Shaving device with improved contour following

Abstract

A shaving head includes at least one cutting unit in which an external cutting member is subjected to a shaving action. The external cutting member is suspended relative to a holder of the shaving head through suspension means. The suspension means includes at least two pivot constructions, wherein one pivot construction enables a member of the suspension means to be pivotable relative to the holder. The other pivot construction enables the external cutting member to be pivotable relative to the suspension member. Furthermore, a pivoting stiffness of a connection of the latter pivot construction is lower than a pivoting stiffness of the first pivot construction. In this manner, good contour following performance is obtained at two levels, in both relatively small and relatively large curvature changing areas.

Claims

1. A shaving head for use in a shaving device for removing hairs from skin by cutting through the hairs, said shaving head comprising at least one cutting unit and a holder configured to hold the at least one cutting unit, said holder being adapted to be mounted on a body portion of the shaving device, said body portion being configured to be held by a user of the shaving device and being adapted to accommodate one or more members of the shaving device; where the at least one cutting unit comprises an external cutting member having a surface configured to contact skin during a shaving action and having openings configured to allow hairs to pass; where the at least one cutting unit further comprises an internal cutting member, said internal cutting member being drivable for movement along the openings in the surface of the external cutting member and being adapted to cut through hairs during such movement; and where the external cutting member is suspended relative to the holder through a suspension assembly comprising: a first suspension member being tiltable with respect to the holder about a tilting axis (c), the tilting axis (c) extending into a circumferential area of the at least one cutting unit at a side of the at least one cutting unit, said side being proximal to a central axis of the shaving head; and a second suspension member being tiltable with respect to the first suspension member about a tilting axis (d), where said tilting axis (d) extends in a direction relative to said tilting axis (c) for enabling tilting of the second suspension member cooperatively with said first suspension member; where the first and second suspension members have respective first and second pivoting stiffness threshold values that need to be exerted to effect a tilting movement about respective ones of the tilting axes (c) and (d), the threshold value for effecting tilting of the second suspension member about axis (d) being lower than the threshold value for effecting tilting of the first suspension member about the axis (c), and where the external cutting member of the at least one cutting unit is mounted to the second suspension member.

2. The shaving head of claim 1, where the first and second suspension members comprise concentrically-arranged rings.

3. The shaving head of claim 2, where when viewed from a side thereof facing skin to be contacted by the at least one cutting unit, the first suspension member underlies the second suspension member and the second suspension member covers at least a portion of the first suspension member, such that the covered portion is prevented from contacting said skin.

4. The shaving head of claim 1, where the tilting axes (c) and (d) extend at mutually different first and second levels with respect to the skin-contacting surface of the external cutting member.

5. The shaving head of claim 4, where the tilting axis (c) extends at the first level with respect to the skin-contacting surface of the external cutting member and the tilting axis (d) extends at the second level with respect to said skin-contacting surface of said external cutting member, said first level being further away than said second level from the skin-contacting surface of the external cutting member.

6. The shaving head of claim 1, where tilting axis (c) extends substantially parallel to tilting axis (d).

7. The shaving head of claim 1, where the internal cutting member is rotatably arranged.

8. The shaving device of claim 1, where the holder is adapted to allow for pivotal movements with respect to said body portion about one of a tilting axis (a) and a tilting axis (b) and where the tilting axis (c) extends substantially parallel to said one of tilting axis (a) and tilting axis (b) of the holder.

9. A shaving device for removing hairs from skin by cutting through the hairs, comprising: a body portion configured to be held by a user of the shaving device and being adapted to accommodate one or more members of the shaving device; and a shaving head comprising at least one cutting unit and a holder configured to hold the at least one cutting unit, said holder being adapted to be mounted on the body portion of the shaving device; where the at least one cutting unit comprises an external cutting member having a surface configured to contact skin during a shaving action and having openings configured to allow hairs to pass; where the at least one cutting unit further comprises an internal cutting member, said internal cutting member being drivable for movement along the openings in the surface of the external cutting member and being adapted to cut through hairs during such movement; and where the external cutting member is suspended relative to the holder through a suspension assembly comprising: a first suspension member being tiltable with respect to the holder about a tilting axis (c), the tilting axis (c) extending into a circumferential area of the at least one cutting unit at a side of the at least one cutting unit, said side being proximal to a central axis of the shaving head; and a second suspension member being tiltable with respect to the first suspension member about a tilting axis (d), where said tilting axis (d) extends in a direction relative to said tilting axis (c) for enabling tilting of the second suspension member cooperatively with said first suspension member; where the first and second suspension members have respective first and second pivoting stiffness threshold values that need to be exerted to effect a tilting movement about respective ones of the tilting axes (c) and (d), the threshold value for effecting tilting of the second suspension member about axis (d) being lower than the threshold value for effecting tilting of the first suspension member about the axis (c).

10. The shaving device of claim 9, where the shaving head comprises at least two cutting units.

11. The shaving device of claim 9 where the holder is adapted to allow for pivotal movements with respect to said body portion about one of a tilting axis (a) and a tilting axis (b) and where the tilting axis (c) extends substantially parallel to one of said tilting axis (a) and said tilting axis (b) of the holder.

12. A shaving head for use in a shaving device for removing hairs from skin by cutting through the hairs, said shaving head comprising at least one cutting unit and a holder configured to hold the at least one cutting unit, said holder being adapted to be mounted on a body portion of the shaving device, said body portion being configured to be held by a user of the shaving device and being adapted to accommodate one or more members of the shaving device; where the at least one cutting unit comprises an external cutting member having a surface configured to contact skin during a shaving action and having openings configured to allow hairs to pass; where the at least one cutting unit further comprises an internal cutting member, said internal cutting member being drivable for movement along the openings in the surface of the external cutting member and being adapted to cut through hairs during such movement; and where the external cutting member is suspended relative to the holder through a suspension assembly comprising: a first suspension member being tiltable with respect to the holder about a tilting axis (c), the tilting axis (c) extending into a circumferential area of the at least one cutting unit at a side of the at least one cutting unit, said side being proximal to a central axis of the shaving head; and a second suspension member being tiltable with respect to the first suspension member about a tilting axis (d), where said tilting axis (d) is parallel to said tilting axis (c); said first and second suspension members having respective first and second pivoting stiffness threshold values that need to be exerted to effect a tilting movement about respective ones of the tilting axes (c) and (d), the threshold value for effecting tilting of the second suspension member about axis (d) being lower than the threshold value for effecting tilting of the first suspension member about the axis (c).

13. A shaving head for use in a shaving device, said shaving head comprising at least one cutting unit and a holder configured to hold the at least one cutting unit, said holder being adapted to be mounted on a body portion of the shaving device, said body portion being configured to be held by a user of the shaving device and being adapted to accommodate one or more members of the shaving device; where the at least one cutting unit comprises an external cutting member having a first surface configured to contact skin during a shaving action, having openings configured to allow hairs to pass and having a second surface opposite the first surface, the second surface being configured to cooperate with an internal cutting member to cut through hairs during such cooperation; and where the external cutting member is suspended relative to the holder through a suspension assembly comprising: a first suspension member being tiltable with respect to the holder about a tilting axis (c), the tilting axis (c) extending into a circumferential area of the at least one cutting unit at a side of the at least one cutting unit, said side being proximal to a central axis of the shaving head; and a second suspension member being tiltable with respect to the first suspension member about a tilting axis (d), where said tilting axis (d) extends in a direction relative to said tilting axis (c) for enabling tilting of the second suspension member cooperatively with said first suspension member; where the first and second suspension members have respective first and second pivoting stiffness threshold values that need to be exerted to effect a tilting movement about respective ones of the tilting axes (c) and (d), the threshold value for effecting tilting of the second suspension member about axis (d) being lower than the threshold value for effecting tilting of the first suspension member about the axis (c), and where the external cutting member of the at least one cutting unit is mounted to the second suspension member.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will now be explained in greater detail with reference to the Figures, in which equal or similar parts are indicated by the same reference signs, and in which:

(2) FIG. 1 diagrammatically shows a perspective view of a shaving device known per se;

(3) FIG. 2 diagrammatically shows a perspective view of a shaving head according to the present invention;

(4) FIG. 3 diagrammatically shows a perspective view of a section of a cutting unit of a shaving head according to the present invention;

(5) FIGS. 4 and 10 illustrate the degrees of freedom of a movement of a cutting unit of a shaving head according to the present invention;

(6) FIGS. 5 and 6 diagrammatically show views of an alternative shaving head, in which an end suspension member of the cutting units is adapted to cover a portion of a basic suspension member; and

(7) FIGS. 7, 8 and 9 diagrammatically show views of another alternative shaving head, in which an end suspension member of the cutting units is adapted to completely cover a basic suspension member.

DETAILED DESCRIPTION OF EMBODIMENTS

(8) FIG. 1 shows a conventional shaving device 1 such as known from WO 2006/067721. The shaving device 1 is a rotary shaving device in which a shaving action is realized by using rotating components. Another well-known type of shaving device is a device in which a shaving action is realized by using reciprocating components. For the sake of completeness, it is noted that the present invention is applicable in various types of shaving devices.

(9) The shaving device 1 comprises a body portion 2 and a shaving head 3 in which a number of cutting units 4 are located. The body portion 2 is intended to be taken hold of by a user of the shaving device 1, while the cutting units 4 are intended to be positioned against skin which is to be subjected to a shaving action, for actually performing a shaving action. In the shown example, the shaving head 3 has three cutting units 4.

(10) Each cutting unit 4 comprises an external cutting member 5 which is shaped like a cap having an external skin contacting surface 6 and openings 7 for letting through hairs to an inside of the cutting unit 4, and an internal cutting member (not shown) having a number of cutting blades which are positioned in an inside space of the cutting unit 4 on a suitable support portion, and which are adapted to cut off the hairs. During operation of the shaving device 1, the support portion having the cutting blades is driven such as to rotate. To this end, the shaving device 1 may be equipped with any suitable driving means (not shown) such as a small electric motor.

(11) The operation of a shaving device 1 comprising a shaving head 3 having one or more cutting units 4, wherein each of the cutting units 4 comprises an external cutting member 5 and an internal cutting member as described in the foregoing, is as follows. When the shaving device 1 is used for performing a shaving action, the external cutting members 5 are moved across a portion of skin to be subjected to the shaving action by a user of the shaving device 1, and the internal cutting members are driven such as to rotate at their position right behind the external cutting members 5. Due to the movement of the cutting units 4 with respect to the skin, there is a continuous process of hairs getting trapped inside the openings 7 of the external cutting members 5 and being encountered by the cutting blades of the internal cutting members, as a result of which the hairs are cut through.

(12) The shaving device 1 comprises a holder 8 for holding the cutting units 4 and mounting the shaving head 3 on the body portion 2. Furthermore, in the conventional situation as illustrated in FIG. 1, each of the cutting units 4 comprises a suspension ring 9 for realizing a pivot connection between the external cutting member 5 and the holder 8, wherein a tilting axis extends in a circumferential area of the cutting unit 4, at a side of the cutting unit 4 which is near a central axis of the shaving head 3. By having the tilting axis in a structure extending from the body portion 2 to the external cutting member 5, the external cutting member 5 and the associated internal cutting member are allowed to follow a given curvature of skin to be subjected to a shaving action.

(13) The present invention relates to the way in which the external cutting members 5 of the cutting units 4 are suspended relative to the holder 8. FIG. 2 shows an embodiment of a shaving head 3 according to the present invention. In comparison with the conventional situation, each cutting unit 4 comprises two suspension rings 9, 10 instead of just one. In particular, there is a basic suspension ring 9 which is comparable to the suspension ring 9 which is present in the conventional situation. This basic suspension ring 9 is an outer ring which is tiltable about a tilting axis located in a circumferential area of the cutting unit 4. Inside the basic suspension ring 9, in a concentric arrangement, another suspension ring 10 is arranged, and in this suspension ring 10 the external cutting member 5 is arranged. The basic suspension ring 9 is pivotably connected to the holder 8, and the additional suspension ring 10, which is also denoted as end suspension ring 10, is pivotably connected to the basic suspension ring 9.

(14) In FIG. 3, the configuration of the external cutting member 5 and the suspension rings 9, 10 is clearly illustrated. In the concentric arrangement as mentioned, the suspension rings 9, 10 are connected to each other at two places which are located on an imaginary straight line intersecting the centre of the concentric arrangement, and in this way, the pivot connection between the suspension rings 9, 10 is obtained. For the sake of completeness, it is noted that in the diagrammatic depiction in FIG. 3, details like the openings 7 in the skin contacting surface 6 of the external cutting member 5 are not shown.

(15) FIGS. 4 and 10 serve to illustrate the various degrees of freedom of movement of a cutting unit 4, which are obtained when at least one additional suspension ring 10 is applied for suspending the external cutting member 5 relative to the holder 8. In the first place, the holder 8 is adapted to allow for rotational movements with respect to the body portion 2, which is only partially shown in FIGS. 4 and 10, about two perpendicular tilting axes a, b. In the second place, the basic suspension ring 9 is tiltable with respect to the holder 8 about a tilting axis c. In the shown example, this tilting axis c extends substantially parallel to one of the tilting axes a, b of the holder 8. In the third place, the end suspension ring 10 is tiltable with respect to the basic suspension ring 9 about a tilting axis d, which, in the shown example, extends substantially parallel to the tilting axis c of the basic suspension ring 9 and one of the tilting axes a, b of the holder 8. Furthermore, FIGS. 4 and 10 clearly show that, in the shown example, the tilting axis c of the basic suspension ring 9 has an off-centre position with respect to the cutting unit 4 and the external cutting member 5, whereas the relative position as mentioned of the tilting axis d of the end suspension ring 10 is a central one. In the fourth place, the external cutting member 5 is tiltable with respect to the end suspension ring 10 about a tilting axis e, which, in the shown example, extends perpendicularly to the tilting axes c, d of the suspensions rings 9, 10.

(16) In view of the overall construction of the shaving device 1 and the desired application of the shaving device 1, it will be understood that there is only a need for tilting movements of the holder 8 and the suspension rings 9, 10 in limited ranges. For example, the tilting movements of the holder 8 may be in a range of 10 in two opposite rotational directions, starting from a default position of the holder 8, and the tilting movements of the basic suspension ring 9 may be in a range of 10 in only one rotational direction, starting from a default position of the basic suspension ring 9, and the tilting movements of the end suspension ring 10 may be in a range of 7 in two opposite rotational directions, starting from a default position of the end suspension ring 10.

(17) In the shaving device 1 according to the present invention, the extent to which the contours of skin to be subjected to a shaving action can be followed is improved. In this respect, it is noted that an important feature of the suspension configuration in which at least two members 9, 10 which are tiltable with respect to each other are present is that a stiffness of the pivot connection of the suspension members 9, 10 with respect to each other is lower than a stiffness of the pivot connection of the basic suspension member 9 to the holder 8. Hence, the momentum needed to rotate the end suspension member 10 is much lower than the momentum needed to rotate the basic suspension member 9. An advantage of this fact appears to be that a good contour following performance is obtained at two levels, namely at the level of an area of relatively small curvature changes and at the level of an area of relatively large curvature changes, wherein the end suspension member 10 is primarily the member which allows for coverage of the first area, and wherein the basic suspension member 9 is primarily the member which allows for coverage of the latter area.

(18) Another factor contributing to contour following is to have a tilting axis which is closer to skin level. In the shown example, the tilting axis d of the end suspension ring 10 with respect to the basic suspension ring 9 is closer to skin level than the tilting axis c of the basic suspension ring 9 with respect to the holder 8. On the basis of this fact, contour following is improved with respect to a situation in which there is only a basic suspension ring 9, i.e. the end suspension ring 10 is omitted. When a tilting axis is closer to skin level, the extent to which the external cutting member 5 slides over the skin during a rotation of the member 9, 10 tilting about the tilting axis is reduced, and the sensitivity to friction forces is reduced as well.

(19) The tilting axes c, d of the various suspension members 9, 10 may be parallel, as is the case in the shown example, but may also have a mutually different orientation, even perpendicular to one another. Another possibility is that there are more than two suspension members 9, 10, wherein an end suspension member 10 and an underlying intermediate suspension member may be tiltable in perpendicular directions. When pivot connections are realized in various directions, the capability of contour following in the various directions is obtained, which is improved contour following with respect to a situation of movability in fewer directions.

(20) FIGS. 5 and 6 show a first alternative design of the cutting units 4. When compared to the design of the cutting units 4 shown in FIGS. 2-4, the shape of the end suspension member 10 has changed. In particular, a portion 11 of the end suspension member 10 is shaped such as to cover a portion of the underlying basic suspension member 9, as seen from a side where contact between the cutting units 4 and the skin is to take place. In the shown example, this portion 11 is a portion which is at a side of the end suspension member 10 facing away from the centre of the shaving head 3.

(21) With the alternative design of the end suspension member 10, the way in which the feel of the shaving units 4 is experienced by a user of the shaving device 1 is improved. The reason is that with the enlarged portion 11 of the end suspension member 10, a smooth skin contacting surface is realized, wherein a length of a transition between the end suspension member 10 and the basic suspension member 9 is covered and thereby prevented from contacting skin. In that way, the possibility of a smooth gliding of the external cutting members 5 and the surrounding structures over the skin is enhanced.

(22) FIGS. 7, 8 and 9 show a second alternative design of the cutting units 4. According to this design, the end suspension member 10 is capable of completely covering the basic suspension member 9, so that there is no longer a transition between the suspension members 9, 10 where contact to the skin may take place.

(23) It will be clear to a person skilled in the art that the scope of the present invention is not limited to the examples discussed in the foregoing, but that several amendments and modifications thereof are possible without deviating from the scope of the present invention as defined in the attached claims. While the present invention has been illustrated and described in detail in the Figures and the description, such illustration and description are to be considered illustrative or exemplary only, and not restrictive. The present invention is not limited to the disclosed embodiments.

(24) Variations to the disclosed embodiments can be understood and effected by a person skilled in the art in practicing the claimed invention, from a study of the Figures, the description and the attached claims. In the claims, the word comprising does not exclude other steps or elements, and the indefinite article a or an does not exclude a plurality. 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 of the present invention.

(25) It is noted that the designs of a cutting unit 4 of the shaving device 1 according to the present invention as shown in the Figures, i.e. designs with suspension members 9, 10 comprising rings in a concentric arrangement, allow for a compact structure of the cutting unit 4. Nevertheless, other shapes and configurations of the suspension members 9, 10 are feasible as well, as long as these members 9, 10 are capable of constituting a connection between the holder 8 and the external cutting member 5, wherein there is a pivot connection both at the location of the connection of the suspension members 9, 10 to the holder 8 and at the location where two suspension members 9, 10 are connected to each other, and wherein a pivoting stiffness of the latter connection is lower than a pivoting stiffness of the first connection. When the suspension means of the shaving unit 4 comprise more than two suspension members, it is important that a stiffness of a pivoting arrangement of a suspension member is lower at a level which is further away from the holder 8 of the shaving device 1 than at a level which is closest to the holder 8.

(26) For the sake of completeness, it is noted that the cutting units 4 may be arranged such as to be detachable with respect to the body portion 2 of the shaving device 1. For example, it may be possible for a user to remove the entire shaving head 3 from the body portion 2 for cleaning purposes, wherein the connection between the holder 8 of the shaving head 3 and the body portion 2 may be realized in any suitable manner for allowing easy detachment and attachment.

(27) In a shaving device 1 comprising more than one cutting unit 4, it is possible for the pivoting stiffness of pivot constructions to vary from cutting unit 4 to cutting unit 4. In other words, the pivoting stiffness of the pivot constructions of one cutting unit 4 does not necessarily need to be the same as the pivoting stiffness of similar pivot constructions of another cutting unit 4. Nevertheless, in a shaving device 1, it is preferred that all cutting units 4 are constructed according to the present invention, namely in such a way that a stiffness of a pivoting arrangement of a suspension member of the cutting unit 4 is lower at a level which is further away from a holder 8 of the shaving device 1 than at a level which is closest to the holder 8, as has been explained in the foregoing.

(28) The present invention can be summarized as follows. A shaving head 3 for use in a shaving device 1 comprises at least one cutting unit 4 in which an external cutting member 5 and an internal cutting member are arranged. In particular, the internal cutting member is movably arranged, and the internal cutting member is adapted to perform a cutting action on hairs when moving with respect to the hairs. The external cutting member 5 serves for contacting skin to be subjected to a shaving action, and allowing hairs to pass from the skin to the internal cutting member. To this end, the external cutting member 5 may be shaped like a cap covering the internal cutting member, which cap is provided with openings 7.

(29) In addition to the cutting unit 4, the shaving head 3 comprises a holder 8 for mounting the cutting unit 4 on a body portion 2 of a shaving device 1. For the purpose of suspending the external cutting member 5 relative to the holder 8, suspension means are provided. According to the present invention, the suspension means comprise at least two pivot constructions, wherein one pivot construction enables a member of the suspension means to be pivotable relative to the holder, and wherein another pivot construction enables the external cutting member to be pivotable relative to the suspension member as mentioned. Furthermore, a pivoting stiffness of a connection of the latter pivot construction is lower than a pivoting stiffness of the first pivot construction.

(30) On the basis of the features of the suspension means as mentioned, skin contour following is improved, wherein good contour following performance is obtained at two levels, namely at the level of an area of relatively small curvature changes and at the level of an area of relatively large curvature changes.