U.S. patent application number 10/534300 was filed with the patent office on 2006-11-02 for pressure container, particularly for frozen substances.
Invention is credited to Ingo Rackwitz.
Application Number | 20060243754 10/534300 |
Document ID | / |
Family ID | 32185400 |
Filed Date | 2006-11-02 |
United States Patent
Application |
20060243754 |
Kind Code |
A1 |
Rackwitz; Ingo |
November 2, 2006 |
Pressure Container, Particularly for Frozen Substances
Abstract
A pressurised container (10) has an outlet valve with a sealing
element (24) disposed in a sealing seat (22). If the viscosity of
the container contents decreases below a limit value, it is
provided that the sealing element (24) be detached from its sealing
seat (22), so that it closes or substantially reduces an opening
cross section, and a discharge of the container contents is
avoided. The function of the outlet valve is furthermore improved
by the provision of an actuating lever (30), which comprises two
hinged parts (40, 42) and which for high-viscosity substances,
particularly in the frozen state, reduces the actuating force to a
practicable level.
Inventors: |
Rackwitz; Ingo; (Steinau a.
d. Str., DE) |
Correspondence
Address: |
STITES & HARBISON PLLC
1199 NORTH FAIRFAX STREET
SUITE 900
ALEXANDRIA
VA
22314
US
|
Family ID: |
32185400 |
Appl. No.: |
10/534300 |
Filed: |
November 3, 2003 |
PCT Filed: |
November 3, 2003 |
PCT NO: |
PCT/EP03/12195 |
371 Date: |
March 27, 2006 |
Current U.S.
Class: |
222/402.15 ;
222/505 |
Current CPC
Class: |
B65D 83/44 20130101;
B65D 83/201 20130101; B65D 83/425 20130101 |
Class at
Publication: |
222/402.15 ;
222/505 |
International
Class: |
B65D 83/00 20060101
B65D083/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 9, 2002 |
DE |
102 52 161.1 |
Claims
1. A pressurized container for holding substances under pressure,
in particular frozen substances (14), having an outlet valve (12),
which is adjustable between a closed position and an opened
position for dispensing the substance (14), and which has a sealing
element (24), disposed in a seat (22), for sealing in the closed
state of the outlet valve (12), characterized in that heating and
in particular a change in the aggregate state of the substance and
an attendant or otherwise-occurring reduction in the viscosity of
the substance bring about an increase in the flow velocity in the
region of the sealing element (24) when the outlet valve (12) is
open, along with an increased pressure drop at the sealing element
(24), as a result of which a force that is substantially increased
compared to the normal state is exerted on the sealing element (24)
in the directions for extracting it from its seat (22), and/or the
reduced viscosity, with the aid of at least one connection (74;
174), provided between the seat (22) and the container interior,
and having a small cross-sectional area brings about an increased
pressure in the seat (22) and thereby an increased force on the
sealing element (24) in a direction out of its seat (22), and the
resultant force on the sealing element (24), if a certain minimum
viscosity of the substance (14) fails to be attained, leads to
extracting the sealing element (24) from its seat, and the detached
sealing element (24) closes or substantially reduces an opening
cross section.
2. The pressurised container of claim 1, characterised in that the
sealing element (24; 124) is embodied annularly, and the seat (22;
122) is in the form of an annular groove.
3. The pressurised container of claim 2, characterised in that a
plurality of connecting bores (74;174) are provided, distributed
over the circumference between the seat (22;122) and the interior
of the container.
4. The pressurised container of claim 2, characterised in that on
the bottom of the seat (122), an annular conduit (123) is provided,
which is narrower than the actual seat (122).
5. The pressurised container of claim 1, characterised in that the
sealing element (24; 124) protrudes from its seat (22; 122) and
protrudes obliquely, in terms of the flow direction, into the
opened flow cross section, and its contour defines the narrowest
point of the flow cross section.
6. The pressurised container of claim 1, characterised in that the
sealing element (22; 122), in the closed state, rests sealingly on
a conical contact face (38; 138).
7. The pressurised container of claim 5, characterised in that the
narrowest point of the flow cross section is contoured in
nozzle-like fashion, preferably similarly to a venturi nozzle.
8. The pressurised container of claim 2, characterised in that the
annular sealing element (24; 124) has a substantially rectangular
cross section, preferably with rounded or chamfered edges (36;
136), and an edge (36; 136) protruding from the seat (22; 122)
defines the contour of the narrowest point.
9. The pressurised container of claim 1, characterised in that the
outlet valve is embodied as a multiple-stage valve and in a
dispensing operation has at least two opening cross sections that
open one after the other, each with an associated sealing element,
and at least the sealing element of the cross section that opens
first is embodied so as to be detachable from its respective seat
if a minimum viscosity fails to be attained.
10. The pressurised container of claim 1, characterised in that the
sealing element (24) detached from its seat (22) can be re-inserted
into its seat (22) by closure of the outlet valve (12).
11. The pressurised container of claim 10, characterised in that
the sealing element (24) comprises an annular disk with a rigid
substrate and a sealing part mounted on the substrate, or comprises
a rigid sealing material, and the substrate is guided in the
extraction direction between the seat (22) and its position that
closes the opening cross section.
12. The pressurised container of claim 11, characterised in that
the sealing element (24) is guided axially on a central protrusion
(64).
13. The pressurised container of claim 1, characterised in that a
valve element (20) is moveable in the direction of the interior of
the can by a tappet element (26) for opening the opening cross
section, and the tappet element (26) can be pressed down by a lever
(30), whose lever arm comprises at least two parts (40, 42) that
are fixed pivotably to one another and can be swiveled between a
collapsed position of repose in which they are preferably locked
together and an open, preferably likewise locked operating position
for lengthening the lever arm.
14. The pressurised container of claim 13, charaterised in that the
axial guidance for the sealing element (24) forms the connection
(64) between the valve element (20) and the tappet element
(26).
15. The pressurised container of claim 14, charaterised in that the
tappet element (26) is embodied in sleevelike fashion and is
connected to the connecting element (64) via obliquely or radially
extending struts (62).
16. The pressurised container of claim 13, characterised in that a
first lever arm part (40) is pivotably connected laterally of the
tappet element (26) to a part (48) connected solidly to the
container (10) and acts on a radial protrusion (58, 60) via
pressure elements (54).
17. The pressurised container of claim 16, characterised in that
the radial protrusion (58) is formed onto a nozzle top unit (28)
that is seated on the tappet element (26, 60).
18. The pressurised container of claim 17, characterised in that
the nozzle top unit (28) is retained between the tappet element
(26) and two opposed pressure element (26) and two opposed pressure
elements (54) of the first lever arm part (40).
19. The pressurised container of claim 16, characterised in that
the two lever arm parts (40, 42) are embodied in hooplike fashion,
and the first lever arm part (40) surrounds the nozzle top unit
(28) and/or the tappet element (26) in both positions, and the
second lever arm part (42) surrounds the nozzle top unit (28)
and/or the tappet element (26) in the position of repose.
20. The pressurised container of claim 1, characterised in that
after the detachment of the sealing element (24; 124) from the
sealing seat (22; 122), a controlled evacuation of the container
contents is effected through an evacuation opening.
21. The pressurised container of claim 1, characterised in that the
outlet valve (12) has, in addition to a first opening cross
section, at least one further opening cross section, which can be
uncovered in order to facilitate filling of the container.
22. The pressurised container of claim 21, characterised in that
the two opening cross sections can be uncovered in succession, in
the manner of a multiple-step valve.
23. The pressurised container of claim 22, characterised in that
the outlet valve is designed such that in the filled operating
state, only the first opening cross section can be uncovered.
24. The pressurised container of claim 21, characterised in that a
disk element (180) is provided between the valve housing (16) and
the valve element (20), and the first sealing point (184) with the
first opening cross section is provided between the disk element
(180) and the valve element (20), and the second sealing point
(186) having the second opening cross section is provided between
the disk element (180) and the valve housing (16).
25. The pressurised container of claim 24, characterised in that
the disk element (180) is guided axially movably along a guide
(182) on the valve housing (16).
Description
[0001] The invention relates to a pressurised container for holding
substances under pressure, in particular frozen substances, having
an outlet valve, which is adjustable between a closed position and
an opened position for dispensing the substance, and which has a
sealing element, disposed in a sealing seat, for sealing in the
closed state of the outlet valve.
[0002] Pressure containers or cans for holding and intentionally
discharging gaseous substances, aerosols, or relatively
high-viscosity substances, such as whipped cream, have already been
known for a long time, as are many outlet valves used with them.
Because of the compressibility of these substances, the sometimes
relatively low pressure, and the defined temperature range in which
these pressurised containers are used, comparatively simple outlet
valves generally suffice and can optionally be combined with an
overpressure valve, to make it possible to reduce dangerous
overpressures in the interior of the can, for instance if the
contents heat up excessively.
[0003] There is a need to be able to put even frozen substances or
high-viscosity substances onto the market in pressurised
containers, which requires a high internal pressure in the
container and/or a large outlet cross section, to enable the
substance to be dispensed in the desired quantity within a defined
length of time. The problem then arises for one thing that the
large opening cross section together with a high internal pressure
in the can leads to very sharply rising actuation forces, which can
no longer be handled using simple push buttons of the kind known
from conventional spray cans. At the same time, the problem arises
that if there is a change in the viscosity of the product stored in
the container, as can occur for instance upon heating up or if
there is a change in the aggregate state, such as thawing of a
frozen product, the high internal pressure of the can and/or the
large outlet cross section can have the effect that the substance
is discharged so vehemently from the container that not only must
unpleasant contamination of the surroundings be feared, but in the
worst case even injuries can occur, for instance if children put
the spray valve of such a container, with thawed contents, into
their mouth and open the outlet valve.
[0004] The object of the present invention is consequently to
create a pressurised container with an outlet valve that makes
improved safety possible with substances whose viscosity varies in
the incident temperature range and/or that makes improved user
control possible.
[0005] A first embodiment according to the invention for attaining
the object provides that heating and in particular a change in the
aggregate state of the substance and an attendant or
otherwise-occurring reduction in the viscosity of the substance
brings about an increase in the flow velocity in the region of the
sealing element when the outlet valve is open, along with an
increased pressure drop at the sealing element, as a result of
which a force that is substantially increased compared to the
normal state is exerted in the extraction direction on the sealing
element, and/or the reduced viscosity, with the aid of at least one
connection provided between the sealing seat and the container
interior and having a small cross-sectional area, brings about an
increased pressure in the sealing seat and thereby an increased
force on the sealing element in a direction out of its sealing
seat; the resultant force on the sealing element, if a certain
minimum viscosity of the substance fails to be attained, is
suitable for extracting the sealing element from its sealing seat,
and the detached sealing element closes or substantially reduces an
opening cross section.
[0006] The embodiment according to the invention offers a safety
function, which prevents the outlet from being uncovered if the
viscosity of the substance stored under pressure in the pressurised
container has decreased, so that even after the outlet valve is
actuated there is no risk of uncontrolled contamination of the
environment or even of injury to the user.
[0007] The present invention makes us of the change in viscosity
conditions in the event of heating and in particular in the event
of a change in the aggregate state, such as thawing, in that by
means of the altered conditions of pressure and force on the
sealing element, this sealing element can be detached from its seat
and used for securely closing a cross section. The change in the
pressure and force conditions is especially serious if there is a
change in the aggregate state, although in the case of ice cream,
for instance, considerable changes in viscosity can already occur
even before the product thaws, or in other substances in the range
of the liquid aggregate state and especially substances with
non-Newtonian properties, changes in viscosity occur that
necessitate tripping the safety device. Even chemical reactions
could cause such a change in viscosity.
[0008] The detachment of the sealing element from its sealing seat
can be attained by means of the pressure drop or by the intentional
provision of connections; preferably both provisions are employed
in combination, so that even with substances of complex behaviour
upon temperature changes, the sealing element can be intentionally
detached if a metered, intentional discharge of the substance is no
longer assured because of the altered viscosity properties.
[0009] In a preferred embodiment of the invention, it is provided
that the sealing element is embodied annularly, and the sealing
seat is in the form of an annular groove; with such a seal,
comparatively large opening cross sections can be sealed off
without great effort, and the internal pressure of the container
can act on the sealing element via the connection and the annular
groove. It is especially preferable to provide a plurality of
connecting bores, distributed over the circumference between the
sealing seat and the interior of the container and/or an annular
conduit on the bottom of the sealing seat, the annular conduit
being narrower than the sealing seat itself. These two provisions,
individually or preferably in combination with one another, assure
that the increased pressure that occurs upon a reduction in the
viscosity of the substance will act uniformly on the sealing
element, so that the sealing element can be pressed uniformly out
of its seat without becoming canted; this is especially
advantageous with sealing rings of a soft sealing material that are
intrinsically not very stable.
[0010] The tripping point, that is, the viscosity at which the
sealing element moves out of its seat, can be intentionally set by
way of the number and cross section of the connecting bores. For
instance, the connecting bores in a frozen substance can be closed
by the formation of ice crystals, so that the pressure cannot force
the sealing element out of its seat, while after thawing and the
attendant disappearance of the crystals, the internal pressure of
the container can act on the sealing element via the connections
and optionally the annular conduit. In higher-viscosity substances,
pressure drops can be intentionally set by way of the cross
sections of the connections without changing the aggregate state;
these pressure drops do not allow a sufficient pressure in the
sealing seat to force the sealing element out until a certain
viscosity fails to be attained.
[0011] The other provision, preferably employed in combination with
the connections, of generating a pressure drop at the sealing
element that builds up a tensile force on the sealing element to
move it out of its seat is preferably attained in such a way that
the sealing element protrudes from its seat and protrudes
obliquely, in relative terms, into the opened flow cross section,
and its contour defines the narrowest point of the flow cross
section. In this way, solely by way of the pressure drop, an
especially high resultant force on the sealing element can be
generated, and this force increases as the viscosity decreases,
since for a certain internal pressure of the can, with reduced
viscosity, the flow velocity in the region of the sealing point and
thus the pressure drop and hence also the extraction force acting
on the sealing element increase.
[0012] In the closed state, the sealing element preferably
co-operates with a conical contact face, which in the opened state
forms the flank of the flow cross section opposite the sealing
element. Preferably, the narrowest point of the flow cross section
is contoured in nozzle-like fashion, for example similarly to a
venturi nozzle, to facilitate dispensing the substance on the one
hand, and on the other to assure a defined pressure drop.
[0013] A sealing ring of disk shape or with a substantially
rectangular cross section, which preferably has rounded or
chamfered edges and with an edge protruding from its seat defines
the contour of the narrowest point, is especially expedient. With
the aid of the rounded edge, the desired nozzle contour can be
achieved very easily, and preferably the opposed contact face is
embodied accordingly.
[0014] An embodiment of the invention in which the outlet valve is
embodied as a multiple-stage valve and has at least two opening
cross sections that open one after the other, each with an
associated sealing element, and at least the sealing element of the
cross section that opens first is embodied so as to be in captive
fashion from its seat if a minimum viscosity fails to be attained,
can be expedient. An embodiment having a multiple-stage valve can
be useful in order to enable successively uncovering an overall
larger opening cross section, and the actuation of the second stage
is simplified, if a frozen structure is for instance loosened up by
opening the first cross section and by the ensuing flowing motion.
As a precaution, all the sealing elements should be embodied in
captive fashion as described above, since if very major force is
expended, it could be possible to open the second opening cross
section as well, once the sealing element of the first opening
cross section has become detached and closes an opening cross
section provided there.
[0015] In an especially preferred embodiment of the invention, it
is provided that the sealing element detached from its seat can be
re-inserted into its seat by closure of the outlet valve. Depending
on the substance, the container can still be used after being
chilled down to the operating temperature again, and even in cases
where usage is no longer recommended after thawing, as in the case
of ice cream, this still makes it possible to empty the can before
throwing it away, so that when disposed of, the container is no
longer under pressure.
[0016] A structural embodiment of this kind of reversibly
detachable sealing element provides that the sealing element
comprises a disk of sealing material of relatively high rigidity or
an annular disk with a rigid substrate and a sealing part mounted
on the substrate, the substrate being guided in the extraction
direction between its seat and its position that closes the opening
cross section. The rigid substrate in conjunction with the guide
assures that the sealing element can be returned to its seat in a
defined way again by closure of the outlet valve, so that for
instance after re-freezing, the outlet valve can be opened normally
again. A guide can for instance be embodied such that the sealing
element is guided axially on a central protrusion, which depending
on the structural embodiment also forms the connection between a
valve element, in which the seat or the contact face for the
sealing element is provided, and a tappet for actuating the outlet
valve.
[0017] A further embodiment according to the invention for
attaining the object of the invention provides, preferably in
combination with the safety function described above, that the
sealing seat is provided in a valve element, which is movable in
the direction of the interior of the can by a tappet element for
opening the opening cross section, and the tappet element can be
pressed down by a lever, whose lever arm comprises at least two
parts that are fixed pivotably to one another and can be swivelled
between a collapsed position of repose, in which they are
preferably locked together, and an open, preferably likewise
locked, operating position for lengthening the lever arm.
[0018] The hinged lever construction offers the advantage that in
the open state, a longer lever travel is available, and actuation
can be done by grasping the second lever part with the user's hand,
making it easier to introduce force. At the same time, the lever
can be folded into the position of repose and the container can be
closed, for instance with a plastic cap whose outer diameter need
be no greater, or only insignificantly greater, than the diameter
of the container. This has major advantages in terms of space,
especially when a plurality of containers are packed in cardboard
boxes.
[0019] An especially preferred lever construction provides that a
first lever arm part is pivotably connected laterally of the tappet
element to a part connected solidly to the container and acts on a
radial protrusion via pressure elements. Such a construction
assures a short lever arm length between the pivot point attached
to the container and the engagement points of the pressure
elements, so that especially low opening forces can be attained. An
especially expedient embodiment provides that the radial protrusion
is formed onto a nozzle top unit that is seated on the tappet
element. A nozzle top unit is for instance provided for ice cream,
so that it can be dispensed in some structured way, and under some
circumstances even in a special shape. It is expedient in this
respect that the nozzle top unit is held above the tappet by two
diametrically opposed pressure elements, so that for securing the
nozzle top unit, no further detent connections or other connecting
elements are necessary and a secure hold is still assured, since
axial forces act on the nozzle top unit only when the lever is
pressed down and the outlet valve is thus opened. In an especially
preferred refinement of the lever, it is provided that the two
lever arm parts are embodied in hooplike fashion, and the first
lever arm part surrounds the nozzle top unit and/or the tappet
element in both positions, and the second lever arm part surrounds
the nozzle top unit and/or the tappet element in the position of
repose. The hooplike embodiment on the one hand makes a
sufficiently stiff design of the lever possible so that the forces
exerted by the user can be transmitted, and on the other is
especially space-saving, again in view of the need to be able to
close the container in the region of the nozzle top unit with a
plastic cap or the like whose diameter exceeds the outer diameter
of the container only insignificantly, if at all.
[0020] In still another preferred embodiment of the invention, the
outlet valve can have, in addition to a first opening cross
section, at least one further opening cross section, which can be
uncovered in order to facilitate filling of the container. This
further opening cross section can for instance be the opening cross
section of a multiple-stage valve, already mentioned above, but it
is also conceivable for the further opening cross section to be
opened solely for the filling operation; that is, after filling,
the at least one further opening cross section remains closed even
when the outlet valve is actuated. This can also be attained for
instance by providing that the opening stroke of the outlet valve
in a normal evacuation operation is not sufficient to uncover the
second cross section. Conversely, in the filling operation,
optionally with the top partly removed, a long enough stroke can be
executed to uncover both opening cross sections and thus make it
easier to introduce the product. In this process, the first opening
cross section is uncovered first, and then the at least one further
opening cross section is uncovered in succession, in the manner of
a multiple-stage valve.
[0021] Exemplary embodiments of the invention are addressed in
further detail below in conjunction with the accompanying drawings.
Shown are:
[0022] FIG. 1 a cross section of a top region of a pressurised
container in the closed state;
[0023] FIG. 2 a cross section similar to FIG. 1, with a slightly
modified outlet valve and with an actuating lever unlocked in
advance;
[0024] FIG. 3 a cross section of the top region of FIG. 2, with the
actuation lever folded open into the operating position;
[0025] FIG. 4 a cross section of the top region of FIGS. 2 and 3
with the outlet valve open;
[0026] FIG. 5 a cross section of the top region of FIGS. 2-4 with
the safety function tripped;
[0027] FIG. 6 a cross section of the embodiment of FIG. 1, with the
lever contour sketched in;
[0028] FIG. 7 a cross section of the embodiment of FIG. 6, with the
outlet valve open;
[0029] FIG. 8 an enlarged cross section of the sealing region of a
further embodiment of an outlet valve; and
[0030] FIG. 9 a cross section of a top region of a pressurised
container with two opening cross sections.
[0031] In FIG. 1, the top region of a pressurised container 10,
which is provided with an outlet valve 12 for dispensing the
pressurised container contents 14, is shown in cross section. In
the exemplary embodiment shown the pressurised container 10 is used
to hold frozen ice cream; that is, as a rule, the container is
deeply frozen, and the contents of the can are of very high
viscosity, corresponding to the substance of ice cream in the
frozen state. The container 10 is at a high pressure, which is
suitable for allowing such a material to be dispensed from the
outlet valve.
[0032] The outlet valve 12 substantially comprises a valve housing
16, which is connected solidly to the pressurised container 10 with
the interposition of a suitable seal 18; a movable valve element 20
with a disc-like sealing element 24, disposed in a sealing seat 22,
for sealing off the outlet valve 12 from the internal pressure in
the container in the closed state; a sleevelike tappet element 26,
connected to the valve element 20; a nozzle top unit 28 seated on
the tappet element 26; and an actuating lever 30, which in a manner
to be described in further detail hereinafter acts on the tappet
element 26 and thus on the valve element 20 via the nozzle top unit
28. Between the tappet element 26 and the valve housing 16, a
helical spring 32 is also provided, as a restoring element, which
after the actuating lever 30 is released returns the tappet element
26 into the position of repose; the outlet valve 12 is closed with
reinforcement from the internal pressure of the container. Once the
internal pressure of the container is reduced, the helical spring
32 assures that no residues from the interior of the container can
escape via the seal.
[0033] Because of the high viscosity of the container contents, the
outlet valve 12 in the open state (see FIG. 4) has a comparatively
large opening cross section, so that a satisfactory volume of the
contents of the container 10 can be dispensed with in a certain
length of time, at the pressure available. As a result, a
comparatively large-area valve element 20 is required, with a
sealing point 34 of relatively large diameter, which is defined by
a circumferential edge 36 of the sealing element 24 and by a
conical contact face 38 on the valve housing 16. The valve element
20 itself is pointed in shape, so that it can more easily penetrate
the frozen composition 14 upon actuation of the outlet valve
12.
[0034] Nevertheless, because of the large projection area of the
valve element 20, a high actuating force on the tappet element 26
is necessary, if the outlet valve 12 is to be opened counter to the
internal pressure. An actuating lever 30 is therefore provided,
which comprises a first lever arm part 40 and a second lever arm
part 42, both embodied in hooplike fashion and, for instance in the
shipment position shown in FIG. 1, surrounding the nozzle top unit
28. In this position shown, the top region can be covered by a
plastic cap (not shown), which can be snapped onto the pressurised
container 10 at an annular bead 44, and whose outer diameter
exceeds the outer diameter of the pressurised container only
slightly, if at all, so that the pressurised containers can be
packaged in a space-saving way.
[0035] The first lever arm part 40, via a hoop 46, engages a slot
48 in the valve housing 16, so that it is swivelably supported
about this pivot point. The second lever arm part 42 is seated with
two lateral snap-on hoops 50 on pivot pegs 52, which are provided
on the first lever arm part 40 and define the hinged pivot point of
the lever arm 30. As can be seen from FIGS. 6 and 7, the first
lever arm part has pressure elements 54, embodied in the region of
the lever bifurcation, which at a point marked 56 rest on a
radially protruding edge 58 of the nozzle top unit 28.
[0036] For folding the actuating lever 30 open, this lever can
easily be raised, in the collapsed, locked state, to the position
shown in FIG. 2, and further swivelling open can be made possible
to enable removing the nozzle top unit from the tappet element 26
for cleaning it or for replacing it with a different nozzle top
unit having a differently embodied through opening. As already
noted, the two lever arm parts 40, 42 are easily detachable locked
together but can be detached from one another without problems and
folded open, by swivelling about the pivot pins 52, into the
operating position shown in FIG. 3; in this state, they are locked
to one another, preferably again detachably, by suitable detent
elements. In this state, the user can exert a large force on the
second lever arm part 42 with the palm of his hand, and this force
is reinforced by the lever arm in accordance with the lever arm
ratio.
[0037] Via the pressure elements 54 of the first lever arm part 40,
the lever 30 acts via the contact point 56 on the radial protrusion
58 of the nozzle top unit 28, and this radial protrusion in turn
rests on a radial shoulder 60 of the tappet element 26. Via the
sleevelike tappet element 26, the actuating forces are transmitted
onward to the valve element 20, via three struts 62 that converse
obliquely toward the middle and via a connecting portion 64
adjoining them centrally. Once the internal pressure of the can is
overcome, the valve element, when the actuating force is exerted,
is moved out of the position shown in FIG. 3 into the dispensing
position shown in FIG. 4, in which a large outlet cross section is
uncovered between the conical contact face 38 and the sealing edge
36 of the sealing element 24. As a rule, the actuating force drops
sharply as soon as the sealing element has lifted from its opposed
contact face 38.
[0038] In the state shown both in FIG. 4 and in FIG. 7, the
substance 14 stored in the container can be discharged through the
opening cross section in the region of the sealing point 34, past
the struts 62, into the hollow tappet element 26 and from there
into the nozzle top unit 28 and onward, through an outlet opening
66, which in this exemplary embodiment is shown in star-shaped
form. The nozzle top unit 28, placed only loosely on the tappet
element 26, is held in position in the discharge position by the
actuating lever 30, even under the pressure forces acting on
it.
[0039] After use, the lever can be collapsed again, and the nozzle
top unit 28 can be removed for cleaning. After cleaning and
collapsing into the position shown in FIG. 1, a protective cap can
be snapped back onto the annular bead 44. During the dispensing of
the container contents, the tappet element 26 is sealed off from
the valve housing 16 with the aid of a sealing ring 68, which upon
the motion of the tappet element 26 slides along a cylindrical wall
70 of the valve housing 16. In the exemplary embodiment shown, the
cylindrical wall 70 and the outer wall of the valve housing 16 form
an annular hollow chamber 72, in which part of the helical spring
32 is disposed.
[0040] While the lever construction in conjunction with the shaping
of the valve element 20 makes opening the outlet valve 12 easier,
the particular structural embodiment of the sealing element 24 and
its sealing seat 22 assures a safety function, which prevents the
container contents, if there is a substantial reduction in
viscosity, such as after ice cream has thawed, from escaping from
the outlet opening 66 uncontrollably fast after the outlet valve 12
is opened. To that end, it is provided that if a certain minimum
viscosity of the substance 14 fails to be attained, the sealing
element 24 will detach from its sealing seat 22 upon opening of the
outlet valve 12 and will remain in its sealed-off position, as
shown in FIG. 5, without following the valve element 20. In this
position, the sealing element 24 is pressed against the conical
contact face 38 by the internal pressure of the can, so that the
sealing point 34 remains closed, and no substance can escape from
the container. The sealing element 24 has sufficient rigidity so
that in this state it undergoes no substantial changes of shape;
either it can comprise a suitable hard sealing material, or it has
a substrate on which the actual seal with the sealing edge 36 is
disposed. The sealing element 24 is guided axially on the
connecting element 64, so that it cannot make a change of position
in the radial direction that could threaten the sealing in this
position.
[0041] In the embodiment shown in FIGS. 1, 6 and 7, the detachment
of the sealing element 24 from its sealing seat 22 if the minimum
viscosity fails to be attained is achieved by the structural
embodiment in the region of the sealing point 34 and by a defined
retention force between the sealing element 24 and the sealing seat
22. While with a frozen substance for instance, this substance can
pass through the opening cross section only at a low flow velocity,
and accordingly only a minimal pressure drop occurs, if the
viscosity is reduced and the flow velocity is correspondingly
higher, a pressure drop is created which can be varied by means of
structural provisions, such as the conicity of the contact face,
the extent of protrusion of the sealing element 24 from the sealing
seat 22, and the contouring of both the sealing edge 36 and the
contact face 38. By way of the effective surface area of the
sealing element 24 downstream of the sealing point 34, with the
resultant underpressure, a certain pressure on the sealing element
24 to force it out of the sealing seat 22 can also be generated
purposefully. These structural factors and the retention force of
the sealing element 24 in the sealing seat 22 are adapted such that
if the viscosity falls below a minimum level, for instance if the
contents 14 of the container thaw, the resulting forces from the
pressure drop acting on the sealing element 24 move the sealing
element, counter to its clamping force, out of the sealing seat 22
into the safety position shown in FIG. 5. Then if at all, only in
the very first instant of the pressing down of the valve element 20
does any slight passage of the substance 14 occur into the interior
of the valve housing 16 or the tappet element 26.
[0042] Since it can be difficult to adapt the structural details to
attain tripping of the safety function when certain parameters are
attained, it can be useful in addition or alternatively to the
effect described above to provide at least one but preferably a
plurality of connecting bores 74 in the valve element, which
connect the sealing seat 22 with the interior of the pressurised
container 10. The diameter and geometry of the at least one
connecting bore 74 (see FIGS. 2-5) are selected such that in the
frozen state of the substance 14, for instance, the opening cross
sections are closed by crystal formation, so that the internal
pressure of the can cannot act in the sealing seat 22 on the
sealing element 24. In the frozen state, upon actuation of the
actuating lever 30, the dispensing position shown in FIG. 4 is
consequently reached.
[0043] If a frozen substance thaws, or if there is a substantial
decrease in viscosity of a substance that as a rule begins in a
higher-viscosity state, the internal pressure of the can container
act on the sealing element 24 via the connecting bores 74 in the
valve element, so that the detachment of the sealing element 24
from its seat 22 is either reinforced or is accomplished solely by
the internal pressure of the can, if the substance 14 has thawed or
a certain minimum viscosity has failed to be attained. In this
embodiment, it is possible to attain the safety position shown in
FIG. 5, without any escape of the substance via the sealing point
34. As already noted, the two effects of the connecting bores that
self-seal because of the high-viscosity substance and the targeted
oncoming flow and the generation of a pressure drop can preferably
be combined, to achieve a defined detachment of the sealing element
24.
[0044] Guiding the sealing element 24 on the connecting element 64
offers the advantage not only of secure sealing if the valve
element 20 moves toward the interior of the can but also the
advantage that after the actuating lever 30 has been released, the
valve element 20 can be returned to its outset position again under
the influence of the restoring spring 32 and in particular of the
internal pressure of the can as well, and in this process the
sealing element 24 is also pressed into its sealing seat 22. A
chamfer 36 on the outer circumference of the sealing seat and/or on
the underside of the sealing element facilitates returning the
sealing element 24 to its seat 22. The connecting bores or other
openings between the sealing seat 22 and the container interior are
also advantageous in this respect, because through their opening
cross sections, the substance 14, which in the safety position of
FIG. 5 can collect between the sealing element 24 and its seat 22,
can easily be forced into the container interior. It is
conceivable, after subsequent chilling of the pressurised container
10 and attainment of the requisite minimum viscosity, to perform a
normal opening operation again and to withdraw the substance 14
from the pressurised container 10 in the usual and desired way.
[0045] While in the embodiments shown in FIGS. 1-7, with a
reversible sealing element 24, are preferred in many cases once the
safety function has been tripped, either to enable further use of
the container contents after re-chilling or at least to enable
evacuation to reduce the pressure before the container is disposed
of, non-reversible embodiments are also conceivable, in which after
the safety function has been tripped an opening cross section
remains permanently closed, for instance to assure that a thawed
food, which may have become spoiled, can no longer be used.
[0046] An embodiment of an outlet valve 112 of this kind is shown
in FIG. 8; for the sake of simplicity, only the region of the
sealing point 134 and the valve element 120 is shown, while the
remaining structural parts can be like those of the embodiment
shown in FIGS. 1-7. In the embodiment of FIG. 8, a sealing element
124 of substantially rectangular cross section and with a rounded
sealing edge 136 is seated in a sealing seat 122, with an annular
conduit 123 disposed on the bottom of the sealing seat; via at
least one connecting bore 174, this annular conduit is in
communication with the container interior. Once again, the sealing
in the closed state is effected by contact of the sealing edge 136
with a conical contact face 138. Unlike the embodiments shown in
FIGS. 1-7, the sealing element 124 entirely comprises a relatively
soft material and is not guided in any special way on the valve
element 120. If the safety function comes to be tripped, once again
by the intentional utilisation of a pressure drop and/or the
pressure build-up through the connecting bores 174, with the
annular conduit 123 making a uniform pressure build-up possible,
which is especially advantageous with the soft sealing element 124,
the sealing element 124 is pressed, after its detachment from the
sealing seat 122, into a gap 102 between the valve housing 116 and
the valve element 120; as a rule, this gap represents the flow
cross section for the substance to be dispensed. Because of its
relatively soft nature, the sealing element is deformed under the
influence of the internal pressure in the container in such a way
that even after the valve element 120 is retracted, the sealing
element 124 can no longer get into the sealing seat 122, and so the
gap 102 remains permanently closed, and a discharge of the
substance is no longer possible even after being chilled again. In
this connection, it would also be conceivable to provide a small
through opening in the region 102, for instance in the form of an
axial conduit on the valve housing 116, which conduit assures slow
evacuation of the container contents after the safety function has
been tripped. It is also conceivable to provide this kind of
intentional dispensing function in embodiments of FIGS. 1-7, for
instance by means of a through opening between the valve element 20
and the connecting element 64.
[0047] The outlet valves described above can also be embodied with
multiple steps; that is, it is conceivable, after the opening of
the valve element 20, to open a further cross section in order to
speed up the discharge and/or the introduction of the substance. In
such an embodiment as well, a safety function can be desirable for
both valve stages, although as a rule, opening the second valve
stage for discharge under pressure necessitates a considerably
greater expenditure of force if the first valve stage could not be
opened or is closed after the safety function has been tripped.
[0048] In FIG. 9, one example of such a multiple-seat valve is
shown, in the form of an outlet valve 212, which is quite similar
in structure to the single-stage variants described above.
Equivalent elements are therefore provided with the same reference
numerals.
[0049] In a departure, the valve housing 16, in the region of the
sealing point 184 of the first opening cross section, is not
provided with an annular protrusion protruding obliquely into the
interior of the can; instead, compared to the embodiments described
above, it has a recessed sealing point 186, while the
aforementioned first sealing point 184, for co-operation with the
disk-like sealing element 24, is formed by a conical disk element
180. The conical disk has a second, annular sealing element 125,
which co-operates with the second sealing point 186. The disk
element 180 is also guided axially movably toward the interior of
the can in an axial guide 182, which may be formed onto the valve
housing 16.
[0050] The second opening cross section, which can be closed by the
second sealing point 186 and the second sealing element 125, can,
depending on the design of the lever mechanism described above and
not shown here, and in conjunction with the position of the struts,
be opened for rapid evacuation by depressing the tappet element 26.
In the exemplary embodiment shown, however, the second opening
cross section serves only to facilitate the process of filling the
container with frozen ice cream. If the lever mechanism is removed
and the nozzle top unit 28 is missing, it is in fact possible for
the tappet 26 to be moved farther into the interior of the can,
where because of the absence of internal pressure in the can the
disk element 180 is moved into a terminal position in the axial
guide 182, uncovering the second opening cross section into the
container interior. If once it reaches the stop the tappet element
26 moves onward toward the interior of the can, then subsequently
the first opening cross section in the region of the first sealing
point 184 will also be uncovered, so that an especially large
opening cross section for rapid filling is available. As soon as
the container is under pressure and the lever mechanism with the
nozzle top unit 28 has been installed, the second opening cross
section remains closed because of the internal pressure in the can,
and the stroke of the tappet element 26 is limited in such a way
that the struts cannot act on the disk element 180.
* * * * *