AU2016216736B1

AU2016216736B1 - Milking system and method

Info

Publication number: AU2016216736B1
Application number: AU2016216736A
Authority: AU
Inventors: Richard Paul Wallace
Original assignee: BULLSEYE AUSTRALIA Pty Ltd
Current assignee: BULLSEYE AUSTRALIA Pty Ltd
Priority date: 2016-05-04
Filing date: 2016-08-19
Publication date: 2017-09-28
Anticipated expiration: 2036-08-19

Abstract

The present disclosure provides a method of milking a mammal which includes, applying a vacuum to the lower end of a milking cup liner; and modulating the pressure in the pulsation volume to cause a milking operation on a teat of an animal that is 5 inserted into the top end of the bore. The modulation includes 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 close the liner bore to thereby stop milk flow from the teat. The modulation includes applying positive 0 pressure to the pulsation volume to apply compressive load to the teat

Description

1001448332 1 2016216736 19 Aug 2016

Milking system and method

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 5 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 0 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 5 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 20 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 25 the liner bore in the off phase of the milking operation. Moreover the inventor has realised that teat damaged may be reduced by providing a controlled compressive load on the teat between milking “on” periods. Most preferably the compressive load should be sufficient to drive blood and lymphatic fluid upwards and out of the teat. The compressive load should be above 2.0N/cm2, but preferably it is at or about 2.5N/cm2. 1001448332 2 2016216736 19 Aug 2016

In one aspect the present invention provides a method of milking a mammal using a milking cup 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 5 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, the method including:

Applying a vacuum to the lower end of the liner; 0 Modulating the 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 5 close the liner bore to thereby stop milk flow from the teat, said modulation including applying positive pressure to the pulsation volume to apply compressive load to the teat.

Preferably the method can include applying compressive load to the teat in a manner that causes application of said load at the lowermost part of the teat before the application of compressive load higher up the teat. Preferably the compressive load is 20 initially applied to the lowermost 1 to 3mm of the teat. Most preferably the compressive load is initially applied to the lowermost 2mm.

The method can include providing collapsing means to cause sequential collapse of the liner against the teat from the lowermost part of the teat. The collapsing means can include an insert placed within the pulsation volume. In other embodiments the 25 collapsing means can include a profiled inner surface of the shell. The 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.

According to a further aspect the present invention provides a method of milking a mammal using a milking cup of the type including a shell and a flexible liner, said liner 30 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 1001448332 3 2016216736 19 Aug 2016 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, the method including:

Applying a vacuum to the lower end of the liner; 5 Modulating the 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 0 close the liner bore to thereby stop milk flow from the teat and to apply compressive load to the teat; the method further including:

Determining a pressure in the bore; and

Applying a positive pressure to the pulsation volume in the off phase, wherein the level of positive pressure applied is determined on the basis of said determined pressure. 5 The pressure can be determined by any one or more of the following:

Measuring pressure at or near the lower end of the bore or other related position;

Estimating pressure at or near the lower end of the bore my measuring a milk flow rate or milk flow volume, from the bore.

The pressure is determined at least at a time when milk is flowing during the “on” phase. 20 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 compressive load applied to the teat by the liner that is caused by the application of increased pressure in the pulsation volume is preferably above 2.0 N/crn2. Most 25 preferably it is at or about 2.5N/cm2.

The method can include connecting the pulsation volume to a source of air to apply the positive pressure. The source can apply a predefined volume of air to the pulsation volume that corresponds to the determined level of positive pressure to be applied.

Preferably the method can include applying compressive load to the teat in a manner 30 that causes application of said load at the lowermost part of the teat before the application of compressive load higher up the teat. Preferably the compressive load is 1001448332 4 2016216736 19 Aug 2016 initially applied to the lowermost 1 to 3mm of the teat. Most preferably the compressive load is initially applied to the lowermost 2mm.

The method can include providing collapsing means to cause sequential collapse of the liner against the teat from the lowermost part of the teat. 5 The milking cup 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). 0 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 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. 5 In a second aspect the present invention provides a method of milking a mammal using a milking cluster 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 being connected (usually indirectly) to a milk tube at the lower end thereof, said milk tube being adapted to apply a vacuum to the bore of the liner and convey milk Ό to a milk reservoir; 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, ; the method including: 25 for each milking cup, applying a vacuum to its liner bore; modulating the 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 30 which the pulsation volume is at an increased pressure relative to the “on” phase to close the liner bore to thereby stop milk flow from the teat and to apply compressive load to the teat; the method further including: 5 2016216736 19 Aug 2016 1001448332 determining a pressure in the bore ; and applying a positive pressure to the pulsation volume in the off phase, wherein the level of positive pressure applied is determined on the basis of said determined pressure.

The pressure can be determined by any one or more of the following: 5 Measuring pressure at or near the lower end of the liner bore or other related position, such as in the milk tube, milk reservoir or a manifold to which one or more of the liner bores are connected;

Estimating pressure at or near the lower end of the liner bore by measuring a milk flow rate or milk flow volume. The milk flow rate or volume can be measured in the liner 0 bore, in the milk tube, in a milk reservoir, or a manifold to which the liner bores are connected, or any downstream point.

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 15 while the animal is being milked.

The compressive load applied to the teat by the liner that is caused by the application of increased pressure in the pulsation volume is preferably above 2.0 N/cm2. Most preferably it is at or about 2.5N/cm2.

The method can include connecting the pulsation volume to a source of air to apply the 20 positive pressure. The source can apply a predefined volume of air to the pulsation volume that corresponds to the determined level of positive pressure to be applied.

Preferably the method can include applying compressive load to the teat in a manner that causes application of said load at the lowermost part of the teat before the application of compressive load higher up the teat. Preferably the compressive load is 25 initially applied to the lowermost 1 to 3mm of the teat. Most preferably the compressive load is initially applied to the lowermost 2mm.

The method can include providing collapsing means to cause sequential collapse of the liner against the teat from the lowermost part of the teat.

The milking cup can include an insert placed within the pulsation volume. The insert 30 may cause one or more of the following: control or limit movement of the liner; 1001448332 6 2016216736 19 Aug 2016 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 5 profiled inner surface of the shell. The 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.

In a further aspect the present invention provides a pressure compensation system for use with a milking system which includes: 0 at least one milking cup 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 5 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, a vacuum system in fluid communication the bore of the liner and the pulsation volume; :0 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 25 which the pulsation volume is at an increased pressure relative to the “on” phase to close the liner bore to thereby stop milk flow from the teat and to apply compressive load to the teat; a milk reservoir in fluid communication with the liner bore and adapted to receive milk; 30 the pressure compensation system including: a sensing system configured to measure a fluid parameter related to a pressure in the bore; 1001448332 7 2016216736 19 Aug 2016 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 5 parameter measurement.

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. 0 The sensing system can determined pressure 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 5 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 20 to control fluid flow in the pressure regulating system.

The compressive load is preferably applied the teat in a manner that causes application of said load at the lowermost part of the teat before the application of compressive load higher up the teat. Preferably the compressive load is initially applied to the lowermost 1 to 3mm of the teat. Most preferably the compressive load is initially applied to the 25 lowermost 2mm.

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: 30 control or iimit movement of the liner; 1001448332 8 2016216736 19 Aug 2016 reduce the volume of the pulsation volume (compared to the volume that would exist absent the insert).

The pressure compensation system can further include a wireless communications system configured to enable communication between at least the sensing system and 0 controller. The wireless communications system may also be configured to enable communication between the controller and the one or more valves or actuators.

The pressure compensation system can be configured to cause a compressive load to be applied to the teat by the liner, that is preferably above 2.0 N/cm2. Most preferably it is at or about 2.5N/cm2. 5 In a further aspect the present invention provides a milking system including at least one milking cup 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 :0 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, a vacuum system in fluid communication the bore of the liner and the pulsation volume; a pressure regulating system configured to modulate the fluid pressure in the pulsation 25 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 30 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; and 1001448332 θ 2016216736 19 Aug 2016 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 5 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.

Preferably the application of positive increased pressure in the pulsation volume causes 0 the application of a compressive load applied to the teat by the liner of more than above 2.0 N/cm2. Most preferably it is at or about 2.5N/cm2.

The compressive load is preferably applied the teat in a manner that causes application of said load at the lowermost part of the teat before the application of compressive load higher up the teat. Preferably the compressive load is initially applied to the lowermost 1 5 to 3mm of the teat. Most preferably the compressive load is initially applied to the lowermost 2mm.

The pressure compensation system can include an insert placed within the pulsation _0 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 25 collapsing means. The collapsing means can additionally or alternatively include a profiled inner surface of the shell. The 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: 1001448332 10 2016216736 19 Aug 2016 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.

The pressure is determined at least at a time when milk is flowing during the “on” phase. 5 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 0 to be applied.

The pressure compensation system can further include one or more valves or actuators to control fluid flow in the pressure regulating system. 5 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 _0 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; 25 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.

In another aspect the present invention provides a milking system configured to perform a method as described herein. 1001448332 11 2016216736 19 Aug 2016

In each of the aspects disclosed herein the compressive load can be greater than about a blood pressure in the animal’s teat, say above a pressure of0.8 to 1.2Ncm'2. In some embodiments the compressive load at or above 1.2Ncm'2. In some embodiments the compressive load is above 1.5Ncm'2. In some embodiments the compressive load is 5 above 2.0Ncm'2. In preferred embodiments the compressive load is above between about 2.0 and 2.5 Ncm'2. In some case a higher compressive load may be desirable.

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: 0 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 5 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; 20 Figures 5a and 5b illustrate time plots of the modified pressure in pulsation volume in an embodiment of the present invention;

Figure 6 illustrates a plot of the compressive load vs operating vacuum in the liner bore in a milking system; and

Figure 7 illustrates a plot similar to that of figure 5b showing the modified pressure in 25 pulsation volume in an embodiment of the present invention having 2x2 pulsation;

Figure 8 illustrates a schematic cross section of a milking cup, including an insert, that can be used in embodiments of the present invention;

Figure 9 illustrates another embodiment of a milking system according to the present invention. 30

Detailed description of the embodiments 1001448332 12 2016216736 19 Aug 2016

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 can be considered to be a conventional milking system that has been modified to include a pressure compensation system according to an embodiment of an aspect of the present 5 invention so that it can implement a method according to an embodiment of a further aspect of the present invention.

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 0 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 the milking claw 114, which in turn connects to a milk tube 116. 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 5 positions so as to create a pulsation volume 110 between them in. 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 0 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. 25 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 30 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 1001448332 13 2016216736 19 Aug 2016 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 5 110 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 pump, compressor, compressed air tank, or other 0 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 standalone 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 5 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 0 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. 25 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 30 communication between the controller 138 and the one or more valves 133 or actuators of the pressure compensation system 130. 1001448332 14 2016216736 19 Aug 2016

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 5 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; 0 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.

Indirect connection to such locations through a pipe, hose, valve or other means is also possible. 5 The choice of where to connect the source or positive air pressure may involve a tradeoff. 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 JO pulsator may require pressurisation of a greater volume of the system, but may provide easier mechanical connection at a single location in the system.

Figure 2 illustrates a plot 200 of the vacuum level applied to the pulsation volume 110 during the 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, 25 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 30 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. 1001448332 15 2016216736 19 Aug 2016 “D” phase, or “off” phase, in which the pressure in the pulsation volume 110 is higher (he, 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. 5 “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 0 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 opening the pulsation volume to atmosphere, air, under positive pressure is introduced into the pulsation volume 110. This causes the 5 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 0 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 25 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.

In a preferred 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 30 injected can be determined by knowing the volume of: the pulsation volume 110 (including any reduction in volume caused by the use of an insert 700), 16 2016216736 19 Aug 2016 1001448332 the short pulsation tube(s) 112, the portion 113’ of the long pulsation tube(s) 113 between the valve 133 and the milking cluster; and any connecting components or manifolds; 5 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 0 more quickly than the pressure based approach, although either may be used.

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 5 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 teat cups 102 or into the short pulsation tubes 112, but !0 these schemes require additional valving so may be less cost effective. Figure 9 also 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 5a. 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 25 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 the D phase equalising at atmospheric pressure, (~101.3 kPa), pressure is increased to above atmospheric pressure, Figure 5b illustrates a similar plot to that of figure 5a but shows the operation over several pulsation cycles. As will be appreciated the C phase is 30 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 releasing the positive pressure that is 1001448332 17 2016216736 19 Aug 2016 added to the pulsation volume 110 during the C and D phases the pulsator 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 5 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 believed that the optimal compressive load is at or about 2.5N/cm2,

Accordingly a key aspect of the preferred embodiments is the control of the pressure 0 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 5 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 :0 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 sensor 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 25 114. Since this chamber may be in fluid communication with the liners of several teat cups, the single measurement will apply to all such cups. However, measurement may be performed on a cup-by-cup basis to enable individual control of compressive load on individual teats. The sensor 136 communicates the measured pressure data back to the controller 138 via a communications network 140. The communications network can be 30 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 sensor systems include with multiple transducers per milking cluster, 18 2016216736 19 Aug 2016 1001448332 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 5 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 0 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 5 be set dynamically so that the compressive load substantially matches a target compressive load level (e.g. 2.5N/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 !0 within predetermined bands (e.g. 2-7kPa, 7-12kPa, 12-17kPa and greater than 17 kPa).

As noted above the operating pressure in the lower part of the liner bore 108 will drop due to milk flow. However the 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 25 sensor 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. 30 Figure 6 illustrates a plot of compressive load applied to the teat of an animal being milked at different levels of operating vacuum under the teat during the pulsation cycle. As can be seen, if the vacuum falls to below 20kPa the liner may (or may not) close, but no compressive load will be applied to the teat. If 45kPa is maintained then a 1001448332 19 2016216736 19 Aug 2016 compressive load at about 2.5 N/cm2 is achieved. However, it has been found that the milk flow in the liner reduces operating vacuum to too lower level. To compensate for this additional positive pressure air (at the right pressure level) is used to raise the compressive load applied to the teat 5 According to preferred embodiments of the present invention, positive pressure can be applied to the pulsation volume during the C phase of the pulsation cycle to lift the compressive load on the teat back into the shaded zone on figure 6, regardless of the operating pressure drop that occurs.

Since the controller 138 knows the volume to be pressurised and the pressure of the air 0 delivered from the source 132 it can calculate the volume of air to be delivered to achieve the determined positive pressure. In the preferred embodiment this is converted to a control signals for solenoid valve 133. The solenoid valve 133 is arranged to connect the positive fluid pressure line to long pulsation tube(s) 113 for a time determined by the pressure level to be applied. This results in the air pressure in the 5 pulsation volume 110 being increased to the determined positive pressure level. When the positive air pressure is injected into the system the pulsator 122 is isolated, from the long pulsation tube 113 by valve 133 so that the pulsator 122 does not release pressure in the pulsation volume 110.

In a preferred form, the controller 138 sends two control signals to the solenoid valve !0 133. A first control signal will indicate when to open, and/or an opening sequence type.

The sequence type will be determined by the timing of the pulsation sequence and type of cluster, e.g. whether the cluster is a 2x2 cluster or 4x0. The second control signal will be either a closing time or the length of time over which the valve should remain open (i.e. a duration of pressurisation). In order to synchronise the pressure compensation 25 system’s 130 controller 138 with the pulsation cycle an input can be received from a control system forming part of the pulsation system 122.

In a preferred form the cluster is a 2x2 cluster, and thus pulsation to the cups occurs in pairs with the pulsation sequences interleaved in time and offset from each other by half a period. When such a system is used the valve 133 can be a three way valve, which 30 alternately connects the positive pressure air source 132 to a respective one of the pair of long pulsation tubes during the C phases or their respective pulsation cycles. As noted above valve 133 also isolates the pressurised portion of the long pulsation tube, 1001448332 20 2016216736 19 Aug 2016 short pulsation tube and pulsation volumes of the two teat cups connected thereto from the pulsator 122 until the D phase ends.

Figure 7 illustrates a plot similar to that of figure 5b showing the modified pressure in pulsation volume in an embodiment of the present invention having 2x2 pulsation. As 5 can be seen two pulsation cycles 500 and 500’ are illustrated. The pulsation cycles 500 and 500’ are interleaved with each other and out of phase by half a cycle.

It should be noted that in alternative forms different valving and connection arrangements for the pulsation system 100 and pressure compensation system 130 may be used. 0 Figure 9 illustrates one such example. The example is similar to the previous embodiment and the same features have been numbered with the same reference numerals to aid understanding. In this example, the pressure compensation system is connected directly to the pulsator 122, so that positive pressure air is provided directly to the pulsator 122. Ih this example, the source of positive pressure 132 is connected to 5 the pulsator 122 by the positive pressure fluid delivery line 134. An isolator valve 133’ is also provided on the positive pressure fluid delivery line 134.

In general the present example operates, as follows. Instead of the pulsator 122 exposing the pulsation volume 110 to atmospheric pressure in the C and D phases of the pulsation cycle (as in the previous embodiment), it is instead exposed to the source !0 of positive pressure 132. The source of positive pressure 132 may be provided with a pressure regulating system, e.g. a regulating valve 133’ or the like, to enable control of the level of positive pressure applied to the pulsator 122. The pressure regulating system can be controlled in accordance with the methods described herein to achieve the desired compressive load on the teat, as the desired time within the pulsation cycle. 25 The regulating valve 133’ could be a stand-alone device, receiving a separate control signal, or integrated into either the pulsator 122 or source of positive pressure 132.

Other than the route by which the source of positive pressure 132 is connected to the pulsation volume, the present embodiment works in the identical manner to the previous embodiments. 30 In preferred forms of each of the embodiments described above, the source 132 will preferably supply air at a pressure of between 1 and 4 bar. The opening durations will typically be between 10 and 130 ms long. Most preferably they are between 30 and 1001448332 21 2016216736 19 Aug 2016 100ms. This may vary depending on liner type, with triangular liners having optimum opening times less than 85ms.

It has also been realised by the present inventor that it is desirable to minimise the duration of the C phase of the pulsation cycle. This allows a longer D phase and 5 possibly a longer B phase, which may be beneficial for milk production rates and animal health.

The application of positive pressure to the pulsation volume 110 itself, may cause a decrease in C phase time, but to further decrease it, and further control the application of compressive load preferred embodiments use a milking cup with a minimised 0 pulsation volume 110, and or a means to control the collapse of the liner bore 108.

In a preferred form this is achieved by providing an insert within the pulsation volume 110. The insert can be of the type described in Australian patent application 2008202821, the contents of which are herein incorporated by reference, and as illustrated schematically in Figure 8 of the present specification. Such inserts are sold 5 under the brand name of “SurePulse”.

Figure 8 illustrates a milking cup 102, that is the same as that shown in figures 1a and 3, and the same features have been numbered with the same reference numerals. However the milking cup 102 has an insert 700 located in the pulsation volume 110. The insert 700 acts to minimise the air volume in the pulsation volume and acts as a !0 collapsing means to cause sequential collapse of the liner against the teat from the lowermost part of the teat. Projections on the lower inner surface of the inert are provided that indent the liner to pinch the liner bore at a location below the tip of the teat. When positive air pressure is applied in the pulsation volume the liner 106 collapses from the position of the indentations so that compressive load is applied to the 25 lowermost part of the teat before the application of compressive load higher up the teat.

The use of the insert can assist in ensuring that the compressive load is initially applied to the lowermost 1 to 3mm of the teat, and most preferably at the lowermost 2mm.

By minimising the pulsation volume 110, the amount of air to be delivered to positively pressurise the pulsation volume is decreased. This enables faster application of the 30 positive pressure and minimisation of the C phase. The reduced volume may also increase the accuracy of pressurisation of the pulsation volume as a lower volume of air needs to be applied. 2016216736 19 Aug 2016 1001448332 22

Finally the insert 700 can have further beneficial effects on teat health by limiting outwards movement of the liner 106, and controlling its collapse from the B phase to the D Phase. In some situations, the liner 108, if left unconstrained by an insert 700, can balloon during the B phase. Consequently when the vacuum is released in the C phase 5 an uncontrolled elastic contraction of the liner 108 onto the teat can occur, which causes damage to the teat. Use of an insert 700 ameliorates this problem. In other embodiments a profiled shell can be used in place of the inserts. When using such shells the inside of the shells is profiled to be dimensionally similar to the inside of the inserts described above. In this case the collapsing means can include a projection 0 formed on a profiled inner surface of the shell which operates like the projection on the insert.

As can be seen from the foregoing, the preferred embodiments of the present invention can enable one or more of the following advantages to be achieved;

An extension of the D phase of the pulsation cycle with sufficient compressive load. This 5 can promote teat health by reducing congestion at the teat tip.

The increased compressive load on the teat during the D phase improves the gripping effect of the teat cup on the teat, which may lead to a decrease in cup slip.

By extension, the ability to achieve these benefits means that the vacuum level applied to the bore of the insert (i.e. milk tube) may be reduced without negatively impacting the :0 milking process. In such case, a decrease in vacuum may additionally aid in promoting good teat health.

It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations 25 constitute various alternative aspects of the invention.

Claims

1. A method of milking a mammal using a milking cluster 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 being connected (usually indirectly) to a milk tube at the lower end thereof, said milk tube being adapted to apply a vacuum to the bore of the liner and convey milk to a milk reservoir; 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; the method including: for each milking cup, applying a vacuum to its liner bore; modulating the 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 close the liner bore to thereby stop milk flow from the teat and to apply compressive load to the teat; the method further including: determining a pressure in the bore; and applying a positive pressure to the pulsation volume in the off phase, wherein the level of positive pressure applied is determined on the basis of said determined pressure.

2. The method as claimed in either of claims 1 which further includes applying compressive load to the teat in a manner that causes application of said load at the lowermost part of the teat before the application of compressive load higher up the teat.

3. The method of claim 2 wherein compressive load is initially applied to the lowermost 1 to 3mm of the teat.

4. The method of any one of the preceding claims which includes providing collapsing means to cause sequential collapse of the liner against the teat from the lowermost part of the teat.

5. The method of claim 4 wherein collapsing means includes either or both of: an insert placed within the pulsation volume a profiled inner surface of the shell.

6. The method of any one of the preceding claims wherein the pressure in the bore is determined by any one or more of the following: Measuring pressure at or near the lower end of the bore or other related position; Estimating pressure at or near the lower end of the bore my measuring a milk flow rate or milk flow volume, from the bore.

7. The method as claimed in any one of the preceding claims wherein the pressure is determined at least at a time when milk is flowing during the “on” phase.

8. The method as claimed in any one of the preceding claims wherein pressure is determined at a plurality of points during the pulsation cycle across both the off and on phases.

9. A method as claimed in any one of the preceding claims wherein the method includes connecting the pulsation volume to a source of air to apply the positive pressure.

10. A method as claimed in claim 11 wherein the method includes applying, from the source of air, a predefined volume of air to the pulsation volume that corresponds to the determined level of positive pressure to be applied.

11. The method as claimed in any one of the preceding claims wherein compressive load applied to the teat by the liner that is caused by the application of increased pressure in the pulsation volume is above 2.0 N/cm2.

12. A pressure compensation system for use with a milking system which includes: at least one milking cup 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, a vacuum system in fluid communication 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 close the liner bore to thereby stop milk flow from the teat and to apply compressive load to the teat; a milk reservoir in fluid communication with the liner bore and adapted to receive milk; the 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.

13. A pressure compensation system as claimed in claim 12 wherein the sensing system further includes any one or more of: 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.

14. A pressure compensation system as claims in either of claims 12 or 13 wherein the sensing system determines pressure at least at a time when milk is flowing during the “on” phase.

15. A pressure compensation system as claims in any one of claims 12 to 14 wherein the sensing system determines pressure at a plurality of points during the pulsation cycle across both the off and on phases.

16. A pressure compensation system as claims in any one of claims 12 to 15 wherein pressure compensation system is configured to supply a predefined volume of air to the pulsation volume that corresponds to the determined level of positive pressure to be applied.

17. A pressure compensation system as claims in any one of claims 12 to 16 which includes one or more fluid delivery lines connected between a source of positive air pressure and the pulsation volume.

18. A pressure compensation system as claims in any one of claims 12 to 17 which further includes one or more valves or actuators to control fluid flow in the pressure regulating system.

19. A pressure compensation system as claims in any one of claims 12 to 18 which further includes collapsing means to cause sequential collapse of the (or each) liner against the teat from the lowermost part of the teat.

20. A pressure compensation system as claims in claim 19 wherein the collapsing means includes either or both of: an insert placed within the (or each) pulsation volume a profiled inner surface of the (or each) shell.

21. A pressure compensation system as claims in any one of claims 12 to 20 which further includes a wireless communications system configured to enable communication between any one or more of: The sensing system and controller; The controller and one or more valves or actuators.

22. A pressure compensation system as claims in any one of claims 12 to 21 which is configured to cause a compressive load to be applied to the teat by the liner, that is preferably above 2.0 N/cm2.

23. A milking system including: at least one milking cup 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, a vacuum system in fluid communication 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; and a pressure compensation system as claimed in any one of claims 12 to 22.