Handpiece for a foot care device with integrated wet technology

Abstract

Handpiece (100; 100') for a foot care device with integrated wet technology, at least comprehensive - a housing (10; 10') which terminates at an end face (14; 14') on which a through-hole for receiving a rotary-driven tool, a water nozzle bore (17) and an air nozzle bore (16) are arranged next to each other, - a drive set comprising an electric motor (40), a gearbox (41) and a chuck (42) for receiving the tool; wherein the housing (10; 10') comprises a base element (11; 11') and a cover element (20), between which a cavity is formed in which the drive set is received. characterized in that - that the base element (11; 11') is formed by an additive manufacturing process and - that at least two non-linear fluid channels (12; 13) are guided through a wall of the base element (11; 11') surrounding the cavity, each extending from a nozzle (17) formed at the end of the handpiece (100; 100') facing away from the front face (14; 14') to the water nozzle bore (17) or the air nozzle bore (16) on the front face (14; 14').

Description

[0001] The invention relates to a handpiece for a foot care device with integrated wet technology having the features of the preamble of claim 1.

[0002] Such a handpiece is known, for example, from DE 202 18 525 U1 and is used in a foot care device that operates with so-called wet technology. A pump generates pressure in a hose system, which directs air and water through separate channels to the handpiece, so that an air-water mixture emerges from its front as a spray mist. Two nozzles are positioned side by side on the front face, from which water and air exit. The handpiece consists structurally of a handpiece housing, a motor, and a clamping system. The handpiece housing encloses the motor and the clamping system, which are connected by a coupling. A rotating instrument, designed for removing skin and nails, can be inserted into the clamping system. The motor drives the inserted instrument. The abrasive dust released in the process is bound by the spray mist.

[0003] The disadvantage of the known handpiece lies in its complex manufacturing process. Firstly, the diameter or circumference of the handpiece housing must be limited for ergonomic reasons, as it is held between the fingers during cosmetic applications, similar to a writing instrument. Secondly, in addition to the motor, gearbox, and clamping system, the housing must accommodate electrical wiring and at least two hoses for conveying two fluids, running the entire length from the rear end to the front, where a spray nozzle is located. This design prevents the housing's circumference from being reduced for improved ergonomics. Furthermore, the design is expensive because additional parts are required for fluid flow through the housing, which must be manually assembled.

[0004] Another handpiece for a foot care device is known from DE 10 2005 056 009 A1. This handpiece also requires installation space to accommodate hose couplings in the rear and to route hoses along the motor through the interior of the housing, finally connecting them to a separate nozzle that protrudes from the housing. This separate nozzle allows the angle at which the spray jet hits the rotating instrument to be adjusted. Nevertheless, the manufacturing of this handpiece is also complex.

[0005] The object of the present invention is therefore to simplify the manufacture of a handpiece for a foot care device with integrated wet technology and at the same time to enable a compact, ergonomic design.

[0006] This task is solved by a handpiece for a foot care device with integrated wet technology having the features of claim 1.

[0007] According to the invention, the two fluid channels required for air and water are integrated directly into the housing wall. They run non-linearly, following the curves of the housing wall. This eliminates the need for hoses that are necessarily routed inside the housing in conventional handpieces. The handpiece housing is additively manufactured, i.e., it is produced using 3D printing. The handpiece housing consists of at least two parts: a base part and a cover part, which together enclose a cavity in which, among other things, the motor, gearbox, and clamping system are located. A further advantage is that the connection to external hoses is only made at the rear of the handpiece, outside the inner cavity where the motor, etc., is housed. Leaks in fluid channels within the cavity, which could damage the drive unit, cannot occur.Should the integrated fluid channels become damaged or blocked, the housing elements can be easily replaced.

[0008] The separation between the base element and the cover element preferably does not occur in a plane of diameter. Instead, a front section of the base element, adjoining an end face of the handpiece, covers the entire circumference of the handpiece housing, thus avoiding a separation plane in the area of ​​the chuck and any spray chamber located there. The separation between the base element and the cover element occurs further along the length of the handpiece, some distance from the end face, where the gearbox and motor are housed. By having the base element alone encompass the entire tip area of ​​the housing, potential widening of a gap between the housing elements in the tip area and any resulting leaks, which could occur, for example, when pressure is applied by the rotating instrument, are avoided.

[0009] An advantage of the fluid channels integrated into the housing is that a nozzle can be formed at their outlet on the end face. This means that a reduction in cross-section can be incorporated to accelerate the exiting fluid jet. A reduction ratio of 3:1 to 2:1, and especially approximately 2.5:1, has proven advantageous. For example, each fluid channel running through the housing has a diameter of 1 mm, and the nozzle opening on the end face has a diameter of 0.4 mm.

[0010] A particularly advantageous embodiment of the invention relates to a spray chamber integrated into the housing, in which a compressed air stream and a water stream are combined. This spray chamber is arranged on the end face of the housing, i.e., in the area where the rotating instrument is inserted. The spray chamber is designed as a recess in the end face and preferably has the shape of a truncated cone: the larger diameter forms the opening towards the rotating instrument, while the smaller diameter forms the bottom of the spray chamber. The diameter ratio is preferably chosen to be 2:1, so that the larger diameter is, for example, about 4 mm and the smaller diameter about 2 mm. The depth of the spray chamber from the outer boundary edge to the bottom is between 1.5 and 3 mm.

[0011] The ratios of the diameters and the depth result in a preferred cone angle for the spray chamber in the range of 45° to 90°.

[0012] The airflow is guided through one of the two fluid channels integrated into the housing and exits through an air nozzle orifice almost centrally located on the rear wall of the spray chamber. It is oriented at a 90° angle to the bottom of the spray chamber. The water enters at the outer diameter of the bottom. A water nozzle orifice is positioned at a 45° angle relative to the airflow. The distance between the air and water nozzle orifices is 1 mm to 2 mm. The streams converge approximately in the center of the spray chamber. The airflow swirls the exiting water, creating a spray mist that emerges from the spray chamber in a cone shape towards the inserted instrument.

[0013] Preferably, the central axis of the spray chamber described above is aligned coaxially with the axis of rotation of the milling or grinding tool to be inserted into the handpiece.

[0014] It is also possible to tilt the entire spray chamber in the direction of the axis of rotation in order to specifically direct the spray pattern onto the tool head.

[0015] By using nozzle bores for air and water at the end of the integrated fluid channels, which are adapted in cross-section to the flow conditions, additional nozzle elements can be dispensed with, saving weight and costs.

[0016] The front part of the handpiece housing is preferably conical, similar to a paraboloid of revolution. The driven axis with the receptacle for the rotating instrument is located at its center.

[0017] Preferably, the entire handpiece is rotationally symmetrical and has a bulbous basic shape that tapers towards both ends.

[0018] In a further embodiment of the invention, at least one LED element with several LEDs is integrated, in particular in a horseshoe-shaped arrangement. The spray mist from the spray chamber exits next to the LED element; that is, the LED element is interrupted there if it is located on the same partial circle as the spray chamber.

[0019] The housing consists primarily of three separate parts: the base element, the cover element, and a union nut. The base and cover elements are connected using a tongue-and-groove system and are additionally sealed against water ingress by a sealing cord.

[0020] On the side where the supply line connects to the handpiece, the union nut is screwed onto a thread, thus firmly holding the base and cover elements together. The thread is formed from components of the two other housing elements, the base and cover elements, and simultaneously serves as their outlet towards the hose.

[0021] For improved ergonomics and handling, the handpiece surface features a textured design, at least in some sections. One section of the surface may have a golf ball-like texture with multiple rows of round indentations, which extends to the underside. Other possible textures include bumps, ribbed structures, or elastomer coatings.

[0022] In addition, the housing of the handpiece preferably has three grip recesses: two larger recesses on the upper shell for the thumb and index finger, which allow a grip-like position as when using a pen, and a smaller recess on the lower shell, which serves as a resting place on the middle finger.

[0023] At least the basic element of the housing is preferably manufactured using the 3D printing process “INKBit” in order to be able to form the non-linear fluid channels watertight within the housing wall.

[0024] The invention is explained in more detail below with reference to the exemplary embodiments shown in the drawings. The figures show in detail: Fig. 1 a handpiece according to a first embodiment of the invention, in perspective view from an oblique front view; Fig. 2 a handpiece according to a second embodiment of the invention, in a perspective view from an oblique front view; Fig. 3 the handpiece according to Fig. 2 with the lid element removed, in perspective view from a slanted front view; Fig. 4 the handpiece according to Fig. 2 in perspective sectional view; Fig. 5 a basic element according to Fig. 1 in a perspective sectional view and Fig. 6 An enlarged perspective view of the front face of the base element.

[0025] In Fig. Figure 1 shows a handpiece 100 according to a first embodiment of the invention in a perspective view from an oblique front angle. A housing 10 essentially consists of a base element 11 and a cover element 20.

[0026] At one rear end, a supply line 31 is inserted into the housing 10, bundling electrical and fluid lines. A union nut 30 connects the elements 11 and 20 of the housing 10 together and clamps the supply line 31 securely.

[0027] The base element 11 has a recessed grip 11.1 and a concealed recessed grip on the underside and is otherwise smooth. The cover element 20 has a recessed grip 23 for the index finger. A multitude of indentations 21 are formed on the outer surface to improve the tactile feel. The difference in surface texture clearly defines a dividing line 22 between the base element 11 and the cover element 20, whereby the dividing line 22 does not, or at least not continuously, lie in a plane of diameter. Rather, the base element 11 rises above the plane of diameter in a front section 11.2, so that at the end of the front section 11.2, the entire circumference of the housing is solely part of the base element 11. This avoids a separation of the housing elements in the area of ​​an end face 14.

[0028] On the front face 14, a through-hole 18 for a chuck receptacle 43 is formed in the center, which allows the shank of rotating machining instruments to be inserted. Eccentrically to this, a concave, frustoconical spray chamber 15 is formed into the front face 14.

[0029] The handpiece 100 is in Fig. 1 shown lying on its side. In use of the handpiece 100, the lid element 20 points upwards, and the spray chamber 15 is located at the bottom.

[0030] In Fig. Figure 2 shows a handpiece 100' according to a second embodiment of the invention in a perspective view from a front oblique angle. Here too, a housing 10' consists of a base element 11' and a cover element 20; the cover element 20 with grip recess 23 is identical to that of the first embodiment. This also applies to the supply line 31 and the union nut 30.

[0031] The only difference lies in the design of an end face 14', which has a horseshoe-shaped recess 14.1', from which only the through-hole 18' for the central chuck mount 43 and the concave spray chamber 15' are excluded. An arc-shaped LED element 50' is placed in the recess to illuminate the working area in front of the end face 14'.

[0032] Fig. Figure 3 shows the handpiece 100' according to the second embodiment with the cover element removed, in a perspective view from a slightly oblique front view. Inside the base element 11', a motor 40, a gearbox 41, and a chuck 42 are connected to each other, forming a drive unit. In the rear area, near the union nut 30, electrical cables 45 are visible, leading to the motor 40 and the LED unit 50'.

[0033] In Fig. Figure 4 shows again the handpiece 100' according to the second embodiment, the difference being that in Figure 4 shows the handpiece 100' according to the second embodiment, the illustration in Figure 4 being the handpiece 100'. Fig. 3 consists in the fact that the base element 11' is cut here in a diameter plane. This in particular halves a front part 11.2', so that a web 51' becomes visible, by which the LED element 50' is held on the drive set and supplied with power.

[0034] In the rear area, in addition to the electrical cables 45, connection nipples 33 are also visible, via which fluid hoses, which are part of the supply line 31, are connected to corresponding bores in the fluid channels integrated into the base element 11. A nozzle 17 with a threaded section is formed on the base element 11, which is supplemented by further threaded sections on the cover element 20, thus forming an external thread for screwing on the union nut 30.

[0035] Fig. Figure 5 shows only the first embodiment of the handpiece 100 according to Fig. Base element 11 belonging to 1 in a perspective section view. The base element 11 has a largely flat front face 14. In the complete, lower section view in Fig. In section 5, the base element 11 is cut in a plane below a diameter plane. In the smaller section view above, only the area of ​​the front part 11.2' of the base element 11 is cut in the diameter plane, thus revealing the central opening for a chuck mount and the spray chamber 15 with an air nozzle bore 16.

[0036] The juxtaposed sections from parallel, vertically offset sections clearly show the course of a fluid channel 12 integrated into the wall of the base element 11. The fluid channel 12 serves to convey water and opens into a water nozzle bore 17. At the rear end of the base element 11, a bore 12.1 is formed on the nozzle 17, which is designed to receive a connecting nipple 33 (see Fig. 4) serves this purpose. A second bore for another connection nipple is formed on nozzle 17. Compressed air is supplied there and guided through a second fluid channel, which is not visible here, to an air nozzle bore in the spray chamber.

[0037] Via an S-bend 12.2, the fluid channel 12 pivots from the center to a peripheral area at the base element 11. Towards the front part 11.2, the fluid channel 12 appears to terminate in an end section 12.3 in the lower sectional view. In reality, it moves obliquely upwards to the section plane and is therefore visible again in the smaller sectional view at the top left. The end section 12.3 terminates in the water nozzle bore 17 in the spray chamber 15.

[0038] Fig. Figure 6 shows an enlarged perspective view of the front face 14, which clearly illustrates the design of the spray chamber 15. The air nozzle bore 16 opens in the center of the bottom of the concave spray chamber. The water nozzle bore 17 emerges precisely at the transition between the bottom and the conical shell and is angled. The axes of bores 16 and 17 intersect.

[0039] The arrangement of the nozzle bores 16, 17 relative to each other is shown in the further sectional view through the front part 11.2 of the base element 11 in Fig. Figure 7 clearly shows that the air nozzle bore 16 exits centrally into the spray chamber 15, and its bore axis is coaxial with the chamber's central axis. The bore axis of the water nozzle bore 17, which is fed from the fluid channel 12 and also integrated into the wall of the base element 11, is inclined at approximately 45° to the central axis. As a result, a water jet enters the spray chamber 15 at the outer diameter of the base at an angle of 45° relative to the airflow. The distance between the air and water nozzle bores is only 1 mm to 2 mm. The cross-sections taper from a diameter of, for example, 1.0 mm at the incoming fluid channel 12 to a diameter of 0.4 mm at the exit of the air nozzle bore 16 or the water nozzle bore 17.

[0040] The fluid flows exiting the air nozzle bore 16 and the water nozzle bore 17 meet approximately in the middle of the spray chamber 15. The airflow swirls the exiting water, creating a spray mist that emerges in a conical shape from the cone-shaped spray chamber 15 towards the instrument inserted into the chuck receptacle 43. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 202 18 525 U1

[0002] DE 10 2005 056 009 A1

[0004]

Claims

[1] Handpiece (100; 100') for a foot care device with integrated wet technology, at least comprising - a housing (10; 10') which terminates at an end face (14; 14') on which a through-hole for receiving a rotary-driven tool, a water nozzle bore (17) and an air nozzle bore (16) are arranged next to each other, - a drive set comprising an electric motor (40), a gearbox (41) and a chuck (42) for receiving the tool; wherein the housing (10; 10') comprises a base element (11; 11') and a cover element (20), between which a cavity is formed in which the drive set is received. characterized by , - that the base element (11; 11') is formed by an additive manufacturing process and - that at least two non-linear fluid channels (12; 13) are guided through a wall of the base element (11; 11') surrounding the cavity, each extending from a nozzle (17) formed at the end of the handpiece (100; 100') facing away from the front face (14; 14') to the water nozzle bore (17) or the air nozzle bore (16) on the front face (14; 14'). [2] Handpiece (100; 100') according to claim 1, characterized by , - that a dividing line (22) between base element (11; 11') and cover element (20) does not run or does not run continuously in a diameter plane of the housing (10; 10') and - that the base element (11; 11') forms the entire circumference of the case (10; 10') at the end of a front part (11.2) adjoining the front face (14; 14'). [3] Handpiece (100; 100') according to claim 1 or 2, characterized by, that a concave spray chamber (15; 15') is formed on the front face (14; 14') into which the water nozzle bore (17) and the air nozzle bore (16) open. [4] Handpiece (100; 100') according to claim 3, characterized by , that the concave spray chamber (15; 15') has the shape of a truncated cone, with the larger diameter forming the outer opening at the end face (14; 14') and the smaller diameter forming the bottom of the spray chamber (15; 15'). [5] Handpiece (100; 100') according to claim 4, characterized by , that the larger diameter is 3.5 to 5 mm and the smaller diameter is approximately 1.5 to 3 mm. [6] Handpiece (100') according to claim 4 or 5, characterized by , that the depth of the spray chamber (15, 15') is 1.5 to 34 mm. [7] Handpiece (100; 100') according to claim 4 or 5, characterized by , that the cone angle of the spray chamber (15; 15') is 45° to 90°. [8] Handpiece (100; 100') according to one of claims 3 to 6, characterized by, that the air nozzle bore (16) is located in the center of the bottom of the spray chamber (15; 15') and the water nozzle bore (17) is located in the periphery of the bottom. [9] Handpiece (100; 100') according to claim 7, characterized by , that a bore axis of the air nozzle bore (16) is aligned coaxially to the central axis of the spray chamber (15; 15') and a bore axis of the water nozzle bore (17) is inclined to it. [10] Handpiece (100; 100') according to claim 8, characterized by , that a virtual intersection of the inclined bore axis of the water nozzle bore (17) and the bore axis of the air nozzle bore (16) is located within the concave spray chamber (15; 15'). [11] Handpiece (100') according to any one of claims 1 to 9, characterized by , that an LED element (50') with several LEDs is arranged on the front face (14'). The spray mist from the spray chamber emerges in the recess of the horseshoe. [12] Handpiece (100') according to claim 10, characterized by, that a horseshoe-shaped recess (14.1') is formed in the front face (14'), from which a chuck receptacle (43) and the concave spray chamber (15') are excluded, and that an arc-shaped LED element (50') is arranged in the recess (14.1'). [13] Handpiece (100') according to any one of claims 1 to 12, characterized by , that the ends of the fluid channels (12; 13) at the nozzle (17) are each enlarged in cross-section by a bore (12.1) to accommodate a double nipple (33) for the connection of a fluid hose. [14] Handpiece (100') according to any one of claims 1 to 13, characterized by , that the cross-sections of the fluid channels (12; 13) taper towards the outlet at the water nozzle bore (17) or the air nozzle bore (16) in a ratio of 3:1 to 2:1.

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