Note: Descriptions are shown in the official language in which they were submitted.
~6~7563Z
This invention xelates to a method and apparatus for milking
and more particularly concerns a method and apparatus of milking
w~ereby vacuum damage to an animals teats can be minimised.
It is believed that high vacuum in a milk line connected to
5.a teat cup, for example approximately 15 inches of mercury, can
lead to v~cuwm damage and inflamation of the teat if high vacuum
is applied to an unstimulated or "slack" teatO In the case o~
an unstimulated teat, the teat may be slack enough to be drawn
down into the teat cup interior, with possible stretching of the
10. teat as the teat cup "crawls" up the teat. In such a case,
the weight of the teat cup is supported by the mouth piece of the
teat cup gripping the base of the teat. To overcome cup crawl
it has been known to weight the teat cup, with consequent
pressure on the base of the teat and discomfort to the anlmal.
15. In addition, existing teat cups ~equire hard mouth pieces to
grip the base of the teat under hi~h vacuum~ This can also give
rise to discomfort.
Apart from possible discomfort to an animal and loss of milk
production, the exposure of an unstimulated teat to high vacuum
20. can stretch the teat, particularly the base of the teat, leading
to cracking and the presence of a blue or discoloured region. In
addition, the high vacuum may give rise to vacuum damage at or
inside the teat orifice, such as by back jetting. This damage
and possible back ietti~g of milk into an unstimulated teat
25. increases the likelihood of mastitus.
Others have sought to minimise vacuwm damage by reducing
the milk line vacuum; For example, New Zealand patent specifi-
cation No. 158416 to Alfa Laval A~B. teaches the use o~ high and
low vacuum lines which can be alternatively coupled tQ the milk
30. line ~epending upon milk flow xate. Apart rom the expense and
i extra equipment required this proposal has not proved to be
entirely satis~actory as tha teat is still subjact to the milk
line vacuwm.
I~ is an object of this in~ention to go ~o~ne way towards
; ~ -2-
~L~7~i~3Z
overcoming the abovementioned disadvantages in providing an
improved method and apparatus for milking~
In accordance with one broad aspect, the invention
relates to a method of milking an animal including applying a
teat cup to a teat to be milked; the teat cup having an
inflation; the interior of the inflation being in communication
with a milk line connected to a source of vacuum; the exterior
of the inflation being in communication with a pulsating vacuum :
~:~ source; characterised in that before milking commences, the
exterior of the inflation is subject to a lower vacuum (or
higher pressure) than the interior of the inflation and wherein -:
the level of the vacuum (or pressure) applied to the exterior ..
: of the inflation is controlled by a regulator positioned in a
vacuum line between a pulsator and the exterior of the inflation.
According to another aspect of this invention, there .:.
is provided a method of milking an animal including applying a ::
teat cup to a teat to be milked, the teat cup having an infla-
tion, the interior of the inflation being in communication with
a milk line connected to a source of vacuum, the exterior of ~.
the inflation being in communication with a pulsating vacuum
source; characterised in that before milking commences, the
exterior of the inflation is subject to a lower vacuum (or
higher pressure) than the interior of the inflation to close the
inflation about the teat and to prevent milk from entering the ~.
milk line. .
.~ By subjecting the exterior of the teat cup inflation
~, to a lower vacuum (or higher pressure) than the interior r the
teat cup inflation can close snugly about the teat and may
effectlvely close off the milk line vacuum from the teat. At
30 the same time the pulsator can continue to operate to beat or .
move the inf1ation about the teat to stimulate the teat so that
~milk is let down. After a predetermined time, or when the
~75632
milk has been let down into the teat, the pressure differential
between the interior and exterior of the teat can be reduced
so that the vacuum applied to the exterior of the teat cup
inflation is increased thus allowing the inflation to open and
milk to be removed by the milk line vacuum.
According to another aspect of this invention, there
i s :
10,
~
,
, '
~' .
~J~ :
'~ -3a
7563Z
provided apparatus for controlling a vacuum level applied
exteriorly to an inflation of a teat cup; including a housing,
an inlet port, capabla of being connected to a source o~ applied
vacuum and an outlet port capable of being connected to the
5. exterior of said teat cup inflation; a valve capable o moving
i~ respo~se to applied vacuum to re~strict or close off the inlet
port; and means for gradually moving the valve to increase the
vacuum level at the outlet port.
By providing means for gradually moving the valve, the
10. vacuwm level applied to the exterior of the teat cup infla~ion
can be gradually increased thus changing over from stimulation
to milking.
Other aspects of this invention, which should be considered
in all its novel aspects, will become apparent from the following
15. description, which is given by wày of example only, with refer-
ence to the accompanying drawings, in which:-
Fiqure 1: illustrates a sch~matic milking installation.
~ .
Fi~ure 2: illustrates a preferred vacuum regulator
constructed in accordance with one fonm of
20~ this invention~
Turning now to figure 1, there is illustrated a single teat
cup 1 connected to vacuum lines. It will be appreciated that
similar connections may be made to other teat cups and preferably
in the case of cows, four teat cups can be provided for each cow,
25. the teat cups being coupled to a vacuum regulator.
As is well known, a teat cup such as 1, has a mouth piece
2 and an inflation 3 which is resilient and can fit about a teat.
The interior of the teat cup inflation is indicated at 4 and is
connected via an outlet 3a to a milk line 6. Tha exterior of
, ~ 30. the teat cup inflation 3 is indicated at 5 and is in communicat-
ion with an air line 7~
The milk line 6 is conneated to a milk receptacle 8 with a
milk outlet 9. A branch vacuum line 10a is connected t~ a main
vacuum line 10.
_4_
,,,, , . , ... , .: . . .
3~75~i3~
The air line 7 from the exterior 5 of the teat cup
inflation 3 is connected via a pulsator 11 to a branch vacuum
line lOb and thus to the main vacuum line 10. The purpose of
the pulsator, is to perio~ically reduce the vacuum in the air
line 7 to cause the teat cup inflation 3 to contract about a
cows teat to promote milking.
A vacuum regulator 12 is situated in air line 7
between the pulsator 11 and the teat cup 1. Connected to the
vacuum regulator 12 is means 13 for gradually increasing the
vacuum level applied to the exterior 5 of the teat cup infla-
tion 3.
The operation of such a milking installation will now
be described by way of example. The main vacuum line 10 is
provided with a constant vacuum of the order of for example
only, 15 inches of mercury. The pulsator 11 is set to
periodically introduce air to reduce the vacuum in the air line
7 to cause the inflation 3 to squeeze about the teat ~not
shown) and to then release as the vacuum in the air line 7
. I . ,
increases once again. The milk line vacuum provides an almost
constant suction.
When the teat cup 3 is applied to a teat, the vacuum
regulator 12 is set so that a vacuum differential appears
; across the teat cup inflation. That is to say, the pressure
on the exterior S of the teat cup inflation 3 is maintained
higher or the vacuum lower than the pressure or vacuum within
the teat cup inflation so that the inflation 3 closes about
the teat and closes off or substantially closes off communica-
tion between the milk line vacuum and the teat within the
inflation 3. By way of example the regulator 12 can be set
initially so that the maximum vacuum applied to the exterior
-
~ ', .
~L~7S632
5 of the teat cup inflation 3 is less than about 5 inches of
mercury and preferably is of the order of 3 inches of mercury.
It will be appreciated from the foregoing that the main vacuum
line is, by way of example, of the order of 15 inches of
mercury and that with no milk in the milk line 6, the milk line
vacuum will be equivalent to that in the main vacuum line
`.
.
"`,
.
., ' ' ' ' `
` `'-. .
'.
~ ~
~; ~ , : ', ',
';
': .' . ,:
:~ . . ,, - . . . - . , , :. ~
~75632
10. The pressure differential between the interior 4 and the
exterior 5 of the teat cup inflation 3 is thus such as to close
off the inflation 3 about a teat and prevent or at least substant-
ially reduce the milk line vacuum from causing vacuum damage to
5. the teat.
As the vacuum regulator 12 is positioned between the
pulsator ll and the teat cup 1, the pulsator 11 will continue
to operate and thus the teat cup inflation 3 will gently stimulate
the teat by squeezing thereagainst.
10. After a time, the setting of the vacuum regulator 12 can he
gradually increased so that the teat cup inflation 3 opens and
the vacuum in the milk line 6 can withdraw milk from the teat.
It will be appreciated that this operation allows the teat to be
stimulated prior to milking and in addition, enables the teat cup
1~. 1 to fit snugly about an unstimuIated teat when first applied.
~s milk rises in milk line 6 to the milk receptacle 8 the
head of milk in the milk line 6 will cause the vacuum in the
, milk line 6 to drop below the level in the main vacuum line lOoWith this in mind, it is preferred that the vacuum regulator 12
20. is set so that the maximum vacuum level applied to ~he exterior
5 of the teat cup 3 during milking is just below or equal to the
vacuum in the milk line 6 at, or adjacent the outlet 3a of the
teat cup. It will be appreciated, that this level can be
determined ~y su~tracting the head of milk in milk line 6 from
.,
25. the vacuum level in the main vacuum line 10. By this means, the
invention enables milking to continue without the teat cup
inflation "ballooning" away from the teat.
It will be appreciated that "ballooning" of the inflation
can occur when there is a slight positive pressure at the
30. interior 4 o inflation 5, (iqe. a lower vacuum than is applied
to the exterior of t~e inflation~. "Ballooning" o~ the
inflation is undesirable as i~ can give rise to vacuum damage
to the teat by stretching the teat, or by allowing the milk line
vacuum to enter the mouth ~iece area of the teat cup.
-6~
- , ~ .: . , ., - . ,.
.
~7563Z
:
Moreover, if the air line vacuum level is set at a level
equal to or below the vacuum level in the milk line when ull
of milk ~say for example ~3 inches of mercury), then when millc
flow stops and milk is removed rom the milk line 6, the vacuum
5. at the interior 4 of the inflation 3 will increase to say for
example 15 inches of mercury. When this occurs the increased
pressure dif~erential across the inflation will cause the
inflation 3 to close snugly against the teat.
Turning now to figure 2 of the drawings, there is illustrated
lOo a preferred form of a vacuum regulator 1~. The vacuum regulator
is shown as having a housing which includes an upper housing
portion 12a and a lower housing portion 12b. 'Fhe upper and
! lower housing portions are adapted to be clamped together about,
for example, the seal 18 of the diaphragm valve (as will be
15. described by way of example hereinafter). This is by way of
example only. In addition, the two housing portions can be
formed with a bayonet type connection. Other means of connec-
tion can however be used to advantage.
The regulator 12 shown in figure 2 of the accompanying
20. drawings is preferably used to control for example a cluster
I
of ~our teat cups. Provision can be made to enable two or more
units to be coupled together. Raference to figure 2 of the
drawings sh~ws that holes or recesses 31 are provided so that
two similar units can be coupled together to provide a dou~le
25. xegulator if re~uired. It is envisaged that this will be
suitable ~r a type of milXing plant where double pulsators are
used, one pulsator being used for each pair of teat cups.
The regulator 12 has an air line passing therethrough, the
air line being in the form of an inlet port 14 and an outlet
, 30. port 15; the inlet port 14 leading into a valve cha~ber 17 and
being connected to the outlet poxt 15 by an outlet passage 16.
. ,
The inlet port 14 leads into and define~s a valve seat 48 in
the form of a shoulder.
The lower wall ~9 vf the valve ahamber L7 defines a hole or
.
~a~7563Z
bore 20 passing therethrough.
A valve 21 such as for example a diaphragm valve is mounted
within the valve chamber 17 and is secured in position about the
; wall o-f the valve chamber, such as by suitable seals~ A valve
5. stem 22 is connected to an under side of the diaphragm valve 21
and passes out through the wall 19 of the housing by way o the
hole or bore 20.
, , An actuating lever 23 is attached to a lower end of the valve
`, stem 22 and is pivotally mounted to the housing as shown in ~igure
10, 2 of the accompanyin~ drawings. The actuating lever 23 is
preferably elongate in formation.
~¦ A valve spring 24 is located about the valve stem 22 between
¦ the a~tuating leYer 23 and the under side of the housing surroun-
~¦ din~ the hole or bore 20.
15~ A side portion of the housing is formed so as to accommodate
and locate means ~or moving the lever 23; for example a timing
mechanism 13 which is provided with a suitable cord 26 which runs
from the timing mechanism 13 and is attached to a distal end 23a
, . . .
I o the actuating lever~23. The cord 26 then passes through or
20. is attached to, and extends away from, the distal end 23a of the
actuating lever 23 and can be provided with a suitable handle or
' ~rip 27 i~ desired.
i A lower portion of the housing mounts two spaced apart limit
stops 28 and 29. The limit stops 28 and 29 are in the form of
25. elongate members having an elongate body and a head portion with
- a cam face~ The limit stops 28 and 29 are position`ed so as to be
,¦ at least one above and at least one below a butt end 23b of ~he
~`' actuating lever 23 and the l~mit stops 28 and 29 are pivotally
mounted to the housing~ -
30. Each limit stop is associated with a plurality of spaced
apart protrusions or setting members 30. In use, the body
portions of the pivotally mounted limit stops 28 and 23 can be
located between two spaced apart protrusions 30 and held in a
predetermined or desired position.
.
`~: . ' '. ' ' ' ' ' ' ,
~7~63;2
In use, the vacuum regulator 12 can be installed in an air
line 7 such as in the position shown in figure 1 of the accom-
panying drawings.
A teat cup is applied to a teat; and the cord 26 is pulled
5. downwardly, thus moving the actuating lever 23 in a dcwnward
direction as shown in the arrow "A" in figure 2 of the accompany-
I ing drawings. This movement is im~arted to the vaive stem 22
which causes the diaphra~m valve 21 to move upwardly in the
~i direction o the arrow "B" shown in figure 2 of the accompanying
10. drawings and thus into juxtaposition with the valve seat 48 at
the shoulder of the inlet port. This will then allow only a very
small amount of vacuum to pass from the vacuum inlet port 14,
through the vacuum passage 16 and to the outlet port 15. A
setting such as this maintains a low vacuum at the exterior of the
15. teat cup inflation for a predetermined or desired period of time. I
The downward movement o the cord 26 will cause the butt end 23b
of the actuating lever to move upwardly and this movement will be
I controlled by the butt end 23b coming into contact with a cam
" face of the limit stop 28. Thus movement of the limit stop 28
20. between various protrusions 30, and thus the adjustment of the
~ cam face of the limit stop 28 can serve to "fine tune" the initial
j , inlet of vaauum following the pulling of the cord 260
i The pulling of the cord 26 will cause the cord 26 to come
out of the timer 13 and the timing arrangement i5 such as to then
25~ cause the cord 26 to be pulled back into the timer; this will also
cause the lever to be gradually moved or pulled upwardly. Any
suitable txpe of timer can be used, but the timer could for
example, be a clockwork timer and may lf desired, have a visual
or audio indicator. In another form of the invention it is
30. envisaged ~hat the timer can be in the form of a music box, and
,
' ll the playing of the music can also have a ~herapeutic and restful
e~ect on co~s.
Following the pulling of the cord 26 and ~he movement of the
diaphragm valve ~ into juxtaposi~ion with the va:Lve seat 48~ a
-9
'
~L~7~63~
small amount of vacuum passes through the passage 16 and into
the vacuum outlet 15. If the vacuum in the inlet port increases,
the increased differential pressure across the diaphragm 21 will
cause it to seal and abut against the valve seat 48; atmospheric
5. pressure being applied to the lower face of the diaphragm whilst
the upper is subjected to vacuum.
As the timer operates, the cord 26 is withdrawn into the
timer and thus the actuating lever 23 is moved upwardly in the
direction of the arrow "C" shown in figure 2 of the drawings.
10~ This movement is imparted to the valve stem 22 and the diaphragm
valve 21, which is caused to move in a downward direction, as
indicated by arrow "D" and thus away from the valve seat 48
and the shoulder. This then increases gradua~ the amount of
vacuum available for passing through the passage 16 into the
15. vacuum outlet 15.
The butt end 23b of the actuating lever 23 is caused to move
downwardly in the direction of the arrow "E" and its downward
~` movement can be controlled by the cam face of the second or lowerlimit stop 29 w~ich can be positioned to "~ine tune" the move-
20. ment, by being positioned between desired or predetermined, and
. spaced apart protrusions 30. The movement of the le~er 23 will
be limited and will cease once the butt end 23b comes into
contact with the cam ~ace of the lower limit stop 29.
; I Sultable means of controlling the operation of the timer 13
; 25. can be provided, for example suitable clockwork timers and the
~;~ like can be provided so that the movement of the valve 21 is such
that the vacuum will gradually increase to enable the milking to
commence, over a predetermined ox desired period of time. For
example, it has been found that in some cases a period of three
30. minutes provides ade~uate time for stimulation prior to milking~
This can vary however, depending upon various cows.
The sqtting of the second or lower limit stop 29 can be suc~
as to provide individual adjustment o an air line 7, during
milking for a paxticular cow. For example, teat sizes vary
.; .
. ~ - . , - ,
~7563Z
between breeds and cows, and teat cups do not always fit as
snugly as is desirable, particularly when a teat is small.
By adjusting the lower or second limit stop 29 the vacuum on
the exterior of the inflation during milking can be set lower
5~ than normal (by causing a lesser opening of the valve) to
thus permit the inflation to fit snugly about a small teat. On
the other hand, the pressuxe differential on the inflation can
be reduced by setting the stop 29 at a highar vacuum limit (by
permitting a greater opening o~ the valve) where the teat is
10. large.
In addition, the setting of the limit stop 29 can take
' I account of the reduction of the milk line vacuwm applied to the
I interior of the 'inflation when a head of milk is present in the
¦ milk line. Thus, the setting of limit stop 29 can be 5uch that
¦ 15. the vacuum level at the exterior of the in~lation is always less
, than or equal to the minimum vacuum present at the interior o~
,~ I the in~lation during mil'king.
It should be appreciated that this invention has been
described by way of example only. In particular it should be
20. appreciated that re~erences to examples such as mercury limits
, ~ and the like are by way o~ example only and can vary from
situation to situation. 'The claims ~orm part o~ the disclosure.
It should be appxeaiated that improvements znd modifications can
' ' be made to the invention without departing ~rom the scope
25. thereof as defined by the appended claims.
,
1 1
.
; .-
