Coupling section of personal care appliance including tolerance compensation and method of making same

Abstract

A coupling section for coupling a handle of a personal care appliance and a replaceable attachment tool includes a cover, a bushing mounted inside the cover, a drive shaft having a free end terminating in the bushing, a first magnetic coupling element mounted in the cover, and a resilient magnet seal disposed between the first magnetic coupling element and the bushing. The magnet seal is configured and configured to flex at least in a direction along the longitudinal axis of the bushing to provide at least longitudinal tolerance compensation of the drive shaft relative to the first magnetic coupling element.

Description

Technical Field

[0001] This disclosure relates to the mass production of multi-component personal care devices, such as, for example, personal care appliances, including electric toothbrushes. Background Technology

[0002] Mass production of multi-part personal care appliances (such as toothbrush handles and similar items) is typically carried out through multi-step processes that require the batch production of multiple parts, which are then assembled into finished products. These multi-part parts must have consistent, nearly identical (within acceptable variation) size and shape to function as designed. The necessary consistency between identical parts can be defined by the degree tolerable for minor variations in the corresponding shape and size between such batch-produced identical parts. This focus on consistency is particularly important when identical multi-part parts are manufactured at multiple locations, which may have slightly different manufacturing conditions, equipment, and suppliers of necessary materials.

[0003] For example, almost all plastic materials to be molded into desired parts are heated, liquefied, cooled, and solidified during the manufacturing process. They typically shrink during cooling (a phenomenon commonly referred to as "molding shrinkage"), resulting in at least some physical dimensions of the resulting parts being smaller than their ideal or nominal dimensions, potentially leading to a lack of consistency between these plastic components. Furthermore, metal parts may undergo deformation due to welding during the assembly of the desired parts, which can also affect the consistency between these parts. Simultaneously, precise positioning of the necessary parts is required to achieve a reliable and stable process for assembling them into the finished product.

[0004] Therefore, variations in the ideal or nominal shape and size of parts assembled into finished appliances need to be within acceptable tolerances. As used herein, the term "tolerance" refers to the acceptable (acceptable) variation in the specified shape and / or measurable dimensions of a part of an assembled appliance from its ideal / nominal shape. Since no article or any part thereof can be manufactured precisely to its exact nominal value in shape and size, tolerances are typically assigned to parts for manufacturing purposes as boundaries of acceptable buildability. Therefore, there exists an acceptable degree of variation / deviation from the exact nominal value applicable to a particular machine, process, or part. Tolerances can be applied to any shape and size. Parts manufactured with shapes and / or dimensions exceeding tolerances are unlikely to be usable parts for their intended purpose.

[0005] The sequential assembly process requires the correct positioning of the parts being assembled. To achieve this, manufacturers need to ensure that the size and geometry of all components (including the manufactured / assembled parts) match each other with high precision, thus requiring tight tolerances. These tight tolerances are often difficult to achieve, especially in the case of mass production of parts, which may occur in various locations and under different business and environmental conditions, as previously mentioned.

[0006] Such mass production requires multiple tools, including, for example, mold tools and components, which are typically mounted on different machines and designed to produce the same parts. For example, in the production of the handle of a personal care tool (such as, for example, an electric toothbrush), the handle is typically designed to house multiple components (including, for example, a motor, battery, electronics, and a drive unit including at least a portion of a drive shaft, as well as other structural and functional properties). Reliable consistency and precision between the different tools and equipment parts are crucial to achieving and maintaining the goal of necessary tolerances. Summary of the Invention

[0007] This disclosure relates to solving the problem of meeting required stringent tolerances in multi-part personal care appliances. This is accomplished by providing a connecting section and handle for the multi-part personal care appliance, the connecting section including a novel functional element—a tolerance compensation element—which will allow the manufacturer to significantly relax the originally stringent tolerances of certain parts and manufacturing processes while maintaining the necessary reliability and functionality of the parts being manufactured and assembled. Therefore, this disclosure provides a novel connecting section and handle for mass-produced multi-part personal care appliances, and a more reliable and stable method for manufacturing and assembling the parts required for such mass-produced multi-part personal care appliances.

[0008] In one aspect, this disclosure relates to a coupling section for a personal care appliance. The coupling section includes a drive shaft having a longitudinal axis and a free end. The personal care appliance may have any suitable operating frequency. In one example embodiment, the drive shaft may be configured to have an operating frequency of about 50 Hz to about 270 Hz. The coupling section may include at least one first magnetic coupling element mounted adjacent to the free end of the drive shaft for connection via magnetic interaction to at least one second magnetic coupling element of a replaceable attachment tool. In the context of oral care, such a replaceable attachment tool may include a movable (e.g., vibrating, rotating, oscillating) brush head.

[0009] In one example embodiment, the connecting section has a cover having a longitudinal axis L2 and including a tubular structure. The cover has a first (open) end and a second end opposite to the first end. The cover can accommodate at least a first magnetic connecting element disposed adjacent to the second end of the cover. The handle may also include a bushing having a first (open) end and a second end opposite to the first end. The bushing can be secured inside the cover adjacent to the first end of the cover, such that the first end of the bushing is adjacent to the first end of the cover.

[0010] A tolerance compensation element may be arranged at the first end of the bushing. This tolerance compensation element has a through-hole sized to receive a drive shaft passing through it. The drive shaft passes through the tolerance compensation element, is inserted into the bushing, and is attached to both the drive shaft and the bushing.

[0011] The bushing can be advantageously designed to loosely receive a portion of the drive shaft within it, such that there is a gap (empty space) between the inner surface of the bushing and the outer surface of the portion of the drive shaft inserted into the bushing. Therefore, the drive shaft can have some (limited) degrees of freedom of movement within the bushing. This allows the drive shaft to move within the bushing and be adjusted therein.

[0012] The drive shaft can be adjusted, for example, by moving it upwards and / or downwards along its longitudinal axis, thereby producing longitudinal tolerance compensation; by adjusting it laterally, creating a distance between the longitudinal axis of the drive shaft and the longitudinal axis of the cover (and / or bushing), thereby producing lateral tolerance compensation; and by adjusting it to tilt (at an angle) the shaft relative to the longitudinal axis of the cover, so that the longitudinal axis of the drive shaft is not parallel to the longitudinal axis of the cover, thereby producing angular tolerance compensation. Of course, any combination of longitudinal, lateral, and angular tolerance compensation can be performed as needed. If necessary, such adjustments can effectively remedy potential or actual misalignment exceeding the original necessary tolerances between the assembled parts, thereby effectively relaxing such stringent tolerances. This simplifies and streamlines the product assembly process, making the process more flexible and the product cheaper.

[0013] After the drive shaft has been adjusted inside the bushing to compensate for variations in the shape and / or size of the assembled parts, tolerance compensation elements can be attached to the drive shaft and bushing, for example, by at least one of adhesive bonding and welding (e.g., laser welding).

[0014] In one embodiment, the tolerance compensation element includes a disc-shaped structure having an outer diameter of about 3 mm to about 12 mm and a through hole having a diameter of about 1 mm to about 6 mm. The tolerance compensation element may have a thickness of about 0.2 mm to about 2 mm.

[0015] At least one first magnetic coupling element may include at least one permanent magnet and / or at least one magnetizable element. The handle may advantageously include a magnetic seal disposed in the cover between the first magnetic coupling element and the bushing.

[0016] On the other hand, this disclosure relates to a handle for a personal care appliance, the handle including a connecting section as described herein.

[0017] In another aspect, this disclosure relates to a method of manufacturing a handle for a personal care appliance, wherein the handle includes a drive unit that includes a drive shaft. The method includes the following steps: providing a cap comprising a tubular structure having a first end and a second end opposite to the first end, the second end of the cap being an open end; inserting at least one first magnetic coupling element into the cap such that the at least one first magnetic coupling element is disposed adjacent to the second end of the cap; providing a bushing having a first end and a second end opposite to the first end, the second end of the bushing being an open end; mounting the bushing inside the cap and adjacent to the second end of the cap such that the second end of the bushing is adjacent to the second end of the cap; providing a tolerance compensation element having a through hole sized to receive a drive shaft passing through the through hole; arranging the tolerance compensation element at the second end of the bushing; inserting a portion of the drive shaft through the through hole of the tolerance compensation element into the bushing, wherein a gap (empty space) exists between the inner surface of the bushing and the outer surface of the portion of the drive shaft inserted into the bushing, such that the drive shaft has a degree of freedom of movement within the bushing; and attaching the tolerance compensation element to the drive shaft and the bushing.

[0018] The method may also include the steps of arranging a magnetic seal in the cover and / or pressing a tolerance compensation element against a second end of the bushing. The step of securing the bushing inside the cover may include installing the bushing by press-fit, crimping, shrink-fit, adhesive bonding, welding, snap-fit, or any combination thereof. In an advantageous embodiment, the step of securing the bushing in the cover further includes laser welding the bushing to the tubular structure of the cover.

[0019] In one embodiment, the step of attaching the tolerance compensation element to the drive shaft and bushing includes laser welding the tolerance compensation element to a second end of the bushing.

[0020] The method may further include adjusting the position of the drive shaft within the bushing prior to attaching the tolerance compensation element to the drive shaft and bushing. Adjusting the position of the drive shaft within the bushing may include: moving the drive shaft along its longitudinal axis (up or down); tilting the drive shaft relative to the longitudinal extension of the cover such that the longitudinal axis of the drive shaft is not parallel to the longitudinal axis of the cover; moving the drive shaft in a transverse direction (i.e., substantially perpendicular to the longitudinal axis of the drive shaft) such that the longitudinal axis of the drive shaft and the longitudinal axis of the cover do not coincide and there is a distance between them; and any combination thereof.

[0021] In another aspect, this disclosure relates to a connection section for connecting a handle of a personal care appliance and a replaceable attachment tool, wherein the connection section includes: a bushing having a longitudinal axis and a first end and a second end opposite to the first end; a drive shaft having a longitudinal axis and a free end terminating in the bushing, the free end of the drive shaft being inserted into the bushing through the first end of the bushing; a first magnetic coupling element mounted adjacent to the second end of the bushing; and an elastomeric magnetic seal disposed between the first magnetic coupling element and the bushing, the magnetic seal being constructed and configured to flex at least in a direction along the longitudinal axis of the bushing, thereby providing at least longitudinal tolerance compensation for the drive shaft relative to the first magnetic coupling element. Attached Figure Description

[0022] Although claims that are specifically pointed out and clearly claimed as the subject matter of the invention are provided after the specification, various embodiments can be better understood from the following description taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a schematic front view of an embodiment of a personal care device, which includes a handle and a replaceable / disposable brush head attached to the handle.

[0023] Figure 2 yes Figure 1 A schematic partial view of an embodiment of the handle and head shown, wherein the head is disconnected from the handle.

[0024] Figure 3 This is a schematic partial cross-sectional view of an embodiment of a personal care device having a connecting section and including a handle and a replaceable / disposable brush head attached to the handle.

[0025] Figure 4 This is a schematic diagram of the disassembled portion of the connection section of a personal care appliance, including tolerance compensation elements.

[0026] Figure 5 This is a schematic cross-sectional view of the implementation scheme of the tolerance compensation element.

[0027] Figure 5A yes Figure 5 A schematic top view of the tolerance compensation element shown.

[0028] Figure 5B This is a schematic top view of the tolerance compensation element that partially surrounds the drive shaft.

[0029] Figure 6 This is a schematic diagram of the assembly section of a personal care appliance, including the connection section with tolerance compensation elements.

[0030] Figure 7 The steps in the process of making a personal care device are schematically illustrated, and a cross-sectional view of the lid is schematically shown.

[0031] Figure 8 The steps in the process of making a personal care appliance are schematically illustrated, and a cross-sectional view of the lid and the magnetic element inserted into the lid is schematically shown.

[0032] Figure 9 The steps in the process of making a personal care appliance are schematically illustrated, and cross-sectional views of the cap, magnetic element, and magnetic seal are schematically shown.

[0033] Figure 10 The steps in the process of making a personal care appliance are schematically illustrated, and cross-sectional views of the cap, magnetic element, magnetic seal, and bushing are schematically shown.

[0034] Figure 11 The steps in the process of manufacturing personal care appliances are schematically illustrated, and cross-sectional views of the cap, magnetic element, magnetic seal, bushing, and tolerance compensation element are schematically shown.

[0035] Figure 12 The steps in the process of manufacturing personal care appliances are schematically illustrated, and cross-sectional views of the cap, magnetic element, magnetic seal, bushing, tolerance compensation element, and drive shaft are schematically shown.

[0036] Figure 12A The diagram schematically illustrates the gap between the inner surface of the bushing and the outer surface of the portion of the drive shaft inserted into the bushing, which allows the drive shaft to have angular freedom of movement within the bushing.

[0037] Figure 12B The schematic diagram illustrates the gap between the inner surface of the bushing and the outer surface of the portion of the drive shaft inserted into the bushing, which allows the drive shaft to have a degree of freedom of movement in the lateral direction within the bushing.

[0038] Figure 13 The steps in the process of manufacturing personal care appliances are illustrated schematically, including laser welding tolerance compensation elements to bushings and drive shafts.

[0039] Figure 14 This is a perspective view of a part of a personal care appliance under construction, schematically showing a clamping tool adjacent to but not in contact with the tolerance compensation element.

[0040] Figure 15 yes Figure 14 The diagram shows a perspective view of a portion of a personal care appliance, and schematically illustrates a clamping tool in contact with a tolerance-compensating element.

[0041] Figures 16A to 16L A segment of the connection section of various example embodiments with magnetic seals is schematically shown.

[0042] Figure 17A An example embodiment of a magnet seal in an assembled connecting section is schematically shown in relation to the dimensions of the surrounding structure, wherein the magnet seal is shown in its uncompressed state for illustrative purposes.

[0043] Figure 17B Similar to Figure 17A Furthermore, another example embodiment of the magnet seal in its uncompressed / unconstrained state within the assembled connection section is schematically shown.

[0044] Figure 18A A side view of an example embodiment of a magnet seal is schematically shown.

[0045] Figure 18B schematically shown Figure 18A A cross-sectional view of an embodiment of the magnet seal shown.

[0046] Figure 19 A segment of a personal care appliance with a connecting section is schematically shown, in which a magnetic seal is used as a tolerance compensation element. Detailed Implementation

[0047] The following description does not attempt to list every possible embodiment of the invention, as that would be impractical if not impossible. Therefore, this disclosure should be construed as including representative examples or embodiments of the invention. That is, any feature, characteristic, structure, component, element, or step described herein may be combined with or replaced, in whole or in part, by any other suitable feature, characteristic, structure, component, element, or step. It should also be understood that the relative proportions of some elements shown in the drawings may not be precise, as the dimensions, including thickness / height, of the components illustrated in several example embodiments may be exaggerated for illustrative purposes.

[0048] Figures 1 to 3An example embodiment of the personal care appliance 10 shown is an electric toothbrush, which includes a handle 300 and a replaceable attachment 200. The attachment 200 shown in this example embodiment is a brush head. As known in the art, the replaceable attachment 200 includes: a housing having a head section and a neck section 210, the head section including a head cavity for receiving a movable oral cleaning head 220, and the neck section having a neck cavity internally; and a coupling section 350 for attaching the replaceable attachment 200 to the handle 300.

[0049] As disclosed in commonly assigned U.S. Patents 8,631,532, 9,226,808, and 9,387,059 (the entire disclosures of which are incorporated herein by reference), the magnetic force between a first magnetic coupling element and a second magnetic coupling element (at least one of which may be a permanent magnet or a magnetizable element) can be used to form a connection with the mechanical shank drive shaft of an alternative attachment tool. One of the magnetic coupling elements may be located at the drive shaft of the shank, and the other may be located inside the attachment tool.

[0050] like Figures 1 to 3 As shown, the handle 300 of the personal care appliance 10 includes a drive unit 330, which includes a drive shaft 310 having a longitudinal axis L1 and a free end 311. As known in the art, the connection section 350 includes components for attaching a replaceable attachment tool 200 (e.g., a brush head) to the handle 300. In electric toothbrushes (… Figure 1 In the case of (as illustrated in the example), the drive shaft 310 may have an operating frequency of about 50 Hz to about 270 Hz. The connection section 350 includes a first magnetic connection element 150 mounted at the free end 311 of the drive shaft 310 for connection by magnetic interaction with a second magnetic connection element 270 (e.g., a metal cylinder) mounted at a motion transmitter that extends from the neck cavity of the neck 210 to the head cavity of a replaceable attachment 200 arranged for brushing motions, such as rotational oscillations. Figure 6 The diagram schematically illustrates the magnetic force F present between the first magnetic connecting element 150 and the second magnetic connecting element 270.

[0051] The connecting section 350 may include a cover 140 having a longitudinal axis L2 and comprising a substantially tubular structure. The cover 140 has a first (open) end 141 and a second end 142 opposite to the first end 141. Figure 4 and Figure 7 The cover 140 has an inner diameter D7 (). Figure 8 , Figure 16A , Figure 17A , Figure 17BThe cover 140 internally accommodates a first magnetic coupling element 150 disposed adjacent to the second end 142 of the cover 140.

[0052] The connecting section 350 may further include a bushing 170 having a first (open) end 171 and a second end 172 opposite to the first end 171. The bushing 170 may be fixed inside the cover 140, for example by press fitting and / or laser welding, positioned adjacent to the first end 141 of the cover 140, such that the first end 171 of the bushing 170 is adjacent to the first end 141 of the cover 140. Figure 10 , Figure 11 Since the bushing 170 is securely fixed within the cover 140, the longitudinal extension of the bushing is substantially parallel to the longitudinal extension of the cover 140, and both the cover 140 and the bushing 170 share the longitudinal axis L2. Figure 10 Therefore, the longitudinal axis L2 can be referred to as "the longitudinal axis L2 of bushing 170" and / or "the longitudinal axis L2 of cover 140" or "the longitudinal axis L2 of bushing 170 and cover 140 (both)".

[0053] like Figure 4 and Figure 11 As best shown herein, the tolerance compensation element 250 may be arranged at the first end 171 of the bushing 170. The embodiment of the tolerance compensation element 250 shown herein has a through-hole 255 having a diameter D2 (…). Figure 5 The through-hole is designed to receive the drive shaft 310 passing through it. The drive shaft 310 is inserted into the bushing 170 through the tolerance compensation element 250 and is attached to both the tolerance compensation element 250 and the bushing 170.

[0054] The bushing 170 is sized to loosely receive the free end of the drive shaft 310 inserted into the bushing 170. In this document, the term "loosely" means that the outer diameter D3 of the portion of the drive shaft 310 inserted into the bushing 170 is slightly smaller than the inner diameter D4 of the bushing 170, such that a gap or empty space exists between the inner surface of the bushing 170 and the outer surface of the portion of the drive shaft 310 inserted into the bushing 170, allowing the shaft 310 to move within the bushing 170 and relative to the bushing. In other words, there is no "tight" fit between the bushing 170 and the portion of the drive shaft 310 inserted into the bushing 170. This gap or empty space between the inner surface of the bushing 170 and the outer surface of the portion of the drive shaft 310 inserted into the bushing 170 allows the drive shaft 310 to have a degree of freedom of movement within the bushing 170 during assembly.

[0055] This degree of freedom of movement of the drive shaft 310 within the bushing 170 may include: a degree of freedom of movement in the axial direction (i.e., along the longitudinal axis L1 of the drive shaft 310), thereby producing longitudinal tolerance compensation; and a degree of freedom of movement in the transverse direction, such that a distance “X” is formed between the longitudinal axis L1 of the drive shaft 310 and the longitudinal axis L2 of the cover 140. Figure 12B This results in lateral tolerance compensation; and angular or tilting motion degrees of freedom, causing the shaft 310 to be slightly tilted or deviated relative to the longitudinal axis L2 of the cover 140, so that the longitudinal axis L1 of the drive shaft 310 is not parallel to the longitudinal axis L2 of the cover 140. Figure 12A ), thereby generating angular tolerance compensation; and any combination of the above.

[0056] The degree of freedom of movement of the drive shaft 310 within the bushing 170 provides the manufacturer with the ability to adjust the drive shaft 310 within the bushing 170 during assembly, thereby compensating for minor variations in the size and dimensions of the assembled parts that may exceed the originally necessary tolerances between those parts and / or surrounding structures. Such adjustments during assembly may include, for example, slightly tilting the drive shaft 310 relative to the longitudinal extension of the cover 140 and / or the bushing 170, resulting in a lack of perfect alignment between the longitudinal axis L1 of the drive shaft 310 and the longitudinal axis L2 of the cover 140. In other words, in some embodiments, the drive shaft 310 may be tilted relative to the longitudinal extension of the cover 140 such that the longitudinal axis L1 of the drive shaft 310 is not parallel to the longitudinal axis L2 of the cover 140, and an angle “A” is formed between the longitudinal axes L1 and L2, such as… Figure 12A As schematically shown. In other words, the drive shaft 310 may have a position characterized by the degree of angular deviation from the axial alignment of the longitudinal extension of the cover 140. Angle "A" may be from 0 degrees to about 25 degrees, more specifically from 0 degrees to about 15 degrees, or even more specifically from 0 degrees to about 5 degrees. In one embodiment, angle "A" may be from about 0.2 degrees to about 6 degrees.

[0057] Alternatively or additionally, such adjustment during assembly may also include moving the drive shaft 310 in the transverse direction relative to the longitudinal extension of the cover 140 and / or bushing 170, such that a distance “X” is formed between the longitudinal axis L1 of the drive shaft 310 and the longitudinal axis L2 of the cover 140 and / or bushing 170. Figure 12B This will result in the drive shaft 310 having a position characterized by a lateral deviation from the axial alignment with the longitudinal extension of the cover 140. The distance “X” can be from about 0.005 mm to about 1 mm, more specifically from about 0.01 mm to about 0.5 mm. In one embodiment, tolerance compensation in the lateral direction can result in a distance “X” of about 0.005 mm to about 0.15 mm being formed between the longitudinal axis L1 of the drive shaft 310 and the longitudinal axis L2 of the bushing 170.

[0058] Similarly, drive shaft 310 can move / adjust upwards and / or downwards along its longitudinal axis L2 to produce longitudinal tolerance compensation, as may be required during assembly. Of course, any tolerance compensation adjustments described herein can be combined as needed. Thus, drive shaft 310 may have a position characterized, for example, by both lateral deviation (lateral tolerance compensation) and angular deviation (angular tolerance compensation) in axial alignment with the longitudinal axis of cover 140. Such adjustments can be effectively implemented, when needed, to compensate for misalignment between assembled parts that may be caused by variations in the shape and size of the parts exceeding necessary tolerances, for example, due to the reasons mentioned above.

[0059] The tolerance compensation element 250 can be attached to the drive shaft 310 and bushing 170 by any means known in the art (e.g., by adhesive bonding and / or welding). In an advantageous embodiment, the tolerance compensation element 250 is attached to the drive shaft 310 and bushing 170 by laser welding, for example, at points 250a, 250b, 250c, and 250d, as shown below. Figure 13 The number of fixed points is shown schematically in the diagram. Figure 13 (The four in the middle are for illustrative purposes only, and any other suitable number of laser welding points may be used to fix the tolerance compensation element 250 if feasible.)

[0060] exist Figure 5 , Figure 5A and Figure 5B In the example implementation shown, the tolerance compensation element 250 essentially comprises a disc structure, or a ring, a complete ring ( Figure 5A ) or part of the ring ( Figure 5B This disclosure envisions other suitable shapes for the tolerance compensation element 250, such as rectangular, polygonal, elliptical, etc. (not shown herein). The tolerance compensation element 250 may have an outer diameter (or the maximum dimension measured through the geometric center of the non-circular tolerance compensation element 250) D1 of about 3 mm to about 12 mm. The through-hole of the tolerance compensation element 250 may have a diameter D2 of about 1 mm to about 6 mm. Figure 5 , Figure 5A and Figure 5B As shown, the through hole can be centered. The tolerance compensation element 250 can have a thickness of approximately 0.2 mm to approximately 2 mm.

[0061] The inner diameter D4 of bushing 170 can be from about 1.5 mm to about 10 mm. The outer diameter D3 of drive shaft 310 can be from about 1 mm to about 6 mm. In a particular arrangement to be assembled, the outer diameter D3 of drive shaft 310 can be slightly smaller (0.5% to 5%) than the diameter D2 of the through hole of tolerance compensating element 250. This will allow drive shaft 310 to have some limited angular freedom of movement relative to tolerance compensating element 250 during appliance assembly. In other words, drive shaft 310 can be slightly tilted relative to tolerance compensating element 250 such that the longitudinal axis L1 of shaft 310 is not strictly perpendicular to the lateral extension of tolerance compensating element 250.

[0062] The first magnetic coupling element 150 may include at least one of a permanent magnet and a magnetizable element for providing a magnetic connection with a corresponding second magnetic coupling element 270 (such as, for example, a metal cylinder) arranged in the replaceable attachment tool 200. Figure 3 , Figure 4 , Figure 6 , Figures 9 to 13 as well as Figures 16A to 16L As shown, the handle 300 may advantageously include a resilient magnetic seal 160 disposed within the cover 140, between the first magnetic coupling element 150 and the bushing 170. The magnetic seal protects the first magnetic coupling element 150 from moisture. This also helps to ensure that the first magnetic coupling element 150 is sufficiently pressed against the inside of the cover surface. Because the magnetic seal 160 is resilient, it can also serve as an impact-absorbing element, protecting the personal care appliance from stress in the event of a drop.

[0063] Furthermore, the magnet seal 160 can be combined with or independently of the previously described tolerance compensation element 250 as a flexible tolerance compensation element. In this way, the magnet seal 160 can be constructed and configured to flex to provide tolerance compensation for the drive shaft 310 at least in the longitudinal direction substantially parallel to the longitudinal axis L2 of the bushing 170. Figure 19 An embodiment of the connection section is shown, wherein the magnet seal 160 (shown in its uncompressed state) serves as a tolerance compensation element. Due to the tolerance compensation in the longitudinal direction, a distance S can be formed between the free end of the drive shaft 310 and the inner surface of the bushing 170 facing the free end of the drive shaft 310. The distance S can be from about 0.001 mm to about 4 mm, more specifically from about 0.01 mm to about 3 mm.

[0064] The magnet seal 160 may also be constructed and configured to flex to provide tolerance compensation for the drive shaft 310 in the following directions: a transverse direction substantially perpendicular to the longitudinal axis L2 of the bushing 170 and / or an angular direction that results in an angle between the longitudinal axis L2 of the bushing 170 and the longitudinal axis L1 of the drive shaft 310, as previously described herein.

[0065] The magnetic seal 160 may typically comprise a three-dimensional annular structure having any suitable shape. The seal 160 may be configured to flex at least in a direction along the longitudinal axis of the bushing 170, thereby providing at least longitudinal tolerance compensation for the drive shaft 310 relative to the first magnetic coupling element 150. As described above, the magnetic seal 160 may also be configured to provide lateral tolerance compensation and / or angular tolerance compensation.

[0066] Various non-limiting example embodiments of the magnet seal 160 are described in Figure 3 , Figure 4 , Figure 6 , Figures 9 to 13 , Figures 16A to 16L , Figure 17A , Figure 17B , Figure 18A and Figure 18B As shown in the diagram. The magnetic seal 160 has an unconstrained outer diameter D5 that is at least 5% larger than the inner diameter D7 of the cover 140. The term "unconstrained" is used herein to define a given parameter / dimension (e.g., outer diameter D5) of the seal 160 in an uncompressed state before it is inserted into the cover 140 and / or compressed by surrounding elements. Figure 17A , Figure 17B and Figure 18A ) or total height K ( Figure 18B The seal 160 is designed to be compressed (or squeezed) by the walls of the cover 140 inside the cover 140. Figure 16K and Figure 16L This provides the necessary isolation. Therefore, the total diameter of the compressed or constrained seal 160 is smaller than the unconstrained diameter D5. The seal 160 is also compressed between the magnet coupling element 150 and the bushing 170, resulting in a compressed or constrained height that is smaller than the unconstrained height K of the seal 160.

[0067] The magnet seal 160 may have an unconstrained outer diameter D5 of about 3 mm to about 13 mm, and more specifically about 5 mm to about 10 mm. The ratio of the unconstrained outer diameter D5 of the magnet seal 160 to the inner diameter D7 of the cover 140 (the constrained outer diameter of the seal 140) may be about 1.05 to about 1.25, and more specifically about 1.1 to about 1.2. The magnet seal 160 may have an unconstrained total height K of about 1 mm to about 4 mm, and more specifically about 1.5 mm to about 3 mm. Figure 18BThe ratio of the unconstrained height K of the magnet seal 140 to the constrained thickness can be from about 1.05 to about 1.4, and more specifically from 1.1 to about 1.3. The ratio of the unconstrained outer diameter D5 of the magnet seal 160 to the unconstrained total height K can be from about 2 to about 5.

[0068] As shown in the accompanying drawings, the magnet seal 160 may have at least one centrally positioned annular protrusion 161 extending outward from at least one side of the magnet seal and having an unconstrained outer diameter D6. Figure 18A At least one annular protrusion 161 extends generally parallel to the longitudinal axis of the cover 140. The unconstrained outer diameter D6 can be from about 2 mm to about 12 mm, and more specifically from about 4 mm to about 10 mm. At least a portion of the surface of the magnet seal 160 may be treated with a non-stick coating, including, for example, fluorination, to provide / promote a coefficient of friction of less than 0.2. The magnet seal 160 can be made of a rubber material with a Shore A hardness of 40 to 60. Non-limiting examples of rubber materials include silicone resin, NBR, or EPDM.

[0069] Figure 17A and Figure 17B The relationship between the dimensions of the magnet seal 160 and the dimensions of the surrounding structure in the assembled connecting section 350 is schematically shown in these figures, with the magnet seal 160 shown in its uncompressed state for illustrative purposes. Figure 17A An example embodiment of the magnet seal 140 is shown, wherein the unconstrained outer diameter D5 of the magnet seal 160 is larger than the inner diameter D7 of the cover 140 (the larger amount is double the interference “A”), and the unconstrained height of the magnet seal 160 is larger than the longitudinal dimension of the space within the cover 140 (the larger amount is longitudinal interference “B”), the space being designed to accommodate the seal 160 when the coupling section 350 is fully assembled. Figure 17B Another example embodiment of the magnet seal 140 is shown, wherein the unconstrained outer diameter D5 of the magnet seal 160 is larger than the inner diameter D7 of the cover 140 (the larger amount is double the interference “C”), and the unconstrained height of the magnet seal 160 is larger than the longitudinal dimension of the space within the cover 140 (the larger amount is longitudinal interference “E”), the space being designed to accommodate the seal 160 when the coupling section 350 is fully assembled.

[0070] In another aspect, this disclosure relates to a connection section 350 for connecting a handle 300 of a personal care appliance 10 and a replaceable attachment tool 200. The connection section 350 includes a drive shaft 310 having a longitudinal axis L1 and a free end 311 terminating in a bushing 170 having a first end 171 and a second end 172 opposite to the first end 171. The free end 311 of the drive shaft 310 passes through the first end 171 of the bushing 170 and is inserted into the bushing 170. A first magnetic coupling element 160 is mounted adjacent to the second end 172 of the bushing.

[0071] The tolerance compensation element 250 has a through-hole 255, the size of which is designed to loosely receive a drive shaft 310 passing through it. The tolerance compensation element 250 is mounted adjacent to a first end 171 of the bushing, and a free end 311 of the drive shaft 310 is disposed in the bushing 170, such that a space exists between the inner surface of the bushing 170 and the outer surface of the drive shaft 310. The tolerance compensation element 250 is attached to the drive shaft 310 and the bushing 170, and at least partially surrounds the portion of the drive shaft 310 adjacent to the first end 171 of the bushing 170. Figure 5B As shown, an embodiment of the tolerance compensation element 250 having a partially ring shape (somewhat similar to the overall outline of a horseshoe) will partially surround a portion of the first end 171 of the adjacent bushing 170 of the drive shaft 310.

[0072] A method of manufacturing a handle 300 for a personal care device 10 includes the following steps: providing a cap 140, the cap comprising a tubular structure and having a first end 141 and a second end 142 opposite to the first end 141, the first end of the cap being an open end. Figure 7 ); Insert the first magnetic connecting element 150 into the cover 140 such that the first magnetic connecting element 150 is positioned adjacent to the second end 142 of the cover 140 ( ); Figure 8 A bushing 170 is provided having a first end 141 and a second end 172 opposite to the first end 171, the first end 171 of the bushing 171 being an open end, and the bushing 170 is mounted inside the cover 140 and adjacent to the first end 171 of the cover, such that the first end of the bushing 170 is adjacent to the first end 141 of the cover 140. Figure 10 ); Provides a tolerance compensation element 250 having a through hole 255, the through hole being sized to receive a drive shaft 310 passing through it, and arranges the tolerance compensation element 250 at the first end 171 of the bushing 170 ( Figure 11 A portion of the drive shaft 310 is inserted into the bushing 170 through the through hole 255 of the tolerance compensation element 250, wherein a gap exists between the inner surface of the bushing 170 and the outer surface of the portion of the drive shaft 310 inserted into the bushing 170, so that the drive shaft 310 has a degree of freedom of movement within the bushing 170 (as previously stated). Figure 12 , Figure 12A and Figure 12B ); and attaching the tolerance compensation element 250 to the drive shaft 310 and bushing 170 ( ); Figure 13 ).

[0073] In one embodiment, the method includes the step of arranging a magnet seal 160 in a cover 140. Figure 9 A magnetic seal 160 may be needed to protect the magnetic coupling element 150 from moisture and to press the magnetic coupling element 150 against the inside of the cover surface. Because the seal 160 is elastic, it can also act as an impact-absorbing element and prevent stress if the appliance is dropped or otherwise shaken or impacted against a hard surface.

[0074] In one embodiment, the method includes the step of pressing the tolerance compensation element 250 against the first end 171 of the bushing 170. Figure 14 , Figure 15 This allows for the fixing of the tolerance compensation element to the bushing 170. For example... Figure 14 and Figure 15 As shown, a clamping tool or clamp 400 can be used to press and hold the tolerance compensation element 250 against and retain it on the first end 171 of the bushing 170. The clamping tool 400 may include, for example, two (or more) opposing pins 410, 420, which are constructed and configured to contact the top of the tolerance compensation element 250 and apply the necessary pressure to hold the tolerance compensation element 250 in place against the bushing 170, thereby attaching the tolerance compensation element 250 to the first end 171 of the bushing 170 and the drive shaft 310. The clamping tool 400 may be pneumatically, electrically, mechanically, hydraulically, or by any other means known in the art and suitable for this purpose.

[0075] The steps of securing the bushing 170 inside the cover 140 may include installing the bushing 170 by press-fit, crimping, shrink fitting, adhesive, welding, snap-fit, or any combination thereof. Figure 10 In one advantageous embodiment, which is schematically shown, the step of securing the bushing 170 in the cover 140 may further include, for example, laser welding the bushing 170 to the tubular structure of the cover 140 at region 175.

[0076] The method may further include adjusting the position of the drive shaft 310 within the bushing 170 prior to the step of attaching the tolerance compensation element 250 to the drive shaft 310 and the bushing 170. In one embodiment, adjusting the position of the drive shaft 310 within the bushing 170 includes positioning the drive shaft 310 within the bushing 170 such that the longitudinal axis L1 of the drive shaft 310 is not strictly parallel to the longitudinal axis L2 of the cover 140, such as... Figure 12A As shown.

[0077] In another aspect, this disclosure relates to a connection section for connecting a handle of a personal care appliance and a replaceable attachment tool, wherein the connection section includes: a bushing having a longitudinal axis and a first end and a second end opposite to the first end; a drive shaft having a longitudinal axis and a free end terminating in the bushing, the free end of the drive shaft being inserted into the bushing through the first end of the bushing; a first magnetic coupling element mounted adjacent to the second end of the bushing; and an elastomeric magnetic seal disposed between the first magnetic coupling element and the bushing, the magnetic seal being constructed and configured to flex at least in a direction along the longitudinal axis of the bushing, thereby providing at least longitudinal tolerance compensation for the drive shaft relative to the first magnetic coupling element.

[0078] The dimensions and values ​​disclosed herein should not be construed as strictly limited to the precise numerical values ​​cited. Rather, unless otherwise specified, each such dimension is intended to represent both the stated value and the range around which it is functionally equivalent. For example, a dimension disclosed as “10 mm” is intended to mean “about 10 mm”.

[0079] Unless expressly excluded or limited, the full text of the disclosure of every document cited herein, including any cross-references or related patents or applications, is incorporated herein by reference. Reference to any document is not an endorsement of it as prior art to any disclosed or protected art herein, nor is it an endorsement of any such invention, either on its own or in combination with any one or more references. Furthermore, where any meaning or definition of a term in this invention conflicts with any meaning or definition of the same term in any document incorporated by reference, the meaning or definition given to that term in this invention shall prevail.

[0080] While specific embodiments of the invention have been illustrated and described, it will be apparent to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, it is intended that all such changes and modifications falling within the scope of the invention be covered by the appended claims.

Claims

1. A connecting section for connecting the handle of a personal care device and a replaceable attachment tool, the connecting section comprising: A lid, comprising a generally tubular structure having an inner diameter, the lid having a first end and a second end opposite to the first end, the first end of the lid being an open end. A bushing, the bushing being installed inside the cover and having a longitudinal axis and a first end and a second end opposite to the first end, the first end of the bushing being an open end, the bushing being adjacent to the first end of the cover such that the first end of the bushing is adjacent to the first end of the cover. A drive shaft having a longitudinal axis and a free end terminating in the bushing, the free end of the drive shaft being inserted into the bushing through a first end of the bushing; A first magnetic coupling element is mounted adjacent to the second end of the bushing; and An elastic magnetic seal is disposed between the first magnetic coupling element and the bushing. The magnetic seal has a first side and a second side opposite to the first side. The magnetic seal is constructed and configured to flex at least in a direction along the longitudinal axis of the bushing, thereby providing at least longitudinal tolerance compensation for the drive shaft relative to the first magnetic coupling element.

2. The connection section according to claim 1, wherein the first magnetic connection element is disposed in the cover and adjacent to the second end of the cover, and wherein the magnet seal is disposed inside the cover, located between the first magnetic connection element and the bushing.

3. The connection section according to claim 1 or claim 2, wherein the magnet seal comprises a generally annular structure having an unconstrained outer diameter at least 5% larger than the inner diameter of the cover, particularly wherein the unconstrained outer diameter is from about 3 mm to about 13 mm, and further particularly wherein the ratio of the unconstrained outer diameter of the magnet seal to the inner diameter of the cover is in the range of 1.05 to 1.

25.

4. The connection section according to claim 3, wherein the magnet seal has an unconstrained total height in the range of 1.0 mm to 4.0 mm.

5. The connection section according to claim 4, wherein the ratio of the unconstrained outer diameter to the unconstrained total height of the magnet seal is in the range of 2.0 to 5.

0.

6. The connection section according to any one of claims 3 to 5, wherein the magnet seal includes a centrally positioned annular protrusion extending outward from at least one side thereof, and particularly, wherein the annular protrusion has an unconstrained outer diameter in the range of 2.0 mm to 12.0 mm.

7. The connection section according to any one of claims 3 to 6, wherein the magnet seal is made of rubber having a Shore A hardness in the range of 40 to 60.

8. The connection section according to claim 7, wherein at least a portion of the surface of the magnet seal is treated with a non-stick coating including fluorination.

9. The connection section according to any one of claims 1 to 8, wherein the magnet seal is constructed and configured to flex, thereby providing tolerance compensation for the drive shaft relative to the longitudinal axis of the bushing, the tolerance compensation being selected from lateral tolerance compensation and angular tolerance compensation, particularly wherein the lateral tolerance compensation results in a distance between the longitudinal axis of the bushing and the longitudinal axis of the drive shaft, or wherein the angular tolerance compensation results in an angle between the longitudinal axis of the bushing and the longitudinal axis of the drive shaft.

10. The connecting section according to claim 9, wherein the distance formed between the longitudinal axis of the bushing and the longitudinal axis of the drive shaft is in the range of 0.005 mm to 1 mm, and / or wherein the angle formed between the longitudinal axis of the bushing and the longitudinal axis of the drive shaft is in the range of about 0.2 degrees to about 6.0 degrees.

11. The connection section according to any one of claims 1 to 10, wherein the at least longitudinal tolerance compensation of the drive shaft relative to the first magnetic connection element results in a distance in the range of 0.001 mm to about 4.0 mm between the free end of the drive shaft and the inner surface of the bushing facing the free end of the drive shaft.

12. A handle of a personal care device having a connecting section for attaching the handle to a replaceable attachment tool, the connecting section comprising: A bushing having a longitudinal axis and a first end and a second end opposite to the first end; A drive shaft having a longitudinal axis and a free end terminating in the bushing, the free end of the drive shaft being inserted into the bushing through a first end of the bushing; A first magnetic coupling element is mounted adjacent to the second end of the bushing; and An elastic magnetic seal is disposed between the first magnetic coupling element and the bushing. The magnetic seal is constructed and configured to flex, thereby providing tolerance compensation for the drive shaft in at least one direction. The at least one direction is selected from a longitudinal direction substantially parallel to the longitudinal axis of the bushing, a transverse direction substantially perpendicular to the longitudinal axis of the bushing, and an angular direction that results in an angle between the longitudinal axis of the bushing and the longitudinal axis of the drive shaft.

13. The shank according to claim 12, wherein the tolerance compensation in the lateral direction results in a distance in the range of 0.005 mm to 0.15 mm between the longitudinal axis of the drive shaft and the longitudinal axis of the bushing.

14. The handle according to claim 13, wherein the angle formed between the longitudinal axis of the bushing and the longitudinal axis of the drive shaft is in the range of 0.2 degrees to 6.0 degrees.

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