Note: Descriptions are shown in the official language in which they were submitted.
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GRATE APPARATUS AND METHOD OF CLEANING
BACKGROUND OF THE INVENTION
This invention relates generally to an appliance, and more particularly, to a
grate apparatus and method such as for a cook top stove.
A cooking appliance includes gas and/or electric heating elements for heating
and cooking food. The cook top may be made out of ceramic or metal. Often the
metal cook top is coated with enamel for added durability. Either a natural
gas or
propane gas cooking unit is generally used.
In a first type, a gas burner is provided which is arranged under a cook top
surface that is typically a closed glass-ceramic panel. In this type, the gas
burner heats
the ceramic cook top that in turn heats a cooking vessel. A second type of gas
cooking unit utilizes a conventional atmospheric gas burner, i.e. that with an
open
flame, which is inserted through an opening in the cook top.
A grate is utilized to provide separation between the cooking vessel and the
burner. The grate is often made of metal or other hard material. The grate
must have a
surface for resting a cooking vessel, and feet for raising the grate above the
cook top.
The cooking grate must be arranged so that it is directly above the gas burner
and
relatively fixed in position, so that the energy transfer from the burner to
the cooking
vessel is optimized. The grate prevents damage to the burner and maintains an
optimal
cook distance between the cook top and the cooking vessel and therefore must
be
sturdy and withstand the high temperatures associated with its location.
The hard material or metal of the grate can scratch or mar the enamel coating
or glass-ceramic cook top. Particularly where the grate can move in relation
to the
cook top. These scratches not only reduce the visual aesthetics of the cook
top, but in
the case of a glass-ceramic cook top, weaken the structural integrity of the
cook top
increasing the possibility of breaking. It has therefore been a concern to
reduce or
eliminate the marring and scratching of the cook top.
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One practice has been to glue inserts made of silicone or another soft
material
onto the bottom or feet of the grate so as to cushion the interface between
the grate and
the cooking area. The feet are regions of the bottom of the grate which are
formed to
be lower than the rest of the periphery to allow point contact with the cook
top. This
creates a more stable interface and prevents rocking of the grate on the cook
top.
Another arrangement has a foot holding device for maintaining the grate in
position on the cook top. The foot holding device includes a plurality of foot
holders
for mating with the feet of the cooking grate. Forming depressed regions in
the
surface of the cook top forms the foot holders. The depressed regions are
formed to fit
the shape of the respective feet of the grate and the foot ends are inserted
into the
depressions for retention. This limits removal and can be difficult to clean
the cook
top as grease and other debris may settle into the depressed regions.
Grates have traditionally been hard to clean due to the intense heat
associated
with their use and the resulting effect it has on food and grease spills. The
food and
grease often becomes cooked onto the surface and becomes difficult to remove.
Generally, harsh chemicals or mechanical methods had been employed with
generally
poor results in cleaning the grates.
Self-clean ovens have become very common. Further, with the temperature,
cycle time and material improvements self-clean ovens are very effective at
removing
debris from the interior surfaces of the oven.
Placing the grates from a gas cook top into the oven during a self-clean cycle
is very effective in cleaning the grates. However, the temperature in the self-
clean
cycle often degrades the interface between the cook top and the grate. During
the high
temperatures of the self-clean cycle the soft material often oxidizes or
sublimes into
carbon ash, or the bonding agent between the soft material and the grate
fails.
Thus, there exists a need in the art for a grate assembly that provides a
sturdy
support for cooking vessels and includes an interface that will not mar or
scratch a
cook top employing the gas burners and can be easily cleaned in the self-clean
cycle
of a self-clean oven.
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There also exists a need in the art for a method of cleaning a grate for
supporting cooking vessels by placing the grate in a self-clean oven during a
self-
clean cycle. Further, the interface for preventing marring or scratching of
the cook top
by the grate should be able to maintain pliability during the cleaning method.
BRIEF DESCRIPTION OF THE INVENTION
As described herein, each of the embodiments of the invention overcomes
one or more of the above or other disadvantages in the art.
In an embodiment, a grate assembly includes a cook top defining a support
surface, and a grate that includes a projection extending from a peripheral
portion.
The projection is configured to support a cooking vessel on the grate. The
peripheral
portion is configured to support the grate on the support surface. A hole is
formed in
one of the peripheral portion of the grate or the support surface of the cook
top. An
insert is disposed within the hole and between the support surface of the cook
top and
the peripheral portion of the grate.
In an embodiment, the invention provides a method of cleaning a grate for a
burner assembly of a cook top, the burner assembly including a gas burner and
a grate
for supporting a cooking vessel. The method includes placing the grate into a
self-
clean oven for at least one cycle of a self-clean feature of the oven, and
removing the
grate from the self-clean oven. The method further includes supporting the
grate on
an interface between the cook top and the grate. The interface includes a
plurality of
pliable inserts in holes, each insert including a shank portion and a head
portion. The
head portion has a cross section greater than the shank portion, and the shank
portion
is positioned within a respective one of the holes.
BRIEF DESCRIPTION OF THE DRAWINGS
The following figures illustrate examples of embodiments of the invention.
The figures are described in detail below.
Figure 1 is a perspective view of a cooking appliance incorporating a grate
assembly in accordance with an embodiment of the present invention.
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Figure 2 is a detail exploded view of the grate assembly of the cooking
appliance of Figure 1.
Figure 3 is a front view of an insert of the grate assembly of Figure 1.
Figure 4 is a detail, partial cross sectional view of another embodiment of
the
present invention.
Figure 5 is a detail view of another embodiment of the present invention.
Figure 6 is a bottom view of another embodiment of the present invention.
Figure 7 is a detail, partial cross sectional view of the grate assembly of
Figure 6.
Figure 8 is a detail, partial cross sectional view of another embodiment of
the
grate assembly of Figure 6.
Figure 9 is a front view of an alternate embodiment of an insert of the grate
assembly of Figure 1.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the invention are described below, with reference to the
figures. Throughout the figures, like reference numbers indicate the same or
similar
components. References to preferred embodiments are for illustration and
understanding, and should not be taken as limiting.
With initial reference to Figures 1 and 2, the present invention is
incorporated in a cooking appliance 100, which is shown as a domestic range.
It is to
be understood that the present invention could also be used in connection with
an
island-type or other countertop mounted cook top. In any event, for exemplary
purposes, cooking appliance 100 is shown to include a cabinet 104 within which
is
formed an interior oven cavity. The oven cavity may be capable of performing a
self-
clean cycle, as is known in the art. Cooking appliance 100 further includes a
cook top
102 that is formed from metal or a glass/ceramic-based material. An upper
portion of
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a front panel 112 defines an upper front face 114 that includes a plurality of
controls.
Arranged below upper front face 114 is an oven door 108 having a handle 110.
In a
manner known in the art, door 108 can be pivoted to access the interior oven
cavity of
cooking appliance 100. Also, as shown, cooking appliance 100 includes a lower
drawer 106 for use in storing pans and the like.
In the figures, upper front face 114 is provided with a plurality of element
control knobs 130, 132, 134 and 136. Element control knobs 130, 132, 134 and
136
are used to control the operation of gas burner heating elements 140, 142, 144
and 146
respectively. Heating elements 140 and 142 are fitted with grates 141 and 143
respectively. Similarly, heating elements 144 and 146 are fitted with grates
145 and
147. In general, the construction and operation of cooking appliance 100, as
described
until this point, is known in the art. Further, the form, number and location
of each of
the elements described may change based on preference and use. To this end,
additional details of this construction or operation will not be provided
here.
Traditionally, cleaning the grates 141, 143, 145 and 147 is labor intensive
and often requires caustic chemicals and harsh abrasives to remove the food
and
grease cooked onto the grate due to the high operational temperatures
involved. By
placing the grate into an oven during the self-clean cycle it was found that
the grates
would become very clean and not lose any luster as harsh chemicals and
abrasives
were not employed. According to one aspect of the present invention, the grate
is
cleaned by removing the grate from the cook top surface and removing the
bumpers
or feet from the grate prior to placing in an oven for the duration of a self-
clean cycle.
Reference will now be made to one of the element assemblies, which include
grate 141, and heating element 140 but is representative of the each of the
element
assemblies including grates 141, 143, 145 and 147 and heating elements 140,
142, 144
and 146. Referring to Figure 2, grate 141 includes a peripheral edge 148 and a
plurality of projections 118 extending from edge 148 toward a center portion
120 of
the respective grate 141. Projections 118 form surfaces for resting a cooking
vessel
(not shown) above gas heating element 140. As shown, each grate interfaces
with
cook top 102 at 150.
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In an embodiment of the invention interface 150 is a plurality of inserts 162
as shown in Figures 2 and 3. Insert 162 is matingly inserted in a hole 168 in
the cook
top 102. Holes 168 are located to correspond to the peripheral edge 148 of
grate 141
when grate 141 is resting on the cook top 102 during normal operation as shown
in
Figure 1. The insert 162 has a head portion 164 and a shank portion 166. Head
portion
164 is substantially larger in cross-section than shank portion 166. Shank 166
is
inserted into hole 168. Preferably shank 166 has a bulge 170 or area larger
than hole
168 to prevent easy removal of insert 162 from cook top 102. Bulge 170 should
be
located a distance 163 from head portion 164 which is less than or equal to
the
thickness of cook top 102. Thus the retention force of bulge 170 on the
underside of
cook top 102 creates a sealing force between head portion 164 and the upper
side of
cook top 102. This seal prevents food and other debris from becoming lodged
between insert 162 and cook top 102, and facilitates cleaning the cook top
surface.
Figure 9 shows an alternate embodiment of insert 162 where shank 166 is
considerably longer then bulge 170 and like numbers indicate similar features.
Alternatively, as shown in Figure 4 the shank portion 166 of insert 162 and
hole 168 of cook top 102 may be correspondingly threaded such that when insert
162
is fully threaded in hole 168 a seal is created between head portion 164 and
the cook
top surface.
In another alternate embodiment shown in Figure 5, an insert 182 includes a
head portion 184 and is located on cook top 102 to correspond to the
peripheral edge
148 of grate 141 when resting on the cook top 102 during normal operation as
shown
in Figure 1. Insert 182 is adhered or otherwise secured to cook top 102 at
interface
186.
In other embodiments of the invention, interface 150 is a plurality of inserts
152, as shown in Figures 6, 7 and 8. In these aspects of the invention insert
152 is
matingly inserted in a hole 158 on the bottom of peripheral edge 148 of grate
141.
Insert 152 has a head portion 154 and a shank portion 156. Head portion 154 is
substantially larger in cross-section than shank portion 156. Shank 156 is
removably
inserted into hole 158. In an embodiment shank 156 and hole 158 are
correspondingly
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threaded, but any means for removable retention of insert 152 is acceptable.
Insert 152
is made of a material that will not mar or scratch the cook top, such as
silicone. In this
embodiment, insert 152 is removed from grate 141 before grate 141 is placed in
an
oven cavity for cleaning during the self-clean cycle.
In the embodiment shown in Figure 8, insert 152 is matingly inserted in hole
158 on the bottom of peripheral edge 148 of grate 141. Shank 156 is inserted
into hole
158. Shank 156 contains a bulge 157 a distance from head 154 less than or
equal to
the thickness of wall 159 of peripheral edge 148. Further, bulge 157 is
greater in
diameter than hole 158. Thus, bulge 157 creates a retaining force for insert
152.
However, any means for retention of insert 152 may be used. Insert 152 is made
of
any material that will not mar or scratch the cook top and can withstand
temperatures
in the 800-900 degree Fahrenheit (425-480 degree Celsius) range, such as
graphite
foil, or flexible graphite also known as GRAFOILTM. In this embodiment, the
insert
152 remains with the grate 141 when placed in an oven for cleaning during the
self-
clean cycle. Other suitable materials for the insert 152 include ceramic wool,
silica
gel, and/or another pliable structure, including a structure formed of an
inorganic
material or compound.
This written description uses examples to disclose embodiments of the
invention, including the best mode, and to enable a person of ordinary skill
in the art
to make and use embodiments of the invention. It is understood that the
patentable
scope of embodiments of the invention is defined by the claims, and can
include
additional components occurring to those skilled in the art. Such other
components
and examples are understood to be within the scope of the claims.
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