Technical Field
[0001] The present disclosure relates to a cooking appliance and a method of protecting
a cooking appliance.
Background
[0002] Examples of cooking appliances include conventional gas or electric ovens or stoves/cookers
generally, convection ovens, microwave ovens, halogen cooktops, induction cooktops,
hot plates, etc. Some cooking appliances comprise one or more frangible portions,
i.e. portions that may be prone to cracking or breaking. Examples of frangible portions
of cooking appliances include a glass door of an oven, a glass-ceramic cooktop or
cooking surface, etc. Cracking or breaking of the frangible portion can be caused
by for example either external force (e.g. impact by an object) or heat. Cracking
or breaking of the frangible portion can present a serious risk of harm to any people
in the vicinity of the appliance.
Summary
[0003] According to a first aspect disclosed herein, there is provided a cooking appliance
comprising: a frangible portion; a sensor arrangement for detecting a crack or imminent
formation of a crack in the frangible portion; and circuitry for causing an airbag
trigger to activate an airbag to deploy; wherein the circuitry is in communication
with the sensor arrangement and is configured to cause a said airbag trigger to activate
a said airbag to cover at least a portion of the frangible portion in response to
the sensor arrangement detecting a crack or imminent formation of a crack in the frangible
portion.
[0004] In an example, the sensor arrangement comprises a light emitter constructed and arranged
to emit light into the frangible portion, and a light sensor constructed and arranged
to detect light emitted by the light emitter and passing through the frangible portion;
and the circuitry is arranged such that a decrease in the intensity of light detected
by the light sensor is taken as being indicative of a crack having formed or being
about to form in the frangible portion.
[0005] In an example, the sensor arrangement comprises a heat sensor constructed and arranged
to detect the temperature of one or more regions of the frangible portion; and the
circuitry is arranged to determine that a crack is about to form in the frangible
portion based on the detected temperature of one or more regions of the frangible
portion.
[0006] In an example, the cooking appliance comprises an airbag and an airbag trigger in
communication with the circuitry.
[0007] In an example, the airbag is mounted above the frangible portion.
[0008] In an example, the airbag is constructed and arranged to cover all or substantially
all of the frangible portion when deployed.
[0009] In an example, the cooking appliance comprises a plurality of airbags, each with
a respective airbag trigger, the plurality of airbags being constructed and arranged
to cover a respective portion of the frangible portion when deployed.
[0010] In an example, the frangible portion is a cooktop of the cooking appliance.
[0011] According to a second aspect disclosed herein, there is provided a method of protecting
a cooking appliance having a frangible portion, the method comprising: detecting a
crack or imminent formation of a crack in the frangible portion; and in response to
detecting a crack or imminent formation of a crack in the frangible portion, causing
an airbag to activate to cover at least a portion of the frangible portion.
[0012] In an example, the method comprises emitting light into the frangible portion and
detecting an intensity of light passing through the frangible portion; and detecting
a crack or imminent formation of a crack in the frangible portion comprises detecting
a decrease in the intensity of light passing through the frangible portion.
[0013] In an example, the method comprises detecting the temperature of one or more regions
of the frangible portion; and detecting a crack or imminent formation of a crack in
the frangible portion is based on the detected temperature of one or more regions
of the frangible portion.
[0014] In an example, the airbag is constructed and arranged to cover all or substantially
all of the frangible portion when deployed.
[0015] In an example, the method comprises causing a plurality of airbags to active to each
cover a respective portion of the frangible portion when deployed.
[0016] In an example, the frangible portion is a cooktop of the cooking appliance.
Brief Description of the Drawings
[0017] To assist understanding of the present disclosure and to show how embodiments may
be put into effect, reference is made by way of example to the accompanying drawings
in which:
Figure 1 shows schematically a perspective view of a cooking appliance in accordance
with examples described herein and a user;
Figures 2 and 3 show schematically plan views from above of a cooking appliance in
accordance with examples described herein respectively before and after an airbag
has deployed;
Figures 4 and 5 show schematically plan views from above of a cooking appliance in
accordance with examples described herein respectively before and after a crack has
formed in a frangible portion; and
Figures 6 and 7 show schematically side elevations of cooking appliances in accordance
with examples described herein to illustrate different examples of how the airbag
and airbag trigger may be mounted.
Detailed Description
[0018] Figure 1 shows schematically a user 200 operating a cooking appliance 100. The cooking
appliance 100 may in general be a gas or electric oven or stove/cooker (that is, a
combined oven and cooktop), a convection oven, a microwave oven, a halogen or induction
or other cooktop, a hot plate, etc.
[0019] The cooking appliance 100 comprises one or more frangible portions 101. The frangible
portions 101 are parts of the cooking appliance 100 that are susceptible to cracking
or fracturing. For example, the frangible portions 101 may be constructed of frangible
material. Frangible materials can crack in response to for example external force,
excessive heat or rapid changes in temperature. Examples of frangible materials include
glass, glass-ceramic, some plastics, etc.
[0020] In this example, the cooking appliance 100 is a kitchen stove (also called a cooker
or range) which has a cooktop and an oven. A saucepan 201 is shown resting on the
surface of the cooktop as an example of a cookware item commonly placed on a cooktop.
In this case, the frangible portion 101 is a surface of the cooktop. Other parts of
the cooking appliance 100 may also be or include frangible portions 101 of the cooking
appliance 100, such as a door of the oven.
[0021] During operation of the cooking appliance 100, the frangible portion 101 can be exposed
to high temperatures: an oven may operate at a temperature around 200°C; and a cooktop
can attain temperatures up to 300°C or more. This can cause the frangible portion
101 to crack. It can also exacerbate pre-existing cracks. Even when not exposed to
heat, the frangible portions 101 can be cracked by external force (e.g. the user 200
may accidentally hit the glass door of the oven or drop an object onto the cooktop).
A cracked or about-to-crack frangible portion 101 may be at risk of exploding, which
is a serious health risk for any persons in the vicinity of the cooking appliance
100. There is therefore a problem of how to improve the safety of a cooking appliance.
[0022] Figures 2 and 3 show schematically plan views from above of a cooking appliance 100
in accordance with examples described herein respectively before and after an airbag
130 has deployed. An airbag 130 and associated airbag trigger 131 are shown. The cooking
appliance 100 comprises circuitry 120 which is operatively coupled to an airbag trigger
131. The circuitry 120 may for example be part of and contained within the body of
cooking appliance 100 itself.
[0023] The airbag 130 comprises a flexible bag which can be inflated by the airbag trigger
131 (also called an inflation module), e.g., using compressed air or via a pyrotechnic
process. In the initial, undeployed state, the airbag 130 is packaged into a housing
which is mounted at a side of the frangible portion 101. This has the advantage that
the airbag 130 does not interfere with normal operation of the cooking appliance 100.
In the deployed state, the airbag 130 covers at least a portion of the frangible portion
101. When the airbag trigger 131 activates (as controlled by the circuitry 120), the
airbag trigger 131 causes the airbag 130 to inflate. As the airbag 130 inflates, it
expands to cover substantially all of the lateral extent of the frangible portion
101, as shown in Figure 3. In this context, "substantially" means that the inflated
airbag 130 covers enough of the frangible portion 101 to prevent fragments of the
frangible portion 101 escaping to injure the user 200. For example, parts of the frangible
portion 101 such as the edges may be directly attached to the cooking appliance 100.
In this case, the airbag 130 may need not cover these portions. Instead, the airbag
130 may only cover a portion of the frangible surface 101 which can separate from
the cooking appliance 100 in case of the frangible portion 101 exploding.
[0024] Cookware items such as cookware item 201 shown in Figure 1 may be placed on top of
the frangible portion 101. Examples of cookware items include saucepans, frying pans,
woks, etc. It is therefore preferably that the airbag 130 deploys in such a way that
it avoids the space above the frangible portion 101 which may be occupied by one or
more cookware items. Example solutions to this are described below with reference
to Figures 6 and 7.
[0025] Airbags and airbag triggers themselves are especially known in the context of automobiles.
In this context, the airbag trigger causes the airbag to deploy in response to high
acceleration (or deceleration) such as experienced during an automobile collision.
Such airbag triggers are therefore unsuitable for use with a cooking appliance as
described herein because cooking appliances do not move (and so are not subject to
high acceleration or deceleration). Accordingly, some other technique is required.
[0026] To address this, in examples of the present disclosure, the circuitry 120 determines
that the airbag 130 should deploy (via the airbag trigger 131) in response to detecting
a crack or imminent formation of a crack in a frangible portion 101.
[0027] Figures 4 and 5 show a top view of the cooking appliance 100 in order to illustrate
an example sensor arrangement 110. The sensor arrangement 110 of this example is provided
for detecting a crack or imminent formation of a crack in a frangible portion 101
of the cooking appliance 100. The sensor arrangement 110 may monitor the frangible
portion 101 and, in response to detecting a crack or imminent formation of a crack,
generate an output indicating this to the circuitry 120.
[0028] The sensor arrangement 110 is operatively coupled to the circuitry 120. The circuitry
120 is configured to cause the airbag trigger 131 to activate the airbag 130 to cover
at least a portion of the frangible portion 101 in response to the sensor arrangement
110 detecting a crack or imminent formation of a crack in the frangible portion 101.
[0029] In the example of Figures 4 and 5, the sensor arrangement 110 comprises a light emitter
111 and a light sensor 112. The light emitter 111 is constructed and arranged to emit
light through the frangible portion 101. The light emitter 111 may be for example
a laser light source, such as for example a laser diode. The light sensor 112 is constructed
and arranged to detect light emitted through the frangible portion 101 by the light
emitter 111. The light sensor 112 may be, for example, a photodiode which generates
an output which is a function of the measured intensity of the light.
[0030] In Figure 4, the frangible portion 101 is shown to be in good repair (that is, not
cracked). The light sensor 112 in this case measures a baseline intensity of light
coming from the light emitter 111. In particular, the light may pass substantially
unimpeded through the frangible portion 101. This is particularly the case when the
light emitter 111 is a laser as the coherent light from the laser is less likely to
be deflected or diffracted or otherwise distorted as it passes through the frangible
portion 101.
[0031] In Figure 5, a crack is shown having formed in the frangible portion 101. The crack
deflects part of the light from the light emitter 111, causing the intensity of light
received at the light sensor 112 to drop. Hence, a measured drop in intensity at the
light sensor 112 is indicative of a crack having formed in the frangible portion 101.
The circuitry 120 may use this to determine to cause the airbag trigger 131 to deploy
the airbag 130. For example, if the intensity of light at the light sensor 112 drops
by more than a threshold amount, the circuitry 120 may cause the airbag trigger 131
to activate.
[0032] In a specific example, the light sensor 112 may generate an output voltage proportional
to the measured light intensity. The circuitry 120 may comprise a comparator having
one input connected to the output voltage of the light sensor 112 and another input
connected to a reference voltage. The circuitry 120 maybe then be configured to activate
the airbag trigger 131 if the voltage from the light sensor 112 drops below the reference
voltage. In other examples, the circuitry 120 may comprise a microcontroller or processor
configured to monitor input from the sensor arrangement 110 and trigger the airbag
130 to deploy (via the airbag trigger 131) accordingly.
[0033] The sensor arrangement 110 may alternatively or additionally comprise one or more
temperature sensors for detecting a temperature of the frangible portion 101 or at
least one or more regions of the frangible portion 101. The or each temperature sensors
may be for example an infrared heat sensor, a thermocouple, etc. In such cases, the
circuitry 120 receives input from the temperature sensor(s) and can use this information
to determine whether to cause the airbag 130 to deploy. The temperature sensor may
detect localised temperature values across the area of the frangible portion 101.
A localised hot spot in the frangible surface 101 having a temperature above a threshold
temperature (e.g. a normal working temperature of the frangible surface), or a temperature
that is markedly different from the temperature of a neighbouring region, can increase
the likelihood of the frangible surface 101 cracking and exploding. As another example,
very rapid increases or decreases in temperature can increase the likelihood of the
frangible surface 101 cracking and exploding. Hence, the circuitry 120 may determine
to cause the airbag 130 to deploy in response to the sensor arrangement 110 indicating
a hot spot in the frangible surface 101 that has a temperature above a threshold temperature
or a temperature difference relative to a neighbouring region that is above a threshold
or a temperature that is rapidly increasing or decreasing above a threshold rate of
change.
[0034] Although the sensor arrangement 110 been described with reference to Figures 4 and
5 which show a cooktop frangible surface, it is understood that similar arrangements
could be used to detect a crack or imminent formation of a crack in other frangible
portions, including for example a door of an oven or a part of a door of an oven.
[0035] Figures 6 and 7 show schematically side elevations of cooking appliances in accordance
with examples described herein to illustrate different examples of how the airbag
130 and airbag trigger 131 may be mounted. A cookware item 201 is shown placed on
the frangible portion 101. Common cookware items that might be placed on the frangible
portion 101 typically do not exceed a maximum of around 30cm in height.
[0036] In Figure 6, the airbag 130 and airbag trigger 131 are mounted at the edge of the
frangible portion 101, as in Figures 5 and 6. In the deployed state, as shown in the
figure, the airbag 130 forms an enclosed space above the frangible portion 101 to
contain the cookware item 201. To do so, the topological construction of the airbag
130 is such that it deploys "up and over" the volume that may be occupied by one or
more cookware items.
[0037] In Figure 7, the airbag 130 and airbag trigger 131 are installed on a mount 140.
The mount 140 is located at the edge of the frangible portion 101 and extends vertically
upwards. The airbag 130 and airbag trigger 131 are installed at the top of the mount
140. In this example, the mount 140 is around twice the maximum height of the cookware
item 210 that it typically used. The airbag 130 is constructed and arranged to avoid
the volume which may be occupied by cookware items during deployment. In this example,
the airbag 130 can deploy in a straight line from the top of the mount 140 to the
opposite edge of the frangible portion 101 while still avoiding this volume. Hence,
the airbag 130 in this example can have a simpler construction than that of Figure
6.
[0038] The cooking appliance 100 may comprise multiple airbags 130, each with a respective
airbag trigger 131. For example, a separate airbag 130 and airbag trigger 131 may
be provided at each edge of a cooktop frangible portion 101 of the cooking appliance
130. The circuitry 120 may be operatively coupled to each of the airbag triggers 131
and configured to cause one or more or all of the plurality of airbags 130 to deploy
in response to the sensor arrangement 110 detecting a crack or imminent formation
of a crack in the frangible portion 101.
[0039] In cases where a plurality of airbags 130 is provided, each of the plurality of airbags
130 may be constructed and arranged to cover a respective portion of the frangible
portion 101 when deployed. The respective portions covered by the deployed plurality
of airbags 130 may be different respective portions. The respective portions covered
by the deployed plurality of airbags 130 may overlap.
[0040] It will be understood that the processor or processing system or circuitry referred
to herein may in practice be provided by a single chip or integrated circuit or plural
chips or integrated circuits, optionally provided as a chipset, an application-specific
integrated circuit (ASIC), field-programmable gate array (FPGA), digital signal processor
(DSP), graphics processing units (GPUs), etc. The chip or chips may comprise circuitry
(as well as possibly firmware) for embodying at least one or more of a data processor
or processors, a digital signal processor or processors, baseband circuitry and radio
frequency circuitry, which are configurable so as to operate in accordance with the
exemplary embodiments. In this regard, the exemplary embodiments may be implemented
at least in part by computer software stored in (non-transitory) memory and executable
by the processor, or by hardware, or by a combination of tangibly stored software
and hardware (and tangibly stored firmware).
[0041] The examples described herein are to be understood as illustrative examples of embodiments
of the invention. Further embodiments and examples are envisaged. Any feature described
in relation to any one example or embodiment may be used alone or in combination with
other features. In addition, any feature described in relation to any one example
or embodiment may also be used in combination with one or more features of any other
of the examples or embodiments, or any combination of any other of the examples or
embodiments. Furthermore, equivalents and modifications not described herein may also
be employed within the scope of the invention, which is defined in the claims.
1. A cooking appliance comprising:
a frangible portion;
a sensor arrangement for detecting a crack or imminent formation of a crack in the
frangible portion; and
circuitry for causing an airbag trigger to activate an airbag to deploy;
wherein the circuitry is in communication with the sensor arrangement and is configured
to cause a said airbag trigger to activate a said airbag to cover at least a portion
of the frangible portion in response to the sensor arrangement detecting a crack or
imminent formation of a crack in the frangible portion.
2. A cooking appliance according to claim 1, wherein:
the sensor arrangement comprises a light emitter constructed and arranged to emit
light into the frangible portion, and a light sensor constructed and arranged to detect
light emitted by the light emitter and passing through the frangible portion;
the circuitry being arranged such that a decrease in the intensity of light detected
by the light sensor is taken as being indicative of a crack having formed or being
about to form in the frangible portion.
3. A cooking appliance according to claim 1 or claim 2, wherein:
the sensor arrangement comprises a heat sensor constructed and arranged to detect
the temperature of one or more regions of the frangible portion;
the circuitry being arranged to determine that a crack is about to form in the frangible
portion based on the detected temperature of one or more regions of the frangible
portion.
4. A cooking appliance according to any of claims 1 to 3, comprising an airbag and an
airbag trigger in communication with the circuitry.
5. A cooking appliance according to claim 4, wherein the airbag is mounted above the
frangible portion.
6. A cooking appliance according to claim 4 or claim 5, wherein the airbag is constructed
and arranged to cover all or substantially all of the frangible portion when deployed.
7. A cooking appliance according to claim 4 or claim 5, comprising a plurality of airbags,
each with a respective airbag trigger, the plurality of airbags being constructed
and arranged to cover a respective portion of the frangible portion when deployed.
8. A cooking appliance according to any of claims 1 to 7, wherein the frangible portion
is a cooktop of the cooking appliance.
9. A method of protecting a cooking appliance having a frangible portion, the method
comprising:
detecting a crack or imminent formation of a crack in the frangible portion; and
in response to detecting a crack or imminent formation of a crack in the frangible
portion, causing an airbag to activate to cover at least a portion of the frangible
portion.
10. A method according to claim 9, comprising emitting light into the frangible portion
and detecting an intensity of light passing through the frangible portion;
wherein detecting a crack or imminent formation of a crack in the frangible portion
comprises detecting a decrease in the intensity of light passing through the frangible
portion.
11. A method according to claim 9 or claim 10, comprising detecting the temperature of
one or more regions of the frangible portion;
wherein detecting a crack or imminent formation of a crack in the frangible portion
is based on the detected temperature of one or more regions of the frangible portion.
12. A method according to any of claims 9 to 11, wherein the airbag is constructed and
arranged to cover all or substantially all of the frangible portion when deployed.
13. A method according to any of claims 9 to 11, comprising causing a plurality of airbags
to active to each cover a respective portion of the frangible portion when deployed.
14. A method according to any of claims 9 to 13, wherein the frangible portion is a cooktop
of the cooking appliance.