U.S. patent application number 12/206760 was filed with the patent office on 2010-03-11 for vent system for a cooking appliance.
Invention is credited to Nicholas Okruch, JR., Timothy Scott Shaffer.
Application Number | 20100059040 12/206760 |
Document ID | / |
Family ID | 41798147 |
Filed Date | 2010-03-11 |
United States Patent
Application |
20100059040 |
Kind Code |
A1 |
Shaffer; Timothy Scott ; et
al. |
March 11, 2010 |
VENT SYSTEM FOR A COOKING APPLIANCE
Abstract
A vent system for a cooking appliance is disclosed. The
appliance has a cooktop surface supporting a plurality of surface
heating units. The vent system includes a vent box mounted beneath
the cooktop surface; a telescopic vent assembly telescopically
mounted relative to the vent box, the telescopic vent assembly
being movable between a retracted position proximate the cooktop
surface and an extended position above the cooktop surface; a
retention unit configured to releasably hold the telescopic vent
assembly in the retracted position; and a stored energy mechanical
drive unit configured to move the telescopic vent assembly in a
first direction to the extended position upon release of the
retention unit.
Inventors: |
Shaffer; Timothy Scott;
(LaGrange, KY) ; Okruch, JR.; Nicholas; (Mount
Washington, KY) |
Correspondence
Address: |
General Electric Company;GE Global Patent Operation
PO Box 861, 2 Corporate Drive, Suite 648
Shelton
CT
06484
US
|
Family ID: |
41798147 |
Appl. No.: |
12/206760 |
Filed: |
September 9, 2008 |
Current U.S.
Class: |
126/299D |
Current CPC
Class: |
F24C 15/2042 20130101;
F24C 15/2092 20130101 |
Class at
Publication: |
126/299.D |
International
Class: |
F24C 15/20 20060101
F24C015/20 |
Claims
1. A vent system for a cooking appliance with a cooking area
comprising a cooktop surface supporting a plurality of surface
heating units, comprising: a vent box mounted substantially beneath
the cooktop surface; a telescopic vent assembly telescopically
mounted relative to the vent box, the telescopic vent assembly
being movable between a retracted position proximate the cooktop
surface and an extended position above the cooktop surface; a
retention unit configured to releasably hold the telescopic vent
assembly in the retracted position; and a stored energy mechanical
drive unit configured to move the telescopic vent assembly in a
first direction to the extended position upon release of the
retention unit.
2. The vent system of claim 1, wherein the stored energy mechanical
drive unit comprises a spring system.
3. The vent system of claim 1, wherein the stored energy mechanical
drive unit is configured to move the telescopic vent assembly to
the extended position within about three seconds.
4. The vent system of claim 1, wherein the retention unit is
configured to release the telescopic vent assembly when the
telescopic vent assembly is moved in a second direction
substantially opposite the first direction.
5. The vent system of claim 1, further comprising a detection unit
configured to detect when the telescopic vent assembly is in the
extended position, wherein the vent system is operable for venting
only when the telescopic vent assembly is in the extended
position.
6. The vent system of claim 1, wherein the surface heating units
are arrayed in rows and wherein the telescopic vent assembly has at
least one vent inlet configured to effect an airflow over and
around the cooking area of the appliance when the telescopic vent
assembly is in the extended position, wherein the airflow has a
substantial V-shape, each leg of the substantially V-shaped airflow
passing over a respective row of the surface heating units.
7. The vent system of claim 1, wherein the telescopic vent assembly
has at least one vent inlet located a predetermined distance above
the cooking area of the appliance when the telescopic vent assembly
is in the extended position such that at most about 15% of vented
air is drawn from a relatively lower region sufficiently close to
the surface heating units to effect heating performance.
8. The vent system of claim 7, wherein the predetermined distance
is about seven inches.
9. The vent system of claim 1, wherein the telescopic vent assembly
comprises a cover which is substantially flush with the cooktop
surface, when the telescopic vent assembly is in the retracted
position.
10. The vent system of claim 1, wherein the surface heating units
are gas burners and the appliance comprises grates positioned above
the gas burners and wherein the telescopic vent assembly comprises
a cover which is substantially flush with the cooktop surface or a
top surface of the grates when the telescopic vent assembly is in
the retracted position.
11. The vent system of claim 1, wherein the vent box is configured
for mounting to the cooktop surface such that the telescopic vent
assembly protrudes through the cooktop surface when in the extended
position.
12. A cooking appliance comprising: a cooktop surface; a plurality
of surface heating units located on the cooktop surface; and a vent
system comprising: a vent box mounted substantially beneath the
cooktop surface; a telescopic vent assembly telescopically
supported by the vent box, the telescopic vent assembly being
movable between a retracted position where the telescopic vent
assembly is substantially disposed within the vent box and an
extended position where part of the telescopic vent assembly is
disposed above the cooktop surface; a retention unit configured to
releasably hold the telescopic vent assembly in the retracted
position; and a stored energy mechanical drive unit configured to
move the telescopic vent assembly in a first direction to the
extended position upon release of the retention unit.
13. The cooking appliance of claim 12, wherein the stored energy
mechanical drive unit comprises a spring system.
14. The cooking appliance of claim 12, wherein the stored energy
mechanical drive unit is configured to move the telescopic vent
assembly to the extended position within about three seconds.
15. The cooking appliance of claim 14, wherein the stored energy
mechanical drive unit is configured to move the telescopic vent
assembly to the extended position no faster than one second.
16. The cooking appliance of claim 12, wherein the retention unit
is configured to release the telescopic duct assembly when the
telescopic duct assembly is moved a predetermined distance in a
second direction substantially opposite the first direction.
17. The cooking appliance of claim 12, wherein the telescopic vent
assembly comprises a vent duct telescopically received in the vent
box, the vent duct having an upper end and a vent inlet adjacent to
the upper end, the vent inlet being configured to effect an airflow
over and around at least one of the surface heating units when the
telescopic vent assembly is in the extended position.
18. The cooking appliance of claim 17, wherein the telescopic vent
assembly further comprises a passing-through cover for covering the
vent inlet.
19. The cooking appliance of claim 17, wherein the telescopic vent
assembly further comprises a filter disposed in the vent duct.
20. The cooking appliance of claim 17, further comprising a seal
disposed between the vent box and the vent duct.
Description
BACKGROUND OF THE INVENTION
[0001] The exemplary embodiments of the invention relate generally
to vent systems. More particularly, the exemplary embodiments
relate to downdraft vent systems for a cooking appliance.
[0002] Some downdraft cooktops have a four-burner layout where
there are two burners on either side of the downdraft vent.
Generally, for gas cooktops, the downdraft vent is located in the
middle of the burners with its vent inlet being substantially flush
with the top surface of the grates. The grates rest on the cooktop
surface directly above the gas burners. On electric cooktops, there
are no grates and the vent inlet is basically flush with the
cooking surface. When the downdraft vent is activated, part of heat
from under and around the bottom of a cooking utensil placed on the
cooktop is pulled directly into the downdraft vent before it has a
chance to heat up the utensil and its contents since this path
represents the path of least resistance into the vent. In addition,
when the cooktop includes gas burners the burner flames as well as
the heat is drawn or pulled toward the downdraft vent. Allowing the
burner flames to be drawn into the downdraft vent affects the
performance of the burners, which generally makes the available or
effective burner sizes smaller. As a result of the heat loss and
lower burner ratings (i.e. smaller burner sizes) the ability of the
downdraft cooktop to, for example, boil water or other fluids is
negatively affected. For example, it can take a downdraft cooktop
almost an hour to boil a six-liter load compared to the fourteen or
fifteen minutes it takes a non-downdraft cooktop to boil the same
load.
[0003] Moreover, generally a downdraft vent with its vent inlet
being substantially flush with the top surface of the grates on gas
cooktop appliances and flush with cooktop surface on electric
appliances is also positioned such that it cannot optimally capture
steam and smoke coming out of the utensils during cooktop use. To
overcome this deficiency, the fan, which is located under the
cooktop appliance and downstream of the vent inlet, will generally
be sized for large airflow movement to obtain the desired smoke and
steam capture rates. These large rates come at the expense of
higher noise emissions, larger room energy losses from ambient room
conditions, and even lower efficiencies in delivering heat from the
burners to the cooking utensils.
[0004] Other downdraft cooktops have separate telescoping vent
hoods that generally attach behind the cooktops. U.S. Pat. No.
3,409,005 discloses a backside retractable ventilating flue. Others
have made refinements to this approach, but these telescoping vent
hoods take up additional space, making the cooktop larger and are
located remotely from the cooking zones thereby decreasing their
venting effectiveness. When the cooktop appliances are installed in
kitchen island located in the middle of the room, the separated
telescoping hoods are not practical from both esthetic and
practical standpoints as they interfering in an unsafe manner with
accessing utensils from the back side of the appliances.
[0005] Still other downdraft cooktops have a rotatable vent hood.
In a retracted position the vent hood may be flush with the cooktop
surface. In its extended position the vent hood is rotated about a
fulcrum so that the vent hood is above the cooktop surface.
However, the height of the vent hood is relatively limited.
Moreover, this vent arrangement prevents the use of the middle
section of the cooktop for moving and resting utensils.
[0006] There are other variations where telescoping vents have been
incorporated as an integral part of the downdraft cooktops. These
approaches require either manual adjustment to properly position
vent into extended position or use of a motor to extend vent hood
into place. Manual adjustment requires a certain level of
dexterity, additional time to set up and potential exposure to hot
components when the vent is not extended prior to using the
cooktop. Motorized approaches address the setup time and hot
component exposure issues, but they are prone to being activated
when cooking utensils may be in the path of the extended vent. This
can lead to unsafe conditions to the consumer and damage to the
household. In addition, motorized approaches require additional
complexity in its control to avoid overloading the motor or
damaging the vent components, which generally adds to lower overall
reliability of the cooking appliance.
[0007] This invention proposes a simplified, non-electronic
approach to extend the telescoping vent, while maintaining the
natural advantages of more efficient cooktop operation and better
smoke/steam capture. In lieu of manual or motorized approaches to
extend the vent, a stored energy mechanical drive unit is used to
smoothly extend the vent to its fully extended position.
BRIEF DESCRIPTION OF THE INVENTION
[0008] As described herein, the exemplary embodiments overcome one
or more of the above or other disadvantages known in the art.
[0009] One aspect of the exemplary embodiments relates to a vent
system for a cooking appliance of the type having a cooktop surface
supporting a plurality of surface heating units. The vent system
includes a vent box mounted substantially beneath the cooktop
surface; a telescopic vent assembly telescopically mounted relative
to the vent box, the telescopic vent assembly being movable between
a retracted position proximate the cooktop surface and an extended
position above the cooktop surface; a retention unit configured to
releasably hold the telescopic vent assembly in the retracted
position; and a stored energy mechanical drive unit configured to
move the telescopic vent assembly in a first direction to the
extended position upon release of the retention unit.
[0010] Another aspect of the exemplary embodiments relates to a
cooking appliance. The cooking appliance includes a cooktop
surface; a plurality of surface heating units located on the
cooktop surface; and a vent system. The vent system includes a vent
box; a telescopic vent assembly telescopically supported by the
vent box, the telescopic vent assembly being movable between a
retracted position where the telescopic vent assembly is
substantially disposed within the vent box and an extended position
where part of the telescopic vent assembly is disposed above the
cooktop surface; a retention unit configured to releasably hold the
telescopic vent assembly in the retracted position; and a stored
energy mechanical drive unit configured to move the telescopic vent
assembly in a first direction to the extended position upon release
of the retention unit.
[0011] These and other aspects and advantages of the exemplary
embodiments will become apparent from the following detailed
description considered in conjunction with the accompanying
drawings. It is to be understood, however, that the drawings are
designed solely for purposes of illustration and not as a
definition of the limits of the invention, for which reference
should be made to the appended claims. Moreover, the drawings are
not necessarily drawn to scale and that, unless otherwise
indicated, they are merely intended to conceptually illustrate the
structures and procedures described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] In the drawings:
[0013] FIG. 1 is a schematic, top view of an exemplary cooking
appliance incorporating a vent system in accordance with an
exemplary embodiment of the invention;
[0014] FIG. 2 is a schematic, partial, perspective view of a vent
system in accordance with an exemplary embodiment of the
invention;
[0015] FIGS. 2A and 2B are partially, schematic illustrations of
the vent system of FIG. 2 in retracted and extended configurations;
FIG. 2C schematically illustrates how a linear spring and a rotary
damper engage the vent duct of another embodiment of the vent
system; FIG. 2D is an enlarged, perspective view of the rotary
damper of FIG. 2C;
[0016] FIGS. 3A and 3B are schematic, partial, perspective views of
a vent system in accordance with an exemplary embodiment of the
invention in retracted and extended configurations,
respectively;
[0017] FIGS. 4A and 4B are respectively schematic perspective and
side views of a vent system in accordance with an exemplary
embodiment of the invention in an extended configurations;
[0018] FIG. 5 illustrates an exemplary intake airflow pattern for a
vent system of FIG. 4A;
[0019] FIG. 6 is a graph illustrating an amount of air pulled from
a bottom region of a cooking area relative to a distance of a vent
inlet of the vent system of FIG. 4A above a cooktop surface;
and
[0020] FIG. 7 is a graph illustrating an amount of airflow from a
bottom region of a cooking area and a top region of the cooking
area relative to a distance of the vent inlet of the vent system of
FIG. 4A above the cooktop surface and relative to boiling time.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS OF THE
INVENTION
[0021] FIG. 1 illustrates an exemplary cooking appliance 100
incorporating a vent system in accordance with an exemplary
embodiment of the invention. By way of example only, the cooking
appliance 100 is shown as a cooktop 100 installed on countertop
190. However, the exemplary embodiments described herein may be
used in other types of cooking appliances including, but not
limited to, free standing ranges, slide in ranges and drop in
ranges. It should also be understood that the exemplary embodiments
may be used in cooking appliances with any suitable burner/heater
types, including but not limited to, electric, gas and induction
burners or any combination thereof.
[0022] As can be seen in FIG. 1, the cooktop 100 includes a cooktop
surface 101 having a generally rectangular shape, although in
alternate embodiments the cooktop surface 101 may have any suitable
shape. In this example, four surface heating units 110A-110D are
arranged in a two by two array (e.g., two rows and two columns) on
the cooktop surface 101. The surface heating units 110A-110D may be
electric surface units, gas burners or induction units. The cooktop
100 also includes surface unit controls 120A-120D, which are shown
as being located to a side of the cooktop surface 101. A telescopic
vent system 130 is located in this example toward the back 101B of
the cooktop surface 101, although in alternate embodiments the vent
system 130 may be located to the sides or front of the cooktop
surface 101. It is noted that the configuration of the cooktop 100
shown in FIG. 1 is for exemplary purposes only and in alternate
embodiments the cooktop 100 may have any suitable configuration and
any number of surface heating units, controls and vents suitably
positioned relative to the cooktop surface 101. For example, the
cooktop 100 may include more than two rows of surface heating units
where a telescopic vent is positioned between each or every other
row of surface heating units. In another example, the surface unit
controls may be located along the front 101F of the cooktop surface
101 or on the countertop 190 or corresponding cabinet adjacent the
cooktop 100.
[0023] Referring to FIG. 2, an exemplary embodiment of the
telescopic vent system 230 is shown in an extended configuration.
As can be seen in FIG. 2, the telescopic vent system 230 is
supported by the cooktop surface 101 (the surface heating units are
not shown in FIG. 2 for clarity). In this example, the telescopic
vent system 230 includes a vent box 240 and a telescoping mechanism
290 movingly mounted at least partly within the vent box 240. The
vent box 240 may suitably mounted to, for example, the underside of
cooktop surface 101 and be in flow or fluid communication with a
fan 102 through suitable duct work for pulling in, for example,
steam, smoke and other airborne particles from the cooking area and
routing the exhaust gas to a suitable outlet. In one example the
outlet may include filter(s) for removing particles and odors from
the exhaust gas. In one exemplary embodiment, the fan may be
configured to draw a flow rate of about 500 CFM (Cubic Feet per
Minute) through the vent system 230. In alternate embodiments the
flow rate of air flowing through the vent system 230 may be more or
less than 500 CFM.
[0024] The telescoping mechanism 290 includes a telescoping vent
duct 234 and a duct cover or lid 236 located at the upper end of
the vent duct 234. In this example the vent duct 234 and the duct
cover 236 are shown as having a substantially rectangular cross
section, but in alternate embodiments the vent duct 234 and the
duct cover 236 may have any suitable cross section including, but
not limited to, round, trapezoidal, triangular and octagonal. A
vent inlet 235 may be located through the duct cover 236 and/or on
at least one side of the vent duct 234 so that the vent inlet 235
is in flow or fluid communication with a fluid passage of the vent
duct 234. In this example the vent inlet 235 is shown as a
rectangular slot for exemplary purposes only. In other exemplary
embodiments the vent inlet 235 may have any suitable shape and
size. The vent inlet 235 may also include a grille or grate to, for
example, keep relatively large foreign objects from entering the
vent duct 234. The vent inlet 235 may be configured to muffle the
sound of the airflow and/or fan noise for reduced noise generation
during the operation of the vent system 230. The vent duct 234, the
vent cover 236 and the vent inlet 235 will be referred to herein
for exemplary purposes as the telescopic vent assembly 233. The
vent assembly 233 may protrude through a mounting plate or grate
280 located on (or recessed in) the cooktop surface 101 so that in
a retracted position the duct cover 236 is recessed within the
mounting plate 280 and the vent inlet 235 is sealed against a
surface of the mounting plate 280. For example, as can be seen in
FIG. 2 the mounting plate 280 may include a tapered recess 281. The
vent cover 236 may have a substantially flat top with sides that
are tapered so that the sides fit within the tapered recess 281
where, when the vent assembly 233 is in a closed or retracted
configuration (see e.g. FIG. 2A) the top of the vent cover 236 is
substantially flush with the top surface 280S of the mounting plate
280. In alternate embodiments, the top of the vent cover 236 may
have any suitable shape (e.g. rounded, ribbed, etc.). The vent
inlet 235 may be located on the side of the duct 234 (or of the
vent cover 236) such that when in the retracted configuration the
tapered recess 281 effectively closes off and substantially seals
the vent inlet 235. In alternate embodiments the mounting plate
recess 281 and the vent cover 236 may respectively have any
suitable reciprocal shapes so that the vent inlet 235 is closed. It
is noted that while the top surface 280S of the mounting plate 280
is shown located above the cooktop surface 101, in alternate
embodiments the top surface 280S of the mounting plate 280 (and the
top of the cover 236) may be substantially flush with the cooktop
surface 101. The duct assembly 233 may also include a filter 231
located within the vent duct 234, adjacent to and preferably
downstream of the vent inlet 235, for example, to capture and
prevent grease and/or other particles from entering the vent
ductwork and depositing on or damaging the fan 102. The filter 231
may be located such that it is easily removable for replacement
and/or cleaning.
[0025] The vent system 230 may also include a mechanical drive unit
270 for causing the duct assembly 233 to move in the direction of
arrow 299 to the extended position shown in FIG. 2B. The mechanical
drive unit 270 may be any suitable drive unit that does not require
a motor for movement. However, in alternate embodiments a motor and
suitable power transmissions may be used to drive the vent assembly
233 between the extended and retracted positions.
[0026] In one exemplary embodiment the mechanical drive unit 270
may include a stored energy system such as a spring system that
provides a steady and/or gradual movement of the duct assembly 233
in the direction of arrow 299, but preferably with a feed control
mechanism such as a rotary damper, an air snubber or a hydraulic
dampening piston. For example, the spring system may include a
spring, one end of which is attached to the vent box 240 and the
other end of which is attached to the vent duct 234. In the
retracted position, the spring is extended. As a result, when the
vent assembly 233 is free to move, the spring contracts, thereby
moving the vent assembly 233 to its extended position.
[0027] FIG. 2C shows another embodiment of the spring system
wherein a linear spring 270A is used. One end of the linear spring
270A is attached to the vent duct 234 at point D, the other end is
attached to a rod 271 attached to a guide sleeve 240A of the vent
box 240. Preferably, the mechanical drive unit 270 also includes a
feed control mechanism which is used to control the moving speed of
the vent duct 234 when it extends outward. In the embodiment of
FIG. 2C, the feed control mechanism includes a rotary damper 270B
attached to the guide sleeve 240A, and an elongate slot 234A formed
on the vent duct 234 for receiving the rotary damper 270B. As shown
in FIG. 2D, the rotary damper 270B includes a main body 272 and a
gear 273 which is rotatably attached to the main body 272 and
engages matching teeth formed on one lateral side of the slot 234A.
The rotary damper 270B is configured to provide a damping only when
the vent duct 234 moves outward. One of the functions of the rotary
damper 270B is to ensure that the vent assembly 233 is not extended
at an accelerating speed. The rotary damper 270B is known in the
art, and therefore will not be discussed in detail here.
[0028] In one example, the linear spring 270A and/or the rotary
damper 270B may be configured to fully extend the vent assembly 233
from the retracted position to a predetermined distance B (see
FIGS. 4A and 4B) within a period of about one to about three
seconds. In alternate embodiments the linear spring 270A and/or the
rotary damper 270B may be configured to fully extend the vent
assembly 233 in less than about one second or more than about three
seconds.
[0029] In alternate embodiments the mechanical drive unit may
include magnets, compressed fluid or any other suitable device
configured to store energy for moving the vent assembly 233.
[0030] As clearly shown in FIG. 2B, a seal 282 may be provided
between the mounting plate 280 and the vent duct 234 to at least
partially control the rate of extension of the vent assembly 233
relative to the vent box 240 by friction as well as to provide a
seal for preventing foreign objects such as cooking debris from
being drawn into the vent box 240 through gaps that may exist
between the vent duct 234 and the mounting plate 280. In alternate
embodiments dampers of the mechanical drive unit 270 may, by
themselves, control the rate of extension of the vent assembly 233.
In still other alternate embodiments, the seal 282 alone may
control the rate of extension of the vent assembly 233, by for
example, frictional engagement with the vent duct 234. In yet other
alternate embodiments the rate of extension of the vent assembly
233 may be controlled in any suitable manner.
[0031] As can be seen in FIGS. 2A and 2B, the vent system 230 may
include a detection unit including one or more relay switches 260,
261 to detect when the vent assembly 233 is in the extended or
retracted positions. In this example, two relay switches 260, 261
are shown in the vent box 240 where one switch 260 is located at
the top of the stroke of the vent assembly 233 and the other switch
261 is located at the bottom of the stroke of the vent assembly
233. The vent duct 234 may include relay triggers including, but
not limited to, protrusions, recesses and/or field generating
devices (e.g. magnetic or otherwise). The relay switches 260, 261
may be configured to sense the relay triggers for detecting a
position of the vent assembly 233. In other embodiments one relay
switch may be configured to detect both the extended and retracted
positions of the vent assembly 233. In one exemplary embodiment,
the relay switches 260, 261 may be configured such that the vent
system 230 may only be operated for venting when the vent assembly
233 is in the fully extended position as shown in, for example,
FIGS. 2 and 2B. In alternate embodiments the vent system 230 may be
configured to draw in air even during extension of the vent
assembly 233 to its raised or extended position.
[0032] The vent system 230 may also include a retention unit for
holding the vent assembly 233 in the retracted position. As can be
seen in FIGS. 2A and 2B, the retention unit includes one or more
latching members configured to hold the vent assembly 233 in the
retracted position. In one exemplary embodiment the mechanical
drive unit 270 may be configured to hold the vent assembly 233 in
the extended position (by for example, the linear spring 270A shown
in FIG. 2C) and the retention unit may be configured to hold the
vent assembly 233 in the retracted position. In alternate
embodiments there may be more than one latching members (e.g.
latches 263, 262) which are configured to releasably hold the vent
assembly 233 in the retracted and the extended positions,
respectively. The latching members 262, 263 may include detents,
fingers, levers, claws, or any other suitable device configured to
grasp and releasably hold the vent assembly 233. It is noted that
while the relay switches and the latching members are shown in
FIGS. 2A and 2B as being separate from each other, in alternate
embodiments the relay switches may be part of (e.g., substantially
incorporated in) the latching members for holding the vent assembly
233 in its extended and/or retracted positions.
[0033] In operation of the vent system 230, the latching members
262, 263 may be configured so that the vent assembly 233 is
released by moving the vent assembly 233 in the direction of arrow
298 (see FIG. 2A) for a short, predetermined distance for example,
by a user pressing down on the duct cover 236 in the direction of
arrow 298. For example, there may be sufficient clearance between
the vent cover 236 and the mounting plate 280 to allow the vent
assembly 233 to travel a predetermined distance in the direction of
arrow 298 from its retracted position so that the latching member
263 releases the vent assembly 233 and the mechanical drive unit
270 then drives the vent assembly 233 in the direction of arrow 299
to its extended position shown in FIG. 2B. In alternate embodiments
there may be a release control such as, for example, a button,
switch, knob or lever that is linked to the retention unit which
when activated causes the latching member 263 to release the duct
assembly 233. The release control may be located in any suitable
location such as, for example, on the duct cover 236 or the
mounting plate 280. In other alternate embodiments the retention
unit may be released in any suitable manner. The vent assembly 233
may be returned to the retracted position shown in FIG. 2A from its
extended position by moving the vent assembly 233 in the direction
of arrow 298 until the latching member 263 grasps the vent duct 234
of the vent assembly 233 for holding the vent assembly 233 in the
retracted position. The vent assembly 233 may be manually returned
to the retracted position by, for example, a user pushing the duct
cover 263 in the direction of arrow 298.
[0034] Referring now to FIGS. 3A and 3B, another exemplary
embodiment of a telescopic vent system 330 is shown. The vent
system 330 may be substantially similar to the vent system 230
described above unless otherwise noted so that like features have
like reference numbers. FIG. 3A illustrates the vent assembly 233
in the retracted position while FIG. 3B illustrates the vent
assembly 233 in the extended position. As can be seen in FIGS. 3A
and 3B, the vent cover 336 includes ribs but may have any other
suitable aesthetic or functional features. In this exemplary
embodiment a matching plate 310, which is also shown as having
ribs, may be located adjacent the vent cover 336 when the vent
assembly 233 is in the retracted position. The matching plate 310
and the duct cover 336 (when in the retracted position) may be
configured for resting cooking utensils such as spoons, ladles and
forks thereon. The matching plate 310 as well as the duct cover 336
may be removable for cleaning. In this exemplary embodiment, the
mounting plate 380 includes a substantially flat surface 380F that
is configured to interface with a substantially flat bottom surface
336B of the duct cover 336 for closing the vent inlet 235 when the
vent assembly 233 is in its retracted position.
[0035] Another exemplary embodiment of a vent system 430 is shown
in FIGS. 4A and 4B in a gas cooktop appliance, however, the system
may be used in combination with electric or induction cooktop
appliances as well. The vent system 430 may be substantially
similar to the vent 230 described above except where otherwise
noted. In this exemplary embodiment the vent assembly 433 includes
a telescoping vent duct 434, a filter 431 and a vent cover 436 that
all have a substantially trapezoidal cross section. It is noted
that while the filter 431 is shown as being between the vent cover
436 and the vent duct 434, the filter 431 may be sized to be
removably inserted into the vent cover 436 or the vent duct 434. In
this example as can be seen best in FIG. 4B the vent cover 436 has
vent inlets 435A, 435B located on lateral sides of the vent cover
436. Here the vent inlets 435A, 435B are located on the
non-parallel lateral sides of the trapezoidal shaped duct cover 436
so that the vent inlets 465A, 465B are angled relative to each
other (and relative to the rows/columns of burners 110A-110D) in a
horizontal plane by any suitable angle. In alternate embodiments
the vent inlets may be located on the vent duct 434 or through both
of the duct cover 436 and the vent duct 434. The angled
relationship between the vent inlets 435A, 435B may allow air (see
FIG. 5) to be drawn from different directions from over and around
the cooking area for the removal of, for example, smoke, steam and
other airborne particles.
[0036] Referring to FIG. 5, the air may be drawn into the vent
system 430 along two paths (e.g. one path corresponding to each
vent inlet 435A, 435B) that form a substantially horizontally
oriented (e.g. in a plane substantially parallel with the cooktop
surface 101), substantial V-shape 500 where each leg of the
substantial V-shape passes over a respective row or column of the
burners 110A to 110D. In alternate embodiments, the vent inlets
435A, 435B may be located on any suitable sides of the vent cover
436 including one or more of the parallel lateral sides of the
trapezoidal shaped duct cover 436. The vent inlets 435A, 435B are
shown as having a rectangular shape having a height, but in
alternate embodiments the vent inlets 435A, 435B may have any
suitable shape and/or configuration. In other alternate embodiments
the vent inlets 435A, 435B may have differing heights (e.g. the
vent inlet 435A has a first height and the vent inlet 435B has a
second height which is different from the first height).
[0037] Referring to FIGS. 4A and 4B, the exemplary vent assembly
433 described herein may be movable between two positions (e.g.
retracted and fully extended positions). In alternate embodiments,
the vent duct 434 of the vent assembly 433 may also be configured
with an adjustable height so that the vent inlets can be held at
any suitable height or location between the retracted and fully
extended positions. In the exemplary embodiments, referring to the
embodiment of FIGS. 4A and 4B as an example, the vent inlets 435A,
435B may be located at a distance B above the cooktop surface 101
when the vent assembly 433 is in the fully extended position as
shown in FIG. 4A. In one example the distance B may be about seven
inches, but in alternate embodiments the distance B may be more or
less than seven inches. The distance B may be determined such that
at most about 15% of the vented air is drawn from a bottom region
GZ. Here the term bottom region GZ is used to describe the area
around the burners that effects heat transfer from the burners to
the cooking utensils and has a height of about 2 inches from the
cooktop surface. As can be seen in FIG. 6, the higher a vent inlet
is located above the cooktop surface 101, the less amount of air is
drawn by the vent inlet from the bottom region GZ.
[0038] FIG. 7 illustrates a graph showing the relationship between
the time it takes to boil a predetermined load (i.e. water or other
liquid, such as for exemplary purposes only, a six liter load), the
distance the vent inlets are located above the cooktop surface and
the percentage of air captured by the vent inlets for a gas cooktop
of the type illustrated in FIG. 4A. In FIG. 7, line 700 represents
the time required to reach the boiling point, line 710 represents
the percentage of the captured air that is drawn from the top
region of the cooking area and line 720 represents the percentage
of captured air that is drawn from the bottom region (e.g. grate
zone) of the cooking area. As can be seen in FIG. 7, the time for
the load to reach the boiling point remains substantially constant
(e.g. no significant or appreciable decrease in time to boil) after
the vent inlet reaches a certain distance above the cooktop. In
FIG. 7, this Height Above Cooktop corresponds to the dimension B
shown in FIG. 4A. For example, at a vent inlet height of about
seven inches above the cooktop, less than about 10% of the vented
air is drawn from the grate zone (i.e., the bottom region GZ) while
more than about 70% of the vented air is drawn from a region above
the grate zone.
[0039] The exemplary embodiments described herein provide a
mechanically driven telescopic vent system that is integral to the
cooktop and allows more heat transfer to occur between the burners
and the cooking utensils. The vent system is sized such that ample
room is provided on the cooktop surface to maneuver and rest
cooking utensils between the burners. The mechanical drive unit may
be user activated through, for example, substantial contact with
the telescoping vent assembly so that inadvertent spills caused by,
for example, pot handles protruding into the path of the moving
vent assembly are prevented. The exemplary embodiments also allow
for quieter operation and lower vent fan flow rates as well as
increased burner sizes, as the size of the burners is not
restricted due to the capture of air from the grate zone. In the
case of gas cooktop appliances, electronic control is rarely
applied due to the robustness and versatility of mechanical gas
valves. This mechanical drive due to its simplicity stays true to
this since there is no need for electronic controls to activate a
motor or solenoid device.
[0040] Thus, while there have been shown and described and pointed
out fundamental novel features of the invention as applied to the
exemplary embodiments thereof, it will be understood that various
omissions and substitutions and changes in the form and details of
devices illustrated, and in their operation, may be made by those
skilled in the art without departing from the spirit of the
invention. For example, it is expressly intended that all
combinations of those elements and/or method steps which perform
substantially the same function in substantially the same way to
achieve the same results are within the scope of the invention.
Moreover, it should be recognized that structures and/or elements
and/or method steps shown and/or described in connection with any
disclosed form or embodiment of the invention may be incorporated
in any other disclosed or described or suggested form or embodiment
as a general matter of design choice. It is the intention,
therefore, to be limited only as indicated by the scope of the
claims appended hereto.
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