction at the end of the supply channel to accelerate the hydraulic stream and the fruit entering the tank. FR2596728 provides profiled guides allowing the floating objects to be channelled to a cylindrical opening in a plate covering the immersed case. These structural designs of the filling device have limited efficiency in relation to the improvement of the productivity of the filling of the cases with objects. 
     FR2175630 recommends fitting a hydraulic transport channel with mobile scoops allowing, in the raised position, fruit to be retained and the height of the hydraulic stream upstream of the scoops to be increased and, in the lowered position, the hydraulic stream and the fruit to be released so as to momentarily increase the flow rate downstream of the scoops. However, this solution does not allow the productivity of the filling method to be increased because it consists, in contrast, of slowing down the hydraulic stream and the fruit. 
     Other documents such as GB 1571400 provide a vacuum chamber placed above the tank and a conveyor inclined downwardly to immerse the products so as to introduce them into the vacuum chamber which creates an upwards depression. U.S. Pat. No. 4,051,645 also describes a device comprising a conveyor inclined downwardly to immerse apples at the end of a hydraulic channel in a receiving station for supplying them into a transfer cage having a lower opening and an upper opening, and then allowing them to be loaded into a case. These solutions are complex, costly and do not sufficiently improve the supply rate of the filling device. The invention thus aims to overcome all of these disadvantages by proposing a method and a device for filling cases with floating objects, having a considerably improved rate and thus productivity. 
     The invention aims in particular to propose such a filling method and such a filling device having a flow and productivity which are in particular compatible with the modern devices for sorting floating objects such as the high-speed and high-rate devices for calibrating or pre-calibrating fruit. 
     The invention likewise aims to propose a device for sorting floating objects such as fruit or vegetables allowing the implementation of such a filling method and/or comprising such a filling device and having the same advantages. 
     The invention likewise aims to achieve these aims without requiring any modifications to the hydraulic channels nor to the general design of the filling device or sorting device, and to do so in simple, quick and less expensive manner. It thus aims in particular to achieve these aims by simply adding on an optional device which is simple and inexpensive. It thus aims in particular to allow a simple and inexpensive modification of the filling devices and/or sorting devices currently in use to considerably increase their overall rate and general productivity. 
     The invention thus relates to a method for the hydraulic filling of cases—in particular cases which are water-permeable but are able to contain objects, such as open crates and/or box pallets, generally known under the name palox—with objects, named floating objects, able to be transported by a hydraulic stream, such as fruit or vegetables, in which: 
     at least one case to be filled is immersed in a receiving tank, 
     during a step of supplying the tank with floating objects, said floating objects are transported to the tank by a hydraulic stream of a supply channel communicating with the tank above an immersed case, 
     characterised in that during at least part of the supplying step, at least some of the floating objects are mechanically forced to move downstream in the hydraulic stream of the supply channel at a mechanical forced-movement speed which is greater than their forced-movement speed, named hydraulic forced-movement speed, downstream solely under the effect of the hydraulic stream, so as to repel them downstream towards the tank and to accelerate their movement speed in the hydraulic stream towards the tank. 
     Therefore, at least some of said floating objects are mechanically forced (i.e. by a mechanism) downstream and are not forced solely hydraulically by the speed of the hydraulic stream. In a method in accordance with the invention, the mechanically forced floating objects are thus forced at a mechanical forced-movement speed which is greater than their forced-movement speed, named hydraulic forced-movement speed, downstream solely under the effect of the hydraulic stream. It should be noted that this hydraulic forced-movement speed does not necessarily correspond precisely to the speed of the hydraulic stream. It is generally slightly less than the flowrate of the hydraulic stream in the supply channel. Consequently, it is necessary and sufficient, in the principle of the invention, that the floating objects are mechanically forced downstream at a mechanical forced-movement speed greater than the hydraulic forced-movement speed of the floating objects, so as to repel them downstream towards the tank and to accelerate their movement speed in the hydraulic stream towards the tank. This mechanical forced-movement speed can thus be, at least in theory, less than the flowrate of the hydraulic stream in the supply channel. 
     That being said, in some advantageous embodiments in accordance with the invention, said floating objects mechanically forced to move downstream are mechanically forced downstream in the hydraulic stream at a speed greater than the flowrate of the hydraulic stream in the supply channel. 
     The act of mechanically forcing at least some of the floating objects downstream at a mechanical forced-movement speed greater than their hydraulic forced-movement speed—in particular greater than the flowrate of the hydraulic stream—allows in particular considerable improvement and acceleration in the filling of the case in a simple and economic manner without risk to the floating objects which may be delicate objects such as fruit or vegetables, e.g. apples or citrus fruit. In should be noted in this regard that such a mechanical forced movement in the supply channel not only increases the general downstream horizontal movement speed of the floating objects (while floating on the surface of the hydraulic stream), and thus thereby the rate of supplying the floating objects into a case immersed in the tank, but also improves the packing and width-wise distribution of the floating objects in this supply channel, also optimising the supply rate of the tank, and thus of the case immersed in this tank. 
     In a method in accordance with the invention, any device allowing floating objects to be mechanically forced to move downstream whilst floating on the surface of the hydraulic stream can be used. In some embodiments, advantageously and in accordance with the invention, in order to mechanically force floating objects to move downstream, at least one gate, named feeding gate, adapted to be able to mechanically force floating objects in the hydraulic stream downstream, is forced to move downstream with respect to the supply channel at a speed selected to come into contact with floating objects in the hydraulic stream, to push them and to accelerate the movement thereof towards the tank. In particular, the downstream forced-movement speed of such a feeding gate is selected to be greater than said hydraulic forced-movement speed of the objects in the hydraulic stream—in particular greater than the flowrate of the hydraulic stream in the supply channel. Such a feeding gate can be formed of teeth spaced apart from each other by a width less than the smallest size of the floating objects to be able to force them downstream in the hydraulic stream in the manner of a rake. Such a feeding gate is transparent to the hydraulic stream which can freely pass therethrough, substantially without any head loss or reduction in speed. 
     In a method in accordance with the invention, it is possible to thus mechanically force downstream all or some of the floating objects in a single batch of floating objects intended to fill a single case. In some advantageous embodiments of a method in accordance with the invention, all of the floating objects of a single batch of floating objects intended to fill a single case are mechanically forced to move downstream in the hydraulic stream of the supply channel. 
     In particular, in some advantageous embodiments of a method in accordance with the invention, the floating objects of a batch of floating objects intended to fill a single case are introduced into the supply channel progressively one behind the other and a feeding gate is placed immediately upstream of the last floating objects of this batch introduced into the supply channel, then this feeding gate is forced to move downstream in the hydraulic stream (at a speed greater than the hydraulic forced-movement speed of the floating objects—in particular greater than the flowrate of the hydraulic stream). 
     Furthermore, such a method in accordance with the invention is particularly advantageous when the floating objects are introduced on one side of the supply channel, in a direction transverse to this supply channel, in particular from hydraulic accumulating channels (allowing sorting of the floating objects in accordance with predetermined sorting criteria such as size, weight, optical analyses . . . , each accumulating channel receiving a batch of floating objects sorted in accordance with said sorting criteria) extending perpendicularly to the supply channel, this latter extending longitudinally along outlets of these accumulating channels. In fact, the floating objects thus introduced on one side of the supply channel tend to spread out and be dispersed in the supply channel, moving away from each other and to take up only some of the width thereof. Consequently, the act of mechanically forcing them downstream results, if the mechanical forced-movement speed of the floating objects is sufficient, in the objects being brought together again and being spread out width-wise such that the entire width of the supply channel is taken up by floating objects before they arrive at the tank, and the supply of objects thereby grouped together into a case immersed in the receiving tank being ensured. Therefore, in particular in these embodiments, the floating objects are advantageously mechanically forced downstream at a mechanical forced-movement speed selected to bring them together and to spread them out width-wise across the entire width of the supply channel before they arrive at the tank whilst floating on the surface of the hydraulic stream. That being said, there is nothing to prevent, in contrast, the provision of a mechanical forced-movement speed slightly less than that necessary to bring the floating objects together, if it proves to be the case that such bringing together is harmful, e.g. may cause damage to the objects. A filling method in accordance with the invention thereby produces forced supply of the immersed case with floating objects, i.e. a type of force-feeding of the case. 
     Likewise, a filling method in accordance with the invention is particularly advantageous when the hydraulic stream in the supply channel passes into the tank and through the case immersed therein downwards to leave the tank via a lower outlet thereof. In fact, in these embodiments, mechanically forcing the objects downstream at the inlet of the tank of the case immersed in the latter produces a forced supply (force-feeding) of the case with floating objects which is particularly efficient and quick. 
     The invention likewise relates to a device for hydraulically filling cases—in particular open crates—with objects, named floating objects, able to be transported by a hydraulic stream, such as fruit or vegetables, for implementing a filling method in accordance with the invention. 
     It thus relates likewise to a device for the hydraulic filling of cases—in particular cases which are water-permeable but are able to contain objects, such as open crates and/or box pallets, generally known under the name palox—with objects, named floating objects, able to be transported by a hydraulic stream, such as fruit or vegetables, comprising: 
     a tank for receiving at least one case to be filled, 
     at least one supply channel communicating with the tank above a case immersed in the tank, 
     a pumping circuit able to maintain a hydraulic stream in each supply channel, the hydraulic stream being suitable to transport floating objects to the tank, characterised in that it comprises a feeding device adapted to be able to, at least during part of a step of supplying the tank with floating objects, mechanically force at least some of the floating objects to move downstream in the hydraulic stream of the supply channel at a mechanical forced-movement speed which is greater than their forced-movement speed, named hydraulic forced-movement speed, downstream solely under the effect of the hydraulic stream, so as to repel them downstream towards the tank and to accelerate their movement speed in the hydraulic stream towards the tank. 
     In a filling device in accordance with the invention, any feeding device able to mechanically force floating objects can be used. 
     In some advantageous embodiments in accordance with the invention, the feeding device is adapted to be able to mechanically force floating objects to move downstream at a mechanical forced-movement speed greater than the forced-movement speed, named hydraulic forced-movement speed, of the floating objects downstream solely under the effect of the hydraulic stream—in particular at a mechanical forced-movement speed greater than the flowrate of the hydraulic stream in the supply channel. 
     In some advantageous embodiments in accordance with the invention, the feeding device comprises at least one gate, named feeding gate, adapted to be able to mechanically force floating objects in the hydraulic stream downstream, and a mechanism for forcing each feeding gate to move downstream with respect to the supply channel at a speed selected such that the feeding gate comes into contact with floating objects in the hydraulic stream, pushes them and accelerates the movement thereof towards the tank in the hydraulic stream. 
     Furthermore, in some advantageous embodiments in accordance with the invention, the feeding device comprises, as a forced-movement mechanism, a self-propelled carriage adapted to be able to move in translation on at least one sidewall of the supply channel. This self-propelled carriage carries at least one motor for driving the self-propelled carriage along the supply channel, and advantageously a feeding gate and at least one actuator adapted to force the feeding gate to move between an active position in which it is able to come into contact with floating objects in the hydraulic stream of the supply channel, and an inactive position in which it is not able to co-operate with floating objects in the hydraulic stream of the supply channel. 
     This self-propelled carriage can advantageously be guided with respect to only one of the sidewalls of the supply channel, e.g. by being provided with rollers rolling on an upper border of the sidewall of the supply channel and with a column having a lower end guided in a chute extending longitudinally to the outside of the sidewall, integral therewith. As a variant, there is nothing to prevent provision of a self-propelled carriage straddling the supply channel, rolling on the two sidewalls thereof, above the hydraulic stream. As another variant, there is also nothing to prevent a self-propelled carriage being guided with respect to a specific guiding device other than the sidewalls of the supply channel. 
     The forced-movement mechanism is also adapted to move the feeding gate upstream with respect to the supply channel so as to allow this feeding gate to return to a position where it can co-operate with a new group of floating objects intended to be supplied to a case to be filled. 
     Such a feeding gate and its forced-movement mechanism are advantageously adapted such that the feeding gate can be forced to move downstream in the downstream part of the supply channel which extends to the tank. However, as a variant, there is nothing to prevent provision being made, in contrast, for the feeding gate to co-operate with the floating objects only over some of the length of the supply channel, optionally without being moved to the tank. 
     Furthermore, the forced-movement mechanism can be controlled in any suitable manner such that the feeding device co-operates with all or some of the floating objects in the supply channel. In particular, there is nothing to prevent the introduction of the feeding gate within a group of floating objects to force only some of the floating objects of this group downstream. That being said, in some advantageous embodiments, the feeding device has a feeding gate adapted to be able to be moved and introduced into the hydraulic stream of the supply channel in an introduction position located at a distance away from the tank determined such that a single batch of floating objects able to be contained within a single case and transported by the hydraulic stream can be fully contained between the introduction position of the feeding gate and the tank. In this manner, the feeding gate can co-operate with all of the floating objects of a single batch of floating objects able to be contained in a single case in order to mechanically force them downstream and to increase their supply rate within the tank, and thus the case. 
     In some advantageous embodiments of a filling device in accordance with the invention, the supply channel has a cross-section restriction at one end communicating with the tank of this supply channel. In these embodiments, advantageously and in accordance with the invention, the feeding device comprises at least one feeding gate upstream of this cross-section restriction. This feeding gate is thus able to be forced to move downstream by the forced-movement mechanism at a speed greater than that of the hydraulic stream, and upstream to be moved back to the initial position, the feeding gate remaining upstream of the cross-section restriction during all of its movements. 
     Furthermore, in some advantageous embodiments of a filling device in accordance with the invention, the supply channel extends along a plurality of outlets of a plurality of channels accumulating floating objects, these accumulating channels being in parallel with each other, each outlet of an accumulating channel communicating with the supply channel on one side thereof. The feeding device of such a filling device in accordance with the invention thus allows the floating objects to be contacted—in particular for them to be brought together—and allows the width-wise distribution of the floating objects in the supply channel upstream of the tank to be improved, which optimises not only the speed and rate of filling of a case immersed in the tank but also the quality of this filling, by minimising shocks and the risks of damage to the floating objects. 
     Furthermore, in some advantageous embodiments and in accordance with the invention, in particular when the number of accumulating channels is high, the supply channel comprises at least one gate, named intermediate gate, adapted to be able to be placed either in the active position in the supply channel in which it holds back the floating objects transported by the hydraulic stream upstream of the intermediate gate, or in an inactive position in which it does not co-operate with floating objects in the hydraulic stream. Such an intermediate gate allows the optimisation of the sequences of introducing, into the supply channel, the different batches of floating objects from different accumulating channels. In particular, a batch of floating objects can be introduced into the supply channel upstream of an intermediate gate from an accumulating channel located upstream of this intermediate gate, whilst another batch of floating objects previously introduced into the supply channel downstream of the intermediate gate from an accumulating channel located downstream of the intermediate gate is supplied into the tank and into a case, the floating objects of this batch being forced to move downstream at a speed greater than that of the hydraulic stream by the feeding device. 
     Advantageously and in accordance with the invention, the feeding device thus comprises a feeding gate between the tank and such an intermediate gate, this intermediate gate being located further downstream in the supply channel. There is likewise nothing to prevent the possible provision of a feeding gate upstream of an intermediate gate, or between two intermediate gates. 
     Likewise, in some advantageous embodiments of a filling device in accordance with the invention, said pumping circuit is adapted to force the hydraulic stream to flow downwards in the tank and through a case immersed in this tank. In this manner, the forced supply resulting from the feeding device is even more efficient. 
     The invention likewise relates to a filling method implemented with a filling device in accordance with the invention. 
     The invention likewise relates to a device for sorting floating objects such as fruit or vegetables, comprising: 
     at least one conveyor for sorting floating objects in accordance with predetermined sorting criteria and adapted to discharge floating objects into hydraulic accumulating channels, 
     at least one device for hydraulically filling cases—in particular open crates—with floating objects, comprising:
         a tank for receiving at least one case to be filled,   at least one channel for supplying a hydraulic stream extending between outlets of the accumulating channels and the receiving tank, each supply channel being able to transport floating objects exiting an accumulating channel, and communicating with the tank above a case immersed in the tank,       

     a pumping circuit able to maintain a hydraulic stream in each accumulating channel and in each supply channel, the hydraulic stream being suitable to transport floating objects to each receiving tank, characterised in that each device for hydraulically filling cases is a filling device in accordance with the invention. 
     The invention likewise relates to a filling device, a filling method and a sorting device which are characterised in combination by all or some of the features mentioned above or below. 
    
    
     
       Other aims, features and advantages of the invention will become apparent upon reading the following description given by way of non-limiting example and which makes reference to the attached figures in which: 
         FIG. 1  is a partial schematic top view of a filling device in accordance one embodiment of the invention in a sorting device in accordance with one embodiment of the invention, 
         FIG. 2  is a partial schematic elevation of the filling device of  FIG. 1 , 
         FIG. 3  is a partial schematic perspective view of a feeding device of a filling device in accordance with the invention in the introduction position during a step of a filling method in accordance with the invention during which a batch of floating objects is introduced into the supply channel downstream of the feeding device from a accumulating channel, 
         FIG. 4  is a partial schematic perspective bottom view of a feeding device of a filling device in accordance with one embodiment of the invention, 
         FIG. 5  is a view similar to  FIG. 3  illustrating a later step of a filling method in accordance with the invention, 
         FIG. 6  is a view similar to  FIG. 3  illustrating a step of a filling method in accordance with the invention during which the feeding device is in the inactive position immediately downstream of an intermediate gate against which accumulate floating objects from an accumulating channel, the outlet of which is upstream of the intermediate gate, 
         FIG. 7  is a view similar to  FIG. 6  illustrating a subsequent step of the method in accordance with the invention during which the floating objects pass beneath the feeding gate of the feeding device. 
     
    
    
       FIG. 1  shows the downstream part of a sorting device in accordance with the invention comprising a plurality of hydraulic accumulating channels  14  in parallel with each other and supplied by a sorting conveyor (not shown) in a conventional manner so as to allow floating objects such as fruit or vegetables to be grouped into batches in the accumulating channels, the floating objects of a single batch meeting the same sorting criteria (e.g. same size, same weight, same colour . . . ) and being intended to fill the same case  10 . The hydraulic channels  14  are supplied by a hydraulic stream by way of a pumping device. Each accumulating channel  14  has an outlet  15  provided with a mobile gate allowing the hydraulic stream to pass therethrough and either allowing the floating objects to be retained within the accumulating channel or to allow the floating objects to pass into a hydraulic supply channel  13  which extends along different outlets  15  of different accumulating channels  14 , perpendicularly to these accumulating channels  14 . 
     The general features of such a sorting device are well known per se (cf. in particular U.S. Pat. Nos. 5,626,238, 7,159,373, . . . ) and only the features unique to the invention will be described in more detail hereinafter. This sorting device is in particular provided with a device  11  for hydraulically filling cases  10 —in particular cases which are water-permeable but are able to contain objects, such as open crates and/or box pallets, generally known under the name palox—with floating objects. Again, the general features of such a hydraulic filling device implementing a method for hydraulically filling cases with floating objects are well known per se (cf. in particular the documents mentioned above) and only the features unique to the invention will be described in more detail hereinafter. Throughout the text, the terms “downstream” and “upstream” refer to the flow direction of the hydraulic stream in the channels. 
     The filling device  11  comprises, at the downstream end of the supply channel  13 , a tank  12  for receiving at least one case  10  to be filled with objects, this case  10  being immersed in the tank  12 . The supply channel  13  communicates with the tank  12  above a case  10  immersed in the tank  12  such that the hydraulic stream provided in the supply channel  13  passes into the tank  12  and into the case  10  contained therein so as to introduce the floating objects transported by the hydraulic stream into the case. The filling device  11  likewise comprises a device  16  for loading/unloading cases  10  into/from the tank  12  which is e.g. an elevator device, and an automatic control arrangement  60 , comprising e.g. in particular a computer system, and adapted to control the different members, actuators and motors of the filling device in accordance with the invention and to implement a filling method in accordance with the invention. 
     The supply channel  13  has a base  53  and vertical sidewalls  17 , including one vertical sidewall  17  extending longitudinally at a distance from the outlets  15  of the accumulating channels  14 , this sidewall  17  having a free upper horizontal border  18  and a U-shaped profile extending longitudinally to the outside of the sidewall  17  beneath the upper border  18  so as to form a chute  19  receiving a flexible sleeve  20 . 
     A feeding device  21  is associated with the sidewall  17  so as to be able to move in translation longitudinally along this sidewall  17 , on its upper border  18 , in either direction. In the illustrated embodiment, this feeding device  21  is a self-propelled device comprising a self-propelled carriage having a mechanically welded frame  22  bearing an electric motor  23  for forcing the feeding device  21  to move along the upper border  18 . 
     The mechanically welded frame  22  comprises a horizontal main beam  24 , a horizontal cross-beam  26  perpendicular to the beam  24 , a reinforcement  27  placed between the beam  24  and the cross-beam  26  to keep them perpendicular to each other, and an outer vertical column  25  extending downwards from the beam  24  such that when the beam  24  is above the upper border  18  of the sidewall  17 , the lower end  28  of the column  25  co-operates with the chute  19 . To do this, this lower end  28  of the column  25  is provided with rollers  44  which can freely rotate about vertical axles rolling on vertical walls of the chute  19  so that it is guided thereby and held therein to prevent tipping of the mechanically welded frame  22  and the cross-beam  26  in the supply channel  13 . Furthermore, the lower end  28  of the column  25  can be provided with an angle-beam  54  co-operating with an upper outer lap  55  of the chute  19  allowing this lower end  28  to be locked in the chute  19 . This angle-beam  54  is integral with a piece which is connected, e.g. bolted, to the lower end  28  of the column  25 , this lower end having been placed in the chute  19 . 
     The beam  24  is provided with rollers allowing it to roll on the upper border  18  of the sidewall  17  of the supply channel and allowing it to be guided horizontally with respect to the sidewall  17 . The beam  24  bears four bearing rollers  29  mounted so as to rotate with respect to the beam  24  on horizontal axes of rotation, at least one of the bearing rollers  29  being forced to rotate by the motor  23 . To do this, the motor  23  is coupled to a transmission block  30  itself coupled to a horizontal transverse shaft  31  rotatably guided with respect to the beam  24  and bearing two bearing rollers  29  fixedly attached to this transverse shaft  31  for conjoint rotation therewith, one bearing roller  29  on either side of the beam  24 . Furthermore, the transverse shaft  31  likewise forces a pulley  32  to rotate which drives a belt  33  driving a pulley  34  coupled to a second horizontal transverse shaft  35  rotatably guided with respect to the beam  24  and bearing two other bearing rollers  29  fixedly attached to this transverse shaft  35  for conjoint rotation therewith, one bearing roller  29  on either side of the beam  24 . Therefore, the beam  24  is supported and forced to move along the upper border  18  by four bearing rollers  29  forced to rotate by the motor  23  in either direction. The motor  23  is fed and controlled by the automatic control arrangement  60  via cables integrated in the flexible sleeve  20 . Upon movement of the feeding device  21  along the upper horizontal border  18  of the sidewall  17  of the supply channel  13 , the flexible sleeve  20  follows the mechanically welded frame  22  exiting the chute  19  to varying extents or remaining to varying extents in this chute  19 . 
     The upper border  18  of the sidewall  17  of the supply channel is formed by a flange turned back towards the outside of the upper part of this sidewall  17 . The beam  24  is guided horizontally with respect to this turned-back flange by rollers  36  mounted so as to rotate freely about vertical axles and spaced apart from each other so as to co-operate by rolling with longitudinal side flanks of this turned-back flange. In this manner, the beam  24 , and thus the self-propelled feeding device  21 , is obliged to move along the upper border  18 . 
     The feeding device  21  bears a feeding gate  37  extending on the side of the beam  24  above the supply channel  13 . This feeding gate  37  comprises a transverse horizontal bar  38  rotatably guided with respect to the cross-beam  26  of the mechanically welded frame  22  by at least two bearings  39 . The feeding gate  37  likewise comprises mutually parallel teeth  40  extending perpendicularly to and from the horizontal bar  38 . The teeth  40  are laterally spaced apart from each other at a distance less than the smallest dimension of the floating objects to be processed. They are also as thin as possible so as to allow the hydraulic stream to pass through the feeding gate  37  with minimal head losses. However, they are rigid enough to allow the floating objects to be forced along with respect to the hydraulic stream, at a speed different from the speed of the hydraulic stream. They are long enough to be able to co-operate with floating objects forced along by the hydraulic stream in the supply channel  13  when said teeth extend vertically downwards from the horizontal bar  38 . 
     The horizontal bar  38  bears a bracket  41  fixedly attached to this bar for conjoint rotation therewith and of which the end is articulated to the actuating rod of a cylinder  42 , the body of which is supported by the beam  24 . The cylinder  42  allows the horizontal bar  38  and thus the feeding gate  37  to be forced to rotate with respect to the cross-beam  26  at least between an inactive position of the feeding gate  37  in which the teeth  40  extend horizontally above the supply channel  13 , without co-operating with the hydraulic stream nor with the floating objects possibly transported by this hydraulic stream, these floating objects being able to pass beneath the feeding gate  37 ; and an active position of the feeding gate  37  in which the teeth  40  extend vertically downwards to co-operate with the hydraulic stream and the floating objects of the supply channel  13 . The cylinder  42  is fed and controlled by the automatic control arrangement  60  via flexible conduits integrated in the sleeve  20 . 
     The cross-beam  26  likewise advantageously bears a plurality of photoelectric cells  43  allowing the detection of the presence or absence of floating objects in the supply channel  13  immediately downstream of the feeding gate  37 , these photoelectric cells  43  being likewise connected to the automatic control arrangement  60  by suitable cables integrated in the sleeve  20 . 
     Furthermore, the filling device likewise comprises a transverse intermediate gate  45 , the longitudinal position of which is fixed with respect to the supply channel  13 , but adapted to be able to be placed either in the active position in the supply channel  13  in which it holds back the floating objects transported by the hydraulic stream arriving upstream of the intermediate gate, or in an inactive position in which it does not co-operate with the hydraulic stream and allows the floating objects transported thereby to pass downstream. 
     In the embodiment illustrated in the figures, this intermediate gate  45  is formed of a lower fixed gate  46  rigidly fixed in the supply channel  13  between its two sidewalls  17  and extending upwards from the base of the supply channel  13 , and an upper mobile gate  47  comprising a transverse horizontal bar  48  rotatably guided by bearings  49  above the supply channel  13  and teeth  50  supported by the transverse horizontal bar  48  and extending perpendicularly to and from this latter. The teeth  50  are mutually parallel and laterally spaced apart from each other at a distance less than the smallest dimension of the floating objects to be processed. They are as thin as possible so as to allow the hydraulic stream to pass through the gate  45  with minimal head losses. However, they are rigid enough to hold back the floating objects with respect to the hydraulic stream when they extend vertically downwards in the active position from the horizontal bar  48 . 
     The horizontal bar  48  bears a bracket  51  fixedly attached to this bar for conjoint rotation therewith and of which the end is articulated to the actuating rod of a cylinder  52 , the body of which is supported by the upper border  18  of the sidewall  17  of the supply channel  13 . The cylinder  52  allows the horizontal bar  48  and thus the mobile intermediate gate  47  to be forced to rotate with respect to the supply channel  13  at least between an inactive position of the intermediate gate  45  in which the teeth  50  of the mobile gate  47  extend horizontally above the supply channel  13 , without co-operating with the hydraulic stream nor with the floating objects possibly transported by this hydraulic stream, these floating objects being able to pass beneath the mobile intermediate gate  47 ; and an active position of the intermediate gate  45  in which the teeth  50  extend vertically downwards to co-operate with the hydraulic stream and the floating objects of the supply channel  13 . 
     The intermediate gate  45  is placed with respect to the supply channel  13  upstream of the receiving tank  12  so as to limit the number of accumulating channels  14 , the outlets  15  of which issue into a downstream portion of the supply channel  13  downstream of the intermediate gate  45 . In this manner, the distance that the floating objects must cover from the moment when a case intended to receive them is immersed in the receiving tank  12  is at most equal to the length of the downstream portion of the supply channel  13 , i.e. to the distance extending between the intermediate gate  45  and the receiving tank  12 . Furthermore, floating objects from an accumulating channel, the outlet  15  of which is upstream of the intermediate gate  45 , can accumulate against this intermediate gate  45  in the active position whilst floating objects from an accumulating channel  14 , the outlet  15  of which is downstream of the intermediate gate  45 , are being used to fill a case in the receiving tank  12 . There is nothing to prevent the provision of a plurality of intermediate gates  45  distributed along the supply channel  13  if the number of accumulating channels  14  justifies this in order to optimise the filling method even further. 
     The feeding device  21  is downstream of the intermediate gate  45  which is the most downstream and the closest to the receiving tank  12 , i.e. which delimits the downstream portion of the supply channel  13 , and can move in translation along the supply channel between this intermediate gate  45  and the receiving tank  12  so as to co-operate with the floating objects transported in the downstream portion of the supply channel  13 . 
       FIG. 3  shows a step of a filling method in accordance with the invention during which floating objects are introduced into the supply channel  13  from an outlet  15  of an accumulating channel  14  located in the downstream portion of the supply channel  13 , the holding gate of this outlet  15  being controlled in the top position. The feeding gate  37  is placed immediately upstream of this outlet  15 . Since the floating objects are forced along by the hydraulic stream of the accumulating channel  14  which arrives perpendicularly to the hydraulic stream flowing in the supply channel  13 , these floating objects spill out into the supply channel  13 , spreading out without taking up the entire width thereof. As long as the photoelectric cells  43  detect the presence of floating objects immediately downstream of the feeding gate  37 , this gate is kept fixed with respect to the supply channel  13 . 
     When the photoelectric cells  43  no longer detect the presence of floating objects immediately downstream of the feeding gate  37 , the self-propelled carriage (and thus the feeding gate  37 ) is forced to move downstream at a mechanical forced-movement speed greater than the hydraulic forced-movement speed of the objects by the hydraulic stream, so as to catch up with the floating objects. When the feeding gate  37  thus comes into contact with the floating objects, as detected by the photoelectric cells  43 , the downstream movement speed of the self-propelled carriage can be further increased to cause the forced supply of the objects into the tank and into the case  10  which it contains. 
       FIG. 5  thus shows a step of the filling method during which, when all of the floating objects of the batch of floating objects initially contained in the accumulating channel  14  have passed into the supply channel  13 , the feeding device  21  is forced downstream with respect to the supply channel  13 , the self-propelled carriage moving horizontally at a speed greater than the hydraulic forced-movement speed of the objects in the hydraulic stream of the supply channel  13 , and in particular at a speed greater than the flowrate of the hydraulic stream flowing in the supply channel  13 , the feeding gate  37  pushing the floating objects downstream in the hydraulic stream flowing in the supply channel  13 , which has the effect of accelerating the movement speed thereof and causing them to take up the entire width of the supply channel  13 . This step is carried out until the feeding gate  37  arrives immediately at the inlet of the receiving tank  12  to repel all of the floating objects into the case immersed in this receiving tank  12 . 
     During a subsequent step of the filling method, the feeding device  21  is returned upstream so as to be able to co-operate with floating objects from another hydraulic channel  14 , the outlet  15  of which issues into the downstream portion of the supply channel  13 , or with floating objects arriving in this downstream portion from the intermediate gate  45  in the inactive position. Simultaneously, the case which has been filled with floating objects can be taken away and replaced by an empty case in the receiving tank  12 . 
       FIG. 6  shows a batch of floating objects accumulating immediately upstream of the intermediate gate  45  in the active position, the feeding device  21  being thus placed immediately downstream of the intermediate gate  45 , the feeding gate  37  being in the inactive position. These floating objects may have accumulated against the intermediate gate  45  whilst other floating objects were being used to fill a case immersed in the receiving tank  12 . 
       FIG. 7  shows a subsequent step of the filling method during which the mobile intermediate gate  47  is placed in the inactive position to release the floating objects downstream, these objects being forced by the hydraulic stream into the downstream portion of the supply channel  13 , passing beneath the mobile intermediate gate  47  and beneath the feeding gate  37 , these two gates being in the inactive position. This taking place, the photoelectric cells  43  of the feeding device  21  detect the presence of floating objects in the supply channel. As soon as the photoelectric cells  43  no longer detect floating objects, the feeding device  21  is forced to move downstream at a speed greater than that of the hydraulic stream so as to come back into contact with floating objects to repel them towards the receiving tank  12 . 
     Preferably, in order to facilitate filling of the case immersed in the receiving tank  12 , the base  53  of the supply channel  13  has a cross-section restriction  57  at its downstream end in communication with the receiving tank  12 . This cross-section restriction  57  is formed by a protuberance on the base  53  such that the height of the hydraulic stream passing above this cross-section restriction  57  is adapted to allow the passing of a single layer of floating objects. This cross-section restriction  57  allows the hydraulic stream to be locally accelerated and thus the speed of the floating objects to be increased immediately prior to them passing into the case immersed in the receiving tank  12 . 
     Furthermore, the pumping circuit of the filling device preferably comprises an outlet  56  of the hydraulic stream in the lower part of the tank  12 , beneath the immersed case  10 , such that the hydraulic stream of the supply channel  13  arriving in the tank flows downwards in the tank and through the case immersed therein. 
     A feeding device  21  of a filling device in accordance with the invention allows forced supply (force-feeding) of the receiving tank  12  with floating objects during at least part of the step of supplying this receiving tank  12  and the immersed case contained therein with such floating objects. The movement speed of the feeding device  21  downstream, which is greater than the hydraulic forced-movement speed of the floating objects in the hydraulic stream of the supply channel, and preferably greater than the flowrate of the hydraulic stream in the supply channel, can be constant or, in contrast, can be variable over time and/or based on the position of the feeding device  21  along the supply channel  13 . The ratio between the speed of the feeding device  21  downstream and the speed of the hydraulic stream can be of any magnitude so long as it is greater than 1. 
     In some advantageous embodiments, it is possible e.g. to provide two different forced-movement speeds downstream of the feeding device  21 : a first speed selected to allow the feeding gate  37  to catch up with floating objects in order to come into contact therewith without risk of damaging them; and a second quicker speed selected to mechanically force these floating objects downstream, bringing the objects together and distributing the objects width-wise across the entire width of the supply channel  13  upstream of their arrival at the receiving tank  12 . 
     For example, with open crates (palox) allowing the reception of 350 kg of apples, the feeding gate  37  can be driven at a speed between 20 and 50 m/min, in particular of the order of 30 to 40 m/min whilst the hydraulic stream in the supply channel  13  flows at a rate between 10 and 40 m/min, in particular of the order of 15 to 25 m/min. It has been noted that the time taken to fill a case with apples was able to be reduced from a time period of the order of 60 seconds to a time period of the order of 40 seconds, and that a sorting device fitted with such a filling device in accordance with the invention can operate at a rate which has been increased by 10 cases per hour to achieve a rate of 40 cases per hour, i.e. an increase of the order of 33% with respect to a conventional filling device and filling method not part of the invention. 
     It goes without saying that the invention can be varied in a large number of ways with respect to the sole embodiments described above and illustrated in the figures. Each feeding device can be formed in a large number of other structural embodiments so long as its allows the floating objects to be forced to move downstream at a speed greater than that of the hydraulic stream. In particular, each feeding gate can be forced to move by any motor-driven forced-movement mechanism other than a self-propelled carriage rolling on at least one sidewall of the supply channel. There is nothing to prevent the provision of a plurality of feeding devices, in particular a plurality of successive feeding devices distributed along the supply channel  13  and separated by one or more intermediate gates and/or several feeding devices moving in a single portion of the supply channel  13  and controlled to move in a continuous loop (e.g. supported and driven not individually by a self-propelled carriage, but collectively by a carrousel or any other motor-driven forced-movement mechanism) along a single path to the receiving tank  12 . There is nothing to prevent the provision of several supply channel  13 , in parallel or non-parallel with each other, each supply channel  13  communicating with a tank  12  and/or at least one tank  12  able to receive floating objects from several supply channels  13  and/or a tank  12  which can contain several immersed cases  10  . . . . 
     Furthermore, the logic for controlling each feeding device can be varied in a large number of ways. Therefore, each feeding device can be used and implemented during the entire process of filling each case, or in contrast only during some of the time period necessary for filling each case, e.g. only at the end of filling, or only for some floating objects or based on the number of floating objects contained in a case or to be introduced into a case, or based on any other suitable criteria. 
     The invention can also advantageously be applied to filling immersed cases such as open crates or palox pallets with fruit or vegetables. It can likewise be applied to filling other types of cases and/or other floating objects for which the same problems arise.