STATIONARY CUTTING BLADE FOR A HAIR CLIPPING DEVICE

• US 20160101530A1
• Filed: 05/19/2014
• Published: 04/14/2016
• Est. Priority Date: 05/30/2013
• Status: Active Application

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips N.V.
• Inventors: SABLATSCHAN, SIEGFRIED, RETHMEIER, ROEL ALEXANDER, MAAT, WILLEM
• Granted Patent: US 10,252,429 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B26B 19/3846 Blades; Cutters B26B19/044, B26B19/141 take precedence
• CPC Class Codes: B26B 19/3893 Manufacturing of shavers or clippers or components thereof

Abstract

The present invention relates to a stationary cutting blade (12) for a hair clipping device (100) with a base body and a plurality of coined cutting teeth (22) which are spaced apart from each other and arranged on a front side (38) of the base body and each extend parallel to a longitudinal axis (40) of the stationary cutting blade (12). The stationary cutting blade (12) is a full metal cutting blade. A thickness ratio between the thickness of the base body (ti) and the thickness of the cutting teeth (t₂) is larger than 1.1. Each of the plurality of cutting teeth (22) has a substantially wedge-shaped cross-section with a scissor angle (a) and a wedge angle (y), wherein a sum of the scissor angle (a) and the wedge angle (y) is smaller than 70°.

Claims

1. A stationary cutting blade for a hair clipping device, comprising:

a base body; and

a plurality of coined cutting teeth which are spaced apart from each other and arranged on a front side of the base body and each extend parallel to a longitudinal axis of the stationary cutting blade;

wherein the stationary cutting blade is a full metal cutting blade and the base body has a first thickness (t₁), said first thickness (t₁) being measured between a top side and a bottom side of the base body along a transverse axis perpendicular to the longitudinal axis, wherein the cutting teeth have a second thickness (t₂) measured parallel to the transverse axis, wherein a thickness ratio between the first and the second thickness (t₁/t₂) is larger than 1.1;

wherein each of the plurality of cutting teeth has a substantially wedge-shaped cross-section with a top face, a bottom face and two opposing lateral faces running in between the top and the bottom face;

wherein a cutting edge that is defined at the intersection between the top face and an upper section of one of the lateral faces has a scissor angle (α

), which is defined between the cutting edge and an imaginary plane that is parallel to the longitudinal axis and the transverse axis, and a wedge angle (γ

), which is defined between said upper section of the one of the lateral faces and the top face;

wherein a sum of the scissor angle (α

) and the wedge angle (γ

) is smaller than 70°

.

2. The stationary cutting blade according to claim 1, wherein the scissor angle (α

) is smaller than 25°

.

3. The stationary cutting blade according to claim 1, wherein the wedge angle (γ

) is smaller than 55°

.

4. The stationary cutting blade according to claim 1, wherein the scissor angle (α

) is between 5° and

25°

.

5. The stationary cutting blade according to claim 1, wherein the wedge angle (γ

) is between 40° and

55°

.

6. The stationary cutting blade according to claim 1, wherein the first thickness (t₁) is larger than 1.3 mm.

7. The stationary cutting blade according to claim 1, wherein each of the plurality of cutting teeth has exactly two of said cutting edges, wherein each of the two cutting edges is a substantially straight cutting edge.

8. The stationary cutting blade according to claim 1, wherein each of the plurality of cutting teeth is symmetrical and comprises two identical opposing lateral faces, wherein each of the two lateral faces comprises an upper section and a lower section that is inclined with respect to the upper section and arranged locally in between the upper section and the bottom face, wherein a distance between the two upper sections of each cutting tooth is larger than a distance between the two lower sections of each cutting tooth.

9. The stationary cutting blade according to claim 8, wherein an angle between the top face and each of the lower sections is larger than the wedge angle (γ

).

10. A cutting assembly for a hair clipping device, comprising:

a stationary cutting blade according to claim 1; and

a moveable cutting blade that is resiliently biased against the stationary cutting blade.

11. A hair clipping device comprising a cutting assembly according to claim 10 and an actuator for moving the moveable cutting blade relative to the stationary cutting blade in a reciprocal manner.

12. A process for manufacturing a stationary cutting blade for a hair clipping device, comprising the steps of:

providing a piece of metal having a first thickness (t₁) that serves as raw material;

creating a tapered shape into the piece of metal in order to create a rough shape of a tip of the stationary cutting blade;

stamping a preliminary teeth geometry into the tip to create a plurality of spaced-apart cutting teeth having a second thickness (t₂) measured in parallel to the first thickness (t₁), such that a thickness ratio between the first and the second thickness (t₁/t₂) is larger than 1.1;

coining the final teeth geometry by means of a coining die to form teeth with a substantially wedge-shaped cross-section, a top face, a bottom face and two opposing lateral faces running in between the top and the bottom face and to simultaneously form a cutting edge at the intersection between the top face and an upper section of one of the lateral faces, wherein at the cutting edge a scissor angle (α

) is created, which is defined between the cutting edge and an imaginary plane that is parallel to a longitudinal axis and a transverse axis of the stationary cutting blade, and a wedge angle (γ

) is created, which is defined between said upper section of the one of the lateral faces and the top face;

wherein a sum of the scissor angle (α

) and the wedge angle (γ

) is smaller than 70°

.

13. The manufacturing process according to claim 12, wherein, before coining the tapered shape into the piece of metal, the process further comprises the step of:

stamping a recess into said piece of metal at a position where the tip of the stationary cutting blade is to be created.

14. The manufacturing process according to claim 12, wherein during coining the final teeth geometry by means of the coining die a scissor angle (α

) of between 5° and

25°

is formed.

15. The manufacturing process according to claim 12, wherein during coining the final teeth geometry by means of the coining die a wedge angle (γ

) between 40° and

55°

is formed.