Note: Descriptions are shown in the official language in which they were submitted.
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Background of the Invention
This invention relates generally to milking machines
and more particularly to a teat receiving milking liner or
inflation for use with a milking machine of the vacuum pulsator
type.
Prior art milking liners commonly used have been made
from various rubber and rubber~ e compounds formed in the shape
of a tube which has a uniform inner diameter. In order to form
a mouthpiece for receiving an animal teat a rigid ring member
is inserted in one end of the liner and is of a much larger
diameter than the diameter of the liner. The expansion of the
liner at the teat receiving end with the ring in place causes
rubber fatigue and deterioration so that the teat receiving end
prematurely distorts in shape so that it will no longer properly
stay on the teat or in many cases breaks down completely.
The present invention provides a milking liner for
use with a milking machine having a rigid outer casing, said
casing having a shouldered enlargement at one end, said liner
comprising: a tube of elastic material having a wa]] thickness
of 1/8 inch, said tube adapted to fit longitudinally within said
casing, a main body portion of said tube having a uniform diame-
ter, a first end of said tube having a conically tapered decreased
diameter portion, the inner diameter of which tapers from 13/16
inch to 9/16 inch, a smoothly rounded e~ternal bead on the outer
end of said first end, said first end of said tube adapted to be
received in the enlarged shoulder portion of the casing when said
first end is expanded by the insertion of a rigid ring member
therein, said wall thickness of the first end of said tube de-
creasing along said tapered portion from an initial thickness
of 1/8 inch to a final thickness of from 3/32 inch to 1/16 inch.
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As a result of the novel design of the teat receiving
end portion of the liner of the present invention there is a
better fit with the animal teat than was possible with prior
art liners.
Moreover, because the rubber in the reduced diameter
portion seeks to return to its original reduced shape and size
after the ring is removed, even with rubber fatigue caused by
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continuous usage, the liner still maintains an adequate fit
on the animal teat.
A further object and advantage of the present
invention resides in the fact that the reduced diameter and
reduced wall thickness at the teat receiving end of the liner
helps minimize the chances of the teat channel being choked
off or of other causes of teat irritation and inflammation
which can lead to the infectlous condition knowll as mastitis.
Other and further objects and advantages of the
present invention will be apparent from the following
description and claims and are illustrated in the
accompanying drawings which, by way of illustration, show
preferred embodiments of the present invention and the
principles thereof and what are now considered to be the best
modes contemplated for applying these principles. Other embodi- -
ments of the invention embodying the same or equivalent princi-
ples may be used and structural changes may be made as desired
by those skilled in the art without departing from the present
invention and the purview of the appended claims.
Brief Description of the Drawing
Fig. 1 is a detached elevational view of the new and
improved milking liner of the present invention.
Fig. 2 is a top end view of the teat receiving end of
the liner of the present invention.
Fig. 3 is a bottom end view of the liner of the present
invention.
Fig. 4 is a vertical longitudinal section showing the
liner of the present invention in use with ~arious other
components of a milking machine.
Fig. 5 is a vertical longitudinal section of a modified
embodiment of the present invention.
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Description of the Preferred Embodiments
Referring to Fig, 1, a tubular milking liner 10 is
shown having a first end portion 12 and a second end portion
14. The liner 10 is made of a flexible elastic material,
preferably rubber compounds having a synthetic or natural
latex base ~hich may utilize various curing agents and other
ingredients to combat deterioration and fatigue, etc. The -
method of making liners is well-known in the art and is not
part of the present invention.
As best shown in Fig. 2 in conjunction with Fig. 1,
the first end 12 of the liner 10 has a conically tapered
portion leading to a reduced diameter at the very outer end
16. The wall thickness of liner lO in the embodiment shown
in Fig. l is constant throughout the entire length of the
liner and excellent results have been achieved using a wall :
thickness of 1/8 inch. The inner diameter of the liner 10 is
preferably 13/16 inch except for the end portion 12 where the
diameter tapers down to a final diameter of 9/16 inch at the
very outer end 16. The length T of the tapered portion is ,
preferably about 3/4 inch to 1-1/2 inches whlle the overall
length of the liner 10 is preferably 5 inches to 6-1/2 inches,
depending upon the length and shape of shell 30, In one form
of liner 10 presently in use, the taper T is 3/4 inch and the
overall length is 6-1/4 inchès. Preferably, a reinforcing lip
18 is provided in the form of a smoothIy rounded bead, The lip
18 increases teat surface contact and increases the tendency of '
the reduced diameter end 16 to seek its original shape. The
smaller diameter tapered end 12 greatly increases the useful
- life of the liner 10 because even with eventual rubber fatigue
the end 12 will still provide an adequate fit on the cow teat.
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As sho~n in Fig. 4, the liner 10 is prepared for use
inside a casing or shell 30 by ~irst inserting an expansion
ring 32 inside the tapered end portion 12 of the liner. The
insertion of the ring 32 in effect forms a mouthpiece to
receive the teat and engage the cow udder. The insertion of
the ring 32 expands the reduced diameter outer end 16 back
toward the inner diameter of the main portion of the liner 10.
However, unlike prior art liners of uniform diameter through-
out, even with rubber fatigue (which is especially great in
the area where the ring is inserted) a good fit is still
maintained with the teat. In prior art liners, the rubber
would fatigue much sooner and the inner diameter of the liner
at the teat receiving end would distort badly resulting in a
poor fit with the teat and eventually resulting in the liner
falling off of the teat.
After the end portion 12 of the liner is expanded by
insertion of the ring 32, the liner is inserted in the sheIl
30 so that the end 12 of the liner sealingly engaged an en-
larged shoulder portion 34 of the sheIl. The liner is then
stretched lengthwise and the second or lower end 14 is turned
upwardly and back over the bottom end 36 of the sheIl in s~aled
relation thereto so that a pressure chamber 38 is provided
between the liner 10 and shell 30. As is well understood by
those skilled in the art, in operation the teat of the animal
passes through the reduced diameter portion 12 of the liner and
is received in the mid-section 10 thereof. The liner is
alternately expanded and contracted by variation of pressure in
; the chamber 38 placed in communication with a suitable pump by
a hose connected to a pipe 40 formed in a side of the casing 30.
A milk delivery tube connected to a suitable suction source then
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removes the milk from the bottom end 36 of the casing.
A modification o~ the invention which has shown
superior results to the embodiment previously discussed is
shown in Fig. 5. In Fig. 5 a tubular liner 50 is shown having
a first end portion 52 and a second end portion 54. The liner
50 is similar to the liner 10 in most respects including the
length (3/4 inch) T' of the tapered end portion and the pro- -
vision of a lip 58 similar to lip 1~ of Fig. 1. An impor~ant
improvement however is the provision of a steadily decreasing
wall thickness throughout the length of the tapered end portion
52. This decrease in wall thickness at the tapered end pro-
vides less restricting contact with the animal teat and
reduces the chànce of the teat streak channel being choked off.
Best results over a 3/4 inch taper length have been obtained
by steadily decreasing the wall thickness from l/8 inch to
from 3/32 to l/16 inch at the very outer end, In general, the
relationship is that the ~all thickness should decrease in
direct relationship with a decrease in diameter.
~hile I have illustrated and described preferred
embodiments of my invention, it is to be understood that these
are capable of variation and modification, and I therefore do
not wish to be limited to the precise details set forth, but
desire to avail myseIf of such changes and alterations as fall
within the purview of the following claims.
