Blade set manufacturing method, blade set and hair cutting appliance

Abstract

A method of manufacturing a blade set assembly, a blade set assembly, and a hair cutting appliance, wherein the method includes providing a base component including a stationary blade, providing a movable component comprising a cutter blade, providing a coupling element, the coupling element being arranged to be interposed between the base component and the movable component, providing a plastic contact bridge, arranging the stationary blade and the cutter blade at a defined relative assembly position, securing the assembly position between the stationary blade and the cutter blade, involving attaching the plastic contact bridge to one of the base component and the movable component, attaching a retaining portion of the coupling element to the other one of the base component and the movable component, and penetrating the plastic contact bridge with at least one insertion end of the coupling element.

Claims

1. A blade set assembly for a hair cutting appliance, the blade set assembly comprising: a stationary blade, a cutter blade, a flexible coupling element including at least one insertion end and at least one retaining portion, and a plastic contact bridge, wherein the stationary blade and the cutter blade are arranged at a defined relative assembly position, wherein the plastic contact bridge is attached to the cutter blade, wherein the at least one retaining portion of the coupling element is attached to the stationary blade, and wherein the at least one insertion end of the coupling element is driven into the plastic contact bridge in a material-displacing fashion, thereby displacing material of the plastic contact bridge and securing the assembly position between the stationary blade and the cutter blade.

2. The blade set assembly as claimed in claim 1, wherein the coupling element is arranged as a leg spring comprising at least one deflection arm and at least one resilient portion arranged between the at least one retaining portion and the at least one deflection arm, wherein the at least one insertion end is arranged at an end of the at least one deflection arm, and wherein the coupling element urges the stationary blade and the cutter blade against one another.

3. The blade set assembly as claimed in claim 1, wherein the coupling element, the stationary blade and the cutter blade define a linkage mechanism that defines, during operation of the blade set assembly, a parallel relative movement between the stationary blade and the cutter blade, and wherein the coupling element comprises two deflection arms that correspondingly extend between the at least one retaining portion and the at least one insertion end and that connect the stationary blade and the cutter blade.

4. The blade set assembly as claimed in claim 1, wherein the plastic contact bridge is a cam follower element, and wherein the at least one retaining portion of the coupling element is attached to a retaining section of the stationary blade.

5. The blade set assembly as claimed in claim 1, comprising: a support part attached to the stationary blade, wherein the at least one retaining portion of the flexible coupling is attached to the stationary blade through the support part.

6. The blade set assembly as claimed in claim 5, wherein the support part includes a retaining section, and wherein the at least one retaining portion of the flexible coupling is attached to the retaining section of the support part.

7. The blade set assembly as claimed in claim 1, comprising: wherein the plastic contact bridge includes a snap-on hook, wherein the cutter blade defines a hole through the cutter blade, wherein the hole is sized to receive the snap-on hook, and wherein the plastic contact bridge is attached to the cutter blade by the snap-on hook being received by the hole through the cutter blade.

8. A hair cutting appliance comprising a blade set assembly as claimed in claim 1.

9. A method of assembling a blade set assembly for a hair cutting appliance, the method comprising acts of: arranging a stationary blade having a series of teeth and a cutter blade having a series of teeth at a defined relative assembly position, and securing the assembly position between the stationary blade and the cutter blade, involving: attaching a plastic contact bridge to cutter blade, attaching a retaining portion of a flexible coupling element to the stationary blade, and penetrating a non-perforated section of the plastic contact bridge with at least one insertion end of the coupling element such that plastic material of the plastic contact bridge is displaced by the at least one insertion end of the coupling element.

10. The method as claimed in claim 9, wherein the coupling element, in the secured assembly position, defines an offset between the series of teeth of the stationary blade and the series of teeth of the cutter blade.

11. The method as claimed in claim 9, wherein the coupling element is a spring element, and wherein the at least one insertion end, in the penetrated state, forms a joint with the cutter blade.

12. The method as claimed in claim 9, wherein the act of penetrating the plastic contact bridge involves: at least partially softening the non-perforated section of the plastic contact bridge, and penetrating the plastic contact bridge at the softened non-perforated section.

13. The method as claimed in claim 12, wherein a resulting position of the penetrating of the plastic contact bridge is dependent on the defined relative assembly position of the stationary blade and the cutter blade.

14. The method as claimed in claim 12, wherein the at least one insertion end of the coupling element is heated, and wherein the coupling element, in the heated state of the at least one insertion end, softens the non-perforated section of the plastic contact bridge.

15. The method as claimed in claim 12, wherein the act of at least partially softening the non-perforated section of the plastic contact bridge involves heating the at least one insertion end of the coupling element, and wherein the heating the at least one insertion end involves laser heating or friction heating.

16. The method as claimed in claim 9, wherein prior to the act of penetrating, the coupling element is arranged in a pretension mounting position which induces an insertion force that urges the at least one insertion end into the plastic contact bridge during the penetrating act.

17. The method as claimed in claim 9, wherein the coupling element, in the secured assembly position, urges the cutter blade into a defined lateral guidance and close fit configuration with the stationary blade.

18. The method as claimed in claim 9, wherein the at least one insertion end of the coupling element comprises a first insertion end of the coupling element and a second insertion end of the coupling element, wherein the act of penetrating the non-perforated section of the plastic contact bridge comprises penetrating the plastic contact bridge with the first insertion end of the coupling element, and penetrating the plastic contact bridge with the second insertion end of the coupling element, wherein resulting penetration spots of the first and second insertion ends of the coupling element are spaced from one another in such a way that a linkage mechanism for a defined relative movement between the stationary blade and the cutter blade is formed.

19. The method as claimed in claim 9, comprising an act of: attaching a support part to the stationary blade, wherein attaching the retaining portion of the flexible coupling comprises attaching the retaining portion of the flexible coupling to the support part.

20. The method as claimed in claim 19, wherein the support part includes a retaining section, and wherein attaching the at least one retaining portion of the flexible coupling comprises attaching the at least one retaining portion of the flexible coupling to the retaining section of the support part.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) These and other aspects of the disclosure will be apparent from and elucidated with reference to the embodiments described hereinafter. In the following drawings

(2) FIG. 1 shows a schematic perspective view of an exemplary embodiment of an electric hair cutting appliance;

(3) FIG. 2 shows a perspective top view of an exemplary embodiment of a blade set assembly;

(4) FIG. 3 shows a exploded view of the blade set assembly of FIG. 2 in a reduced size representation;

(5) FIG. 4 shows a perspective bottom view of the blade set assembly of FIG. 2;

(6) FIG. 5 shows an exploded view of the arrangement of FIG. 4 in a reduced size representation;

(7) FIG. 6 shows a perspective view of the blade set assembly in accordance with the view of FIG. 2, wherein components are omitted in FIG. 6 for illustrative purposes;

(8) FIG. 7 shows a lateral view of an embodiment of a blade set assembly in a manufacturing configuration;

(9) FIG. 8 shows a detail view of the arrangement of FIG. 7 in a resulting assembled configuration;

(10) FIG. 9 shows a bottom view of the arrangement of FIG. 4;

(11) FIG. 10 shows a lateral cross-sectional view of the arrangement of FIG. 9 along the line X-X;

(12) FIG. 11 shows another lateral cross-sectional view of the arrangement of FIG. 9 along the line XI-XI; and

(13) FIG. 12 shows a simplified block diagram of an embodiment of a method of manufacturing a blade set assembly.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(14) FIG. 1 shows a schematic perspective rear view of a hair cutting appliance 10, particularly an electrically operated hair cutting appliance 10. The appliance 10 may also be referred to as hair clipper or hair trimmer. The appliance 10 comprises a housing or housing portion 12 having a generally elongated shape. At a first, top end thereof, a cutting head 14 is provided. The cutting head 14 comprises a blade set assembly 16. The blade set assembly 16 comprises a movable blade 52 and a stationary blade 34 (refer to FIG. 3) that may be moved with respect to each other to cut hair. At a central portion and a second, bottom end of the housing 12, a handle or grip portion 18 is formed. A user may grasp or grab the housing 12 at the grip portion 18.

(15) The appliance 10 in accordance with the exemplary embodiment of FIG. 1 further comprises operator controls. For instance, an on-off switch or button 20 may be provided. Furthermore, in case the appliance 10 is provided with a comb length adjustment mechanism, a length adjustment control 22 may be provided at the housing 12 of the appliance 10. In the embodiment of FIG. 1, the length adjustment control 22 is arranged as a length adjustment wheel.

(16) A front side of the housing portion 12 is indicated in FIG. 1 by reference numeral 24. An opposite rear side is indicated by reference numeral 26. Consequently, for illustrative purposes, the housing 12 of the hair cutting appliance 10 comprises a top side, where the blade set assembly 16 is mounted, a bottom side that is opposite to the top side, a front side 24 which typically faces the skin of the to-be-groomed subject when the appliance 10 is in operation, and a rear side 26 that is opposite to the front side 24.

(17) As shown in at least some Figures discussed herein, for illustrative purposes, a coordinate system (Cartesian coordinate system) X-Y-Z is provided. The coordinate system X-Y-Z is used in the following for describing orientations and locations of components of the hair cutting appliance 10, particularly of the blade set assembly 16 thereof. However, as can be already seen from FIG. 1, not in each case a perfect match of components or parts of the appliance 10 with any of the axis X-Y-Z is provided. By way of example, the housing 12 may exhibit an elongated but somewhat curved shape for ergonomic and design reasons. Therefore, a main elongation direction of the housing 12 does not perfectly match the direction of the X-axis and the Z-axis, but will be rather somewhat inclined or curved in relation thereto. It goes without saying that the skilled person is capable of adapting or, if necessary, transforming or converting the coordinate system X-Y-Z when being confronted with new embodiments, illustrations and/or orientations as the coordinate system X-Y-Z is merely an illustrative means for describing elements of the presented exemplary embodiment of the appliance 10 and their interrelation.

(18) For illustrative purposes, the X-axis will be hereinafter associated with a longitudinal or length direction. Accordingly, the Y-axis will be hereinafter associated with a lateral or width direction. Accordingly, the Z-axis will be hereinafter associated with a height or vertical direction. The coordinate system X-Y-Z describes main extension directions of the blade set assembly 16.

(19) With particular reference to FIGS. 2 to 5, an exemplary arrangement of a blade set assembly 16 for a hair cutting appliance 10 will be explained and further detailed. FIG. 2 is a perspective top and front view. FIG. 3 is an exploded view of the arrangement of FIG. 2. FIG. 4 is a perspective bottom and rear view. FIG. 5 is an exploded view of the arrangement of FIG. 4.

(20) The blade set assembly 16 illustrated in FIGS. 2 to 5 is arranged to be coupled with a housing 12 of a hair cutting appliance 10, refer also to FIG. 1.

(21) The blade set assembly 16 comprises a base component 32 which is, when the appliance 10 is operated, attached to the housing 12 thereof which may involve a fixed or firm attachment. The base component 32 comprises a stationary blade 34 and a support part 36. The stationary blade 34 may be also referred to as guard. The support part 36 may be also referred to as support frame. The stationary blade 34 is attached to the support part 36 by fasteners 38 which engage corresponding recesses 40 at the support part 36, refer also to FIG. 3. In the illustrated exemplary embodiment, the fasteners 38 are arranged as screws.

(22) The support part 36 comprises mounting features 42 through which the support part 36 and, consequently, the base component 32, may be attached to the housing 12 in a detachable fashion, at least in some embodiments.

(23) The stationary blade 34 comprises a toothed section comprising a series of teeth 46. Further, a support wall 44 is provided. The toothed section extends from the support wall 44 in the longitudinal direction X.

(24) The blade set assembly 16 further comprises a movable component 50, refer to FIG. 3. The movable component 50 comprises a cutter blade 52. Further, in the exemplary embodiment of FIGS. 2 through 5, the movable component 50 further comprises a contact bridge 54 which is preferably arranged as a plastic contact bridge. Further, at the cutter blade 52, a toothed section comprising a series of teeth 56 is provided. The teeth 46 of the stationary blade 34 and the teeth 56 of the cutter blade 52 are moved with respect to one another in a reciprocating fashion when the blade set assembly 16 is operated, refer also to the double arrow 80 in FIG. 2 and in FIG. 4.

(25) The contact bridge 54 may be also referred to as driving bridge. More generally, the contact bridge 54 may be referred to as contact element. In at least some embodiments, the contact bridge 54 is attached to or forms a part of the movable component 50. However, the tolerance accommodating joint between the coupling element 62 and the respective plastic contact bridge 54 may be also formed at the base component 32 in alternative embodiments.

(26) As can be best seen in FIG. 3 and in FIG. 5, bearing balls 58 may be provided is exemplary embodiments as a bearing means for facilitating the relative movement between the stationary blade 34 and the cutter blade 52.

(27) So as to secure and define a relative assembly position between the stationary blade 34 and the cutter blade 52, a coupling element 62 is provided which is arranged as a spring element. More particularly, the coupling element 62 may be arranged as a leg spring element. At the coupling element 62, a retaining portion 64 is provided which may be also referred to as retaining arm or retaining bracket. The retaining portion 64 is arranged at a central portion of the coupling element 62. Adjacent to the retaining portion 64, a first spiral portion 66 and a second spiral portion 68 is provided. The spiral portions 66, 68 may be also referred to as resilient or flexible portions.

(28) At a first lateral side of the coupling element 62, a first deflection arm 70 is provided. At a second lateral side of the coupling element 62, a second deflection arm 72 is provided. A first insertion end 74 is provided at the first deflection arm 70. A second insertion end 76 is provided at the second deflection arm 72. The deflection arms 70, 72 and, consequently, the insertion ends 74, 76 are spaced away from one another in the lateral direction Y. In the embodiment as shown in FIGS. 2 to 5, the spiral portions 66, 68 define a common axis which is basically parallel to the lateral direction Y. The deflection arms 70, 72 basically extend in the longitudinal direction X, at least in the neutral orientation of FIGS. 3 and 5. The insertion ends 74, 76 basically extend in the height (vertical) direction Z. Needless to say, alternative embodiments and arrangements of the coupling element 62 may be envisaged, involving non-wire spring element, for instance flat spring elements, plastic spring elements, and composite metal-plastic spring elements.

(29) The coupling element 62 secures and maintains a defined relative orientation between the stationary blade 34 and the cutter blade 52 which also applies when the blade set assembly 16 is operated involving a movement of the cutter blade 52 in a reciprocating fashion in the movement direction 80 with respect to the stationary blade 34. Hence, at least the deflection arms 70, 72 are swiveled or deflected when the blade set assembly 16 is operated. As a consequence, the insertion ends 74, 76 are reciprocatingly moved along with the cutter blade 52, wherein a movement path of the insertion ends 74, 76 is substantially parallel to the lateral direction Y but also involves a small component in the longitudinal direction X, as will be discussed further below in more detail.

(30) As can be best seen in FIG. 4, the insertion ends 74, 76 of the coupling element 62 engage (or is inserted in) the contact bridge 54 which is attached to the cutter blade 52. This may involve that the insertion ends 74, 76 are driven into the contact bridge 54.

(31) Further, as can be best seen in FIG. 4 and in the corresponding exploded view of FIG. 5, the retaining portion 64 of the coupling element 62 is, in the mounted state, retained by or supported at a retaining section 84 of the support part 36. The retaining section 84 may be also referred to as retaining recess or retaining seat. Further, a respective receiving recess or mounting recess 86 for each of the spiral portions 66, 68 of the coupling element 62 is provided at the support part 36. As can be already concluded from the arrangement of FIG. 4, when the coupling element 62 is received at the base component 32 which involves that the retaining portion 64 of the coupling element 62 is received at the retaining section 84 in a pre-tensioned or preloaded fashion, a resulting torque or force at the deflection arms 70, 72 may be generated. Typically, the retaining portion 64 and the deflection arms 70, 72 of the coupling element 62 tend to move (swivel) away from one another and to rotate in an opposite fashion, thereby unwinding the spiral or coil portions 66, 68.

(32) With reference to FIG. 4, FIG. 5 and to FIG. 6, the plastic contact bridge 54 which is engaged by the coupling element 62 in the assembled state of the blade set assembly 16 is further detailed.

(33) FIG. 6 is a view that is basically similar to the view of FIG. 2, wherein, for illustrative purposes, the stationary blade 34 and the fasteners 38 are omitted. Hence, an interior of the blade set assembly 16 is visible. As can be deduced from FIG. 6, the bearing balls 58 are received in guide openings 94 of the contact bridge 54. In the fully assembled state of the blade set assembly 16, the bearing balls 58 are arranged between the stationary blade 34 and the cutter blade 52 and guided for lateral movement by the guide openings 94. Hence, sliding friction between the cutter blade 52 and the stationary blade 34 may be significantly reduced, particularly at a portion thereof that is rearwardly spaced away from a cutting zone that is defined by the respective teeth 56, 46 of the cutter blade 52 and the stationary blade 34 (refer also to the cross-sectional view of FIG. 11 in this context).

(34) At the contact bridge 54, further a follower 92 is formed. The follower 92 may be also referred to as cam follower. The follower 92 as shown in the exemplary embodiment comprises a funnel section so as to simplify the mounting procedure of the blade set assembly 16. The follower 92 is arranged to be engaged by a driving shaft of a drive train (not explicitly shown) of the haircutting appliance 10. Typically, such a driving shaft involves an eccentric cam portion which revolves when the driving shaft is rotated. Between the eccentric cam portion and the follower 92, a joint is formed which translates the revolving input movement into a substantially reciprocating output movement of the cutter blade 52.

(35) Main embodiments and aspects of the present disclosure relate to the connection or joint between the coupling element 62 and the contact bridge 54. In FIG. 3 and FIG. 5, the contact bridge 54 is shown in a non-engagement state. At the contact bridge 54, engagement regions 98, 100 are provided. The engagement region 98 is associated to the insertion end 74. The engagement region 100 is associated to the insertion end 76. The engagement regions 98, 100 define a possible contact region where the insertion ends 74, 76 may penetrate the contact bridge 54, as already discussed herein before.

(36) As can be best seen in FIG. 5, the engagement regions 98, 100 do not comprise a predefined or pre-processed mounting recess or a similar position indication. Rather, the engagement regions 98, 100 are basically non-perforated and extend in an basically continuous, even and non-interrupted fashion in such a way that the insertion ends 74, 76 are not urged into a predefined penetration spot setting.

(37) The contact bridge 54 may be arranged to be attached to the cutter blade 52 in a snap-on or snap-in fashion. Consequently, snap-on features 104 are provided at the cutter blade 52. Corresponding snap-on features 106 are provided at the contact bridge 54. As can be best seen in FIG. 6 and in FIG. 10, the snap-on features 104 of the cutter blade 52 involve respective holes or recesses. The snap-on features 106 of the contact bridge 54 involve deflectable snap-on hooks. Further, positional alignment features 108 may be provided at the cutter blade 52 and the contact bridge 54 to ensure a defined relative assembly position and orientation of the cutter blade 52 and the contact bridge 54.

(38) With reference to FIG. 7 and FIG. 8, an engagement or bonding procedure for the coupling element 62 and the contact bridge 54 is illustrated. FIG. 7 is a side view of the blade set assembly 16 in a subassembly state. FIG. 8 is a detail view of a frontal end of the blade set assembly 16 as shown in FIG. 7 in an assembled and bonded state.

(39) As indicated by d in FIG. 8, a frontal distance in the longitudinal direction between the teeth 46 of the stationary blade 34 and the teeth 56 of the cutter blade 52 is provided. The distance d is somewhat crucial for the operating performance of the blade assembly 16. The offset d may be also referred to as tip-to-tip distance. Preferably, the teeth 46 of the stationary blade 34 slightly extend beyond the longitudinal extension of the teeth 56 of the cutter blade 52, as shown in FIG. 8. As already indicated above, defining and setting the distance d is in some respect a tradeoff between the risk of skin injuries and the cutting performance, particularly the styling performance of a respective appliance 10. It is therefore desirable to bring the distance d close to a minimum positive offset between the stationary blade 34 and the cutter blade 52 while ensuring that the teeth 56 of the cutter blade 52 do not protrude beyond the teeth 46 of the stationary blade 34 in the longitudinal direction X.

(40) As indicated in FIG. 7 by reference numeral 112, a gage may be provided in the assembly line for the blade set assembly 16. The gage 112 may define a desired offset d between the frontal ends of the teeth 56 and 46. So as to secure or lock the desired setting between the cutter blade 52 and the stationary blade 34, it is proposed to drive or insert the insertion ends 74, 76 of the coupling element 62 into the contact bridge 54 in a penetrating or squeezing fashion. Therefore, the bonding or mating process between the coupling element 62 the contact bridge 54 does not require any predefined recess or positional indication for the insertion ends 74, 76. Hence, involved manufacturing tolerances of the coupling element 62 and of further involved components of the blade set assembly 16 may be accommodated and compensated. The recess or hole that is formed by the penetrating insertion ends 74, 76 is, as a matter of course, positioned in a precise and accurate fashion involving a great reduction of the resulting tolerance range for the tip-to-tip distance d.

(41) As indicated in FIG. 7 by an arrow F, a bending force or torque is provided by the coupling element 62 as the retaining portion 64 is received in a preloaded fashion at the retaining section 84 of the support part 36. Given the exemplary illustrative arrangement of FIG. 7, the retaining portion 64 would tend to rotate in a clockwise direction, whereas the deflection arm 72 would tend to rotate in a counter clockwise direction. Needless to say, alternative embodiments and view orientations may involve opposite rotation directions.

(42) Due to the pretension of the coupling element 62, the insertion end 76 at the deflection arm 72 is urged against the engagement region 100 of the contact bridge 54. So as to facilitate the penetration action, it is proposed to soften the engagement region 100.

(43) In an exemplary embodiment, it is proposed to soften the engagement region 100 through heating. More particularly, in at least some embodiments as discussed herein, the engagement region 100 of the contact bridge 54 is mediately heated and softened by heating the insertion end 76 of the coupling element 62.

(44) As indicated in FIG. 7 by reference numeral 110, a non-contact heat source may be provided. For instance, the heat source 110 may be arranged as a laser-based heat source. Alternative heat sources may be envisaged, involving for instance friction heating sources, particularly ultrasonic heating sources. Typically, the coupling element 62 is made from a metal material, particularly from a steel material. The contact bridge 54 is typically made from an injection-moldable plastic material. Hence, a softening temperature of the contact bridge 54 is much lower than any temperature that would soften the metal material of the coupling element 62. As a result, the insertion end 76 of the coupling element 62 acts as a heated and pushing spike or drift that softens and penetrates the plastic material at the engagement region 100 of the contact bridge 54.

(45) As a result, as shown in FIG. 8, the insertion end 76 penetrates the engagement region 100 and thereby forms a firm bonding between the coupling element 62 and the contact bridge 54. Preferably, at least in some embodiments, the gage 112 arrangement engages the cutter blade 52 and the stationary blade 34 when the at least one insertion end 74, 76 of the coupling element 62 is driven into the plastic contact bridge 54.

(46) With particular reference to FIG. 8 and with additional reference to FIGS. 9 to 11, an assembly state of the blade set assembly 16 is further detailed.

(47) FIG. 9 is a bottom view of the assembled blade set assembly 16. FIG. 10 and FIG. 11 show respective lateral cross-sectional views along the lines X-X and XI-XI in FIG. 9. FIG. 10 shows a basically central cross-sectional view. FIG. 11 shows a cross-sectional view through a deflection arm 72 of the coupling element 62. In the views as shown in FIGS. 9, 10, and 11, the cutter blade 52 is shown in a neutral, central orientation, i.e. not displaced in the lateral direction Y.

(48) It is preferred in at least some embodiments, that also in the assembled state a remaining force F generated by the coupling element 62 is present that urges the cutter blade 52 against the stationary blade 34 (refer to FIG. 10). Basically the same type of force F generated by the coupling element 62 and transferred by the deflection arm 70, 72 may be used, at the assembly stage, to penetrate the engagement regions 98, 100 of the contact bridge 54 and, at the operating stage, to ensure a tight fit sliding contact mating between the stationary blade 34 and the cutter blade 52.

(49) FIG. 10 exemplifies a mounted state of the retaining portion 64 of the coupling element 62 which is mounted to or received at the retaining section 84 of the support part 36. Further, FIG. 10 exemplifies an engaged state of the snap-on feature 106 of the contact bridge 54. FIG. 11 exemplifies an engaged state of the insertion end 76 which is inserted in the engagement region 100 of the contact bridge 54. FIG. 11 further exemplifies a longitudinal guide arrangement between the stationary blade 34 and the cutter blade 52 which involves the bearing balls 58 and guide openings 94 provided by the contact bridge 54.

(50) As can be best seen from FIG. 11, the insertion ends 74, 76 of the deflectable arms 70, 72 may extend through the entire height/wall thickness of the engagement regions 98, 100. This may involve a contact between frontal faces of the insertion ends 74, 76 and the cutter blade 52. However, in alternative embodiments, the insertion ends 74, 76 of the deflectable arms 70, 72 may not extend through the entire wall thickness of the engagement regions 98, 100. Hence, frontal faces of the insertion ends 74, 76 may be covered by plastic material at the engagement regions 98, 100. However, in still further exemplary embodiments, the insertion ends 74, 76 of the deflectable arms 70, 72 extend and protrude beyond the engagement regions 98, 100 towards the stationary blade 34. This may involve that the insertion ends 74, 76 engage respective recesses at the cutter blade 52.

(51) Again, reference is made to FIG. 9. It can be best seen from the bottom view of FIG. 9 that the stationary blade 34, the cutter blade 52 and the coupling element 62 define a linkage mechanism 116 which resembles or is similar to a four-bar linkage mechanism that is basically arranged as a parallelogram linkage which may be also referred to as parallel double rocker linkage. A base bar of the linkage mechanism 116 is commonly defined by the base component 32 and those portions of the coupling element 62 that are fixedly received or supported thereon. Lateral bars of the linkage mechanism 116 are defined by the deflection arms 70, 72 of the coupling element 62. A movable bar that is basically arranged in a parallel fashion to the base bar is defined by the movable component 50, particularly the contact bridge 54 thereof, to which the deflection arms 70, 72 are connected by the insertion ends 74, 76. It has been observed that, in some embodiments, the insertion ends 74, 76 may rotate or swivel with respect to their recesses in the engagement regions 98, 100 that are formed through insertion. Hence, involved friction can be further reduced which ensures ease of movement at the involved joints of the linkage mechanism 116. Needless to say, at least some joints of the four-bar linkage mechanism 116 may be arranged as integral joints or living hinge joints and do not necessarily involve separate components that are arranged to be rotated with respect to one another.

(52) Hence, the coupling element 62 that forms a major part of the linkage mechanism 116 also provides a guidance for the cutter blade 52 in a plane that is basically parallel to the longitudinal direction X and the lateral direction Y. Preferably, no further guide element for the reciprocating movement of the cutter blade 52 in the X-Y plane is provided (except for limit stops, etc.). As already discussed above, the coupling element 62 further provides for a defined, slightly preloaded mating or contact between the stationary blade 34 and the cutter blade 52 and therefore urges the cutter blade 52 in the height/vertical direction Z against the stationary blade 34.

(53) When a driving movement is transferred to the stationary blade 34 via the follower 92 of the contact bridge 54, a reciprocating movement of the cutter blade 52 with respect to the stationary blade 34 is induced. A major component of the reciprocating movement is a lateral movement, refer to the double arrow 80 in FIG. 9. However, due to the design of the linkage mechanism 116, also a small movement component in the longitudinal direction X is present, refer to the double arrow 118 of FIG. 9.

(54) Hence, the reciprocating movement of the cutter blade 52 involves a slightly curved movement path, wherein the cutter blade 52, however, maintains the parallel orientation with respect to the stationary blade 34.

(55) Further reference is made to FIG. 12 which is a block diagram illustrating several steps of an exemplary embodiment of a method of manufacturing a blade set assembly.

(56) The method involves a step S10 which includes the provision of a base component which preferably comprises a stationary blade. The base component may further comprise a support part.

(57) Another step S12 includes providing a movable component which preferably comprises a cutter blade. In at least some embodiments as discussed herein, a further step S16 is provided which involves the provision of a plastic contact bridge. However, in alternative embodiments, the step S14 may be already implemented in the step S12 as the plastic contact bridge may form a part of the movable component.

(58) Further, a step S16 is provided which involves the provision of a coupling element. Preferably, the coupling element is arranged as a flexible coupling element, particularly as a leg spring.

(59) An optional step S18 may follow which involves an attachment of the contact bridge to the movable component, particularly to the cutter blade thereof. Attaching the contact bridge may involve a snap-on attachment. Hence, in the step S18 a further assembled movable component may be formed.

(60) A further assembly step S20 may follow which involves an arrangement of the base component, the movable component and the coupling element in a desired assembly orientation. For instance, the coupling element may be received at the base component in such a way that an auxiliary mounting force urging the movable component against the base component is induced.

(61) In a further step S22 which may be also referred to as gaging step, teeth of the stationary blade and the cutter blade may be positioned at a defined relative assembly position so as so set a tip-to-tip distance therebetween. This may involve providing a respective assembly gage for the desired relative orientation between the stationary blade and the cutter blade.

(62) In a further, optional step S24, the contact bridge is at least partially directly or mediately heated. This may for instance involve an indirect heating via respective insertion ends of the coupling element that contact respective to-be-heated portions of the contact bridge. The step S24 may for instance involve applying friction heating, particularly ultrasonic heating to the insertion ends. In the alternative, the step S24 may involve applying laser heating. Needless to say, at least in some embodiments, the step S24 involves a direct heating of potential engagement portions of the contact bridge.

(63) The step S24 may be followed by a further step S26 which involves an at least partial softening of the contact bridge, particularly in the vicinity of the insertion ends. Hence, the steps S24 and S26 may be interrelated as the plastic material of the contact bridge may be softened through heating.

(64) A further step S28 may involve driving or inserting the insertion ends of the coupling element into the contact bridge so as to bond the two components to one another. Preferably, a certain pretension is present at the coupling element which enables the coupling element to penetrate the contact bridge by itself, i.e. without the need of additional external penetrations forces applied by actuators.

(65) 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.

(66) 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.

(67) Any reference signs in the claims should not be construed as limiting the scope.