TECHN ICAL FIELD OF THE INVENTION The present invention refers to a milk sampling device configured to be incorporated in a milking plant for enabling output of milk samples to be delivered to various test equipment. More precisely, the present invention refers to a milk sampling device according to the preamble of claim 1 .

BACKGROU ND OF THE INVENTION AN D PRIOR ART

When milking an animal in a milking plant comprising a large number of milking places, the milk from the animal may be collected in an end unit for each milking place, or possibly for several milking places. A milk pump is provided downstream the end unit for feeding the milk from the end unit to a common milk tank provided to collect the milk from all milking places of the milking plant. From the milk tank, the milk may then be delivered to the diary industry for further processing .

Before or during feeding of the mil k to the milk tank, milk samples may be taken for different tests regarding the quality of the milk, such as fat content, quantity of microorganisms (cell counting), etc. An example of a prior art milk sampling device is shown in EP 1 123 651 .

EP 1 123 651 shows a milk sampling device of the kind initially defined , which comprises a housing enclosing an inner space having a determined volume and config ured to house a determined quantity of milk. An inlet conduit is connected to the inner space for supplying milk to the inner space. An output device is connected to the inner space and configured to output said determined quantity from the inner space. The output device comprises a distributor in the form of a milk pump having two outlet passages, one passage for pumping the milk to a milk tank and one outlet passage for alternatively delivering milk samples to one or more milk collecting elements.

A problem with the existing technique is the difficulty to ensure a precise determined quantity of milk of each sample. The milk pump disclosed in EP 1 123 651 cannot address this problem in a proper manner. The milk sensors in the housing are provided for sensing and calculating the whole quantity of the milk produced but not the quantity of milk samples. The existing technique also does not offer any convenient solution for taking of a plurality of samples of milk, each of a determined quantity, from one and the same milking operation of one animal. A further problem with the existing device is the complexity and the large number of separate components needed for setting up the device in a milking plant.

SUMMARY OF THE I NVENTION

The object of the present invention is to provide a solution to the problems discussed above. More specifically, the invention aims at a milk sampling device by means of which a plurality of samples of milk of a determined quantity can be taken in a reliable and convenient manner. This problem is solved by the milk sampling device of the kind initially defined , which is characterised in that the milk sampling device comprises a forcing member operable to be movable in the inner space to force, in an output operation , the milk in the inner space to the distributor and through at least one of the outlet passages.

By the provision of such a forcing member in the inner space, the size, or the length , of the movement of the forcing member is an indication of the quantity of mi lk discharged in the output operation from the inner space. The size of the movement of the forcing member can easily be measured or sensed and thus determined. The quantity of milk discharged is proportional to the size of the movement. Consequently, the movement of the forcing member may be used for determining in an easy and reliable manner, the quantity of milk discharged in the output operation through one, or possibly more, of the outlet passages, possibly via a pipe to a suitable milk testing or analyzing apparatus.

According to an embodiment of the invention, the output device comprises a valve device configured to act selectively on the output passages for selectively permitting output of said determined quantity of milk from the inner space via at least one of the plurality of outlet passages. By means of such a valve device, it is possible to control in an convenient manner to which outlet passage, or possibly which outlet passages, the determined quantity of milk is to be delivered. Advantageously, only one of the plurality of outlet passages is open so that all of the determined quantity of milk is delivered to this outlet passage. It is however also possible to let more than one of the outlet passages be open thereby distributing the whole determined quantity of milk to one or more of the outlet passages. It is also possible to open more than one of the outlet channels successively in order to distribute a determined quantity of milk to each of these outlet passages. The determined quantity of milk may be equal or different for the different outlet passages.

According to a further embodiment of the invention, the valve device is configured to act selectively on the output passages distributing said determined quantity of milk from the inner space to at least two of the plurality of outlet passages, wherein equal or unequal quantities of milk are discharged to said at least two outlet passages. According to a further embodiment of the invention the determined volume in the inner space is defined by means of the forcing member, wherein the determined quantity of milk is discharged in the output operation by moving the forcing member form a first position in the inner space to a second position in the inner space. The movement of the forcing member from the first position to the second position reduces the volume of the inner space and corresponds to the determined quantity of milk.

According to a further embodiment of the invention, the forcing member is operable in the i nner space to draw, in an input operation , the determined quantity of milk into the inner space via the inlet conduit. Advantageously, the forcing member is moved in one direction during the input operation and in the opposite direction during the output operation.

According to a further embodiment of the invention, the forcing member comprises a piston which is movable in the inner space. A piston is a suitable forcing member. The movement of the piston in the inner space, which then has a at least partly cylindrical shape, may during the input operation draw a determined quantity of milk via the inlet conduit into the inner space, and during the output operation output the determined quantity of milk from the inner space. The length of the movement of the piston, between said first and second positions, may be easily sensed and determined , and corresponds to the determined quantity of milk.

According to a further em bodiment of the invention , the distributor is attached to the housing. Advantageously, the distributor is attached to an open end of the inner space. Furthermore, the distributor may comprise a distributor block having an inner side surface facing the inner space and being attached to the housing . According to a further embodiment of the invention, the outlet passages extend through the inner side surface and the distributor block, and through a respective outlet member provided on an outer side surface of the distributor block. Advantageously, the outer side surface of the distributor block may be a peripheral surface.

According to a further embodiment of the invention, each outlet passage comprises a valve channel, a valve seat, an outlet chamber and an outlet channel, wherein the valve channel extends through the inner side surface to the valve seat provided in the outlet chamber of the distributor block, and wherein the outlet channel extends from the outlet chamber to the outlet member. Advantageously, the output device may comprise a valve device configured to act selectively on the output passages for selectively permitting output of said determined quantity of milk from the inner space via at least one of the plurality of outlet passages, wherein the valve device may comprise a drive mechanism , which is attached to the distributor block and configured to act selectively on the valve seats. Furthermore, the valve device may comprise a membrane arranged at a distance from the valve seats thereby maintaining the outlet passages in an open state, and configured to abut the valve seats for maintaining the outlet passages in a closed state. The membrane may in a rest state extend in a plane provided at said distance from and in parallel with a common plane of the valve seats.

According to a further embodiment of the invention , the drive mechanism comprises a plurality of movable valve pistons each acting on the membrane opposite to a respective one of the valve seats to press the membrane to abut the valve seats. According to a first alternative solution , the valve pistons may be controlled pneumatically. According to a second alternative solution, the valve pistons may be controlled mechanically by displacement of a pressure member. According to a further embodiment of the invention, the iniet conduit extends through the distributor block and the inner side surface. Advantageously, one of the outlet passages may form the inlet conduit, or in other words the inlet conduit extends through the distributor and is configured in the same manner as the outlet passages. Furthermore, the valve mechanism may then be configured to open and close also the inlet conduit.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be explained more cioseiy through the following description of various embodiments and with reference to the drawings attached hereto.

Fig 1 discloses schematically a milk sampling device according to a first embodiment provided in a milking plant.

Fig 2 discloses schematically the milk sampling device in

Fig 1 .

Fig 3 discloses an exploded view of a the milk sampling device according to a second embodiment. Fig 4 discloses a sectional view through an outlet device of the milk sampling device in Fig 3.

Fig 5 discloses discloses an exploded view of a the milk sampling device according to a third embodiment. Fig 8 discloses a sectional view through an outlet device of the milk sampling device in Fig 5.

Fig 7 discloses a schematic view of a milk sampling device according to a fourth embodiment.

DETAILED DESCRIPTION OF VA IOUS EMBODIMENTS

Fig 1 discloses a milki g plant com ri ing a num er of milking places, preferably a large number of milking places, one of which is Indicated. Each milking place comprises a milking member having a number of teatcups 1 , such as four teatcups 1 , to be applied to the teats of an animal to be milked at the milking place. Each milk place may also comprise an end unit 2. The teatcups 1 are connected to the end unit 2 via suitable milk conduits 3, and optionally via a teatcup claw (not disclosed) as a part of the milking member. The milk obtained during each milking operation or milking round of an animal is thus supplied via the milk conduits 3 to the end unit 2 in which it is temporarily collected. The end unit 2 comprises stirring means, in the embodiments disclosed a motor-driven stirrer 4, which ensures appropriate stirring and mixing of the milk collected in the end unit 2. Alternative or supplementary stirring means may comprise recirculation of milk discharged from the end unit 2.

Each end unit 2 is connected to a milk tank 5 provided for collecting the milk from all milking places of the milking plant. Each milking place comprises a local milk pipe 6 connected to the end unit 2 for the discharge of milk from the end unit 2. The local milk pipe 6 is connected to a main milk pi pe 7, which is connected to the milk tank 5. Furthermore, each milking place may advantageously comprise a milk pump 8 provided on the local milk pipe 6. The milk from the end unit 2 may thus be discharged to the milk tank 5 by being pumped by the milk pump 8 via the local milk pipe 6 and the main milk pipe 7 to which all, or substantially all , milking places of the milking plant may be connected .

The milking plant also comprises a number of milk sampling devices 20, see also Figs 2 and 3 showing a first embodiment of the milk sampling device 20. Preferably, each milking place comprises a respective milk sampling device 20. The milk sampling device 20 is configured to take a plurality of milk samples from the milk collected in the end unit 2, i.e. a plurality of milk samples from each milking operation of an animal .

The milk sampling device 20 comprises a housing 21 enclosing an inner space 22. The inner space 22 has a determined volume. The inner space 22 is configured to house a determined quantity of milk.

The milk sampling device 20 also comprises an inlet conduit 23, which is connected to the inner space 22 for supplying milk to the inner space 22 from the end unit. The inlet conduit 23 is connected directly to the end unit 2 or to the local milk pipe 6 upstream the milk pump 8. A valve 24 is provided on the inlet conduit 23 for opening and closing the inlet conduit 23.

The milk sampling device 20 also comprises an output device 25, which is connected to the inner space 22 and configured to output the determined quantity of milk from the inner space 22. The output device 25 comprises a distributor 26, see especially Figs 2, 4 and 6. The distributor 26 comprises a plurality of outlet passages 27. In the embodiments disclosed, five outlet passages 27 are provided. However, it is to be noted that the output device 25 may comprise another number of outlet passages 27, for instance 2, 3, 4, 6, 7 etc. In the embodiments disclosed four of the outlet passages 27 are connected to a respective sample pipe 28 for a respective milk sample to be delivered to a suitable milk analysing apparatus, schematically indicated at 29. The sample pipes 28 and the milk analysing apparatus 29 may optionally be included as a part of the milk sample device 20. The distributor 26 also comprises an inlet passage 23' connected to the inlet conduit 23.

The apparatus 29 may comprise equipment for establishing the fat content of the milk, the concentration of different microorganisms, presence of blood in the milk, concentrations of different hormones or other substances in the m ilk, concentration of cells, etc. One of the outlet passages 27 is connected to the drainage via a drainage pipe 30. Furthermore, the milk sampling device 20 comprises a forcing member 32 operable in the inner space 22 to force, in an output operation , the milk in the inner space 22 to the distributor 26 and through at least one of the outlet passages 27. To that end, the output device 25 comprises a valve device 33, schematically indicated in Figs 1 and 2, which is configured to act selectively on the output passages 27 for selectively permitting output of said determined quantity of milk from the inner space 22 via at least one the plurality of outlet passages 27 to one or more of the sample pipes 28, or to the drainage pipe 30. The forcing member 32 is also operable in the inner space 22 to draw, in an input operation, the determined quantity of milk into the inner space 22 via the inlet conduit 23.

The inner space 22, or the volume of the inner space 22, is defined by the inner surface of the housing 21 and the forcing member 32, and thus the determined quantity of milk in the inner space 22 is defined by means of the forcing member 32. The determined quantity of milk is discharged in the output operation by moving the forcing member 32 form a first position p1 in the inner space 22 to a second position p2 in the inner space 22, see Fig 2. In a corresponding manner, determined quantity of milk to be discharged in the output operation from the inner space 22 is introduced into the inner space 22 by moving the forcing member 32 form the second position p2 in the inner space 22 to the first position p 1 in the inner space 22.

The forcing member 32 may be comprised by a suitable displacement pump, such as a piston pump, wherein the forcing member 32 comprises a piston 34 which is movable in the inner space 22 of the housing 21 . In this case, the housing 21 has a cylindrical shape at least in a zone extending between the first position p1 and the second position p2 of the piston 34. Consequently, th e movement, or the length of the movement, of the piston 34 is proportional to the quantity of milk displaced by the piston 34 during the movement. The movement of the piston 34 is performed by a drive member 35 of the forcing member 32, to which the piston 34 is attached via a piston rod 36. A sensor 37, of any suitable kind, is provided for sensing the movement provided by the forcing member 32. The sensor 37 communicates with a control unit 38 of the milking plant for transferring information of the momentary position of the piston 34 of the forcing member 32. The control unit 38 communicates with the drive member 35 for controlling the movement of the forcing member 32, and the piston 34. Consequently, the control unit 38 may, by controlling the movement of the forcing member 32, or the piston 34, determine the quantity of milk discharged in the output operation through one, or possibly more, of the outlet passages 27. The housing 21 , see Fig 2, has a first end 21 a, which is open, and an opposite second end 21 b. The output device 25 and the distributor 26 are attached to the first end 21 a of the housing 21 . In the proximity of the first end 21 a, the housing 21 has a first widened portion 21 c. In the proximity of and adjacent to the second end 21 b, the housing has a second widened portion 21 d. A cover 39 is attached to the second end 21 b. A drainage pipe 40 extends from the second end 21 b through the cover 39 to the drainage. The output device 25 and the distributor 26 will now be explained more closely with reference to the second embodiment and Figs 3 and 4. It is to be noted that the same reference signs have been used for identical or similar elements in all embodiments. The mere difference between the first embodiment and the second embodiment is that the output device 25 a nd further elements are disclosed in greater detail in the second embodiment.

The distributor 26 comprises a distributor block 44 attached to the open end 21 a of the housing 21 and having an inner side surface 45 facing the inner space 22. The inner side surface 45 covers the open first end 21 a meaning that the volume of the inner space 22 is also determined by means of this inner side surface 45. The outlet passages 27 extend through the inner side surface 45 and the distributor block 26. Each outlet passage 27 aiso extends through a respective outlet member 46 provided on an outer side surface 47 of the distributor block 26. In the second embodiment, the outer side surface 47 is a peripheral surface. Each outlet member 46 is designed as a pipe nipple to which the sample pipes 28, the drainage pipe 30, and, in the second embodiment, the inlet conduit 23, may be attached in an easy and convenient manner. Each outlet passage 27, which extends through the distributor block 44, comprises a valve channel 50, a valve seat 51 , an outlet chamber 52 and an outlet channel 53. The valve channel

50 extends through the inner side surface 45 to the valve seat

51 provided in the outlet chamber 52 of the distributor block 44. The outlet channel 53 extends from the outlet chamber 52 to the outlet member 46. The valve seats 51 are all annular and provided in a common plane, i.e. all valve seats 51 has a seat surface lying in the common plane. The valve device 33 comprises a membrane 55 arranged, in a rest state, at a distance from the valve seats 51 for maintaining the outlet passages 27 in an open state. The membrane 55 is configured to abut the valve seats 51 for maintaining the outlet passages 27 in a closed state. The membrane 55 is in the rest state flat and extends in a plane at said distance from and in parallel with the common plane of the valve seats 51 .

Furthermore, the valve device 33 comprises a drive mechanism 58, which is attached by means of a faste ing member 57, for instance in the form of a screw, to the distributor block 46. The drive mechanism 56 is configured to act selectively on the valve seats 51 . The drive mechanism 56 comprises a plurality of movable valve pistons 58 each acting on the membrane 55 opposite to a respective one of the valve seats 51 to press the membrane 55 to abut the valve seats 51 , and thus to close the outlet passages 27.

In the second embodiment, the valve pistons 58 are controlled or activated pneumatically. Each valve piston 58 is provided in a respective cylinder space 59 of a valve housing 60 of the drive mechanism 56. Each valve piston 58 is pre-tensioned by means of a respective spring 61 to a non-active position in which it is positioned at a distance from the membrane 55. The cylinder spaces 59 are connected via standard pneumatic couplings 62 to a source of pressurised air (not disclosed). The source of pressurised air may be controlled, for instance by means of the control unit 38, to supply selectively pressurised air to the cylinder spaces 59, thereby pushing the selected valve piston 58 against the membrane 55 to abut the membrane 55 against the adjacent valve seat 51 .

In the second embodiment, there are six outlet passages 27, but one of these outlet passages 27 forms an inlet passage and is as mentioned above connected to the inlet channel 23, which thus extends through the distributor block 44 and the inner side surface 45.

The third embodiment is disclosed more closely in Figs 5 and 6. The third embodiment differs from the second embodiment in the design of the drive mechanism 56 and in that a separate inlet passage 23', which is connected to the inlet conduit 23 , is provided . The inlet passage 23' extends through the distributor block 44. For closing and opening the inlet conduit 23 the valve 24 is used. In the third embodiment, the valve pistons 58, provided in the cylinder spaces 59, are controlled mechanically by displacement of a pressure member 70. The pressure member 70 is rotatable in relation to the valve housing 60 by means of a motor 71 which communicates with and is controlled by the control unit 38. The motor 71 rotates a motor gear 72 engaging an external gear 73 provided on the pressure member 70 to rotate the pressure member 70. The pressure member 70 has a guide surface 74 facing the valve pistons 58 and provided with a recess 75, or possibly several recesses 75. When the pressure member 70 is rotated to a position in which all the valve pistons 58 are positioned beside the recess 75, all the outlet passages 27 will be closed. The pressure member 70 may be rotated for selectively moving the valve pistons 58 towards the valve seats 51 in order to open a selected one or more of the outlet passages 27. The rotary position of the pressure member 70 thus determines which of the outlet passages 27 are open and closed, respectively.

Fig 7 discloses a fourth embodiment which differs from the previous embodiments with regard to the design of the forcing member 32. In the fourth embodiment, the forcing member 32 comprises a membrane pump. In the housing 21 , a membrane 80 is provided . A volume is present between the membrane and the first end 21 a of the housing 2 , i .e. between the membrane 80 and the inner side surface 45 of the distributor 44. The drive member 35 of the forcing member 32 comprises a hydraulic motor containing an incompressible fluid , which may be supplied to the housing 21 in the inner space 22 between the membrane 80 and the second end 2 b via a supply conduit 81 . The sensor 37 is designed to sense the volume of the supplied fluid. Consequently, the quantity of the milk in the inner space 22 may be calculated by means of the control unit 38.

It is to be noted that the forcing member 32 may be realised also by other pumping means. Every displacement pump displacing a determinable volume may be used for the milk sampling device 20, such as rotary lob pumps, gear pumps etc. The milk sampling device 20, or the milking plant, also comprises means for emptying the outlet passages 27 and the sample pipes 28 so that no milk will remain and influence the calculation of the determined quantity of milk. This emptying means comprises a source of pressurised air (not disclosed) and an emptying conduit 90 connected to the inlet conduit 23. Pressurised air is supplied through the emptying conduit 90 into the inner space 22 via the inlet conduit and out through one or more of the outlet passages 27 and sample pipes 28, thereby removing any milk remaining in these spaces. Excess air is discharged via the drainage pipe 30.

Furthermore, means are provided for cleaning the milk sampling device. This means comprises a source of cleaning and rinsing liquid supplied to the inlet conduit and the inner space 22 via a cleaning conduit 93. The cleaning/rinsing liquid is supplied to the outlet passages 27 and the sample pipes 28. Furthermore, during cleaning , the piston 34 may be retracted to the second widened portion 21 d enabling cleaning and rinsing of the inner space 22 behind the piston 34. After cleaning , the cleaning/rinsing liquid is discharged via the drainage pipe 40.

The present invention is not limited to the embodiments disclosed but may be varied or modified within the scope of the following claims. For instance, the invention is applicable also to milking parlours having several milking places connected to a common end unit, and preferably also a common milk pump positioned downstream the common end u nit.