EP1871575B1 - Clipping system for an electric hair-cutting appliance - Google Patents

Abstract

A shaving cutter assembly for an electric hair cutting appliance the shaving cutter assembly including a shaving cutter and a carrier to which the shaving cutter is fixedly connected via at least one metallic weld.

Description

The invention relates to a shaving system for an electric hair trimmer and an electric hair trimmer with such a shaving system.

A shaving system for an electric shaver typically has a bottom blade and a top blade that closely abut each other and move relative to each other. By this relative movement whiskers, which reach into the area between the upper blade and the lower blade, severed.

Such a razor is for example from the EP 1 182 014 A2 known. There, an electric razor is disclosed which has two bottom blades and a trained as a shear foil upper blade. The lower blades are placed in a linear oscillating motion and thereby cut through in cooperation with the upper knife the whiskers.

From the WO 2004/076135 A1 Also known is an electric shaver having two lower blades that oscillate relative to a top blade formed as a foil. The lower blades are each connected via a coupling element with a drive element. For this purpose, the respective lower blade is arranged on the coupling element such that projections formed on the coupling element engage in recesses of the lower blade.

From the US 3,201,178 and from the US 2,841,867 are known shear blades, which are fastened by means of metallic welded connection to a machine part.

The achievable with such razors shaving result depends in particular on how exactly cooperate lower blade and upper blade.

The invention has for its object to permanently fix a shearing blade of an electric hair clipper on a machine part and thereby achieve the highest possible precision with a reasonable cost.

This object is achieved by the combination of features of claim 1.

The shearing system for an electric hair trimmer according to the invention comprises a shearing blade for severing hair and a machine part with which the shearing blade is firmly connected, wherein the shearing blade and the machine part are connected to each other via at least one metallic welded joint, at least one holder is formed on the shearing blade and the holder between the welded joint and the shearing blade has a reduced material cross-section area.

The invention has the advantage that the shearing blade is precisely and permanently fixed to the machine part. The metallic weld is very durable, takes up little space and can be made quickly and inexpensively.

In the formation of the welded joint resulting stresses cause deformations mainly in the region of the reduced material cross-section and are therefore not or only in reduced form transferred to the shear blade. Consequently, an undesirable deformation of the doctor can be avoided and thus a good dimensional stability can be achieved. This is an important prerequisite for achieving a good shaving result.

In a preferred embodiment of the invention, the welded joint is arranged in the region of the holder. It is advantageous if the holder is easier to deform than the shearing blade.

Per bracket several welds can be formed. The welded joints are preferably arranged so that at least partially compensate for the stresses caused by the welds. For example, the welds are formed at mutually symmetrical locations of the holder. These measures in turn lead to any stresses in the blade and associated delays are limited to an acceptable level.

The holder is preferably formed integrally with the shearing blade. Furthermore, it is advantageous if the holder is connected via a web to the shear blade. The web also leads to a certain decoupling of the welded connection or of the several welded connections from the shearing blade and thereby to a reduction of welding-induced distortions.

The holder can surround the machine part in some areas. This facilitates the fixation of the shear blade on the machine part and gives a reliable grip. In this case, the holder follows in accordance with a variant in the entire Umschließungsbereich with their machine part facing surface of the molding of the machine part. According to a further variant, the holder differs regionally, in particular in an area adjacent to the welded joint with its surface facing the machine part from the shape of the machine part that the distance of the holder is increased by the machine part in this area. In the area of deviating shaping, the holder thus has a reduced material cross-section, so that any stresses, in particular in this area, cause deformations and, if necessary, are transmitted in an attenuated form to the shearing blade.

The shearing system according to the invention can be designed so that the holder has at least one holding arm. It is particularly advantageous if the holder has two, in particular symmetrically designed holding arms, between which the machine part is arranged. In this embodiment, a particularly effective suppression or compensation of voltages is possible.

The shearing blade may be formed as a lower blade, which is driven in particular oscillating over the machine part. In particular, the shearing blade may have a U-shaped cross-section. The shearing blade may have a material thickness of less than 1 mm, preferably less than 0.5 mm and in particular about 0.3 mm. Preferably, in the shear system according to the invention, a further shearing blade is provided, with which cooperates the shearing blade.

The invention further relates to an electric hair trimmer with at least one inventively designed shear system.

It is particularly advantageous if several welded joints are formed simultaneously. In this way, the formation of stresses in the formation of welded joints can be contained. The same can be achieved in that the energy supply to form a plurality of welded joints takes place in succession, wherein the time difference is selected in each case so small that molten material is present at the same time in the region of the plurality of welded joints.

The invention is explained below with reference to the embodiments illustrated in the drawings.

Fig. 1

ein Ausführungsbeispiel eines elektrischen Rasierapparats in Seitenansicht,

Fig. 2

ein Ausführungsbeispiel eines erfindungsgemäß ausgebildeten Untermessers in Seitenansicht,

Fig. 3

das Untermesser aus Fig. 2 in Schnittdarstellung,

Fig. 4

einen vergrößerten Ausschnitt aus Fig. 2 im Bereich einer der Halterungen,

Fig. 5 und 6

weitere Ausführungsbeispiele für das Untermesser, wobei die Halterungen mit je zwei Schweißpunkten an der Achse fixiert sind, in einer Fig. 4 entsprechen- den Darstellung und

Fig. 7 bis 10

Ausführungsbeispiele für das Untermesser, wobei die Halterungen mit je ei- nem Schweißpunkt an der Achse fixiert sind, in einer Fig. 4 entsprechenden Darstellung.

• Fig. 1 zeigt ein Ausführungsbeispiel eines elektrischen Rasierapparats 1 in Seitenansicht. Der Rasierapparat 1 weist ein in der Hand haltbares Gehäuse 2 und einen daran befestigten Scherkopf 3 auf. Am Gehäuse 2 ist ein Schalter 4 zum Ein- und Ausschalten des Rasierapparats 1 angeordnet. Der Scherkopf 3 weist ein Schersystem 5 auf, von dem in Fig. 1 lediglich eine in einem Halterahmen 6 angeordnete Scherfolie 7 sichtbar ist.
• Fig. 2 zeigt ein Ausführungsbeispiel eines erfindungsgemäß ausgebildeten Untermessers 8 in Seitenansicht. Eine zugehörige Schnittdarstellung ist in Fig. 3 dargestellt. Das Untermesser 8 stellt einen weiteren Bestandteil des Schersystems 5 dar und liegt im montierten Zustand eng an der Innenseite der in Fig. 1 dargestellten Scherfolie 7 an. Beim Betrieb des Rasierapparats 1 wird das Untermesser 8 relativ zur Scherfolie 7 in eine linear oszillierende Bewegung versetzt. Diese Bewegung führt dazu, daß Haare, die durch die Scherfolie 7 bis zum Untermesser 8 vordringen, vom Untermesser 8 erfaßt und in Zusammenwirkung mit der Scherfolie 7 durchtrennt werden.

Show it:

Fig. 1

an embodiment of an electric shaver in side view,

Fig. 2

an embodiment of an inventively designed lower blade in side view,

Fig. 3

the bottom knife off Fig. 2 in section,

Fig. 4

an enlarged section Fig. 2 in the area of one of the brackets,

FIGS. 5 and 6

Further embodiments of the lower blade, wherein the brackets are fixed with two welding points on the axis, in one Fig. 4 corresponding illustration and

Fig. 7 to 10

Exemplary embodiments of the lower blade, wherein the holders are fixed to the axle with one welding point each, in one Fig. 4 corresponding representation.

• Fig. 1 shows an embodiment of an electric shaver 1 in side view. The razor 1 has a housing 2 durable in the hand and a shaving head 3 attached thereto. On the housing 2, a switch 4 for switching on and off of the shaver 1 is arranged. The shaving head 3 has a shearing system 5, of which in Fig. 1 only one arranged in a holding frame 6 shaving foil 7 is visible.
• Fig. 2 shows an embodiment of an inventively designed lower blade 8 in side view. An associated sectional view is in Fig. 3 shown. The lower blade 8 is another component of the shear system 5 and is in the mounted state closely to the inside of in Fig. 1 shown shear foil 7 at. During operation of the razor 1, the lower blade 8 is displaced relative to the shear foil 7 in a linear oscillating movement. This movement causes hair, which penetrate through the shear foil 7 to the lower blade 8, detected by the lower blade 8 and severed in cooperation with the shear foil 7.

In cross-section, the lower blade 8 is U-shaped and is composed of a first leg 9, a second leg 10 and an arranged between the legs 9 and 10 elbow piece 11 together. In the longitudinal direction of the lower blade 8 a plurality of individual blades 12 are arranged at regular intervals from each other. The individual blades 12 are formed in particular sharp. On each leg 9 and 10 of the lower blade 8 each two brackets 13 are formed, with which the lower blade 8 is fixed to two axles 14 which are oriented transversely to the longitudinal extent of the lower blade 8. The axes 14 may be components of an otherwise not figuratively illustrated carrier, which couples the lower blade 8 with a drive of the razor 1, by means of which the lower blade 8 is set in a linear oscillating movement. The formation of the brackets 13 is based on Fig. 4 explained in more detail.

Fig. 4 shows an enlarged section Fig. 2 in the region of one of the holders 13. In the illustrated embodiment, the holder 13 is symmetrically shaped and formed integrally with the first leg 9 of the lower blade 8. In this case, the holder 13 has two retaining arms 15, which together form a fork and partially encompass the illustrated axis 14. The two holding arms 15 unite in the region of a web 16, via which the holder 13 is connected to the first leg 9 of the lower blade 8. The web 16 has a lateral extent parallel to the outer contour of the first leg 9 of the lower blade 8, which is smaller than the entire lateral extent of the two support arms 15. At the axis 14, the support arms 15 are formed with arcuate inner surfaces 17 at.

The axis 14 is made of metal, preferably made of steel. The lower blade 8 is made of metal at least in the region of the brackets 13. Preferably, the lower blade 8 is made entirely of metal, in turn, steel is particularly well suited as a material. The material thickness of the lower blade 8 is less than 1 mm. Preferably, a material thickness of less than 0.5 mm is selected. In the illustrated embodiment, the material thickness is about 0.3 mm.

To fix the holder 13 on the axis 14, the holder 13 and the axis 14 are welded together. In the illustrated embodiment, two welding points 18 are formed in the vicinity of the free ends of the support arms 15 in mutually symmetrical positions. Between the welding points 18 and the web 16, the holding arms 15 each have a partially reduced material cross section.

The welding spots 18 are preferably formed by laser welding. For this purpose, the designated boundary areas between the support arms 15 and the axle 14 are briefly exposed to a high-energy laser beam. This leads to a local melting of the material in the region of the laser beam. Upon cooling, the molten material of the holding arms 15 connects to the molten material of the axis 14. The melting takes place in a period of about 1 ms to 10 ms and is carried out for both welding points 18 simultaneously or in short succession. The time offset of the melting between the two welding points 18 is a maximum of about 1 ms, so that the material in the region of the second welding point 18 is already melted before the material is solidified in the first melting point 18. The simultaneous melting in the region of the two welding spots 18 can be achieved, for example, with the aid of a bifocal laser beam, which is adjusted so that one focus is formed in the region of each of the two welding spots 18. As the molten areas solidify, volumetric shrinkage and contraction of the cooling melt create stresses. In particular, tensile stresses arise normal to the envelope surface of the melt volume, which corresponds to the illustrated spot welds 18. The stresses can be reduced to some degree by a low melt volume and a small weld gap.

In the context of the invention, several measures are provided with which the voltages can be limited to very small values. One of these measures is that a plurality of welds 18 are formed in the manner described at least approximately simultaneously, so that partially cancel the tensions in the contraction of the melt volume. For example, the four welding points 18, via which the axle 14 is connected to a holder 13 of the first leg 9 and a holder 13 of the second leg 10 of the lower cutter 8, can be generated simultaneously or approximately simultaneously.

A second measure is that the individual welding points 18 are preferably arranged so that after cooling the melt in the welding gap normal to the envelope surface of the melt volume can be a cancellation of the voltages. In the embodiment of Fig. 4 the welding points 18 are arranged symmetrically opposite each other for this purpose.

As far as tensions nevertheless arise, their effect on the shape of the lower blade 8 can be limited according to a third measure in that the brackets 13 deform more easily than the lower blade 8. This is due to the fork shape of the brackets 13 and the partially reduced material cross section of the support arms 15th reached.

Particularly effectively, the stresses acting on the lower blade 8 can be limited by the fact that the measures described are used in combination. But it is also possible to apply the measures individually or as subcombinations. The described arrangement of the welding points 18 and the at least approximately simultaneous melting are preferably used in combination. Further embodiments of this are in the FIGS. 5 and 6 shown. As an individual measure in particular the slight deformability of the brackets 13 can be used. Exemplary embodiments of this show the Fig. 7 to 10 ,

FIGS. 5 and 6 show further embodiments of the lower blade 8, wherein the brackets 13 are fixed with two welding points 18 on the axis 14, in a Fig. 4 corresponding representation. In both embodiments, the axis 14 is almost completely enclosed by the holding arms 15 of the holder 13 except for a small gap 19. The gap 19 is formed in each case on a web 16 of the opposite side of the holder 13 between the free ends of the support arms 15. On both sides of the gap 19 each have a weld 18 is formed. At the in Fig. 5 illustrated embodiment, each of the entire inner surface 17 of the two support arms 15 is formed circular arc. According to the embodiment Fig. 6 on the other hand, only a portion of the inner surface 17 of the two retaining arms 15 is formed in a circular arc shape. In this embodiment, the inner surface 17 deviates in each case in an adjacent to the welding point 18 portion of the support arm 15 of the shape of a circular arc such that initially increasingly larger radii are assumed and then reduce the radii again until the arc is reached again. Thus, each support arm 15 adjacent to its welding point 18 on a bulge 20, in the region of which the inner surface 17 of the support arm 15 is spaced from the axis 14 and the material cross-section of the support arm 15 is thereby reduced. In this way, a further improved stress relief is possible.

Fig. 7 to 10 show exemplary embodiments of the lower blade 8, wherein the brackets 13 are fixed, each with a welding point 18 on the axis 14, in one Fig. 4 appropriate Presentation. In these embodiments, the holder 13 in each case only one holding arm 15 and is formed overall hook-shaped. In the vicinity of its free end of the support arm 15 is connected by a weld 18 with the axis 14.

In the embodiments of the FIGS. 7 and 8 encloses the support arm 15 approximately half the circumferential area of the axis 14. Here, the inner surface 17 of the support arm 15 in the embodiment of Fig. 7 formed through a circular arc. The embodiment of Fig. 8 has in addition to the welding point 18 on a bulge 20, so that the inner surface 17 of the support arm 15 is formed only partially circular arc.

In the embodiments of the FIGS. 9 and 10 encloses the support arm 15, the axis 14 in each case almost completely, so that the free end of the support arm 15 each extends almost to the web 16. The welding point 18 is also formed again in the vicinity of the free end of the support arm 15 in these embodiments. The embodiment of Fig. 9 has a continuous circular arc-shaped inner surface 17 of the holding arm 15. In the embodiment of Fig. 10 is next to the welding point 18, a bulge 20 is formed. Outside the bulge 20, the inner surface 17 of the support arm 15 is formed in a circular arc.

In all embodiments, the weld spots 18 can be made not only with the above-described laser welding, but also with other high energy sealing processes, such as micro plasma or electron beam welding.

Claims (17)

1. A clipping system for an electric hair-cutting appliance (1), with a clipping blade (8) for cutting hair and a machine part (14), to which the clipping blade (8) is firmly connected, wherein the clipping blade (8) and the machine part (14) are connected to one another by means of at least one metal weld connection (18) and the clipping blade (8) has at least one holder (13) and the weld connection (18) is located in the area of the holder (13), characterized in that the holder (13) has a somewhat reduced material cross-section between the weld connection (18) and the clipping blade (8).
2. The clipping system according to Claim 1, characterized in that the holder (13) is more easily deformable than the clipping blade (8).
3. The clipping system according to either Claim 1 or Claim 2, characterized in that each holder (13) has multiple weld connections (18).
4. The clipping system according to Claim 3, characterized in that the weld connections (18) are located such that tensions caused by the weld connections (18) are at least partially compensated for.
5. The clipping system according to either Claim 3 or Claim 4, characterized in that the weld connections (18) are placed at points on the holder (13) that are symmetrical to one another.
6. The clipping system according to any of the preceding claims, characterized in that the holder (13) is designed as a single piece with the clipping blade (8).
7. The clipping system according to any of the preceding claims, characterized in that the holder (13) is connected to the clipping blade (8) by means of a stud (16).
8. The clipping system according to any of the preceding claims, characterized in that the holder (13) partially encloses the machine part (14).
9. The clipping system according to Claim 8, characterized in that the holder (13), with its surface (17) facing toward the machine part (14), follows the shape of the machine part (14), over the entire enclosure area.
10. The clipping system according to Claim 9, characterized in that the holder (13), with its surface (17) facing toward the machine part (14), deviates somewhat from the shape of the machine part (14), particularly in an area adjacent to the weld connection (18), such that the distance between the holder (13) and the machine part (14) is increased in this area.
11. The clipping system according to any of the preceding claims, characterized in that the holder (13) has at least one supporting arm (15).
12. The clipping system according to any of the preceding claims, characterized in that the holder (13) has two, particularly symmetrically formed, support arms (15), in between which the machine part (14) is located.
13. The clipping system according to any of the preceding claims, characterized in that the clipping blade (8) is designed as a bottom blade, which can be driven, particularly in an oscillating manner, via the machine part (14).
14. The clipping system according to any of the preceding claims, characterized in that the clipping blade (8) has a U-shaped cross-section.
15. The clipping system according to any of the preceding claims, characterized in that the clipping blade (8) has a material thickness of less than 1 mm, preferably less than 0.5 mm, and particularly around 0.3 mm.
16. The clipping system according to any of the preceding claims, characterized in that an additional clipping blade (7) is provided, which interacts with the clipping blade (8).
17. An electric hair-cutting appliance with at least one clipping system (5), characterized in that the clipping system (5) is designed in accordance with any of the preceding claims.

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