Reducing sound production in a hair-cutting unit comprising an external cutting member and a rotatable internal cutting member

Patent metadata

Field	Value
Publication number	US-12240132-B2
Application number	US-202117917047-A
Country	US
Kind code	B2
Filing date	Apr 13, 2021
Priority date	Apr 14, 2020
Publication date	Mar 4, 2025
Grant date	Mar 4, 2025

Abstract

In an external cutting member ( 10 ) which is configured to be used in a hair-cutting unit in combination with a rotatable internal cutting member, a base ( 11 ) includes at least one hair-cutting track ( 21 ) which is provided with a plurality of hair-entry openings, and an annular base portion ( 31 ) located between a central portion ( 17 ) of the base ( 11 ) and an innermost one of the at least one hair-cutting track ( 21 ). The annular base portion ( 31 ) is provided with a profiled section which is located between a straight inner section ( 32 ) and a straight outer section ( 33 ) of the annular base portion ( 31 ), which is annular about a central axis ( 16 ) of the external cutting member ( 10 ), and which is shaped according to a predefined profile, seen in a cross-section of the external cutting member ( 10 ) comprising the central axis ( 16 ).

First claim

The invention claimed is:

1. An external cutting member which is configured to be used in a hair-cutting unit in combination with a rotatable internal cutting member having at least one hair-cutting edge for the purpose of subjecting a portion of skin to a hair-cutting action,
wherein the external cutting member is generally cup-shaped and comprises a base and an annular wall extending from a circumferential area of the base,
wherein, at an exterior side thereof, the base has an exterior base surface configured to face the portion of skin to be subjected to a hair-cutting action, and at an interior side thereof, the base has an interior base surface configured to face the internal cutting member,
wherein the base includes at least one hair-cutting track which is annular about a central axis of the external cutting member and provided with a plurality of hair-entry openings, and an annular base portion located between a central portion of the base and an innermost one of the at least one hair-cutting track which is closest to the central axis,
wherein, seen in a cross-section of the external cutting member comprising the central axis, the annular base portion is provided with a profiled section which is located between a straight inner section and a straight outer section of the annular base portion, which is annular about the central axis, and which is shaped according to a predefined profile,
wherein the profiled section comprises a first bent connection zone at a location of connection to the straight inner section and a second bent connection zone at a location of connection to the straight outer section, and
wherein, in an axial direction parallel to the central axis, the predefined profile of the profiled section involves an axial height difference of at least one of the exterior base surface and the interior base surface of at least 80 μm over a radial measuring distance in the profiled section of at most 800 μm in a radial direction relative to the central axis.

2. The external cutting member according to claim 1 , wherein the predefined profile of the profiled section involves an axial height difference of at least one of the exterior base surface and the interior base surface of between 80 and 150 μm over the radial measuring distance in the profiled section of at most 800 μm.

3. The external cutting member according to claim 1 , wherein the predefined profile of the profiled section involves an axial height difference of at least one of the exterior base surface and the interior base surface of at least 130 μm over a radial measuring distance in the profiled section of at most 650 μm.

4. The external cutting member according to claim 3 , wherein the predefined profile of the profiled section involves an axial height difference of at least one of the exterior base surface and the interior base surface of between 130 and 200 μm over the radial measuring distance in the profiled section of at most 650 μm.

5. The external cutting member according to claim 1 , wherein, seen in said cross-section of the external cutting member, an outline of the exterior base surface and an outline of the interior base surface correspond to each other, at least at the position of the profiled section.

6. The external cutting member according to claim 1 , wherein, at the position of at least a major part of the profiled section, the base is further indented in the axial direction towards the interior side of the base than at the position of the straight outer section.

7. The external cutting member according to claim 1 , wherein the predefined profile of the profiled section is shaped as a U, wherein the profiled section comprises an intermediate zone at a location between the first and second bent connection zones, and wherein each of the first and second bent connection zones of the profiled section comprises two oppositely bent parts.

8. The external cutting member according to claim 7 , wherein, at the position of the intermediate zone of the profiled section, the base is further indented in the axial direction towards the interior side of the base than at the positions of both the first bent connection zone of the profiled section at the location of connection to the straight inner section and the second bent connection zone of the profiled section at the location of connection to the straight outer section.

9. The external cutting member according to claim 1 , wherein the predefined profile of the profiled section is shaped as a horizontally stretched S.

10. The external cutting member according to claim 9 , wherein, at the position of the first bent connection zone of the profiled section, the base is further indented in the axial direction towards the interior side of the base than at the position of the second bent connection zone of the profiled section.

11. The external cutting member according to claim 1 , wherein the central portion of the base comprises a central bearing portion configured to be used in rotationally supporting the internal cutting member.

12. The external cutting member according to claim 1 , comprising a deformed sheet having a thickness of less than 100 μm at the position of the at least one hair-cutting track.

13. A hair-cutting unit, comprising an external cutting member according to claim 1 and a rotatably arranged internal cutting member having at least one hair-cutting edge, wherein the external cutting member is arranged in the hair-cutting unit to cover the internal cutting member.

14. A hair-cutting appliance, comprising at least one hair-cutting unit according to claim 13 and a mechanism configured to drive the internal cutting member of the at least one hair-cutting unit.

Assignees

• Koninklijke Philips Nv

Inventors

• Klaseboer Gerrit
• Van Tijum Redmer

Classifications

• B26B19/141

  Details of inner cutters having their axes of rotation perpendicular to the cutting surface · CPC title

• B26B19/143 Primary

  Details of outer cutters · CPC title