Linkage unit and hair cutting appliance

Patent metadata

Field	Value
Publication number	US-2016288348-A1
Application number	US-201415038353-A
Country	US
Kind code	A1
Filing date	Nov 6, 2014
Priority date	Nov 22, 2013
Publication date	Oct 6, 2016
Grant date	—

Abstract

The present invention relates to a hair cutting appliance ( 10 ) comprising a linkage unit ( 30 ) for a cutting unit ( 18 ), and to a cutting unit ( 18 ) and a linkage unit ( 30 ) for coupling the cutting unit ( 18 ) and a housing ( 12 ) of a hair cutting appliance ( 10 ). The linkage unit ( 30 ) comprises a four-bar linkage mechanism ( 32 ) comprising a first arm ( 42 ) and a second arm ( 44 ), the first arm ( 42 ) comprising a first base pivot ( 48 ) coupled to a base ( 38 ), the second arm ( 44 ) comprising a second base pivot ( 50 ) coupled to a base ( 38 ), the first base pivot ( 48 ) and the second base pivot ( 50 ) being arranged at the base ( 38 ) at a fixed distance, the first arm ( 42 ) further comprising a first top pivot ( 52 ) coupled to a connecting bar ( 46 ), the second arm ( 44 ) further comprising a second top pivot ( 54 ) coupled to the connecting bar ( 46 ), wherein the connecting bar ( 46 ) is arranged to be coupled to a cutting unit ( 18 ), such that, during operation, the cutting unit ( 18 ) is pivotably supported by the linkage mechanism ( 32 ). Preferably, at least one of the first base pivot ( 48 ) and the second base pivot ( 50 ) and the first top pivot ( 52 ) and the second top pivot ( 54 ) is arranged as a living hinge.

First claim

1 . A cutting unit and a linkage unit for a hair cutting appliance, wherein the cutting unit is arranged to be coupled to a housing of the hair cutting appliance by the linkage unit,
the cutting unit comprising a blade set comprising a stationary blade, a movable blade and at least one basically laterally extending cutting edge, wherein the stationary blade is arranged to house and to guide the movable blade for lateral movement with respect to the stationary blade, the stationary blade comprising a cross-section, viewed in a plane perpendicular to a lateral direction (Y), that is basically U-shaped, particularly at the at least one cutting edge, wherein the U-shaped form comprises a first leg and a second leg, wherein a guiding slot for the movable blade is provided between the first leg and the second leg, and wherein the stationary blade basically encloses the movable blade at the side thereof facing the skin when cutting hair and, at least partially, at the side thereof facing away from the skin when cutting hair, the linkage unit comprising a four-bar linkage mechanism, the four-bar linkage mechanism comprising a first arm and a second arm opposite to the first arm, the first arm comprising a first base pivot coupled to a base, the second arm comprising a second base pivot coupled to a base, the first base pivot and the second base pivot being arranged at the base at a defined distance, the first arm further comprising a first top pivot coupled to a connecting bar, the second arm further comprising a second top pivot coupled to the connecting bar, wherein the connecting bar is arranged to be coupled to a cutting unit, such that, during operation, the cutting unit is pivotably supported by the linkage mechanism and wherein the cutting unit and the linkage unit further comprise at least one end stop element for preventing undesired motion of the four-bar linkage mechanism, wherein the least one end stop element comprises ate least one protruding contract tab at least one of the first arm, the second arm and the connecting bar, and at least one corresponding contact surface at the other one thereof, such that the at least one protruding contract tab and the least one corresponding contract surface define a maximal relative rotation between the first and second arms and the connecting bar.

2 . The cutting unit and the linkage unit as claimed in claim 1 , wherein the four-bar linkage mechanism defines a virtual pivot for the cutting unit, the virtual pivot comprising a virtual pivot axis (p) that is substantially parallel to a cutting edge of the copying unit.

3 . (canceled)

4 . The cutting unit and the linkage unit as claimed in claim 1 , wherein at least the first arm, the second arm and the connecting bar and their respective base pivots and top pivots are integrally formed as a single piece.

5 . The cutting unit and the linkage unit as claimed in claim 1 , wherein the four-bar linkage mechanism is an integrally formed injection molded plastic part.

6 . The cutting unit and the linkage unit as claimed in claim 1 , wherein the four-bar linkage mechanism is a three-dimensional near-net shaped molded part, and wherein the hinges forming the pivots thereof are basically unbiased when the linkage mechanism is in a neutral position.

7 . The cutting unit and the linkage unit as claimed in claim 1 , wherein the length of the base, defined by a distance between the first base pivot and the second base pivot, is greater than the length of the connecting bar, defined by a distance between the first top pivot and the second top pivot.

8 . The cutting unit and the linkage unit as claimed in claim 1 , further comprising at least one biasing element that urges the four-bar linkage mechanism into a defined start position.

9 . The cutting unit and the linkage unit as claimed in claim 8 , wherein the at least one biasing element is a torsion bar spring arranged at the base, the torsion bar spring comprising a torsion bar pivotably received at the base, the torsion bar being arranged between a first leg and a second leg, wherein the first leg is coupled to the base, and wherein the second leg is coupled to one of the first arm and the second arm.

10 . (canceled)

11 . The cutting unit and the linkage unit as claimed in claim 10 , wherein the at least one end stop element cooperates with at least one biasing element, wherein a resulting biasing force urges the four-bar linkage mechanism against at least one of the at least one end stop element.

12 . The cutting unit and the linkage unit as claimed in claim 10 , wherein the at least one end stop element is connected to the base and arranged to limit the guided motion of the cutting unit, particularly to limit the motion of at least one of the first and the second arm and the connecting bar.

13 . The cutting unit and the linkage unit as claimed in claim 10 , wherein the at least one end stop element is arranged at an end stop support comprising at least one end stop beam, the at least one end stop beam comprising at least one end face, wherein the at least one end face preferably abuts a bottom side of the cutting unit for limiting the motion of the cutting unit.

14 . (canceled)

15 . A hair cutting appliance comprising a housing accommodating a motor, a cutting unit, and a linkage unit as claimed in claim 1 for coupling the cutting unit and the housing.

16 . The cutting unit and the linkage unit as claimed in claim 2 , wherein the pivot axis (p) is arranged in the vicinity of a top surface of the cutting unit facing away, when mounted, from the housing of the hair cutting appliance, and wherein the pivot axis (p) is offset from the top surface, in a neutral position of the four-bar linkage mechanism, by a pivot offset dimension (1 o ) in the range of about −2.0 mm to about +5.0 mm, preferably in the range of about −1.0 mm to about +2.0 mm, more preferably in the range of about +0.25 mm to about +0.75 mm.

17 . The cutting unit and the linkage unit as claimed in claim 4 , wherein all pivots of the four-bar linkage mechanism are arranged as living hinges, particularly as film hinges.

Assignees

• Koninklijke Philips Nv

Inventors

• Molema Jeroen
• Tuijp Bram
• De Goeij Geert Willem

Classifications

• B26B19/042

  Long hair cutters or older types comprising a cutting grid · CPC title

• B26B19/048

  Complete cutting head being movable · CPC title

• B26B19/386 Primary

  Means for attaching the head thereto · CPC title

• B26B19/3846

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

• B26B21/225

  the changeable unit being resiliently mounted on the handle · CPC title