U.S. patent application number 12/724664 was filed with the patent office on 2010-09-23 for method for controlling a cooking point of a gas oven and device.
This patent application is currently assigned to E.G.O. Elektro-Geraetebau GmbH. Invention is credited to Martin BAIER.
Application Number | 20100239987 12/724664 |
Document ID | / |
Family ID | 42331073 |
Filed Date | 2010-09-23 |
United States Patent
Application |
20100239987 |
Kind Code |
A1 |
BAIER; Martin |
September 23, 2010 |
METHOD FOR CONTROLLING A COOKING POINT OF A GAS OVEN AND DEVICE
Abstract
In one embodiment, a method for operating a cooking point with a
gas burner of a gas hob is disclosed in which pan detection is
provided for switching off the gas burner when the pan is removed,
wherein the pan detection unit can detect the re-placement of a
removed pan onto the cooking point and then cause a further
operation of the gas burner by igniting the gas burner. When the
gas burner is ignited after re-placement of the pan, a power level
originally set for the gas burner is only achieved after a time
delay, thereby preventing any injury to the user.
Inventors: |
BAIER; Martin; (Ettlingen,
DE) |
Correspondence
Address: |
ALSTON & BIRD LLP
BANK OF AMERICA PLAZA, 101 SOUTH TRYON STREET, SUITE 4000
CHARLOTTE
NC
28280-4000
US
|
Assignee: |
E.G.O. Elektro-Geraetebau
GmbH
|
Family ID: |
42331073 |
Appl. No.: |
12/724664 |
Filed: |
March 16, 2010 |
Current U.S.
Class: |
431/6 ;
126/39E |
Current CPC
Class: |
F24C 3/126 20130101 |
Class at
Publication: |
431/6 ;
126/39.E |
International
Class: |
F23N 5/00 20060101
F23N005/00; F24C 3/12 20060101 F24C003/12 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 17, 2009 |
DE |
10 2009 014 570.2 |
Claims
1. A method for operating a cooking point with a gas burner of a
gas hob comprising: switching off the gas burner by a pan detection
unit by switching off the gas burner by closing a corresponding gas
valve when a pan is detected initially at the cooking point and
then detected as being removed at the cooking point; detecting by
the pan detection unit when a removed pan is re-placed onto the
cooking point; and causing a renewed operation of the gas burner by
igniting the gas burner by opening the gas valve, wherein, when the
gas burner is ignited after the pan is placed on said cooking point
again, wherein the set power level originally set for the gas
burner only takes place to the full extent with a delay.
2. The method as claimed in claim 1, wherein the delay is half a
second to five seconds.
3. The method as claimed in claim 1, wherein the pan detection unit
detects immediately when said pan is placed on again and only
re-ignites the gas burner again after the time delay.
4. The method as claimed in claim 3, wherein said re-ignition of
the gas burner after the delay takes place with the power level
previously set.
5. The method as claimed in claim 1, wherein the gas burner is
ignited immediately when said pan is placed on again, or
immediately after detection of said pan occurs by the pan detection
unit, with a power level which lies below the power level
previously set, the power level then being increased up to the
power level previously set over the time period of the delay.
6. The method as claimed in claim 5, wherein the gas burner is
ignited with a power level in the range of the minimum power
required for the ignition of the gas burner and followed by
increasing the power level of the gas burner.
7. The method as claimed in claim 1, wherein removal of the pan
from the cooking point is optically indicated.
8. The method as claimed in claim 7, wherein the removal of the pan
is optically indicated by an illumination source.
9. The method as claimed in claim 1, wherein a signal is output
shortly before re-ignition of the gas burner.
10. The method as claimed in claim 1, wherein the signal is an
acoustic signal.
11. The method as claimed in claim 1, wherein, after a maximum time
is exceeded, the power level setting is cancelled and operation of
the cooking point when the pan is replaced does not take place
automatically but wherein a power level is manually set.
12. The method as claimed in claim 11, wherein the power level is
set by manually resetting the power level to zero and subsequently
increasing the power.
13. The method as claimed in claim 11, wherein the maximum time is
three minutes to fifteen minutes.
14. The method as claimed in claim 1, wherein slow turning-off with
a turning-off time of a few seconds is provided for switching off
the cooking point by turning off the gas burner.
15. The method as claimed in claim 14, wherein the turning off
takes place with one or more of an optical or acoustic indication
taking place at the same time.
16. An apparatus for operating a cooking point of a gas burner of a
gas hob comprising: a pan detection unit for detecting the presence
of a pan on said cooking point; a gas valve configured to control
the flow of gas provided to said gas burner of said cooking point;
and a controller configured to receive a first signal from said pan
detection unit indicating the presence of said pan, said controller
configured to close said gas valve from a set value when removal of
said pan is determined from a second signal received from said pan
detection unit, said controller configured to open said gas valve
when a third signal is received from said pan detection unit
indicating replacement of said pan onto the cooking point, wherein
said gas valve is opened to said set value after a time delay.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to German Application
Number 10 2009 014 570.2, filed on Mar. 17, 2009, the contents of
which are incorporated by reference for all that it teaches.
FIELD OF THE INVENTION
[0002] The invention relates to a method for operating a gas burner
at a cooking point, as used in a gas hob. Similarly, the invention
relates to a corresponding device.
BACKGROUND OF THE INVENTION
[0003] There are known hobs with pan detection at a cooking point,
the pan detection detecting whether a pan has been placed on or
removed. With the removal of the pan, the cooking point is switched
off, but a power level (i.e., gas output level) that has been set
continues to be maintained. If a pan is then placed on again, the
burner ignites immediately and, on account of the pressure
conditions in the gas system and the delay of the igniting process,
a briefly larger gas flame may occur, even reaching to beyond the
handles of the pan. The gas flame will at least be of the size of
the level that has been set, possibly even larger because of the
briefly larger flame. The user must therefore quickly remove
his/her hands from the handles of the pan in order not to be burned
by the flame.
[0004] One aspect of the invention addresses the problem of
providing a method mentioned at the beginning and a corresponding
device by which disadvantages of the prior art can be overcome and,
in particular, provides more convenient operation of a cooking
point with a gas burner with reduced risk of injury.
SUMMARY
[0005] This problem is solved by a method and device with the
features as claimed herein. Advantageous and preferred refinements
of the invention are the subject of the further claims and are
explained in more detail below. The wording of the claims is
incorporated in the description by express reference.
[0006] It is provided that, as described above, at the cooking
point there is a pan detection, by means of which the gas burner is
switched off or a corresponding gas valve on the gas burner is
closed when the pan is removed or when the pan detection
establishes this. For this purpose, the pan detection may
advantageously be formed in the customary way that is known in
principle, with capacitive, optical or mechanical systems being
suitable in particular. Furthermore, the pan detection together
with a control of the cooking point or the gas burner or the gas
valve thereof, in particular together with an ignition device for
the flame, brings about the effect that the pan detection detects
when a pan that has previously been removed is re-placed onto the
cooking point. It then reactivates the gas burner by igniting the
gas burner and/or opening the gas valve, in order that the cooking
process is therefore continued as it were of its own accord after
the pan is placed on again.
[0007] According to one aspect of the invention, when the gas
burner is ignited, that is to say when the pan has been placed on
again, the originally set operation of the gas burner or a power
level originally set for the gas burner, only takes place or is
reached to the full extent after a certain time delay. A user
therefore then has time, at least the time of this delay, to remove
his/her hands from the pan again, and in this way the risk of
burning is reduced or eliminated.
[0008] Said delay may advantageously be a few seconds, for example
half a second to three or even five seconds. For instance, one to
two seconds have proven to be advantageous, in order indeed to
allow sufficient time on the one hand for the hands to be removed
from the pan and on the other hand for a user to see relatively
quickly that the cooking point is in operation again, or in turn in
order that the cooking process is also not interrupted
unnecessarily long.
[0009] According to a one embodiment of the invention, it is
possible that the pan detection detects the re-placed pan
immediately or only with minimal delay, but the gas burner only
ignites at all after said delay of a few seconds. This therefore
means that the ignition of the gas burner waits for a short time
after detection of the re-placed pan in order that the user can
remove his/her hands from the pan. Only after the time delay is the
gas burner ignited again. This may take place with a lower power
level than that previously set or used. Since, however, a certain
time is already available to remove the hands from the pan,
re-ignition of the gas burner after the delay may also take place
right away with the full power level previously set.
[0010] In another embodiment of the invention, the pan detection
may likewise detect the re-placement of the pan immediately or with
minimal delay and also ignite the gas burner immediately or as soon
as possible. However, this ignition of the gas burner takes place
with a power level which, though high enough that the gas burner
reliably ignites, is at the same time well below the power level
previously set. This immediate ignition advantageously takes place
with the lowest possible power level of the gas burner at which
reliable ignition occurs. Then, however, the power level is slowly
increased, until the power level previously set is reached. This
slow increase of the power level proceeds over the aforementioned
time delay and may indeed take the few seconds mentioned.
[0011] In the case of this embodiment of the invention, the gas
burner is therefore ignited immediately when the re-placed pan is
detected and when a user, in all probability, still has his/her
hands on the pan. Since, however, the power level used is not the
full level previously set, which could possibly lead to burns, but
only a lower or the smallest possible level, the risk of burning is
in turn reduced or eliminated. By the time the power level is
increased to that previously set, the time delay has in turn
elapsed and a user has sufficient time to remove his/her hands. A
gas flame with a very small or the smallest possible power level
will generally not be sufficient to cause burning of the hands
holding the pan placed on.
[0012] In the case of this embodiment of the invention, the power
level is possibly increased continuously to the value of the power
level previously set. In further embodiments, it may first be
increased slowly and then to ever increasing degree or finally,
also at the end of the delay, be increased abruptly.
[0013] In another embodiment of the invention, it may be provided
that the removal of the pan from the cooking point is optically
indicated. For this purpose, indicating means such as illuminating
source or the like, for example light-emitting diodes, may be
arranged in the region of the cooking point. Furthermore, an
acoustic signal output may also take place. A signal output may
continue for as long as the pan is removed and at the same time the
cooking point has not yet been switched off as a result of a
maximum time being exceeded.
[0014] In another embodiment of the invention, it may be provided
that, after a maximum time is exceeded, possibly in the range
between 3 minutes and 15 minutes, advantageously between 5 minutes
and 10 minutes, the readiness of the cooking point is cancelled.
For this purpose, the power level setting is cancelled. Therefore,
when a pan is placed on again, there is no automatic further
operation of the cooking point or automatic switching back on of
the gas burner. It may be provided in this respect that first an
operating element for the power level setting has to be actuated,
that is to say a power level setting has to be manually set again.
In this way, the control can reliably detect that a user is again
in attendance. In particular, the power level first may be set
again right back to zero and subsequently set to the desired
degree. Also in this respect it may be provided that such exceeding
of the maximum time in the way prescribed is optically and/or
acoustically indicated.
[0015] In another embodiment of the invention, an additional safety
feature may be provided that a signal is outputted shortly before
the gas burner is re-ignited or shortly before the previously set
power level is reached. This may be an optical signal or
advantageously an acoustic signal. Such a signal may, for example,
be generated half a second or a second before the power level
originally set is reached when the pan is placed on again and the
gas burner is automatically ignited.
[0016] In another embodiment of the invention, when the cooking
point is switched off or the gas burner is turned off, in
particular when a placed-on pan is removed, a slow turning-off
operation takes place, or the power level is as it were slowly
brought to zero. This may last a number of seconds, for example two
seconds to five seconds. Furthermore, it may at the same time be
indicated, once again optically and/or acoustically in the
aforementioned way. In particular, such slow turning off may also
mean that, after the pan is removed, said few seconds are waited
before the power level is brought down or the gas burner is turned
off. As a result, the gas burner is not switched off unwantedly,
which can result due to a malfunctions or the like when a pan is
briefly not detected as placed-on.
[0017] A control in which both the pan detection and the control
for the gas valve of the gas burner are integrated together with
measurement of the time or the delay may possibly be provided in a
central control of a corresponding gas hob. Alternatively, it may
be designed as an additional control for certain cooking
points.
[0018] The output of a signal, in particular an acoustic signal,
before the ignition of the gas burner may have the advantage of
detecting an object other than a pan has been placed on, for
example a cooking spoon or the like, and warning an operator of the
imminent ignition of the gas burner. Then, the object inadvertently
placed on can be removed again thus avoiding an accident.
[0019] These and further features are evident not only from the
claims, but also from the description and the drawings, where the
individual features can be realized in each case by themselves or
as a plurality in the form of sub-combinations in an embodiment of
the invention and in other fields and can constitute advantageous
and inherently protectable embodiments for which protection is
claimed here. The subdivision of the application into individual
sections and subheadings do not restrict the general validity of
the statements made thereunder.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Exemplary embodiments of the invention are illustrated
schematically in the drawings and are explained in greater detail
below. In the drawings:
[0021] FIG. 1 shows a side view of a gas hob according to one
embodiment of the invention with a device for the time-delayed
ignition of a gas burner of a cooking point and
[0022] FIG. 2 shows a diagram of one embodiment of the power
progression over time for various ways of increasing the power.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0023] FIG. 1 illustrates a gas hob 11 as a device according to the
invention, on which the method according to the invention can be
carried out. The gas hob 11 has a conventional hob panel 12, and a
cooking point 14 thereof is illustrated. The cooking point 14 has a
conventional gas burner 16 with a gas valve 17 arranged under the
hob panel 12, from which valve said burner is supplied. Provided at
the gas burner 16 is an ignition device 18 and advantageously a
monitoring device (not illustrated) for the gas flames 19. An
essentially conventional pan support 20, on which a pan 22 is
placed over the gas burner 16 and the cooking point 14, is also
provided. This pan support has yet further functions, as still to
be explained below. As usual, the pan has side handles 23, which
are being gripped by hands 24 of the user, for example because said
user has just placed the pan 22 on again.
[0024] Provided on the gas hob 11 is a controller 26, which is
connected not only to the gas valve 17, for the activation thereof,
and to the ignition device 18 but also, though not of any
consequence here, to a possible flame monitor. Furthermore, the
controller 26 is connected to a pan detection device, which is not
described in any more detail but is formed as a known reflex light
barrier and is arranged underneath the hob panel 12. Furthermore,
the controller 26 is connected to signal transmitters under the hob
panel 12, such as an acoustic signal transmitter 28a and an optical
signal transmitter 28b. It is also possible to omit the signal
transmitters or to provide only one of the two.
[0025] When the pan 22 is removed from the cooking point 14, as the
thick arrow indicates, the pan detection device 21 together with
the controller 26 detects this. The latter then closes the gas
valve 17, so that the gas burner 16 goes out or the gas flames 19
are extinguished. If the pan 22 is then placed on again with the
hands 24 on the handles 23, the pan detection device 21 detects the
pan 22. This then corresponds to the point in time t.sub.0 in the
diagram of the power P over the time t according to FIG. 2, to be
specific when the power of the gas burner 16 is increased from
zero, that is when the gas valve 17 is closed. Here there may be an
abrupt increase according to the solid line to a power P.sub.min,
which is chosen such that it is the minimum power or minimum power
level or minimum amount of gas with which the gas burner 16 can
ignite and burn. Up until the point in time t.sub.1, which is
reached after a delay time T.sub.V, which is the delay time
mentioned at the beginning, there may be a few seconds,
advantageously one to two seconds. Over this delay time T.sub.V,
the power P is then not increased over the minimum power P.sub.min,
as shown by the solid line. This only happens abruptly at the point
in time t.sub.1, and then specifically to the power originally set
P.sub.0. This power P.sub.0 was the power before the pan 22 was
removed. During the delay time T.sub.V, an operator therefore has
sufficient time after placing the pan 22 onto the cooking point 14,
that is the said one to two seconds, to remove the hands 24 again
from the region in which the gas flames 19 can come. Although the
gas burner 16 ignites again, the gas flames 19 scarcely reach over
the base of the pan 22 to the sides and up to the handles 23 or the
hands 24, since said burner operates with the lowest possible
minimum power.
[0026] As an alternative to keeping to the minimum power P.sub.min
along with an abrupt increase, the power may, as from the point in
time t.sub.0, first increase slightly and then ever more quickly as
shown by a dotted curve in the manner of a parabola or
non-linearly. As a result, it can also at the same time be
signalled to a user that not only has re-ignition taken place but
there has also been an increase in the power automatically beyond
the minimum power P.sub.min. The user therefore does not have to
worry that the cooking point 14 is malfunctioning.
[0027] In another alternative embodiment, the increase in output
level as from the point in time t.sub.o may take place uniformly as
shown by the dash-dotted representation. Although an increase in
the burning power once again takes place here somewhat more quickly
than in the case of the two previous curves, it is still always in
such a way that, for example after the elapse of a time T.sub.V/2
after the point in time t.sub.0, there is still a much lower power
than the power previously set P.sub.0.
[0028] In yet a further alternative refinement of the method, at
the point in time t.sub.0, the gas burner 16 is still out or the
gas valve 17 is closed. Only at the point in time t.sub.1, that is
after the delay time T.sub.V, is the gas burner 16 ignited by
opening of the gas valve 17 and actuation of the ignition device
18, then however right away as shown by the dashed curve with the
full pre-set power P.sub.0. This has the advantage that even a
possibly existing risk of burning caused by a gas flame with the
low minimum power P.sub.min is eliminated, since indeed there are
still no gas flames 19. At the same time, it must then be noted
however that the re-ignition of the gas burner 16 at the point in
time t.sub.1 then takes place with the full pre-set power P.sub.0
and abruptly.
[0029] As explained previously, an acoustic and/or optical signal
output by the signal transmitters 28a and 28b may take place at a
point in time t.sub.0, t.sub.1 or a point in time in between. This
may signal re-ignition of the gas burner 16, that the full power
previously set P.sub.0 will soon be reached or has been reached, or
something similar.
* * * * *