Electric beard trimmer

Abstract

The invention relates to cutting body hair, such as stubble of a multi-day beard. More specifically, the invention relates to a cutter system 3 for an electric shaver and / or trimmer 1, the cutter system comprising a pair of cooperating cutting elements 4, 5 having two rows of comb-like cutting teeth 6, 7 at their opposite edges and at least one region of cutting perforations 8 between the rows of comb-like cutting teeth, formed in a skin contact surface or skin facing surface 50 of the cutting elements, wherein the cutting elements are movably supported relative to each other by a support structure 14 providing a pivot axis 21 about which the cooperating cutting elements are pivotable to follow the skin contour, the pivot axis extending substantially parallel to a longitudinal direction of the rows of comb-like cutting teeth. The pivot axis is positioned more proximal to a first one of the rows of comb-like cutting teeth than to a second one of the rows of comb-like cutting teeth, the first one forming a leading front edge and the second one forming a trailing edge when moving the cutter system along the skin in a normal direction of movement which is intuitively preferred by most users.

Description

TECHNICAL FIELD

[0001] The present invention relates to cutting body hair, such as stubble of a multi-day beard. More specifically, the present invention relates to a cutter system for an electric shaver and / or trimmer, the cutter system comprising a pair of cooperating cutting elements having two rows of comb-like cutting teeth at their opposite edges and at least one area of cutting perforations between the rows of comb-like cutting teeth, the cutting perforations being formed in a skin-contacting surface or skin-facing surface of the cutting elements, wherein the cutting elements are movably supported relative to each other by a support structure providing a pivot axis about which the cooperating cutting elements are pivotable to follow the skin contour, the pivot axis extending substantially parallel to a longitudinal direction of the rows of comb-like cutting teeth. BACKGROUND

[0002] Electric shavers and trimmers utilize various mechanisms to provide the hair cutting function. Some electric shavers include a perforated cutting foil cooperating with an undercutter movable relative thereto to cut hair into perforations in the cutting foil. Such cutting foil type shavers are typically used daily to provide a clean shave with short stubble being cut immediately at the skin surface.

[0003] On the other hand, other cutter systems including a pair of cooperating cutting elements having comb-like edges, the cutting elements including one or more rows of comb-like or bevel-like cutting teeth reciprocating or rotating relative to each other, are typically used to cut longer stubble or problem hairs that are difficult to cut due to, for example, a very small angle to the skin or growing from very elastic skin. Depending on the type of driving motion, the teeth of such comb-like or bevel-like cutting elements typically project substantially parallel to each other or substantially radially and can cut hair into the gap between the cutting teeth, where the cut or shear is achieved in a scissors-like manner when the cutting teeth of the cooperating elements close the gap between the finger-like cutting teeth and pass over each other.

[0004] Such cutter systems for longer hairs can be integrated into an electric shaver or trimmer, which can be provided with the aforementioned cutting foil cutter at the same time. For example, the cutting elements can include two rows of comb-like cutting teeth arranged at, for example, opposite sides of the cutting elements and a cutting foil-like cutting perforation area between the rows of comb-like cutting teeth.

[0005] For example, EP 24 25 938 B1 shows a shaver with a pair of long hair trimmers integrated between a pair of foil cutters. Further, EP 27 47 958 B1 and CN 206 287 174 U disclose hair trimmers with two rows of cooperating cutting teeth arranged at opposite sides of a shaver head, wherein the cutting teeth of the upper comb-like cutting element are provided with rounded and thickened tooth tips that overhang the tooth tips of the lower cutting element in order to prevent the protruding tooth tips from piercing into the skin and to prevent irritation of the skin.

[0006] Similar cutter systems are shown in US 2017 / 0050326 A1, wherein in such cutter systems the lower comb-like cutting element is fixed and the upper comb-like cutting element is movable.

[0007] Shavers and / or trimmers that combine rows of comb-like cutting teeth at opposite edges and foil-like cutting perforations between the rows of comb teeth sometimes comprise a C-shaped outer cutting element, the edges of which are crimped to form limbs that bend inward like the limbs of a C or U, wherein such crimped limbs are held by a support frame. The transition edge portion connecting the crimped limbs with the central section of the outer cutting element is contoured or configured to form rows of comb teeth for cutting longer stubble, while the central section of the cutting element is provided with at least one region with perforations for cutting short hair. The outer cutting element cooperates with an inner cutting element, which can be plate-shaped and can comprise rows of comb teeth at opposite edges to cooperate with the comb teeth of the outer cutting element, and in addition can comprise at least one region between the comb teeth edges with perforations or other incisions for cooperating with the perforations in the outer cutting element.

[0008] Thus, foil and comb-like cutting teeth for cutting short hair and longer hair or stubble, respectively, can be integrated into the same cutting element, wherein the inner cutting element can be biased against the outer cutting element by means of a spring device, which can comprise a pair of flexible spring arms extending from a central base portion of the support structure towards the inner cutting element. The spring arms can have a V-shaped configuration and can contact the inner cutting element at a section between the central region of the perforations and the opposite tooth edges. Due to such biasing of the inner cutting element against the outer cutting element, pulling and tugging of the hair to be cut in the perforations can be avoided, but on the other hand, the friction between the cutting elements is rather high, which leads to high energy consumption of the drive unit and in addition to heating of the cutting elements, which often can be perceived as unpleasant or uncomfortable. Such cutter systems are shown in documents CN 209 478 241 U and US 2018 / 0257248 A1.

[0009] EP 31 31 716 B1 discloses a similar cutter system, wherein the support structure comprises an outer frame holding the outer cutting elements at its opposite edge portions, wherein such outer frame comprises at its inner surface a stepped protrusion forming a shoulder for supporting the inner cutting elements at the toothed comb-like edge. The support structure comprises a four-bar linkage connecting the cutter system to the handle of the trimmer and allowing the cutting elements to pivot about a pivot axis parallel to the reciprocation axis. Due to the four-bar linkage system, the pivot axis is not a fixed axis, but can be moved along a path defining the possible positions of the instantaneous center of rotation. Such four-bar linkage tends to be flexible and can thus influence the transmission of the driving action to the cutting elements via a drive train bridging the gap between the handle and the cutter head.

[0010] Such beard stubble trimmers and razors need to address very different and diverging functional requirements and performance issues such as closeness, coarseness, good visibility of the cutting position, efficient and pleasant skin feel, good ergonomics and handling. Closeness refers to short or very short remaining stubble, while coarseness refers to less missed hairs, especially in problem areas such as the neck. Efficiency refers to fewer and faster strokes sufficient to achieve the desired trimming result. Pleasant skin feel depends on the individual user, but generally includes less irritation in the form of cuts, nicks or abrasions and better glide on the skin. In the case of a styling or edging profile, the visibility of the cutting position is especially important to achieve hair removal locally precisely.

[0011] It is quite difficult to meet such various performance issues simultaneously. It becomes even more difficult to meet such needs when different types of cutting profiles such as shearing foil-like perforations and comb-like teeth are integrated into the same cutting element such as C-shaped cutting blades reciprocating relative to each other, because such multifunctional cutter elements can not be specifically adapted to one particular cutting function. SUMMARY

[0012] It is an object of the present invention to provide an improved cutter system avoiding at least one of the drawbacks of the prior art and / or further developing the existing solutions. It is a more particular object of the present invention to provide a close and thorough cutting of hairs and longer stubbles, including a good control of the edging profile, while avoiding skin irritation. It is a further object to provide a good adaptation of the cutter system to the skin profile, without the risk of skin damage due to uncontrolled pivoting of the cutting elements. It is a further object of the present invention to provide a reliable and clean cutting action of the cooperating cutting teeth and optionally cutting perforations to avoid pulling and tugging of the hairs, without sacrificing low friction between the cutting elements, low temperature of the cutting teeth and low energy consumption, thus without sacrificing long energy storage life.

[0013] According to one aspect, the cutter system can be pivoted relative to the handle about an eccentric pivot axis which is not arranged symmetrically relative to the opposing beveled cutting edges for cutting longer hairs, so that pivoting the cutting element about said pivot axis results in one of the beveled cutting edges having a larger movement than the other. More specifically, the pivot axis is positioned offset from a mid-plane which extends perpendicular to a central section of the skin contact surface and / or the skin facing surface of the cutter element, so that the pivot axis is closer to a first of the rows of comb-like cutting teeth than to a second of the rows of comb-like cutting teeth. When pivoted, the first row of comb-like cutting teeth, which is closer to the pivot axis, makes less or shorter lateral movements, while the second row of comb-like cutting teeth, which is further away from the pivot axis, makes more or larger lateral movements. The lateral movements follow a circular path around the pivot axis, wherein the length of the movement depends on the lever arm or pivot arm, i.e. the distance from the pivot axis. Furthermore, the cutting system comprises a biasing means for biasing the cutting element about the pivot axis towards a home position, and wherein the pivot axis has a fixed position relative to one of the cutting elements and a fixed position relative to the handle of the shaver / trimmer.

[0014] More specifically, the pivot axis can be arranged closer to the row of comb-like cutting teeth which generally serves as a leading edge when advancing the cutter system along the skin to be shaved. Depending on certain aspects of the shaver and / or trimmer, such as the position and / or orientation of the cutting element relative to the handle and / or its position and orientation relative to the skin contact surface in the home position of the cutting element, and / or the protrusion of the cutting element towards a certain side of the handle, and / or the offset and / or the curvature of the cutter head relative to the longitudinal axis of the handle, and / or the arrangement of operating keys at the handle such as the on / off key which suggest a certain way of gripping the handle, the cutter system can have a normal direction of movement or a preferred direction of movement in which most users intuitively move the cutter system over the skin to be shaved, so that one beveled cutting edge is the leading edge and the other beveled cutting edge is the trailing edge, which is moved in such a direction of movement preferred by most users.

[0015] Offsetting the pivot axis towards the preferred leading edge of the cutter system, i.e. towards this row of comb-like cutting teeth which forms the leading edge when the cutter system is moved in the normal direction of movement of most users, so that the leading edge moves transversely to the skin to be shaved, and less pivoting over the pivot axis occurs, so that the user is more comfortable and the risk of skin irritation or damage such as small cuts is reduced. Due to this pivoting of the cutter system, the larger transverse movement on the opposite side, i.e. at the trailing edge, is less important and does not negatively affect the comfort or the risk of damage and skin irritation.

[0016] In the original position or neutral position or initial position of the cutting element relative to the pivot axis, the cutting element can be inclined at an acute angle relative to the longitudinal handle axis, such that the skin contact and / or skin facing surface of the cutter element is oriented towards the front side of the shaper / trimmer's handle. In view of this inclination of the cutting element towards the front side in the original position, the pivot axis is positioned closer to the this row of comb-like teeth positioned at the front side, while the opposite row of comb-like cutting teeth positioned at the rear side of the handle are positioned further away from the pivot axis.

[0017] The positioning of the pivot axis closer to the front row of comb-like teeth can improve the user's comfort and can reduce the risk of skin irritation or even skin damage, such as cuts that can be caused when the comb-like cutting teeth move into the skin due to the pivot or the pitch angle towards the skin becoming too steep, when the user uses the front row of cutting teeth forming the front edge to pull the cutter system along the skin to be shaved.

[0018] These and other advantages become more apparent from the following description with reference to the drawings and possible examples. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 : perspective view of an electric shaver / trimmer comprising a cutting system with a pair of cooperating comb-like cutting elements reciprocating relative to each other, wherein partial view (a) shows the front side of the electric shaver and partial view (b) shows the shaver working on the chin,

[0020] Figure 2 : cross-sectional view of a shaver / trimmer showing the cooperating comb-like cutting elements and a drive system for driving the cutting elements,

[0021] Figure 3 : perspective view of a cutter system comprising a pair of cooperating comb-like cutting elements and a support structure for supporting the cutting elements relative to each other,

[0022] Fig. 4: cross-sectional view of a cutter system and support structure, wherein the C-shaped outer cutting element is shown bent or folded around an outer frame portion and the inner cutting element is shown supported by a V-shaped inner support frame forming a rigid support rib extending from a base portion of the support structure at a steeper angle than the outer frame portion, wherein partial view (a) shows a rigid support rib and view (b) shows a flexible spring-like support rib,

[0023] Figure 5exploded perspective view of elements of a cutter system comprising an outer cutting element and an inner cutting element, an outer support frame for holding the outer cutting element, a trough- or valley-shaped inner support frame comprising rigid support ribs for supporting the inner cutting element, a drive element for reciprocating the inner cutting element, and a guide block for guiding the reciprocating drive element,

[0024] Figure 6 side view showing that the support structure allows the cutter system to pivot relative to the handle of the shaver / trimmer,

[0025] Figure 7 side view showing that the cutter system pivots around its pivot axis when following the contour of the skin,

[0026] Figure 8 plan view of an outer cutting element showing its individual perforated area,

[0027] Figure 9 cross-sectional view of a perforation with a conical or non-cylindrical profile expanding towards the skin contact surface to help hair enter the perforation, wherein the left side view (small and enlarged) is for a planar cutting element and the right side view (small and enlarged) is for a convexly rounded / convexly curved cutting element, and

[0028] Figure 10 exploded perspective view of a pivot bearing structure providing a pivot axis for the cutting element. DETAILED DESCRIPTION

[0029] In order to allow for a more comfortable shaving and / or trimming using the self-adaptation of the skin contour by the cutter blade, and at the same time to reduce the risk of skin irritation or even skin damage, it is suggested to improve the pivot axis support structure to reduce the lateral movement of the front cutting edge into the skin due to the pivoting of the cutting element when moving the cutter system along the skin to be shaved and adjusting the pitch angle of the cutter system to the skin contour.

[0030] More specifically, it is suggested that the cutter system can be pivoted about an off-center pivot axis relative to the handle of the trimmer / razor, which is not symmetrically arranged relative to the opposing beveled cutting edges for cutting longer hairs, so that pivoting the cutting element about said pivot axis results in one of the beveled cutting edges having a smaller movement compared to the other beveled cutting edge. More specifically, the pivot axis is positioned offset from a mid-plane extending perpendicular to a central section of the skin contact surface and / or skin facing surface of the cutter element, so that the pivot axis is closer to a first row of the rows of comb-like cutting teeth compared to a second row of the rows of comb-like cutting teeth. When pivoted, the first row of comb-like cutting teeth closer to the pivot axis makes a shorter lateral movement, while the second row of comb-like cutting teeth further away from the pivot axis makes a longer lateral movement, wherein such lateral movements follow a circular path around said pivot axis, wherein the length of the movement depends on the distance of the rows of teeth from the pivot axis.

[0031] More specifically, the pivot axis can be arranged closer to the row of comb-like cutting teeth that typically serves as a leading edge when advancing the cutter system along the skin to be shaved. Depending on certain aspects of the razor and / or trimmer, such as the position and orientation of the cutting element or its skin contact surface in the original position of the cutting element, and / or the protrusion of the cutting element towards a certain side of the handle, and / or the offset and / or curvature of the cutter head relative to the longitudinal axis of the handle, and / or the arrangement of operating keys such as the on / off key suggesting a certain way of gripping the handle, the cutter system can have a common direction of movement or a preferred direction of movement in which most users intuitively move the cutter system over the skin to be shaved, so that one beveled cutting edge is the leading edge and the other beveled cutting edge is the trailing edge, which is moved in such common direction of movement preferred intuitively by most users.

[0032] Offsetting the pivot axis towards the preferred leading edge of the cutter system, i.e. towards this row of comb-like cutting teeth that forms the leading edge when the cutter system is moved in the common direction of movement of most users, so that the leading edge moves laterally to the skin to be shaved, and a smaller pivoting over the pivot axis occurs, so that the user is more comfortable and the risk of skin irritation or damage like small cuts is reduced. Due to this pivoting of the cutter system, the larger lateral movement of the trailing edge is less important and has no negative impact on comfort or the risk of damage and skin irritation.

[0033] In the original or neutral or initial position of the cutting element relative to the pivot axis, the cutting element can be inclined at an acute angle relative to the longitudinal handle axis, such that the skin contact and / or skin facing surface of the cutter element is oriented towards the front side of the handle of the shaper / trimmer. In view of this inclination of the cutting element towards the front side in the original position, the pivot axis is positioned closer to this row of comb-like teeth positioned at the front side, while the opposite row of comb-like cutting teeth positioned at the back side of the handle are positioned further away from the pivot axis. Many users pull the cutter system along the skin to be shaved using the front row of cutting teeth forming the front edge, such that positioning the pivot axis closer to the front row of comb-like teeth can improve the comfort of the user and can reduce the risk of skin irritation or even skin damage such as cuts that can be caused when the comb-like cutting teeth move into the skin due to a pivot or a pitch angle towards the skin becoming too steep.

[0034] Basically, when the pivot axis is positioned directly at the front cutting edge, the lateral movement of the front cutting edge can be completely eliminated, as this position will eliminate the lever arm or the pivot radius in terms of the distance from the pivot axis. Thus, depending on the aggressiveness of the comb-like cutting teeth and the desired level of comfort, it can be desirable to position the pivot axis relatively close to the front edge. For example, the pivot axis can be positioned in between the row of comb-like teeth formed in the skin contact surface and the perforation area.

[0035] However, when moving the cutter system in the opposite or non-preferred direction of movement over the skin to be shaved, positioning the pivot axis too far from the center of the cutter system can compromise comfort and safety. To achieve a good compromise, the pivot axis can be spaced apart from the first row of comb-like teeth by a distance that is about 60-90% or 70-90% or 75-85% of the distance between the pivot axis and the opposite second row of comb-like teeth.

[0036] Thus, the pivot axis can be positioned closer to one row of comb-like cutting teeth than to the other row of comb-like cutting teeth by about 10-40%.

[0037] To achieve a good responsiveness of the pivoting of the cutting element and thus a good adaptation to the skin profile of different users that can exert different levels of skin contact pressure, the pivot axis can be positioned close to the skin contact surface in order to reduce the torque and thus the pivoting effect of friction. When pressing the cutter system against the skin and moving it along the skin, the friction induced between the skin contact surface and the skin to be shaved tends to or tries to pivot the cutter system around the pivot axis, wherein the lever arm of such friction forces becomes smaller the closer the pivot axis is to the skin contact surface.

[0038] More specifically, the pivot axis can be positioned slightly below the skin contact surface and / or within a cutter head chamber surrounded by a frame portion of the support structure and by the cutting element holding opposite edges of said cutting element. This position significantly reduces the lever action of friction forces relative to the pivot axis and, thus, on the one hand the pivot torque caused by such friction forces and, on the other hand, allows a compact, space-saving arrangement of the support structure.

[0039] In order to allow an easy and intuitive use of the shaver / trimmer, the support structure can be configured to provide a pivot range of the cutting element which is asymmetric with respect to the longitudinal handle axis. In other words, the pivot range can be larger towards one side of the handle than towards the opposite side of the handle. More specifically, the pivot range can be configured such that the skin contact and / or skin facing surface of the cutting element is directed towards the same side of the handle over at least 2 / 3 or 3 / 4 of said pivot range.

[0040] A natural shaver feel and an easy and intuitive use can be achieved when said pivot range allows for various pivot positions of the cutting element using inclination angles in the range of -20° to +60° or 0°-40° + / -10° or + / -5° defined between a virtual plane extending perpendicular to said longitudinal handle axis and another virtual plane tangential to said skin contact / facing surface of said cutting element.

[0041] In order to urge the cutting element into a certain home position, a biasing device can be associated with said pivot axis. Such biasing device can be configured to bias the cutting element around said pivot axis towards the end of the limited pivot range. In other words, the biasing device, which can comprise a spring device, does not urge the cutting element into a neutral intermediate position from which the cutting element can be pivoted in opposite directions, but attempts to urge the cutting element into an extreme or end pivot position from which the cutting element can be pivoted in only one direction.

[0042] More specifically, the biasing device can be configured to bias the cutting element into an angular pivot position having a minimum possible inclination angle of the skin contact surface relative to the longitudinal handle axis. If the cutting element is pivoted out of said biased home position, the plane tangential to the skin contact surface becomes more and more transversal to the longitudinal handle axis and / or attempts to approach a position perpendicular to said longitudinal handle axis.

[0043] Due to the original position of this bias (in which the skin contact surface is inclined at a rather small angle with respect to the longitudinal handle axis), the user intuitively pulls the cutter system with the aforementioned first row of cutting teeth ahead in the skin to be shaved. The eccentric or offset pivot axis thus allows a fine adaptation of the cutting element to the skin profile and avoids uncontrolled lateral movements, which can pose a risk of skin irritation.

[0044] Irrespective of such preferred direction of movement of the cutter system, biasing the cutting element at the end of the pivot range into said original position also reduces the risk of skin irritation or even skin damage when moving the cutter system in the opposite, non-preferred direction over the skin to be shaved, i.e. when the second row of comb-like cutting teeth is the leading edge, because the second row of comb-like teeth can easily be deflected and come into contact with the skin due to the rather large distance from the pivot axis and thus the large lever action of this skin contact force at the opposite edge, where only very low skin contact forces are required.

[0045] In order to avoid too much flexibility being detrimental to the effective transmission of driving forces and / or torques to the cutting element, the pivot axis can have a fixed position with respect to the non-reciprocating cutting element of said cutting elements and / or with respect to the handle of the shaver / trimmer. Such a fixed pivot axis position allows avoiding a soft and bulky lever connection mechanism.

[0046] The support structure can comprise a rigid pivot axis holder having a mounting portion for fixedly attaching the pivot axis holder to the handle or base portion of the shaver / trimmer, wherein the pivot axis holder can comprise two frame portions extending into or towards a cutter head chamber defined by the cutting elements and an outer frame portion of the support structure (14) holding the opposite edge of one of the cutting elements.

[0047] More specifically, the pivot axis holder can comprise a U-shaped or V-shaped holding frame element made of metal.

[0048] In order to achieve a smooth, comfortable cutting action, it is helpful to avoid the cutting elements from separating, thus avoiding the mating comb-like teeth and / or mating cutting perforations from separating from each other, in order to avoid that hairs are no longer properly cut or even clamped between the teeth moving relative to each other or between the cutting perforations moving relative to each other. Basically, this can be prevented by pressing the mating cutting elements against each other, e.g. by a spring means such as a flexible support rib pressing the teeth / perforations of one cutting element against the teeth / perforations of the other cutting element.

[0049] Instead of or in addition to this flexible support rib, one of the cutting elements can be sandwiched between the other cutting element and a support element or support structure, such as a support frame, which can comprise a rigid rib or webbing that precisely and rigidly supports and guides the inner cutting element at a predetermined position underneath the outer cutting element and sufficiently close to it, said rigid support rib and outer cutting element defining a gap in which the sandwiched cutting element is slidably and / or movably received, wherein said gap can be slightly thicker than the sandwiched cutting element to provide some clearance at least during non-use, reducing friction and heat generation. When the outer cutting element is pressed against the skin or at least contacts the skin during operation of the shaver / trimmer, it can deflect and at least subsequently fit closely onto the inner cutting element. Although the sandwiched cutting element can move frictionless or with very low friction relative to the other cutting element, it is nevertheless prevented from flexing even when the thickness of the sandwiched cutting element is very small.

[0050] More specifically, one of the cutting elements can be sandwiched between the other cutting element and said flexible or rigid support rib or webbing that supports and guides the inner cutting element at a predetermined position underneath the outer cutting element and sufficiently close to it, said rigid or flexible support rib and outer cutting element defining a gap in which the sandwiched cutting element is slidably and / or movably received, wherein when said rib is a rigid rib, said gap can be slightly thicker than the sandwiched cutting element to provide some clearance at least during non-use, reducing friction and heat generation. When the outer cutting element is pressed against the skin or at least contacts the skin during operation of the shaver / trimmer, it can deflect and at least subsequently fit closely onto the inner cutting element. When a flexible rib is used, said gap can be zero or at least less than the thickness of said blade without the blade accommodated therein to provide some biasing. Although the sandwiched cutting element can move frictionless or with very low friction relative to the other cutting element, it is nevertheless prevented from flexing even when the thickness of the sandwiched cutting element is very small.

[0051] To achieve low friction and at the same time avoid hairs being pinched between the cutting teeth, the thickness of said gap from the end portion of the support rib to the outer cutting element can be only slightly smaller than the thickness of the sandwiched cutting element by an amount that is less than the thickness of the hair to be cut.

[0052] More specifically, the width of said gap can be less than 40 pm by an amount that is more than the thickness of the sandwiched cutting element. For example, it can be in the range of 20 pm to 40 pm. Such a configuration is a good compromise between still being easy to manufacture and being sufficiently small in the risk of pulling and tugging the hair to be cut.

[0053] The skin contact / facing surface defined by the outer cutting element can be substantially planar or flat. In an alternative, the skin contact surface defined by the outer cutting element can be slightly convex or slightly dome shaped when viewed in a cross section taken perpendicular to the direction of the reciprocating motion. The skin contact surface can be linear when viewed in a cross section plane parallel to the axis of the reciprocating motion. Thus, the skin contact surface can be slightly smoothly convex in terms of a shallow trough or valley like shape.

[0054] Both the outer cutting element and the inner cutting element can have such a shape corresponding to the skin contact surface.

[0055] To keep the inner cutting element and the outer cutting element in close cooperation with each other in the area where the cutting perforations are formed, it can be helpful when the rigid or flexible support ribs extend directly adjacent or closely abutting the outer boundary of the perforation area with their support edges. The support ribs with their support edges can immediately contact the inner cutting element along the outermost row of perforations.

[0056] In an alternative, the support edges of the support ribs can contact the inner cutting element along a line spaced apart from the outermost row of perforations. However, the support edges of the support ribs can be positioned closer to the outermost row of perforations and then closer to the cutting teeth at the opposite edges of the cutting element. More specifically, the support edges of the support ribs can be at a distance from the perforation area that is less than 1 / 3 or 1 / 4 of the distance of the support edges from the cutting teeth of the comb-like cutting teeth.

[0057] To absorb the skin contact pressure induced in the inner cutting element via the outer cutting element in a balanced manner, the support edges of the support ribs facing the inner cutting element can be spaced apart from each other at a distance in the range of 35% to 70% or 40% to 60% of the distance defined between the rows of comb-like teeth at the opposite edges of the cutting element. Depending on the preference of the user, different portions of the skin contact surface defined by the outer cutting element can be pressed against the skin with different forces, so that different skin pressures can be generated. To balance such different pressures, it is helpful when the inner cutting element is supported by the rigid support ribs at about 1 / 3 and about 2 / 3 of the span width of the inner cutting element when considering a cross-sectional view thereof.

[0058] At the opposite edges of the cutting element, the support ribs and / or their support edges contacting the inner cutting element can extend parallel to the axis of the reciprocating motion and / or parallel to the rows of comb-like teeth.

[0059] The support ribs can be anchored at the base portion of the support structure in different ways. For example, the support ribs can be welded to the base portion or embedded in the material of the base portion. For example, when there are separate support ribs, each of the ribs can be inserted into a slot-like recess in the base portion to hold the support ribs in a desired orientation and position.

[0060] In an alternative, the support ribs that are inclined to each other at an acute angle can be integrally connected to each other and / or form an integral part of the support rib element. More specifically, the support ribs can be formed by V-shaped or crimped limbs of a support frame insert that can be inserted into and / or attached to a base portion of a support structure of the support cutting element. Such support rib inserts can have a trough-like or valley-like configuration comprising a strip-like bottom portion from which the two support ribs extend at said inclinations. Such trough-like inserts can be inserted into the support structure and fixedly attached to a base portion thereof. For example, the bottom portion of the insert can be seated onto an inner surface of a bottom portion of an outer support frame at a central portion thereof, wherein the central bottom portion of the outer support frame can form a seat for the support rib insert. Seating the support rib insert onto the bottom portion of the outer support frame can absorb support forces and pressures introduced into the support ribs, thereby pressing the support rib insert onto the bottom portion of the outer support frame.

[0061] The inner support frame insert can be fixedly attached to the outer support frame, for example glued and / or welded and / or form-fitted thereto.

[0062] The outer support frame portion holding the outer cutting element at its opposite edge portions can define a cutter head chamber together with the outer cutting element, which can be configured as a tube or cylinder with an open or closed end face. In order to discharge hair dust or cut hair stubble from such a cutter head chamber, axial end sides of the cutter head chamber can be open.

[0063] More specifically, such a cutter head chamber defined by the outer frame portion and the outer cutting element can be divided by the above-mentioned support ribs of the inner support frame into a plurality of sub-chambers. More specifically, the cutter head chamber can be divided by the rigid support ribs into an inner sub-chamber for collecting short hair particles from the cutting perforations and a pair of outer sub-chambers for collecting long hair particles cut by the comb-like cutting teeth.

[0064] The hair dust collected in the inner sub-chamber and from the perforations as well as the cut hair stubble collected in the outer sub-chambers can be discharged from the respective sub-chambers via at least one open end face, wherein each of the opposite end portions of the sub-chambers can be opened to enhance cleaning of the sub-chambers and discharge of the collected hair dust therefrom.

[0065] The sandwiched cutting element can be driven by a driver connected to the inner cutting element and coupled to a drive train transmitting the driving action of the drive unit, wherein the aforementioned inner support frame comprising the rigid support ribs and the outer support frame comprising the outer frame portion holding the outer cutting element and the base portion supporting the inner support frame can comprise one or more central elongated or slit-like through holes in which a portion of the driver and / or the drive train can be slidably received. In other words, the driver and / or the drive train extends through said through holes in the inner support frame and the outer support frame and is slidably received therein to allow the driver to reciprocate and thus the sandwiched cutting element to reciprocate relative to the other cutting element.

[0066] The driver can comprise an elongated rod-like portion attached to opposite end portions of the inner cutting element and housed in an inner sub-chamber defined between the rigid support ribs and the inner cutting element.

[0067] Depending on the type of driver, the sandwiched cutting element can be a reciprocating or rotating driven cutting element.

[0068] Basically, each of the cooperating cutting elements can be driven. However, to combine a convenient drive system with a safe and soft cutting action, the upper cutting element or outer cutting element having a skin contact surface can be upright and / or can be non-reciprocating and non-rotating, while the lower cutting element or inner cutting element, which can be the sandwiched cutting element, can reciprocate or rotate oscillate.

[0069] As can be seen from Figure 1 and Figure 2 The cutter system 3 can be part of a cutter head 2 attachable to a handle 100 of a shaver and / or trimmer 1. More specifically, the shaver and / or trimmer 1 can comprise an elongated handle 100 housing a battery 104, electronic and / or electric components such as a control unit 111, an electric or magnetic drive motor 103 and a drive train 109 for transmitting the driving action of the motor to the cutter system at the cutter head 2, which can be positioned at one end of the elongated handle 100, see Figure 2 .

[0070] The cutter system 3 comprising a pair of cooperating cutting elements 4 and 5 can be the only cutter system of the cutter head 2, as is the case with the example shown in Figure 1 On the other hand, the cutter system 3 can be incorporated into a shaver head 2 having other cutter systems such as foil cutters, wherein for example the cutter system 3 having at least one row of cooperating cutting teeth 6, 7 can be positioned between a pair of foil cutters or, in an alternative, in front of such foil cutters.

[0071] As shown in Figure 1 , the cutter system 3 can comprise elongated rows of cutting teeth 6 and 7 which can be reciprocated relative to each other along a linear path in order to effect a cutting action by closing the gap between the teeth and passing over each other. On the other hand, the cutter system 3 can also comprise cutting teeth 6 and 7 which are aligned and / or arranged along a circle. Such rotary cutting elements 4 and 5 can have cutting teeth 6 and 7 which project substantially radially, wherein the cutting elements 4 and 5 can be driven to rotate and / or rotate oscillate relative to each other. When rotating and / or rotate oscillating, cyclically closing and reopening the gap between adjacent teeth and passing over each other like scissors, the cutting action is substantially similar to reciprocating cutting elements, like radially extending teeth.

[0072] As shown in Figure 2 , the drive system can comprise a motor, the shaft of which can rotate an eccentric drive pin which is received between the slotted profiles of a driver 18 which is connected to one of the cutting elements 4 which due to the engagement of the rotating eccentric drive pin with the profiles of the driver 18 causes a reciprocating movement.

[0073] As shown in Figure 3 , Fig. 4 and Figure 5 , the cooperating cutting elements 4 and 5 can substantially have a (at least approximately) plate-like configuration, wherein each cutting element 4 and 5 comprises two rows of cutting teeth 6 and 7 which can be arranged at opposite longitudinal sides of the plate-like cutting elements 4 and 5, see Fig. 4 and Figure 5 . The cutting elements 4 and 5 are supported and positioned such that their flat sides are superimposed to each other. More specifically, the cutting teeth 6 and 7 of the cutting elements 4 and 5 contact each other back-to-back like the blades of a pair of scissors.

[0074] In addition to such comb-like cutting teeth 6 and 7, the cooperating cutting elements 4 and 5 can be provided with at least one cutting perforated area which is arranged between the rows of cutting teeth 6 and 7 in the middle portion of the cutting elements 4 and 5. More specifically, the outer cutting element 4 which defines the skin contact surface of the cutter system 3 can comprise at least two rows of perforations 8 which can be formed as small size through holes having a circular, oval, elliptical or polygonal shape.

[0075] In particular, such small size through holes forming the perforations 8 can have a hexagonal shape, wherein the long axis of such hexagonal through holes, i.e. the axis passing through the opposite corners of the hexagonal shape, can be oriented transversely to the reciprocating axis 10 of the cutting elements 4 and 5.

[0076] As can be seen from Figure 9 , the perforations 8 can expand towards the skin contact / facing surface, i.e. the cross-sectional area of the perforations 8 becomes larger towards the skin contact surface. Such horn- or conical- or truncated-pyramidal shape helps the hair to enter the perforations, as can be seen fromFigure 9 It can be seen.

[0077] As can be seen from Figure 8 It can be seen that the perforations 8 can not be distributed over the entire central section of the skin contact surface, but are arranged in limited areas only. More specifically, the cutting perforations 8 for cutting short hair can be limited to areas 70, 90 of the skin contact or skin facing surface 50 of the cutting elements 4 following the rows of comb-like cutting teeth 6, 7, wherein one row of comb-like teeth moves forward when the cutter system 3 is moved along the skin to be shaved, while an intermediate portion 80 of the skin contact / facing surface defined by the cutting elements in between the relative rows of comb-like teeth can be free of perforations.

[0078] Such an arrangement of limited areas 70, 90 of perforations 8 spaced apart from each other takes into account that very short hairs are cut by the perforations 8 immediately following the previous one in the bevel-like cutting edge, while perforations further away from the front comb-like cutting edge are less effective in cutting very short hairs. By eliminating perforations in areas of the skin contact surface 50, the less effective cutting of very short hairs reduces the friction between the cutting elements 4, 5 without sacrificing the efficiency of cutting very short hairs. The friction is reduced because less cutting edges with less perforations need to pass over each other when the cutting elements move relative to each other, and thus hair particles that have already been cut or hair dust from the cutting perforations moving forward on the skin to be shaved are no longer cut or abraded, thus the friction loss is reduced.

[0079] More specifically, the cutting perforations 8 can be arranged in two separate elongated areas 70, 90 of perforations separated from each other by an elongated non-perforated central section 80 of the outer cutting elements defining the skin contact surface 50 in said cutting elements 4, and each comprising at least two rows of perforations 8 extending along and / or parallel to the rows of comb-like cutting teeth 6, 7.

[0080] In order to allow sufficient support of the cutting elements moving relative to each other without hindering the cutting action of the comb-like teeth 6, 7 and perforations 8, said perforated areas 70, 90 can also be separated or spaced apart from the rows of comb-like teeth 6, 7 by elongated non-perforated side portions 61, 62 of said outer cutting elements, wherein the support structure can comprise a pair of flexible or rigid support ribs 19 supporting the inner cutting elements in said cutting elements 5 under said non-perforated side portions 61, 62 adjacent or along the outer boundaries of said perforated areas 70, 90.

[0081] In order to reduce the friction caused by the engagement of the support structure 14 with the moving cutting elements 5, the inner cutting elements 5 can extend unsupported under said non-perforated central section 80 between said areas 70, 90 of perforations 8.

[0082] The elongated non-perforated central section 80 of the skin contact surface 50 defined by the outer cutting element can have a size or width that is greater than the size or width of each of the perforated areas 70, 90. More specifically, the non-perforated central section of the skin contact surface can extend over an area that is in the range of 100-250% or 110-175% of the area defined by each of the perforated areas, see Figure 8 .

[0083] More generally, more than 2 / 3 or more than 3 / 4 of the area of the skin contact surface 50 of the cutter element 4 between the comb-like cutting teeth can be non-perforated. In other words, only 1 / 4-2 / 3 of the skin contact surface 50 between the opposing bevel-like tooth edges of the cutter system 3 can be perforated, as Figure 8 illustrated. Such limitation of the area of the perforations 8 can significantly reduce friction when the cutting elements 4, 5 are moved relative to each other.

[0084] Such perforations 8 in the outer cutter element 4 can cooperate with perforations 9 in the inner cutter element 5 when the cutting elements 4, 5 are reciprocated relative to each other along the axis of reciprocation 10. The perforations 9 in the inner cutter element 5 can also be formed as small size through holes, the shape of which corresponds to or differs from the shape of the perforations 8 in the outer cutter element 4. However, as can be seen from Figure 5 the illustration, the perforations 9 in the inner cutter element 5 need not be small size through holes, but can be larger size cuts, each cooperating with more than one perforation 8 in the other cutter element 4. More specifically, the perforations 9 in the inner cutter element 5 can be formed as longitudinal slot-like cuts, the longitudinal axis of which extends transversely to the axis of reciprocation 10. Thus, each elongated transverse perforation 9 in the inner cutter element 5 can cooperate with each row of perforations in the outer cutter element 4.

[0085] The cuts in the inner cutter element 5 overlap the perforations 8 in the outer cutter element 4 and close the perforations 8 depending on the reciprocating action to achieve a shearing action and / or to cut off the hair introduced into the perforations 8 and 9.

[0086] To support the cutting elements 4 and 5 in the aforementioned positions, the cutting elements are stacked and / or seated back-to-back to each other, but still allow the cutting teeth 6 and 7 and the perforations 8 and 9 to reciprocate relative to each other, the inner cutter element 5 being sandwiched between the outer cutter element 4 and a support structure 14 comprising an inner frame supporting the inner cutter element 5 and an outer frame 12 holding the outer cutter element 4.

[0087] More specifically, the support structure 14 can define a gap 16, wherein the inner cutting element 5 is moveable relative to the outer cutting element 4, wherein the inner cutting element 5 is slidably guided in said gap 16.

[0088] More specifically, as can be seen from Fig. 4 and Figure 5 As can be seen, when viewed in cross-section, the outer cutting element 4 can have a substantially C-shaped configuration with edge portions 4a and 4b that are curved or folded away from the skin contact surface and form a holding flange that is attached or fixed to the outer frame portion 12 of the support structure 14. The edge portions 4a and 4b can be folded or bent back around the edge portion of the outer frame 12, as can be seen from Fig. 4. However, in an alternative, the holding flange 4a and 4b of the cutting element 4 can also be seated on the inside of the outer frame 12.

[0089] The cutting element 4 can be rigidly or fixedly fastened to the outer frame portion 12. For example, the cutting element 4 can be welded or glued to the outer frame 12.

[0090] As can be seen from Fig. 4 and Figure 5 As can be seen, the outer frame portion 12 of the support structure 14 can comprise a pair of diverging legs forming a shallow trough or valley, wherein the edge portions of the support legs of the outer frame 12 can be provided with slot-like cut-outs 13 that form substantially correspond to the tooth edges of the cutting teeth 6 and 7 of the cutting elements 4 and 5. More specifically, the cut-outs 13 in the edge of the outer frame 12 allow hair to be cut into the teeth 6 and 7 of the cutting elements 4 and 5, but at the same time provide some support to the cutting teeth 6 of the outer cutting element 4.

[0091] The cutting teeth 6 of the outer cutting element 4 can be formed in a transition area between the folded-back support flanges 4a and 4b and the front side of the cutting element 4 that defines the skin contact surface of the cutter system 3.

[0092] The outer cutting element 4 can form a C-shaped plate-like cutting element, the edges of which are rolled over to form limbs that curve inwards like the limbs of a C or U, wherein such rolled-over limbs 4a and 4b are held by the outer support frame portion 12. The transition edge portions connecting the rolled-over limbs with the central section of the outer cutting element are contoured or configured to form rows of comb-like teeth 6 for cutting longer stubbles, whereas the central section 4c of the cutting element 4 is provided with the area of the perforations 8 for cutting short hair.

[0093] As can be seen from Fig. 4, the outer cutting element 4 together with the outer frame 12 of the support structure 14 defines a chamber 17 that is surrounded by the outer cutting element 4 and the outer frame 12.

[0094] Within such chamber 17, an inner frame 11 is arranged for supporting the inner cutting elements 5. Said inner frame 11 comprises at least one pair of rigid support ribs 19 extending from a base section 20 of the support structure 14 towards the inner cutting elements 5 which are stacked back-to-back on the outer cutting elements 4.

[0095] More specifically, as can be seen from Fig. 4, said rigid support ribs 19 originate from a central section of the outer frame 12 at which the diverging support legs of the outer frame 12 engage each other. Said support ribs 19 of the inner frame 11 extend at an angle β from said base section 20 towards the inner cutting elements 5 which is steeper than the angle between the outer frames 12. As can be seen from Fig. 4, the support ribs 19 of the inner frame 11 can define an angle β between each other of 2x20° to 2x40° or 2x25° to 2x30°, wherein said rigid support ribs 19 can be arranged symmetrically with respect to a central plane perpendicular to the skin contact surface and parallel to the axis of reciprocating motion 10.

[0096] In order to impart sufficient rigidity to the rigid support ribs 19, said ribs 19 can have a straight longitudinal axis when viewed in a cross-sectional view as shown in Fig. 4. In other words, the inner and outer surfaces of the support ribs 19 can be planar and flat in order to achieve a buckling rigidity. These support ribs 19 can define a V-shaped configuration originating from the base portion 20.

[0097] In an alternative, said ribs 19 can be configured to be flexible and / or elastic in order to bias the inner cutting elements 5 onto the outer cutting elements 4 as Figure 4b shown. For example, when viewed in cross-section, see Figure 4b , the ribs 19 can have a flexing curved profile in order to elastically urge the cutting elements 5 against the other cutting elements 4.

[0098] As can be seen from Figure 5 , the support ribs 19 can be part of a support insert and / or formed integrally with each other. More specifically, the inner frame 11 can have a channel-like or valley-like configuration comprising a strip-like bottom portion from which said pair of support ribs 19 extend from edges of said strip-like bottom portion. For example, said inner frame 11 comprising the support ribs 19 can be formed from a substantially rectangular metal plate, wherein strip-like edge portions can be bent with respect to an intermediate section in order to form the inclined support ribs 19.

[0099] Said inner frame 11 can form an insert which can be inserted into the chamber 17 defined by the outer frame 12 and the outer cutting elements 4. More specifically, said insert forming the inner frame 11 can be seated onto the base portion 20 of the outer frame 12 which bears the forces and pressures induced into the inner frame 11 when the cutter system 3 is pressed against the skin to be shaved.

[0100] The inner frame 11 is configured such that the aforementioned gap 16 is defined on the one hand between the support edges of the rigid support ribs 19 and on the other hand between the inner sides of the outer cutting elements 4. More specifically, the height of the support ribs 19 is configured such that the gap 16 between the support edges of the ribs 19 and the outer cutting elements 4 substantially corresponds to the thickness of the inner cutting elements 5, wherein the gap 16 can be configured slightly wider than the thickness of the plate-like cutting elements 5 in order to reduce friction and provide some clearance between the inner cutting elements 5 and the support ribs 19 as well as between the inner cutting elements 5 and the outer cutting elements 4. Such a gap can be given when the cutter system 3 is unloaded, i.e. not pressed against the skin to be shaved. In the operating state, when the outer cutting elements 4 are pressed against the skin to be shaved, such a gap is eliminated and the cutting elements 4 and 5 fit tightly onto each other to achieve a smooth cutting of the hair.

[0101] Despite such a possible gap provided by the support structure 14, the support ribs 19 are configured such that the gap 16 exceeds the thickness of the inner cutting elements 4 in its width by an amount which is less than the thickness of the hair to be cut. For example, the width of the gap 16 can be less than 40 pm or in the range of 20 pm to 40 pm than the thickness of the sandwiched cutting elements 5.

[0102] As can be seen from Fig. 4, the inner cutting elements 4 and the outer cutting elements 5 can have a slightly convex profile. More specifically, the skin contact surface defined by the outer cutting elements 4 can have a slightly convex substantially trough-like configuration. When viewed in a cross-section taken perpendicular to the reciprocation axis 10, the outer surface of the outer cutting elements 4 can be slightly dome-shaped, see Fig. 4.

[0103] In terms of the slightly convex trough-like shape, the inner cutting elements 5 substantially correspond to the shape of the outer cutting elements 4.

[0104] As can be seen from Fig. 4, the support edges of the support ribs 19 facing the inner cutting elements 5 can be spaced apart from each other by a distance in the range of about 35% to 70% or 40% to 60% of the distance defined between the rows of comb teeth 6 and 7 at the opposite edges of the outer cutting elements 4. Thus, when viewed in a cross-section perpendicular to the reciprocation axis 10, the rigid support ribs 19 can support the inner cutting elements 4 at about 1 / 3 and about 2 / 3 of their span width. More specifically, the support edges of the ribs 19 can extend directly adjacent to the outer boundaries of the areas of the perforations 8, wherein the support ribs 19 can contact the inner cutting elements 5 along the outer longitudinal profile of the cut-outs forming the perforations 9 in the inner cutter elements 5.

[0105] Since the configuration of the support rib 19 extends from the base portion 20 of the support structure 14 at a steeper angle than the support legs of the outer frame 12, the chamber 17 defined by the outer frame 12 and the outer cutting element 4 attached thereto is divided by the support rib 19 into an inner sub-chamber 17i and a pair of outer sub-chambers 17o, see Figure 4, wherein the outer sub-chambers 17o together may have a volume substantially corresponding to the volume of the inner sub-chamber 17i.

[0106] The rigid support ribs 19 of the inner frame 11 may extend substantially parallel to the reciprocating motion axis 10. More specifically, the support edges of the contact inner cutting elements 5 of the ribs 19 may extend parallel to the reciprocating motion axis 10.

[0107] As from Figure 6 and Figure 7 As can be seen, the cutter head 2, including the cutter system 3, can be pivotally supported relative to the handle of the razor / trimmer 1 about a pivot axis 21, which can extend substantially parallel to the reciprocating motion axis 10.

[0108] The pivot axis 21 can be positioned close to the cutting elements 4 and 5 and / or within the chamber 17 surrounded by the outer cutting elements 4 and the outer frame 12. (As from...) Figure 5 and Figure 6 As can be seen, the outer frame 12 that holds the support structure 14 of the outer cutting element 4 may include a pair of pivot bearing sections 12a and 12b, which may be spaced apart from each other and / or positioned at opposite end faces of the outer frame 12. On the other hand, a pair of support flanges may be provided on the cutter head side of the handle 100, wherein the pivot bearing flanges are rotatably connected to the pivot bearing sections 12a and 12b of the outer frame 12 to form a pivot axis 21.

[0109] More specifically, to avoid excessive flexibility that could be detrimental to the effective transmission of driving force and / or torque to the cutting element, the pivot axis 21 may have a fixed position relative to the non-reciprocating cutting element in the cutting element 4 and / or a fixed position relative to the handle 100 of the razor / trimmer 1. Such a fixed pivot axis position allows for the avoidance of soft and cumbersome rod connection mechanisms.

[0110] The support structure 14 may include a rigid pivot axis retainer 41 having a mounting portion 44 for securely attaching the pivot axis retainer 41 to the handle 100 or base portion 101 of the razor / trimmer 1. The pivot axis retainer 41 may include two frame portions 42 extending into or toward the cutter head chamber 17 defined by the cutting elements 4, 5 and the outer frame portion 12 of the support structure 14, the outer frame portions holding opposite edges of the outer cutting elements 4, such as... Figure 10 As shown.

[0111] More specifically, the pivot axis holder 41 can comprise a U-shaped or V-shaped holding frame element 43 made of metal, see Figure 10 .

[0112] The spring device 22 can be associated with the pivot axis 21 so as to urge the cutter head 2 in a desired mutual pivoting position or orientation, which can be an intermediate orientation allowing pivoting into opposite directions, or in the alternative, an end position or end orientation allowing pivoting into only one direction.

[0113] The spring device 22 can engage the support flange 43 of the pivot axis holder 41 attached to the handle 100 on the one hand and the outer frame 12 of the support structure 14 on the other hand.

[0114] More specifically, the pivot axis 21 is not arranged symmetrically with respect to the opposing bevel-like cutting edges for cutting longer hairs, so that pivoting the cutting elements 4, 5 around the pivot axis 21 results in one of the bevel-like cutting edges having a smaller movement compared to the other bevel-like cutting edge. More specifically, the pivot axis 21 is positioned offset from an intermediate plane 30 extending perpendicular to the central section 80 of the skin contact / facing surface 50 of the cutter elements 4, 5, so that the pivot axis 21 is closer to the first row of comb-like cutting teeth 6 compared to the second row of comb-like cutting teeth 7. When pivoting, the rows closer to the pivot axis 21 perform a shorter lateral movement, while the rows further away from the pivot axis 21 perform a longer lateral movement, wherein such lateral movements follow a circular path around the pivot axis 21, wherein the length of the movement depends on the distance of the rows from the pivot axis 21.

[0115] More specifically, the pivot axis 21 can be arranged closer to the row of comb-like cutting teeth 6, which typically serves as a leading edge advancing when moving the cutter system 3 along the skin to be shaved. Such common movement direction 106 preferred intuitively by most users can depend, inter alia, on the inclination of the skin contact / facing surface of the cutter system 3 relative to the handle 100 in the original position of the cutting elements 4, 5 relative to the pivot axis 21. Alternatively or in addition, the preferred movement direction 106 of most users can be towards the on / off button 105 of the handle.

[0116] From Figure 6It can be seen that in the home position or neutral position or initial position in which the cutting elements 4, 5 are held without an external force caused by the user, the cutting elements 4, 5 can be inclined at an acute angle δ with respect to the longitudinal handle axis 110, so that the skin contact and / or skin facing surface 50 of the cutter elements 4, 5 is directed towards the front side 108 of the handle 100 of the shaper / trimmer 1. The front side 108 of the handle is the same side of the handle on which the on / off button 105 for switching the motor on / off operation is located and / or where the user's thumb can rest 107. Considering this inclination of the cutting elements 4, 5 towards the front side in the home position, the pivot axis 21 is positioned closer to the front row of comb-like teeth 6 located at the front side, while the opposite row of comb-like cutting teeth 7 located at the back side of the handle 100 is positioned further away from the pivot axis 21.

[0117] Many users use the front row of cutting teeth 6 forming the front edge to pull the cutter system along the skin to be shaved as indicated by the arrow in Figure 7 , i.e. downwards in Figure 7 , so that the pivot axis 21 is positioned closer to the front row of comb-like teeth 6. This can improve the user's comfort and can reduce the risk of skin irritation or even skin damage such as wounds that can be caused when the comb-like cutting teeth 6 move into the skin due to the pivot or pitch angle towards the skin becoming too steep.

[0118] Basically, when the pivot axis 21 would be positioned directly at the front cutting edge 6, the lateral movement of the front cutting edge 6 could be completely eliminated, since this position would eliminate the lever arm or the pivot radius in terms of the distance from the pivot axis. However, when the cutter system is moved in the opposite or non-preferred direction of movement on the skin to be shaved, having the pivot axis 21 too much offset from the center of the cutter system 3 can compromise the comfort and safety. To achieve a good compromise, the pivot axis 21 can be spaced apart from the first row of comb-like teeth 6 by a distance LI which is about 60-90% or 70-90% or 75-85% of the distance L2 between the pivot axis and the opposite second row of comb-like teeth, see Figure 6 .

[0119] Thus, the pivot axis 21 can be positioned closer to one row of comb-like cutting teeth 6 than to the other row of comb-like cutting teeth 7 by about 10-40%.

[0120] To achieve a good responsiveness of the pivoting of the cutting elements 4, 5 and thus a good adaptation to the skin profile of different users who can exert different levels of skin contact pressure, the pivot axis 21 can be positioned close to the skin contact surface, see Figure 6in order to reduce the torque and thus the pivoting effect of the friction. When pressing the cutter system against the skin and moving along the skin, the friction induced between the skin contact surface 50 and the skin to be shaved tends to or tries to pivot the cutter system around the pivot axis 21, see Figure 7 where the lever arm of such friction forces becomes smaller, the closer the pivot axis 21 is to the skin contact surface 50.

[0121] More specifically, the pivot axis 21 can be positioned slightly below the skin contact surface 50 and / or within a cutter head chamber 17 encircled by a frame portion of the support structure 14 and the cutting element 4, said frame portion holding opposite edges of the outer C-shaped cutting element 4. This position significantly reduces the lever action of the friction forces relative to the pivot axis 21 and, thus, on the one hand the pivoting torque induced by such friction forces and, on the other hand, allows a compact, space-saving arrangement of the support structure 14.

[0122] In order to allow an easy and intuitive use of the shaver / trimmer, the support structure can be configured to provide an asymmetric pivoting range 45 of the cutting element with respect to the longitudinal handle axis 21, as shown in Figure 6 In other words, the pivoting range 45 can be larger towards one side of the handle 100 than towards the opposite side of the handle 100. More specifically, the pivoting range 45 can be configured such that the skin contact and / or skin facing surface 50 of the cutting element is oriented towards the same side of the handle over at least 2 / 3 or 3 / 4 of said pivoting range 45.

[0123] A natural shaver feel and easy and intuitive use can be achieved when said pivoting range allows for various pivoting positions of the cutting element at an inclination angle a in the range of -20° to +60° or 0°-40° + / -10° or + / -5°, said inclination angle being defined between a virtual plane 46 extending perpendicular to said longitudinal handle axis 110 and another virtual plane 47 tangential to said skin contact / facing surface 50 of said cutting element 4, 5.

[0124] In order to urge the cutting element 4, 5 into its pivoted home position, the aforementioned biasing means 22 can be associated with said pivot axis 21. Such biasing means 22 can be configured to bias the cutting element 4, 5 around said pivot axis 21 towards the end of the limited pivoting range. In other words, the biasing means, which can comprise a spring means, does not urge the cutting element into a neutral intermediate position from which the cutting element can be pivoted in opposite directions, but the biasing means 22 tries to urge the cutting element into an extreme or end pivoting position in which the cutting element can be pivoted in only one direction.

[0125] More specifically, the biasing means 22 can be configured to bias the cutting elements 4, 5 into an angular pivot position having a smallest possible inclination angle δ of the skin contact surface 50 relative to the longitudinal handle axis 110. If the cutting elements are pivoted out of said biased home position, the plane 47 tangential to the skin contact surface 50 becomes more and more transversal to the longitudinal handle axis 110 and / or tries to approach a position perpendicular to said longitudinal handle axis 110.

[0126] Due to such a biased home position (where the skin contact surface 50 is inclined at a rather small angle δ relative to the longitudinal handle axis 110), the user intuitively pulls the cutter system 3 with the aforesaid first row of cutting teeth 6 advancing over the skin to be shaved. Thus, the eccentric or offset pivot axis 21 allows for a fine adaptation of the cutting elements to the skin profile and avoids uncontrolled lateral movements which can pose a risk of skin irritation.

[0127] Irrespective of such preferred directions of moving the cutter system, biasing the cutting elements 4, 5 into said home position at the end of the pivot range also reduces the risk of skin irritation or even skin damage when moving the cutter system in the opposite, non-preferred direction over the skin to be shaved, i.e. when the second row of comb-like cutting teeth 7 is leading, because the second row of comb-like teeth 7 can easily be deflected and contact the skin due to the rather large distance from the pivot axis 21 and thus a large lever action of such skin contact forces at the opposite edge where only very low skin contact forces are required.

[0128] For driving the cutting elements 4 and 5 relative to each other in a reciprocating manner, a driver 18 can be connected to the inner cutting element 5, wherein such a driver 18 can comprise a rod-like driving element attached to opposite end portions of the inner cutting element 5. On the other hand, said driver 18 can comprise a coupling section 18c which couples with a driving element extending from the handle 100 to the cutter head 2. More specifically, the inner frame 11 and the outer frame 12 of the support structure 14 can comprise an elongated recess 23 or cut-out extending through a base section 20 of the support structure 14, wherein the aforesaid coupling section 18c of the driver 18 can extend through said elongated cut-out 23, see Figure 5 and Fig. 4, to allow coupling with a driving element from a drive train of a motor in the handle 100.

[0129] Said driver 18 can be slidably guided at the inner frame 11 and / or the outer frame 12. For example, one or more guide blocks 24 or bearings 24 can be provided at the outer frame 12. For example, such guide blocks 24 can be inserted into a central elongated recess 23 extending in a base portion of the outer frame 12, wherein said guide blocks 24 can comprise a slot-like groove 25 in which the rod-like driver 18 can be slidably guided.

[0130] The drive 18 can be accommodated between the rigid support ribs 19 of the inner frame 11. In particular, the drive 18 can be accommodated within the inner sub-chamber 17i and can thus be surrounded by a slot-like insert of the inner frame 11 comprising the rigid support ribs 19, wherein the coupling section 18c of the drive 18 can extend through a central elongated recess 23 in a bottom portion of the insert forming the inner frame 11.

Claims

1. A cutter system for an electric razor or trimmer (1), the cutter system comprising a pair of mating cutting elements (4, 5) having two rows of comb-like cutting teeth (6, 7) at their opposite edges and skin contact surfaces (50) or skin-facing surfaces of the cutting elements (4, 5), wherein the cutting elements (4, 5) are movably supported relative to each other by a support structure (14) providing a pivot axis (21), the mating cutting elements being pivotable about the pivot axis to follow The pivot axis (21) extends substantially parallel to the longitudinal direction of the two rows of comb-shaped cutting teeth (6, 7), wherein the pivot axis (21) is positioned offset from the intermediate plane (30), which extends perpendicularly to the central segment (80) of the skin contact surface (50) or skin-facing surface of the cutting element (4, 5), and is therefore closer to the first row of comb-shaped cutting teeth (6) than to the second row of comb-shaped cutting teeth (7) of the two rows of comb-shaped cutting teeth, wherein It also includes a biasing device (22) for biasing the cutting elements (4, 5) toward their original position about the pivot axis (21), wherein the pivot axis (21) has a fixed position relative to the outer cutting element (4) of the cutting elements and a fixed position relative to the handle (100) of the electric razor or trimmer (1), wherein the support structure (14) includes a rigid support rib (19) defining a gap (16) between the support rib (19) and the outer cutting element (4), and the inner cutting element of the cutting elements The element (5) is slidably guided in the gap (16), wherein the gap (16) is configured to be slightly wider than the thickness of the inner cutting element (5) so as to provide a gap between the inner cutting element (5) and the support structure (14) and between the inner cutting element (5) and the outer cutting element (4), and when the outer cutting element (4) presses against or at least contacts the skin during operation of the electric razor or trimmer (1), it can deflect and at least subsequently fit tightly onto the inner cutting element (5).

2. The cutter system according to claim 1, wherein at least one cutting perforation region of a cutting perforation (8) is provided between the two rows of comb-shaped cutting teeth (6, 7), the cutting perforation (8) being formed in the skin contact surface (50) or skin-facing surface of the cutting element (4, 5).

3. The cutter system according to claim 1, wherein when the cutting element (4, 5) is moved along the skin to be shaved in a movement direction (106) toward the on / off button, the first row of comb-like cutting teeth (6) closer to the pivot axis (21) forms a front row of cutting teeth at the leading edge of the cutting element (4, 5).

4. The cutter system according to claim 1, wherein in the original position of the cutting elements (4, 5) relative to the pivot axis (21), the cutting elements (4, 5) are inclined at an acute angle (δ) relative to the longitudinal handle axis (110) of the handle (100) of the electric razor or trimmer (1).

5. The cutter system of claim 4, wherein the tilt of the cutting elements (4, 5) in the original position is provided such that the skin contact surface (50) or skin facing surface of the cutting elements (4, 5) faces the front side (108) of the handle (100) of the electric razor or trimmer (1), wherein the first row of comb-shaped cutting teeth (6) closer to the pivot axis (21) faces the front side (108), while the second row of comb-shaped cutting teeth (7) faces the opposite rear side.

6. The cutter system according to claim 1, wherein the pivot axis (21) is spaced apart from the first row of comb-shaped cutting teeth (6) by a distance (L1) that is within 60% to 90% of the distance (L2) between the pivot axis (21) and the second row of comb-shaped cutting teeth (7).

7. The cutter system according to claim 1, wherein the pivot axis (21) is spaced apart from the first row of comb-shaped cutting teeth (6) by a distance (L1) that is within 70% to 90% of the distance (L2) between the pivot axis (21) and the second row of comb-shaped cutting teeth (7).

8. The cutter system according to claim 1, wherein the pivot axis (21) is spaced apart from the first row of comb-shaped cutting teeth (6) by a distance (L1) that is within 75% to 85% of the distance (L2) between the pivot axis (21) and the second row of comb-shaped cutting teeth (7).

9. The cutter system of claim 1, wherein the pivot axis (21) is located slightly below the skin contact surface (50) or skin facing surface of the cutting elements (4, 5) and / or extends within a cutter head chamber (17) surrounded by an outer frame portion (12) of the cutting elements (4, 5) and the support structure (14), the outer frame portion holding the opposite edges of the outer cutting elements (4) in the cutting elements.

10. The cutter system of claim 4, wherein the support structure (14) is configured to provide a pivot range (45) about the pivot axis (21), the pivot range (45) being asymmetrical about the longitudinal handle axis (110), wherein the skin contact surface (50) or skin facing surface of the cutting elements (4, 5) faces the same side of the handle (100) at least 2 / 3 of the pivot range (45).

11. The cutter system of claim 4, wherein the support structure (14) is configured to provide a pivot range (45) about the pivot axis (21), the pivot range (45) being asymmetrical about the longitudinal handle axis (110), wherein the skin contact surface (50) or skin facing surface of the cutting elements (4, 5) faces the same side of the handle (100) at least 3 / 4 of the pivot range (45).

12. The cutter system of claim 4, wherein the support structure (14) is configured to provide a pivot angle (α) in the range of -20° to +60°, the angle (α) being defined between a virtual plane (46) extending perpendicular to the longitudinal handle axis (110) and a virtual plane (47) tangent to the skin contact surface (50) or skin facing surface of the cutting element (4, 5).

13. The cutter system of claim 4, wherein the support structure (14) is configured to provide a pivot angle (α) in the range of 0° to 40° + / - 10°, the angle (α) being defined between a virtual plane (46) extending perpendicular to the longitudinal handle axis (110) and a virtual plane (47) tangent to the skin contact surface (50) or skin facing surface of the cutting element (4, 5).

14. The cutter system according to claim 4, wherein the biasing device (22) is adapted to bias the cutting element (4, 5) about the pivot axis (21) toward the end of a limited pivot range (45).

15. The cutter system of claim 14, wherein the biasing device (22) is configured to press the cutting elements (4, 5) into a pivot position having a minimum tilt angle (δ) of the skin contact surface (50) or skin facing surface relative to the longitudinal handle axis (110).

16. The cutter system of claim 1, wherein the support structure (14) includes a rigid pivot axis retainer (41) having a mounting portion for securely attaching the pivot axis retainer (41) to the handle (100) or base portion (101) of the electric razor or trimmer (1), the pivot axis retainer (41) including two frame portions (42) extending into or toward the cutter head chamber defined by the outer frame portion (12) of the cutting elements (4, 5) and the support structure (14), the outer frame portion holding the opposing edges of the outer cutting elements (4) in the cutting elements.

17. The cutter system of claim 16, wherein the pivot axis retainer (41) comprises a U-shaped or V-shaped retaining frame element (43) made of metal.

18. The cutter system of claim 2, wherein the support structure (14) further comprises an outer frame portion holding the outer cutting element (4) at their opposite edge portions, wherein the support rib extends from the base portion of the support structure (14) and forms a support edge supporting the inner cutting element along the outer edge of the cutting perforation area.

19. The cutter system of claim 18, wherein the support rib (19) is wherein... - Extends from the base portion (20) of the support structure (14) at an angle (β) of 2×20° to 2×40°, and / or - They are spaced apart from each other by a distance that is within 35% to 70% of the distance between the two rows of comb-like cutting teeth (6, 7) at the opposite edges of the cutting elements (4, 5), and / or - Defines a V-shaped shape and has a linear profile when viewed in cross-section, the linear profile having flat, substantially parallel side surfaces.

20. The cutter system according to claim 19, wherein the angle (β) at which the support rib (19) extends from the base portion (20) of the support structure (14) is 2×25° to 2×30°.

21. The cutter system of claim 19, wherein the distance between the support ribs (19) and each other is in the range of 40% to 60% of the distance between the two rows of comb-shaped cutting teeth (6, 7) defined at the opposite edges of the cutting elements (4, 5).

22. The cutter system of claim 1, wherein the outer cutting element (4) has a C-shaped shape when viewed in cross-section, the C-shaped shape comprising a pair of rolled retaining flanges attached to the support structure (14) and a slightly domed or flat central section.

23. An electric razor or trimmer, the electric razor or trimmer comprising a cutter system constructed according to any one of the preceding claims.

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