razor cartridge

Abstract

A shaving razor cartridge (20) has a housing (30) with a blade mounting area (70) between a guard (40) and a cap (50). First, second and third shaving razor blades (80, 90, 100) are mounted in the blade mounting area in sequence. An upper guard (129) is secured over the blades. The cutting edges (82, 92, 102) of the blades have defined increased sharpness. The blades are mounted at a reduced angle A between each blade portion that supports the cutting edge and a reference plane (200) that is tangential to the cutting edges of the first and third blades. Single longitudinal members (150, 160, 170) of the upper guard are positioned over each blade and have heights H1, H2, H3 that progressively decrease in a front-to-back direction of the shaving razor cartridge above the reference plane. Another longitudinal member (140) is positioned forward of the first blade and has a height H0 above the reference plane.

Description

Technical Field

[0001] This disclosure generally relates to safety razors, and more specifically, to razor blade holders with protective upper guards. Background Technology

[0002] Some razor users suffer from skin conditions such as pseudofolliculitis of the beard (PFB) and acne. These users want to be able to shave successfully without irritating or worsening their existing conditions. Some other users prefer the look of a permanent "5 o'clock shadow" and want to be able to shave to maintain that look. Summary of the Invention

[0003] The purpose of this disclosure is to substantially alleviate the limitations of prior art razor blade holders by providing a razor blade holder with an upper guard. The razor blade holder has a housing having a guard in a front region, a cover in a rear region, and opposing end walls connecting the guard and the cover. The housing defines a blade mounting area between the guard and the cover. First, second, and third razor blades are sequentially mounted in the blade mounting area, with the first blade closest to the guard, and each razor blade has a cutting edge. A reference plane is tangent to the cutting edges of the first and third razor blades, and the blade body portions supporting the cutting edges are each angled to the reference plane. The upper guard is fixed above the blades and includes a first longitudinal member located in front of the first blade, and second, third, and fourth longitudinal members respectively positioned above the first, second, and third razor blades. Each of the first, second, third, and fourth longitudinal members has a corresponding height above the reference plane.

[0004] In some aspects, the upper guard has front-to-back extending slots in the first, second, and third longitudinal members. In some aspects, the slots are aligned in the front-to-back direction of the razor blade holder. In other aspects, these slots may be omitted.

[0005] In some respects, the upper protective member further has front and rear transverse ribs extending from the first longitudinal member to the fourth longitudinal member.

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

[0007] In some respects, the angle between the blade body portion supporting the cutting edge and the reference plane is 20.5 degrees.

[0008] In some respects, the heights of the second, third, and fourth longitudinal members above the reference plane gradually decrease in the longitudinal direction of the razor blade holder. In some respects, the height of the second longitudinal member above the reference plane is in the range of approximately 0.287 to 0.212 mm. The height of the third longitudinal member above the reference plane is in the range of approximately 0.150 to 0.129 mm. The height of the fourth longitudinal member above the reference plane is approximately 0.039 mm. The height of the first longitudinal member above the reference plane is equal to the height of the second longitudinal member above the reference plane (200).

[0009] Using the razor blade holder in the defined manner will not provide a typical "close" shave, but will offer sufficient comfort. The above features and advantages will be more fully understood when the accompanying drawings are consulted with reference to the detailed description below. Attached Figure Description

[0010] Figure 1 This is a top perspective view of the razor blade holder disclosed herein;

[0011] Figure 2 This is a cross-sectional view of the blade holder;

[0012] Figure 3 for Figure 2 The detailed parts; and

[0013] Figure 4 This is a perspective view of another upper protective component of the present invention. Detailed Implementation

[0014] Now refer to the attached diagram, especially Figure 1 The image depicts a razor blade holder 20. The blade holder 20 has a housing 30 having a guard 40 in a front region and a cover 50 in a rear region of the housing 30. The guard 40 may optionally be provided with skin-engaging fins, such as elastomeric fins, as shown. In the context of this disclosure, the terms front, forward, leading edge, etc., and rear, tail, trailing edge, etc., are used relative to the direction of movement of the razor blade holder 20 in use. The term "longitudinal" is used relative to the elongation direction 32 of the housing. The housing has opposing end walls 60 connecting the guard 40 and the cover 50. The housing defines a blade mounting area 70 between the guard 40 and the cover 50 (see...). Figure 2 The first razor blade 80 closest to the guard 40, the second razor blade 90 following it, and the third razor blade 100 are mounted in the blade mounting area 70. Each razor blade 80, 90, 100 has a corresponding cutting edge 82, 92, 102 (see...). Figure 2 and 3Three razor blades 80, 90, and 100 are described as being mounted in the blade holder 20 of this disclosure; however, this number should not be limiting, and fewer (e.g., two) or more (e.g., four, five, etc.) razor blades can be effectively used. An upper guard 120, a separate component of the blade holder 20, is located above the blades 80, 90, and 100. A retainer 130, such as one or more aluminum clips, is formed around the housing 30 to retain the blades 80, 90, and 100 and the upper guard 120 to the housing 30. Figure 1 In the illustrated embodiment, certain elements of the upper protective member 120 are provided with hair alignment slots 122 on the skin-contacting surface. The slots 122 may have a width of 0.8 mm, a depth of 0.52 mm, and a spacing of 1.6 mm. The slots 122 may be aligned in the front-rear direction of the blade holder 20, or they may be staggered.

[0015] The housing 30 is manufactured by injection molding with a suitable thermoplastic polymer. For example, the housing 30 may be formed from ABS (acrylonitrile-butadiene-styrene) to improve chemical resistance (to substances commonly found in use), impact resistance, and dimensional stability.

[0016] The upper protective element is made of a material with a tensile modulus of 1.4 - 210 GPa. For example, the upper protective element 120 can be injection-molded ABS or POM. The upper protective element 120 can be die-cast zinc alloy. The upper protective element 120 can be (stainless) steel, for example, formed in a perforation tool, or it can be granular stainless steel sintered to provide a solid body.

[0017] For reference Figure 2 The image depicts a transverse sectional view of the blade holder 20. The upper guard 120 of the blade holder 20 for three blades essentially comprises four longitudinally extending longitudinal members. A first longitudinal member 140 is positioned in front of the first blade 80 and has a leg 142 providing structural (stiffness) benefits. Longitudinal members 150, 160, and 170 are positioned above the three blades 80, 90, and 100, respectively, and each has its own leg 152, 162, and 172, also for structural (stiffness) benefits. (See again...) Figure 1 The upper protective member 120 is provided with a transverse rib 180 from front to back, which extends from the longitudinal member 140 to the longitudinal member 170 to obtain further structural stability benefits.

[0018] Figure 4 Another upper protective element 120 is depicted, but details are omitted. Figure 1 The slot 122 in the figure. As can be seen in the figure, all four longitudinally extending longitudinal members are connected to each other at opposite elongated ends of the upper guard 120.

[0019] For reference Figure 3 It depicts Figure 2 The detailed section describes the process. Reference plane 200 is tangent to the cutting edges 82 and 102 of the first and last (e.g., third) blades 80 and 100. Plane 200 may also be tangent to the cutting edge 92 of another (e.g., second) blade 90, particularly in embodiments where the razor blade holder has two blades. The blade cutting edges are spaced along plane 200 by spans S1 and S2 equal to 2.72 mm. Each blade cutting edge 82, 92, and 102 is spaced from its respective adjacent front longitudinal members 140, 150, and 160 by distances 202, 212, and 222, respectively, within the range of 0.8-0.9 mm. Distances 202, 212, and 222 are measured from the respective cutting edge to the next skin-engagement tangent point in front of the upper guard 120. The longitudinal members 150, 160, and 170 have heights H1, H2, and H3 from their respective upper skin-engagement surfaces to reference plane 200. The height of the first longitudinal member 140 from the upper skin engagement surface to the reference plane 200 is equal to the height H1. Blades 80, 90, and 100 are each positioned such that the blade body portion supporting the cutting edge forms an angle A relative to the reference plane 200, which has a value of approximately 20.5 degrees (e.g., in the range of 19 to 21.5 degrees). 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 it can be defined (as shown) between the reference plane 200 and an imaginary central plane of the blade body portion. This value is slightly lower than the angle found in many typical modern wet razor blade holders (which can be in the range of 22-28 degrees) and has been found advantageous when used in this device with blades having a cutting edge that increases sharpness, as described below.

[0020] The cutting edges 82, 92, and 102 of blades 80, 90, and 100 can have a conventional sharpness, as is common in typical modern wet razor blade holders, approximately 7-14 N, with a median of approximately 10-10.5 N measured in cutting force tests, as described below. More preferably, the blades have increased sharpness, for example, approximately 5-6.5 N. In the cutting force test, the blade is perpendicularly cut (relative to the medium being cut) 15 times into fully water-saturated WHATMAN cellulose chromatography paper, 0.9 mm thick and 25.4 mm wide. The cutting speed is 15 mm / min, and the depth of cut into the paper is 0.8 mm. The aforementioned sharpness cutting force is the average plateau force from cut #7 to cut #9.

[0021] In the experimental setup, blade holders with the following heights were evaluated: H1, H2, and H3.

[0022] H1 (mm) H2 (mm) H3 (mm) Example 1 0.287 0.212 0.116 Example 2 0.150 0.129 0.069 Example 3 0.039 0.039 0.037

[0023] The values ​​of H1, H2, and H3 gradually decrease in the direction from front to back of the blade holder. In controlled shaving tests, the applicant of this disclosure has found that the combination of a “sharper” blade cutting edge, a “reduced” angle between the blade body and the reference plane, and a larger longitudinal member height of the upper guard above the reference plane (e.g., Examples 2 and 1) provides benefits to PFB patients and also provides users with a controlled beard length trimming that gives them a permanent “5 o’clock shaved” appearance.

[0024] Although various embodiments have been described above, it should be understood that these embodiments are illustrative only and not limiting. For example, modifications or changes may be made within the scope of the appended claims, and features disclosed in any one embodiment may be used alone or in combination with each feature of the corresponding other embodiments. Therefore, the breadth and scope of any embodiment should not be limited by any of the exemplary embodiments described above, but should be defined solely by the appended claims and their equivalents.

Claims

1. A razor blade holder (20), comprising: The housing (30) has a protective member (40) located in the front region of the housing (30), a cover (50) located in the rear region of the housing (30), and opposing end walls (60) connecting the protective member (40) and the cover (50), the housing (30) defining a blade mounting area (70) between the protective member (40) and the cover (50). The first razor blade (80) closest to the guard (40), the immediately adjacent second razor blade (90) and the last third razor blade (100) are installed in the blade mounting area (70), each razor blade having a corresponding cutting edge (82, 92, 102) with sharpness; A reference plane (200) is tangent to the cutting edge (82) of the first razor blade (80) and the cutting edge (102) of the third razor blade (100), and the blade body portions supporting the cutting edges (82, 92, 102) are each at an angle (A) to the reference plane (200). The upper guard (120) is fixed above the blades (80, 90, 100) and includes a first longitudinal member (140) in front of the first blade (80) and second, third and fourth longitudinal members (150, 160, 170) respectively positioned above the razor blades (80, 90, 100); the second, third and fourth longitudinal members (150, 160, 170) each have a corresponding height (H1, H2, H3) above the reference plane (200).

2. The razor blade holder (20) according to claim 1, wherein, The upper protective member (120) has slots (122) extending from front to rear in the first, second, and third longitudinal members (140, 150, 160).

3. The razor blade holder (20) according to claim 1 or claim 2, wherein, The upper protective member further includes a front-to-back transverse rib (180) extending from the first longitudinal member (140) to the fourth longitudinal member (170).

4. The razor blade holder (20) according to claim 1, wherein, Each razor blade (80, 90, 100) has a cutting edge (82, 92, 102) with a cutting force sharpness in the range of 5-6.5N.

5. The razor blade holder (20) according to claim 1, wherein, The angle (A) is 20.5 degrees.

6. The razor blade holder (20) according to claim 1, wherein, The heights (H1, H2, H3) of the longitudinal members (150, 160, 170) above the reference plane (200) gradually decrease in the front-back direction of the razor blade holder (20).

7. The razor blade holder (20) according to claim 1, wherein, The height (H1) of the second longitudinal member (150) above the reference plane (200) is in the range of 0.287 to 0.212 mm.

8. The razor blade holder (20) according to claim 1, wherein, The height (H2) of the third longitudinal member (160) above the reference plane (200) is in the range of 0.150 to 0.129 mm.

9. The razor blade holder (20) according to claim 1, wherein, The height (H3) of the fourth longitudinal member (170) above the reference plane (200) is 0.039 mm.

10. The razor blade holder (20) according to claim 1, wherein, The height (H0) of the first longitudinal member (140) above the reference plane (200) is equal to the height (H1) of the second longitudinal member (150) above the reference plane (200).

11. The razor blade holder (20) according to claim 1, wherein, The upper protective component (120) is a separate part.

12. The razor blade holder (20) according to claim 1, wherein, The upper protective member (120) has a slot (122) extending back and forth in the fourth longitudinal member (170).

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