Note: Descriptions are shown in the official language in which they were submitted.
CA 02680781 2009-09-14
WO 2008/118056
PCT/SE2008/000174
A device for measuring an electrical parameter in milk and a
milking apparatus including such a device.
Technical field
The present invention relates to a device for measuring an electrical
parameter in
milk. The device is indented for arrangement in a substantially vertical
conduit of a
milking apparatus, and comprises a measuring chamber having electrodes. The in-
vention also relates to a milking apparatus comprising such a device.
Background of the invention
The measurement of an electrical parameter, such as electrical conductivity,
is of
importance in the field of milking, since it can be used as a means for
detecting in-
fections such as mastitis in dairy animals. When milk is affected because of
mastitis
or milk fever, the electrical conductivity of the milk is changed. Mastitis
infections
in dairy animals can thus be diagnosed based upon the altered pattern in the
electri-
cal conductivity of the milk which, in the case of a mastitis infection is
substantially
increased in a characteristic way. The electrical conductivity can be
measured, for
example, by means of electrodes between which an A.C. or D.C. voltage
prevails. In
order to obtain comparable conductivity values between different measuring
occa-
sions, the measurement of the conductivity should be performed on a known vol-
ume. The measuring electrodes should thus preferably be arranged such that the
measuring volume is substantially the same in each measuring occasioh, so that
comparable values of the electrical conductivity can be obtained.
Various arrangements for measuring of conductivity in milk are known in the
art.
Electrodes for measuring the conductivity are typically mounted in a sample
cham-
ber, in which a milk sample can be received. For continuous in-line measuring,
the
sample chamber is normally arranged in the milking apparatus in a position
between
the teat cups and the milk line, and is filled with milk when a milk flow
passes by.
CA 02680781 2014-10-28
2
Examples of such devices are shown in WO 95/22888 and W099/18774, in which
sample chambers are located in a milk claw. Milk enters the chambers from
above
and slowly drains away via a small opening provided in the bottom of the
sample
chamber. Another known device is shown in EP 0397274 A 1, in which a sample
chamber is provided, which is closed at the bottom, and the milk both enters
and ex-
its the sample chamber through an upper opening.
These and other hitherto known devices for measuring electrical conductivity
in
milk suffer from difficulties in drainage of the milk. In a sample chamber of
the type
shown in WO 95/22888 or W099/18774, the drainage opening must be small
enough to retain a milk sample in the chamber. However, such a small opening
eas-
ily becomes clogged by fat agglomerations or dirt particles in the milk. In
the type
shown in EP 0397274 Al a small amount of milk remains, also when the milk has
ceased to flow through the device. The impeded milk drainage in the sample
cham-
ber is an obstacle in cleaning of the equipment and might also adversely
affect the
reliability of the measuring result.
Summary of the invention
The present invention aims at providing an improved device for measuring of an
electrical parameter for use in a milking apparatus, which does not suffer
from the
above disadvantages, but allows a reliable measurement and can easily be
cleaned.
This is achieved according to the present invention by means of a device
arranged
in a substantially vertical milk flow conduit of a milking apparatus, which
device
comprises a measuring chamber having at least two electrodes, characterised in
that milk is intended to flow in an upward direction in said conduit, and that
the
measuring chamber is closed in said upward direction and has a downwardly
directed opening for entry and exit of milk, such that it will be filled with
milk
when milk flows through the device, and instantly empties when the milk ceases
CA 02680781 2014-10-28
,
2a
to flow, the device further comprising a valve having a diaphragm, wherein the
measuring chamber is arranged prior to the diaphragm in the flow direction.
This
device is arranged in a substantially vertical milk flow conduit of a milking
apparatus and comprises a measuring chamber having at least two electrodes.
Milk is
intended to flow in an upward direction in the milk flow conduit, and the
measuring
chamber is closed in an upward direction and has a downwardly directed opening
for
entry and exit of milk. The chamber will thus be filled when milk flows
upwards
through the device, and instantly empties through the opening, due to
CA 02680781 2009-09-14
WO 2008/118056 PCT/SE2008/000174
_
3
gravity, when the milk ceases to flow. When the measuring chamber is filled
with
milk, a signal can be obtained from the measuring chamber via the electrodes.
The
signal can be used for evaluation of whether the animal suffers from a disease
such
as mastitis, by comparing the maximum value of the conductivity at different
milk-
ing occasions. The presence of a signal also reliably indicates the presence
of a milk
flow through the device. A signal will be given continuously during the
passage of a
milk slug through the device and will cease when the milk slug has passed
since any
small remaining amount of milk will directly drain from the measuring chamber.
The time period needed for the milk slug to pass through the device is thus
easily
detected, which together with the known volume of the milk conduit allows the
milk
flow volume to be calculated. Because the device is adapted to be arranged in
a sub-
stantially vertical milk conduit in which the milk flows upwardly, it is
particularly
useful in high-line milking applications, where the milk anyway must be must
trans-
ferred upwards to the milk line.
The measuring chamber is preferably arranged in the device such that when milk
flows through the device the milk flow direction is changed. When the milk
flow
deviates from its original direction any air trapped in the measuring chamber
will be
dragged along with the milk flowing by and the chamber will accordingly be com-
pletely filled with milk and no air is trapped in the chamber, and thus a
reliable
value of the electrical parameter is obtained. The device comprises a lower
inlet
passage, and an upper outlet passage for the milk flow. The measuring chamber
is
positioned such that its opening is positioned directly above the lower milk
flow
inlet passage, so that a milk flow entering the device is directed straight
into the
measuring chamber, which is delimited between an outer wall of the device and
a
protruding element that extends from the outer wall.
The device may further comprise a diaphragm valve, and the measuring chamber
is
then arranged prior to the diaphragm in the flow direction. The valve
comprises a
fluid chamber, which has a fluid inlet opening and a fluid outlet opening,
which is
CA 02680781 2014-10-28
4
directed towards the diaphragm, at the end of the milk flow outlet passage
which ex-
tends into the fluid chamber. The measuring chamber is positioned in the fluid
chamber opposite to the diaphragm and underneath the outlet passage. This
makes
the device compact and effective, and several purposes can be fulfilled by
means of
a single piece of equipment, particularly when the end portion of the outlet
passage,
extending into the fluid chamber, is used as the protruding element confining
the
measuring chamber. The electrodes are preferably arranged in, and extend
substan-
tially horizontally through the outer wall, for easy mounting and access.
The invention also relates to a milking apparatus for milking of an animal,
compris-
ing a milking member 30 intended to be applied to the teats of said animal, a
milk
conduit 31 for transportation of milk from the milking member 30 to a milk
line 32
that is located higher than the milking member, in which a device as described
above is arranged in the milk conduit, such that the opening of the measuring
cham-
ber is directed towards the milking member 30.
According to an aspect of the present invention there is provided a milking
apparatus comprising a substantially vertical milk flow conduit arranged for
milk
to flow in an upward direction through the conduit, and a measuring chamber
arranged in the conduit and including at least two electrodes,
wherein the measuring chamber is closed in said upward direction and has
a downwardly directed opening for entry and exit of milk, such that it will be
filled with milk when milk flows upwardly through the conduit, and instantly
empties when the milk ceases to flow, and
wherein the measuring chamber is delimited by an outer wall of the
conduit and a protruding element extending from said outer wall, so that the
measuring chamber is closed in the upward direction by means of said
protruding
element, said at least two electrodes being arranged below the point from
which
said protruding element extends from said outer wall.
CA 02680781 2014-10-28
4a
Short description of the drawings
In the following, embodiments of the present invention will be described, by
way of
example, with reference to the appended drawings, wherein
Fig. 1 shows a cross-sectional view of a first preferred embodiment of the
invention;
Fig. 2 shows a front view of a second preferred embodiment of the device, in
which
a diaphragm is not shown;
Fig. 3 shows a cross-sectional view taken on the line A-A in Fig. 2, in which
the
diaphragm is shown;
Fig. 4 shows a rear view of the device in Fig. 2;
Fig. 5 shows a perspective front view of the device in Fig. 2; and
Fig. 6 shows a perspective rear view of the device in Fig. 2;
CA 02680781 2009-09-14
WO 2008/118056
PCT/SE2008/000174
Fig. 7, shows schematically a milking apparatus comprising the device shown in
Figures 1-6.
Detailed description of the invention
The overall idea of the present invention is to provide in a milk conduit, a
measuring
chamber that is closed at the upper end and open at the lower end, whereby the
inte-
rior space of the chamber is easily accessed by upwardly flowing milk, and no
risk
of clogging exists and the chamber is very easy to clean.
The measuring chamber of the invention may be arranged in a milking apparatus,
in
practically any location between the teat cups of the milking member and the
milk
line, as long as it is arranged in a milk conduit in which the milk flows
upwards in a
substantially vertical direction. Throughout the following description the
spatial ori-
entation of the device is presupposed to be the same as when arranged in the
sub-
stantially vertical milk conduit. Accordingly a lower or bottom element of the
device
will be located closer to the milking member than an upper or top element.
In a first embodiment of the invention, shown in Fig. 1, the device 1
comprises a tu-
bular portion inside which a measuring chamber 9 is arranged, which comprises
two
electrodes 2. The measuring chamber is delimited by a protruding element 3
extend-
ing from the wall 4 of the tubular portion. Millc enters the device from below
through an inlet passage 5 and is directed straight into the measuring chamber
9.
The protruding element 3 is located in the flow direction of the milk and thus
hin-
ders the milk flow to continue in its original direction, and instead forces
the milk
flow to deviate and flow through the gap left in the tubular element beside
the
measuring chamber 9. The milk then leaves the device through an upper outlet
pas-
sage 6.
CA 02680781 2009-09-14
WO 2008/118056
PCT/SE2008/000174
6
The measuring chamber 9 is closed in the upward direction by means of the
protrud-
ing element 3 and is open in the downward direction for entry and exit of
milk. The
protruding element 3 preferably includes a plurality of substantially vertical
wall
members 7 defining the side walls of the measuring chamber 9, and an upper
wall
member 8 defining the upper wall of the measuring chamber. In a particularly
ad-
vantageous alternative the upper wall member 8 is inclined such that is
slopes, pref-
erably along a parabolic curve, from the point on the wall from which it
extends (at
the back end of the measuring chamber) downwards to the opening of the
measuring
chamber. The measuring chamber 9 is thus upwardly tapered and is narrower at
the
upper back end, than at the opening, such that it is deeper in the area
closest to the
wall 4, and is rather shallow in the area near the lower portion of the upper
wall
member 8. This will enhance the efficiency of the milk flow into and out of
the
measuring chamber, as well as the removal of any trapped air inside the
measuring
chamber.
Figures 2-6 show a second embodiment of the invention, in which a vacuum
regula-
tion diaphragm valve (shut-off valve) is incorporated in the device 10. The
valve in-
cludes a fluid chamber 11 which encompasses a somewhat cup-shaped element 27
and a diaphragm 26. The diaphragm is shown only in Fig 3. The fluid chamber 11
comprises a milk inlet opening 20 at its bottom, and a substantially tubular
milk inlet
passage 15 is attached to the inlet opening below the fluid chamber. A milk
outlet
passage 16 is arranged at the upper end of the fluid chamber. The outlet
passage 16
is comprised of an upper substantially tubular portion mainly located outside
the
fluid chamber 11 and a lower extending portion 18, 21 located inside the fluid
chamber. A milk outlet opening 22 from the fluid chamber 11 is located at the
end
of the extending portion 18, 21, and the edge rim 23 surrounding the outlet
opening
22 forms a sealing surface against which the diaphragm 26 can seal, such that
the
size of a passage through the outlet opening can be controlled by means of
move-
ments of the diaphragm 26. It is also possible to completely close the outlet
opening
22 by means of the diaphragm 26. The milk exits through the outlet opening 22
in a
CA 02680781 2009-09-14
WO 2008/118056
PCT/SE2008/000174
7
substantially horizontal direction and then turns upwards in a substantially
vertical
direction through the outlet passage 16.
In this embodiment the measuring chamber 19 is positioned inside the fluid
chamber
11 and is located beneath and partially behind the lower extending portion 18
of the
outlet passage 16, as seen from the diaphragm point of view. The measuring
cham-
ber may be formed as a groove that is delimited by a protruding element 13,
which
is a part of the lower extending portion 18, 21 of the outlet passage; and
substan-
tially vertical side wall surfaces 17. The interior shape of the measuring
chamber
may be the same as described above for the first embodiment, i.e. being
narrower at
the upper back end than at the opening.
The device is preferably moulded from a plastics material one piece integrally
com-
prising the fluid chamber 11, the inlet passage 15, the measuring chamber 19
and
the outlet passage 16. Two electrodes 12 are arranged in the measuring chamber
19,
extending substantially horizontally through openings in the rear wall 14. The
elec-
trode connection is protected by protective walls 24 arranged around the
openings
25.
In use the milk flows upwards through the device similarly as described for
the first
embodiment. After having changed direction in the area of the measuring
chamber
19 the milk flow leaves the fluid chamber 11 through the outlet passage, via
the out-
let opening 22 of the fluid chamber.
A milking apparatus for milking of an animal comprising a device as described
above is shown in Fig. 7. The apparatus comprises a milking member 30 intended
to
be applied to the teats of an animal, a milk conduit 31 for transportation of
milk
from the milking member 30 to a milk line 32 that is located higher than the
milking
member. The device 1; 10 as described above is arranged in the milk conduit,
such
CA 02680781 2009-09-14
WO 2008/118056
PCT/SE2008/000174
8
that the opening of the measuring chamber is directed towards the milking
member
30.
Many changes and modifications in the above embodiments may, of course, be car-
ried out without departing from the scope of the invention. Accordingly, that
scope
is intended to be limited only by the appended claims.
