U.S. patent application number 11/918600 was filed with the patent office on 2009-02-12 for refrigerator and method for the operation thereof.
This patent application is currently assigned to BSH Bosch und Siemens Hausgerate GmbH. Invention is credited to Hans Gerd Keller, Matthias Mrzyglod, Michael Neumann.
Application Number | 20090039751 11/918600 |
Document ID | / |
Family ID | 36579975 |
Filed Date | 2009-02-12 |
United States Patent
Application |
20090039751 |
Kind Code |
A1 |
Keller; Hans Gerd ; et
al. |
February 12, 2009 |
Refrigerator and method for the operation thereof
Abstract
A method for operating a refrigerator having two movably
connected housing parts, a frame and a door which jointly delimit a
heat-insulated interior, as well as a seal that is fastened to a
first of the housing parts and contacts the other of the housing
parts in an airtight manner in the closed position of both housing
parts. The method includes a step in which the airtight contact
between the seal and the second housing part is prevented for a
specific period of time along a section of the seal while the
sealing contact between the seal and the second housing part is
subsequently restored along said section of the seal in a step. The
invention also relates to a refrigerator for carrying out the
method.
Inventors: |
Keller; Hans Gerd; (Giengen,
DE) ; Mrzyglod; Matthias; (Ulm, DE) ; Neumann;
Michael; (Munchen (L/Chuzhou), DE) |
Correspondence
Address: |
BSH HOME APPLIANCES CORPORATION;INTELLECTUAL PROPERTY DEPARTMENT
100 BOSCH BOULEVARD
NEW BERN
NC
28562
US
|
Assignee: |
BSH Bosch und Siemens Hausgerate
GmbH
Munchen
DE
|
Family ID: |
36579975 |
Appl. No.: |
11/918600 |
Filed: |
March 30, 2006 |
PCT Filed: |
March 30, 2006 |
PCT NO: |
PCT/EP2006/061160 |
371 Date: |
October 15, 2007 |
Current U.S.
Class: |
312/405 |
Current CPC
Class: |
F25D 23/087 20130101;
F25D 17/047 20130101 |
Class at
Publication: |
312/405 |
International
Class: |
A47B 96/00 20060101
A47B096/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 10, 2005 |
DE |
10 2005 021 587.4 |
Claims
1-12. (canceled)
13. A method for operating a refrigerator, the method comprising:
a.) on a refrigerator having two movably connected housing parts, a
carcass, and a door, all of which together delimit a heat-insulated
interior space, and a seal member fastened to a first one of the
housing parts and operable to establish an airtight seal between
the first housing part and the other housing part when the two
housing parts are in a closed disposition, the step of preventing,
following a closing of the door, the establishment of the airtight
seal for a predetermined time along a predetermined extent of the
airtight seal path while the two housing parts are in a closed
disposition; and b.) after the step of preventing the establishment
of the airtight seal for a predetermined time along a predetermined
extent of the airtight seal path, the step of restoring the
airtight seal between the first housing part and the other housing
part along the predetermined extent of the airtight seal path,
whereupon the airtight seal is established along the full extent of
the airtight seal path.
14. The method as claimed in claim 13, wherein the predetermined
time during which the airtight seal is prevented in the step of
preventing the establishment of the airtight seal for a
predetermined time along a predetermined extent of the airtight
seal path is a time of approximately five seconds to one
minute.
15. The method as claimed in claim 13, wherein, during the step of
preventing the establishment of the airtight seal for a
predetermined time along a predetermined extent of the airtight
seal path, the seal member is pressed away from a contact surface
for the seal member on the second housing part by means of a
lifting element.
16. The method as claimed in claim 15, wherein the lifting element
is formed at least partly from a temperature-dependent deformable
material and the step of restoring the airtight seal between the
first housing part and the other housing part along the
predetermined extent of the airtight seal path includes at least
one of heating the lifting element and cooling the lifting element
to effect lifting of the seal member.
17. The method as claimed in claim 16, wherein the step of
restoring the airtight seal between the first housing part and the
other housing part along the predetermined extent of the airtight
seal path includes heating the lifting element via switching on a
heating device for heating the lifting element upon an opening of
the door.
18. The method as claimed in claim 17, wherein the step of
restoring the airtight seal between the first housing part and the
other housing part along the predetermined extent of the airtight
seal path including heating the lifting element further includes
switching off the heating device upon a closing of the door.
19. A refrigerator comprising: a.) two movably connected housing
parts; b.) a carcass; c.) a door, the housing parts, the carcass,
and door together delimiting a heat-insulated interior space; d.) a
seal member fastened to a first one of the housing parts and
operable to establish an airtight seal between the first housing
part and the other housing part when the two housing parts are in a
closed disposition; e.) a lifting element movable between a first
position in which it permits an impermeable contact between the
seal member and the second housing part and a second position in
which, in a closed position of the housing parts, the lifting
element lifts the seal member away from the second housing part
along part of its length; f.) a drive unit for the lifting element;
and g.) a control device for controlling, in response to a signal
indicating a respective opening or closing operation of the door,
the drive unit to move the lifting element from the first position
of the lifting element in which it permits an impermeable contact
between the seal member and the second housing part to the second
position of the lifting element to thereby effect lifting of the
seal member.
20. The refrigerator as claimed in claim 19, wherein the lifting
element is arranged in a recess of the second housing part in its
first position and rises at least partly above a contact surface
for the seal member on the second housing part in its second
position.
21. The refrigerator as claimed in claim 19, wherein the control
device includes a switch that is changed over upon an opening or
closing of the door and triggers the drive unit for the lifting
element.
22. The refrigerator as claimed in claim 19, wherein the lifting
element is formed at least partly from a temperature-dependent
deformable material, in particular a bimetal or a shape memory
alloy.
23. The refrigerator as claimed in claim 19, wherein the drive unit
for the lifting element includes a heating device, in particular a
PTC heating element.
24. The refrigerator as claimed in claim 19, wherein the drive unit
for the lifting element includes one of a mechanical unit,
electrical unit, and a magnetic drive unit.
Description
[0001] The present invention relates to a refrigerator and a method
for operating same. The refrigerator encompasses two movably
connected housing parts, a carcass and a door, which jointly
delimit a heat-insulated interior space, and also a seal fastened
to a first of the housing parts which seal makes airtight contact
with the other, second housing part in the closed position of the
two housing parts. For the purposes of pressure equalization
between an external atmosphere surrounding the refrigerator and the
interior space of the refrigerator, the airtight contact between
the seal and the second housing part is prevented for a period
along part of the seal length in the closed position of the two
housing parts in a method step (a). The invention also relates to a
refrigerator for carrying out the method. This encompasses a
lifting element, which allows an impermeable contact between the
seal and the second housing part in a first position and can be
transposed into a second position in which it lifts the seal along
part of its length away from the second housing part in the closed
position of the two housing parts for the purposes of enabling
pressure equalization between the interior space and an external
atmosphere surrounding the refrigerator.
[0002] An operating method of this type and refrigerator is known
from DE 36 02 200 A1. In this case, a lifting element 14, 15
realized on a handle 13 engages in a fold 8 of a magnetic door seal
4. Pulling on the handle 13 lifts the magnetic door seal 4 along
part of its length away from a contact margin on the carcass of the
refrigerator, with the result that a flow path for air is created.
A partial vacuum in the refrigerator, which can arise, for example,
if warm air enters the interior space of the appliance upon the
opening of the door and cools in there following a closing of the
door, should therefore be dissipated immediately prior to the
actual opening of the door. A partial vacuum prevailing in the
interior space of the refrigerator is disadvantageous since it
makes it considerably more difficult to open the door. Since the
user has to displace the handle 13 over a specific distance for the
purposes of operating the lifting element 14, 15 and the pressure
equalization between the environment and the interior space of the
refrigerator needs a certain amount of time, the actual opening
operation of the door is delayed.
[0003] The object of the present invention is to provide an
operating method for a refrigerator and a refrigerator for carrying
out the method, in which the build-up of a partial vacuum, which
hinders opening of the door, in the interior space of the
refrigerator is prevented.
[0004] The object is achieved with the aid of a method as claimed
in claim 1 and a refrigerator as claimed in claim 7. The dependent
claims relate to preferred configurations.
[0005] Accordingly, a method is provided for operating a
refrigerator which has two movably connected housing parts, a
carcass and a door, which jointly delimit a heat-insulated interior
space, and also a seal fastened to a first of the housing parts
which seal makes airtight contact with the other, second housing
part in the closed position of the two housing parts, the method
encompassing a step (a) in which the airtight contact between the
seal and the second housing part is prevented for a period along
part of the seal length in the closed position of the two housing
parts. According to the invention, the step (a) is effected in
temporal conjunction with a closing of the door, preferably
immediately after its closing, the sealing contact between the seal
and the second housing part along said part of the seal length
being restored subsequently in a step (b).
[0006] An air path between the environment of the refrigerator and
the interior space of the refrigerator is therefore created
following a closing of the door or preferably maintained upon the
closing of the door so that air can flow in from the environment
into the interior space of the refrigerator for pressure
equalization. This prevents the build-up of a partial vacuum which
would hinder a renewed opening of the door shortly after the
closing. To open the door, the user only has to overcome the
closing force of the magnetic seal used as a rule. To keep cold
losses and therefore energy losses as low as possible, the sealing
contact between the seal and the second housing part is restored as
soon as a pressure equalization has essentially taken place. The
time required for this, typically of about five seconds to a
minute, is easy to determine experimentally. By particular
preference, the airtight contact between the seal and the second
housing part after a closing of the door is prevented for about
five seconds to 25 seconds along part of the seal length in method
step (a).
[0007] A refrigerator for carrying out the method described in the
foregoing is also provided in accordance with claim 7. This
encompasses a lifting element which allows an airtight contact
between the seal and the second housing part in a first position
and can be transposed into a second position in which it lifts the
seal along part of its length away from the second housing part in
the closed position of the two housing parts for the purposes of
enabling a pressure equalization between the interior space and an
external atmosphere surrounding the refrigerator. According to the
invention, the refrigerator has a drive unit for the lifting
element and also a control device which, after capturing an
operation of the door, triggers the drive unit of the lifting
element for the purposes of lifting the seal. The force necessary
for lifting the seal does not therefore have to be applied by a
user of the refrigerator and can be effected irrespective of an
operation of a door handle.
[0008] Preferably, the seal is pressed away from a contact surface
for the seal on the second housing part by means of the lifting
element. The lifting element therefore exerts a pressure on the
seal for the purposes of lifting the seal away from its contact
surface on the second housing part.
[0009] Preferably, the lifting element is arranged in a recess of
the second housing part in its first position and rises at least
partly above the contact surface for the seal on the second housing
part in its second position. In the recess, the lifting element is
protected from external influences in an advantageous manner. Due
to the sunken arrangement in the recess, the lifting element is not
visually conspicuous on the refrigerator so that this also
represents an aesthetic solution which is also inexpensive due to
the simple construction.
[0010] The lifting element is preferably formed at least partly
from a temperature-dependent deformable material, for example a
bimetal or a shape memory alloy. Heating or cooling changes the
form or shape of these materials. This change of form or shape can
then be utilized in such a way that the lifting element allows an
impermeable contact between the seal and the second housing part in
a first form and lifts the seal away from the second housing part
along part of its seal length in a second form into which it can be
transposed by means of heating or cooling. In this respect the
first form corresponds to the first position of the lifting element
referred to in the foregoing and the second form the second
position of the lifting element stated in the foregoing. The
lifting element therefore just needs to be cooled or heated to lift
the seal.
[0011] Preferably, a change of form of the lifting element from its
first form into its second is caused by heating of the lifting
element. The refrigerator therefore preferably has, as the drive
unit for the lifting element, a heating device such as a PTC
heating element with the aid of which short heating times can be
implemented. Alternatively, it is also conceivable, however, to
heat the lifting element by means of ambient air which flows past
the lifting element upon the opening of the door. In this case, it
is then necessary for the lifting element to possess its second
form at normal room temperature, in particular in the range from
roughly 15.degree. C. to roughly 35.degree. C. It would also be
conceivable for the heating device to be connected to a frame
heating system of the refrigerator, which is present as a rule, so
that the frame heating system is utilized as the heat source for
heating the lifting element.
[0012] Alternatively, the lifting element can also be realized as a
simple actuator made from, for example, a non-temperature-dependent
deformable material which is brought from its first position into
its second or vice versa by means of a mechanical, electrical or
magnetic drive unit. The lifting element can be realized in the
form of a linear actuator, for example.
[0013] Preferably, the control device encompasses a switch which,
upon an opening or closing of the door, i.e. a movement of the door
relative to the carcass of the refrigerator, is changed over and
triggers the drive unit for the lifting element. This ensures that
after every time that the door stands open, a pressure equalization
operation takes place by means of lifting of the seal so that a
partial vacuum, which hinders a subsequent opening of the door,
cannot be formed in the interior space of the refrigerator.
Preferably, the switch comprises the door switch, which is present
in every refrigerator as a rule, for operating an interior space
illumination. But it may also comprise a door switch that is
separate from the interior space illumination.
[0014] Preferably, the drive unit for the lifting element, that is
to say the heating device for heating the lifting element in the
case of the lifting element formed at least partly from
temperature-dependent deformable material, is switched on upon an
opening of the door. As a result of this, the lifting element takes
up its second form or second position in which it protrudes above
the contact surface for the seal on the second housing part. If the
door is then closed, the lifting element holds the seal lifted,
along part of its length, away from the second housing part and
releases an air path for air flowing into the interior space with
the result that the build-up of a partial vacuum, which hinders an
opening of the door, in the interior space of the refrigerator is
prevented. Upon a closing of the door, the heating device is
preferably switched off. The lifting element cools down slowly but
remains in its second form for a certain period after the closing
of the door before it reverts to its first form again after the
cooling. The pressure equalization can take place during this
period.
[0015] In the case of the lifting element realized in the form of a
simple actuator, the possibility exists, for the purposes of
returning the lifting element from its second position to its
first, of providing a timer which is activated after a closing of
the door and triggers the drive unit of the lifting element after
the expiry of a predetermined period of time and brings about a
return of the lifting element to its first position.
[0016] The inventive refrigerator may comprise a refrigerator or
frozen food storage appliance.
[0017] Developments and advantages of the present invention are
explained in the following on the basis of embodiments of the
present invention. In this respect, the diagrams show:
[0018] FIG. 1 A schematic section through a first embodiment of a
refrigerator for carrying out the inventive method;
[0019] FIG. 2 A control scheme;
[0020] FIG. 3 A detailed section through a lower area of the
carcass 1 and the door 2 of the refrigerator in FIG. 1 in the
closed condition of the door 2 with the seal 4 lying against the
carcass 1;
[0021] FIG. 4 The same section as FIG. 2, the lifting element 7
lifting the seal 4 along part of its length away from the contact
surface 5 on the carcass 1;
[0022] FIG. 5 A schematic perspective sectional view through the
arrangement shown in FIG. 2;
[0023] FIG. 6 A cross-section through the arrangement shown in FIG.
4 in a plane A-A;
[0024] FIG. 7 A longitudinal section through the arrangement shown
in FIG. 2 in a plane B-B;
[0025] FIG. 8 A perspective side view corresponding to FIG. 4, the
lifting element 7 lifting the seal 4 along part of its length away
from the contact surface 5 on the carcass 1;
[0026] FIG. 9 A perspective sectional view of the arrangement of
FIG. 7 in a space C-C-C;
[0027] FIG. 10 A longitudinal section through the arrangement shown
in FIG. 7 in a plane B-B;
[0028] FIG. 11 A sectional view corresponding to FIG. 3 through a
refrigerator in accordance with a second embodiment for carrying
out the inventive method;
[0029] FIG. 12 A sectional view analogous to FIG. 4, the lifting
element 7 lifting the seal 4 along part of its length away from the
contact surface 5 on the carcass 1.
[0030] FIG. 1 shows, in highly schematic form, a refrigerator with
a carcass 1 and a door 2 pivoting on same which jointly delimit an
interior space 3 and also a magnetic seal 4 which is fastened all
round the inner side of the door 2 and adheres to a contact surface
5 on the front side of the carcass 1 in an airtight manner by means
of magnetic force so that a partial vacuum could form in its
interior space 3 if, after the penetration of warm air into the
interior space 3, the door 2 were closed in an airtight manner and
the air cools down in the interior space 3.
[0031] In the heat-insulating wall 6 on the bottom of the carcass
1, a lifting element 7 is arranged in a recess 8. The lifting
element 7 is formed in a single piece from a temperature-dependent
deformable material such as a shape memory alloy or a bimetal.
Underneath the lifting element 7, a heating device 10, in this case
a PTC heating element 10, is arranged in the recess 8, which
heating device is used for heating the lifting element 7.
[0032] FIG. 3 shows the lower edge area of the carcass 1 and the
door 2 in an enlarged section. The carcass 1 is constructed from an
external container 11 formed out of sheet metal and a deep-drawn
plastic internal container 12, which enclose a cavity 9 filled with
insulating material. To the front side of the refrigerator, the
external container 11 forms the frame-shaped contact surface 5 for
the magnetic seal 4. Just like the carcass 1, the door 2 of the
refrigerator is constructed from an external wall 13 formed out of
sheet metal and a deep-drawn plastic internal wall 14, which are
connected to each other at their vertical edges and enclose a
cavity 15 filled with insulating material which is closed off at
the top and bottom by means of profile strips 16 made of
plastic.
[0033] A groove 17 is formed in an edge area of the internal wall
14 in which a head section, which is provided with a retaining
hook, of the magnetic seal 4 is latched. The magnetic seal 4
possesses a plurality of elongated chambers which lend it
flexibility and of which one chamber, which is designated with the
reference number 18, is filled with a magnetic material which holds
a sealing surface of the magnetic seal 4 pressed against the
contact surface 5 realized out of sheet metal.
[0034] In FIG. 3, the lifting element 7 possesses a first, inactive
position in which it is completely accommodated in the recess 8 of
the carcass 1 and is flush with the contact surface 5 or falls back
slightly behind same and therefore allows an airtight contact
between the magnetic seal 4 and the contact surface 5 on the
carcass 1.
[0035] FIG. 4 shows the same sectional view as FIG. 3 immediately,
for example 1 second, after a closing of the door 2. The lifting
element 7 is located in an active second position in which it rises
above the contact surface 5 of the magnetic seal 4 out of the
recess 8 and presses the chamber 18, which is filled with the
magnetic material, of the magnetic seal 4 away from the carcass 1.
Air can flow into the interior space 3 of the refrigerator through
the gap between the carcass 1 and the magnetic seal 4 thus arising
in front of the lifting element 7 and shown in FIG. 8, with the
result that the build-up of a partial vacuum, which hinders a
renewed opening of the door 2, in the interior space 3 of the
refrigerator is prevented. After a specific period of time after
the closing of the door 2, the lifting element 7 is brought into
its first inactive position shown in FIG. 3 again so that the
magnetic seal 4 again lies against the carcass 1 in an airtight
manner.
[0036] The change of position of the lifting element 7 from its
first position shown in FIG. 3 to its second position shown in FIG.
4 is achieved by heating the lifting element 7, formed in one piece
from a temperature-dependent deformable material, with the aid of
the heating element 10. After deactivation of the heating element
10 and cooling by means of air flowing past it, the lifting element
7 reverts to its first position. The construction of the lifting
element 7 and its mode of functioning are explained in detail on
the basis of FIGS. 5 to 10 at a later point.
[0037] As shown in FIG. 2, the heating element 10 is triggered with
a switch 31 which is switched by means of an opening and closing of
the door 2. This can trigger an interior space illumination, which
is not shown, of the refrigerator. Upon the opening of the door 2
of the refrigerator, the switch 31 is operated and the heating
element 10 switched on for the duration of the door opening. The
heating element 10 brings about a heating of the lifting element 7
with the result that this is transposed from its first form shown
in FIG. 3 into the second form shown in FIG. 4 in which, in the
case of the door being open, it rises partly above the contact
surface 5 of the magnetic seal 4 out of the recess 8. If the door 2
is then closed, the lifting element 7 lifts the magnetic seal 4, as
shown in FIG. 4, along part of its length away from the contact
surface 5. The build-up of a partial vacuum, which hinders a
subsequent opening of the door, in the refrigerator is prevented by
air flowing in.
[0038] Upon the closing of the door 2, the switch 31 is operated
once again and the heating element 10 switched off. It cools down
together with the lifting element 7 which then, after a specific
period of time, reverts to its first form in which it allows an
impermeable contact between the previously lifted part of the
magnetic seal 4 and the contact surface 5. The lifting element 7 or
the heating element 10 are designed in such a way that the magnetic
seal 4 remains open for a period of time of roughly 5 seconds to a
minute after the closing of the door 2, that is to say a period of
time in which a pressure equalization has essentially taken place.
This prevents a partial vacuum which hinders the opening of the
refrigerator door 2. In the case of a subsequent opening of the
door 2, the user just has to overcome the magnetic force which acts
between the magnetic material and the metal contact surface 5.
[0039] By way of divergence from the arrangement shown in FIG. 1,
in which the lifting element 7 is located at the lower,
horizontally aligned edge of the carcass 1, it is also possible to
arrange the lifting element 7 on one of the two lateral, vertically
aligned edges of the carcass 1. As an alternative to a fastening of
the magnetic seal 4 to the door 2, it is also conceivable to fasten
the magnetic seal 4 to the carcass 1 of the refrigerator. In this
case, the lifting element 7 would then be arranged in a recess of
the door 2.
[0040] The lifting element 7 is now described in detail in terms of
its construction and its mode of functioning on the basis of the
following schematic FIGS. 5 to 10.
[0041] FIGS. 5, 6, and 7 show schematic sectional views of the
carcass 1, the door 2, and the lifting element 7 in its first form
in the case of a closed door 2. In its first form, the lifting
element 7 is realized in the shape of a leaf-like strip 7 which is
completely accommodated in the rectangular-shaped recess 8 of the
carcass 1 and ends flush with the contact surface 5 of the magnetic
seal 4. It also completely fills the recess 8 in its base area.
This prevents foreign bodies such as dirt-particles being able to
get into the recess 8. The lifting element 7 is aligned parallel to
the magnetic seal 4 and therefore extends along part of its length
in its longitudinal direction.
[0042] Transverse to the magnetic seal 4, the lifting element 7
only extends along part of its width but over the entire width of
the chamber 18 which contains a magnetic material. As a result, it
is not the overcoming of a magnetic force but just a partial
deformation of the magnetic seal 4 that is required to lift the
magnetic seal 4 in the area of the lifting element 7 in the event
that the magnetic seal 4 were in contact with the contact surface 5
briefly after a closing of the door 2. The lifting element 7 and
therefore also the recess 8 extend beyond the edge of the magnetic
seal 4 on the sides of the chamber 18 with the result that the
lifting element 7 has a freestanding section 20 which is not
covered by the magnetic seal 4 in the closed condition of the door
2. This enables a convective heat exchange between the lifting
element 7 and the external atmosphere surrounding the refrigerator
or the air in the interior space 3 of the refrigerator and
therefore a rapid cooling of the heated lifting element 4. By way
of divergence from the arrangement shown in FIGS. 1, 3, and 4, it
is also possible for the lifting element 7 to be partly not covered
by the magnetic seal 4 toward the interior space 3 of the
refrigerator, i.e. the section 20 of the lifting element 7 is in
contact with the air in the interior space 3 of the refrigerator.
This embodiment is also encompassed by FIGS. 5 and 6. In this case,
the interior space 3 would then be located to the right of the
magnetic seal 4.
[0043] FIG. 7 shows a longitudinal section through the arrangement
in FIGS. 5 and 6. The lifting element 7 has a first end 22 which is
fixed to the carcass 1 and also a second end 23 which is freely
movable. Underneath the first end 22 of the lifting element 7, the
heating element 10 is arranged in the recess 8, covered by the
lifting element 7. It is flush with the first end 22 of the lifting
element 7 and only extends along part of its length so that a
cavity 24 remains free in the recess 8 underneath the lifting
element 7. As can be seen from FIG. 6, the heating element 10 also
only extends along part of the width of the lifting element 7.
[0044] FIGS. 8 to 10 show sectional views of the arrangement in
FIGS. 5 to 7, the lifting element 7 being in its second form due to
heating by means of the heating element 10. In this second form,
the strip-shaped lifting element 7 possesses a curved shape in
which its second, free end 23 protrudes beyond the carcass 1 or the
contact surface 5 of the magnetic seal 4 on the carcass 1, touches
the magnetic seal 4, exerts a pressure against said seal, and holds
it lifted along part of its length away from the contact surface 5.
Air can flow through the gap thus present in front of the first end
22 of the lifting element 7 for the purposes of pressure
equalization between the interior space 3 of the refrigerator and
the external atmosphere surrounding the refrigerator in the case of
a closed door 2 with the result that, as already described in the
foregoing with reference to FIGS. 1 to 4, the build-up of a partial
vacuum, which hinders an opening of the door 2, in the interior
space 3 of the refrigerator can be prevented.
[0045] As FIG. 9 or in particular FIG. 10 shows, the lifting
element 7 is only curved in its second form to the extent that a
face side 25 terminating the lifting element 7 toward the free end
23 remains at least partly sunk into the recess 8. This ensures
that no foreign substances such as dirt particles can get into the
recess 8 and block the lifting element 7.
[0046] Alongside the embodiment described with reference to FIGS. 1
to 10 with an electric heating device 10, an embodiment is also
conceivable as an alternative in which a heating of the lifting
element 7 is effected by means of warm ambient air which flows over
the lifting element 7 upon the opening of the door 2 with the
result that said lifting element then takes on its second form.
Just the lifting element 7 would then have to be arranged in the
recess 8. After the closing of the door 2, the deformed lifting
element 7 would cool down. Until its reversion to its first form,
the lifting element 7 would lift the magnetic seal 4 in the manner
already described and therefore prevent the build-up of a partial
vacuum, which hinders the opening of the door 2, in the interior
space 3. In this embodiment, the lifting element would then have to
be in thermal contact with the interior space 3 or be cooled with
the aid of a refrigerant flow of the refrigerator in order for a
reversion of the lifting element 7 to its first form to be
possible.
[0047] FIGS. 11 and 12 show a second embodiment of a refrigerator
for carrying out the inventive method. The views shown correspond
to those in FIGS. 3 and 4 in each case. The refrigerator has a coil
40 in a recess 8 in the lower edge area of the carcass 1 through
the opening of which, in the longitudinal direction of the coil 40,
a piston 41 is mounted in a movable manner. On the end of the
piston 37 turned toward the door 2, there is a lifting element 37
which extends along part of the length and width of the magnetic
seal 4, matching the lifting element 7 of the first embodiment
shown in FIG. 3, in the closed condition of the door 2.
[0048] FIG. 11 shows the lifting element 37 in a first position in
which it is completely accommodated in the recess 8 in the case of
a closed door 2 and ends flush with the contact surface 5 on the
carcass 1 and therefore allows an airtight contact between the
magnetic seal 4 and the contact surface 5 on the carcass 1.
[0049] FIG. 12 shows the arrangement in FIG. 11 shortly, for
example 1 second, after a closing of the door 2. The lifting
element 37 is located in a second, advanced position in which it
lifts the magnetic seal 4 away from the contact surface 5 along
part of the seal length and thus prevents an airtight contact
between the magnetic seal 4 and the contact surface 5 along this
part of the length. This position is reached by applying a voltage
to the coil 40 with the result that the piston 41 and therefore the
lifting element 37 are moved to the right. Air enters the interior
space 3 of the refrigerator through the gap, which is present to
the side of the lifting element 37, between the carcass 1 and the
magnetic seal 4 and prevents the build-up of a partial vacuum,
which hinders an opening of the door 2, in the interior space 3 in
the manner already described with reference to FIG. 4. After a
certain period of time, the coil 40 is switched off with the result
that the lifting element 37 returns to its first position again and
the magnetic seal 4, as shown in FIG. 11, has an airtight contact
with the contact surface 5 on the carcass 1 again.
[0050] FIG. 2 shows a scheme for controlling the lifting element
37. The refrigerator has a switch 31 which captures an operation of
the door 2. The switch 31 is connected to the coil 40 on the one
hand and to a timer 32 on the other. Upon a closing of the door 2,
the switch 31 is operated with the result that it then activates
the coil 40 which brings the lifting element 37 from its first
position into its second by means of the piston 41. In the case of
a closed door 2, air can then flow into the interior space 3 for
the purposes of pressure equalization immediately after a closing
of the door 2.
[0051] The closing of the door 2 also activates, by way of the
switch 31, a timer 32 which deactivates the coil 40 after the
expiry of a predetermined period of time with the result that the
lifting element 37 reverts to its first position again and the
magnetic seal 4 makes airtight contact with the contact surface 5.
The period of time over which a pressure equalization should be
made possible between the interior space 3 and the environment of
the refrigerator after a closing of the door can therefore be
established precisely. Usually, time periods of 5 seconds to a
minute are specified.
[0052] By way of divergence from the control system described in
the foregoing, it is also possible to bring the lifting element 37
into its second position as early as upon an opening of the door 2
so that the lifting element 37 already takes up its second position
in the case of an open door 2, i.e. prior to the subsequent closing
of the door 2. This ensures that air can flow into the interior
space 3 immediately after a closing of the door 2 and therefore no
time delays of any kind occur which, even if only briefly after a
closing of the door 2, could cause a partial vacuum to arise. In
this control variant also, the timer 32 is not triggered until a
closing of the door 2 to ensure that the magnetic seal 4 remains
open for a predetermined period of time after the closing of the
door 2.
* * * * *