U.S. patent application number 11/990530 was filed with the patent office on 2009-03-05 for cooking appliance mounted in an elevated manner.
This patent application is currently assigned to BSH Bosch und Siemens Hausgerate GmbH. Invention is credited to Ingo Bally, Kerstin Feldmann, Wolfgang Fuchs, Martin Keller, Edmund Kuttalek, Maximilian Neuhauser, Klemens Roch, Wolfgang Schnell, Gunter Zschau.
Application Number | 20090058237 11/990530 |
Document ID | / |
Family ID | 37248333 |
Filed Date | 2009-03-05 |
United States Patent
Application |
20090058237 |
Kind Code |
A1 |
Bally; Ingo ; et
al. |
March 5, 2009 |
Cooking Appliance Mounted in an Elevated Manner
Abstract
A cooking appliance which is mounted in an elevated manner and
which comprises at least one muffle which defines a cooking area,
whereby said muffle comprises an opening in the base thereof and
which is surrounded by a muffle frame, a base door which is
displaced by means of a drive device and which is used to close the
muffle opening, at least one switch panel which is used to displace
the base door in a directional manner. Said cooking appliance also
comprises a memory unit which is used to memorise at least one
target position of the base door, wherein the base door can be
displaced in an automatic manner to the stored target position
after the switch panel is actuated, until at least one target
position is reached.
Inventors: |
Bally; Ingo; (Traunstein,
DE) ; Feldmann; Kerstin; (Bretten, DE) ;
Fuchs; Wolfgang; (Altenmarkt a.d. Alz, DE) ; Keller;
Martin; (Traunreut, DE) ; Kuttalek; Edmund;
(Grassau, DE) ; Neuhauser; Maximilian;
(Chieming/Egerer, DE) ; Roch; Klemens; (Trostberg,
DE) ; Schnell; Wolfgang; (Trostberg, DE) ;
Zschau; Gunter; (Traunwalchen, DE) |
Correspondence
Address: |
BSH HOME APPLIANCES CORPORATION;INTELLECTUAL PROPERTY DEPARTMENT
100 BOSCH BOULEVARD
NEW BERN
NC
28562
US
|
Assignee: |
BSH Bosch und Siemens Hausgerate
GmbH
Munchen
DE
|
Family ID: |
37248333 |
Appl. No.: |
11/990530 |
Filed: |
August 1, 2006 |
PCT Filed: |
August 1, 2006 |
PCT NO: |
PCT/EP2006/064882 |
371 Date: |
February 14, 2008 |
Current U.S.
Class: |
312/228 |
Current CPC
Class: |
F24C 7/08 20130101; F24C
15/027 20130101 |
Class at
Publication: |
312/228 |
International
Class: |
F24C 15/02 20060101
F24C015/02 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 17, 2005 |
DE |
10 2005 038 916.3 |
Claims
1-21. (canceled)
22. An elevated cooking appliance comprising: at least one muffle
defining a cooking chamber, with the at least one muffle having a
base side and a muffle opening formed on the base side; a base door
for moving into and out of a covering relationship with the muffle
opening; a drive device operatively associated with the base door,
with the base door being movable by the drive device into and out
of a covering relationship with the muffle opening; at least one
displacement switch for selectively moving the base door in a
selected direction; and a memory unit for storing at least one
target position of the base door whereby upon storing a target
position and actuation of the at least one displacement switch, the
base door is automatically moved to a next selected target position
present in the relevant displacement direction.
23. The elevated cooking appliance as set forth in claim 22 further
including an actuation button; the at least one target position
being stored by actuating the actuation button with the base door
at the target position.
24. The elevated cooking appliance as set forth in claim 23 further
including at least one optical and/or acoustic signaling device;
the at least one optical and/or acoustic signaling device being
activated when the actuation button has been actuated and a target
position stored thereby.
25. The elevated cooking appliance as set forth in claim 22 further
including a jamming protection device; the jamming-protection
device being activated when a target position has been stored.
26. The elevated cooking appliance as set forth in claim 22 wherein
the memory unit includes at least one volatile memory chip for
storing the target position.
27. The elevated cooking appliance as set forth in claim 22 further
including means for gently starting the movement of the base door
and gently braking the base door when a target position has been
stored.
28. The elevated cooking appliance as set forth in claim 22 whereby
in the absence of a stored target position for a displacement
direction, the base door can be displaced only by appropriately
actuating at least one of the displacement switch panel
continuously.
29. The elevated cooking appliance as claimed in claim 28 further
including a second displacement switch panel whereby in the absence
of a stored target position for a displacement direction, the base
door can be displaced only by actuating both displacement switch
panels continuously and simultaneously.
30. The elevated cooking appliance as set forth in claim 29 further
including a housing; the displacement switch panels being attached
to the front of the housing.
31. The elevated cooking appliance as set forth in claim 29 further
including a housing; the displacement switch panels being attached
to opposite sides of the housing.
32. The elevated cooking appliance as set forth in claim 28,
further including means for gently starting the movement of the
base door and for abruptly stopping the moving of the base door in
the absence of a stored target position.
33. The elevated cooking appliance as set forth in claim 25 further
including means for deactivating the jamming-protection device in
the absence of a stored target position.
34. The elevated cooking appliance as set forth in claim 22 further
including a power-failure buffer; means for re-initializing travel
measuring of the base door at the zero position, wherein travel
measuring of the displacement path is carried out incrementally;
and wherein the drive device includes a motor shaft; at least one
sensor for travel measuring of the displacement path of the base
door, with the sensor located on the motor shaft of the drive
device.
35. The elevated cooking appliance as set forth in claim 37 wherein
the sensor is a Hall sensor.
36. The elevated cooking appliance as set forth in claim 22 further
including a main switch; the base door being displaceable with the
main switch deactivated.
37. The elevated cooking appliance as set forth in claim 22 wherein
automatic displacement of the base door can be deactivated when the
displacement switch panel has been actuated for longer than a
predetermined actuating time.
38. The elevated cooking appliance as set forth in claim 34 wherein
said predetermined actuating time is 0.4 seconds.
39. A method for operating an elevated cooking appliance having at
least one muffle that delimits a cooking chamber, a base side, a
muffle opening on the base side, a base door and a drive device
with the base door being displaceable by the drive device for
closing the muffle opening, at least one displacement switch panel
for enabling the displacement of the base door
direction-dependently, and a memory unit, comprising: storing at
least one target position of the base door in the memory unit;
actuating the at least one displacement switch panel; and
automatically displacing the base door to the next target position
present in the relevant displacement direction.
40. The method as set forth in claim 39 further including, in the
absence of a stored target function for a direction, continuing to
displace the base door in the relevant displacement direction only
while at least one displacement switch panel is being actuated.
41. The method as set forth in claim 40 further including
displacing the base door in the relevant displacement direction
only while two (2) displacement switch panels are actuated
simultaneously.
Description
[0001] The present invention relates to a high-fitted cooking
appliance having at least one muffle that delimits a cooking
chamber and has on its base side a muffle opening, a base door that
is displaceable by means of a drive device for closing the muffle
opening, and at least one displacement switch panel for displacing
the base door direction-dependently.
[0002] Known from, for example, U.S. Pat. No. 2,944,540, DE 102 28
140 A1, and DE 101 64 239 A1 are high-fitted cooking appliances in
the case of which a base door is displaceable by means of a drive
motor, with the base door being displaceable in the desired
direction when a displacement button has been actuated.
[0003] It is disadvantageous that such an operating manner is
inconvenient for the user, especially since the desired final
position can frequently be reproduced only with difficulty if not
corresponding to a resting position on a work plate or to a final
position specified in the design.
[0004] The object of the present invention is therefore to provide
a high-fitted cooking appliance that is simpler to operate and
flexible in terms of adjusting and displacing its base door.
[0005] The present object is achieved by means of the cooking
appliance having the features of claim 1 and of the method as
claimed in claim 18.
[0006] A memory unit for storing at least one target position of
the base door is provided for that purpose. If a target position
requiring to be attained has been stored, then the base door will
keep moving automatically once the displacement switch panel has
been actuated accordingly until said (next) target position has
been reached (automatic operation).
[0007] It will be advantageous if the at least one target position
can be stored by actuating an actuating button, for example for 2
to 4 seconds, with the base door at the target position. An
actuating or storing signal, for example an optical and/or acoustic
signal, is then favorably fed out.
[0008] Since the at least one displacement button, which is not
limited in type, shape, or arrangement, needs to be actuated only
briefly during automatic operation, for increased operational
safety it will be advantageous for a jamming-protection device to
have been activated when a target position has been stored.
[0009] To ensure that the--then possibly incorrect or unsafe target
position(s)--will have been cleared following a relocation or a
structural alteration, the memory unit includes volatile memory
chips, for example RAMs such as DRAMs, SRAMs, MRAMs etc., for
storing the target position. However, so that not every fluctuation
in the a.c. power supply will clear the target positions (also
called displacement positions), a power-failure buffer is provided
typically for bridging fluctuations or outages in said supply
lasting up to a few seconds.
[0010] For quiet operation the base door can advantageously be
started up gently and braked gently, favorably by means of a speed
or load ramp, once a target position has been stored.
[0011] The base door can in the absence of a stored target position
for a displacement direction preferably be displaced only by
appropriately actuating at least one of the displacement switch
panels continuously (manual operation). Said target position can be
absent if, for example, either no target position has been stored
for that displacement direction--for example only a target position
for an open position has been stored, which in the closing
direction can mean the absence of a target position that can be
moved to--or the single or last target position for that
displacement direction has already been reached and no further
target position is available for a further displacement in the same
displacement direction. Manual operation will also become active if
the displacement switch panel is actuated for longer than a
specific maximum actuating time for automatic operation, in
particular 0.4 seconds. Manual operation will then take precedence
over automatic operation even in the presence of a target position
that can be moved to.
[0012] For increased operational safety, in the absence of a stored
target position for a displacement direction it is advantageous for
the base door to be displaceable only by appropriately actuating
two displacement switch panels continuously and simultaneously,
i.e. with both hands.
[0013] For convenient displacing it is advantageous for the
displacement switch panels to be attached to the front of a
permanently installable housing. They can, though, also be attached
to, for example, opposite sides of the permanently installable
housing or at other locations.
[0014] For increased operational safety it is also advantageous if
during manual operation--i.e. when the base door will move only
when the displacement switch panel has been actuated--the base door
will, although starting by moving gently, stop abruptly, i.e. will
halt, for example through short-circuiting of the drive motor, as
soon as the relevant displacement panel has been released.
[0015] A jamming-protection device will advantageously have been
deactivated during manual operation and activated during automatic
operation.
[0016] The base door can advantageously be displaced, during manual
and/or automatic operation, even when the main switch is off.
[0017] For moving more precisely to the target positions it is
possible to initialize travel measuring at the zero position,
meaning in the defined closed condition. It is also favorable for
travel measuring of the displacement path to be carried out
incrementally and also for travel measuring of the displacement
path--and hence of the position--of the base door to be carried out
by means of at least one sensor, in particular a Hall sensor,
located on a motor shaft of the drive device.
[0018] There are two displacement switch panels for that purpose so
that the base door can be displaced only when both displacement
switch panels have been actuated in the same direction for
displacing the base door. That two-handed operation will prevent
jamming of a free hand.
[0019] At least one displacement switch panel preferably includes a
separate displacement button for each displacement direction, thus
typically in each case an opening switch "OPEN" and a closing
switch "CLOSE", for example pushbuttons. Thus both "OPEN" switches
must have been actuated for displacing the base door in an opening
direction and both "CLOSE" switches must have been actuated for
displacing the base door in a closing direction.
[0020] The invention is described schematically in more detail
below with the aid of the attached figures:
[0021] FIG. 1 is a perspective view of a high-fitted cooking
appliance mounted on a wall and having a lowered base door;
[0022] FIG. 2 is a perspective view of the high-fitted cooking
appliance having a closed base door;
[0023] FIG. 3 is a perspective view of a housing of the high-fitted
cooking appliance without the base door;
[0024] FIG. 4 is a schematic side view, in cross-section along the
line I-I shown in FIG. 1, of the high-fitted cooking appliance
mounted on the wall and having a lowered base door;
[0025] FIG. 5 is a front view of a further embodiment variant of a
high-fitted cooking appliance;
[0026] FIGS. 6 to 11 are graphs of displacement movements of a base
door under different boundary conditions;
[0027] FIGS. 12 and 13 are force-time profile graphs for a base
door.
[0028] FIG. 1 shows a high-fitted cooking appliance having a
housing 1. The rear of the housing 1 is mounted in the manner of a
hanging cabinet on a wall 2. Defined in the housing 1 is a cooking
chamber 3 that can be checked via a viewing window 4 provided at
the front in the housing 1. It can be seen in FIG. 4 that the
cooking chamber 3 is delimited by a muffle 5 provided with a
thermally insulating casing (not shown) and that the muffle 5 has a
muffle opening 6 on its base. The muffle opening 6 can be closed by
means of a base door 7. The base door 7 is shown lowered in FIG. 1,
resting with its underside on a work plate 8 of an item of kitchen
furniture. In order to close the cooking chamber 3 the base door 7
must be moved into the position shown in FIG. 2, which is termed
the "zero position". For moving the base door 7 the high-fitted
cooking appliance has a drive device 9, 10. The drive device 9, 10
has a drive motor 9, indicated in FIGS. 1, 2, and 4 by means of
dashed lines, which is located between the muffle 5 and an exterior
wall of the housing 1. The drive motor 9 is located in the area of
the rear of the housing 1 and, as shown in FIG. 1 or 4, is
operatively connected to a pair of lifting elements 10 linked to
the base door 7. According to the schematic side view shown in FIG.
4 each lifting element 10 is therein embodied as an L-shaped
support whose vertical limb extends from the drive motor 9 on the
housing side. For moving the base door 7 the drive motor 9 can be
actuated with the aid of an operating panel 12 and a control
circuit 13, which panel is according to FIGS. 1 and 2 located at
the front on the base door 7. As shown in FIG. 4, the control
circuit 13 is located behind the operating panel 12 inside the base
door 7. The control circuit 13, consisting here of a plurality of
spatially and functionally separate printed-circuit boards that
communicate via a communication bus, constitutes a central control
unit for operating the appliance and controls and/or regulates, for
example, heating, displacing of the base door 3, implementing of
user inputs, illuminating, jamming protection, clocking the heating
elements 16, 17, 18, 22, and much more.
[0029] It can be seen from FIG. 1 that a top side of the base door
7 has a cooking area 15. Virtually the entire surface of the
cooking area 15 is occupied by heating elements 16, 17, 18,
indicated in FIG. 1 by dot-and-dash lining. The heating elements
16, 17 are in FIG. 1 two differently sized cooking-hob heating
elements spaced apart, while the heating element 18 is a panel
heating element provided between and almost enclosing the two
cooking-hob heating elements 16, 17. For the user, the cooking-hob
heating elements 16, 17 define associated cooking zones or cooking
troughs; together with the panel heating element 18, the
cooking-hob heating elements 16, 17 define a bottom-heat zone. The
zones can be indicated by means of a suitable decorative design on
the surface. The heating elements 16, 17, 18 can each be controlled
via the control circuit 13.
[0030] In the exemplary embodiment shown the heating elements 16,
17, 18 are embodied as radiating heating elements covered by a
glass ceramic plate 19. The glass ceramic plate 19 has
approximately the same dimensions as the top side of the base door
7. The glass ceramic plate 19 is furthermore fitted with mounting
openings (not shown) through which protrude bases for fixing
securing parts 20 for supports 21 for items being cooked, as also
shown in FIG. 4. Instead of a glass ceramic plate 19 it is also
possible to employ other--preferably fast-reacting--coverings, for
example a thin metal plate.
[0031] The high-fitted cooking appliance can with the aid of an
operating knob provided in the operating panel 12 be switched to a
cooking-hob operating mode or bottom-heat operating mode, which are
explained below.
[0032] The cooking-hob heating elements 16, 17 can in the
cooking-hob operating mode be controlled individually via the
control circuit 13 by means of control elements 11 provided in the
operating panel 12, while the panel heating element 18 remains in
the non-operating state.
[0033] The cooking-hob operating mode can be used with the base
door 7 lowered, as is shown in FIG. 1. However it can also be used
within the scope of an energy-saving function when the cooking
chamber 3 is closed with the base door 7 raised.
[0034] In the bottom-heat operating mode not only the cooking-hob
heating elements 16, 17 but also the panel heating element 18 are
controlled by the control device 13.
[0035] To achieve maximally even browning of items being cooked
using the bottom-heat mode it is crucial for the cooking area 15
providing the bottom heat to distribute the heating output evenly
across the surface of the cooking area 15, although the heating
elements 16, 17, 18 have different nominal outputs. The heating
elements 16, 17, 18 are therefore preferably not switched to
continuous operation by the control circuit 13; the power supply to
the heating elements 16, 17, 18 is instead clocked. The different
nominal heat outputs of the heating elements 16, 17, 18 are therein
reduced individually in such a way that the heating elements 16,
17, 18 will distribute the heating output evenly across the cooking
area's surface.
[0036] FIG. 4 shows schematically the position of a fan 23, for
example for producing circulating air in the case of hot-air
operation or for ducting fresh air inward. Further provided
attached to a top side of the muffle 5 is a top-heat heating
element 22 that can be embodied as of single-circuit or
multiple-circuit design, for example having an inner and an outer
circuit. There can also be further heating elements--not shown here
for the sake of greater clarity--, such as a ring-shaped heating
element, between the back wall of the housing 1 and the muffle. The
various operating modes such as, for example, also top-heat,
hot-air, or quick-heat mode can be set by means of the control
circuit 13 by appropriately switching or setting the heat output of
the heating elements 16, 17, 18, 22, possibly with activating of
the fan 23. The heat output can be set by means of suitable
clocking. The cooking area 15 can furthermore be embodied
otherwise, for example with or without a frying zone, as a
pure--single-circuit or multiple-circuit--warming zone without
cooking troughs, and so forth. The housing 1 has a seal 24 toward
the base door 7.
[0037] The operating panel 12 is arranged chiefly on the front of
the base door 7. Other arrangements are alternatively also
conceivable, for example on the front of the housing 1, distributed
over different partial panels, and/or in part on side surfaces of
the cooking appliance. Further embodiments are possible. The
control elements 11 are not limited in their structural design and
can include, for example, operating knobs, toggle switches,
pushbuttons, and membrane keys that include display elements 14,
for example LED, LCD, and/or touchscreen displays.
[0038] FIG. 5 is a schematic front view, not to scale, of a
high-fitted cooking appliance in which the base door 7 is open and
resting on the work plate 8. The closed condition is indicated by
dashed lining.
[0039] In that embodiment variant there are two displacement switch
panels 25 on the front of the permanently attached housing 1. Each
displacement switch panel 25 includes two pushbuttons, namely a top
CLOSE pushbutton 25a for a base door 7 moving upward in the closing
direction and a bottom OPEN pushbutton 25b for a base door 7 moving
downward in the opening direction. The base door 7 will without
automatic operation (see below) move upward, if possible, only
through continuously simultaneously pressing the CLOSE buttons 25a
on both displacement switch panels 25; the base door 7 will also
move downward, if possible, only through continuously
simultaneously pressing the OPEN buttons 25b on both displacement
switch panels 25 (manual operation). Since the user will be more
attentive to operation during manual operation and, moreover, both
hands are used in that case, jamming protection will then only be
optional. Displacement switch panels 26 are in an alternative
embodiment variant attached to opposite outer sides of the housing
1 along with corresponding CLOSE buttons 26a and OPEN buttons 26b,
as indicated by dotted lining.
[0040] The control circuit 13 that is indicated by dot-and-dash
lining and located inside the base door 7 behind the operating
panel 12 switches the drive motor 9 in such a way that the base
door 7 will start moving gently, i.e. not abruptly through simple
turning on of the drive motor 9 but by means of a defined ramp.
[0041] The control circuit 13 includes in that exemplary embodiment
a memory unit 27 for storing at least one target or displacement
position P0, P1, P2, PZ of the base door 7, preferably with
volatile memory chips, for example DRAMs. After one of the buttons
25a, 25b or, as the case may be, 26a, 26b on the displacement
switch panels 25 or, as the case may be, 26 has been actuated, if a
target position P0, P1, P2, PZ has been stored the base door can
continue moving automatically in the direction set until the next
target position has been reached or one of the buttons 25a, 25b or,
as the case may be, 26a, 26b has been actuated again (automatic
operation). The bottommost target position PZ corresponds in that
exemplary embodiment to the maximum opening, the (zero) position P0
corresponds to the closed condition, and P1 and P2 are freely
configurable intermediate positions. When the last target position
for a direction has been reached, it will thereafter be necessary
to proceed using manual operation if that is possible (meaning if
the last end positions do not correspond to a maximum open
condition or to the closed final condition). Analogously, if no
target position has been stored for a direction--which would be the
case, for example, for an upward direction to the closed position
if only PZ has been stored but not P0, P1, P2--, a displacement in
said direction will have to take place using manual operation.
Automatic operation will not be possible if no target position has
been stored, for example in the case of a new installation or
following a disconnection from the a.c. power supply. Jamming
protection will preferably have been activated if the base door 7
is displaced using automatic operation.
[0042] Automatic and manual operation are not mutually exclusive:
The base door 7 will through continuously actuating the
displacement switch panel(s) 25, 26 also move using manual
operation if a target position could be moved to in said direction.
It is therein possible to, for example, specify a maximum actuating
time, for instance 0.4 seconds, for the displacement panels 25 or,
as the case may be, 26, or for the associated buttons 25a, 25b or,
as the case may be, 26a, 26b, for activating automatic
operation.
[0043] A target position P0, P1, P2, PZ can be any position of the
base door 7 between and including the zero position P0 and the
maximum open position PZ. However the maximum stored open position
PZ does not have to be the position resting on the work plate 8.
The target position P0, P1, P2, PZ can be stored with the base door
7 at the desired target position P0, P1, P2, PZ by, for example,
actuating an actuating button 28 in the operating panel 12 for
several seconds (for example two seconds continuously). For the
sake of greater clarity existing optical and/or acoustic signaling
devices that feed out relevant signals when a target position has
been stored have not been drawn. The desired target position P0,
P1, P2, PZ requiring to be set is moved to by, for example, --in
this exemplary embodiment--operating the displacement switch panels
25 or, as the case may be, 26 with both hands and performing a
manual displacement up to said position.
[0044] Just one target position or, as shown in this exemplary
embodiment, also a plurality of target positions P0, P1, P2, PZ can
be capable of being stored in the memory unit 27. In the case of a
plurality of target positions P0, P1, P2, PZ, they can be moved to
consecutively by actuating the corresponding displacement buttons
25a, 25b or, as the case may be, 26a, 26b. A plurality of target
positions P0, P1, P2, PZ will allow the high-fitted cooking
appliance to be matched conveniently to the different operating
heights desired by several users. The target position(s) can
advantageously be cleared and/or overwritten. For example just one
target position can in one embodiment variant be stored in the open
condition while the zero position P0 will be detected automatically
and can be moved to automatically. The zero position P0 must
alternatively also be stored so that it can be moved to
automatically.
[0045] For an ergonomic use it is particularly advantageous for the
or a target position P1, P2, PZ to open the base door 7 at least
approximately 400 mm to approximately 540 mm (meaning P1-P0, P2-P0,
PZ-P0.gtoreq.40 cm to 54 cm). The supports 21 for items being
cooked will at that opening extent be easy to insert into the
securing parts 20. It is therein favorable for the viewing window 4
to be mounted approximately at the user's eye level or somewhat
lower, for example by means of a template indicating the cooking
appliance's dimensions.
[0046] Not drawn is a power-failure buffer for bridging power
outages lasting approximately 1 to 3 s, preferably up to 1.5 s.
[0047] The drive motor 9 shown in FIG. 1 has at least one sensor
unit 31, 32 located on a motor shaft 30, where applicable in front
of or behind a gear, for measuring a displacement path or, as the
case may be, a position and/or speed of the base door 7. The sensor
unit can include, for example, one or more induction, Hall,
optical, or OFW sensors, and so forth. For simple path and speed
measuring two Hall (sub-)elements 31 are here attached displaced
through 180.degree. to the motor shaft 30--thus placing them
mutually opposite--and a Hall sensing element 32 is statically
attached to that area of the motor shaft at a distance. When a Hall
element 31 then passes the sensing element 32 when the motor shaft
30 turns, a measuring or sensor signal will be produced that is
very approximately digital. Two signals will hence be fed out with
(not necessarily) two Hall elements 31 when the motor shaft 30
turns once. The speed vL of the base door 7 can be determined by
evaluating the time of said signals, for example their time
difference, for instance by way of comparison tables or through
real-time conversion in the control circuit 13. A displacement path
or, as the case may be, a position of the base door 7 can be
determined by adding or, as the case may be, subtracting the
measurement signals.
[0048] A speed-regulating means can implement the speed via, for
example, a PWM-controlled power-semiconductor device.
[0049] For determining the zero point, travel measuring is
automatically realigned by initializing in the zero position P0 of
the base door 7 each time it is moved so that for example a faulty
sensor-signal output or, as the case may be, reception will not
propagate.
[0050] The drive motor 9 can also be operated by actuating both
displacement switch panels 25 or 26 with the main switch 29
deactivated.
[0051] Instead of two separate switches per displacement panel 25,
26 a single switch per displacement panel is also possible, for
example a toggle switch that has a neutral position and switches
only under pressure. Other forms are also possible. The nature and
arrangement of the control elements 28, 29 of the operating panel
12 are not limited, either.
[0052] The arrangement of the control circuit 13 and the way it is
distributed is therein flexible and not limited, so it can also
include a plurality of boards, for example a display board, a
control board, and a lift board, that are spatially separated.
[0053] A 4-mm opening extent can be detected by means of end
switches 33 which on actuation deactivate jamming protection.
[0054] The high-fitted cooking appliance can be embodied also
without a memory unit 27, with automatic operation then not being
possible. That can be expedient for increased operating safety, for
example as a safeguard against jamming.
[0055] FIG. 6 is a graph, not to scale, plotting the displacement
speed vL of the base door 7 in mm/s against said door's position in
mm from the zero position P0 for a displacement of the base door 7
from the closed condition at P0=0 mm to PZ=maximum opening at, in
this case, 530 mm during a manual displacement operation (thus
without automatic-displacing means) as well as, indicated by the
dotted arrow, stopping of the displacement movement between P0 and
PZ. The curve runs in the direction of the arrow, meaning from
right to left. The downward arrows above the curve indicate
actuating of the operating panel 12.
[0056] The downward displacement movement of the base door 7 starts
with two-handed actuating of the displacement switch panels 25, 26
or, as the case may be, of the OPEN switches 25b or, as the case
may be, 26b, as indicated by the top left vertical arrow. The
control circuit 13 regulates the drive motor 9 in such a way that
the base door 7 will be moved gently, i.e. with a defined ramp R1,
up to its setpoint speed of, in this case, vL=50 mm/s. The ramp R1
is in that case linear. So the drive motor 9 is not simply turned
on.
[0057] The displacement movement is as a result also
load-independent, in particular independent of any additional
loading of the base door 7 or of any changes in the frictional
conditions within the mechanism. An initial variable for this can
be the rotational speed, measurable by, for example, Hall sensors,
of the drive motor 9.
[0058] The base door 7 moves constantly downward after reaching the
setpoint speed of vL=50 mm/s until approaching the maximum opening
PZ determined by the maximum displacement of the base door 7
specified in its design or by reaching of the work plate 8. It is
assumed in that figure that the maximum opening PZ specified in the
design is reached. In that case the control circuit 13 will detect
said approaching and automatically brake the base door 7 gently,
i.e. with a defined ramp R2, at PZ. Both ramps R1 and R2 can have
other inclinations or shapes. Approaching of the base plate can be
detected by end switches 33 and/or through monitoring of the
displacement path.
[0059] If one or both of the displacement switches 25b, 26b is/are
released, as indicated by the top left vertical arrow, the base
door 7 will stop abruptly without a ramp, as indicated by the
dotted arrow. So although moving starts gently in that mode, it
will stop abruptly--except when the final position has been
reached.
[0060] The cooking chamber 3 will not be opened, meaning the base
door 7 will not be displaced from the zero position P0, if an
opening-protection means is active, so if, for example, a specific
temperature in the cooking chamber, for example 425.degree. C. or
600.degree. F., has been exceeded or a child-protection means has
been activated.
[0061] FIG. 7 is a graph, not to scale, analogous to FIG. 6
relating to a displacement of the base door 7 from the closed
condition to a stored position P1=476 mm during automatic
displacement operation.
[0062] In that case the base door 7 starts moving automatically
toward the position P1 through brief actuating of one of the OPEN
switches 25b or, as the case may be, 26b, as indicated by the top
right vertical arrow. The base door 7 will in that case, too, start
being moved gently (right ramp) and braked automatically (left
ramp). With that embodiment variant it is possible during automatic
operation to select between two fixed setpoint speeds, namely 75
mm/s (dashed line) and 50 mm/s (unbroken line), with the slower
speed being favorable especially for older users. The slower speed
setting is the default in, for example, the condition as supplied.
More than two speed settings or, as the case may be, setpoint
speeds can also be provided; flexible setting of the setpoint
speed(s) by the user is also conceivable. It is favorably also
possible to change over between at least two speed settings of 50
mm/s and 65 mm/s, for example when the appliance is being
initialized.
[0063] FIG. 8 is a graph, not to scale, relating to a displacement
of the base door 7 from the maximum open position PZ to the zero
position P0, meaning to the closed condition, during manual
operation.
[0064] The upward displacement movement of the base door 7 starts
with two-handed actuating of the CLOSE switches 25a or, as the case
may be, 26a, as indicated by the top left vertical arrow. The
control circuit 13 regulates the drive motor 9 in such a way that
the base door 7 will be moved gently from PZ up to its setpoint
speed of vL=50 mm/s, then be moved constantly at that setpoint
speed (to the right).
[0065] The control circuit 13 will detect approaching of the zero
position P0 and gently brake the base door 7 in good time in
advance. However, instead of its then continuing down to the zero
position P0 directly by means of the linear ramp, 4 mm before the
zero position P0 speed-dependent controlling will be switched over
to controlling by means of a defined voltage, i.e. through
supplying the motor 9 with an appropriate voltage. That will allow
maximum force to develop with blocking of the drive motor 9. Said
voltage will differ depending on the prior displacement history
(additional loading, frictional conditions etc.). The 4-mm opening
extent is detected through travel measuring or additionally or
alternatively by way of the end switches 33. It is also possible to
dispense with jamming protection in the range from P0 to P0+4
mm.
[0066] If, as in FIG. 6, one or both of the displacement switches
25b, 26b is/are released, as indicated by the top right vertical
arrow, the base door 7 will stop abruptly without a ramp, as
indicated by the dotted arrow.
[0067] FIG. 9 is a graph, not to scale, relating to a displacement
of the base door 7 from a stored position P1=476 mm to the closed
condition P0 during automatic displacement operation. In contrast
to the manual displacement operation shown in FIG. 8, only one of
the CLOSE switches 25a, 26a now needs to be briefly actuated, as
indicated by the top vertical arrow. The base door 7, analogous to
FIG. 7, will then only move in the other direction. When the zero
position P0 is approached, then analogously to the situation shown
in FIG. 8 for the last 4 mm of opening the brake ramp will change
from a speed-controlled condition to one controlled by load or, as
the case may be, closing force.
[0068] FIG. 10 is a graph, analogous to FIG. 8, in the case of
which jamming now occurs at a setpoint speed of vL=50 mm/s, as
indicated by the top vertical arrow. The speed of the base door 7
will drop when a hand or a pot for example becomes jammed between
the base door 7 and the housing 1 because the object will prevent
further displacing. The lifting speed is here monitored by, for
example, evaluating the motor shaft's sensor signals, with, for
example, the time between the measuring signals or, as the case may
be, pulses being evaluated. The motor current is monitored only as
a secondary measure, which is a somewhat slower method. The force
that can be produced by the motor 9 for displacing is in particular
limited to prevent accidents due to too tight jamming (see also
FIGS. 12 and 13). Any deviations from the setpoint speed will be
detected by the control circuit 13 based on, for example, a
deviation in speed or change therein over time. The base door will
then reverse so that the object can be removed; an acoustic, for
instance, warning signal may also be fed out. The base door 7 will
thereafter only start moving once a displacement-button panel 25,
26 has been actuated again appropriately.
[0069] So that a jamming incident will not be triggered erroneously
owing to, for example, changed additional loading or a change in
the mechanism's running properties, firstly, jamming protection can
be activated only once the base door 7 has reached its setpoint
speed (the base door 7 will stop immediately if a displacement
button 25a, 25b, 26a, 26b is released before that) and, secondly, a
plurality of sensor signals can be evaluated, for example
averaged.
[0070] FIG. 11 shows a jamming incident (top vertical arrow)
occurring while the base door 7 is being displaced into an open
target position P1 during automatic operation during which an
object becomes jammed between the underside of the base door 7 and
the work plate 8. In that case jamming can be detected via two
redundant end switches that detect--in particular uneven--unloading
of the base door 7, whereupon the drive motor 9 will reverse. The
maximum permitted force-time profile (see FIGS. 12 and 13) will
therein not be exceeded.
[0071] FIG. 12 shows as a first force-time profile FT1 a maximum
force F in N that can be applied to the base door 7 during a
jamming incident occurring during displacement in a closing
direction (meaning upward), plotted against the expired time t in
s.
[0072] During a jamming incident at t=0 s the possible closing
force is limited for 5 s to 100 N, corresponding approximately to
10 kg. That will be expedient if, for example, the motor 9 is
stepped up by the control device 13 in order to maintain the
setpoint speed. This will ensure in particular that parts of the
body will not be injured. If the base door is pulled for 5 s with a
force of (at most) 100 N, the maximum force that can be applied
will be further reduced to 25 N, for example for 5 seconds. Said
force level can thereafter either be maintained or further reduced
to, for example, 0 N. It must be emphasized that said force-time
profile FT1 indicates only the maximum force that can be applied
and that the force actually applied will as a rule be less if, for
example, the jamming incident is detected by the control device 13
and the base door 7 reversed accordingly after t=0.5 s, whereupon
the force being applied will drop from 100 N to, for instance, 0
N.
[0073] The maximum force threshold of 100 N can also apply to other
displacement situations.
[0074] FIG. 13 shows as a second force-time profile FT2 a maximum
force F in N that can be applied to the base door 7 during a
jamming incident occurring during displacement in an opening to the
base door 7 during a jamming incident occurring during displacement
in an opening direction (meaning downward), plotted against the
expired time t in s. The drive motor 9 can here in a first block of
t=[0 s; 0.5 s] be applied to the base door 7 with a force of up to
400 N, thereafter at t=[0.5 s; 5 s] with a force of 150 N, and
thereafter with a force of 25 N.
[0075] The time intervals and force thresholds of the force-time
profiles FT1, FT2 can of course be accommodated to physical
structure and other boundary conditions.
LIST OF REFERENCES
[0076] 1 Housing [0077] 2 Wall [0078] 3 Cooking chamber [0079] 4
Viewing window [0080] 5 Muffle [0081] 6 Muffle opening [0082] 7
Base door [0083] 8 Work plate [0084] 9 Drive motor [0085] 10
Lifting element [0086] 11 Control element [0087] 12 Operating panel
[0088] 13 Control circuit [0089] 14 Display elements [0090] 15
Cooking area [0091] 16 Cooking-hob heating element [0092] 17
Cooking-hob heating element [0093] 18 Panel heating element [0094]
19 Glass ceramic plate [0095] 20 Securing part [0096] 21 Support
for items being cooked [0097] 22 Top-heat heating element [0098] 23
Fan [0099] 24 Seal [0100] 25 Displacement switch panel [0101] 25a
Displacement switch, upward [0102] 25b Displacement switch,
downward [0103] 26 Displacement switch panel [0104] 26a
Displacement switch, upward [0105] 26b Displacement switch,
downward [0106] 27 Memory unit [0107] 28 Actuating button [0108] 29
Main switch [0109] 30 Motor shaft [0110] 31 Hall element [0111] 32
Sensing element [0112] 33 End switch [0113] FT1 First force-time
profile [0114] FT2 Second force-time profile [0115] P0 Zero
position [0116] P1 Intermediate position [0117] P2 Intermediate
position [0118] PZ Final position [0119] R1 Speed ramp [0120] R2
Speed ramp [0121] vL Displacement speed of the base door
* * * * *