Integrated mixing device for spraying

Abstract

The invention relates to a dental handpiece (1) equipped with an integrated internal jet device comprising a first water delivery channel (171) and a second air delivery channel (172) and a combined outlet channel (14) leading to a single spray hole (15) for a mixture of air and water, characterized in that the dental handpiece comprises an air-water mixing element (2) having a first water supply conduit (21) connectable to the first water delivery channel (171) and a second air supply conduit (22) connectable to the second air delivery channel (172), and in that the first water supply conduit (21) and the second air supply conduit (22) lead into a main conduit (24) of the air-water mixing element (2) at a junction area (23) between the first water supply conduit (21) and the second air supply conduit (22).

Description

Technical Field

[0001] This invention relates to the field of handheld parts equipped with air-water mixing jets, and more particularly to counter-angle handheld parts equipped with such integrated jetting devices. Background Technology

[0002] Dental appliances (turbine, reverse-angle handpieces, and straight handpieces) are typically equipped with internal jets to cool the working area—the area of ​​the tooth subjected to cutting, grinding, or preventative / cleaning tools. Since friction between the working tool and the tooth tissue (enamel and dentin) is a significant heat source, the presence of the jet is essential to prevent necrosis of the tooth tissue and / or burns to the patient's oral mucosa. Therefore, the internal jet of a dental appliance serves to protect the patient during treatment. Furthermore, the spray allows for the removal of debris generated during treatment, resulting in higher quality work. If the user (dentist or dental assistant) cannot use an appliance equipped with an internal jet, they are forced to use an external irrigation system, which significantly complicates dental treatment (managing two separate instruments with limited space in the patient's mouth).

[0003] Medium and high-speed devices (air turbines or motorized speed multiplier reverse angle handheld devices) are typically equipped with three or four jet outlets, into which air and water are supplied via dedicated channels (typically for medium ranges) or mixed (for high ranges). In cases where the device head has separate jets, there are three or four openings for water outlets and three or four openings for air outlets: the presence of several openings oriented in an optimized manner allows for effective rinsing of the tool (grinding head) attached to the head of the dental device, as the air separates the water jet into droplets that settle on most of the grinding head's surface and flow within the ground tooth tissue. However, the presence of visible water droplets can reduce the visibility of dental practitioners in the work area.

[0004] For this reason, the mixed spray logically improves flushing and cooling efficiency as well as visibility: in this case, a water-air mixture is generated inside the device head, in a component called a "diffuser," which also incorporates 3-4 openings that allow the water-air mixture to escape. In this case, the spray (which is a stable mixture of water and air) looks more like a relatively uniform mist or aerosol, in which water exists in the form of microscopic droplets or tiny droplets.

[0005] Systems of this type with multiple spray outlets are effective, especially when the mixed spray is generated directly in the head of the device via a diffuser. However, they are also expensive and difficult to manufacture. Furthermore, the diffuser design is very complex because the flow rate at the three or four spray outlets must be relatively uniform to avoid excessive turbulence.

[0006] For low-speed units, particularly direct-drive reverse-angle handheld units (1:1 gear ratio) and / or entry-level units, the internal jet is typically simplified to a single air outlet and a single water outlet at the head, rather than employing a diffuser integrated into the head of the unit. This is primarily due to the fact that low speeds do not require such effective cooling of the working tool (grinding head). Therefore, it is acceptable to directly rinse only one angled portion of the working area relying solely on the diffusion generated by the rotation of the grinding head.

[0007] These systems, with two separate outlets—one for air and one for water—are significantly cheaper and simpler to design and manufacture, but they are functionally limited because the rinsing quality is limited: the air and water cannot mix effectively outside the device before reaching the grinding head, and therefore the water jet is not broken into droplets, which results in uneven cooling of the grinding head and significantly obstructs visibility in the working area.

[0008] For this reason, a compromise is sought by providing an air-water mixture inside the handpiece, thus eliminating the need for a diffuser integrated into the head of the device, wherein a single outlet for the air-water mixture spray is located in or near the head of the device. Patent document WO 95 / 12361 describes such a solution, wherein the air-water mixture is generated via an adapter located at the rear of the handpiece body, at the connection to the motor. This component incorporates two inlet pipes for air and water, and a conduit with a V-shaped cross-section, wherein the two inlet pipes lead into the conduit, which connects to an outlet channel that slopes towards the head and sprays the air-water mixture toward the bottom of the grinding head.

[0009] The solution for a dental irrigation system described in document FR2570268 similarly includes air and water inlet pipes leading to pipes for mixing air and water, which is then delivered to a spray nozzle located in the head. However, these pipes are located externally to the handheld unit, making the solution relatively ergonomic.

[0010] The last two solutions—which operate based on a mixture of air and water—allow for the generation of a mist at the jet outlet, but only under very specific air and water pressure conditions. This limitation stems from the fact that the air-water mixture conduit can be too long, or the relative orientation of the conduit and the placement of its joints can be inappropriate, thus creating turbulence. This can significantly reduce the spray output velocity, making it insufficient to ensure effective rinsing. Consequently, it becomes inconvenient for practitioners to specifically adjust their dental units for such devices.

[0011] Therefore, a solution that does not have these known limitations is needed.

[0012] Document JP2011097984 also discloses an injector solution having a mixing region located between an air passage and a water passage at a spray orifice near the head; document CA1166490 similarly relates to a mixing diffusion system via a spray chamber located near the head.

[0013] Document FR2570268 relates to a dental irrigation system that delivers a mixture of air and water for direct diffusion into the head via a spray orifice; however, the channel is located on the exterior of the handpiece body. Summary of the Invention

[0014] One object of the present invention is to provide an injector with improved quality compared with existing technology.

[0015] Another object of the present invention is to provide a mixing device that does not require an increased head size and has a simple design.

[0016] Another object of the present invention is to provide an injector solution using a single outlet mixer that has a more optimized operating range in terms of air and water pressure.

[0017] These objectives are achieved by the features of the main claim, and particularly by a dental handpiece equipped with an integrated internal jetting device comprising a first water delivery channel and a second air delivery channel, and a combined outlet channel leading to one or more single spray orifices for a mixture of air and water. The integrated internal jetting device is characterized by including an air-water mixing element having a first water supply conduit connectable to the first water delivery channel and a second air supply conduit connectable to the second air delivery channel, and the first water supply conduit and the second air supply conduit leading at a junction between the first water supply conduit and the second air supply conduit to a main conduit of the air-water mixing element, which connects to the combined outlet channel.

[0018] One advantage of the proposed solution is that it ensures the formation of a more uniform mist compared to existing solutions that use a single spray orifice for air-water mixtures.

[0019] Another advantage of the proposed solution is its high-quality hybrid design, which is relatively simple and modular compared to existing standards, enabling integration with the head of a reverse-angle handpiece, a straight handpiece, or a dental turbine. These existing standards are particularly relevant for motor components attached to a reverse-angle handpiece or for connecting the turbine to an air injection hose or quick connector. Furthermore, this configuration allows for a smaller head size, facilitating access to the patient's mouth, while also simplifying the design of handpieces with integrated diffusers.

[0020] Another advantage of the proposed solution is that it allows for a wider operating range, enabling the same air and water pressure settings for the dental unit to be used in several different devices.

[0021] According to a preferred embodiment of the dental handpiece equipped with an integrated internal jet device based on the present invention, at least one of the first water supply pipe and the second air supply pipe of the air-water mixing element has a curved portion that forms an angle between 10° and 80° at the joint area relative to the other of the first water supply pipe and the second air supply pipe.

[0022] This configuration allows for better fluid flow, especially at the junction area where the air supply and water supply lines converge, and also improves the efficiency of cleaning and removing machining oil.

[0023] According to a more preferred embodiment of the dental handpiece equipped with an integrated internal jet device based on the present invention, the second water supply conduit has a curved portion and leads directly into the first air supply conduit, which is arranged in a generally straight manner.

[0024] Compared to solutions where the air passage is curved and air is injected into the water, this implementation variation has shown surprisingly effective results in terms of the stability of air-water mixtures. In fact, it produces minimal turbulence and provides maximum flexibility in terms of parameter settings for regulating the flow rate of the resulting mixture.

[0025] According to another preferred embodiment of the dental handpiece equipped with an integrated internal jet device based on the present invention, the first water supply pipe and the second air supply pipe each have a first curved portion and a second curved portion, and form a completely symmetrical Y shape with the main pipe of the mixing element.

[0026] The advantage of this variant is that it is the easiest to machine, and because the angle of each bend is minimized, it is still particularly easy to clean and degrease the machining oil.

[0027] According to another preferred embodiment of the dental handpiece equipped with an integrated internal jet device based on the present invention, at least one element selected from the first water supply pipe and the second air supply pipe does not have a constant cross-section and has a narrowing at the joint area.

[0028] This variant is designed to maximize the Venturi effect at the junction area, and is therefore advantageous for variants where the air supply pipe is bent rather than the water supply pipe, so as to maximize the efficiency of air extraction.

[0029] According to another preferred embodiment of the dental handpiece equipped with an integrated internal jetting device based on the present invention, the air-water mixing element is arranged in the form of a modular component, which is held in the rear body of the rear gripping portion of the dental handpiece.

[0030] This implementation variation is particularly advantageous because it allows the air-water mixing element to be modularly arranged as a consumable component that can be easily replaced during use if necessary, and is also easy to assemble and disassemble. Furthermore, this consumable component is advantageously arranged away from the tool head to minimize the size of the handpiece at that location.

[0031] According to a more preferred variant of the dental handpiece based on the present invention, which is equipped with an integrated internal jet device and uses a modular air-water mixing element, the modular air-water mixing element is suspended by an O-ring seal.

[0032] Therefore, this implementation variation is particularly simple because the O-ring seal is used solely for sealing purposes.

[0033] According to a more preferred variant of the dental handpiece equipped with an integrated internal jet device based on the invention, using a modular air-water mixing element, an outlet pipe for delivering the air-water mixture to the spray orifice is driven into the main jet pipe. In this case, a second O-ring seal can be advantageously positioned around the outlet pipe at the insertion point to ensure a tight seal between the main jet pipe and the outlet pipe.

[0034] This implementation variant greatly facilitates assembly and disassembly operations when replacing the air-water mixing element, and also ensures optimal interoperability with standard parts typically used for handheld components that can form outlet channels, such as pipes or channels.

[0035] According to another preferred variant of the dental handpiece equipped with an integrated internal jet device based on the present invention, the modular air-water mixing element is attached to the rear body of the dental handpiece, and an outlet pipe made of elastic material is bonded to the modular air-water mixing element (2).

[0036] This variation makes assembly operations even easier and allows for easy compensation of running clearances between different parts to be assembled.

[0037] According to another preferred variant of the dental handpiece equipped with an integrated internal jet device based on the present invention, the modular air-water mixing element is oblong in shape and extends in a direction substantially perpendicular to the direction defined by the outlet pipe of the air-water mixture.

[0038] This configuration allows for a minimum reduction in radial volume in the handpiece, thereby allowing, for example, additional channels for optical fibers or cooling channels for the kinetic chain in the case of a reverse-angle handpiece; furthermore, again in the case of a reverse-angle handpiece, minimizing the volume required to implement the hybrid internal jetting device according to the invention allows for maximizing the tooth size, and thus maximizing transmission efficiency.

[0039] According to another preferred variant of the dental handpiece equipped with an integrated internal jet device based on the present invention, the modular air-water mixing element is characterized in that it is made as a single piece.

[0040] This configuration significantly improves the ease and simplicity of machining such parts, which are essential for the implementation of this invention.

[0041] According to even more preferred variations for implementing the integral air-water mixing element, the integral air-water mixing element can preferably be produced by 3D printing.

[0042] This variation allows for further optimization of the pipe geometry and cross-section even beyond what can be achieved through molding and / or cut-out operations, and allows the use of any type of material, i.e., not only plastics but also metals.

[0043] According to an even more preferred variant for implementing the invention, not only the air-water mixing element is 3D printed, but also the frame equipped with integrated pneumatic pipes is produced as a single piece by 3D printing.

[0044] This configuration therefore allows for optimization of the geometry of all components that can be fitted with channels, and preferably, they are all made of metal rather than just plastic. It should be noted that, according to this variation, not only can the frame and hybrid element be manufactured separately as single-piece components, but the entire handpiece can also be configured as a single-piece component, i.e., the hybrid element is directly integrated into the frame, and the frame may be encapsulated in an external cover designed for dental practitioners to grip the tool. This variation thus significantly simplifies the assembly of the handpiece.

[0045] According to another preferred embodiment of the dental handpiece equipped with an integrated internal jetting device based on the present invention, the air-water mixing element is preferably positioned substantially equidistant from both ends of the handpiece.

[0046] In this variant, the positioning of the air-water mixing element is optimized because the transit time of the air-water mixture is not too long relative to the head, but its position at the rear is far enough from the motor connection interface to allow connection with standard tools (the connection front of a dental motor is a few centimeters, typically between 1.5 and 3.5 centimeters). This configuration is also advantageous because it allows for minimization of vibration and noise generated at the head, as the air-water mixing element is centrally isolated towards the handpiece.

[0047] According to another preferred embodiment of the dental handpiece equipped with an integrated internal jetting device based on the present invention, the air-water mixing element is positioned in the rear body of the rear gripping portion, at a predetermined distance from the rear end of the handpiece. This predetermined distance is preferably equal to at least 2 centimeters.

[0048] In this way, whether the hybrid element is designed as a consumable or as an integral part of the handheld housing, it is advantageously positioned far enough from the tool head to minimize its size at that location, and also far enough from the motor connection interface to ensure full compatibility with existing standards. Attached Figure Description

[0049] The invention will be better understood by reading the following description, which is given by way of example and with reference to the accompanying drawings, in which: - Figure 1A This is a sagittal half-section view of a handheld device equipped with a hybrid element according to a preferred embodiment of the invention, wherein only the rear body of the rear gripping portion of the handheld device is shown in section, the rear body including the hybrid element arranged here in the form of modular parts (the front of the handheld device is shown as an external view, the front including a head and a grinding head to be mounted on the head). - Figure 1B yes Figure 1AThe sagittal cross-sectional view of the handheld component shown in the figure illustrates details of the mixing region M surrounding the mixing element, which is shown here in dashed lines; - Figure 1C yes Figure 1A and Figure 1B The rear view of the handheld component shown highlights the components used for... Figure 1A EE section; - Figure 2A This is a sagittal cross-sectional view of a hybrid element according to another preferred embodiment of the invention, the hybrid element being in a Y-shaped form with overall symmetry; - Figure 2B It is a sagittal cross-sectional view of a hybrid element used to implement a variant of the invention, wherein the water supply pipe and the air supply pipe do not have constant cross-sections and narrow at the joint region; - Figure 3A A hybrid element implemented according to a particularly preferred embodiment is shown, wherein the hybrid element is implemented as a monolithic piece via 3D printing and has an elongated oval shape as observed in a three-dimensional profile; - Figure 3B It shows the relationship with Figure 3A The same single-piece hybrid element is shown in the image, but viewed from the side and the internal conduits are highlighted (as shown by the dashed lines). - Figure 3C A three-dimensional external view of the handheld component is shown. Figure 3A and Figure 3B The hybrid components are integrated into the rear portion of the handheld device; - Figure 4A and Figure 4B An alternative embodiment of the invention using a straight handheld component is shown, wherein... Figure 4A A half-section view is shown—compared to the view for the reverse angle handpiece. Figure 1A Similar—and Figure 4B A rear view is shown, highlighting the area used for Figure 4A BB section. Detailed Implementation

[0050] The following combination Figure 1A , Figure 1B and Figure 1C The preferred embodiments of the invention are described in these figures, which show three different views of the handheld component 1, which is in the form of a reverse-angle handheld component. Figure 1A This is a sagittal half-section view of a handheld device 1 equipped with an air-water mixing element 2, which is arranged in the rear body 122 of the rear grip portion 12 of the reverse angle handheld device. The air-water mixing element 2, arranged here as a modular part... Figure 1BThe mixing region M, which is described in further detail, is shown in cross section, while the front of the handpiece—including the head 13 and the grinding head 10 to be mounted on the head—is shown in an external view. Figure 1C yes Figure 1A and Figure 1B The rear view of the handheld component shown highlights the components used for... Figure 1A EE section.

[0051] Figure 1A The left side prominently displays the handpiece 1 according to the invention, which includes an integrated jetting device having a single combined outlet channel 14 into which air and water are introduced. This combined outlet channel 14 is visible in dashed lines inside the front gripping section 11 of the handpiece 1 and terminates at a spray orifice 15 towards the working area toward the grinding head 10. Positioning the air-water mixing element approximately in the middle of the handpiece 1, and in this case more specifically in the middle of the rear gripping portion 12 of the handpiece, rather than in the head 13 or the handle near the head, allows for the design of an optimal solution without size issues. In fact, the handle of the dental device—i.e., the front gripping portion 11—and the head 13 typically have a diameter of less than 1 cm because this part of the device must easily enter the patient's mouth, while the outer cover 121 of the rear gripping portion 12 has a diameter of 2 cm. Furthermore, at the connection between the handpiece and the motor (i.e., Figure 1A Placing the air-water mixing element 2 too far back on the handheld part 1 at the motor connection interface 120 shown, or more generally at the turbine-to-hose connection or quick coupling, has the disadvantage that the design of the mixing element needs to be adapted to the design of the connection, which is standardized (ISO 3964 for motorized devices and ISO 9168 for turbines). For this purpose, it is advantageous to maintain two separate conduits between the connection area and the middle of the handheld part 1, or at least the middle of the rear grip portion 121, so that they are in the area with the largest diameter.

[0052] Therefore, according to the example shown, the rear of the air-water mixing element 2, or more precisely, the air-water mixing element, is located at a first predetermined distance D1 from the rear end of the handheld part 1 at the motor connection interface 120. This first predetermined distance is preferably equal to at least 1.5 cm, and preferably equal to at least 2 cm, in order to be compatible with the aforementioned effective connection standards (ISO 3964 and ISO 9168). In this figure, the first predetermined distance D1 is approximately 3 cm.

[0053] Meanwhile, the front of the air-water mixing element 2, or more precisely, the air-water mixing element, is also located at a second predetermined distance D2 from the front of the rear grip portion 12 of the handheld part 1, which is preferably equal to at least 2 cm, so that the air-water mixing element can be positioned substantially in the center of the rear grip portion 12 of the handheld part 1, where the size constraint is minimal.

[0054] exist Figure 1A On the right side, a water delivery channel 171 leading to the mixing area M located in the middle of the rear gripping portion 12 of the handheld part 1, and an air delivery channel 171 are readily visible. According to the described preferred embodiment, the air-water mixing element 2 is mounted in the rear body 122 of the rear gripping portion 12 of the handheld part 1, which forms the internal frame of the rear gripping portion, and an outer cover 121 is mounted around the rear body for gripping and manipulating by a dental practitioner. On the left side, an outlet channel 16 is designed to deliver water from below via... Figure 1B The air-water mixture produced by the described mixing element Figure 1B It shows Figure 1A Details of the mixed region M indicated in the text. Figure 1B The air-water mixing element 2 is shown to be formed from modular elements—that is, parts that constitute the components installed inside the rear body 122 of the handheld component 1. This air-water mixing element 2 allows both air and water flows to converge, which are separately delivered at the inlet via water delivery channels 171 and air delivery channels 172, respectively arranged in the rear body 122 of the handheld component. This convergence occurs at a junction area 23, where a first water supply pipe 21 connected to the water delivery channel 171 and a second air supply pipe 22 connected to the air delivery channel 172 meet to lead to the outlet of a main jet pipe 24, which connects to a mixing outlet pipe 16 designed to deliver the air-water mixture to the head 13. The first water supply pipe 21, the second air supply pipe 22, and the main pipe 24 thus form an asymmetrical "Y" shape. The presence of an O-ring seal 25 disposed in an outer peripheral annular groove 251 ensures a tight seal of the system in a particularly simple manner.

[0055] According to the described preferred embodiment, the first water supply conduit 21 has a curved portion C, while the second air supply conduit 22 is completely straight. This configuration improves the properties of the air-water mixture. Preferably, at the junction region 23, the angle α formed between the curved portion C of the first water supply conduit 21 and the second air supply conduit 22 is preferably between 10° and 80°, and according to even more preferred variations, this angle is between 20° and 70°, so as to facilitate fluid flow in the curved portion C and also facilitate cleaning of the curved portion and degreasing after machining. According to the proposed configuration, it can be noted that the same angle α also exists at the top between the curved portion C of the water supply conduit 21 and the portion connecting it to the second air delivery channel 172, which is parallel to the first water delivery channel 171 connected to the second air supply conduit 22 of the air-water mixing element 2, and is arranged in a completely straight manner. Therefore, the angles of all internal channels of the air-water mixing element 2 are kept sufficiently small so as not to interfere with fluid flow and to allow easy and efficient cleaning of its interior.

[0056] As in Figure 1B As can be seen on the left, the main jet pipe 24 is also perfectly straight, and its diameter is slightly larger than that of the second air supply pipe 22 into which the first water supply pipe 21 enters. However, this larger diameter is intended to allow the outlet pipe 16 to be driven in and / or adhered, at which the air-water mixture will flow to the head 13. Figure 1B In the illustrated embodiment, the outlet pipe 16 is, for example, made of non-flexible steel pipe, but the outlet pipe may preferably be made wholly or partially of flexible pipe in order to simplify assembly and possibly compensate for slight operational clearance.

[0057] Figure 1C It is the previous one Figure 1A and Figure 1B The rear view of the handheld component 1 shows its connection to... Figure 1A The right side of the diagram shows the corresponding EE section, thus allowing the radial positioning of the air-water mixing element 2 to be seen in the rear grip portion 12 of the handheld part 1, whose head 13 can be seen at the opposite end of the motor connection interface 120. The air-water mixing element 2 is therefore preferably located at the lower left of the rear body 122 of the rear grip portion 12 of the handheld part.

[0058] Corresponding to the above Figures 1A to 1CThe preferred embodiment of the technical solution enables the provision of an economical handheld device 1 with a hybrid injector that is superior in quality to separate injectors, and the integration of the hybrid injector does not require any special adaptation in terms of motor connection at the rear gripping portion. Furthermore, the air-water mixing element 2 is positioned substantially in the middle of the handheld device 1, with air delivered via a slightly curved section—i.e., a relatively small angle (preferably less than 20°) in the water supply conduit—which allows for maximizing the operating range of air and water pressures; thus, the air-water mixture can be effective for a water pressure / air pressure ratio equal to or greater than 1 / 3 (e.g., 1 bar of water and 3 bar of air). Finally, positioning the air-water mixing element in a modular arrangement within the rear body 122 of the rear gripping portion 12 of the handheld device, i.e., away from the head 13, minimizes vibration and noise caused by the generation of the mixture, as the mixture can be generated in a well-insulated portion at the center of the handheld device 1.

[0059] However, according to a variation (not shown), the air-water mixing element 2 can be disposed directly in the rear gripping portion 12 without being inserted into the rear body 122. In this way, the air-water mixing element 2 can be arranged in a more central portion of the rear gripping portion 12, but still sufficiently away from the head 13 to ensure the quality of the sprayed air-water mixture.

[0060] In the following text, Figure 2A and Figure 2B Other alternative variations for implementing the air-water mixing element 2 are shown; however, the air-water mixing element is always preferably configured as a modular component separate from the rear body 122 of the dental handpiece 1, which is envisioned to be installed in the rear body of the dental handpiece.

[0061] In these figures, not all are related to Figure 1B The same reference numerals will all be repeated in detail; in fact, the focus will be mainly on the differences from the preferred embodiments described above.

[0062] and Figure 1B The difference is, according to the corresponding Figure 2A The modified air-water mixing element 2 corresponds to a symmetrical "Y" shape, i.e., each of the water supply pipe and the air supply pipe—referred to as 21 and 22 respectively—has a first bend C1 and a second bend C2, resulting in a mutual angle α at the junction region 23 that is always less than 20° and preferably less than 10°. Tests conducted with this configuration showed slightly inferior performance compared to that obtained with the aforementioned embodiment; however, it has the advantages of being easier to machine and even easier to clean. Similar to Figure 1BIn the case where the diameter of the main pipe 24 at the outlet of the junction region 23 of the mixing element 2 is always larger than the diameter of the first water supply pipe 21 and the second air supply pipe 22, the outlet pipe 16 for the air-water mixture will preferably be assembled in the same manner, i.e., by driving the outlet pipe into and / or bonding it to the interior of the main pipe 24, such that the effective diameter of the fluid flow is slightly smaller, and the cross-sectional area of ​​the fluid flow corresponds to the sum of the cross-sectional areas of the first water supply pipe 21 and the second air supply pipe 22. When the outlet pipe 16 is simply driven into the main pipe, it is advantageous to insert an O-ring seal around the outlet pipe 16 to ensure the sealing of the assembly.

[0063] Figure 2B The air-water mixing element in all aspects is compatible with Figure 1B Corresponding to the air-water mixing element, except that the second air supply duct 22 does not have a constant cross-section and has a narrowing R at the upstream inlet of the joint region 23 to emphasize the Venturi effect. This slightly complicates the machining of the air-water mixing element, but has little impact on injection- or printed parts. (As in...) Figure 2B As can be seen on the left, the main pipe 24 has a symmetrical widening A at the outlet of the junction region 23, which is even slightly larger than the narrowing R of the second air supply pipe 22 upstream of the junction region 23. This optimizes fluid flow at the outlet of this region. Furthermore, the ratio between the cross-sectional areas of the two pipes can be optimized to improve the quality of the mixture, as shown below with reference to the air-water mixing element 2, which is manufactured as a single piece using 3D printing. Figure 3A and Figure 3B The explanation given.

[0064] The preferred choice of 3D printing, for example, using plastic, to implement air-water hybrid elements is based on the fact that it is desirable to simplify the production process as much as possible without having to carve out the channels after molding, while optimizing the quality of the obtained dimensions and the flexibility in terms of the geometry to be implemented (e.g., channels that may alternatively have curved shapes, etc.). Figure 3A and Figure 3B The same component corresponding to the air-water mixing element 2 is shown, which is oblong in shape and extends in direction D, in this case upward, perpendicular to the flow direction F of the fluid mixture, which corresponds to the orientation direction of the straight main pipe 24. Figure 3AThe air-water mixing element 2 is shown in three dimensions from a three-quarter viewpoint, highlighting a first cross-section S1 of the first water supply conduit 21 and a second cross-section S2 of the second air supply conduit 22. These cross-sections are substantially identical, and each cross-section has a circular profile. An O-ring seal for sealing purposes is not shown in this figure, but only the annular groove 251 in which the O-ring seal is placed can be distinguished.

[0065] Figure 3B A 3D diagram is shown, but with... Figure 3A Compared to a more side view, the internal channels of the air-water mixing element 2, namely the outline of the first water supply pipe 21 and its curved portion (C), the angle α between the inclined portion at the junction region 23 and the second air supply pipe 22, and the main jet outlet pipe 24 oriented along the fluid flow direction F and perpendicular to the elongated oval shape of the air-water mixing element 2, are highlighted. It can also be seen that the diameter of the third section S3 of the main jet pipe 24 is approximately 1.5 times the diameter of the first section S1 of the first water supply pipe 21 and the second section S2 of the second air supply pipe 22, such that the cross-sectional ratio between the air-water mixing outlet pipes 16—significantly smaller than the cross-sectional ratio of the third section S3—is approximately twice that of each of the first section S1 and the second section S2. When they are equal, this means that the fluid flow cross-section at the outlet of the junction region 23 substantially corresponds to the sum of the fluid flow cross-sections of the two supply pipes for air and water, respectively.

[0066] As shown in the diagram, this elongated oval air-water mixing element 2 is installed in the rear body of the handheld component. Figure 3C As can be seen, the purpose of using this shape instead of a cylindrical shape is to reduce the radial space required outwards, and thus allow for the arrangement of other components (light channels, cooling channels, etc.). The fluid flow direction F is in... Figure 3B This is manifested in the extension direction of the main injection pipe 24 corresponding to the air-water mixing element 2, which now corresponds to the extension direction of the outlet pipe 16, the end of which is preferably driven into the main pipe 24. Figure 3C The front grip portion 11 is also shown on the left and the rear motor connection interface 120 is shown on the right. In fact, only the outer cover 121 of the rear grip portion 12 has been removed from this figure to show that the air-water mixing element is integrated as a modular consumable component into the rear body 122 of the handheld part; otherwise, this view would be a simple external view of the handheld part in three dimensions.

[0067] According to a preferred embodiment, the handheld frame can be implemented using 3D printing, allowing all fluid conduits and / or light conduits to be produced directly and automatically simultaneously. In other words, it is possible to simultaneously implement the rear body 122 with integrated air and water delivery channels, and possibly the outlet conduit 16, and similarly, the front gripping portion 11 with an integrated mixing jet outlet channel 14 via 3D printing. More generally, according to an embodiment not shown, it is conceivable to implement almost the entire handheld component 1 via 3D printing, i.e., not only the internal parts (rear body 122 and the water and air delivery channels, designated 171 and 172 respectively), but also the external parts, including the motor connection interface 120 and the rear cover 121. In this configuration, it is possible to directly implement the air-water mixing element 2 as a single piece within the rear body 122.

[0068] In the embodiment shown above, the handheld component 1 used is a reverse-angle handheld component. However, this solution can be applied to all types of handheld components (straight handheld components, reverse-angle handheld components, and turbines) because the design of the mixer does not depend on the specific characteristics of each device: the shape of the head, the angled or straight shape of the handle, the length of the device, and the type of connection (connected to a motor, connected to a turbine connector, or directly connected to a hose). Therefore, the air-water mixing element 2 can be "standardized" and integrated as a submodule into products that are very different in ergonomics and technology.

[0069] Figure 4A An example of a straight handheld member 1 is shown, comprising a grinding head 10 attached to the end of a head 13, wherein an outlet channel 14 for spraying is arranged inside the head, the outlet channel leading to a spray orifice 15 for spraying an air-water mixture generated in a mixing zone M via an air-water mixing element 2, which is similar in all respects to Figure 1A The air-water mixing element shown is described in detail (and for this reason will not be described in detail again). Like... Figure 1A Same, Figure 4A It consists of a half-section view of the handheld component, wherein according to Figure 4B The cross-section BB shown illustrates the rear gripping portion 12, which Figure 4B The straight handpiece 1 is shown from the rear. In this figure, only the motor connection interface 120 is marked, except for the BB cross-sectional view. Figure 4AAs can be seen, once again, the air-water mixing element 2 is far enough from the motor connection interface 120 at the rear that no special design is required that does not conform to existing standards. Instead, it is placed in the rear body of the rear grip portion 12 of the handheld part 1 as far as possible in the direction of the front grip portion 11 of the handheld part 1, so as to minimize the length of the jet outlet pipe 16 in which air and water are mixed and the mixture is delivered to the head 13.

[0070] according to Figure 4A In the example shown, the air-water mixing element 2 is located substantially at the center of the rear grip portion 12 of the handheld part 1, but with... Figures 1A to 1C Compared to the example of the reverse-angled handheld device shown, this one is slightly more oriented towards the front of the handheld device. The rear of the air-water mixing element 2 is always located at a first predetermined distance D1 from the rear end of the handheld device 1 at the motor connection interface 120, in order to be compatible with the aforementioned valid connection standards (ISO3964 and ISO9168). In this figure, the first predetermined distance D1 is approximately 2.5 cm. At the same time, the front of the air-water mixing element 2, or more precisely, the air-water mixing element, is also located at a second predetermined distance D2 from the front of the rear grip portion 12 of the handheld device 1, where the second predetermined distance is approximately 2 cm. In this way, the air-water mixing element 2 can be positioned at a location on the rear grip portion 12 of the handheld device 1 where, although it narrows slightly after the motor connection interface 120, the space constraints are still acceptable.

[0071] According to the preferred embodiment described in conjunction with the present invention, it can be seen that the reliability of the sprayer is systematically improved in the event of a drop of the handheld component, because the air-water mixing element 2 is now protected in the middle of the handheld component 1 or even in the middle of the rear grip portion 12. Conversely, when the mixer / diffuser is located in the head 13 of the handheld component, it is usually damaged upon a drop, thereby significantly reducing the quality of the spray (causing a risk of burns to the patient), or in the case of severe damage, being sprayed into the patient's mouth, a risk completely eliminated by the mixing system according to the present invention.

[0072] Those skilled in the art will understand that, without departing from the scope of the invention, certain features (the shape of the pipe, adjusting the position of the mixing element according to the longitudinal direction of the handheld device, etc.) can be adapted as needed.

Claims

1. A dental handpiece (1) equipped with an integrated internal jet device, the internal jet device comprising a first water delivery channel (171) and a second air delivery channel (172) and a combined outlet channel (14) leading to a single spray hole (15) for a mixture of air and water. Its features are, The dental handpiece includes an air-water mixing element (2) having a first water supply pipe (21) that can be connected to the first water delivery channel (171) and a second air supply pipe (22) that can be connected to the second air delivery channel (172). Furthermore, the first water supply pipe (21) and the second air supply pipe (22) lead to the main pipe (24) of the air-water mixing element (2) at the junction area (23) between the first water supply pipe (21) and the second air supply pipe (22), and the main pipe can be connected to the outlet channel (14) of the combination.

2. The dental handpiece (1) equipped with an integrated internal jet device according to claim 1, wherein, At least one of the first water supply pipe (21) and the second air supply pipe (22) of the air-water mixing element (2) has a bend (C) that forms an angle (α) between 10° and 80° at the joint area (23) relative to the other pipe of the first water supply pipe (21) and the second air supply pipe (22).

3. The dental handpiece (1) equipped with an integrated internal jet device according to claim 2, wherein, The second water supply pipe (21) has a bend (C) and leads directly into the first air supply pipe (22), which is arranged in a generally straight manner.

4. The dental handpiece (1) equipped with an integrated internal jet device according to claim 2, wherein, The first water supply pipe (21) and the second air supply pipe (22) each have a first bend (C1) and a second bend (C2), and form a completely symmetrical Y shape with the main pipe (24) of the mixing element (2).

5. A dental handpiece (1) equipped with an integrated internal jet device according to any one of the preceding claims, wherein, At least one element selected from the first water supply pipe (21) and the second air supply pipe (22) does not have a constant cross section and has a narrowing (R) at the joint area (23).

6. A dental handpiece (1) equipped with an integrated internal jet device according to any one of the preceding claims, wherein, The air-water mixing element (2) is arranged in the form of modular components, which are held in the rear gripping portion (12) of the dental handpiece (1).

7. The dental handpiece (1) equipped with an integrated internal jet device according to claim 6, wherein, The air-water mixing element (2) is suspended by an O-ring seal (25).

8. The dental handpiece (1) equipped with an integrated internal jetting device according to claim 6 or 7, wherein, The outlet pipe (16) that delivers the air-water mixture to the spray hole (15) is driven into the main injection pipe (24).

9. The dental handpiece (1) equipped with an integrated internal jetting device according to claim 6 or 7, wherein, The modular air-water mixing element (2) is attached to the rear body (122) of the rear gripping portion (12) of the dental handpiece (1), and the outlet pipe (16) made of elastic material is bonded to the modular air-water mixing element (2).

10. The dental handpiece (1) equipped with an integrated internal jet device according to any one of claims 6 to 9, characterized in that, The modular mixing element (2) is oblong in shape and extends in a direction (D) that is substantially perpendicular to the direction defined by the outlet pipe (16) of the air-water mixture.

11. The dental handpiece (1) equipped with an integrated internal jet device according to any one of claims 6 to 10, characterized in that, The modular air-water mixing element (2) is composed of a single piece.

12. The dental handpiece (1) equipped with an integrated internal jet device according to claim 11, characterized in that, The modular air-water hybrid element (2) is produced using 3D printing.

13. The dental handpiece (1) equipped with an integrated internal jet device according to claim 11, characterized in that, The frame equipped with integrated pneumatic piping and the hybrid element (2) are produced as a single piece by 3D printing.

14. The dental handpiece (1) equipped with an integrated internal jet device according to any one of the preceding claims, characterized in that, The air-water mixing element (2) is positioned substantially equidistant from both ends of the handheld component (1).

15. The dental handpiece (1) equipped with an integrated internal jet device according to any one of claims 6 to 13, characterized in that, The air-water mixing element (2) is positioned in the rear body (122) of the rear gripping portion (12) at a first predetermined distance (D1) from the rear end of the handheld part (1).

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