A personal care device as well as a cutting unit for such a personal care device

Patent metadata

Field	Value
Publication number	US-2016158947-A1
Application number	US-201414904976-A
Country	US
Kind code	A1
Filing date	Jul 16, 2014
Priority date	Jul 25, 2013
Publication date	Jun 9, 2016
Grant date	—

Abstract

A personal care device, such as a shaving apparatus, provided with at least one cutting unit ( 21 ) comprising an external cutting member ( 23 ) and an internal cutting member ( 22 ) which is moveable relative to the external cutting member ( 23 ) in at least one direction of movement. A virtual skin plane ( 10 ) is located on a side of the external cutting member ( 23 ) facing away from the internal cutting member ( 22 ). The virtual skin plane ( 10 ) extends parallel to said direction of movement and parallel to a skin surface when the cutting unit ( 21 ) is in an operational position relative to the skin surface. The internal cutting member ( 22 ) comprises a plurality of cutting elements ( 39 ) each comprising a first cutting edge ( 50 ). A projection of the first cutting edge ( 50 ) in the virtual skin plane ( 10 ) encloses at least a first shearing angle with said direction of movement. The external cutting member ( 23 ) comprises a plurality of hair-entry apertures ( 34 ) each comprising a second cutting edge ( 51 ) for cooperation with at least one of the first cutting edges ( 50 ). A projection of the second cutting edge ( 51 ) in the virtual skin plane ( 10 ) encloses at least a second shearing angle with the direction of movement. For at least 60% (per cent) of all hair-entry apertures ( 34 ) of the external cutting member ( 23 ) which comprise a second cutting edge ( 51 ) for cooperation with at least one of the first cutting edges ( 50 ) of the internal cutting member ( 22 ), projections of the first and second cutting edges ( 50, 51 ) in a plane extending perpendicularly to the direction of movement enclose, respectively, a first inclination angle and a second inclination angle with the virtual skin plane ( 10 ) of the cutting unit ( 21 ), wherein the first and second inclination angles and the first and second shearing angles are selected such that, at least in a starting position of cutting a virtual cylindrical hair ( 70 ) with a diameter of 150 microns, situated in a cutting position in the hair-entry aperture ( 34 ) and extending perpendicularly to the virtual skin plane( 10 ), the first cutting edge ( 50 ) is in contact with the virtual cylindrical hair ( 70 ) in a first contact position ( 74 ) and the second cutting edge ( 51 ) is in contact with the virtual cylindrical hair ( 70 ) in a second contact position ( 75 ), wherein the first contact position ( 74 ) is closer to the virtual skin plane ( 10 ) than the second contact position ( 75 ).

First claim

1 . A personal care device, such as a shaving apparatus, provided with at least one cutting unit comprising an external cutting member and an internal cutting member which is moveable relative to the external cutting member in at least one direction of movement, which internal cutting member comprises a plurality of cutting elements each comprising a first cutting, wherein a projection of the first cutting edge in a virtual skin plane, which is located on a side of the external cutting member facing away from the internal cutting member and which extends parallel to said direction of movement and parallel to a skin surface when the cutting unit is in an operational position relative to the skin surface, encloses at least a first shearing angle with said direction of movement, and which external cutting member comprises a plurality of hair-entry apertures each comprising a second cutting edge for cooperation with at least one of the first cutting edges, wherein a projection of the second cutting edge in the virtual skin plane encloses at least a second shearing angle with the direction of movement, characterized in that, for at least P% (per cent) of all hair-entry apertures of the external cutting member which comprise a second cutting edge for cooperation with at least one of the first cutting edges of the internal cutting member, projections of the first and second cutting edges in a plane extending perpendicularly to the direction of movement enclose, respectively, a first inclination angle and a second inclination angle with the virtual skin plane of the cutting unit, wherein the first and second inclination angles and the first and second shearing angles are selected such that, at least in a starting position of cutting a virtual cylindrical hair with a diameter of 150 microns situated in a cutting position in the hair-entry aperture and extending perpendicularly to the virtual skin plane, the first cutting edge is in contact with the virtual cylindrical hair in a first contact position and the second cutting edge is in contact with the virtual cylindrical hair in a second contact position, wherein the first contact position is closer to the virtual skin plane than the second contact position, and wherein P is at least 60.

2 . A personal care device according to claim 1 , wherein P is at least 80.

3 . A personal care device according to claim 1 , wherein P is 100.

4 . A personal care device according to claim 1 , wherein, for said at least P% (per cent) of all hair-entry apertures of the external cutting member which comprise a second cutting edge for cooperation with at least one of the first cutting edges of the internal cutting member, in each possible cutting position of the virtual cylindrical hair in the hair-entry aperture the first contact position is closer to the virtual skin plane than the second contact position in said starting position, wherein the virtual cylindrical hair perpendicularly to the virtual skin plane.

5 . A personal care device according to claim 1 , wherein the internal cutting member is rotatable relative to the external cutting member about a central axis of the cutting unit, wherein the virtual skin plane extends perpendicularly to the central axis.

6 . A personal care device according to claim 1 , wherein at least one of the hair-entry apertures is bounded by the second cutting edge and an opposite edge, wherein near a first end of the hair-entry aperture the second cutting edge and the opposite edge are connected to each other by a curved part, whilst near a second end of the hair-entry aperture on a side remote from the curved part the hair-entry aperture is open.

7 . A personal care device according to claim 1 , wherein at least one of the hair-entry apertures is bounded by the second cutting edge and an opposite edge, wherein near a first end of the hair-entry aperture the second cutting edge and the opposite edge are connected to each other by a curved part, whilst near a second end of the hair-entry aperture on a side remote from the curved part the hair-entry aperture is open, wherein the second cutting edge comprises a first cutting part and a second cutting part connected to the first cutting part, wherein the first cutting part is located closer to the central axis than the second cutting part, wherein a shearing angle enclosed between the first cutting part and the direction of movement is smaller than a shearing angle enclosed by the second cutting part and the direction of movement, and wherein the first and second inclination angles, the first shearing angle and the shearing angle of the first cutting part are selected such that, in a starting position of cutting said virtual cylindrical hair in a position between the first cutting edge and the first cutting part of the second cutting edge, said first contact position is closer to the virtual skin plane than said second contact position.

8 . A personal care device according to claim 1 , wherein the first and second inclination angles are between 5 and 30 degrees, preferably 15 degrees.

9 . A cutting unit for a personal care device, such as a shaving apparatus, according to claim 1 .

Assignees

• Koninkl Philips Nv

Inventors

• Pragt Johan
• Van Kempen Wouter
• Eibergen Santhagens Robert Alexander
• Zeineldin Tarek

Classifications

• B26B19/143

  Details of outer cutters · CPC title

• B26B19/3846 Primary

  Blades; Cutters (B26B19/044, B26B19/141 take precedence) · CPC title

• B26B19/141

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

• B26B19/14 Primary

  of the rotary-cutter type; Cutting heads therefor; Cutters therefor (B26B19/04 takes precedence) · CPC title