Patent Application
20210362359
The present disclosure relates to a processing head for a hair cutting appliance and to a combined blade unit that incorporates a powered blade set and a razor blade. More specifically, but not to be understood in a limiting sense, the present disclosure also relates to contour following mechanisms for hair cutting appliances that enable a certain pivoting movement of blade sets when the appliance is operated.
EP 1 410 884 A1 discloses a shaving apparatus comprising a drivable shaving unit having a skin-engaging cutter for performing a first shaving action on a user's skin; a motor adapted to drive said shaving unit to perform said first shaving action; a blade having a razor-sharp cutting edge positioned for shaving engagement with the user's skin; and a guard surface provided in front of said razor-sharp cutting edge, whereby said blade performs a second shaving action to cut hair during use of said shaving unit to perform said first shaving action.
EP 0 297 300 A1 discloses a dry shaving apparatus comprising a housing, a drive assembly and a shearing head including at least one arcuate short hair cutter assembly and at least one long hair cutter assembly associated therewith, said shearing head being pivotally mounted on said housing about a pivot axis extending in the longitudinal direction of said shearing head.
Contour following mechanisms have a positive effect on the user comfort as a relatively close contact between the blade set and the skin can be maintained. Contour following mechanisms may involve hinges and linkage mechanisms to induce a certain adjustment movement in reaction to external forces acting on the blade set.
An exemplary design of a contour following mechanism for a hair cutting appliance is disclosed in WO 2015/074882 A1. It is proposed therein to implement the contour following mechanism in a hair cutting appliance that utilizes a double-walled stationary blade having a top wall and a bottom wall that jointly define a guide slot for a movable blade that is movably received therein. The blade set that is composed of the stationary blade and the movable blade is, on the one hand, suited for trimming procedures. However, due to the double-walled shape of the stationary blade, the top wall thereof that is facing the skin when in operation may be arranged to be considerably thin. Therefore, to some extent, the blade set is also operable for shaving procedures, styling procedures, etc.
Manufacturing approaches to double walled stationary blades are disclosed in WO 2016/001019 A1 and WO 2016/042158 A1 that describe arrangements wherein at least the top wall of the stationary blade is at least substantially made from sheet metal material. In both documents, an integral design of metal parts and non-metal parts is proposed, involving integrally manufacturing sheet metal and injection molding parts. Hence, insert molding and/or overmolding are proposed to combine the benefits of metal components and non-metal molded components.
However, it has been observed that the achievable smoothness of the shave does not in each case equal the smoothness of a conventional wet shaving procedure using a razor.
There exist several approaches to combine trimming blade sets and razor blades in one appliance. However, the trimming blade set and the razor blade are typically arranged at distinct and different positions at the housing of a hair cutting appliance. In this context, reference is made to any of EP 2 243 605 A1, US 2011/0010943 A1, and US 2005/0217115 A1. These references describe multi-purpose hair cutting apparatuses having razor blades and trimmer blades. However, these documents illustrate conventional design approaches, wherein the trimmer blade and the razor blade are considerably spaced from one another, and/or wherein relatively complicated mechanisms are to be operated to switch between a trimming mode and a shaving mode. This makes the apparatuses bulky and results in a cumbersome operation.
Hence, a user has to change the grip to switch between a trimming operation mode and a shaving operation mode, or to actuate a mechanism that displaces one of the trimming blade and to razor blade. Further, even if a contour following mechanism is provided for one of the trimming blade set and the razor blade, one and the same contour following mechanism cannot be used for both the trimming blade set and the razor blade. Further, it is difficult and often even impossible to use the razor blade and the trimmer blade simultaneously.
To achieve a certain performance level for both trimming procedures and shaving procedures, many users still tend to use two separate devices.
Hence, in this respect, there is still room for improvement in the design of blade sets for hair cutting appliances.
In view of the above, it is an object of the present disclosure to present a combined processing head for a hair cutting appliance that addresses at least some of the afore-mentioned drawbacks. Preferably, the processing head enhances and extends the field of application of the hair cutting appliance. It would be desirous to present a single appliance that is capable of trimming, shaving, styling, and, in addition thereto, of smooth wet shaving using a razor blade. Hence, it is desirable to present a combined device that enables a user to perform several grooming procedures without the need of using two or even more devices.
Further, the processing head is preferably arranged in such a way that the appliance that is equipped with the processing head has a compact design and is generally easy to manufacture. However, the operating performance both in a trimming operation mode and a wet shaving operation mode shall be good enough and convincing so that the user is not prompted to use separate devices.
Further, preferably, a contour following capability of the appliance shall be provided and maintained both in the trimming operation mode and the wet shaving operation mode.
In a first aspect of the present disclosure there is presented a processing head for a hair cutting appliance, the processing head comprising:
The present disclosure is based on the idea that the powered blade set that is provided with a contour following feature may be operated as a carrier for the razor blade. When the razor blade is supported by the powered blade set in a pivotable fashion, also the razor blade is provided with a contour following feature.
When the razor blade is attached to the powered blade set, particularly to the stationary blade thereof, cutting edges and leading edges of the involved blades are arranged close to one another. Preferably, the razor blade is arranged in the vicinity of a leading edge of the powered blade set that is formed by a series of teeth thereof. Hence, a basically similar orientation of the appliance in the shaving mode and the trimming mode is possible. This has the effect that no considerable reorientation or grip change for the appliance is necessary when the user switches between the powered blade set and the razor blade.
It is to be noted that in another operation mode, in certain embodiments, the user may simultaneously operate the powered blade set and the razor blade as they are positioned next or adjacent to one another in respectively adapted orientations. Hence, at least in some embodiments, cutting edges of the razor blade and a neighboring leading edge of the powered blade set are positioned and/or at least substantially aligned to enable simultaneous skin contact for both the razor blade and the powered blade set in respectively operable orientations in relation to the skin level. As a result, the used may first trim hair and subsequently shave remaining stubbles in one combined shaving procedure, even in one stroke.
In accordance with exemplary embodiments, the razor blade is attached to a skin-facing top wall of the stationary blade of the blade set.
In an exemplary arrangement of the processing head, the razor blade is permanently attached to the powered blade set. In other words, the razor blade is fixedly attached to the powered blade set in a non-detachable manner.
In yet another exemplary embodiment, the razor blade is bonded or molded to the powered blade set. In accordance with this embodiment, the powered blade set and the razor blade may be integrally manufactured and/or assembled using manufacturing techniques such as insert molding, outsert molding, overmolding, etc.
In yet another exemplary embodiment of the processing head, the razor blade is removably attached to the powered blade set. Hence, the razor blade is detachable, for instance for replacement.
In still another exemplary embodiment of the processing head, a snap-lock interface is formed between the razor blade and the powered blade set. Hence, attaching and detaching the razor blade does not require additional tools.
In yet another exemplary embodiment of the processing head, the razor blade is arranged at a top side of the powered blade set. Preferably, the razor blade is arranged at the top wall of the stationary blade that may also be referred to as guard wall or first wall.
It is generally preferred that the razor blade and the powered blade set are positioned very close to one another.
In yet another exemplary embodiment of the processing head, the razor blade is provided with a cutting edge that is parallel to a leading edge of the powered blade set that is defined by the tips of the teeth of the stationary blade. In this way, generally one and the same advancing direction may be used to move the appliance along the skin in both the trimming mode and the shaving mode.
In yet another exemplary embodiment of the processing head, the linkage unit defines a virtual pivot axis for the powered blade set and the razor blade. A virtual pivot axis may also be referred to as instantaneous pivot axis. A virtual pivot axis may be defined using a linkage having several links that are movable with respect to one another so that a resulting pivoting movement for the blade set is achieved. A virtual pivot axis may be placed “above” the top wall of the stationary blade in a region where it is basically impossible to provide a discrete link providing a corresponding pivot axis.
In yet another exemplary embodiment of the processing head, the linkage unit is a four-bar linkage unit. Other types of linkage units having a smaller or higher number of joints are conceivable.
In another exemplary embodiment of the processing head, the four-bar linkage unit comprises a first side bar, a second side bar and a top bar, wherein the first side bar and the second side bar are spaced away from one another, wherein the top bar is arranged between a top end of the first side bar and a top end of the second side bar, and wherein a bottom side of the powered blade set is arranged at or forms the top bar.
Using a four-bar linkage unit involves a great freedom of design so that desired characteristics of the contour following feature can be achieved by adjusting the linkage unit.
In yet another exemplary embodiment of the processing head, at least one hinge of the linkage unit is formed as a living hinge. Generally, a living hinge is formed by a defined weak point having only a very small wall thickness. The use of living hinges may generally reduce manufacturing costs, assembly costs, etc.
In yet another exemplary embodiment of the processing head, the razor blade is inclined with respect to the powered blade set in such a way that the processing head is operable to engage the user's skin with the powered blade set and the razor blade simultaneously in one stroke. Preferably, first the powered blade set and second the razor blade approaches a particular processing zone to cut hair. In other words, a dual-action two-stage shaving procedure may be performed, wherein a particular skin portion is first contacted by the leading edge of the powered blade set (for a trimming-style cutting action) and thereafter contacted by the cutting edge of the razor blade (for a shaving-style cutting action). Hence, a smooth shave may be achieved in only one go.
In still another exemplary embodiment of the processing head, the razor blade is inclined with respect to the powered blade set in such a way that the processing head is operable in a first operating orientation for the powered blade set, and a second operating orientation for the razor blade, wherein the first operating orientation and the second operating orientation are inclined in relation to one another by an angle of less than 30 degrees, preferably less than 15 degrees, more preferably less than 10 degrees. As with the dual-action embodiment discussed hereinbefore, basically a nearly aligned arrangement of the first operating orientation and the second operating orientation is useful to have a basically parallel (simultaneous) interaction of the powered blade set and the razor blade with the skin.
Hence, in some embodiments, the inclination angle between the first operating orientation and the second operating orientation approaches zero. This may involve an embodiment, wherein an imaginary line that connects cutting edges of the blades of the razor blades also intersects or at least approaches the leading edge of the powered blade set. However, as the human skin is generally relatively soft, also a certain inclination angle between the first operating orientation and the second operating orientation may be accepted as both the powered blade set and the razor blade may still simultaneously contact the skin to cut hair there.
The first operation orientation involves a certain operating angle for the powered blade set. The second operation orientation involves a certain operating angle for the razor blade that is different from the operating angle of the first operation orientation. The operating angle describes an inclination of the appliance with respect to the skin of the user whose hair is to be processed/cut.
As indicated above, it is not necessary to use the appliance in a totally deviating orientation in the second operating mode. Switching between the first operating mode and the second operating mode involves a relatively small tilting movement. Optionally, also a combined operating mode for trimming and shaving in one go is possible.
In yet another exemplary embodiment of the processing head, at a stroke movement of the processing head, depending on an angular orientation of the processing head, one of the razor blade and the powered blade set contacts the skin in a respective operating orientation.
In other words, for shaving procedures, the processing head is brought into a first inclination with respect to the skin. For the trimming or styling operation, the processing head is brought into a second inclination with respect to the skin. Preferably, the transition between the two operating orientations does not involve excessive movements.
In another aspect of the present disclosure there is presented a combined blade unit for a hair cutting appliance, the blade unit comprising:
In an exemplary embodiment of the combined blade unit, the powered blade set is arranged to be detachably attached to the hair cutting appliance via the linkage unit.
In yet another aspect of the present disclosure there is presented an electrically powered hair cutting appliance, said hair cutting appliance being arranged to be moved through hair in a moving direction to cut hair, said hair cutting appliance comprising a processing head in accordance with at least one embodiment as described herein that is fitted with a combined blade unit comprising a powered blade set and a razor blade.
In yet another aspect of the present disclosure there is presented a hair cutting appliance arranged to be moved through hair in a moving direction to cut hair, the appliance comprising a processing head in accordance with at least one embodiment as discussed herein. The processing head is fitted with a combined blade unit comprising a powered blade set and a razor blade.
Optionally, the appliance comprises a housing comprising a handle section and a drive unit arranged in the housing.
Generally, the powered blade set may comprise a basically linear leading edge defined by a respective series of stationary blade teeth (and movable blade teeth). In accordance with this embodiment, a basically reciprocating and substantially linear relative movement between the movable blade and the stationary blade is present. However, this does not exclude embodiments, wherein an at least somewhat curved (oscillatory) movement path of the movable blade with respect to the stationary blade is present. This may be caused, for instance, by a respective guiding linkage for the movable blade.
Further, in addition to basically linear arrangements of blade sets, also curved or even circular arrangements of blade sets may be envisaged. Hence, accordingly, a somewhat curved or circular leading edge defined by a respective arrangement of stationary blade teeth (and movable blade teeth) may be provided. Therefore, whenever reference herein is made to a longitudinal direction, a lateral direction and/or a height direction, this shall not be interpreted in a limiting sense. A curved or circular blade set may be defined and described with reference to similar directions, but also with reference to polar directions and/or further appropriate directional information. Hence, Cartesian coordinate systems, but also polar coordinate systems and further appropriate coordinate systems may be used to describe linear and/or curved designs of blade sets.
In some embodiments, the powered blade set is provided with two opposite leading edges, i.e. two opposite series of stationary blade teeth and movable blade teeth. In this way, both a pulling and a pushing movement of the powered blade set may be used for the cutting operation. Further, in this way the hair cutting appliance can be deployed more flexibly which may facilitate styling operations and hair cutting operations in hard-to-reach areas.
These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. In the following drawings
The appliance 10 comprises a housing 12 which is arranged in an elongated fashion. At the housing 12, a handle section 14 is defined. In the housing 12, a drive unit 16 is arranged. Further, a battery 18 may be arranged in the housing 12. In
At a top end thereof, the appliance 10 comprises a processing head 24 that is attached to the housing 12. The processing head 24 comprises a blade set 26. The blade set 26, particularly a movable blade thereof, may be actuated and driven by the drive unit 16 in a reciprocating fashion, refer also to the double arrow 28 in
The blades of the blade set 26 may be arranged at a first leading edge 32 and, in at least some embodiments, at a second leading edge 34 that is opposite to the first leading edge 32. The first leading edge 32 may be also referred to as frontal leading edge. A second leading edge 34 may be also referred to as rear leading edge.
Further, a general advancing or moving direction of the appliance 10 is indicated in
In the following, exemplary embodiments of stationary blades and blade sets 26 will be elucidated and described in more detail. The blade sets 26 may be attached to the appliance 10, or to a similar appliance. It goes without saying the single features disclosed in the context of a respective embodiment may be combined with any of the other embodiments, also in isolated fashion, thereby forming further embodiments that still fall under the scope of the present disclosure.
In some Figures shown herein, exemplary coordinate systems are shown for illustrative purposes. As used herein, an X-axis is assigned to a longitudinal direction. Further, a Y-axis is assigned to a lateral direction. Accordingly, a Z-axis is assigned to a vertical (height) direction. Respective associations of the axes/directions X, Y, Z with respective features and extensions of the blade set 26 can be derived from those Figures. It should be understood that the coordinate system X, Y, Z is primarily provided for illustrative purposes and not intended to limit the scope of the disclosure. This involves that the skilled person may readily convert and transform the coordinate system when being confronted with further embodiments, illustrations and deviating view orientations. Also a conversation of Cartesian coordinate systems into polar coordinate system may be envisaged, particularly in the context of a circular or curved blade set.
In
The movable blade of the blade set 26 that is not visible in
In
With reference to
As indicated above, the processing head 24 incorporates a blade set 26 which is arranged as a powered (motor operated) blade set. Generally, the processing head 24 may also be referred to as cutting head. The blade set 26 comprises a stationary blade 42 (refer to
In accordance with at least some exemplary embodiments, the stationary blade 42 is a double-walled blade comprising a first, top wall 72 and a second, bottom wall 74. In the exemplary embodiment illustrated in
Optionally, in other alternative embodiments, the top wall 72 and the bottom wall 76 are entirely formed from metal material. In the embodiment in accordance with
As the plastic component 70 is an injection-molded part, at least in some embodiments, further design features may be formed thereon. For instance, a driving slot 80 is formed in a central portion of the plastic component 70. In the mounted state of the processing head 24, a driving connector 82 is arranged in and extends through the driving slot 80 from a bottom side thereof into the guide slot 60. In the guide slot 60, the driving connector 82 is attached to the movable blade 62. As indicated in
At the plastic component 80, there may be further formed mounting features 84, for instance snap-in hooks, etc. The mounting features 84 are provided at a bottom side of the plastic component 70 to attach the blade set 26 to the contour following mechanism 58. At the contour following mechanism 58, a mating snap-lock interface 88 is provided that may involve, for instance, recesses that are arranged to be engaged by the mounting features 84 of the blade set 26. Hence, a snap-lock connection is possible so that the blade set 26 is detachable, for instance for replacement.
At a bottom side of the contour following mechanism 58 that is facing away from the blade set 26, a further mounting interface 90 is provided. Via the mounting interface 90, the contour following mechanism 58 and, consequently, the blade set 26 may be attached to a housing 12 of the hair cutting appliance 10.
In the exemplary embodiment of
As illustrated in
Between the bottom bar 100 and the first side bar 94, a hinge 102 is provided. Between the bottom bar 100 and the second side bar 96, a hinge 104 is provided. Between the first side bar 94 and the top bar 98, a hinge 106 is provided. Between the second side bar 96 and the top bar 98, a hinge 108 is provided. Hence, four swivel bars are provided that are respectively coupled by the hinges 102, 104, 106, 108. As a result, a contour following pivot movement 112 is possible for the top bar 98 and, consequently, for the blade set 26 attached thereto.
It is to be noted that the top bar 98 and/or the bottom bar 100 do not necessarily have to be arranged as distinct elements. Optionally, the top bar 98 may be embodied by the bottom wall 74 of the stationary blade 42. Similarly, the bottom bar 100 may be embodied by the housing 12 of the hair cutting appliance, refer also to
Arranging the linkage unit 92 as a four-bar linkage may have the result that the pivot movement 112 that is induced at the top bar 98 actually involves a virtual (instantaneous) pivot axis that is defined in a region where actually no discrete pivot axis is possible, due to manufacturing constraints, assembly space constraints, etc. Further, such a virtual pivot axis is an instantaneous pivot axis. In other words, the actual position of the virtual pivot axis depends on the actual pivot state of the linkage unit 92.
Having introduced the processing head 24 and the blade set 26 in detail herein before, reference is now made to
As shown in
However, the combined blade unit 126 is augmented as also a razor blade 130 is provided in addition to the powered blade set 26. As can be seen in
The razor blade 130 comprises a frame 132 that supports and carries at least one blade 134 or a row of blades 134. In the exemplary embodiment of
Further, in the exemplary embodiment of
In
A main aspect of the arrangement of the processing head 124 illustrated in
There may be several embodiments of the connector 140. In some embodiments, the razor blade 130 is permanently attached to the stationary blade 42. This may involve an integral and combined manufacture. Optionally, the blade set 26 and the razor blade 130 may be separately produced and bonded with one another to form the combined blade unit 126. Optionally, the bonding procedure may involve any of welding, gluing, soldering, riveting, etc. Further, integral manufacture methods such as insert molding may be used.
In alternative embodiments, the razor blade 130 is arranged to be attached to and detached from the stationary blade 42 by means of an interface, for instance a snap-lock or snap-on/snap-in/snap-lock interface.
As shown in
The appliance illustrated in
The arrangement illustrated in
Further, as the blades 134 of the razor blade 130 and the leading edge 32 of the powered blade set 26 are relatively close to one another, visibility and reachability conditions basically remain the same.
In
In
In at least some embodiments, the linkage unit 92 is a single integrally formed component. This has a positive effect on manufacturing costs, assembly costs, durability, etc.
In the cross-sectional view of
The mounting features 84 and the snap-lock interface 88 form a mounting interface 164 arranged as a snap-lock connection. In
In
Preferably, the offset angle α is considerably small, and may be for instance less than 30 degrees, preferably less than 15 degrees, more preferably less than 10 degrees. As a result, only a slight change of the overall orientation of the processing head 124 with respect to the skin is necessary to switch between the operation of the powered blade set 26 and the operation of the non-powered razor blade. This has a positive effect on visibility, reachability, and on the overall operating performance of the processing head 124.
Further, in at least some embodiments, a parallel (simultaneous) cutting action involving both the razor blade 130 and the powered blade set 26 is possible. To this end, the angle α between the two imaginary orientations 156, 158 may approach zero, resulting in the desired parallel (simultaneous) engagement of the razor blade 130 and the powered blade set 26 in a respectively operable orientation.
As with the embodiments already discussed herein before, the processing head 124 illustrated in
As already discussed herein before, the linkage unit 92 comprises a top bar 98, a bottom bar 100, and side bars 94, 96. For illustrative purposes, discrete hinges 102, 104, 106, 108 are shown in
The operating orientation 156 for the blade set 26, particularly for the first leading edge 32 thereof, is defined by the tips of the stationary blade teeth 44, and by the shape of the frame 132 of the razor blade 130 which is present at the top wall of the stationary blade 42. The operating orientation 158 of the razor blade 130 is defined in the exemplary embodiment of
Connecting lines 170, 172 that respectively connect two of the hinges 102, 104, 106, 108 form at their point of intersection an instantaneous virtual pivot 174. The design of the linkage unit 92 may be adapted to achieve a desired motion transmission characteristic. As shown in
It is to be noted that while aspects and embodiments of the present disclosure have been described with reference to a double-wall arrangement of the stationary blade 42 of the powered blade set 26, this shall not be understood to be limiting. Rather, optionally, alternative embodiments of the powered blade set 26 are possible that implement a single-wall stationary blade 42 that is not provided with a bottom wall 74 in addition to the top wall 72. In such a case, mounting interfaces for the blade set 26 are not formed at the bottom wall but rather at a frame or support thereof.
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.
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.
Any reference signs in the claims should not be construed as limiting the scope.
| Number | Date | Country | Kind |
|---|---|---|---|
| 17188500.7 | Aug 2017 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2018/072756 | 8/23/2018 | WO | 00 |
