Patent Application
20210023728
The invention relates to a shaving device for shaving hairs. More specifically, the invention relates to a cutting unit for use in a shaving device for shaving hairs, said cutting unit comprising:
The invention also relates to a shaving head for use in a shaving device for shaving hairs, wherein said shaving head comprises at least one cutting unit of the type described here before.
For cutting units and shaving heads of the above-identified types, there are a number of desirable design requirements.
A first desirable design requirement is that changing the condition of the external and internal cutting members from the abovementioned interconnected condition into the abovementioned disconnected condition, and vice versa, should be possible through manual operations by a user.
A second desirable design requirement is that said manual operations should neither require nor allow the user to directly touch the internal cutting member at a moment when the internal cutting member is drivably connected to its rotative drive structure. Thus, it is prevented that the user might get hurt in case of inadvertent activation of the rotative drive structure.
A third desirable design requirement is that, after the external and internal cutting members have been correctly brought into the abovementioned interconnected condition, the internal cutting member will be kept correctly positioned against the external cutting member during the subsequent connecting of the internal cutting member to its rotative drive structure. Thus, it is prevented that the cutting members, due to incorrect relative positioning thereof, might get damaged upon activation of the rotative drive structure.
In view of these desirable design requirements, a cutting unit of a shaving head of the initially identified type often is designed with a separate support device, also referred to as “retainer”. This separate retainer is manually moveable between a retaining position, in which the internal cutting member is retained by the retainer in a correct operating position relative to the external cutting member, and a release position in which a user can remove the internal cutting member from the external cutting member.
An example of a known shaving head having such a retainer is disclosed in WO 2011/055323 A1. This shaving head 3 and details thereof are shown in FIGS. 1-8 of WO 2011/055323 A1. It is shown that each cutting unit 6 of the shaving head 3 has an external cutting member 7, an internal cutting member 10, and a retainer 21. The retainer 21 is connected to the external cutting member 7 in a pivotable manner so as to enable said manual moveability between said retaining position and said release position. In its retaining position, the retainer 21 can be locked relative to the external cutting member 7, while the internal cutting member 10 is retained in-between the retainer 21 and the external cutting member 7.
It is also clearly seen that the internal cutting member 10 can be manually moved out of the cutting unit when the internal cutting member 10 is not drivably connected to the drive shaft 30, see FIG. 7 of WO 2011/055323 A1. Furthermore, it is clear that the cutting unit 6 does not allow the user to directly touch the internal cutting member at a moment when the internal cutting member is drivably connected to its rotative drive structure.
It is noted that in practice various other types of separate retainers are known, which can be locked relative to an external cutting member, while retaining an internal cutting member in-between the retainer and the external cutting member. Most of these other separate retainers are not pivotably connected to the external cutting member. Instead, after a user has manually unlocked such other retainer relative to its corresponding cutting unit, such other retainer is fully detachable from the external cutting member in a translation direction parallel to the rotation axis of the cutting unit. Most of these other retainers are small, more or less ring-like parts, while there exist many different locking mechanisms for the existing many different retainer types.
A general drawback of most of these known retainers is that the manual operations required for removing and inserting the internal cutting members relative to their cutting units are not easy for users to understand and/or perform and/or remember. For example, the locking and unlocking of the retainers relative to their corresponding cutting units often is cumbersome, especially because most of these retainers are small parts which are difficult to operate accurately with the fingers, and which have very tiny locking parts which are difficult to discern with the naked eye.
Another general drawback of most of these known retainers is that these known retainers are in fact additional parts of the cutting unit or shaving head, and that they require additional space within the cutting unit or shaving head.
It is an object of the invention to meet the above-described three desirable design requirements, while at the same time the internal cutting members can be manually removed and inserted relative to their cutting units in a very easy, comfortable and intuitive manner, and while at the same time the structure to achieve all this is non-complex and compact.
For that purpose, the invention provides a cutting unit and a shaving head. Consequently, the invention provides a cutting unit for use in a shaving device for shaving hairs, said cutting unit comprising:
Consequently, according to the invention, said holding force is provided directly between the external cutting member and the internal cutting member, which obviates the need for an additional separate retainer to retain the internal cutting member in-between the retainer and the external cutting member. The fact that said holding force is provided, more specifically, via said two central portions of the internal and external cutting members, respectively, still allows for rotative movement of the internal and external cutting members relative to one another about the rotation axis, which is aligned with the centre line of the two central portions. Furthermore, in order to disconnect the internal cutting member from the external cutting member, a user only needs to exert a simple and intuitive one-directional pulling force to overcome said holding force.
A preferable embodiment of the invention is defined in that, in said interconnected condition, the first central portion and the second central portion are mutually co-operating portions providing radial bearing support for said rotative movement. In this way, the two central portions of the internal and external cutting members have a multifunctional character, which further improves the compactness of the cutting unit.
A further preferable embodiment of the invention is defined in that the first central portion of the external cutting member comprises a first snap connection structure and the second central portion of the internal cutting member comprises a second snap connection structure, and wherein the first snap connection structure and the second snap connection structure mutually co-operate for providing at least part of said holding force by means of a snap connection. For users, such a snap connection is an easy and intuitive manner of realizing said holding forces.
Preferably, in said interconnected condition, the first snap connection structure and the second snap connection structure provide radial bearing support for said rotative movement. In this way, the snap connection has a multifunctional character, which further improves the compactness of the cutting unit.
Preferably, in said interconnected condition, the first snap connection structure and the second snap connection structure allow an amount of play of at least 0.2 millimeter, and preferably at least 0.4 millimeter, in respect of translational movement of the internal cutting member relative to the external cutting member in a direction parallel to said rotation axis. Said allowed translational movement improves the performance of the cutting unit, since during the cutting of a hair, the cutting forces present tend to press the cooperating cutting edges of the internal and external cutting member somewhat apart from one another. It is important to allow these cutting edges to thus move apart, since it will cause the contact pressure between the internal and external cutting member to be decreased during cutting of a hair, which decreases friction. As a further clarification, it is noted that usually in rotary shavers the drive member of the internal cutting member resiliently presses the internal cutting member in the direction of the external cutting member, which is usually realized by using a helical spring or the like. In such a case, a short time after the hair has been cut, spring force will cause the internal cutting member to move back in the direction of the external cutting member again. Some degree of decaying vibratory effect (known as the “bouncing effect”) may then occur, wherein the internal cutting member under said spring force bounces a few times against the external cutting member.
In a further preferable embodiment of the invention, the cutting unit further comprises a magnet system configured, arranged and effective to provide magnetic attraction at least between the first central portion and the second central portion for providing at least part of said holding force. The use of such a magnet system provides the user with a very easy, comfortable and intuitive way to precisely position the internal cutting member relative to the external cutting member. It is noted that such a magnet system may comprise a permanent magnet or an electromagnet. The first central portion may contain a magnet. Similarly, the second central portion may contain a magnet.
In a further preferable embodiment, said magnet system comprises a magnet associated with and arranged in and/or at the first central portion for providing said magnetic attraction. In such an embodiment, the second central portion may contain magnetizable material.
Preferably, in said interconnected condition a magnetic axis of said magnet associated with the first central portion is aligned with said rotation axis. By virtue of this alignment of said magnetic axis and the rotation axis, said magnetic attraction is very effective, while at the same time said rotative movement is very smooth.
In a further preferable embodiment, said magnet system comprises a magnet associated with and arranged in and/or at the second central portion for providing said magnetic attraction. In such an embodiment the first central portion may contain magnetizable material.
Preferably, in said interconnected condition a magnetic axis of said magnet associated with the second central portion is aligned with said rotation axis. By virtue of this alignment of said magnetic axis and the rotation axis, said magnetic attraction is very effective, while at the same time said rotative movement is very smooth.
The invention may also be embodied in a shaving head for use in a shaving device for shaving hairs, said shaving head comprising at least one cutting unit according to the invention.
In a preferable embodiment of a shaving head according to the invention, the shaving head comprises at least one cutting unit, wherein each cutting unit comprises:
In a further embodiment, said at least one cutting unit is a multiplicity of respective cutting units, and the shaving head comprises a magnet system configured, arranged and effective to provide magnetic attraction at least between the first central portion and the second central portion of each respective cutting unit for providing at least part of said holding force, and said magnet system comprises a magnet associated with the shaving head and arranged in and/or at the shaving head so as to be remote from the first central portion and the second central portion of each respective cutting unit for simultaneously magnetically influencing said first and second central portions of each respective cutting unit for providing said magnetic attraction between the first and second central portions of each respective cutting unit. The use of such a magnet associated with the shaving head allows the manufacture of the internal and external cutting members of the shaving head without providing any magnets therein. All that is needed is magnetizable material in and/or at the first and second central portions of the external and internal cutting members.
The invention may also be embodied in a shaving device for shaving hairs, comprising:
The above mentioned aspects and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter by way of non-limiting examples only and with reference to the schematic figures in the enclosed drawing.
The reference signs used in the abovementioned
Reference is first made to
In the shown example, the first snap connection structure 31 includes a first radial extension 34 and a bearing stud 38, extending from the first radial extension 34, wherein a free end 35 of the bearing stud 38 has a locally increased diameter, while the second snap connection structure 32 defines a cylindrical recess 39, whose entry opening has a locally decreased diameter provided by a second radial extension 36 extending radially from a circumferential wall 37 of the second snap connection structure 32, while allowing the play 20. In general, the bearing surfaces of the rotative movement between the external and internal cutting members may, amongst others, be formed with such a locally decreased diameter surface of the entry opening of the cylindrical recess and/or such a locally increased diameter surface of the free end of the bearing stud and/or with any other surfaces of the external and internal cutting members.
Generally, the first snap connection structure and/or the second snap connection structure may for example be made of a resilient material. In the shown example, the structure defining the cylindrical recess 32 may for example be made of a resilient plastic material.
The snap connection is preferably designed in such a manner that said holding forces in the first place are sufficient for the internal cutting members to remain in the external cutting members at least when the shaving head 3 is being taken apart from the situation as shown in
Reference is now made to
Furthermore it is seen that, in the shown example, the magnet 230 is associated with, and arranged in, the second central portion 222 for providing the abovementioned magnetic attraction between the first central portion 221 and the second central portion 222. In the shown example, the first central portion 221 comprises magnetizable material.
In
A practical shape for the magnet used is a cylindrical shape having a diameter of between 2 and 3 mm and a height of between 1 and 3 mm. The force-density requirements are modest, so a relatively low-cost grade of neodymium magnet is already sufficient.
Reference is now made to
Furthermore, it is seen that, in the shown example, the magnet 330 is associated with the shaving head and arranged in the shaving head so as to be remote from the first central portions 321 and 321A and from the second central portions 322 and 322A for magnetically influencing these first central portions and these second central portions for providing the abovementioned magnetic attraction between the first central portion 321 and the second central portion 322, as well as for simultaneously providing the abovementioned magnetic attraction between the first central portion 321A and the second central portion 322A.
In
While the invention has been described and illustrated in detail in the foregoing description and in the figures, such description and illustration are to be considered exemplary and/or illustrative 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 processor or other unit may fulfill the functions of several items recited in the claims. For the purpose of clarity and a concise description, features are disclosed herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features disclosed. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures can not be used to advantage.
Any reference signs in the claims should not be construed as limiting the scope.
| Number | Date | Country | Kind |
|---|---|---|---|
| 15168613.6 | May 2015 | EP | regional |
This application is a Divisional of U.S. patent application Ser. No. 15/572,183, filed on Nov. 7, 2017, which is the U.S. National Phase application under 35 U.S.C. § 371 of International Application No. PCT/EP2016/060116, filed on May 5, 2016, which claims the benefit of European Patent Application No. 15168613.6 filed on May 21, 2015. These applications are hereby incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15572183 | Nov 2017 | US |
| Child | 17069914 | US |
