Patent Application
20190389084
The invention relates to a shaving unit, comprising at least a first cutting unit and a second cutting unit.
A further aspect of the invention is a shaving apparatus incorporating such a shaving unit.
Shaving units and apparatuses are used for shaving, in particular for shaving a men's skin in the lower facial region and the neck region. In such shaving applications it is a specific task of such shaving units and apparatuses to follow the contour of the skin to reach a good shaving result. Such contour following is particularly difficult in the region of the chin or the lower edge of the jaw.
Generally, shaving apparatuses are known wherein the cutting units are pivotal in relation to the handle of the shaving apparatus such as to improve the ability of the cutting units to follow the contour of the skin. However, such simple pivoting action always results in some sectors or even large sectors of the shaving tracks of the external cutting members of the cutting units being not in contact with the skin. Thus the shaving efficiency is not satisfying.
U.S. Pat. No. 6,584,691B1 discloses an electric shaver with two blades which rotate about their centrelines and at the same time orbit around another axis. The axis and the centrelines are hold in a parallel orientation to each other and thus do not allow a good contour following. Further, cleaning of the shaving head will be difficult since the blades are not easy accessible and sensitive parts of the drive train might be involved and damaged during such cleaning procedure.
CN101683739B discloses a shaving apparatus with three cutting units. Each cutting unit comprises a rotatable blade which is driven by a drive train. The drive train comprises a central drive gear wheel driving to three driven gear wheels which are coupled to the cutters. The cutting units and the drive train are encapsulated by a housing from the environment. Cleaning of the shaver requires the cutting units to be opened since no access is possible otherwise. This opening procedure makes the cleaning cumbersome and complicates the design of the cutting units.
US2006/156550A1 discloses a shaving apparatus with three cutting units. Each cutting unit comprises a rotatable blade which is driven by a drive train. The drive train comprises a central drive gear wheel driving to three driven gear wheels which are coupled to the cutters. The cutting units and the drive train are encapsulated by a housing from the environment. A specific channel for removing cut hair is provided which shall discharge water or air introduced into the cutting units out of the shaving head. By this, a specific additional structure inside the shaving head is provided which increases the manufacturing costs.
WO 2006/067721A1 discloses a shaving apparatus comprising a main housing accommodating a motor, and a shaving unit which is releasably coupled to the main housing by means of a central coupling member. The central coupling member of the shaving unit accommodates a central drive shaft, which is coupled to a motor shaft of the motor in the main housing when the shaving unit is coupled to the main housing. The shaving unit comprises three cutting units, which are each pivotal about an individual pivot axis relative to a central support member of the shaving unit. The cutting units each comprise a housing which accommodates a driven gear wheel coupled to an internal cutting member of the cutting unit. The driven gear wheels of the cutting units are driven by a central gear wheel accommodated in the central support member and coupled to the central drive shaft. To maintain the engagement of the central gear wheel with the driven gear wheels during the pivotal motion of the cutting units relative to the central support member, the pivot axis of each cutting unit coincides with a tangential line between the central gear wheel and the driven gear wheel of the cutting unit. In the configuration of this shaving apparatus the gear wheels and the cutting units are provided as a compact shaving unit of the apparatus having only a single central drive shaft for the three cutting units, which can be easily decoupled from the main housing in order to, for example, exchange the shaving unit by another functional attachment or clean the shaving unit. The configuration also ensures a mechanically stiff torque transmission from the central drive shaft to the internal cutting members. Thus, a reliable design with small losses in the transmission path and a silent transmission of the rotation is provided. However, the design has shown that these advantages are accompanied by a limited range of movement of the cutters for a pivotal movement when following the skin contour and a limited accessibility of the cutters for cleaning them and removing cut hair.
It is an object of the invention to provide a shaving unit and a shaving apparatus incorporating such a shaving unit, wherein the releasable shaving unit has a single central drive shaft that can be releasably coupled to the motor shaft of the motor in the main housing to provide an easy detachment and attachment of the shaving unit from and to the main housing and to provide an easy accessibility of the shaving unit for cleaning the cutting units from cut hair, while at the same time providing a reliant and resilient torque transmission to the cutting units and an improved capability of the cutting units to follow the skin contours.
This object is achieved by a shaving unit for a shaving apparatus, comprising at least a first cutting unit and a second cutting unit, wherein:
the first cutting unit comprises a first external cutting member having a plurality of hair entry openings which define a first shaving track, a first internal cutting member which is rotatable relative to the first external cutting member about a first axis of rotation, and a first housing accommodating a first hair collection chamber;
the second cutting unit comprises a second external cutting member having a plurality of hair entry openings which define a second shaving track, a second internal cutting member which is rotatable relative to the second external cutting member about a second axis of rotation, and a second housing accommodating a second hair collection chamber; the shaving unit further comprising a central support member comprising a coupling member by means of which the shaving unit can be releasably coupled to a main housing of the shaving apparatus, wherein:
the coupling member accommodates a central drive shaft which is connected to a central transmission element;
the first housing is pivotally mounted to the central support member by means of a first primary pivot axis arranged between the first axis of rotation and the second axis of rotation;
the second housing is pivotally mounted to the central support member by means of a second primary pivot axis arranged between the second axis of rotation and the first axis of rotation;
the first internal cutting member is connected to a first driven transmission element via a first drive spindle;
the second internal cutting member is connected to a second driven transmission element via a second drive spindle; and
the first and second driven transmission elements are arranged to be driven by the central transmission element;
wherein the central transmission element and the first and second driven transmission elements are arranged as a transmission unit between the coupling member and the first and second cutting units, wherein the first and second drive spindles extend from the transmission unit via an open space, which is present between the transmission unit and the first and second cutting units and surrounds the central support member, and through an opening in a bottom wall of, respectively, the first housing and the second housing.
According to the invention the shaving unit comprises at least two cutting units and may in particular comprise three, four, five or even more cutting units to form a two-, three-, four-headed or five-headed or multi headed shaving unit. Each cutting unit comprises an external cutting member which is provided with a plurality of hair entry openings like circular openings or slits through which the hair which is to be cut can reach through. The external cutting member provides cutting edges at the hair entry openings which interact with cutting edges at the internal cutting member which is rotatable relative to the external cutting member. By this rotation of the internal versus the external cutting member a shearing force is imparted by the cutting edges of the internal and the external cutting members on the hairs which reach through the hair entry openings, and this shearing or cutting force effects the shaving action. The cut hairs fall into a hair collection chamber which is provided in a housing incorporated in each cutting unit.
Each cutting unit, having the internal cutting member, the external cutting member and the housing incorporating the hair collection chamber, is pivotal, preferably individually pivotal independent of the other cutting unit or units, relative to the central support member about a primary pivot axis to allow a good contour following of the cutting units along the skin.
Further, a drive train is provided for driving each internal cutting member into rotation in relation to the external cutting member. The drive train comprises a central drive shaft, in particular a single central drive shaft, which is accommodated in a central coupling member of the central support member of the shaving unit. The single central drive shaft is adapted to be coupled to a main drive shaft of a drive unit, like an electric motor, in the main housing. For this purpose the central drive shaft may have a suitable coupling element to be driven into rotation by a mating coupling element of the main drive shaft when coupled thereto. The central drive shaft is connected to a central transmission element, like a central gear wheel or the like, which engages a first and a second driven transmission element, like driven gear wheels, such that a rotation of the central transmission element effects a rotation of the first and second driven transmission elements. The first and second driven transmission elements are coupled via a first and a second drive spindle, respectively, to the first and second cutting units such as to drive the first and second internal cutting members, respectively, into rotation.
The spindles extend outside the central support member, which serves to centrally support the first and the second cutting units. The first and the second spindles extend in an open space which is present between a transmission unit, comprising the central transmission element and the first and second driven transmission elements, and the first and second cutting units. An open space is understood to be a space which is not physically separated from the environment of the shaving unit, i.e. which is not encapsulated by a housing. In this regard, the open space is understood to be accessible from outside, i.e. the open space may be used to direct a flush water stream or an airflow or compressed air jet to clean the cutting units. By this arrangement of the spindles, the transmission unit, including the central transmission element and the first and second driven transmission elements, is arranged at a distance from the first and second cutting units and separated from the first and second cutting units by the open space.
The first and second cutting units and any optional further cutting units form a type of cutting head of the shaving unit which is carried by the central support member and connected to the transmission unit by this central support member. The spindles extend sideways from the central support member in the open space surrounding the central support member. By this, the cutting units have a large range of motion to follow the skin contour and can pivot about large angles and multiple pivot axes. In particular, the pivotal motions of the cutting units about their primary pivot axes are not restricted by the required engagement between the central transmission element and the driven transmission elements. Further, the open space provided adjacent to the bottom sides of the cutting units allows a direct access to the housings of the cutting units accommodating the hair collection chambers, and thus facilitates the access to the hair collection chambers of the cutting units for cleaning the cutting units and removing cut hair out of the cutting units.
According to a first preferred embodiment, the central transmission element is rotatable about a central transmission axis, the first driven transmission element is rotatable about a first transmission axis, and the second driven transmission element is rotatable about a second transmission axis, wherein the central transmission axis and the first and second transmission axes are arranged in stationary positions relative to the coupling member. According to this embodiment, the transmission axis of the central transmission element and the first and second driven transmission elements are in a constant orientation relative to the coupling member, such that the transmission axis and the driven transmission axes do not change their angular orientation in relation to each other, and each of the transmission axis and driven transmission axes does not change its angular orientation in relation to the coupling member in case of a pivotal movement of any cutting unit. By this, the transmission via the drive train from the central drive shaft in the coupling member to the first and second driven transmission elements is free of any pivoting movement, such that a transmission of the rotational movement and torque is achieved at low friction and wear of the components involved in the transmission. In particular, no pivoting movement of any of the driven transmission elements in relation to the central transmission element is required in the course of the pivoting movement of the cutting units when following the skin contour. Hereby, increased wear and friction in the transmission can be avoided and the shaving unit can be driven at a low noise level. It is understood that the stationary position of the axes of the central transmission element and the driven transmission elements relative to the coupling member as described beforehand does not exclude a pivotal movement of other components of the drive train such as to follow a pivotal movement of the cutting units or a translational movement of any such components.
According to a further preferred embodiment, the central transmission element and the first and second driven transmission elements are accommodated in a transmission housing which is arranged in a stationary position relative to the coupling member between the coupling member and the open space. According to this embodiment the central transmission element, the first driven transmission element and the second driven transmission element are encapsulated in a transmission housing and thus protected from impact or environmental influence. It is understood that the transmission housing may be part of a housing which accommodates additional parts, and the transmission housing may have a section comprising the coupling member to realize the releasable coupling of the shaving unit to the main housing. Preferably, the open space is positioned between the cutting units and the transmission housing such that a sufficient range of pivotal motions of the cutting units is provided by said open space without the cutting units contacting the transmission housing in any pivotal position.
It is further preferred that the central transmission element comprises a central gear wheel and the first and second driven transmission elements each comprise a driven gear wheel. According to this embodiment, the transmission via the central transmission element and the driven transmission elements is accomplished by gear wheels like e.g. spur-gears, bevel gears or the like. The gear wheels may provide a gear reduction or a gear transmission ratio with speed increaser such as to adapt the rotational speed of the drive unit to an appropriate rotational speed of the internal cutting members.
According to a further preferred embodiment, the shaving unit is improved in that, seen in a direction parallel to the first axis of rotation, the first primary pivot axis is arranged between the first shaving track and the second axis of rotation, and wherein, seen in a direction parallel to the second axis of rotation, the second primary pivot axis is arranged between the second shaving track and the first axis of rotation. By this particular arrangement of the first and second primary pivot axes it is achieved that the shaving track of a cutting unit can pivot about the primary pivot axis in such a way that the whole shaving track not only makes a pivoting action but further makes a translational movement in a tangential direction in relation to the respective primary pivot axis. Thus, any sector of the shaving track is positioned at a distance from the respective primary pivot axis, seen in a direction parallel to the axis of rotation of the internal cutting member of the cutting unit. By this, the whole shaving track will conduct a translational movement along a curved path in the same direction, i.e. either in the direction towards the skin or away from the skin, if the cutting unit pivots about the primary pivot axis. It is understood that some sectors may make a larger movement than others, depending on the distance to the primary pivot axis. It is however avoided that any sector of the shaving track is not able to make such a translational movement, but is positioned in a fixed position and only changes its angular orientation in relation to the skin when following the contour of the skin, or may even conduct a translational movement opposed to other regions of the shaving track. The inventors have found that, in particular by avoiding such fixed positions of parts of the shaving track with regard to the translational movement and by avoiding such opposed translational movements of parts of the shaving track versus other parts of the shaving track, pressure peaks between the contact surface of the shaving track and the skin, resulting in an uncomfortable and inconvenient shaving procedure with less shaving efficiency, are avoided.
According to a further preferred embodiment, the first primary pivot axis and the second primary pivot axis coincide. Such coinciding pivot axes will allow for a close relationship between the first and second cutting units and at the same time provide a rigid mechanical setup of the pivoting action about the first and second primary pivot axes.
According to a further preferred embodiment, the central support member comprises a stationary portion, which comprises the coupling member, and a movable portion, which is pivotal relative to the stationary portion about a secondary pivot axis, wherein the first housing is pivotally mounted to the movable portion by means of the first primary pivot axis and the second housing is pivotally mounted to the movable portion by means of the second primary pivot axis, and wherein the secondary pivot axis is not parallel to the first and second primary pivot axes. According to this embodiment, a secondary pivot axis is provided, so that the first and second cutting units can pivot relative to the stationary portion of the central support member both about, respectively, the first and the second primary pivot axis and about said secondary pivot axis. The secondary pivot axis is not parallel to the first and the second primary pivot axis. For this purpose, the central support member comprises two portions, namely a stationary portion and a movable portion, wherein the movable portion is pivotal relative to the stationary portion about said secondary pivot axis. It is understood that such pivotal movement of the movable portion versus the stationary portion may be provided by an axle or shaft mutually coupling the movable and the stationary portions, but instead of such a coupling via an axle or shaft the movable and the stationary portions of the central support member may be coupled via a guiding structure comprising a curved path, or the like, along which the movable portion is guided relative to the stationary portion, such that the secondary pivot axis is provided as a virtual axis outside of the central support member, in particular outside of the shaving unit. like e.g. in the plane or close to the plane defined by the skin contact surface of the first or second shaving track. The secondary pivot axis is not arranged parallel to the first and second primary pivot axis, so that the pivotal movement about the secondary pivot axis follows a different path and direction than the pivotal movement about the first and the second primary pivot axis, and thus provides an increased skin-contour following ability of the cutting units. The first primary pivot axis, the second primary pivot axis and/or the secondary pivot axis may lie in planes which are parallel to each other. It is understood that, whilst the first and second cutting unit may pivot individually and independently from each other about the first and second primary pivot axis, respectively, the pivotal movement of the first and second cutting unit about the secondary pivot axis is a synchronous pivotal movement of both cutting units.
The embodiment of the shaving unit comprising a secondary pivot axis may be further improved in that the first housing and the second housing have a height, seen in respective directions parallel to the first axis of rotation and parallel to the second axis of rotation, and that a distance between the secondary pivot axis and a first skin contact surface comprising the first shaving track and a distance between the secondary pivot axis and a second skin contact surface comprising the second shaving track are smaller than 50% of said height. In this embodiment, the position of the secondary pivot axis is relatively close to the skin contact surface of the first and second shaving track, wherein it is understood that the secondary pivot axis may be positioned inside or outside the shaving unit. As a result, the position of the secondary pivot axis is optimized for a smooth pivotal movement of the first and second cutting units about said secondary pivot axis with low pivotal forces required for the pivoting movement. It is understood that the height of the first housing and the second housing may be similar, and that said height corresponds to the height of a single of said two housings such that the distance between the secondary pivot axis and the first skin contact surface is less than half of the height of the first housing. In particular, the secondary pivot axis may be positioned in a plane which includes the first and second primary pivot axes, or the secondary pivot axis may preferably be arranged outside the shaving unit, such that the first and second shaving tracks are positioned between the secondary pivot axis and the first and second internal cutting members. The secondary pivot axis may be realized as a physical or as a virtual secondary pivotal axis.
According to a further preferred embodiment, the first and second drive spindles each comprise a spindle axis, wherein the secondary pivot axis and the spindle axes of the first and second drive spindles extend in a common imaginary plane, and wherein the first and second primary pivot axes extend perpendicularly to the secondary pivot axis. The position of the secondary pivot axis and the spindle axes of the first and second drive spindles in a common imaginary plane allows the cutting units to pivot about the secondary pivot axis without any required displacement of the drive spindles, and in particular without any required displacement of the spindle axes of the drive spindles out of said imaginary plane. The orientation of the first and second primary pivot axes perpendicular to the secondary pivot axis in addition allows the cutting units to pivot about the primary pivot axes without any required displacement of the spindle axes of the drive spindles out of said imaginary.
According to a further preferred embodiment, the first drive spindle is pivotally arranged relative to the first driven transmission element, and the second drive spindle is pivotally arranged relative to the second driven transmission element. This pivotal arrangement of the first and the second drive spindles in relation to the first and the second driven transmission elements, respectively, allows the first and second drive spindles to follow the pivoting movement of the first and second cutting units, respectively. This may comprise any pivotal movement of the drive spindles following a pivotal movement of the cutting units about the first and second primary pivot axis, respectively, and/or about the secondary pivot axis. In particular, the first and second drive spindles may be coupled to the first and second driven transmission elements, respectively, by way of a form-locking torque transmission element which allows such pivotal movement. The pivot axis of the pivotal movement of the first and second drive spindles relative to the first and second driven transmission elements, respectively, may be oriented perpendicular to the rotational axis of the first and second driven transmission elements, respectively, and may in particular intersect the rotational axis of the respective driven transmission elements. The pivotal movement of the first and second drive spindles relative to the first and second driven transmission elements may be such that a movement about two perpendicular pivot axes or an arbitrary pivotal movement is possible, such as to form a cardan joint or a ball-joint bearing between the first and second drive spindles and the first and second driven transmission elements, respectively. This will allow the first and second drive spindles to follow a pivotal movement of the internal cutting members of the cutting units, which are driven by the respective drive spindles, in any rotational position of the respective driven transmission elements.
Further, it is generally preferred to have a coupling between the first and second drive spindles and the first and second driven transmission elements, respectively, which coupling allows a pivotal movement corresponding to a cardan joint or a ball-joint bearing, but at the same time provides a torque transmission about the first and second spindle axes and the couplings thereof, respectively.
According to a further preferred embodiment, the first and second drive spindles each comprise a spindle axis, wherein the first drive spindle is displaceable relative to the first driven transmission element in a direction parallel to the spindle axis of the first drive spindle and against a first spring force, and wherein the second drive spindle is displaceable relative to the second driven transmission element in a direction parallel to the spindle axis of the second drive spindle and against a second spring force. According to this embodiment, the first and second drive spindles are adapted to compensate a change of distance between the first and second cutting units, respectively, and the first and second driven transmission elements, respectively. Such a change of the distance may occur if the cutting units are pivoted about the first and second primary pivot axes, respectively, or about the secondary pivot axis. The expression “the first and second drive spindles being displaceable relative to the first and second driven transmission elements, respectively” may be understood such that the whole drive spindle may conduct a translational movement parallel to the respective spindle axis, e.g. such that the first and second drive spindles are coupled to the first and second driven transmission elements, respectively, by a coupling structure, which allows such a translational movement of the drive spindles in relation to the driven transmission elements and at the same time maintains the torque transfer from the first and second driven transmission elements to the first and second drive spindles, respectively. Alternatively, the first and second drive spindles may be displaceable in such a way that a first axial section of each drive spindle can conduct a movement parallel to the drive spindle axis in relation to a second axial section of the drive spindle, such that the drive spindle may change its length. The spring force is understood to act in a direction such as to bias the drive spindle into its maximally extended configuration, namely such as to bias the drive spindle towards the associated cutting unit by the spring force. In embodiments wherein the drive spindles have two mutually displaceable axial sections, the two axial sections of the drive spindle are biased by the spring force into a maximally extended configuration of the drive spindle. By this, a permanent contact and transmission from the driven transmission elements to the internal cutting members is provided by the drive spindles during any displacements of the cutting units in relation to the driven transmission elements in a direction parallel to the spindle axis, in particular as a result of any pivotal motion of the cutting units.
According to a further preferred embodiment, the first drive spindle is pivotally arranged relative to the first internal cutting member, and the second drive spindle is pivotally arranged relative to the second internal cutting member. According to this embodiment, the drive spindles are pivotally arranged in relation to the internal cutting members to which they are respectively coupled for transmission of rotational movement and torque. This arrangement further improves the ability of the drive spindles to follow any pivotal movement of the cutting units. Preferably, the drive spindles are pivotal in relation to the driven transmission elements and also pivotal in relation to the internal cutting members, such that a change of the angular orientation of the internal cutting members relative to the driven transmission elements, which may occur as a result of a pivotal movement of the cutting units about the primary pivot axes or about the secondary pivot axis, can be compensated and followed by the drive spindles, and the torque transmission from the driven transmission elements to the internal cutting members is maintained via the drive spindles in any pivotal position of the cutting unit. It is understood that the pivotal movement of the drive spindles versus the internal cutting members may be accomplished by a coupling structure allowing the freedom to move according to a ball-joint bearing with torque transmission about the spindle axes, or by a coupling structure providing two pivot axes forming a cardan joint, as described beforehand with respect to the pivotal movement of the drive spindles relative to the driven transmission elements.
According to a further preferred embodiment, the shaving unit comprises a third cutting unit comprising a third external cutting member having a plurality of hair entry openings, a third internal cutting member which is rotatable relative to the third external cutting member about a third axis of rotation, and a third housing accommodating a third hair collection chamber, wherein:
the third housing is pivotal relative to the central support member about a third primary pivot axis arranged between the third axis of rotation and each of the first and second axes of rotation;
the third internal cutting member is connected, via a third drive spindle, to a third driven transmission element of the transmission unit arranged to be driven by the central transmission element; and
the third drive spindle extends from the transmission unit via the open space and through an opening in a bottom wall of the third housing.
According to this embodiment, a third cutting unit is provided which is pivotal relative to the central support structure about a third primary pivot axis. Said third primary pivot axis may be arranged between each of the first and second axes of rotation and a shaving track of the third external cutting member defined by the hair entry openings of the third external cutting member, and may in particular be arranged between each of the first and second axes of rotation and the third external cutting member, as was described beforehand with respect to the corresponding positions of the first and the second primary pivot axes relative to the first and the second cutting units, respectively.
The third housing of the third cutting unit may be pivotally mounted to the central support member directly, or may be pivotally mounted to the first housing, to the second housing, or to both the first housing and the second housing. In particular, the third primary pivot axis may be mounted to both the first housing and the second housing in such a way that it allows a pivotal movement of the first and the second housings about the first and the second primary pivot axes, respectively, but at the same time provides a pivotal bearing of the third housing.
It is further preferred that the third primary pivot axis extends perpendicularly to the first and second primary axes. The third primary pivot axis may in such case form a T-like arrangement with the first and the second primary axes, in particular in embodiments wherein the first and second primary axes coincide. Said T-like arrangement formed by the first, second and third primary pivot axes may be positioned between the first, second and third cutting units. In another preferred embodiment, the first, second and third primary pivot axes may be arranged in a triangular arrangement relative to each other, e.g. such that a triangle formed by said three primary pivot axes is positioned between the first, second and third cutting units.
The internal cutting member of the third cutting unit is connected to a third driven transmission element via a third drive spindle. Said third drive spindle may be configured in the same way like the first and second drive spindles and may be displaceable parallel to the spindle axis of the third drive spindle and pivotal in relation to the third driven transmission element and/or the third internal cutting member to follow a pivotal movement of the third cutting unit. The first, second and third drive spindles may be arranged in such a way as to be evenly distributed in angular relationship about the rotational axis of the central transmission element, i.e. to be in angular displacement of 120 degree to each other. All three drive spindles may extend in the open space such as to provide a sufficient range of pivotal motions for the three cutting units and a good accessibility of the cutting units for cleaning purposes.
In a shaving unit comprising a third cutting unit as described beforehand, it is further preferred that the first and second primary pivot axes are mutually parallel or coinciding, and that the third housing is connected to the first housing and to the second housing by means of, respectively, a first hinge structure and a second hinge structure, wherein the first and second hinge structures each comprise a bearing pin engaging a bearing bush, wherein the bearing bush, seen in a longitudinal sectional view along the third primary pivot axis, has a non-cylindrical, in particular a convex bearing surface such as to allow mutual rotation of the bearing pin and the bearing bush about an axis parallel to the first and second primary pivot axes. Generally, it is preferred that the third primary pivot axis is not parallel to the first and/or the second primary pivot axis such as to allow a non-parallel pivotal movement of the three cutting units to achieve a good contour following efficiency of the shaving unit. Whilst generally the pivotal coupling of each cutting unit might be established directly between the housing of the cutting unit and the central support member, according to this embodiment it is preferred that the housing of the third cutting unit is pivotally coupled directly to the housings of both the first cutting unit and the second cutting unit. This allows for a close arrangement of the three cutting units with a relatively small distance between each of the three cutting units, which is preferred for an efficient shaving procedure. The first and second hinge structures provided for the third primary axis in this case compensate for any pivotal movement of the first and/or the second cutting unit about the first and second primary pivot axes, respectively. For this purpose, in the first and second hinge structures the bearing bush receiving the bearing pin is not formed as a straight cylindrical bush, but has a convex bearing surface to allow a tilting motion of the associated bearing pin in the bearing bush to a certain degree. This allows the bearing pin to follow any pivotal motion of the bearing bush about, respectively, the first or the second primary pivot axis while being accommodated in the bearing bush, and thus to compensate a tilted arrangement of the bearing pin, when mounted in a fixed position relative to the housing of the third cutting unit, relative to the bearing bush, when mounted in a fixed position relative to the housing of the first or the second cutting unit, respectively. The shape of the bearing surface of the bearing bush may be bevelled, e.g. convergent, i.e. funnel-shaped to allow such tilting of the bearing pin, or the bearing surface may have a central portion with a diameter corresponding to the diameter of the bearing pin, wherein the diameter of the bearing bush widens from the central portion towards both end portions of the bearing bush. As a result, a double-bevelled shape of the bearing surface, as e.g. known from an hour-glass, is provided, which allows tilting of the bearing pin in the bearing bush to a certain degree. The third primary pivot axis may be formed by at least one bearing pin extending along the third primary pivot axis, said bearing pin being accommodated in a corresponding at least one bearing bush, wherein said bearing pin or bearing bush is provided in the first or second housing and said bearing bush has a converging shape or an hourglass shape to allow pivoting of the bearing pin about the first or the second primary pivot axis.
According to a further preferred embodiment, the first housing and the second housing each comprise, near its opening in its bottom wall, a first sealing structure which is symmetrical relative to, respectively, the first axis of rotation and the second axis of rotation, wherein the first internal cutting member and the second internal cutting member each comprise a second sealing structure, which is symmetrical relative to, respectively, the first axis of rotation and the second axis of rotation and arranged for cooperation with the first sealing structure of, respectively, the first housing and the second housing. According to this embodiment, first and second sealing structures are provided in, respectively, the first and the second housings and in the first and the second internal cutting members such as to provide a sealing between the first and second housing and, respectively, the first and second internal cutting members. The first and the second sealing structures engage and cooperate with each other in such a way as to provide a sealing gap between the internal cutting members and the housings. These sealing gaps in particular prevent cut hairs to escape out of the hair collection chambers accommodated in the housings via the openings of the housings through which the drive spindles extend. The sealing gaps may allow flush water to flow from outside, in particular from the open space, into the hair collection chambers so as to effect a cleaning of the hair collection chambers by removing cut hairs out of the hair collection chambers. The first sealing structure may be an annular structure, like a ring-shaped plane, and the second sealing structure may be a further annular structure which is opposed to the first sealing structure such that a sealing gap is provided between said two annular structures. The annular structures may both have a ring-like configuration and may be rotationally symmetric about the axis of rotation of the associated internal cutting member. In particular, the sealing gap may have a convergent geometry in a longitudinal sectional view in such a way that the width of the sealing gap decreases in a flow direction from the opening in the housing towards the hair collection chamber. This particular convergent shape of the sealing gap will prevent cut hairs from passing through the sealing gap, but at the same time will allow flush water to enter through the sealing gap into the hair collection chamber.
It is understood that also the third internal cutting member and the third housing may incorporate such a first and second sealing structure and a sealing gap formed by said first and second sealing structure in the same way such as to seal the opening in the third housing to prevent cut hairs from escaping out of the hair collection chamber through said opening and to allow flush water to enter into the third hair collection chamber for removal of the cut hair.
A further aspect of the invention is a shaving apparatus comprising a main housing accommodating a motor, and comprising a shaving unit as described beforehand, wherein the shaving unit is releasably coupled to the main housing by means of the coupling member. Said shaving apparatus may incorporate in said main housing a drive unit, like an electric motor, to drive the first, second and, if present, third internal cutting member when the shaving unit is coupled to the main housing by means of the coupling member. The drive unit may have a main drive shaft which is coupled to the central drive shaft, accommodated in the coupling member of the shaving unit, when the shaving unit is coupled to the main housing. The main housing may further comprise a main coupling member to cooperate with the coupling member of the shaving unit.
It shall be understood that a shaving unit according to the invention and a shaving apparatus according to the invention may have similar and/or identical preferred embodiments, in particular as defined in the dependent claims.
It shall be understood that a preferred embodiment of the present invention can also be any combination of the dependent claims or above embodiments with the respective independent claim.
These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.
Preferred embodiments of the invention are described with reference to the drawings.
In the drawings:
With reference to
The first housing 20a of the first cutting unit 10a is pivotally mounted to the central support member 50 by means of a first primary pivot axis 1a, and the second housing 20b of the second cutting unit 10b is pivotally mounted to the central support member 50 by means of a second primary pivot axis 1b. In the embodiment shown in
As will be described further in detail in the following, the central support member 50 comprises a stationary portion, which comprises the coupling member 70, and a movable portion. The first and second housings 20a, 20b of the cutting units 10a, 10b are pivotal about the first and second primary pivot axes 1a, 1b relative to the movable portion of the central support member 50. The movable portion of the central support member 50 is pivotal relative to the stationary portion of the central support member 50 about a secondary pivot axis 3 as indicated in
As shown in
As shown in
The bearing pins 55, 55′ define the position of the coinciding primary pivot axes 1a, 1b relative to the housings 20a, 20b. The bearing pins 55, 55′ are arranged between the housings 20a, 20b, seen in directions parallel to the axes of rotation 6a, 6b of the cutting units 10a, 10b as e.g. in
The movable portion 51 of the central support member 50 is pivotally guided along a curved path 57 relative to the stationary portion 52 of the central support member 50. Seen in the cross-sectional view of the shaving unit in
As can be further seen in
Furthermore, the assembly of the cutting units 10a, 10b is biased into a neutral pivoted position relative to the secondary pivot axis 3 by a further spring element 23c. The further spring element 23c is arranged in the stationary portion 52 of the central support member 50 and exerts a biasing force on the movable portion 51 of the central support member 50. Starting from the neutral pivoted position relative to the secondary pivot axis 3 as shown in
The first cutting unit 110a and the second cutting unit 110b are pivotal relative to a central support member 150 of the shaving unit about, respectively, a first primary pivot axis 101a and a second primary pivot axis 101b. Like the first and second primary pivot axes 1a, 1b in the embodiment of the shaving unit shown in
The third cutting unit 110c is pivotal relative to the central support member 150 about a third primary pivot axis 102, which extends perpendicularly to the coinciding first and second pivot axes 101a, 101b. Seen in a direction parallel to the axis of rotation 106c of the third cutting unit 110c, the third primary pivot axis 102 is arranged between the shaving track 161c of the third cutting unit 110c and the axes of rotation 106a, 106b of the first and second cutting units 110a, 110b, as is shown in
In the embodiment of the shaving unit shown in
As shown in
Furthermore, in the embodiment shown in
The rotatable coupling component 472 and the central drive shaft 478 are parts of the drive train of the shaving unit. The central drive shaft 478 is connected to a central transmission element, embodied as a central gear wheel 473. Said central gear wheel 473 is rotatable about a central transmission axis 409, which corresponds to the main drive axis 9 described beforehand with reference to the embodiment shown in
A first driven transmission element and a second driven transmission element, embodied as, respectively, a first driven gear wheel 475a and a second driven gear wheel 475b, are arranged to be driven by the central gear wheel 473. The first and second driven gear wheels 475a, 475b are positioned adjacent to and on opposite sides of the central gear wheel 473 and each engage the central gear wheel 473 for torque transmission. The first driven gear wheel 475a and the second driven gear wheel 475b are positioned, relative to the central transmission axis 409, radially outwardly from the central gear wheel 473, and are each arranged in a slightly oblique orientation with respect to the central transmission axis 409. Thus, the first driven gear wheel 475a is rotatable about a first transmission axis 405a, which has a slightly oblique orientation with respect to the central transmission axis 409. Likewise, the second driven gear wheel 475b is rotatable about a second transmission axis 405b, which also has a slightly oblique orientation with respect to the central transmission axis 409. The first and second transmission axes 405a, 405b are symmetrically arranged with respect to the central transmission axis 409.
The first and second transmission axes 405a, 405b and the central transmission axis 409 are each arranged in a stationary position relative to the coupling member 470 and relative to the stationary portion 452 of the central support member 450 of the shaving unit. The central gear wheel 473 and the first and second driven gear wheels 475a, 475b are accommodated in a transmission housing 479, which is also arranged in a stationary position relative to the coupling member 470 and relative to the stationary portion 452 of the central support member 450 of the shaving unit. The central gear wheel 473 and the first and second driven gear wheels 475a, 475b are arranged as a transmission unit, accommodated in the transmission housing 479, between the coupling member 470 and the first and second cutting units 410a, 410b. Between the transmission housing 479 and the first and second cutting units 410a, 410b, an open space 490 is present which surrounds the central support member 450 as shown in
The internal cutting member 480a of the first cutting unit 410a is connected to the first driven gear wheel 475a by means of a first drive spindle 476a, and the internal cutting member 480b of the second cutting unit 410b is connected to the second driven gear wheel 475b by means of a second drive spindle 476b. The first drive spindle 476a extends from the transmission unit in the transmission housing 479 to the internal cutting member 480a of the first cutting unit 410a via the open space 490 and through the opening 425a in the bottom wall of the housing 420a of the first cutting unit 410a. Likewise, the second drive spindle 476b extends from the transmission unit in the transmission housing 479 to the internal cutting member 480b of the second cutting unit 410b via the open space 490 and through the opening 425b in the bottom wall of the housing 420b of the second cutting unit 410. The openings 425a, 425b in the bottom walls of the housings 420a, 420b of the first and second cutting units 410a, 410b shown in
The first and second driven gear wheels 475a, 475b are circumferentially provided and integrally formed on, respectively, a first cup-shaped rotatable carrier 474a and a second cup-shaped rotatable carrier 474b. A lower end portion of the first drive spindle 476a engages the first rotatable carrier 474a, and a lower end portion of the second drive spindle 476b engages the second rotatable carrier 474b. The lower end portions of the first and second drive spindles 476a, 476b are configured in such a manner that the drive spindles 476a, 476b can slide in the two opposite directions parallel to, respectively, the first transmission axis 405a and the second transmission axes 405b inside, respectively, the first cup-shaped rotatable carrier 474a and the second cup-shaped rotatable carrier 474b. A mechanical spring is arranged in each of the first and second drive spindles 476a, 476b, as shown in
Furthermore, the lower end portions of the first and second drive spindles 476a, 476b are configured in such a manner that the drive spindles 476a, 476b can pivot relative to, respectively, the first driven gear wheel 475a and the second driven gear wheel 475b to a limited extent about any axis perpendicular to, respectively, the first transmission axis 405a and the second transmission axes 405b. Finally, the lower end portions of the first and second drive spindles 476a, 476b are configured in such a manner that the first and second cup-shaped rotatable carriers 474a, 474b can transmit a driving torque to, respectively, the first drive spindle 476a and the second spindle 476b by engagement with the lower end portions thereof.
As further shown in
During operation, the internal cutting members 480a, 480b of the first and second cutting units 410a, 410b are driven into a rotational movement about the first and second axes of rotation 406a, 406b relative to the external cutting members 460a, 460b of the first and second cutting units 410a, 410b by the first and second drive spindles 476a, 476b, respectively. As described here before, the first and second drive spindles 476a, 476b are displaceable against a spring force in directions parallel to their spindle axes relative to, respectively, the first and second driven gear wheels 475a, 475b. Furthermore, as described here before, the first and second drive spindles 476a, 476b are pivotally arranged relative to, respectively, the first and second driven gear wheels 475a, 475b and relative to the internal cutting member 480a, 480b of, respectively, the first and second cutting units 410a. As a result, the first and second drive spindles 476a, 476b can follow pivotal movements of the first and second cutting units 410a, 410b about their primary pivot axis 1a, 1b as described with respect to the embodiment of the shaving unit of
In the embodiment of the shaving unit shown in
It is to be understood that, in embodiments of a shaving unit comprising three cutting units as e.g. shown in
The opening 425a is in fluid communication with the hair collecting chamber 427a. As a result, the hair collecting chamber 427a can be cleaned by providing a flow of a cleaning liquid, e.g. water, via the opening 425a into the hair collecting chamber 427a. Such a flow of e.g. water can be easily provided to the opening 425a via the open space 490 which is present between the transmission housing 479 and the cutting units 410a, 410b. To prevent cut hairs and other shaving debris from escaping from the hair collecting chamber 427a via the opening 425a into the open space 490 during normal use of the shaving unit, a sealing structure 465a is provided in the flow path between the opening 425a and the hair collecting chamber 427a. The sealing structure 465a is configured and arranged to prevent cut hairs from escaping from the hair collecting chamber 427a via the opening 425a, but to allow a cleaning liquid, in particular water, to flow or flush via the opening 425a into the hair collecting chamber 427a. An embodiment of the sealing structure 465a will be described in the following. It is to be understood that the second cutting unit 410b has a similar sealing structure.
As shown in detail in
In particular, the sealing structure 465a comprises a first sealing gap 467a, which is rotationally symmetrical relative to the axis of rotation 406a and has a main direction of extension parallel to the axis of rotation 406a. The first sealing gap 467a is bounded by a first sealing surface 468a of said opposed sealing surfaces, which is provided on the central carrying member 436a of the internal cutting member 480a, and by a second sealing surface 428a of said opposed sealing surfaces, which is provided on the edge structure 423a in the bottom wall 424a of the housing 420a. The first and second sealing surfaces 468a, 428a are each rotationally symmetrical relative to the axis of rotation 406a and each have a main direction of extension parallel to the axis of rotation 406a. In particular, the first and second sealing surfaces 468a, 428a and the first sealing gap 467a, bounded by the first and second sealing surfaces 468a, 428a, are each annular.
Further, the sealing structure 465a comprises a second sealing gap 469a, which is rotationally symmetrical relative to the axis of rotation 406a and has a main direction of extension perpendicular to the axis of rotation 406a. The second sealing gap 469a is bounded by a third sealing surface 466a of said opposed sealing surfaces, which is provided on the central carrying member 436a of the internal cutting member 480a, and by a fourth sealing surface 426a of said opposed sealing surfaces, which is provided on the edge structure 423a in the bottom wall 424a of the housing 420a. The third and fourth sealing surfaces 466a, 426a are each rotationally symmetrical relative to the axis of rotation 406a and each have a main direction of extension perpendicular to the axis of rotation 406a. In particular, the third and fourth sealing surfaces 466a, 426a and the second sealing gap 469a, bounded by the third and fourth sealing surfaces 466a, 426a, are each annular.
Seen in a cross-sectional view along the axis of rotation 406a, the axially oriented first sealing gap 467a and the radially oriented second sealing gap 469a together provide the sealing structure 465a with an L-shaped gap structure provided between the edge structure 423a and the central carrying member 436a, which is rotatable relative to the edge structure 423a about the axis of rotation 406a. In order to achieve an effective preventing of cut hairs from escaping from the hair collecting chamber 427a via the sealing structure 465a during a shaving procedure, while allowing an effective flow of water from the opening 425a via the sealing structure 465a into the hair collecting chamber 427a, a minimum distance between the first sealing surface 468a and the second sealing surface 428a, measured in a direction perpendicular to the axis of rotation 406a, is preferably in a range between 0.1 mm and 1.5 mm. For similar reasons, a minimum distance between the third sealing surface 466a and the fourth sealing surface 426a, measured in a direction parallel to the axis of rotation 406a, is preferably in a range between 0.1 mm and 1.5 mm. To further improve the sealing function of the sealing structure 465a, the first and second sealing gaps 467a, 469a may each converge, seen in a direction of the water flow from the central opening 425a to the hair collecting chamber 427a.
a-18b are detailed views of the first cutting unit 410a of the shaving unit of
As shown in
As further shown in
As shown in
Starting from the opened condition of the housing 520 with the external cutting member 560 and the internal cutting member 580 being held in their operating positions in the cover portion 530 by the holding component 517 as shown in
In particular, in this embodiment the abutment structure formed by the abutting surfaces 595 of the supporting elements 519a, 519b, 519c, 519d provides, in the closed condition of the housing 520 and in said axial direction, a form-locking engagement with the external cutting member 560, wherein the external cutting member 560 is locked in the axial direction between the abutting surfaces 595 and the cover portion 530. Preferably, the abutment structure also provides a form-locking engagement with the external cutting member 560 in radial directions perpendicular to the axis of rotation 506. For this purpose, in the embodiment shown in
It is to be understood that a direct support of the external cutting member 560 by the base portion 551 of the housing 520 in the axial direction parallel to the axis of rotation 506 may also be achieved by a supporting structure different from the supporting structure having the four supporting elements 519a, 519b, 519c, 519d as described here before. The supporting structure may have a different number of supporting elements, although in embodiments having a plurality of supporting elements at least three supporting elements are preferred for a stable support of the external cutting member. Instead of being provided on the bottom wall 524 of the base portion 551, the supporting structure may alternatively be provided on e.g. a side wall of the base portion 551, e.g. as a supporting surface extending circumferentially around the hair collecting chamber 527. A skilled person will be able to define suitable alternative embodiments wherein the supporting structure is provided in the base portion of the housing such as to support the external cutting member at least in the axial direction parallel to the axis of rotation in the closed condition of the housing of the cutting unit.
The invention further relates to a shaving apparatus comprising a main housing accommodating a motor and comprising a shaving unit as described here before. In particular, the shaving unit is or may be releasably coupled to the main housing by means of the coupling member 70, 170, 470. The main housing accommodating the motor and any further components of such a shaving apparatus, such as a rechargeable battery, user interface, and electrical control circuitry, are not shown in the figures and are not described in any further detail, as they are generally known to a person skilled in the art.
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.
Any reference signs in the claims should not be construed as limiting the scope.
| Number | Date | Country | Kind |
|---|---|---|---|
| 17153536.2 | Jan 2017 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2018/051763 | 1/25/2018 | WO | 00 |
