AU2018263296A1

AU2018263296A1 - Milking system and apparatus used in milking

Info

Publication number: AU2018263296A1
Application number: AU2018263296A
Authority: AU
Inventors: Richard Paul Wallace
Original assignee: BULLSEYE AUSTRALIA Pty Ltd
Current assignee: BULLSEYE AUSTRALIA Pty Ltd
Priority date: 2017-05-04
Filing date: 2018-05-04
Publication date: 2019-12-05
Also published as: WO2018201204A1

Abstract

A claw usable with in a milking system. The claw can include at least one milk collecting bowl defining at least part of a chamber formed within the claw for holding a vacuum within the claw and for receiving milk, the collecting bowl having an operationally upper and lower ends. It can further include a plurality of milk inlets in fluid communication with the chamber, each connectable to a respective one a plurality of milk tubes to receive milk from a milking cup liner that is in fluid communication with the milk inlet. The claw can include a plurality of outlets arranged at the operationally lower end of the milk collecting bowl.

Description

Milking system and apparatus used in milking

Field of the invention

The present invention relates to milking systems and methods, e.g. of the type used to milk mammals. For convenience only, illustrative embodiments of the present invention will be described with reference to milking cows, but the present systems and method should not be considered as being limited to this use.

Background of the invention

US patent 5,178,095, (the contents of which are incorporated herein by reference) describes a system for milking mammals which applies a positive pressure between a shell wall of a teat-cup and its flexible liner to during the “off” phase of the pulsation cycle in order to isolate the teat tip from the negative pressure applied to the milk delivery tube of the teat cup. During the “on” phase of the pulsation cycle negative pressure is applied between the liner and teat-cup shell to partially open a flow path through the liner along which milk can flow via negative pressure applied to the milk tube.

However this proposal only partly addresses the issues of minimising damage to the teat of the animal through the application of vacuum to the tip of the teat during the milking process. The present invention seeks to provide improved milking systems and methods that ameliorate some of the drawbacks of such a system or at least provide a useful alternative for the public.

Summary of the invention

The present inventor has determined that the milk flow in the liner bore during the “on” cycle reduces vacuum level in the milking tube to a sufficient extent that the pressure differential across the liner wall can be affected sufficiently to compromise the closing the liner bore in the off phase of the milking operation.

In a first aspect the present invention provides a claw usable in a milking system.

The claw includes:

At least one milk collecting bowl defining at least part of a chamber formed within the claw for holding a vacuum within the claw and for receiving milk, the collecting bowl having an operationally upper and lower ends;

a plurality of milk inlets in fluid communication with the chamber, each connectable to a respective one a plurality of milk tubes to receive milk from a milking cup liner that is in fluid communication with the milk inlet;

a plurality of outlets arranged at the operationally lower end of the milk collecting bowl, said milk outlets each being connectable to a vacuum source to enable, application of vacuum to the milking cup liners of the plurality of milking cups and the drawing away of milk from the milk collecting bowl.

Preferably there are two outlets from the milk collecting bowl. The two milk outlets can be arranged at the same level between the operationally upper and lower ends of the milk collecting bowl so that in use the

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PCT/AU2018/050416 milk in the bowl occludes approximately the same proportion of each outlet. The two milk outlets can be alternatively arranged at different levels between the operationally upper and lower ends of the milk collecting bowl. In this case a rising milk level in the bowl will occludes an operationally lower outlet before an operationally higher outlet.

In preferred form the outlets comprise a milk outlet tube having a first end within the milk collecting bowl and a second end outside the milk collecting bowl. The first end of the milk outlet tube is preferably positioned at or near an operationally lower end of the milk collecting bowl.

Preferably the first end is spaced from an inside wall of the milk collecting bowl by less than 5mm. More preferably it is spaced apart from the inside wall by less than 3mm. The separation could be around 1 mm. The first end may touch the milk collecting bowl, or be integrally formed with it and include inlet ports arranged at or near the operationally lower end of the milk collecting bowl.

The second end of the milk outlet tube can be arranged to be connected to the vacuum source, e.g. to a vacuum line.

In a second aspect of the present disclosure there is disclosed a claw usable with in a milking system, said claw including: at least one milk collecting bowl defining at least part of a chamber formed within the claw for holding a vacuum within the claw and for receiving milk, the collecting bowl having an operationally upper and lower ends; a plurality of milk inlets in fluid communication with the chamber, each connectable to a respective one a plurality of milk tubes to receive milk from a milking cup liner that is in fluid communication with the milk inlet; at least one outlet arranged at the operationally lower end of the milk collecting bowl, wherein said outlet comprises a milk outlet tube having a first end and a second end, the first end being located within the chamber and at or near the operationally lower end of the milk collecting bowl, the second end being located outside the milk collecting bowl and being connectable to a vacuum source to enable application of vacuum to the milking cup liners of the plurality of milking cups and the drawing away of milk from the milk collecting bowl though the milk outlet tube.

In a preferred form the second end of the milk outlet tube is located above the operationally lower end of the milk collecting bowl. Most preferably it is above the operationally upper end of the milk collecting bowl. Preferably the application of vacuum to second end of the milk outlet tube draws milk from the milk collecting bowl upwards though the milk outlet tube.

The claw can include a plurality of outlets from the milk collecting bowl (preferably 2 outlets). The outlets can preferably comprise a milk outlet tube as set out above.

Preferably the first end of the milk collecting bowl (and inlet ports, if present) are arranged to be below an expected milk level consistently (e.g. more than 50% of the time while milk is flowing, preferably more than 75% of the time, and more preferably, more than 90% of the time).

The claw can comprise part of a cluster including a plurality of milking cups connected to a respective one of the plurality of milk inlets.

Preferably the claw or cluster includes at least one transducer to measure a fluid parameter for use in an embodiment of a method described herein.

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Such a cluster constitutes a further aspect of the present invention. A milking system using such a cluster or claw should be considered to be a further aspect of the present invention.

In a further aspect the present invention provides a milking system including a plurality of milking cups of the type including a shell and a flexible liner, said liner including a hollow bore for receiving an animal’s teat at a top end thereof, and for being connected to a vacuum source at the lower end thereof; the liner and shell being disposed relative to one another to create a pulsation volume between them in which fluid pressure can be controlled in order to control a pressure differential across the liner between its bore and the pulsation volume to thereby control movement of the liner and the application of air pressure to the animal’s teat, each of the plurality of milking cups being connected to a milk inlet of a claw according to an embodiment of the present invention;

a vacuum system in fluid communication with the bore of the liner and the pulsation volume;

a pressure regulating system configured to modulate the fluid pressure in the pulsation volume to cause a milking operation on a teat of an animal that is inserted into the top end of the bore; said modulation including an “on” phase in which the vacuum applied to the liner bore is less than a vacuum applied to the pulsation volume to thereby enable milk flow from the teat, and an “off” phase in which the pulsation volume is at an increased pressure relative to the “on” phase to cause the liner bore to close to thereby stop milk flow from the teat and apply a compressive load to the teat;

at least one milk receiving sub-system, in fluid communication with the liner bore and adapted to receive milk via the claw; and a pressure compensation system including:

a sensing system configured to measure a fluid parameter related to a pressure in the bore;

a source of positive air pressure air in fluid communication with the pulsation volume; and a controller configured to control the pressure compensation system to adjust a level of positive pressure applied to the pulsation volume based on said determined fluid parameter measurement.

The pressure compensation system can include collapsing means to cause sequential collapse of the liner against the teat from the lowermost part of the teat.

The pressure compensation system can include an insert placed within the pulsation volume. The insert may cause one or more of the following:

control or limit movement of the liner;

reduce the volume of the pulsation volume (compared to the volume that would exist absent the insert).

Controlling or limiting the movement of the liner can include acting as the, or part of the collapsing means. The collapsing means can additionally or alternatively include a profiled inner surface of the shell. The

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PCT/AU2018/050416 insert or profiled inner surface of the shell can include an inwards projection configured to indent the liner to pinch the liner bore at a location below the tip of the teat to thereby induce initial liner collapse at said location.

The sensing system can include any one or more of the following:

a transducer to measure pressure located at or near the lower end of the bore or other related position.

a sensor to determine milk flow rate or milk flow volume, from the bore.

Preferably the transducer to measure pressure, measures pressure in the chamber of the claw, but the pressure measurement could in some embodiments take place elsewhere in the system.

The pressure is determined at least at a time when milk is flowing during the “on” phase. Most preferably it is determined at a plurality of points during the pulsation cycle across both the off and on phases. In some embodiments pressure is determined continuously while the animal is being milked.

The pressure compensation system can be configured to supply a predefined volume of air to the pulsation volume that corresponds to the determined level of positive pressure to be applied.

The pressure compensation system can include one or more fluid delivery lines connected between the source of positive air pressure and the pulsation volume.

The pressure compensation system can further include one or more valves or actuators to control fluid flow in the pressure regulating system.

The pressure compensation system can further include a wireless communications system configured to enable communication between at least the sensing system and controller. The wireless communications system may also be configured to enable communication between the controller and the one or more valves or actuators.

In one form the pressure compensation system forms part of the pressure regulating system.

In the above aspects of the present invention the source of positive air pressure can be connected, for example, directly or indirectly to any one of the following locations:

An inlet to a pulsator;

A pulsation volume;

At a position adjacent to or along the length of either a long pulsation tube or a short pulsation tube;

A volume or manifold in fluid communication with any one of the above.

It should be noted that the concept of applied vacuum level, relates not to the actual instantaneous vacuum level measured at a point within the system, but an intended vacuum level, also termed “system vacuum” herein. The actual instantaneous vacuum level measured at a point within the system will differ from this level because of factors such as milk flow within a limited space and the available “air space” between the milk line and the cluster. This vacuum level is also called the “operating vacuum” herein. In particular the concept of applying a vacuum to the lower end of the liner at a given pressure level should

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PCT/AU2018/050416 be understood to mean the system vacuum level applied by a vacuum system, e.g. to the long milk tube, and not the resultant (and highly variable) instantaneous teat-end vacuum (operating vacuum) experienced by the animal.

Embodiments of the various aspects of the present invention, preferably using the parameters described herein, can advantageously be applied to the milking of cows.

Brief description of the drawings

Embodiments of the present invention will be described by way of non-limiting example only with reference to the accompanying drawings. In the drawings:

Figure 1a is a schematic illustration of a milking system according to an embodiment of the present invention;

Figure 1b illustrates a conventional milking cup, which may be used in some embodiments;

Figure 2 is a plot of the pressure level (vacuum) applied in the pulsation volume of a milk cup during a conventional pulsation cycle;

Figure 3 illustrates a milking cup with a teat inserted therein during an “off” phase of the pulsation cycle;

Figure 4 illustrates a timing diagram for the application of positive air pressure to the pulsation volume of a milking cup during the pulsation cycle;

Figures 5 and 6 illustrate time plots of the modified pressure in pulsation volume in an embodiment of the present invention;

Figure 7 illustrates a schematic cross section of a milking cup, including an insert, that can be used in embodiments of the present invention;

Figure 8 illustrates another embodiment of a milking system according to the present invention;

Figures 9 and 10 illustrate two further exemplary milking systems (equivalent to those of figures 1 and 8) respectively but having a double long milk tube;

Figure 11 illustrates a conventional milking claw that can be used in some milking systems;

Figures 12 and 13 illustrate a milking claw of an embodiment of the present invention having two outlets from its milk chamber;

Figure 14 is a schematic representation of components of a milking system including a pressure compensation system according to an embodiment of an aspect of the present invention and a claw according to an embodiment of another aspect of the present invention;

Figure 15 is a schematic representation of components of another milking system including a pressure compensation system according to another embodiment of an aspect of the present invention and a claw according to an embodiment of another aspect of the present invention.

Figures 16 to 18 show a further embodiment of a claw according to the present invention

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Detailed description of the embodiments

Figure 1a and 1b are a schematic illustration of a milking system 100 according to an embodiment of an aspect of the present invention. The milking system 100 includes a pressure compensation system.

The milking system includes at least one (in this example 4) milking cup 102, details of which are shown in figure 1B. The milking cup 102 generally includes a shell 104 and a flexible liner 106. The liner 106 is generally tubular (but may have a non-round cross section, e.g. triangular) and includes a hollow bore 108. In use the bore receives the animal’s teat at its top end for milking. The lower end of the bore 108 is connected to a milking claw 114, which in turn connects to a milk tube 116. The milk tube differs from a conventional milking system in that it has two connections, one for each of the two milk outlets of the claw 114. The connections can be integral with the claw, or the end of the milk tube 116, or provided by a separate fitting. The milk tube 116 connects the liner bore 108 to a vacuum system 120 in a manner that will be known to those skilled in the art. The liner 106 and shell 104 are sealed to each other in relative positions so as to create a pulsation volume 110 between them in. Details of an exemplary milking claw according to several embodiments of the present invention are described in connection with figures 12 to 14 and 20a to 20c.

As is known in the art, in order to milk the animal the fluid pressure (vacuum) in the pulsation volume 110 is modulated control a pressure differential across the liner between its bore and the pulsation volume. Conventionally the vacuum in the pulsation volume is used to open the bore 108 of the liner 106 to enable milk to flow within the bore 108 towards the milk tube 116. Typically the milking claw 114 will have a manifold within it that connects several liners 106 to the milk tube 116.

The vacuum system 120 generally comprises a vacuum pump that is connected to, the bore of the liner 106 (possibly via intervening connections), and the pulsation volume 110 via a pressure regulating system 122.

The pressure regulating system 122, which may conventionally be a pulsator, is configured to modulate the fluid pressure in the pulsation volume 110 of the milking cup(s) 102, to cause a milking operation on the teat. The pulsator 122 is fluidly connected to the pulsation volume 110 of one or more teat cups by one or more long pulsation tube(s) 113 and respective short pulsation tubes 112. In this example the system has a 2x2 milking cluster and hence 2 long pulsation tubes are used. In other embodiments a different number of long pulsation tubes may be used. As will be known the pulsation cycle of the milking operation generally includes an “on” phase in which the vacuum that is applied to the liner bore is less than a vacuum applied to the pulsation volume. The pressure differential across the liner 106 causes its bore 108 to be opened so that the teat is exposed to the vacuum in the bore 108 to thereby enable milk flow from the teat. In an “off” phase the pressure in the pulsation volume 110 is increased relative to the “on” phase. Conventionally, the pulsation volume 110 is opened to atmosphere by the pressure regulation system 122. The pressure differential across the liner 106 causes the liner bore 108 to close.

The present embodiment additionally includes a pressure compensation system 130. The pressure compensation system 130 primarily includes a source 132 of positive air pressure. The source could be a

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PCT/AU2018/050416 pump, compressor, compressed air tank, or other source of air at a pressure above atmosphere. The pressure of air delivered from the source can be controlled or set using any known mechanism, e.g. using a regulator, orifice plate, or the like. The mechanism may form part of the source 132 or be a stand-alone component of the pressure compensation system. The source 132 is in fluid communication with the pulsation volume 110 of (the or) each milking cup 102 via a positive pressure fluid delivery line 134, which in this example joins the long pulsation tube via valve 133. As will be described in further detail below the pressure compensation system 130 is used to selectively apply positive air pressure to the pulsation volume 110 during the “off” phase of the pulsation cycle, so that a compressive load is applied to the teat during at least part of the off cycle. To aid this process the pressure compensation system 130 further includes a:

a sensing system 136 for measuring a fluid parameter (typically pressure, volume or flow) related to a pressure in the bore 108; and a controller 138 configured to control the pressure compensation 130 system to adjust a level of positive pressure applied to the pulsation volume 110.

The controller 138 receives outputs from the sensing system 136 via a communications system 140. In the present diagrams the communication system 140 is illustrated to indicate logical connections between its elements. The system is preferably a wireless communications system, as this may reduce wires in an already cluttered environment and may also minimise installation costs. The communications system 140 may enable communication between the controller 138 and the one or more valves 133 or actuators of the pressure compensation system 130.

As will be appreciated from the following description, the pressure compensation system 130 may be a stand-alone system (e.g. that may be retro-fitted to an existing milking system) or its functions and components could be integrated, mutatis mutandis, into the pressure regulating system 122. Furthermore the source of positive air pressure can be connected to any convenient location from which positive pressure can be delivered to the pulsation volume, in the manner required. For example, it may be connected directly to any one of the following locations:

An inlet to a pulsator;

A pulsation volume;

A volume or manifold in fluid communication with any one of the above.

Indirect connection to such locations through a pipe, hose, valve or other means is also possible.

The choice of where to connect the source or positive air pressure may involve a trade-off. Connection closer to the pulsation volume may be advantageous because it reduces the volume to be pressurised and improve system efficiency, but conversely it may be mechanically more difficult or less convenient, as it introduces more hardware nearer to the already complex cluster. On the other hand, connection nearer the pulsator may require pressurisation of a greater volume of the system, but may provide easier mechanical connection at a single location in the system.

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Figure 2 illustrates a plot 200 of the vacuum level applied to the pulsation volume 110 during a conventiontal pulsation cycle. The plot 200 takes a generally saw-toothed form. Transitions from the bottom of the cycle (point of lowest vacuum) to the top of the cycle is gradual, whereas, at the onset of vacuum release, a sharper drop occurs. As should be recognised by those skilled in the art, the cycle has four phases as follows:

“B” phase, or the “On” phase in which a relatively high vacuum level is applied to the pulsation volume 110. In this phase, the vacuum applied is sufficient for the liner 106 to be pulled open by the vacuum applied in the pulsation volume Conventionally the vacuum applied will be in the vicinity of 46kPa (say 40 to 50 kPa). Moreover the vacuum applied is the same as that applied to the milk tube 116. In preferred embodiments of the present invention however, the vacuum applied is less than 42kPa. The vacuum applied can be less than 40kPa. Preferably it is less than 38kPa. Most preferably it is less than 36 kPa. A preferred form uses about 35kPa.

“D” phase, or “off” phase, in which the pressure in the pulsation volume 110 is higher (i.e. vacuum decreased) than in the B phase. In this phase the liner 106 collapses around the teat. Conventionally, in this phase the pulsation volume is at atmospheric pressure.

“A” phase is a transition between the end of the D phase and the beginning of the B phase. During this phase the pulsator 122 connects the pulsation volume 110 to the vacuum system 120 to draw air out of the pulsation volume 110.

“C” phase is a transition from the B phase to the D phase. In this phase the vacuum in the pulsation volume 110 is released (i.e. air is allowed into the pulsation volume). Conventionally this is achieved by the pressure regulation system 122 opening the pulsation volume to atmosphere. Embodiments of the present invention modify this conventional process as follows:

During the C phase, instead of merely opening the pulsation volume to atmosphere, air under positive pressure is introduced into the pulsation volume 110. This causes the pressure in the D phase to be greater than atmospheric pressure. In turn this ensures that a positive compressive load is applied to the teat by the liner 106. Figure 3 illustrates a milking cup 102 in which a teat 300 has been inserted. The milking cup is shown during the D phase, in which the pulsation volume 110 is positively pressurised. As illustrated the concept of compressive load applied to the teat is illustrated by the arrows near the teat’s 300 end. The compressive load is applied by the liner 106 to the teat measured in a direction normal to the surface of the liner 106 at the point of contact.

The pressure compensation applied to the pulsation volume is illustrated in figure 4. In this figure the pulsation pressure modulation plot 200 is illustrated along with a plot 400 of the positive pressure applied by the pressure compensation system 130. As can be seen, the pressure compensation system applies positive pressure at a point during the C phase which is maintained during the D phase.

In a one form, the positive pressure is applied by injecting a predetermined volume of air of known pressure air into the pulsation volume 110. The volume of air to be injected can be determined by knowing the volume of:

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PCT/AU2018/050416 the pulsation volume 110 (including any reduction in volume caused by the use of an insert

700), the short pulsation tube(s) 112, the portion 113’ of the long pulsation tube(s) 113 between the valve 133 and the milking cluster;

any connecting components or manifolds;

and then injecting an appropriate volume of air at the known pressure. This may advantageously be performed by allowing air at a known pressure to flow into the positive pressure fluid delivery line 134 for a determined period of time.

This has been found to be preferable to, measuring pressure and injecting air until the desired pressure has been reached, as the volume based approach can be performed more quickly than the pressure based approach, although either may be used.

In one form, when the positive air pressure is injected into the long pulsation tubes 113, the pulsator 122 is isolated from the long pulsation tube by valve 133, so that the pulsator 122 does not release the positive pressure in pulsation volume 110. In a preferred embodiment the valve 133 is placed as close to the cluster as practical, however it may be placed at any point. Minimising the distance between the valve 133 and the cluster decreases the volume of the portion of the pulsation tube 133’ to be positively pressurised, which in turn minimises the time taken to perform pressurisation, and reduces pressure loss. In other embodiments, the positive pressure air could be introduced directly to the cluster or pulsation volume 110 of the milking cups 102 or into the short pulsation tubes 112, but these schemes require additional valving so may be less cost effective. Figure 8 shows an embodiment in which positive air pressure is introduced at the pulsator 122.

The resulting pressure modulation profile 500 within the pulsation volume 110 is illustrated in figure 5. After the B phase, the pulsator 122 releases the vacuum in the pulsation volume 110 and the C phase is entered. Shortly thereafter (on the order of 10ms) the air under positive pressure is applied to the pulsation volume 110 and the pressure in the pulsation volume 110 increases. However, instead of equalising at atmospheric pressure, (-101.3 kPa), pressure is increased to above atmospheric pressure. Figure 6 illustrates a similar plot to that of figure 5 but shows the operation over several pulsation cycles. As will be appreciated the C phase is conventionally initiated by the pulsator 122 opening the long pulsation tube volume to atmosphere to release the vacuum. The A phase is initiated by connecting it back to vacuum. However in order to avoid the pulsator 122 releasing the positive pressure that is added to the pulsation volume 110 during the C and D phases the pulsator 122 is isolated from the pulsation volume 110 by a valve (valve 133 in this example).

As noted above the introduction of positively pressurised air into the pulsation volume 110 is to apply compressive load to the teat to drive blood and lymphatic fluid upwards and out of the teat during the off phase of the pulsation cycle. To do this the compressive load applied is preferably be above blood pressure level, say about 0.8 to 1,2N/cm², but may preferably be in a range of 2.0N/cm² to 3.0N/cm². It is

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PCT/AU2018/050416 believed that the an effective compressive load is at or about 2.5N/cm², but in other embodiments additional compressive load may be advantageous, for example in the range of 2.5N/cm² to 3.5N/cm².

Accordingly a key aspect of the system is the control of the pressure compensation system 130 and in particular the determination of the level of positive pressure to be applied during the D phase, so as to achieve the desired compressive load on the teat. This is preferably performed by determining the pressure in the liner’s bore 108, below the teat. The measurement, at least during the on (B) phase, of the pulsation cycle is important as it has been determined by the inventor that the flow of milk in the liner bore 108 causes a significant reduction in the vacuum level actually experienced at the teat, regardless of the constant vacuum applied by the vacuum source 120. Thus the pressure can be determined by direct measurement of pressure in the bore 108, if suitable sensors are available, or measurement of any value that is related to this pressure. For example pressure could be measured at or near the lower end of the liner bore 108. Alternatively it could be measured in the chamber of the claw 114 or even the milk tube 116. In other forms the pressure can be estimated by measuring milk flow rate or milk volume at the same or similar locations. To this end, a sensing system is provided that includes at least one transducer to measure a fluid parameter. In this example the transducer is an air pressure sensor 136 in the claw 114. Since this chamber is in fluid communication with the liners of several teat cups, the single measurement will apply to all such cups. The sensor 136 communicates the measured pressure data back to the controller 138 via a communications network 140. The communications network can be any type of suitable wired or wireless network. However a communications network using one or more wireless channels, (e.g. Bluetooth, Wi-Fi, ZigBee, IR, RFID, NFC, cellular technologies like 3G or 4G and the like) may be advantageously employed. In systems whose sensing systems include with multiple transducers per milking cluster, the communications components for a cluster can be shared amongst the transducers, or dedicated per-transducer communications components used.

The pressure sensor is arranged to transmit measured pressure data to the controller 138. The data can be sent according to any scheme, for example it may be pushed by the sensor 136 or sent in response to a request from the controller 138. Moreover measurement can be performed continuously, intermittently or periodically depending on requirements.

The controller processes the received value and determines therefrom the pressure drop in the insert bore 108 and the necessary positive pressure to apply to the pulsation volume 110 in order to cause closing of the liner bore and application of the desired compressive load to the teat. The correlation between the compressive load applied to the teat, and pressure drop in the liner bore 108, and the necessary positive pressure to be applied to the pulsation volume can be determined empirically or by calculation. The level of compensatory positive pressure to be applied to the pulsation volume 110 can be set dynamically so that the compressive load substantially matches a target compressive load level (e.g. 2.5N/cm² to 3.5N/cm².) or by a pressure level selected from a set predetermined pressure levels. For example the controller 138 can have access to a look up table that includes a series of compensatory pressure values (P1,P2, P3,P4) which will be used if the determined operating pressure drop in the liner bore 108 falls within predetermined bands (e.g. 2-7kPa, 7-12kPa, 12-17kPa and greater than 17 kPa).

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Details of exemplary mechanisms for determining the level of positive pressure air to be applied can be found in the Applicant’s co-pending application PCT/AU2017/050412, which is incorporated herein for all purposes.

As will be appreciated by those skilled in the art, different milking systems will have different physical configurations. These are typically classified as either high line or low line systems depending on the route followed by the milk after it leaves the cluster. In high line systems the milk tube runs to a point above the cluster so the milk needs to be drawn up the milk tube. The height to which the milk must be drawn varies from dairy to dairy, but will typically be over a metre and possibly as high as 1.8 metres. This affects the level of vacuum that needs to be applied to the milk tube to lift the milk to this height. Conventionally a high line system that raises the milk by between 1.2 and 1.4 metres will use 46kPa of vacuum on the milk tube, whereas a system that raises the milk by between 1.4 and 1.8 metres may use 48kPa of vacuum on the milk tube. These high system vacuums translate to correspondingly high operational vacuums applied to the teat during milking. So called low line systems and rotary systems do not need to lift milk above the cluster, hence gravity assists in drawing milk away from the cluster. As a result these systems typically use a lower system vacuum approaching 42kPa.

Different compressive loads could be achieved by selecting the appropriate “pressure level” to apply and the volume of positive pressure air to be added can readily be computed by the controller 138. The controller will be suitably programmed to output control signals to the valve 133 to operate as desired.

However, the operating pressure in the lower part of the liner bore 108 will drop due to milk flow. This pressure drop may not be uniform over time, for example hydraulic effects can cause variations in vacuum level on time scales ranging from fractions of a second to many seconds, thus the fluid parameter measured by the sensing system may also fluctuate. To compensate for this the (or each) measured parameter, a corresponding determined pressure value or compensation pressure value can be averaged, low-pass filtered or otherwise smoothed to take out such variations. For example, the sensor outputs or determined pressure can be a rolling average over a window of between 1 and 10 seconds.

The present inventor has also found that in systems with lower milk tube vacuum levels as described above, that milk removal can be enhanced, and/or vacuum drop in the milk tube can be minimised by using a modified claw for a milking cluster as described in connection with figures 13 to 14.

Figure 11 illustrates a conventional claw 114 useable in a milking system such as that illustrated in figures 1 a or 9. The claw includes a milk collecting bowl 1200 that has a chamber 1202 formed within it. The bowl 1204 is closed with a lid 1203 so that a vacuum can be held within the chamber 1202. The chamber 1202 also receives milk through milk inlets 1204. In this case there are 4 milk inlets for connecting to four milking cups. In particular the milk inlets 1204 connects via a short milk tube to the bore of the milking cup liner 108 so that vacuum can be transferred to the liner bore 108 and milk can flow down to the bowl. In use the claw is oriented in the manner illustrated under the animal being milker, thus the collecting bowl can be seen to have an operationally upper end 1206 and an operationally lower end 1208. The bowl also has an outlet 1210 that connects to the long milk tube 116. The long milk tube is connected to a vacuum system 120 so that a vacuum can be applied to the liner bore 108, and so that milk can be drawn away

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PCT/AU2018/050416 from the cluster to the reservoir (Res.). Typically the outlet 1210 will be placed at a portion where the milk occlusion level may get to about 80% up the height of the outlet 1210. As explained above (when used in embodiments of the previously described embodiments of the present invention), but not illustrated here, the claw 114 can accommodate a sensing system 136 for measuring a fluid parameter (typically pressure, volume or flow in the chamber 1202) related to a pressure in the bore 108 of all or many liners.

In conventional claws, such as the one illustrated, the outlet is tubular and has a radius of around 8mm approximately. This gives a cross sectional area of around 218mm². In use, during milking, milk partly fills the chamber 1202 within the bowl and rests by gravity a level part way up the outlet 1210 from the lower end 1208 of the bowl 1200. The continued application of vacuum to the outlet 1210 and increasing volume of milk within the chamber 1202 causes suction to draw milk out of the bowl down the long milking tube 116. Depending on a number of factors, milk may flow either in the form of a transient flow where “slugs” of milk form and are drawn away; or, in the form of a continuous stratified flow in which milk flows as a layer of milk below a layer of air in the milk tube. The factors that affect which type of flow occurs include: the configuration of the dairy, e.g. if a high-line milking system in which the milk tube is raised above the level of the claw, or a low-line system in which the milk line falls in height towards the reservoir; and the milk flow rate. High-line systems tend to rely on transient flow more than low-line systems to achieve suitable milk flow rates. When milk slugs form, the milk flow and temporary occlusion of the outlet 1210 by milk causes a variation in the vacuum level applied to the teat of the animal via the bore 108 of the milking cup liner. This variation can be as much as 10 to 20 kPa.

To address this issue, dairies may choose to increase the vacuum applied to the claw, to counteract the decrease in vacuum, but this can be damaging to the animal’s teats. Alternatively the diameter of the milk tube can be increased to promote stratified flow, but the ability to use different sized milk tubes is limited due to the dairy configuration.

As noted above, embodiments of the present aspect of the invention differ from this arrangement by providing a plurality of outlets arranged at the operationally lower end of the milk collecting bowl to enable, application of vacuum to the bores of the milking cup liners and the drawing away of milk from the milk collecting bowl. Figure 12 illustrates a first embodiment of such a system. As can be seen the claw 114 is generally the same as the embodiment of figure 11, accordingly like components have been given the same reference numerals, and will not be explained again for brevity. In this example the bowl 1200 includes two outlets 1210 from the chamber 1202. These outlets 1210 perform the same function as those of figure 11. However due to the larger total cross section provided by the pair of outlets 1210, the milk occlusion level will tend to be lower on the outlet 1210, for example at a height of less than 50% of the height of the outlet 1210. In this example the outlets 1210 have a smaller individual radius than the outlet of figure 11. In this regard each outlet 1210 of figure 12 has an internal radius of approximately 7.25mm and the total cross sectional area of the pair of outlets is 359mm². The generally lower level of milk in the bowl relative to the outlets 1210 is believed to minimise the likelihood of slug formation and when slugs are formed minimise their size, thus contributing to a smoothing of the actual vacuum level within the chamber 1202. Other forms may have different radius outlets. For example the outlets of other embodiments may have a radius of above 6mm but below 8mm. Most commonly the radius will be between 7mm and 7.5mm.

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Figure 13 shows a second embodiment of a claw 114 in which the two milk outlets 1210 are arranged at different levels between the operationally upper 1206 and lower 1208 ends of the milk collecting bowl 1200 so that in use a rising milk level in the bowl will occludes an operationally lower outlet 1210(b) before an operationally higher outlet 1210(a). In this example the lower outlet 1210(b) will tend to drain away milk, whilst the higher outlet 1210(a) will tend to maintain a vacuum path to the chamber 1202, as the milk level will rarely occlude the higher outlet 1210(a). It is believed that this set-up will rarely have transient flow forming in the operationally higher outlet 1210(a) and as such will achieve a more consistent vacuum level within the claw.

Again, the claws 114 of figures 12 and 13 can accommodate a sensing system 136 for measuring a fluid parameter (typically pressure, volume or flow in the chamber 1202) related to a pressure in the bore 108 of all or many liners.

Figures 9 and 10 illustrate two exemplary a milking systems equivalent to those of figures 1a and 8 respectively. The systems of Figures 9 and 10 differ from those of figures 1 a and 8 insofar as they have a pair of long milk tubes 116(a) and 116(b) to individually connect to the two outlets 1210 of the claw, as illustrated in figures 12 and 13. In these examples the milk tubes 116(a) and 116(b) meet at a junction and are provided with vacuum from a common shared section of milk tube. The junction can be placed at any distance along the milk tube and be of any suitable type, e.g. a simple Y or T junction, a manifold, a reservoir or vessel with a single outlet into which both milk tubes enter. In some embodiments the milk tubes 116(a) and 116(b) may never join and may remain separated until the vacuum system 120 or even connect to separate vacuum systems.

Figure 14 is a schematic representation of selected components of another milking system. In particular, the figure shows part of the claw 114, the pressure compensation system 130 and a sensor system in the form of a milk flow sensor 136 in each of the milk tubes leading from the claw 114. In this example, the pressure compensation system includes:

a source 132 of compressed air, for use in applying compensatory pressure to the pulsation volume of the cluster’s milking cups (not shown).

A pressure regulating system 122, in the form of a vacuum driven pulsator, similar or such as the Surepulse 300D pulsator.

A controller 138 configured to control the pressure compensation system to adjust at least one of (and preferably both) a level and timing of application of positive air pressure to the pulsation volume from the compressed air source 132.

A valve 133 for selectively connecting the source of positive air pressure 132 to the pulsation tube 133’ for delivery to the pulsation volume via the claw 114. The valve operates as instructed by control commands (signals) issued by the controller 138.

A wired communications system 140 for communicating data between the sensor system 136 and the controller 138, and the controller 138 and the valve 133.

As will be seen the claw includes a double outlet according to the embodiment of figure 12.

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This embodiment operates as described in the embodiments described above, and will not be described for again for the sake of brevity.

Figure 15 is a schematic representation of selected components of an alternative milking system. The system is generally similar to that of figure 14, and like features are commonly numbered and perform equivalent functions. However the systems differ in that in this embodiment the sensor system 136 employed is mounted within the claw 114, and directly measures absolute pressure in its bowl. Moreover the communications system 140 includes at least one wireless link communicating data between the sensor system 136 and the controller 138.

The present inventors believe that the use of two outlets 1210 from the bowl 1200 of the claw 114, as disclosed herein, or a single outlet with a lifting design (as described below), may provide more stable operating vacuum in the milking system, and in particular at the teat end.

In turn, in conjunction with the use of the introduction of positive air into the pulsation volume to apply compressive load to the teat, this enables the system vacuum to be dialled down without causing undue cup-slip. In high line milking systems it is believed that the system vacuum can be turned down to less than 40kPa, e.g. to 39kPa, or 38 kPa, or 37 kPa, or 36 kPa or 35 kPa to achieve a target operating vacuum at the teat end of less than 37kPa, or 36 kPa or 35 Kpa, or 34kPa, 33 Kpa. In low line systems this is can be reduced further, say to a system vacuum of 35 kPa, 34kPa, 33kPa. to achieve the target operating vacuum at the teat end of less than 35kPa.

Figure 16 to 18 shows a further embodiment of a claw 114 useable in a milking system such as disclosed herein. The claw includes a milk collecting bowl 1200 that has a chamber 1202 formed within it. The bowl 1204 is generally cylindrical and is closed with a lid (not shown) so that a vacuum can be held within the chamber 1202. The chamber 1202 also receives milk through milk inlets 1204. In this case there are 4 milk inlets for connecting to four milking cups. In particular the milk inlets 1204 connects via a short milk tube to the bore of the milking cup liner 108 so that vacuum can be transferred to the liner bore 108 and milk can flow down to the bowl. In use the claw is oriented in the manner illustrated under the animal being milked, thus the collecting bowl can be seen to have an operationally upper end 1206 and an operationally lower end 1208. The bowl also has an outlet 1210 that connects to the long milk tube 116. The outlet 1210 is in the form of an outlet tube that has an opening at its first, operationally lower end 1210a. The long milk tube is connected to a second end 1210b of the outlet tube. The second end 1210b is located outside the chamber 1202. The long milk tube is connected at its other end to a vacuum system 120 so that a vacuum can be applied to the liner bore 108, and so that milk can be drawn away from the cluster to the reservoir (Res.). In this example, the outlet 1210 will be placed so that its first end 1210a is located very close to the inner wall of the chamber 1201, at its lowest point. Preferably the space left 1208a is less than 5mm, but may be less than 3mm or even less than 1mm. In other embodiments the outlet tube can touch the inner wall of the chamber, in which case an inlet port (not shown) can be provided through the wall of the tube near its lowermost end. The opening (or inlet port) is preferably placed so that it is fully occluded by milk during milking. As explained above (when used in embodiments of the previously described embodiments of the present invention), the claw 114 includes a sensing system 136 for measuring a fluid parameter (typically pressure, volume or flow in the chamber 1202).

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In use, during milking, milk partly fills the chamber 1202 within the bowl and rests by gravity a level part way up the outlet tube 1210 from the lower end 1208 of the bowl 1200. Because of the location of the opening or inlet port of the outlet pipe, at or near the lowest point in the chamber 1202 the opening is fully occluded by milk. The application of vacuum to the second end of outlet tube1210b and increasing volume of milk within the chamber 1202 causes suction to draw milk out of the bowl down the long milking tube 116. Milk will, instead of flowing in the form of a transient flow where “slugs” of milk form and are drawn away, flow in a continuous manner in the milk tube. The cross sectional diameter of the milk tubes can be as set out in the previous embodiment.

In an alternative embodiment the claw can be substantially identical to that of figures 16 to 18, but omit 10 the second milk outlet tube. Such an embodiment still utilises a lifting milk outlet tube that cause milk to be drawn upwards out of the milk collecting bowl though the milk outlet tube. In such an embodiment a single milk tube system can be used, and at least some of the advantages of the present disclosure realised.

It will be understood that the invention disclosed and defined in this specification extends to all alternative 15 combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.

Claims

1. A claw usable with in a milking system, said claw including:

2. A claw as claimed in claim 1 wherein there are two outlets from the milk collecting bowl.

3. A claw as claimed in any one of the preceding claims wherein the milk outlet are arranged at the same level between the operationally upper and lower ends of the milk collecting bowl.

4. A claw as claimed in any one of claims 1 or 2 wherein the milk outlets are arranged at different levels between the operationally upper and lower ends of the milk collecting bowl..

5. A claw as claimed in any one of the preceding claims wherein the outlets comprise a milk outlet tube having a first end within the milk collecting bowl and a second end outside the milk collecting bowl.

6. A claw as claimed in claim 5 wherein the first end of the milk outlet tube is positioned at or near an operationally lower end of the milk collecting bowl.

7. A claw usable with in a milking system, said claw including:

at least one outlet arranged at the operationally lower end of the milk collecting bowl, wherein said outlet comprises a milk outlet tube having a first end and a second end, the first end being located within the chamber and at or near the operationally lower end of the milk collecting bowl, the second end being located outside the milk collecting bowl and being connectable to a vacuum source to enable application of vacuum to the milking cup liners of the plurality of milking cups and the drawing away of milk from the milk collecting bowl though the milk outlet tube.

8. A claw as claimed in claim 7 wherein the second end of the milk outlet tube is located above the operationally lower end of the milk collecting bowl.

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9. A claw as claimed in any one of claims 7 or 8 wherein the second end of the milk collecting tube is located near to or above the operationally upper end of the milk collecting bowl.

10. A claw as claimed in any one of claims 7 to 9 wherein application of a vacuum source to the second end of the milking tube draws milk away milk from the milk collecting bowl upwards though the milk outlet tube.

11. A claw as claimed in any one of claims 7 to 10 which includes a plurality of outlets from the milk collecting bowl.

12. A claw as claimed in claim 11 wherein each outlet comprises a milk outlet tube having a first end and a second end, the first end being located within the chamber and at or near the operationally lower end of the milk collecting bowl, the second end being located above the operationally lower end of the milk collecting bowl and being connectable to a vacuum source to enable application of vacuum to the milking cup liners of the plurality of milking cups and the drawing away of milk from the milk collecting bowl upwards though the milk outlet tube.

13. A claw as claimed in any one of claims 11 or 12 wherein there are two outlets from the milk collecting bowl.

14. A claw as claimed in any one of claims 6 to 13 wherein the first end is spaced from an inside wall of the milk collecting bowl by less than 5mm.

15. A claw as claimed in any one of claims 5 to 6 wherein the second end of the milk outlet tube is arranged to be connected to the vacuum source.

16. A claw as claimed in any one of the preceding claims includes at least one transducer to measure a fluid parameter.

17. A milking cluster including a claw as claimed in any one of the preceding claims and a plurality of milking cups each connected to a respective one of the plurality of milk inlets.

18. A milking system including either one of a cluster as claimed in claim 17; or a claw as claimed in any one of claims 1 to 16.