Note: Descriptions are shown in the official language in which they were submitted.
CA 02648899 2008-10-09
Agent Ref: 68877/00016
ADJUSTABLE PRESSURE COOKING APPLIANCE WITH CONTROLLED
DECOMPRESSION
TECHNICAL FIELD
The present invention relates to the general technical field of
appliances for cooking food, in particular for home use, and designed to form
a leaktight cooking enclosure within which food is cooked under steam
pressure.
The present invention relates more particularly to an appliance for
cooking food under pressure, the appliance being arranged to form a cooking
enclosure that includes an orifice for putting the inside of the enclosure
into
communication with the outside, a settable pressure-regulation valve co-
operating with the orifice to maintain the pressure that exists inside the
enclosure at a predetermined level, and adjustment means for adjusting the
setting of said settable valve, said adjustment means being capable of moving
between at least two positions corresponding respectively to two distinct
values for said predetermined level.
PRIOR ART
Pressure cooking appliances, in particular for home use, such as
pressure cookers, are well known in the prior art. Such appliances generally
comprise a vessel and a lid designed to be fitted on the vessel to form a
hermetically closed cooking enclosure within which the food for cooking is
placed.
The enclosure can thus reach high pressures and temperatures when
the appliance is subjected to the influence of a source of heat.
Those known appliances are also provided with an axially-slidable
pressure-regulation valve co-operating with a leakage orifice formed through
the lid so as to close or open said orifice as a function of the pressure that
exists within the enclosure, in order to maintain said pressure at a
predetermined level commonly referred to as the "operating pressure".
In order to optimize the cooking cycle, certain known appliances have a
settable pressure-regulation valve together with means for adjusting the
setting of said settable valve. The setting adjustment means are capable of
moving between a plurality of indexed positions corresponding to respective
distinct values for the predetermined pressure level, each of those values
thus
corresponding to a specific operating pressure, e.g. adapted to a particular
21816448.1 1
CA 02648899 2008-10-09
Agent Ref: 68877/00016
type of food (e.g. vegetables or meat) and/or to a particular state of the
food
(e.g. deep-frozen). Those known appliances also have a setting adjustment
member capable of moving the setting adjustment means between its indexed
positions, thereby enabling an operating pressure to be selected.
More particularly, the pressure-regulation valve of those known
appliances is set with the help of a helical spring mounted to bear between
firstly a slidable cap forming the setting adjustment means, and secondly the
valve, such that the bearing force exerted by the spring on the valve
(corresponding to the set level of the valve) is a function of the position of
the
cap, which cap compresses the spring to a greater or lesser extent depending
on its position.
The setting adjustment member is formed by a ramp carried by a rotary
selector that can be turned manually by the user, the ramp then compressing
the slidable cap to a greater or lesser extent depending on the angular
position of the selector, and thus compressing the spring to a greater or
lesser
extent, thereby enabling the setting and thus the operating pressure to be
adjusted.
Furthermore, in order to enable the user to open the lid, it is necessary
to begin by decompressing the appliance, because its high level of operating
pressure is incompatible with safe opening, i.e. there is a danger of the lid
escaping suddenly under the effect of the pressure.
To achieve such decompression with the above-described prior art
cooking appliance, the user places the rotary selector in an indexed angular
position for decompression, in which position the ramp exerts a bearing force
on the cap that is small enough to set the valve to a minimum set level,
thereby enabling the pressure that exists inside the enclosure to be brought
down to a low level that is compatible with the lid being opened safely.
Although those known appliances generally give full satisfaction to the
user, they nevertheless present a certain number of drawbacks.
The user of those known appliances is not in a position to have
effective control over ensuring that decompression gas flow is progressive,
given that when the selector is in the indexed position for decompression, the
leakage orifice remains subjected to the automatic closure action of the
settable valve.
That technical provision can lead to a large steam leakage section
opening suddenly and in uncontrolled manner, which can lead to food and/or
water being ejected from the appliance due to the appearance of a "foaming"
21816448.1 2
CA 02648899 2008-10-09
Agent Ref: 68877/00016
phenomenon in the food (sometimes also referred to as an "emulsion" by the
person skilled in the art) that is well known in this field.
In addition, since decompression is obtained merely by reducing to a
minimum the level at which the pressure-regulation valve is set,
decompression cannot be complete. The regulation valve will end up closing
the leakage orifice completely once the pressure that exists inside the
enclosure has reached the level that corresponds to said minimum set level
(which level is greater than atmospheric pressure). Such an impossibility of
achieving genuine complete decompression of the enclosure prior to opening
the lid can lead to the user being subjected, on opening the lid, to a puff of
residual steam, and although that is not dangerous, it is nevertheless
unpleasant.
SUMMARY OF THE INVENTION
The objects assigned to the invention seek consequently to provide a
novel appliance for cooking food under pressure that provides a remedy to the
various drawbacks of the prior art as mentioned above and, while being of a
construction that is particularly reliable, simple, and inexpensive, makes it
possible simultaneously to achieve decompression that is complete, fast, and
controlled, and also to select different operating pressure levels.
Another object of the invention is to provide a novel appliance for
cooking food under pressure that is particularly easy to use.
Another object of the invention is to provide a novel appliance for
cooking food under pressure that is of particularly robust construction.
Another object of the invention is to provide a novel appliance for
cooking food under pressure that is of particularly simple design.
Another object of the invention is to provide a novel appliance for
cooking food under pressure that provides excellent control over
decompression.
Another object of the invention is to provide a novel appliance for
cooking food under pressure that is of construction that is particularly
compact, inexpensive, and safe.
The objects assigned to the invention are achieved with the help of an
appliance for cooking food under pressure, the appliance being arranged to
form a cooking enclosure that includes an orifice for putting the inside of
the
enclosure into communication with the outside, a settable pressure-regulation
valve co-operating with the orifice to maintain the pressure that exists
inside
21816448,1 3
CA 02648899 2008-10-09
Agent Ref: 68877/00016
the enclosure at a predetermined level, and adjustment means for adjusting
the setting of said settable valve, said adjustment means being capable of
moving between at least two positions corresponding respectively to two
distinct values for said predetermined level, the appliance being
characterized
in that it includes a member for controlling decompression of the enclosure,
which member is capable of moving the sellable pressure-regulation valve so
that it opens the orifice in such a manner as to put the inside of the
enclosure
into communication with the outside, and in that it includes a setting
adjustment member capable of moving the setting adjustment means
independently of the pressure-regulation valve, to modify the value of the
predetermined level.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of the invention appear and can be
seen in greater detail on reading the following description made with
reference to the accompanying drawings purely by way of non-limiting
illustration, and in which:
= Figure 1 is an exploded general view in perspective showing a
cooking appliance in accordance with the invention;
Figure 2 is a diagrammatic perspective view showing the lid of the
Figure 1 appliance;
= Figure 3 comprises three views (from top to bottom) respectively
showing the bottom, the side, and the top of a control module that
incorporates the sellable pressure-regulation valve of the appliance and that
is designed to be fitted to the lid shown in Figure 2 and releasably fastened
thereto;
Figure 4 is a fragmentary section view showing an embodiment detail
of the Figure 3 module, when fitted to the lid shown in Figure 2;
= Figure 5 is a perspective view showing an internal embodiment detail
of the module shown in the above figures;
= Figure 6 is a section view of the embodiment detail shown in Figure 4,
the pressure-regulation valve being submitting to a first set level;
= Figure 7 is a section view showing the embodiment detail shown in
Figure 6, the pressure-regulation valve being subjected to a second set level
greater than the first set level; and
= Figure 8 is a section view showing the embodiment detail shown in
Figures 6 and 7, the pressure-regulation valve releasing the orifice under the
21816448.1 4
CA 02648899 2008-10-09
Agent Ref; 68877/00016
action of the member for controlling decompression of the enclosure, in order
to decompress the enclosure.
BEST MANNER OF PERFORMING THE INVENTION
The appliance 1 in accordance with the invention for cooking food
under pressure is designed to cook various kinds of food, under steam
pressure, preferably in a home context.
Preferably, the cooking appliance 1 in accordance with the invention is
constituted by a home pressure cooker. To simplify the description, below,
when referring to the accompanying drawings, reference is made exclusively
to an appliance 1 constituted by a home pressure cooker, it being understood
that the invention can optionally also apply to appliances of professional or
semi-professional type.
In conventional manner, the appliance 1 in accordance with the
invention is arranged to form a cooking enclosure that is preferably
substantially leaktight and designed to be subjected to the action of a source
of heat, whether external (e.g. a hot plate) or internal (e.g. an on-board
electrical resistance element).
Advantageously, the cooking appliance 1 in accordance with the
invention comprises a vessel 2 forming a cooking receptacle and preferably
presenting a shape that is substantially a body of revolution about an axis X-
X'
(cf. Figures 1, 4, and 5). Below, the adjective "axial" is used to refer to
the
direction of said axis of symmetry X-X', which direction is substantially
vertical
when the appliance is in normal operation. Naturally, the shape of the vessel
2 need not be a body of revolution (for example it could be oval in shape),
without that going beyond the ambit of the invention. The vessel 2 is
conventionally made of a metallic material such as stainless steel or
aluminum, and it is preferably provided with a heat-conducting bottom 2A
secured to the vessel, e.g. by hot forming.
The vessel 2 may also include a grip member, e.g. formed by one or
more handles 2B, 2C, which are preferably two in number and fastened to the
vessel 2 in diametrically opposite positions.
The appliance 1 in accordance with the invention also advantageously
includes a lid 3 designed to be fitted and locked onto the vessel 2 so as to
co-
operate therewith via a gasket 30 to form the cooking enclosure. The vessel
2 and the lid 3 are designed so that the enclosure they form is sealed
sufficiently hermetically to enable pressure inside the appliance to rise.
21816448.1 5
CA 02648899 2008-10-09
Agent Ref 68877/00016
The lid 3 is preferably complementary in shape to the vessel 2, for
example being substantially disk-shaped, and it comprises firstly an inside
face 3A for facing the vessel 2 when the lid is locked thereon, and secondly
an outside face 3B opposite from said inside face 3A, said outside face 3B
being designed to face towards the outside of the vessel 2 when the vessel 2
and the lid 3 forming the cooking enclosure. The lid 3 can be locked or
unlocked relative to the vessel 2 by locking/unlocking means 4. These means
may be of any type known to the person skilled in the art, and for example
they may be constituted by a jaw system (corresponding to the variant shown
in the figures), to a segment system, to a bayonet system, or indeed to a
clamp system, this list not being limiting in any way.
In a manner that is purely optional, but preferred, and as shown in the
figures, the appliance 1 has a control module 5 for fitting onto the lid 3,
preferably releasably by means of a threaded shaft 6 co-operating with a hole
7 formed in the lid 3 and with a retaining nut 8 designed to be screwed onto
the threaded shaft 6. In the variant shown in the figures, the module 5
carries
a series of functional and safety members, such as two control buttons 9, 10
respectively controlling closing and opening of the locking/unlocking means 4,
a removable timer 11, a safety valve 12 against excess pressure, and a
sliding finger 13 serving firstly to prevent the appliance from rising in
pressure
in the event of the lid being improperly closed, and secondly to prevent the
lid
from being opened so long as the pressure inside the appliance is
incompatible with user safety. These various control and safety members are
well known as such and are therefore not described in greater detail herein.
In accordance with the invention, the appliance 1 includes an orifice 17
for putting the inside of the enclosure in communication with the outside. The
orifice 17 thus enables a leakage flow of steam to be established from the
inside of the enclosure to the outside. The term "steam" should be
understood broadly herein, i.e. as designating the gaseous or pseudo-
gaseous phase present within the cooking enclosure and coexisting with the
food and the cooking liquid.
Preferably, and as shown in the figures, the orifice 17 is a through
orifice formed right through the thickness of the lid 3, and for example
presenting a shape that is substantially circular, about an axis of symmetry Y-
Y'.
In an optional design for the variant shown in the figures, the appliance
1 is also provided with a duct 14 serving to channel any steam leakage flow
21816448.1 6
CA 02648899 2008-10-09
Agent Ref: 68877/00016
that might escape via the orifice 17 from the inside of the enclosure to the
outside. In the variant shown in the figures, the duct 14 thus extends from
the
orifice 17 and continues within the module 5 until it reaches the outside of
the
appliance 1. For example, and preferably, the module 5 has a bottom 5A for
pressing against the top face 3B of the lid 3. A chamber 15 is formed in the
bottom 5A, the chamber being defined laterally by an annular gasket 15A
extending upwards from the bottom 5A and surrounding the inside volume
defined by said chamber 15. The chamber 15 communicates with an exhaust
pipe 16.
When the module 5 is fitted and fastened to the lid 3, the annular
gasket 15A bears in leaktight manner against the top face 3B of the lid so as
to surround the orifice 17 formed through the lid 3. Thus, when the module 5
is put into place on the lid 3, the chamber 15 is in leaktight communication
firstly with the inside of the enclosure via the orifice 17, and secondly with
the
outside of the appliance via the exhaust pipe 16, the chamber 15 being
interposed between the orifice 17 and the exhaust pipe 16. The duct 14 is
shaped in this particular embodiment by juxtaposing the orifice 17, the
chamber 15, and the exhaust pipe 16 and putting them mutually into
communication.
Naturally, the presence of a duct 14 is not necessary, and it is entirely
possible for the appliance 1 to be provided merely with a simple orifice 17
that
opens out directly to the outside of the appliance 1.
In accordance with the invention, the appliance 1 has a settable
pressure-regulation valve 18 co-operating with the orifice 17 to maintain the
pressure that exists inside the enclosure at a predetermined level,
corresponding to its operating pressure. More precisely, the settable
pressure-regulation valve 18 closes or opens the orifice 17 under the effect
of
the pressure that exists in the enclosure so as to maintain the pressure in
the
enclosure at a substantially constant level, corresponding to said
predetermined level.
The settable pressure-regulation valve 18 is thus capable of moving
under the effect of the pressure that exists in the enclosure between:
= a steam leakage position in which it opens the orifice 17 if the
instantaneous pressure that exists inside the enclosure is greater than the
predetermined level; and
= a closed position (shown in Figures 4, 6, and 7) in which it closes the
orifice 17 in substantially hermetically sealed manner if the instantaneous
21816448.1 7
CA 02648899 2008-10-09
Agent Ref: 68877/00016
pressure that exists in the enclosure is substantially less than the
predetermined level, so as to enable pressure within the appliance 1 to rise
(or be limited).
In other words, the sellable pressure-regulation valve 18 is designed
firstly to prevent any communication from the inside of the enclosure to the
outside so long as the pressure that exists inside the enclosure is less than
or
equal to the predetermined level, and secondly to act automatically to put the
inside of the enclosure into communication with the outside under the effect
of
the pressure as soon as the pressure that exists inside the enclosure exceeds
said predetermined level.
Advantageously, the sellable pressure-regulation valve 18 extends
between firstly a head 19 designed to close the orifice 17 under the effect of
the setting, and secondly a free tail 20. Preferably, the valve 18
conventionally comprises a valve stem 21 extending along an axis Y-Y'
parallel to the axis X-X' and preferably situated at a distance therefrom,
between a first end corresponding to the head 19 and an opposite, second
end corresponding to the tail 20. In other words, the valve 18 advantageously
has a stem 21 extending axially between the tail 20 and the head 19.
The head 19 preferably extends substantially perpendicularly to the
axis Y-Y' and is advantageously generally disk-shaped, as shown in the
figures. Advantageously, the valve 18 includes an annular gasket 19A
extending upwards from the head 19, preferably at the periphery thereof. This
annular gasket 19A is designed to bear in substantially leaktight manner
against the cooking enclosure, i.e. specifically against the outside face 3B
of
the lid 3, so as to surround the orifice 17 and thus prevent the inside of the
enclosure being put into communication with the outside, since the orifice 17
then opens out into a chamber that is closed by the annular gasket 19A and
the head 19.
Preferably, the gasket 19A is made integrally with the head 19, i.e.
together they constitute a single one-piece part. In particularly preferred
manner, the tail 20 forms an integral portion of the stem 21 and is formed
integrally therewith, while the head 19 comprises a cover that is fitted on
and
fastened to the stem 21. Preferably, said cover is made of an elastomer
material, e.g. of the silicone kind, and it is designed to be engaged by force
onto the corresponding end of the stem 21.
Advantageously, the sellable pressure-regulation valve 18 is mounted
to slide relative to the cooking enclosure. In particularly preferred manner,
21816448.1 8
CA 02648899 2008-10-09
Agent Ref: 68877/00016
when the valve 18 comprises, as in the variant shown in the figures, a step 21
extending between the head 19 and the tail 20, said stem 21 is mounted to
slide axially along its own axis Y-Y'.
Advantageously, the stem 21 is engaged in a guide well 22 formed in
the module 5. The well 22 has a cylindrical side wall 22A extending inside the
module 5 from a hole formed in the bottom 5A of the module 5 and designed
to open out into the chamber 15 over the orifice 17, and on the same axis.
The stem 21 is slidably inserted in the well 22 and is guided thereby to move
in translation, so as to move in translation along the axis Y-Y'.
In the embodiment described above and shown in the figures, the
pressure-regulation valve 18 is mounted on board the module 5.
Naturally, it is entirely possible, without thereby going beyond the ambit
of the invention, for said valve 18 to be mounted directly on the lid 3.
As mentioned above, the pressure-regulation valve 18 is set, i.e. it is
subjected to a predetermined calibrated return force urging it towards the
closed position, in which position it closes the orifice 17 hermetically.
Implementing such settings for the valve 18 is well known in itself and can be
performed by any means known to the person skilled in the art.
Preferably, the pressure-regulation valve 18 is set with the help of a
resilient body 23 exerting a return force on the valve 18 to hold it in its
closed
position (shown in Figures 4, 6, and 7) in which it prevents the inside of the
enclosure being put into communication with the outside. Preferably, the
resilient body 23 comprises a helical spring 24 mounted coaxially about the
stem 21 inside the well 22 so as to exert return thrust on said stem 21. For
this purpose, the stem 21 preferably has a first shoulder 21A (cf. Figures 4
and 8) against which a first end of the helical spring 24 rests and comes to
bear.
In accordance with the invention, the appliance 1 further includes
means 25 for adjusting the setting of the settable valve 18 serving to vary
the
set level, i.e. the magnitude of the return force towards the closed position
as
exerted by the pressure-regulation valve 18. The adjustment means 25 are
thus capable of moving between at least two positions (shown respectively in
Figures 6 and 7) corresponding respectively to two distinct values for the
predetermined pressure level. In other words, the adjustment means 25
enable the operating pressure to be modified by increasing or decreasing the
setting of the valve 18, depending on the position occupied by said means
relative to the cooking enclosure. In the example shown in the figures, the
21816448.1 9
CA 02648899 2008-10-09
Agent Ref: 68877/00016
adjustment means 25 are capable of moving between only two stable
positions corresponding to two different values for the predetermined pressure
level, said positions being furthermore both predetermined and indexed so as
to be directly and easily identifiable by the user. In other words, in the
example shown in the figures, the adjustment means 25 are of a discrete
nature since they can occupy only two stable positions corresponding to two
distinct operating pressures. Nevertheless, it is entirely possible to
implement
adjustment means 25 that make it possible to adjust the setting of the valve
18 continuously, i.e. making the valve capable, within the limits of its
travel
stroke, of occupying an infinity of distinct positions corresponding to as
many
different settings.
Preferably, and as shown in the figures, the setting adjustment means
25 are mounted to slide on the pressure enclosure, preferably along the axis
Y-Y'. Preferably, the setting adjustment means 25 are capable of moving in
pure translation, without any rotation component. Advantageously, the setting
adjustment means 25 comprise a slidable abutment 26 capable of bearing
against the setting means proper, constituted in this example by the resilient
body 23, so that the sliding of said sliding abutment 26 varies the bearing
force exerted by the sliding abutment 26 on the resilient body 23. In other
words, the valve 18 is set with the help of a resilient body 23 exerting a
bearing force on a slidable abutment 26 forming the means 25 for adjusting
the setting of the valve 18, with setting adjustment advantageously not giving
rise directly to any movement of said valve.
In the example shown in the figures, the slidable abutment 26 is
preferably formed by a cap slidably inserted in the well 22 and covering the
spring 24, in such a manner that a first end thereof bears against the valve
18
(and more precisely against the first shoulder 21A of the stem 21), while a
second end of the spring 24, opposite from the first, bears against the cap
26,
the cap being guided to move in translation along the axis Y-Y' by the well
22.
In particularly advantageous manner, the helical spring 24 is engaged on the
stem 21 so as to bear against the first shoulder 21A, while the cap is pierced
by a hole of section that is large enough to enable the cap to be likewise
engaged on the stem 21, but small enough to ensure that the cap forms an
abutment against which the second end of the spring 24 comes into
abutment. It will be understood that sliding the cap 26 towards the bottom 5A
of the module 5 causes the spring 24 to be compressed progressively,
thereby corresponding to an increase in the pressure setting of the valve 18.
21816448.1 10
CA 02648899 2008-10-09
Agent Ref 68877/00016
Conversely, when the cap 26 is moved away from the bottom 5A of the
module 5, that leads to the spring 24 relaxing and thus to a reduction in the
pressure setting of the valve 18. The progressive compression or progressive
relaxation of the spring 24 under the action of the cap 26 preferably does not
give rise to any movement of the valve 18 which is kept stationary.
The appliance 1 in accordance with the invention includes a control
member 27 for controlling decompression of the enclosure and capable of
moving the settable pressure-regulation valve 18 so that it opens the orifice
17, preferably progressively, thereby putting the inside of the enclosure into
communication with the outside. In other words, the decompression control
member 27 is arranged to force the valve 18 to open the orifice 17, regardless
of the level of pressure that exists inside the enclosure, and for the purpose
of
decompressing the appliance 1, i.e. for causing the pressure that exists
inside
the enclosure to drop to a value that is substantially equal to the
atmospheric
pressure that exists outside the appliance 1.
Thus, the decompression control member 27 serves to bring the
settable pressure-regulation valve 18 into a decompression position (shown in
Figure 8) that is preferably stable, predetermined, and stationary, and to
hold
said valve therein, with the valve 18 in said position opening the orifice 17
in
substantially permanent manner (i.e. independently of the setting) so as to
enable a steam leakage flow to be established that leads to the enclosure
becoming decompressed.
Preferably, the decompression control member 27 is movable relative
to the enclosure and is arranged to entrain the pressure-regulation valve 18
directly, i.e. it is specifically designed so that moving it generates a
direct
movement force on the pressure-regulation valve 18. Preferably, the
decompression control member 27 is capable of exerting a progressive drive
force on the tail 20 of the stem 21 that is sufficient to overcome the
pressure
setting and to move the head 19 away from the orifice 17, so as to open the
orifice and allow a steam leakage flow to become established progressively.
Advantageously, the tail 20 is provided for this purpose with force
transmission means 20A on which the decompression control member 27 is
capable of exerting thrust, said thrust forming said drive force that is
sufficient
to overcome the pressure setting. The force exerted by the control member
27 on the stem 21 thus gives rise to axial traction on said stem 21 towards
the
outside of the enclosure.
21816448.1 11
CA 02648899 2008-10-09
Agent Ref: 68877/00016
Preferably, the stem 21 presents a second shoulder forming the
transmission means 20A, as shown in the figures. The decompression
control member 27 is thus arranged to exert axial thrust along the axis Y-Y'
against said second shoulder and thus cause the valve 18 to slide in the well
22 against the return force exerted by the spring 24 so as to move the head
18 away from the orifice 17, thus enabling the steam contained in the
enclosure to escape via the orifice 17.
Advantageously, and as can be seen in particular in Figure 5, the
decompression control member 27 comprises a first rotary part 28 provided
with a first ramp 29 for engaging the valve 18, and more precisely its tail
20,
via the second shoulder, so as to exert drive force on the valve 18 when said
first rotary part 28 is turned.
Preferably, the first rotary part 28 is mounted to turn about the axis X-X'
on a shaft 31 that projects inside the module 5 from the bottom 5A. The first
rotary part 28 preferably extends in a plane that is substantially
perpendicular
to its axis of rotation X-X', such that the first ramp 29 projects
substantially
parallel to said axis X-X'. More precisely, the first rotary part 28 presents
a
first face 28A facing towards the outside of the appliance 1 and a second face
28B that is opposite therefrom and that faces towards the outside face 3B of
the lid 3, the first face 28A being positioned under the head 20, and more
precisely under its second shoulder forming the drive means 20A.
The first ramp 29 projects from the first face 28A towards the outside of
the appliance 1 and preferably forms a progressive slope projecting from the
surface of the face 28A. Thus, when the first rotary part 28 turns about the
axis X-X', the first ramp 29 slides under the tail 20 and raises it
progressively
so as to bring the valve 28 progressively into the decompression position. For
=
this purpose, the first ramp 29 preferably presents a slope 29A that is
continuously progressive extending from the first face 28A up to a flat 29B
forming a stable bearing surface for the second shoulder formed in the stem
21, in the tail 20.
When the tail 20 thus rests on the flat 29B of the first ramp 29 (as
shown in Figure 8), the valve 18 is held stationary in stable manner in its
decompression position.
In order to enhance the mechanical strength and reliability of the
appliance 1, the first rotary part 28 is preferably provided with a slot
extending
over a circular segment centered on the axis X-X' between the first face 28A
and the second face 28B. Under such circumstances, the first ramp 29 is
21816448.1 12
CA 02648899 2008-10-09
Agent Ref: 68877/00016
formed by two individual ramps extending on either side of the slot. The slot
receives the stem 21, with the two individual ramps being suitable for
engaging the tail 20 on diametrically opposite sides about the axis X-X',
thereby contributing to the mechanical stability of the assembly.
In accordance with the invention, the appliance 1 further includes a
setting adjustment member 32 capable of moving the setting adjustment
means 25 independently of the pressure-regulation valve 18 in order to modify
the predetermined level, i.e. the value of the operating pressure. The setting
adjustment member 32 is thus capable of influencing the position of the
setting adjustment means 25 and of doing so without acting on the pressure-
regulation valve 18. In other words, the setting adjustment member 32 is
capable of moving the setting adjustment means 25 so as to modify the
predetermined value for the pressure level, but without simultaneously moving
the pressure-regulation valve 18, i.e. without imparting any simultaneous
drive
force thereto, whether in translation along the axis Y-Y' or in rotation about
the
axis Y-Y'. By virtue of this technical measure, it is possible to modify the
setting of the valve without acting mechanically thereon, thereby limiting
wear,
and in particular avoiding unwanted wear friction between firstly the head 19
with its gasket 19A, and secondly the outside face 3B of the lid 3.
Advantageously, and in reciprocal manner, the decompression control
member 27 acts on the valve 18 without acting on the member 32 for
adjusting the setting of the valve 18.
Advantageously, the decompression control member 27 is distinct from
the setting adjustment member 32, i.e., preferably, the decompression control
member 27 and the setting adjustment member 32 are functionally
independent, such that moving the decompression control member does not
necessarily cause the setting adjustment member 32 to move, and vice versa.
Nevertheless, the decompression control member 27 and the setting control
member 32 can perfectly well be carried by a single part without thereby going
beyond the ambit of the invention, and as described in greater detail below.
Advantageously, the setting adjustment member 32 is capable of
exerting a propulsion force on the slidable abutment 26 forming the setting
adjustment means 25 in opposition to the bearing force exerted by the
resilient body 23 on the slidable abutment 26, said propulsion force being
sufficient to cause the abutment 26 to slide, thereby adjusting the setting of
the valve 18. In other words, the setting adjustment member 32 is capable of
exerting a force on the setting adjustment means 25 that is sufficient to
21816448.1 13
CA 02648899 2008-10-09
Agent Ref: 68877/00016
overcome the force exerted by the resilient body 23 so as to bring the setting
adjustment means 25 into a predetermined position and hold said setting
adjustment means 25 in said predetermined position, opposing the reaction
force exerted by the resilient body 23 on the adjustment means 25.
In the preferred variant shown in the figures, the setting adjustment
means 25 are distinct from the setting adjustment member 32, i.e. the setting
adjustment means 25 and the setting adjustment member 32 are preferably
formed by two respective parts that are distinct and independent of each
other. Nevertheless, it is quite possible for the setting adjustment means 25
and the setting adjustment member 32 to constitute a single part, i.e. for
both
of them to be constituted by single functional means, preferably then
constituted by a single part. Under such circumstances, the adjustment
member 32 might act, for example, directly on the spring 24 to adjust the
compression thereof. Nevertheless, it is preferable, in order to improve the
mechanical interface between the setting means (now formed by the spring
24) and the setting adjustment member 32, to interpose between them
adjustment means 25 that are distinct and independent.
Advantageously, the setting adjustment member 32 includes a second
rotary part. In the example shown in the figures, this second rotary part is
the
same as the first rotary part 28, i.e. the first rotary part 28 and the second
rotary part are both formed by a single rotary control part 28. Below, the
reference 28 is therefore used without distinction to designate the first
rotary
part, the second rotary part, or the rotary control part. Nevertheless, it is
entirely possible, without going beyond the ambit of the invention, for the
first
and second rotary parts to be distinct and independent, without that going
beyond the ambit of the invention.
Advantageously, the second rotary part 28 is provided with a second
ramp 33 designed to engage the slidable abutment 26 forming the setting
adjustment means 25 to as to act during rotation of said second part 28 to
exert said propulsion force that is sufficient to cause the abutment 26 to
slide.
The second ramp 33 projects from the second face 286 of the second
rotary part 28 towards the inside of the appliance 1 and preferably forms a
progressive slope projecting from the surface of the second face 286, the
surface of the first face 28A preferably being plane in the location where the
second ramp 33 is positioned (i.e. in register therewith), so that the valve
remains held at the same altitude (i.e. at an altitude that is substantially
constant) while pressure is being set. Thus, when the second rotary part 28
21816448.1 14
CA 02648899 2008-10-09
Agent Ref: 68877/00016
turns about the axis X-X', the second ramp 33 slides against the cap forming
the abutment 26 and progressively pushes against said cap so as to increase
the pressure setting of the valve 28. Preferably, the second ramp 33
comprises for this purpose a continuously progressive slope 33A projecting
from the second face 28B up to a flat 33B forming a stable bearing surface for
the cap forming the abutment 26. The cap advantageously does not act
directly on the positioning of said valve, which remains at the same altitude
while pressure is being set. It is thus possible to adjust the setting without
acting simultaneously directly on the valve itself.
When the cap rests in this way against the flat 33B of the second ramp
33 (as shown in Figure 7), the spring 24 is held stationary in stable manner
in
a configuration that corresponds to a predetermined setting level.
Preferably, the second ramp 33 is also made up of two individual
ramps extending on either side of the slot.
To summarize, and in particularly preferred manner, the invention
makes use of a rotary control part 28 presenting a first face 28A that bears
against the transmission means 20A and a second face 28B that is opposite
from the first face 28A and that bears against the abutment 26, the first ramp
29 projecting from the first face 28A while the second ramp 33 projects from
the second face 28B, in a direction opposite to that in which the first ramp
29
projects. The face 28A is plane where it is in register with the ramp 33 and
the face 28B is plane where it is in register with the ramp 29. Thus, and in
preferred manner, the rotary movement of the control member 27 lifts the
valve 18 from the orifice 17, into the decompression position, as it passes
over the ramp 29, or holds said valve at a constant altitude, in the setting
position, as it passes over the ramp 33.
Advantageously, the decompression control member 27 is functionally
connected to the setting adjustment member 32 so that while the
decompression control member 27 is moving the settable pressure-regulation
valve 18 so that it opens the orifice 17, the setting adjustment member 32
keeps the setting adjustment means 25 substantially stationary, such that
decompression takes place at a setting that is substantially constant. This
technical measure provides the user with excellent control over the
progressive nature of decompression, excluding any uncontrolled drop in
pressure that would happen as a result of the pressure setting of the valve 18
being reduced as the result of the action of the decompression control
member 27.
21816448.1 15
CA 02648899 2008-10-09
Agent Ref 68877/00016
Preferably, in order to perform this decompression function at a
constant setting, the second face 28B of the control part 28 is substantially
plane where it is in register with the first ramp 29 so as to keep the
abutment
26 stationary in position during rotation of the rotary control part 28, as
shown
in the figures.
The control part 28 may advantageously turn through an angular stroke
that is defined by the size of the slot formed therethrough and providing a
passage for the stem 21. This slot is enlarged to form a mounting opening 34,
e.g. formed close to the flat 29B of the first ramp 29 so as to allow the tail
20
to pass therethrough. Naturally, once the module 5 has been fully assembled,
an abutment (not shown) prevents the tail 20 from dropping into the assembly
hole 34. Opposite from the assembly hole 34, there is provided a first
enlargement 35 (e.g. formed by locally enlarging the slot) formed for the tail
20, said enlargement 35 being positioned in register with the flat 33B of the
second ramp 33.
When the tail 20 is positioned in register with the enlargement 35, that
corresponds to a first setting level (shown in Figure 7) in which the abutment
26 is subjected to the compression action exerted by the second ramp 33. A
second enlargement 36 is advantageously formed in the slot, e.g. halfway
therealong, between the first enlargement 35 and the mounting hole 34. This
second enlargement 36 advantageously corresponds to a second setting level
(shown in Figure 6) in which, in the example shown in the figures, the
abutment 26 is no longer subjected to the compression action of the second
ramp 33. Naturally, it is entirely possible for the second set level to be
obtained while the abutment 26 remains subjected to the action of the second
ramp 33, which ramp then, by virtue of its sloping shape, exerts a
compression force on the abutment 26 that is smaller than the force it exerts
when the tail 20 is in register with the first enlargement 35.
The control part 28 is preferably fastened to a rotary selector 37
mounted to turn relative to the module 5 about the axis X-X'. The selector 37
is provided with a handle 37A enabling the user to cause the part 28 to turn
via an engagement provided by inserting a pin 37B formed integrally with the
selector 37 in a corresponding socket 38 formed in the control part 28.
The selector 37 is also provided with an indicator tab, in this example
coinciding with the handle 37A, that co-operates with stationary visual
markers 39, 40, 41 formed on the module 5 to enable the user to know
immediately the configuration in which the valve 18 is to be found.
21816448.1 16
CA 02648899 2008-10-09
Agent Ref 68877/00016
The marker 39 thus corresponds to selecting a first setting (in which
the tail 20 is positioned in register with the first enlargement 35), the
marker
40 corresponding to a second setting lower than the first (the tail 20 then
being in register with the second enlargement 36), while the marker 41
corresponds to the decompression position (the tail 20 then bearing on and
against the flat 29B of the first ramp 29).
The operation of a cooking appliance 1 of the invention, in the
embodiment shown in Figures 1 to 8, is described below.
The user initially fits the module 5 on the lid 3, by engaging the
threaded shaft 6 into the corresponding orifice formed in the lid 3 and
fastening the module 5 with the help of the retaining nut 8 screwed onto the
threaded shaft 6. In this configuration, the annular gasket 15A bears in
leaktight manner against the outside face 3B of the lid 3, thus putting the
orifice 17 into leaktight communication with the chamber 15 and with the
exhaust duct 16.
The user inserts the food for cooking into the vessel 2, where
necessary with the help of a cooking basket (not shown), itself disposed
within
the vessel 2. Thereafter, the user fits the lid 3 together with its control
module
5 on the vessel 2 and proceeds to lock the appliance 1 with the help of the
jaws 4, with radial movement of the jaws being controlled by the buttons 9 and
10.
Using the rotary selector 37, the user selects one or the other of the
available indexed setting positions, corresponding respectively to the markers
39 and 40 represented by pictograms on the module 5. For example, the user
turns the part 28 by means of the selector 37 so as to bring the tail 20 into
register with the first enlargement 35, thereby acting via the ramp 33 to
press
against the abutment 28, thereby imparting a maximum pressure setting to
the valve 18 (configuration shown in Figure 7).
The appliance 1 is then subjected to heat from a hot plate on which it
stands. The heat given off by the hot plate is transmitted via the bottom 2A
to
the food disposed inside the cooking enclosure formed by assembling the lid
3 onto the vessel 2. Under the effect of this provision of heat, the pressure
that exists inside the enclosure rises. As soon as this pressure becomes
greater than a predetermined level, corresponding to the pressure setting
exerted by the spring, the head 19 and the gasket 19A move away from the
outside face 3B of the lid 3, thereby causing steam to leak to the outside,
and
thus enabling the pressure inside the enclosure to be regulated automatically.
21816448.1 17
CA 02648899 2008-10-09
Agent Ref: 68877/00016
This flow of leakage steam passes firstly through the orifice 17 and then via
the chamber 15 in order to escape finally via the exhaust pipe 16.
The user can at any time change the setting level applied to the valve
18 by acting on the selector 37 to bring the second enlargement 36 into
register with the tail 20. Such an operation has the effect of causing the
interaction between the ramp 33 and the abutment 26 to be reduced
progressively until the abutment 26 comes to bear directly against the second
face 28B, thereby enabling the spring 24 to be relaxed progressively so as to
obtain a second predetermined setting level lower than the previously applied
maximum, first level. The configuration corresponding to this second setting
level is shown more specifically in Figures 5 and 6.
At the end of the cooking cycle, the user can decompress the
appliance 1 by bringing the selector 37 into the indexed decompression
position represented by the pictogram corresponding to the marker 41. Acting
via the first ramp 29, this leads to an axial force being exerted on the valve
18
opposite to and greater than the return force exerted by the spring 24, while
the axial position of the abutment 26 remains unchanged because of the
plane nature of the second face 28B in register with the first ramp 29.
While the setting level remains constant and corresponds to the
second predetermined set level, this axial force exerted by the first ramp 29
then serves to raise the valve 18 to a predetermined height that is sufficient
to
cause the gasket 19A to lose contact with the outside face 3B of the lid 3,
thereby opening the orifice 17. Because of the progressive nature of the
slope of the ramp 29, the user can also control the extent to which the
orifice
17 is opened, thereby progressively adapting the leakage flow rate and
avoiding any dangerous projection. Furthermore, because a single control
part 28 is used for controlling both decompression and pressure setting, the
use is certain not to leave the appliance 1 in its decompression position
inadvertently while an operating pressure is selected.
Thus, in its most advantageous variant, the invention enables the user
to control a multitude of functions finely and independently, while using an
arrangement that is particularly reliable and inexpensive, requiring a minimum
number of parts. Furthermore, the invention makes use of movements that
are simple (pure translation for the pressure-regulation valve 18 and the
abutment 26, pure rotation for the control part 28), without any movement that
is complex and liable to give rise to jamming, such as helical movement
(screwing/unscrewing). In addition, the appliance 1 shown in the figures
21816448.1 18
CA 02648899 2008-10-09
Agent Ref: 68877/00016
makes use of a disposition of the parts in which the chain of design
dimensions is minimized, thereby contributing to a construction that is
robust,
since each of the reference and bearing points for the chain of dimensions
lies
substantially on the axis Y-Y' of the valve 18, thereby minimizing
inaccuracies.
SUSCEPTIBILITY OF INDUSTRIAL APPLICATION
The invention finds industrial application in the design and fabrication
of pressure cooking vessels.
21816448.1 19
