Blade set, cutting unit and hair cutting appliance
The blade set for hair cutting appliances enhances cutting efficiency by incorporating inclined inner cutting slots and a dual-action design, addressing inefficiencies and skin irritation issues in conventional designs.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- KONINKLIJKE PHILIPS NV
- Filing Date
- 2025-12-17
- Publication Date
- 2026-06-25
AI Technical Summary
Conventional hair cutting appliances often fail to effectively process all hairs during shaving or trimming, leading to inefficiencies and increased time requirements, with a risk of skin irritation due to missed hairs.
A blade set with a guard blade and cutter blade configuration featuring coplanar outer and inner cutting zones, where the inner cutting slots are inclined relative to the outer slots, increasing the likelihood of catching missed hairs, and a dual-action design for enhanced cutting performance.
The blade set design reduces shaving time, ensures a closer shave, and minimizes skin irritation by effectively processing hairs in a single stroke, while maintaining structural integrity and ease of manufacturing.
Smart Images
Figure EP2025087853_25062026_PF_FP_ABST
Abstract
Description
[0001] BLADE SET, CUTTING UNIT AND HAIR CUTTING APPLIANCE
[0002] FIELD OF THE INVENTION
[0003] The present disclosure relates to a blade set for an electrically operated hair cutting appliance, a cutting unit, and to a hair cutting appliance.
[0004] BACKGROUND OF THE INVENTION
[0005] Hair cutting appliances are generally known in the art and may involve trimming appliances, shaving appliances, and combined (dual-purpose or multi-purpose) appliances. Electrically operated hair cutting appliances comprise a motor that is configured to actuate a blade set, for instance by setting a movable blade into relative reciprocating movement relative to a guard blade. Hence, hair can be cut between cutting edges of the blades of the blade set in a shearing or scissor-like action.
[0006] When used for shaving purposes, the blade set contacts the skin to cut hair directly at the skin. When used for trimming, the hair cutting appliance is typically equipped with a so-called spacing comb that is arranged to space away the blade set of the hair cutting appliance from the skin. Other operation modes can be envisaged, such as beard / hair styling and the like.
[0007] WO 2023 / 285546 Al discloses a blade set for a hair cutting appliance comprising a guard blade and a cutter blade, wherein the blade set has two opposite ends, where comb-like outer cutting teeth are formed at the guard blade and the cutter blade, and an inner section having a curved shape, wherein in the inner section multiple cutting perforations are formed at the guard blade, wherein a series of elongated slots with cutting edges is formed at the cutter blade, wherein the cutting edges are adapted to the curved shape of the inner section, and wherein each of the cutting edges has a length that covers a plurality of cutting perforations of the guard blade.
[0008] US 2021 / 347071 Al relates to a cutter system for an electric shaver and trimmer, comprising a pair of cooperating cutting elements with two rows of comb-like cutting teeth at opposite edges thereof and cutting perforations between said rows of comb-like cutting teeth, wherein said cutting elements are movably supported relative to each other by a support structure. The cutting perforations are arranged in two separated elongated fields of perforations which are separated from each other by an elongated unperforated center section of an outer one of said cutting elements defining a skin contact surface, and which include each at least two rows of perforations extending along the rows of comb-like cutting teeth.
[0009] WO 2015 / 158571 Al discloses a blade set for a hair cutting appliance, the blade set having an integrally formed metal-plastic composite stationary blade that has a first wall portion and a second wall portion, such that a moveable cutter blade can be received in a guide slot formed therebetween. The first wall portion is a skin-facing portion that is at least partially made from metal material, and the second wall portion is at least partially made from plastic material. With this approach, it is possible to provide a stationary blade having a significantly thin first wall portion, which results in great shaving performance, and at the same time a considerable stiffness, due to the second wall portion that acts as a reinforcement that strengthens that stationary blade. WO 2016 / 042158 Al discloses a similar manufacturing concept. WO 2015 / 158571 Al also discloses an embodiment, wherein at the second wall portion of the stationary blade two contact ridges are formed that define the height of the guide slot for the cutter blade in a region adjoining the comb-like cutting teeth of the blade set.
[0010] WO 2015 / 074882 Al discloses a cutting unit for a hair cutting appliance that has a considerable contour following capacity when in operation for cutting hair. To this end, the blade set of the cutting unit is connected with a housing of the appliance through a contour-following mechanism formed as a swivel mechanism that comprises a four-bar linkage and a biasing element acting thereon to urge the four-bar linkage into a defined position. The four-bar linkage may include one or more living hinges. WO 2023 / 275143 Al discloses a similar contour following arrangement that adds a further degree of freedom due to a flexible design of involved couplings.
[0011] WO 2015 / 074853 Al discloses a mounting interface between a cutting unit and a housing of a hair cutting appliance. In certain embodiments, the cutting unit comprises a connector plug that can be releasably inserted into a corresponding receiving socket at the housing. In some embodiments, the cutting unit is a consumable that can be replaced periodically.
[0012] With hair cutting appliances, cutting performance is a major characteristic. Increasing cutting performance can reduce the time that is necessary to bring about a proper haircut or a clean shave. Reducing the number of strokes required to process an area may also reduce the risk of skin irritations.
[0013] It has been observed that with conventional blade sets, there is a certain likelihood that some of the hairs encountering the blade set in a shaving or trimming stroke are omitted rather than effectively processed by the appliance. This may be the case when a hair does not encounter a cutting slot but is rather bent down by a blunt portion, e.g. a blunt tip of a prong (tooth) of the comb-like cutting zone.
[0014] SUMMARY OF THE INVENTION
[0015] It is an object of the present disclosure to provide a blade set for a hair cutting appliance that may increase the efficiency and performance of the hair cutting appliance in a cutting operation. Preferably, the blade set enables a reduction of the time that is necessary to carry out the hair cutting operation. Preferably, the blade set enables a smooth and complete shave or haircut without numerous of the hairs being omitted during the shaving or hair cutting operation. Preferably, the blade set provides a good compromise between cutting performance and skin safety. Preferably, the blade set is particularly suitable for shaving relatively short stubbles, at least in certain embodiments.
[0016] It is a further object of the present disclosure to provide a hair cutting appliance that is equipped or can be equipped with a respective blade set. Further, it is an object of the present disclosure to present a replacement cutting unit that includes a respective blade set and that can be used to replace a worn-out cutting unit to restore the cutting performance of the appliance.
[0017] In a first aspect of the present disclosure there is presented a blade set for an electrically operated hair cutting appliance, said blade set being arranged to be moved through hair in a moving direction to cut hair, said blade set comprising: a guard blade comprising: a top wall portion and a bottom wall portion at least partially offset from the top wall portion, thereby defining a guide slot, a series of outer cutting slots alternating with corresponding comb-like teeth, and a series of elongated inner cutting slots inwardly offset from the outer cutting slots, a cutter blade slidingly accommodated in the guide slot and comprising: a series of outer cutting slots alternating with corresponding comb-like teeth, and a series of elongated inner cutting slots inwardly offset from the outer cutting slots, wherein the outer cutting slots of the guard blade and the cutter blade together define an outer cutting zone, wherein the inner cutting slots of the guard blade and the cutter blade together define an inner cutting zone, wherein the cutter blade is arranged to be reciprocally moved relative to the guard blade to cut hair therebetween in a scissor action in the outer cutting zone and the inner cutting zone, wherein the outer cutting slots of the guard blade have a main extension direction, wherein the outer cutting zone and the inner cutting zone are coplanar, and wherein the inner cutting slots of the guard blade have a main extension direction that is inclined with respect to the main extension direction of the outer cutting slots.
[0018] This aspect is based on the insight that hair catching performance can be increased by incorporating additional rows of angled slots behind the existing slot geometry of the outermost cutting elements. In this way, shaving time can be reduced, a closer shave is possible. The likelihood of hairs being caught and cut in one stroke can be increased. In particular, hairs that have been missed by the outer cutting zone can still be processed in the inner cutting zone during a particular stroke. In particular, cutting / shaving relatively short hair (stubbles) can benefit from the presented design.
[0019] The outer cutting zone and the inner cutting zone are coplanar at the side of the blade set that typically contacts the skin during shaving. In this way, manufacturing can be simplified. Further, necessary tolerances between the guard blade and the cutter blade can be defined and maintained more easily. As used herein, the coplanar relation between the inner cutting zone and the outer cutting zone relates to a basically planar surface which may however be provided with a pattern, for instance for aesthetic reasons. The coplanar relation between the inner cutting zone and the outer cutting zone excludes a curved or bulged design of the inner cutting zone. Further, with a relatively flat non-curved blade set, defined shaving operations are possible, but also other applications benefit from such design, such as trimming applications (with an attachment comb mounted to the blade set) and / or so-called styling operations (where the blade set is guided at a relatively large angle with respect to the skin). There may be other features formed at the guard blade and / or the cutter blade that are not coplanar. Coplanarity is particularly present in the zones where the cutting action actually takes place.
[0020] In certain embodiments, the elongated inner cutting slots are formed primarily in the top wall portion of the guard blade, in particular in a metal component (e.g., sheet-metal component) that forms part of the top wall portion of the guard blade.
[0021] In an exemplary embodiment, an angle of inclination between the inner cutting slots and the outer cutting slots of the guard blade is in the range from 10° to 60°, preferably in the range from 25° to 50°, more preferably in the range from 30 to 45°.
[0022] In other words, the inner cutting slots are inclined with respect to the outer cutting slots. Generally, the outer cutting slots may have a main extension direction that is basically parallel to the moving direction (longitudinal direction). Hence, the main extension direction of the inner cutting slots is inclined with respect to the moving direction. This increases the likelihood of hairs being caught for cutting.
[0023] In another exemplary embodiment, the inner cutting slots of the guard blade have a length and a width, with the length being at least twice the width, preferably at least three times the width, more preferably at least four times the width. Generally, the inner cutting slots are not formed as circular perforations, but as elongated cutouts, such as elongated slots. With this design, skin damage can be prevented while still more hair can be caught. If the inner cutting slots have an elongated, slender shape, sufficient material can remain on the guard blade, which increases its rigidity.
[0024] In another exemplary embodiment, the series of outer cutting slots and the series of inner cutting slots of the guard blade are parallel to one another. That is, at the macroscopic level, the two series / row a parallel to one another. Hence, during a cutting / shaving stroke a particular hair portion is first processed by the outer cutting slots in the outer cutting zone and later on processed by the inner cutting slots in the inner cutting zone. In this way, a uniform cutting performance across the width of the blade set can be provided.
[0025] In another exemplary embodiment, the outer cutting slots are parallel to one another within the outer cutting zone, and / or the inner cutting slots are parallel to one another within the inner cutting zone. Hence, also on the microscopic level within the outer cutting zone and / or the inner cutting zone, the respective cutting slots are parallel to one another.
[0026] In another exemplary embodiment, the inner cutting slots of the guard blade have two opposing cutting edges, wherein the corresponding cutting slots of the cutter blade have two opposing cutting edges, and wherein a shearing angle defined between cooperating cutting edges of the guard blade and the cutter blade is in the range from 3° to 15°, preferably in the range from 5° to 10°.
[0027] With the shearing angle in these ranges, sufficient cutting performance can be provided. As used herein, the shearing angle is the angle between the cutting edges of two associated cutting slots when they are moved towards one another to cut hair in a shearing action therebetween. Likewise, the shearing angle is the angle between two cooperating cutting edges, one at the guard blade and the other at the cutter blade, that is present when hair is cut in a shearing action between the two cooperating cutting edges.
[0028] If the shearing angle was 0°, then the two opposing cutting edges would shear any hair therebetween at the same time. With the shearing angle being in the indicated ranges, the shearing action can be spread over time, resulting in a smoother and more efficient cutting with reduced force requirements. Likewise, hair pulling can be reduced.
[0029] In another exemplary embodiment, the two opposing cutting edges of the inner cutting slots of the guard blade are parallel to one another, wherein the two opposing cutting edges of the inner cutting slots of the cutter blade are arranged at an inclination angle with respect to one another that is twice the shearing angle. With this design, the inner cutting slots of the guard blade have a relatively narrow shape, resulting in considerable strength of the guard blade as the material is weakened only in a limited area.
[0030] The desirable shearing angle that ensures the cutting performance is thus formed by a V- shaped design of the opposing cutting edges of the inner cutting slots of the cutter blade.
[0031] In another exemplary embodiment, the inner cutting slots of the cutter blade are smaller in width at their outer end that is facing the outer cutting zone than at their opposite inner end. The wider end of the inner cutting slots of the cutter blade is facing a central portion of the cutter blade. The narrow end of the inner cutting slots of the cutter blade is facing the outer cutting slots of the cutter blade.
[0032] In other words, the inner slots of the cutter blade are tapered, while the orientation of the tapering is selected such that the material of the cutter blade is weakened no more than necessary to maintain a considerable strength.
[0033] In another exemplary embodiment, the two opposing cutting edges of the inner cutting slots of the guard blade are parallel to one another, wherein the two opposing cutting edges of the inner cutting slots of the cutter blade are parallel to one another, with the shearing angle formed by an inclination between the main extension directions of the inner cutting slots of the guard blade and the inner cutting slots of the cutter blade. Also with this design, the desirable shearing angle can be achieved.
[0034] In yet another exemplary embodiment, two opposite outer cutting zones are provided at two opposite leading edges that are facing away from one another, wherein the inner cutting zone is arranged therebetween.
[0035] In this way, the blade set is a dual action blade set that can be used to cut / shave hair in a back and forth movement. Cutting performance can thus be further increased. The blade set is suitable for several applications such as shaving, trimming and styling. Further, hard-to-reach body regions can be reached more easily with a dual action blade set that is provided with two leading edges, and an inner cutting zone therebetween.
[0036] In yet another exemplary embodiment, two opposite outer cutting zones are provided at opposite leading edges of the blade set that are facing away from one another, wherein a first inner cutting zone is adjacent to a first outer cutting zone, and wherein a second inner cutting zone is adjacent to a second outer cutting zone. Also in this way, a dual action characteristic is provided, resulting in improved cutting performance. Hard-to-reach body regions can be reached more easily. When each of the leading edges is provided with an outer cutting zone and, inwardly offset therefrom, an inner cutting zone, then the overall cutting performance can be increased.
[0037] In yet another exemplary embodiment, at least the two inner cutting zones are arranged in a mirror-symmetric fashion, in particular with respect to a central plane through the blade set that is parallel to the leading edges and orthogonal to the top wall portion of the guard blade. The mirror- symmetric design ensures uniform performance on both sides of the blade. Further, in view of the inclined orientation of the cutting slots of the inner cutting zone(s), hair that has been missed by the first outer cutting zone and the first inner cutting zone can still be caught by the following second inner cutting zone in one stroke. It is thus beneficial that due to the mirror-symmetric design, the inclination of the cutting slots in the second inner cutting zone is opposite to the inclination of the cutting slots in the first inner cutting zone. This makes it more likely to cut hair that has been missed by the other cutting zones.
[0038] Further, the mirror-symmetric design ensures equivalent cutting performance in either moving direction (of a back and forth movement).
[0039] In yet another exemplary embodiment, as seen in the moving direction, the inner cutting slots of the guard blade cover a width extension of the spacing between two neighboring outer cutting slots of the guard blade. The inner cutting slots are inclined with respect to the outer cutting slots and thus broader when seen in the moving direction.
[0040] Hence, if there is a hair that has been missed by the outer cutting slots, e.g. as it has been bent down by an outer tooth / prong, there is a considerable likelihood that the hair can still be caught by the inclined inner cutting slots that are arranged behind the outer cutting slots. There is a certain likelihood that hair that has escaped the outer cutting zone (e.g. at the prong-like teeth) can be cut in the inner cutting zone. Fewer hairs are rejected in one particular stroke, as there is a lower risk of misalignment.
[0041] In yet another exemplary embodiment, as seen in the moving direction, the inner cutting slots overlap a plurality of comb-like teeth at the outer cutting zone of the guard blade that are each arranged between two outer cutting slots. As used herein, the overlap of the inner cutting slots with respect to the teeth at the outer cutting zone means that the inner cutting slots of the guard blade are arranged and inclined in such a way that during one stroke in the moving direction a hair that has been missed in the outer cutting zone (e.g., as it has been pushed down by a prong -like tooth between two outer cutting slots) encounters an inner cutting slot that is placed right behind the tooth to be there in the inner cutting zone. Hence, there is a certain likelihood that hairs that have been missed in the outer cutting zone can be cut in the inner cutting zone.
[0042] In yet another exemplary embodiment, the inner cutting slots of the guard blade are arranged such that, as seen in the moving direction, an overlap between neighboring inner cutting slots is present. As the inner cutting slots are not strictly parallel to the moving direction, their inclination results in an overlap (seen in the moving direction) within the inner cutting zone by neighboring inner cutting slots. It is thus less likely that a hair that has been missed in the outer cutting zone is also missed in the inner cutting zone, e.g. pushed down by small strips that separate the inner cutting slots. The inclined orientation of the inner cutting slots makes it less possible that a single hair is missed during one straight cutting stroke of the blade set.
[0043] In certain embodiments, the inner cutting slots and the outer cutting slots have a different pitch. In certain embodiments, the inner cutting slots and the outer cutting slots have the same pitch.
[0044] In yet another exemplary embodiment, a motion transmitting element is coupled to the cutter blade in a central portion thereof, wherein the inner cutting zone with the inner cutting slots is offset from the central portion. In accordance with this embodiment, the at least one inner cutting zone does not interfere with the central portion where the motion transmitting element is coupled to the cutter blade.
[0045] In yet another exemplary embodiment, in the outer cutting zone at least some of the comb-like teeth of the guard blade have a top leg at the top wall portion and a bottom leg at the bottom wall portion that are connected at respective tips, with the cutter blade teeth arranged therebetween. In this way, the cutter blade is shielded between the top wall portion and the bottom wall portion of the guard blade.
[0046] In certain embodiments, the guard blade is a metal-plastic composite part, wherein the top wall portion is at least partially made from sheet metal material, and wherein the bottom portion is at least partially made from plastic material. In certain embodiments, the guard blade is an overmolded or insert molded part, where a metal component and a plastic component are bonded by overmolding or insert molding.
[0047] In certain embodiments, the comb-like teeth of the guard blade have a metal component, in particular at the top leg, and a plastic component, in particular at the bottom leg. For user / skin safety purposes, the tips can be primarily made from plastic material. Since the plastic component is generally not present where the cutting action actually takes place, the plastic component may protrude beyond a plane of coplanarity.
[0048] In another aspect of the present disclosure there is presented a replacement cutting unit, comprising: a blade set in accordance with at least one embodiment as described herein, a mounting interface, and preferably a contour following mechanism formed between the guard blade and the mounting interface.
[0049] With such a design, worn out blade sets can be easily replaced to maintain the cutting performance.
[0050] As used herein, the term contour-following relates to a dynamic adaptability of the orientation of the blade set with respect to the skin. This may be brought about by one or more swivel mechanisms that cooperate with one or more biasing elements to alter the orientation of the blade set in response to forces that occur during shaving, etc.
[0051] The contour-following mechanism improves comfort and performance. In certain embodiments, the contour following mechanism includes a four-bar linkage.
[0052] In yet another aspect of the present disclosure there is presented a hair cutting appliance comprising a housing, a motor arranged in the housing, at least one control element accessible at the housing, and a blade in accordance with at least one embodiment as described herein or a cutting unit in accordance with at least one embodiment as described herein. The hair cutting appliance may further comprise a power transmission unit that transmits an output motion of the motor into the desired oscillating reciprocating movement of the cutter blade.
[0053] BRIEF DESCRIPTION OF THE DRAWINGS
[0054] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. In the following drawings
[0055] Fig. 1 shows a perspective view of a hair cutting appliance;
[0056] Fig. 2 shows a partial perspective frontal view of a hair cutting appliance, with a cutting unit thereof shown in a detached state;
[0057] Fig. 3 shows a perspective view of an embodiment of a cutting unit for a hair cutting appliance, the cutting unit comprising a blade set and a contour following mechanism;
[0058] Fig. 4 shows a perspective top view of a blade set for a hair cutting appliance;
[0059] Fig. 5 shows a side view of the arrangement of Fig. 4;
[0060] Fig. 6 shows another perspective top view of the arrangement of Fig. 4, with the guard blade being partially cut away to reveal the cutter blade;
[0061] Fig. 7 shows a perspective bottom view of the blade set of Fig. 4 in an exploded state;
[0062] Fig. 8 shows a top view of the arrangement of Fig. 6;
[0063] Fig. 9 shows a partial detail view based on Fig. 8;
[0064] Fig. 10 shows a schematic partial detail view based on Fig. 9;
[0065] Fig. 11 shows a perspective cross-sectional view of the blade set shown in Fig. 8;
[0066] Fig. 12 shows a cross-sectional side view of the arrangement of Fig. 11 with the view plane extending through outer cutting slots of the guard blade; Fig. 13 shows another cross-sectional side view based on the arrangement of Fig. 12, with the view plane extending through teeth of the guard blade;
[0067] Fig. 14 shows a side view of an embodiment of a guard blade to illustrate two approaches to forming inner protruding contact portions;
[0068] Fig. 15 shows a top view of another embodiment of a blade set with the guard blade thereof being partially cut away to reveal the cutter blade;
[0069] Fig. 16 shows a top view of yet another embodiment of a blade set with the guard blade thereof being partially cut away to reveal the cutter blade; and
[0070] Fig. 17 is based on the arrangement of Fig. 10 and illustrates an alternative embodiment.
[0071] DETAILED DESCRIPTION OF THE EMBODIMENTS
[0072] Fig. 1 shows a perspective view of a hair cutting appliance that is overall designated by 10. The hair cutting appliance 10 includes a housing 12. The housing 12 accommodates components such as a motor 16, a battery 18, operator controls 20 and the like. The appliance 10 may be a battery-powered appliance. Likewise, the appliance 10 may also be mains operated and / or a hybrid appliance 10 that can be used with or without being connected to a power grid.
[0073] Operator controls 20 may involve on / off buttons, capacity indicators for the battery 18 and the like. At a top portion of the housing 12 a processing head is provided. A cutting unit 24 is attached to the housing 12 there. The cutting unit 24 comprises a blade set 26 for cutting hair. When used for shaving, the appliance 10 is moved in a moving direction 30 through hair to cut hair. When used for shaving, the blade set 26 is guided along the skin basically parallel or only with a small inclination with respect to the skin.
[0074] Other orientations (i.e., inclinations) of the blade set 26 with respect to the skin or the hair can be envisaged for other applications, such as styling applications. Furthermore, there may be trimming applications, where an attachment comb is fitted to the appliance 10 that defines the spacing between the skin and the blade set 26 to cut hair at a desired length.
[0075] A coordinate system indicated by 30, 32, 34 in Figs. 1-3 and other Figures shown herein illustrates main directions of the blade set 26. The moving direction 30 may also be referred to as longitudinal direction. Reference numeral 32 illustrates a lateral direction that is orthogonal to the moving direction 30. Reference numeral 34 illustrates a height direction that is orthogonal to both the moving direction 30 and the lateral direction 32. As used herein, the axes 30, 32, 34 generally define the longitudinal, lateral and height extension of the blade set 26.
[0076] The moving direction 30 elucidates the orientation of the blade set 26 that is typically assumed by the blade set 26 during a shaving application. As already explained hereinbefore, for other applications there may be other orientations of the blade set 26 with respect to the skin / hair. The person skilled in the art is capable of applying respective transformations. Furthermore, when a contour following mechanism is implemented, the orientation of the blade set 26 may be dynamically adapted during a hair cutting or shaving operation.
[0077] Fig. 2 shows a simplified view of a cutting unit 26 being detached from a (partially shown) housing 12 of a hair cutting appliance 10. The cutting unit 26 and the housing 12 each have a corresponding mounting interface 36, 38. In the exemplary embodiment, the mounting interface 36, 38 is arranged as a socket (on the part of the housing 12) and plug (on the part of the cutting unit 24) interface. With the mounting interface 36, 38 the cutting unit 24 can be easily replaced.
[0078] Fig. 3 illustrates a simplified perspective view of a cutting unit 24 that is provided with a contour following mechanism 40 enabling a swivel movement (refer to the curved double arrow 42) of the blade set 26 when in operation. In this way, the blade set 26 can be adapted to the skin contour during shaving or hair cutting, which results in a better cutting performance and a closer shave. Further, skin irritations can be reduced as the blade set can be aligned with the skin due to the contour following mechanism 40. The contour following mechanism 40 enables a dynamic adaptation of the orientation of the blade set 26. In certain embodiments, the contour following mechanism comprises a four-bar linkage mechanism enabling pivot movements about instantaneous pivot axes that are parallel to the lateral direction 32. The contour following mechanism 40 may include one or more biasing elements that urge the contour following mechanism 40 into a defined position.
[0079] An exemplary embodiment of the blade set 26 is elucidated hereinafter with reference to Figs. 4-6. In the illustrated embodiment, the blade set 26 has two opposite leading edges 40. That is, the blade set 26 is a dual action blade that can be used in a back and forth movement for cutting hair.
[0080] The blade set 26 comprises a guard blade 46 and a cutter blade 66 (see Fig. 5 and Fig. 6). The guard blade 46 comprises, on each leading edge 40, a plurality of outer cutting slots 48 and, inwardly offset therefrom, a plurality of elongated inner cutting slots 50.
[0081] As can be seen from the side view of Fig. 5, the guard blade 46 comprises a top wall portion 56 and a bottom wall portion 58 that together define a guide slot 60 in which a cutter blade 66 is accommodated, refer also to the perspective view of Fig. 6 with the guard blade 46 being partially cut away. The cutting action is produced by the interaction between the guard blade 46 and the cutter blade 66. Both blades 46, 66 are involved in the cutting action.
[0082] The cutter blade 66 comprises, at each of the leading edges 40, a plurality of outer cutting slots 68 and, inwardly offset therefrom, a plurality of elongated inner cutting slots 70.
[0083] The guard blade 46 may also be referred to as stationary blade. The cutter blade 66 may also be referred to as movable blade. The guard blade 46 is typically the blade that is contacting the skin, at least in a shaving operation. The cutter blade 66 is typically the blade that is set in motion to generate the relative cutting movement between the guard blade 46 and the cutter blade 66.
[0084] At each cutting edge 40, the outer cutting slots 48 of the guard blade 46 and the outer cutting slots 68 of the cutter blade 66 each form a row or series. Together, the outer cutting slots 48 of the guard blade 46 and the outer cutting slots 68 define an outer cutting zone 74. Likewise, the elongated inner cutting slots 50 of the guard blade 46 and the elongated inner cutting slots 70 of the cutter blade 66 each form a row or series. Together, the elongated inner cutting slots 50 of the guard blade 46 and the elongated inner cutting slots 70 of the cutter blade 66 define an inner cutting zone 76 that is inwardly spaced from the outer cutting zone 74. In the embodiment illustrated in Figs. 4-6, the blade set 26 comprises two outer cutting zones 74 and two inner cutting zones 76 inwardly spaced therefrom. A central portion 78 is formed between the two inner cutting zones 76.
[0085] A motion transmitting element 80 (refer also to Fig. 7) is connected to a connection zone 82 of the cutter blade 66 in the central portion 78. The connection zone 82 is adjacent to a central guide recess 86 formed in the cutter blade 66. In the central guide recess 86, a guide element 84 is arranged that guides the reciprocating movement of the cutter blade 66 in the lateral direction 32. The guide element 84 defines the play for the cutter blade 66 in the longitudinal direction 30. The guide element 84 may be regarded as a stationary element as the cutter blade 66 is moved with respect thereto.
[0086] Fig. 5 illustrates that the cutter blade 66 is accommodated in the guide slot 60, whereas the cutter blade 66 is arranged close to or even contacts the top wall portion 56 of the guard blade 46. At the bottom wall portion 58, one or more outer protruding contact portions 88 and one or more inner protruding contact portions 90 are formed that define the play in the height direction (arrow 34 in Fig. 4) for the cutter blade 66 within the guide slot 60.
[0087] Fig. 7 shows a perspective exploded view of the blade set 26. Accordingly, the guard blade 46 is formed by a plastic component 96 (particularly an injection molded plastic component) and a metal component 98 (particularly a sheet metal component) that are bonded / joined to form an arrangement having a top wall portion 56 and a bottom wall portion 58. At the top wall 56, the cutting action takes place, this is why the metal component 98 is provided there. The bottom wall portion 58 strengthens the guard blade 46 and provides skin protection features, mounting features, etc. This is why the plastic component 96 is present at the bottom wall portion 58.
[0088] In the exemplary embodiment, the elongated inner cutting slots 50 are formed in the metal component 98 of the guard blade 26. Generally, the elongated inner cutting slots 50 may be formed primarily in the top wall portion 56 of the guard blade 26.
[0089] The motion transmitting element 80 is arranged as a connector bridge 104 having two ends 106, each of which being coupled to a connecting zone 82 of the cutter blade 66 that is adjacent to the central guide recess 86 and the cutter blade 66. When in use, the guide element 84 is fixed to the guard blade 46 and guides the movement of the cutter blade 66 relative to the guard blade 46.
[0090] Fig. 8 is a top view of the blade set 26 with the guard blade 46 being partially cut away to reveal the cutter blade 66. When in operation, the cutter blade 66 is actuated via the motion transmitting element 80 (refer to Fig. 7) and set into a reciprocating movement in the lateral direction 32 relative to the guard blade 46.
[0091] With the exemplary design of the blade set 26, hair can be cut in both the outer cutting zones 74 and the inner cutting zones 76. As the blade set 26 is moved in the moving direction 30 for shaving, hairs first encounter the outer cutting zone 74 and thereafter the inner cutting zone 76. That is, hairs that have been missed in the outer cutting zone 74 can still be cut in the inner cutting zone 76.
[0092] Fig. 8 also illustrates a mirror-symmetric design of the blade set 26. In the exemplary embodiment, the blade set 26 is mirror-symmetric with respect to a central plane 110 that is perpendicular to the view plane. This applies in particular to the two opposite inner cutting zones 76 with the respective inner cutting slots 50 (on the part of the guard blade 46) and the inner cutting slots 70 (on the part of the cutter blade 66).
[0093] In some embodiments, the inclination of the opposite inner cutting slots 50 is symmetric with respect to the central plane 110. In some embodiments, the inclination of the opposite inner cutting slots 70 is symmetric with respect to the central plane 110. With these embodiments, primarily the inclination, but not necessarily the actual lateral position of the inner cutting slots 50, 70 is symmetric. In other words, the series of inner cutting slots 50, 70 on opposite sides of the central plane 110 may be laterally shifted with respect to one another.
[0094] A hair that is not cut in the (front) outer cutting zone 74 still encounters the following (front) inner cutting zone 76 to be cut there. If that hair is not cut in the (front) inner cutting zone 76, then it will still encounter the (rear) inner cutting zone 76 and finally the (rear) outer cutting zone 74, so the likelihood of the hair being cut in one stroke is much higher.
[0095] Figs. 9 and 10 illustrate enlarged schematic detail views of the arrangement of Fig. 8 to explain the design of the outer cutting slots 48 and the elongated inner cutting slots 50 on the part of the guard blade 46 and the design of the outer cutting slots 68 and the elongated inner cutting slots 70 on the part of the cutter blade 66.
[0096] Fig. 9 shows a detailed view where the guard blade 46 is partially cut away. Fig. 10 shows a partial view in greater detail, where the guard blade 46 overlaps the cutter blade 66.
[0097] The outer cutting slots 48 of the guard blade 46 alternate with comb-like teeth 112. The outer cutting slots 48 have a main extension direction 116. In the exemplary embodiment, the main extension direction 116 is parallel to the (assumed) moving (or: longitudinal) direction 30. The elongated inner cutting slots 50 are inclined with respect to the outer cutting slots 48. The elongated inner cutting slots 50 have a main extension direction 118 that is arranged at an angle 120 with respect to the main extension direction 116 of the outer cutting slots 48. The angle of inclination 120 is in the range from 10° to 60°, preferably in the range from 25° to 50°, more preferably in the range from 30 to 45°.
[0098] Likewise, the outer cutting slots 68 of the cutter blade 66 alternate with comb-like teeth 122. The outer cutting slots 68 have a main extension direction 126. In the exemplary embodiment, the main extension direction 126 is parallel to the (assumed) moving (or: longitudinal) direction 30. The elongated inner cutting slots 70 are inclined with respect to the outer cutting slots 68. The elongated inner cutting slots 70 have a main extension direction 128 that is arranged at an angle 130 with respect to the main extension direction 126 of the outer cutting slots 68. In certain embodiments, the angle of inclination 130 is in the range from 10° to 60°, preferably in the range from 25° to 50°, more preferably in the range from 30 to 45°.
[0099] As a result of the inclination between the cutting slots 50, 70 in the inner cutting zones 76 (see also Fig. 8) and the cutting slots 48, 68 in the outer cutting zones 74, hair that has escaped the outer cutting zones 74 can still be cut in the inner cutting zones 76. In Fig. 9 reference numeral 134 designates a width of a comb-like tooth 112, that is, a width extension of the spacing between two neighboring outer cutting slots 48. A hair that is contacted by the blade set 26 in this particular region during a shaving procedure, can perhaps be bent down instead of being cut in the cutting slots 48. However, as the inner cutting slot 50 has an effective width 136 (as seen in the moving direction 30) due to its inclination, the inner cutting slots 50, so to speak, compensate for the inactive portion (width 134) that is caused by the presence of the teeth 112 between the outer cutting slots 48. A hair that has missed one of the outer cutting slots 48 may still be cut in one of the inner cutting slots 50 arranged therebehind.
[0100] Fig. 10 illustrates by means of a schematic enlarged view an exemplary design of the respective cutting slots 48, 50, 68, 70. The outer cutting slots 48 of the guard blade 46 have two opposite cutting edges 140. The corresponding outer cutting slots 68 of the cutter blade 66 have two opposite cutting edges 142. The cutting edges 140 and the cutting edges 142 are not parallel to one another, rather, a shearing angle 144 is formed between a respective cutting edge 140 of an outer cutting slot 48 and a respective cutting edge 142 of an outer cutting slot 68 when the two cutting edges 140, 142 cooperate to cut hair therebetween. In certain embodiments, the shearing angle 144 is in the range from 3° to 15°, preferably in the range from 5° to 10°.
[0101] In the exemplary embodiment, the cutting edges 140 of the outer cutting slots 48 of the guard blade 46 are basically parallel to one another. As a result, an opening angle 146 between the two opposite cutting edges 142 of the outer cutting slots 68 of the cutter blade 66 is present that is twice the shearing angle 144. This is not to be understood to be limiting.
[0102] In the exemplary embodiment, the outer cutting slots 48 are inwardly tapered, whereas the corresponding comb-like teeth 112 are outwardly tapered.
[0103] The inner cutting slots 50 of the guard blade 46 have two opposite cutting edges 150. The corresponding inner cutting slot 70 of the cutter blade 66 have two opposite cutting edges 152. The cutting edges 150 and the cutting edges 152 are not parallel to one another, rather, a shearing angle 154 is formed between a respective cutting edge 150 of an inner cutting slot 50 and a respective cutting edge 152 of an inner cutting slot 70 when the two cutting edges 150, 152 cooperate to cut hair therebetween. In certain embodiments, the shearing angle 154 is in the range from 3° to 15°, preferably in the range from 5° to 10°.
[0104] In the exemplary embodiment, the cutting edges 150 of the inner cutting slots 50 of the guard blade 46 are basically parallel to one another. As a result, an opening angle 156 between the two opposite cutting edges 152 of the inner cutting slots 70 of the cutter blade 66 is present that is twice the shearing angle 154. This is not to be understood to be limiting. In certain embodiments, the shearing angles 144, 154 that ensure the cutting performance are formed by a V-shaped design of the opposing cutting edges 142, 152 of the outer and inner cutting slots 48, 68 of the cutter blade 66.
[0105] The inner cutting slots 50 of the guard blade 46 have a length 160 and a width 162. In the exemplary embodiment, the length 160 amounts to at least twice the width 162, preferably at least three times the width 162, more preferably at least four times the width 162.
[0106] The inner cutting slots 70 of the cutter blade 66 are adapted to the length 160 and width 162 of the inner cutting slots 50 of the guard blade 46. To provide the desired shearing angle 154, the inner cutting slots 70 are tapered towards the outer cutting slots 48, 68 (i.e., tapered towards the outer cutting zone 74). Consequently, the inner cutting slots 70 have an inner end 166 and an outer end 168. In the exemplary embodiment, the inner cutting slots 70 of the cutter blade 66 are smaller in width at their outer end 168 that is facing the outer cutting zone 74 than at their opposite inner end 166. As a result, as can be seen in Fig. 9, only a moderate weakening of the material of the cutter blade 66 is necessary to provide the inner cutting slots 70. This applies in particular to a transition region between the inner cutting zone 76 and the outer cutting zones 74. The cutter blade 66 is still considerably stiff to ensure cutting performance and durability.
[0107] Fig. 11 shows a perspective partially cross-sectional view of the blade set 26, wherein different cross-sectional planes have been applied to the plastic component 96 of the guard blade 46, the cutter blade 66, and the metal component 98 of the guard blade 46 for illustrative purposes. Additional reference is made to Figs. 12 to 14, whereas Figs. 12 and 13 illustrate different cross-sectional side views, and whereas Fig. 14 shows a corresponding side view (no cross-section and with the cutter blade 66 omitted).
[0108] As already illustrated in Fig. 5, the cutter blade 66 is arranged in the guide slot 60 (see also Fig. 14) that is formed between the top wall portion 56 and the bottom wall portion 58 of the guard blade 46. In the exemplary embodiment, the room provided for the cutter blade 66 in the guide slot 60 is defined by outer protruding contact portions 88 and inner protruding contact portions 90.
[0109] As can be seen in Fig. 12, the outer protruding contact portions 88 are arranged at a transition between the outer cutting zone 74 and the inner cutting zones 76. The inner protruding contact portions 90 are arranged at a transition between the inner cutting zones 76 and the central portion 78.
[0110] In the exemplary embodiment, the outer protruding contact portions 88 are arranged as laterally extending ridges 174, and the inner protruding contact portions 90 are likewise arranged as laterally extending ridges 176. In certain embodiments, the laterally extending ridges 174, 176 have a continuous (non-interrupted) extension along the lateral extension of the blade set 26. That is, the cutter blade 66 is guided between the laterally extending ridges 174, 176 on the rear (bottom) side and the metal component 98 at the top wall portion 56 of the guard blade 46. In the exemplary embodiment, in total four protruding contact portions 88, 90 are distributed along the longitudinal extension (along the arrow 30) of the guide slot 60. This is insofar beneficial as not only in the outer cutting zones 74 but also in the inner cutting zones 76 a sufficiently tight and accurately defined contact between the cutter blade 66 and the top wall portion 56 of the guard blade 46 is ensured.
[0111] In the central portion 78, a base profile 180 is formed at the bottom wall 58. The base profile is part of the plastic component 96. The base profile 180 defines a guide groove 182, in which the motion transmitting element 80 is guided for lateral movement, refer also to Fig. 7. The guide element 84 is arranged between the top wall portion 56 and the base profile 180 of the guard blade 46 to provide a guideway for a lateral movement of the cutter blade 66.
[0112] In the exemplary embodiment(s) of Figs. 11-14, the bottom wall portion 58 of the guard blade 46 is not planar but includes two opposite inclined wall portions 184 that extend between the comblike teeth 112 in the outer cutting zones 74 and the base profile 182 in the central portion 78. The design of the bottom wall portion 58 provides the guard blade with sufficient strength and stiffness. This enables the implementation of a very thin metal component 98 that forms the major part of the top wall portion 56.
[0113] The cross-sectional view of Fig. 12 is based on a cross-sectional plane through the outer cutting slots 48, whereas the cross-sectional view of Fig. 13 is based on a cross-sectional plane through the comb-like teeth 112 (that are arranged between the cutting slots 48). Figs. 12 and 13 illustrate that the comb-like teeth 112 each have atop leg 190 and a bottom leg 192 that are connected at respective tips 188. As shown in the cross-sectional view of Fig. 13, the tips 188 are primarily formed by the plastic component 96 in the illustrated embodiment. Since the top legs 190 and the bottom legs 192 are connected at the tips 188, a U-shaped profile is formed that guards the comb-like teeth 122 of the cutter blade 66, see also Fig. 11. This contributes to user safety and strengthens the guard blade 46.
[0114] Figs. 11 to 13 also illustrate that the outer cutting zone 74 and the inner cutting zone 76 are coplanar. This may also apply to the central portion 78 as seen on the top side of the guard blade 46. As used herein, the coplanar arrangement relates to a design where the inner cutting zones 76 and the corresponding cutting slots 50, 70 are not outwardly curved or bulged. In this context, the outer cutting zone 74 and the inner cutting zone 76 are primarily defined by the series of respective outer cutting slots 48, 68 and inner cutting slots 50, 70. In this way, a plane of coplanarity is defined where the cutting action actually takes place between the guard blade 46 and the cutter blade 66 in the outer cutting zone 74 and the inner cutting zone 76. Hence, there may be features formed at the guard blade 46 and / or the cutter blade 66 that are not coplanar.
[0115] Overall, the guard blade 46 may have a basically flat design, in particular in the region of the top wall portion 56 where the cutting action takes place. Needless to say, for skin protection and other purposes, the plastic component 96 may protrude beyond the plane of coplanarity of the inner and outer cutting zones 74, 76. In view of the above definition, such design does not interfere with the concept of coplanarity. Further, a pattern may be formed in the top wall portion 56 of the guard blade 46, in particular in the metal component 98 thereof, e.g., for design reasons. Making the inner cutting zones 76 and the outer cutting zones 74 basically coplanar facilitates the manufacturing of the cutter blade 66 and the metal component 98 of the guard blade 46. Defining and maintaining the desired height of the guide slot 60 is also facilitated in this way.
[0116] Figs. 12-14 also exemplify the mirror-symmetric design of the exemplary embodiment of the blade set 26 with respect to the central plane 110.
[0117] As illustrated in Fig. 14, a guide gap 196 is defined in the guide slot 60 to accommodate the cutter blade 66 therein for a defined lateral movement. In the exemplary embodiment, the guide gap 196 is jointly defined by the outer protruding contact portions 88 and the inner protruding contact portions 90 that are arranged opposite the top wall 56 of the guard blade 46.
[0118] With regard to the particular design of the inner protruding contact portion 90, Fig. 14 illustrates two alternatives. On the left-hand side of Fig. 14, the inner protruding contact portion 90 extends from the inclined wall portion 184. On the right-hand side of Fig. 14, the inner protruding contact portion 90 extends from the base profile 182. In either case, the guide gap 196 can be accurately defined.
[0119] Further reference is made to Figs. 15 and 16 illustrating similar embodiments of blade sets 226 (Fig. 15) and 326 (Fig. 16). The blade sets 226, 326 basically correspond to the embodiments illustrated hereinbefore with reference to Figs. 1-14. For the avoidance of repetitions, only differences will be elucidated hereinafter.
[0120] The design of the blade set 226 involves two opposite outer cutting zones 74, whereas only one of the two outer cutting zones 74 is adjoined by an inner cutting zone 76. In the alternative, the inner cutting zone 76 may also be arranged centrally between the two outer cutting zones 74.
[0121] The design of the blade set 326 involves only one outer cutting zone 74 that is adjoined by an inner cutting zone 76.
[0122] The blade sets 226, 326 may also benefit from the specific designs of the cutting slots in the outer cutting zones 74 and the inner cutting zones 76 as discussed hereinbefore.
[0123] Fig. 17 is based on Fig. 10 and illustrates an alternative embodiment. In Figs. 8-10, it has been illustrated that the two opposing cutting edges 152 of the inner cutting slots 70 of the cutter blade 66 are arranged at an inclination angle 156 that is twice the shearing angle 154. By contrast, Fig. 17 illustrates that the desired shearing angle 154 can also be provided with parallel cutting edges 150, 152 in either of the inner cutting slots 50, 70 of the guard blade 46 and the cutter blade 66. The shearing angle 154 is thus brought about by an inclination between the main extension directions 118, 128 of the inner cutting slots 50 of the guard blade 46 and the inner cutting slots 70 of the cutter blade 66.
[0124] Apart from that, the overall design of the embodiment of Fig. 17 can be derived from the description of the foregoing embodiments. Further, also hybrid designs are conceivable that combine nonparallel cutting edges 152 (as with Fig. 10) with an inclination between the main extension directions 118, 128 of the inner cutting slots 50, 70 (as with Fig. 17) to arrive at the desired shearing angle 154.
[0125] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.
[0126] In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single element or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.
Claims
CLAIMS:Claim 1. A blade set (26, 226, 326) for an electrically operated hair cutting appliance (10), said blade set (26, 226, 326) being arranged to be moved through hair in a moving direction (30) to cut hair, said blade set (26, 226, 326) comprising: a guard blade (46) comprising: a top wall portion (56) and a bottom wall portion (58) at least partially offset from the top wall portion (56), thereby defining a guide slot (60), a series of outer cutting slots (48) alternating with corresponding comb-like teeth (112), and a series of elongated inner cutting slots (50) inwardly offset from the outer cutting slots (48), a cutter blade (66) slidingly accommodated in the guide slot (60) and comprising: a series of outer cutting slots (68) alternating with corresponding comb-like teeth (122), and a series of elongated inner cutting slots (70) inwardly offset from the outer cutting slots (68), wherein the outer cutting slots (48, 68) of the guard blade (46) and the cutter blade (66) together define an outer cutting zone (74), wherein the inner cutting slots (50, 70) of the guard blade (46) and the cutter blade (66) together define an inner cutting zone (76), wherein the cutter blade (66) is arranged to be reciprocally moved relative to the guard blade (46) to cut hair therebetween in a scissor action in the outer cutting zone (74) and the inner cutting zone (76), wherein the outer cutting slots (48) of the guard blade (46) have a main extension direction (116), wherein the outer cutting zone (74) and the inner cutting zone (76) are coplanar, and wherein the inner cutting slots (50) of the guard blade (46) have a main extension direction (118) that is inclined with respect to the main extension direction (116) of the outer cutting slots (48).Claim 2. The blade set (26, 226, 326) as claimed in claim 1, wherein an angle of inclination (120) between the inner cutting slots (50) and the outer cutting slots (48) of the guard blade (46) is in the range from 10° to 60°, preferably in the range from 25° to 50°, more preferably in the range from 30 to 45°.Claim 3. The blade set (26, 226, 326) as claimed in claim 1 or 2, wherein the inner cutting slots (50) of the guard blade (46) have a length (160) and a width (162), with the length (160) being at least twice the width (162), preferably at least three times the width (162), more preferably at least four times the width (162).Claim 4. The blade set (26, 226, 326) as claimed in any one of claims 1-3, wherein the series of outer cutting slots (48) and the series of inner cutting slots (50) of the guard blade (46) are parallel to one another.Claim 5. The blade set (26, 226, 326) as claimed in any one of claims 1-4, wherein the inner cutting slots (50) of the guard blade (46) have two opposing cutting edges (150), wherein the corresponding cutting slots (70) of the cutter blade (66) have two opposing cutting edges (152), and wherein a shearing angle (154) defined between cooperating cutting edges (150, 152) of the guard blade (46) and the cutter blade (66) is in the range from 3° to 15°, preferably in the range from 5° to 10°.Claim 6. The blade set (26, 226, 326) as claimed in claim 5, wherein the two opposing cutting edges (150) of the inner cutting slots (50) of the guard blade (46) are parallel to one another, and wherein the two opposing cutting edges (152) of the inner cutting slots (70) of the cutter blade (66) are arranged at an inclination angle (156) with respect to one another that is twice the shearing angle (154), or wherein the two opposing cutting edges (152) of the inner cutting slots (70) of the cutter blade (66) are parallel to one another, with the shearing angle (1 4) formed by an inclination between the main extension directions (118, 128) of the inner cutting slots (50) of the guard blade (46) and the inner cutting slots (70) of the cutter blade (66).Claim 7. The blade set (26, 226, 326) as claimed in any one of claims 1-6, wherein the inner cutting slots (70) of the cutter blade (66) are smaller in width at their outer end (168) that is facing the outer cutting zone (74) than at their opposite inner end (166).Claim 8. The blade set (26, 226, 326) as claimed in any one of claims 1-7, wherein two opposite outer cutting zones (74) are provided at two opposite leading edges (40) that are facing away from one another, and wherein the inner cutting zone (76) is arranged therebetween.Claim 9. The blade set (26, 226, 326) as claimed in any one of claims 1-7, wherein two opposite outer cutting zones (74) are provided at opposite leading edges (40) of the blade set (26, 226, 326) that are facing away from one another, wherein a first inner cutting zone (76) is adjacent to a first outer cutting zone (74), and wherein a second inner cutting zone (76) is adjacent to a second outer cutting zone (74).Claim 10. The blade set (26, 226, 326) as claimed in claim 9, wherein at least the two inner cutting zones (76) are arranged in a mirror-symmetric fashion, in particular with respect to a central plane (110) through the blade set (26, 226, 326) that is parallel to the leading edges (40) and orthogonal to the top wall portion (56) of the guard blade (46).Claim 11. The blade set (26, 226, 326) as claimed in any one of claims 1-10, wherein, as seen in the moving direction (30), the inner cutting slots (50) of the guard blade (46) cover a width extension (134) of the spacing between two neighboring outer cutting slots (48) of the guard blade (46).Claim 12. The blade set (26, 226, 326) as claimed in any one of claims 1-11, wherein, as seen in the moving direction (30), the inner cutting slots (50) overlap a plurality of comb-like teeth (112) at the outer cutting zone (74) of the guard blade (46) that are each arranged between two outer cutting slots (48), and / or wherein the inner cutting slots (50) of the guard blade (46) are arranged such that, as seen in the moving direction (30), an overlap between neighboring inner cutting slots (50) is present.Claim 13. The blade set (26, 226, 326) as claimed in any one of claims 1-12, wherein in the outer cutting zone (74) at least some of the comb-like teeth (112) of the guard blade (46) have a top leg (190) at the top wall portion (56) and a bottom leg (192) at the bottom wall portion (58) that are connected at respective tips (188), with the cutter blade teeth (122) arranged therebetween.Claim 14. A replacement cutting unit (24), comprising: a blade set (26, 226, 326) as claimed in any one of claims 1-13, a mounting interface (38), and preferably a contour following mechanism (40) formed between the guard blade (46) and the mounting interface (38).21Claim 15. A hair cutting appliance (10) comprising a housing (12), a motor (16) arranged in the housing (12), at least one control element (20) accessible at the housing (12), and a blade set (26, 226, 326) as claimed in any one of claims 1-13 or a cutting unit (24) as claimed in claim 14.