Milking apparatus

An inflation for a teat cup assembly which reduces the capacity of the inflation to twist radially during the installation process. The inflation has an elongated flexible portion adapted to receive the teat of an animal to be milked and comprises a first end formed with an opening into the interior of said elongated portion which is adapted to receive said teat and which sealingly engages a first open end of a hollow elongated teat cup upon vacuum being applied to the inside of said cup; a middle portion adapted to be received in the second end of the elongated teat cup, said middle portion being formed with a plurality of peripheral flat sections thereon, said flat sections being receivable in a correspondingly shaped opening in the second end of the teat cup, said middle portion being sealingly engaged in the opening in said second end upon vacuum being applied to the inside of said cup; the inflation having a second end adapted to extend from the teat cup and be connected to the vacuum line of a milking machine.

BACKGROUND OF THE INVENTION 
This invention concerns improvements in or relating to milking apparatus, 
in particular, the invention is concerned with improvements in or relating 
to inflations, used in milking machine claw assemblies, which attach to 
the udder of a cow. 
Those skilled in the art will appreciate that a milking machine teat cup 
claw assembly is composed of four teat cup assemblies, connected via a 
"claw" to a pulsing mechanism and to the vacuum milk flow line of a 
milking machine. 
A teat assembly is made up a rigid outer teat cup having two open ends in 
which is positioned a inflation, the inflation usually being made from 
synthetic rubber. 
For the efficient milking of a cow, without risking damage to the teat or 
udder, the inflation must flex smoothly, and in the manner in which it has 
been designed. In this way the milking operation is able to extract the 
maximum amount of milk from the cow without distressing the animal. 
The inflations are consumable items, in that they require replacement at 
regular intervals of time. In some areas, replacement each year is 
required, and in others, more frequent replacement occurs. If undue wear 
occurs on the inflation or other deleterious factors apply, then 
replacement at shorter than usual intervals of time becomes necessary. 
Because the inflation must seal against the teat cup at both ends, referred 
to as the bottom and the top ends, of the cup, to allow the pulsed vacuum 
applied to the cup of change the shape of the inflation, it is, by 
necessity, a tight fit at each end of the cup. Removal and replacement of 
inflations in teat cups, or, installation of inflations in the first 
instance, requires some effort and produces difficulties in many cases. 
It is not uncommon in using milking machine apparatus to find that one or 
more of the four teat cup assemblies in a claw assembly does not milk 
satisfactorily. That is to say, it does not extract milk efficiently from 
the animal being milked. It has been found that this is often attributable 
to incorrect fitting of the inflation in the cup, due to the difficulties 
mentioned above, or, the lack of care shown when inserting the inflation 
into the cup at installation or replacement. 
It has been found that what happens is the end of the inflation at the top 
of the teat cup is twisted radially with respect to that part of the 
inflation at the bottom end of the teat cup. It is believed that this 
occurs in the final positioning of the inflation into a sealing contact 
with the ends of the teat cup. The torsional resilience of the inflation 
is not sufficient to unwind the radial twisting, once the inflation is 
fully fitted in the cup. As a result, the milking operation is conducted 
with the inflation operating with a twist, causing it not to expand and 
contract as designed, or as desired, for efficient milking. It is believed 
that premature wearing of the inflation may also occur when it is operated 
in that condition. 
This problem is difficult to identify where the cup itself is not 
transparent, which is the usual one. This is because it is not possible to 
inspect the inflation within the cup, once it has been inserted. While a 
number of solutions to the problem of twisted inflation have been 
proposed, these suggested solutions are ineffective when inflations are 
replaced under poor light, or in the dark, as may be the case in milking 
sheds. In an event, these attempts to solve the problem still rely 
entirely upon the operator separately checking the alignment of each end 
of the inflation after it has been inserted in the cup. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a teat cup inflation 
which is constructed and configured in such a manner that assembly within 
a teat cup is achieved which eliminates or minimises the capacity of the 
inflation to twist radially during the installation process. 
In one aspect of the invention there is provided an inflation for a teat 
cup assembly, the inflation having an elongated flexible portion adapted 
to receive the teat of an animal to be milked, comprising, a first end 
formed with an opening into the interior of said elongated portion which 
is adapted to receive said teat and, which sealingly engages a first open 
end of a hollow elongated teat cup upon vacuum being applied to the inside 
of said cup; a middle portion adapted to be received in the second end of 
the elongated teat cup; a middle portion adapted to be formed with a 
plurality of peripheral flat sections thereon, said flat sections being 
receivable in a correspondingly shaped opening in the second end of the 
teat cup; said middle portion being sealingly engaged in the opening in 
said second end upon vacuum being applied to the inside of said cup; the 
inflation having a second end adapted to extend from the teat cup and be 
connected to the vacuum line of a milking machine. 
In one embodiment of the invention the first end of the inflation is also 
provided with a plurality of peripheral flat sections, which are adapted 
to be received by corresponding flat portions at the first open end of the 
teat cup. 
The shaped opening in the second end of the teat cup may be formed by 
flattened portions of a cylindrical cup, which define a shape 
corresponding to the cross-section of the middle portion, or, by a hole in 
the rolled over end of the teat cup which corresponds to that 
cross-section. 
In a preferred embodiment of the invention the middle portion of the 
inflation is triangular or rectangular, and, the second end of the teat 
cup which receives that portion is of a corresponding shape. 
In another embodiment of the invention the first end of the inflation is 
formed as a rolled over section and the first open end of the teat cup is 
received underneath that rolled over portion. Where a plurality of flat 
sections are provided at that end of the inflation, they are provided 
underneath that rolled over portion and on the outside of the body of the 
inflation. 
As will be appreciated by those skilled in the art, the second end of the 
inflation referred to above is conveniently formed as a length of flow 
tube integral with the middle portion. This length of flow tube may be 
used to assist in insertion of the inflation into the teat cup by 
providing a part of the inflation which may be grasped by the hand, after 
being fed through the cup, to allow the inflation to be pulled into 
position in the cup. The flow tube also provides flexibility of movement 
of the teat cup assembly after attachment to the vacuum line. 
In use, an inflation of this invention is installed in a teat cup in a 
conventional manner, that is, by inserting the second end through the 
first and then the second open end of the teat cup and by then pulling the 
inflation through the teat cup by the second end. Because the middle 
portion of the inflation, which is to be positioned at the second end of 
the teat cup, is provided with a plurality of peripheral flat sections, 
and the cup is provided with an opening at its second end which 
corresponds in shape to the shape of the middle portion, as the inflation 
is pulled and/or pushed into the cup the flat sections of the inflation 
align with the flat portion of the opening and prevent radial twisting of 
the middle portion and therefore of the inflation with respect to the teat 
cup as the inflation is moved into its final position, in sealing 
engagement at both ends of the teat cup. 
As is understood by the skilled person, it is necessary that both the top 
and bottom of the teat cup are sealingly engaged with the top and middle 
portions of the inflation to ensure that vacuum applied to the interior of 
the inflation from the flow line, is able to be matched by an equal vacuum 
applied to the volume between the outside of the inflation and the inside 
of the teat cup, in a pulsating fashion whereby to cause the inflation to 
contact and expand against the teat of the animal being milked, during the 
milking process. 
Where the inflation is provided with peripheral flat sections at its first 
end, then the teat cup is preferably provided with corresponding flattened 
portions at its first open end. In this situation, as the inflation to 
being inserted in the teat cup, the flat sections formed on the middle 
portion engage the corresponding flattened portions of the opening as 
before, and in addition the flat peripheral sections at the first end of 
the inflation engage the corresponding flat portions of the first open end 
of the cup, so that as the inflation is moved into its final position in 
the cup, relative rotation between the top portion and the middle portion 
of the inflation, in a radial direction, is not possible. 
It is essential to the invention that the configuration of flat sections on 
the inflation and flat portions at the ends of the teat cup is such that 
when the inflation is fitted in the teat cup, the part of the inflation 
within the cup is twist free, that is, the first end portion is aligned 
with the middle portion. 
As the flat sections of the inflation restrain the degree of rotation of 
the inflation within the teat cup before installation of the inflation is 
complete, the possibility of twisting of the inflation during installation 
is substantially removed which results in the inflation being positioned 
in the teat cup with its open end portion in alignment with its middle 
portion. 
It should be noted that the greater the number of flat sections formed on 
the inflation, and correspondingly at the ends of the teat cup, the 
greater would be the possibility that some inadvertent rotation of the 
inflation to the next series of flats could occur at one part of the 
inflation and not the other. For that reason, a smaller rather than larger 
number of flats are desired on the inflation. However this potential 
inadvertent rotation is reduced if the flat sections are not equally 
spaced and sized. 
In a particularly preferred embodiment, the invention employs an inflation 
having a generally triangular portion formed at its middle portion and 
first end portion, with a corresponding triangular shape being provided at 
the ends of the teat cup into which the inflation is to be inserted. It 
will be understood that the body of the inflation between the first end 
and the middle portion may be cylindrical, or, may have other 
configurations, as desired.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S) 
Referring to FIG. 1 there is seen an inflation 1 for use with a milking 
machine, comprising a first end 10 adapted to be received in a teat cup, 
which is provided with an opening to receive the teat of an animal to be 
milked. As the opening is on the top of first end 10 it is not seen in 
this figure. First end 10 is also provided with a rolled over collar 12. 
Inflation 1 has a middle portion 14 and a second end 16, only part of the 
latter being shown. Second end 16 is adapted to be connected to the vacuum 
milk line of a milking machine. Middle portion 14 is provided with a 
series of flat section 20 joined by rounded corner sections 18. As can be 
seen from FIG. 6, middle portion 14 is generally triangular in 
cross-section with a generally circular bore 22 passing therethrough. 
Provided on the outside surface of middle portion 14 are a series of 
retaining hackles 24 whose purpose will be described hereinafter. 
Between first end 10 and middle portion 14 is an elongated portion 26 which 
in use receives the teat of the animal to be milked. 
At first end 10 there is provided a series of flat sections 28 joined by 
rounded corner sections 30. Three flat sections 28 are provided so that, 
as seen in FIG. 5, the shape of first end 10 is generally triangularly in 
cross-section with a generally circular bore 32 extending therethrough. 
Flat sections 28 extend under the rolled over collar 12 to approximately 
line 34, shown in outline. 
Both triangular sections, at first end 10 and middle portion 14 are 
slightly tapered, reducing in cross-sectional area in the direction of 
second end 16. 
Referring now to FIG. 2 and FIG. 3 there is seen a teat cup 2 comprising a 
hollow elongated up 36 having a first open end 38 which is not clearly 
seen in the figure, being at the top of cup 36, and a second open end 40. 
A vacuum connection 42 is provided adjacent end 40 and will be recognized 
by the person skilled in this art. 
The shape of open end 40 is such as to allow middle portion 14 to be 
received therein in sealing engagement, when retaining hackles 24 are 
located on either side of the opening. Thus it can be seen that the shape 
of open end 40 is generally triangular with rounded corners. 
Open end 38 if formed with three flat sections 44, 46 and 48 formed 
therein, as best seen in FIG. 3. Those sections are conveniently formed by 
pressing flat sections from a cylindrical body. Open end 38 is thus seen 
to be generally triangular with rounded corners. Open end 40 is smaller 
than open end 38, as seen in FIG. 3, and because the flat sections 20 and 
28 on inflation 1 are aligned, the flat portions of open end 40 and flat 
sections 44, 46 and 48 are also aligned. To install inflation 1 in teat 
cup 2 second end 16 is passed firstly through open-end 38 and then through 
open end 40. Because the openings are substantially larger than second end 
16, it passes through easily. 
As middle portion 14 approaches open end 40, flat sections 20 begin to 
align themselves with the flat portions of end 40 so that an alignment of 
middle portion 14 within end 40 commences. At the same time flat portion 
28 of first end 10 begin to align themselves with flat sections 44, 46 and 
48 of end 38. 
As the inflation continues to enter teat cup 2, usually by continuing to 
pull second end 16 through end 40, the flat sections of inflation 1 engage 
the flat sections of teat cup 2, and as inflation 1 approaches its final 
position in teat cup 2 it becomes impossible for relative of end 10 and 
middle 14 to occur. 
Thus, upon drawing one, two or all of retaining hackles 24 through end 40, 
the extremity of end 38 abuts the end of groove 50 and sealing engagement 
of both ends 38 and 40 of teat cup 2 is made with end 10 and middle 14 of 
inflation 1, which is now installed and which has the portion retained 
within teat cup 2 free from any radially induced distortion. 
Many variations to the invention may be realised by those skilled in the 
art, and all such variations are deemed to be within the scope of the 
invention. 
One variation would be to provide both end 38 and end 40 with similar 
flattened sections to define a shape corresponding to middle portion 14. 
That is, to provide a series of flats at that end, rather than a hole. 
Also, a cross-sectional shape for end 10 and middle 14 other than generally 
triangular may be envisaged. Such as two sided with rounded ends, 
rectangular, square and pentagonal. The ends of teat cup 2 would then be 
required to confirm to those shapes. 
Also, flat sections 44, 46 and 48 at open end 38 of the teat cup 2 may be 
formed by flaring out the sections from a cylindrical body.