DESCRIPTION The present invention relates to clawbowl for a milking cluster.

Milking clusters typically comprise a plurality of teat cups which each yield a flow of milk from an animal, and a clawbowl whose function is to combine the flows of milk into a single flow of milk for onward delivery.

A clawbowl typically comprises a plurality of milk inlets for short milk tubes leading to the teat cups, and a milk outlet for a long milk tube that delivers milk from the milking cluster. If, during the milking of an animal, the milking cluster falls from the teats of the animal and onto the floor, the teat cups may suck up unwanted fluids from the floor. There is then a risk of the unwanted fluids entering the milk line and contaminating the milk. Therefore, many clawbowls include some form of shut-off mechanism to stop the teat cups from continuing to suck after the milking cluster has fallen to the floor. One such shut-off mechanism is disclosed in US 3,014,455, which discloses a valve body that is movable between a closed position where the valve body blocks the milk outlet of the clawbowl, and an open position where the valve body unblocks the milk outlet. During milking, a vacuum is applied through the long milk tube and into the clawbowl via the milk outlet of the clawbowl. The vacuum is transmitted to the animal's teats via the milk inlets and the short milk tubes, to draw milk from the animal. The valve body is held in the open position by a pressure differential between the vacuum in the clawbowl and atmospheric pressure. If the milking cluster falls to the floor, then the teat cups are no longer filled by the animal's teats, and so the vacuum within the clawbowl drops towards atmospheric pressure, releasing the valve body and allowing it to fall into the closed position to block off the milk outlet and the vacuum so that the teat cups cease to suck. Whilst the known arrangement is effective at shutting off the milk outlet and vacuum, any unwanted fluids that enter the clawbowl from the floor via the teat cups after the valve body shuts off will remain in the clawbowl. Then, when milking is restarted, the fluids may get sucked out through the milk outlet of the clawbowl and into the milk, causing contamination of the milk.

Furthermore, when the milking cluster is cleaned with washing and/or flushing fluids, there is risk that some cleaning fluids may still remain in the clawbowl after cleaning has been completed, and that these left-over fluids could find their way into the milk in a subsequent milking cycle.

It is therefore an aim of the invention to help reduce any risk of unwanted fluids contaminating milk extracted from an animal.

According to a first aspect of the invention, there is provided a clawbowl for a milking cluster, the clawbowl comprising a plurality of milk inlets for receiving milk from a plurality of teat cups of the milking cluster, and a milk outlet for outletting the received milk for onward delivery. The clawbowl comprises a valve body that is movable between a closed position where the valve body blocks the milk outlet, and an open position where the valve body unblocks the milk outlet, and further comprises a drain passageway leading from an inside of the clawbowl to an outside of the clawbowl, wherein the valve body blocks the drain

passageway when the valve body is in the open position, and unblocks the drain passageway when the valve body is in the closed position to allow fluid to drain from the inside to the outside of the clawbowl.

Due to the drain passageway, any unwanted fluids that enter the clawbowl from the floor via the teat cups, or which still remain in the clawbowl after cleaning, are able to drain out of the clawbowl through the drain passageway whilst the valve body is in the closed position, so that they do not exit the clawbowl through the milk outlet and into the milk when milking is restarted. Since the drain passageway is blocked by the valve member when the valve member is in the open position, the drain passageway does not cause any unwanted loss of vacuum or loss of milk during milking. The drain passageway is considered to be blocked when fluids inside the clawbowl are not able to leave the clawbowl by entering and leaving the drain passageway.

The valve body may comprise a shaft extending from an inside to an outside the clawbowl, a milk plug connected to the shaft at the inside of the clawbowl, and a pressure plug connected to the shaft at an outside of the clawbowl. The milk outlet may be blocked by the milk plug when the valve body is in the closed position, and unblocked by the milk plug when the valve body is in the open position. The drain passageway may be blocked by the pressure plug when the valve body is in the open position, and unblocked by the pressure plug when the valve body is in the closed position. This provides a convenient arrangement for controlling the blocking and unblocking of the milk outlet and the drain passageway.

The clawbowl may comprise an aperture through which the shaft passes, and the valve body may be movable from the closed position to the open position by moving the shaft through the aperture in a direction towards the inside of the clawbowl. Advantageously, the aperture may form at least part of the drain passageway, so that another separate aperture for the drain passageway does not need to be formed. A channel between the milk plug and the clawbowl when the valve body is in the closed position may form at least part of the drain passageway. This may be particularly advantageous when the aperture through which the shaft passes also forms part of the drain passageway, since the channel allows the entrance to the drain passageway at the inside of the clawbowl to remain unblocked even when the milk plug is moved to the entrance of the aperture in the closed position.

Accordingly, by virtue of the channel, the drain passageway leads into the inside of the clawbowl at a position beyond the milk plug when the valve body is in the closed position. Alternatively, the drain passageway may be entirely separate from the aperture through which the shaft passes. The clawbowl may comprise an inner valve seating for the valve body at the inside of the clawbowl, and an outer valve seating for the valve body at the outside of the clawbowl, and the drain passageway may lead from beyond the inner valve seating at the inside of the clawbowl to within the outer valve seating at the outside of the clawbowl. The milk plug may seal against the inner valve seating when the valve body is in the closed position and not the open position, and the pressure plug may seal against the outer valve seating when the valve body is in the open position and not the closed position.

Preferably, the inner valve seating surrounds the milk outlet such that the milk plug blocks the milk outlet when valve body is in the closed position, and the outer valve seating surrounds an entrance to the drain passageway at the outside of the clawbowl such that the pressure plug blocks the drain passageway when the valve body is in the open position.

The valve body may be configured to remain in the open position when a vacuum exists inside the clawbowl, by the vacuum holding the pressure plug against the outer valve seating, so that the milk outlet remains open during milking and milk can exit the clawbowl via the milk outlet.

The valve body may be configured to move into the closed position when a vacuum is applied to the milk outlet and the pressure inside the clawbowl rises towards atmospheric pressure, so that the milk outlet is closed when the teat cups are opened to atmospheric pressure, as occurs if the teat cups fall away from the animal's teat. The closure may be achieved by the vacuum at the milk outlet drawing the milk plug of the valve body towards the milk outlet, and/or by the milk plug of the valve body moving downwardly under its own weight towards the milk outlet when a pressure difference between the inside of the clawbowl and atmospheric pressure drops below a threshold level and can no longer retain the valve body up in the open position.

The valve member and the drain passageway may be at a bottom of the clawbowl, and the milk outlet may be at a side of the clawbowl adjacent the valve member. Placing the drain passageway at the bottom of the clawbowl helps any unwanted fluids enter the drain passageway, and placing the milk outlet at the side of the clawbowl adjacent the valve member means that the valve member can easily block and unblock the milk outlet by moving downwards and upwards.

To aid construction of the milking cluster, the clawbowl may be formed of a base having the valve member and the milk outlet, and a lid having the milk inlets, wherein the lid is for fitting on the base. According to a second aspect of the invention, there is provided a milking cluster comprising the clawbowl of the first aspect, and a plurality of teat cups that are connected to the milk inlets of the clawbowl via short milk tubes.

Embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings, in which:

Fig. 1 shows a schematic perspective diagram of a milking cluster that incorporates a clawbowl according to a first embodiment of the invention;

Fig. 2 shows a schematic perspective diagram of a clawbowl forming part of the milking cluster of Fig. 1 ;

Fig. 3 shows a schematic cross-sectional diagram of the clawbowl of Fig. 2 with a valve body in an open position;

Fig. 4 shows a schematic cross-sectional diagram of the clawbowl of Fig. 2 with the valve body in a closed position;

Fig. 5 shows a schematic plan view of an alternative base of a clawbowl according to a second embodiment of the invention;

Fig. 6 shows an enlarged view of part of the base of Fig. 5; and

Fig. 7 shows a perspective view of the base of Fig. 5 when fitted with a valve body.

The drawings are not to scale. Same or similar reference signs denote same or similar features. The schematic diagram of Fig. 1 shows a milking cluster 1 of teat cups according to a first embodiment of the invention. The milking cluster connects milking equipment installed at a milking point of an animal stall within a milking parlour to the teats of an animal to be milked. The milking cluster comprises four teat cups 2, a clawbowl 3 having a milk outlet nipple 4 for connecting the clawbowl to a long milk tube (not shown) and a distributor 5 clamped to the top side of the clawbowl for connecting the cluster to long pulsation tubes (not shown) supplying milking pulses from a pulsator. The teat cups 2 are each composed of a rigid outer shell 6, for example made of stainless steel or plastic, and a flexible liner 7 which has a barrel portion for engaging about a teat, and at its upper end has a head portion 8 with a mouth through which the teat is engagable with the barrel of the liner. At the opposite, discharge end 9 of the teat cup, the liner is integral with a flexible short milk tube 10 connecting the teat cup to milk inlet nipples 1 1 on the top of the clawbowl so that milk extracted from an animal's teats is delivered to the clawbowl 3 from which the collected milk is supplied via the long milk tube to the milk line.

An annular space (not shown) between the shell 6 and the barrel of the liner 7 of each teat cup is called the pulse chamber and is connected via a short pulse tube 12 to the distributor 5 on the claw, via which vacuum and atmospheric pressure fed from the pulsator is automatically and alternately supplied to the pulse chambers of the four teat cups in order to flex the liners and stimulate milking of the engaged teats. Exiting internally into the head 8 of each liner 7 is an injection nozzle (not shown) for injecting treatment fluid internally into the liner. It is designed so as to direct fluid sprayed from the nozzle inwardly and towards the interior of the barrel of the liner. These nozzles are supplied with treatment fluid for sanitizing the teats, upon take-off, and disinfecting and rinsing the teat cups when the latter fall into their downwardly hanging position, by small diameter flexible tubes 16 connected to a treatment fluid distributor 5a clamped to the top of the clawbowl underneath the pulse distributor 5. The short milk tubes 10 have weaker sections 13 at positions immediately above the nipples 1 1 connecting the short milk tubes to the clawbowl. Following the end of the milking cycle, which is detected via a milk flow metre of the stall control unit as a reduction of milk flow below a predetermined level, an automatic cluster remover is signalled to take off the cluster from the cow's udder so that the teat cups are removed from the teats and fall into a downwardly hanging position, with the short milk tubes folding about their weaker sections 13, which serves to shut-off the short milk tubes from the clawbowl 3 and prevent treatment fluid sprayed upwardly into the liners 7 from contaminating the clawbowl.

Further details of the clawbowl 3 will now be described with reference to Figs 2 - 4, which show the clawbowl 3 in isolation from the other components of the milking cluster 1 . As shown in the perspective view of Fig. 2, the clawbowl 3 comprises a clear plastic base 24 having sidewalls 17 and a bottom 19. The milk outlet nipple 4 is positioned in the sidewalls 17 near the base 19. The clawbowl 3 further comprises metal lid 20 having a rim 22 which is sealed over the tops of the sidewalls 17 of the base 24 of the clawbowl by a gasket. The milk inlet nipples 1 1 are positioned in the lid 20 of the clawbowl. A rod 18 for mounting the distributors 5 and 5a extends upwardly through the centre of the clawbowl 3, and is threaded at its upper end above the lid 20.

The interior of the clawbowl 3 will now be described with reference to Figs. 3 and 4, which are cross-sectional views taken looking in along line CXS that is marked on Fig. 2. Fig. 3 shows the clawbowl 3 with the valve body 30 in an open position during milking, so that milk flows MLK1 received into the clawbowl 3 from each one of the milk inlet nipples 1 1 , are combined within the clawbowl and exit the clawbowl as milk flow MLK2 through the milk outlet nipple 4.

As can be seen in Fig. 3, the bottom 19 of the clawbowl is slopped towards the milk outlet nipple 4 to help encourage all milk to drain out of the milk outlet nipple 4, and the rod 18 extends through a tube 25 running right through the centre of the clawbowl 3. In this particular embodiment, a valve body 30 comprises a milk plug 32 and a pressure plug 36 which are connected to one another by a shaft 34.

However, other types of valve body may be implemented in alternative

embodiments.

The milk plug 32 and the shaft 34 are integrally formed from rubber, and the rubber pressure plug 36 is attached to the shaft 34. The milk plug 32 is

substantially hemispherical, and the shaft 34 extends from the centre of the hemispherical surface of the milk plug. The hemispherical surface of the milk plug defines a lower sealing surface 44. The pressure plug 36 is disk shaped, and the shaft 34 extends from the centre of the disk. The surface of the disc that is nearest the milk plug forms an upper sealing surface 46.

The shaft 34 passes through an aperture 26a that is formed through the bottom 19 of the clawbowl. To fit the valve body in the base of the clawbowl, the shaft 34 is passed through the aperture 26a from inside of the clawbowl, and then the pressure plug 36 is attached to the shaft 34.

The aperture 26a is slightly larger than the cross-section of the shaft 34, and so the shaft 34 is free to move up and down through the aperture 26a. When the valve body is moved upwardly into the open position shown in Fig. 3, the upper sealing surface 46 of the pressure plug 36 impacts against an outer valve seating 28 of the clawbowl. Furthermore, the lower sealing surface 44 of the milk plug is raised above an inner valve seating 29a of the clawbowl by the shaft 34, to allow the milk MLK1 to pass into the milk outlet nipple 4.

The valve body 30 is retained in the open position shown in Fig. 3 by a pressure differential between a vacuum in the inside of the clawbowl, which draws the milk MLK1 , MLK2 out the milk outlet nipple 4, and atmospheric pressure outside of the clawbowl. The upper sealing surface 46 sealing against the outer valve seating 28 helps prevent loss of vacuum or loss of milk occurring through the aperture 26a. A drain passageway 27 extends from the inside to the outside of the bottom 19 of the clawbowl. The entrance 40 to the drain passageway 27 at the inside of the clawbowl is beyond the inner valve seating 29a, and so in this embodiment the entrance 40 to the valve passageway 27 is always open regardless of the position of the valve body 30. The exit 42 of the drain passageway 27 at the outside of the clawbowl is within the outer valve seating 28, and so the drain passageway 27 is currently sealed off (blocked) by the upper sealing surface 46 of the pressure plug 36, to prevent loss of vacuum or loss of milk occurring through the drain

passageway 27.

Once the teat cups are withdrawn from the animal's teats, for example once all the milk from the animal has been harvested, or if the milking cluster unintentionally falls from the animal's teats, then air from the teat cups rushes into the clawbowl 3 via the milk inlet nipples 1 1 , raising the pressure within the clawbowl 3 towards atmospheric pressure. Once the pressure difference between the inside of the clawbowl and atmospheric pressure drops below a threshold level, the pressure difference is no longer sufficient to retain valve body 30 is the open position shown in Fig. 3, and the valve body 30 falls downwardly into a closed position under its own weight and under the influence of the air rushing from the milk inlet nipples 1 1 into the milk outlet nipple 4.

The schematic cross-sectional diagram of Fig. 4 shows the clawbowl 3 after the valve body 30 has fallen downwardly into the closed position by moving in the direction DIR. It can be seen that the valve body 30 falls downwardly until the lower sealing surface 44 of the milk plug impacts the inner valve seating 29a of the clawbowl. This seals off the milk outlet nipple 4 and the aperture 26a from the inside of the clawbowl, and prevents any further fluids from travelling into the milk outlet nipple 4 from the clawbowl. The shaft 34 suspends the upper sealing surface 46 of the pressure plug 36 some distance beneath the outer valve seating 28 of the clawbowl, thereby unblocking the drain passageway 27. Since the drain passageway 27 is

unblocked, any fluids within the clawbowl can simply drain out of the clawbowl via the drain passageway 27. Such fluids could include, for example, any unwanted fluids sucked up from the floor by the teat cups, before the vacuum within the clawbowl is blocked off by the milk plug 32 closing the milk outlet nipple 4, or any cleaning fluids which un-intentionally reach the clawbowl 3 via the milk inlet nipples 1 1 during cleaning of the teat cups.

When another animal is to be milked, a user can manually push the pressure plug upwardly towards the outer valve seating 28 to move the valve body 30 into the open position, unblocking the milk outlet nipple 4 to re-start the vacuum supply so that the teat cups can be applied to the animal. The valve member 30 is retained in the open position by the pressure differential between the inside and the outside of clawbowl, and vacuum transmitted along the drain passageway 27 also assists in keeping the upper sealing surface 46 of the pressure plug up against the outer valve seating 28 of the clawbowl. A second embodiment of the invention, which differs from the first embodiment only by the base of the clawbowl, will now be described with reference to Figs 5 - 7. Fig. 5 shows a plan schematic diagram of the alternate base of the clawbowl, and it can be seen that the drain passageway 27 of the first embodiment has been omitted, and has been replaced by enlarging the aperture for the shaft of the valve body, and adding channels to lead from the enlarged portions of the aperture to the beyond the inner valve seating.

Referring to Fig. 6, which shows an enlarged view of the bottom of the clawbowl base of Fig. 5, the aperture 26b for the shaft 34 of the valve body has been enlarged with cutaways 50 through the bottom of the clawbowl. The cutaways 50 are connected to channels 55, which lead from the inner valve seating 29b of the clawbowl, to beyond the inner valve seating 29b. The channels 55 are formed as grooves within the inner valve seating 29b. The entrance 23 to the milk outlet nipple 4 is also visible in Fig. 6.

The perspective diagram of Fig. 7 shows the clawbowl base of Figs 5 and 6, with the addition of the valve body 30. The valve body 30 is shown in the closed position, with the milk plug 32 resting upon the inner valve seating 29b, and blocking the entrance 23 to the milk outlet nipple 4. Since the channels 55 lead from beyond the inner valve seating 29b to the aperture 26b, any unwanted fluids UFL within the clawbowl are able to drain out of the clawbowl via the channels 55 and the aperture 26b. Therefore, the drain passageway in this embodiment is part formed by the channels 55, and part formed by the aperture 26b. The sloped bottom 19 helps direct any fluids present in the clawbowl into the channels 55.

When the valve body 30 is moved into the open position for milking, to open the entrance 23 to the milk outlet nipple 4, the pressure plug 36 of the valve body 30 blocks off the cutaways 50, just the same as the drain passageway 27 is blocked off in the first embodiment.

The channels 55 help allow the same aperture as used for the shaft 34 to be used for the drain passageway, saving the need to create a separate aperture through the bottom of the clawbowl.

Further embodiments falling within the scope of the appended claims will also be apparent to the skilled person.