GB2051344A - A High Frequency Heating Apparatus - Google Patents
A High Frequency Heating Apparatus Download PDFInfo
- Publication number
- GB2051344A GB2051344A GB8014871A GB8014871A GB2051344A GB 2051344 A GB2051344 A GB 2051344A GB 8014871 A GB8014871 A GB 8014871A GB 8014871 A GB8014871 A GB 8014871A GB 2051344 A GB2051344 A GB 2051344A
- Authority
- GB
- United Kingdom
- Prior art keywords
- door assembly
- chamber
- oven
- rail members
- vertical portion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000010438 heat treatment Methods 0.000 title claims abstract description 87
- 238000003780 insertion Methods 0.000 claims description 7
- 230000037431 insertion Effects 0.000 claims description 7
- 230000008878 coupling Effects 0.000 claims description 5
- 238000010168 coupling process Methods 0.000 claims description 5
- 238000005859 coupling reaction Methods 0.000 claims description 5
- 229910010293 ceramic material Inorganic materials 0.000 claims description 3
- 239000012777 electrically insulating material Substances 0.000 claims 1
- 239000002184 metal Substances 0.000 description 11
- 230000002093 peripheral effect Effects 0.000 description 7
- 210000000078 claw Anatomy 0.000 description 4
- 238000010276 construction Methods 0.000 description 4
- 238000010411 cooking Methods 0.000 description 4
- 238000009413 insulation Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 238000005452 bending Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 239000011521 glass Substances 0.000 description 3
- 230000002159 abnormal effect Effects 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 230000000994 depressogenic effect Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000010355 oscillation Effects 0.000 description 2
- 230000002265 prevention Effects 0.000 description 2
- 102100025490 Slit homolog 1 protein Human genes 0.000 description 1
- 101710123186 Slit homolog 1 protein Proteins 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005485 electric heating Methods 0.000 description 1
- 238000007667 floating Methods 0.000 description 1
- 239000003365 glass fiber Substances 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000002787 reinforcement Effects 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- 239000000057 synthetic resin Substances 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B6/00—Heating by electric, magnetic or electromagnetic fields
- H05B6/64—Heating using microwaves
- H05B6/647—Aspects related to microwave heating combined with other heating techniques
- H05B6/6482—Aspects related to microwave heating combined with other heating techniques combined with radiant heating, e.g. infrared heating
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24C—DOMESTIC STOVES OR RANGES ; DETAILS OF DOMESTIC STOVES OR RANGES, OF GENERAL APPLICATION
- F24C15/00—Details
- F24C15/16—Shelves, racks or trays inside ovens; Supports therefor
- F24C15/162—Co-operating with a door, e.g. operated by the door
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B6/00—Heating by electric, magnetic or electromagnetic fields
- H05B6/64—Heating using microwaves
- H05B6/6408—Supports or covers specially adapted for use in microwave heating apparatus
- H05B6/6411—Supports or covers specially adapted for use in microwave heating apparatus the supports being rotated
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B6/00—Heating by electric, magnetic or electromagnetic fields
- H05B6/64—Heating using microwaves
- H05B6/6414—Aspects relating to the door of the microwave heating apparatus
Abstract
A microwave oven comprises a heating chamber 2 closable by an L- shaped door assembly 3, the assembly 3 having a shelf 26 supporting a turntable 25, to prevent uneven heating, fixed to the back of the door. A pair of rollers (35, Fig. 17) are provided on the opposite edge of the shelf 26 to the door in order to support the shelf in the closed position on the bottom wall 2b of the heating chamber 2. The turntable is provided with magnets (38, Fig. 19) secured to its under surface in positions corresponding to magnets (37) fixed to a drivable pulley (36), which is rotatably supported on the under surface of the bottom wall 2b. <IMAGE>
Description
SPECIFICATION
A High Frequency Heating Apparatus
The present invention relates to a high frequency heating apparatus, and more particularly to a high frequency heating apparatus for cooking or a microwave oven.
Generally, in a high frequency heating apparatus which is arranged to heat-treat objects or foodstuffs on the principle of dielectric heating, the object to be heated is cooked through generation of heat at the interior of said object, as distinguished from heating by electric heaters and the like wherein the object is heated from the exterior thereof. In the former method of heating, there is the possibility that the interior of the object to be heated is cooked excessively while its exterior appears to be undone, thus resulting in complete failure of the intended cooking.
For preventing such uneven heating as described above, various arrangements have been proposed, in which rotation of the object to be heated, the object being mounted on a turntable, during cooking is often employed as one method.
In that case, an arrangement in which the turntable is driven by a magnetic coupling through remote control from outside the heating chamber is considered to be extremely convenient for practical use from the viewpoint of cleaning, etc., in the interior of the heating chamber. If the heating apparatus is to be used at a low position, for example, directly placed on a floor or the like, it is convenient to use a heating apparatus of a type in which the door assembly is arranged to reciprocate in the direction of depth of the apparatus for selective closing and opening of an access opening. A support shelf of the turntable is mounted at one edge to the door assembly and is inserted into or withdrawn from the heating chamber following closing or opening of said door assembly.
For meeting the requirements in the construction as described above, in which the turntable is driven by an external drive and the turntable and support shelf therefor are insertable in or withdrawable from the heating chamber as the door assembly is moved for closing and opening, there are serious problems concerning stable holding of the support shelf in position.
More specifically, when the support shelf is intended to be held in position only at one edge thereof by the door assembly alone, the height and inclination of the turntable may be undesirably altered due to bending or warping when the item to be heated is placed on the turntable, thus prejudicing smooth driving of the turntable. On the other hand, if it is arranged so that the support shelf is supported at its opposite edges, with the one edge thereof being held by the door assembly and with rollers or the like arranged at its other edge and contacting the bottom wall of the heating chamber at all times, the depth or length of the support shelf has to be larger than the stroke or distance necessary for the movement of the door assembly for the closing and opening. Accordingly, the depth of the heating chamber is undesirably increased.
However, it is difficult to remove the object or receptacle therefor from the heating chamber unless the object or the receptacle is considerably smaller than the stroke for opening and closing the door assembly. Therefore, it is convenient that the depth of the heating chamber is longer than the stroke for opening or closing the door assembly.
Accordingly, in the high frequency heating apparatus with a turntable driven through remote control from the exterior of the heating chamber and with a support shelf for the turntable arranged to be inserted into or withdrawn from the heating chamber following movement of the door assembly in the direction of depth of the heating chamber, it is important that the stroke for opening and closing the door assembly may be set as desired irrespective of the depth of the heating chamber, and that during driving of the turntable, the positional relationship between the turntable and the bottom surface of the heating chamber is correctly maintained.
According to the present invention there is provided a high frequency heating apparatus comprising an oven-defining structure having a heating chamber and an access opening leading to the chamber, means for supplying high frequency energy to the chamber, a substantially
L-shaped door assembly arranged to be insertable into and withdrawable from the structure for selective closing and opening of the access opening, a shelf member cantilevered at one edge thereof from the door assembly, a turntable mounted on the shelf member and rotatably drivable from outside the chamber, and drive means provided in the vicinity of a bottom wall of the chamber for rotating the turntable through magnetic coupling means, the shelf member additionally being supported at an edge thereof opposite to said one edge by the bottom wall of the chamber on insertion of the door assembly into the structure and being located adjacent to the bottom wall of the chamber when the door assembly is inserted in the structure.
An embodiment of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which:
Fig. 1 is a perspective view showing a high frequency heating apparatus in the form of a microwave oven according to a preferred embodiment of the present invention, with the door assembly thereof in the opened state,
Fig. 2 is a similar view to Fig. 1, which shows in a reduced scale, the microwave oven, with the door assembly thereof in the closed state,
Fig. 3 is a perspective view of an outer casing employed in the microwave oven of Fig. 1,
Fig. 4 is a perspective view, as observed slantwise from the bottom, of an inner main structure defining a heating chamber, with the outer casing of Fig. 3 removed and with the door assembly drawn out therefrom for clarity,
Fig. 5 is a schematic front section view of the microwave oven of Fig. 1,
Fig. 6 is a fragmentary top plan view, partly in section, showing an enlarged scale the sliding portion of the door assembly of the microwave oven of Fig. 1,
Fig. 7 is a fragmentary side elevational view,
partly in section, showing on an enlarged scale
the sliding portion of the door assembly of the
microwave oven of Fig. 1,
Fig. 8 is a fragmentary cross sectional view of the arrangement of Fig. 6,
Fig. 9 is a schematic diagram explanatory of attaching and detaching of the door assembly with respect to the inner main structure of Fig. 4,
Fig. 10 is a perspective view of the door assembly employed in the microwave oven in Fig.
1, with the vertical portion thereof being disengaged from its horizontal portion for clarity,
Fig. 11 is a schematic side elevational view, partly broken away and on an enlarged scale, of the door assembly explanatory of the state of connection between the vertical and horizontal portions thereof,
Fig. 12 is a cross-section of the vertical portion of the door assembly showing the detailed construction thereof,
Fig. 13 is a fragmentary cross sectional view explanatory of the arrangement of a switch member provided at the upper portion of the inner main structure and associated in its function with the door assembly,
Fig. 14 is a fragmentary perspective view explanatory of another switch member provided at the lower portion of the inner main structure and associated in its function with the door assembly,
Fig. 1 5 is an electrical circuit diagram showing the arrangement of the switch members of Figs.
13 and 14,
Figs. 1 6(A) and 1 6(B) are fragmentary side elevational views explanatory of the state of the door assembly during closing thereof,
Fig. 17 is a perspective view, partly broken away, of the door assembly with a support shelf for a turn-table attached thereto,
Fig. 18 is a schematic side sectional view of the microwave oven of Fig. 1 illustrating a driving mechanism for the turn-table,
Fig. 1 9 is a schematic front elevational view, partly broken away, of the microwave oven of Fig.
1, with the door assembly removed, illustrating the driving mechanism for the turn-table,
Fig. 20 is a fragmentary sectional view of one portion of the driving mechanism of Figs. 19 and 20, particularly showing the arrangement of magnets therefor,
Fig. 21 is a fragmentary top plan view, on an enlarged scale, of the turn-table support shelf showing the engagement thereof with the door assembly,
Fig. 22 is a fragmentary side sectional view showing the arrangement for metallic pins
employed for the engagement of the turn-table support shelf with the door assembly.
Fig. 23 is a fragmentary side elevational view
showing on an enlarged scale, the structure of
metal plates with hook members attached to the
door assembly, and
Fig. 24 is a perspective view, partly broken
away, of the door assembly, with the oven plate
attached thereto.
Before the description of the embodiment
commences, it is to be noted that like parts are
designated by like reference numerals throughout
several views of the accompanying drawings.
Referring now to the drawings, there is shown
in Figs. 1 to 4 a high frequency heating apparatus
or microwave oven M to which the present
invention may be applied. The microwave oven M
heat-treats objects or food material based on the
principle of dielectric heating by utilizing high
frequency energy, for example, on the order of
about 2,450 MHz, and generally includes an outer
casing 1 of cubic box-like configuration (Fig. 3)
open at the front side thereof, an inner main
structure 4 (Fig. 4) defining a heating cavity or
heating chamber 2 and forming a double wall
construction together with the outer casing 1, and
a generally L-shaped door assembly 3 (Fig. 4) of
drawer type which is arranged to be slidable in
the direction of the depth of said heating chamber
2 for selectively opening and closing an access
opening 0 of the heating chamber 2 as shown in
Figs. 1 and 2.
The inner main structure 4 is arranged
to be detachable from the outer casing 1
through a pair of rail members 5 (Fig. 3) each
having generally U-shaped cross section and
secured to opposite side walls of the casing 1 in a
manner as described hereinbelow.
More specifically, the inner wall structure 4
includes a base plate 9, for example, of metallic
plate material which supports the weight of the
heating chamber 2 defined by a top wall 2t, side walls 2s, a rear wall 2r and a bottom wall 2b to form the access opening 0 at its front portion and secured to the base plate 9 by screws or the like, a high tension transformer 6 and a high frequency energy source, for example, a magnetron 7 capable of emitting microwaves upon energization, a waveguide 45 coupling the magnetron 7 with the heating chamber 2 in a known manner, a cooling fan 8 for cooling the magnetron 7, and a control panel 44 provided at the right front portion of the structure 4 in Figs. 1 and 2 and carrying thereon suitable knobs, indicator lamps, etc. for controlling the functioning of the magnetron 7 and electric heating arrangement such as heaters 27 and the like provided at the upper portion of the heating chamber 2. On the under surface of the base plate 9, there are provided an under structure 4H (Fig.
4) defined, for example, by opposite side plates 11, a front and a rear reinforcing plates 12 and 13, a pair of rail members 10 of generally Ushaped cross section secured to the side plates 11, and a housing 1 5 provided at one corner of the under structure 4H for accommodating therein a switch member 14 to be mentioned later. When the outer casing 1 is combined with the inner main structure 4, the base plate 9 is engaged at its opposite edges 9a, with the rail members 5 of the outer casing 1 as shown in Fig.
5.
Referring also to Figs. 6 to 10, the door assembly 3 having a vertical front portion 3Y with a handle 23 and a horizontal portion 3X laterally extending from the lower part of the portion 3Y includes a pair of rail members 16 each having generally Z-shaped cross section and secured at one end thereof to said portion 3Y by corresponding L-shaped metal pieces 1 7 in a manner mentioned later while a support plate 18 is held between the rail members 1 6 for reinforcement thereof, with the L-shaped metal pieces 1 7 and rail members 16 being fixed together with the support plate 1 8 by set screws 18a.At the other end of each of the rail members 16, a corresponding pair of rollers 16a, for example, of ball bearings are rotatably mounted, while another pair of similar rollers 1 Oa are also rotatably supported by the stationary rail members 10 in positions adjacent to the lower part of the vertical portion 3Y of the door assembly 3. For the smooth sliding movement of the movable rail members 1 6 of the door assembly 3 with respect to the stationary rail members 10 of the inner main structure 4, the rollers 1 Oa contacting the rail members 1 6 at the peripheries thereof roll over said movable rail members 16, while the rollers 1 6a of the movable rail members 1 6 contacting the stationary rail members 10 at the peripheries thereof roll along said rail members 10.
The side plays of the door assembly 3 in the lateral direction with respect to the inner main structure 4 may be regulated by loosening the set screws 1 8a for the rail members 1 6 and support plate 18, and adjusting the distance I (Fig. 10) between the rail members 1 6 which are secured to each other through the plate 1 8 so that side faces of the rollers 1 Oa contact the movable rail members 1 6, and side faces of the rollers 1 6a contact the stationary rail members 1 0. In the above case, if side plays of the door assembly 3 in the vertical direction, i.e. vertical side plays between the movable rail members 16 and stationary rail members 10 have been completely eliminated, no allowance is provided against any slight curving or bending of the rail members 10 and 16, etc.
and thus, it becomes impossible to achieve smooth sliding movement between the movable rail members 1 6 and stationary rail members 10 even by very slight dimensional variations or deformation.
In order to overcome the inconveniences as described above, there is provided a side play prevention projection 1 6b extending upwardly to a certain extent from one portion on the upper surface of the folded upper edge of each of the movable rail members 1 6 in a position adjacent to the lower part of the vertical portion 3Y of said door assembly 3. The projections 1 6b engage the stationary rail members 1 0 upon closing of the door assembly 3 so as to render the vertical side plays of the door assembly 3 to be substantially zero, whereby undesirable leakage of microwaves through peripheral portions of the door assembly 3 due to positional deviation thereof may be advantageously eliminated.Meanwhile, in the state where the door assembly 3 is withdrawn or opened, an allowance or clearance S for the vertical side plays for smooth movement of the door assembly 3 is provided as shown in Fig. 7.
As illustrated in Fig. 9, another projections or stoppers 1 6c extending downwardly to a certain extent from the under surface of each of the folded upper edges of the movable rail members 1 6 in a direction opposite to that of the projections 1 6b are formed in positions remote from said projections 16b. For detaching or attaching the door assembly 3, it is necessary for the rollers 1 Oa to ride over the stoppers 1 6c, with the movable rail members 1 6 of the door assembly 3 being inclined to some extent with respect to the stationary rail members 10. In the above case, since the allowance S for the side plays is provided as the door assembly 3 is moved, the detaching or attaching of the door assembly 3 is facilitated.
Referring particularly to Figs. 10 and 1 2 showing the state of connection between the vertical portion 3Y of the door assembly 3 and Lshaped metal pieces 1 7 mentioned earlier, the vertical portion 3Y of the door assembly 3 includes a choke structure ch having a groove or hollow portion 3a of S14 wavelength (where A is the inner tube wavelength of high frequency waves) and surrounding the peripheral edge portions of the portion 3Y for preventing microwave leakage, while the L-shaped metal pieces M are fixed to the lower sides of the vertical portion 3Y of the door assembly 3 at fixing portions 3b outside the choke structure ch, for example, by three set screws 19 extending through corresponding openings formed in the metal pieces 1 7. Since the upper two openings for the set screws 19 for each of the metal pieces 17 are elongated, the vertical portion 3Y of the door assembly 3 is adjustable to a certain extent through pivoting about the lowest screw 1 9 in Fig. 11 with respect to the horizontal portion 3X, and consequently to the heating chamber 2, and thus, the vertical portion 3Y of the door assembly 3 can be favorably brought into close contact with peripheral portion 2a of the access opening 0 of the heating chamber 2. Furthermore, since the set screws 1 9 screwed into corresponding openings 3c formed at the lower sieves of the vertical portion 3Y are releasable from outside, the mounting of the L-shaped metal pieces 1 7 to the vertical portion 3Y and adjustment of inclination of the portion 3Y with respect to the opening 2a of the heating chamber 2 may be effected after assembling of the door assembly 3 for facilitated and accurate assembly and adjustments. Moreover, by providing the fixing portions 3b at the outside of the choke groove 3a,
i.e. at the lower opposite sides of the door
assembly 3, more perfect choke effect can be
achieved.
Still referring to Fig. 12, the vertical portion 3Y
of the door assembly 3 has an observation
window 3w of a known construction including a
pair of transparent plates 3d and 3e, for example,
of reinforced glass and a punched metal 3f held
therebetween, while the peripheral portion of the
observation window 3w is surrounded by
metallic contact plate 39 for contact with the
corresponding peripheral portion 2a of the access
opening 0 of the heating chamber 2, with a cover
member 3h of microwave transmitting material
such as synthetic resins being provided between
the peripheral portions of the contact plate 39 and
vertical portion 3Y. The glass plates 3d and 3e,
punched metal 3f, contact plate 39, etc. as
described above are secured to the vertical
portion 3Y, for example, by suitable set screws.
Referring to Figs. 1 3 and 14 showing switch
members for actuating a high frequency
generation circuit, at the upper portion of the
inner main structure 4, there is disposed a first
switch 21 having normally open contacts so as to
correspond to keys 20 (Figs. 10 and 11) slidably
provided at the upper edge of the vertical portion
3Y and normally urged upwardly by suitable
spring means (not shown). When the door
assembly 3 is closed, the keys 20 contacting an
inclined portion of an engaging wall 22 provided
at the upper part of the inner main structure 4 are
depressed so as to engage corresponding
openings 22a formed in the engaging wall 22,
and in the above case, the keys 20 are restored to
push up a lever 21a of the switch 21 by the
corresponding one of said keys 20 to close said
switch 21.Subsequently, when the handle 23
provided at the upper front portion of the door assembly 3 is pulled for opening, the keys 20 are
again depressed by the engaging wall 22 so as to
be disengaged from the openings 22a, and thus,
the door assembly 3 is withdrawn, with the
switch 21 opened. Upon opening of the door
assembly 3, the keys 20 are restored to project
again. At the edge of the support plate 1 8 remote
from the vertical portion 3Y of the door assembly
3, a projection or pin 24 (Figs. 10 and 14) is
suitably secured, for example, by a screw in a position corresponding to the housing 1 5 (Figs. 4 and 14) for the second switch 14 having normally
open contacts mentioned earlier.The housing 1 5 has a slit 1 5a formed at its front face for allowing
the pin 24 to extend therethrough as the door
assembly 3 is closed so that the normally open
second switch 14 in the housing 1 5 is closed by
the pin 24.
As is seen from Fig. 1 5 showing a schematic
electrical diagram of the circuit for effecting the
high frequency heating, the first switch 21 and
second switch 14 are connected in series with
respect to the high frequency oscillation circuit G
and power source V. Therefore, the circuit G is not
brought into operation unless both of the first and second switches 21 and 14 are closed.In connection with the above, since the vertical portion 3Y of the door assembly 3 is adjustable for the inclination with respect to the horizontal portion 3X and the fixing portions 3b are particularly provided at the outside of the choke groove 3a, the strength in coupling the vertical portion 3Y and L-shaped metal pieces 1 7 is rather restricted, and upon exertion of external force on the door assembly 3, deviations tend to take place in the direction of the inclination adjustment.
However, according to the arrangement of the embodiment, when the vertical portion 3Y is deviated to incline inwardly with respect to the heating chamber 2 as shown in Fig. 1 6(A), the second switch 14 is not closed, while upon inclination of the portion 3Y outwardly as shown in Fig. 16(B), the first switch 21 is not actuated,
Therefore, the high frequency oscillation circuit G is not operated in either of the above cases, and consequently, such dangers as abnormal leakage of microwave energy through peripheral portions of the door assembly 3 may be prevented
Meanwhile, when the door assembly 3 is arranged to be detachable, there might be a possibility of accidentally dropping the assembly 3.According to the arrangement of the embodiment, however, should the door assembly 3 be accidentally dropped during handling, some deformation takes place in the pin 24, and when the deformation exceeds a predetermined extent, the pin 24 restricted by the slit 15a can not go fully into the housing 1 5 even when the door assembly 3 is closed, and therefore, the second switch 14 is not closed for securing safety.
Reference is had to Figs. 1 7 to 24 showing the relation between the door assembly 3, and a turntable shelf 26 for a turn-table 25 to prevent uneven heating, which is supported at its one edge by the vertical portion 3Y of the door assembly 3 so as to be selectively inserted into or withdrawn from the heating chamber 2 together with the door assembly 3, with an object 41 to be heated mounted on the turn-table 25, and also showing the relation between the door assembly 3 and an oven plate 28 (Figs. 23 and 24) to be used for placing the object 41 to be heated thereon so as to alter the state of heating, etc. in the case of heating by a separate heat source or electric heaters 27.
The turn-table shelf 26 is made of metallic material with permeability such as SUS 304. On the contact plate 39 for the vertical portion 3Y of the door assembly 3 which contacts the periphery 2a of the opening 0 of the heating chamber 2, a pair of metallic plates 29 of L-shaped cross section are secured by the screws connecting the contact prate 39 with the vertical portion 3Y, while a plurality of hooks 29a' are formed in the projecting wall 29a of each hook plate 29 extending in the direction of depth of the heating chamber 2 for engagement with the oven plate 28.At predetermined portions of the projecting walls 29a of plates 29, corresponding pairs of
opposed metallic pins 30 and 31 are fixed, for example, by staking so as to support the turn table shelf 26, while hollow insulation rings 32 and 33 made of ceramic materials such as alumina ceramics are releasably applied upon the pins 30 and 31 so as to be retained by suitable retainer rings 34 (Figs. 21 and 22). In the above embodiment, the pins 30 and 31 and insulation rings 32and 33 are formed as common parts.At the opposite sides of one edge of the shelf 26, a pair of claw members 26a are fixed so as to be releasably engaged with the insulation rings 32 and 33, while a pair of rollers 35 (Figs. 17 and 18) made of insulating material such as glass fiber, are rotatably provided adjacent to the other edge of the shelf 26, so that in a state where the door
assembly 3 is withdrawn as in Fig. 17, the shelf 26 is supported only at the claw members 26a thereof as in a cantilever, and when the door
assembly 3 is inserted or closed, the rollers 35
contact the bottom wall 2b of the heating chamber 2 so that the shelf 26 is supported at the opposite edges as shown in Fig. 1 8. On the other
hand, the turn-table 25 is provided with a plurality of magnets 38 (Figs.19 and 20) secured to its under surface in positions corresponding to
magnets 37 fixed to a pulley 36 which is rotatably supported on the under surface of the bottom wall 2b of the heating chamber 2 through a shaft 2c, and the turn-table 25 rotatably supported by rollers 40 is rotated on the shelf 26 by the magnetic force acting between the magnets 37 and 38 as the pulley 36 contacting the under surface of the bottom wall 26 via rollers 39 thereof is driven by a motor F through suitable driving force transmission means. The shelf 26
and turn-table 25 are used during the high frequency heating or heating by the heaters 27, with a receptacle or vessel 42, for example, of
glass and object 41 to be heated being placed thereon.
For smoothly bringing the shelf 26 which is supported at its one edge as in the cantilever into the state where it is held at its both edges as described with reference to Figs. 1 7 and 1 8 or vice versa following the insertion or withdrawal of the door assembly 3, raised portions (not particularly shown) are provided on the bottom wall 2b of the heating chamber 2 in positions adjacent to the access opening 0 to correspond to the rollers 35 of the support shelf 26.
As shown in Figs. 23 and 24, the oven plate 28 made of metallic plate material is intended for use, with the object 41 to be heated placed thereon, only during heating by the electric heaters 27 mentioned earlier. To opposite sides at one edge of the plate 28, there are secured a pair of supporting fixtures 43 of U-shaped cross section each having a square opening 43a formed in its upper surface adjacent to the distal end thereof. The oven plate 28 is supported at the ends of the corresponding hook members 29a' by the engagement of the hook member 29a' with the square opening 34a and one side 43b of each of the fixtures 43. Since the hook members 29a' are provided in plurality at proper intervals therebetween, the height of the oven plate 28 can be altered in several steps. For the heating by the electric heaters 27, either one of the shelf 26 or oven plate 28 is to be employed.
As is clear from the foregoing description, by the arrangement of the embodiment in which the shelf 26 is supported at its one edge only by the door assembly 3 in the cantilever fashion when the door assembly 3 is opened, while it is supported at its opposite edges, with the other edge thereof supported by the bottom wall 2b of the heating chamber 2 upon closing of the door assembly 3, the stroke for opening and closing of the door assembly 3 may be designed as desired irrespective of the depth of the heating chamber 2, and moreover, during rotation of the turn-table 25, the distance between the magnets 37 and 38 are accurately maintained, and thus, the turntable 25 rotates stably without being affected by the weight of the object 41 to be heated, or by warping thereof with time, etc.Furthermore, by the arrangement in which the under surface of the shelf 26 is spaced from the bottom wall 2b of the heating chamber 2 by the presence of the rollers 35, the danger of spark discharge or generation of abnormal heat during the high frequency heating due to extreme proximity between the shelf 26 and bottom wall 2b has been advantageously eliminated. Additionally, at the one edge of the shelf 26, the claw members 26a are provided to be engaged with the pins 30 and 31 of the metallic plates 29 of the door assembly 3 through the insulating rings 32 and 33, while the other edge of the shelf 26 is electrically insulated from the bottom wall 2b of the heating chamber 2 through the rollers 35, which arrangement is very advantageous from the viewpoints of stable heating and prevention of spark generation at the engaging portions.
More specifically, as is weli known, in the case of high frequency heating, the size of the heating chamber 2 has close connection with stable heating due to the relation thereof with the size of the object 41 to be heated. For example, the microwaves in the heating chamber 2 are varied in the wavelength thereof upon insertion of the object to be heated thereinto by the relation represented by
1 (where Re is the effective wavelangth and E is dielectric constant of the object to be heated), with consequent variations in the conditions of heating.In the above case, if the size of the heating chamber 2 is small as compared with the size of the object 41 to be heated, the state of the microwaves within the heating chamber 2 varies to an extreme extent by the presence and absence of the object 41 to be heated in the chamber 2 according to the relation as described above, and also largely varies even by a slight difference in the amount and kind of the object 41 to be heated, thus making it very difficult to obtain a
uniform and stable heating condition. Meanwhile, if the size of the heating chamber 2 is sufficiently larger than the object 41 to be heated, the state of the microwave energy within the heating chamber 2 is not much affected by the variations in the amount and kind of the object 41, thus more uniform heating being obtained irrespective of the amount and kind thereof.Particularly, in the
arrangement according to the embodiment, the support shelf 26 is arranged to electrically "float" in the heating chamber 2, and the portion below the support shelf 26 constitutes part of the heating chamber 2 with respect to the microwave energy so as to increase the space in the chamber 2 for the uniform heating condition as described above. Moreover, the support shelf 26 electrically floating advantageously prevents generation of spark discharge, etc. between the heating chamber 2 and metallic plates 29.
Generally, the ceramic materials such as alumina ceramics, etc. are extremely strong against compressive loads, but very weak against bending, etc. In the arrangement according to-the embodiment, however, since only the simple compressive load is applied to the insulation rings 32 and 33 as described earlier, the rings 32 and 33 are free from breakage even if a large load is applied to the support shelf 26, and even when the rings 32 and 33 are broken by some causes, they can be readily replaced by removing the retaining rings 34.
Additionally, since the engaging structures of the engaging portions of the support shelf 26 and oven plate 28 with respect to the door assembly 3 are arranged to be different from each other, accidental engagement of the support shelf 26 with the portion of the door assembly 3 for the oven plate 28 or vice versa is prevented, and thus, not only troubles due to spark discharge, generation of heat, etc. arising therefrom are eliminated, but inconveniences such as failure in cooking by uneven heating of the object to be heated due to faulty rotation of the turn-table 25 resulting from increase of the distance between the magnets 38 of the turntable 25 and magnets 37 of the pulley 36 are removed.Moreover, since the structures of the metallic plates 29 for engagement with the engaging portions of the oven plate 28 and support shelf 26 are arranged to be different, with the engaging portion for the oven plate 28 being constituted by the hook members 29a' formed in the projecting walls 29a of the metallic plates 29 which extend inwardly at right angles from the vertical portion of the door assembly 3, while the engaging portion for the support shelf 26 is constituted by providing the pins 30 and 31 directed to be at right angles with respect to the projecting walls 29a of the metallic plates 29, when the support shelf 26 is lowered downwards from the door assembly 3 for engagement with the pins 30 and 31, the shelf 26 can be readily engaged therewith by simply lowering it downwards without being obstructed by the hook members, thus providing the structure very convenient for use. Furthermore, owing to the arrangement in which the claw members 26a of the support shelf 26 are engaged in the state where they are located at the inside of the projecting walls 29a of the metallic plates 29, the engaging portion between the shelf 26 and plates 29 is readily observed from above the door assembly 3 for still easier attachment and detachment of the support shelf 26.
It will be readily apparent that the heating apparatus may be modified without departing from the scope of the invention as defined in the appended claims.
Claims (11)
1. High frequency heating apparatus comprising an oven-defining structure having a heating chamber and an access opening leading to the chamber, means for supplying high frequency energy to the chamber, a substantially
L-shaped door assembly arranged to be insertable into and withdrawable from the structure for selective closing and opening of the access opening, a shelf member cantilevered at one edge from the door assembly, a turntable mounted on the shelf member and rotatably drivable from outside the chamber, and drive means provided in the vicinity of a bottom wall of the chamber for rotating the turntable through magnetic coupling means, the shelf member additionally being supported at an edge thereof opposite to said one edge of the bottom wall of the chamber on insertion of the door assembly into the structure and being located adjacent to the bottom wall of the chamber when the door assembly is inserted in the structure.
2. Apparatus as claimed in claim 1, wherein the shelf member is electrically insulated from walls defining the chamber.
3. Apparatus as claimed in either claim 1 of claim 2, wherein the shelf member is provided with rotatable rollers of electrically insulating material so arranged at said opposite edge that on insertion of the door assembly into the structure the rollers contact the bottom wall of the chamber.
4. Apparatus as claimed in any one of the preceding claims, wherein the shelf member is detachably mounted at said one edge thereof on the door assembly by means of a pair of metallic plates of substantially L-shaped cross-section, the plates being provided on the inner surface of a vertical portion of the door assembly and having projecting walls extending towards the chamber at right angles from said inner surface, a pair of pin members secured to the projecting walls, and electrically insulating members of ceramic material applied to the pin members.
5. Apparatus as claimed in any one of the preceding claims, wherein the door assembly is provided at the inner surface of a vertical portion thereof with a first engaging portion for supporting the shelf member and a second engaging portion for supporting a separate oven plate for an object to be heated, said first and second engaging portions being arranged to be different from each other in the structures thereof for respective engagement with the shelf member and oven plate.
6. Apparatus as claimed in any one of the
preceding claims, wherein the door assembly has a choke structure provided at the periphery of an inner surface of a vertical portion of the door assembly for preventing leakage of the high frequency energy therethrough, and movable rail
members provided at the lower portion of said vertical portion for engagement with corresponding stationary rail members provided in the oven-defining structure said vertical portion being arranged to be adjustable in its inclination about the lower portion thereof with respect to the movable rail members by adjusting means provided outside the choke structure.
7. Apparatus as claimed in any one of the preceding claims, wherein the oven-defining structure has a first safety switch member provided in a position corresponding to the upper portion of a vertical portion of the door assembly and a second safety switch member provided in a position corresponding to the lower portion of said vertical portion, the first and second safety switch members being arranged to cause the supply of high frequency energy to cease when the door assembly is withdrawn for opening the access opening.
8. Apparatus as claimed in any one of the preceding claims, wherein the oven-defining structure has a safety switch member provided in a position corresponding to the lower portion of a vertical portion of the door assembly, the door assembly being provided with a pin member for actuating the safety switch member and the safety switch member being provided with means for restricting the functioning thereof upon deformation of the pin member.
9. Apparatus as claimed in any one of the preceding claims, wherein the door assembly is provided with a pair of movable rail members, the oven-defining structure being provided with a corresponding pair of stationary rail members which engage the movable rail members for slidably guiding the door assembly during insertion and withdrawal of the door assembly from the oven-defining structure, and the movable rail members being provided with projections for positional restriction thereof with respect to the stationary rail members so as to prevent side play of the door assembly on insertion into the oven-defining structure.
10. Apparatus as claimed in any one of the preceding claims, wherein the oven-defining structure comprises an outer casing and an inner main structure defining the heating chamber, and a base plate member releasably engaged at its opposite edges with corresponding rail members provided in the outer casing.
11. High frequency heating apparatus substantially as hereinbefore described with reference to the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5732979A JPS6059485B2 (en) | 1979-05-09 | 1979-05-09 | High frequency heating device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2051344A true GB2051344A (en) | 1981-01-14 |
| GB2051344B GB2051344B (en) | 1983-09-07 |
Family
ID=13052523
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8014871A Expired GB2051344B (en) | 1979-05-09 | 1980-05-02 | High frequency heating apparatus |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPS6059485B2 (en) |
| DE (2) | DE3050813C2 (en) |
| FR (1) | FR2456287A1 (en) |
| GB (1) | GB2051344B (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2271045A (en) * | 1992-09-25 | 1994-03-30 | Morphy Ltd Richards | Turntable drive in a microwave oven |
| EP1818620A1 (en) * | 2006-02-10 | 2007-08-15 | Filippi S.r.l. | Oven having a pull out door with integral heating element and cooking grids |
| DE10139083B4 (en) * | 2001-08-09 | 2010-08-05 | BSH Bosch und Siemens Hausgeräte GmbH | baking tray |
| EP2343484A2 (en) | 2009-12-31 | 2011-07-13 | BSH Bosch und Siemens Hausgeräte GmbH | An oven with a rotatable tray inside the cooking chamber thereof |
| EP2757322A1 (en) * | 2013-01-18 | 2014-07-23 | Electrolux Home Products Corporation N.V. | A side grid system for an oven cavity |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3038216C2 (en) * | 1980-10-09 | 1984-10-04 | Bosch-Siemens Hausgeräte GmbH, 7000 Stuttgart | Oven with baking trolley |
| FR2636409B1 (en) * | 1988-09-09 | 1994-02-25 | Equipement Menager Cie Europ | COOKING APPLIANCE COMPRISING A MULTI-FUNCTIONAL COOKING ENCLOSURE WITH A MICROWAVE SOURCE |
| DE3929805A1 (en) * | 1989-09-07 | 1991-03-21 | Bosch Siemens Hausgeraete | OVEN FOR TREATMENT OF FOODSTUFFS |
| JP2520881Y2 (en) * | 1990-09-18 | 1996-12-18 | シャープ株式会社 | Heating cooker |
| FR2687460B1 (en) * | 1992-02-17 | 1995-03-24 | Samsung Electronics Co Ltd | TRAY EXTENSION DEVICE FOR A MICROWAVE OVEN. |
| DE10219915A1 (en) * | 2002-05-03 | 2003-11-20 | Bsh Bosch Siemens Hausgeraete | Domestic oven unit has separate rigid trough-shaped screening element with flat base and projecting walls acting as holder and positioner elements for components |
| EP2063184B1 (en) * | 2007-11-26 | 2010-01-20 | Electrolux Home Products Corporation N.V. | Self cleaning cooking oven |
| DE102007058940A1 (en) * | 2007-12-07 | 2009-06-10 | BSH Bosch und Siemens Hausgeräte GmbH | Door device for household appliance, particularly baking oven, has front unit which has outer panel for door device, and support unit which is movable relative to front unit |
| CN102538036B (en) * | 2010-12-16 | 2016-08-10 | 乐金电子(天津)电器有限公司 | Microwave oven |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2036828A1 (en) * | 1970-07-24 | 1972-01-27 | Siemens Elektrogeraete Gmbh | Oven and roasting tube |
| CH585518A5 (en) * | 1975-06-12 | 1977-03-15 | Elektromaschinen Ag | |
| US4092512A (en) * | 1975-08-27 | 1978-05-30 | Matsushita Electric Industrial Co. Ltd. | Turntable drive mechanism in electronic oven |
| DE2817514C2 (en) * | 1978-04-21 | 1982-10-14 | Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt | Door for an oven and roasting tube |
-
1979
- 1979-05-09 JP JP5732979A patent/JPS6059485B2/en not_active Expired
-
1980
- 1980-04-15 DE DE19803050813 patent/DE3050813C2/de not_active Expired
- 1980-04-15 DE DE19803014458 patent/DE3014458C2/en not_active Expired
- 1980-05-02 GB GB8014871A patent/GB2051344B/en not_active Expired
- 1980-05-07 FR FR8010213A patent/FR2456287A1/en active Granted
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2271045A (en) * | 1992-09-25 | 1994-03-30 | Morphy Ltd Richards | Turntable drive in a microwave oven |
| GB2271045B (en) * | 1992-09-25 | 1996-03-06 | Morphy Ltd Richards | Ovens |
| DE10139083B4 (en) * | 2001-08-09 | 2010-08-05 | BSH Bosch und Siemens Hausgeräte GmbH | baking tray |
| EP1818620A1 (en) * | 2006-02-10 | 2007-08-15 | Filippi S.r.l. | Oven having a pull out door with integral heating element and cooking grids |
| EP2343484A2 (en) | 2009-12-31 | 2011-07-13 | BSH Bosch und Siemens Hausgeräte GmbH | An oven with a rotatable tray inside the cooking chamber thereof |
| EP2757322A1 (en) * | 2013-01-18 | 2014-07-23 | Electrolux Home Products Corporation N.V. | A side grid system for an oven cavity |
Also Published As
| Publication number | Publication date |
|---|---|
| DE3050813C2 (en) | 1989-05-24 |
| FR2456287A1 (en) | 1980-12-05 |
| DE3014458A1 (en) | 1980-11-13 |
| JPS55150433A (en) | 1980-11-22 |
| GB2051344B (en) | 1983-09-07 |
| JPS6059485B2 (en) | 1985-12-25 |
| FR2456287B1 (en) | 1983-07-29 |
| DE3014458C2 (en) | 1985-05-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4335292A (en) | High frequency oven with drawer type door | |
| GB2051344A (en) | A High Frequency Heating Apparatus | |
| EP0023827B1 (en) | Cooking appliance of hot air circulating type | |
| US4369347A (en) | Damper activation in a combined microwave and electric heating oven | |
| US3733456A (en) | Microwave oven door latch | |
| US4131778A (en) | Microwave oven | |
| US6921888B2 (en) | Microwave oven | |
| KR100516660B1 (en) | Door interlock system of electric oven range | |
| US4330697A (en) | Drive motor assembly for use in a microwave oven | |
| KR880001087B1 (en) | Microwave oven | |
| JP2005188800A (en) | Microwave oven | |
| JPS5928246Y2 (en) | High frequency heating device | |
| KR200146956Y1 (en) | Control apparatus of tray for microwave oven | |
| KR200396065Y1 (en) | Device of door interlock for Microwave oven | |
| KR100562105B1 (en) | Door locking system of electric oven | |
| KR100265632B1 (en) | Microwaveoven | |
| KR100272226B1 (en) | a mounting structure of a door for microwave oven | |
| KR102567526B1 (en) | Cooking Appliance | |
| KR200169604Y1 (en) | Door for microwave oven | |
| KR20040087219A (en) | A microwave oven | |
| KR960004459Y1 (en) | Air guide apparatus for microwave oven | |
| KR960004835B1 (en) | Tray carrying apparatus in microwave oven | |
| KR20040087220A (en) | A microwave oven | |
| KR20020022957A (en) | Supporting device of cooking tray for microwave oven | |
| KR960004462Y1 (en) | Membrane switch protection structure for a microwave oven |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 732 | Registration of transactions, instruments or events in the register (sect. 32/1977) | ||
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19980502 |