EP0480147B1 - Shaving foil - Google Patents

Abstract

The shearing foil has humps on the webs to face the skin between the numerous adjacent perforations in the foil. The humps (12) are sited at the nodal junctions of the webs (8) of several perforations (6), pref. at the intercepts between the centre lines of the webs. - The perforations are pref. polygonal and the humps are made of material with a different coefft. of friction than the remaining material.

Description

The invention relates to a shaving foil for a dry shaver with numerous, elongated and / or round and / or polygonal openings arranged next to one another, knob-like elevations being provided in the region of webs lying between the openings on the side facing the skin surface.

A shaving blade for dry shavers (DE OS 1 957 551) is already known, which is provided with numerous elevations on the skin contact side. The elevations are shaped like a hill and are sharp-edged, knife-like and lie in the edge region of the respective opening provided in the shaving foil. They have a steeply sloping part towards the edge of the openings and a flatly sloping part towards the next opening. The elevations are intended to reinforce part of the border of the shear opening and serve as a means of straightening the hair. However, since the elevations drop sharply only to one side of the openings, the dry shaving device is only effective in one direction, so that the shaving result of the device is greatly impaired.

Furthermore, a dry shaving device of the type mentioned at the outset is known (JA OS 58-15883), which is equipped with a shaving foil with numerous elongated hole openings arranged next to one another. The individual elongated holes are arranged in several rows, with each row being slightly offset from the neighboring row. There is only an elevation between the opposite ends of three adjacent elongated hole openings. The elevations are conical or hemispherical. This is to facilitate the threading process. However, since the web width is wider than the width across flats of the openings and the individual elevations are at a relatively large distance have the edges of the openings, the threading process of the whiskers is not supported in the desired manner. In addition, in the known arrangement, a maximum of three surveys are grouped around an elongated hole, which is completely inadequate. In order to ensure sufficient stability of the known shaving foil, a certain thickness of the foil must not be undercut with such an arrangement of the individual openings and the elevations associated with them. Another disadvantage is that the total area of the elevations is very small with respect to the total area of the web.

In contrast, the object of the invention is to design and arrange the individual elevations provided on the webs in such a way that a sufficient size of the openings can be maintained in order to achieve good cutting quality with optimal protection of the skin. The object is achieved according to the invention in that the elevations are provided at least on each node of intersecting webs and the webs surrounding the openings. The increases in the area of the nodes lead to an improvement in the skin walk effect and to the optimization of the threading process of the whiskers during the shaving process. This can improve the quality of the cut and thus the overall shaving performance.

An improvement in the shaving performance can also be achieved by using the shaving foil as a double shaving foil for double cutter heads. The knife blocks can have a diameter between 8 and 13 mm in order to achieve optimal shaving performance.

By increasing the webs in the area of the nodes of the webs of round and / or polygonal openings, the webs are strengthened in particular in the area in which the webs are exposed to constantly changing loads, in particular compressive, tensile or bending forces. As can be seen from the course of the line of force, the mentioned forces are maximized in the area of the node points, so that a greater force absorption in the critical node point area is possible through the use of the elevations. The use of the elevations therefore also offers the possibility of both reducing the film thickness and reducing the web width, in order to thereby either increase the width across flats, whereby the width across flats may only be increased until the limit is reached at which skin irritation could occur and / or the number of openings in the perforated field of the film could be increased.

In a further embodiment of the invention, it is advantageous that the elevations are provided on the intersections of intersecting center lines of webs or openings, the web width being smaller than the width across flats of the openings.

Another development of the device according to the invention is that the openings are polygonal, advantageously hexagonal and at least one elevation is provided in the area of each corner. It is also advantageous that the elevations are arranged at regular intervals and surround each opening in a circle. This results in a symmetrical arrangement of the elevations around each opening, so that a good shaving performance is always guaranteed, no matter in which direction the shaver is moved.

It is of particular importance for the present invention that the elevations have a height which is equal to or less than the height of the web.

According to a further embodiment of the invention, it is finally provided that the elevations are formed from the same material as the rest of the shaving foil. It is also possible for the elevations to be formed from a different material than the rest of the shaving foil. In this way, the skin walk effect can be influenced or optimized in a simple manner.

Overall, the advantageous use of the elevations or knobs provided on the shaving foil, in particular in the knot bw. Gusset area of the webs formed by the openings, in addition to good shaving performance, also significantly increases the service life of the shaving foil, since the shear foil is able to withstand high loads while maintaining high elasticity. The shaving quality is influenced in a simple manner by the favorable ratio of the hole opening to the web width and by the favorable web height in the region of the knobs.

Details of the invention are shown in the description and the figures, it being noted that all individual features and all combinations of individual features are essential to the invention.

Figur 1

eine perspektivische Darstellung eines Trockenrasiergeräts mit einem beweglichen Schwingkopf und der erfindungsgemäßen Scherfolie,

Figur 2

eine perspektivische Darstellung eines oberen Teils der Scherfolie sowie den Einfädelvorgang der Barthaare,

Figur 3

einen Schnitt durch die Scherfolie entlang der Linie 4-4 gemäß Fig 4,

Figur 4

eine Teilansicht der Scherfolie mit einer Sechskantöffnung und den in den Knotenpunkten der Stege angeordneten Noppen,

Figur 5

eine perspektivische Teilansicht der Scherfolie mit den auf der Hautkontaktseite der Scherfolie vorgesehenen Noppen,

Figur 6

einen Querschnitt des oberen Teils der Scherfolie mit den auf den Stegen angeordneten Noppen sowie den Walkvorgang der Haut bei Verwendung der erfindungsgemäßen Noppen,

Figur 7

einen Querschnitt des oberen gewölbten Teils der Scherfolie mit den auf den Stegen angeordneten Noppen,

Figur 8

eine Draufsicht der Scherfolie mit unterschiedlich gestalteten Öffnungen und den in den Knotenpunkten vorgesehenen Noppen,

Figur 9

ein Schliffbild eines aus drei zusammenlaufenden Stegen gebildeten Knotenpunkts sowie einen Einblick in den Kraftlinienverlauf in diesem Bereich bei einer bestimmten Beanspruchungsart.

In the figures, an embodiment of the invention is shown, for example, without being limited to this embodiment. It shows:

Figure 1

2 shows a perspective illustration of a dry shaving device with a movable oscillating head and the shaving foil according to the invention,

Figure 2

a perspective view of an upper part of the shaving foil and the threading process of the whiskers,

Figure 3

4 shows a section through the shaving foil along the line 4-4 according to FIG. 4,

Figure 4

2 shows a partial view of the shaving foil with a hexagonal opening and the knobs arranged in the nodes of the webs,

Figure 5

2 shows a perspective partial view of the shaving foil with the knobs provided on the skin contact side of the shaving foil,

Figure 6

2 shows a cross section of the upper part of the shaving foil with the knobs arranged on the webs and the flexing process of the skin when using the knobs according to the invention,

Figure 7

3 shows a cross section of the upper curved part of the shaving foil with the knobs arranged on the webs,

Figure 8

2 shows a top view of the shaving foil with differently shaped openings and the knobs provided in the nodes,

Figure 9

a micrograph of a node formed from three converging webs and an insight into the course of the force lines in this area with a certain type of stress.

In the drawing, 1 denotes a dry shaving apparatus in FIG. 1, which consists of a housing 5 with an electric motor (not shown in the drawing) for driving a knife block 7. On the outside of the housing 5 there is a slide switch 9, by means of which the electric motor can be switched on and off. At the upper end of the housing 5, the knife block 7, which is surrounded by a shaving foil 2, is arranged on an oscillation axis.

The dry shaving apparatus 1 can be equipped with a single knife block according to FIG. 1 or with a double knife block 7a according to FIG. 2. As can clearly be seen in FIG. 2, the flexing effect of the double shaving film on the skin is improved by the two closely spaced double shaving films 2a, and the whiskers are thereby straightened up, so that they can be threaded into the openings 6 of the double shaving film 2a much more easily. In this way, in connection with the pivotable shaving head and the double shaving foil 2a, constant optimal skin contact is guaranteed, since the perfect shaving angle is always established. This gives you a thorough and gentle shave. A further improvement in the flexing effect results from the use of knobs 12, as explained in more detail in the description below.

FIG. 8 shows a shaving foil 2 in the unwound state. The shaving foil 2 has numerous openings 6 arranged next to one another, which can advantageously be round, oval, oblong or polygonal, in particular hexagonal. In the exemplary embodiment according to FIGS. 4 and 8, the individual openings 6 are hexagonal. This results in a honeycomb arrangement of the individual openings 6. The individual openings 6 are delimited by straight webs 8. However, the individual webs 8 can also be curved, circular or slightly corrugated.

V =

Verhältniszahl

Fö =

Gesamtfläche einer Öffnung 6

Fst =

halbe Gesamtfläche des Steges, der eine Öffnung umgibt

$$\text{V =}\frac{\text{Fö}}{\text{Fst}}\text{> 1}$$

The ratio of half the total area of the webs 8 surrounding an opening 6 to the total area of the associated opening 6 is advantageously greater than one. In the formula below:

V =

Ratio

Fö =

Total area of an opening 6

Fst =

half the total area of the web that surrounds an opening

$$\text{V =}\frac{\text{Fö}}{\text{Fst}}\text{> 1}$$

This gives a relatively large passage cross section. Since the shaving performance is composed of the quality of threading the whiskers into the openings 6 and the quality of the cutting, the opening size is not decisive for a good shaving performance.

The larger the radius R (FIG. 7) of the shaving foil 2, the more flexible is the shaving foil 2 and the easier it is to contact the outer contour of the knife block 7 or 7a. With increasing radius R, however, the shaving performance decreases from a certain size. For this reason, it is advantageous to make the radius R of the shaving foil 2 relatively small. As a result, however, the shaving foil 2 is curved to a greater extent and is therefore also subjected to greater bending stresses, so that the thickness of the shaving foil 2 must be dimensioned accordingly.

When using a film with knobs, there is the possibility of stressing the thinner shaving film 2 more, ie bending it more strongly, since the knobs 12 represent a reinforcement of the film in the region of the nodes, ie in the region of the critical points that there is no fear of breakage of the shaving foil if it is made thinner by the proportion of the nub height.

As can be seen from FIG. 3, 7 and in particular from FIG. 6, the shaving foil 2 is composed of the web height SH and the nub height NH of the elevations or nubs 12 arranged on the webs 8. The thickness of the shaving foil GSH results from NH and SH. $$\text{GSH = NH + SH}$$

If it is assumed that a shaving foil without knobs SH has, for example, 60 μm, then when using the knobs 12 according to the invention, the thickness of the shaving foil can be reduced by the proportion of the knob height NH.

Example:

$$\text{60µ - 20µ = 40µ}$$

Total film thickness without nubs 60µ, nub height 20µ $$\text{GSH - NH = SH}$$

$$\text{60µ - 20µ = 40µ}$$

As can be seen from FIGS. 4 and 8, the knobs 12 are advantageously arranged in the nodes 13 of the webs 8. The point 13 is to be understood as the point at which at least two center lines 3 of two or more webs 8 intersect.

During the shaving process, as can be seen from FIG. 9, the junction 13 of the webs 8 is most subjected to tension, pressure, bending and twisting, so that inadequate dimensioning of the shaving foil 2, particularly in the area of the junction, can result in breakage. For this reason, the knobs 12 are provided in an advantageous manner, in particular in the junction area of the webs 8, and thus contribute to the reinforcement of the critical points of the shaving foil 2. This also makes it possible to reduce the normal web height SH by approximately the amount of the nub height NH (cf. FIG. 3).

As can be seen from FIG. 4, the knobs 12 are arranged at regular intervals and surround each opening 6 in a circle. By means of the reinforcement of the webs 8 by the knobs 12 in the area of the nodes, the opening 6, that is to say the width across flats SW in, can also be opened make the shaving foil 2 larger than the opening of a shaving foil, which is equipped without knobs - see dashed line. This gives a better ratio V, even with the same web width. you get a larger proportion of holes in relation to the web width. Furthermore, film material is advantageously saved as a side effect. Furthermore, the elevations 12 with their lower outlet ends can gradually merge into the front edge 11 of a web 8 (see FIG. 3 and FIG. 7).

As can be seen from FIG. 6, the knobs 12 have a further advantage, namely that they contribute significantly to improving the skin walk effect. By sliding the knobs 12 over the skin, this is partially stretched and the whiskers emerge more from the pores, so that after the threading process into the opening 6 they are gripped and separated by the knife of the blade block much better.

As can be seen from Figure 7, the diameter d 1 of the knobs 12 at the upper end is somewhat larger than the diameter d 2 of the opening 6. This results in an approximately funnel-shaped expansion of the opening 6. The threading process of the whiskers is thereby facilitated. In Figure 7, the angle A is 90 °. The angle A is advantageously between 70 ° and 100 °. The knobs 12 are spherical or hemispherical in accordance with FIG. They can have the shape of a truncated cone or pyramid.

It is also possible that the knobs 12 are made of a different material than the rest of the shaving foil 2, the surface of the knobs 12 having a different sliding effect than the rest of the material of the shaving foil 2. For example, the knobs 12 can be made of to produce a galvanoplastic material, a thermoplastic material or a ceramic material. This can have a positive effect on the skin walk effect.

Furthermore, it is possible that at least one further elevation 12 is provided on the webs 8 between the individual elevations 12 provided on the corner points (see in particular FIG. 8).

Claims (10)

1. A shaving foil (2) for a dry shaving apparatus (1), including a plurality of adjacent apertures (6), with knob-type protuberances (12) being provided in the area of partitions (8) separating the apertures (6) on the side (10) engaging the skin surface, characterized in that the protuberances (12) are provided at least on each nodal point (13) of intersecting partitions (8) surrounding the apertures (6).
2. The shaving foil as claimed in claim 1, characterized in that the protuberances (12) are provided on the points of intersection of intersecting center lines (3) of partitions (8) or apertures (6), with the partition width being smaller than the span of the apertures (6).
3. The shaving foil as claimed in one or several of the preceding claims, characterized in that at least one further protuberance (12) is provided between the individual protuberances (12) arranged on the nodal points.
4. The shaving foil as claimed in one or several of the preceding claims, characterized in that the apertures (6) are polygonal and that at least one protuberance (12) is provided in each corner area.
5. The shaving foil as claimed in one or several of the preceding claims, characterized in that the protuberances (12) are spaced at uniform distances and surround each aperture (6) in a circular pattern.
6. The shaving foil as claimed in one or several of the preceding claims, characterized in that the lower ends of the protuberances (12) gradually extend into the side (11) of a partition (8).
7. The shaving foil as claimed in one or several of the preceding claims, characterized in that the protuberances (12) are of a height equal to or smaller than the height of the partition.
8. The shaving foil as claimed in one or several of the preceding claims, characterized in that the protuberances (12) are made of the same material as the remaining part of the shaving foil (2).
9. The shaving foil as claimed in one or several of the preceding claims, characterized in that the protuberances (12) are made of a material other than the remaining part of the shaving foil (2).
10. The shaving foil as claimed in one or several of the preceding claims, characterized in that the protuberances (12) are made of a material having a coefficient of friction other than the remaining material.

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