A device for manufacturing mouthpieces

Abstract

The present invention relates to an apparatus for manufacturing a mouthpiece, comprising a calculation unit (1), a thermoforming station (2) for a film on a dental model (3), and a laser cutting device (4) for separating the mouthpiece from the film. To enable the mouthpiece manufacturing process to be as fully automated and rapid as possible, in which case the required space for the necessary equipment should be minimized and a complex robotic system for transporting the mouthpiece should be eliminated, the apparatus is configured with multiple work stations, each work station including at least one 3D printer (5) for creating a dental model (3) on a workpiece support (10), a thermoforming station (2), a separation device (6) for separating the thermoformed film from the dental model (3), and a laser cutting system (4), the work stations being arranged along a transport system (7), the transport system (7) including a guide (8) and transport means for transporting the workpiece support (10) into and out of the work stations, which are displaceable along the guide (8).

Description

Technical Field

[0001] The present invention relates to an apparatus for manufacturing a mouthpiece, the apparatus comprising an arithmetic unit, a thermoforming station for a film on a dental model, and a laser cutting system for separating the mouthpiece from the film, and a plurality of work stations are provided, and the work stations include at least one 3D printer for manufacturing a dental model on a workpiece support, a thermoforming station, a separating device for separating a film thermoformed from the dental model, and a laser cutting system.

Background Art

[0002] In order to manufacture a mouthpiece for correcting tooth displacement, a series of work steps that are spatially and temporally separated are required. After the actual position of the teeth is captured by an image generation method, the target position must be determined by an expert. Subsequently, a plurality of 3D dental models are created starting from the actual position, and at that time, the position of the teeth is gradually changed to the target position. These models are used as mold parts for thermoforming a thermoplastic film, and the plastic film must be detached from the mold parts, appropriately cut, and deburred, so that the patient can use these processed films as a mouthpiece. Therefore, in the prior art, it is known to arrange a plurality of work stations that can automatically execute individual work steps on a production line and supply intermediate products to the individual work stations sequentially.

[0003] However, according to the drawbacks in the prior art, some work steps, particularly the production of a dental model using a curable resin or plaster, take an extremely long time, and the dental model and the film must be frequently moved between work stations during production, which makes it difficult to automate the production process to save time and labor. In particular, complex robotic arms and belt conveyors are required for transporting and positioning the mouthpiece, and thus the mouthpiece can only be automatically produced under a large required space.

[0004] Apparatus that perform multiple work steps in the same location to minimize movement between work stations has already been disclosed. European Patent No. 2101674, for example, discloses an apparatus that can store a film detached from a mouthpiece on a movable platform, where it can be automatically processed using a similarly movable thermoforming tool based on a CAD original and cut by laser. There also exists an apparatus for 3D printing a dental model that has a ball cutter for trimming the film. However, even here, two work steps are performed, which makes automated production impossible. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] European Patent No. 2101674 [Overview of the project] [Problems that the invention aims to solve]

[0006] Therefore, the fundamental problem of the present invention is to enable a fully automated and rapid mouthpiece manufacturing process, in which the required space for the necessary equipment should be minimized, and complex robotic systems for transporting the mouthpieces should be eliminated. [Means for solving the problem]

[0007] The present invention solves the given problem by having a work station arranged along a transport system, the transport system including a vertical linear guide and a transport means for loading and unloading workpiece supports, which are displaceable along the vertical linear guide, into and out of the work station. Dental models and / or mouthpieces, due to their fine and individual surface characteristics and brittle materials, generally cannot be automatically transported without considerable effort. Since a 3D printer controlled by a computing unit prints the dental model directly onto the workpiece support based on stored patient data, the transport means only needs to be designed to receive and transport robust and geometrically simple workpiece supports with respect to the guide, but not to receive and transport elaborate dental models. As a result of this means, the transport means requires only a simple receiving mechanism that allows displacement of the workpiece support, and optionally films and mouthpieces, for loading and unloading into and out of the work station. This may be, for example, a transport member having a sliding stopper. All manufacturing steps, from the fabrication of the dental model to the subsequent processing of the mouthpiece, are performed at the work station. Since the work stations are arranged along the transport system, control of the transport means can be easily maintained. That is, loading and unloading to and from multiple, preferably all, work stations can be performed via transport means that are displaceable along the guides of the transport system, and in this case, the transport means only needs to move along a single axis between the work stations. The transport system transports the workpiece support having the dental model and the film from the film storage unit to the thermoforming station, where the film is stretched over the dental model in a known form. To facilitate loading into the thermoforming station and accurate positioning of the film, a centering ring or a tightening ring may be provided on the film. Subsequently, the thermoformed film is separated from the dental model by a separation device using a method known from the prior art.For example, before thermoforming, a lubricant can be applied to the dental model in an optional additional work step, and / or positive or negative pressure can be applied to the stretched film. The separated, thermoformed film is then fed by a transport system to a laser cutting system, where it is cut and trimmed to the appropriate shape for the mouthpiece. As a result of these means, care must be taken to position the film or to capture the film's position by the laser cutting system only in this processing step. However, since the diameter of the film itself does not change much after thermoforming, a stopper adapted to the diameter may be provided in the laser cutting system for the film, and as a result, control of the transport system can be simply maintained for accurate loading into the laser cutting system. The calculation unit has an interface for sending commands and for transmitting data such as a CAD plan of the dental model. In addition, additional work stations may be provided for performing further work steps. Preferably, transport means arranged in guides perform loading and unloading to all work stations, being suitable not only for transporting workpiece supports but also for receiving films or mouthpieces made from films. The apparatus may further include a film storage unit, from which the film can be transported to a thermoforming station by a transport system. Furthermore, a removable waste container may be provided, into which the dental model and film residue can be disposed of via the transport system. The required space of the apparatus is reduced by the use of vertically extending linear guides. As a result, both the maximum distance traveled between different work stations and the required area of ​​the apparatus are minimized. This reduces the size of the apparatus, not only in area but also in height, allowing it to be used, for example, in a small dental clinic.

[0008] According to the present invention, the apparatus can manufacture mouthpieces fully automatically simply by using a transport means already in place for loading and unloading. However, for this to work, the transport means must be able to receive both the robust workpiece support and the delicate film without damage or error. However, in order to keep the transport means as easy to handle as possible and to preferably make the apparatus more compact, the transport system may include a second transport means for transporting the film from the separation device to the laser cutting system. As a result of this means, the transport means only loads and unloads at work stations where the workpiece support is being worked on, such as a 3D printer, thermoforming station and separation device, in which case the transport of the film is taken over by the second transport system. Thus, mouthpieces can still be manufactured fully automatically, and the configuration and control of the transport system can be kept simple, since only the robust workpiece support needs to be transported. In this case, the second transport system may also be displaceable on a guide, and preferably, this second transport system is displaceable on a special guide. This allows for greater structural freedom regarding the spatial arrangement of the work stations, since the travel path of the second transport means can be configured independently of the first transport means. The second transport system may, for example, similarly include a gripper. When the device includes a film storage unit, the second transport means is preferably designed to transport the film from the film storage unit to a separation device and further to a laser cutting system. Furthermore, the second transport means is preferably designed to receive the mouthpiece after the final processing step of the last work station and to be placed in a location where the mouthpiece can be easily received by the user, preferably at an access opening.

[0009] The workpiece support may include multiple receiving mechanisms, and indeed, if a negative pressure system is provided in the first and / or second transport means, including at least one nozzle positioned on a suction plate, the workpiece support, film, and stretched film can be received, positioned, and transported particularly easily. Both the workpiece support and the film and stretched film have sufficiently large and smooth surfaces to which the workpiece support, film, or stretched film can be sucked to the suction plate for reversible retention on the suction plate. In this case, the suction plate prevents the film or stretched film from deforming based on the negative pressure, thereby preventing detachment or damage. Furthermore, if the suction plate is positioned on the underside of the transport means, the workpiece support, film, or stretched film can adhere across its upper surface while its underside remains exposed. This allows for easy positioning and positioning at the work station. In one preferred embodiment, the negative pressure provided can be adjusted so that the adhesive force is adapted to the object to be transported. The interaction surface of the suction plate on which the film is adsorbed may be smooth or configured as a suction cup.

[0010] If the first transport means has a magnet for displacing a magnetizable workpiece support, and at least one work station has a workpiece support housing equipped with a stopper for the magnetizable workpiece support, the number of mechanical components of the transport system required for receiving and positioning the workpiece support can be reduced. The workpiece support adheres to the transport means based on magnetic interaction, in which case there is no need to provide a mechanical receiving or positioning mechanism. The magnet may be an electromagnet, so the adhesion between the workpiece support and the transport means can be adjusted via electric current, and a workpiece support housing with a stopper may use a low-cost permanent magnet, eliminating the need for magnetic field control. That is, the transport means can position the workpiece support in the area of ​​the stopper in the workpiece support housing and then continue to move it in the contact direction, so that the adhesion between the transport system and the workpiece support is released by the stopper as the transport system is gradually displaced. Preferably, the workpiece support housing section forms a vertical stopper, so the transport system positions the workpiece support in the workpiece support housing section by displacing it downward, thereby avoiding undesirable movement of the workpiece support as the transport means approaches.

[0011] Having two 3D printers as a workspace enhances the mouthpiece manufacturing process with only a slight increase in the equipment dimensions. Since 3D printing constitutes the most time-consuming step in mouthpiece manufacturing, it allows for the simultaneous printing of two dental models, preferably the mandible and maxilla, thereby avoiding waiting time at other workspaces. This reduces the manufacturing time for the complementary first pair of mouthpieces, so that the patient can preferably receive the first pair of mouthpieces by the end of their initial consultation, without any further waiting time.

[0012] While positive or negative pressure can generally be supplied during film thermoforming, additional work steps or part modifications can be avoided if the thermoforming station includes a chamber that forms a pressure chamber capable of supplying compressed air together with the workpiece support at the forming position. As a result of this means, at the forming position, the chamber is lowered onto the workpiece support into which the gear model is fed and pressed against it upon contact. A heated film is positioned between the chamber and the gear model, parallel to the tool support. The film can be preheated to the temperature required for thermoforming on a heating platform assigned to the thermoforming station. The tool support forms a stopper for the chamber at the forming position, so that the tool support and the chamber form a chamber capable of supplying compressed air. The edge of the chamber facing the tool support may include a sealing ring. Even when the diameter of the film is greater than the diameter of the tool support and therefore positioned between the tool support and the chamber at the forming position, a pressure chamber is still formed between the tool support and the chamber based on the pressing force applied to the chamber, so that the thermoforming process can be carried out using the positive pressure generated by the compressed air. In one preferred embodiment, the positive pressure is at least 5 bar. When the second conveying means is used for conveying the film, the thermoforming station is preferably capable of not only loading and unloading tool supports having a toothed model via the first conveying means, but also loading and unloading the film via the second conveying means. In this case, in a more preferred embodiment, the loading and unloading of the two conveying means can be performed at opposite ends of the thermoforming station, thereby making the apparatus more compact and avoiding collisions between the two conveying means.

[0013] A further possibility for increasing and simplifying production speed lies in the use of fused deposition modeling (FDM) printers. Fused deposition modeling (FDM) printers produce dental models layer by layer from molten resin that hardens itself, unlike stereolithography (SLA) 3D printers. Therefore, the additional exposure step required for SLA is eliminated. In a preferred embodiment, the apparatus may include a filament storage unit for the 3D printer.

[0014] To facilitate loading and unloading not only by control technology but also mechanically, it is proposed that a first and / or second transport means is positioned to be displaceable along a guide via a scissor joint arm. Typically, the movement of the transport means can be divided into two movement stages: transport of workpiece supports or films between work stations, and loading into or unloading from work stations, in which case transport is performed along the guide, and loading and unloading are performed laterally with respect to the guide. When a scissor joint arm is used according to the present invention, no special mechanism is required for movement laterally with respect to the guide, because movement laterally with respect to the guide, as well as movement along the guide, can be controlled via the absolute position of the pivot point of the scissor joint arm on the guide and the relative position of the pivot points along a single axis, i.e., the axis of the guide.

[0015] To enhance operational safety and ensure high product quality, it is recommended that the work station, and preferably guides and transport means, be housed within a box-shaped housing. This protects the work station, dental models, films, and mouthpieces from contamination and the potential deterioration of product quality, as well as preventing undesirable contact with the work station and the risk of injury. Furthermore, the box arrangement facilitates transport and stacking capabilities. The housing may have maintenance openings and / or doors and / or covers for removing mouthpieces and dental models and for loading starting materials. Additionally, the housing may include a blower and / or exhaust hood and / or waste container to ventilate or collect waste, aerosols, particles, and vapors generated during manufacturing. A further advantage of the housing according to the present invention is that environmental conditions during manufacturing can be better controlled. Therefore, it is preferable to provide air conditioning equipment to adjust the temperature and / or humidity inside the box, since films typically used must be stored at a maximum humidity of 30%.

[0016] It is proposed that a box-shaped housing has a removal opening that penetrates it, eliminating the need to open the housing to remove the mouthpiece and / or dental model. This removal opening is connected via a duct to a mouthpiece dispensing opening assigned to the laser cutting system. This also reduces contamination by dirt particles and the risk of injury, as access is made to a designated location that is physically separated from the work station by the duct. The dental model and / or mouthpiece can be fed to the dispensing opening by a transport system, or a separate tool, such as a slide arm, may be provided for this purpose.

[0017] Although the apparatus according to the present invention requires only simple transport means, if at least one work station includes a centering means for the workpiece support, the tool support can be easily and reproducibly positioned at the same location on the work station. For example, the work station may be provided with a stopper adapted to the geometry of the tool support, which sets the optimal position for machining at each work station. In this case, the transport system may be programmed to release the tool support within the work station at a predetermined force threshold induced by the physical resistance of the stopper on the tool support. If the work station includes a workpiece support housing with a stopper, this workpiece support housing may also include a centering means.

[0018] The drawings illustrate the scope of the present invention. [Brief explanation of the drawing]

[0019] [Figure 1] A schematic side view of the apparatus according to the present invention is shown. [Figure 2] A schematic side view of the first transport system for transporting the workpiece support to the work station is shown at a relatively large scale. [Figure 3] This shows a side view corresponding to Figure 2 after the equipment has been moved into the work station. [Modes for carrying out the invention]

[0020] The apparatus for manufacturing a mouthpiece according to the present invention includes, as a work station, a calculation unit 1, a thermoforming station 2 for a film on a dental arch model 3, a laser cutting system 4, at least one 3D printer 5, and a separation device 6. Typically, upper and lower mouthpieces are manufactured, and printing the dental arch model 3 is a more time-consuming work step; therefore, in the illustrated embodiment, two 3D printers 5 are provided, so that the upper dental arch model 3 and the lower dental arch model 3 can be printed simultaneously. The work station is arranged along a transport system 7, in this case the transport system has a guide 8, and a transport means 9 is displaceable along the guide 8, thereby transporting the workpiece support 10. In the illustrated embodiment, the transport means 9 is a scissor joint arm (scissor lift arm) because the scissor joint arm allows for easy control and transport of the workpiece support 10 along and laterally to the guide 8. To achieve the most compact structural form possible for a device usable in a dental clinic, guide 8 is a vertically extending linear guide. In this case, the workpiece support is displaced vertically along guide 8 for transport between work stations and laterally relative to guide 8 for loading into and unloading from work stations.

[0021] The conveying means 9 conveys the workpiece support 10 into the 3D printer 5. Subsequently, on the workpiece support 10, the 3D printer 5 prints the three-dimensional dental model 3 of the patient's dentition on the workpiece support 10 based on the data stored in the arithmetic unit 1. Subsequently, the conveying means 9 conveys the dental model 3 out of the workpiece support 10 and conveys the dental model 3 to the thermoforming station 2, where the three-dimensional contour of the dental model 3 is transferred to the film by thermoforming. For example, after being heated, the film can be positioned above the dental model 3 and pressed against the dental model 3 through the applied pressure difference, so that the film inherits the contour of the dental model 3. Subsequently, the thermoformed film and the dental model 3 are separated from each other, for example, by mechanically fixing the film and pulling it from the locked dental model 3. In the illustrated embodiment, since the separating device 6 is located close to the thermoforming station 2, the conveying system 7 does not have to displace the dental model 3 between the two stations together with the film.

[0022] The thermoformed film is then conveyed to the laser cutting system 4. For this purpose, for example, the conveying means 9 may be configured to receive and convey not only the workpiece support 10 but also the thermoformed film. Moreover, in the illustrated embodiment, the conveying system 7 includes a second conveying means 11 for conveying the thermoformed film, and in this case, the second conveying means 11 must be designed to convey only the film and not the workpiece support 10. Conversely, in the illustrated embodiment, the conveying means 10 is designed to convey only the workpiece support 10. For this purpose, the work station may include centering means for the workpiece support 10, and the centering means makes it easier for the conveying means 9 to place the workpiece support 10 in a predetermined position, so that the automatic processing steps of each work station can be executed more easily. Therefore, the conveying means 10 can fix the workpiece support, for example, magnetically. The second conveying means 11 is provided with a negative pressure system (not shown), and the negative pressure system includes a suction plate having nozzles, so that the thermoformed film can be received and arranged through the supplied negative pressure. In a preferred embodiment, the conveying means 9 also has such a negative pressure system.

[0023] In the illustrated embodiment, the thermoformed film separated from the dental arch model 3 is displaced from the separating device 6 to the second conveying means 11, where it is received by the second conveying means 11 and conveyed to the laser cutting system 4. There, the second conveying means 11 places the thermoformed film on the support 12 assigned to the laser cutting system 4. Subsequently, the laser cutting system 4 cuts the mouthpiece from the thermoformed film.

[0024] All the work steps executed by the various work stations and the conveyance between the work stations can be controlled by the arithmetic unit 1.

[0025] In the illustrated embodiment, all work stations are located within a box-shaped housing 13, thereby reducing undesirable external influences on mouthpiece production and the risk of injury to the user. The housing 13 may preferably have a plurality of removal openings 14, from which mouthpieces can be removed after processing at the last work station. The removal openings 14 may be connected via ducts to a dispensing opening (neither of which is shown), into which a first or second transport system 9, 11 or a support 12 of a laser cutting system feeds the mouthpieces.

[0026] Figures 2 and 3 show the loading of the workpiece support 10 into and out of a work station. In the illustrated embodiment, the thermoforming station 2 is shown as an exemplary work station, but essentially, it is not important which work station the workpiece is loaded into or unloaded from for the illustrated preferred loading or unloading process. The workpiece support 10 is magnetizable, and the transport means 9 includes a magnet. As a result of these means, the workpiece support 10 can adhere to the transport means 9 based on magnetic interaction, so that the workpiece support 10 can be displaced by the transport means 9 without falling from it. An electromagnet may be provided for the transport means 9 so that the adhesion of the workpiece support 10 to the transport means can be controlled by supplying power to the electromagnet, although in the illustrated embodiment which is particularly easily controlled, the magnet is a permanent magnet (not shown). In this case, in order to reliably transport the workpiece support 10 into and out of the work station, the work station, in this example, is essentially a thermoforming station 2, has a workpiece support housing 15, which includes a stopper 16 for the workpiece support 10. To transport the workpiece support 10, which is magnetically attached to the transport means 9, approaches the workpiece support housing 15, at which point the workpiece support housing 15 in the illustrated embodiment includes a recess 16 as a guide for the transport means 9, and the recess 16 allows the workpiece support 10 to be reproducibly positioned in the same location on the work station. In the illustrated embodiment, an additional horizontally acting stopper for the transport means 9 is used as a centering means 17 for the workpiece support 10. Therefore, when the transport means 9 approaches the workpiece support housing 15 and contacts the centering means 17, and thus the workpiece support 10 is pre-positioned in the desired manner, the transport means 9 then moves further in the contact direction 18 toward the stopper 16, and when the force acting on the stopper 16 exceeds the magnetic attractive force between the workpiece support 10 and the transport means 9, the workpiece support 10 detaches from the transport means 9 and moves there until it comes to rest on the workpiece housing 15 at the desired position. After detachment, the transport means 9 can be easily moved away from the work station in the discharge direction 19.In the illustrated embodiment, the stopper 16 acts in the vertical direction. Furthermore, in the illustrated embodiment, the transport means 9 has a stopper pin 20, which itself facilitates the guidance of the transport means 9 in the recess 16 and forms a stopper with the workpiece housing 15 when the transport means 9 moves in the contact direction 18 and detaches from the workpiece support 9.

Claims

1. A device for manufacturing mouthpieces, The system comprises a calculation unit (1), a thermoforming station (2) for a film on a dental arch model (3), and a laser cutting device (4) for separating the mouthpiece from the film. Multiple work stations are provided, and these work stations are, An apparatus comprising at least one 3D printer (5) for fabricating a dental arch model (3) on a workpiece support (10), a thermoforming station (2), a separation device (6) for separating a thermoformed film from the dental arch model (3), and a laser cutting system (4), The apparatus is characterized in that a work station is arranged along a transport system (7), the transport system (7) includes a vertical linear guide (8) and a transport means (9) that is displaceable along the vertical linear guide (8) for bringing a work support (10) into and out of the work station.

2. The apparatus according to claim 1, characterized in that the transport system (9) includes a second transport means (11) for transporting the film from the separation device (6) to the laser cutting device (4).

3. The apparatus according to claim 1 or 2, characterized in that the first and / or second transport means (9, 11) is provided with a negative pressure system including at least one nozzle disposed on a suction plate.

4. The apparatus according to any one of claims 1 to 3, characterized in that the first transport means (9) has a magnet for displacing a magnetizable workpiece support (10), and at least one work station has a workpiece support housing section (15) equipped with a stopper (16) for the magnetizable workpiece support (10).

5. The apparatus according to any one of claims 1 to 4, characterized in that two 3D printers (5) are provided as a work station.

6. The apparatus according to any one of claims 1 to 5, wherein the thermoforming station (2) includes a chamber, the chamber forming a pressure chamber capable of supplying compressed air together with the workpiece support (10) at the forming position.

7. The apparatus according to any one of claims 1 to 6, characterized in that the first and / or second transport means (9, 11) are arranged to be displaceable along the guide (8) via a scissor joint arm.

8. The apparatus according to any one of claims 1 to 7, characterized in that the work station is located inside a box-shaped housing (13).

9. The apparatus according to claim 8, characterized in that a box-shaped housing (13) is penetrated by an extraction opening (14), and the extraction opening (14) is connected via a duct to a mouthpiece dispensing opening allocated to a laser cutting system (4).

10. The apparatus according to any one of claims 1 to 9, characterized in that at least one work station includes a centering means (17) for a tool support (10).

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