Bread maker with weighing function

Abstract

Bread maker comprehensive: - a heated baking chamber in which a baking container for holding ingredients for a dough is arranged, - a mixing tool in the baking container for stirring the ingredients and kneading dough, - a motor with drive for the mixing tool, - an electronic control unit with display, - a housing that at least accommodates the baking container, the mixing mechanism and the motor, and forms the baking chamber inside it, - at least 2 feet, in particular 3 or 4 feet, supporting the housing, wherein at least one of the feet includes a weight sensor that detects the weight of the bread maker including the ingredients placed inside and transmits it to the control unit for weight determination.

Description

[0001] The invention relates to a bread maker with a weighing sensor integrated into at least one base, among other things for measuring the weight of ingredients to be added. General state of the art

[0002] Bread makers are known from the prior art. For these, ingredients must be weighed using external kitchen scales. Furthermore, kitchen appliances with integrated scales are known, in which the weighing sensors are either located in a separately mounted base plate as part of the chassis or in a central weighing unit. However, these kitchen appliances are not bread makers, as they can only be used to prepare bread dough by stirring and kneading in a mixing bowl. They lack an integrated baking function, and the mixing bowl is not located in a heated baking chamber. Disadvantages of the prior art and the objective of the invention

[0003] A disadvantage of the current technology is that an external weighing function does not allow for complete user guidance and control when operating the food processor. For example, it cannot be determined whether ingredients were weighed incorrectly beforehand or whether the desired order of adding the ingredients was followed.

[0004] Weighing a mixing bowl requires a complex mechanical decoupling of the agitator from the drive train. Otherwise, the weighing device between the chassis and the mixing bowl necessitates increased installation space and can lead to reduced stability of the mixing bowl's suspension.

[0005] The object of the invention is to provide a bread maker that enables space-saving, simple and sufficiently precise weight measurement and improved operation by allowing the various operating steps to be easily recorded with regard to their weight changes and, in particular, to be controlled step by step. Furthermore, reliable signal transmission of the measurement data to the control unit should be ensured. Summary of the invention

[0006] The task is solved comprehensively by a bread maker: - a heated baking chamber in which a baking container for holding ingredients for a dough is arranged, - a mixing tool in the baking container for stirring the ingredients and kneading dough, - a motor with drive for the mixing tool, - an electronic control unit with display, - a housing that accommodates the baking container, the mixing mechanism and the motor, and forms the baking chamber inside it, - at least 2 feet, in particular 3 or 4 feet, supporting the housing, wherein at least one of the feet includes a weight sensor that detects the weight of the bread maker including the ingredients added and transmits it to the control unit for weight determination.

[0007] The weight sensors are connected to the control unit, with the signal transmission from the weight sensors to the control unit optionally via cable or wirelessly, e.g. via NFC (Near Field Communication).

[0008] The weight values ​​of the individual ingredients can thus be displayed successively while filling the container with ingredients.

[0009] The weight can also be determined during the baking process. Water evaporates during baking, resulting in weight loss. Often, it is desirable to continue baking until a certain weight loss is reached and then stop the process. The mixing tool is switched off during baking. Detailed description of the invention

[0010] The bread maker according to the invention is a kitchen machine with a mixing mechanism, heated baking chamber, baking container and electronic control unit, which can automatically carry out the bread baking process from dough preparation to baking.

[0011] A removable baking container is inserted into the baking chamber, which has a base and surrounding side walls and is preferably non-stick coated on the inside.

[0012] At least one rotatably mounted mixing tool is located in the base of the baking container. This tool can be coupled to the motor via a shaft and a drive train located within the housing. The drive train can be connected directly to the motor shaft or via a belt drive. A planetary gear system is also possible. The mixing tool can be a paddle, dough hook, or spiral mixer. Two spiral mixers arranged parallel to each other can also be used. Retractable dough hooks that disappear after kneading the dough are also possible.

[0013] The heated baking chamber includes, for example, one or more electric heating elements that, when in use, at least partially surround the baking container and are designed to generate a defined baking temperature. Heating elements used are primarily heating wires or PTC heaters for maintaining a constant temperature during kneading, proofing, and baking. A PTC heater comprises a PTC ceramic heating element (positive temperature coefficient) and a power supply, typically made of aluminum, which is electrically connected to the ceramic element to supply current. In one embodiment, a heating coil, an inductive heater, or a heating film is used in the baking chamber.

[0014] The bread maker also includes an operating and display element, preferably an electronic control panel with buttons and / or rotary encoders and a display, via which a user selects operating programs to control, for example, the bread size and the degree of browning. The control unit is designed to control the motor and the heating device according to a predefined time and temperature profile, thereby implementing different program phases such as adding ingredients, mixing, kneading, dough resting (proofing phase), and baking.

[0015] The control unit can also be controlled externally using a mobile phone, or the mobile phone can serve as a display, e.g. via WiFi or NFC.

[0016] After selecting a bread recipe, the control unit also specifies the order and quantity (by weight) of the ingredients, allowing them to be weighed into the baking hopper. For example, liquids such as water, milk, oil, eggs, or honey can be weighed into the hopper first, followed by dry ingredients like flour, salt, sugar, and spices. The leavening agent, such as yeast, is often added last, after a mixing / stirring cycle has already been completed.

[0017] A lid seals the baking chamber and may optionally have a viewing window through which the user can observe the dough and baking process. The baking chamber can be illuminated. Temperature sensors are located in the baking chamber and / or on the baking tray, which report the current temperature values ​​to the control unit in order to regulate the heating power.

[0018] The weighing sensor(s), designed as a base, act like a load cell, which is constructed in such a way that the device weight is introduced via this "base" and recorded as an electrical measurement signal.

[0019] In one design, the base contains a metallic spring element (e.g., steel or aluminum) or an elastic plastic body, onto which or within which strain gauges are glued or integrated. When the device is loaded, the base's contact surface transfers the weight force to the spring element or elastic plastic body, which deforms slightly under load. This expansion or compression changes the electrical resistance of the strain gauges (which are usually connected as a Wheatstone bridge) and produces a voltage change that is directly proportional to the applied force. A measuring amplifier and evaluation electronics within the device amplify this signal, digitize it, and convert it into a weight measurement.

[0020] Any change in load due to added ingredients leads to an additional elastic deformation of the sensor and thus to a change in the electronic signal.

[0021] In one design, the stand's height is adjustable by turning a threaded mechanism. Alternatively, the feet can be adjusted by extending or retracting a mounting element with weight sensors, for example, by rotating the feet. To ensure the bread maker is level, it can be equipped with a spirit level to align the housing using the height-adjustable feet.

[0022] When the machine is placed on a flat surface, a defined portion of the total load rests on the sensor-bearing base (e.g., on four sensor feet if there are multiple bases). The electronics add the signals from all four weight sensors; this allows the total weight to be averaged and, at the same time, largely compensates for any imbalances due to an asymmetrical weight distribution.

[0023] The control electronics can cyclically acquire the measurement signal, correct it for offset and temperature drift, and calculate a weight from it. If desired, calibration can be performed by applying known weights and storing a calibration factor or calibration curve.

[0024] By integrating it into the base, no separate weighing platform is required; the base simultaneously serves as a support and measuring element.

[0025] The design must provide sufficient overload resistance, vibration resistance, and protection against moisture and contamination, typically by potting or sealing the sensor cavity.

[0026] The bread baking process in a bread maker includes, for example, the following steps: The user places the baking container into the receiving chamber so that the kneading element's shaft can engage with the drive mechanism. Then, the ingredients required for a loaf of bread, in particular flour, water, leavening agent (yeast), salt, and optionally fats, sugar, and additives such as spices or flavorings, are added to the baking container in a predetermined order. The addition of the ingredients is measured using a weight sensor, at least for flour and water.

[0027] The control unit starts the motor, causing the mixing tool to rotate in the baking bowl and blend the ingredients into a homogeneous dough. This is followed by more intensive kneading, during which the dough is mechanically processed for several minutes; the motor can be operated according to predefined speed or interval profiles during this process.

[0028] After the kneading phase is complete, the motor is switched off, and the control unit operates the heating device in such a way that a relatively low temperature is set in the baking bowl, typically in the range of 20 to 45 °C, especially 27–38 °C, to promote fermentation of the dough. During this phase, the dough rests, expands as a result of the fermentation activity, and increases in volume; the machine can provide for several successive proofing phases with intermediate mixing.

[0029] For some programs, a further, shorter kneading phase follows to optimize the dough structure and distribute trapped gases more evenly. Afterwards, another proofing phase is carried out at a moderate temperature, during which the dough reaches its final volume for the subsequent baking phase.

[0030] After the final proofing phase, the control unit deactivates the motor and increases the heating element's power to a significantly higher temperature in the baking pan for baking the bread (typically between 100 and 250 °C, especially 150 to 200 °C). During this phase, the loaf is baked in the pan without further kneading, with the baking time depending on the selected program and the bread's weight. The weight reduction is recorded during this time. Depending on the recipe, a weight reduction of, for example, 5 to 20% by weight is desired or set.

[0031] Once the baking time is complete, the control unit can reduce the heating power and maintain a low temperature for a defined warming period to keep the finished bread warm until it is removed. The user then opens the lid, removes the baking pan, and turns the baked bread out.

[0032] Fig. Figure 1 shows a bread maker 1. The display 3 is visible on the top of the housing 2, and the housing 2 is supported at the bottom by 4 feet 4, each with an integrated weight sensor 5. The housing 2 also has a lid 6 with a viewing window 7, which closes the baking chamber.

Claims

[1] Bread maker including: - a heated baking chamber in which a baking container for holding ingredients for a dough is arranged, - a mixing tool in the baking container for stirring the ingredients and kneading dough, - a motor with drive for the mixing tool, - an electronic control unit with display, - a housing that at least accommodates the baking container, the mixing mechanism and the motor, and forms the baking chamber inside it, - at least 2 feet, in particular 3 or 4 feet, supporting the housing, wherein at least one of the feet includes a weight sensor that detects the weight of the bread maker including the ingredients placed inside and transmits it to the control unit for weight determination. [2] Bread maker according to claim 1, wherein four feet are provided and the four feet each have a weight sensor to support the housing. [3] Bread maker according to claim 1 or 2, wherein the control unit is configured to display the weight of the added ingredients in a unit of weight. [4] Bread maker according to at least one of the preceding claims, wherein the feet or feet are height-adjustable, in particular by making a mounting element with the weight sensors extend or retract from them, e.g. by turning the feet. [5] Bread maker according to claim 4, wherein the bread maker has a spirit level for leveling the housing by means of the height-adjustable feet. [6] Bread maker according to at least one of the preceding claims, wherein the control unit is configured to weigh the ingredients successively and preferably also to specify the weight and type of ingredients. [7] Bread maker according to at least one of the preceding claims, wherein the control unit is configured to measure the weight loss during the baking process and to take the weight loss into account as a parameter for controlling the length of the baking time and / or the temperature profile, preferably when the weight loss is at least 5 wt.% of the weight of the ingredients.

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