Note: Descriptions are shown in the official language in which they were submitted.
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MILKIN-, INFLATION
BACKGROUND OF THE INVENTION
This invention relates to liners or
inflations for teat cup assemblies of vacuum-operated
milking machines and, more particularly, to such
liners or inflations including a milking tube section
which extends from a teat cup shell and is attached
to the nipple of the milking machine claw.
Automatic milking machines employ teat
cup assemblies including a hollow, rigid outer shell
which is attached to a pulsating vacuum line and a
resilient, tubular liner or inflation installed in
the shell in a manner to form a seal at both ends of
the shell. The cow's teat is inserted into the upper
end of the inflation and the lower end is connected
to a so-called claw of the milking machine. During
the milking operation, the teat cup assembly is
suspended from a co~'s teat, primarily by the
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engagement between an opening or mouth in the upper
or head end of the inflation ~nd the cow's teat and
milk flows through the inflation under the influence
of a vacuum maintained in the milking machine claw.
One type inflation is a one-piece unit
including an upper or shell section adapted to fit
inside the shell and a lower or milking tube section
which is pulled through and extends from an opening
in the lower end of the shell and is adapted to be
connected to the nipple of the milking claw.
Another type inflation includes an
upper or shell section having a lower end which fits
through an opening in the lower end of the shell and
a separate milking tube section which is connected to
the lower end of the shell section via a rigid,
sleeve connector which is press-fitted inside the
lower end of the shell section.
A further type inflation includes an
upper shell section having a lower end which is
adapted to be folded back over the open lower end of
the shell and a separate milking tube section having
a cup-shaped upper end adapted to fit over the folded
back portion of the shell section.
The following United States patents are
representative of prior art constructions for milking
tube sections of milking inflations:
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Patentee Patent No. Issue Date
Green 2,099,884 November 23, 1937
Scott 2,341,953 February 15, 1944
Hein 2,694,379 November 16, 1954
Norton 3,611,993 October 12, 1971
O1ander 4,196,696 April 8, 1980
Larson 4,324,201 April 13, 1982
Larson 4,372,250 February 8, 1983
Originally, the inside diameter of the
flow passage through the milking tube section of
milking inflations could be relatively small because
milk flow was quite small. The milking tube section
was quite f].exible because the small inside diameter
permitted the walls to be made relatively thin and
still not collapse when subjected to a vacuum during
the milking operation. This flexibility permitted
the teat cup to be conveniently lifted up and slipped
onto a cow's teat without imparting a significant
side force on the teat.
Modern dairy cows produce milk at
substantially higher flows and, consequently, it has
become necessary to increase the inside diameter of
the milking tube section in order to accommodate this
increase in milk flow. As the inside diameter of the
milking tube increases, the wall thickness also must
be increased to prevent the walls from collapsing
during the milking operation. The increased wall
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thickness makes the milking tube section relatively
stiff.
This stiffness resists movement of the
shell into proper orientation for attachment to a
cow's teat and can cause the mouthpiece of the
inflation to engage a cow's teat at an angle andior
to exert a side force on the teat. This can cause
discomfort for the cow. More importantly, such a
side force can cause the opening to become slightly
distorted, resulting in a non-uniform seal around
the teat and undesirable admission of air through the
mouthpiece opening which can cause slurping and
produce unhealthy conditions for the teat.
The above-identified Hein Patent
2,694,379 discloses forming a weakened portion of
reduced wall thickness in the milking tube adjacent
the milker claw. This weakened portion is designed
to cause the milking tube to collapse or crimp and
shutoff air flow therethrough when a teat cup falls
off a cow's teat. Thus, such an arrangement could
not be used to solve the above-described problem.
SUMMARY OF THE INVENTION
An object of the invention is to
provide a milking inflation including simple,
inexpensive means for increasing the capability of
the stem portion of the milking tube section to be
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bent or flexed for proper orientation of the shell for attachment of the
mouthpiece to a cow's teat.
Another object of the invention is to provide such a milking
inflation having improved teat-hanging characteristics.
Another objec-t of the invention is to provide such a milking
inflation having a milking tube portion which includes a substantially
crevice-free inner wall defining a flow passage therethrough and which
can be easily bent or flexed to facilitate installation of the inflation
onto a cow's teat without substantial crimping which causes a reduction
in the internal cross sectional area of a Flow passage extending through
the milking tube portion.
Other objects, aspects and advantages of the invention will
become apparent to those skilled in the art upon reviewing the following
detailed description, the drawing, and the appended claims.
Generally speaking, the above objects are met by the present
invention which provides a milking inflation for use with a teat cup
assembly including a rigid shell having a lower end, the inflation
being made from an elastomeric material and having an elongated
tubular milking tube section extending from the lower end of the shell,
the milking tube section including an elongated stem portion having an
exterior wall including an outer surface; upper and lower end portions
and a substantially crevice-free inner wall defining a flow passage
therethrough; a circumferentially-extending, generally V-shaped groove
in the outer surface of the exterior wall of the stem portion at a
location below and spaced from the lower end of the shell and adjacent
a thicker part or an internally supported part of the stem portion,
the groove having a sharp bottom and being arranged to permit substantial
movement of the shell relative to the stem portion without substantial
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crimping which causes a reduction in -the cross sectional area of the
flow passage.
The groove preferably includes a sharp pointed bottommost
portion having a longitudinal dimension which does not exceed about
1/32 inch. The wall thickness of the stem portion at the bottommost
portion of the groove preferably is about 20 to 50% of the wall thickness
of the stem portion and the longitudinal dimension of the groove at the
outer surface of the exterior wall of the stem portion preferably is
' about 1/4 to about 3/16 inch.
In one embodiment the milking inflation is a one-piece unit
and has a shell section which extends from the milking tube section and
is adapted to fit inside the teat cup shell. The milking tube section
includes an externally enlarged
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retaining section between the shell section and the
stem portion and located adjacent the lower end of
the shell when the inflation is installed therein.
The groove in the upper end of the stem portion is
located at the juncture between the retaining portion
and the stem portion.
In one embodiment, the inflation is a
multi-piece unit and includes a separate shell
portion which is adapted to fit inside the shell and
has a lower end portion adapted to extend through an
opening in the lower end of the shell and to be
folded back over the outer surface of the shell. The
milking tube section is a separate part and includes
a cup-shaped upper end portion extending from the
upper end of the stem portion and adapted to fit over
such folded back portion. The groove in the upper
end of the stem portion is adjacent the juncture
between the stem portion and the cup-shaped upper end
portion.
In one embodiment, the inflation is a
multi-piece unit including a separate shell section
which is adapted to fit inside a teat cup shell and
has a lower end portion adapted to extend through an
opening in the bottom of the shell. The inflation
further includes a rigid sleeve connector havi.ng an
upper end adapted to fit inside the lor~er end of the
shell section and press the outer surface thereof
into sealing engagement with the shell and a lower end
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adapted to receive the upper end Ot the stem portion
o~ the milking tube section which is a separate
part. rhe groove in the upper end of the sleeve
portion is located below and adjacent the lower end
of the connector.
BRIEF DESCRIPTION OF THE DRAWING
Fig. l is a partially sectioned, side
elevational view o~ a teat cup assembly carrying a
milking inflation of the invention, shown with the
mouthpiece attached to a cow's teat and the milking
tube section connected to a nipple on a milker claw.
Fig. 2 is an enlarged, sectioned, side
elevational ~iew of the milking inflation shown in
Fig. l.
Fig. 3 is a sectioned, side elevational
view of an alternate type milking inflation
incorporating the invention.
Fig. 4 is a sectioned, side elevational
view of a further alternate type of a milking
inflation incorporating the invention.
Fig. 5 is an enlarged, fragmentary,
sectional view of the milking tube section in the
vicinity of the upper groove.
Fig. 6 is an enlarged, fragmentary,
sectional view of the milking tube section in the
vicinity of the lower groove.
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DESCRIPTION OF THE PREFERRED EMBODIMEMTS
Illustrated in Fig. 1 is a teat cup
assembly 10 including a rigid, generally cylindrical
outer shell 12 which surrounds and supports a liner
or inflation 14 connected to a milker claw 16 (shown
fragmentarily). The milker claw 16 is connected to a
suitable vacuurn system (not shown) in the usual
manner and includes a plurality of nipples 18 (one
shown) which project upwardly and outwardly and have
a beveled outer end 20.
The shell 12 is formed from a metal,
such as stainless steel, or another suitable rigid
material, such as a synthetic thermoplastic or a
thermosetting resin. The shell 12 has a bottom 22
including an opening 24 of reduced diameter and an
upper end terminating in a rim 28.
Located in the side of the shell 12 is
a nipple 28 connected, via suitable tubing (not
shown), in communication with a pulsator which
alternately opens to atmospheric pressure and
evacuates the chamber between the interior wall of
the shell 12 and the inflation 14 to alternately
contract and expand the inflation for milking.
The inflation 14 is a tubular rnember
molded from a flexible or elastomeric material,
preferably a synthetic or natural rubber composition
including curing agents and the like. In the
construction illustrated in Figs. 1 and 2, the
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inflation 14 is a one-piece unit and includes an
elongated, generally cylindrical suction slee~e or
barrel section 30 which fits inside the shell 12, a
head section 32 which fits over the sheil rim 28 and
has a mouthpiece 34 including a circular opening 36
for receiving a cow's teat and a generally
cylindrical, reduced diameter milking tube section 38
which extends from the shell 12.
The head end section 32 has a
peripheral, downwardly extending cuff 40 which
sùrrounds and fits snugly over the upper end of the
shell 12 and sealingly engages the shell rim 28. The
milking tùbe section 38 includes an externally
enlarged or thicker-walled shell end or retaining
portion 42 which is squeezed through the opening 24
in the shell lower end 22 by pulling on the milking
tube section 38 after the cuff 40 is fitted into
place over the shell rim 28. The shell end or
retaining portion 42 has a flange 44 which surrounds
the shell opening 24 and is retained in sealing
engagement with the shell 12 after the milking tube
section 38 is released.
As best shown in Fig. 2, the milking
tube section 38 also includes an elongated stem
portion 46 having an upper end 48 connected to the
shell end or retaining portion 42. The ste,m portion
46 includes a substantially crevice-free inner wall
51 defining a flow passage 52 extending .
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therethrough. The inner wall 51 should be smooth or
at least s~lbstantially crevice free in order to
facilitate cleaning between milking operations. If
the inner wall 51 has corrugations or similar
crevices, it is difficult to remove all the residual
milk and know that it has been removed, particularly
after the inflation has been allowed to sit long
enough for the milk to dry.
The milking tube section 38 further
includes a claw end portion 50 which extends from the
lower end 53 of the stem portion 4 and is adapted to
be slipped onto a claw nipple 18. The claw end
portion 50 preferably includes an externally enlarged
reinforcement section 54 located in the region near
the outer end 20 of the claw nipple 18 and having a
wall thickness somewhat greater than the wall
thickness of the stem portion 46.
When the teat cup 10 is in the position
illustrated by solid lines in Fig. 1 with the
mouthpiece 34 of the inflation 14 slipped onto a
cow's teat, milk flows through the inflation 14,
through the claw nipple 18 and into the claw 16.
When the teat cup 10 is removed from a cow's teat
and drops to the position shown in phantom in Fig.
1, the inner wall of the claw end portion 50 of the
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milking tube section 38 sealingly engages the beveled
end 20 of the claw nipple 18 to shut ofr
communication between the claw 16 and the
atmosphere. Thus, the vacuum within the vacuum
system is maintained, even though one or more of the
teat cups have dropped from cooperative engagement
with the cow's teat.
The reinforcement section 54 is
arranged to provide protection against tears, splits,
and cuts and yet be flexible enough to ensure
complete shutofE. A preEerred arrangement for the
reinforcement section 54 is disclosed in United
States Patent 9,324,201,
The inside diameter of the stem portion
46 typically is in the order of about 7/16 to 1/2
inch and the wall thickness typically is in the order
of about 3/16 inch. The stem portions oE
conventional large tube inflations can be relatively
stiff and ordinarily resist bending when the teat cup
assembly is lifted upwardly for attachment to a cow's
teat. Consequently, the mouthpiece can engage the
cow's teat an at angle and/or exert a side force on
the teat with the attendant problem discussed above.
The stem portion 46 is arranged to
minimize this undesirable condition. This is
accomplished by providing in the stem portion 46 a
circumferentially-extending notch or groove 55 at a
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location near the lower end 22 of rhe shell 12 and/or
a circumferentially-extending notch or qroo;;e 56 at a
location adjacent the upper end 58 of the claw end
portion 50 which is located above the outer end o~
the claw nipple 18. The grooves 55 and 56 are
arranged to permit relative bending between the stem
portion 46 and the retaining portion 42 and between
the stem portlon 46 and the claw end portion 50,
respectively, without substantial crimping which
causes a reduction in the internal cross sectional
area of the flow passage 52. The grooves 55 and 56
pre~erably extend around the entire circumference of
the stem portion 46 so that this bending action can
take place in any radial direction throughout 360.
Thus, the yrooves 55 and 56 function somewhat like
swivel joints.
To best perform the desired function,
the grooves 55 and 56 are located adjacent a
relatively thick or stiff portion or adjacent an
internal support and are shaped with a sharp bottom
and generally tapered side walls which provide a
clearance space to permit one portion of the stem
portion 46 to be folded toward another portion
without substantia] crimping.
In the specific instruction illustrated
in Figs. 1 and 2, the groove 55 is located at the
juncture between the stem portion 46 and the enlarged
retaining porticn 42. The added wall thickness of
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the retaining pcrtion 47 pro~ides {esistance for
miniinizing crimping r"hen there is relative bending
between the stem.~ portion 45 and the shell 12. The
claw nipple 18 provides internal support for
resisting crimping when there is relative bending
between the stem portion 46 and the claw end portion
50. The added wall thickness of the reinforcement
section 54 provides further resistance for minimizing
crimping. It should be understood that the invention
can be incorporated into milking inflations which do
not have reinforced claw end portions as well as
those which do.
As a guide, the ~7all thickness of the
stem portion 46 at the bottommost portion 60 of each
groove 55 and 56 can be about 20 to about 50% of the
wall thickness of the stem portion 46. The side
walls 110 and 112 of the upper groove 55 and the side
walls 114 and 116 of the lower groove 56 preferably
converge to a relatively sharp point as illustrated
in Figs. 5 and 6. That is, the grooves 55 and 56
preferably are generally V-shaped. The longitudinal
dimension of the area of minimum wall thickness,
i.e., longitudinal dimension of the bottommost
portion 60 (designated by the letter B) should not
exceed about 1/32 inch. Greater longitudinal
dimensions in this area tend to provide a higher than
desired arnount of flexibility, resulting in crimping
at the bottommost portion 60. While somewhat less
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important, the longitudinal dimension of the grooves
55 and 56 at the outer surface (designa~ed by the
letter A) of the stem portion 46 should be about 1/4
to about 3/16 inch.
The curved side wall 110 and the
beveled or tapered side wall 112 of the upper groove
55 permit substantial relative bending between the
stem portion 46 and the retaining portion 42 at the
bottommost portion 60 before the side walls touch.
Likewise, the beveled or tapered side walls 114 and
116 of the lower groove 56 permit substantial
relative bending between the stem portion 46 and the
reinforcement section 54.
The effect of the additional
flexibility and swivel-like action afforded by the
grooves 55 and 56 is illustrated in Fig. 1. The
grooves 55 and 56 afford easy relative bending
between the upper end of the stem portion 46 and the
retaining portion 42 and between the lower end of the
stem portion 46 and the reinforcement section 54.
This permits the milking tube section 38 to be bent
into a generally S-shape as illustrated without
reducing the cross sectional area of the flow passage
52. While the stem portion 46 can be bent to the
degree shown, the bend is someThThat less during normal
use. Accordingly, Fig. 1 is intended to illustrate
the degree of flexibility imparted by the grooves 55
and 56 and not the condition under actual use.
The teat cup assembly 10 can be
conveniently vertically oriented for installation on
a cow's teat. The force required to bend the milking
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tube section 38 into such a shape is relatively low,
so the side forces exerted on the cow's teat after
installation are minimal. As a result, the teat cup
assembly 10 hangs comfortably from the cow's teat and
distortion of the rnouthpiece opening 36 is minimized.
ln some constructions only one groove,
either the upper groove 55 or the lower groove 56,
provide sufficient bending to accommodate
misalignment. However, in many cases use of both an
upper groove 55 and a lower groove 56 is preferred.
If only one groove is used, the upper groove 55 is
preferred because, during molding, it can be
conveniently formed into the configuration which
permits an angular misalignment up to about 30-35
without crimping. It is us usually more difficult to
mold the lower groove 56 with a configuration which
permits an angular misalignment much over about 15
without crimping.
Fig. 3 illustrates a three-piece type
milking inflation 60 including a separate shell part
62 (illustrated fragmentarily) having a lower end 64
which fits inside an opening 66 in the lower end of a
shell 68. The inflation 60 31so includes a separate
milking tube part 70 having an elongated stem portion
46a similar to stem portion 46 above and a
reinforcement section 54a similar o reinforcement
section 54 above. The inflation 60 further includes
a sleeve connector 72 having an enlarged upper end
portion 74 which fits inside the lower end 66 of the
shell part 62 and presses the outer wall of the lower
end 64 into sealing engagement with the shell opening
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66. The sleeve connector 72 has a reduced lower end
portion 76 which receives the upper end 78 of the
milking tube part 70.
The stem portion 46a of the milking
tube part 70 includes a generally ~-shaped,
circumferentially extending notch or groove 55a
located near the lower end of the shell 68 and/or a
generally V-shaped, circumferentially extending notch
or groove 56a located adjacent the upper end 80 of
the reinorcement section 52a. The grooves 55a and
56b are arranged and function in substantially the
same manner as grooves 55 and 56 described above. In
the specific construction illustrated in Fig. 3, the
groove 55a is located in a region adjacent the
lowermost end 82 of the sleeve connector 72 which
provides internal support for resisting crimping like
the retaining portion 42 in the embodiment discussed
above.
Fig. 4 illustrates a two-piece type
milking inflation 90 including a separate shell part
92 (illustrated fragmentarily) which fits inside a
shell 94 and has a lower end portion 96 which extends
through the open lower end 98 of the shell 94 and is
folded back over the outer surface of the lower end
of the shell 94. The inflation 90 also includes a
separate milking tube part 100 having a stem portion
46b similar to stem portion 46 above and a
reinforcement section 54b similar to reinorcement
section 54 above. The milking tube part 100 has an
enlarged, cup-shaped upper end portion 102 which fits
over and sealingly engages the folded over portion
104 of the shell part 92.
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The stem portion 46b of the milking
tube part 100 includes a generally V-shaped groove
55b located near the lower end of the shell 98 and/or
a generally V-shaped groove 56b located adjacent the
upper end 106 of the reinforcement section 54b. The
grooves 55b and 56b are arranged and function in
substantially the same manner as the grooves 55 and
56 described abo~e. In the specific construction
illustrated in Fig. 4, the groove 55b is located at
the juncture between the thicker, cup-shaped portion
102 and the upper end 108 of the stem portion 46b.
F'rom the foregoing description, one
skilled in the art can easily ascertain the essential
characteristics of the invention and, without
departing ~rom the spirit and scope thereof, make
various changes and modifications to adapt it to
various usages.
