U.S. patent application number 15/027668 was filed with the patent office on 2016-09-15 for pressure relief one-way valve, hermetic container and method to manufacture a pressure relief one-way valve.
The applicant listed for this patent is AROMA SYSTEM SRL. Invention is credited to Bruno LANZI, Gino RAPPARINI.
Application Number | 20160264332 15/027668 |
Document ID | / |
Family ID | 49817146 |
Filed Date | 2016-09-15 |
United States Patent
Application |
20160264332 |
Kind Code |
A1 |
RAPPARINI; Gino ; et
al. |
September 15, 2016 |
PRESSURE RELIEF ONE-WAY VALVE, HERMETIC CONTAINER AND METHOD TO
MANUFACTURE A PRESSURE RELIEF ONE-WAY VALVE
Abstract
The present invention relates to pressure relief one-way valves
for hermetic packaging, A pressure relief one-way valve for
hermetic packaging is provided, comprising a valve body (A), a
valve cap (B) and a valve membrane (C), wherein the valve body (A)
comprises a base (13) comprising a sealing seat (11) for the valve
membrane (C) and one or more holes (6) adapted to let the gas flow
through the valve (1), wherein the valve cap (B) is housed in the
valve body (A) and comprises a pressure relief one-way opening (4)
wherein the valve membrane (C) is flexible and is placed between
the valve body (A) and the valve cap (B) in the sealing seat (11).
The pressure relief one-way valve is such that the valve cap (B)
comprises a first rib (2) placed laterally with respect to the
pressure relief opening (4) in order to keep the valve membrane (C)
in the sealing seat (11) so that the valve membrane can lift,
during the pressure relief operation, only on one side and so that
the portion of the valve membrane (C) free to lift has a length (L,
L') equal to or less than the distance between the first rib (2)
and the non-fixed end (12) of the valve membrane (C). A hermetic
container and a method for manufacturing a pressure relief one-way
valve (1) are also shown.
Inventors: |
RAPPARINI; Gino; (Bologna,
IT) ; LANZI; Bruno; (Bologna, IT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AROMA SYSTEM SRL |
Bologna |
|
IT |
|
|
Family ID: |
49817146 |
Appl. No.: |
15/027668 |
Filed: |
October 7, 2014 |
PCT Filed: |
October 7, 2014 |
PCT NO: |
PCT/IB2014/065117 |
371 Date: |
April 6, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B65D 65/466 20130101;
B65D 77/225 20130101 |
International
Class: |
B65D 77/22 20060101
B65D077/22; B65D 65/46 20060101 B65D065/46 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 7, 2013 |
IT |
BO2013A000550 |
Claims
1. Pressure-relief one-way valve for hermetic packaging, comprising
a valve body, a valve cap and a valve membrane, wherein said valve
body comprises a base comprising a sealing seat for said valve
membrane and one or more holes adapted to let the gas flow through
the valve, wherein said valve cap is housed in said valve body and
comprises a pressure-relief opening and wherein said valve membrane
is flexible and is placed between said valve body and said valve
cap in said sealing seat, wherein said valve cap comprises a first
rib placed laterally with respect to said pressure-relief opening
so as to keep said valve membrane in said sealing seat so that said
valve membrane can lift, during the pressure-relieve operation,
only on one side and so that the portion of said valve membrane
free to lift has a length equal to or less than the distance
between said first rib and the non-fixed end of said valve
membrane, and in that said valve cap comprises a second rib, placed
on the same side of the valve cap with respect to said
pressure-relief opening on which said first rib is placed, so that
the portion of said valve membrane free to lift, during the
pressure-relief operation has a fixed length smaller than the
distance between said first rib and said non-fixed end of said
valve membrane.
2. Pressure-relief one-way valve according to claim 1, wherein said
fixed length, is equal to at least half of the maximum width of
said valve membrane, preferably at least two thirds or four fifths
of the maximum width of the valve membrane.
3. Pressure-relief one-way valve according to claim 1, wherein said
pressure relief opening is in the center of said valve cap.
4. Pressure-relief one-way valve according to claim 1, wherein said
valve membrane has a thickness comprised between 10 micron and 100
micron.
5. Pressure-relief one-way valve, according to claim 1, wherein
said valve cap further comprises a projecting element adapted to
limit the bend of said valve membrane during the pressure-relief
operation.
6. Pressure-relief one-way valve, according to claim 1, wherein the
upper surface of said valve cap is coplanar with the upper surface
of said valve body.
7. Pressure-relief one-way valve according to claim 1, wherein the
upper surface of said valve cap is on a lower level with respect to
the upper surface of said valve body.
8. Pressure-relief one-way valve according to claim 1, wherein said
valve cap is symmetric with respect to a plane parallel to said
base of said valve body and going through a center of said valve
cap so that said valve cap has not to be pre-oriented according to
a preferential orientation to be placed into the valve body.
9. Pressure-relief one-way valve according to claim 1, wherein said
sealing seat is covered by a viscous layer so as to improve the
sealing of said valve membrane.
10. Pressure-relief one-way valve according to claim 1, further
comprising a filtering element adapted to filter the gas that flows
through said one or more holes of said valve body.
11. Pressure-relief one-way valve according to claim 10, wherein
said filtering element comprises a non woven polyester.
12. Pressure-relief one-way valve according to claim 10, wherein
said filtering element is impermeable to liquids.
13. Pressure-relief one-way valve according to claim 1, wherein
said valve body and/or said valve cap are made of biodegradable
material.
14. Pressure-relief one-way valve according to claim 1, wherein
said valve membrane comprises a non-biodegradable material.
15. Pressure-relief one-way valve according to claim 1, wherein the
weight of said valve membrane is equal to 0.1% or less of the total
weight of said valve.
16. Hermetic container, preferably for food products, characterized
in that it comprises a comprising the valve according claim 1.
17. Method for manufacturing a pressure relief one way valve for
hermetic packaging, comprising a valve body, a valve cap and a
valve membrane, wherein said valve body comprises a base comprising
a sealing seat for said valve membrane and one or more holes
adapted to let the gas flow through the valve, wherein said valve
cap is housed in said valve body and comprises a pressure-relief
opening and wherein said valve membrane is flexible and it is
placed between said valve body and said valve cap in said sealing
seat, wherein said method comprises the following steps: formation
in said valve cap of a first rib placed laterally with respect to
said pressure-relief opening so as to keep said valve membrane in
said sealing seat so that said valve membrane can lift, during the
pressure-relieve operation, only on one side and so that the
portion of said valve membrane free to lift has a length equal to
or less than the distance between said first rib and the non-fixed
end of said valve membrane and formation in said valve cap of a
second rib placed on the same side of the valve cap with respect to
said pressure relief opening on which said first rib is placed, so
that the portion of said valve membrane free to lift, during the
pressure relief operation has a fixed length less than the distance
between said first rib and said non-fixed end of said valve
membrane.
18. Method for the production of a pressure-relief one-way valve
according to claim 17, wherein said valve membrane is cut from tape
and placed in said sealing seat of said valve body in a single
method step.
19. A pressure-relief one-way valve for hermetic packaging
comprising: a valve body having a base with through holes and a
sealing seat circumscribing the through holes; a valve membrane
placed on the sealing seat covering the through holes; and a valve
cap placed within said valve body and held therein, said valve cap
having a first rib on one end and a protruding element on another
end, the first rib holding a first portion of said valve membrane
securely fixed against a first portion of the sealing seat, wherein
a second portion of said valve membrane is not fixed against a
second portion of the sealing seat and is free to move so as be
capable of separating from the second portion of the sealing seat
and positioned to contact the protruding element limiting a
distance of separation of said valve membrane from the second
portion of the sealing seat, whereby when a pressure is
communicated through the through holes the distance of separation
of said valve membrane from the second portion of the sealing seat
is limited.
20. The pressure-relief one-way valve of claim 19 further
comprising: a second rib formed on said valve cap and positioned
between the first rib and the protruding element and having a
distal end extending adjacent said valve membrane, whereby said
second rib is capable of being positioned so as to contact said
valve membrane at a predetermined location away from the first
portion of said valve membrane securely fixed against the first
portion of the sealing seat and closer to the second portion of
said valve membrane not fixed against the second portion of the
sealing seat so that opening pressure is capable of being
controlled.
Description
TECHNICAL FIELD
[0001] The present invention relates to the field of pressure
relief one-way valve for hermetic containers, for example, for
hermetic food containers.
PRIOR ART
[0002] Several types of pressure relief one-way valves are known
from the prior art. Recently, the market for these valves has
considerably increased, to the point of requesting an annual
production of a few billion units. The high request of the market,
which is still growing at the moment, requires the quick and low
cost production of such valves.
[0003] The valves known from the state of the art normally have
rubber membranes, held in place in the body of the valve by a layer
of silicon oil, on the sealing seat of the membrane. When the high
pressure gas, produced by the substance inside the hermetic
container, needs to come out of the container, it pushes the rubber
membrane which separates from its seat, allowing the gas to escape,
and then returns to its place.
[0004] The type of valve described above can present
inconveniences. In particular, the closing and opening of the
valves of the known type from the state of the art are often
defective. More particularly, some of the known valves do not
properly reclose after the pressure relief operation. In this way,
the air can enter inside the container, compromising the
maintenance of the quality of the product inside same.
Alternatively, some of the known valves may not open correctly,
preventing the pressure relief and the dangerous increase of the
pressure inside the container.
[0005] Since in some known valves from the state of the art the
rubber membrane is held in place only by the layer of silicone oil,
if the air passage is too violent, it may completely detach the
membrane from the body valve. If this happens, the membrane stops
its one-way function because, when the membrane is detached, air
can enter inside the container.
[0006] Moreover, the rubber membrane has to be transported from the
place where it is produced to the place in which it has to be
assembled to the other parts of the valve.
[0007] This clearly increases, in a significant way, the time and
the costs of the valve production process.
[0008] It is, therefore, an aim of the present invention to solve
the above-cited problems.
[0009] More specifically, it is an aim of the present invention to
provide valves for hermetic containers having optimum opening and
closing functions.
[0010] It is a further aim of the present invention to provide
economic and easy to assemble valves for hermetic containers.
SUMMARY
[0011] The present invention is based on the idea of providing a
pressure relief one-way valve comprising a valve body, a valve cap
and a membrane, in which the valve cap comprises at least a rib
which holds the valve membrane in its sealing seat in the valve
body and which allows it to lift only on one side of a fixed
length. In particular, according to the present invention, the
membrane has only one portion which lifts up due to the effect of
the pressure of the gas contained inside the packaging on which the
valve is applied. The free to lift portion has, in section, a fixed
length. In this way, the valve membrane is firmly held in position
by the rib. The probability that the membrane irreparably exits
from its seat is significantly reduced. Furthermore, since the
membrane is free to lift only on one side, the opening of the valve
is optimized.
[0012] The valve according to the present invention can be used for
hermetic containers or packages containing food, for example,
roasted coffee.
[0013] According to an embodiment of the present invention a
pressure relief one-way valve for hermetic packing is provided, the
valve comprising a valve body, a valve cap and a valve membrane,
wherein the valve body comprises a base comprising a sealing seat
for the valve membrane and one or more holes adapted to let the gas
flow through the valve, wherein the valve cap is housed in said
valve body and comprises a pressure relief opening wherein said
valve membrane is flexible and is placed between the valve body and
the valve cap in the sealing seat. The pressure relief one-way
valve is such that the valve cap comprises a first rib placed
laterally with respect to the pressure relief opening so as to keep
the valve membrane in said sealing seat so that the valve membrane
can lift, during the pressure relief operation, only on one side,
and so that the free to lift portion of said valve membrane has a
length equal to or less than the distance between the first rib and
the non-fixed end of the valve membrane. In this way, the valve
membrane, kept in its sealing seat by the first rib, never
completely moves far from it, ensuring the one-way function of the
valve. In addition, maximizing the fixed length of the free to lift
portion of the valve membrane, the maximum possible opening degree
for the valve is maximized. Moreover, the configuration of the
valve cap according to the present invention allows working with
valve membranes, particularly thin, that can for example be
advantageously obtained by cutting them from a film. Even if the
membrane is very thin, the configuration of the valve cap according
to the present invention ensures the tightness of the valve. In
particular, the valve membrane is efficiently held in its sealing
seat even after several opening and closing operations of the
valve.
[0014] According to a further embodiment of the present invention,
the valve cap comprises a second rib, placed on the same side of
the valve cap with respect to the pressure relief opening, on which
the first rib is placed, so that the portion of the valve membrane
free to lift during the pressure relief operation has a fixed
length smaller than the distance between the first rib and the
non-fixed end of the valve membrane. The second rib is preferably
placed between the first rib and the tangent to the pressure relief
opening of the valve cap parallel to the first rib. In this way,
the valve membrane is not only held in its sealing seat by the
first and second rib, so that it never completely move away from
it, ensuring the one-way function of the valve, but it ensures that
the opening of the valve, during the pressure relief operation, is
smaller and therefore faster. The opening pressure limit of the
valve is, therefore, higher and the closing of the same is quicker.
The position of the second rib, more or less close to the first
rib, determining the length of the free to lift portion of the
valve membrane, affects the opening pressure limit of the valve.
Moreover, the configuration of the valve cap according to this
embodiment of the present invention allows working with
particularly thin valve membranes, which can be for example
advantageously obtained by cutting them from a thin film. Even if
the membrane is particularly thin, the configuration of the valve
cap according to this embodiment of the present invention ensures
the tightness of the valve. In particular, the valve membrane is
efficiently held in the sealing seat even after several opening and
closing operations of the valve.
[0015] According to a further embodiment of the present invention,
the fixed length of the free to lift portion of the membrane is
equal to at least half the maximum width of the membrane,
preferably at least two-thirds or four fifths of the maximum width
of the valve membrane.
[0016] According to a further embodiment of the present invention
the pressure relief opening is at the centre of the valve cap.
[0017] According to a further embodiment of the present invention,
the valve membrane has a thickness comprised between 10 micron and
100 micron, preferably between 40 micron and 60 micron, preferably
equal to 50 micron. These thicknesses improve the flexibility and
elasticity properties of the membrane, optimizing the functionality
of the valve. The membrane can have a diameter of about 9 mm.
[0018] According to a further embodiment of the present invention,
the valve cap further comprises a projecting element adapted to
limit the bending of the membrane during the pressure relief
operation. In this way, the valve membrane never completely lies on
the valve cap, ensuring that air does not find barriers in its way
out of the valve during the pressure relief.
[0019] According to a further embodiment of the present invention,
the upper surface of the valve cap is coplanar with the upper
surface of the valve body. The valve is therefore of the flat
type.
[0020] According to a further embodiment of the present invention,
the upper surface of the valve cap is on a lower level with respect
to the upper surface of the valve body.
[0021] According to a further embodiment of the present invention,
the valve cap is two-faced, namely it is made in such a way that
its functionality is identical independently of the orientation
with which it can be inserted into the valve body. In this way, the
valve cap does not need to be oriented according to a preferred
orientation in order to be inserted in the valve body. This, of
course, significantly simplifies the assembly operations of the
valve.
[0022] According to a further embodiment of the present invention,
the valve cap is symmetrical with respect to a plane parallel to
the base of the valve body and passing through the centre of the
valve cap so that the valve cap does not have to be oriented
according to a preferred orientation in order to be placed into the
valve body. This simplifies and speeds up the assembly operations
of the valve. The valve cap, in fact, does not need to be
pre-oriented, before being placed into the valve body.
[0023] According to a further embodiment of the present invention,
the sealing seat is covered with a viscous layer, for example, made
of silicone oil, so as to improve the tightness of the valve
membrane. In this way, the valve membrane is kept in its sealing
seat not only by the first and/or the second rib, but also by the
viscous layer which ensures that the membrane closes the one or
more holes on the base of the valve body, when the valve is not
working.
[0024] According to a further embodiment of the present invention
the pressure relief one-way valve further comprises a filtering
element adapted to filter the gas that flows through the one or
more holes of the valve body. In this way, while the air molecules
are free to pass through the valve, and to exit, therefore, from
the hermetic container, the aroma molecules can be kept inside the
container by the filtering element. This allows optimizing the
organoleptic properties of the product contained in the container
to which the valve is applied.
[0025] According to a further embodiment of the present invention
the filtering element comprises a nonwoven polyester, for example,
SMASH.TM.. SMASH.TM. is a particular polyester made from a nonwoven
fabric made of a continuous fabric. SMASH.TM. is a thermoplastic
material, it is easily deformable at high temperatures and can be
hot pressed. Moreover, it resists very well to hot water and can be
steadily extracted. This material is cheap and it is particularly
suitable for conveniently filtering the gas inside the hermetic
container.
[0026] According to a further embodiment of the present invention,
the valve body and/or the valve cap are made of biodegradable
material, for example oxo-biodegradable material. This has the
known advantages for the environment.
[0027] According to a further embodiment of the present invention
the valve membrane comprises a non-biodegradable material, for
example PET.
[0028] According to a further embodiment of the present invention
the weight of the valve membrane is equal to 0.1% or less of the
total weight of the valve, for example equal to 0.06% of the total
weight of the valve. In this way, even if the valve membrane is not
made of biodegradable material, the valve can be considered to be
biodegradable, because the percentage of non-biodegradable material
with respect to the total amount of material of the valve falls
within the limits set by the current regulations. For example, the
valve membrane can have a weight of about 0.0006 g and the valve
may have a total weight of about 1 g.
[0029] According to a further embodiment of the present invention
the materials of which the valve is made can be enriched with
additives. This allows simplifying the operations of quality
control of the valve during the production process since the
additives allows an easier identification of defects in the
structure of the valve.
[0030] According to a further embodiment of the present invention,
an hermetic container is provided, preferably a container for food,
to which a valve according to the present invention is applied. The
hermetic container can be, for example, a package for coffee
beans.
[0031] According to a further embodiment of the present invention a
method is provided for manufacturing a pressure relief one-way
valve for hermetic packaging comprising a valve body, a valve cap
and a valve membrane, in which the valve body comprises a base
comprising a sealing seat for the valve membrane and one or more
holes suitable for letting the gas go through the valve, in which
the valve cap is seated in the valve body and comprises a pressure
relief opening and in which the valve membrane is flexible and
placed between the valve body and the valve cap in the sealing
seat, in which the method comprises the following step: the
formation in the valve cap of a first rib laterally placed with
respect to the pressure relief opening so as to keep the valve
membrane locked in its sealing seat so that the valve membrane is
free to lift, during the pressure relief operation, only on one
side and so that the free to lift portion of the valve membrane has
a length equal to or less than the distance between the first rib
and the fixed end of the valve membrane.
[0032] According to a further embodiment of the present invention a
method is provided for manufacturing a pressure relief one-way
valve for hermetic packaging comprising a valve body, a valve cap
and a valve membrane, in which the valve body comprises a base
comprising a sealing seat for the valve membrane and one or more
holes suitable for letting the gas pass through the valve, in which
the valve cap is seated in the body valve and comprises a pressure
relief hole and in which the valve membrane is flexible and it is
placed between the valve body and the valve cap in the sealing
seat, in which the method comprises the following step: the
formation in the valve cap of a first rib, placed laterally with
respect to the pressure relief opening so as to keep the valve
membrane in the sealing seat so that the valve membrane can lift,
during the pressure relief operation, only on one side and so that
the free to lift portion of the valve membrane has a length equal
to or less than the distance between the first rib and the
non-fixed end of the valve membrane.
[0033] According to a further embodiment of the present invention a
method is provided further comprising the following step: the
formation in the valve cap of a second rib placed on the same side
of the valve cap with respect to the pressure relief opening on
which the first rib is placed, so that the portion of the valve
membrane free to lift during the pressure relief operation has a
fixed length less than the distance between the first rib and the
non-fixed end of the valve membrane.
[0034] According to a further embodiment of the present invention a
method is provided for the production of a pressure relief one-way
valve, in which the valve membrane is cut from a film and placed in
its sealing seat of the valve body in a single operation. In this
way, a fast and cheap method is provided for the production of the
valve.
[0035] According to a further embodiment of the present invention a
method is provided for the production of a pressure relief one-way
valve, in which the valve body and/or the valve cap are injection
moulded.
BRIEF DESCRIPTION OF THE FIGURES
[0036] The present invention will be described with reference to
the attached Figures in which identical numbers and/or reference
signs indicate the same parts and/or similar parts and/or
corresponding parts of the system.
[0037] FIG. 1A schematically shows a pressure relief one-way valve
for hermetic packaging, according to an embodiment of the present
invention, seen in vertical section along one of its diameters.
[0038] FIG. 1B schematically shows the pressure relief one-way
valve shown in FIG. 1A, seen in vertical section along one of its
diameters and applied to a hermetic food container.
[0039] FIG. 1C schematically shows the pressure relief one-way
valve shown in FIG. 1A, seen from above.
[0040] FIG. 1D schematically shows a 3D view of the pressure relief
one-way valve shown in FIG. 1A, positioned so as to show the base
of the valve body.
[0041] FIG. 1E schematically shows a 3D view of the pressure relief
one-way valve shown in FIG. 1A, positioned so as to show the valve
cap.
[0042] FIG. 1F schematically shows a zoom of the region of the
pressure relief one-way valve shown in FIG. 1A, in which the valve
cap wedges into the valve body.
[0043] FIG. 2A schematically shows a pressure relief one-way valve
for hermetic packaging, according to a further embodiment of the
present invention, seen in vertical section along one of its
diameters.
[0044] FIG. 2B schematically shows the pressure relief one-way
valve shown in FIG. 2A, seen in vertical section along one of its
diameters and applied to a hermetic food container.
[0045] FIG. 2C schematically shows the pressure relief one-way
valve shown in FIG. 2A, seen from above.
[0046] FIG. 2D schematically shows a 3D view of the pressure relief
one-way valve shown in FIG. 2A, positioned so as to show the base
of the valve body.
[0047] FIG. 2E schematically shows a 3D view of the pressure relief
one-way valve shown in FIG. 2A, positioned so as to show the valve
cap.
[0048] FIG. 3A schematically shows a pressure relief one-way valve
for hermetic packaging, according to a further embodiment of the
present invention, seen in vertical section along one of its
diameters.
[0049] FIG. 3B schematically shows the pressure relief one-way
valve shown in FIG. 3A, seen in vertical section along one of its
diameters and applied to a hermetic food container.
[0050] FIG. 4A schematically shows a pressure relief one-way valve
for hermetic packaging, according to a further embodiment of the
present invention, seen in vertical section along one of its
diameters.
[0051] FIG. 4B schematically shows the pressure relief one-way
valve shown in FIG. 4A, seen in section along one of its diameters
and applied to a hermetic food container.
[0052] FIG. 5 schematically shows the valve membrane production
system for a pressure relief one-way valve according to an
embodiment of the present invention.
DETAILED DESCRIPTION
[0053] In the following, the present invention will be described
with reference to particular embodiments, as shown in the attached
Figures. However, the present invention is not restricted to the
particular embodiments described in the following detailed
description and as shown in the Figures, rather the described
embodiments merely show several aspects of the present invention
whose scope is defined by the claims. Further modifications and
variations of the present invention will be clear for the person
skilled in the art.
[0054] FIG. 1A schematically shows a pressure relief one-way valve
for hermetic packaging, according to an embodiment of the present
invention.
[0055] The hermetic container to which the valve can be applied can
be a food container, for example, a package for roasted coffee.
[0056] The valve comprises three main elements: a valve body A, a
valve cap B and a valve membrane C. The valve body A comprises a
base comprising a sealing seat 11 for the valve membrane C and one
or more holes 6 suitable for letting the gas coming from the
container go out through the valve 1. The valve body A further
comprises a seat for the valve cap B. The valve cap B is, in fact,
placed in the valve body A. The sealing seat 11 is formed at the
base of the seat for the valve cap B. The valve cap B comprises a
pressure relief opening 4. The pressure relief opening 4 of the
valve cap B can advantageously be placed at the centre of the valve
cap B, as shown in FIG. 1A. The valve membrane C is flexible and it
is placed between the valve body A and the valve cap B in the
sealing seat 11.
[0057] The sealing seat 11 can comprise a cavity formed in the base
of the valve body A and having dimensions corresponding to the
dimensions of the valve membrane C. In particular, the depth of the
cavity can be equal to the thickness of the membrane C. The sealing
seat can be filled with sealing material 5, for example, silicone
oil so as to maintain the membrane in contact with the valve cap B
and so as to keep the valve membrane in contact with the valve cap
B and so as to ensure the valve tightness when no portion of the
valve membrane C is lifted.
[0058] The valve body A may have a frusto-conical shape, open on
the wide side and closed on the opposite side. We will refer to
this closed side of the valve body A as the base 13 of the valve
body. The valve body A comprises, moreover, a flat border 10,
protruding from the valve body, from the open side of the cone,
toward the outside of the same, and parallel to the base 13 of the
valve body. The border 10 is suitable for fixing the valve 1 to the
hermetic container, to which the valve is applied.
[0059] The valve 1 shown in FIG. 1A is an internal valve. The valve
1, in fact, is suitable to be applied to the hermetic container by
fixing the upper surface of the border 10 of the valve body A to
the inner surface of the container itself. In FIG. 1B, the valve 1
is shown applied to a hermetic food container. In FIG. 1B, F is the
film of the hermetic container which is fixed to the valve 1. The
film F, after the application of the valve 1 inside the hermetic
container, can be pierced by a needle P, in correspondence of the
pressure relief opening 4 of the valve cap B. The hermetic food
container, schematically shown in FIG. 1B, contains coffee
beans.
[0060] On the inner surface of the base 13 of the valve body, that
is the one facing towards the inside of the hermetic container when
the valve is applied to the same, a filtering element 7 can
advantageously be placed, as for example, a membrane made of filter
paper or made of a nonwoven polyester, for example, SMASH.TM..
SMASH.TM. is a particular polyester made of a nonwoven continuous
fibre. SMASH.TM. is a thermoplastic material, is easily deformed at
high temperatures and can be hot moulded. Moreover, it
substantially resists hot water and can be stably extracted. The
filtering element can let air molecules exit from the hermetic
container and at the same time secure inside same the aroma
molecules produced by the food contained in it. Moreover, the
filtering element 7 can be permeable to gases but impermeable to
liquids. In this case, the valve with a filtering element with such
features can advantageously be applied to hermetic containers which
contain liquids which produce gases, after they have been
hermetically packaged, as for example liquid yeast.
[0061] The valve cap B is wedged in the valve body A, as shown in
detail in FIG. 1F, where the wedging zone between the cap B and the
valve body A is shown enlarged. It has to be noted that the side
wall of the seat for the cap B of the valve body A is structured so
as to fit together with the side surface of the valve cap B. In
particular, the side wall of the seat A comprises an indentation
14. The side surface of the valve cap B comprises a protrusion 15.
The indentation 14 accommodates the protrusion 15 so as to fix the
valve cap B inside of the valve body A. In this way the valve cap B
is stably fixed inside the valve body A.
[0062] The valve cap B can advantageously be two-faced. The valve
cap B shown in FIG. 1A is, for example, made so that its
functionality is the same independently from the orientation with
which it can be inserted in the valve body A. In this way, the
valve cap B does not need to be oriented according to a preferred
orientation in order to be placed inside the valve body A. Clearly,
this substantially simplifies the assembly process of the valve 1.
In a possible embodiment, not shown in the figure, the valve cap
can be made so as to be symmetric with respect to a plane X
parallel to the base of the valve body and passing through the
central point of the valve cap O.
[0063] The valve cap B comprises, moreover, the first rib 2 placed
laterally with respect to the pressure relief opening 4 in order to
fix the valve membrane C in the sealing seat 11 so that the valve
membrane C is free to lift during the pressure relief operation,
only on one side and so that the free to lift portion of the valve
membrane C has a fixed length L equal to or less than the distance
between the first rib 2 and the fixed end of the valve membrane C.
The first rib 2 may extend along the valve cap C, between two
points of its peripheral edge. The fixed length L can be equal to
at least half of the maximum length of the valve membrane.
Preferably, the default length L can be 4/5 (four fifths) of the
maximum length of the valve membrane C.
[0064] As shown in FIG. 1A, the first rib 2 divides the membrane C
in two portions: a first portion free to lift as an effect of the
gas under pressure contained inside the container on which the
valve is applied and a second portion which cannot lift. The first
portion, seen in section, has length L. The first portion is the
only portion of the membrane C that lifts due to the gas under
pressure contained in the container on which the valve is
applied.
[0065] The valve cap B comprises, moreover, a protruding element 3,
suitable for limiting the bending of the valve membrane C during
the pressure relief operation. The protruding element 3 avoids that
the valve membrane C completely leans on the valve cap B. In this
way, it is efficiently avoided that the lifted portion of the valve
membrane blocks the exit of the gas from the valve. In other words,
the protruding element 3 allows forming exit routes for the gas
even when the free to lift portion of the membrane is completely
lifted due to the effect of the gas under pressure coming from the
container on which the valve is applied. The protruding element 3
may comprise a hemisphere or a sphere placed along one of the
diameters of the valve cap B. The protruding element 3 is
advantageously placed laterally with respect to the pressure relief
opening 4 of the valve cap B on the side opposite with respect to
the one on which the first rib 2 is formed.
[0066] The upper surface of the valve cap B, facing the outside of
the valve 1, is, in the embodiment shown in FIG. 1A, coplanar with
the upper surface of the flat border of the valve body A. The valve
1 is, therefore, of the flat type.
[0067] The valve membrane C is placed between the valve body A and
the valve cap B in its sealing seat 11. The valve membrane C is a
flexible membrane, preferably made of plastic material, for example
PET. The valve membrane C may have a thickness comprised between 10
microns and 100 microns. Preferably, the valve membrane C has a
thickness comprised between 40 microns and 60 microns. For example,
the thickness may be equal to 50 microns.
[0068] Between the valve body A and the valve membrane C a layer of
viscous material 5, for example silicone oil can be inserted. This
layer contributes with the rib 2 to keep the valve membrane C in
the sealing seat 11, when the valve is in a rest position and
allows the valve to close, in a hermetic way, the one or more holes
6 of the valve body A. In particular, the layer of viscous material
5 allows optimizing the tightness between the sealing seat 11 and
the portion of the membrane C free to lift during the pressure
relief operation.
[0069] In this case, the thin valve membrane C is held in position,
not only by the viscous layer 5 but also by the first rib 2 of the
valve cap C. In this way, if during the operational phase, that is
during the pressure relief phase, the passage of air takes place in
a violent way, there is no risk that the valve membrane C
completely exits from its sealing seat 11. The membrane, in fact,
never completely leaves its sealing seat 11, and once the push of
the gas exiting from the hermetic container stops, it closes
returning in the sealing seat. On the contrary, in the valves of
the type known from the state of the art, the membrane made of
rubber may completely separate from its seat. Once the membrane is
detached, the valve loses its one way functionality because the
holes of the valve body remain open.
[0070] The valve body A and/or the valve cap B of the valve 1 may
advantageously be made of biodegradable material. More in
particular, the valve body A, and/or the valve cap B may be made in
an oxo-biodegradable material. Advantageously, both the valve body
A and the valve cap B are made of biodegradable material.
[0071] Examples of biodegradable materials that can be used
according to the present invention are aliphatic polyester,
polylactic acid (PLA) and blends of different proportions of
aliphatic polyester and polylactic acid.
[0072] The valve membrane C can have a weight equal to or less than
0.1% of the total weight of the valve 1, for example equal to
0.06%. For this reason, if the valve body A and the valve cap B
valve are made of biodegradable material, the valve 1 can be
considered to be completely biodegradable even if the membrane C is
not made of biodegradable material, for example if it is made of
PET.
[0073] FIG. 1C schematically shows the valve 1 shown in FIG. 1A,
seen from above, that is, so as to show the valve cap B. From this
figure it is possible to see the border 10 of the valve body A,
which is suitable to seal the hermetic container to the valve 1,
the central opening 4 of the valve cap B and the first rib 2, which
keeps the membrane C in place in its sealing seat inside the valve
body A. The first rib 2 may extend along the valve cap B between
two points of its peripheral edge.
[0074] The valve 1, according to the embodiment shown in the
figure, has a valve body A having a circular shape. Moreover, also
the seat for the valve cap B has a circular shape. The valve cap B
and the valve membrane C are circular. More in particular, the
valve cap B is such that it can be placed in the seat of the valve
body A so as to close the valve 1. The first rib 2 that keeps the
valve membrane C in the seat 11 is made along a first chord of the
valve cap B so as not cross the pressure relief opening 4. The
first rib 2 extends along the entire length of the first chord.
[0075] FIG. 1D schematically shows the valve 1 in 3D placed so as
to show the base of the valve body 13. In this figure the filtering
element filter 7 is visible and the holes 6 on the base of the
valve body 13, under the filtering element 7, are shown with dotted
lines. FIG. 1E schematically shows valve 1 in 3D placed so as to
show the valve cap. In this image, the flat border 10 of the valve
body A, the pressure relief opening 4 of the valve cap B and the
first rib 2 are visible.
[0076] Figures from 2A to 2E correspond to Figures from 1A to 1E,
respectively, and show a pressure relief one-way valve according to
the already indicated views. The difference between the valve shown
in Figures from 1A to 1D and the one shown in Figures from 2A to 2E
consists in that the valve 1 shown in Figures from 2A to 2E
comprises a valve cap B further comprising a second rib 8. FIG. 2B
shows the pressure relief valve shown in FIG. 2A applied to a
hermetic container containing roasted coffee. The film F of the
hermetic packaging for food, the needle P which is suitable to
perforate the film F in correspondence to the pressure relief
opening of the valve cap and the coffee beans are shown.
[0077] The second rib 8 is placed on the valve cap B on the same
side of the first rib 2 with respect to pressure relief opening 4.
More in particular, the second rib 8 is placed between the first
rib 2 and the tangent to the pressure relief opening 4 of the valve
cap B parallel to the first rib 2. The second rib 8 further keeps
the valve membrane C blocked in its sealing seat 11. In this way,
during the pressure relief operation, the valve membrane C can lift
only on one side, of a length L', smaller than L, and equal to the
distance between the second rib 8 and the non-fixed end of the
valve membrane 12. During the pressure relief operation, the
portion of the membrane which lifts also bends, rotating around the
second rib 8. The second rib 8 may extend along the valve cap C,
between any two points of the peripheral border, parallel to the
first rib 2 but so as to be nearer to the pressure relief opening
4.
[0078] As shown in FIG. 2A, the first rib 2 and the second rib 8
divide the membrane C into three portions: a first portion free to
lift due to the effect of the gas under pressure contained in the
container on which the valve is applied, a second portion between
the two ribs 2 and 8 and a third portion. The second and third
portion cannot lift. The first portion, seen in section, has length
L'. The length L' can be equal at least to half of the maximum
length of the valve membrane. Preferably, the predefined length L'
can be 2/3 (two thirds) of the maximum length of the valve membrane
C. The first portion is the only portion of the valve membrane C
which lifts due to the effect of the gas under pressure contained
in the container on which the valve is applied.
[0079] The valve 1 according to the embodiment shown in FIG. 2C has
a valve body A with a circular shape. Moreover, also the housing
for the valve cap B has a circular shape. The valve cap B and the
valve membrane C are circular. More in particular, the valve cap B
can be placed in the housing in the valve body A so as to close the
valve 1. The first rib 2 is made along a chord of the valve cap B
and the second rib 8 is made along a second chord of the valve cap
B parallel to the first chord on which the first rib 2 is made and
so as to be nearer to the pressure relief opening 4 with respect to
it. The second rib 2 extends along the entire length of the second
chord. The second rib may be a continuous line or a non continuous
line, for example, it can be a line formed by a series of two or
more sections separated by empty space.
[0080] The advantages due to the presence of the second rib 8 are
the ones already cited for the first rib 2 and, therefore, related
to the security with which the one-way functionality of the
pressure relief valve 1 is ensured. In addition, in this case,
since the length L' of which the membrane C can lift during the
pressure relief operation is smaller than the length L, an opening
pressure limit, of the pressure relief valve 1, inside the hermetic
container, higher than for the pressure relief valve 1 shown in
FIGS. 1A to 1E is ensured. More in particular, depending on the
needs, valves can be made having the second rib 8 positioned so
that the valve membrane C can laterally lift of different lengths
L', according to the opening pressure limit needed.
[0081] Also in this embodiment the valve cap B is wedge in the
valve body A, as described above, with reference to FIG. 1F.
[0082] FIGS. 3A and 3B schematically show a pressure relief one-way
valve according to a further embodiment of the present
invention.
[0083] FIGS. 3A and 3B correspond to FIGS. 1A and 1B, respectively,
and show a pressure relief one-way valve according to the same
prospective already indicated. The difference between the valve
shown in FIGS. 1A and 1B and the one shown in FIGS. 3A and 3B is
that the valve 1 shown in FIGS. 3A and 3B comprises a valve body A
with a border 10 higher than the upper surface of the valve cap B.
In particular, in the cross section view of FIG. 3A it is possible
to see that the border 10 of the valve body A is placed at an upper
level with respect to the upper surface of the valve cap B, facing
the outside of the valve. FIGS. 4A and 4B correspond to FIGS. 2A
and 2B, respectively, and show a pressure relief one-way valve
according to the same prospective already indicated. The difference
between the valve shown in FIGS. 2A and 2B and the one shown in
FIGS. 4A and 4B consists in that the valve 1 shown in FIGS. 4A and
4B comprises a valve body with a border 10 higher than the upper
surface of the valve cap B, in particular, in the cross section
view of FIG. 4A it is possible to see that the border 10 of the
valve body A is placed at an upper level with respect to the upper
surface of the valve cap B facing the outside of the valve.
[0084] According to the present invention, a method is provided for
the production of a pressure relief one-way valve which comprises a
valve body A, a valve cap B, and a valve membrane C, in which the
valve body A comprises a base comprising a sealing seat 11 for the
valve membrane C and one or more holes 6 suitable to let the gas
pass through the valve 1, in which the valve B is placed in the
valve body A and comprises a pressure relief opening 4 and in which
the valve membrane C is flexible and is placed between the valve
body A and the cap B in the sealing seat 11.
[0085] In particular, the method for manufacturing a one-way valve
1 according to the present invention comprises the following step:
formation in the valve cap B of a first rib 2 placed laterally with
respect to the pressure relief opening 4 so as to block the valve
membrane C in the sealing seat 11 so that the valve membrane C is
free to lift during the pressure relief operation, only on one side
and so that the free to lift portion of the valve membrane C has a
length L, equal to or less than the distance between the first rib
2 and the non-fixed end of the valve membrane C. According to the
present invention, the valve body A and/or the valve cap B can be
injection moulded.
[0086] According to a further embodiment of the present invention,
the method for manufacturing a one-way valve further comprises the
following step: formation in the valve cap B of a second rib 8,
placed on the same side of the valve cap B with respect to the
pressure relief opening 4 on which the first rib 2 is placed, so
that the portion of the valve membrane C free to lift during the
pressure relief operation has a fixed length L', less than the
distance L between the first rib 2 and the non-fixed end 12 of the
valve membrane C.
[0087] Also in this case the valve body A and/or the valve cap B
can advantageously be injection moulded.
[0088] According to a further particularly advantageous embodiment
of the present invention, the valve membrane C is obtained from a
film, cut and inserted in its sealing seat 11 inside the valve body
A, in one single operation. In particular, the cut of the valve
membrane C from the film and its placing into the sealing seat 11
of the valve body A are performed in a single step of the method
for manufacturing a one way valve according to an embodiment of the
present invention.
[0089] This is schematically shown in FIG. 5. The film 17 made of
the same material of which the valve membrane C is made, is
transported from an unwinding bobbin 16 to a winding bobbin 18. The
sliding of the film can be assisted by using one or more guides 21
and 22, for example, by using guiding rollers. Between the bobbins
16 and 17 one or more cutters can be placed. In the case shown in
the Figures, two cutters 19 and 20 are shown, but the number of
cutters is not limited to this value. The valve body A is placed in
correspondence to one cutter 19 so that the cutter does not only
cut the valve membrane C from the film 17, but also pushes the cut
valve membrane C directly inside the sealing seat 11 of the valve
body A. In practice, every cutter 19, 20 is configured so as to
contemporarily carry out the cutting and the placing of the valve
membrane in the sealing seat 11 of the valve body. For example, in
the system shown in FIG. 5, the cutter 19 lowers down to cut the
valve membrane C from the film 17 and then continues its run
downwards pushing the newly cut membrane C inside the sealing seat
11 of the valve body A.
[0090] The valve 1 so obtained has considerably reduced production
costs, since the valve membrane C, which is placed into the seat as
shown in FIG. 5, has production costs lower with respect to a
rubber valve membrane, which has to be transported from the place
in which it is produced to the place in which the valve is
assembled.
[0091] Although the present invention has been described with
reference to the embodiments described above, it is clear for the
skilled person that several modifications, variations and
improvements of the present invention may be made, in view of the
teaching described above and within the scope of the appended
claims, without departing from the object and the scope of
protection of the invention.
[0092] For example, even if the pressure relief one-way valves
having a circular shape have been shown, it is clear that these can
be properly made in different shapes, for example, polygonal, such
as square or hexagonal.
[0093] Moreover, the valves according to the present invention may
have different dimensions and thicknesses. For example, according
to an embodiment of the present invention the valve can have a
diameter of about 2 cm and a thickness of about 0.4 cm. However,
different ranges of sizes for these quantities are allowable.
[0094] Additionally, those aspects which are deemed to be known by
the skilled person have not been described in order to avoid unduly
obfuscating the described invention. Consequently, the invention is
not limited by the embodiments described above but is only limited
by the scope of protection of the appended claims.
REFERENCE SIGNS
[0095] 1: Pressure relief valve; [0096] A: Valve body; [0097] B:
Valve cap; [0098] C: Valve membrane; [0099] O: Center of the valve
cap [0100] L, L': Length of the portion of the valve membrane which
is free to lift; [0101] 2: The first rib of the valve cap; [0102]
3: Protruding element; [0103] 4: Pressure relief opening of the
valve cap; [0104] 5: Layer of silicone oil; [0105] 6: Through holes
of the valve body; [0106] 7: Filter element; [0107] 8: Second rib
of the valve cap; [0108] 10: Flat rim of the valve cap; [0109] 11:
Sealing seat of the valve membrane; [0110] 12: Non-fixed end of the
valve membrane; [0111] 13: Base of the valve body; [0112] 14:
Indentation of the valve body; [0113] 15: Protrusion of the valve
cap; [0114] 16: Unwinding bobbin [0115] 17: Film from which the
valve membrane is obtained [0116] 18: Winding bobbin; [0117] 19,
20: Cutters [0118] 21, 22: Guides
* * * * *