The present invention relates to a hair-cutting apparatus.
Hair clippers employing vacuum to collect cut hair parts during clipping are known for quite a while already. One of the design challenges is to optimize hair debris collection, thus minimizing the amount of cut hair parts spreading into the grooming environment. For example, WO 2004/002691 A1 describes a hair-cutting apparatus with means for preventing cut hair from flying off. The means has a boundary wall extending close to the cutting arrangement. The boundary wall has a stationary portion and a portion that is movable relative to the stationary portion. The movable portion is arranged and positioned to cooperate with the hair to be cut. Further, U.S. Pat. No. 9,381,655 B2 discloses a double-blade hair trimming device having a trimmer handle and a blade head, the blade head having a blade unit for cutting long hair and a blade unit for short hair. The fixed blade of the long hair cutter has teeth adjacent to teeth of a blade had protective cover.
There may be a need to improve hair debris collection.
The object of the present invention is solved by the subject-matter of the independent claims, wherein further embodiments are incorporated in the dependent claims. It should be noted that the following described aspects of the invention apply also for the hair-cutting apparatus.
A first aspect of the present invention provides a hair-cutting apparatus. A hair-cutting apparatus comprises:
a cutting arrangement (12) for cutting hair; and
a cut-hair-blocking element (18) arranged in front of a cutting zone (20) of the cutting arrangement in a direction in which the hair-cutting apparatus is moved to cut hairs during use, and sufficiently close to an upper side (22) of the cutting arrangement for counter-acting flying off cut hair (60) from the hair-cutting apparatus, wherein the upper side is opposite to a skin-touching side (24) of the cutting arrangement;
wherein the cut-hair-blocking element has a hair receiving portion (26) at a bottom of the cut-hair-blocking element close to the cutting zone for allowing hair to be cut to pass through the hair receiving portion to enter the cutting zone;
wherein the hair receiving portion has a row of cut-hair-blocking members (28, 28a, 28b), wherein adjacent cut-hair-blocking members have an interspace (29) therebetween that is sufficiently small to prevent the cut hair from passing through the interspace, or wherein adjacent cut-hair-blocking members have no interspace therebetween;
wherein the cut-hair-blocking members comprise barrier members (28b);
wherein the barrier members (28b) are sufficiently flexible such that the barrier members (28b) undergo sufficiently large deformation under a force caused by the hair to be cut for allowing the hair to be cut to pass through the barrier members (28b) to enter the cutting zone; and
wherein the barrier members (28b) are sufficiently stiff such that the barrier members (28b) undergo no or little deformation under a force caused by the cut hair for preventing the cut hair from flying off; and
wherein the cut-hair-blocking members are contiguous to a tip of a guard blade of the cutting arrangement.
According to an embodiment of the present invention, the cut-hair-blocking members comprise both barrier members and shield members, wherein the shield members are sufficiently stiff such that the shield members undergo no or little deformation under a force caused by the hair to be cut and under a force caused by the cut hair for preventing the cut hair from flying off; wherein the interspace between adjacent shield members is sufficiently large to allow the hair to be cut to pass through the interspace to enter the cutting zone; and wherein the barrier members are arranged within the interspace between adjacent shield members. In such an embodiment a better barrier function is realized within the interspace between adjacent shield members.
In other words, in first aspect of the invention it is proposed to use the bottom portion of a cut-hair-blocking element to provide two functions: a) receiving uncut hair: allowing hair to be cut, i.e. hair on skin, to pass through the bottom portion to enter a cutting zone, and b) blocking cut hair: preventing cut hair from passing through the bottom portion of the cut-hair blocking element. That is to say, the bottom portion of the cut-hair-blocking element defines a hair receiving portion. In order to allow hair to be cut to pass through the hair receiving portion, it is proposed to partition the bottom portion of the cut-hair-blocking element, i.e. the hair receiving portion, thereby creating one or more rows of cut-hair-blocking members. The one or more rows of cut-hair-blocking members may have any number of cut-hair-blocking members. According to an exemplary embodiment, the number of the cut-hair-blocking members may be 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 30, 40, 60, 80, 100, 200, 300 or the number may be even higher.
Two types of cut-hair-blocking members are proposed, shield members and barrier members. The shield members are also referred to as rigid members, which are stiffer than the hair to be cut and function as walls blocking the hair to be cut. Hair stiffness may vary between body parts and between individuals. For a detailed discussion concerning the mechanical properties of hair, reference is made to the following publication: George T. Rado and Harry Suhl M. Benzarti, M. B. Tkaya, C. P. Mattei, and H. Zahouani, Hair mechanical properties depending on age and origin, Word Academy of Science, Engineering and Technology, International Journal of Biotechnology and Bioengineering, Vol. 5, No. 2, 2011. This publication states that the statistical axial stiffness of the hair varies between 1000 N/m and 1600 N/m. The shield members may be configured to be resistant against bending deformation under a force caused by the hair to be cut. That is, the shield member may be configured to have a sufficiently high bending stiffness such that the shield members undergo no or little bending deformation under a force caused by the hair to be cut. The bending stiffness of the shield members is a function based upon two essential properties: the elastic modulus (stress per unit strain) of the material that composes it, and the moment of inertia, a function of the cross-sectional geometry. The bending stiffness of the shield members is also dependent on the length of the shield members. Therefore, by carefully selecting the material, the cross-sectional geometry, and the length of the shield members, the shield members can be configured to undergo no or little bending deformation under a force caused by the hair to be cut during cutting. For example, the shield members may be made of rigid plastic or metal.
The barrier members may also be referred to as flexible members, which are less stiff than the hair to be cut. In other words, the barrier members may be configured to have a sufficiently low bending stiffness such that the barrier members undergo sufficiently large bending deformation under a force caused by the hair to be cut. In this way, the barrier members may form entrance points for allowing the hair to be cut to enter the cutting zone. The bending stiffness of the barrier members is also a function based upon the elastic modulus (stress per unit strain) of the material that composes it, the moment of inertia, and a length of the barrier members. Therefore, by carefully selecting the material, the cross-sectional geometry, and the length of the barrier members, the barrier members can be configured to undergo relatively large deformation under a force caused by the hair to be cut during cutting. According to an exemplary embodiment, the material stiffness of the barrier members may be in a range between 0 and 1800 N/m, such as 100 N/m, 200 N/m, 300 N/m, 400 N/m, 500 N/m, 600 N/m, 700 N/m, 800 N/m, 1000 N/m, 1100 N/m, 1200 N/m, 1300 N/m, 1400 N/m, 1500 N/m, 1600 N/m, 1700 N/m, and 1800 N/m.
The shield members and the barrier members have at least one characteristic in common—they function as a “wall” to prevent cut hair from passing through the shield members and the barrier members, but differ in the functionality with respect to the hair to be cut. As will be explained hereafter and particularly with respect to
With the shield members and the barrier members, there are several possibilities to realize the above-mentioned functions.
The first option is that the bottom portion of the cut-hair-blocking element has the shield members only. This options is not part of the present invention. The shield members may be arranged in a comb-like structure, and therefore the shield members represent teeth. As the shield members are rigid, they are stiffer than the hair to be cut and undergo no or little deformation under a force caused by the hair to be cut. Thus, the interspace between adjacent shield members functions as an entrance point to let the hair to be cut to enter the cutting zone. Therefore, the interspace between adjacent shield members should be sufficiently large to allow the hair to be cut to pass through the interspace. However, as the cut hair may also fly out from the same interspace. The interspace has to be sufficiently small to prevent cut hair from passing through the interspace. The diameter of the hair may vary between 50 μm to 220 μm at different anatomical positions. The size, geometry, and/or pattern of the interspaces may be optimized to improve the efficiency of receiving hair to be cut to enter the cutting zone on the one hand, and the efficiency of preventing cut hair from passing through the interspace on the other hand. According to an exemplary embodiment, the interspace may have a width in a range between 0.1 mm and 2 mm, such as 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, and 2 mm. An exemplary implementation of the shield members is illustrated in
The second option is that the bottom portion of the cut-hair-blocking element has the barrier members only. This option is part of the present invention. Unlike the shield members, the barrier members are flexible, i.e. less stiff than the hair to be cut. Thus, the hair to be cut can pass undisturbed through the barrier members, as the flexible barrier members undergo sufficiently large deformation under a force caused by the hair to be cut. In other words, the working principle of the barrier members is different from that of the shield members. Therefore, unlike shield members, a sufficiently large interspace between adjacent barrier members is not required for receiving the hair to be cut. The same barrier function of the barrier members should also prevent the hair debris from passing through the barrier members. The barrier members make use of the difference in properties of hair before and after it is cut. In other words, the barrier members are less stiff than the hair to be cut, but sufficiently stiff to such that the barrier members undergo no or little deformation under a force caused by the cut hair for preventing the cut hair from flying off, i.e. impact speed and mass of hair debris, i.e. cut hair, is too low to pass through the barrier. The difference in properties of hair before and after it is cut thus defines a working window of optimally functioning barrier members. The barrier members may be arranged in a brush-like structure and thus barrier members represent bristles. Alternatively or additionally, the barrier members may be arranged in a strip-curtain-like structure, each barrier member representing a segment flap element. In other words, the barrier members can function as entrance points for allowing hair to be cut to enter the cutting zone. Therefore, it is not required to provide interspaces between adjacent barrier members to allow hair to be cut to enter the cutting zone. The barrier members alone can function as an opening under the force caused by the hair to be cut. This will be explained particularly with respect to the exemplary embodiment in the example (ii) of
The third option is that the cut-hair-blocking members have both the shield members and barrier members. This option is part of the present invention. In this case, the barrier members may be arranged within the interspace between adjacent shield members. In other words, the barrier members provide a barrier function within the interspace between adjacent shield members.
As the bottom portion of the cut-hair-blocking element itself functions as hair receiving portion, the cut-hair-blocking element may be arranged in front of the cutting zone of the cutting arrangement, and sufficiently close to an upper side of the cutting arrangement for counter acting flying off cut hair. In fact, the bottom portion of the cut-hair-blocking element may be contiguous to a tip of the guard blade. On the one hand, as the interspace between adjacent shield members and/or barrier members is sufficiently small, hair debris are prevented from passing through the cut-hair-blocking element. On the other hand, the bottom portion of the cut-hair-blocking element does not disturb or prevent uncut hair entering the cutting zone, as the interspace between adjacent shield members and/or the flexibility of the barrier members will allow the hair to be cut to enter the cutting zone.
Using the proposed hair-cutting apparatus has at least one of the following advantages:
The cut-hair-blocking members are contiguous to a tip of a guard blade of the cutting arrangement. Such an arrangement will not disturb the cutting operation of the hair-cutting apparatus, since the flexible barrier members and the interspace between adjacent shield members allow uncut hair to enter the cutting zone.
According to an embodiment of the present invention, the hair-cutting apparatus further comprises a vacuum nozzle for transporting cut hair to a hair chamber. The cut-hair-blocking element is arranged and positioned for reducing an opening area between the vacuum nozzle and the cutting arrangement.
For example, the cut-hair-blocking element may be arranged between the vacuum nozzle and the cutting arrangement. The reduction of the opening area may lead to, based on the same vacuum force, increasing airflow speed in the area where the hair cutting takes place. This arrangement that cut-hair-blocking members are contiguous to a tip of a guard blade of the cutting arrangement. may further improve the hair catching efficiency of the vacuum system.
According to an embodiment of the present invention, the shield members are provided in form of a comb-like structure.
This will be explained hereafter and particularly with respect to the exemplary embodiment in
According to an embodiment of the present invention, the barrier members are provided in form of a brush-like structure and/or a strip-curtain-like structure.
This will be explained hereafter and particularly with respect to the exemplary embodiments in
According to an embodiment of the present invention, the cut-hair-blocking element has a boundary wall for counter-acting the flying off cut hair from the hair-cutting apparatus.
As the hairs bounce against the boundary wall, their velocity is drastically reduced to levels that are not exceeding that of the vacuum suction airflow and can therefore be easily sucked into the hair container.
According to an embodiment of the present invention, the shield members have a pitch that matches a pitch of the guard blade.
In other words, the shield members and the guard blade have aligned teeth slots. This may facilitate receiving uncut hair.
According to an embodiment of the present invention, the cut-hair-blocking element is retractable such that the cut-hair-blocking element is positionable in an extended position and a retracted position. In the extended position, the cut-hair-blocking element is positioned sufficiently close to the upper side of the cutting arrangement for counter-acting flying off cut hair from the hair-cutting apparatus. In the retracted position, the cut-hair-blocking element is distanced further away from the upper side of the cutting arrangement as compared to the extended position. In other words, in the retracted position, the cut-hair-blocking element has a larger distance from the upper side of the cutting arrangement as compared to the extended position.
For example, if the hair-cutting apparatus is a vacuum assisted clipper, when the cut-hair-blocking element is in the extended position, the cut-hair-blocking element may be arranged and positioned for reducing an opening area between the vacuum nozzle and the guard blade. When the cut-hair-blocking element is in the retracted position, the cut-hair-blocking element may be arranged and positioned for unblocking the opening area. An advantage of having a retractable cut-hair-blocking element may be seen in that in the retracted position, it may be easier to clean hair debris on the surface of the cutting arrangement, as the cut-hair-blocking element is positioned sufficiently away from the upper side of the cutting arrangement.
According to an embodiment of the present invention, the cut-hair-blocking element is an element integrated with the hair-cutting apparatus.
According to an embodiment of the present invention, the cut-hair-blocking element is a detachable element.
In other words, the cut-hair-blocking element may be removed and separated from the hair-cutting apparatus. An advantage of having a detachable element may be seen in that one cut-hair-blocking element may be replaced by another cut-hair-blocking element e.g. for setting a different initial hair length entrance.
According to an embodiment of the present invention, the hair-cutting apparatus comprises a series of detachable cut-hair-blocking elements. The series of detachable cut-hair-blocking elements comprises at least a first detachable cut-hair-blocking element and a second detachable cut-hair-blocking element. The first detachable cut-hair-blocking element has a hair receiving portion that allows hair to be cut with a first length to pass through hair receiving portion to enter a cutting zone. The second detachable cut-hair-blocking element has a hair receiving portion that allows hair to be cut with a second length to pass through hair receiving portion to enter the cutting zone. The first length is different from the second length.
According to an embodiment of the present invention, the shield members are configured such that the interspace between adjacent shield members has a geometry that is adapted to a desired haircut length including at least one of the first length and the second length.
According to an embodiment of the present invention, the barrier members are configured to have a height that is adapted to a desired haircut length including at least one of the first length and the second length.
As used herein, the expression “shield members are sufficiently stiff”, or “barrier members are sufficiently flexible/stiff” refers to the extent of the resistance of the shield members and barrier members against bending deformation when subjected to a force caused by hair to be cut and/or cut hair when the hair-cutting apparatus is moved to cut hairs during use.
As used herein, the term “sufficiently” refers to the complete or nearly complete extent or degree of a state as indicated. For example, a reference that the shield members are sufficiently stiff such that the shield members undergo no or little deformation under a force caused by the cut hair would mean that the shield members are sufficiently stiff to carry out a particular function, i.e. preventing the cut hair from flying off. The exact allowable degree of deviation from absolute completeness may depend on the desired barrier function.
These and other aspects of the present invention will become apparent from and be elucidated with reference to the embodiments described hereinafter.
These and other aspects of the invention will be apparent from and elucidated further with reference to the embodiments described by way of examples in the following description and with reference to the accompanying drawings, in which
It should be noted that the figures are purely diagrammatic and not drawn to scale. In the figures, elements which correspond to elements already described may have the same reference numerals. Examples, embodiments or optional features, whether indicated as non-limiting or not, are not to be understood as limiting the invention as claimed.
The cut-hair-blocking element 18 has a hair receiving portion 26 at a bottom of the cut-hair-blocking element close to the cutting zone 20 for allowing hair to be cut to pass through the hair receiving portion to enter the cutting zone 20. The hair receiving portion 26 has a row of cut-hair-blocking members 28. The number of the cut-hair-blocking members may be, for example, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 30, 40, 60, 80, 100, or even more. Adjacent cut-hair-blocking members 28 may have an interspace 29 therebetween that is sufficiently small to prevent cut hair from passing through the interspace, which will be explained hereafter and particularly with respect to the exemplary embodiments in
In the first example, as illustrated in
In the second example, as illustrated in
In the third example, as illustrated in
The hair-cutting apparatus 10 may be a vacuum assisted clipper. In the following, the use of different types of cut-hair-blocking elements 18 in a vacuum assisted clipper have been discussed. The hair-cutting apparatus 10 has a vacuum nozzle 32 for transporting cut hair to a hair chamber (not shown). It is also noted, as previously mentioned, that the cut-hair-blocking element can also be applied in a non-vacuum hair removal appliance to reduce the hair scatter.
The comb-like structure may allow for a smaller air inlet, which further reduces the opening area 34. The reduction of the opening area 34 at the cutter that the shield members create will generate a higher airspeed at the position, where a high airspeed is required. With the cut-hair-blocking element, the opening area 34 may be four times smaller. Therefore, the air speed may be about three to four times higher and the forces on each hair about nine to sixteen times higher. This makes it more likely to counteract the cutting energy that sprays the hair clippings. Therefore, a higher catching efficiency of the cut hair can be achieved in the hair container. The geometry of the cut-hair-blocking element may be tuned to reduce up to 50% of the opening area between the cutter blade and conventional nozzle, or up to 75% thus tuning the increase in airflow speed at the nozzle.
Additionally, the geometry of the shield members 28a may be tuned in order to tune for both the airflow increase and initial hair length entrance to cutter blade. When specifically focusing on initial hair length entrance in the vacuum nozzle, hair that needs a long length reduction may find the small openings to increase the airspeed too small to reach to the cutter. Due to the short length of the shield teeth in comparison to the long length of the incoming hairs, the latter will not reach the cutter blade as the shield is flattening the hairs, which forces them under the cutter blade. Therefore, the teeth geometry may be tuned to extend their height that allow long incoming hairs to pass through the vacuum nozzle and reach the cutter blade.
That is to say, balancing out the barrier functions mentioned in
The cut-hair-blocking element in the above described embodiments and examples may be retractable such that the cut-hair-blocking element is positionable in an extended position and a retracted position. In the extended position, the cut-hair-blocking element is positioned sufficiently close to the upper side of the cutting arrangement for counter-acting flying off cut hair from the hair-cutting apparatus. In the retracted position, the cut-hair-blocking element is distanced further away from the upper side of the cutting arrangement as compared to the extended position. For example, the cut-hair-blocking element may be positioned to block cut hair from exiting the hair collection system in the process of cutting, whereas the cut-hair-blocking element may be retracted e.g. for the purpose of cleaning the hair-cutting apparatus. Alternatively, the cut-hair-blocking element may be fixed.
The cut-hair-blocking element in the above described embodiments and examples may be integrated to the nozzle design of the appliance without requires an additional component. An example of the integrated cut-hair-blocking element is shown in
An advantage of having the example hair-cutting apparatus kit in
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 a claimed invention, from a study of the drawings, the disclosure, and the dependent 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 processor or other unit may fulfil the functions of several items re-cited in the claims. The mere fact that certain measures are re-cited 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 |
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19189104.3 | Jul 2019 | EP | regional |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2020/071321 | 7/28/2020 | WO |