Razor Cartridge

Abstract

The razor cartridge (20) has a housing (30) having a blade mounting area (70) between a guard (40) and a cap (50). First, second, and third razor blades (80, 90, 100) are mounted contiguously in the blade mounting area. An overguard (120) is secured above the blades. The blade edges (82, 92, 102) have a defined high sharpness. The blades are mounted at a reduced angle between the respective blade base portions that support the edges and a reference plane (200) that is tangent to the cutting edges of the first and third blades. Individual longitudinal members (150, 160, 170) of the overguard are above each blade and have heights (H1, H2, H3) that taper above the reference plane in the front-to-rear direction of the razor cartridge. A further longitudinal member (140) is forward of the first blade and has a height above the reference plane.

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE This disclosure relates generally to safety razors and, more particularly, to a razor cartridge having a protective overguard. [Background technology]

[0002] Some shaver users suffer from skin conditions such as pseudofolliculitis barbae (PFB) and acne. These shaver users would like to be able to shave successfully without irritation or aggravating pre-existing conditions. Some other users would rather have a permanent "5 o'clock shadow" look and would like to be able to shave in a way that maintains this look. Summary of the Invention

[0003] It is an object of the present disclosure to substantially alleviate the limitations of prior art razor cartridges by providing a razor cartridge having an overguard. The razor cartridge has a housing having a guard at a front region of the housing, a cap at a rear region of the housing, and opposing end walls connecting the guard and the cap. The housing defines a blade mounting area between the guard and the cap. First, second, and third razor blades are mounted consecutively in the blade mounting area, the first blade being closest to the guard, and each razor blade has a cutting edge. A reference plane is tangential to the cutting edge of the first razor blade and the cutting edge of the third razor blade, and each blade body portion supporting the cutting edge is at an angle relative to the reference plane. The overguard is secured above the blades and includes a first longitudinal member forward of the first blade and second, third, and fourth longitudinal members above the first, second, and third razor blades, respectively. Each of the first, second, third and fourth longitudinal members has a respective height above a reference plane.

[0004] In some embodiments, the overguard has a slot extending in the front-to-rear direction in the first, second, and third longitudinal members. In some embodiments of this embodiment, the slot is aligned with the front-to-rear direction of the razor cartridge. In other embodiments, the slot can be omitted.

[0005] In some embodiments, the overguard further includes a front-to-rear cross rib extending from the first longitudinal member to the fourth longitudinal member.

[0006] In some embodiments, the cutting edge of each razor blade has a cutting force sharpness, as defined herein, in the range of about 5-6.5 N.

[0007] In some embodiments, the angle between the portion of the blade body that supports the cutting edge and the reference surface is 20.5 degrees.

[0008] In some embodiments, the height of the second, third, and fourth longitudinal members above the reference plane tapers in the front-to-rear direction of the razor cartridge. In some embodiments, the height of the second longitudinal member above the reference plane is in the range of about 0.287 to 0.212 mm. The height of the third longitudinal member above the reference plane is in the range of about 0.150 to 0.129 mm. The height of the fourth longitudinal member above the reference plane is about 0.039 mm. The height of the first longitudinal member above the reference plane is the same as the height of the second longitudinal member above the reference plane (200).

[0009] A razor cartridge used in the prescribed manner does not provide a typically close shave, but does provide sufficient comfort. The above features and advantages will be more fully understood by reference to the following detailed description when considered in conjunction with the accompanying drawings. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a top perspective view of a razor cartridge of the present disclosure; [Diagram 2] FIG. [Diagram 3] A detailed portion of FIG. [Figure 4] FIG. 13 is a perspective view of another overguard of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Referring now to the drawings, and in particular to FIG. 1, a razor cartridge 20 is shown. The cartridge 20 has a housing 30 with a guard 40 at a front region of the housing 30 and a cap 50 at a rear region of the housing 30. The guard 40 may optionally include skin-engaging fins, e.g., elastomeric fins, as shown. In the context of this disclosure, the terms front, forward, leading, etc., and rear, trailing, etc., are used with respect to the direction of movement of the razor cartridge 20 during use. The term longitudinal is used with respect to the direction of extension 32 of the housing. The housing has opposed end walls 60 connecting the guard 40 and the cap 50. The housing defines a blade attachment area 70 (see FIG. 2) between the guard 40 and the cap 50. A first razor blade 80 closest to the guard 40, a second trailing razor blade 90, and a third rearmost razor blade 100 are attached to the blade attachment area 70. Each razor blade 80, 90, 100 has a respective cutting edge 82, 92, 102 (see Figures 2 and 3). Although the cartridge 20 of the present disclosure is described as having three razor blades 80, 90, 100 attached thereto, this number should not be limited and fewer (e.g., two) or more (e.g., four, five, etc.) razor blades can be usefully used. An overguard 120, which is a separate component of the cartridge 20 assembly, is positioned above the blades 80, 90, 100. A retainer 130, e.g., one or more aluminum clips, is formed around the housing 30 to retain the blades 80, 90, 100 and overguard 120 to the housing 30. In the embodiment shown in Figure 1, certain elements of the overguard 120 include hair-alignment slots 122 on the skin-engaging surface. The slots 122 can be 0.8 mm wide, 0.52 mm deep, and 1.6 mm pitch. The slots 122 may be located or offset in the front-to-rear direction of the cartridge 20 .

[0012] The housing 30 is manufactured by injection molding a suitable thermoplastic polymer. For example, the housing 30 may be formed from ABS (acrylonitrile butadiene styrene) for its chemical resistance (to commonly used substances), impact resistance, and dimensional stability.

[0013] The overguard is manufactured from a material with a tensile modulus of 1.4-210 GPa. For example, the overguard 120 can be injection molded from ABS or POM. The overguard 120 can be a die cast zinc alloy. The overguard 120 can be, for example, a punch tool formed (stainless) steel or a particulate stainless steel that is sintered to provide a solid body.

[0014] 2, a cross section of the cartridge 20 is shown. The overguard 120 for the three-blade cartridge 20 essentially comprises four longitudinally extending members. A first member 140 is in front of the first blade 80 and has legs 142 which provide a structural (rigidity) advantage. Members 150, 160, 170 are above the three blades 80, 90, 100, respectively, and have respective legs 152, 162, 172 which provide a structural (rigidity) advantage. Returning to FIG. 1, the overguard 120 comprises front and rear cross ribs 180 which extend from members 140 to members 170 for additional structural stability advantages.

[0015] In Figure 4, an alternative overguard 120 is shown, in which the slots 122 of Figure 1 have been omitted. In Figure 4, it can be seen that all four longitudinally extending members are interconnected at opposing extending ends of the overguard 120.

[0016] Referring now to Figure 3, a detailed portion of Figure 2 is shown. The reference plane 200 is tangent to the cutting edge 82, 102 of the first and last (e.g., third) blade 80, 100. The reference plane 200 may also be tangent to the cutting edge 92 of the other (e.g., second) blade 90, particularly in embodiments where the razor cartridge has two blades. Each cutting edge is spaced apart by a span S1, S2 equal to 2.72 mm, a span dimension along the reference plane 200. Each cutting edge 82, 92, 102 is spaced apart from the immediately adjacent forward longitudinal member 140, 150, 160, respectively, by a distance 202, 212, 222 in the range of 0.8-0.9 mm. The distances 202, 212, 222 are measured from the respective cutting edge to the next forward skin-engaging contact point of the overguard 120. The longitudinal members 150, 160, 170 each have a height H1, H2, H3 from their respective upper skin-engaging surfaces to the reference plane 200. The first longitudinal member 140 has a height from the upper skin-engaging surface to the reference plane 200 that is equal to the height H1. Each of the blades 80, 90, 100 is positioned such that the blade body portion bearing the cutting edge is at an angle A having a value of about 20.5 degrees (e.g., in the range of 19 to 21.5 degrees) with respect to the reference plane 200. The angle A can be defined between the reference plane 200 and one (i.e., upper or lower) outer surface of the blade body portion, or between the reference plane 200 and a notional center plane of the blade body portion (as shown). This value is slightly less than the angle found in many typical modern wet shaving cartridges, which may be in the range of 22-28 degrees, and has been found to be beneficial when used in the present device in combination with a cutting edge of high sharpness, as described below.

[0017] The cutting edges 82, 92, 102 of the blades 80, 90, 100 may have conventional sharpness, i.e., about 7 to 14 N, as generally found in a typical modern wet shaving cartridge, as described below, with a median value of about 10-10.5 N, as measured in a cutting force test. More preferably, the blades have a high sharpness, e.g., about 5-6.5 N. In the cutting force test, the blades make 15 cuts perpendicularly (to the media being cut) through a 0.9 mm thick, 25.4 mm wide, fully water saturated WHATMAN cellulose chromatography paper. The cutting speed is 15 mm / min, and the cutting depth into the paper is 0.8 mm. The cutting forces for the above sharpnesses are the average plateau forces for cut numbers 7 to 9.

[0018] In the experimental setup, cartridges having the following heights H1, H2, H3 were evaluated. (table) TIFF2024510214000002.tif26141

[0019] The values ​​of H1, H2, and H3 decrease progressively from front to back in the cartridge. In controlled shaving tests, applicants of the present disclosure have found that the combination of a "sharper" cutting edge, along with a "reduced" blade body angle relative to the reference plane, along with a larger overguard longitudinal member height above the reference plane (e.g., in Examples 2 and 1) provides benefits to those suffering from PFB and allows the user to control beard length trimming for the purpose of a permanent "5 o'clock shadow" appearance.

[0020] Although various embodiments have been described above, it should be understood that they are presented by way of example only and are not limiting. For example, modifications or variations that can be made within the scope of the claims and features disclosed in connection with any one embodiment can be used alone or in combination with each feature of the other respective embodiments. Thus, the breadth and scope of any embodiment should not be limited by any of the exemplary embodiments described above, but should be defined only by the following claims and their equivalents. [Explanation of symbols]

[0021] 30 Housing 40 Guard 50 Cap 60 End wall 70 Blade attachment area 82 Cutting Edge 92 Cutting Edge 102 Cutting Edge 80 First Razor Blade 90 Second Razor Blade 100 Third Razor Blade 120 Overguard 140 First longitudinal member 150 second longitudinal member 160 third longitudinal member 170 fourth longitudinal member 200 Reference plane

Claims

1. 1. A razor cartridge comprising: a housing (30) having a guard (40) at a front region, a cap (50) at a rear region, and opposing end walls (60) connecting said guard (40) and said cap (50), said housing (30) defining a blade mounting region (70) between said guard (40) and said cap (50); a first razor blade (80) closest to said guard (40), a next adjacent second razor blade (90), and a final third razor blade (100), each having a respective cutting edge (82, 92, 102) having a sharpness as defined herein; a reference plane (200) that is tangential to the cutting edge (82) of the first razor blade (80) and the cutting edge (102) of the third razor blade (100), each of the blade body portions bearing the cutting edges (80, 90, 100) being at an angle (A) to the reference plane (200); an overguard (120) secured above said razor blades (80, 90, 100) and attached to said blade attachment area (70), said overguard (120) including a first longitudinal member (140) forward of said first razor blade (80), and second, third and fourth longitudinal members (150, 160, 170) above said razor blades (80, 90, 100); Equipped with The razor cartridge wherein each of said second, third, and fourth longitudinal members (150, 160, 170) has a respective height (H1, H2, H3) above said reference plane (200).

2. 2. The razor cartridge (20) of claim 1, wherein said overguard (120) has a slot (122) extending in a front-to-rear direction in said first, second and third longitudinal members (140, 150, 160).

3. 3. The razor cartridge (20) of claim 1 or 2, wherein said overguard (120) further comprises front-to-rear cross ribs (180) extending from said first longitudinal member (140) to said fourth longitudinal member (170).

4. The razor cartridge (20) of any of claims 1 to 3, wherein the cutting edge (82, 92, 102) of each of the razor blades (80, 90, 100) has a cutting force sharpness, as defined herein, in the range of about 5-6.5 N.

5. 5. The razor cartridge (20) of any of claims 1 to 4, wherein said angle (A) is approximately 20.5 degrees.

6. 6. The razor cartridge (20) of any of claims 1 to 5, wherein the height (H1, H2, H3) of the longitudinal members (150, 160, 170) above the reference plane (200) gradually decreases in a front-to-rear direction of the razor cartridge (200).

7. 7. The razor cartridge (20) of any of claims 1-6, wherein said height (H1) of said second longitudinal member (150) above said reference plane (200) is within a range of approximately 0.287 to 0.212 mm.

8. 8. The razor cartridge (20) of any of claims 1-7, wherein said height (H2) of said third longitudinal member (160) above said reference plane (200) is within a range of approximately 0.150 to 0.129 mm.

9. 9. The razor cartridge (20) of any of claims 1-8, wherein the height (H3) of the fourth longitudinal member (170) above the reference plane (200) is approximately 0.039 mm.

10. 10. The razor cartridge (20) of any of claims 1 to 9, wherein the height (H0) of the first longitudinal member (140) above the reference plane (200) is the same as the height (H1) of the second longitudinal member (150) above the reference plane (200).

11. The razor cartridge (20) of any of claims 1-10, wherein said overguard (120) is a separate component.

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