DE1765206C - Microwave oven - Google Patents

Description

9. Microwave oven according to one of the foregoing claims, characterized in that the door (10) has a low-friction surface coating that is at least partially made of plastic (48) has at those points where it is in the Schüeßlage on the front side Jes Ofens is attached.

10. Microwave oven according to claim ^ characterized in that the surface coating (48) on the surface of a seal made of electrically conductive rubber, which are arranged on the edge zones of the door (10) lying on the furnace end face (16) is upset.

11. microwave oven according to claim 10, characterized characterized in that the surface coating (48) contains molybdenum disulfide.

12. Microwave oven according to claim ¹ or 10, characterized in that the surface coating is applied by heating the door to a temperature required for the plastic to adhere and by immersing the door in a plastic bath.

13. Microwave oven according to claim 12, characterized in that the surface layering applied by dipping the door in a bath of liquid made from plastic powder is.

14. Microwave oven according to one of claims 2 to 13, characterized in that the plate (44) of the solenoid (40) in the closed position of the door (10) a switch (72) in the closed position that is in the circuit of the furnace's oscillator.

15. Microwave oven according to one of claims 2 to 13, characterized in that the plate (44) of the solenoid (40) actuates a contact lever (60) in such a way that it is in the open position the door (10) connects the circuit of the oven's oscillator to earth.

The invention relates to a microwave oven with an end face in the closed position of the oven and door guide.

which allow the door to be shifted in the vertical direction between the closed and open positions and at the end of the closing movement, press the door against the front of the furnace like a wedge.

Microwave ovens have become known in which the heating interior is replaced by an overhead Flap is accessible. During the heating operation, the flap is held in place by an electromagnet Maintained closed position to prevent high frequency energy from escaping. The flap is biased by a tension spring in the opening direction so that it is in the open position when the magnet is de-energized is moved. The overhead access is for microwave ovens for heating near-

funds are relatively unfavorable for reasons of space and convenience (USA.-Paten-schrifl 2,442,451) and British patent specification 622,774).

It has also become known a microwave oven whose horizontally arranged tubular The boiler room is accessible from both sides. The front sides can be locked by sliding doors, which are guided in guide rails of the furnace housing. Each sliding door has on its inner

printed above. This force should not be sufficient to open the door completely, but rather only initiate the movement of the door. Therefore, the solenoid can be much smaller than if it would have to carry the door between the closed and open position, the entire encryption ί shift. Also, the weight balancer need only be so excessive that the door will continue upward movement after the solenoid is de-energized

side has a spring-loaded sealing plate that can be used with io. As with ovens where the door is at the end of the door

closed. , The door rests firmly on the front of the furnace in order to ensure the appropriate sealing of the heating interior and thus prevent high-frequency energy from escaping as much as possible.

Closing movement is clamped like a wedge Door guides are normally designed so that the door remains open for the remainder of its opening

_ "". . ". _no>% . "6 .. ^ .. ^ ^ , ^. can slide very easily, the weight balance must

prevent what is an important requirement in after the 15 equalizer - apart from the weight of the Dielectric process operating heating devices - door - as a result, only a low resistance gen (British patent I QM 683V. Since the door is in

- - _{reaches their} open position, become mechanical

Avoided shocks.

Preferably, the solenoid is a plate that moves the door in excitation of the solenoid from the closed position to the top, where d \ c ~ r plate with an upwardly directed spring force charged

is that when lifting the door by the solenoid

There is also the use of a sliding door with a wedge-like jam on the face of the oven known, so that the door is at the end of its closing movement is printed in close contact with the face of the furnace. True, with a microwave oven of the type mentioned by such a

trained door opposite an oven with springy,

with the door pressed down the risk of leakage of the contact between the panel and the door upright-high frequency energy decreases, but requires that hold. Because of the further lifting of the door in the Opening the door requires a considerable amount of force, the opening position creates a solid connection between especially when between the door and the plate and door is not possible through this Front side of the furnace a seal made of conductive measure ensures that during the stroke of the Rubber is inserted to reduce the escape of high-30 door the rattle between the plate and the door irequence energy becomes too low to an even greater extent, whereby the door is given a smoother run, tie. When the wedged door is opened, the solenoid can only operate during the short time of the

The force required to open it is not exactly what is needed to loosen the wedge engagement between the door and the face Time at which the wedge reef of the furnace must be excited, it is advisable to is released between the door and the front of the furnace; 35 to provide an electrical switch, the purpose of as a result, the door will often open the solenoid excitation circuit very quickly at the upper end of your entire opening path. a predetermined section of the opening path where it is then suddenly braked. Consequently, the door is operated.

such a door is subject to considerable mechanical In a further advantageous embodiment of the invention

Bumps. This can lead to a misalignment of the door 40. what a leakage of high frequency device via a leichgie in relation to the door and also difficulties in lifting the th support shoe on the door, the 1 ur Door from its wedge-like wedge-like position to a movement in the direction of movement opposite Consequence. the support shoe, and that the furnace has an in

It is therefore the object of the invention to provide a 45 path of movement of the support shoe Microwave oven of the type mentioned has to stop, which interacts with the support shoe, but does not prevent the door from moving upwards.

Mechanisehe also when opening the door further To avoid knocks, there can be a weight balancing spring on each side of the door, at the end of the door

create, in which the door despite being firmly wedged with the front of the furnace after the completion of the Heating season can be easily opened by the operator.

This object is achieved according to the invention by a weight balancing device which opening of the door easier, a holding device for holding the door in the closed position, a disconnection device, which automatically switches off the microwave radiation at the end of the heating season, and at least one solenoid energized at the end of the heating season, which opens the door with one of the initial movements

the support shoe is attached, and a nose that is passed through a in the corresponding support shoe provided opening runs, be arranged.

Since the support shoes have a low weight compared to the weight of the door and the the opening position of the door is determined by stops in the movement paths of the support shoe are lying, the support shoes are opened when the

• ··· ·,, _ · 1 1_ "" 1.1 ü "

movement resistance of the door exceeding force via .. ~ _D -., -

an initial portion of the entire opening path 60 door stopped by the stops; however blow

moved up so far that the weight does not hit the door against these stops, but instead

Compensation device irr ·, connection to the upward movement of the sole over a short «

noid movement caused the door to slide a distance further and then falls onto the one at the ends

the * fully open position is permitted. attached to the weight compensation springs

After the end of the heating season, a 65 storage shoes will be returned. Therefore, at the end of the public

Furnace according to the invention energizes the solenoid and prevents the voltage movement noticeable shocks that some

Door out of its clamped position could cause the solenoid to misalign the door

Usually the doors are microwaves after a short section of their opening path

Furnaces with a perforated viewing window that connects the door of the furnace with the earth. This is a safeguard, which is so important to the diameter of the perforation holes, that the oscillator is measured so that the holes are normally always switched off when the door is opened.
essentially emit radio frequency energy. As already mentioned above, the function of the prevent. Since the door to the toilet oven is tightly closed during operation of the micro-wedge effect, grease is sprayed from the inside against the window. With one of the known frequent cleaning must be done. In order to make it easier to enter these microwave ovens on the inside of the door, the door can have a thin sheet of metal (for example made of aluminum that can be moved away from the support shoe and can be made of stainless steel) on the edge of the inside of the door attached at its upper ends and in the closed position of the door will be swept so that the door can be pulled out upwards against the metal face of the furnace. The buttons on either side of the door. Between the two touching senes facilitate removal and the re-metal surfaces can insert the door as a result of the inclusion of the door. 15 particles of pollution contribute to the formation of sparks

Bci an oven with a vertically movable men. This can also occur when there is between Door without automatic lifting of the same and with the touching metal surfaces an air arrangement the control switch has formed in the area of the upper gap. With known microwave edge The operator would have to open the door to the door, creating an air gap as a result Pull upwards by hand, whereby it easily prevents ao that along the door circumference on the forehead unintentional actuation of the control switch grain ropes a seal made of an electrically conductive men can. Preferably they are attached to a micro-rubber.

len oven according to the invention, the control switch for In order to achieve a good seal, it is also arranged above the door of the oven in such a way that they are concealed in the case of a wedging door, one of the other opening positions of the door. At the »5 tigc seal made of an electrically conductive rubber to be used at the end of the heating season and after the brine has been energized. However, the coefficient of friction is raised so that the door is raised to such an extent that the control switch for controlling the high frequency is efficiently high between the door and the furnace face, so that the friction frequency radiation covers to release the. As a result of the energizing engagement of the solenoid, a considerable force will be exerted by the solenoid at the same time as the door 30 must be released. Even if metallic surfaces are caused by the wedge engagement and an inadvertent contact of the door and furnace front side must be avoided when the switch is released. When biting into the wedged door, considerable force must be exerted on the microwave oven. It is therefore expedient for two independent types of door, one after the other, to have a low-friction, at least partially accessible, door: First the door must be connected with a plastic surface coating, and only then can the controls have those points where They are operated in the switch. It is extremely untrue- the closed position is applied to the front of the furnace. It appears that both operations are carried out with an empty use of a seal from electrically conductive furnace. In the case of ovens, however, where rubber, which is attached to the doors attached to the front of the oven, for example by hinges, is the edge zone of the door, the doors are normally closed, and surface coating on the top can very easily occur. that the control panel of the seal is applied. In the case of the latter, the inadvertent actuation and also in the case of the lee embodiment reduces the surface over the furnace, a heating period is triggered. This stratification of the friction between the two can lead to damage to the food receiving tray and the door seal. Aside, without the scattering losses of the high frequency increasing noticeably in accordance with the automatically opening furnace according to the energy.

Finding in which the door slides upwards needs to be particularly even and dense

the door in the open position does not achieve any side surface coating that leads to a

Space in the vicinity of the furnace and will result in 50 small coefficients of friction, the surface is

consequently normally from the end of a heated spoke coating, preferably by heating the

The bark is left open until the oven for the next door requires one for the plastic to adhere.

Heating periodc is charged again. similar temperature and by immersing the door The automatic sliding of the door along the line is applied in a plastic wheel. Here recommends

short initial section of the entire opening 55 especially the door in a plastic powder

path through the solenoid allows another automatic whirling bath to immerse, since such effects

of the operation of the microwave oven, since the baths allow easy processing of the plastic

Allow the short stroke of the solenoid to operate powder.

Switching elements for safe switching of the current As plastic, for example, polytetrafluorocircle of the oscillator of the furnace can be used 60 ethylene with a resin binder can be used. Preferably, therefore, the plate of the brine maintains the plastic can also molybdenum disulfide contributed noids in the closed position of the door adds a switch to be in, whereby an extremely hard, non scha- Schließstelhmg that in the circuit of the oscillator of the Bende surface with a very low friction Furnace. When the door reaches its closed position, coefficient is achieved. Also using the normally open switch is closed. 65 of a low friction nylon extrusion

It is also useful that the plate of the sole possible, which is on the outer surface of the conductive

no'ds actuated a contact lever in such a way that it is glued in rubbers.

Open position of the TQr the circuit of the Oszjlla- The door can be opened in a known manner in

(ο

inside and inside the layer of synthetic parts 22 and 24 made of low-friction plastic.

fabric have a groove that drew for the microwaves. The guides are on both sides of the

represents a resistance. The condenser, the furnace provided, and the T-.r owns on either side

through the sirh with the door closed between the door a part that between the extruded parts II and

and the face of the furnace located on the surface 5 24 slides.

Stratification is built up, represents on its own or as ta FIGS. 2, 4 and 5 shown

together with the micro-corner blocking section a short side wall 26 at right angles from the St.

"" J ,, "orinni.n wiHpr" tflnd the wall of the door 10, and from the rear edges of the side

^ affluTÄiShr on the basis of an austen wall 26, stripes 28 run parallel to the forehead

example in connection with the drawing i. Wall. These strips 28 grip between the strand

gen Säher explained. It shows parts 22 and 24 of the door guides on each side

FiE I is a perspective view of the furnace of the furnace and are guided by these

and the door in its closed position From Figures 4 and 5 it can be seen that each

Fig. A is a similar view of one corner of the strips 28 on the inner portion of its lower The front of the furnace, with the door slightly raised, is provided with a nose 30 in _{5 Kwte.} That nose FiR 2 a partially broken side part runs through an opening 32 (F.g.3) in entern

view of the furnace, with the door in the open support shoe 34 on which the end of a steel band

nnnMctHtuno is ^{the 36} totere ^{1 isl} «which is in a weight

nungssteiung ~ ™ | «| j _{on one on one} open side of the same box 38 runs into it. In box 38 is

anecordered door guide ^a ° ^eme weight compensation spring housed, the

Fig. 4 is a rear view of one held in place by its inner end and attached to its

nt ", ifprntpn the outer end of the band 36 is connected. the

Πε5 Se perspeküvischc view in which the spring exerts on the band 36 and therefore on the

Operation of the weight balancing device bearing shoe 34 from a tensile force, and the support

«RTnJc & chtwird» 5 ^schuh ** S ^matures ** i upward movement under the

T · i ρ 6 opens a section through the edge section of the sliding door and takes it with you. On each side of the

'' * "Furnaces are each a counterbalance spring and

T'i ο 7 the solenoid and corresponding switch a support shoe 34 is arranged.

«» A See desOfens and Aus F ig. 2 it can be seen that the end face 16

Ρίο R pin circuit diagram for a simple door 30 of the oven not parallel to the one between the guide

l 1 g 8 a acnauwiu ^^ _Jg ^ _{running F} ühningsschlitz lies,

According to the "de" representation in FIG. 1, one closes but rather forms an angle with it. The door 10 is an opening in the front of the oven, the front wall of the door is at a similar angle through which the food to be heated can be introduced into the oven located opposite to the rear of the door. The door 10 contains 35 neten guide strips 28 inclined, the AIv a derforated viewing window 12, which allows an extension between the end wall and the strips 28 of the heating process, the perforation being dimensioned such that the end face is close to the tSn in such a way are dimensioned so that there is radiation on the front side 16 of the furnace when the door in von HocnSqSeneigie is impossible. The door is in its closed position. Because of the angular ankanr. in the vertical direction between the closing and 40 ordered surfaces, the front of the door is at oZ ^^ S ^ JS ^ Jwc ^ . Downward movement of the same (with the strips 28 above the door are control switches 14 and one is guided in the Fuhrungsschhtzen) against the indicator light 15 in the front 16 sunk pressed on the furnace front wall and between the front eeordinated The control switches 14 allow an exit 16 and the guide slot Hegende section of the choice of the 'time duration during which the food 45 oven side wall acts like a wedge between the forehead being heated and the triggering of the start of heating, want ^{1 of} the door and the penalty 28. When the door is in its closed position downwards, as mentioned above, this wedge effect is extremely pressing. The lighting of the indicator light 15 is advantageous to ensure a tight fit and advised a heating season. The heating period will automatically prevent the high-frequency energy from escaping after the time limit set by the control switch has expired, but has the disadvantage that the door can only be closed with difficulty after the time interval set at gate 14 and then moved out of its closed position. how and a force expander applied to release the door is described below. When the door is open, the door may cover the control switch while it is in place and slide movement will prevent a new heater from being triggered. To prevent this, a solenoid is used until the door is closed again. (F 1 g. 2) provided that at the end of the preselected InFi e 1 A, the position of a permanent magnet 17 heating period and after switching off the micro at the lower left corner of the furnace is shown. When wave radiation detaches the door from its wedge position, the lower right corner of the stove is a second permanent one, but this can only be seen over a short initial section Opening path transport-! SL ri ^ Saßmschlae door forms the door that. The solenoid 40 is fitted with an armature 42 and is consequently held in place, which at the end has a plate 44 in the open position. FIG. 2 is able to open the plate 44 in the opened position of the door in the extended position

-Ξηd ^ TdTtaftrerClosed position. FIG. 2 is able to place the plate 44 in the

Indene Figure 2 and 3 are before vertical guide 6 assumes _S opening Stel Ranked the door in solid of the door causing guides 18 IMD 20 in the side lines, and in the position in which they in the closed position infi ^ A After DaiSteBiffig the F i g. 3 frame the door, shown in broken lines. DieBndfnSer Vürführung with extrusion Eir.e spring 46 pushes the plate 44 in the upper layer,

however, the spring force is far less than that of opening the door without energizing the solenoid could. The only purpose of the spring 46 is that when one of the energization of the solenoid the following Upward movement of the door maintains contact between the plate 44 and the support shoe 34 will. Without this spring, when the solenoid is excited, between the plate and the bearing shoe, apart from an excitation by a fully smoothed direct current, an intermittent one Contact occur. This intermittent touch is undesirable because it leads to a rough opening movement of the door and on the other hand leads to noise.

If the door is moved by hand from the open to the closed position, it takes the support shoe 34 with, the plate 44 in the position shown in Figure 2 in dashed lines presses. In the closed position, the door is pressed against the front of the furnace and additionally through the Permanent magnets held. At the end of the heating season, the solenoid 40 is energized and the plate 44 transfers on the support shoe 34 an upwardly directed and sufficient for the solution of the door Power. The plate 44 moves the door over the first one to two centimeters of its displacement path, However, it remains in the position shown in solid lines in FIG. 2. When the door through the Solenoid is lifted from its closed position, the effect of the permanent magnets on the door is negligible small. The counterbalancing springs then ensure that the upward movement of the Door can continue. Two solenoids can also be provided.

From using a conductive rubber strip around the inside surface of the door bulkhead is lying around, has already been said. When the door is in its closed position, will the rubber strip pressed against the front of the furnace. To reduce the friction between the door and The front side of the furnace without the microwave scattering increasing significantly is a surface coating 48 made of plastic on a rubber extrusion 50 (Fig.4 and 6) applied to a Aluminum flange running along the edge of the inner surface of the door 52 is attached

The flange 52 forms part of an aluminum section, which includes a microwave barrier 54. This is a recess that faces the inside opens towards the door and is dimensioned such that it absorbs microwaves, which is one of the operating data of the furnace have the appropriate frequency. The lock can, for example, with foamed Polyurethane to be filled, the aluminum oxide is mixed. A surface covering Polytetrafluoroethylene is then conductive over the entire inner surface of the door including the Rubber layer applied and cured. This results in a smooth door surface that is easy to clean hold is.

Because the high frictional forces between the door and the front of the furnace are caused by the surface coating were reduced and when using two solenoids these the door only above the one starting section need to transport the opening path and are only briefly excited, the Dimensions of the two solenoids can be very small and the solenoids can be conveniently behind the side walls of the furnace. Solenoids so strong that they pull the door out of its lock Transport their open position could not be used in a furnace of this type.

In the embodiment shown, the furnace side shown in FIG. 2 is arranged Plate 44 is also used to control the position of a lever 60 designed as a pivot lever The pivot lever 60 creates an additional safety device which ensures that the oscillator no longer works when the door is open. The automatic timer ensures that the door is opened and for actuating a first switch that supplies power to a high-voltage relay of the

The heat circuit interrupts the power supply to the oscillator and therefore the high frequency energy in the Oven switches off. Although such facilities very rarely fail, for example by a »Welding« the relay contacts to faults

ao kick. According to Figure 2, the punch 64 is with the High-voltage circuit connected and the contact 66 is via a not shown in the pivot lever 60 arranged resistor and grounded via the spring 62. As a result, if the solenoid in de;

When the door is in the closed position, an excitation pulse is applied, the plate 44 pushes the door out of its closed position, _{and the spring 62} can bring the earthed contact 66 into electrical connection with the plunger 64 when the door is opened. Therefore, if the relay

the high voltage circuit is not interrupted hai. the circuit is grounded via contact 66. In which embodiment shown, the pivot lever 60 carries a second contact 68, which in the gestri held position of the pivot lever is resiliently pushed away from the contact 66. When she ;, opens the door contact 68 touches contact 66 shortly after contact 66 connects to punch 64 would. The contact 68 is grounded via a switching relay, which is connected to the in the pivot lever arranged resistor applied voltage is excited The switching relay opens a contact in the Circuit of the high voltage transformer, and this contact is then locked in the open position,

« * ° uv η ^ei r? ^{ch not} ** »de-energizing the circuit

closes. The arrangement of this switching relay in the

Circuit prevents repeated connection

the high voltage cue with earth when the door

repeatedly opened and closed in the event of malfunctions

t ^ A ^ f *, I ^{TUr m} ' ^{± Kt} open position, so hold each spring 46 the plate 44 in its upper position and therefore the pivot lever 60 remains in the fully extended position until the door is closed again. ^&

On the other side of the door, a similar

high formed solenoid plate 44 (Fig.7) two

Microswitches 7 · and 72. How they work

- ^ gPjt from _Flg .g _{emerge from the norma} j _prove

Open microswitch 72 is closed by closing the door. When one of the control switches

ihfh! ^^^ "^ ^{vhd 6} ^ ^{& η3ΐίεΓ 74} 'η a £ 5 ?? ^teI ™ ^chtun 8 ⁷⁶ closed. Each of the control switches 14 stent a different length of heating

2? Th ^ TI * *** ■ * ⁷² ** 74 ILhSn <SJ * N fjfS *; ? ** ^Ht «nvoltage relay er SL £? ^J Sfi ^at ** ^{Hrazpenode set by} ** Steneifcalter! 4 opens the switch

SZEi ° *? 5 ^{ώε S} P ^ule ™ «« «St and an open switch 80 closed

which closes the excitation circuit of the solenoid 40, the switch 80 then by a latch circuit is retained in the closed position. The solenoid lifts the door, and once the panel 44 the in F i g. 7 has reached the position shown

Microswitch 70 opened, causing the solenoid excitation circuit is interrupted. This also leads to a de-excitation of the above-mentioned ver control circuit and to enable the microsc! 5 ters70.

For this purpose 2 sheets of drawings

Claims (8)

Patent claims: I. Microwave oven with one in the closed position the front of the stove covering the door and door guides that allow a shift allow the door in the vertical direction between the closed and open position and the At the end of the closing movement, press the door like a wedge against the front of the furnace, characterized by a weight compensation device (38), which makes it easier to open the door (10), a holding device (17) for holding the door in the closed position, a disconnection device (76), which automatically switches off the microwave radiation at the end of the heating season, and at least one solenoid (40) energized at the end of the heating season. that the door with one of the exceeding the door's initial resistance to movement Force over an initial section of the entire opening path so far upwards moves that the weight balancer following the movement effected by the solenoid the door can be moved into the fully open position. 2. A microwave oven according to claim I, characterized in that the solenoid (40) has a plate (44) which moves the door (10) when the solenoid is energized from the closed position upward, the plate (44) having a is biased upwardly directed spring force (46) during lifting of the door since ^ solenoid durcli the contact between the plate and 1 ÜR maintains. 3. Microwave oven according to claim 1 or 2, characterized by an electrical switch (70), the purpose of interrupting the solenoid excitation circuit after a predetermined section the opening path of the door is operated. 4. Microwave oven according to claim 1, 2 or 3, characterized in that the disconnection device (76) at the same time as the switch-off of the microwave radiation also one Excitation of the solenoid (40) causes. 5. Microwave oven according to one of claims I to 4, characterized in that the Control switches (14) for the oven are arranged above the door (10) in such a way that they are in the open position the door are covered. 6. Microwave oven according to one of the preceding claims, characterized in that the weight compensation device (38) via a support shoe that is light in relation to the door (34) engages the door (10), the door having a play in the direction of movement opposite the support shoe (34), and that the furnace has one in the path of movement of the support shoe arranged stop (30) which cooperates with the support shoe (34), however does not prevent the door (10) from moving upwards. 7. A microwave oven according to claim 6, characterized by one on each side of the door arranged weight compensation spring, the end of which is connected to the support shoe (34), and by a tab (30) located on each side of the door through one in the corresponding one The opening provided for the support shoe (32 · runs. 8. Microwave oven according to claims, characterized in that the door freely after rests movably above on the support shoe (34) and the door guides (18, 20) on their upper ones Ends are designed such that the door can be pulled out upwards.