work table

Abstract

Work table (1), comprising a frame (2), with a worktop (3), a hood (4) and a rear wall (5) connecting at least the worktop (3) to the hood (4), further comprising an air supply device (6) and a suction device (7), wherein the air supply device (6) has at least one fan, the air flow of which, emerging via at least two blower nozzles (8, 9), forms an air shield, for which purpose the blower nozzles (8, 9) are arranged opposite one another in or on the worktop (3) and in or on the hood (4) located at a distance above the worktop (3), and in the hood (4) there are several flow channels separated from one another by guide plates (10) as components of the suction device (7), characterized in that between the hood (4) and the worktop (3), on the front region of the rear wall (5) of the work table (1) facing the worktop (3), a Carbon nanotube heater (11) is arranged.

Description

[0001] The invention relates to a work table according to the preamble of patent claim 1.

[0002] Such workbenches are predominantly used in workshops, where, in addition to their conventional use, they can also be used for soldering, welding, or other activities that generate exhaust gases that require extraction. The resulting exhaust gases, such as aerosols, dust, or odors, are not only annoying but can also be harmful to health, so the more pollutants are present, the more important it is to ensure careful extraction. The intensity of the extraction can be increased to a certain extent by extracting a larger volume of air per unit of time, so that a higher percentage of the pollutants generated at the workbench is extracted. However, this requires increasing energy consumption, which must be used for the fan(s), depending on the intensity of the extraction.On the other hand, increasing the extraction power results in high air speeds, which can have a draughty character and be perceived as unpleasant by the people working at the desk or can even be harmful to their health.

[0003] DE 32 38 110 A1 discloses a workbench that has both an air supply device and an extraction device. The air supply device consists of a fan whose air stream, discharging through at least two nozzles, forms an air shield. The nozzles are arranged circumferentially around the outer edge of a worktop, with the extraction device located approximately centrally above the worktop.

[0004] However, a disadvantage of such a workbench is that the air, which forms an air shield and constantly flows from the outer perimeter of the worktop to the extraction system, is interrupted while the person working at the workbench is processing a workpiece on the worktop. As a result of the operator reaching through the air shield and the resulting interruption of the flow, the airflow becomes turbulent, i.e., it swirls, so that the exhaust gases mix with the swirled air and can escape unhindered into the open space. The functionality of such a workbench cannot therefore be guaranteed permanently or safely.The permanent air flow generated by the blower nozzles also creates a draft effect, so that in addition to the already mentioned risk of health impairments, a subjective feeling of discomfort arises for the operator working at this work table.

[0005] DE 295 17 454 U1 further describes a work table with an air supply device and an extraction device. The air supply device consists of a fan whose air flow forms an air shield. The blower nozzles are arranged both at the work area and at the hood, i.e., opposite one another. In the solution disclosed in this document, the extraction device is formed by a baffle element in the form of a baffle plate attached to the rear wall of the work table. However, this baffle plate, which runs approximately parallel to the rear wall, has the aerodynamic disadvantage that the extraction device located behind it generates considerable turbulence in the enriched air to be extracted due to the negative pressure created at the edge areas.This not only creates noise that subjectively and objectively worsens working conditions, but also poses the risk of contaminant-laden air being transported through the air shield into the open air. Furthermore, the work table described in DE 295 17 454 U1 has side walls and is preferably designed to be lockable with additional doors, resulting in a rather complex design overall.

[0006] Finally, DE 199 18 445 A1 discloses a workbench with an air supply device and an extraction device. The air supply device consists of a fan whose air stream, exiting through at least two blower nozzles, forms an air shield. The blower nozzles are arranged opposite one another. Above the workbench, the workbench has a hood in which several flow channels separated from one another by guide plates are located as components of the extraction device. An extraction fan is integrated in the area where the flow channels meet, discharging the drawn-in air into an exhaust air system. The flow-optimized air flow through several guide plates in the hood, which thus form flow channels, enables reliable extraction of enriched, polluted air that is improved compared to known workbenches.This type of workbench design makes it possible to direct the resulting exhaust gases to the extraction system using two interacting air streams supplied from different directions. From the extraction system, the exhaust gases are extracted in a conventional manner and disposed of properly. This workbench already significantly improves working conditions.

[0007] Nevertheless, it was found that the permanent air flow creates a certain cooling effect, which is ultimately perceived as unpleasant by the operator.

[0008] The invention is based on the object of developing a work table with a simple structure that ensures reliable extraction of air enriched with pollutants and compensates for air currents that are perceived as unpleasant.

[0009] This problem is solved by the features of patent claim 1. Further embodiments of the invention are the subject of the subsequent subclaims.

[0010] A work table, comprising a frame, with a worktop, a hood and a rear wall connecting at least the worktop to the hood, further comprising an air supply device and a suction device, wherein the air supply device has at least one fan, the air flow of which, emerging via at least two blower nozzles, forms an air shield, for which purpose the blower nozzles are arranged opposite one another in or on a worktop and in or on a hood located at a distance above the worktop, and in the hood there are several flow channels separated from one another by baffles as components of the suction device, was further developed according to the invention in that a carbon nanotube heater is arranged between the hood and the worktop, on the front region of the rear wall of the work table facing the worktop.

[0011] The structural design of a workbench according to the invention initially consists of a frame in which a worktop and a hood, as well as a rear wall connecting the worktop to the hood, are accommodated. The extraction device has several flow channels separated from one another by baffles, in the merging area of ​​which an extraction fan should be integrated, which discharges the sucked-in air into an exhaust air system. The flow channels of the extraction device, separated by baffles, are preferably arranged in the hood and / or in the rear wall. The extraction device is thus preferably located near the rear wall of the workbench. Filters can be integrated into the extraction device, as well as into the air supply device, in a conventional manner to achieve additional air purification.The use of filters even makes it possible to filter the extracted, pollutant-laden air and return it to the workspace, i.e., the environment, as purified air. This is particularly useful in winter for reasons of heat energy savings. It is also particularly advantageous to design the baffles as cladding panels, so that, in addition to their function, a visual design of the work table is achieved that is both appealing and aesthetically pleasing. Accordingly, the baffles are primed and then painted. A heat-resistant paint is preferably used here. Powder coatings and other surface finishing processes are also possible. Simple, stamped designs can be chosen as baffles or cladding panels, for example.These are connected to the frame using screws, adhesives, welding, rivets or other known types of connections.

[0012] A key feature of the workbench according to the invention is that the air supply device generates an airflow via at least two blower nozzles, which acts as an air shield to prevent contamination of the surroundings with the contaminated air generated on the workbench's worktop during the processing of workpieces. However, such an air shield has the disadvantage that the resulting airflow creates a cooling effect for the operator, at least subjectively, so that the working conditions are perceived as unpleasant. This is where the new solution comes in. It consists in arranging a carbon nanotube heater on the rear wall of the workbench connecting the hood to the worktop. The heat radiation from this heater creates a heating effect and thus significantly improves the comfort of the workbench.

[0013] The carbon nanotube heater is an energy-efficient infrared heater. Its principle is based on electrically conductive carbon fibers embedded between special materials. When powered, this fiber system emits comfortable heat through dark radiation. The infrared rays are then absorbed by the floor or walls, for example, which heat up as a result. Air heating does not generally occur. The heat absorbed by the heated objects is slowly released back into the environment, thereby achieving a pleasant room temperature and preventing mold growth. Furthermore, virtually no dust is produced, as the air circulation effect is much less pronounced than with conventional heaters. The relative humidity remains virtually unchanged compared to conventional heaters, ensuring a pleasant, tolerable climate.The calculated efficiency of such carbon nanotube heaters is 135% – theoretically, more energy is used for heating than the input energy. A power input of 400 watts corresponds to a power input of approximately 1000 watts for conventional heating or radiant devices. Surface temperatures of 50–400°C can be achieved if required. Carbon nanotube heaters can also be operated with voltages between 24 and 240 volts direct or alternating current and can, for example, be connected directly to a photovoltaic system, which makes them very flexible. The carbon nanotube heater used in the invention has no moving parts and is therefore maintenance-free, wear-free, and has a very long service life. Operating and installation costs are also significantly lower than with other heating systems.The installation effort is low, so that retrofitting to existing work tables is also possible without any problems.

[0014] The carbon nanotube heater consists of a frame housing. According to a first embodiment of the invention, an isotropic, thermally and electrically conductive glass fiber fabric accommodated therein serves as the carrier material and features a gold conductor system for the carbon nanotube dispersion. This achieves a very uniform current application. Previously, the current leads were routed diagonally across the heating surface, resulting in poorer efficiency. A screen-printing process also achieves a uniform coating with the carbon nanotube dispersion, which also leads to a uniform surface temperature. By using the glass fiber fabric with a larger spacing between the fabric fibers, the carbon nanotube dispersion can be applied very thinly and over the entire surface using the screen-printing process.

[0015] A safety temperature limiter prevents excessive heating. The materials used for the carbon nanotube heater are non-flammable and therefore comply with DIN 4102-4, Class A2.

[0016] The surface of the carbon nanotube heater used has a structure that enables nonlinear radiation. This results in a noticeably better perception of the heat rays. The angular radiation from the visible surface of the infrared radiation is achieved by using a material with a differently offset surface, which can be imagined as a shattered mirror surface that changes the angle of the surface structure countless times.

[0017] A further, highly advantageous feature of the invention is the inclusion of a carbon nanotube heater on the rear wall, beneath the worktop. This not only heats the work area directly above the worktop, but also the foot area, so that the operator develops an overall feeling of comfort at their workstation, which ultimately also has a positive effect on the quality of work.

[0018] In areas of the workbench that have an opening to the outside and no air nozzles, and therefore no air shield is created between the hood and the worktop, it is advantageous to provide a shield from the outside. This shield can be a simple slatted curtain or a solid wall.

[0019] If a solid wall is provided as a shield, it is possible, according to one embodiment of the invention, to arrange a carbon nanotube heater on each shield. This measure achieves uniform heating on several sides of the work table and effectively counteracts the cooling effect mentioned above.

[0020] To make the work table portable, for example, it is advantageous if the frame consists of hollow profiles, preferably square hollow profiles with a square cross-section. A very advantageous embodiment of the invention further consists in using the hollow profiles as components of the air supply device and / or the extraction device, specifically in such a way that the air is guided through the existing cavities. Thus, no additional pipes or connections installed on the work table are necessary, which greatly simplifies the overall structure of the work table according to the invention, making it cost-effective to manufacture.

[0021] The worktop and the hood are arranged opposite each other and each accommodates at least one blowing nozzle. Common types of blowing nozzles, such as wide-slot blowing nozzles, or others, can be used.

[0022] The opposing blower nozzles generate air currents that form an air shield and preferably flow toward the rear wall of the workbench. The overall effectiveness of the air flow can be improved, for example, by arranging several rows of blower nozzles in the hood, separated from each other by baffles. According to the invention, the blower nozzles are primarily located in the worktop and in the hood in the front area opposite the rear wall.

[0023] The air streams exiting the nozzles located in the hood and the worktop are directed toward the rear wall and form an angle between them that is greater than 0° and less than 180°. The angle between the air shields should preferably be less than 180° to avoid the air streams being directed exactly against each other.

[0024] To avoid subjectively unpleasant drafts, it is within the scope of the invention to design the air supply device and / or the extraction device in an adjustable manner. This control of the intensity of the extraction device or the air supply device can be achieved, for example, by varying the angular position of the associated baffles or by changing the associated fan speed.

[0025] A further embodiment of the invention further comprises arranging the blower nozzles on multiple sides of the work table and designing them to be individually or side-by-side switchable or deactivated. This design allows the operator to change their position and process the workpiece from multiple sides of the work table, while simultaneously ensuring optimal removal of pollutant-laden air, for example, by switching on the blower nozzles on the opposite side of the work table while switching them off in the work area. This avoids unpleasant drafts in the operator's work area and enables optimal pollutant removal.

[0026] Another highly advantageous embodiment of the workbench according to the invention further comprises openings in the worktop, beneath which a collecting container is arranged. Contaminants generated during the processing of a workpiece can be easily removed through these openings and collected in the collecting container. The collecting container is preferably detachably attached below the worktop.

[0027] However, according to the invention, the openings in the worktop can also be combined with an additional extraction system, so that the contaminants are automatically removed from the worktop. The suction power of this extraction system must be significantly lower than that of the work table's air extraction system. When integrated into the work table's extraction system, throttle devices and, if necessary, separate filters must be provided.

[0028] The aim of designing the work table as ergonomically as possible and thus improving the working conditions leads to a further development of the invention, which consists in the worktop being adjustable in its height and / or its inclination and / or the work table as a whole being adjustable in its height.

[0029] A further embodiment of the invention further comprises inserting the worktop of the work table into a frame support for vibration-damping or sound-damping purposes. Vibration damping or sound-damping can be easily achieved by inserting elastomer bodies or other bodies with limited elasticity or springiness between the frame and the inserted worktop.

[0030] Depending on the area of ​​application of the work table according to the invention, it may happen that workpieces that have to be processed on the worktop are very heavy. In this case, it is often difficult for the person working at the work table to transport these workpieces onto the worktop or to remove them from the worktop after processing. The use of a crane is very helpful in such a case, which is why a work table according to the invention advantageously has a slotted opening in its hood on the front of the work table that projects into the hood to a suitable depth, for example to the middle of the hood. The slotted opening serves to introduce the lifting device of the crane, on which the load-handling device with the workpiece held in or on it is arranged. In a crane, the lifting device can be a chain, for example, and the load-handling device can be a crane hook, for example.

[0031] Since the slotted opening is only used in specific applications, a further feature of the invention is that the slotted opening can be closed when not in use by at least one locking element pivoting about a joint. However, when the crane is in use, the locking element is opened, exposing the slotted opening and allowing the crane's load-bearing means to be inserted into the slotted opening in the manner described above.

[0032] The work table, which consists entirely of a simple frame, whose hollow profiles make it portable due to its lightweight construction, can also be combined with, for example, lockable casters arranged underneath the frame. This creates a mobile work table that is transportable and can be moved to another workshop area as needed. This is particularly useful when using a work table according to the invention as a welding table. In addition, the work table should be provided with additional electrical connections, such as sockets, to connect devices required during the work process. Additional hydraulic, pneumatic, or other connections are also considered.The simple and portable design of a workbench according to the invention also suggests the possibility of connecting several workbenches together using plug-in or screw connections. This allows, for example, a training workshop to be equipped with one or more combined workbenches as needed.

[0033] Of course, the features of the invention mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations, in addition or alone, without thereby departing from the scope of the invention.

[0034] Two preferred embodiments of a work table according to the invention are explained in more detail below with reference to the accompanying drawings.

[0035] They show: Fig. 1: a perspective view of a work table according to the invention, Fig. 2: the work table according to the invention Fig. 1 in the side view, according to the direction of arrow II in Fig. 1, Fig. 3: a view of the hood of a special design variant of a work table and Fig. 4: another view of the hood from Fig. 3.

[0036] The one in the Fig. The work table 1 shown in Figure 1 consists overall of a frame 2 which, viewed in cross-section, is made up of square hollow profiles. The frame 2 has rollers 22 in the lower area, i.e. beneath the worktop 3, by means of which the work table 1 is mobile as a whole and can, for example, be moved back and forth between different workshop areas when necessary. The frame 2 has a hood 4 and, beneath the hood, a worktop 3. The connection between the hood 4 and the worktop 3 is formed by a rear wall 5. In the present embodiment, a plurality of openings 15 are provided in the worktop 3. Below these openings 15 is a collecting container 25 which catches impurities falling through the openings 15.The collecting container 25 is detachably held within a sliding guide and is designed here as a drawer so that the contaminants can be disposed of at regular intervals.

[0037] A further characteristic of the work table 1 is that it is equipped with an air supply device 6, which, by means of a fan and via the cavities in the frame 2, supplies air to blower nozzles 8, 9, via which an air shield is formed, which removes exhaust gases generated within the work area via a suction device 7 that is also present and at the same time forms a shield against the environment, so that the resulting pollutants are not released into the ambient air. The blower nozzles 8 and 9 thus generate directed air flows, which together form air shields. The air flows are predominantly directed towards the rear wall 5 and enclose an angle with each other that is greater than 0° and less than 180°, so that the widest possible section above the worktop 3 is air-flowed and the air flows converge approximately in the central area between the hood 4 and the worktop 3.In this area, the effect of the extraction device 7 also begins to take full effect, so that the air supplied via the air supply device 6 combines optimally with the pollutants that arise and rise in the area of ​​the worktop 3, in order to then be removed by the extraction device 7.

[0038] The extraction device 7 opens into the hood 4 and also has a fan in the form of an extraction fan, which is an integral component of an extraction system. Furthermore, guide plates 10 are provided, which in turn form flow channels. In the illustrated embodiment, the guide plates 10 are mounted in the area of ​​the rear wall 5 of the work table 1 and are present both on the rear wall 5 itself and in the hood 4.

[0039] On the side of the worktop 3, the Fig. The work table 1 shown in Figure 1 has screens 13 and 14, respectively. These screens are slatted blinds that can be pushed together as needed. In the illustration, these screens 13, 14 cover the otherwise open sides of the space between the worktop 3 and the hood 4.

[0040] As from the Fig. As is also clear from Figure 1, the blower nozzles 8, 9, designed as wide-slot nozzles, are arranged in the front area of ​​the worktop 3 and the hood 4, so that the air shield directed toward the rear wall 5 is formed in this area. However, the worker working at the work table 1 is also located here, so that the generated air flow creates a cooling effect that can be perceived as unpleasant. For this reason, the rear wall 5 has a carbon nanotube heater 11 on one of the existing guide plates 10, the heat radiation of which counteracts the aforementioned cooling effects.

[0041] Another carbon nanotube heater 11 is located below the worktop 3, i.e. in the foot area of ​​the work table 1.

[0042] The Fig. 2 shows the side view of the in connection with the description of the Fig. 1 explained work table 1, i.e. the viewing direction in the direction of arrow II in Fig. 1. This clearly shows that the blower nozzles 8, 9 are arranged on the front side 16 of the hood 4 and the worktop 3, respectively. The screen 13, designed as a slatted curtain, forms the lateral closure of the worktop 3 and is suspended below the hood 4.

[0043] Another very special embodiment of a work table 1 according to the invention is shown in the Fig. 3 and Fig. 4 in different views. Only one connection of the extraction device 7 is visible. This also applies to the air supply device 6, of which connection pieces 23 and 24 are shown, which lead directly into the hollow profiles of the frame 2. The special feature of the Fig. 3 and Fig. 4 is that it has a slotted opening 17 on the front side 16 of the hood 4, which extends approximately to the middle of the hood 4. The slotted opening 17 serves to insert a lifting device of a crane, for example its chain. In this way, a workpiece with a high weight can be transported onto the worktop 3 and removed from it without the person working at the worktable 1 having to perform heavy physical work. When the slotted opening 17 is not in use, it can be closed by two locking elements 20 and 21 arranged to the side of the slotted opening 17, each pivotable about a joint 18 and 19, respectively. The pivoting direction of the locking elements 20, 21 is shown in the Fig. 4 symbolized by the arrows A and B. LIST OF REFERENCE SYMBOLS: 1 work table 2 frame 3 worktop 4 hood 5 Rear wall 6 Air supply device 7 Extraction device 8 Blow nozzle 9 Blow nozzle 10 guide plate 11 Carbon nanotube heater 12 Carbon nanotube heater 13 Shielding 14 Shielding 15 Opening 16 Front 17 Slot opening 18 joint 19 joint 20 locking element 21 Closure element 22 casters (lockable) 23 connecting pieces 24 connecting pieces

Claims

[1] Work table (1) comprising a frame (2) with a worktop (3), a hood (4) and a rear wall (5) connecting at least the worktop (3) to the hood (4), further comprising an air supply device (6) and a suction device (7), wherein the air supply device (6) comprises at least one fan, the air flow of which, emerging via at least two blower nozzles (8, 9), forms an air shield, for which purpose the blower nozzles (8, 9) are arranged opposite one another in or on the worktop (3) and in or on the hood (4) provided at a distance above the worktop (3), and in the hood (4) there are several flow channels separated from one another by guide plates (10) as components of the suction device (7), characterized by that a carbon nanotube heater (11) is arranged between the hood (4) and the worktop (3), on the front area of ​​the rear wall (5) of the work table (1) facing the worktop (3). [2] Work table according to claim 1, characterized by that an isotropic, thermally and electrically conductive glass fiber fabric accommodated in a frame housing of the carbon nanotube heater (11) forms a carrier material for a carbon nanotube dispersion applied by means of a screen printing process and has a gold conductor system. [3] Work table according to one of the preceding claims, characterized by that there is also a carbon nanotube heater (12) on the rear wall below the worktop (3). [4] Work table according to one of the preceding claims, characterized by that at least on one side of the worktop (3) there is a shield (13, 14) against the environment. [5] Work table according to claim 4, characterized by that a carbon nanotube heater is arranged on each shield (13, 14) present on the side of the worktop (3). [6] Work table according to one of the preceding claims, characterized by that the frame (2) consists of hollow profiles which are components of the air supply device (6) and / or the extraction device (7) in such a way that the air is guided through the existing cavities. [7] Work table according to one of the preceding claims, characterized by that the blowing nozzles (8, 9) are arranged in the worktop (3) and in the hood (4) in the front area opposite the rear wall (5). [8] Work table according to one of the preceding claims, characterized by that the air streams emerging from the blower nozzles (8, 9) accommodated in the hood (4) and in the worktop (3) are directed in the direction of the rear wall (5) and enclose an angle with each other which is greater than 0° and less than 180°. [9] Work table according to one of the preceding claims, characterized bythat the intensity of both the extraction device (7) and the air supply device (6) is controlled by changing the angular position of the associated guide plates (10) or by changing the associated fan speed. [10] Work table according to one of the preceding claims, characterized by that blowing nozzles are arranged on several sides of the work table and can be switched on or off individually and / or side by side. [11] Work table according to one of the preceding claims, characterized by that openings (15) are provided in the worktop (3) through which impurities can be removed into a collecting container placed beneath the openings (15) and / or that an extraction system for extracting the impurities is provided beneath the openings (15). [12] Work table according to one of the preceding claims, characterized bythat the worktop (3) is adjustable in height and / or inclination and / or the work table (1) is adjustable in height as a whole. [13] Work table according to one of the preceding claims, characterized by that the worktop (3) of the work table (1), which is adjustable in its working height, is inserted into a receptacle of the frame (2) in a vibration-damping and / or sound-damping manner. [14] Work table according to one of the preceding claims, characterized by that a slotted opening (17) open on the front side (16) of the work table (1) is made in the hood (4). [15] Work table according to claim 14, characterized by that the slot opening (17) can be closed when not in use by at least one closure element (20, 21) pivotable about a joint (18, 19). [16] Work table according to one of the preceding claims, characterized by that the work table (1) is designed to be transportable.

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