Height adjustment device for a cooker hood, cooker hood and method for adjusting the position of a cooker hood

Abstract

Height adjustment device (1) for a cooker hood (2), comprising at least one rope (100), at least one winding unit (10) for at least one rope (100) and a drive device (11) for the winding unit (10) with a motor (111), characterized in that the height adjustment device (1) comprises a determining unit for determining the position of the cooker hood (2) and the determining unit comprises at least one reference switch (12) and a detection unit (130) for detecting the rotary movement of at least one part of the drive device (11) of the winding unit (10), wherein the reference switch (12) is a mechanical switch.

Description

The present invention relates to a height adjustment device for a cooker hood according to the preamble of claim 1, as well as a cooker hood with such a height adjustment device and a method for adjusting the position of a cooker hood by means of such a height adjustment device. For ceiling-mounted extractor hoods, also known as ceiling fans, it is necessary to be able to move the hood from a resting position, in which it is retracted into or resting against the ceiling, to an operating position. In the operating position, the extractor hood is lowered from the ceiling and is therefore closer to a cooktop located below it. This allows for the reliable extraction of cooking fumes and vapors. When the extractor hood is no longer in use, it must be moved from the operating position to the resting position. Motorized extractor hoods are equipped with a stop or mechanical limit switch that indicates when the resting position has been reached. When operating a range hood above a cooker, certain standards must be observed. For example, lowering the range hood to near the level of the cooker is not permitted. This applies particularly to gas cookers. A mechanical limit switch can be provided for this purpose; it is activated when the range hood reaches its maximum lowering position and prevents further lowering. Additionally or alternatively, the cables that attach the range hood to the height adjustment mechanism can be cut to a length that prevents it from being lowered too far. One disadvantage of these height adjustment devices is that they require complex installation and the position of the extractor hood cannot be adjusted flexibly. From EP 2 327 936 A1, a kitchen hood unit is known with a hood above a cooktop, which is attached to a support element on the ceiling by means of suspension means. The suspension means have a length that can be varied by the user, so that the hood is moved closer to or further away from the cooktop. A fume extraction duct can also be provided, the length of which varies based on the change in length of the suspension means. From EP 2 317 232 A1, a vapor extraction device, in particular a recirculating extractor hood, is known, comprising a housing in which one or more filters and one or more fans are arranged, and with suspension means with which the housing can be suspended in a height-adjustable manner, wherein the suspension means have a drive and at least two tension members, each with a first end and each with a second end. From JP S63-17334 A, a range hood is known that has a duct with an extendable section and a fan that draws in and expels air. The range hood further has a sensor that controls a drive unit to extend or shorten the extendable section of the duct by detecting contaminated air. A height-adjustable range hood is known from CN 2013 68516 Y. The vertical extraction pipe of the original range hood is replaced by a foldable and stretchable soft asbestos fabric or an anti-inflammatory soft cloth. Several iron rings are fixed in parallel and positioned perpendicular to the pipe wall at the internal fittings. Two or three pull ropes are used to secure the range hood and are controlled by a motor via a reversing switch, allowing the height of the range hood to be adjusted. From DE 198 14 000 C2, a cooker hood with a chimney is known, to which an exhaust duct is connected in the direction of flow, which opens into an exhaust opening closed by means of at least one filter element, which is arranged at least approximately vertically above the point of origin of a vapor, preferably above a cooking area, such that at least a partial area of ​​the cross-section of the exhaust opening forms an active extraction surface for extracting the vapor, wherein the cooker hood is provided with an adjustment device for changing the active extraction surface, wherein the adjustment device is connected with a distance sensor for detecting the distance of the respective operator. The object of the present invention is therefore to provide a solution by means of which the position of a cooker hood can be adjusted in a simple, flexible and reliable manner. The invention is based on the understanding that this problem can be solved by determining a reference point during assembly and using this point, together with an angle and direction specification of the drive shaft or rotor position of a drive motor, to determine and control the position of the extractor hood. According to a first aspect, the problem is therefore solved by a height adjustment device for a cooker hood, which has at least one cable, at least one winding unit for at least one cable, and a drive device for the winding unit with a motor. The height adjustment device is characterized in that it has a determining unit for determining the position of the cooker hood, and the determining unit has at least one reference switch and a detection unit for detecting the rotary movement of at least one part of the drive device of the winding unit. According to the invention, a height adjustment device is defined as a device by means of which the position of a range hood relative to the ceiling of the room in which the range hood is operated can be changed. In particular, the height adjustment device is a device by means of which the range hood can be lowered from the ceiling and raised towards the ceiling. The height adjustment device thus enables a vertical movement of the range hood. The range hood preferably represents a ceiling fan. A ceiling fan is defined as a range hood that, in its resting position, is recessed into the ceiling, i.e., retracted into it, or that, in its resting position, is housed in a casing attached to the ceiling or rests against the ceiling.To operate the extractor hood, it is moved downwards from its resting position until it is at a defined distance from a cooktop located below it. This position is also referred to as the operating position of the extractor hood. The height adjustment device can be located in the ceiling or in a housing on the ceiling. Alternatively, it is also possible to integrate the height adjustment device into the extractor hood itself. The height adjustment device has at least one cable. Preferably, the height adjustment device has at least four cables. One end of the cable or cables is connected to a winding unit of the height adjustment device. Depending on the embodiment, the other end of the cable or cables is connected to the extractor hood or attached to the ceiling or a housing on the ceiling. A wire rope is preferably used as the cable. However, other cables, for example, a fine-link chain or a cable made of another material, can also be used, as long as they can support the weight of the extractor hood. The winding unit for the rope preferably takes the form of a roller. One end of the rope is connected to the roller, and the rope is wound onto the roller by its rotation. The winding unit is a motor-driven unit. In particular, the height adjustment device includes a drive unit with a motor. The winding unit is driven by the motor, which can also be referred to as the drive motor. The drive unit preferably comprises, in addition to the motor, a drive shaft and a gearbox. The height adjustment device according to the invention includes a determining unit for determining the position of the extractor hood. The position of the extractor hood is understood to be its relative position to the ceiling. The determining unit includes at least one reference switch and a sensing unit for detecting the rotary movement of at least part of the drive mechanism of the winding unit.A reference switch is a switch used to determine a reference point. The switch can be mechanical or electrical. For example, the reference switch can be a roller limit switch. The activation of the switch is detected, and its position is stored in the detection unit and used as the reference point. The reference point is preferably determined only once. In particular, the reference point is determined during the installation of the extractor hood. In addition to the reference switch, the detection unit includes at least one sensing unit for detecting the rotational movement of at least a part of the drive mechanism of the winding unit. Preferably, the direction of rotation is also detected. The part of the drive mechanism whose rotational movement is detected can be the drive shaft of the drive motor or the rotor of the motor.The detection unit can be integrated into the motor or the motor's control unit, or it can be mounted on the drive shaft. The unit of the height adjustment device, referred to as the determination unit, thus consists of several components that are interconnected, at least for signal transmission. By having a positioning unit for the extractor hood, and by including at least one reference switch and a sensing unit for detecting the rotational movement of at least a part of the winding unit's drive mechanism, the position of the extractor hood can be easily determined at any time. Since a reference switch is used to determine the position, a reference point can be established, and the change in the extractor hood's position can then be determined by the rotational movement detected by the sensing unit. In particular, the length of the cable unwound from the winding unit relative to the reference point can be calculated based on the angular position of a part of the drive mechanism. This calculation can be performed in the height adjustment device's motor control unit or in a separate control unit of the height adjustment device.The motor control unit or a separate control unit of the height adjustment device can also contain various restrictions regarding the position of the extractor hood. Since the position of the extractor hood can be reliably determined at any time with the height adjustment device according to the invention, compliance with these restrictions can be easily verified. Furthermore, defined positions of the extractor hood can be stored in the motor control unit or the separate control unit of the height adjustment device according to the invention and, since the position of the extractor hood can be determined at any time, can be precisely targeted. Finally, the extraction hood can be reliably retracted into its rest position without the need for switches, stops, or sensors in the visible area of ​​the extractor hood or on the ceiling. According to a preferred embodiment, the control unit has at least one actuating means for actuating the reference switch. The actuating means can preferably convert a rotational movement into a linear movement. Particularly preferably, multiple rotational movements, for example, of a drive shaft of the winding unit, can be converted into a linear movement. The actuating means can thus be, for example, a block guided on a spindle or a gear with an engaging rack. Alternatively, the actuating means can also be a gearbox. In this case, for example, a multiple rotational movement can be reduced to less than one revolution in the gearbox. The reference switch is arranged with respect to the actuating means such that there is exactly one switching point along the travel path of the extractor hood. This means that the switch is actuated at exactly one position of the extractor hood. According to a preferred embodiment, the drive device for the winding unit comprises a drive shaft, and the determining unit comprises, as actuating means, at least one spindle on the drive shaft of the winding unit and a block movable on the spindle. When the drive shaft rotates, the spindle is driven, and the block is thereby moved on the spindle. In this embodiment, the reference switch is arranged such that it is actuated by the block moving on the spindle, at least in one position of the block. By incorporating a spindle with a block that interacts with the reference switch, a tamper-proof method for defining a reference point is created, as the reference switch is not accessible from the outside, thus preventing accidental activation. Furthermore, this design is easy to manufacture. These advantages of tamper resistance and ease of construction also apply when using other actuation devices, such as a rack and pinion or a gearbox that converts the rotary motion of the drive shaft into linear motion. According to one embodiment, the detection unit comprises at least one incremental encoder. An incremental encoder is understood to be one or more sensors for detecting the change in angle and direction of rotation. The incremental encoder can also be referred to as a rotary encoder. By using an incremental encoder, the change in angle and direction of rotation of the drive shaft or the rotor of the motor can thus be easily detected. From this information, the position of the extractor hood can be calculated. This position is determined with respect to the reference point, which is defined by the reference switch. Alternatively or additionally to one or more incremental encoders, the sensing unit can include a calculation unit for determining the rotor position in the motor's control system. The position of the extractor hood relative to the reference point can also be determined using this calculation unit and the rotor position calculated within it. In one embodiment, the reference switch is coupled to the drive shaft. Coupling the reference switch to the drive shaft is particularly advantageous if the drive shaft has some play. This coupling ensures that the reference switch is still reliably actuated. According to one embodiment, the reference switch is arranged such that it is actuated shortly before the extractor hood reaches its rest position, and at least one actuating element, for example a movable block or a rack, has a switching edge that actuates the reference switch until the rest position is reached. This embodiment allows the movement of the extractor hood to be slowed down during the final part of its retraction path when the extractor hood is retracted into the ceiling or a housing on the ceiling. In particular, the reference switch can be triggered, for example, 70 mm before the rest position, which can also be referred to as the end position, is reached and held in place by the actuating element.This makes it possible, without knowing the initial position of the extractor hood from which it is to be moved to its resting position, to first move the extractor hood upwards at high speed and only reduce the speed for, for example, the last 50 cm. The speeds to be set can be stored in the motor control or a separate control unit, and in particular, stored in software. According to a further embodiment, at least one additional switch is provided alongside the reference switch. By providing multiple switches, strategically important positions can be detected. For example, the maximum lowering of the extractor hood from the ceiling can be detected. Furthermore, if the initial position of the extractor hood is unknown, it is not necessary to fully retract the hood to determine the reference point, provided that additional switches are provided that detect the position of the extractor hood based on its retraction distance. The additional switches are preferably also arranged so that they are actuated by at least one actuator on the drive shaft. These actuators can be designed like the actuators for the reference switch described above. According to another embodiment, an incremental encoder is provided on the motor and another incremental encoder on the motor's drive shaft. Providing two incremental encoders creates redundancy. Furthermore, this design allows for the immediate detection of a defect in the gearbox connecting the motor to the drive shaft. Alternatively, only one incremental encoder can be provided on the drive shaft, and the motor's rotor position can be calculated in the motor control unit. This achieves the same advantages as using two incremental encoders. According to one embodiment, the height adjustment device comprises a control unit that is connected to at least the reference switch and the sensing unit. The control unit can be a separate unit from the motor control. In this case, the control unit is preferably connected to the motor control. Alternatively, the control unit is integrated into the motor control. Preferably, the control unit has at least one memory in which at least the reference point, which is set via the reference switch during the installation of the extractor hood, is stored. In addition, restrictions or further positions can be stored in the memory. According to a further aspect, the invention relates to a cooker hood characterized in that it has a height adjustment device according to the invention. The height adjustment device can be at least partially integrated into the cooker hood. For example, the drive unit and the winding unit can be integrated into the cooker hood. The cable(s) of the height adjustment device project beyond the top of the cooker hood when it is extended and are attached to the ceiling or a housing provided on the ceiling. Advantages and features that have been and will be described with regard to the height adjustment device and the method according to the invention also apply - insofar as applicable - to the extractor hood according to the invention and vice versa. According to a further aspect, the invention relates to a method for adjusting the position of a range hood using a height adjustment device according to the invention. The method is characterized in that a reference point is detected by the at least one reference switch, a rotary movement of at least a part of the drive device of the winding unit is detected by the sensing unit, and the position of the range hood is determined from these results. Based on the position of the range hood thus determined, predetermined positions, such as the operating position or the rest position of the range hood, can be easily set. Advantages and features described with regard to the height adjustment device and the extractor hood also apply – insofar as applicable – to the method according to the invention and vice versa. According to one embodiment, if no initial position is specified, and if the activation of the reference switch is detected, the extractor hood is moved downwards by means of the height adjustment device until the reference switch is no longer activated. This embodiment is advantageous, for example, in the event of a power failure. The invention is described again below with reference to the accompanying drawings. These show: Fig. 1: a schematic block representation of an embodiment of a cooker hood with a height adjustment device; and Fig. 2: a schematic block representation of an embodiment of the height adjustment device. Figure 1 shows an embodiment of a range hood 2, which is attached to a ceiling 3 via a height adjustment device 1. Only the cables 100 of the height adjustment device 1 are visible in Figure 1. The range hood 2 is lowered relative to the ceiling 3 by means of the height adjustment device 1. The lowered position of the range hood 2, shown in Figure 1, is also referred to as the operating position. A cooker 4 is arranged below the range hood 2. To comply with safety standards, particularly for gas cookers, the range hood 2 must not be lowered closer to the cooker 4 than indicated by the boundary G in Figure 1. The area above the boundary G can therefore also be referred to as the permitted area. The area below the boundary G can be referred to as the prohibited area. From the operating position shown in Fig. 1, the extractor hood 2 can be moved upwards towards the ceiling 3.The extractor hood 2 can be raised until it fits into a recess provided in the ceiling 3 (not shown). Alternatively, if no recess is provided, the extractor hood 2 can also be raised until its top surface rests against the ceiling 3. The position in which the extractor hood 2 rests in or against the ceiling 3 is also referred to as its resting position. The height adjustment device 1 is used to move the extractor hood 2 between the operating position and the rest position. An embodiment of a height adjustment device 1 is shown schematically in Fig. 2. The height adjustment device 1 comprises one or more cables 100 and at least one winding unit 10, onto which a cable 100 can be wound and from which the cable 100 can be unwound. The winding unit 10 is driven by a drive device 11. The drive device 11 comprises a drive motor, which is hereinafter referred to as motor 111. The motor 111 is preferably a BLDC (brushless direct current) motor. In the illustrated embodiment, the drive device 11 comprises a gearbox 113. Furthermore, an incremental encoder 131 is provided in the motor 111 as part of the sensing unit 130. The drive unit also comprises a drive shaft 112. The winding unit 10 is connected to the motor 111 via the drive shaft 112. A spindle 141 is formed on the drive shaft 112, at least in one section.A block 140 is movably guided on this spindle 141, meaning that the block 140 is moved by the rotation of the spindle 141. A reference switch 12 is arranged offset from the spindle 141 and the block 140. The reference switch 12 is positioned such that when the block 140 is moved on the spindle 141, the block 140 can actuate the reference switch 12. The spindle 141 and the block 140 are thus referred to as the actuating means 14. The reference switch 12 can also be coupled to the drive shaft 112 to detect any play in the drive shaft 112.Although the invention is essentially described with reference to an embodiment which has a spindle 141 and a block 140 as actuating means 14, other actuating means (not shown), such as a gear arranged on the drive shaft and a rack engaging with it or another transmission (also not shown), can of course also be used. Furthermore, in Fig. 2, an incremental encoder 131 is arranged on the drive shaft 112 as a further part of the detection unit 130. The angular position of the drive shaft 112 can be detected and tracked via this incremental encoder 131. This provides redundancy for the incremental encoder 131 located on the motor 111. On the one hand, this creates redundancy with respect to the incremental encoder 131 on the motor 111, and on the other hand, a defect in the gearbox 113 can be detected. The motor 111 is controlled by a motor controller 15. According to one embodiment, the position of the rotor of the motor 111 can be detected in this motor controller 15. For this purpose, a calculation unit 132 is provided as part of the detection unit 130 in the motor controller 15. The calculation unit can be software. If the position detection takes place in the motor controller 15, the incremental encoder 131 on the motor 111 can be omitted. The height adjustment device 1 is preferably arranged in the ceiling 3 of the room in which the extractor hood 2 is operated. However, it is also within the scope of the invention that the height adjustment device 1 is arranged in a housing (not shown) that is mounted below the ceiling 3. According to one embodiment, the extractor hood 1 can also be housed in this housing in its rest position. A reference point can be determined by the reference switch 12, which is a limit switch and can, for example, be a roller limit switch for the winding unit 10. The reference switch 12 is not accessible from the outside, thus preventing misuse and accidental activation. The reference point determined by the reference switch can be stored in the motor controller 15 or a separate control unit (not shown). The reference point is preferably set during the installation of the extractor hood 2. By providing either an incremental encoder 131 in the height adjustment device 1 and / or by calculating the rotor position of the motor 111 via the motor controller 15 and specifying a reference point, the position of the extractor hood 2 can be determined at any time. Limits can also be stored in the motor controller 15 or a separate control unit (not shown).The restriction could, for example, be the limit G, beyond which the extractor hood 2 may not move further downwards. In addition, predefined positions of the extractor hood 2 can also be stored in the motor control unit 15 or a separate control unit (not shown). These can then be easily accessed by the motor control unit 15. According to one embodiment, the reference switch 12 is arranged such that it is triggered at a position, for example, 70 mm before the rest position, i.e., the end position. The reference switch 12 can be triggered and held in place by the block 140. In this embodiment, it is not necessary to determine the initial position of the extractor hood 2 when it is retracted into or against the ceiling 3. Regardless of the initial position, the extractor hood 2 can be raised at a predetermined speed, and when the reference switch 12 is triggered, a reduction in speed can occur, i.e., a slow movement of less than 15 mm / s can be initiated. For example, when the reference switch 12 is triggered at 70 mm from the rest position, the reduction in speed can occur 50 mm before the rest position.This ensures a smooth and easy retraction of the extractor hood 2. If the reference switch 12 is pressed in an unknown initial position, the extractor hood 2 can first be moved downwards to determine the reference point, i.e. the point at which the reference switch 12 is no longer actuated, or is actuated again when the extractor hood 2 is raised. Although the invention has been described essentially with a reference switch 12, the height adjustment device can also include additional switches (not shown). These allow for the detection of further strategically important positions. The present invention offers several advantages. Firstly, it eliminates the need for a complex construction, thus preventing errors. Furthermore, shortening and re-crimping cables is unnecessary with this invention. Instead, a pre-assembled cable with a fixed attachment can be used. Additionally, the present invention requires no switches, triggers, or sensors in visible locations. During installation, the height adjustment device can be set quickly and easily. Readjusting the device after changes is also quick and easy with this invention. For example, when switching from a gas stove to an electric stove, the lowering limit of the range hood can be set lower. Finally, no mechanical stop on the ceiling is required.Therefore, for example, it is possible to adjust the height adjustment device if the extractor hood is to be retracted into the ceiling instead of being mounted on the ceiling. Reference sign 1 Height adjustment device 10 Winding unit 100 Rope 11 Drive device 111 Motor 112 Drive shaft 113 Gearbox 12 Reference switch 130 Detection unit 131 Incremental encoder 132 Calculation unit 14 Actuator 140 Block 141 Spindle 15 Motor control 2 Extractor hood 3 Ceiling 4 Stove G Limit

Claims

Height adjustment device (1) for a cooker hood (2), comprising at least one rope (100), at least one winding unit (10) for at least one rope (100) and a drive device (11) for the winding unit (10) with a motor (111), characterized in that the height adjustment device (1) comprises a determining unit for determining the position of the cooker hood (2) and the determining unit comprises at least one reference switch (12) and a detection unit (130) for detecting the rotary movement of at least one part of the drive device (11) of the winding unit (10), wherein the reference switch (12) is a mechanical switch. Height adjustment device (1) according to claim 1, characterized in that the determining unit has at least one actuating means (14) for actuating the reference switch (12) which converts a rotational movement into a linear movement, or represents a gear. Height adjustment device (1) according to one of claims 1 or 2, characterized in that the drive device (11) for the winding unit (10) comprises a drive shaft (112) and that the determining unit as an actuating means (14) for actuating the reference switch (12) comprises at least one spindle (141) on the drive shaft (112) of the winding unit (10) and a block (140) movable on the spindle (141). Height adjustment device (1) according to one of claims 1 to 3, characterized in that the detection unit (130) comprises at least one incremental encoder (131). Height adjustment device (1) according to one of claims 1 to 4, characterized in that the detection unit (130) comprises a calculation unit (132) for calculating the rotor position in a motor control (15) of the motor (111). Height adjustment device (1) according to one of claims 3 to 5, characterized in that the reference switch (12) is coupled to the drive shaft (112). Height adjustment device (1) according to one of claims 2 to 6, characterized in that the reference switch (12) is arranged such that it is actuated shortly before reaching a rest position of the extractor hood (2) and at least one actuating means (14) has a switching edge which actuates the reference switch (12) until the rest position is reached. Height adjustment device (1) according to one of claims 1 to 7, characterized in that at least one additional switch is provided for the reference switch (12). Height adjustment device (1) according to one of claims 4 to 8, characterized in that an incremental encoder (131) is provided on the motor (111) and a further incremental encoder (131) is provided on the drive shaft (112) of the motor (111). Height adjustment device (1) according to one of claims 5 to 9, characterized in that the height adjustment device (1) comprises a control unit which is connected to or integrated into at least the reference switch (12) and the detection unit (130) and preferably additionally with the motor control (15) of the motor (111). Extractor hood (2), characterized in that it has a height adjustment device (1) according to one of claims 1 to 10. Method for adjusting the position of a cooker hood (2) by means of a height adjustment device (1) according to one of claims 1 to 10, characterized in that a reference point is detected by the at least one reference switch (12), a rotary movement of at least one part of the drive device (11) of the winding unit (10) is detected by the detection unit (130) and the position of the cooker hood (2) is determined from these results. Method according to claim 12, characterized in that, in the absence of information on the initial position, the extractor hood (2) and, upon simultaneous detection of the actuation of the reference switch (12), the extractor hood (2) is moved downwards by means of the height adjustment device (1) until the reference switch (12) is no longer actuated.

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