The present disclosure relates to a (hair) cutting appliance, particularly to a cutter and a stationary blade of a blade set for such an appliance. The present disclosure further relates to corresponding manufacturing methods.
WO 2013/150412 A1 discloses a cutting appliance and a corresponding blade set of a cutting appliance. The blade set comprises a stationary blade and a movable blade, wherein the movable blade can be reciprocatingly driven with respect to the stationary blade for cutting hair.
For the purpose of cutting body hair, there exist basically two customarily distinguished types of electrically powered appliances: the razor, and the hair trimmer or clipper. Generally, the razor is used for shaving, i.e. slicing body hairs at the level of the skin so as to obtain a smooth skin without stubbles. The hair trimmer is typically used to sever the hairs at a chosen distance from the skin, i.e. for cutting the hairs to a desired length. The difference in application is reflected in the different structure and architectures of the cutting blade arrangement implemented on either appliance.
Common electric razors are not particularly suited for cutting hair to a desired variable length above the skin, i.e., for precise trimming operations. Similarly, common hair trimmers are not particularly suited for shaving. Furthermore, combined shaving and trimming devices show several drawbacks since they basically require two cutting blade sets and respective drive mechanisms.
The above WO 2013/150412 A1 tackles some of these drawbacks by providing a blade set comprising a stationary blade that houses the movable blade such that a first portion of the stationary blade is arranged at the side of the movable blade facing the skin, when used for shaving, and that a second portion of the stationary blade is arranged at the side of the movable blade facing away from the skin when in use. Furthermore, at a toothed cutting edge, the first portion and the second portion of the stationary blade are connected, thereby forming a plurality of stationary teeth that cover respective teeth of the movable blade. Consequently, the movable blade is guarded by the stationary blade.
However, there is still a need for improvement in hair cutting devices and respective blade sets. This may particularly involve user comfort related aspects, performance related aspects, and manufacturing related aspects. Manufacturing related aspects may involve suitability for series production or mass production.
It is an object of the present disclosure to provide an alternative stationary cutter blade, and a corresponding blade set that that contribute to a pleasant user experience in both shaving and trimming operations. More preferably, the present disclosure may address at least some drawbacks inherent in known prior art hair cutting blades as discussed above, for instance. It would be further advantageous to provide for a blade set that may exhibit an improved operating performance while preferably reducing the time required for cutting operations. It is preferred desired to present an adequate corresponding manufacturing method.
According to a first aspect of the present disclosure, a cutter for a blade set of a hair cutting appliance according to claim 1 is presented. As used herein, the cutter may be referred to as movable cutter blade.
According to another aspect of the disclosure a blade set for a cutting appliance according to claim 10 is presented.
According to another aspect of the disclosure a method of manufacturing a blade set for a cutting appliance according to claim 12 is presented.
The cutter-related aspect is based on the insight that the at least one scraping portion may act as a scraper or pusher when the cutter and the stationary blade are moved with respect to each other so as to remove accumulated dirt and debris, such as hair remainders, etc. from the guide slot. This is particularly beneficial when the cutter is mounted at a stationary blade that is arranged as a double-walled stationary blade which at least partially encompasses and guards the cutter at two opposite sides thereof. Since the stationary blade according to at least some embodiments of the present disclosure comprises a first wall and a second wall that define therebetween the guide slot for the cutter, the guide slot as such is hard to reach and therefore hardly accessible for a manual cleaning operation. Generally, the first wall may be referred to as first wall portion. Generally, the second wall may be referred to as second wall portion. Further, as it is preferred that the cutter is arranged in the guide slot in a defined manner without considerable (vertical) play, providing the cutter with sufficient dirt removing capabilities may further improve the long-time performance of the blade set. Generally, the scraper profile may also be referred to as pusher profile. Further, the relatively flat main portion of the cutter may also be referred to as planar main portion.
As a consequence, the cutter that is provided with at least one scraping portion itself may clean the guide slot and remove the deposits and accumulations. Consequently, long-term performance and operational life span of the blade set may be increased. At least to some extent, the blade set that is fitted with a respective cutter may provide self-cleaning capabilities.
In one embodiment of a cutter, the tapered scraper profile of the at least one scraping portion is arranged as a longitudinally extending pointed profile comprising a tip edge at the side of the cutter that is facing the first wall in the mounted state. Hence, the tapered scraper profile may be arranged at the cutting surface where respective cutting edges of the stationary blade and the cutter cooperate with each other. Consequently, hair remainders and further particles that may be generated and accumulated at the very cutting spot may be removed in this way. As a consequence, those particles can be prevented from sticking on in the guide slot which might for instance increase frictional effects between the cutter and the stationary blade when the blade set is operated.
In another embodiment of the cutter, the scraper profile of the at least one scraping portion comprises a cross-section selected from the group consisting of wedge shape, triangle shape, C-shape, double wedge shape, and double triangle shape. Generally, it is preferred that a relatively sharp tip is provided at the profile of the at least one scraping portion. In case a profile is implemented that comprises two respective tip edges, a first and a second tip edge may be provided at opposite sides of the cutter so as to contact and clean the first wall and the second wall of the stationary blade. It may be preferred that the cross-section of the tapered scraper profile comprises an acute angle so as to form the relatively sharp tip edge.
Generally, the tip edge may be defined by an angle of inclination β (beta) between a side of the profile that is basically parallel to a longitudinal direction Y and a side that is inclined thereto. The angle may be in the range of about 5° (degrees) to about 60°, preferably in the range of about 15° to about 45°, more preferably in the range of about 22.5° to about 30°. However, at least in some embodiments, the side of the cross-section of the tapered scraper profile that is inclined with respect to the side that is basically parallel to the lateral direction Y may be at least partially curved, for instance convexly curved or concavely curved.
In another embodiment of the cutter that is fitted with at least one scraping portion, the cutter further comprises a guide opening, particularly a laterally extending slot, wherein the at least one scraping portion is formed at a respective lateral end surface of the guide opening. Preferably, the guide opening or guide slot is arranged to encompass an intermediate wall of a stationary blade of the blade set. In a further embodiment of the cutter, a first scraping portion is formed at a first lateral end and a second scraping portion is formed at a second lateral end of the guide opening, wherein the first scraping portion and the second scraping portion are facing each other. Generally, the intermediate wall may be referred to as intermediate wall portion.
At least in some embodiments, the cutter is reciprocatingly driven with respect to the stationary blade. Consequently, the stationary blade may be oscillatingly driven in a back and forth fashion. By providing a first scraping portion and a second scraping portion that is opposite to the first scraping portion, each direction of a single stroke of the cutter may be used for the cleaning action. Further, the first scraping portion and the second scraping portion may be arranged as basically inwardly facing scraping portions at the guide opening. Therefore, the relatively sharp tips of the scraping portion are hardly accessible for a user of the blade set. Hence, even though relatively sharp edges are provided, the risk of injuries for the (end) user is considerably low.
In a refinement of the guide opening-implementing embodiment, at least one scraping portion at the lateral end surface of the guide opening is arranged as an interrupted scraping portion comprising at least two sections, wherein an inwardly protruding abutment tab is arranged between the sections. Particular in embodiments of the blade set wherein the stationary blade thereof is fitted with an intermediate wall that is arranged between the first wall and the second wall and that is at least partially extending through the guide opening, the protruding abutment tab may protect the tip edge. More particularly, the protruding abutment tab may prevent the tip edge of the scraper profile from contacting the intermediate wall. Preferably, a first protruding abutment tab is provided at the first lateral end and a second protruding abutment tab is provided at the second lateral end of the guide opening.
In a further embodiment of the cutter that is provided with at least one scraping portion, at least one respective scraping portion is provided that comprises a tapered scraper profile including a first tip edge and a second tip edge, wherein the first tip edge is arranged at a first, skin-facing surface of the cutter, and wherein the second tip edge is arranged at a second surface of the cutter that is facing away from the skin, when in operation. As indicated above, such a scraping portion may comprise a scraper profile having a cross-section that may be selected from the group consisting of C-shape, double-wedge shape and double-triangle shape. Consequently, the cutter may be arranged to scrape off accumulations at both the first wall and a second wall of the stationary blade. To this end, in a further refinement of this embodiment, the first tip edge is associated with the first wall and the second tip edge is associated with the second wall of the stationary blade.
In another embodiment of the cutter that is fitted with at least one scraping portion, a plurality of similarly oriented scraping portions is provided that are laterally displaced from one another, wherein an offset between the scraping portions is adapted to an expected stroke of the cutter. Consequently, a large portion of the stationary blade may be cleaned by the cutter. As used herein, similarly oriented scraping portions are provided with tip edges that are arranged at the same side of the cutter, preferably the top side or surface of the cutter that is facing the first wall of the stationary blade in a mounted state. Further, similarly oriented scraping portions may be arranged in the same fashion with respect to the lateral extension of the cutter, i.e. not facing each other. Consequently, a first number of similarly oriented scraping portions and a second number of similarly oriented scraping portions may be provided, wherein the two groups of scraping portions are facing each other. For instance, two or more scraping portions of a first type and two or more scraping portions of a second type of scraping portions may be provided.
By way of example, an offset between respective ones of the plurality of similarly oriented scraping portions may be defined to correspond to or be at least slightly smaller than an expected stroke of the cutter in the operational state. Consequently, at least a certain portion of the first wall and/or the second wall of the stationary blade may be cleaned.
In another embodiment of the cutter according to the above aspect, at least one outwardly-facing scraping portion is provided at a lateral end portion of the cutter. Preferably, a first outwardly-facing scraping portion is provided at a first lateral end and a second outwardly-facing scraping portion is provided at a second lateral end of the cutter.
In another embodiment of this aspect, the cutter is further provided with a plurality of scraping portions that are laterally displaced from one another and that are oriented in an opposite fashion. As used herein, the term opposite fashion shall primarily relate to the vertical orientation of the tip edges of the respective scraping portions. Hence, a first type of scraping portions may be provided with tip edges that are arranged to contact the first wall. Further, a second type of scraping portions may be provided with tip edges that are arranged to contact the second wall of the blade set.
Generally, the scraping portions may be processed and/or manufactured by machining processes that are similar or correspond to the machining processes that are utilized to form the teeth of the cutter. By way of example, etching processes, more generally, electro-chemical machining processes may be utilized. Further, also a combination of stamping and etching may be used. More generally, appropriate material-removing processes may be used to define and form the at least one scraping portion including the respective tip edge.
According to a further aspect of the present disclosure, a stationary blade for a blade set of a cutting appliance is presented, said blade set being arranged to be moved through hair in a moving direction to cut hair, said stationary blade comprising:
a first wall arranged to serve as a skin facing wall when in operation,
a second wall at least partially offset from the first wall, such that the first wall and the second wall define therebetween a guide slot arranged to receive a cutter,
at least one toothed leading edge jointly formed by the first wall and the second wall,
wherein the at least one toothed leading edge comprises a plurality of teeth, and
wherein the first wall and the second wall are connected at a frontal end of the at least one toothed leading edge, thereby forming tips of the teeth.
Preferably, the stationary blade according to this aspect cooperates with a cutter according to another aspect of the present disclosure which will be further described hereinafter.
According to one embodiment of this aspect, the stationary blade is an integrally formed metal-plastic composite stationary blade, wherein the first wall is at least partially made from metal material, and wherein the second wall is at least partially made from plastic material.
According to another embodiment, the stationary blade further comprises an intermediate wall arranged between a first wall and a second wall, wherein the intermediate wall defines a central offset between the first wall and the second wall, and wherein the intermediate wall is adapted to a respective opening with a to-be-mounted cutter.
According to another embodiment the stationary blade further comprises cutteran intermediate wall arranged between the first wall and the second wall, wherein the intermediate wall defines a central offset lco between the first wall and the second wall, and wherein the intermediate wall is adapted to a respective opening of a to-be-mounted cutter.
According to another aspect of the disclosure, the stationary blade is arranged as an integrally formed metal-plastic composite stationary blade, wherein the first wall is at least partially made from metal material, and wherein the second wall is at least partially made from plastic material.
Some of the stationary blade-related embodiments are based on the insight that the first wall which may be in close contact with the skin, and which is basically configured to cooperate with a cutter to cut hair preferably exhibits considerable stiffness and robustness properties. The first wall is at least partially made from metal material, particularly from steel material such as stainless steel, for instance. Consequently, even though the first wall is preferably considerably thin-walled so as to allow cutting hairs close to the skin, it may provide adequate strength. Furthermore, the second wall may be added at the side typically facing away from the skin to further strengthen the stationary blade. Preferably, the stationary blade may be obtained from a combined manufacturing process which involves forming the plastic material and bonding the plastic material to the metal material, basically at the same time. It is particularly preferred that the stationary blade consists of the first wall and the second wall, i.e. no further essential components need to be mounted thereto to accomplish the stationary blade. Generally, the stationary blade may be regarded as a two-component part wherein the two components are integrally and fixedly interconnected.
However, according to the above embodiment, the stationary blade—in its final state—may provide even further functions. In addition to the first wall and the second wall an intermediate wall may be present which preferably further stiffens the stationary blade. As a consequence, the first wall may be shaped even thinner without facing the risk of an increased flexing tendency. Hence, the intermediate wall may serve as a backbone that may connect the first wall and the second wall. So the first wall and the second wall may be connected at their leading edge(s) and in addition in a further area where the intermediate wall is arranged. This may greatly improve the strength of the stationary blade and a respective blade set.
The intermediate wall may further define (or: set) the central offset between the first wall and the second wall at high accuracy. This may be further beneficial since it is intended at least in some embodiments to receive the cutter without additional biasing by pretensioning members in the guide slot of the stationary blade. In conventional blade sets, typically spring elements are provided to ensure a tight fit of the respective teeth of the stationary blade and the cutter. Generally, the cutter is at least slightly biased towards the stationary blade so as to achieve a desired clearance or contact at the toothed leading edges. Generally, a considerably small gap at a contact region is desirable. If the gap would be too big, cutting performance would be decreased. If the gap would be too small, higher contact pressure and increased friction would occur. This would also increase power consumption and heat generation. It is therefore beneficial that the intermediate wall may set an offset distance between the first wall and the second wall which may have a positive effect on the accuracy and the precision of the desired gap at the contact region between the teeth of the stationary blade and the movable blade.
The intermediate wall may be further adapted to an opening in the cutter which may also be referred to as guide opening or opening guide slot. Hence, the cutter may be received and guided by the intermediate wall. This may improve the setting of the longitudinal position of the cutter with respect to the stationary blade. Hence, not only the vertical gap (or: height gap) at the contact region but also the longitudinal alignment of the respective teeth of the toothed leading edges may be defined by the structure of the stationary blade as such at high accuracy and precision. This may have the further advantage that power transmission to the cutter may be even further simplified since respective coupling members and/or transmission members do not have to provide this function as well. By contrast, the drive train of the cutting appliance may be suitably designed to set the cutter into motion with respect to the stationary blade without having to consider huge direct impacts on the longitudinal guide of the cutter. Hence, the design of the drive train may be focused on its primary function—power transmission.
In one embodiment, the intermediate wall is fixedly attached to the first wall, particularly to a metal surface thereof. This may further strengthen the stationary blade. It is generally preferred in this context that the intermediate wall and the first wall are made from a similar material, at least at their contact surface.
In one embodiment, the intermediate wall is made from metal material, particularly from sheet metal material. Hence, the intermediate wall may exhibit a considerable wear resistance. Further, the intermediate wall may exhibit a considerable heat transfer capacity.
In one embodiment, the intermediate wall is bonded, particularly laser-welded to the first wall. Bonding may generally involve soldering and welding. Welding may involve spot welding. It is preferred that the intermediate wall is laser-spot-welded to the first wall.
In one embodiment, the intermediate wall contacts the second wall, particularly a plastic surface thereof. This may involve that the intermediate wall abuts the second wall. Generally the intermediate wall may act as a gage for defining the central offset lco between the first wall and the second wall. Consequently, the height of the intermediate wall may correspond to the central offset lco. The intermediate wall may be at least slightly pre-tensioned between the first wall and the second wall due to a tight fit mating. Hence, the position of the intermediate wall may be defined even more precisely. A contact and/or abutment of the intermediate wall at the second wall does not necessarily involve that the intermediate wall is actually firmly fixed and/or bonded to the second wall. Since the intermediate wall is preferably firmly fixed to the first wall, and since the first wall and the second wall may be integrally formed and bonded, the stationary blade as such may be well-defined and sufficiently rigid.
In one embodiment, the stationary blade comprises a metal component, particularly a sheet metal insert, and a plastic component bonded to the metal component, wherein at least a central portion of the first wall is formed by the metal component. This may have the advantage that the metal component may be particularly thin which may allow cutting hairs very close to the skin of a user. Consequently, shaving performance may be improved.
In one embodiment, the metal component further comprises tooth stem portions comprising cutting edges that are configured to cooperate with cutting edges of respective teeth of the cutter to cut hairs that are trapped therebetween when in operation. Hence, cutting edges at the first wall may be formed at the metal component at the tooth stem portions thereof.
In one embodiment, the metal component comprises at least one anchoring element, particularly at least one positive-fit anchoring element extending from a respective tooth stem portion, wherein the plastic component and the metal component are connected at the at least one anchoring element. The at least one anchoring element may provide a locking geometry that may be engaged by or filled with the plastic material of the plastic component. Generally, the at least one anchoring element may longitudinally protrude from frontal ends of the tooth stem portions.
In one embodiment, the at least one anchoring element is inclined with respect to a top surface of the first wall, particularly rearwardly bended. In one embodiment, the at least one anchoring element is T-shaped, U-shaped or O-shaped, particularly when viewed from the top. In one embodiment, the at least one anchoring element is rearwardly offset from a top surface of the first wall. This may allow the plastic component to contact and cover a top side of the at least one anchoring element.
In one embodiment, the tips of the teeth are formed by the plastic component, wherein the plastic component further engages the positive-fit anchoring elements at a bonding area between the tooth stem portions of the metal component and the tips of the teeth. Consequently, the plastic component may be firmly bonded to the metal component and connected with the metal component in a form-fit or positive-fit manner at the same time.
In one embodiment, the plastic component and the metal component form an integrally formed part selected from the group consisting of insert-molded part, outsert-molded part and overmolded part. By way of example, the metal component may be provided as a metal insert component. The metal insert component may be arranged in a mold for the plastic component and at least sectionally overmolded with the plastic component.
In one embodiment, the teeth of the at least one toothed leading edge comprise, when viewed in a cross-sectional plane perpendicular to the lateral direction Y, a substantially U-shaped form comprising a first leg at the first wall and a second leg at the second wall, wherein the first leg and the second leg merge into one another at the tooth tips. Between the first leg and the second leg, a mounting gap or slot for the cutter may be provided, particularly for the teeth thereof.
According to a further aspect of the disclosure a blade set for a cutting appliance is presented. The blade set may comprise a stationary blade and a cutter formed according to at least some of the principles of the present disclosure. In some embodiments, the cutter comprises a guide opening, particularly a laterally extending slot, in which the intermediate wall of the stationary blade is arranged.
It is particularly preferred that the blade set consists of the stationary blade and the cutter. This may involve a driving force transmitting member for the cutter. In other words, it is preferred in some embodiments that the blade set comprises no further element. However, it is particularly preferred that the cutter is arranged in the guide slot without being biased by a separate biasing member, such as a biasing spring element. Consequently, it is preferred that a top side of the cutter is in contact with the first wall and that a bottom side of the cutter is in contact with the second wall. It goes without saying that the cutter may be arranged in the guide slot with a certain clearance with respect to the first wall and the second wall, respectively, since the cutter is preferably slidably arranged at the guide slot.
Relative motion may involve reciprocating motion of the cutter with respect to the stationary blade. In some embodiments, relative motion may involve rotation of the movable blade with respect to the cutter blade.
According to the above aspect, the guide opening of the cutter and the intermediate wall of the stationary blade may cooperate so as to define the longitudinal position of the cutter with respect to the stationary blade. Further, the intermediate wall of the stationary blade may retain the movable cutter at the stationary blade. Preferably, the intermediate wall at least partially extends through the guide opening. In other words, the intermediate wall may comprise a height extension (or: vertical extension) that fits in the guide opening of the cutter such that the cutter cannot be removed from the stationary blade without destroying or damaging at least one component of the assembly.
A respective assembly can be accomplished by inserting a paired arrangement of the cutter and the intermediate wall in the guide slot of the (intermediate) stationary blade and then attaching, particularly fixedly attaching, the intermediate wall to the stationary blade, particularly to the first wall thereof.
In one embodiment of the blade set, the guide opening is adapted to the intermediate wall such that the intermediate wall defines the longitudinal position of the cutter with respect to the stationary blade. In other words, the guide opening of the cutter may comprise a longitudinal extension (generally perpendicular to the lateral extension of the at least one toothed leading edge) that is adapted to a respective longitudinal extension of the intermediate wall. Since the cutter is basically adapted to be moved with respect to the stationary blade, a defined longitudinal clearance fit between the guide opening and the intermediate wall is preferred. The movement of the cutter may involve lateral movement. Generally, the cutter is configured for sliding movement with respect to the stationary blade.
The guide slot of the stationary blade may be jointly defined by the first wall, the second wall, and the intermediate wall. Hence, the guide slot of the stationary blade may position the cutter in the vertical direction (or: height direction) and in the longitudinal direction. Further, the stationary blade, particularly the intermediate wall may provide at least one lateral limit stop for the cutter, preferably two opposite lateral limit stops. The lateral limit stop may be defined by a respective lateral end face of the intermediate wall that cooperates with an inner lateral face of the guide slot of the cutter. It is worth mentioning in this context that the transmitting member may be relieved from respective guide and retaining functions.
In one embodiment of the blade set, the intermediate wall comprises a plurality of longitudinally protruding contact elements that are configured to contact laterally extending inner guide faces of the guide opening of the cutter. This may have the advantage that a resulting slide contact surface between the intermediate wall and the cutter can be reduced which may reduce frictional losses and, accordingly, power consumption and heat generation.
In one embodiment of the blade set, the intermediate wall of the a stationary blade comprises a guiding portion and a retaining portion, wherein the retaining portion at least partially protrudes beyond the guiding portion such that the cutter is retained at the stationary blade. Hence, the cutter may be undetachably retained but reciprocatingly movable with respect to the stationary blade in the lateral direction. It is preferred that the retaining portion at least partially protrudes beyond the guiding portion in the longitudinal direction. By way of example, the first wall and the intermediate wall may define a double-T shaped section (also referred to as I-beam section) which provides a receiving and guiding contour for the cutter.
In one embodiment of the blade set, the thickness of the guiding portion is adapted to the height of the cutter so as to enable a defined clearance fit of the cutter at the stationary blade. The thickness of the guiding portion may be slightly greater than the thickness of the cutter, at least in the vicinity of the guide opening. Hence, the cutter may be received in a tight but somewhat slidingly movable manner
In one embodiment of the blade set, each of the guiding portion and the retaining portion is made from a respective sheet metal layer, and wherein the guiding portion and the retaining portion are fixedly interconnected. Consequently, the intermediate wall may comprise a layered structure. By way of example, the guiding portion and the retaining portion may be obtained through respective cutting processes from sheet metal blanks or coils. Cutting may generally involve blanking, particularly stamping and fine punching. Respective layers forming the the guiding portion and the retaining portion can be fixedly interconnected, particularly bonded, more particularly welded to each other.
In the alternative, the guiding portion and the retaining portion of the intermediate wall may be integrally formed. Hence, the guiding portion and the retaining portion may be manufactured as a single piece. By way of example, the guiding portion and the retaining portion may be obtained by machining a respective intermediate blank intermediate wall.
In some embodiments, the retaining portion may have an overall longitudinal extension that is at least slightly greater that the an overall longitudinal extension of the guiding portion and a respective overall longitudinal extension of the guide opening. Generally, the retaining portion may be shaped as a cover plate that at least partially protrudes beyond the guiding portion.
In one embodiment of the blade set, the tapered scraper profile of the at least one scraping portion engages the first wall of the stationary blade upon relative motion between the cutter and the stationary blade to scrape off accumulated dirt and debris when in operation. In some embodiments, the cutter comprises at least one scraping portion comprising a tapered scraper profile that, upon relative motion between the cutter and the stationary blade, at least partially engages the second wall of the stationary blade to scrape off accumulated dirt and debris.
According to still another aspect of the disclosure a method of manufacturing a blade set for a cutting appliance is presented, said method comprising the following steps:
manufacturing a stationary blade formed according to at least some aspects of the present disclosure, the stationary blade comprising an intermediate wall;
providing a cutter comprising at least one toothed leading edge arranged to cooperate with at least one respective toothed leading edge of the stationary blade, wherein the cutter further comprises a guide opening, particularly a laterally extending slot;
positioning the intermediate wall in the guide opening of the cutter;
jointly inserting the cutter and the intermediate wall into the guide slot of the stationary blade, particularly jointly feeding the movable cutting blade and the intermediate wall through a lateral opening of the stationary blade; and
attaching the intermediate wall to the first wall, particularly bonding the intermediate wall to the first wall.
In one embodiment of the blade set manufacturing method, the stationary blade is configured such that the intermediate wall defines a central offset between the first wall and the second wall. Furthermore, the step of jointly inserting the cutter and the intermediate wall may be preceded by the step of providing a package comprising the intermediate wall and the cutter. It should therefore be understood that the step of manufacturing the stationary blade does not necessarily involve fixing or attaching the intermediate wall to the first wall. By contrast, manufacturing the stationary blade may actually result in providing a semi-finished stationary blade and an intermediate wall, whereas in another step, the (final) stationary blade may be formed by attaching the intermediate wall to the first wall. This may involve locking or securing the cutter at the stationary blade.
According to another aspect of the present disclosure, a method of manufacturing a cutter for a blade set of a cutting appliance is presented, the method comprising at least one of the following steps:
providing sheet metal material;
processing the sheet metal material to obtain a cutter comprising at least one toothed leading edge arranged to cooperate with at least one respective toothed leading edge of a stationary blade,
processing the cutter to form at least one scraping portion comprising a tapered scraper profile at least partially extending in a longitudinal direction that is perpendicular to a cutting motion direction of the cutter, wherein the at least one scraping portion is, in a mounted state, arranged to contact a stationary blade of the blade set at a first wall thereof to scrape off accumulated dirt and debris when the cutter and the stationary blade are moved with respect to each other when in operation.
Preferably, the method further comprises forming a guide opening, particularly a laterally extending slot, at the cutter, and forming at least one scraping portion at a lateral end surface of the guide opening.
In a further refined embodiment of the cutter manufacturing method, at least one scraping portion is processed at a lateral end surface of the guide opening, wherein the scraping portion is arranged as an interrupted scraping portion, comprising at least two sections, and wherein an inwardly protruding abutment tab is arranged between the sections. This may facilitate an exemplary assembly process for the blade set, particularly a step when the cutter and the intermediate wall are jointly inserted into the guide slot of the stationary blade. Further, the at least one inwardly protruding abutment tab may prevent the tapered scraper profile from contacting the intermediate wall when the blade set is in operation.
Preferred embodiments of the invention are defined in the dependent claims. It shall be understood that the claimed method has similar and/or identical preferred embodiments as the claimed device and as defined in the dependent claims.
Several aspects of the disclosure will be apparent from and elucidated with reference to the embodiments described hereinafter. In the following drawings
The cutting appliance 10 may further comprise a cutting head 18. At the cutting head 18, a blade set 20 may be attached to the cutting appliance 10. The blade set 20 may be driven by the motor 14 via the drive mechanism or drivetrain 16 to enable a cutting motion. The cutting motion may generally be regarded as a relative motion between a stationary blade 22 and a movable blade 24 which are shown and illustrated in more detail in
When being guided moved through hair, the cutting appliance 10 including the blade set 20 is typically moved along a common moving direction which is indicated by the reference numeral 28 in
For ease of reference, coordinate systems are indicated in several drawings herein. By way of example, a Cartesian coordinate system X-Y-Z is indicated in
The stationary blade 22 further comprises a top surface 32 which may be regarded as a skin-facing surface. Typically, when in operation as a shaving device, the cutting appliance 10 is oriented in such a way that the top surface 32 is basically parallel to or slightly inclined with respect to the skin. However, also alternative operation modes may be envisaged, where the top surface 32 is not necessarily parallel or, at least, substantially parallel to the skin. For instance, the cutting appliance 10 may be further used for beard styling or, more generally, hair styling. Hair styling may aim at the processing of considerably sharp edges or transitions between differently treated hair portions or beard portions of the user. By way of example, hair styling may involve precise shaping of sideburns or further distinct patches of facial hair. Consequently, when used in a styling mode, the top surface 32 and the currently to-be-treated skin portion are arranged at an angle, particularly substantially perpendicular to each other.
However, primarily for illustrative purposes, the top surface 32 and similarly oriented portions and components of the cutting appliance 10 may be regarded as skin-facing components and portions hereinafter. Consequently, elements and portions that are oriented in an opposite manner may be regarded as rearwardly oriented elements and portions or rather as elements and portions facing away from the skin hereinafter, for the purpose of disclosure.
As shown in
The stationary blade 22 may be arranged as a metal-plastic composite component, for instance. In other words, the stationary blade 22 may be obtained from a multi-step manufacturing method that may include providing a metal component 40 (see also
Forming the stationary blade 22 from of different components, particularly integrally forming the stationary blade 22 may further have the advantage that portions thereof that have to endure high loads during operation may be formed from respective high-strength materials (e.g. metal materials) while portions thereof that are generally not exposed to huge loads when in operation may be formed from different materials which may significantly reduce manufacturing costs. Forming the stationary blade 22 as a plastic-metal composite part may further have the advantage that skin contact may be experienced by the user as being more comfortable. Particularly the plastic component 38 may exhibit a greatly reduced thermal conductivity when compared with the metal component 40. Consequently, heat emission sensed by the user when cutting hair may be reduced. In conventional cutting appliances, heat generation may be regarded as a huge barrier for improving the cutting performance. Heat generation basically limits the power and/or cutting speed of cutting appliances. By adding basically heat insulating materials (e.g. plastic materials) heat transfer from heat-generating spots (e.g. cutting edges) to the user's skin may be greatly reduced. This applies in particular at the tips of the teeth 36 of the stationary blade 22 which may be formed of plastic material.
By way of example, the plastic component 38 of the stationary blade 22 may be fitted with lateral protecting elements 42 which may also be referred to as so-called lateral side protectors. The lateral protecting elements 42 may cover lateral ends of the stationary blade 22, refer also to
The stationary blade 22 may be further provided with mounting elements 48. The mounting elements 48 may be arranged at the plastic component 38, particularly integrally formed with the plastic component 38, refer also to
The linkage mechanism 50 (refer to
With further reference to the embodiments shown in exploded view in
However, at least in some embodiments, the connector bridge 74 or a similar connecting element of the transmitting member 70 may be rather attached to the cutter 24. As used herein, attaching may involve plugging in, pushing in, pressing in or similar mounting operations. The transmitting member 70 may further comprise a mounting element 76 which may be arranged at the connector bridge 74. At the mounting element 76, the reciprocating element 72 may be attached to the connector bridge 74. By way of example, the connector bridge 74 and the mounting element 76 may be arranged as a metal part. By way of example, the reciprocating element 72 may be arranged as a plastic part. For instance, the mounting element 76 may involve snap-on elements for fixing the reciprocating element 72 at the connector bridge 74. However, in the alternative, the mounting element 76 may be regarded as an anchoring element for the reciprocating element 72 when the latter one is firmly bonded to the connector bridge 74.
It is worth mentioning in this regard that the transmitting member 70 may be primarily arranged to transmit a lateral reciprocating driving motion to the cutter 24. However, the transmitting member 70 may be further arranged to serve as a loss prevention device for the cutter 24 at the blade set 20.
As can be seen from
Further reference in this regard is made to
With further reference to
As can be seen from
Generally, the intermediate wall 44 and the metal component 40 may cooperate to secure the cutter 24 at the stationary blade 22 in an undetachable manner. This may be accomplished by the embodiment as shown in
The stationary blade 22 may comprise at least one lateral opening 68 through which the cutter 24 may be inserted. Consequently, the cutter may be inserted in the lateral direction Y. However, at least in some embodiments, the transmitting member 70 may be moved to the cutter 24 basically along the vertical direction Z. Mating the cutter 24 and the transmitting member 70 may therefore involve firstly inserting the cutter 24 through the lateral opening 68 of the stationary blade 22 and secondly, when the cutter 24 is arranged in the stationary blade 22, feeding or moving the transmitting member along the vertical direction Z to the stationary blade 22 so as to be connected to the cutter 24.
Generally, the cutter 24 may comprise at least one toothed leading edge 80 adjacent to the main portion 78. Particularly, the cutter 24 may comprise a first leading edge 80a and a second leading edge 80b that is longitudinally offset from the first leading edge 80a. At the at least one leading edge 80, a plurality of teeth 82 may be formed that are alternating with respective tooth slots. Each of the teeth 82 may be provided with respective cutting edges 84, particularly at their lateral flanks. The at least one toothed leading edge 80 of the cutter 24 may be arranged to cooperate with a respective toothed leading edge 30 of the stationary blade 22 when relative motion of the cutter 24 and the stationary blade 22 is induced. Consequently, the teeth 36 of the stationary blade 22 and the teeth 82 of the cutter 24 may cooperate to cut hair.
With particular reference to
By way of example, the anchoring elements 90 may be provided with undercuts or recess portions. Consequently, the anchoring elements 90 may be arranged as barbed anchoring elements. Preferably, a respective portion of the plastic component 38 that contacts the anchoring elements 90 may not be detached or released from the metal component 40 without being damaged or even destroyed. In other words, the plastic component 38 may be inextricably linked with the metal component 40. As shown in
As can be best seen from the cross-sectional views of
With further reference to
Mainly for illustrative purposes, the
Hence, the cutter 24 may be received in the guide slot 94 in an accurate and precise manner. As can be seen from
As can be seen from
The first wall 100 and the second wall 102 may jointly define the teeth 36 of the stationary blade 22. The teeth 36 may comprise a slot or gap for the cutter 24, particularly for the teeth 82 thereof arranged at the at least one toothed leading edge 80. As indicated above, at least a substantial portion of the first wall 100 may be formed by the metal component 40. At least a substantial portion of the second wall 102 may be formed by the plastic component 38. At the embodiment illustrated in
As can be further seen from
In one embodiment, the second wall 102 may comprise, adjacent to the second leg 112 at the respective leading edge 30, an inclined portion 116. Assuming that the stationary blade 22 is basically symmetrically shaped with respect to a central plane defined by the vertical direction Z and the lateral direction Y, the second wall 102 may further comprise a central portion 118 adjacent to the inclined portion 116. Consequently, the central portion 118 may be interposed between a first inclined portion 116 and a second inclined portion 116. The first inclined portion 116 may be positioned adjacent to a respective second leg 112 at a first leading edge 30a. The second inclined portion 116 may be positioned adjacent to a respective second leg at the second leading edge 30b. As can be best seen in
With further reference to
As can be best seen from
It is further worth mentioning in this regard that the central portion 118 and particularly the at least one opening slot 120 for the transmitting member 70 may be differently configured in alternative embodiments. By way of example, in one embodiment, the central portion 118 is interrupted by a single opening slot 120 through which the connector bridge 74 may contact the cutter 24. It is therefore emphasized that the connector bridge 74 of the transmitting member 70 does not necessarily have to comprise two contact spots for the cutter 24 that are considerably spaced from each other in the lateral direction Y, as can be seen in
With particular reference to
The transmitting member 70 which is basically configured to transmit the driving motion to the cutter 24 may extend through the stationary blade 22, particularly through the at least one opening slot 120 associated with the central portion 118 of the stationary blade 22, refer to
It is particularly preferred that, at least in some embodiments, the cutter 24 is arranged in the guide slot 96 in a defined manner. It may be further preferred that no further mounting member, particularly no biasing member is required for keeping the cutter 24 in its desired position and in close contact with the first wall 100. This may be achieved since the stationary blade 22 is provided with the first wall 100 and the second wall 102 opposite to the first wall 100. Both walls 100, 102 may define a precise mating slot for the cutter 24, particularly for the teeth 82 thereof, such that the vertical position (Z-position) of the cutter 24 may be defined at close tolerances. This may significantly reduce manufacturing and assembly costs of the blade set 20.
By way of example, the stationary blade 22 and the cutter 24 may be configured such that the cutter 24 at least sectionally contacts the first wall 100 in a substantially planar fashion. This may particularly apply to respective tooth portions. It is worth mentioning in this connection that such a configuration does not require perfect surface contact in practice when the blade set 20 is operated. By contrast, it may be assumed that the stationary blade 22 and/or the cutter 24 may be flexed or preloaded, at least when in operation, such that only small contact areas remain. However, the first wall 100 may serve at least as a defined limit stop for the cutter 24 in the (vertical) direction Z. The first wall 100 and the second wall 102 may define a resulting gap or height dimension at the guide slot 96 for the cutter 24. The resulting gap lcl (refer to
It is generally preferred that the anchoring elements 90 are provided with form-fit elements so that the metal component 40 and the plastic component 38 may be connected as the anchoring elements in a bonded but also in a form-fit manner.
Further reference is made to
As can be seen from the side view of
The tooth stem portions 88 may comprise a lateral extension or width ws that is greater than a lateral extension or width wa of the anchoring elements 90. In this respect, reference is made to
The anchoring elements 90 according to the embodiment illustrated in
A partial perspective view of a metal component 40 that is provided with respective curved anchoring elements 90 is shown in
With reference to
Further reference is made to
It should be understood that further alternative tooling concepts and/or demolding approaches may be envisaged. For instance, at least a central portion of the plastic component 38 may be demolded in the Z-direction. Consequently, also respective slides may be present in the mold for the stationary blade 22.
In another embodiment, the substitute component 140 may be arranged as a component that is separate from the mold 136. In other words, the substitute component alternatingly may be arranged as an insert component that may be inserted into the cavity defined by the mold 136 along with the metal component 40. However, it is preferred that such an insert substitute component 140 is removable from the molded stationary blade 22 after molding, cooling down and removing the stationary blade 22 from the mold 136. Thus, the substitute component 140 may be a re-usable substitute component.
As shown in
The stationary blade 22 may be provided with mounting elements 48, particularly at the second wall 102 thereof, such that the second wall 102 may contact the top 214 of the linkage element. Consequently, the blade set 20 and the top 214 may jointly swivel or pivot with respect to the base 210 of the at least one linkage element 208. At the top 214 of the linkage element 208, a limit stop arrangement 218 may be provided.
As exemplarily shown in
With reference to
The cutter 24 is provided with at least one scraping portion 300 which is provided at a lateral end surface of the guide opening 46. Similarly, a corresponding scraping portion 300 may be provided at the opposite lateral end surface of the guide slot 46 (not visible in
As used herein, the top side or first surface 296 is the side that is facing the first wall 100 of the stationary blade 22, refer also to
Further reference is made to
Further, the abutment tab 318 may be useful when the intermediate wall 44 and the cutter 24 are jointly inserted into the guide slot 96 that is defined by the first wall 100 and the second wall 102 of the stationary blade, as is the case with at least some embodiments of manufacturing methods as discussed herein. The abutment tab 318 may further prevents the scraper profile 302 from reaching under the intermediate wall 44, which could be the case at a stage of the manufacturing process when the intermediate wall 44 is not yet fixedly attached or bonded to the first wall 100.
However, as with the embodiment illustrated in
Further reference is made to
Generally, the scraping portions 300 including the respective scraper profiles 302, 304, 306 may be regarded as pushers or bulldozers that are arranged to clean the inwardly facing surface of the first wall 100 and/or a second wall 102. It is further emphasized in this connection that the main purpose of the respective scraping portions 300 is not to cut hairs but rather to scrape off accumulations, hair filaments, etc. at the guide slot 96 of the stationary blade 22.
Reference is made to
An alternate embodiment of a blade set 24 is shown in
The scraping portions 300 of the embodiment as illustrated in
As a consequence, the scraper profiles 306 may be arranged to clean both the first wall 100 and the second wall 102 of a corresponding stationary blade 22. This may be particularly beneficial in embodiments of the stationary blade 22, wherein not only the first wall 100 but also the second wall 102 contacts the cutter 24 in an areal fashion, i.e. at a relatively large contact surface. Such an embodiment may for instance include that both the first wall 100 and the second wall 102 are formed from metal material, particularly from sheet metal material. If this is the case, the guide slot 96 defined by the first wall 100 and the second wall 102 is relatively narrow and arranged to receive the cutter 24 in a basically close fit fashion. Consequently, also dirt or debris accumulations at the second wall 102 may impair the cutting performance of the blade set 20. Therefore, the second tip edges 310 of the scraper profile 306 may clean the second wall 102 so as to re-establish and maintain the blade set's 20 hair cutting capabilities.
The scraper profile 306 of the scraping portions 300 of
The embodiment as shown in
Further embodiments of cutters 24 may be envisaged. The cutters 24 may implement single aspects of the embodiments as discussed herein in connection with
With reference to
A further step S12 may follow which may include forming intermediate leading edges, particularly intermediate toothed leading edges of the to-be-processed metal components. By way of example, the step S12 may involve forming tooth stem portions at the leading edges. Forming the tooth stem portions may involve removing material between respective tooth stem portions so as to define slots therebetween. This may involve an adequate material-removing process, for instance stamping, laser cutting, wire cutting and etching. Further material-removing processes may be envisaged. Forming tooth stem portions at respective leading edges of the metal components may further involve forming considerably sharp cutting edges at the tooth stem portions, particularly at lateral flanks thereof. Etching the tooth stem portions may involve processing a general form of the tooth stem portions and further creating relatively sharp cutting edges at their flanks.
A further step S14 may follow which may include forming or processing anchoring portions. Preferably, the anchoring portions extend from longitudinal ends of the tooth stem portions at the leading edges. The anchoring portions preferably include recesses or similar elements that may be engaged by and filled with a moldable material. It is further preferred that the anchoring portions at the tooth stem portions are further machined at skin-facing and lateral sides thereof (refer also to
At a further step S16, which may be regarded as an optional step, the anchoring elements or anchoring portions may be bended with respect to the tooth stem portions. Bending the anchoring portions may further strengthen the fixation of the molded material and the metal component since more space may be provided for the plastic material. There may be at least some embodiments of the manufacturing method which do not require the step S16.
A further optional step S18 may follow which may include separating a plurality of precursors for the metal component from a respective row or array at the supplied metal material, particularly at the supplied sheet metal material, for instance at the supplied sheet metal coil.
A further step S20 may follow which may involve placing the metal component in a cavity of a molding tool. Placing the metal component may include placing the metal component in a defined orientation in the cavity of the mold. As already indicated above, the metal component may be placed in the mold cavity in its separated state. However, at least in some embodiments, placing a plurality of metal components in a mold comprising a respective plurality of cavities may be envisaged. The respective metal components of the plurality of metal components may be separated from each other. However, in the alternative, the metal components may be attached to a common supporting structure.
Having placed the metal component in the cavity of the mold, placing a substitute component in the mold may follow. The substitute component may cover or fill a space in the mold cavity to define a guide slot in the to-be-formed stationary blade. Placing the substitute component in the mold may include placing a re-usable or a non-re-usable substitute component in the mold. By way of example, the step S22 may include inserting at least one slide into the cavity of the mold. The at least one slide may be arranged as a component of the molding tool. For instance, the molding tool may be provided with two opposite slides that form the substitute component.
A further step S24 may follow which may be regarded as molding step. At the molding step S24 a molded or moldable (plastic) material may be injected into the cavity of the mold. The plastic material may define a plastic component of the to-be-formed stationary blade. The plastic component may be bonded to the metal component, particularly to anchoring elements or anchoring portions thereof. Connecting the metal component and the plastic component may further involve engaging recessed portions at the anchoring portions with the molded plastic material.
A further step S26 may follow which may include removing the at least one slide, if any, from the cavity of the mold. Consequently, the guide slot formed at the stationary blade may be cleared. The guide slot may provide for a defined mating for a to-be-mounted cutter at the stationary blade.
A further step S28 may follow which may be regarded as an optional step. The step S28 may include separating single stationary blades from an array or row including a plurality of stationary blades formed in a mold comprising a plurality of respective molding cavities.
The method of manufacturing a stationary blade according to
A further S54 step may follow which may include forming or processing toothed leading edges of the cutter. The step S54 may further include processing relatively sharp cutting edges at respective teeth of the toothed leading edge. The step S54 may include adequate material-removing processes. By way of example, the step S54 may include an integrated etching step comprising forming a general toothed shape at the toothed leading edge, and forming relatively sharp cutting edges at the teeth. Preferably, the steps S52 and S54 make use of material removing processes that utilize etching (which may be also referred to as chemical milling). It goes without saying that the order of the steps S52 and S54 may be changed. In some embodiments, both steps S52 and S54 may be jointly performed. A further step S56 may follow which may include separating respective cutters from a supporting structure including a row or an array of a plurality of cutters.
According to at least some aspects, the step S54 may further involve processing the cutter so as to define or form at least one scraping portion. The at least one scraping portion comprises at least one tapered scraper profile that typically involves at least one tip edge, or in some embodiments, a first tip edge and a second tip edge. Preferably, at least one or two of the scraping portions are arranged at lateral end surfaces of the guide opening that is formed in step S52. Further scraping portions may be formed at lateral ends of the cutter. In some embodiments, additional slots or openings may be formed at the cutter so as to enable an even greater number of scraping portions. This may involve, in some further embodiments, that recesses are formed that do not extend through the whole vertical dimension (height) of the cutter.
In a further step S104, the intermediate wall and the movable cutter blade may be mated which simplifies the insertion of the components into a guide slot of the (semi-finished) stationary blade. This may involve arranging the intermediate wall, particularly a guide portion thereof, in a guide opening of the cutter. A joining or mating step S106 may follow in which the cutter and the intermediate wall are jointly inserted into the guide slot at the stationary blade. Inserting the cutter and the intermediate wall into the guide slot of the stationary blade may involve laterally inserting the cutter and the intermediate wall through a lateral opening of the stationary blade.
In a further step S108, the intermediate wall may be attached to the stationary blade, particularly to the first wall thereof. Preferably, the intermediate wall is bonded to the first wall, particularly laser-welded and/or sport-welded. Attaching the intermediate wall may include securing the cutter at the stationary blade and, more preferably, setting the longitudinal position and the vertical position (or: height position) of the cutter.
A further step S110 may follow which may involve feeding a transmitting member 70 to the semi-finished assembly of the blade set. The step S110 may particularly involve feeding the transmitting member 70 in a feeding direction that is different from an insertion direction of the cutter. A further step S112 may follow which includes attaching the transmitting member 70 to the cutter 24. The step S112 may further include bonding the transmitting member to the cutter. Bonding may involve welding, particularly laser welding. Attaching the cutter and the transmitting member while both elements are positioned at the stationary blade may also lock the cutter at the stationary blade. This may be also beneficial since in this way no separate fastening or locking components for the cutter are required.
While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.
In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single element or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.
Any reference signs in the claims should not be construed as limiting the scope.
Number | Date | Country | Kind |
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14185272.3 | Sep 2014 | EP | regional |
15157561.0 | Mar 2015 | EP | regional |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2015/070314 | 9/7/2015 | WO | 00 |