# US 10,369,714 B2 · Razor blade and razor cartridge using the same

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- Number: US 10,369,714 B2
- Document ID: US10369714B2
- Status: Granted
- Kind: B2
- Application number: 15/052,251
- Filed: 2016-02-24
- Published: 2016-06-16
- Granted: 2019-08-06
- Earliest claimed: 2014-08-25
- Assignees: Dorco Co., Ltd.
- Applicants: DORCO Co. Ltd.
- Inventors: Ho Jun Noh; Jun soo Chang
- Web page: https://patentgrep.com/patent/US10369714B2

## CPC

- B26B 21/56: characterised by the shape
- B26B 21/222: {with the blades moulded into, or attached to, a changeable unit (B26B21/4006 takes precedence)}
- B26B 21/4012: {Housing details, e.g. for cartridges}
- B26B 21/4031: {characterised by special geometric shaving parameters, e.g. blade span or exposure}
- B26B 21/565: {Bent razor blades; Razor blades with bent carriers}
- B26B: HAND-HELD CUTTING TOOLS NOT OTHERWISE PROVIDED FOR (for harvesting A01D; for horticulture, for forestry A01G; for butchering or meat treatment A22; for manufactering or repairing footwear A43D; nail clippers or cutters A45D29/02; kitchen equipment A47J; {vegetable slicers, julienne cutters and similar devices and holders therefor, B26D3/28}; for surgical purposes A61B; for metal B23D; cutting by abrasive fluid jets B24C5/02; plier-like tools with cutting edges B25B7/22; pincers B25C11/02; handles for hand implements, in general B25G; guillotine-type cutters B26D; {perforating by non-mechanical means, e.g. by fluid jet, B26F1/26}; for erasing B43L19/00; for textile materials D06H)

## Abstract

An integral razor blade which is thin and has improved strength by shaping a geometrical structure of the razor blade and a razor cartridge using the same. The razor blade includes a base portion, a bent portion extending in a bent manner from one end of the base portion, and an edge portion extending from one end of the bent portion, a cutting edge being formed at one end of the edge portion. A first separation distance X between a straight line extending in a longitudinal direction from a front surface of the base portion and an end point of the cutting edge ranges from 0.3 mm to 1.0 mm.

## Claims

### Claim 1

A razor blade, wherein each distal end of a widthwise direction is configured to be secured by a housing and wherein a thickness of the razor blade ranges from 0.05 mm to 0.1 mm, the razor blade comprising:
a base portion;
a bent portion extending in a bent manner from one end of the base portion, the bent portion which is heat-treated; and,
an edge portion extending from one end of the bent portion, a cutting edge being formed at one end of the edge portion,
wherein the cutting edge is formed in an arch having a middle portion along the widthwise direction protruding toward a shaving direction with respect to a straight line connecting each end of the cutting edge,
wherein a first separation distance (X) between a curved plane coinciding with a front surface of the base portion and a corresponding point along the cutting edge toward the shaving direction ranges from 0.3 mm to 0.85 mm,
wherein an angle between the edge portion and the base portion ranges from 105 degrees to 115 degrees,
wherein a second separation distance (Y) between a straight line extending in a forward and backward direction from the other end of the base portion and the end point of the cutting edge ranges from 2.3 mm to 2.7 mm,
wherein the forward direction is a direction that the front surface of the base portion faces,
wherein:
a thickness of the razor blade at the bent portion is thinner than a thickness of the razor blade at the base portion,
an inner curvature radius of the bent portion at the middle portion along the widthwise direction of the razor blade is larger than an inner curvature radius of the bent portion at each distal end of the razor blade, and
the bent portion at the middle portion along the widthwise direction is thinner than the bent portion at each distal end of the razor blade,
wherein a ratio (X/Y) of the first separation distance (X) to the second separation distance (Y) ranges from 0.15 to 0.4,
wherein a height (h1) of the base portion ranges from 1.7 mm to 2.1 mm, and
wherein the first separation distance (X) is smaller than twice the inner curvature radius (R).

### Claim 2 (depends on 1)

The razor blade of claim 1, wherein a ratio (X/t) of the first separation distance (X) to the thickness (t) of the razor blade ranges from 4 to 10.

### Claim 3 (depends on 1)

The razor blade of claim 1, wherein an inner curvature radius (R) of the bent portion ranges from 0.3 mm to 1.2 mm.

### Claim 4 (depends on 1)

The razor blade of claim 1, wherein the thickness of the razor blade ranges from 0.07 mm to 0.08 mm, and
wherein the inner curvature radius (R) of the bent portion ranges form 0.45 mm to 0.9 mm.

### Claim 5

A razor cartridge comprising:
a plurality of razor blades including a base portion, a thickness of each of the razor blades ranging from 0.05 mm to 0.1 mm, a bent portion extending in a bent manner from one end of the base portion, the bent portion which is heat-treated, and an edge portion extending from one end of the bent portion, a cutting edge being formed at one end of the edge portion; and
a housing configured to secure the plurality of razor blades where each distal end of a respective razor blade along a widthwise direction is secured by the housing,
wherein the cutting edge is formed in an arch having a middle portion along the widthwise direction protruding toward a shaving direction with respect to a straight line connecting each end of the cutting edge,
wherein a first separation distance (X) between a curved plane coinciding with a front surface of the base portion and a corresponding point along the cutting edge toward the shaving direction ranges from 0.3 mm to 0.85 mm,
wherein an angle between the edge portion and the base portion ranges from 105 degrees to 115 degrees,
wherein a second separation distance (Y) between a straight line extending in a forward and backward direction from the other end of the base portion and the end point of the cutting edge ranges from 2.3 mm to 2.7 mm,
wherein the forward direction is a direction that the front surface of the base portion faces,
wherein:
a thickness of the razor blade at the bent portion is thinner than a thickness of the razor blade at the base portion,
an inner curvature radius of the bent portion at the middle portion along the widthwise direction of the razor blade is larger than an inner curvature radius of the bent portion at each distal end of the razor blade, and
the bent portion at the middle portion along the widthwise direction is thinner than the bent portion at each distal end of the razor blade,
wherein a ratio (X/Y) of the first separation distance (X) to the second separation distance (Y) ranges from 0.15 to 0.4,
wherein a height (h1) of the base portion ranges from 1.7 mm to 2.1 mm, and
wherein the first separation distance (X) is smaller than twice the inner curvature radius (R).

### Claim 6 (depends on 5)

The razor cartridge of claim 5, wherein a ratio (X/t) of the first separation distance (X) to the thickness (t) of the razor blade ranges from 4 to 10.

### Claim 7 (depends on 5)

The razor cartridge of claim 5, wherein an inner curvature radius (R) of the bent portion ranges from 0.3 mm to 1.2 mm.

### Claim 8 (depends on 5)

The razor cartridge of claim 5, wherein the thickness of the razor blade ranges from 0.07 mm to 0.08 mm, and
wherein the inner curvature radius (R) of the bent portion ranges from 0.45 mm to 0.9 mm.