Note: Descriptions are shown in the official language in which they were submitted.
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LIOUID CONTAINMENT AND DISPENSING DEVICE WITH
IMPROVED ATTACHMENT OF LIOUID CONTAINING
POUCH TO CHASSIS
Cross-Reference to Related Ap~lication
This application is directed to improvements in the
invention of co-pending U.S. patent application Serial
No. 08/429,987, an application in which I am named as a
joint inventor.
Field of the Invention
This invention relates to a liquid containment
device with a self-contained pump for dispensing liquid
in small doses of a predetermined volume. More
particularly, this invention relates to a replaceable
containment device of the foregoing character which is
useful in an ink-jet printer for containing a supply of
printing ink and for dispensing the printlng ink to a
printing head upon the actuation of the self-contained
pump.
Backqround and Brief Description of the Invention
A pending U.S. patent application filed by Bruce
Cowger and Norman Pawlowski, Jr., for an invention
entitled "Ink Supply For An Ink-Jet Printer," describes
an ink supply for an ink-jet printer that is separate
from the printer ink pen, and can be replaced upon the
emptying of the ink supply without the need to replace
the printer ink pen. The ink supply of the aforesaid
U.S. patent application incorporates a self-contained
2~ pumping device for dispensing ink from a pumping chamber,
and describes, as an embodiment of such a pumping device,
a bellows pump. However, a bellows pump requires a
relatively large extended surface of a semi-rigid
material, such as a polymeric material, and is subject to
3~ a relatively high rate of oxygen and moisture transfer
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through the material of the bellows. This oxygen and/or
moisture transfer can result in the degradation of the
ink within the ink supply, especially in a printer that
is used only infrequently. Further, the bellows is
subject to leakage at the location of its attachment to
another portion of the ink supply. According to the
aforesaid pending U.S. patent application Serial
No. 08/429,987, these and other problems associated with
the use of a bellows can be avoided by the use of a
pumping device having a rigid perimetrical wall,
preferably formed integrally with the associated chassis
structure of the ink supply, with a linearly acting
pumping member that is moveable within a pumping chamber
defined by the rigid wall to pressurize ink within the
pumping chamber, and a flexible moisture and oxygen
barrier film heat sealed to an edge of the perimetrical
wall in a continuous pattern and overlying the pumping
member.
An ink supply according to the aforesaid U.S. Patent
application Serial No. 08/429,987 incorporates a pouch
fabricated from a sheet of thermoplastic material, and
the pouch is attached to the underside of the chassis by
heat staking. Thus, the forces acting to displace the
pouch from the chassis put the thermoplastic material in
tension, whereas the optimum strength of a heat staked
joint between a film and a more rigid member occurs when
the forces acting on the film tend to peel it from the
~tructure to which it is heat staked.
It has also now been found to be desirable to
fabricate the pouch from a co-extruded multiple layer
material with an innermost layer formed from a material
that is particularly resistant to degradation from
contact with ink, such as linear low density
polyethylene, supported by an outermost, strength-
3s providing material with good vapor barrier properties
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such as polyethylene terephthalate, with a layer of an
adhesive, such as silicon dioxide, therebetween.
However, in securing the pouch to the chassis according
to the teachings of the aforesaid U.S. patent application
Serial No. 08/429,987, it was necessary to puncture the
pouch at the location of the fill port and the inlet
port. This exposes edges of the material to ink, and can
lead to degradation of the layers of the pouch that are
otherwise not directly in contact with ink.
The aforesaid and other problems with the joint
between the flexible pouch and the chassis of the liquid
containment and dispensing device of the aforesaid U.S.
patent application Serial No. 08/429,987 are overcome by
the present invention in which the pouch is fabricated
with an open end that is heat staked to an exterior
surface of the chassis in an endless pattern. This mode
of attachment of the pouch to the chassis also increases
the internal volume of the pouch that can be filled with
ink for a given overall size of the liquid containment
and dispensing device.
Because an ink containment and dispensing device
according to the aforesaid U.S. patent application Serial
No. 08/429,987 i9 normally installed in a printer in an
inverted orientation, that is, with the chassis
positioned below the pouch, there is a potential problem
of leakage from the ink outlet due to gravitational
forces. Such a problem is overcome, however, in
accordance with an embodiment of the present invention in
which the outlet is provided with an elastomeric septum.
Accordingly, it is an object of the present
invention to provide an improved liquid containing and
dispensing device. More particularly, it is an object of
the present invention to provide an improved device of
the foregoing character that is useful in containing and
dispensing ink in an ink-jet printer.
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It is also an object of the present invention to
provide a liquid containment and dispensing device with
improved engagement between a liquid containing pouch of
the device and a rigid molded plastic chassis of the
device. More particularly, it is an object of the
present invention to provide an improved device of the
foregoing character that is useful in containing and
dispensing ink in an ink-jet printer.
It is also an object of the present invention to
provide a printing ink containment and dispensing device
with improved resistance to leakage by gravity when
installed in an inverted position.
For a further understanding of the present invention
and the objects thereof, attention is directed to the
drawing and the following brief description thereof, to
the detailed de~cription of the preferred embodiment of
the invention, and to the appended claims.
Brief Descri~tion of the Drawing
Fig. 1 is a side view of a liquid containment and
dispensing device according to an embodiment of the
present invention;
Fig. 2 is a an exploded view of the device of Fig.
l;
Fig. 3 is a plan view of the device of Figs. 1 and 2
taken on line 3-3 of Fig. 1;
Fig. 4 is a plan view of a component of the device
of Figs. 1-3 taken on line 4-4 of Fig. S;
Fig. 5 is a side view of the component of Fig. 4;
Fig. 6 is a plan view of the component of Figs. 4
and 5 taken on line 6-6 of Fig. 5;
Fig. 7 is a fragmentary sectional view taken on line
7-7 of Fig. 3 and at an enlarged scale;
Fig. 8 is a fragmentary exploded view of a portion
of the device of Figs. 1-7;
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Fig. 9 is a fragmentary view similar to Fig. 8
showing the elements of Fig. 8 in assembled relationship
to one another;
Fig. 10 is a view similar to Fig. 7 of an
alternative embodiment of the present invention; and
Fig. 11 is a view similar to Figs. 7 and 10 of
another alternative embodiment of the present invention.
Detailed Description of the Preferred Embodiment
An ink containment and dispensing device in
accordance with the embodiment of the invention described
in the aforesaid U.S. patent application Serial No.
08/429,987 is identified in Fig. 1 by reference
numeral 10. The device 10 has a hard protective shell 12
which contains a flexible pouch 14 for containing ink.
The shell 12 is attached to a chassis 16, which houses a
pump 18 and a fluid outlet 20. A protective cap 22 is
attached to the chassis 16 and a label 24 is glued to the
outside of the shell 12 and cap 22 elements of the
device 10 to secure the shell 12, chassis 16, and cap 22
firmly together. The cap 22 is provided with apertures
which allow access to the pump and the fluid outlet.
The device 10 is adapted to be removably inserted
into a docking bay (not shown) within an ink-jet printer.
When the device 10 is inserted into the printer, a fluid
inlet in the docking bay is adapted to engage the fluid
outlet 20 to allow ink flow from the device 10 to the
printer. An actuator (not shown) in the docking bay is
adapted to engage the pump 18. Operation of the actuator
causes the pump 18 to provide ink in a series of small
doses of a predetermined volume from the flexible
pouch 14, through the fluid outlet 20, to the fluid inlet
of the docking bay and then to the printer.
The chassis 16 is provided with a fill port 32 at
one end and an exhaust port 34 at the other end. Ink can
be added to the ink supply through the fill port 32 while
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air displaced by the added ink is exhausted through the
exhaust port 34. After the ink supply is filled, the
fill port 32 is sealed with a ball 35 press fit into the
fill port 32.
A pumping chamber 36 having an open bottom is formed
on the bottom of the ChaBBi9 16 within a rigid
perimetrical wall 37, which is preferably formed
integrally with the chassis 16. As described in more
detail below, the chamber 36 can be pressured to supply
ink to the printer without pressurizing the interior of
the pouch 14. The top of the chamber 36 is provided with
an inlet port 38 through which ink may enter the
chamber 36 from the pouch 14 by gravity and/or by a
negative pressure within the chamber 36. An outlet
port 40 through which ink may be expelled from the
chamber 36 iB alBo provided.
A one-way flapper valve 42 located at the bottom of
the inlet port 38 serveB to limit the return of ink from
the chamber 36 to the pouch 14. The flapper valve 42 is
a rectangular piece of flexible material. In the
illustrated embodiment the valve 42 is positioned over
the bottom of the inlet port 38 and is heat staked to the
chassis 16 at the midpoints of its short sides. When the
pressure within the chamber 36 drops below that in the
pouch 14, the unstaked sides of the valve 42 each flex to
allow the flow of ink through the inlet port 38 and into
the chamber 36. By heat staking the valve 42 to the
chassis 16 along an opposed pair of sides, less flexing
of the valve 42 is required or permitted than would be
the case if the valve 42 were staked only along a single
side, thereby ensuring that it closes more securely, and
this effect iB enhanced by doing the heat staking at the
midpoints of the shorter sides, as opposed to the longer
sides.
In the illustrated embodiment the flapper valve 42
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is made of a two ply material. The outer ply is a layer
of low density polyethylene 0.0015 inches thick. The
inner ply is a layer of polyethylene terephthalate (PET)
0.0005 inches thick. The illustrated flapper valve 42 is
approximately 5.5 millimeters wide and 8.7 millimeters
long. Such a material is impervious to the flow of ink
therethrough when the valve 42 is in its closed position.
The bottom of the chamber 36 is covered with a
flexible diaphragm 44. The diaphragm 44 is slightly
larger than the opening at the bottom of the chamber and
is sealed around the free edge of the perimetrical
wall 37 that defines the chamber 36. The excess material
in the oversized diaphragm 44 allows the diaphragm to
flex up and down to vary the volume of the chamber 36.
In the illustrated device, the displacement of the
diaphragm 44 allows the volume of the chamber 36 to be
varied by about 0.7 cubic centimeters. The fully
expanded volume of the illustrated chamber 36 i8 between
about 2.2 and 2.5 cubic centimeters.
In the illustrated embodiment, the diaphragm 44 is
made of a multi-ply material having a layer of low
density polyethylene 0.0005 inches thick, a layer of
adhesive, a layer of metallized polyethylene
terephthalate (PET) 0.00048 inches thick, a layer of
adhesive, and a layer of low density polyethylene 0.0005
inches thick. Of course, other suitable materials may
also be used to form the diaphragm 44. The diaphragm 44
in the illustrated embodiment is heat staked, using
conventional methods, to the free edge of the wall 37 of
the chamber 36. During the heat staking process, the low
density polyethylene in the diaphragm will seal any folds
or wrinkles in the diaphragm 44. The diaphragm 44, thus,
is impervious to the transmission of oxygen and moisture
therethrough, thereby safeguarding the ink in the
chamber 36 from degradation by exposure to any such
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substance.
Within the chamber 36 a pressure plate 46 is
positioned adjacent the diaphragm 44, the pressure
plate 46 serving as a piston with respect to the
chamber 36. A pump spring 48, made of stainless steel in
the illustrated embodiment, biases the pressure plate 46
against the diaphragm 44 to urge the diaphragm outward so
as to expand the size of the chamber 36. One end of the
pump spring 48 is received on a spike 50 formed on the
top of the chamber 36 and the other end of the pump
spring 48 i9 received on a spil~e 52 formed on the
pressure plate 46 in order to retain the pump spring 48
in position. The pressure plate 46 in the illustrated
embodiment is molded of high density polyethylene.
A hollow cylindrical boss 54 extends downward from
the chassis 16 to form the housing of the fluid
outlet 20, the boss 54 being formed integrally with the
chassis 16. A bore 56 of the hollow boss 54 has a narrow
throat 54a at its lower end. A sealing ball 58, made of
stainless steel in the illustrated embodiment, is
positioned within the bore 56. The sealing ball 58 is
sized such that it can move freely within the bore 56,
but cannot pass through the narrow throat portion 54a
thereof. A sealing spring 60 is positioned within the
bore 56 to urge the sealing ball 58 against the narrow
throat 54a to form a seal and prevent the flow of ink
through the fluid outlet. A retaining ball 62, made of
stainless steel in the illustrated embodiment, is press
fit into the top of the bore to retain the sealing
spring 60 in place. The bore 56 is configured to allow
the free flow of ink past the retaining ball 62 and into
the bore 56.
A raised manifold 64 is formed on the top of the
chassis 16. The manifold 64 forms a cylindrical boss
around the top of the fill port 32 and a similar boss
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around the top of the inlet port 3 8 SO that each of these
ports is isolated. The manifold 64 extends around the
base of the fluid outlet 20 and the outlet port 40 to
form an open-topped conduit 66 joining the two outlets.
The flexible ink pouch 14 iS attached to the top of
the manifold 64 SO as to form a top cover for the
conduit 66. In the illustrated embodiment, this is
accomplished by heat staking a rectangular plastic
sheet 68 to the top surface of the manifold 64 to enclose
the conduit 66. In the illustrated embodiment, the
chassis 16 is molded of high density polyethylene and the
plastic sheet is low density polyethylene that is 0.002
inches thick. These two materials can be easily heat
staked to one another using conventional methods and are
also readily recyclable.
After the plastic sheet 68 iS attached to the
chassis 16, the 9heet is folded and sealed around its two
sides and top to form the flexible ink pouch 14. Again,
in the illustrated embodiment, heat staking can be used
to seal the perimeter of the flexible pouch 14. The
plastic sheet over the fill port 32 and over the inlet
port 38 can be punctured, pierced, or otherwise removed
so as not to block the flow of ink through these ports.
Although the flexible pouch 14 provides an ideal way
to contain ink, it may be easily punctured or ruptured
and allows a relatively high amount of water loss from
the ink. Accordingly, to protect the pouch 14 and to
limit watçr loss, the pouch 14 i8 enclosed within the
protective shell 12. In the illustrated embodiment, the
shell 12 is made of clarified polypropylene, which i~
sufficiently translucent to permit inspection of the ink
within the pouch 14 to determine that an adequate volume
of ink remains for proper operation of the printer. A
thickness of about one millimeter has been found to
provide robust protection and to prevent unacceptable
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water loss from the ink. However, the material and
thickness of the shell may vary in other embodiments.
The top of the shell 12 has a number of raised
ribs 70 to facilitate gripping of the shell 12 as it is
inserted in or withdrawn from the docking bay. A
vertical rib 72 projects laterally from each side of the
shell 12. The vertical rib 72 can be received within a
slot (not shown) in the docking bay to provide lateral
support and stability to the ink supply when it is
positioned within the printer. The bottom of the
shell 12 iS provided with two circumferential grooves or
reCeSSe9 76 which engage two circumferential ribs or
beads 78 formed on a depending perimetrical wall 79 of
the chassis 16 to attach the shell 12 to the chassis 16
in a snap fit.
The attachment between the shell 12 and-the
chassis 16 should, preferably, be snug enough to prevent
accidental separation of the chassis from the shell and
to resist the flow of ink from the shell should the
flexible pouch develop a leak. However, it is also
desirable that the attachment not form a hermetic seal to
allow the slow ingress of air into the shell as ink is
depleted from the pouch 14 to maintain the pressure
inside the shell generally the same as the ambient
pressure. Otherwise, a negative pre~sure may develop
inside the shell and inhibit the flow of ink from the
pouch. The ingress of air should be limited, however, in
order to maintain a high humidity within the shell and
minimize water 1099 from the ink.
In the illustrated embodiment, the shell 12 and the
flexible pouch 14 which it contains have the capacity to
hold approximately thirty cubic centimeters of ink. The
shell is approximately 67 millimeters wide, 15
millimeters thick, and 60 millimeters high. The flexible
pouch 14 is sized so as to fill the shell without undue
CA 022343~3 l998-04-08
16972
excess material. Of course, other dimensions and shapes
can also be used depending on the particular needs of a
given printer.
To fill the device 10, ink can be injected through
the fill port 32. As it is filled, the flexible pouch 14
expands so as to substantially fill the shell 12. As ink
is being introduced into the pouch, the sealing ball 58
can be depressed to open the fluid outlet and a partial
vacuum can be applied to the fluid outlet 20. The
partial vacuum at the fluid outlet causes ink from the
pouch 14 to fill the chamber 36, the conduit 66, and the
bore of the cylindrical boss 54 such that little, if any,
air remains in contact with the ink. The partial vacuum
applied to the fluid outlet also speeds the filling
process. To further facilitate the rapid filling of the
pouch, the exhaust port 34 is provided to allow the
escape of air from the ~hell as the pouch expands. Once
the ink supply is filled, the ball 35 is press fit into
the fill port 32 to prevent the escape of ink or the
entry of air.
Of course, there are a variety of other ways which
can also be used to fill the present ink containment and
dispensing device. In some in~tances, it may be
desirable to flush the entire device with carbon dioxide
prior to filling it with ink. In this way, any gas
trapped within the device during the filling process will
be carbon dioxide, not air. This may be preferable
because carbon dioxide may dissolve in some inks while
air may not. In general, it is preferable to remove as
much gas from the device as possible so that bubbles and
the like do not enter the print head or the trailing
tube.
The protective cap 22 is placed on the device 10
after the pouch is filled. The protective cap is
provided with a groove 80 which receives a rib 82 on the
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chassis to attach the cap to the chassis. The cap
carries a lug 84 which plugs the exhaust port 34 to limit
the flow of air into the chassis and reduce water 1099
from the ink. A stud 86 extends from each end of the
chassis 16 and is received within an aperture in the
cap 22 to aid in aligning the cap and to strengthen the
union between the cap and the chassis. The free ends of
the studs 86, which extend beyond the apertures of the
cap 22, are preferably deformed after the cap 22 is in
place, for example, by contacting them with a heated
tool, to provide a tamper resistant attachment of the
cap 22 to the chassis 16. Further, the label 24 iS glued
to the sides of the device 10 to hold the shell 12,
chassis 16, and cap 22 firmly together. In the
illustrated embodiment, a hot-melt pressure sensitive or
other adhesive is used to adhere the label in a manner
that prevents the label from being peeled off and
inhibits tampering with the ink supply.
The cap 22 in the illustrated embodiment is provided
with a vertical rib 90 protruding from each side. The
rib 90 is an extension of the vertical rib 72 on the
shell and is received within the slot provided in the
docking bay in a manner similar to the vertical rib 72.
In addition to the rib 90, the cap 22 has protruding
keys 92 located on each side of the rib 90. One or more
of the keys 92 can be optionally deleted or altered so as
to provide a unique identification of the particular ink
supply by color or type. Mating keys (not shown),
identifying a particular type or color of ink supply can
be formed in the docking bay. In this manner, a user
cannot inadvertently insert an ink supply of the wrong
type or color into a docking bay. This arrangement is
particularly advantageous for a multi-color printer where
there are adjacent docking bays for ink supplies of
various colors.
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In the embodiment of the invention illustrated in
Fig. 10, elements corresponding to the elements of the
embodiment of Figs. 1 through 9 are identified by a 100
series numeral, the last two digits of which are the
digits of the corresponding element of the invention of
Figs. 1 through 9.
The ink containment and dispensing device of Fig. 10
is generally identified by reference numeral 110 and,
except as hereinafter described, corresponds to the
device 10 of Figs. 1 through 9. The device 110 has a
hard protective shell 112 which is opened at one end and
contains a flexible pouch 114 for containing ink. The
shell 112 and an open end of the pouch 114 are attached
to a chassis 116 which houses a pump 118 and a fluid
outlet 120. A protective cap 122 is attached to the
chassis 116. The opposed end of the pouch 11~, not
shown, is closed.
The device 110 is adapted to be removably inserted
into a docking bay, not shown, within an ink-jet printer.
When the device 110 is inserted into the printer, a fluid
inlet in the docking bay is adapted to engage the fluid
outlet 120 to allow ink to flow from the device 110 to
the printer. An actuator, not shown, in the docking bay
is adapted to engage the pump 118. Operation of the
actuator causes the pump 118 to provide ink in a series
of small dose~ of a predetermined volume from the
flexible pouch 114, through the fluid outlet 120, to the
fluid inlet of the docking bay and then to the printer.
The chassis 116 is provided with a fill port 132.
Ink can be added to the ink supply in the pouch 114
through the fill port 132, and after the ink supply is
filled, the fill port 132 is sealed with a ball 135 that
is press fit into the fill port 132.
A pumping chamber 136 having an open bottom is
formed on the bottom of the chassis 116 within a rigid
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perimetrical wall 137, which is preferably formed
integrally with the chassis 116. As described in more
detail below, the chamber 136 can be pressured to supply
ink to the printer without pressurizing the interior of
the pouch 114. The top of the chamber 136 iS provided
with an inlet port 138 through which ink may enter the
chamber 136 from the pouch 114 by gravity and/or by a
negative pressure within the chamber 136.
A one-way flapper valve 142 located at the bottom of
the inlet port 138 serves to limit the return of ink from
the chamber 136 to the pouch 114. The flapper valve 142
is a rectangular piece of flexible material and is
positioned over the bottom of the inlet port 138. When
pressure within the chamber 136 drops below that in the
pouch 114, the valve 142 flexes to allow the flow of ink
through the inlet port 138 into the chamber 136.
The bottom of the chamber 136 iS covered with a
flexible diaphragm 144. The diaphragm 144 iS slightly
larger than the opening at the bottom of the chamber 13 6
and is sealed around the free edge of the perimetrical
wall 137 that defines the chamber 136. The excess
material in the oversized diaphragm 144 allows the
diaphragm to flex up and down to vary the volume of the
chamber 136. Within the chamber 13 6, a pressure
plate 146 iS positioned adjacent the diaphragm 144, the
pressure plate 146 serving as a piston with respect to
the chamber 136. A pump spring 14 8 biases the pressure
plate 146 against the diaphragm 144 to urge the diaphragm
outward so as to expand the size of the chamber 136. One
end of the pump spring 148 iS received on a spike 150
formed in the top of the chamber 136, and the other end
of the pump spring 148 iS received on a spike 152 formed
on the pressure plate 146 in order to retain the pump
spring 148 in position. The pressure plate 146 in the
illustrated embodiment is molded of high density
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polyethene.
A hollow cylindrical boss 154 extends downwardly
from the chassis 116 to form the housing of the fluid
outlet 120, the boss 154 being formed integrally with the
chassis 116. A bore 156 of the hollow boss 154 has a
narrow throat 154a at its lower end. A sealing ball 158
is sized such that it can move freely within the
bore 156, but cannot pass through the narrow throat
portion 154a thereof. A sealing spring 160 is position
within the bore 156 to resiliently urge the sealing ball
158 against the narrow throat 154a to form a seal and
prevent the flow of ink through the fluid outlet 120 when
the device 110 is not inserted into a docking bay of a
printer.
The flexible ink pouch 114 has an open end 114a
positioned adjacent to the chassis 116, the chassis 116
having an endless annular skirt 116a. The inside of the
open end 114a of the pouch 114 is heat staked against the
outside of the skirt 116a of the chassis 116 in an
endless pattern. Thus, any load that tends to separate
the pouch 114 from the chassis 116 will tend to peel the
open end 114a of the pouch 114 from the skirt 116a of the
chassi~ 116, and the peel strength of plastic films from
rigid plastic members is especially strong, especially if
the overlap between the open end 114a of the pouch 114
and the skirt 116a of the chassis 116 is sufficient to
provide a heat staked area of substantial axial extent.
The head staking of the open end 114a of the pouch
114 to the outside of the annular skirt 116a protects the
free edge of the open end 114a of the pouch 114 from
contact with ink and degradation that may result
therefrom. Of course, insinuations where the contents of
the pouch 114 does not pose a risk of degradation any
constituent material of the pouch 114, the open end 114a
of the pouch 114 may also be heat staked to the interior
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of the annular skirt 116a.
When such a multiple layer material is used to form
the pouch 114, an adhesive is applied between the
innermost layer and the outermost layer, actually between
the outermost layer and a layer of silicon dioxide that
is deposited on the inside of the innermost layer. In any
case, using the construction herebefore described, it is
not possible for ink to contact any portion of the
pouch 114 except the innermost layer, the edge of the
open end 114a of the pouch 114 being protected from
contact with ink by virtue of the heat staking of the
open end 114a of the pouch 114 to the skirt 116a of the
chassis 116.
For optimum service, the pouch 114 is formed from
multiple layers, for example, by co-extrusion. When the
pouch 114 is formed from multiple layers, it will
preferably be provided with an innermost layer that is
especially resistant to degradation from contact with
ink, and linear low density polyethylene is a
particularly good material for such service. The
material of the pouch 114 further has an outermost layer
of high tensile strength and good oxygen impermeability,
such as polyethylene terephthalate or polypropylene.
In the embodiment of the invention illustrated in
Fig. 11, elements of Figs. 1 through 9 are identified by
a 200 series numeral, the last two digits of which are
the two digits of the corresponding element of the
invention of Figs. 1 through 9.
The ink containment and dispensing device of Fig. ll
is generally identified as reference numeral 210 and,
except as hereinafter described, corresponds to the
device 10 of Figs. 1 through 9. The device 210 has a
hard protective shell 212, which is open at one end, and
contains a flexible pouch 214 for containing ink. The
shell 212 and an open end of the pouch 214 are attached
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to a molded plastic chassis 216, which houses a pump 218
and a fluid outlet 220. A protective cap 222 iS attached
to the chassis 216. The opposed end, not shown, of the
pouch 214 iS closed.
The device 210 iS adapted to be removably inserted
into a docking bay, not shown, within an ink-jet printer
in the same manner as the device 10 of the embodiment of
Figs. 1 through 9. When the device 210 iS inserted into
the printer, a fluid inlet in the docking bay is adapted
to engage the fluid outlet 220 to allow ink to flow from
the device 210 to the printer, similar to the arrangement
of the device of the embodiment of Figs. 1 through 9. An
actuator, not shown, in the docking bay is adapted to
engage the pump 218. Operation of the actuator causes
the pump 218 to provide ink in a series of small doses of
a predetermined volume from the flexible pouch 214,
through the fluid outlet 220, to the fluid inlet of the
docking bay and then to the printer.
The chassis 216 iS provided with a fill port 232 at
one end. Ink can be added to the ink supply through the
fill port 232 and after the ink supply is filled, the
fill port 232 iS sealed with a ball 235 press fit into
the fill port 232. A pumping chamber 236 having an open
bottom is formed on the bottom of the chassis 216 within
a rigid perimetrical wall 237, which is preferably formed
integrally with the chassis 216. As described in more
detail below, the chamber 236 can be pressured to supply
ink to the printer without pressurizing the interior of
the pouch 214. The top of the chamber 236 iS provided
with an inlet port 238 through which ink may enter the
chamber 236 from the pouch 214 by gravity and/or by a
negative pressure within the chamber 236.
A one-way flapper valve 242 iS located at the bottom
of the inlet port 238 and serves to limit the return of
ink from the chamber 236 to the pouch 214. When the
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pressure to the chamber drops below that in the
pouch 214, the valve 242 flexes to allow the flow of ink
through the inlet port 238 and into the chamber 236.
The bottom of the chamber 236 is covered with a
flexible diaphragm 244. The diaphragm 244 is slightly
larger than the opening at the bottom of the chamber, and
is sealed around a free edge of the perimetrical wall 237
that defines the chamber 236. The excess material in the
oversized diaphragm 244 allows the diaphragm to flex up
and down to vary the volume of the chamber 236.
Within the chamber 236, a pressure plate 246 is
positioned adjacent the diaphragm 244, the pressure
plate 246 serving as a piston with respect to the
chamber 236. A leaf-type pump spring 248 biases the
pressure plate 246 against the diaphragm 244 to urge the
diaphragm 244 outward so as to expand the size of the
chamber 236.
A hollow cylindrical boss 254 extends downward from
the chassis 216 to form the housing of the fluid
outlet 220, the boss 254 being formed integrally with the
chassis 216. A bore 256 of the hollow boss 254 has an
outlet opening 256a at an end thereof, and the
opening 256a is closed by an elastomeric septum 255
frictionally secured thereto. The septum 255 has a
narrow slit 255a leading therefrom to permit ink to flow
therethrough when the ink is pressurized, but the
slit 255a of the septum 255 closes to prevent the leakage
of ink through the septum 255 when the ink is pressurized
solely by gravity. Further, a sealing ball 258 is
positioned within the bore 256. A sealing spring 260 is
positioned within the bore 256 to resiliently urge the
sealing ball 258 against the interior of the septum 255
and particularly against the portion of the septum 255
that contains the slit 255a.
The liquid containment and dispensing device of the
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various embodiments of the present invention has been
specifically described as a device for containing and
dispensing a supply of printing ink in an ink-jet printer
as the preferred embodiment of the invention. However,
it is also contemplated that the present invention can
easily be adapted to the containment and dispensing of
other Newtonian (low viscosity) liquids.
Although the best mode contemplated by the inventor
for carrying out the present invention as of the filing
date hereof has been shown and described herein, it will
be apparent to those skilled in the art that suitable
modifications, variations and equivalents may be made
without departing from the scope of the invention, such
scope being limited solely by the terms of the following
claims and the legal equivalents thereof.
