FR2582291A1 - Handling vessel dispenser - Google Patents

Abstract

This dispenser is of the type comprising, at the base of a magazine 30 in which the vessels 10 to be dispensed are called upon to travel by means of gravity, a pulling and separation device capable of detaching these vessels 10 individually and of releasing them. According to the invention, this pulling and separation device comprises a plurality of rollers 35, forming cams, all of which are mounted rotatably in a synchronous manner, and of which at least two, located on the same side of the magazine 30 in question, are preferably mounted so as to float with respect to their axis. Application, in particular, to the dispensing of handling vessels made from synthetic material or from sheet metal.

Description

 The present invention relates generally to containers, commonly known as handling bins, of the type used for example for serving any machine, upstream or downstream thereof, for its supply or disposal of its production, and suitable for handling the parts, products or sub-assemblies concerned as well as for their storage.

 These tanks are for example made of synthetic material, called plastic.

 But they can also be made of sheet metal, solid or perforated.

 Anyway, they usually have a rim on at least two opposite sides, and their shape is generally trunk-pyramidal.

 Thanks to such a shape, they can be nested in a stack one inside the other, which advantageously reduces the volume of empty storage.

 For their use, they must therefore be removed one by one from such a battery.

 The present invention relates more particularly to the distributors usually used for this purpose.

 Overall, such a distributor includes a store, which is adapted to receive the bins to be distributed in a stack, and in which these are called to travel by gravity, and, at the base of this store, a drawing and separation device , which is capable of detaching, one by one, in a controlled manner, from such a stack, that of these tanks which is at the base of it, and to release it, while retaining the rest of the stack.

 The tray thus freed can then be filled with parts, products or sub-assemblies to be handled or stored, either at the same place where it was released, or after its transportation to the corresponding place by a conveyor.

 With regard to the distributor, the problem is twofold.

 On the one hand, the pulling and separation device which the team must be made sufficiently simple and robust to be able to operate in a reliable and safe manner despite a harsh surrounding environment of the type that usually prevails in industrial and necessarily intensive work rates.

 And, on the other hand, even though in principle such a distributor is normally only suitable for doing this in containers of perfectly defined dimensions, it must in practice be able to be satisfied with more or less large deviations in the dimensions size of these bins.

 This is the case, for example, for tubs made of so-called plastic material, a change in the material of these tubs, imposed by a change in their use or the requirement of particular resistance to any operating agents , which can result in a different shrinkage during molding, and therefore in a more or less significant modification of their dimensions.

 I1 can be the same for sheet metal tanks, when, for a particular treatment, a dip treatment for example, it is implemented, instead of full-walled tanks, perforated-walled tanks, their wall then being most often reinforced by ribs or folds, which are intended to compensate for the weakening due to the perforations, but which inevitably involve a modification of the corresponding dimensions.

 If no particular precaution is taken for the distributor, such as a modification or an adjustment, always expensive, of its drawing and separation device, or even its replacement, the drawing and separation device of such a distributor can let several traps escape simultaneously, or grasp them with too much firmness, with the risk of a deterioration of these trays and / or the risk of an operational incident leading to the blocking of the assembly.

 The present invention generally relates to a distributor of handling bins making it possible, in particular, to avoid these drawbacks, by responding in a particularly satisfactory manner to the double requirement succinctly set out above.

 This dispenser is of the type comprising a magazine, which is adapted to receive the trays to be dispensed in a stack and in which these are called to travel by gravity, and, at the base of said magazine, a draw-off and separation device, which is capable of detaching, one by one, in a controlled manner, from such a stack, that of these tanks which is at the base of it, and to releasing it, while retaining the rest of said stack, and it is generally characterized in that, according to a first aspect, said drawing and separation device comprises, distributed around said magazine, a plurality of rollers, forming cams, all of which are rotatably mounted, synchronously, around an axis parallel to the latter, and each of which has, on its periphery, on the one hand, transversely with respect to said axis, and stepped axially with respect to one another along the latter, two shoulders separate restraints, one upper, the other lower, which each extend only over one portion of circumference, being circumferentially alternating with respect to each other, and which are both oriented towards the upper end of the magazine, and, on the other hand, oriented in opposite direction, a helical ramp.

 The tanks to be treated having in practice a flange on at least two, opposite, their sides, they come in turn to carry by these flanges first on the upper retaining shoulder of the rollers forming cams implemented, then on the lower retaining shoulder of these, while, jointly, the helical ramp associated with these retaining shoulders ensures a suitable separation from the others.

 Likely to implement only rotary movements, such an arrangement advantageously leads, as sought, to particularly robust, reliable and safe embodiments.

 In addition, it is advantageously suitable, also in a particularly simple, reliable and safe manner, for the implementation of at least one degree of elastic freedom for the rollers forming cams concerned.

 In this regard the distributor according to the invention is further characterized in that, according to a second aspect, at least one of its rollers is mounted floating transversely with respect to its axis.

 In practice, this is the case at least for all the rollers located on the same side of the magazine.

 For example, at each end of such a roller intervenes between it and its shaft, a joint with crossed grooves, of the type of those commonly called OLDHAn joints, that is to say a joint comprising, overall, three blocks, namely, two end blocks, one of which is wedged on said shaft and the other on said roller, for example being in one piece with it, and a median block, which is mounted movable relative to the one of the two others in a first direction and relative to the other of these in a direction orthogonal to the previous one, in cooperation with elastic return means, which, interposed between said middle block and said extreme blocks, urge in permanently this middle block towards an average position of rest.

 Thanks to such a floating mounting of at least some of the rollers forming cams which equip it, the dispenser according to the invention is advantageously able to treat without incident the operation of the handling bins having, with a fairly wide tolerance, possible variations. their overall dimensions, this floating assembly being able to compensate for itself such variations in dimensions.

 No specific intervention is therefore necessary to do this.

 In short, the distributor of handling bins according to the invention is advantageously robust and self-adjusting.

 In addition, capable of being used indifferently on the most diverse processing lines, and capable of adapting to the most diverse handling bins, whether these handling bins are stackable or not, or whether or not they have handles, they advantageously have great versatility.

The characteristics and advantages of the invention will become apparent from the description which follows, by way of example, with reference to the appended schematic drawings in which
Figure 1 is, with a local cutaway, an elevational view of a distributor of handling bins according to the invention
Figure 2 is, on a larger scale, a plan view, along arrow II of Figure 1
Figures 3, 4, 5 and 6 are partial views in cross section, respectively on the lines III-III, IV-IV, VV and VI-VI of Figure 2
Figure 7, takes, on a larger scale, the detail of Figure 4 identified by an insert VII thereon
Figure 8 is a cross-sectional view of the cam roller concerned with this detail, along line VIII-VIII of Figure 7
Figure 9 is an exploded perspective view of this roller, and more specifically, in this case, the upper part thereof
Figures 10A, 10B, 10C are, according to various levels, identified by the arrows XA, XB, XC in Figure 9, plan views or sectional view of the single rim, or outer part, of this roller
FIGS. 11A, 11B, 11C are schematic views, in elevation, illustrating, each respectively, various phases of intervention of such a roller forming a cam.

 As shown diagrammatically in fine lines in FIGS. 1 and 11, it is the handling of handling tanks 10, which generally have a troncpyramidal shape, being open on the side of their largest base, and which, out of two at less, opposite, on the sides of the latter, and, in practice, on each of these, have, projecting outwards1 a flange 11.

 The constitution of such a handling container being well known in itself, and not falling within the scope of the present invention, it will not be described here.

 it will suffice to indicate that, for the empty storage of a plurality of such handling bins 10, these are simply nested, in a stack, one inside the other, as shown.

 It is therefore, for their commissioning, to ensure their release one by one from such a battery.

 In the embodiment shown, the dispenser 13 used for this purpose has a frame 14 which is in the form of a generally parallelepipedal box, and which, at its periphery, in the vicinity of its edges, is carried, adjustable in height, by feet 15.

 As shown, these can for example be fitted with rollers 16, FIG. 1.

 Anyway, they allow the distributor 13 to step over if desired any conveyor, not shown, for the evacuation of the handling bins 10 released and their routing to their places of use.

 Overall, in the embodiment shown, the frame 14 comprises, parallel to one another, two plates 18, 19, one upper, the other lower, which have the same generally rectangular outline, and which, in their angles, are braced to each other by legs 20, Figures 4, 5 and 6.

 These legs 20, in practice simple flanges, project protruding ears 21 by which the assembly is attached, and clamped in an adjustable manner in height, on the feet 15.

 The plates 18 and 19 are further connected to each other, at their periphery, by cover elements 22, made of sheet metal or the like, which are suitably attached, for example by screwing, to the legs 20 which brace them. , and which close laterally, on its edge, the parallelepiped volume that they delimit.

 In correspondence with one another, the plates 18, 19 are each hollowed out, in their central zone, with an opening 24, which in practice has a generally rectangular configuration, at the contour of the large base of the handling tanks 11 .

 In the embodiment shown, this aperture 24 has, on either side of its central part 25, which forms the current part thereof, enlarged ends 26.

 These enlarged ends 26 are provided for the case where the handling bins 10 to be treated are themselves provided, at their ends, with handles extending laterally over their own bulk.

 Anyway, thus hollowed out with a hole 24, the plates 18 and 19 have the overall shape of frames.

 On two, opposite, at least, the sides of their aperture 24, they are connected to each other by two cheeks 28A, 28B, which, parallel to each other, extend generally perpendicular to their planes overflowing on either side of them.

 In the embodiment shown, these cheeks 28A, 28B affect only the longer sides of the openings 24, being limited moreover to only the middle part, of lesser width, 25, of these.

 They are applied to the corresponding edges of the plates 18, 19, for example being attached by brackets 29 to the first of these, as shown, FIGS. 3 and 4.

 At their upper part, above the upper plate 18, the cheeks 28A, 28B have their ends which widen one with respect to the other, in the manner of a hopper, by moving apart oblique to one another.

 At its lower part, below the plate 19, the cheek 28A extends widely beyond the cheek 28B, and it alone has an end which, like the previous ones, extends obliquely, but which, conversely to these, goes closer to the cheek 28B in the embodiment shown.

 Overall, the cheeks 28A, 28B form, vertically, a chimney.

 More specifically, by their upper part, they form a store 30, which is adapted to receive in stack the handling bins 10 to be distributed, as shown diagrammatically in FIG. 1, and in which these handling bins 10 are called to walk by simple gravity, and, by their lower part, they form a discharge chute 32, suitable for guiding, in their fall, handling bins 10 successively released from the stack thus initially put in place in the magazine 30.

 Of course, for the constitution of such a magazine 30 and such a discharge chute 32, it can be associated, laterally, with the outline of the aperture 24 of the plates 18 and 19, guide plates.

 Anyway, at the base of the store 30, between it and the discharge chute 32 which immediately follows, the distributor 13 according to the invention comprises, between the plates 18 and 19 of its frame 14 , a drawing and separation device 33, which is capable of detaching, one by one, in a controlled manner, from the stack of overlying handling bins 10, that of these handling bins 10 which is the basis of this stack, and to release this tray while retaining the rest of said stack.

 According to 1-invention, this drawing and separation device comprises, distributed around the magazine 30, a plurality of rollers 35, forming cams, all of which are rotatably mounted, synchronously around an axis parallel to said magazine 30.

 In the embodiment shown, four rollers 35 are thus provided, namely two rollers 35A established parallel to each other, and at a distance from each other, on a first side of the magazine 30, and , more precisely, on the side of the aperture 24 of the plates 18, 19 with which the cheek 28A is associated, and two rollers 35B established parallel to one another, at a distance from each other, and in correspondence to the preceding ones, on the other side of the magazine 30, and, more precisely, on the side of the aperture 24 of the plates 18, 19 with which the cheek 28B is associated.

 In practice, by at least a portion of their outer part, or rim, these rollers 35 protrude into the magazine 30, between the cheeks 28A, 28B, by means of recesses 36 provided for this purpose therein.

 Each of the rollers 35 thus implemented is carried by a shaft 38, which extends from a plate 18, 19 to the other, being mounted so as to rotate with respect thereto, and on which it is fixed both axially only angularly, and therefore in rotation.

 On such a shaft 38, at the base of the latter is also wedged in rotation a pinion 39, FIGS. 1, 2 and 4.

 For the synchronism sought, the pinions 39 on which the rollers 35 are thus each individually locked in rotation all mesh with the same chain 40 with which also mesh, between the pinions 39, intermediate pinions 41, and, at the angles of the plates 18, 19, return gears 42.

 In the embodiment shown, the chain is thus closed in an endless loop, and one of the intermediate sprockets 41 is a drive sprocket, this intermediate sprocket 41 being set in rotation, as well as in translation, on the output shaft 43 of a geared motor drive unit 44, FIG. 3.

 Alternatively, the chain 40 could be coupled, at one of its ends, to the piston of a double-acting cylinder, and, at the other of its ends, to a winding member.

 Anyway, preferably, and as shown, at least one of the return pinions 42 forms a tensioning pinion, this return pinion 42 being for this purpose carried by a bracket 45 mounted adjustable in position on the lower plate 19 while being lockable in position thereon, FIG. 6.

 The corresponding methods are those of skill in the art and will therefore not be described in detail here.

 According to the invention, each of the rollers 35 has, on its periphery, to form a cam, on the one hand, transversely with respect to its axis, and stepped axially with respect to each other along the latter, two separate retaining shoulders 46, 48, one upper, the other lower, which each extend only over a portion of the circumference, being circumferentially alternating with respect to each other, and which are l one and the other oriented towards the upper end of the magazine 30, and, on the other hand, oriented in the opposite direction, a helical ramp 50.

 In practice, in the embodiment shown, the upper 46 and lower 48 retaining shoulders thus presented by a roller 35, and for example the roller 35B shown in isolation in FIG. 9, as well as its belicoidal ramp 50, belong jointly , to a boss 51, which, projecting from the cylindrical lateral surface 52 forming the running surface of the outer part, or rim, of such a roller 35, extends generally in a helix between the upper end edges 53 and lower 55 thereof, said retaining shoulders 46, 48 themselves forming, each for their part, the upper edge of such a boss 51, while said helical ramp 50 forms the lower edge.

 Laterally, the boss 51 itself forms a cylindrical surface 54, coaxially with respect to the cylindrical surface 52 on which it projects.

 In practice, the upper retaining shoulder 46 of a roller 35 is level with its upper edge 53, while its lower retaining shoulder 48 extends between its upper 53 and lower 55 sections.

 In practice, too, each of the upper 46 and lower 48 retaining shoulders of a roller 35 extends substantially over 1809.

 However, in the embodiment shown, the ends 56 of the upper retaining shoulder 46 are tapered, being directed circumferentially towards one another.

 It is, as well, its upstream end 56T relative to the direction of rotation of the rollers 35, as indicated by the arrow F1 for one of them in FIGS. 10, as well as its downstream end 56L.

 Given the tapered ends 56 thus presented by the upper retaining shoulder 46 of such a roller 35, this upper retaining shoulder 46 extends over an arc of a circle slightly greater than 180 ° in the embodiment shown.

 In practice, to form the thus tapered ends 56 of its upper retaining shoulder 46, the boss 51 of a roller 35 is tangentially connected, by a cutaway 57T, 57L, to its cylindrical surface 52, to each of the ends of said shoulder upper retainer 46.

 On the other hand, that at least, 58T, of the ends of the lower retaining shoulder 48 of a roller 35 which is upstream relative to the direction of rotation indicated by the arrow F1 in FIGS. 10 is straight, along a radial by relative to the axis of such a roller 35.

 For the constitution of such a straight end 58T for the lower retaining shoulder 48, the boss 51 of a roller 35 is connected by a radial plane 59T to its cylindrical surface 52 at the relevant end of this lower retaining shoulder 48, perpendicularly, therefore, to said cylindrical surface 52.

 Relative to the direction of rotation of the rollers 35, as indicated by the arrow F1 for one of them in FIGS. 10, the upstream end 58T of the lower retaining shoulder 48 is slightly upstream relative to the 'downstream end 56L of the upper retaining shoulder 46 taking into account the tapered configuration of the latter.

 In practice, the radial plane 59T circumferentially delimiting the upstream end 58T of the lower retaining shoulder 48 passes through the edge along which the cutaway 571 laterally delimiting the downstream end 56L of the upper retaining shoulder 46 intersects the cylindrical surface 54 of the boss 51.

 Given the cutaway 57T laterally delimiting the upstream end 56T of the upper retaining shoulder 46, the downstream end 58L of the lower retaining shoulder 48 is also tapered, in the embodiment shown, this downstream end 58L being delimited by this cutaway 57L, on the side of the axis of a roller 35, and by the cylindrical lateral surface 54 of the boss 51 thereof, on the opposite side.

 As for the helical ramp 50, it extends over 180 in the embodiment shown.

 Its downstream end 59L relative to the direction of rotation of the rollers 35, as marked by the arrow F1 for one of them in FIGS. 10, is substantially perpendicular to the corresponding downstream end 56L of the shoulder upper retainer 46.

 In practice, this helical ramp 50 is cant, its edge, along the cylindrical surface 54 of the boss 31 of a roller 35 being at a level higher than that of its edge along the cylindrical surface 52 forming the current surface. of the outer part of such a roller 35.

 According to the invention, at least one of the rollers 35 thus formed is mounted floating transversely relative to its axis.

 In the embodiment shown, this is only the case for the two rollers 35B associated with the cheek 28B of the magazine 30.

 They are therefore rollers mounted on the same side of the latter.

 In the embodiment shown, at each end of such a roller 35B there intervenes, between itself and its shaft 38, a joint with crossed grooves 60.

 Such a joint with crossed grooves 60, of the type of those commonly known as OLDHAM joints, comprises, overall, successively axially, three blocks, namely, two end blocks 61, 63, and a middle block 62, FIGS. 7 to 9.

 The end block 61 is locked in rotation on the shaft 38, at the corresponding end thereof.

 The extreme block 63 is wedged on the roller 35B concerned.

 In practice, in the embodiment shown, it is integral with this roller 35B, being integral with it.

 More specifically, the end block 63 is formed by the bottom of a recess in a bowl 64, which, provided axially at the corresponding end of such a roller 35B, allows the housing therein of the middle block 62 and at least part of the other extreme block 61.

 Anyway, the middle block 62 is mounted movable relative to the end block 61 in a first direction and it is mounted movable relative to the end block 63 in a second direction orthogonal to the previous one.

 Crossed grooves are provided for this purpose between these various blocks 61, 62, 63.

 In practice, the middle block 62 is in the form of a washer, with, projecting on one of its faces, aligned in a first direction, a boss 65, by which it meshes with a groove 66 formed at this point. effect on the underside of the upper end block 61, and, projecting from its other face, and aligned in a second direction orthogonal to the previous one, a boss 67, by which it meshes with a groove 68 provided for this purpose on the face upper end block 63, at the bottom of the recess 64 of the roller 35B concerned.

 In the embodiment shown, and in particular for the passage of the shaft 38, each of the bosses 65, 67 that the middle block 62 thus presents are split into two half-bosses, and these two half-bosses are slightly offset transversely l 'one over the other.

 In cooperation with the blocks 61, 62, 63 thus formed, there are provided elastic return means which, interposed between the middle block 62 and the end blocks 61, 63, permanently urge this middle block 62 towards a middle position rest for which, in practice, it is generally centered with respect to the previous ones.

 In the embodiment shown, these elastic return means are constituted by springs, of the coil spring type.

 There are thus, for the upper boss 65 of the median block 62, two springs 70, which, passing through, parallel to one another, the half-bosses constituting it by means of bores 71 formed in these half-bosses, relate to bosses 72 provided for this purpose on the underside of the upper end block 61, said springs 70 themselves bearing on plugs 73 reported by screwing on the corresponding end of said holes 71, FIGS. 8 and 9.

 Similarly, there are, for the lower boss 67 of the middle block 62, perpendicular to the previous springs 70, two springs 75 capable of cooperating in abutment with bosses 1 not visible in the figures, provided for this purpose on the bottom of the recess 64 of the roller 35B concerned, said springs 75 passing through holes 76 for this purpose made in said lower boss 67 and bearing on plugs 77 brought by screwing to the concerned end of these holes 76.

 The rollers 35A, for their part, are massive, and they are each directly wedged on their respective shafts 38, FIG. 4.

 But their outer part, or rim, has an identical constitution, with retaining shoulders 46, 48 and helical ramp 50, to that described above.

 By construction, those, 35A or 35B, of the rollers 35 thus engaged with the chain 40 which are situated on the same side of the 3D store have the same angular orientation around their respective shafts 38, this angular orientation being diametrically opposite of from one side to the other of said store 30.

 In other words, the rollers 35A have an angular orientation around their respective shafts 38 diametrically opposite to that of the rollers 35B.

 It will be assumed that, as shown diagrammatically in FIGS. 11, at the start of a cycle a stack of handling bins 10 is present in the magazine 30 of the distributor 13 according to the invention.

 By the rim 11 of that of these tanks 10 which is at its base, this stack then rests on the rollers 35, forming cams, present according to the invention at the base of this magazine 30, and, more precisely, on the shoulder upper retaining 46 of these rollers 35, Figure IIA.

 During the rotation of the rollers 35, as shown diagrammatically by the arrow F1 in FIGS. 10 and by the arrow F2 in FIGS. 11, the upper retaining shoulder 46 of each of them runs circumferentially, from its downstream end 56L to its upstream end 56T, in contact with the rim 11 of the tank 10 present at the base of such a stack, until the latter escaping from the upstream end 56T in question of such an upper retaining shoulder 46 , the stack of trays 11 falls, as a whole, by a notch, by simple gravity, in the magazine 30, and comes to bear on the lower retaining shoulder 48 of the rollers 35, starting with the downstream end 58L d such a lower retaining shoulder 48, FIG. 11B.

 From this instant it is the lower retaining shoulder 48 of the rollers 35 which runs circumferentially, from its downstream end 58L to its upstream end 58T, in contact with the rim 11 of that of the tanks 10 present at the base of the stack being processed.

 However, slightly before the upstream end 58T of the lower retaining shoulder 48 in turn escapes such a rim 11, and taking into account the arrangements described above, the boss 51 of the rollers 35 is inserted between this rim 11 and the rim 11 of the immediately overlying container 10, FIG. 11C, so that, with the exception of that present at its base, the stack of containers 10 therefore rests again on the upper retaining shoulder 46 rollers 35, Figure 11C.

 When the rim 11 of the container 10 initially present at the base of this stack escapes the upstream end 58T of the lower retaining shoulder 48 of the rollers 35, this container 10 is free to fall, by gravity, into the chute 32 forming following the magazine 30, as shown diagrammatically by an arrow F3 in FIG. 11C, and, in practice, it is forced to do so by the helical ramp 50 of the rollers 35, the latter gradually applying to it, in the direction sought, an extraction effort capable of ensuring effective dislocation with respect to the overlying tray 10.

 A new work cycle can then begin for the rollers 35.

 Of course, the present invention is not limited to the embodiment described and shown, but encompasses any variant.

 In particular, if, in the foregoing, it has been assumed that the rollers 35A formed massive blocks wedged on their respective shafts 38 without the possibility of transverse displacement relative to these, these rollers 35A could as well be mounted floating, like the rollers 35B.

 But, for the desired absorption of the most frequent tolerances, experience shows that it is generally sufficient to be satisfied with rollers mounted floating on one and the same side of the store concerned.

 Anyway, and for at least some applications, it may suffice, for the floating mounting of which thus are preferably the subject at least some of the rollers used, to interpose, between the shaft such a roller and the frame of the assembly, at at least one of the ends of such a shaft, and taking into account the bearings possibly used elsewhere, a ring made of elastic material.

Claims (18)

 1. Distributor of handling bins, of the type comprising a magazine (30), which is adapted to receive in stack the bins (10) to be distributed and in which these are called to travel by gravity, and at the base of said magazine (30), a drawing and separation device (33) which is capable of detaching, one by one, in a controlled manner, from such a stack7 that of these trays (10) which is at the base thereof, and to release it while retaining the remainder of said stack, characterized in that said drawing and separation device (33) comprises, distributed around said magazine, a plurality of rollers (35) forming cams, all of which are rotatably mounted, synchronously, around an axis parallel to the latter, and each of which has, on its periphery, on the one hand, transversely with respect to said axis, and stepped axially with respect to one another along that -this, two separate retaining shoulders (46, 48), one upper, the other lower, which each extend only over one inch. circumference, being circumferentially alternating with respect to each other, and which are both oriented towards the upper end of the magazine, and, on the other hand, oriented in opposite direction, a helical ramp (50).  2. Dispenser according to claim 1, characterized in that the upper retaining shoulder (46) of a roller (35) is level with its upper edge while its lower retaining shoulder (48) extends between its upper and lower edges.  3. Distributor according to claim 1, characterized in that the upper (46) and lower (48) retaining shoulders of a roller (35) as well as its helical ramp (50) jointly belong to a boss (51), which, projecting from a cylindrical lateral surface (52) forming the current surface of said roller (35), extends generally in a helix between the upper and lower edges thereof, said retaining shoulders (46, 48) forming the upper edge of said boss and said helical ramp (50) its lower edge.  4. Dispenser according to claim 1, characterized in that the ends (56) of the upper retaining shoulder (46) of a roller (35) are tapered, being directed circumferentially towards one another.  5. Distributor according to claims 3 and 4, taken together, characterized in that the boss (51) of a roller (35) is connected tangentially, by a cutaway (57), to its cylindrical surface (52), each end (56) of its upper retaining shoulder (46).  6. Distributor according to claim 1, characterized in that that at least (58T) of the ends (58) of the lower retaining shoulder (48) of a roller (35) which is upstream relative to its direction of rotation is straight, along a radial with respect to its axis.  7. Distributor according to claims 3 and 6, taken together, characterized in that the boss (51) of a roller (35) is connected by a radial plane to its cylindrical surface (52) at the relevant end of its shoulder lower retainer (48).  8. Distributor according to claim 1 characterized in that each of the retaining shoulders (46, 48) of a roller (35) extends substantially over 180-.  9. Distributor according to claim 1, characterized in that, relative to the direction of rotation of a roller (35), the upstream end (58T) of the lower retaining shoulder (48) of such a roller ( 35) is slightly upstream relative to the downstream end (56L) of its upper retaining shoulder (46).  10. Distributor according to claim 1, characterized in that the helical ramp (50) of a roller (35) extends over more than 180.  11. Distributor according to claim 1, characterized in that that (59L) of the ends of the helical ramp (50) of a roller (35) which is downstream relative to its direction of rotation is substantially perpendicular to the corresponding downstream end (56L) of its upper retaining shoulder (46).  12. Distributor according to claim 1, characterized in that the helical ramp (50) of a roller (35) is cant.  13. Distributor according to any one of claims 1 to 12, characterized in that at least one of the rollers (35) is mounted floating transversely with respect to its axis.  14. Distributor according to claim 13, characterized in that, at each of the ends of the floating roller (35), there intervenes, between itself and its shaft (38), a joint with crossed grooves (60), comprising three blocks, namely two end blocks (61, 63), one of which is wedged on said shaft (38) and the other on said roller (35), and a middle block (62), which is mounted movable relative to one of the two others in a first direction and with respect to the other of these in a second direction orthogonal to the previous one, in cooperation with elastic return means (70, 75) which, interposed between said median block (62) and said extreme blocks (61, 63), permanently urge this middle block (62) in the direction of an average rest position.  15. Distributor according to claim 14, characterized in that the one (63) of the end blocks of a joint with crossed grooves (60) which is wedged on the roller (35) is integral with it.  16. Dispenser according to any one of claims 13 to 15, characterized in that only the rollers (35B) located on the same side of the magazine (30) are mounted floating.  17. Distributor according to any one of claims 1 to 16, characterized in that the separation and drawing device (33) comprises two rollers (35A) on a first side of the magazine (30), and two rollers (35B ) on the opposite side.  18. Distributor according to any one of claims 1 to 17, characterized in that all the rollers (35) are each individually locked in rotation on pinions (39) which all mesh with the same chain (40) with which also meshes a motor pinion (41).