Abstract:
This machine comprises a hopper ( 2 ) for storing empty straws, a station ( 5 ) for filling the straws, and a transfer device ( 3 ), such as a rotary barrel, which is provided with notches for receiving and holding the straws (p) and with which straws removed from the hopper are conveyed to the filling station ( 5 ); it is designed to process at least two categories of straws of different diameters, notches being subdivided into at least two distinct series that can be used selectively, the elements ( 90 ) of one of the two series being designed to adapt to straws of large diameter, while the elements ( 91 ) of the other series are designed to adapt to straws of small diameter. Machine that can be used in more than one way in the packaging of semen for artificial insemination, particularly of cows.

Description:
The present invention relates to a machine for filling artificial insemination straws with semen. 
     The semen is animal semen, bovine for example, such as diluted bull sperm. 
     BACKGROUND OF THE INVENTION 
     More precisely, the invention relates to the type of machine comprising a hopper for storing empty straws, a filling station for straws, as well as a transport device provided with elements for receiving and holding the straws and capable of conveying straws taken from the hopper to present them at the filling station. 
     Machines of this type are described for example in documents FR 2,700,313 and U.S. Pat. No. 4,478,261, according to which the transporter is a fluted rotating barrel, and CH 533,542, according to which the transporter is constituted by several likewise fluted mobile endless bands. 
     The grooves ensure reception of the straws coming from the hopper, their transfer to the filling station, and being held during filling. 
     The transporters function step by step, such that a straw, or a group of straws, is immobilised at the filling station during this operation. 
     Such a machine is generally adapted to filling straws whereof one of the two ends, known as distal, is blocked by a stopper initially permeable to air, but capable of becoming watertight when it is soaked in a liquid. The stopper is made for example from polyvinyl alcohol powder intercalated between two buffers of fibrous material. 
     The filling station comprises means for introducing semen at the opposite end, or “proximal” of the straws, as well as means for suctioning the semen via their distal end, through the porous stoppers. 
     On contact with the semen, or a certain quantity of non-spermicidal intermediary liquid, in keeping with the ideas of FR 2,810,535, the stopper hardens and becomes impermeable, tightly blocking the distal end. 
     Located downstream of the filling station is a closing station for the proximal end of the straws, this closing generally being completed by ultrasound welding. 
     After filling and closing, the straws are released from the transporter and collected in a receptacle ad hoc. 
     They are then frozen for later use. 
     Straws being used currently are fine cylindrical tubes, made of flexible and transparent plastic, such as PVC (polyvinyl chloride) in particular. 
     The majority of straws available on the market has a length of 133 mm, and there are two categories of straws of differing diameters, specifically straws having a diameter of the order of 2 mm (in practice 1.95 mm) and straws having a diameter of the order of 3 mm (in practice 2.85 mm). 
     BRIEF SUMMARY OF THE INVENTION 
     A main aim of the invention is to propose a machine of the type described hereinabove of polyvalent character, which is capable of processing both these categories of straws, without the passage from one to the other of the categories requiring significant intervention from the operator. 
     Another aim of the invention is to propose a compact, reliable machine, easy to use and capable of running at a high rate. 
     To this end, and according to the invention, this machine is adapted to process at least two categories of straws having different diameters, the elements for receiving and holding the straws with which the transporter is equipped being subdivided into at least two distinct series able to be used selectively, the elements of one of the two series conforming to adapt to straws of large diameter, whereas the elements of the other series conform to adapt to straws of small diameter. 
     It should be mentioned that a feed device for a machine for filling tubes is already known from document FR 2,564,064. This is a device with chains, capable of transporting tubes of different diameters. For this purpose, the transport chains comprise reception elements constituted by a pair of wafers having variable clearance. When the tube diameter is changed, it is necessary to regulate this clearance by playing on the relative positions of two adjacent chains. 
     In this known embodiment, all the receiver elements are utilised for transport, irrespective of the diameter of the relevant tubes. 
     According to other advantageous and non-limiting characteristics of the invention: 
     said transporter is endless, and each series of elements of a given category is composed of several groups formed from a certain number of adjacent elements, the groups of a given category alternating with those of the other, the filling station being designed to simultaneously fill the batch of straws supported by a group of adjacent elements; 
     the groups of the two categories have the same number of elements; 
     said elements are grooves or notches in which the straws are fitted; 
     the axle spacing between the grooves or the notches is constant over the entire length of the transporter, and independent of its category; 
     the machine comprises an electric motor controlled by a computer and operating step by step, capable of driving the transporter with successive and repeated phases of advance, at a low pitch, then at a high pitch, of an amplitude multiple that of the low pitch, then a stop phase; 
     the transporter is a rotating barrel placed at the hopper outlet and constituted by two coaxial discs integral with one another and bearing at their periphery said elements for receiving and holding the straws; 
     said hopper comprises means for distributing the straws one by one, which are synchronised with the advance of the transporter; 
     said hopper is removable and comprises identification means of the category of straws it contains, whereas the machine is equipped with detection means for cooperating with said identification means as the hopper is being put in place, so as to automatically determine the category of the straws to be treated; 
     said detection means are connected to a control and command circuit of the drive motor of the transporter, so as to index the position of the latter on startup, such that the elements for receiving and holding the straws which are adapted to their diameter are active, while the others are inactive; 
     the machine is adapted to filling straws whereof one of the two ends, the distal end, is blocked by an initially porous stopper, but capable of becoming watertight when it is soaked in a liquid, and this machine comprises a station placed upstream of the filling station, this station being adapted for introducing a small quantity of non-spermicidal and non-adherent liquid into the straws, by their opposite end, the “proximal” end; 
     said filling station comprises means for introducing semen at said proximal end of the straws, as well as means for suctioning semen and, if required, the small quantity of liquid introduced previously into the straws, this suctioning being carried out via their distal end through the stoppers; 
     the machine comprises an ultrasound welding station of the proximal end of the straws, located downstream of the filling station; 
     this welding station comprises a sonotrode connected to an anvil, provided with additional indentations for gripping the proximal end of the straws, these indentations being subdivided into two alternating groups respectively adapted to the welding of small-diameter straws and of large-diameter straws of, control means being provided for shifting the sonotrode and the anvil together to make one of the two groups of indentations active and the other inactive, respective to the category of straws to be processed; 
     the machine, which comprises a transporter consisting of a rotating barrel placed at the hopper outlet and constituted by two coaxial discs integral with one another, and bearing at their periphery notches for receiving and holding the straws, is provided with two fixed ramps profiled in such way that one ensures extraction of the proximal end of the straws from the notches of one of the discs, just before the straws arrive at the welding station, and the other ensures extraction of the distal end of the straws from the notches of the other disc after the straws have left the welding station, such that the filled and welded straws then drop into a receptacle; 
     said transporter is a rotating barrel placed at the hopper outlet and constituted by two coaxial discs integral with one another, whereof the mutual clearance is substantially less than the length of the straws, and each bearing at its periphery 64 notches for receiving and holding the straws, each notch comprising a substantially semi-circular base wall and a flared mouthpiece facilitating centring of the straws, said notches being subdivided into two series of 32 notches adapted to different diameters, specifically large notches for receiving straws having an external diameter of the order of 3 mm, and small notches for receiving straws having an external diameter of the order of 2 mm, each series of notches being distributed into eight groups of 4 notches, and the groups of large notches alternating with the groups of small notches, the axle spacing between two adjacent notches being constant over the entire periphery of the disc and independent of the category of notch concerned, this axle spacing being advantageously of the order of 10 mm. 
     Other characteristics and advantages of the invention will emerge from the following description of a preferred embodiment of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
       This description is given in reference to the attached diagrams, in which: 
         FIG. 1  is a general frontal view of the machine; 
         FIGS. 2 and 3  are views in vertical section according to the planes referenced respectively II and III in  FIG. 1 ; 
         FIG. 4  is a view in horizontal section according to the plane referenced IV-IV in  FIG. 1 ; 
         FIG. 5  is a view in vertical section according to the plan referenced V-V in  FIG. 1 ; 
         FIG. 6  is a general plan view of the machine; 
         FIG. 7  is a detail showing a side elevation of the hopper put in place on the machine; 
         FIGS. 8 and 9  are detailed sectional views according to the broken plane VIII-VIII of  FIG. 7 , relating to two hoppers containing straws of different categories; 
         FIG. 10  is a schematic view of the introduction station of a non-spermicidal liquid into the straws; 
         FIG. 11  is a schematic view of the station serving to fill the straws with semen; 
         FIG. 12  is a detail which illustrates the ultrasound welding tools of one end of the straws; 
         FIG. 13  is a sectional view according to the plane XIII-XIII of  FIG. 12 ; 
         FIG. 14  is a side elevation, in vertical section, of a hopper in place on the machine, this view intended to show the blocking means of the outlet channel of the hopper; 
         FIG. 15  is a sketch illustrating the configuration of the barrel equipping the machine; 
         FIG. 16  is a partial view, on an enlarged scale, which illustrates the periphery of a notched disc making up this barrel; 
         FIGS. 17 and 17A  are details illustrating insertion of a large-diameter straw into a notch, respectively during and after its being put in place; 
         FIGS. 18 and 18A  are details illustrating insertion of a small-diameter straw into a notch, respectively during and after its being put in place; 
         FIGS. 19 ,  19 A and  19 B are sketches illustrating the receiving, by the barrel, of small-diameter straws at the hopper outlet. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The machine  1 , such as illustrated especially in  FIGS. 1 to 6 , comprises a certain amount of apparatus and equipment whereof only the main ones relating directly to the present invention will be described so as not to unnecessarily complicate the description. 
     It comprises a fixed frame  10  for supporting a removable and interchangeable hopper  2  containing straws, a rotating transporter barrel  3 , a station  4  for introduction of a non-spermicidal liquid to the straws, a station  5  for filling the straws with semen, an ultrasound welding station  6  for one end of the straws and a receptacle  100  for collecting the filled and welded straws. 
     The hopper  2  designed to contain straws to be filled has the general shape of a rectangular parallelepiped box, open at the top, while the base of which is embodied by a pair of inclined parallel rectilinear guides (flat rods)  20 . The width of this box is very slightly greater than the length of the straws the latter being placed in batches into the hopper on the guides  20 , perpendicularly to the latter. 
     In  FIG. 14 , reference numeral  26  designates two transversal rods serving as cross bars for the guides  20  which ensure they are fixed to the side walls  22  of the hopper. 
     Mounted at the front of the hopper (to the left in  FIG. 14 ), is a pair of vertical flat rods  21  each placed in the same vertical plane as one of the guides. Each rod  21  is articulated in its upper part about an axis  210  borne by a wall  22 . A lug/hole guiding system  212  limits the range of this articulation. In its central zone, the lever  21  is fitted with a forward facing shoulder  211 . 
     The front end portion of each guide  20  is more inclined than its main part, and the lower end portion of each lever  21  is chamfered, such that its lower edge has the same inclination. 
     When the hopper is withdrawn from the machine, the lever  21  is inclined slightly to the rear relative to the vertical, under the effect of its own weight, and its lower chamfered edge comes to rest against the front portion of the guide  20 . 
     This prevents the straws (which have a tendency to descend along the rods) from being taken out of the hopper. 
     However, for a hopper to be placed on the machine, it is positioned between two lateral cheeks  11  solid with the frame  10 . Outside each of its side walls  22 , the hopper  2  is fitted with a pair of centring and holding lugs  220 ,  221 , adapted to lodge in flared notches, open to the top, made in said cheeks  11 . 
     In this way, after it has been put in place, the hopper is retained by these lugs which are supported at the base of the notches, in a well-defined position, illustrated in  FIG. 7 . 
     During this placing, the two shoulders  211  come to be supported against the upper edge of a transversal partition  112  solid with the frame, the effect of which is to slightly correct the levers  21 , and release the hopper outlet; in fact, the levers  21  are vertical and their chamfered lower edge is parallel to the front part of a guide  20 , making a small channel  200  in which the straws can descend and be placed against one another in single file. 
     The two channels  200  form an exit spout for the straws. 
     However, the exiting of the straws is now controlled by a pair of levers  7 , connected by cross bars, each articulated about a transversal axis  700  solid with the frame; they have a free upper end  701  in the shape of a finger. 
     A control member  70 , such as a jack or an electromagnet, is connected to a crossbeam which joins the lower ends of this set of levers and can impart to them an oscillating movement, symbolised by the double arrow Y in  FIG. 14 , to make them pivot together in one direction or the other about the axis  700 . 
     Lug/hole guide systems  702  limit the range of this articulation. 
     Each lever  7  is positioned towards the interior of the hopper, relative to a guide  20 , quite close to the latter. 
     According to the state of the control member  70  (retracted or extended), the fingers  701  block or, on the contrary, release the two exit channels  200  of the hopper. 
     This control member is controlled such that the straws can be released individually only (one by one), at a determined frequency. 
     One of the side walls  22  of the hopper is fitted, at the level of its lower rear angle, on its inner face, with a pin  25  acting as identification means of the category of the straws which it contains. 
     As is evident from  FIGS. 8 and 9 , the position of the pin, designated by reference numeral  25 ′ in  FIG. 9 , is different to that of the pin  25  of  FIG. 8 . 
     In the embodiment illustrated, they are offset in height. 
     One position is made use of when the hopper  2  contains small-diameter straws (of the order of 2 mm); the other position is utilised when the hopper contains large-diameter straws (of the order of 3 mm). 
     A detection device  8  comprising a pair of detectors  80 ,  81  borne by a support  82  is mounted on the frame  10 . These are fibreoptic detectors, placed in opposite positions likely to be occupied by the pins  25  and  25 ′ respectively. 
     Optical cables  800 ,  810  are connected to a command and control circuit of the machine to address a corresponding signal to it; this circuit is therefore informed automatically of the category of the straws to be processed. 
     Machine  1  is equipped with a transporter  3  which consists of a rotating barrel constituted by a pair of coaxial discs  30 ,  31 , having a horizontal and transversal axis  300 . They are borne by a hub  301  driven in rotation, via a transmission belt  302 , by an electric motor M (see especially  FIGS. 3 and 4 ). 
     This motor is a motor operating step by step, with variable and adjustable speed and amplitude. 
     As is evident in particular from  FIGS. 2 and 3 , in which the direction of rotation of the barrel is symbolised by the arrow W, the upper ascending zone of this barrel is substantially tangential to the outlet of the channels  200 . 
     These same figures show, in cross-section, a transversal bar, square in cross-section and with truncated angles, placed in the lower zone of the hopper  2  between the guides  20 . This bar is mounted to rotate; its function is to stir the straws contained in the hopper to properly align them with the inlet of the exit channels  200 . 
     As is evident from  FIG. 1 , in which the straws bear reference numeral p, the pair of discs  30 - 31  is offset laterally relative to the vertical plane of symmetry of the hopper  2 . 
     Also, their mutual clearance is substantially less than the width of the hopper (and therefore than the length of the straws p). 
     Due to this arrangement, one of the ends of the straws, to be called “distal” (to the left in  FIG. 1 ) does not go beyond, or only slightly so, the disc  31  holding it in place; however, their other end, to be called “proximal” (to the right in  FIG. 1 ) goes considerably beyond the disc  30  holding it in place. 
     The two discs  30  and  31  are identical. 
     Their plane is perpendicular to the axis of the straws contained in the hopper  2 . 
     They are provided at their periphery with a plurality of evenly spaced notches  9 . 
     As is evident from  FIGS. 15 and 16  there are two series of notches. 
     In the illustrated embodiment there are 64 notches in total which are subdivided into two series of thirty-two notches adapted to different diameters, specifically large notches  90  for receiving straws p having an external diameter of the order of 3 mm, and small notches  91  for receiving straws p having an external diameter of the order of 2 mm, each series of notches being distributed in eight groups of four notches. 
     The groups of large notches  90  alternate with the groups of small notches  91 , and the axle spacing between two adjacent notches is constant over the entire periphery of the disc and independent of the category of the notch concerned. 
     The angular spread between the axes of the notches is accordingly 5.625 degrees. 
     The axle spacing value (developed length of arc of circle) is for example 10 mm. 
     By way of indication, this corresponds to a disc diameter slightly over 200 mm. 
     It is understood that the two discs  30  and  31  are set tightly on their hub such that the groups of similar notches are in correspondence. 
     In  FIG. 15 , and in  FIGS. 19 ,  19 A and  19 B, thick and thin angular areas symbolise the groups of notches  90  and  91  respectively, with which one of the discs is provided, in this case the disc  30 . 
     Each angular area has the same developed length (length of arc) λ, whether it comprises small or large notches. 
     Each of the processing stations  4 ,  5  and  6  likewise has a width substantially equal to the value λ, as it is adapted to process all the straws lodged in the notches of an area. 
     The disc  30  is pierced with an orifice  300  which, during rotation of the disc, scrolls at each turn in front of a fixed sensor C, for example an inductive sensor. 
     The coinciding of the sensor C and of the orifice  300  corresponds to a “zero” or indexed position of the disc  30 , such as a given site of the disc, marked R in  FIG. 15 , opposite the outlet channel  200  of the hopper  2 . 
     It is supposed that this site corresponds to the first notch of a group of small notches. 
     The station  4  is located at a developed distance (that is, a length of arc) λ from this site R, whereas the stations  5  and  6  are located at a developed distance  3  λ and  5  λ respectively from the latter. 
     As is evident in  FIGS. 17 and 18 , the large and small notches  90 ,  91  have a flared inlet  901 , respectively  910 , which facilitates centring and penetration of a large-diameter straw p 1  (arrow i) and, respectively, of a small-diameter straw p 2  (arrow j). They have a substantially semi-cylindrical base zone  901 , respectively  911 , capable of properly gripping and retaining the straw p 1 , respectively p 2  ( FIGS. 17A and 18A ). 
       FIG. 2  shows the presence of fixed ramps  72  (bordering discs  30  and  31 ), the role of which is to progressively push back each straw which has left the hopper to fit it into its receiving notch. 
     As is evident in particular in  FIG. 2 , the operating stations  4 ,  5  and  6  are placed respectively substantially at the level of the high part of the barrel, towards the middle of its descending upper part and towards the middle of its descending part. 
     The barrel successively leads a group of four straws, previously taken at the hopper outlet, to each of these stations then stops for a certain period, at least long enough for the longest operation of the three to be completed. 
     The operation executed at the station  4  is illustrated in  FIG. 10 . 
     A group of four straws p each held in a pair of notches  9  of the discs  30  and  31  is processed here simultaneously. 
     Their portion of distal end (to the left in the figure) is packed in the inside by a porous stopper b. 
     In keeping with the ideas of the already cited FR 2,810,535, which could be referred to if needed, with the aim of economising on semen, a small quantity of non-spermicidal and non-adherent liquid is injected at the opposite proximal end. 
     For this purpose, an injection head comprising an axially mobile slide is used, provided with four hollow needles  42 , each adapted to penetrate inside the proximal end of a straw p. This liquid L is contained in an appropriate vial  41 , integrated or not in the machine, and pressurised by means of a pressure source SP. 
     This pressure is relatively low, by way of indication of the order of 20 millibars (2000 Pa). 
     The vial  41  is connected to the needles  42  by means of flexible conduits  410 , via electrovalves  400 . 
     The double arrow F symbolises the reciprocal movement of the slide  40  for introducing the needles  42  into the straws and for withdrawing them once the desired dose of liquid has been deposited. 
     The volume of this dose is a function of how long it takes to open the electrovalves  400  and of the pressure used to extrude the liquid L. 
     The operation executed at the station  5  is illustrated in  FIG. 11 . 
     This station comprises two additional sets of tools located at the proximal and distal ends of the straws, whereof the references are marked respectively by the index a and b. 
     The proximal set of tools comprises an axially mobile slide  50   a , the movements of which are symbolised by the double arrow Ga. 
     This slide carries four hollow needles  52   a , each capable of penetrating without clearance (that is, airtight, or almost airtight) into the portion of proximal end of a straw p, in which a drop g of the liquid L has previously been deposited. 
     The semen S is contained in a container  51 , integrated or not into the machine, and connected to the needles  52   a  by means of flexible conduits  510   a  via devices for gripping the conduits, or clamps  511   a , actuated by electromagnet. 
     The distal set of tools similarly comprises an axially mobile slide  50   b , whereof its shifts are symbolised by the double arrow Gb. 
     This slide bears four hollow needles  52   b  each capable of penetrating without clearance (that is, airtight, or almost airtight) into the portion of the distal end of the straw p. 
     The needles  52   b  are connected by means of flexible conduits  510   b , via clamps  511   b  actuated by electromagnet, to a vacuum source SV. 
     The straws are filled by suctioning of the semen at the distal end through their stopper porous b. The semen S penetrates into each straw via the proximal end and progressively pushes the drop g back to the other end, such that it finally comes to soak the stopper b. 
     The value of the vacuum and the opening time of the clamps  511   a  and  511   b  are selected so as to optimise the time necessary for filling the straws. 
       FIGS. 12 and 13  represent a set of ultrasound welding tools for the proximal end of the straws, located at the station  6 . 
     This set of tools comprises a sonotrode  61  and an anvil  60 . 
     These two elements comprise two series of four additional indentations, one  610 A- 600 A intended for welding small-diameter straws p, the other  610 B- 600 B intended for welding large-diameter straws p. 
     The sonotrode  61  can be moved towards and away from the anvil  60  by means of an appropriate control member, such as a jack for example, as symbolised by the double arrow H, so as to crimp the end of the straw for welding it and for releasing it after welding. 
     The indentations of a given category (large or small) are spaced by a value e equal to pitch of the notches, 10 mm for example. 
     The two series alternate, such that the axle spacing between a small and a large indentation is equal to e/2, or 5 mm for example. 
     Due to this arrangement, it suffices to shift the pair of tools  60 - 61  vertically and together on a course of e/2 as a function of the category of the straws concerned so that the latter present correctly vis-à-vis the adequate group of indentations when they arrive at the station  6 . 
     It should be noted that the machine is provided with a pair of profiled ramps  150 ,  151  located on the edges of the discs  30 , respectively  31 , in the descending zone corresponding to this station  6  (see  FIG. 1 ). 
     The ramp  150  located to the proximal side is conformed such that it progressively withdraws the straws from their notch  9 , on the disc  30 , just before they arrive at the station  6 . They are therefore held only by their opposite end embedded in a notch of the disc  31 . 
     Due to this arrangement, the proximal part of the straws has a certain suppleness favouring proper centring in the indentations of the set of welding tools and improves the reliability of the operation. 
     The ramp  151 , as such, ensures subsequent extraction (after welding) of the distal end of the straws from the notches of the disc  31 , such that the straws are fully released and fall under the effect of gravity into the receptacle  100 . 
     A computer, referenced  83  in  FIG. 19 , controls functioning of the machine, in particular the command of the motor M rotating the barrel, the command of the actuating means  70  of the lever  7 , synchronising with rotation of the barrel, as well as the set of tools kept at the stations  5 ,  6  and  7 . 
     In reference to  FIGS. 19 ,  19 A and  19 B, the way in which the automatic indexing of the barrel as a function of the category of the straws concerned, and how the processing of the straws is carried out, will be explained. 
     It is assumed that at the outset the barrel is immobilised in any angular position. 
     The levers  7  occupy a position such that each of their ends  701 , symbolised by a segment in  FIG. 19 , blocks an outlet channel  200  of the hopper. 
     A hopper  2  packed with a batch of small-diameter straws p 2  is placed on the machine. 
     In this batch, the straws are oriented such that their distal end, fitted with a stopper, is turned to the side of the disc  31 . 
     The detector  8  recognises this “small diameter” category, and sends the computer  83  a corresponding information signal. 
     These are consequently the groups of small notches  91  which must be utilised to process this batch of straws. 
     If there is a need for it, the computer also commands displacement of the welding tools  61 - 60  so that they are placed in the position adapted to closing small-diameter straws. 
     When the motor M starts up, the computer controls the latter to have it rotate the disc  30  (and therefore the whole barrel), as symbolised by the arrow W 1  in  FIG. 19 , until the orifice  300  moves opposite the sensor C. 
     The motor is then temporarily stopped in the “zero” position of the disc. 
     Yet, in this position, illustrated in  FIG. 19  A, the mark R is in a position favourable for taking up straws p 2 , since it corresponds to the first notch of a group of four small notches. 
     The operation can then commence. 
     In a first phase, the computer controls the intermittent advance, at low pitch, of the barrel, as well as the alternative opening and closing of the valve  701 , such that four straws p 2  are placed one after the other in the first group of small notches. The fixed ramp  72  mentioned hereinabove ensures progressive but complete fitting of each straw in the notches. 
     This “low pitch” is equal to the value of the axle spacing between notches; it corresponds to a rotation of angle α (or 5.625°) of the barrel  3 . 
     In a second phase, the computer controls the closing of the valve  701  as well as the advance of the barrel  3 , at a high pitch. 
     This “large pitch” is equal to the value of the axle spacing λ of an area of notches; it corresponds to a rotation of angle 4α of the barrel  3 , or 22.5°. 
     During this phase, symbolised by the arrow W 2  in  FIG. 19B , the area of large notches not used passes empty under the hopper outlet  200 , whereas the group of four straws p 2  arrives at the station  4 , and positions itself there, each straw being placed vis-à-vis a needle  42 . 
     In a third phase, the motor M is stopped for a sufficient period so that the operation of introducing a drop of liquid L in each of the straws p 2  can be completed correctly. 
     This process comprising a small-pitch advance phase (with distribution of empty straws), a large-pitch advance phase, and a stop phase, is repeated a first time such that a fresh group of empty straws arrives at the station  4  and the group of straws processed at the station  4  arrives at the station  5 . 
     The operations in these two stations are completed simultaneously during the stop phase of the barrel. 
     The process is repeated for a second time such that a fresh group of empty straws arrives at the station  4 , the group of straws which have just been processed at the station  4  arrives at the station  5 , and the group of straws which have just been filled at the station  5  arrives at the station  6 . 
     The operations in these three stations are completed simultaneously during the stop phase of the barrel. 
     The process is repeated for a third time such that a fresh group of empty straws arrives at the station  4 , the group of straws which have just been processed at the station  4  arrives at the station  5 , the group of straws which have just been filled at the station  5  arrives at the station  6 , and the group of straws which have just been welded at the station  6  is ejected and collected in the receptacle  100 . 
     Cruise control is reached in this way, and this process is then repeated until the quantity of semen is exhausted, semen which originates from a given animal and contained in the container  51  and distributed at the station  5 . 
     By way of indication, a volume of semen corresponding to bull ejaculate fills between 400 and 550 straws approximately. 
     After the operation, new sterilised tools are substituted for the tools which have been in contact with the semen (needles, electrovalves and flexible conduits in particular) at the stations  4  and  5 . 
     The diameter of the new needles is adapted to the category of the new batch of straws to be processed. 
     In the event where the new straws are likewise of small diameter, the operation proceeds in the same way as that described hereinabove. 
     If large-diameter straws which the computer  83  recognises automatically due to the detector  83  are used, the computer modifies the positioning of the welding tools by a semi-pitch (e/2). 
     Also, the initial indexing of the barrel is modified. 
     From the position illustrated in  FIG. 19A  additional rotation corresponding to the angle of an area of notches, or 22.5°, is imparted to the barrel such that this is the first notch of an area of large notches moving vis-à-vis the outlet  200  of the hopper. 
     From this initial position, the process proceeds exactly as for the previous one, the areas of small notches (not used) this time filing past “empty” in front of the hopper outlet during the “large-pitch” advances of the barrel. 
     Reference numeral  73  in  FIGS. 2 and 3  designates a detector for straws leaving the hopper. 
     This can be for example a fibreoptic detector for detecting anomalies, in particular the unannounced non-distribution of a straw on the barrel, and supplies a corresponding signal to the computer  83 , which then causes the motor to stop immediately. 
     By way of example, this type of machine is capable of processing around 240 straws per minute. 
     It is understood that the number and arrangement of the notches are not necessarily the same as those used on the barrel described hereinabove. More than two series of notches of different sizes could be provided, for example three series of notches to allow processing of three categories of straws of different diameters. 
     Instead of being constituted by a pair of coaxial discs, the barrel could consist of a fluted cylindrical drum comprising two (or more) series of grooves of different width placed according to generatrices of the drum. 
     The transporter is not necessarily a barrel; it could especially be an endless fluted mat or a pair of endless notched belts.