US3382580A - Perforated cutter foil for dry shavers - Google Patents

Description

May 14, 1968 c. l.. RlNcK ET A. 3,382,580

PERFORATED CUTTER` FOIL FOR DRY SHAVERS Filed Nov. 26, 1965 mmh Alll ,l

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INVENTQRS BY 41/ @XM/PQM* MRNEYJ- United States Patent O PERFORATED CUTTER FGIL FOR DRY SHAVERS Cornelis Ludwig Rinck andv Adam Koroncai, Klagenfurt,

Carinthia, Austria, assignors to Firma Carinthia Elektrogerate Gesellschaft m.h.H., Karnten, Austria Filed Nov. 26, 1965, Ser. No. 509,966 Claims priority, application Austria, Dec. 7, 1964, A 10,363/64 Claims. (Cl. Btl-346.51)

ABSTRACT 0F THE DISCLOSURE A perforated cutter foil for dry shavers having a plurality of diamond-shaped hair entry openings with adjacent sides of each making angles with one another of 60 and 120 respectively, and all the openings constituting a network which has groups of openings with the groups having the principal diagonals extending in three diiferent directions which make angles of 120 with each other.

The invention relates to the construction of a cutter foil for dry Shavers with a lower knife arranged beneath the foil.

It is known that in such apparatus both the quality of the shave and also the time taken up for a good shave depends not only on the so-called opening ratio (relationship of the total area taken up by the hair entry openings to the total area of the cutter foil) but also on the size and shape of the hair entry openings. Already numerous shapes for the boundaries af these entry openings have been proposed, namely from simple geometrical shapes, such as circle, ellipse, oval, rectangular, diamond, polygon, especially hexagon up to complicated boundaries, eg. closed shapes provided with waves, points etc.

It is also known, that openings in the form of longitudinal slits are particularly well suited to erect and grasp longer beard hairs, which lie in the direction of the length of such openings, so that they can be cut off. Moreover it is also already known, to distribute such longitudinal slits over the entire area of the foil with different directions of their longitudinal extents, to take account of the fact that the natural growth of the beard hairs, even in relatively small areas of the skin, often follows sharply different directions. In all cutter foils which have hitherto become known with differently oriented hair entry openings of elongated shape there is however either, by reason of the presence of broad bars, a very unfavorable opening ratio, or there is a relatively small strength, which is unequal in various directions or in various areas by reason of the unfavorable arrangement of the bars between the openings.

These disadvantages are, according to the invention, avoided in a cutter foil with a plurality of diamondshaped hair entry openings, in that the adjacent sides of the diamond-shaped hair entry openings make angles with one another of 60 and 120 respectively, and that the totality of the openings constitutes a network, which predominantly or exclusively contains groups of diamondshaped openings, in which the directions of the principal diagonals of the openings make angles of 60 between each other. In this way it is possible to arrange the openings alongside one another except for narrow bars, that is to say to achieve a high opening ratio, but at the same time to ensure that bars extend in directions uniformly angularly inclined to one another at 120, so that the cutter foil is not inadmissibly weakened in any direction.

A particularly favourable arrangement is produced if the groups of diamond-shaped openings form six-pointed symmetrical stars. Then between each two adjacent starshaped groups there can lie an additional diamond-shaped opening, or between three adjacent star-shaped groups there can lie a hexagonal opening.

There have been doubts hitherto against the employment of diamond-shaped hair entry openings, which apparently have been based on the fact that thought has only been of an arrangement with the principal diagonals lying parallel. Thorough research has however shown that, with the diamond arrangement according to the invention, with consideration of the known rules for the dimensioning of hair entry openings, the diamond-shaped openings can be made so large that on the one hand no abnormal irritation of the skin occurs, but on the other hand long beared hairs, even with very irregular beard growth, can be excellently grasped, while at the same time both a very large opening ratio can be chosen and with it a very good shaving performance can be achieved, because the network produced by the bars between the hair entry openings, in which at the junctions up to six bars meet, permits the bars to be chosen especially narrow, without the strength of the foil suffering by it.

The invention will now be explained in more detail with reference to the drawings which have been kept schematic. FIGURE 1 shows the group of hair entry openings in the form of a six-pointed symmetrical star which is preferably employed within the scope of the invention, while FIGURES 2, 3 and 4 show various possibilities of arranging such star-shaped groups in relation to one another. FIGURE 5 shows an arrangement of hexagonal groups alongside one another according to another way of carrying out the invention.

The group of hair entry openings shown in FIGURE l consists of six openings 1 of diamond shape, in which the adjacent sides of the diamond-shaped openings make angles with one another of 60 and 120 respectively. Six openings 1 of this kind are assembled into a symmetrical six-pointed star, While `between the openings there only remain narrow bars 2 and six of such bars which extend in three directions displaced angularly from one another by l20 meet at junctions 3. Some corners of the diamond-shaped hair entry openings, preferably the acute corners 4, can be rounded.

In FIGURES 2 to 4 there are shown schematic portions of cutter foils, in which star-shaped groups according to FIGURE 1 are assembled in various network arrangements. The individual star groups are shaded to permit clearer identification.

In the arrangement according lto FIGURE 2 there lie between each two star-shaped groups 5 additional diamond-shaped openings 6, while in the arrangement according to FIGURE 3 between each three adjacent starshaped groups 5 there are openings 7 in the form of regular hexagons.

The arrangement according to FIGURE 4 is similar to that according to FIGURE 3, except that in this case the hexagonal openings are divided by three bars angularly displaced from one another by into diamond-shaped openings of the same size as the openings 1.

In the arrangement according -to FIGURE 5 the individual groups are hexagonal, and inside each hexagon boundary there lie twelve diamond-shaped openings 1, of which each four have the same direction of the principal diagonal, While the result is three directions of principal diagonal, which are angularly displaced from one another by 120.

It can be seen that, in each of the examples of construction shown, the principal diagonals of the diamondshaped hair entry openings extend in three directions which are angularly displaced from one another by 120, and that the bars between these openings are also angularly displaced from one another by 120. Thus in all 3 directions a good grasping of the beard hairs is ensured, and furthermore an adequate strength in all directions is maintained. Over and above the arrangements of openings shown, the diamonds with angles of 60 and 120 respectively also permit numerous other groupings, and assemblies of groups into networks.

We claim:

1. Perforated cutter foil for dry Shavers, comprising a plurality of diamond-shaped hair entry openings, the adiacent sides of each of said diamond-shaped hair entry openings making angles with one another of 60 degrees and 120 degrees respectively, and the .totality of the openings constituting a network which contains groups of at least three diamond-shaped openings abutting at a common apex, in which groups the principal and longer diagonals of the openings extend in three different directions which make angles of 60 degrees with each other.

2. Perforated cutter foil according to claim 1 in which the network contains groups of six diamond-shaped openings abutting at a common apex to form a six-pointed symmetrical star.

3. Perforated cutter foil according to claim 1 in which the network contains groups of three diamond-shaped openings abutting at a common apex to form an equilateral hexagon.

4. Perforated cutter foil according to claim 1 in which the network contains groups of six diamond-shaped openings abutting at a common apex to form a six-pointed symmetrical star, each of said groups of openings having two apices in common with a similar adjacent group of openings, while between two adjacent groups there is an additional diamond-shaped opening.

5. Perforated cutter foil according to claim 1 in which the network contains two types of groups of openings, of which one group is six diamond-shaped openings which abut at a common apex to form a six-pointed symmetrical star and a group of three diamond-shaped openings abut at a common apex to form an equilateral hexagon, each group of openings having one apex in common with a similar adjacent group of openings.

References Cited UNITED STATES PATENTS 2,183,442 12/1939 Blackwell 30--346.51 X 2,198,833 4/ 1940 Muros 30--346.51 X 2,223,156 11/1940 Benner 30a-346.51 X 2,289,323 7/1942 Dettle 'S0-346.51 X 2,292,858 8/1942 Alexay Sti-346.51 X 2,360,785 10/1944 Mehl 30-346.51 X 2,573,758 11/1951 Bailey .3G-346.51 X 2,824,367 2/1958 McWilliams 30-4-1.5 3,093,899 6/ 1963 Futterer E50-346.51 X

FOREIGN PATENTS 663,487 8/ i938 Germany. 64,863 5/ 1942 Norway.

) MYRON C. KRUSE, Primary Examiner.

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