WO2006067713A1

WO2006067713A1 - Shaver with improved drive mechanism

Info

Publication number: WO2006067713A1
Application number: PCT/IB2005/054281
Authority: WO
Inventors: Robert A. Van Eibergen Santhagens
Original assignee: Koninklijke Philips Electronics N.V.
Priority date: 2004-12-22
Filing date: 2005-12-16
Publication date: 2006-06-29

Abstract

The invention relates to a shaver (1) comprising a shaving body (2), a shaving unit (3) with at least two rotary shaving heads (5) and drive means (4) for driving an internal cutter member (8) of each shaving head (5) along an external cutter member (7) of such head (5), said drive means (4) comprising a motor (10), at least one drive shaft (15), wherein said motor (10) is accommodated in the shaving body (2), separated from the shaving unit (3) by a partition (16) and wherein only a single drive shaft (15) extends through said partition (16) for driving the respective cutter members (8) of the shaving unit (3) via suitable transmission means (20, 25).

Description

Shaver with improved drive mechanism

The invention relates to a shaver, comprising a shaving body, a shaving unit with at least two rotary shaving heads, and drive means for rotating an internal cutter member of the shaving heads along an external cutter member thereof.

Such shavers are known. The drive means may comprise a number of drive shafts, in particular one shaft per shaving head, and at least one motor for driving said shafts via suitable transmission means. The individual drive shafts allow the shaving heads to be resiliently supported in such way that their positions can be adapted independent from each other, during use, thereby allowing the shaving surface to conform to the contours of a user's skin, which helps to achieve a close shave. Usually, the at least one motor is accommodated in the shaving body, separated from the shaving unit by a partition. Such partition may help to protect the motor against contamination, for instance by hairs, moist or shaving lotion, which during use may enter the shaving heads, especially when such shavers are used in combination with shaving lotion or in a wet environments, such as in a shower. A disadvantage of this known shaver is that in order to properly guide the drive shafts through said partition, without undue energy losses, additional measures need to be taken. For instance, to minimize friction, wear and/or slanting of the shafts, the shafts may need additional support near the partition, for instance by means of bearings or the like guiding means. Also, to render the partition waterproof, additional seals are needed to seal off the passages for the shafts in the partition. Such seals may introduce additional friction and consequently result in increased energy consumption. Also, these additional parts add to the complexity, costs, and vulnerability of the shaver.

It is therefore an object of the present invention to provide a shaver of the above-described type, wherein the disadvantages of the known shavers are avoided, while maintaining the advantages thereof. To that end, a shaver according to the invention is characterised by the features of claim 1.

In a shaver according to the invention, at least part of the transmission means, which transmit a rotational motion of the motor to the shaving heads, is relocated from a position at the same side of the partition as the motor, to a position at the other side of the partition. By doing so, only a single drive shaft needs to pass said partition, and consequently, only a minimum of adjustment means, such as bearings and seals, is needed to properly guide said shaft through the partition. Meanwhile, the motor can maintain its relatively well protected position behind the partition. In a preferred embodiment, the partition may be of watertight design, thereby protecting the motor against moist and shaving lotion. In such case, only a single seal suffices to seal off the shaft passage in the partition and maintain the partition watertight.

Preferably, the transmission means are mounted in or on the shaving unit, so that the shaving unit can at least partly conceal said transmission means and protect these means and a user against direct contact. It furthermore allows the transmission means to be positioned closely to the shaving heads, resulting in a compact design. It may also allow the transmission means to be detached from the shaver, together with said shaving unit, which may for instance be beneficial for maintenance and/or cleaning purposes. Of course, in the latter case, the transmission means need to be detachably coupled to the single drive shaft. In a preferred embodiment the internal cutter members are directly fastened to a transmission means, that is without intermediate parts. For instance, in case the transmission means is a gear wheel, this gear wheel may be directly attached to the internal cutter member, and rotate together with this cutter member along the external cutter member. Thanks to such configuration, the number of components may be even further reduced, as well as the dimensions of the shaving head and shaving unit.

In a further advantageous embodiment, the shaving unit and shaving body may be designed to enclose a chamber, for collecting hairs, shaving lotion, and the like, which during use may enter the shaver via the shaving heads. To clean the chamber, the shaving head is preferably detachably coupled to the shaving body. Thanks to the drive mechanism according to the invention, the chamber will be traversed by a single shaft only, instead of a number of shafts, rendering the chamber readily accessible and therefore easy to clean. In an alternative embodiment, the shaving unit may be connected to the shaving body via a central support structure, extending around the single drive shaft, in such way that the space between the shaving unit and the shaving body is substantially open, apart from said central support. Thanks to such open space, the shaving heads will be visible during use, thereby providing a user with visual feedback, which allows him to accurately control his shaving movements. Also, such shaver will be easy to clean, for instance by immersing the shaving unit into water. Further advantageous embodiments of a shaver according to the present invention are set forth in the dependent claims.

To explain the invention, exemplary embodiments thereof will hereinafter be described with reference to the accompanying drawings, wherein:

Fig. 1 schematically shows a shaver according to the invention, in cross sectional view;

Fig. 2 shows in perspective view a further embodiment of a shaver according to the invention;

Fig. 3 A₅B show in more detail the shaving unit of the shaver of Fig. 2 in perspective view and cross sectional view respectively;

Fig. 4 shows in exploded view a shaving head of the shaving unit of Fig. 3; and Fig. 5 shows in exploded view a holder for the shaving unit of Fig. 3, for mounting three shaving heads according to Fig. 4.

In this description, identical or corresponding parts have identical or corresponding reference numerals.

Fig. 1 shows, very schematically, an upper portion of a shaver 1 according to the invention, comprising a shaving body 2, a shaving unit 3 with a number of shaving heads 5 and drive means 4 for driving said shaving heads 5. The shaving unit 3 furthermore comprises a holder 6, for supporting the shaving heads 5. This holder 6 is preferably hingedly or detachably connected to the shaving body 2. In the embodiment of Fig. 1, only one shaving head 5 is visible. It will be understood that the embodiment as described may comprise two or more shaving heads 5, which may be arranged in every possible formation, such as a triangle according to the embodiment of Fig. 2.

Each shaving head 5 comprises a substantially cap-shaped external cutter member 7 and an internal cutter member 8. The external cutter member 7 comprises an annular running groove 9, provided with hair entry apertures 11 (for instance as shown in the embodiment of FIG. 2). The internal cutter member 8 comprises a base plate 12, provided with cutters 14, arranged to be rotated along the annular running groove 9, for cutting off hairs entering said hair-entry apertures 11. In alternative embodiments, the shaving heads 5 may comprise multiple running grooves 9 and cutters 14.

The external cutter member 7 is at its bottom side provided with a central tube 13, which may be integrally formed therewith, and which serves as a bearing for rotatably supporting the internal cutter member 8 around rotation axis R. In the given embodiment, the internal cutter member 8 is furthermore supported by biasing means 18, in particular a spring, which is arranged to urge the member 8 towards the external cutter member 7, wherein the cutter member 8 is guided in axial direction by the central tube 13. Thanks to the biasing means 18, a cutting gap between the internal and external cutter members 7, 8 will be minimised, enabling a close shave.

The external cutter member 7 is furthermore at its bottom side provided with a circumferential flange 17, for hooking the member 7 behind the holder 6. This flange 17 may be fixedly attached to the holder 6 via the usual fastening means or be biased in abutting contact with said holder via spring means (not shown), allowing the external cutter member 7 some freedom of movement, e.g. in axial direction and/or for tilting its position.

The drive means 4 comprise a rotary motor 10 including a drive shaft 15, a primary gear wheel 20, driven by said shaft 15 around a rotation axis M, and secondary gear wheels 25 (one per shaving head 5), arranged around the primary gear wheel 20 so as to be rotated thereby, around rotation axes R. Although in the illustrated embodiment, the primary gear wheel 20 directly engages the secondary gear wheels 25, it will be clear that additional transmission means can be provided, for instance to reverse a rotation direction of the shaving heads 5 or to effect a desired speed reduction or increase. Also, it is possible to have the rotation axes M, R of the respective gear wheels 20, 25 include an angle, thereby allowing the shaving heads 5 to extend under an angle, for instance to adjust to the curvature of a user's skin. Alternatively, the drive shaft 15 may take on an eccentric position and drive one of the secondary gear wheels 25, which in turn may drive the other secondary gear wheels via suitable intermediate transmission means such as the primary gear wheel 20.

As seen in Fig. 1, the motor 10 is largely accommodated in the shaver body 2, preferably sealed off watertight from the shaving unit 3 by a partition 16. The passage around the shaft 15 may be provided with a seal 22, to avoid leakage yet allow smooth rotation of the shaft 15, with a minimum of friction. The seal 22 can for instance be made of natural or synthetic rubber. It will be appreciated that thanks to the single drive shaft configuration of the present invention, only one such seal 22 is needed, which helps to reduce friction and energy losses. As further seen in Fig. 1, the primary gear wheel 20 is rotatably attached to the holder 6, on a spindle 23, extending in line with the single drive shaft 15. Furthermore, coupling means 24 are provided, for detachably coupling the primary gear wheel 20 to the single drive shaft 15, thereby allowing the shaving unit 3 to be detached from the shaver body 2, with gear wheel 20. The coupling means 24 may for instance comprise an angular or otherwise rotation asymmetric cross section, or make use of a key or spline. The coupling means 24 may further comprise second biasing means 28, which are arranged to restore some misalignment between the gear wheel 20 and the drive shaft 15 when the shaving unit 3 is placed back onto the shaving body 2. In the embodiment shown in Fig. 1, the secondary gear wheels 25 are directly attached to the base plates 12 of the respective internal cutter members 8. Thanks to such direct connection, the height of the shaving unit 3 can be small. Of course, in an alternative embodiment, the secondary gear wheel 25 and internal cutter member 8 may be interconnected via an intermediate part, such as an auxiliary drive shaft. The base plate/gear wheel-combination is provided with a central opening, lined with a tubular guiding piece 19, for mounting said combination onto the aforementioned bearing 13 of the external cutter member 7, thereby allowing said combination to rotate and move in axial direction with respect to the external cutter member 7.

In the illustrated embodiment, the holder 6 is provided with a circumferential skirt 6B that, together with partition 16, encloses a chamber 26 for collecting hairs, moisture, shaving lotion and the like, which during use may enter the shaver 1 via the shaving heads 5. To clean this chamber 26, the shaver unit 3 is preferably detachably connected to the shaver body 2.

It will be appreciated that a shaver 1 according to Fig. 1 features an improved drive mechanism. By positioning the less sensitive transmission means 20, 25 of the drive means 4 outside the sealed off shaving body 2, the number of seals 22 can be reduced to a single one, since the sealed off environment only needs to be protruded by a single drive shaft 15. Hence, the disadvantages associated with such seals will be reduced accordingly, such as complicated assembly, increased friction, increased energy consumption and wear. Also, thanks to the single drive shaft 15, only a single coupling means 24 is needed, to allow the shaving unit 3 to be detached from the shaving body 2. This too adds to the simplicity and robustness of the drive means 4 according to the invention.

Furthermore, the shaver 1 is easy to clean. Thanks to the primary gear wheel 20 being detachable together with the shaving unit 3, the chamber 26 will be readily accessibly for cleaning. The accessibility is further improved thanks to the fact that the chamber 26 is traversed by a single shaft 15 only, as compared to prior art shavers, having a drive shaft per shaving head. The shaving unit 3 with the shaving heads 5 and transmission means 20, 25 can be easily rinsed in water. Figs. 2-5 illustrate another embodiment of a shaver according to the invention, wherein like parts have been denoted with like reference numerals. Basically, the drive means 4 of this embodiment are similar to those of Fig. 1, including a motor (not shown), accommodated in a sealed off shaver body 2, a protruding single drive shaft 15, arranged to drive a primary gear wheel or pinion 20, which in turn is arranged to drive three secondary gear wheels 25, disposed at equiangular positions around said pinion 20.

Perhaps the most eye-catching difference with the shaver 1 of Fig. 1 is that the shaving unit 3 no longer encloses a hair-collecting chamber. Instead, the shaving heads 5 are centrally supported on the shaving body 2 via a central holder base, to be described below. Thanks to such central support (which is possible thanks to the above described drive means 4 with the single drive shaft 15) the space between the shaving heads 5 and the body 2 can remain substantially open, i.e. free of obstacles. This offers several advantages. First of all, such shaver 1 can very easily be cleaned, by simply rinsing the shaver in running water. No need to detach the shaving unit 3 first. Furthermore, during use, the open structure provides a good view on the shaver heads 5, thereby allowing a user to accurately control its shaving manoeuvres.

The special support structure will now be described referring to Fig. 3-5 showing respectively the shaving unit 3 of Fig. 2 in partly cut away view, and a shaving head 5 and the holder assembly 6 in exploded view. The shaving unit 3 comprises three shaving heads 5, which basically are comprised of the same components as described before, i.e. an external cutter member 7 and an internal cutter member 8, the latter being rotatably mounted in the external cutter member with a secondary gear wheel 25 directly attached to its bottom side. As seen in Fig. 4, the shaving head 5 may further comprise a cover plate 30, for example for aesthetic purposes, and a skin stretcher 32, for properly approaching a user's skin. The skin stretcher 32 in the present example furthermore serves to clamp the external cutter member 7 onto a ringshaped subholder 6C, wherein a spring 18 is provided to bias the internal cutter member 8 against the external cutter member 7.

The subholders 6C are each hingedly connected to a central holder base 106 (see Fig. 5), so as to be pivotal around pivot axes P, extending substantially tangential to the respective shaving heads 5. Furthermore, biasing means 34 are provided (see also Fig. 5) for biasing the shaver heads 5 towards a neutral position, as depicted in Fig. 2, in which the shaving heads 5 define a slightly concave shaving surface S. During use, the heads 5 can be pivoted around their respective pivot axes P through some external force exerted thereon by a user, wherein the biasing means 34 will produce a counter force, which will keep the heads 5 in close contact with a user's kin, thus ensuring good contour following of the shaving heads 5.

In the presented embodiment the subholders 6C have a substantially open bottom (see particularly Fig. 4), thereby allowing a good view on the cutter members 7, 8 and furthermore allowing cut off hairs, shaving lotion and the like, to pass through the shaving heads 5 and leave the shaver 1 via the open space surrounding the single drive shaft 15. This is especially advantageous for so called wet shavers 1, intended to be used in wet environments, preferably with shaving lotion. When, the shaver 1 is meant for dry shaving, the shaver 1 may be provided with a hair collecting chamber as shown in Fig. 1, for preventing shaving waste, such as cut off hairs from being dispersed, during shaving. Alternatively, the bottoms of the respective subholders 6C in Figs. 2-5 may be closed, for instance by means of small cups or discs (not shown), arranged to collect said cut off hairs and prevent them from flying around, during shaving. The cups or discs are preferably hingedly or otherwise detachably connected to said subholders 6C, so as to allow collected hairs to be removed. Thanks to such configuration, cut off hairs may be collected, while maintaining a good sight on the shaving heads 5 or at least the contour thereof, thereby facilitating accurate shaving.

The central holder base 106 is centrally connected to the shaver body 2, around the drive shaft 15. Furthermore, a cover 36 is provided, which can be mounted on top of the holder base 106, and which is provided with a central spindle 23 for rotatably mounting the primary gearwheel 20, in such way that this gear wheel 20 engages the secondary gear wheels 25 of the shaving heads 5. The cover 36 may furthermore serve to determine the neutral, concave position of the shaving heads 5 and to shield off the single drive shaft 15. The cover 36, holder base 106 and/or the subholders 6C may furthermore be designed so as to allow the shaving heads 5 to be detached from the shaving body 2, together, or individually, for instance for reparation or replacement purposes or for allowing the shaving body 2 to be used with a set of various shaving units 3. Also, a decoupling provision in the central holder base 106, may serve as a safety provision, which can prevent serious damage to the shaving unit 3, by allowing the shaving unit to be decoupled upon large external forces and/or shocks, such as for instance encountered when the shaver is accidentally dropped.

The shavers 1 according to the invention may be provided with a lotion supply system, of which in Fig. 2 only one supply line 35 is visible. This line 35 may for instance end adjacent a shaving head, for instance in the cover 36 of the central holder base 106, or may end in the shaving head 5. In the latter case, the cover plate 30 of the shaving head 5 may be provided with a nozzle or other suitable distribution means. Moreover, the cover plate

30 may be designed to help distribute such shaving lotion or foam over the shaving surface of said shaving heads 5. Alternatively, the cover plate 30 may be omitted and the diameter of the central tube 13 of the external cutter member 7 may be extended up to the inner diameter of the running groove. The opening in the internal cutter 8 may be extended accordingly.

This will result in an even more open, more transparent shaving unit 3, allowing a user to even better monitor and control his shaving manoeuvres.

The invention is not in any way limited to the exemplary embodiments presented in the description and drawing. All combinations (of parts) of the embodiments shown and described in this description are explicitly understood to be incorporated within this description and are explicitly understood to fall within the scope of the invention.

Moreover, many variations are possible within the scope of the invention, as outlined by the claims.

Claims

CLAIMS:

1. Shaver (1) comprising a shaving body (2), a shaving unit (3) with at least two rotary shaving heads (5) and drive means (4) for rotating an internal cutter member (8) of the shaving head (5) along an external cutter member (7) of such head (5), said drive means (4) comprising a motor (10) and at least one drive shaft (15), wherein said motor (10) is accommodated in the shaving body (2), separated from the shaving unit (3) by a partition (16), and wherein only a single drive shaft (15) extends through said partition (16) for driving the respective cutter members (8) via suitable transmission means (20, 25).

2. Shaver (1) according to claim 1, wherein the partition (16) between the motor (10) and the shaving unit (3) is substantially watertight, and wherein the passage for the single drive shaft (15) is provided with a seal (22) for maintaining said partition (16) watertight.

3. Shaver (1) according to claim 1 or 2, wherein the transmission means (20, 25) comprise at least a primary gear wheel (20), driven by the single drive shaft (15) and secondary gear wheels (25), driven by said primary gear wheel (20), for driving an or each internal cutter member (8).

4. Shaver (1) according to claim 3, wherein the internal cutter members (8) are rotatably mounted on a central portion (13) of the external cutter member (7).

5. Shaver (1) according to claim 3 or 4, wherein the secondary gear wheels (25) are rotatably mounted on a central portion (13) of the external cutter members (7).

6. Shaver (1) according to anyone of claims 3-5, wherein the internal cutter members (8) are directly fastened to a transmission means, in particular a primary or secondary gear wheel (20, 25).

7. Shaver (1) according to anyone of claims 3-6, wherein biasing means (18) are provided to bias the internal cutter member (8) against the external cutter member (7), so as to minimise a cutting gap between these members (7, 8).

8. Shaver (1) according to anyone of the preceding claims, wherein the transmission means (20, 25) are detachably coupled to the single drive shaft (15) via suitable coupling means (24).

9. Shaver (1) according to anyone of the preceding claims, wherein the single drive shaft (15) is positioned centrally with regard to a shaving surface (S) defined by the external cutter members (7).

10. Shaver (1) according to anyone of the preceding claims, wherein the shaving unit (3) is designed to enclose a chamber (26) between the shaving heads (5) and the partition (16) of the shaving body (2).

11. Shaver (1) according to anyone of claims 1-9, wherein the shaving unit (3) is supported on the shaving body (2) via a central support structure (106), extending closely adjacent and/or around the single drive shaft (15), in such way that a space between the shaving body (2) and the shaving unit (3) is substantially open, i.e. free from components, apart from said central support structure, the single drive shaft (15) and possibly a lotion supply conduit, for supplying shaving lotion to the shaving unit (3).

12. Shaver (1) according to claim 11, wherein the central support structure (106) substantially extends within a space confined by a cylinder passing through the rotation axes

(R) of the shaving heads (5).

13. Shaver (1) according to claim 11 or 12, wherein each shaving head (5) comprises a closed bottom side, arranged to collect shaving waste such as cut off hairs during use, and discharge means, for allowing said shaving waste to be removed from said shaving heads (5).