Background of: the Invention

Field of the Invention

The invention relates to claws for use in milking machines .

Summary of the Prior Art

Milking machines are used to harvest milk from animals when manual milking becomes inefficient or labour intensive. The milking unit is the portion of a milking machine for removing milk from an udder. Typically, it is made up of several teatcups connected to a claw, a pulsation system and milk flow tubing. The claw is an assembly in which the streams of milk from the teatcups are combined. The number of teatcups may vary depending on the animal being milked. By way of example, a milking machine for a cow will comprise four teatcups, whereas there will only be two teatcups for a sheep or goat milking machine. The claw connects the short milk and pulse tubes from the teatcups to the long milk tube connected to a milk collection container. Claws are

commonly made from thin steel, plastic or glass.

The interior milk-contact surfaces of the machine must be kept clean, to comply with food preparation and storage regulations. It is therefore very important that the machine can be readily disassembled for cleaning. It is also important that they can be easily reassembled.

Known milking machine claws typically comprise a pulsation manifold, a bowl portion and a lid portion. In one such known device, the pulsation manifold is attached to the lid portion, which is threadedly engaged with the bowl portion. To enable the claw components to be cleaned, the lid and bowl portions must be unscrewed from one another. However, a rubber seal around the bowl rim between the bowl and lid, which has a large surface area, creates a large frictional force resisting any unscrewing. This also resists the screwing action as the parts are engaged, which may lead to insufficient force being applied and an

incomplete seal being formed. An incomplete seal may allow milk to leak from the claw, or allow dirt to access milk contact surfaces. Once the bowl and lid portions are separated, tools are needed to break down the assemblies further. Also, in claw of this type the lid can work loose from the bowl with use.

Summary of Invention

Another known claw has an axial bore running through the centre of it. A bolt inserted through the bore threadedly engages a nut at the other end of the bore. It takes time to engage and disengage the nut and bolt from the claw.

Further, as the nut and bolt are unscrewed, components of the claw fall apart. As with the claw described above, the adjustable clamping force applied by the nut and bolt allows for an incomplete seal to be formed, resulting in milk leakage in use and/or dirt accessing milk contact surfaces. In claws of this type, the nut can work loose with use.

At its most general, the invention provides a claw for a milking machine, the claw having many components including a clamp which holds the other components together, the clamp being engaged in a clamping position through mating of a pin with a socket. The pin and socket may be a bayonet pin and bayonet socket.

Preferably, the invention provides a claw for a milking machine, the claw comprising a bowl, a lid, a pulsation manifold, a clamp and a compressible biasing element. An axial tubular passage is provided through the bowl, lid and pulsation manifold, through which the clamp extends, the clamp having two stopping or clamping surfaces which

sandwich the lid, bowl, pulsation manifold and compressible biasing element. The compressible biasing element is biased to act against the stopping or clamping surfaces. The clamp can be moved between an open position and a clamping position. The clamp comprises a first mating element which is a socket or a pin. In the clamping position, this is in mating engagement with a second mating element. The second mating element is a complementary pin or socket provided on the bowl, lid or pulsation manifold in the clamping

position. The first and second mating elements are

disengaged in the open position. The compressible biasing element is compressed when the clamp is the clamping position so that the clamp is maintained under tension.

The clamp can be quickly and easily disengaged. The claw can then be separated into subassemblies, which can be readily broken down further by hand. Each part can then be cleaned. On reassembly, the clamp can be easily and readily engaged, and provides a reproducible clamping force and consequently a good seal. The engagement of the pin and socket forms a positive lock that cannot work loose with use, resulting in a secure seal.

The compressible biasing element means that tight tolerances between the clamp, pulsation manifold, lid and bowl are not necessary.

The clamp may be moved between the open position and clamping position through rotation. When the pin and socket are releasably mated, the clamp cannot be rotated.

In some embodiments, a ramp may be provided adjacent to the socket. The socket has a mouth and a depth for

receiving the pin. The ramp is inclined from the mouth of the socket in the direction of the socket depth. The socket depth may extend in the axial direction, and hence the ramp is inclined in the axial direction. In such embodiments, the pin can be urged into camming engagement with the ramp to effect compression of the biasing element and application of a clamping force. The restorative force of the biasing element effects engagement of the pin with the socket when the pin reaches the socket mouth. Alternatively or additionally, a ramp may be provided for engaging the stopping surface distal to the pin and socket. The ramp in this case is inclined in the direction of the socket depth, increasing in height away from the socket. The stopping surface can be urged into camming engagement with the ramp.

In other embodiments, a ramp may be provided on one of the stopping or clamping surfaces. The ramp may be provided on either of the stopping surfaces, and is inclined in the direction of the socket depth, increasing in height away from the other stopping surface. In such embodiments, the clamping surface can be urged into camming engagement with a cooperating surface of the bowl, lid, pulsation manifold or compressible biasing element, to effect compression of the biasing element and application of a clamping force. The restorative force of the biasing element effects engagement of the pin with the socket when the pin reaches the socket mouth. Preferably, the ramp is provided on the stopping surfaces distal to the socket and pin.

Such configurations allow for easy engagement and securing of the clamp.

Preferably, the clamp comprises a pin, and a

complementary socket is provided on the bowl, lid or pulsation manifold.

For ease of manufacture, the first and second stopping surfaces may be a fixed distance apart.

The passage through the bowl, lid and pulsation manifold may be sealed by a rubber clamp seal to prevent milk

leakage. A second rubber seal may be provided between the outer rim of the bowl and the outer rim of the lid.

The compressible biasing element may be one of the rubber seals. It is preferably the rubber clamp seal. The rubber clamp seal may be made from a more compressible rubber than the bowl seal.

The socket may comprise a recess provided in the bowl, lid or pulsation manifold. It is preferably provided on an outside surface of the bowl. The pin of the clamp is moved into mating engagement with that recess as the clamp is moved into the clamping position. To effect such mating engagement, the biasing element is compressed. The

restorative force of the compressed biasing element then locks the pin in the recess. In a particularly preferred case, the bowl comprises a bump stop which is provided on an outside surface of the bowl, and the socket comprises a recess provided in the bump stop.

The claw may be configured such that the bowl, lid and pulsation manifold fit together in one or more discrete spatial arrangements. This ensures that there is no undesirable relative rotational movement between the components. This may be particularly important where a ramp is provided on one of the stopping surfaces and where the pin and socket lock the relative position of the clamp and only one other component, to prevent unintentional

disengagement by rotation of a component relative to the clamp. Of course, in cases where the clamp is a tight fit, friction alone may prevent relative rotation of the

components .

Where multiple discrete spatial arrangements are

possible, the claw can be arranged in numerous

configurations whilst prohibiting relative rotational movement. By way of example, such a claw can be used in a parallel milking configuration, or a herringbone milking configuration. There may preferably be four discrete positive positions in which the components sit.

At least a part of the bowl and/or the lid may be made from a transparent material, for example a transparent polymer, to allow milk flow to be checked visually when the milking machine is in use.

The invention also provides a kit of parts for a claw for a milking machine, the kit comprising a bowl, a lid, a pulsation manifold, a compressible biasing element and a clamp, the clamp comprising two stopping surfaces. The clamp has a socket or pin, and the bowl, lid, or pulsation manifold has a complementary pin or socket. The bowl, lid and pulsation manifold can be arranged so that an axial tubular passage extends through them, such that the clamp can be slid through the passage. The clamp stopping surfaces then sandwich the bowl, lid, pulsation manifold and compressible biasing element. The clamp is then rotatable to effect mating of the socket and pin, which secures the clamp in a clamping position, the compressible biasing element being arranged such that it is compressed when the clamp is the clamping position so that the clamp is

maintained under tension.

Optional and alternative features described above in relation to the claw may be applicable to the kit of parts, to the extent that they are compatible.

The invention also provides a milking machine comprising a claw as described above.

Brief Description of the Drawings

Embodiments of the invention are now described by way of example, with reference to the accompanying drawings, in which,

Figure 1 shows a perspective view of a claw embodying the invention;

Figure 2 shows an exploded perspective view of the claw of Figure 1 split into three sub-assemblies;

Figure 3 shows a sectional elevation of the claw of Figure 1 ;

Figure 4 shows a perspective view of the clamp used in the claw of Figure 1;

Figure 5 shows a partial sectional elevation of the claw of Figure 1;

Figure 6 shows a sectional elevation of the claw of Figure 1;

Figure 7 shows a perspective view of the claw of

Figure 1 when completely disassembled;

Figure 8 shows a sectional elevation of a second claw embodying the invention; Figure 9 shows a perspective view of the clamp used in the claw of Figure 8;

Figure 10 shows an exploded perspective view of the claw of Figure 8 split into four sub-assemblies; and

Figure 11 shows a perspective view of the claw of

Figure 8 when completely disassembled.

Detailed Description

Figure 1 shows a claw for use in a milking machine. In use, the claw is connected to four teatcups (not shown) , a pulsation system and milk flow tubing. The four streams of milk from the teatcups are combined in the claw. The milk outlet from the claw is connected to a milk collection container.

The claw 1 shown in Figure 1 comprises a bowl 30 and a covering lid 20. The bowl 30 and lid 20 have a rubber bowl seal 40 between them to prevent egress of milk in use. The claw 1 further comprises a pulsation manifold 15, disposed on or above the covering lid 20. A clamp 10 passes through a central passage formed in the bowl 30, the lid 20 and the pulsation manifold 15, holding the assembly together. The central passage is sealed to prevent egress of milk in use.

The clamp 10 shown in Figure 4 comprises a handle 11 at one end of an elongate cylindrical shaft 13 with a diameter 13a. The handle 11 can double as an attachment point for securing the claw to an automatic cluster remover. A lip 12 protrudes outwardly from the shaft 13 close to the handle 11. The lip 12 acts as an upper clamping surface. A transversely extending spigot 14 is provided at the other end of the elongate shaft 13. The spigot 14 acts as a lower clamping surface. The spigot 14 is cylindrical, and the diameter of the spigot 14a is less than that of the shaft 13a. The length of the spigot 14b is greater than the diameter of the elongate shaft 13a, and the spigot 14 extends from the shaft 13 at two diametrically opposed positions . The pulsation manifold 15 has a central bore 151 in it. When the claw is assembled, the elongate shaft 13 of the clamp 10 extends through the central bore 151 of the pulsation manifold 15. The lip 12 abuts the upper face of the pulsation manifold 15. The diameter of the central bore 151 is greater than the elongate shaft diameter 13a, but less than the spigot length 14b such that the spigot 14 cannot pass through the central bore 151. Diametrically opposed channels are provided in communication with the central bore 151, to allow passage of the spigot 14, resulting in complete disassembly of the clamp and pulsation manifold. The lip 12 is wider than the central bore 151 of the pulsation manifold 15, such that the lip 12 cannot pass through the bore 151.

The lid 20 comprises a domed lid body 21 and four milk inlet tubes 22 arranged on the outside of the lid body 21, for connecting to the teatcups (not shown) in use. A square central hole 212 is provided in the centre of the domed lid body 21. An annular rubber clamp seal 210 extends around the inside of the square central hole 212. The elongate shaft 13 of the clamp 10 extends through the central hole 212 of the lid body 21. The pulsation manifold 15 abuts the upper edge of the clamp seal 210.

The clamp seal 210 is made from a resiliently

compressible rubber. It acts as a spring, biased against the clamping action. This keeps the clamp under tension, and the assembly together.

The bowl 30 comprises a bowl body 31, a bump stop 34, a milk outlet tube 32 and a valve assembly 33 for shutting off the vacuum when teat-cups are not connected to teats. The bump stop 34, milk outlet tube 32 and valve assembly 33 are arranged on the outside of the bowl body 31.

The bowl body 31 comprises a tubular boss 310 inside the bowl, upwardly extending towards the covering lid 20. The tubular boss 310 provides an elongate axial bore which is open at both ends. The clamp 10 extends partially through the elongate bore. The elongate axial bore of the tubular boss 310 has a square upper section 312 and a lower section 311. The upper section 312 has a narrower cross section than the lower section 311. A step 313 is present in the tubular boss between the upper and lower sections. The upper surface of the step abuts the lower surface of the clamp seal 210 and a seal is formed preventing egress of milk in use. The square upper section 312 of the tubular boss extends through the square central hole 212 of the lid, and is surrounded by the clamp seal 210.

The elongate clamp shaft 13 extends through the upper section 312 of the tubular boss 310. The upper section 312 has a channel extending through it which includes a

cylindrical bore. The diameter of the bore is slightly larger than the diameter 13a of the elongate clamp shaft, such that the clamp shaft is supported transversely by the bore, and can freely rotate in the bore. The channel includes two diametrically opposing groves which communicate with the bore. The grooves correspond in shape to the spigot 14 on the end of the shaft so that the shaft and spigot can be slid through the channel in the upper section

312 of the boss 310 for removal of the clamp from the bowl body. The grooves in the upper section 312 of the tubular boss 310 are out of register with the channels provided in the central bore 151 of the pulsation manifold 15.

The lower section 311 is substantially cylindrical, and has a diameter larger that the length of the spigot 14. A camming ramp 314 is provided on the underside of the step

313 in the lower section 311 of the tubular boss 310, for engaging the spigot 14. The ramp 314 extends downwardly from the step. A recess 316 is provided adjacent to the maximum height of the camming ramp 314, the recess

corresponding in size to the spigot 14 for receiving the spigot. The camming ramp effects compression of the rubber clamp seal 210, the restorative force of the compressed clamp seal then forcing the spigot 14 into the recess 316. In the clamping position, the spigot 14 is in the recess 316. The resilient nature of the clamp seal 210 keeps the clamp under tension. The restorative force of the clamp seal pushes the bowl 30 against the spigot 14 and the pulsation manifold 15 against the clamp lip 12.

The clamp 10 is disengaged by rotation through 90°. A threshold force must be applied to the clamp to urge the spigot 14 out of the recess 316. This involves compression of the clamp seal 210.

After rotation through 90°, the spigot 14 is aligned with diametrically opposed grooves in the upper section 312 of the tubular boss 310. The clamp 10 can be withdrawn from the bowl 30 and lid 20. The spigot 14 cannot pass through the pulsation manifold 15 because the spigot length 14b is greater than the diameter of the pulsation manifold central bore 151, and because the channels in the central bore 151 of the pulsation manifold are out of register with the grooves provided in the upper section 312 of the tubular boss 310. The pulsation manifold 15 lifts off the lid 20 with the clamp 10. The bowl 30 and lid 20 can then be separated.

Thus, once the clamp is removed, the claw is in three subassemblies as shown in Figure 2; the lid portion, the bowl portion, and the pulsation manifold with the clamp. These can be further disassembled as shown in Figure 7 for cleaning. This disassembly can be completed by hand, and without the use of tools.

For reassembly, each of the three subassemblies is reassembled by hand. The lid 20 is then placed on the bowl 30, with the clamp seal 310 and bowl seal 40 aligned as described above. The square boss and square holes in the subassemblies means that they can only be fitted together in four discrete arrangements. The clamp 10 is first

orientated such that the spigot 14 is aligned with the diametrically opposed grooves in the upper section 312 of the tubular boss 310. The clamp is pushed through the lid and bowl portions, so that the elongate shaft 13 of the clamp 10 passes through the central hole 212 of the lid 20 and the upper section 312 of the tubular boss 310. The spigot 14 is then in the lower section 311 of the boss 310. The clamp is rotated to urge the spigot 14 into camming engagement with the ramp 314. The camming ramp height increases through 90°. The camming engagement causes compression of the clamp seal 210. When the clamp is rotated through 90°, the compression of the clamp seal 210 forces the spigot 14 into the recess 316. This locks the clamp in place.

Figures 8 to 11 show a second embodiment of the

invention. Parts having the same function as the first embodiment are labelled with the same reference numeral and will not be described again.

The clamp 100 shown in Figure 9 has an elongate

cylindrical shaft 13, and a lip 12 protrudes outwardly from that shaft. The lip 12 is an upper clamping surface. Two locking bosses 140 extend downwardly from the lip.

Transverse protrusions 142 extend outwardly at the other end of the elongate shaft 13. The protrusions are a lower clamping surface. The protrusions 142 are ramped in the direction of the elongated shaft 13, such that the ramps lie on a helical path arranged around the elongate shaft 13. The protrusions 142 pass through the central bore 151 of the pulsation manifold, the central hole 212 of the lid body and the tubular boss 310 of the bowl body in the same manner as the spigot 14 in the first embodiment.

Two locking recesses 155 are provided in the upper surface of the pulsation manifold 15. When the claw is assembled, the lip 12 abuts the upper face of the pulsation manifold 15 and the locking bosses 140 fit snugly into these locking recesses 155, locking the relative configuration of the components.

As in the first embodiment, the bowl 30 comprises a bowl body 31 and a bump stop 34. The bump stop 34 is arranged on the outside of the bowl body 31. The bump stop 34 is positioned at the downward end of the elongate bore. The bump stop 34 includes a planar clamping plate 341, which has a central hole through it 342, In contrast to the first embodiment, the clamp 100 extends entirely through the elongate bore of the tubular boss 310 of the bowl body 31, and the protrusions 142 of the clamp 100 pass through the central hole of the clamping plate 341.

In the clamping position, the locking bosses 140 are in the locking recesses 155 in the pulsation manifold 15. The resilient nature of the clamp seal 210 keeps the clamp under tension. The restorative force of the clamp seal pushes the bowl 30 against the transverse protrusion 142 of the clamp 100, and the pulsation manifold 15 against the clamp lip 12.

The clamp 100 is disengaged by rotation through 90°. A threshold force must be applied to the clamp to urge the locking bosses 140 out of the cooperating locking recesses 155. This involves compression of the clamp seal 210.

As in the first embodiment, after rotation through 90°, the clamp 100 can be withdrawn from the bowl 30 and lid 20. In this embodiment, the bump stop 34 forms a separate subassembly to the body. Thus once the clamp is removed, the claw is in four subassemblies as shown in Figure 10; the lid portion, the bowl portion, the bump stop, and the pulsation manifold with the clamp. These can be further disassembled as shown in Figure 11 for cleaning. This disassembly can be completed by hand, and without the use of tools.

For reassembly, each of the four subassemblies is reassembled by hand. The lid 20 is then placed on the bowl 30, with the clamp seal 310 and bowl seal 40 aligned as described above. The square boss and square holes in the subassemblies means that they can only be fitted together in four discrete arrangements. Further, four small knobs 156 on the pulsation manifold fit into four small recesses 157 in the lid to further lock the components' relative

configuration. Similar knobs 218 are also found on the rubber clamp seal 210, which also fit into the recesses 157.

The clamp pushed through the lid and bowl portions as described above in relation to the first embodiment. The protrusions 142 on the clamp also pass through the central hole 342 of the clamping plate 341.

The clamp is rotated to urge the ramped protrusions 142 into camming engagement with the planar clamping plate 341. The camming ramp height increases through 90°. The camming engagement causes compression of the clamp seal 210. When the clamp is rotated through 90° , the compression of the clamp seal 210 forces the locking bosses 140 into the locking recesses 155. This locks the clamp in place by preventing rotation of the clamp 100 relative to the

pulsation manifold 15. The components cannot rotate

relative to the clamp because they have a discrete number of possible spatial arrangements, and are thus locked relative to the pulsation manifold 15.