EP1461570B1 - Wall-mounted cooking device - Google Patents

Abstract

A wall-mounted cooking appliance has a muffle and a bottom opening that can be closed by a lowerable bottom door. A drive mechanism is provided for lifting the bottom door. To prevent the jamming of objects that have been inadvertently placed below the base door, the novel wall-mounted cooking appliance has a control unit that detects an angle of inclination of the base door and controls the drive device in accordance with the magnitude of the angle of inclination to reduce the latter.

Description

The present invention relates to a Hocheinbaugargerät with a muffle, which has a bottom-side muffle opening, which is closable with a lowerable bottom door, and with a drive device for lifting movement of the bottom door.

As a generic Hocheinbaugargerät the known from US-A-2944540 wall furnace is to be considered. The wall oven has a cooking chamber or a furnace chamber, which is surrounded by side walls, a front, rear and top wall and has a bottom-side furnace chamber opening. The wall oven is to be fixed with its back wall in the manner of a hanging cupboard to a wall. The bottom-side furnace chamber opening can be closed with a lowerable bottom door. The bottom door is connected via a bottom door guide with the housing. By means of the bottom door guide, the bottom door is pivotally adjustable via a stroke.

The object of the invention is to provide a Hocheinbaugargerät, in which pinching of objects when lowering the bottom door of the Hocheinbaugargeräts is reliably avoided.

The object is achieved by the Hocheinbaugargerät with the features of claim 1. According to the characterizing part of claim 1, the control device detects a tilt angle of the bottom door and controls the drive means for reducing the inclination angle according to the size of the inclination angle. According to the invention, therefore, the fact is used that the bottom door tilts from its normally horizontal position into a slight inclination, if the underside thereof comes into abutment during the lowering process with an article, for example a food container, which is inadvertently arranged under the bottom door. In doing so, it sets the above-mentioned inclination angle of the floor door.

To detect the angle of inclination angle sensors can be used that monitor the angular position of the bottom door. Alternatively, according to a preferred embodiment, the size of tensile forces of at least two with the bottom door detected connected tension elements. Depending on a tensile force difference between these detected tensile forces, the control device determines the angle of inclination of the bottom door.

The above-mentioned tensile force difference can be determined, for example, by at least one first and one second switch. These switches generate switching signals when the tensile forces in the at least two tension elements change. The control device compares corresponding switching signals of the two switches and determines therefrom the traction force difference.

In a further advantageous embodiment of the invention, the lowering of the bottom door can always be terminated by means of the control device when the detected tensile force falls below a certain threshold. This is the case when the bottom door comes into contact with a countertop or other object located below the bottom door.

In addition, the control device can interrupt the floor door drive even if an upper threshold value of the tensile force is exceeded. This is the case when the bottom door moves against an upper stop, for example against the bottom-side muffle opening in the cooking appliance housing.

For detecting the tensile force, the drive means, for example a pull cable, of the drive device can be biased by a spring. The spring adjusts to a change in traction over a spring travel. Depending on the size of the spring travel, the control device can determine the size of the tensile force. Alternatively, it is also possible to use a tensile force sensor which detects, for example, the tensile forces acting on a deflection roller for the traction cable.

Figur 1

eine perspektivische Ansicht eines an einer vertikalen Wand montierten Hocheinbaugargeräts mit abgesenkter Bodentür;

Figur 2

eine perspektivische schematische Ansicht, in der eine Bodentürführung des Hocheinbaugargeräts hervorgehoben ist;

Figur 3

eine vergrößerte Schnittansicht entlang der Linie II-II aus der Figur 2;

Figur 4

eine abschnittsweise vergrößerte Seitenschnittansicht entlang der Linie I-I aus der Figur 1;

Figur 5

eine perspektivische schematische Ansicht, in der eine Antriebseinrichtung des Hocheinbaugargeräts hervorgehoben ist;

Figur 6

eine perspektivische Explosionsdarstellung eines Elektromotors der Antriebseinrichtung;

Figur 7

eine perspektivische Darstellung des zusammengebauten Elektromotors;

Figuren 8a und 8b

schematische Schnittdarstellungen entlang der Linie III-III aus der Figur 7;

Figuren 9

eine Einzelheit Y aus der Figur 5 in vergrößerter Vorderansicht;

Figur 10

ein Blockdiagramm, das einen Signalverlauf zwischen den Schalteinrichtungen und einer Steuereinrichtung darstellt; und

Figur 11

ein Belastungsdiagramm des Elektromotors der Antriebseinrichtung.

Hereinafter, an embodiment of the invention with reference to the accompanying figures will be described. Show it:

FIG. 1

a perspective view of a mounted on a vertical wall Hocheinbaugargeräts with lowered bottom door;

FIG. 2

a perspective schematic view in which a bottom door guide of the Hocheinbaugargeräts is highlighted;

FIG. 3

an enlarged sectional view taken along the line II-II of Figure 2;

FIG. 4

a sectionally enlarged side sectional view along the line II of Figure 1;

FIG. 5

a perspective schematic view in which a drive device of the Hocheinbaugargeräts is highlighted;

FIG. 6

an exploded perspective view of an electric motor of the drive device;

FIG. 7

a perspective view of the assembled electric motor;

FIGS. 8a and 8b

schematic sectional views along the line III-III of Figure 7;

Figures 9

a detail Y of Figure 5 in an enlarged front view;

FIG. 10

a block diagram illustrating a waveform between the switching means and a control device; and

FIG. 11

a load diagram of the electric motor of the drive device.

1 shows a Hocheinbaugargerät with a housing 1 is shown. The back of the housing 1 is mounted on a vertical wall 3 in the manner of a hanging cabinet. In the housing 1, a muffle 5 adjoins a cooking chamber, which can be controlled via a front window introduced into the housing 1 viewing window. The muffle 5 is provided with a heat-insulating sheath, not shown, and has a bottom-side muffle opening 7. The muffle opening 7 is closable with a lowerable bottom door 9. In the figure 1, the bottom door 9 is shown in a lowered state in which it lies with its underside on a worktop 11 of a kitchen equipment. On one of the muffle opening 7 facing top of the bottom door 9, a hob 13 is provided. The hob 13 is actuated via a control panel 14 which is provided on the front side of the bottom door 9.

As can be seen from FIG. 1, the housing 1 is connected to the housing 1 via a bottom door guide 15. In the present case, the bottom door guide is formed in the manner of a telescopic guide. By means of the telescopic guide, the bottom door 9 is guided over a stroke, which is limited by the housing 1 and the work surface 11. For this purpose, the telescopic guide 15 on each side of the Hocheinbaugargeräts each have a first fixed to the housing 1 guide rail 17 and a second attached to the bottom door 9 guide rail 23, as shown in Figure 2. The two guide rails 17 and 23 are longitudinally displaceable via a central rail 21 with each other. According to FIG. 2, the first guide rail 17 is fixedly mounted within the housing 1 indicated by dashed lines via a screw connection 19 on the housing rear wall. The center rail 21 is longitudinally displaceable with the bottom door side guide rail 23 in sliding connection. In the figure 2, the top of the bottom door 9 is shown partially broken. It can be seen that the guide rail 23 is formed as an L-shaped carrier, the horizontal support leg 31 is in engagement with the bottom door 9 to carry them.

FIG. 3 shows an enlarged sectional view along the line II-II from FIG. Accordingly, the guide rails 17, 23 and the intermediate rail 21 are formed as rigid, rigid U-profile parts which are telescopically displaceable one inside the other. The bottom door-side guide rail 23 is guided in the middle rail 21, while the center rail 21 is slidably mounted in the housing-side guide rail 17. When the bottom door 9 is closed, the housing-side guide rail 17 is thus arranged in the telescopic bottom door guide 15 to extremely. As a result, the outer guide rail 17 can be easily mounted on the rear wall of the housing. The rails are preferably mounted on balls, rollers or rollers. These are received in a known manner in bearing cages, not shown between the rails.

The U-shaped rails 17, 21, 23 form a channel line 35 according to FIG. In the duct 35 electrical supply or signal lines 37 are laid to connect the hob 13 and the control panel 14 in the bottom door 9 with control devices in the housing 1. In the channel line 35 and a rotatably mounted about a rotation axis 38 guide roller 39 is arranged. To this guide roller 39 is a pull cord 41 of a drive device described later of Hocheinbaugargerätes performed in the manner of a pulley. The left open channel line 35 is covered by channel-shaped apertures 43, 47. As a result, the channel line 35 is not visible to an operator when the bottom door 9 is lowered. The panel 43 is associated with the movable guide rail 23 and removably attached to the side walls thereof. In the same way, the diaphragm 47 is assigned to the middle rail 23. The aperture 43, 47 are telescopically slidable according to the rails 21, 23. When the bottom door 9 is closed so that the aperture 43 is disposed within the aperture 47. On a front side of the aperture 43, an infrared sensor 45 is provided for non-contact temperature measurement of a cooking utensil arranged on the hob 13.

In the figure 4 are shown in enlarged scale sections of a sectional view along the line II of Figure 1. Accordingly, an electric motor 49 is arranged in the interior of the housing 1 as a drive device. The electric motor 49 is driven by means not shown power or signal lines 37 provided by the front side of the bottom door 9 control panel 14. The lines 37 extend within the guide channel and intermediate rails 17, 21, 23 formed in the duct 35. As is apparent from Figure 5, the electric motor 49 is disposed approximately centrally between the two side walls of the housing 1 in the region of the rear wall. The housing 1 is indicated in FIG. 5 in a highly schematic manner with a dot-dash line. It can also be seen from FIG. 5 that tension elements 41 a, 41 b are assigned to the electric motor 49. The tension members 41 are in the present embodiment tension cables, which are initially performed horizontally from the electric motor 49 to laterally arranged housing-side guide rollers 51 and then guided in the vertical direction to the dash-dotted bottom door 9. In the bottom door-side guide elements 23, the already mentioned deflection rollers 39 are mounted. The traction cables 41 a, 41 b are in the manner of a pulley to the Bottom door side pulleys 39 out and again run into the housing 1. The ends 53 of the traction cables are fixedly secured to the housing side mounted switching devices 55a, 55b. These are arranged according to the figure 5 in approximately the same height as the housing-side guide rollers 51, in the housing 1. The structure and operation of the switching devices 55a, 55b will be described later.

In Figures 6 and 7, the electric motor 49 for the traction cables 41 is shown in perspective in an exploded view and in the assembled state. The electric motor 49 has an output shaft 57, on which two windings 59 and 61 are mounted, as shown in the perspective view of FIG. Depending on the direction of rotation of the output shaft 57, each winding drum 59, 61 winds up or down the associated pulling cable 41a, 41b. For this purpose, the winding drum 59, 61 are provided with left-handed and right-handed rope grooves 63 and 65. The ends 67 of the tension cables 41 a, 41 b are fixed to the Wickeitrommein 59 and 61 are supported. In the figure 7, a direction of rotation X of the output shaft 57 is indicated in the clockwise direction. In this case, the two tension cables 41a, 41b are unwound from their associated winding drums 59, 61. The bottom door 9 therefore sinks down. Accordingly, with a rotation of the output shaft 57 in the counterclockwise direction, each cable 41a, 41b wound on its associated winding drum. As the figure 6 is further removed, a disc-like carrier 67 is attached to the output shaft 57. The driver 67 has on its two opposite end faces driver teeth 69. When the output shaft 57 rotates, flanks of these driver teeth 69 press on corresponding face teeth 71 of the winding drums 59, 61. The driver teeth 69 of the driver 67 act as rotational angle stops. Between these rotational stops, each of the winding drums 59, 61 is pivotable over a rotation angle of approximately 90 °. Further, between the driver 67 and each of the winding drum 59, 61 a coil spring 73a, 73b braced. In manufacturing technology advantageously, the two coil springs 73a, 73b are integrally connected to each other at its one spring end via a web 74 according to the figure 6. The coil springs 73a, 73b are supported on the one hand in a holding groove 75 of the driver 67 with their common spring bar 74. On the other hand, the coil springs 73a, 73b are supported with their other spring ends in openings 77 of the winding drums 59 and 61.

As is apparent from the figure 7, the Wickeltrommein 59 and 61 are frontally mounted in contact with each other and rotatable. The two winding drums 59, 61 adjoin a receiving space 79. In the receiving space 79 of the driver 67, the front teeth 71 of the winding drums and the springs 73 a and 73 b are housed in a space-saving manner.

The arrangement described with reference to FIGS. 6 and 7 serves for slack rope securing of the traction ropes 41a, 41b. The mode of operation of this slack rope safety device is described below with reference to FIGS. 8a and 8b. According to FIG. 8a, the traction cable 41b is tensioned by the weight force F _{G of} the bottom door 9. As a result, a torque M _G acts on the winding drum 59 in a clockwise direction. The torque M _G presses the front teeth 71 of the winding drum 59 against first flanks 70 of the driver teeth 69. Thus, the winding drum 59 is held in firm contact with the driver 67. Depending on the direction of rotation of the output shaft 57 thus the driver 67 can rotate the winding drum in the clockwise or counterclockwise direction. In the state according to FIG. 8a, the helical spring 73a supported between points 75 and 77 is pretensioned. Therefore, the coil spring 73a exerts a torque M _G counteracting tightening torque M _Sp to the winding drum 59th

FIG. 8b shows a state which occurs when the base door 9 comes into contact with a stop, for example with the work surface 11, during lowering. In such a case, as described later, first switching devices 55a, 55b are activated. These send corresponding switching signals to a control device 103, which switches off the electric motor 49. Due to the Sigrialwegs between the switching devices 55a, 55b and the electric motor 49 and due to inertia effects of the electric motor 49 is switched off only after a time delay after the triggering of the switching signals. The lag of the electric motor 49 within this time delay has the consequence that the weight of the bottom door 9 is received by the countertop 11 and the tension cable 41b is relieved. As a result, the torque M _G applied to the winding drum 59 is also reduced. Such a strain relief is prevented by the clamping torque M _Sp . The clamping torque M _Sp acts in a counterclockwise direction on the front teeth 71 of the winding drum 59. As a result, the winding drum 59 is adjusted in relation to the output shaft 57 in the counterclockwise direction and therefore tightens the pull cable 41 b. A minimum value of the tensile force in the traction cable 41 b is thus maintained so that slackening of the traction cable 41 b is prevented.

The construction and the mode of operation of the switching devices 55a, 55b mentioned above are described by way of example with reference to the switching device 55a shown on the right in FIG. 5. The switching device 55a has a carrier plate 81 with a bore 83 through which the traction cable end 53 is guided. At Zugseilende 53 a switching flag 84 is attached. This protrudes through a introduced at the front of the support plate 81 switching window 85. The switching flag 84 is slidably guided within the switching window 85 and is supported by a spring 87 on a lower support surface 89 of the switching window 85 from. By means of the switching lug 84 are arranged opposite one another on the support plate 81 switches 91, 93. For this purpose, the scarf flag 83 two opposite switching ramps 95, 97, which are offset in Zugseil longitudinal direction to each other. The switching ramps 95, 97 switch in response to a height position of the switching flag 93 switching pins 99, 101 of the switches 91, 93. The height position of the switching flag 93 depends on the size of the tensile force F _Za , with the switch flag 83 presses the spring 87. Upon actuation of the switching pins 99, 101 switching signals S _a1 , S _{a2 are} generated in the switches 91, 93 of the switching device 55 a, which are passed according to the block diagram of Figure 10 to a control device 103. The control device 103 controlled in dependence of these switching signals the electric motor 49th

In FIG. 9, the left switching pin 101 of the switch 93 is actuated by the switching ramp 97. This is the case according to the invention if the value of the tensile force F _{Za is} greater than a minimum value of the tensile force or the same. In the event that a non-weight-loaded bottom door 9 moves against a lower stop, for example against the work surface 11 or against an object lying on the worktop, the traction cable 41a relieved. The tensile force F _Za in the traction cable 41 a therefore drops below the minimum value. As a result, the left switching ramp 97 according to FIG. 9 shifts upwards and comes out of engagement with the switching pin 101. The control device 103 thus receives - as shown in FIG. 10 - a corresponding switching signal S _a1 from the switch 93 for switching off the electric motor 49.

The right in Figure 9 switching pin 99 is shown out of engagement with the right switching ramp 95. This is the case when the value of the tensile force F _{Za is} smaller than a maximum value of the tensile force F _Za . This maximum value corresponds, for example, to a tensile force F _Za , which occurs at a predetermined maximum weight load of the bottom door 9. The value of the tensile force F _Za can exceed the maximum value if the bottom door 9 is overloaded or if the bottom door 9 moves when closing the cooking chamber 3 against an upper stop, for example against a bottom muffle flange of the muffle 5. In such a case, the tensile force increases , The switching flag 84 is pressed against the spring 87 down. This brings the right switching ramp 95 into engagement with the switching pin 99. The control device 103 thus receives a corresponding switching signal S _a2 from the switching device 55a for switching off the electric motor 49. The operation described with reference to the switching device 55a applies in the same way to the switching device 55b , which is arranged in the figure 5 on the right side of the housing 1. According to FIG. 10, the right switching device 55b forwards corresponding switching signals S _b1 and S _b2 to the control device 103.

The control device 103 according to the invention detects a time delay Δt between corresponding switching signals S _a1 and S _a2 and between S _b1 and S _{b2 of} the switching devices 55a, 55b. This time delay .DELTA.t is obtained, for example, when the bottom door comes into contact with an object, for example a cooking product container arranged below the bottom door 9, during a lowering operation. In such a case, the bottom door 9 tilts from its normally horizontal position in a slight tilt. Such an inclined position of the bottom door 9 is indicated in FIG. Accordingly, the bottom door 9 is tilted with an inclination angle α from its horizontal position. The inclined position causes the tension cables 41 a, 41 b are loaded with tensile forces F _Za , F _Zb different sizes. As a result, the lower threshold is not simultaneously undershot by the tensile forces F _Za , F _Zb . Consequently, the switches 99 and 101 of the switching devices 55a, 55b are switched in the time delay of Δt. Corresponding switching signals S _a1 and S _b1 are therefore also generated with a time delay. If the time delay between the switching signals S _a1 and S _{b1 is} greater than a value stored in the control device 103, for example 0.2 s, then the control device 103 reverses the electric motor 49. The bottom door 9 is thus raised in order to reduce the inclination angle α.

By the above-described detection of the inclination angle α of the bottom door and the control of the electric motor 49 as a function of the size of the inclination angle α in particular accidental trapping of human body parts during shutdown of the bottom door 9 is prevented.

In order to determine a weight load on the base door 9, the electrical current received by the electric motor 49 is detected by the control device 103 according to the invention. In this case, the fact is used that the current I received by the electric motor 49 is proportional to a load torque which is applied to the output shaft 57 of the electric motor 49. This relationship is set forth in a load diagram according to FIG.

For detecting the weight of a parked on the bottom door 9 Gargutbehältnisses at least two lifting operations are required. In the first lifting operation, the control device 103 first detects a current value I ₁ for a load torque M ₁ as the reference value. The load moment M ₁ is exerted on the output shaft 57 and is necessary to lift the non-weighted bottom door 9. The current value I ₁ is stored by the control device 103. In the subsequent second lifting operation, the current value I _{2 is} detected for a load torque M ₂ , which is necessary for lifting the weight-loaded bottom door 9. Depending on the size of the difference value (I ₂ -I ₁ ), the control device 103 determines the weight load of the bottom door 9.

The power requirement of the electric motor 49 is influenced by the height of the temperature in the electric motor 49. To compensate for this influence, a temperature sensor 105 is advantageously arranged in the electric motor 49, as indicated in FIG. This is in signal communication with the control device 103. Depending on the temperature measured at the temperature sensor 105, the control device 103 selects corresponding correction factors. By means of these correction factors, the influence of temperature on the power consumption of the electric motor is compensated.

To avoid a temperature influence on the weight detection, the weight load of the bottom door 9 can be detected according to the tension force sensor 107 indicated in FIG. The sensor 107 is connected to the control device 103 in FIG Signal connection and the rotation axis 38 of the guide roller 39 assigned. During a lifting operation, the traction cable 41 exerts a tensile force F _Z shown in FIG. 5 on the tensile force sensor 107. Depending on the magnitude of the tensile force F _Z on the bottom door 9, the tensile force sensor 107 generates signals which are sent to the control device 103.

The signal of the tensile force sensor 107 can also be used to control the electric motor 49 as a function of the magnitude of the tensile force: If the value of the tensile force measured by means of the tensile force sensor is below a lower threshold value stored in the control device 103, the electric motor 49 is switched off. If the tensile force sensor 107 detects a value of the tensile force which is above an upper threshold value of the tensile force, the electric motor 49 is likewise switched off.

The tensile force sensor 105 may alternatively be replaced by a torque sensor that detects a load torque applied to the output shaft 57 of the electric motor 49. As sensors for measuring the weight load, piezoelectric pressure sensors or deformation or voltage sensors can also be used, for example adhesive strip or materials with voltage-dependent optical properties and optical sensors cooperating therewith.

In the accompanying figures, the worktop 11 serves as a lower end stop for the lowered bottom door 9. Alternatively, the end stop may be provided by Auszugsbegrenzer in the telescopic rails 17, 21, 23. This allows any installation height of the Hocheinbaugargerätes on the vertical wall 3. The maximum stroke is reached when the telescopic parts 17, 21 and 23 are completely pulled apart and the Auszugsbegrenzer prevents separation of the rails.

Claims (9)

1. Overhead built-in cooking appliance with a muffle (1) having a muffle opening (7), which is at the bottom and closable by a lowerable bottom door (9), the built-in cooking appliance having a control device (103), and with a drive device (49) for stroke movement of the bottom door (9), characterised in that the control device (103) detects an angle (α) of inclination of the bottom door (9) and in dependence on the size of the angle (α) of inclination controls the drive device (49) for reducing the angle (α) of inclination.
2. Overhead built-in cooking appliance according to claim 1, characterised in that at least one first and at least one second drive means (41 a, 41 b), which are loaded against a weight force (F_G) of the bottom door (9) by a first and a second traction force (F_Za, F_Zb), are provided for detection of the angle (α) of inclination, which control device (103) ascertains the angle (α) of inclination in dependence on a traction force difference (ΔF) between the first and second traction forces (F_Za, F_Zb).
3. Overhead built-in cooking appliance according to claim 2, characterised in that for detection of the first and second traction force (F_Za, F_Zb) each of the drive means (41 a, 41 b) is biased by a spring (87), that the spring (87) adjusts itself over a spring travel in the case of change in the traction force (F_Za, F_Zb) and that the control device (103) ascertains the magnitude of the first and second traction force in dependence on the amount of the spring travel.
4. Overhead built-in cooking appliance according to claim 3, characterised in that an end (79a, 79b) of each of the drive means (41 a, 41 b) is biased by means of the spring (87) and that the biased end (53) adjusts itself over the spring travel.
5. Overhead built-in cooking appliance according to claim 3 or 4, characterised in that for detection of the traction force difference (ΔF) the control device (103) comprises at least one first and at least one second switch (93, 95) which generate a first and second switching signal (S_a, S_b) through the adjustment of the first and second drive means (41 a, 41 b), and that the control device (103) detects a time delay (Δt) between the generation of the first and second switching signal and ascertains the traction force difference (ΔF) in dependence on the magnitude of the time delay (Δt).
6. Overhead built-in cooking appliance according to claim 5, characterised in that in the case of exceeding an upper threshold value of the time delay (Δt) the control device (103) reverses the drive device.
7. Overhead built-in cooking appliance according to one of claims 2 to 6, characterised in that in the case of exceeding an upper threshold value of the first and/or second traction force the control device (103) interrupts the drive device (49).
8. Overhead built-in cooking appliance according to one of the preceding claims 2 to 7, characterised in that in the case of falling below a lower threshold value of the first and/or second traction force the control device (103) interrupts the drive device (49).
9. Overhead built-in cooking appliance according to one of the preceding claims 2 to 8, characterised in that in the case of falling below a lower threshold of the traction force the control device (103) reverses the direction of the stroke movement, which is predetermined by the drive device (49), of the bottom door (9).

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