Hair guiding element, hair trimming assembly, electric shaver and manufacturing method

Abstract

A hair guide element (10) for an electric shaver is provided. The hair guide element has a skin contact surface (12) for contacting skin and a shaving element facing surface (14) for facing a shaving element (16), wherein the shaving element facing surface faces in an opposite direction relative to a direction in which the skin contact surface faces. A perimeter of the hair guide element provides the hair guide element with a toothed profile comprising teeth (20) arranged along a main axis (MA) of the hair guide element, wherein the teeth each comprise a portion of the skin contact surface and a portion of the shaving element facing surface. A hair shaving assembly (10, 16) comprising the hair guide element and the shaving element and an electric shaver comprising such a hair shaving assembly are also provided. Further, a method of manufacturing the hair guide element is provided.

Description

Technical Field

[0001] This disclosure relates to a hair guiding element for an electric razor, a hair trimming assembly including a hair guiding element and a trimming element, an electric razor including a hair guiding element or a hair trimming assembly, and a method of manufacturing a hair guiding element. Background Technology

[0002] The hair trimming and hair guiding components of an electric shaver (such as a dry electric shaver) can be manufactured in various ways. Typically, the hair trimming assembly of an electric shaver includes two trimming elements: a stationary blade, such as a comb or foil, having a surface for contacting the skin and designed to guide / transport the hair; and a moving blade, which is usually located below the stationary blade. The moving blade does not contact the skin but receives the hair fed into it via the stationary blade and moves in a reciprocating manner to trim the hair. The blades of the hair trimming assembly can function as a scissor system for trimming hair.

[0003] Both trimming elements can achieve their respective functions by having specific two-dimensional geometries (when the corresponding elements are viewed in a plane) and trimming edges, the geometry of which is designed to achieve effective hair trimming. Such geometries can be produced via photochemical processing (also known as etching), a wet chemical process that does not utilize electric current. Another possible process is precision (or pulsed) electrochemical machining (PECM), in which the trimming element typically acts as the anode, and the material is removed via an electrochemical process. Trimming elements can also be produced via mechanical methods such as stamping, welding, bending, etc.

[0004] It is desirable to provide hair trimming and / or hair guiding components for electric razors with enhanced geometry, and methods for manufacturing such improved hair trimming and / or hair guiding components. It is also desirable to provide an enhanced etching method that can be used to manufacture hair trimming and / or hair guiding components and other types of articles. Summary of the Invention

[0005] According to a first aspect of this disclosure, a hair guiding element for an electric razor is provided, the hair guiding element comprising: a skin contact surface for contacting skin; a trimming element facing surface for facing a trimming element, wherein the trimming element facing surface faces a direction opposite to that facing the skin contact surface; a hair guiding surface on which hair from the skin can be received, so as to guide the hair on the hair guiding surface when the skin contact surface contacts the skin; and a periphery providing a toothed profile for the hair guiding element, the toothed profile including teeth arranged along the main axis of the hair guiding element, wherein each tooth includes a portion of the skin contact surface and a portion of the trimming element facing surface. The tooth comprises at least some of its teeth, each including a portion of a hair guiding surface and a tip region arranged to receive hair thereon as the hair guiding element moves on the skin. A portion of the hair guiding surface extends away from the tip region in a direction transverse to the main axis and toward a portion of the surface facing the trimming element, such that the portion of the hair guiding surface can guide hair already received on the tip region toward the portion of the surface facing the trimming element. The tooth thickness at the tip region is less than 250 μm, the tooth thickness being the diameter of a minimum imaginary circle whose circumference intersects both the portion of the hair guiding surface and the portion of the skin contact surface, wherein the plane of the minimum imaginary circle is perpendicular to the main axis.

[0006] Optionally, the minimum imaginary circle does not extend beyond the tooth. Therefore, the tooth thickness can be measured from the end of the tip region in a direction transverse to the main axis (125 μm is the maximum radius of a circle with a diameter of 250 μm).

[0007] When the hair guide element moves on the skin, if the skin contact surface is in contact with the skin, the hair may move upward to the tip area and slide along a portion of the hair guide surface toward the portion facing the trimming element.

[0008] Users of regular electric shavers may find that although the shaver's comb moves across the skin where hair is present, the hair may remain untrimmed. This can cause users to move the comb across the skin in the same spot multiple times, potentially leading to skin irritation.

[0009] It has been found that one reason hair remains untrimmed is the angle of the hair relative to the skin surface, especially a relatively small angle. For example, hair on the neck can protrude from the skin surface at an angle of only about 10°.

[0010] By making the tooth thickness at the tip region less than 250 μm, preferably less than 200 μm, it has been found that more hair can be successfully trimmed with fewer passes of the hair guiding element on the skin, thereby reducing skin irritation.

[0011] This is because when the hair protrudes from the skin surface at an angle of about 10° and the hair length is about 1.5 mm (which corresponds to the upper limit of facial hair growth in 3 days (0.5 mm per day), the teeth with a thickness of less than 250 μm at the tip can enter the gap of about 260 μm between the hair tip and the skin surface.

[0012] It should be noted that the skin contact surface may have a single plane in which the circumference of the smallest imaginary circle whose diameter defines the tooth thickness intersects with the single plane of the skin contact surface.

[0013] The term "transverse to the principal axis" can mean that when a hair guide element is viewed in a plane such that the skin-contact surface or the surface facing the trimming element is facing the observer, it is perpendicular to or at least substantially perpendicular to the principal axis.

[0014] The qualifier "basically" can refer to a deviation from the vertical direction of up to 10°.

[0015] In some embodiments, at least some of the teeth have hair-guiding surfaces that include sloping surfaces that descend from the tip region toward the surface facing the trimming element as the sloping surfaces extend transversely to the main axis, and simultaneously become further away from the skin-contacting surface as the sloping surfaces descend toward the surface facing the trimming element. Therefore, hair received at the tip can slide down the sloping surfaces toward the surface facing the trimming element.

[0016] Separating the hair from the skin in this way helps to properly orient the hair for trimming as it slides down the sloping surface toward the surface facing the trimming element.

[0017] In some embodiments, a step is defined between the lowest region of the descending sloping surface and the portion of the surface facing the trimming element, wherein the step provides a height difference of no more than 50 μm between the portion of the surface facing the trimming element and the lowest region. In such embodiments, hair can slide down the sloping surface until it reaches the step, at which point the sliding motion of the hair may terminate, but the hair can cross the step, for example by bouncing or rolling from the lowest region of the sloping surface onto the portion of the surface facing the trimming element.

[0018] By limiting the height difference to no more than 50 μm, ordinary hairs that slide down the sloping surface to reach the lowest region can relatively easily traverse the steps. This is because the height difference does not exceed half the average diameter of facial hairs, in other words, 50 μm.

[0019] The inclined surface may have a gradient defined by the lateral extent of the inclined surface being greater than the height of the inclined surface, wherein the lateral extent extends parallel to the skin contact surface from the tip region to a first point aligned with the lowest region of the inclined surface at the base of the step, and wherein the height extends perpendicular to the skin contact surface from the tip region to a second point aligned with the lowest region.

[0020] By making the lateral range greater than the height, for example, compared to the case where the lateral range is equal to or less than the height, the inclined surface descends relatively gently from the tip region to the lowest region of the inclined surface.

[0021] This relatively gently sloping surface can help the hair on it slide onto the surface facing the trimming element.

[0022] In some implementations, the lateral range is at least twice the height. Alternatively or additionally, the lateral range may be at least 200 μm, while the height may be 100 μm or less.

[0023] In some embodiments, the lowest region of the inclined surface is the location where the inclined surface reaches the surface facing the trimming element in a stepless manner. Therefore, hair can slide continuously down the inclined surface to reach the surface facing the trimming element. This can be advantageous for guiding hair to the surface facing the trimming element, particularly relative to embodiments where hair needs to traverse a step defined between the portion of the surface facing the trimming element and the lowest region of the inclined surface.

[0024] In such embodiments, the inclined surface may, for example, have a gradient defined by the lateral extent of the inclined surface being greater than its height, wherein the lateral extent extends parallel to the skin contact surface from the tip region to a first point aligned with the lowermost region of the inclined surface, and wherein the height extends perpendicularly to the skin contact surface from the tip region to a second point aligned with the lowermost region. The lateral extent may, for example, be at least twice the height. Alternatively or additionally, the lateral extent may be at least 200 μm, while the height may be 100 μm or less.

[0025] To reiterate, by making the lateral range greater than the height, the sloping surface descends relatively gently from the tip region to the lowest region of the sloping surface, thereby helping the hair on it to slide onto the surface facing the trimming element.

[0026] In some examples, a sloping surface may include a sloping planar region.

[0027] In some embodiments, the teeth include a first set of teeth extending transversely to the main axis in a first direction, and a second set of teeth extending transversely to the main axis in a second direction opposite to the first direction. When the hair guiding element moves across the skin in the opposite direction, the first and second sets of teeth enable the hair guiding element to guide hair toward the surface facing the trimming element.

[0028] At least some of the teeth (each tooth including a portion of the hair-guiding surface and a tip region with a tooth thickness of less than 250 μm) may be included in the first group of teeth and the second group of teeth.

[0029] When the hair guiding element is moved on the skin in each of the opposite directions, the hair lifting and hair guiding properties of the tip area and the hair guiding surface can be exhibited accordingly.

[0030] In some embodiments, the slots that separate adjacent teeth from each other along the main axis include slot pairs, wherein each pair of slots includes a longer slot and a shorter slot. In such embodiments, the longer and shorter slots of each pair may extend along a common slot axis transverse to the main axis, wherein one of the longer and shorter slots is defined between adjacent teeth of a first set of teeth, and the other of the longer and shorter slots is defined between adjacent teeth of a second set of teeth.

[0031] In other words, the shorter and longer slots in each pair of slots can be arranged back to back, such that the shorter slot receives hair in the opposite direction to the direction in which the longer slot receives hair.

[0032] As the skin-contact surface of the hair guide element moves across the skin, hair can be received in the slots and subsequently reach the surface facing the trimming element. Longer slots provide more opportunities for hair, especially longer hair, to be received, thus contributing to improved trimming efficiency. However, providing two relatively long slots in a back-to-back arrangement may pose a risk of making the hair guide element too wide, which could reduce the compactness of the razor head of an electric razor incorporating such a hair guide element, and therefore potentially impair its application in relatively narrow skin areas, such as between the nose and upper lip.

[0033] Therefore, the pairing of longer and shorter slots back to back can balance the effective trimming of longer hair with the compact design of the hair guiding element.

[0034] It should be noted that the length of each slot can be defined along the central slot axis that extends laterally to the main axis and bisects the slot. The starting point is the connecting area between adjacent teeth that define the corresponding slot, and the ending point is the point located between the ends / end surfaces of adjacent teeth.

[0035] In some embodiments, the hair guiding element includes a ridge from which a first set of teeth extends transversely to the main axis in a first direction, and a second set of teeth extends transversely to the main axis in a second direction. The ridge has a zigzag shape such that longer and shorter slots alternate along the first set of teeth, while shorter and longer slots alternate along the second set of teeth. In such embodiments, a balance between effectively trimming longer hairs and design compactness can be provided along the length of the ridge of the hair guiding element.

[0036] In some implementations, the skin-contact surface is at least partially defined by a rounded edge portion that convexly curves toward the surface facing the trimming element. The convex curvature of the rounded edge portion can help enhance comfort when a user moves the hair guide element across the skin. This is because the convex curvature helps reduce or eliminate the scratching sensation that a user might otherwise experience if the hair guide element did not include such a convexly curved rounded edge portion.

[0037] In some implementations, the radius of curvature of the rounded edge portion is at least 30 μm, for example, at least 50 μm. This minimum radius of curvature can provide the user with particularly enhanced comfort when the hair guiding element is moved across the user's skin.

[0038] According to a second aspect of this disclosure, a hair trimming assembly is provided, comprising: a hair guiding element according to any embodiment of the embodiments described herein; and a trimming element arranged to face the surface facing the trimming element.

[0039] For example, the surface facing the trimming element can contact the trimming element, but the hair guiding surface does not contact the trimming element.

[0040] The trimming element may include multiple trimming sections with a gap between each pair of adjacent trimming sections. Hair can be trimmed between a first edge of the trimming section and a second edge of a section belonging to the teeth of the hair guiding element on the surface facing the trimming element.

[0041] In some implementations, the first edge of the trimming portion is sharper than the second edge of the portion facing the surface of the trimming element.

[0042] According to a third aspect of this disclosure, an electric razor is provided, comprising: a hair trimming assembly according to any embodiment of the embodiments described herein; and a motorized drive system for moving the trimming element.

[0043] The motorized drive system enables the trimming element to move reciprocally along an axis parallel to the main axis of the hair guide element on the surface facing the trimming element.

[0044] This movement allows the hair to be trimmed between the trimming element and the hair guiding element.

[0045] In some embodiments, the hair trimming component is arranged in the razor head of the electric razor adjacent to at least one other hair trimming component.

[0046] For example, a hair trimming component is arranged in the razor head of an electric razor adjacent to at least one additional hair trimming component, which includes a perforated mesh and a bottom trimmer arranged to trim hair protruding through an opening in the perforated mesh.

[0047] The perforated mesh-bottom trimmer arrangement of other hair trimming components can help trim shorter hair, while the hair trimming components (which include hair guiding elements and trimming elements) can be used to trim longer hair.

[0048] In some implementations, the hair trimming component is arranged between a first additional hair trimming component and a second additional hair trimming component.

[0049] In such embodiments, a first additional hair trimming assembly may include a first perforated mesh and a first bottom trimmer arranged to trim hair protruding through a first opening of the first perforated mesh, and a second additional hair trimming assembly includes a second perforated mesh and a second bottom trimmer arranged to trim hair protruding through a second opening of the second perforated mesh.

[0050] According to a fourth aspect of this disclosure, a method of manufacturing a hair guiding element according to any embodiment of the embodiments described herein is provided, the method comprising etching a metal substrate to form at least a portion of the hair guiding element.

[0051] The hair guiding element can be formed by etching a stainless steel substrate. In other words, the method can include etching such a stainless steel substrate to form at least a portion of the hair guiding element.

[0052] In some embodiments, an etch-resistant material is disposed on a metal substrate to mask the metal substrate, through which holes are defined, wherein the etch-resistant material includes a continuous region extending continuously between and around the holes, wherein etching includes delivering an etchant to the metal substrate through the holes such that discrete recessed regions in the metal substrate are etched beneath the holes, the etch-resistant material is resistant to the etchant, and wherein etching continues until at least some of the discrete recessed regions merge beneath the continuous region of the etch-resistant material to form one or more merged etched regions, and after etching, a portion of the metal substrate remains beneath the one or more merged etched regions.

[0053] In such embodiments, the formation of one or more merged etched regions may, for example, be included in the formation of the hair guiding surface and tip region of the hair guiding element.

[0054] This can provide an advantageous way to implement hair guiding elements using methods that include, for example, a single etching step.

[0055] The metal substrate may have a first thickness before etching, wherein etching continues until the thickness of the metal substrate is reduced such that the metal substrate has one or more second thicknesses below one or more merged etched regions, and the one or more second thicknesses are non-zero but less than the first thickness.

[0056] In some embodiments, etching continues until a portion below one or more merged etched areas comprises a planar region of the etched metal substrate, the planar region being disposed below at least some of the holes in the apertures and below a location where a continuous region of the etch-resistant material extends between at least some of the holes in the apertures.

[0057] In some implementations, the holes may include larger and smaller holes, with the larger hole allowing more etchant to pass through and reach the metal substrate during etching.

[0058] In such embodiments, larger and smaller holes can be arranged, for example, relative to each other, such that the etching provides an inclined profile, such as an inclined planar region that slopes from a lower region of the etched metal substrate to an upper region of the etched metal substrate, in which more metal substrate is removed below the larger hole in the lower region and less metal substrate is removed below the smaller hole in the upper region.

[0059] Providing a sloping profile in this way can be included in the formation of the sloping surface of the hair guiding element.

[0060] In some implementations, one or more unmasked regions are positioned adjacent to the location where the etch-resistant material masks the metal substrate, wherein etching continues until the metal substrate is completely removed by etching beneath one or more unmasked regions, but a portion of the metal substrate remains beneath one or more combined etched regions.

[0061] Therefore, a single etching step can be used to completely etch through the entire thickness of the metal substrate under the unmasked area, but only partially etch the metal substrate at the merged etched area.

[0062] In some implementations, the continuous region is connected to the surrounding region of the etch-resistant material, and when one or more merged etched regions are formed, the continuous region remains connected to the surrounding region after the material is etched.

[0063] The surrounding area can help keep the continuous area in place during etching, thereby reducing the risk of the continuous area being removed during etching and the resulting unintentional over-etching of the metal substrate.

[0064] At least some of the holes can be arranged in an ordered pattern; and / or at least some of the holes can be distributed in an irregular manner.

[0065] In some implementations, the ordered pattern includes an array of holes. The ordered pattern may include, for example, at least one of a rectangular array of holes and a hexagonal array of holes.

[0066] In a hexagonal array, each aperture is spaced a single distance from its six nearest neighbors. Therefore, a hexagonal array can help provide relatively uniform etching in the merged etch region below the hexagonal aperture array.

[0067] In some implementations, the open area of ​​the continuous region is 25% or less, for example, in the range of 0.01% to 25%, such as 1% to 25%, wherein the open area is determined by (i) obtaining a fraction by dividing the total area of ​​the holes by the total area of ​​the etch-resistant material in which the continuous region and the holes are provided, and (ii) multiplying the fraction by 100.

[0068] This maximum aperture ratio of 25% can help minimize the risk of over-etching the metal substrate.

[0069] The method may include removing the etch-resistant material to leave an etched metal substrate including one or more merged etched areas, with a portion of the metal substrate remaining beneath the one or more merged etched areas.

[0070] In some embodiments, etching includes spraying an etchant onto a metal substrate on which an etch-resistant material is disposed. Alternatively or additionally, etching may include moving the metal substrate on which the etch-resistant material is disposed through an etching zone in which an etchant is delivered to the metal substrate.

[0071] The etchant may include at least one selected from ferric chloride solution, copper sulfate solution, nitric acid solution, and picric acid solution. Such etchants are particularly suitable for etching stainless steel.

[0072] In some embodiments, an anti-etching material is disposed on the unetched surface of the metal substrate. For example, the anti-etching material may be disposed on a surface of the metal substrate that has been surface-treated (e.g., cleaned) but has not been etched by a previous etching process. Attached Figure Description

[0073] Figure 1A A perspective view of a hair trimming component based on an example is provided;

[0074] Figure 1B Provided Figure 1A A cross-sectional view of the hair trimming component shown;

[0075] Figure 1C Provided Figure 1A An enlarged cross-sectional view of the hair trimming component shown;

[0076] Figure 1D Provided Figure 1A Another enlarged cross-sectional view of the hair trimming component shown;

[0077] Figure 1E Provides a view from the front of the skin contact surface of the hair guiding element. Figure 1A A plan view of the hair guiding element of the hair trimming assembly shown;

[0078] Figure 2 Provided Figure 1E The first cross-sectional view of the hair guiding element shown;

[0079] Figure 3A Provided Figure 1E An enlarged plan view of a portion of the hair guiding element is shown, wherein the inset provides a perspective view of the hair on the hair guiding surface of the hair guiding element;

[0080] Figure 3B schematically depicted Figure 1E The movement of the hair guiding element on the skin is shown;

[0081] Figure 4A Provided Figure 1E The second cross-sectional view of the hair guiding element shown;

[0082] Figure 4B Provided Figure 4A An enlarged view of a portion of the second cross-sectional view provided in the document;

[0083] Figure 5 copied Figure 4A The second cross-sectional view provided in the image shows hair being guided by the hair guiding surface of the hair guiding element;

[0084] Figure 6 A portion of a hair-guiding element according to another example is shown;

[0085] Figure 7A A portion of a hair guiding element according to an example is shown, wherein a step is defined between the hair guiding surface of the hair guiding element and the surface facing the trimming element;

[0086] Figure 7B Provided Figure 7AAn enlarged view of a portion of the hair guiding element shown;

[0087] Figure 8 copied Figure 7A The second cross-sectional view provided in the image shows hair being guided by the hair guiding surface of the hair guiding element;

[0088] Figure 9 Provided Figure 1E An enlarged plan view of a portion of the hair guiding element is shown, wherein the inset provides a perspective view of the hair between the teeth of the hair guiding element;

[0089] Figure 10 The mesh cover of an electric razor is shown as an example;

[0090] Figure 11A and Figure 11B The process of etching a metal substrate is schematically depicted;

[0091] Figure 12 A schematic cross-sectional view is provided showing the delivery of etchant and the gradual removal of the metal substrate by the etchant.

[0092] Figure 13 A schematic cross-sectional view is provided showing the delivery of etchant to one side of a metal substrate;

[0093] Figure 14 An etch-resistant material (left) arranged on a metal substrate according to an example and the resulting etched metal substrate (right) are schematically depicted.

[0094] Figure 15 An etch-resistant material (left) disposed on a metal substrate according to another example and the resulting etched metal substrate (right) are schematically depicted.

[0095] Figure 16 An etch-resistant material (left) disposed on a metal substrate according to yet another example and the resulting etched metal substrate (right) are schematically depicted.

[0096] Figure 17 A cross-sectional view of a hair trimming component based on an example is provided, wherein the hair guide element of the hair trimming component is manufactured using an etching method;

[0097] Figure 18 An etch-resistant material (left) disposed on a metal substrate according to yet another example and the resulting etched metal substrate (right) are schematically depicted.

[0098] Figure 19 An etch-resistant material disposed on a metal substrate (left) and the resulting etched metal substrate (right) are schematically depicted according to a further example.

[0099] Figure 20 A cross-sectional view of another hair trimming component according to an example is provided, wherein the hair guide element of the hair trimming component is manufactured using an etching method.

[0100] Figure 21 A plan view of an etch-resistant material defining a rectangular aperture array through which an etchant can be delivered to a metal substrate is provided.

[0101] Figure 22 A plan view is provided defining an etch-resistant material for an array of hexagonal apertures through which an etchant can be delivered to a metal substrate;

[0102] Figure 23 A plan view of an etch-resistant material defining irregularly distributed holes through which an etchant can be delivered to a metal substrate; and

[0103] Figure 24 A plan view is provided defining the etch-resistant material through which the etchant can be delivered to the metal substrate. Detailed Implementation

[0104] A hair guiding element for an electric razor is provided. The hair guiding element has a skin contact surface for contacting skin and a trimming element facing surface for facing a trimming element, wherein the trimming element facing surface faces a direction opposite to that of the skin contact surface. The periphery of the hair guiding element provides a toothed profile comprising teeth arranged along the main axis of the hair guiding element, wherein each tooth includes a portion of the skin contact surface and a portion of the trimming element facing surface.

[0105] A hair trimming assembly including a hair guiding element and a trimming element is also provided, as well as an electric razor including such a hair trimming assembly. A method for manufacturing the hair guiding element is also provided.

[0106] Figures 1A to 1D Various views of hair trimming components 10, 16 according to an example are provided. Hair trimming components 10, 16 can be used (e.g., included in) an electric razor. Hair trimming components 10, 16 include hair guiding elements 10 for guiding hair before it is trimmed by the hair trimming components 10, 16.

[0107] Hair guiding element 10 may include a feature for contacting the skin (in) Figures 1A to 1DThe trimming assembly 10, 16 includes a skin contact surface 12 (not visible in the image) and a trimming element-facing surface 14 for facing the trimming element 16, which may be included in the trimming assembly 10, 16 together with the hair guiding element 10. The trimming element-facing surface 14 may face a direction opposite to that of the skin contact surface 12.

[0108] When the hair guiding element 10 and the trimming element 16 are arranged together in the hair trimming assembly 10, 16, the surface 14 facing the trimming element can contact the trimming element 16 in addition to facing the trimming element 16.

[0109] The motor drive system included in the electric razor can move the trimming element 16 on the surface 14 facing the trimming element, for example, when the surface 14 facing the trimming element contacts the trimming element 16, by moving the trimming element in a reciprocating manner along an axis parallel to the main axis MA of the hair guide element 10.

[0110] This movement allows the hair to be trimmed between the trimming element 16 and the hair guiding element 10.

[0111] It should be noted that the hair guiding element 10 can be considered as an outer trimmer, outer blade, or comb, and the trimming element 16 is an inner trimmer or inner blade. Hair can be trimmed between the first edge of the hair guiding element 10 and the second edge of the trimming element 16. For example, the second edge of the trimming element 16 can be sharper than the first edge of the hair guiding element 10, in other words, have a smaller radius of curvature. Alternatively, it is conceivable that the first edge of the hair guiding element 10 is sharper than the second edge of the trimming element 16, in other words, has a smaller radius of curvature.

[0112] like Figure 1C As shown, the skin contact surface 12 can be at least partially defined by a rounded edge portion 17, which is convexly curved toward the surface 14 facing the trimming element.

[0113] When a user moves the hair guide element 10 across their skin, the convex curvature of the rounded edge portion 17 can help enhance comfort. This is because the convex curvature helps reduce or eliminate the scratching sensation that a user might otherwise experience if the hair guide element 10 did not include such a convexly curved rounded edge portion 17.

[0114] The hair guiding element 10 (e.g., a comb) can be formed of any suitable material, such as a metal. Of particular note is an embodiment in which the hair guiding element 10 is made of stainless steel. Alternatively or additionally, the trimming element 16 (e.g., an inner trimmer or inner blade) can be made of a metal, such as stainless steel. Of particular note is an embodiment in which both the hair guiding element 10 and the trimming element 16 are made of stainless steel.

[0115] In some embodiments, the hair guiding element 10 and / or trimming element 16 are formed by etching a stainless steel substrate. The etching process that can be used to manufacture the hair guiding element 10 and / or trimming element 16 is described in detail below.

[0116] refer to Figure 1C and Figure 1D The hair guiding element 10 may include a hair guiding surface 18 on which hair from the skin can be received, so that the hair is guided on the hair guiding surface 18 when the skin contact surface 12 contacts the skin. The hair may be guided along the hair guiding surface 18 toward the surface 14 facing the trimming element, wherein the hair may be trimmed between the hair guiding element 10 and the trimming element 16.

[0117] It should be noted that the difference between the hair guiding surface 18 and the surface 14 facing the trimming element may (at least) be that the surface 14 facing the trimming element can contact the trimming element 16, while the hair guiding surface 18 does not contact the trimming element 16.

[0118] The following describes in more detail an embodiment relating to the design and manufacture of a hair guiding element 10 having such a hair guiding surface 18.

[0119] In some implementation schemes, and in reference to Figure 1A and Figure 1E The hair guiding element 10 has a periphery that provides a toothed profile for the hair guiding element 10, the toothed profile including teeth 20 arranged along the main axis MA of the hair guiding element 10. Hair can be captured and trimmed between the teeth 20 of the hair guiding element 10. It should be noted that in embodiments where the hair guiding element 10 includes such a toothed profile, the hair guiding element 10 can be regarded as a comb.

[0120] Each tooth 20 may include a portion of the skin contact surface 12 and a portion of the surface 14 facing the trimming element. Therefore, and referring to... Figure 1B and Figure 1C The upper surface of the tooth 20 can contact the skin, while the lower surface of the tooth 20 faces and, for example, contacts the trimming element 16.

[0121] It should be noted that, as used in this context, the terms "upper" and "lower" refer to, for example... Figure 1B and Figure 1CThe orientation shown is as follows. For example, when the hair guiding element 10 is used to trim hair below the chin, the skin contact surface 12 faces upward to contact the skin below the chin. This orientation may be appropriate, but it should be understood that the hair guiding element 10, the hair trimming assemblies 10, 16, and the electric razor including the hair trimming assemblies 10, 16 can be oriented in any suitable manner so that the skin contact surface 12 contacts the skin at any given location, thereby enabling the trimming of hair growing from that location.

[0122] The trimming element 16 may include a plurality of trimming portions with a gap between each pair of adjacent trimming portions. Hair can be trimmed between a first edge of the portion belonging to the teeth 20 of the hair guiding element 10 on the surface 14 facing the trimming element and a second edge of the trimming portion.

[0123] In some embodiments, the second edge of the trimmed portion is sharper than the first edge of the portion facing the surface 14 of the trimmed element, in other words, it has a smaller radius of curvature. Alternatively, it is conceivable that the first edge of the portion facing the surface 14 of the trimmed element is sharper than the second edge of the trimmed portion in order to have a smaller radius of curvature.

[0124] The hair guiding element 10 can be mounted in the hair trimming assemblies 10, 16 in any suitable manner. In some embodiments, and referring to… Figure 1A and Figure 1D The connecting element 22 of the hair guide element 10 can connect the hair guide element 10 to the side member 24 of the trimming assembly 10, 16, such as the side member 24 in the form of a side plate. The connecting element 22 supports the hair guide element 10 for mounting it in the hair trimming assembly 10.

[0125] The connection between the connecting element 22 and the side member 24 can be provided using any suitable attachment technique, such as by welding (e.g., laser welding) the connecting element 22 to the side member 24.

[0126] refer to Figure 2 (It provides) Figure 1E The first cross-sectional view (AA) of the hair guiding element 10 shown may indicate that the connecting elements 22 may each include a portion of the skin contact surface 12 and / or may each include a portion of the surface 14 facing the trimming element. In such embodiments, the rounded edge portion 17 may be convexly curved from the portion of the skin contact surface 12 toward the portion facing the surface 14 of the trimming element.

[0127] In some embodiments (not shown), the connecting element 22 includes a portion of the hair guiding surface 18. Alternatively, and as... Figures 1A to 1E and Figure 2As shown, tooth 20 includes a portion of hair guiding surface 18, while connecting element 22 does not include any portion of hair guiding surface 18.

[0128] In some embodiments, the connecting element 22 may be included in a toothed profile such that hair can be received in the space defined between one of the connecting elements 22 and one of the teeth 20 and / or between adjacent connecting elements 22 and between adjacent teeth 20.

[0129] A plurality of connecting elements 22 may be provided to support the hair guiding element 10 at intervals along the main axis. The connecting elements 22 and the teeth 20 may be staggered in a regular or irregular pattern. In some embodiments, two to five teeth in a first set of teeth may be arranged between consecutive connecting elements 22. Similarly, two to five teeth in a second set of teeth may be arranged between consecutive connecting elements 22. Figure 1A and Figure 1E In the specific example shown, the three teeth of the first group and the three teeth of the second group are arranged between consecutive connecting elements 22.

[0130] Alternatively or additionally, the connecting element 22 may be shorter than at least some of the teeth in the gear 20, such that the at least some of the teeth in the gear 20 extend laterally to the main axis MA further than the connecting element 22.

[0131] To identify whether the connecting element 22 is shorter than the tooth 20, the lengths of the connecting element 22 and the tooth 20 can be considered as the distance from the main axis MA to the farthest end of the relevant connecting element 22 or tooth 20 from the main axis MA (on the same side of the main axis MA).

[0132] At least some (optionally all) of the teeth in the first group may have the same length or substantially the same length. At least some (optionally all) of the teeth in the second group may have the same length or substantially the same length. (Here, length is also measured from the main axis to the end of the corresponding tooth.) "Substantially the same length" can be understood as teeth whose lengths differ by no more than 10%.

[0133] Providing teeth of equal length on one or both sides of the main axis MA can help further optimize the use of space in the razor head. This allows individual teeth to be as long as possible while minimizing the overall size of the hair guiding element 10 in the direction transverse to the main axis MA.

[0134] However, in some implementations, some teeth in the set of teeth may have different lengths (i.e., a difference of more than 10%). In particular, some teeth in the first set of teeth may have different lengths, and / or some teeth in the second set of teeth may have different lengths.

[0135] The term "transverse to the main axis MA" can mean that when the hair guiding element 10 is viewed in a plane such that the skin contact surface 12 or the surface 14 facing the trimming element is facing the observer, it is perpendicular to or at least substantially perpendicular to the main axis MA. Figure 1E A plan view is shown in which the skin-contact surface 12 faces the observer. The qualifier "substantially" can refer to a deviation from the vertical direction of up to 10°.

[0136] It is generally important to note that, regarding the main axis MA of the hair guide element 10 (e.g., a comb), the main axis MA can extend from the first end 25A to the second end 25B of the hair guide element 10 along its length (in other words, along its longest dimension).

[0137] The main axis MA can, for example, bisect the hair guiding element 10, such that the main axis MA divides the hair guiding element 10 into a pair of elongated halves of the hair guiding element 10.

[0138] The ends 25A, 25B of the hair guiding element 10 may, for example, be toothless, such that the toothed profile of the hair guiding element 10 extends between the ends 25A, 25B, but is not included in the ends 25A, 25B.

[0139] In at least some embodiments, the tooth 20 includes a first set of teeth extending transversely to the main axis MA in a first direction, and a second set of teeth extending transversely to the main axis MA in a second direction opposite to the first direction. When the hair guiding element 10 moves on the skin in the opposite direction, the first set of teeth and the second set of teeth enable the hair guiding element 10 to guide hair toward the surface 14 facing the trimming element.

[0140] Implicit in the toothed profile of the hair guiding element 10 is that slots 26, 26', 28, 28' separate adjacent teeth 20 from each other along the main axis MA.

[0141] In an embodiment where tooth 20 includes a first set of teeth and a second set of teeth, slots 26, 26', 28, 28' may include slots 26, 28' that separate adjacent teeth of the first set of teeth from each other, and slots 26', 28 that separate adjacent teeth of the second set of teeth from each other.

[0142] Alternatively or additionally, slots 26, 26', 28, 28' may include first slots 26, 26' and second slots 28, 28', which differ from each other (at least) in their length transverse to the main axis MA. Embodiments providing such first and second slots 26, 26', 28, 28' of different lengths in the hair guiding element 10 are described in more detail below.

[0143] In some implementations, and now referenced Figures 1B to 1D, Figure 3A and Figure 3B At least some of the teeth in the teeth 20 (e.g., the teeth in the teeth 20 that extend transversely to the main axis MA beyond the connecting element 22) each include a portion of a hair guiding surface 18 and a tip region 30, which is arranged to receive hair HA thereon as the hair guiding element 10 moves on the skin SK. A portion of the hair guiding surface 18 may extend away from the tip region 30 and toward a portion of the surface 14 facing the trimming element in a direction transverse to the main axis MA, so that the portion of the hair guiding surface 18 can guide the hair HA already received on the tip region 30 toward the portion of the surface 14 facing the trimming element.

[0144] like Figure 3A and Figure 3B As shown, when the hair guiding element 10 moves on the skin SK in the direction indicated by the arrow DR, when the skin contact surface 12 is in contact with the skin SK, the hair HA may move upward (relative to the surface of the skin SK) to the tip region 30 and slide along a portion of the hair guiding surface 18 toward a portion of the surface 14 facing the trimming element.

[0145] Part 18 of the hair guiding surface is in Figure 4A and Figure 4B The middle part is also obvious and needs attention. Figure 4A Provided Figure 1E The second cross-sectional view BB of the hair guiding element 10 shown. Figure 4B An enlarged schematic diagram is provided, showing the tip region 30, etc.

[0146] Users of regular electric shavers may find that, although the shaver's comb moves across the skin SK in areas where hair HA (hypertrophic hair) is present, this hair HA may remain untrimmed. This can cause the user to move the comb across the skin SK in the same area multiple times, potentially causing skin irritation.

[0147] Refer again Figure 3B It has been found that one reason why hair HA remains untrimmed is the angle α of the hair HA relative to the skin SK surface, especially the relatively small angle α relative to the skin SK surface. For example, hair HA on the neck can protrude from the skin surface at an angle α of only about 10°.

[0148] Therefore, and refer to Figure 4B The tooth thickness T1 at the tip region can be less than 250 μm. This tooth thickness T1 is the diameter of the minimum imaginary circle C1, the circumference of which intersects both a portion of the hair guiding surface 18 and a portion of the skin contact surface 12, wherein the plane of the minimum imaginary circle C1 is perpendicular to the principal axis MA. Figure 4BIt should be obvious from the example that using the “minimum imaginary circle” to measure tooth thickness T1 does not require the tip region to have a circular geometry.

[0149] By ensuring that the tooth thickness T1 at the tip region 30 is less than 250 μm, preferably less than 200 μm, it has been found that more hairs HA can be successfully trimmed with fewer passes of the hair guiding element 10 across the skin SK, thereby reducing skin irritation. This is because when the hair HA protrudes from the skin SK surface at an angle of approximately 10° and the length of the hair HA is approximately 1.5 mm (which corresponds to the upper limit of facial hair growth over 3 days (0.5 mm per day), the tooth 20 with a thickness T1 of less than 250 μm at the tip region 30 can enter the approximately 260 μm gap between the hair HA tip and the skin SK surface.

[0150] It is generally important to note that the skin contact surface 12 may have a single plane in which the circumference of the smallest imaginary circle C1, whose diameter defines the tooth thickness T1, intersects the single plane of the skin contact surface 12.

[0151] At least some of the teeth in the teeth 20 (each tooth including a portion of the hair guiding surface 18 and a tip region 30 with a tooth thickness T1 less than 250 μm) may be included in the first group of teeth and the second group of teeth.

[0152] Therefore, when the hair guiding element 10 is moved on the skin SK in each of the opposite directions, the hair lifting and hair guiding properties of the tip region 30 and the hair guiding surface 18 can be exhibited accordingly.

[0153] In some implementation schemes, and in reference to Figure 3A , Figure 3B , Figure 4A , Figure 4B , Figure 5 and Figure 6 At least some of the teeth in the tooth 20 have hair guiding surfaces 18 portions that include sloping surfaces that descend from the tip region 30 toward the surface 14 facing the trimming element as the sloping surfaces extend transversely to the main axis MA. As the sloping surfaces descend toward the surface 14 facing the trimming element, they become further away from the skin contact surface 12.

[0154] Therefore, and refer to Figure 5 The hair HA received on the tip region 30 can slide down the inclined surface toward the surface 14 facing the trimming element in the direction indicated by arrow 31. Separating the hair HA from the skin SK in this way can help to properly orient the hair HA for trimming as it slides down the inclined surface toward the surface 14 facing the trimming element.

[0155] The inclined surface can be considered, for example, as a chamfer for conveying hair HA to a trimming plane defined by the surface 14 facing the trimming element. Thus, after being lifted onto the tip region 30, the hair HA can be conveyed along the inclined surface / chamfer, wherein the hair HA can be trimmed between the hair guide element 10 and the trimming element 16 upon reaching the surface 14 facing the trimming element.

[0156] It should be reiterated that the hair guiding surface 18 may not contact the trimming element 16, and in embodiments where the hair guiding surface 18 includes an inclined surface, the inclined surface may not contact the trimming element 16.

[0157] Alternatively or additionally, at least some of the teeth in the teeth 20 including the inclined surface may extend laterally to the main axis MA beyond the connecting element 22. For example, at least some of the teeth in the teeth 20 including the inclined surface may extend from the side member 24 of the hair trimming assemblies 10, 16, while the end of the connecting element 22 may be flush with the side member 24, or protrude from the side member 24 to a lesser extent than the at least some of the teeth in the teeth 20 including the inclined surface.

[0158] The portion of at least some of the teeth in the tooth 20 that protrudes laterally from the main axis MA beyond the connecting element 22 may include the tip portion 30 and at least a portion of the inclined surface.

[0159] In some implementation schemes, and in reference to Figure 4B The lowest region 32 of the inclined surface is the position where the inclined surface reaches the surface 14 facing the trimming element in a stepless manner. Therefore, the hair HA can slide continuously down the inclined surface to reach the surface 14 facing the trimming element.

[0160] This can facilitate guiding the hair HA to the surface 14 facing the trimming element, especially relative to surfaces such as... Figure 7A , Figure 7B and Figure 8 The embodiment shown requires hair HA to cross the step 36 defined between the portion of the surface 14 facing the trimming element and the lowest region 32 of the inclined surface.

[0161] It should be noted that whether such a step 36 is defined between the portion of the surface 14 facing the trimming element and the lowermost region 32 of the inclined surface may depend on the technique used to create the inclined surface, such as chemical etching, electrochemical etching (ECM), precision (or pulsed) electrochemical machining (PECM), laser removal, and / or wire cutting. Chemical etching methods that can be used to obtain the inclined surface of the hair guiding element 10 are described in detail below.

[0162] In some implementation schemes, and in reference to Figure 4BThe inclined surface has a gradient defined by the fact that the lateral extent L1 of the inclined surface is greater than the height H1 of the inclined surface, wherein the lateral extent L1 extends parallel to the skin contact surface 12 from the tip region 30 to a first point P1 aligned with the lowermost region 32 of the inclined surface, and wherein the height H1 extends perpendicularly to the skin contact surface 12 from the tip region 30 to a second point P2 aligned with the lowermost region 32.

[0163] By making the lateral range L1 greater than the height H1, for example, as shown in the example... Figure 6 Compared to the case where the lateral range L1 in the example shown is equal to or less than the height H1, the inclined surface descends relatively gently from the tip region 30 to the lowest region 32 of the inclined surface.

[0164] This relatively gently sloping surface can help the hairs HA on it slide towards the surface 14 facing the trimming element.

[0165] In some implementations, the lateral range L1 is at least twice the height H1. Alternatively or additionally, the lateral range L1 may be at least 200 μm, while the height H1 may be 100 μm or less.

[0166] In such Figure 7A , Figure 7B and Figure 8 In the embodiment shown where a step 36 is defined between the lowest region 32 of the descending inclined surface and the portion of the surface 14 facing the trimming element, the step 36 can provide a height difference of no more than 50 μm, for example, no more than 40 μm, between the portion of the surface 14 facing the trimming element and the lowest region 32.

[0167] In such implementations, the hair HA can slide down the inclined surface until it reaches step 36, at which point the sliding motion of the hair HA may terminate, but the hair HA can cross step 36, for example by bouncing or rolling from the lowest region 32 of the inclined surface onto the portion of the surface 14 facing the trimming element.

[0168] By limiting the height difference HD to no more than 50 μm, ordinary hair HA that slides down the sloping surface to reach the lowermost region 32 can relatively easily cross the step 36. This is because the height difference HD does not exceed half the average diameter of facial hair HA, in other words, 50 μm.

[0169] In one embodiment, a step 36 is defined between the lowermost region 32 of the descending inclined surface and the portion of the surface 14 facing the trimming element, and reference is made to... Figure 7BThe inclined surface may have a gradient defined by the lateral extent L1 of the inclined surface being greater than the height H1 of the inclined surface, wherein in this case, the lateral extent L1 extends parallel to the skin contact surface 12 from the tip region 30 to a first point P1 aligned with the lowermost region 32 of the inclined surface at the base of the step 36, and wherein the height H1 extends perpendicularly to the skin contact surface 12 from the tip region 30 to a second point P2 aligned with the lowermost region 32. For example, the lateral extent L1 is at least twice the height H1. Alternatively or additionally, the lateral extent L1 may be at least 200 μm, while the height H1 may be 100 μm or less.

[0170] To reiterate, by making the lateral range L1 greater than the height H1, the inclined surface descends relatively gently from the tip region 30 to the lowest region 32 of the inclined surface, thereby facilitating the sliding of the hair HA thereon towards the surface 14 facing the trimming element.

[0171] In an embodiment where the rounded edge portion 17 is convexly curved from the portion of the skin-contact surface 12 toward the portion facing the trimming element surface 14, and now referring to... Figure 4A , Figure 5 , Figure 7A and Figure 8 The rounded edge portion 17 may have a radius of curvature R1 of at least 30 μm, for example, at least 50 μm. This minimum radius of curvature R1 of the rounded edge portion 17 can provide the user with particularly enhanced comfort when the hair guiding element 10 is moved on the user's skin SK.

[0172] The rounded edge portion 17 (e.g., a rounded edge portion 17 having a radius of curvature R1 of at least 30 μm (such as at least 50 μm)) can be arranged around the entire periphery of the hair guiding element 10.

[0173] In some embodiments, the rounded edge portion 17 (e.g., a rounded edge portion 17 having a radius of curvature R1 of at least 30 μm (such as at least 50 μm)) may be included in the tooth 20 and the connecting element 22.

[0174] The radius of curvature R1 of the rounded edge portion 17 (e.g., the rounded edge portion 17 of the tooth 20 and the rounded edge portion 17 of the connecting element 22) can be in the range of 30 μm to 70 μm.

[0175] In some implementation schemes, and in reference to Figure 4A , Figure 4B , Figure 5 , Figure 6 , Figure 7A , Figure 7B and Figure 8Each of the teeth 20 includes an end surface 37 and a rounded edge portion 17 that curves convexly from the portion of the skin contact surface 12 to the end surface 37.

[0176] A portion of the end surface 37 may, for example, intersect with the circumference of the smallest imaginary circle C1 whose diameter defines the tooth thickness T1.

[0177] An additional edge portion 38 may be defined between the end surface 37 and a portion of the hair guiding surface 18. The additional edge portion 38 may, for example, have a radius of curvature R2 of at least 7 μm.

[0178] When the hair guiding element 10 moves on the skin SK, this minimum radius of curvature R2 of the additional edge portion 38 can help minimize or prevent the hair HA from being caught by the additional edge portion 38.

[0179] The radius of curvature R2 of the other edge portion 38 can be, for example, in the range of 7 μm to 13 μm.

[0180] In some embodiments, the radius of curvature R1 of the rounded edge portion 17 is at least 30 μm, and the radius of curvature R2 of the additional edge portion 38 is at least 7 μm.

[0181] For example, the radius of curvature R1 of the rounded edge portion 17 is at least 50 μm, and the radius of curvature R2 of the other edge portion 38 is at least 7 μm. In a non-limiting example, the radius of curvature R1 of the rounded edge portion 17 is in the range of 30 μm to 70 μm, and the radius of curvature R2 of the other edge portion 38 is in the range of 7 μm to 13 μm.

[0182] It should be reiterated that hair HA can be trimmed between the first edge of the hair guiding element 10 and the second edge of the trimming element 16. In some embodiments, the radius of curvature R3 of the first edge of the hair guiding element 10 is at most 3.5 μm, for example, from 1 μm to 3.5 μm.

[0183] The maximum radius of curvature R3 of the first edge can help to trim hair HA against it.

[0184] In some embodiments, the radius of curvature R1 of the rounded edge portion 17 is at least 30 μm, and the radius of curvature R3 of the first edge of the hair guiding element 10 is at most 3.5 μm. For example, the radius of curvature R1 of the rounded edge portion 17 is at least 50 μm, and the radius of curvature R3 of the first edge of the hair guiding element 10 is at most 3.5 μm.

[0185] In some embodiments, the radius of curvature R2 of the additional edge portion 38 is at least 7 μm, and the radius of curvature R3 of the first edge of the hair guiding element 10 is at most 3.5 μm. For example, the radius of curvature R2 of the additional edge portion 38 is in the range of 7 μm to 13 μm, and the radius of curvature R3 of the first edge of the hair guiding element 10 is in the range of 1 μm to 3.5 μm.

[0186] In some embodiments, the radius of curvature R1 of the rounded edge portion 17 is at least 30 μm, the radius of curvature R2 of the other edge portion 38 is at least 7 μm, and the radius of curvature R3 of the first edge of the hair guiding element 10 is at most 3.5 μm. For example, the radius of curvature R1 of the rounded edge portion 17 is at least 50 μm, the radius of curvature R2 of the other edge portion 38 is at least 7 μm, and the radius of curvature R3 of the first edge of the hair guiding element 10 is at most 3.5 μm.

[0187] In a non-limiting example, the radius of curvature R1 of the rounded edge portion 17 is in the range of 30 μm to 70 μm, the radius of curvature R2 of the other edge portion 38 is in the range of 7 μm to 13 μm, and the radius of curvature R3 of the first edge of the hair guiding element 10 is in the range of 1 μm to 3.5 μm.

[0188] In some implementations, and now referenced Figure 9 The slots 26, 26', 28, 28' that separate adjacent teeth 20 from each other along the main axis MA include slot pairs 26, 28; 26', 28', wherein each of the slot pairs 26, 28; 26', 28' includes a longer slot 26; 26' and a shorter slot 28; 28'. The longer slot 26; 26' and the shorter slot 28; 28' in each pair of slots 26, 28; 26', 28' extend along a common slot axis A2; A2' transverse to the main axis MA, wherein one of the longer slot 26; 26' and the shorter slot 28; 28' is defined between adjacent teeth of a first group of teeth, and the other of the longer slot 26; 26' and the shorter slot 28; 28' is defined between adjacent teeth of a second group of teeth.

[0189] In other words, the shorter slot 28; 28' and the longer slot 26; 26' of each of the slot pairs 26, 28; 26' can be arranged back to back, such that the shorter slot 28; 28' receives hair HA in the opposite direction to the direction in which the longer slot 26; 26' receives hair HA.

[0190] When the skin contact surface 12 of the hair guiding element 10 is Figure 9As the hair HA moves across the skin SK in the direction indicated by the middle arrow DR, it can be received in slots 26, 28' and subsequently reach the surface 14 facing the trimming element. Longer slots 26, 26' can provide more opportunities for hair HA (especially longer hair HA) to be received therein, thus contributing to improved trimming efficiency. However, providing two relatively long slots 26, 26' in a back-to-back arrangement may pose a risk of making the width of the hair guiding element 10 excessive, which could reduce the compactness of the razor head of an electric razor including such a hair guiding element 10, and therefore may impair the application of the hair guiding element 10 in relatively narrow areas of the skin SK, such as between the nose and upper lip.

[0191] Therefore, the pair of longer and shorter slots 26, 28; 26', 28' can balance the effective trimming of longer hair HA with the compact design of the hair guiding element 10.

[0192] In some implementations, and still referencing Figure 9 The hair guiding element 10 includes a ridge 39, a first set of teeth extending from the ridge 39 transversely to the main axis MA in a first direction, and a second set of teeth extending from the ridge 39 transversely to the main axis MA in a second direction.

[0193] The ridge 39 may have a zigzag shape such that longer and shorter slots 26, 28' alternate along a first set of teeth, while shorter and longer slots 28, 26' alternate along a second set of teeth. In other words, the ridge may include continuous segments offset from each other in a direction transverse to the main axis.

[0194] In such implementations, a balance can be achieved between effectively trimming longer hairs HA and design compactness along the length of the ridge 39 of the hair guiding element 10.

[0195] exist Figure 9 In the illustrated example, all teeth are supported only by the ridge. Each tooth has a cantilever design, supported by the ridge at one end and unsupported at the other end (away from the ridge). This cantilever design helps the teeth lift hair more effectively, especially relatively flat hair. It is believed that a combination of any two or more of (i) the cantilever tooth, (ii) the hair guiding surface 18, and (iii) the finite tooth thickness T1 at the tip region 30 can provide particularly effective hair lifting.

[0196] It should be noted that the length of each slot 26, 26', 28, 28' can be along the central slot axis A2, which extends transversely to the main axis MA and bisects the slots 26, 26', 28, 28'. A2' is defined with its starting point being the connection area 40, 40', 42, 42' of the adjacent teeth 20 that define the corresponding slots 26, 26', 28, 28', and its ending point being the points 44, 44', 46, 46' located between the end points / end surfaces 37 of the adjacent teeth 20.

[0197] The distance D1 along the central slot axis A2;A2' of each slot 26, 26', 28, 28', between the connecting regions 40, 40', 42, 42' and the point aligned with the termination position of the portion facing the trimming element surface 14, defines the trimming length. Without being bound by theory, it is believed that the trimming length of the slots has a significant impact on the efficiency of trimming long hair. When the skin contact surface 12 of the hair guiding element 10 is... Figure 9 As the hair guide element moves along the skin SK in the direction indicated by the middle arrow DR, the hair HA may initially be trapped under the ridge 39 and pressed against the skin. As the hair guide element continues its movement in the direction indicated by DR, the free end of the hair HA is released from under the ridge 39, and the hair bounces off the skin. Figure 9 As shown, at the point where the hair stands upright, the base of the hair (where it meets the skin) remains positioned between the two portions of the surface 14 facing the trimming element. This means that the hair is properly positioned to be trimmed by the trimming element 16 (e.g., between the trimming element 16 and the hair guide element 10).

[0198] This shows that the length of the slit is related to the maximum length of hair HA that can be trimmed in this manner. This partly explains why a long slit is desirable. If the hair HA is longer than the trimming length (defined by the extent of the surface 14 facing the trimming element), the base of the hair may have already exceeded the reach of the trimming element 16 at the point where the free end of the hair is released from below the ridge 39 and springs vertically, for example, beyond the end of the slit 26'.

[0199] It should be understood that the slots can have various shapes. The opposite sides of each slot (defined by adjacent teeth) can be parallel or can define a tapering width. The width of each slot (e.g., measured parallel to the main axis) can be substantially constant over at least a portion of the slot's length. Alternatively, the width can taper such that the open end of the slot is wider than the opposite closed end of the slot. (This shape may be preferred to facilitate the introduction of hair into the open end of the slot.) Alternatively, in some examples, the width can taper such that the open end of the slot is narrower than the opposite closed end of the slot.

[0200] More generally, this disclosure relates in part to the hair guiding element 10 itself, since the hair guiding element 10 can, in principle, be provided separately from any other component, such as the trimming element 16.

[0201] It is further envisioned that the hair guiding element 10, together with the trimming element 16, is provided in the hair trimming assemblies 10, 16.

[0202] This disclosure also provides an electric razor that includes hair trimming components 10, 16 according to any of the embodiments described herein, and a motor drive system for moving the trimming element 16.

[0203] In some embodiments, hair trimming components 10, 16 are arranged in the razor head of an electric razor adjacent to at least one additional hair trimming component.

[0204] For example, hair trimming components 10, 16 are arranged in the razor head of an electric razor adjacent to at least one additional hair trimming component, which includes, for example... Figure 10 A perforated mesh cover 50 and a bottom trimmer of the type shown, the bottom trimmer being arranged to trim hair HA protruding through the opening 52 of the perforated mesh cover 50.

[0205] The perforated mesh-bottom trimmer arrangement of the additional hair trimming components can help trim shorter hair HA, while the hair trimming components 10, 16 (which include hair guide element 10 and trimming element 16) can be used to trim longer hair HA.

[0206] It should be noted that the perforated mesh 50 can be statically mounted in the razor head, so that the perforated mesh 50 itself is not driven by the motorized drive system. Instead, the undercut can be driven by the motorized drive system, so that the undercut moves relative to the statically mounted perforated mesh 50 to trim hairs HA protruding through the openings 52 of the perforated mesh 50.

[0207] In some embodiments, hair trimming components 10, 16 are arranged between a first additional hair trimming component and a second additional hair trimming component in the razor head.

[0208] In such embodiments, a first additional hair trimming assembly may include a first perforated mesh cover 50 and a first bottom trimmer arranged to trim hair HA protruding through a first opening 52 of the first perforated mesh cover 50, and a second additional hair trimming assembly includes a second perforated mesh cover 50 and a second bottom trimmer arranged to trim hair HA protruding through a second opening 52 of the second perforated mesh cover 50.

[0209] The perforated mesh cover 50 can be formed from any suitable material. In some embodiments, the perforated mesh cover comprises a metallic material, such as stainless steel.

[0210] The hair trimming components 10, 16 and / or other hair trimming components (such as hair guiding element 10, trimming element 16 and / or perforated mesh 50) may be manufactured via a process including etching a metal substrate (such as a stainless steel substrate). Such processes are explained in detail below.

[0211] Figure 11A and 11B Such a metal substrate 100 is schematically depicted (see Figure 11A a) and Figure 11B (a)), for example, a stainless steel substrate, the surface of which may be pretreated (e.g., cleaned) before photoresist layers 102A and 102B are deposited on it (see Figure 11A b) and Figure 11B (b)). Arranging photoresist layers 102A and 102B on the metal substrate 100 may include applying a pre-formed photoresist film (which may be, for example, considered a dry photoresist film) to the metal substrate 100. Alternatively or additionally, arranging the photoresist layers 102A and 102B on the metal substrate 100 may include applying a paint to the metal substrate 100, which dries to form the photoresist layers 102A and 102B.

[0212] In the case of a pre-formed photoresist film, this can be applied to the metal substrate 100 by rolling (e.g., hot rolling) the pre-formed photoresist film onto the metal substrate 100.

[0213] It should be noted that the metal substrate 100 can be a metal plate, in other words, a metal material plate, such as a stainless steel plate.

[0214] In some implementation schemes, and in reference to Figure 11B The arrangement of photoresist layers 102A and 102B on the metal substrate 100 includes the arrangement of a first photoresist layer 102A on a first side of the metal substrate 100 and the arrangement of a second photoresist layer 102B on a second side of the metal substrate 100, the second side being opposite to the first side.

[0215] Etching-resistant materials 104A and 104B can be formed by selectively irradiating photoresist layers 102A and 102B disposed on a metal substrate 100 (see [link]). Figure 11A c) and Figure 11B c) and d) in the text.

[0216] In some implementation schemes, and in reference to Figure 11AThe pattern can be printed onto the photoresist layers 102A and 102B using a direct imager, wherein the photoresist layers 102A and 102B polymerize and thus completely adhere to the surface of the metal substrate 100 within the irradiated area.

[0217] Figure 11B An optical tool, such as a photomask, is shown having optically transmissive regions 106A, 106B and optically opaque regions 108A, 108B. The optically transmissive regions allow light 110A, 110B to reach photoresist layers 102A, 102B and cause the photoresist layers 102A, 102B to polymerize to form an etch-resistant material 104A, 104B. The optically opaque regions block light 110A, 110B from reaching the photoresist layers 102A, 102B so that the underlying photoresist layers 102A, 102B do not polymerize.

[0218] In the subsequent development step, the photoresist layers 102A and 102B can be removed from areas where the photoresist layers 102A and 102B have not yet been irradiated to form the etch-resistant material 104A and 104B (see [reference]). Figure 11A d) and Figure 11B (d)). For example, a solvent that can dissolve the photoresist layer but not the etch-resistant materials 104A and 104B can be applied to remove (in other words, wash away) the photoresist layers 102A and 102B where the etch-resistant materials 104A and 104B have not yet been formed by irradiation of the photoresist layers 102A and 102B. Therefore, after development, a masked region of the metal substrate 100 whose surface is masked by the etch-resistant materials 104A and 104B is provided, and unmasked regions 112A and 112B of the metal substrate 100 where the etch-resistant materials 104A and 104B are not masked are provided.

[0219] During etching, etchants 114A and 114B are delivered to a metal substrate 100 on which anti-etching materials 104A and 104B are disposed (see [reference]). Figure 11A e) and Figure 11B (e)). The anti-etching materials 104A and 104B are resistant to the etchants 114A and 114B, thus protecting the lower layer of the metal substrate 100 from being etched by the etchants 114A and 114B. Simultaneously, etched regions 116A and 116B are formed below the unmasked regions 112A and 112B, where the metal material of the metal substrate 100 is etched away by the etchants 114A and 114B.

[0220] Etching agents 114A and 114B can be delivered to a first side and / or a second side of a metal substrate 100 (on which anti-etching materials 104A and 104B are disposed).

[0221] Etching may include spraying an etchant 114A, 114B onto a metal substrate 100 on which an anti-etching material 104A, 104B is disposed, for example, spraying an etchant 114A, 114B onto a first side and / or a second side of the metal substrate 100.

[0222] Alternatively or additionally, etching may include moving a metal substrate 100 on which anti-etching materials 104A, 104B are disposed through an etching zone in which etchants 114A, 114B are delivered (e.g., sprayed onto) the metal substrate 100.

[0223] In such embodiments, etching can be controlled, for example, by controlling the speed at which the metal substrate 100 moves through the etching zone and / or by adjusting dispensing parameters that determine, for example, how much etchant 114A, 114B is dispensed per unit time. Such dispensing parameters may include, for example, the delivery pressure of the etchant 114A, 114B.

[0224] Any suitable etchant 114A, 114B can be used, as long as it is capable of etching the metallic material (e.g., stainless steel) constituting the metal substrate 100. In some embodiments, etchants 114A, 114B include at least one selected from ferric chloride solution, copper sulfate solution, nitric acid solution, and picric acid solution. Such etchants may be particularly effective when, for example, the metal substrate 100 is a stainless steel substrate.

[0225] After etching, the etching resist materials 104A and 104B can be removed to leave the etched metal substrate 100. For example, the (polymerized) photoresist layers 102A and 102B can be removed and their residues stripped to provide a clean, all-metal surface of the etched metal substrate 100 (see [link to documentation]). Figure 11A f) and Figure 11B f in the middle).

[0226] In embodiments where such etching process is used to manufacture components of hair trimming components 10, 16 and / or other hair trimming components, the etching produced by delivering etchants 114A, 114B to a metal substrate 100 (on which anti-etching materials 104A, 104B are disposed) can at least partially define the geometry of the component, for example, it can define trimming edges included in the component.

[0227] Such parts manufactured in this way can have defined overall geometry, including, for example, overall dimensions and edge geometry, such as trimmed edge geometry.

[0228] It should be noted that the edge geometry (e.g., trimmed edge geometry) can be generated by a combination of the etching process and the pattern of the anti-etching materials 104A, 104B, which may result in defined edge angles, and may also result in defined radii of curvature (or multiple defined radii of curvature) considering the adhesion properties of the anti-etching materials 104A, 104B on the surface of the metal substrate 100.

[0229] The aforementioned radii of curvature R1, R2, and / or R3 can be achieved by controlling the etching process and the pattern of the anti-etching materials 104A and 104B (including their adhesion to the metal substrate 100).

[0230] For example, one method is to use a metal substrate 100 having the same patterned anti-etching materials 104A, 104B on each of the first and second sides of the metal substrate 100, and to perform spray etching toward both sides of the metal substrate 100.

[0231] This can result in defined edge angles (e.g., trimmed edge angles) and defined radii of curvature.

[0232] Figure 12 The outline development during a one-sided etching process of a metal substrate 100 in the form of a metal plate is schematically depicted. In this non-limiting example, a defined trimmed edge geometry is provided on one side of the etched metal substrate 100 (see [reference]). Figure 12 (circle 118 in the image), this side is opposite to the side of the metal substrate 100 to which the etchant 114A is delivered (e.g., sprayed).

[0233] The initially formed etched region 116A (in which the metal material of the metal substrate 100 is etched away by the etchant 114A) is formed below the unmasked region 112A, and some under-etching may also exist below the portion of the anti-etching material 114A disposed between the unmasked regions 112A, such as... Figure 12 The middle arrow 120 indicates this.

[0234] exist Figure 12 In the case shown, the metal material of the metal substrate 100 is eventually completely removed by the etchant 114A below the unmasked area 112A in order to provide a defined trimmed edge geometry 118 adjacent to the location where the metal material is completely removed.

[0235] More generally, refer to Figure 11A f) and Figure 11B Note that etching can remove all metal material from the metal substrate 100 below the unmasked areas 112A and 112B (see f). Figure 11A and Figure 11BIn region 122), and / or the metal material of the metal substrate 100 may be partially removed to reduce the thickness of the metal substrate 100, without completely removing the metal material beneath the unmasked regions 112A, 112B (see [reference]). Figure 11B Partial etched area 124).

[0236] Regarding the partially etched region 124 where the thickness of the metal substrate 100 is reduced rather than the metal material being completely removed, one possibility for obtaining such a partially etched region 124 is to arrange a first anti-etching material 104A on a first side of the metal substrate 100 and a second anti-etching material 104B on a second side of the metal substrate 100. For example... Figure 13 As shown, the unmasked region 112A can expose part of the first side of the metal substrate 100, but the second etch-resistant material 104B forms a closed etch-resistant layer on the second side of the metal substrate 100. In this example, less than half of the metal material can be removed by delivering the etchant 114B only in the direction of the second side with the closed etch-resistant layer, and by partially removing the metal material by relying on the atmosphere of the etchant through contact with the first side of the metal substrate 100 where the unmasked region 112A is provided. However, implementing this partial etched region 124 in this way may not allow for the simultaneous complete removal of metal material from adjacent areas of the metal substrate 100.

[0237] Therefore, it is desirable to provide an etching method that can provide a partially etched region 124 in a more controlled manner, for example, by providing a partially etched region 124 while completely removing the metal material in the region of the metal substrate 100 adjacent to the partially etched region 124.

[0238] Now for reference Figure 14 The etching method according to this disclosure includes providing a metal substrate 100, on which anti-etching materials 104A and 104B are disposed to mask the metal substrate 100, and through which holes 126 are defined by the anti-etching materials 104A and 104B. The anti-etching materials 104A and 104B include continuous regions 128 extending continuously between and around the holes 126.

[0239] Therefore, the holes 126 are separated from each other by continuous regions 128, so that the holes 126 are not connected to each other.

[0240] The etching method includes etching a metal substrate 100, wherein etching includes delivering etchant 114A, 114B to the metal substrate 100 through a hole 126, such that discrete recessed regions in the metal substrate 100 are initially etched below the hole 126. This process is similar to... Figure 12The initial formation of the etched region 116A is shown, but it should be noted that the discrete recessed regions are formed below the holes 126 defined in the continuous regions 128 of the resist materials 104A, 104B, rather than below the unmasked region 112A. Etching continues until at least some of the discrete recessed regions merge below the continuous regions 128 of the resist materials 104A, 104B, such that the continuous regions 128 extend over the metal substrate 100 at a location between the initially formed discrete recessed regions, where the metal material of the metal substrate 100 is removed as the discrete recessed regions merge to form one or more merged etched regions 130. The etching leaves a portion 132 of the metal substrate 100, which remains below the one or more merged etched regions 130.

[0241] Hole 126 provides a way to control the dispensing of etchants 114A and 114B to the metal substrate 100, so that after etching, a portion 132 of the metal substrate 100 remains below the merged etched area 130.

[0242] The portion 132 created in this way can, for example, be included in the formation of the hair guiding surface 18 of the hair guiding element 10.

[0243] The diameter of each hole in the aperture 126 (or, if not circular, the maximum dimension on the corresponding aperture 126) can be in the range of 5 μm to 500 μm. Alternatively or additionally, the spacing between the nearest adjacent apertures 126 can be in the range of 5 μm to 500 μm.

[0244] It should be noted that pore 126 can be considered, for example, as a micropore, such as a micropore whose diameter or maximum size (if not circular) is in the range of 5 μm to 500 μm.

[0245] To avoid any ambiguity, the diameter or maximum dimension refers to the diameter facing a continuous region of 128 (e.g., in a plane). Figures 14 to 16 (As shown on the left side of each figure in the image) Observe the measurement results of the corresponding hole 126 when viewing the metal substrate 100.

[0246] In some embodiments, the aperture ratio of the continuous region 128 is 25% or less, for example, in the range of 0.01% to 25%, such as 1% to 25%, wherein the aperture ratio is determined by (i) obtaining a fraction by dividing the total area of ​​the holes 126 by the total area of ​​the etch-resistant materials 104A, 104B in which the continuous region 128 and the holes 126 are provided, and (ii) multiplying the fraction by 100.

[0247] This maximum aperture ratio of 25% can help minimize the risk of 100% over-etching of the metal substrate.

[0248] For illustration, the resolution limit of the illuminator used for selectively irradiating the photoresist layers 102A and 102B can be 20 μm to 25 μm, resulting in an area of ​​314 μm for each aperture 126 (circular in this non-limiting example). 2 Up to 525μm 2 A 25% aperture ratio corresponds to a 3:1 ratio of the covered area of ​​the continuous region 128 to the uncovered area corresponding to the aperture. Therefore, the area of ​​each aperture 126 is 314 μm. 2 Up to 525μm 2 The minimum total area of ​​the etch-resistant materials 104A and 104B for each hole 126 will be 1256 μm. 2 Up to 2100μm 2 .

[0249] It should be noted that the area of ​​the continuous region 128 used to determine the aperture ratio can be defined by an imaginary boundary corresponding to the shortest line that can be drawn around the outermost hole 126 in the holes 126, where the line intersects the periphery of each hole in the outermost hole 126.

[0250] For example, the aperture 126 can be provided by selectively irradiating the photoresist layers 102A and 102B, for example, by using a photomask so that the photoresist layers 102A and 102B are not irradiated at the points where the aperture 126 is to be provided. Therefore, during development, the photoresist layers 102A and 102B can be removed at these points to provide the aperture 126.

[0251] Once the hole 126 is defined by the anti-etching materials 104A and 104B, the delivery of etchant 114A and 114B through the hole 126 will result in the formation of a merged etch region 130, and after etching, a portion 132 of the metal substrate 100 will remain below the merged etch region 130.

[0252] Regarding the delivery of etchants 114A and 114B, if it is desired to keep the distribution parameters (such as delivery pressure) constant, then if the degree of etching of the metal substrate 100 exceeds the desired degree, for example, if the metal substrate 100 below the hole 126 is unintentionally completely etched through, the speed at which the metal substrate 100 moves through the etched area can be increased. On the other hand, if a greater degree of etching is required to provide a merged etched area 130, the speed at which the metal substrate 100 moves through the etched area can be decreased.

[0253] If it is desired to keep the speed at which the metal substrate 100 moves through the etched area constant, the distribution parameters can be adjusted to provide a merged etched region 130, and a portion 132 of the metal substrate 100 remains below the merged etched region 130. For example, if the metal substrate 100 is etched to a greater extent than desired, such as unintentionally etching the metal substrate 100 completely through the hole 126, the etchant delivery pressure can be reduced. On the other hand, if a greater degree of etching is required to provide the merged etched region 130, the delivery pressure can be increased.

[0254] If it is desirable to keep existing distribution parameters (e.g., delivery pressure) constant and also to maintain the existing speed at which the metal substrate 100 passes through the etched region, the holes 126, such as their diameter or maximum size (e.g., in the range of 5 μm to 500 μm), spacing (e.g., in the range of 5 μm to 500 μm), and / or number, can be adjusted to provide a merged etched region 130, and a portion 132 of the metal substrate 100 remains below the merged etched region 130. For example, if the metal substrate 100 is etched to a greater extent than desired, such as unintentionally etching through the metal substrate 100 completely, the diameter / maximum size of the holes 126 can be reduced. On the other hand, if a greater degree of etching is required to provide a merged etched region 130, the diameter / maximum size of the holes 126 can be increased.

[0255] This can represent the benefit of the etching method according to this disclosure, since adjusting the size, spacing and / or number of the holes 126 can provide a way to achieve an etched metal substrate 100 having a three-dimensional shape associated with portion 132 without having to adjust existing process settings.

[0256] refer to Figures 14 to 16 The metal substrate 100 (e.g., a metal plate) may have a first thickness TH1 before etching. The first thickness TH1 may be, for example, 0.04 mm to 2.5 mm.

[0257] Etching can continue until the thickness of the metal substrate is reduced such that the metal substrate 100 has one or more second thicknesses TH2; TH2A, TH2B below one or more merged etched regions 130, and the one or more second thicknesses TH2; TH2A, TH2B are non-zero but less than the first thickness TH1, for example less than the first thickness TH1 from 0.04 mm to 2.5 mm.

[0258] In some embodiments, etching continues until a portion 132 below one or more merged etched areas 130 includes a planar region of the etched metal substrate 100, which is disposed below at least some of the holes in the holes 126 and below the location where a continuous region 128 of the anti-etching materials 104A, 104B extends between at least some of the holes in the holes 126.

[0259] Figure 14 and Figure 15 This schematically illustrates how the size of hole 126 can affect how much of portion 132 remains after etching. Figure 15 In, and due to Figure 14 Compared to the smaller hole 126 provided for the portion 132, the larger hole 126 results in the removal of more metal substrate 100, thus providing a thinner portion 132. This may be due to the ability to reach... Figure 14 Compared to the amount of etchant in the region of the metal substrate 100 below the smaller hole 126, more etchant 114A and 114B can reach. Figure 15 The area of ​​the metal substrate 100 below the larger hole 126 shown.

[0260] In some implementations, such as Figure 16 As shown, the holes 126 passing through the same continuous region 128 include a larger hole 126A and a smaller hole 126B, wherein during etching, the larger hole 126A allows more etchant 114A, 114B to pass through and reach the metal substrate 100 than the smaller hole 126B.

[0261] In such embodiments, the larger hole 126A and the smaller hole 126B may be arranged, for example, relative to each other, such that the etching provides an inclined profile, such as an inclined planar region, which slopes from the lower region of the etched metal substrate 100 to the upper region of the etched metal substrate 100, in which more metal substrate 100 is removed below the larger hole 126A in the lower region, and less metal substrate 100 is removed below the smaller hole 126B in the upper region.

[0262] For example, this inclined profile can be achieved by gradually changing the size of the hole 126, such that a hole 126C of intermediate size, between the larger hole 126A and the smaller hole 126B, is arranged between the larger hole 126A and the smaller hole 126B.

[0263] It should be noted that the implied aspect of the slanted profile is that the etched metal substrate 100 has multiple second thicknesses TH2A and TH2B, of which only two of the second thicknesses are within the... Figure 16 The middle part is represented by a double-headed arrow.

[0264] refer to Figure 17 The inclined profile provided by the larger hole 126A and the smaller hole 126B can be included in the formation of the inclined surface of the hair guiding surface 18 of the hair guiding element 10. In addition, the size of the hole 126 (especially the larger hole 126A in the case of forming an inclined surface) can help control the etching so that the desired tooth thickness T1 is obtained at the tip region 30.

[0265] It should be noted that the etching method according to this disclosure can achieve inclined profiles, such as chamfered geometries, wherein the length of the inclined profile is longer than half the thickness TH1 of the metal substrate 100. Therefore, for example, an etching method can be used to obtain an inclined surface whose lateral extent L1 is greater than its height H1 (e.g., at least twice its height H1). To reiterate, the lateral extent L1 can be, for example, at least 200 μm, while the height H1 can be 100 μm or less.

[0266] In some implementation schemes, and again refer to Figures 14 to 16 One or more unmasked regions 112A, 112B are positioned adjacent to the location of the metal substrate 100 masked by the etch-resistant materials 104A, 104B, wherein etching continues until the metal substrate 100 is completely removed by etching under one or more unmasked regions 112A, 112B, but a portion 132 of the metal substrate 100 remains under one or more merged etched regions 130.

[0267] Therefore, a single etching step can be used to completely etch through the entire thickness of the metal substrate 100 under the unmasked regions 112A, 112B, but only partially etch the metal substrate 100 at the merged etching region 130.

[0268] This single etching step may mean, for example, that etching-resistant materials 104A and 104B can be disposed on the (currently) unetched surface of the metal substrate 100 (e.g., a metal plate). For example, etching-resistant materials 104A and 104B can be disposed on the surface of the metal substrate 100 (e.g., a metal plate) that has been surface-treated (e.g., cleaned) but has not been etched by the previous etching process.

[0269] Alternatively or additionally, the etching method may also include removing the etch-resistant materials 104A, 104B after etching to leave an etched metal substrate 100 including one or more merged etched regions 130, and a portion 132 of the metal substrate 100 remains below the one or more merged etched regions 130.

[0270] Still referencing Figures 14 to 16The continuous region 128 of the etch-resistant materials 104A and 104B can be connected to the peripheral region 134 of the etch-resistant materials 104A and 104B, and after etching, the continuous region 128 remains connected to the peripheral region 134 to form one or more merged etched regions 130. The peripheral region 134 may, for example, be without holes.

[0271] The peripheral region 134 can help keep the continuous region 128 in place during etching, thereby reducing the risk of the continuous region 128 being removed during etching and the resulting unintentional over-etching of the metal substrate 100.

[0272] When the metal substrate 100 is viewed in a plane facing the continuous region 128 of the etch-resistant materials 104A and 104B, the continuous region 128 may be in the form of a tongue-shaped protrusion that protrudes relative to the surrounding region 134.

[0273] Since the etchants 114A and 114B are delivered through the hole 126, the delivery direction of the etchants 114A and 114B can be toward one side of the metal substrate 100 where the continuous region 128 on which the anti-etching material 104A and 104B is disposed.

[0274] Etching agent 114B can be delivered only towards one side of the metal substrate 100, such as... Figure 18 As shown, etchants 114A and 114B can be delivered toward both sides of the metal substrate 100, such as... Figure 19 As shown.

[0275] The ability to spray etch evenly from both sides of a metal substrate 100 (e.g., a metal plate) can provide, for example, the desired trimmed edge geometry, but still allow for the formation of a three-dimensional shape associated with the portion 132 of the metal substrate 100 that remains after etching.

[0276] When the etchant 114B is delivered only toward one side of the metal substrate 100, the continuous region 128 (defining hole 126) can be arranged on the side of the metal substrate 100 to which the etchant 114B is delivered.

[0277] In such embodiments, the anti-etching materials 104A, 104B may still include a (first) anti-etching material 104A disposed on one side of the metal substrate 100, which is opposite to one side of the metal substrate 100 to which the etchant 114B is guided.

[0278] The advantage of delivering (e.g., spraying) etchants 114A and 114B to only one side of the metal substrate 100 in this manner is that different radii of curvature (and different trimming angles when manufacturing the blades) can be obtained compared to delivering etchants 114A and 114B to both sides of the metal substrate 100.

[0279] More generally, in embodiments in which the etch-resistant materials 104A and 104B include a first etch-resistant material 104A disposed to mask a first side of the metal substrate 100 and a second etch-resistant material 104B disposed to mask a second side of the metal substrate 100 (wherein the second side faces away from the first side), the first etch-resistant material 104A may include a continuous region 128 surrounding the holes 126 and extending between these holes, and the second etch-resistant material 104B may include an additional continuous region defining additional holes.

[0280] Additional continuous regions may, for example, extend around other holes and between other holes.

[0281] In implementations employing continuous region 128 and other continuous regions, such as Figure 19 As shown, after etching, a portion of the metal substrate 100 in which one or more merged etched regions 130 are formed is sandwiched between a continuous region 128 and another continuous region.

[0282] In some implementations, such as Figure 19 As shown, one or more unmasked regions 112A are configured to be adjacent to the position where the first etch-resistant material 104A is arranged to mask the first side of the metal substrate 100, and / or one or more (additional) unmasked regions 112B are configured to be adjacent to the position where the second etch-resistant material 104B is arranged to mask the second side of the metal substrate 100.

[0283] For example, at least one of one or more (other) unmasked areas 112B is aligned with one of one or more unmasked areas 112A.

[0284] This can help to completely etch through the entire thickness of the metal substrate 100 between the aligned unmasked area 112A and (another) unmasked area 112B.

[0285] Now for reference Figure 20 The continuous region 128 defining the hole 126 enables the formation of a hair guiding element 10 including the hair guiding surface 18 and the tip region 30 as described above, while the additional continuous region defining the additional hole enables the formation of a recessed portion 136 of the skin contact surface 12 of the hair guiding element 10.

[0286] As in Figures 14 to 16 , Figure 21 , Figure 22 and Figure 24 In the illustrated embodiment, at least some of the holes in hole 126 may be arranged in an ordered pattern. Alternatively or additionally, such as Figure 23In the illustrated embodiment, at least some of the holes in hole 126 may be distributed in an irregular manner.

[0287] In some embodiments, the ordered pattern includes an array of 126 holes. The ordered pattern may include, for example, a rectangular array of 126 holes (see...). Figure 21 ) and hexagonal aperture array (see Figure 22 At least one of them.

[0288] In a hexagonal array, and with reference Figure 22 Each aperture 126 is spaced a single distance SP1 from its six nearest neighboring apertures. Therefore, the hexagonal array can help to provide relatively uniform etching in the merged etch region 130 below the array of hexagonal apertures 126.

[0289] In comparison, and referencing Figure 21 In a rectangular array, there may be a first nearest neighbor distance SP2 between a given hole 126 and four of the eight holes 126 surrounding the given hole 126 in the rectangular array, and there may be a second distance SP3 greater than the first nearest neighbor distance SP2 between a given hole 126 and the other four of the eight holes 126 surrounding the given hole 126 in the rectangular array.

[0290] It should be noted that Figure 24 An ordered array of holes 126 is shown, the size of which gradually changes, such that intermediate-sized holes 126C1, 126C2, 126C3 are arranged between larger holes 126A and smaller holes 126B.

[0291] For example, intermediate-sized holes 126C1, 126C2, and 126C3 may include a maximum intermediate-sized hole 126C1, a minimum intermediate-sized hole 126C3, and a medium-sized hole 126C2, the size of which is between the size of the maximum intermediate-sized hole 126C1 and the minimum intermediate-sized hole 126C3.

[0292] More generally, this disclosure provides a method of manufacturing a mesh 50, comb, or blade 10, 16 for an electric razor, wherein the method includes performing an etching method according to any embodiment of the embodiments described herein to provide an etched article having one or more merged etched regions 130, and a portion 132 of a metal substrate 100 remaining beneath the one or more merged etched regions 130. The etched article may define the mesh 50, comb, or blade 10, 16, or the mesh 50, comb, or blade 10, 16 may be formed by subjecting the etched article to one or more post-processing performed after etching.

[0293] It should be noted that the term "blade" can, in principle, encompass both the mesh 50 and the hair guiding element 10 (e.g., a comb), because the mesh 50 and the hair guiding element 10 can interact with the undercutter or trimming element 16 to trim hair HA between the mesh 50 / hair guiding element 10 and the undercutter / trimming element 16. The term "blade" can also encompass both the undercutter and the trimming element 16.

[0294] One or more post-processing steps may include, for example, polishing the etched article and / or subjecting the etched article to precision (or pulsed) electrochemical machining (PECM).

[0295] However, the advantage of the etching method described herein is that it may be possible to generate a three-dimensional shape in which only a portion of the metal material of the metal substrate 100 is removed without additional process steps (such as additional process steps including PECM).

[0296] Regarding the perforated mesh cover 50, the etching method described herein, particularly the portion 132 retained after etching, can additionally provide the three-dimensional geometry of the perforated mesh cover 50 beyond the opening 52. The perforated mesh cover 50 can be made of, for example, stainless steel and etched using the etching method described herein.

[0297] It should be reiterated that the etching method described herein can generate the three-dimensional shape of the etched metal substrate 100 because the portion 132 remains below the merged etched region 130 after etching, for example, so that only one sequence of masking, irradiation and etching with photoresist layers 102A, 102B is required, instead of performing multiple such sequences.

[0298] Three-dimensional shapes can, for example, serve to reduce friction, create defined geometries to improve hair delivery, lifting, sliding, etc., in components of an electric shaver such as hair guiding elements 10 (e.g., combs), trimming elements 16, and / or perforated mesh 50.

[0299] 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 the stated value and the range surrounding its functional equivalent. For example, a dimension disclosed as “40 mm” is intended to represent “approximately 40 mm”.

[0300] Unless expressly excluded or otherwise limited, every reference cited herein, including any cross-references or related patents or patent applications, and any patent application or patent claiming priority to or benefiting from it, is incorporated herein by reference in its entirety. Reference to any reference 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 referenced documents, the meaning or definition given to that term in this invention shall prevail.

[0301] While specific embodiments of the invention have been illustrated and described, it will be apparent to those skilled in the art that numerous 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. No reference numerals in the claims should be construed as limiting the scope.

Claims

1. A hair guiding element (10) for an electric shaver, the hair guiding element comprising: Skin contact surface (12) for contact with skin (SK); A surface (14) for facing the trimming element (16), wherein the surface facing the trimming element faces a direction opposite to the direction facing the skin contact surface; Hair guiding surface (18), on which hair (HA) from the skin can be received, so as to guide the hair on the hair guiding surface when the skin contact surface comes into contact with the skin; as well as The toothed profile includes teeth (20) arranged along the main axis (MA) of the hair guiding element, wherein each tooth includes a portion of the skin contact surface and a portion of the surface facing the trimming element. At least some of the teeth each include a portion of the hair guiding surface and a tip region (30), the tip region being arranged to receive the hair thereon as the hair guiding element moves on the skin, wherein the portion of the hair guiding surface extends away from the tip region and toward the portion of the surface facing the trimming element in a direction transverse to the main axis, so that the portion of the hair guiding surface can guide the hair already received on the tip region toward the portion of the surface facing the trimming element, and The tooth thickness (T1) at the tip region is less than 250 μm, the tooth thickness is the diameter of the minimum imaginary circle (C1), the circumference of the minimum imaginary circle intersects both the portion of the hair guiding surface and the portion of the skin contact surface, and the plane of the minimum imaginary circle is perpendicular to the principal axis.

2. The hair guiding element (10) according to claim 1, wherein a portion of the hair guiding surface (18) of at least some of the teeth (20) includes an inclined surface that descends from the tip region (30) toward the portion of the surface (14) facing the trimming element as the inclined surface descends toward the portion of the surface facing the trimming element, and simultaneously becomes further away from the skin contact surface (12) as the inclined surface descends toward the portion of the surface facing the trimming element.

3. The hair guiding element (10) according to claim 2, wherein a step (36) is defined between the lowest region (32) of the descending inclined surface and the portion of the surface (14) facing the trimming element, wherein the step provides a height difference (HD) of no more than 50 μm between the portion of the surface facing the trimming element and the lowest region.

4. The hair guiding element (10) according to claim 3, wherein the inclined surface has a gradient defined by the lateral extent (L1) of the inclined surface being greater than the height (H1) of the inclined surface, wherein the lateral extent extends parallel to the skin contact surface (12) from the tip region (30) to a first point (P1) aligned with the lowermost region (32) of the inclined surface at the base of the step (36), and wherein the height extends perpendicular to the skin contact surface from the tip region to a second point (P2) aligned with the lowermost region; optionally wherein the lateral extent is at least twice the height.

5. The hair guiding element (10) according to claim 2, wherein the lowermost region (32) of the inclined surface is the position where the inclined surface reaches the surface (14) facing the trimming element in a stepless manner.

6. The hair guiding element (10) according to claim 5, wherein the inclined surface has a gradient defined by the lateral extent (L1) of the inclined surface being greater than the height (H1) of the inclined surface, wherein the lateral extent extends parallel to the skin contact surface (12) from the tip region (30) to a first point (P1) aligned with the lowermost region (32) of the inclined surface, and wherein the height extends perpendicular to the skin contact surface from the tip region to a second point (P2) aligned with the lowermost region; optionally wherein the lateral extent is at least twice the height.

7. The hair guiding element (10) according to any one of claims 1 to 6, wherein the teeth (20) include a first set of teeth extending transversely to the main axis (MA) of the hair guiding element in a first direction, and a second set of teeth extending transversely to the main axis of the hair guiding element in a second direction opposite to the first direction.

8. The hair guiding element (10) of claim 7, wherein slots (26, 26', 28, 28') separate adjacent teeth (20) from each other along the main axis (MA) of the hair guiding element, wherein the slots comprise slot pairs (26, 28; 26', 28'), wherein each of the slot pairs comprises a longer slot (26; 26') and a shorter slot (28; 28'), wherein the longer slot and the shorter slot in each pair extend along a common slot axis (A2; A2') transverse to the main axis, wherein one of the longer slot and the shorter slot is defined between adjacent teeth of the first set of teeth, and the other of the longer slot and the shorter slot is defined between adjacent teeth of the second set of teeth.

9. The hair guiding element (10) according to claim 7 or claim 8, the hair guiding element comprising a ridge (39), a first set of teeth extending from the ridge transverse to the main axis (MA) in a first direction, and a second set of teeth extending from the ridge transverse to the main axis in a second direction, wherein the ridge has a zigzag shape such that longer and shorter slots (26, 28') alternate along the first set of teeth, while shorter and longer slots (28, 26') alternate along the second set of teeth.

10. The hair guiding element (10) according to any one of claims 1 to 9, wherein the skin contact surface (12) is at least partially defined by a rounded edge portion (13) which is convexly curved toward the surface (14) facing the trimming element.

11. The hair guiding element (10) according to claim 10, wherein the rounded edge portion (13) has a radius of curvature (R1) of at least 30 μm.

12. A hair trimming assembly (10, 16), the hair trimming assembly comprising: Hair guiding element (10) according to any one of claims 1 to 11; as well as Trimming element (16), the trimming element being arranged to face the surface (14) facing the trimming element.

13. An electric razor, said electric razor include: The hair trimming assembly (10, 16) according to claim 12; and A motor drive system for moving the trimming element (16).

14. A method of manufacturing a hair guiding element (10) according to any one of claims 1 to 11, the method comprising etching a metal substrate (100) to form at least a portion of the hair guiding element.

15. The method of claim 14, wherein an anti-etching material (104A, 104B) is disposed on the metal substrate (100) to mask the metal substrate, defining an aperture (126) through the anti-etching material, wherein the anti-etching material includes a continuous region (128) extending continuously between and around the aperture, wherein the etching includes delivering an etchant (114A, 114B) to the metal substrate through the aperture, such that discrete recessed regions in the metal substrate are etched below the aperture, the anti-etching material being resistant to the etchant, wherein the etching continues until at least some of the discrete recessed regions merge below the continuous region of the anti-etching material to form one or more merged etched regions (130), a portion (132) of the metal substrate remains below the one or more merged etched regions after the etching, and wherein the formation of the one or more merged etched regions is included in the formation of the hair guiding surface (18) and the tip region (30) of the hair guiding element (10).

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