KR100433159B1 - Oval frame razor - Google Patents

Abstract

The shaver blade unit for a safety shaver has an optimal shape and dimensions for shaving the body, especially the underarm area. Such a blade unit includes an elongated blade with a straight, sharp edge, and a skin-contacting surface having a length of 1 to 4 times and a width of 60 mm or less, preferably 40 to 45 mm. Wherein the skin contact surface comprises a footprint area of at least 450 mm 2, preferably 600 to 750 mm 2, and a roundness of 65% or more, and having a corner radius of 30% of the width and an overall width and length equal to the skin- ≪ / RTI > In a plane perpendicular to the blade edge, the skin contact surface should be convex and formed to have at least three point contacts with an imaginary circle with a radius of 15 to 70 mm, preferably 25 mm. At the front and rear of the blade edge, the protective surface and the cap surface include a skin contact area of at least 140 mm < 2 >, the combined area of which is at least 400 mm < 2 >, preferably 450 to 500 mm & The preferred form is a rectangle with a semicircular end.

Description

Oval frame razor

Recently, shaver blade units have a tendency to reduce the size, especially the surface area in contact with the skin around the blades during shaving, and the majority of blade units currently on the market are in the direction perpendicular to the skin contact surface It takes a long, narrow shape of almost rectangular shape. Generally, shaver blade units of this size and shape are known to provide enhanced shaving performance over earlier large blade units.

The present invention focuses on blade units for body shaving, especially for shaving in the underarm area. In the current market, female shavers for underarm shaving are commonly used, and most shavers have a strong desire to take the form of a narrow rectangle as described above, as well as other shavers, for a female shavers blade unit. In the art, such a blade unit of such a small size is accepted as good because it is easily inserted into the recessed and deep socket of the side.

The present invention relates to a safety razor having a blade unit carried by a handle, said blade unit comprising an elongated blade with a straight, sharp edge, or a plurality of blades with a parallel edge. The blade unit is fixedly mounted on a handle on which the entire razor is to be discarded when the blade edge becomes dull. Optionally, the blade unit can be releasably connected to the handle so that the used blade unit can be replaced with a new blade unit. Replaceable blade units are commonly referred to as " cartridges ".

1 to 9 are schematic plan views of a razor blade unit according to the present invention.

Figure 10 shows the results for a prior art blade unit and the blade unit of Figures 1 to 9 and is a graph showing the roundness for the aspect ratio (maximum length / maximum width);

Figure 11 is a schematic cross-sectional view of the blade unit of Figure 1;

12 is a view showing a deformed shape of a protective surface and a cap surface of the blade unit of FIG. 1;

Figure 13 is a perspective view of the blade housing of the blade unit shown in Figure 1;

Figure 14 is a partial perspective view of the blade unit shown in Figure 1 with a protective surface and a cap surface similar to the embodiment of Figure 13;

Figures 15 and 16 correspond to Figure 14, showing a blade unit with two to three front facing blades.

The present invention begins with this conventional thinking and questions all the recent developments in the field of blade unit dimensions. Surprisingly, the shaving test, unlike what we had foreseen, not only allows the large blade unit to provide the same effect as the shaving effect of a small conventional blade unit, but also allows the large blade unit to conform to the underarm area of the body The shaving performance is not reduced, and it is found that the performance is superior to the conventional blade unit and satisfies the user when viewed from the viewpoint of overall stability. The increase in the stability obtained by widening the contact area with the skin provides a considerable degree of confidence in the shaving of the armpit, which can not be easily seen in the shaving process. As a result, it has been recognized that the comfort is improved by the user, It has been found that it does not cause any deterioration in performance.

For most women, the underarm cavity has a minimum radius of curvature of about 25 to 30 mm. Therefore, the razor blade unit according to the present invention has a length of 60 mm or less, preferably 50 mm or less, more preferably 40 mm to 45 mm. It is preferable that the width of the blade unit is selected such that the aspect ratio, that is, the ratio of the total length to the entire width measured perpendicular to the blade falls within the range of 1 to 4, and in the preferred embodiment of the present invention , The ratio is from 1.5 to 2.8, and the precision range is from 2.0 to 2.5. In a preferred embodiment, the width of the blade unit is from 12 mm to 23 mm, preferably from 15 mm to 20 mm. The protective surface and the cap surface are formed in front of and behind the blade for contact with the skin in front of or behind the blade during shaving, and each protective surface and cap surface has a width of 4 mm or less when the width of the blade unit is maximum. The protective surface and the cap surface have a skin surface area of 140 mm 2 or less, and the combined skin surface area of the cap surface and the protection surface is at least 400 mm 2, most of which is 450 mm 2 to 500 mm 2. Since the blade unit of the present invention is large in order to promote contact with the skin in the armpit in most of the protection area and the cap area, the skin contact surface becomes convex. The term " convex " as used in the present invention means that the skin contact surface is gently curved, which extends upward in a direction away from the edge where the protective surface and cap surface are spaced from the blade, It is at a level above the spaced edges of the surface. In particular, the straight line connecting the inner and outer limit points of each protective surface and cap surface is inclined by at least 5 [deg.] And at most 25 [deg.] Relative to the plane contacting the skin contact surface immediately in front of the blade. In a preferred embodiment, the angle of inclination is between 10 ° and 20 °, preferably between 15 °. Due to the convexity of the skin contact surface, the blade unit is manufactured to have an imaginary circle with a diameter of 30 mm to 100 mm, preferably 50 mm, and at least three contact points so that the convexity of the blade unit has a shape at least similar to the shape of the armpit .

An important feature of the blade unit according to the invention is that the area of contact with the skin during shaving is broad and the circumference extending around the skin contact surface defines an area referred to below as a " footprint area " It is. The best footprint area is 600 mm2 to 750 mm2, preferably 650 mm2 to 720 mm2.

Because the present invention proposes a blade unit of a long and wide type, at least edges of the rectangular shape at the edge adjacent to the protective surface are inadequate. In the present invention, the angle of the edge is about 120 DEG or less, and the radius of curvature of the edge is 3 mm. The radius of curvature at the corners is preferably at least 5 mm. The purpose of providing a large area of skin contact and the inability of a rectangle to be in the form of a shape to obtain a relatively large area within the limits of the overall length and width dimension when viewed in a plane perpendicular to the skin contact area . The "circularity" of a two-dimensional shape is obtained by obtaining the area enclosed by the circumference of the circumference of the circumference and expressing it as a ratio compared to a circle providing the maximum area for a given circumference length . Thus, the circle form for a given shape is given by:

Where A is the area and P is the circumference. In the shaver blade unit according to the present invention, the lower limit value (a) for the circular formation is 65%, the limit value (b) for the circular formation has the same length and width as the width and length of the skin contact region, Lt; RTI ID = 0.0 > a < / RTI > The circular formation according to the present invention is larger than a rectangular circular formation with rounded corners having the same overall length and width and a radius equal to 10% of the length. For a blade unit having an aspect ratio of 3 or less, the lower limit value (a) will be applied, although it is preferable that the circle formation exceeds the limit value b.

An elliptical blade unit having an aspect ratio of 3.25 or more has a roundness of 65% or less. Preferred embodiments having a longitudinal aspect ratio of 2.75 or less have a roundness of 70% or more, preferably 80%. A typical conventional blade unit has a roundness of 65% or less. A blade unit having a relatively large circular formation according to the present invention has rounded corners at the end of a blade unit having a relatively large radius of curvature of at least 6 mm or takes an oval or polygonal shape that does not require symmetry.

As described above, the present invention provides a method of manufacturing a blade having at least one elongated blade mounted on a carrier that is not rigid and having a rectangular shape, and a skin contact surface surrounding the blade edge and including a protective surface and a cap surface on opposite sides of the blade edge Wherein a length-to-length ratio of the length to the skin contact surface is in the range of 1 to 4 when viewed in a plane perpendicular to the edge of the blade, the skin contact surface is convex and the skin contact surface is convex, The total length is 60 mm or less and the skin contact surface has a circumference limited to a footprint region of at least 450 mm 2, and the circumference is formed such that the footprint region defined by the circumference has a circle formation of 65% or more, Has the same length and width as the skin contact area and has a corner half of 30% of the width Preferably, the edge at the edge of the blade unit adjacent to the protective surface is formed at an obtuse angle rather than an acute angle.

The shaver with the blade unit described above has proven to have significantly improved shaving performance in the armpit and has proven to be highly effective in shaving other parts of the legs and the like.

It should be noted that all dimensions and areas mentioned are measured in the projected plane and that the effect of the convex radius of curvature of the skin contact surface of the blade unit when viewed in plan view is not taken into account in determining the associated dimensional data.

Best Mode for Carrying Out the Invention Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Each of the blade units shown in Figs. 1-9 includes a blade housing that utilizes an inflexible blade carrier frame that is molded from a plastic material. The housing defines a skin contact area surrounding an elongated rectangular opening 2 to which a blade with a sharp, rectangular edge (not shown in FIGS. 1-9) is mounted. Although a single blade is provided, two or more blades having parallel and sharp edges may also be mounted in the aperture 2. [ In the embodiment shown in Figure 14, three blades are provided, one facing the other and the other facing back, so that the shaver blade unit will provide a very good result, It will provide a two-way shave. FIG. 15 shows an embodiment in which two blades are connected in series, and FIG. 16 shows another embodiment in which all the edges have three blades parallel to the forward direction. Each of the blade units of FIGS. 1-9 accommodates two or three blades, which are mounted as shown in FIG. 14 or both are connected in series. The blade housing in each of the embodiments shown in Figures 1 to 9 comprises a protective region 3 located behind (downward in the figure) a blade opening and a rear region (upward in the figure) of the blade opening 2, And a cap region (4).

The blade unit of Fig. 1 is elliptical with a semicircular end. The dimensions measured in the protruded plane are as follows.

The blade unit of Fig. 2 is a rectangular shape having corners of a large radius of curvature. The respective dimensions for this embodiment are as follows.

Figure 3 shows an asymmetric blade unit. At the end of the front edge of the blade unit housing, there is a rounded corner with a large radius as shown in FIG. 2, and the edge at the end of the rear edge is rounded to a greater extent than the radius of curvature. The dimensions are as follows.

4 to 6 show a blade unit having a housing having the same size and elliptical shape as the one shown in Fig. 1 but having different blade opening positions. 4, the opening is located so that the cap region is the same as the cap region, but in FIG. 5 the cap region is positioned to be smaller than the cap region (but at least 140 mm2) (But at least 140 mm2).

7 shows a rectangular polygonal blade unit with edges 7 rounded at 135 degrees to the longitudinal front and rear sides and to the ends. In the case of a blade unit having an overall length of 42 mm and an overall width of 18 mm, the chamfer is 5 mm x 5 mm and is formed along the diagonal line.

All embodiments of Figures 1 to 7 have straight front and rear edge portions, at least a majority of the blade length being parallel to the blade edge. This facilitates the orientation of the blade unit and helps the user to recognize the direction in which the blade unit is moving over the skin. However, this is not a basic one, and the criteria for the size of the blade unit using the present invention may be obtained in other forms. For example, FIG. 8 shows a blade unit whose outer periphery is elliptical, and is not the most preferred embodiment, but the circle shown in FIG. 9 is also possible.

FIG. 10 is a graph showing the aspect ratio, that is, the circular formation of the maximum length / maximum width of the blade unit. 1 to 9 are shown as (1) to (9), and three conventional female shaving blade units currently in commercial use are shown as A, B and C, The square is shown as S. The line Rw, which traverses the diagonal line of the graph, represents a rectangle with a corner radius of 30% of the rectangular width. The dotted line R _L represents a rectangle with a corner radius of 10% of the rectangular length. The horizontal line represents 65% circle formation. It can be seen that all embodiments of the invention shown on the graph have aspect ratios of 1.5 to 2.8 and most aspect ratios fall in the range of 2.0 to 2.5. Also, embodiments of the present invention are capable of forming a larger circle than a corresponding rectangular shape having a 10% radius of the rectangular length Rw or a 30% radius of the rectangular width Rw at the same aspect ratio . In addition, it can be seen that embodiments of the present invention have larger roundness than conventional blade units, and that all included in the graph have a value of at least 60%, in particular at least 70% Two points 8 are shown to show an ellipse.

In all of the embodiments of the present invention, the skin contact surface is not planar and shows the simply protruding planar regions of Figs. 1-9. The surface should be made to form at least four points in contact with an imaginary circle of at least three points, preferably a radius of 25 mm. Fig. 11 shows a good relationship with a blade, which may be, for example, the blade unit of Fig. The imaginary circle is shown by the dotted line, and it can be seen that the cap surface and the protective surface substantially coincide with these circles. In Fig. 11, the protective surface and the cap surface are basically flat, but can be convexly curved to provide a more tightened integrity, as schematically shown in Fig. In the illustrated embodiment, the cap surface and the protective surface are inclined at an angle of 15 degrees with respect to the plane P, which is a plane view, which is in contact with the skin contact surface immediately before and behind the blade. In a particular embodiment, the most appropriate tilt angle will be selected accordingly because it depends on the width of the blade unit, and an angle within the range of 10 [deg.] To 20 [deg.] Will be required to ensure close integration with the imaginary circle. As shown in Fig. 12, when the protective surface and the cap surface are convex, the tilt angle of the code line crossing the edge of the surface is considered to be spaced apart from the adjacent blades.

13 shows a blade unit housing of the preferred type. The housing includes a frame 10 defining openings 2 for receiving blades and parts for securing them to the frame. On the frame are mounted guard and cap parts, each of which has an elastomeric surface element 12 defining a skin contact area formed by an array of cylindrical pockets 13 uniformly distributed over the entire surface. For ease of assembly and mounting, the elastomeric element is molded on a support 14 that is securely fastened to the frame 10. Figures 14-16 illustrate a modified structure in which the elastomeric element is directly supported by the frame of the blade unit. This figure also shows the blades 15 inserted into the frame and the retaining clips 16 provided at each end of the blade unit to hold the blades in place.

As described above, all the dimensions, length, width, and areas described in the present invention are based on the shape of the blade unit skin contact surface that is perpendicular to the plane of the plane view, that is, . Further, in the calculation of the circle formation, the irregular surfaces of the circumference due to the small recesses such as narrow notches and protrusions that considerably change the circumference without changing the area should be ignored.

Claims (17)

At least one elongated blade (15) mounted on a non-flexible carrier and having a straight, sharp edge, A skin contact surface surrounding the blade edge and including a protective surface (3) and a cap surface (4) on opposite sides of the blade edge, The length to width aspect ratio to the skin contacting surface is in the range of from 1 to 4 when viewed in cross-section in a plane perpendicular to the blade edge; The skin contact surface is convex and the total length from one end of the blade unit to the other end at the skin contact surface is 60 mm or less; Said skin contact surface having a circumference defined by a footprint region of at least 450 mm < 2 >; Wherein the circumference is formed such that the circle formation of the footprint region defined by the circumference is greater than 65%; The circular formation of the rectangular region has the same length and width as the footprint region of the skin contact region and has a corner radius of 30% of the width; Characterized in that the edge at the edge of the blade unit adjacent to the protective surface (3) is formed at an obtuse angle. The razor blade unit of claim 1, wherein the footprint region comprises an area of 600 mm 2 to 750 mm 2, preferably 650 mm 2 to 720 mm 2. 3. The razor blade unit of claim 2, wherein the length to width aspect ratio ranges from 1.5 to 2.8, preferably from 2.0 to 2.5. 4. A method as claimed in claim 3, characterized in that each protective surface (3) and cap surface (4) has an area of at least 140 mm2 and each protective surface (3) and cap surface (4) Wherein the blade unit has a width of 4.0 mm. 5. A razor blade unit according to claim 4, wherein the total area of the protective surface (3) and the cap surface (4) lies within the range of 400 mm2 to 500 mm2. 6. A method as claimed in claim 5, characterized in that each protective surface (3) and cap surface (4) has a straight line passing through the nearest edge and the farthest away edge from the blade at an angle of at least 5 [ Wherein the blade unit is inclined in a plane contacting the contact surface. The razor blade unit according to claim 6, wherein the skin contact surface is formed so as to have a cross-section with at least three point contacts with an imaginary circle having a radius of 15 mm to 70 mm, preferably 25 mm. 8. The razor blade unit of claim 7, wherein the region defined by the circumference of the skin contacting surface comprises a circle ranging from 70% to 85%. 9. The method of claim 8, wherein the region formed by the circumference of the skin contacting surface has a greater circular formation than the circular formation of the rectangular region; Wherein the circular formation of the rectangular region is circular when the length and width of the rectangular region are the same as the length and width of the skin contact surface and the corner radius of the rectangular region is 10% of the length of the rectangular region. 10. The method of claim 9 wherein the aspect ratio is less than or equal to 3 and the circular formation of the area defined by the circumference of the skin contacting surface is greater than the corner radius of 30% of the width and greater than the rectangular formation having the same overall width and length as the skin contacting surface Wherein the shaver blade unit comprises: 11. The razor blade unit of claim 10, wherein at least one front and rear edge of the blade unit comprises a linear portion extending along and parallel to the blade edge length and a gently curved edge portion located at both ends of the straight portion. . 12. The razor blade unit of claim 11, wherein the blade unit comprises a semicircular end. 11. The razor blade unit of claim 10, wherein the skin contact surface has an elliptical shape. 14. A razor blade unit according to claim 12 or 13, characterized in that the protective surface (3) and the cap surface (4) are formed by an elastomeric element. 15. A razor blade unit according to claim 14, wherein the elastomeric element (12) forms a surface on which the pockets (13) are distributed. 16. The razor blade unit of claim 15, wherein at least two blades having a forward facing edge are mounted to the blade carrier. A plurality of elongated blades (15) permanently mounted spaced apart from the carrier and having sharp edges elongated in the longitudinal direction, a skin contact surface surrounding the sharp blade edges and having a skin contact protective surface (3) and a cap surface ; Wherein the carrier comprises a molding of a plastic material, the protective surface (3) is located in front of the blade unit, the cap surface (4) is located in the rear of the blade unit; The plurality of blades 15 are positioned between a front protective surface 3 and a rear cap surface 4 and include a sharp edge oriented in a direction facing the protective surface 3, (3), a plurality of sharp blade edges, and a cap face (4) in continuous contact with the skin, The aspect ratio defined by the ratio of the length to the width measured perpendicular to the blade 15 is in the range of 1 to 4, The length of the blade unit at the skin contact surface is 60 mm or less, Wherein the skin contact surface defines a footprint region comprising a contact surface by a circumference, the footprint region comprising an area of 450 mm < 2 >; Characterized in that the protective surface (3) has an area of at least 140 mm 2 in the footprint region and occupies 18.6% of the footprint region.