U.S. patent application number 14/051590 was filed with the patent office on 2014-04-24 for epilator.
This patent application is currently assigned to Braun GmbH. The applicant listed for this patent is Braun GmbH. Invention is credited to Luis Burrell-Diez, Frieder Grieshaber, Markus Halm, Bernhard Kraus, Andreas Lennartz, Tarik Mehaddene, Tobias Schwarz.
Application Number | 20140114328 14/051590 |
Document ID | / |
Family ID | 47018070 |
Filed Date | 2014-04-24 |
United States Patent
Application |
20140114328 |
Kind Code |
A1 |
Grieshaber; Frieder ; et
al. |
April 24, 2014 |
Epilator
Abstract
The present disclosure is concerned with an attachment for an
epilator or an epilator having at least a clamping unit for
clamping and plucking hairs. The clamping unit is arranged for
driven movement relative to a housing of the attachment or the
epilator along a hair capture direction. The clamping unit has a
moveable clamping element having a clamping surface and a hair
guiding surface and a fixed clamping element having a clamping
surface and a hair guiding surface, wherein the moveable clamping
element and the fixed clamping element are arranged to be
cyclically moveable between an open position and a closed
position.
Inventors: |
Grieshaber; Frieder;
(Neu-Anspach, DE) ; Mehaddene; Tarik; (Karben,
DE) ; Kraus; Bernhard; (Braunfels, DE) ;
Burrell-Diez; Luis; (Frankfurt am Main, DE) ;
Lennartz; Andreas; (Kressbronn, DE) ; Schwarz;
Tobias; (Schmitten, DE) ; Halm; Markus;
(Koenigstein, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Braun GmbH |
Kronberg |
|
DE |
|
|
Assignee: |
Braun GmbH
Kronberg
DE
|
Family ID: |
47018070 |
Appl. No.: |
14/051590 |
Filed: |
October 11, 2013 |
Current U.S.
Class: |
606/133 |
Current CPC
Class: |
A45D 26/0028 20130101;
A45D 26/0023 20130101; A45D 26/0038 20130101 |
Class at
Publication: |
606/133 |
International
Class: |
A45D 26/00 20060101
A45D026/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 12, 2012 |
EP |
12188286.4 |
Claims
1. An epilator comprising: a clamping cylinder arranged for
rotation around a longitudinal cylinder axis; at least one clamping
unit provided on the clamping cylinder for clamping and plucking
hairs, the clamping unit being arranged for driven movement along a
hair capture direction, wherein the clamping unit forms a
protruding portion of the perimeter of the clamping cylinder,
wherein said clamping cylinder comprises portions with a friction
coefficient, and said clamping cylinder comprises a lower level
surface that is not intended for contacting the skin of a user
during operation, and wherein at least a part of a lower level
surface of the clamping cylinder comprises one of the following: a
regular structuring; or a lower level surface portion provided with
a friction coefficient with respect to hair that is higher than
friction coefficient with respect to hair at another portion of the
clamping cylinder.
2. The epilator in accordance with claim 1, wherein the regular
structuring comprises ridges that extend parallel to the
longitudinal cylinder axis.
3. The epilator in accordance with claim 2, wherein the ridges have
a radial height in the range of between 0.05 mm to about 0.5
mm.
4. The epilator in accordance with claim 3, wherein the radial
height is in the range of between about 0.08 mm and about 0.2
mm.
5. The epilator in accordance with claim 2, wherein the
circumferential distance between the ridges is in a range of
between about 0.2 mm to about 2 mm.
6. The epilator in accordance with claim 1, wherein the lower level
surface portion provided with an increased friction coefficient
with respect to hair comprises a rough surface that is rougher
relative to another portion of the clamping cylinder.
7. The epilator in accordance with claim 6, wherein the rough
surface comprises depressions with a depth between 0.05 mm to about
0.5 mm.
8. The epilator in accordance with claim 1, wherein the lower level
surface portion provided with an increased friction coefficient
with respect to hair comprises a coated surface.
9. The epilator in accordance with claim 8, wherein the coated
surface comprises an elastomer.
10. The epilator in accordance with claim 1, wherein the clamping
unit further comprises: a moveable first clamping element having a
clamping section and at least a winged section, wherein the
clamping section has a clamping surface and the winged section has
a guiding surface, which guiding surface angles outwards away from
the clamping surface at least with respect to the hair capture
direction; and a fixed second clamping element having a clamping
section and at least a winged section, wherein the clamping section
has a clamping surface and the winged section has a guiding
surface, which guiding surface angles outwards away from the
clamping surface at least with respect to the hair capture
direction; wherein the clamping unit is arranged for cyclical
movement between an open position in which a gap for receiving
hairs and having a minimum width in a width direction perpendicular
to the hair capture direction extends between the clamping surfaces
of the moveable first clamping element and the fixed second
clamping element and a closed position in which the clamping
surfaces of the moveable first clamping element and the fixed
second clamping element abut on each other at least along a
clamping line; and wherein the guiding surface of the moveable
first clamping element defines a first side of a funnel for guiding
hairs towards the gap and the guiding surface of the fixed second
clamping element defines a second side of the funnel, wherein the
width of the hair guiding surface of the fixed second clamping
element measured in a width direction perpendicular to the hair
capture direction is larger than the respective width of the hair
guiding surface of the moveable first clamping element.
11. The epilator in accordance with claim 10, wherein the width of
the hair guiding surface of the fixed second clamping element is
about as large as the sum of the width of the hair guiding surface
of the moveable first clamping element and the width of the gap in
the open position.
12. The epilator in accordance with claim 10, wherein the first and
second clamping elements have outer surfaces that lie on the
surface of an imaginary enveloping cylinder.
13. The epilator in accordance with claim 10, wherein the clamping
unit is arranged on a clamping cylinder rotating around an axis of
rotation and wherein the moveable first clamping element is
moveable in a direction perpendicular to the hair capture direction
or in a direction parallel with said axis of rotation.
14. The epilator in accordance with claim 10, wherein the total
effective width over which the clamping unit catches hairs is
between 2 mm to 7 mm which is the sum of the widths of both
adjacent winged sections within a clamping unit and of the gap
width between both clamping sections in its open position.
15. An epilator comprising a clamping cylinder arranged for
rotation around a longitudinal cylinder axis, at least one clamping
unit provided on the clamping cylinder for clamping and plucking
hairs, the clamping unit being arranged for driven movement along a
hair capture direction, wherein a surface portion of the clamping
cylinder is provided with a hair erecting structure which is
provided with a radial height extension of between 0.05 mm to 0.5
mm
16. The epilator in accordance with claim 15, wherein the hair
erecting structure has a larger extension in a direction parallel
to the longitudinal cylinder axis than perpendicular to that along
the rotational direction of the clamping cylinder perimeter.
17. An epilator comprising a clamping cylinder arranged for
rotation around a longitudinal cylinder axis, at least one clamping
unit provided on the clamping cylinder for clamping and plucking
hairs, the clamping unit being arranged for driven movement along a
hair capture direction, wherein a surface portion of the clamping
cylinder is provided with a hair erecting surface, said hair
erecting surface is made of an elastomer soft material and said
clamping cylinder comprises an injection molded hard-soft polymer
material.
Description
FIELD OF THE INVENTION
[0001] The present invention is concerned with an epilator.
BACKGROUND OF THE INVENTION
[0002] It is known that epilators may comprise a clamping cylinder
on which clamping units comprising two clamping elements are
arranged. During operation, the clamping cylinder is driven into
rotation around its cylinder axis. The clamping units are arranged
to be cyclically moved between an open position in which a gap
extends between the two clamping elements into which gap hairs can
enter and a closed position in which the two clamping element abut
on each other at least along a clamping line such that hairs that
are clamped in between the clamping elements are plucked from the
user's skin when the clamping unit continues to rotate on the
clamping cylinder while being in the closed position. EP 1 796 501
B1 generally describes a clamping cylinder having a plurality of
clamping units.
[0003] It is a general desire to increase the efficiency of
epilators, i.e. to increase the number of hairs that are clamped
and plucked.
[0004] It is hence an object of the present disclosure to provide
an epilator having an increased clamping and plucking efficiency
over the known devices.
SUMMARY OF THE INVENTION
[0005] In accordance with one aspect there is provided an epilator
comprising a clamping cylinder arranged for rotation around its
longitudinal cylinder axis, at least one clamping unit provided on
the clamping cylinder for clamping and plucking hairs, the clamping
unit being arranged for driven movement along a hair capture
direction, wherein the clamping unit forms a protruding portion of
the perimeter of the clamping cylinder and wherein at least a part
of a lower level surface of the clamping cylinder that is not
intended for contacting the skin of a user during operation either
comprises a regular structuring, or a lower level surface portion
provided with an increased friction coefficient with respect to
hair that is higher relative to a friction coefficient with respect
to hair at another portion of the clamping cylinder. Alternatively
it may be provided just a higher friction coefficient (not
specifically related to hair) of a lower level surface portion than
the friction coefficient provided by another portion of the
clamping unit. This other portion may be e.g. the outer skin
contacting surface of the clamping unit. The clamping units are
then arranged to smoothly glide over the skin while the lower level
surface which is not in contact with skin exhibits the opposite
characteristic, thus facilitating grasping and reorienting hair.
This effect may be also achieved by the surface structure of said
lower level portion of the clamping cylinder. The lower level of
the clamping cylinder is defined as a base level relative to other
protrusions of the clamping cylinder. The clamping unit may be one
example of such a protrusion. These hair erecting/reorienting
related aspects above and below may be independent from other
features of the clamping unit or in combination therewith.
[0006] In accordance with one aspect it is provided that the
regular structuring comprises ridges that extend parallel to the
longitudinal cylinder axis. Thus the ridges extend transverse to
the movement direction of the clamping cylinder over the body to be
treated. This facilitates grasping of hair to be erected. The
ridges may create a zig-zag perimeter of the cross section of the
clamping cylinder. Alternatively it may create grooves or waves or
other structures in the lower surface portion.
[0007] In accordance with one aspect it is provided that the ridges
have a radial height in the range of between 0.05 mm to about 0.5
mm The hair erecting structure is preferably provided at a micro
level. With the above number range the ridge structure is around at
least in a depth or height range between one average hair diameter
to 10 times of an average hair diameter. The radial height (or
depth) refers to a direction of an imaginary extension of the
longitudinal axis to radial line provided through point at the
perimeter of the clamping cylinder. Further with this range and
minimal extension it is assured that the structured surface is not
pressed against the skin during epilation.
[0008] In accordance with one aspect it is provided that the radial
height is in the range of between about 0.08 mm and about 0.2
mm
[0009] In accordance with one aspect it is provided that the
circumferential distance between the ridges is in a range of
between about 0.2 mm to about 2 mm This improves grasping
efficiency of hair to be erected while still being well manufacture
able by injection molding.
[0010] In accordance with one aspect it is provided that the lower
level surface portion provided with an increased friction
coefficient with respect to hair comprises a rough surface that is
rougher relative to another portion of the clamping cylinder. Thus
those portions in contact with skin are preferably smoother and
still glide well over skin than the lower level portion of the
clamping cylinder that is intended as being in non contact with
skin but helps erecting hair. The hair is erected as the hair ends
are caught by a roughness depression and are thus forced to
reorient.
[0011] In accordance with one aspect it is provided that the rough
surface comprises depressions with a depth between 0.05 mm to about
0.5 mm The depth refers to a direction of an imaginary extension of
the longitudinal axis to a radial line provided through a point at
the perimeter of the clamping cylinder. It is thus measured in a
perpendicular to the surface. Further with this range and minimal
extension it is assured that the structured surface is not pressed
against the skin during epilation.
[0012] In accordance with one aspect it is provided that the lower
level surface portion provided with an increased friction
coefficient with respect to hair comprises a coated surface. It
revealed that coated surfaces may increase the coefficient of
friction so that hair may not glide away along that surface.
[0013] In accordance with one aspect it is provided that the coated
surface comprises an elastomer.
[0014] In accordance with one aspect it is provided an epilator
comprising at least a clamping unit for clamping and plucking
hairs, the clamping unit being arranged for driven movement along a
hair capture direction, the clamping unit comprising a moveable
(first) clamping element having a clamping section and at least a
winged section, wherein the clamping section has a clamping surface
and the winged section has a guiding surface, which guiding surface
angles outwards away from the clamping surface at least with
respect to the hair capture direction; and a fixed (second)
clamping element having a clamping section and at least a winged
section, wherein the clamping section has a clamping surface and
the winged section has a guiding surface, which guiding surface
angles outwards away from the clamping surface at least with
respect to the hair capture direction; wherein the clamping unit is
arranged for cyclical movement between an open position in which a
gap for receiving hairs and having a minimum width in a width
direction perpendicular to the hair capture direction extends
between the clamping surfaces of the moveable clamping element and
the fixed clamping element and a closed position in which the
clamping surfaces of the moveable clamping element and the fixed
clamping element abut on each other at least along a clamping line;
and wherein the guiding surface of the moveable clamping element
defines a first side of a funnel for guiding hairs towards the gap
and the guiding surface of the fixed clamping element defines a
second side of the funnel, wherein the width of the hair guiding
surface of the fixed clamping element measured in a width direction
perpendicular to the hair capture direction is larger than the
respective width of the hair guiding surface of the moveable
clamping element.
[0015] In accordance with one aspect it is provided that the width
of the hair guiding surface of the fixed clamping element is about
as large as the sum of the width of the hair guiding surface of the
moveable clamping element and the width of the gap in the open
position.
[0016] In accordance with one aspect it is provided that the
clamping elements have outer surfaces that lie on the surface of an
imaginary enveloping cylinder.
[0017] In accordance with one aspect it is provided that the
clamping unit is arranged on a clamping cylinder rotating around an
axis of rotation and wherein the moveable clamping element is
moveable in a direction perpendicular to the hair capture direction
or in a direction parallel with said axis of rotation.
[0018] In accordance with one aspect it is provided that the total
effective width over which the clamping unit catches hairs is
between 2 mm to 7 mm which is the sum of the widths of both
adjacent winged sections within a clamping unit and of the gap
width between both clamping sections in its open position.
[0019] In accordance with one aspect there is provided an epilator
comprising a clamping cylinder arranged for rotation around its
longitudinal cylinder axis, at least one clamping unit provided on
the clamping cylinder for clamping and plucking hairs, the clamping
unit being arranged for driven movement along a hair capture
direction, wherein a surface portion of the clamping cylinder is
provided with a hair erecting structure which is provided with a
radial height extension of between 0.05 mm to 0.5 mm
[0020] In accordance with one aspect there is provided the hair
erecting structure has a larger extension in a direction parallel
to the longitudinal cylinder axis than perpendicular to that along
the rotational direction of the clamping cylinder perimeter.
[0021] In accordance with one aspect there is provided an epilator
comprising a clamping cylinder arranged for rotation around its
longitudinal cylinder axis, at least one clamping unit provided on
the clamping cylinder for clamping and plucking hairs, the clamping
unit being arranged for driven movement along a hair capture
direction, wherein a surface portion of the clamping cylinder is
provided with a hair erecting surface, said hair erecting surface
is made of an elastomer soft material and said clamping cylinder
comprises an injection molded hard-soft polymer material. The
provision of a hard polymer clamping cylinder base with a
2-component injection molded elastomer component combines well ease
of manufacturability with strength and hair erecting requirements
of the clamping cylinder.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The present disclosure will be further elucidated by a
detailed description of example embodiments and with reference to
figures. In the figures:
[0023] FIG. 1 is a generic depiction of an epilator comprising an
attachment and a housing section;
[0024] FIG. 2 is a depiction of the attachment shown in FIG. 1 in a
detached state;
[0025] FIG. 3A is a depiction of an example embodiment of a
clamping cylinder in accordance with at least one aspect of the
present disclosure;
[0026] FIG. 3B is a depiction of an example embodiment of an
enlarged view of a portion of the clamping cylinder in accordance
with at least one aspect of the present disclosure
[0027] FIG. 4A is a schematic depiction of an example embodiment of
a clamping unit in accordance with at least one aspect of the
present description shown in an open position;
[0028] FIG. 4B is a depiction of the clamping unit shown in FIG. 4A
in a closed position;
[0029] FIG. 5A is a schematic depiction of another example
embodiment of a clamping unit in accordance with at least one
aspect of the present description shown in an open position;
[0030] FIG. 5B is a depiction of the clamping unit shown in FIG. 5A
in a closed position; and
[0031] FIG. 6 is a cross sectional cut though a clamping cylinder,
the cut taken in a plane being perpendicular to the longitudinal
cylinder axis.
DETAILED DESCRIPTION OF THE INVENTION
[0032] An attachment for an epilator or an epilator in accordance
with any aspect of the present disclosure may in particular
comprise a carrier, e.g. a clamping cylinder or a clamping disc, on
which at least one clamping unit is arranged, which clamping unit
comprises two clamping elements, at least one of these clamping
elements being a moveable clamping element and the other clamping
element being either also a moveable clamping element or a fixed
clamping element. The clamping unit forms a discrete portion of the
perimeter of the clamping cylinder that protrudes from the clamping
cylinder. The clamping unit (i.e. the carrier--e.g. a clamping
cylinder) may be arranged for driven movement along a hair capture
direction. Each of the clamping elements has a clamping section
having a clamping surface. The clamping elements of the clamping
unit are arranged to be cyclically moveable between an open
position in which a free gap having a minimal gap width extends
between the clamping surfaces of the clamping elements such that
hairs can be fed into the gap (i.e. the clamping surfaces are
arranged vis-a-vis) and a closed position in which the clamping
surfaces abut on each other at least along a clamping line (as is
explained further below, the clamping surfaces may abut on each
other also in a laminar manner). Hairs that are clamped between the
clamping surfaces in the closed position will eventually be plucked
from the skin when the clamping unit continues to be moved along
the hair capture direction relative to the skin of a user while
being in the closed position. The clamping elements may in
particular each comprise a clamping section on which the clamping
surface is arranged and a winged section that is arranged in front
of the clamping unit with respect to the hair capture direction and
on which a guiding surface is arranged. The winged section angles
outwardly away from the clamping section with respect to the hair
capture direction such that each of the guiding surfaces of the
winged sections of the two clamping elements of the clamping unit
form one side of a funnel for guiding hairs towards the gap
extending between the clamping surfaces while the clamping unit is
in the open position and while the clamping unit is being closed,
i.e. hairs are guided into the narrowing gap by the guiding
surfaces until the gap is closed (i.e. until the gap is so small
that hairs do not feed into the gap anymore). The two such formed
sides of the funnel each have a width that is measured in a width
direction perpendicular to the hair capture direction (wherein the
width direction is also essentially perpendicular to the clamping
surfaces in the closed position), wherein in particular in
accordance with at least one aspect of the present disclosure where
the clamping unit comprises a moveable clamping element and a fixed
clamping element, the width of the guiding surface of the moveable
clamping element is smaller than the width of the guiding surface
of the fixed clamping element. In some embodiments, the width of
the guiding surface of the fixed clamping element may then be
chosen about as large as the sum of the width of the guiding
surface of the moveable clamping element plus the width of the gap
in the open position.
[0033] In some embodiments of an attachment for an epilator or an
epilator in accordance with at least one aspect of the present
disclosure, a plurality of clamping units is arranged on a clamping
cylinder that is arranged for driven movement around its
longitudinal centre axis. Thus the clamping unit is arranged on a
clamping cylinder rotating around an axis of rotation and the
moveable clamping element is moveable in a direction perpendicular
to the hair capture direction or in other words in a direction
parallel with said axis of rotation (which is the same axis as the
clamping cylinder longitudinal centre axis). The width direction is
then parallel to the longitudinal cylinder axis. The clamping units
may then be arranged such that the gaps of the clamping units in
their open positions do not overlap in the longitudinal cylinder
direction, i.e. such that the sum of the widths of all gaps of the
plurality of clamping units covers an effective width of the
clamping cylinder (which is the width over which the clamping
cylinder epilates) by less than 100%, in particular less than 90%,
less than 80%, less than 70% or less than 65%. Thus the sum of all
gaps between the clamping sections of all clamping units is smaller
than the total width of the clamping cylinder. In some embodiments,
where each of the plurality of clamping units has a funnel formed
in front of the clamping unit, the sum of the total widths of all
funnels of all clamping units covers the effective width of the
clamping cylinder by more than 100%, in particular more than 200%,
or more than 300%. Thus a high hair removal efficacy is achieved
although less clamping gaps/clamping units are provided.
[0034] In some embodiments of an attachment for an epilator or an
epilator in accordance with at least one aspect of the present
disclosure, at least one clamping unit comprising two clamping
elements is arranged on a clamping cylinder and the length along
which two clamping elements abut on each other in a closed position
of the clamping unit is in a range of between about 8% to 12% of
the perimeter of an enveloping cylinder of the clamping cylinder,
in particular in a range of between about 8.5% and about 10.5%,
further in particular has a value of about 10%.
[0035] In some embodiments of an attachment for an epilator or an
epilator in accordance with at least one aspect of the present
disclosure, a carrier, e.g. a clamping cylinder or a clamping disc,
has a lower lying surface not intended for contact with the skin of
a user during regular operation, which lower lying surface has a
microscopic or macroscopic texture or has a surface coating or
surface layer of a friction enhancing material that has an enhanced
friction with hair when compared to the friction between the base
material from which the carrier is made and hair. The macroscopic
texture may in particular be realized as ridges extending in
longitudinal cylinder direction, which ridges may have a height in
a range of between about 0.02 mm to about 2.0 mm, in particular of
between about 0.05 mm to 0.5 mm, further in particular a value of
about 0.1 mm In addition, the circumferential distance between the
ridges may lie in a range of between 0.2 mm to about 2.0 mm The
microscopic texture may in particular be achieved by a certain
roughness, which may be realized by filling material in the base
material, e.g. glass fibers or ceramic particles.
[0036] In some embodiments of an attachment for an epilator or an
epilator in accordance with at least one aspect of the present
disclosure, at least a clamping unit is arranged on a carrier, e.g.
a clamping cylinder or a clamping disc, which clamping unit has a
clamping element having a clamping section that has a clamping
surface and a winged section that has a guiding surface, which
guiding surfaces angles outwardly away from the clamping surface
(i.e. the winged section angles outwardly away from the clamping
section) and wherein the guiding surface has a three-dimensional
shape, i.e. the guiding surface does not lie in a plane in a
Cartesian coordinate system.
[0037] In some embodiments of an attachment for an epilator or an
epilator in accordance with at least one aspect of the present
disclosure, at least a clamping unit is arranged on a carrier, e.g.
a clamping cylinder or a clamping disc, which clamping unit has a
moveable clamping element having a clamping section and a winged
section, wherein the winged section is flexible or is hinged at the
clamping section and wherein the winged section is under a
pre-stress such that it outwardly angles away from the clamping
section at a preset value in an unconstraint value and wherein the
angle with which the winged section angles away from the clamping
section can be modified (in particular reduced) by a force acting
against the pre-stress. In particular, the force acting against the
pre-stress may be provided by a fixed wall element against which a
free end of the winged section abuts, while the clamping unit is in
an open position and along which fixed wall element the free end of
the winged section will glide at least during a part of the
movement when the moveable clamping element is moved such that the
angle with which the winged section angles away from the clamping
section is modified (in particular is increased).
[0038] FIG. 1 is a depiction of an example embodiment of an
epilator 1 having a detachable attachment 10 and a housing section
20 that can be held in a user's hand. The housing section 20 may
comprise an on/off-switch 21 (which may also be used to switch
between different speed settings) and/or a grip area 22 that may be
made from a (in particular structured) friction-enhanced material,
e.g. a thermoplastic elastomer or a natural rubber. The housing
section may also comprise a drive and/or an energy source (e.g. an
accumulator). In the shown embodiment, the attachment 10 comprises
a clamping cylinder 11 having a plurality of clamping units 12. The
clamping cylinder 11 is arranged for driven movement around its
centre axis A (i.e. the longitudinal cylinder axis) such that the
clamping units 12 move along a hair capture direction D. The
attachment 10 may comprise a detachable cap unit 13 havening an
opening 14 through which the clamping cylinder 11 extends for being
brought into contact with a user's skin. The opening 14 defines an
effective width E of the clamping cylinder 11 measured in
longitudinal cylinder direction, which is the width over which the
epilator can clamp and pluck hairs during operation. A user will
typically move the epilator over the skin along a movement
direction M which coincides with the hair capture direction D. As
will be explained in more detail further below, the clamping units
12 each comprise two clamping elements of which at least one
clamping element is arranged to be moveable. The clamping elements
are arranged for cyclical movement between an open position in
which hairs can enter into a gap extending between clamping
surfaces of the clamping elements and a closed position in which
the clamping surfaces abut on each other at least along a clamping
line. As is generally known, hairs that are clamped by the clamping
units in the closed position will be eventually plucked from the
skin when the clamping unit continues to move along the hair
capture direction D while the clamping unit continues being in the
closed position. Patent document EP 1 796 501 B1 generally
describes an epilator having a clamping cylinder with a plurality
of clamping units; the content of said document shall be
incorporated herein by reference.
[0039] While in FIG. 1 and in the below example embodiments, an
epilator or an attachment for an epilator is discussed that has a
clamping cylinder carrying the clamping unit, the clamping unit may
be arranged at any other carrier arranged for being driven along a
hair capture direction. E.g. the clamping unit may be provided at a
disc that is arranged for driven rotation around its centre
axis.
[0040] FIG. 2 shows an example embodiment of an attachment 10 for
an epilator shown in its detached state, which attachment 10 is in
accordance with the attachment discussed with respect to FIG. 1.
While it is here shown that an attachment for an epilator is
detachable, this shall not exclude that the features discussed with
respect to an attachment can also be realized at an epilator not
having a detachable attachment, i.e. where the clamping unit is
arranged at a carrier (e.g. a clamping cylinder) at the
epilator.
[0041] Both Epilator and attachment of FIGS. 1 and 2 comprise a
clamping cylinder with a lower level surface that is provided with
a (non gliding) friction surface 23 which is either made by an
elastomeric coating or an increased surface roughness.
[0042] FIG. 3A shows an example embodiment of a clamping cylinder
30 shown in a perspective view.
[0043] A plurality of clamping units 31 is arranged on the clamping
cylinder 30. Each clamping unit 31 comprises a fixed clamping
element 32 and a moveable clamping element 33. The fixed clamping
elements 32 may be made integral with the clamping cylinder base
material, e.g. the fixed clamping units may be made from a plastic
material and may be manufactured by a plastic injection molding
process together with a part of the clamping cylinder. As has been
mentioned before, the clamping elements 32, 33 are arranged for
cyclic movement between an open position in which a gap 34 extends
between the clamping elements such that hairs can enter into the
gap and a closed position in which the clamping elements abut on
each other and thus clamp hairs having been in the gap. At least
one wing section of one of the moveable or fixed clamping element
comprises an outermost arc shaped portion. The clamping section of
at least one of the moveable or fixed clamping element comprises
also an outermost arc shaped portion. Thus the clamping elements
32, 33 have outer surfaces 32A, 33A that essentially lie on the
surface of an enveloping cylinder. The outer surfaces 32A, 33A are
intended for contact with a user's skin during operation. A regular
pattern of ridges 36 extending in longitudinal cylinder direction
on a lower level of the clamping cylinder surface (i.e. on a level
of the clamping cylinder below the enveloping cylinder--see FIG. 6)
is provided in the shown example embodiment. In some embodiments,
the enveloping cylinder may have a diameter of about 19 mm and the
cylinder defined by the lower level surface (i.e. the surface that
is defined by the top parts of the ridges) may have a diameter of
about 17 mm. In some embodiments, the ridges may have a height of
between 0.05 mm to 0.5 mm or e.g. 0.1 mm. The geometry and function
of the ridges (or similar structures) will be explained further
below in more detail, but such structures as the shown ridges serve
to erect hairs that lie close to the skin. The clamping cylinder 30
comprises an axis 39 that may be borne by respective bearings
provided at the attachment so that the clamping cylinder 30 is
enabled to rotate around its central axis C in rotation direction
R. A spring 38 presses the clamping cylinder parts together and
provides the clamping force with which the clamping elements are
pressed together in their closed position. The clamping cylinder 30
may also comprise at least one gear wheel 37 provided for meshing
with a further gear wheel that may be driven during operation,
which further gear wheel may be a part of the housing section.
[0044] While the example embodiment of a clamping cylinder shown in
FIG. 3A has a plurality of clamping elements, it is noted that in
accordance with the present disclosure it is sufficient that a
clamping cylinder has at least one clamping unit. It is also noted
that in case of two or more clamping units, the clamping units may
each be different, e.g. one clamping unit may comprise a fixed and
a moveable clamping element, another clamping unit may comprise two
moveable clamping units. It is also generally noted that all
features shown and discussed with respect to an example embodiment
do not necessarily need to be seen as disclosed only in that
combination but that all features that can be separated without
violating the gist and scope of the present disclosure shall be
considered as being disclosed independently from all other
features. E.g. the ridges provided on the clamping cylinder
discussed in connection with FIG. 3A may not only be an optional
feature but may indeed be considered as an independent aspect of
the present disclosure.
[0045] It is noted that in general an epilation cylinder may be
equipped with a friction enhanced lower level surface, which
friction enhancement (with respect to hairs) may be achieved by
macroscopic structures (e.g. ridges as shown in and discussed with
respect to FIG. 3A) or by microscopic structures (e.g. a certain
roughness) or by a material choice providing an increased friction
with hairs (e.g. keratin filaments) when compared to the plastic
material used for making the clamping cylinder. E.g. the lower
level surface of the clamping cylinder may have a coating of an
artificial rubber. The friction enhancement of a lower level
surface was found to potentially increase the number of hairs that
become erected out of a position where they lie close to the skin.
Hairs lying close to skin still have a certain elevation above the
skin surface. The lower level surface is thus retracted from the
enveloping cylinder by a typical value of between about 0.25 mm to
about 3.0 mm, in particular of between about 0.5 mm to 1.5 mm, in
order to provide a good hair erection effectiveness. With
additional hairs being erect, the efficiency of the epilator is
likely to be increased. Whether the enhanced friction of the lower
level surface of the epilator is provided by microscopic or
macroscopic structures realized in the base material of the
clamping cylinder or by a coating or layer of a different material
covering the lower level surface, this feature is considered as an
independent aspect of the present disclosure, while this feature
may also be combined with all other features of the present
disclosure.
[0046] FIG. 3B shows a portion of a clamping cylinder similar to
that of FIG. 3A. The enlarged view of FIG. 3B illustrates the
ridges 36 which may be in this example provided as grooves
alternating with flattened high portions on a lower level portion
of the clamping cylinder 30. It is a regular repeating pattern that
is injection molded into the surface structure. The ridges 36
extend parallel to the longitudinal cylinder axis C (shown in FIG.
3A).
[0047] FIG. 4A shows an example embodiment of a schematically drawn
clamping unit 100 shown in an open position, which clamping unit
100 may be arranged on a clamping cylinder as shown in FIG. 3A. The
clamping unit has a moveable clamping element 110 and a fixed
clamping element 120 that are arranged vis-a-vis. The moveable
clamping element 110 may be made from a metal sheet such as a
stainless steel sheet material, while it should not be excluded
that the moveable clamping element may be made from other materials
such as plastic or reinforced plastic. The fixed clamping element
120 may be an integral part of at least a part of a clamping
cylinder and may be made from a plastic material (e.g. via a
plastic injection molding process), in particular from a plastic
material that is reinforced by a filling substance such as glass
fibers or ceramic particles.
[0048] The moveable clamping element 110 has a clamping section 111
and a winged section 112. The clamping section 111 extends in a
length direction L with a length L1 and has a clamping surface 113.
The length direction L coincides with the hair capture direction
(see reference numeral D in FIG. 1) along which the clamping unit
100 will be moved during operation. The fixed clamping element 120
has a clamping section 121 and a winged section 122. The clamping
section 121 extends in a length direction L with a length L1 and
has a clamping surface 123 that faces the clamping surface 113 of
the moveable clamping element 110. The position of the two
oppositely arranged clamping elements 110, 120 coincide in length
direction L so that in a closed position (FIG. 4B), the effective
clamping length is also L1. In the open position as shown in FIG.
4A, a gap 130 extends between the clamping surfaces 113, 123 of the
moveable and fixed clamping elements 110, 120. The gap 130 has in
the open position a minimal gap width W2 in a width direction W
(the width direction W being perpendicular to the length direction
L, i.e. the width direction is perpendicular to the hair capture
direction). As the clamping sections 111, 121 may not necessarily
be parallel to each other in the open position, the minimal gap
width W2 may not be the same over the whole gap extension. The
minimal gap width W2 is sized such that hairs can feed into the
gap. While the diameter of typical human hairs may lie in a range
of 80 micrometer .+-.40 micrometer, the gap width W2 may lie in a
range of between about 0.1 mm to about 2.0 mm, in particular in a
range of between about 0.4 mm to about 1.4 mm In some embodiments,
the minimal gap width W2 may be about 0.6 mm.
[0049] The winged section 122 of the fixed clamping element 120 has
a guiding surface 124 that outwardly angles away from the clamping
surface 123 of the clamping section 121 with an angle 125 such that
a first side of a funnel is formed on a front side 101 of the
clamping unit 100. The front side 101 of the clamping unit 100 is
the side from which hairs approach the clamping unit 100 during
operation, when the clamping unit 100 is moved along the hair
capture direction that here coincides with the length direction L.
The guiding surface 124 of the winged section 122 extends in length
direction L over a length L2 and in the width direction W over a
width W3. The winged section 112 of the moveable clamping element
110 has a guiding surface 114 that outwardly angles away from the
clamping surface 113 of the clamping section 111 with an angle 115
such that a second side of the funnel is formed. The guiding
surface 114 of the winged section 112 extends in length direction L
over a length L3 and in the width direction W over a width W1. The
total effective width W4 over which the clamping unit 100 thus may
catch and hence plug hairs is given by the sum of the widths' of
the winged sections 112 and 122 and of the gap width W2,
W4=W1+W2+W3. The total effective width over which the clamping unit
catches hairs may be between 2 mm to 7 mm which is the sum of the
widths' of both adjacent winged sections within a clamping unit and
of the gap width between both clamping sections in its open
position.
[0050] As is generally known, the moveable clamping element 120 may
be spring loaded such that the clamping unit 100 is in the open
position as long as a respective actuator is not forcing the two
clamping elements 110, 120 together.
[0051] During operation, the clamping unit 100 will be moved
relatively to the user's skin such that hairs growing on the skin
will approach the clamping unit 100 from the front side 101 of the
clamping unit 100 and will be guided by the guiding surfaces 114
and 124 into the gap 130, which gap will be closed until the
clamping surfaces 113, 123 are urged together so that hairs in the
gap 130 will then be clamped and will eventually be plugged from
the skin due to the relative movement between the clamping unit 100
and the user's skin. The relative movement between the clamping
unit 100 and the user's skin typically has two components: the
usually faster component is provided by the drive of the epilator
that drives the clamping unit 100 into motion, e.g. by rotating a
clamping cylinder into rotation, and by a usually slower component
that is given by the movement the user introduces by manually
moving the epilator over the skin. The clamping cylinder may be
driven with a number of rotations per minute (rpm) that lie in a
range of between about 500 rpm to about 5000 rpm, in particular in
a range of between about 1000 rpm to about 2500 rpm. In some
embodiments, the clamping cylinder may rotate in a range of between
about 1300 rpm to about 1900 rpm.
[0052] In some embodiments, the width W3 by which the guiding
surface 124 of the fixed clamping element 120 extends in width
direction W may be set to a value that allows hairs that are caught
at the outer edge of the first side of the funnel to become clamped
by the clamping unit. This value may in particular depend on the
typical hair length of hairs that will become epilated and a
typical time period between epilation events. A typical growth
length for hairs growing on human skin is about 0.2 mm per day. A
typical period between epilation events may be 2 weeks, i.e. 14
days, so that the hair has grown 2.8 mm between respective
epilation events. During epilation, some hairs that are not plucked
from the skin typically break about 0.5 mm-10 mm below the skin
surface, so that the hair length of the broken hairs above the skin
may roughly be in the range of 1.8 mm to 2.3 mm (hairs that are
plucked together with at least a part of the hair root require a
certain period for growing again as first the hair root needs to be
rebuild). Assuming that a certain length of the hair needs to
extend into the gap of the clamping unit for reliable epilation,
typical values for the width W3 of the guiding surface of the fixed
clamping element may thus lie in a range of between about 0.4 mm to
about 2.0 mm As the moveable clamping element 110 moves towards the
fixed clamping element 120, the effective width of the second side
of the funnel is determined by the sum of the gap width W2 and the
width W1 of the guiding surface 114 of the moveable clamping
element 110. Thus, a symmetric setting of the funnel widths would
require W1 to be set to W3 minus W2, W1=W3-W2. That means that for
a symmetric guiding efficiency the winged sections may be
asymmetrically realized, e.g. the guiding surface 114 of the winged
section 112 of the moveable clamping element 110 may have a shorter
width W1 in comparison to the width W3 of the guiding surface 124
of the winged section 122 of the fixed clamping element 120. In
other words the fixed clamping unit comprises a winged section that
is longer and/or with broader width extension than the winged
section of the moveable clamping unit.
[0053] In some embodiments, the length L2 of the guiding surface
124 of the winged section 122 of the fixed clamping element 120 may
lie in a range of between about 2 mm and about 8 mm and the
respective width W3 may be in a range of between about 0.5 mm and
about 3.0 mm. In some embodiments, the length L2 may be about 5 mm.
In some embodiments, the width W3 may be about 1.5 mm, which may be
considered a value that nicely considers the above mentioned hair
length of broken hairs after two weeks and thus provides an adapted
high efficiency based on the typical hair length. A larger width W3
may increase efficiency further if hairs are longer (e.g. in case
that a longer period lies between epilation events), but a larger
width w3 also requires more available space on the carrier (e.g.
the clamping cylinder) on which the clamping unit is arranged. In
some embodiments, the length L3 of the guiding surface 114 of the
winged section 112 of the moveable clamping element 110 may be in a
range of between about 0.1 mm and about 4.0 mm and the width W1 may
be in a range of between about 0.1 mm and about 2.0 mm. In some
embodiments, the length L3 may be about 2 mm. In some embodiments,
the width W1 may be about 0.8 mm.
[0054] In some embodiments, the angle 115 between the clamping
surface 113 and the guiding surface 114 of the winged section 112
of the moveable clamping element 110 and/or the angle 125 between
the clamping surface 123 and the guiding surface 124 of the winged
section 122 of the fixed clamping element 120 may lie in a range of
between about 5 degree to about 45 degree, in particular in a range
of between about 10 degree to about 30 degree. In some embodiments,
the respective angles 115, 125 may be different; in particular, the
angle 115 may be larger than the angle 125. In some embodiments,
the angle 115 between the clamping surface 113 and the guiding
surface 114 of the winged section 112 of the moveable clamping
element 110 may be about 22.5 degrees. In some embodiments, the
angle 125 between the clamping surface 123 and the guiding surface
124 of the winged section 122 of the fixed clamping element 120 may
be about 16 degrees.
[0055] In some embodiments, alternatively or additionally the width
W3 by which the guiding surface 124 of the fixed clamping element
120 extends in width direction W is about the same as the sum of
the minimal gap width W2 and of the width W1 of the guiding surface
114 of the winged section 112 of the moveable clamping element 110,
W3.apprxeq.W1+W2, in particular wherein W3 differs by not more than
10% from W2+W1, optionally by not more than 5%, further in
particular where W3 is identical to W1+W2, W3=W1+W2.
[0056] FIG. 4B schematically shows the clamping unit 100 shown in
FIG. 4A in its open position in its closed position. In order to
reach the closed position, the moveable clamping element 110 is
moved generally along a closure direction M as indicated in FIG. 4A
towards the fixed clamping element 120 such that in the closed
position the clamping surface 113 of the moveable clamping element
110 abuts onto the clamping surface 123 of the fixed clamping
element 120 at least along a clamping line, optionally wherein the
clamping surfaces 113, 123 abut on each other in a laminar manner.
While it may be sufficient that the clamping surfaces only abut on
each other along a clamping line, a high pressure may be present
along the clamping line and hairs may be cut or may break during
the plucking procedure due to this high pressure. Hence, a laminar
clamping area may tend to reduce the number of hairs that are cut
or that break.
[0057] One may define an effective hair catching area A, which is
the area from which hairs are clamped by a clamping unit,
neglecting the effect of guiding surfaces that may guide hairs from
an enlarged area into the gap. The effective hair catching area A
is then depending on the clamping length l of the clamping unit,
the closure velocity c with which the clamping elements of the
clamping unit are closed, the gap width d, and the velocity v with
which the clamping unit is moved relative to the skin, so that
A=d(l-1/2vd/c). A typical closure speed c may lie in the range of
between about 0.7 m/s to about 1.3 m/s, in particular at about 1
m/s. Thus, the effective hair catching area in relation to the
closure time for a closure speed of 1000 mm.sup.2/s for a typical
clamping length of 4.0 mm as known from prior art devices, a gap
width of 0.9 mm and a movement velocity of 2000 mm/s is 2790 mm/s.
The overall hair epilation effectiveness will become increased if
the parameters of a clamping unit and the epilator are chosen such
that the effective hair catching area in relation to the closure
time is at least 3500 mm.sup.2/s or at least 4000 mm.sup.2/s or at
least 4500 mm.sup.2/s.
[0058] FIG. 5A is a schematic depiction of a clamping unit 200 of
an epilator in accordance with at least an aspect of the present
disclosure, which clamping unit 200 is shown in an open position.
The clamping unit 200 comprises a moveable clamping element 210 and
a fixed clamping element 220. Similarly to the clamping unit 100
shown in FIGS. 4A and 4B, the moveable clamping element has a
clamping section 211 and a winged section 212, where the clamping
section 211 has a clamping surface 213 and the winged section 212
has a guiding surface 214 that angles outwardly away from the
clamping surface 213 at an angle 215. Accordingly, the fixed
clamping element 220 has a clamping section 221 and a winged
section 222, where the clamping section 221 has a clamping surface
223 and the winged section 222 has a guiding surface 224 that
angles outwardly away from the clamping surface 223 at an angle
225. The clamping surfaces 213 and 223 are arranged essentially
opposite to each other and are separated in the open position by a
gap 230 that is sized to receive hairs. In the shown example
embodiment, the winged section 212 of the moveable clamping element
210 is hinged at the clamping section 211 with a hinge 219 and the
winged section 211 has a free end 216 that is in contact with a
stopper element 240. The hinge 219 may be realized by an elastic
material arranged between the clamping section 211 and the winged
section 212, which both may be made from a metal sheet material.
The winged section 212 is under a pre-stress F such that the angle
at which the guiding surface 214 would angle outwardly away from
the clamping surface 213 in an unconditioned situation would be
larger than angle 215 indicated in FIG. 5A, which angle 215 is
determined by the relative position of a stopper element 240
providing a constraint for the winged section 212 to move under the
present pre-stress F. As is indicated by arrow N, the moveable
clamping element 210 will be moved towards the fixed clamping
element 220 in order to achieve the closed position shown in FIG.
5B. When the movable clamping element 210 is moved along direction
N, the free end 216 of the winged section 212 of the moveable
clamping element 210 will stay in contact with the stopper element
240 due to the acting pre-stress F and will move along direction P.
FIG. 5B schematically shows the closed position of the clamping
unit 200 shown in FIG. 5A. In the closed position, the clamping
surfaces 213, 223 of the moveable and the fixed clamping elements
210, 220 abut on each other at least along a clamping line. In the
closed position, the guiding surface 214 of the winged section 212
of the moveable clamping element 210 is angled outwardly away from
the clamping surface 213 at an angle 215A that is larger than the
angle 21 the respective surfaces have in the open position shown in
FIG. 5A.
[0059] It is noted that the provision of a winged section of a
moveable clamping element being under a pre-stress such that the
width of the guiding surface of the winged section increases when
the clamping unit is closed is considered as an independent aspect
of the present disclosure, while it shall not be excluded that this
feature may be combined with all other features described in the
present disclosure.
[0060] In some embodiments, a plurality of 40 clamping units as
shown in FIG. 4A or 5A may be arranged on a clamping cylinder as
shown in FIG. 3A. The clamping cylinder may have an effective
clamping width of 31.9 mm, while the gap width of each clamping
unit may be 0.6 mm and the total funnel width of each clamping unit
may be about 2.6 mm. Then, assuming that the gaps of the clamping
units are arranged on the clamping cylinder such that they do not
overlap in longitudinal cylinder axis direction, the total gap
width (i.e. the sum of all the 40 gap widths of each 0.6 mm) is 24
mm, which means that the clamping cylinder has a gap coverage of
only about 61%. On the other hand, as the added total funnel width
of all clamping units is 104 mm, this means that the clamping
cylinder is covered by the funnels at about 326%. In other words,
each hair growing on the skin may get clamped and plucked by more
than three clamping units per revolution of the clamping cylinder.
It is considered a general aspect of the present disclosure that
the gap coverage of an epilation cylinder is less than 100% while
the funnel coverage is above 100%. In particular, the gap coverage
may be in a range of between about 20% to about 95% (in particular
of between about 50% to about 80%) and additionally or
alternatively the funnel coverage may be in a range of about 105%
to about 500% (in particular of between about 150% to about 450%
and further optionally where the lower funnel coverage value may be
at least 200% or even at least 300%). It has been found that a
distance between clamping units in longitudinal cylinder axis
direction that is larger than the gap width (in particular wherein
the distance is at least 25% larger than the gap width or further
in particular wherein the distance is at least 30% larger than the
gap width) and optionally additionally with a circumferential
arrangement of the clamping units such that each clamping unit has
a different angular position on the circumference of the clamping
cylinder (e.g. in case of 40 clamping units, the angular distance
between the clamping units may be 9 degrees) supports the provision
of enough space to realize the large funnel widths for the clamping
units.
[0061] FIG. 6 is a cross sectional cut through an example
embodiment of a clamping cylinder 300, where the cross sectional
cut was taken in a plane perpendicular to the longitudinal cylinder
axis. A movable clamping element 310 can be seen that has a
clamping surface 313 that extends along a clamping length l (the
clamping length l being measured at the top level of the moveable
clamping element 310, which top level is defined by the top surface
310A of the moveable clamping element 310, which top surface 310A
is intended to contact the skin of a user during operation). It is
also noted that in the shown embodiment, the outer surface 310A of
the moveable clamping element follows the curvature of the
cylinder. Also, three cuts through fixed clamping element parts can
be seen, one of which is exemplary identified as fixed clamping
element 320 having a top surface 320A intended for contact with the
skin of a user during operation. The outer surfaces 310A, 320A lie
on an outer enveloping cylinder that has a diameter D1, which
diameter D1 may lie in a range of between about 10 mm to about 40
mm. It can further be seen in FIG. 6 that a regular pattern of
ridges 336 (which may extend parallel to the cylinder axis C as is
shown in FIG. 3A) is arranged on a lower level cylinder surface,
which lower level cylinder is coaxial with the enveloping cylinder
and has a diameter D2, where D2<D1. In some embodiments, D2 may
be around 80% of D1. In some embodiments, the clamping length l
extends over about 36 degrees of the angular range measured from
the centre point of the cross sectional cut or in other words, the
clamping length l may be about 10% of the perimeter of the outer
enveloping cylinder, i.e. l=0.12.pi.D1/2. Generally, the clamping
length l may be in a range of between about 8% to about 12% of the
perimeter of the enveloping cylinder, in particular it may lie in a
range of between about 8.5% to about 10.5%. While generally an
increase of the clamping length 1 may increase the efficiency of
the clamping cylinder, the clamping element also needs to have
contact with the skin over its clamping length as otherwise the
efficiency may not further increase due to non-clamped hairs. It
has been found that a clamping length of about one tenth of the
perimeter of the clamping cylinder defines a compromise between
efficiency increase due to length increase and reliable skin
contact over the full length extension.
[0062] The dimensions and values disclosed herein are not to be
understood as being strictly limited to the exact numerical values
recited. Instead, unless otherwise specified, each such dimension
is intended to mean both the recited value and a functionally
equivalent range surrounding that value. For example, a dimension
disclosed as "40 mm" is intended to mean "about 40 mm."
[0063] Every document cited herein, including any cross referenced
or related patent or application, is hereby incorporated herein by
reference in its entirety unless expressly excluded or otherwise
limited. The citation of any document is not an admission that it
is prior art with respect to any invention disclosed or claimed
herein or that it alone, or in any combination with any other
reference or references, teaches, suggests or discloses any such
invention. Further, to the extent that any meaning or definition of
a term in this document conflicts with any meaning or definition of
the same term in a document incorporated by reference, the meaning
or definition assigned to that term in this document shall
govern.
[0064] While particular embodiments of the present invention have
been illustrated and described, it would be obvious to those
skilled in the art that various other changes and modifications can
be made without departing from the spirit and scope of the
invention. It is therefore intended to cover in the appended claims
all such changes and modifications that are within the scope of
this invention.
* * * * *