Cosmetic Applicator

Abstract

A cosmetic applicator with which eyelashes can be easily increased in apparent fullness and/or curled may include an applying portion consisting of a linear core wire portion comprising at least two metal core wires helically twisted together, and a multiplicity of bristles pinched by a twisted portion of the core wires and continuing in helicoidal fashion in an axial direction of the core wire portion while being distributed in radial fashion thereabout. The applying portion may have a three-dimensional external shape which is a locus formed by causing a shape that is substantially polygonal with interior angles that are each not greater than 180° as seen in sectional view at any position along an axial direction of the core wire portion to be rotated in continuous fashion in a circumferential direction about the axis of the core wire portion as it is made to advance in the axis direction of the core wire portion.

Description

CROSS-REFERENCE TO RELATED APPLICATION, BENEFIT CLAIM, AND INCORPORATION BY REFERENCE

This application claims benefit of priority under 35 USC 119(a)-(d) to Japanese Patent Application No. 2017-106909, entitled “Cosmetic Applicator”, filed 30 May 2017, the content of which is hereby incorporated herein in its entirety by reference.

FIELD OF THE INVENTION

The present invention relates to a cosmetic applicator to be used to apply a cosmetic such as mascara, and a manufacturing method thereof.

BACKGROUND

In accordance with one embodiment of a cosmetic applicator for applying cosmetic such as mascara to eyelashes, the cosmetic applicator might include an applying portion consisting of a linear core wire portion comprising a pair of metal core wires and bristles distributed in radial fashion from a twisted portion of the core wires that continues in helicoidal fashion and is formed by causing a multiplicity of bristles with prescribed lengths that are arranged in parallel band-like fashion to be pinched between the pair of core wires and twisted thereabout in helical fashion.

There being a need for a cosmetic applicator such as might easily increase the apparent fullness of eyelashes and easily curl eyelashes, and it being preferred that such different purposes might be achieved in the context of a single cosmetic applicator, in one embodiment, a portion with short bristles and a portion with long bristles might be formed in the applying portion. For example, where a groove is formed in the applying portion, this may easily permit attainment of increase in apparent fullness of eyelashes by permitting cosmetic to be retained in a portion with short bristles at the groove portion, and may easily permit attainment of curling of eyelashes by a portion with long bristles other than the groove portion.

In an embodiment in which the cosmetic applicator has a groove and the groove is in a circumferential direction, when applying a cosmetic to eyelashes, it may be difficult for eyelashes to enter the groove portion, preventing attainment of the desired increase in apparent fullness of eyelashes, and the difference in level produced by the groove portion may make curling difficult, which would be inconvenient for use.

Furthermore, in an embodiment in which the cosmetic applicator has a groove and the groove is in an axial direction of the brush, it may sometimes be the case that eyelashes are increased in apparent fullness only at the groove portion, and are not curled, as a result of which there may be nonuniformity in the manner in which makeup is applied.

There is therefore a need for a cosmetic applicator which may be conveniently used and with which eyelashes can be easily increased in apparent fullness and/or curled.

SUMMARY OF INVENTION

The present invention relates to a cosmetic applicator to be used to apply a cosmetic such as mascara, and a manufacturing method thereof.

To address one or more of the needs described above, one aspect of the present invention provides a cosmetic applicator comprising applying portion(s).

In some embodiments, an applying portion may have a linear core wire portion formed of at least two metal core wires helically twisted together.

In some embodiments, the applying portion may further have a multiplicity of bristles pinched by a twisted portion of the core wires and continuing in helicoidal fashion in an axial direction of the core wire portion while being distributed in radial fashion thereabout.

The applying portion may have a three-dimensional external shape which is a locus formed by causing a third shape that is substantially polygonal with interior angles that are each not greater than 180° as seen in sectional view at any position along the axial direction of the core wire portion to be rotated in continuous fashion in a circumferential direction about an axis of the core wire portion as it is made to advance along the axial direction of the core wire portion.

In some embodiments, the third shape may be a bilaterally symmetrical shape formed by superposing a first shape and a second shape. The first shape may be a bilaterally symmetrical polygonal shape. An uppermost side of the first shape might be the longest side of the first shape. The second shape might be an isosceles triangle. The bottommost side of the second shape might be the uppermost side of the first shape. The bottommost side of the second shape might be straddled in isogonal fashion by two sides of the second shape that are each longer than any of the sides making up the first shape except for the uppermost side of the first shape.

In some embodiments, the core wire portion may be eccentrically located, being disposed in the direction of the first shape, from a midpoint along a line of bilateral symmetry of the third shape.

In one embodiment, the third shape may be a bilaterally symmetrical pentagonal shape. In such an embodiment, the first shape might be an isosceles trapezoid obtained by bisecting a regular hexagon at two vertices thereof. In such an embodiment, the second shape might be an isosceles triangle, the bottommost side of which is the longest side of the first shape. In such an embodiment, the second shape might have two sides that are each longer than any one side of the regular hexagon.

In another embodiment, the third shape may be a substantially hexagonal shape. In such an embodiment, the first shape might be a bilaterally symmetrical trapezoid. In such an embodiment, the second shape might be a substantially quadrilateral shape in which what would otherwise be an angle formed by the two sides of the second shape that are each longer than any of the sides making up the first shape except for the uppermost side of the first shape is instead made to be an arc centered on the core wire portion.

A constitution having features of one or more embodiments described above in accordance with the foregoing aspect of present invention may make it possible to provide an applicator which is such that the entirety thereof can be easily inserted in the spaces between eyelashes, and which is such that the corners thereof can be made to easily catch eyelashes, and with which eyelashes can be easily increased in apparent fullness and easily curled.

Another aspect of the present invention provides a method for manufacturing such a cosmetic applicator.

Such a manufacturing method may comprise a preparation step. The preparation step may comprise forming a cosmetic brush precursor that includes an applying portion consisting of a linear core wire portion formed of at least two core wires and bristles distributed in radial fashion from a twisted portion of the core wires that continues in helicoidal fashion and is formed by causing a multiplicity of bristles with prescribed lengths that are arranged in parallel band-like fashion to be pinched between the at least two core wires and twisted thereabout in helical fashion.

Such a manufacturing method may further comprise a trimming step. The trimming step may comprise forming an external shape of the applying portion into a substantially columnar shape by uniformly cutting tip ends of the bristles constituting the applying portion.

Such a manufacturing method may further comprise a position adjusting step. The position adjusting step may comprise adjusting a positional relationship between the cosmetic brush precursor and a machining device including a cutting blade and a receiving blade which are of prescribed width and are flat blades to shear the bristles constituting the applying portion.

Such a manufacturing method may further comprise a main machining step. The main machining step may comprise forming a shear surface extending in helicoidal fashion on the external shape of the applying portion by shearing tip ends of the bristles of the applying portion by relatively moving the machining device parallel to the axial direction of the core wire portion while rotating the cosmetic brush precursor around the core wire portion.

It is preferred at the main machining step that the cosmetic brush precursor be rotated a prescribed angle about the core wire portion, and that by carrying out position adjusting step(s) and main machining step(s) in iterative fashion a prescribed number of times, it is preferred that form an applying portion with a desired shape.

Preferably, the prescribed number of times is equal to the number of straight sides constituting the third shape.

By the manufacturing method according to this aspect, a cosmetic applicator which is conveniently used and with which eyelashes are easily increased in apparent fullness and easily curled, can be manufactured.

Although the present invention is preferably applied for use with liquid mascara or other such liquid cosmetic, the present invention is not limited thereto, it also being possible to apply the present invention for use with mascara or other such cosmetic in solid, semi-solid, cake, cream, and/or other form.

BENEFIT OF INVENTION

Some embodiments of the present invention make it possible to provide a cosmetic brush which is conveniently used and with which eyelashes can be easily increased in apparent fullness and/or curled.

BRIEF DESCRIPTION OF DRAWINGS

Many aspects of the invention can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is a sectional view, except that applying portion 8 is not shown, of a mascara cosmetic product 1 showing an example of a cosmetic applicator according to a first embodiment.

FIG. 2 schematically shows external shape of a cosmetic brush 19 according to the first embodiment, (a) being a front view thereof, (b) being a view of an end surface 34 toward a base end of the applying portion 8, (c) being an explanatory view of a shape of the surface 34, (d) being a perspective view thereof, (e) being a perspective view thereof observed from a different direction, (f) being a sectional view thereof along II(f)-II(f) indicated at (a), (g) being a sectional view thereof along II(g)-II(g) indicated at (a), (h) being a sectional view thereof along II(h)-II(h) indicated at (a), (i) being a sectional view thereof along II(i)-II(i) indicated at (a), and (j) being a sectional view thereof along II(j)-II(j) indicated at (a).

FIG. 3 schematically shows external shape of a cosmetic brush 119 according to a second embodiment, (a) being a front view thereof, (b) being a view of an end surface 64 toward a base end of an applying portion 108, (c) being an explanatory view of a shape of the surface 64, (d) being a perspective view thereof, (e) being a perspective view thereof observed from a different direction, (f) being a sectional view thereof along III(f)-III(f) indicated at (a), (g) being a sectional view thereof along III(g)-III(g) indicated at (a), (h) being a sectional view thereof along III(h)-III(h) indicated at (a), (i) being a sectional view thereof along III(i)-III(i) indicated at (a), (j) being a sectional view thereof along III(j)-III(j) indicated at (a), and (k) being a sectional view thereof along III(k)-III(k) indicated at (a).

FIG. 4 is a flowchart of a manufacturing method.

FIG. 5 is an explanatory view describing a preparation step.

FIG. 6 is an outline drawing of a cosmetic brush precursor 39.

FIG. 7 shows explanatory views of a position adjusting step and a machining device 40, (a) being a perspective view thereof, and (b) being a front view thereof.

FIG. 8 is a detail view of a surface 34.

FIG. 9 is a detail view of a surface 64.

FIG. 10 shows variations on sectional shape which may be employed at applying portion 8.

FIG. 11 shows variations on cosmetic applicator 2.

FIG. 12 shows position adjusting steps and main machining steps for forming applying portion 8, column (a) showing positional relationship between machining device 40 and surface 34 as it exists before the main machining step, column (b) showing shape of applying portion 8 as it exists after the main machining step, and column (c) showing the surface 34 as it exists after the main machining step, with the sequence (Machining Operation No.) of the position adjusting step and the main machining step that takes place at each respective row being indicated in the leftmost column.

FIG. 13 shows position adjusting steps and main machining steps for forming applying portion 108, column (a) showing positional relationship between machining device 40 and surface 64 as it exists before the main machining step, column (b) showing shape of applying portion 108 as it exists after the main machining step, and column (c) showing surface 64 as it exists after the main machining step, with the sequence (Machining Operation No.) of the position adjusting step and the main machining step that takes place at each respective row being indicated in the leftmost column.

DETAILED DESCRIPTION

Hereinafter, preferred embodiments of a cosmetic applicator and a manufacturing method thereof according to the present invention are described with reference to the drawings.

First Embodiment

As shown in FIG. 1, a mascara cosmetic product 1 in accordance with the present embodiment includes mascara container 10 that contains mascara 16, and a cosmetic applicator 2 that can be mounted on a reduced-diameter portion 12 of the mascara container 10.

The cosmetic applicator 2 of the present embodiment includes a cap 4, a base shaft 6, and a cosmetic brush 19. The cosmetic brush 19 includes a core wire portion 18 and an applying portion 8.

With additional reference to FIGS. 5 and 6, applying portion 8 in the present embodiment is such that, from a twisted portion of twisted core wires 18a (hereinafter “core wire portion 18”), bristles 20 pinched by the core wire portion 18 extend radially therefrom uniformly about the circumferential direction of the core wire portion 18 so as to be uniformly distributed after the fashion of a helicoid that extends along the axial direction of the core wire portion 18. A base shaft portion 18b of the core wire portion 18 engages with a hole 6b provided in the base shaft 6, and the base shaft 6 and the cosmetic brush 19 are formed in integral fashion with respect to each other. The cap 4 of the cosmetic applicator 2 which is screwed to the mascara container 10 is joined in integral fashion to a cylindrical base end portion 6a of increased diameter at the base shaft 6.

Mascara container 10 of the present embodiment is a bottomed cylinder having an upper end portion of reduced diameter, an opening being formed at the upper end of this reduced-diameter portion 12, and a wiper 14 being press-fit within or otherwise secured to the inner circumferential surface thereof. Male threads are provided on an outer circumferential surface of the reduced-diameter portion 12, and female threads are provided on a lower portion inner circumferential surface of the cap 4, to enable the cap 4 to be screwed to the reduced-diameter portion 12 of the mascara container 10. A wiper 14 disposed on an inner circumferential surface of the reduced-diameter portion 12 is formed of a cylindrical body made, for example, of rubber or plastic material, its bottom wall being at least partially open such that when the cosmetic applicator 2 is pulled out from the mascara container 10, this causes the base shaft 6 and the cosmetic brush 19 to be pulled out, and the applying portion 8 to be scraped off thereby, such that excessive mascara 16 adhering to the applying portion 8 is scraped off therefrom. The cosmetic applicator 2 is removably inserted within the mascara container 10, permitting a user to grasp the cap 4 and apply mascara 16 to eyelashes. When the mascara container 10 and the cap 4 are screwed to each other, the applying portion 8 is positioned slightly higher than the bottom portion of the mascara container 10.

Shape of Applying Portion

As shown in FIG. 2, external shape of applying portion 8 in the present embodiment is such that applying portion 8 has an end surface 34 toward the base shaft (hereinafter “base end surface 34”), an end surface 36 toward the tip (hereinafter “tip end surface 36”), and five side surfaces 22, 24, 26, 28, 30. The five side surfaces 22, 24, 26, 28, 30 are the side surfaces of a helicoid that extends along the central axis X of the core wire portion 18, the respective planes of these helicoid side surfaces being made to rotate about the central axis X by the same angular amount (e.g., 180°) in going from base end surface 34 to tip end surface 36.

As seen in sectional view, base end surface 34 of the present embodiment has a pentagonal shape comprising five line segments 22a, 24a, 26a, 28a, 30a which are respectively tangent to the five side surfaces 22, 24, 26, 28, 30. Note in the present embodiment that, as seen in sectional view, vertex 38a is farther from the center X′ of the core wire portion than the other vertices are therefrom, and the interior angle β at that vertex 38a is smaller than the interior angles at the other vertices. In the present embodiment, three line segments 28a, 30a, 22a are of mutually equal length, and perpendiculars 28d, 30d, 22d respectively drawn from these line segments 28a, 30a, 22a to center point X′ are also of mutually equal length. In the present embodiment, the remaining two line segments 24a, 26a are also of mutually equal length, and perpendiculars respectively drawn from these line segments 24a, 26a to the center point X′ are also of mutually equal length. In the present embodiment, end surface 34 has a symmetrical shape, exhibiting reflectional symmetry, as viewed along the central axis X of the core wire portion 18.

The applying portion 8 has a three-dimensional external shape formed by causing the sectional shape described above to be rotated, e.g., by 180°, in continuous fashion in the circumferential direction about central axis X as one proceeds along central axis X from end surface 34 to end surface 36. Therefore, as shown at (e) through (i) in FIG. 2, the cross-sectional shape of applying portion 8, comprising line segments 22b, 24b, 26b, 28b, 30b, 32b respectively tangent to the five side surfaces 22, 24, 26, 28, 30, is of the same pentagonal shape as end surface 34 regardless of where along central axis X the sectional view is taken, sectional views along central axis X being different from the sectional view of end surface 34 only with respect to the angle by which the sectional view at that location is rotated relative to the sectional view of end surface 34.

Benefit of First Embodiment

In accordance with the present embodiment, applying portion 8 includes a multiplicity of bristles 20 spreading out in radial fashion uniformly in a circumferential direction about core wire portion 18. Cross-sectional shape of applying portion 8 is pentagonal, and as seen in sectional view there are angular domain(s), i.e., positions in the circumferential direction, at which distances from tips of bristles 20 to central core wire portion 18, i.e., lengths of bristles 20, are short, and there are angular domain(s), i.e., positions in the circumferential direction, at which lengths of bristles are long. At portion(s) with long bristles 20, the bristles 20 may be better able to enter the spaces between eyelashes to curl and lift eyelashes. Portion(s) with short bristles 20 may be better able to retain mascara 16, more easily reach roots of eyelashes, and/or increase apparent fullness of eyelashes. By causing both types of portions to be present in the circumferential direction, it will be possible to apply mascara 16 to eyelashes by slightly rotating the cap 4 serving as grip, as a result of which both types of portions may be made to touch the eyelashes by one action. because this permits increase in apparent fullness and curling of eyelashes to be performed in a single motion, this is efficient and convenient for use. Furthermore, as portion(s) with long bristles 20 and portion(s) with short bristles 20 are continuously formed in helicoidal fashion about the central axis X about the core wire portion 18 in the central axis X direction, both types of portion(s) may be easily made to become intertwined with eyelashes when the cap 4 is rotated during use, as a result of which excellent usability is provided thereby.

Furthermore, the pentagonal cross-sectional shape of applying portion 8 in the present embodiment has interior angles that are each not greater than 180°, and presents no recess to the exterior. That is, in the present embodiment, applying portion 8 does not have a groove in the circumferential direction. In an embodiment in which a groove is present in the circumferential direction, it may be difficult for eyelashes to enter the groove, as a result of which application may be difficult. But since applying portion 8 of the present embodiment does not have a groove in the circumferential direction, bristles can more easily touch the eyelashes and can more easily become intertwined with eyelashes as described above. Because in the present embodiment the same cross-sectional shape is continuously present along the central axis X direction but is merely rotated thereabout, maximum outer diameter is equal at any position along the central axis X, as a result of which it is possible by rotating the applicator during use to cause eyelashes to be uniformly curled.

In accordance with the present embodiment, as eyelashes can be curled and increased in apparent fullness in a single motion using only a single cosmetic applicator 2, it is not necessary to separately perform curling and increase in apparent fullness, as a result of which mascara 16 can be efficiently applied and eyelashes can be neatly groomed. In such an embodiment, increase in apparent fullness and curling of eyelashes can be easily performed, and usability of the cosmetic applicator is excellent.

In the present embodiment, perpendiculars respectively drawn from line segments 28a, 30a, and 22a to center point X′ are of mutually equal length, and these line segments 28a, 30a, and 22a together resemble an arc about center point X′. Line segments 26a and 24a are connected to the endpoints of this arc, giving surface 34 a teardrop-like shape which is the superposition of the arc defined byline segments 28a, 30a, and 22a and the triangle defined by line segments 26a and 24a. In the present embodiment, center point X′ is not located at the center of surface 34 but is eccentrically located so as to be closer to the arc side of the teardrop-like shape, bristles 20 at this teardrop-like shape being such that the bristles 20 on the triangle side thereof are longer than the bristles 20 on the arc side thereof. That is, in the embodiment shown in FIG. 2, surface 26 and surface 24 define a pointed peak-like portion of the applying portion 8 at which bristles 20 are relatively long. This peak-like portion easily enters the spaces between eyelashes and easily combs eyelashes like a comb, and more efficiently curls eyelashes. This shape may make grooming of eyelashes easier than would be the case in an embodiment where the cross-sectional shape is that of, e.g., an equilateral pentagon. In the embodiment shown in FIG. 2, surfaces 28, 30, 22 have bristles 20 which are comparatively short and which are more or less uniform in length, permitting eyelashes to be easily touched thereby and permitting mascara 16 to be retained thereby, as a result of which they are well-suited for use to increase the apparent fullness of eyelashes. In the present embodiment, because the portion with long bristles 20 and the portion with short bristles 20 are disposed on mutually opposite sides in the circumferential direction, they can be used in a well-balanced manner while providing the characteristics for which they are respectively best suited, as a result of which usability of the cosmetic applicator is excellent.

Second Embodiment

Next, a second embodiment is described. As shown in FIG. 3, the second embodiment differs from the first embodiment only with respect to the configuration of the cosmetic brush. A cosmetic brush 119 according to the second embodiment is formed in integral fashion with respect to a base shaft 6 on a tip of a cosmetic applicator 2 as was the case in the first embodiment, and includes a core wire portion 118 and an applying portion 108, the applying portion 108 including a main portion 102 provided toward the base shaft and a reduced-diameter portion 104 provided toward the tip. As was the case in the first embodiment, applying portion 108 is such that, from a twisted portion of twisted core wires 118a (hereinafter “core wire portion 118”), bristles 120 pinched by the core wire portion 118 extend radially therefrom uniformly about the circumferential direction of the core wire portion 118 so as to be uniformly distributed after the fashion of a helicoid that extends along the axial direction of the core wire portion 118.

As seen in axial view, end surface 64 toward the base shaft of the applying portion 108 is of substantially hexagonal shape, being formed from five line segments 52a, 54a, 56a, 58a, 60a and arc 62a which is centered on center point X′ of a section of the core wire portion. Perpendiculars 52d, 54d, 56d, 58d, 60d respectively drawn from these five line segments 52a, 54a, 56a, 58a, 60a to center point X′ are of mutually equal length, the length of each of these perpendiculars being shorter than the distance from arc 62a to center point X′ on which arc 62a is centered.

Main portion 102 has a three-dimensional external shape formed by causing the substantially hexagonal shape described above to be rotated, e.g., by 150°, in continuous fashion in the circumferential direction about the central axis of the core wire portion 118 as one proceeds along central axis X from end surface 64 until one reaches reduced-diameter portion 104. As shown at (f) through (k) in FIG. 3, the cross-sectional shape of main portion 102, comprising projections 52b, 54b, 56b, 58b, 60b, 62b thereon of the six side surfaces 52, 54, 56, 58, 60, 62 is of the same substantially hexagonal shape as end surface 64 regardless of where along central axis X the sectional view is taken, sectional views along central axis X being different from the sectional view of end surface 64 only with respect to the angle by which the sectional view at that location is rotated relative to the sectional view of end surface 64.

Reduced-diameter portion 104 is substantially in the shape of a truncated cone, the diameter of which is reduced toward the tip end thereof, end surface 66 toward the tip being of circular cross-sectional shape. The five side surfaces 52, 54, 56, 58, 60 are the side surfaces of a helicoid that extends along the central axis X of the core wire portion 118, the respective planes of these helicoid side surfaces being made to rotate about the central axis X by the same angular amount (e.g., 150°) in going from end surface 64 of main portion 102 to reduced-diameter portion 104, and that moreover extends midway into the reduced diameter portion 104.

Benefit of Second Embodiment

In accordance with the present embodiment, end surface 64 is such that distances from line segments 54a, 56a, 58a to center point X′ are mutually equal; among the curves from which the substantially hexagonal cross-sectional shape of end surface 64 is formed, arc 62a has the longest distance to center point X′ ; and the distance between line segments 52a and 60a decreases as they approach arc 62a. Furthermore, end surface 64 of the present embodiment has a teardrop-like shape which is such that an angle in what would otherwise be a triangle is rounded due to presence of arc 62a. As was the case in the first embodiment, surface 52, surface 62, and surface 60 define a peak-like portion with long bristles 120, and when the cosmetic applicator 2 including the cosmetic brush 119 is rotated during use, this makes it possible for peak-like portion(s) to easily enter the spaces between eyelashes and easily become intertwined therewith and lift eyelashes. In the present embodiment, because the peak-like portion is rounded due to presence of surface 62, it has a prescribed width and an increased area that touches the eyelashes, and easily enters between and combs eyelashes, and easily becomes intertwined with eyelashes. Whereas the peak-like portion tends to become deformed due to repeated passage thereover of wiper 14, the tendency toward such deformation may be reduced due to employment of rounded surface 62.

In the present embodiment, lengths of perpendiculars drawn from the five line segments 52a, 54a, 56a, 58a, 60a constituting surface 64 to center point X′ of core wire portion 118 are mutually equal. This makes it possible to reduce the number of steps required to form applying portion 108 when manufacturing cosmetic brush 119 using the manufacturing method described below. Such shape is preferred from the standpoint of efficient manufacturing with reduced machining time.

In the present embodiment, reduced-diameter portion 104 is provided at the tip of applying portion 108. This being the case, when cosmetic brush 119 is inserted into and housed within mascara container 10, since the tip end portion is of reduced diameter, insertion is easily carried out. Furthermore, deformation of the tip end portion due to repeated use can be reduced.

Method for Manufacturing Cosmetic Brush 19

Next, a method for manufacturing the cosmetic brush 19 according to the first embodiment is described with reference to the flowchart of FIG. 4.

First, at preparation step S1 , as shown in FIG. 5, the bristles 20 are cut to the same length and sandwiched between a pair of core wires 18a, and the core wires 18a are twisted to secure the bristles 20 therebetween to form the applying portion 8.

Next, at trimming step S2, as shown in FIG. 6, the bristles 20 constituting applying portion 8 are uniformly cut so that the applying portion assumes a columnar shape. This completes steps for fabricating cosmetic brush precursor 39.

By causing the bristles 20 of cosmetic brush precursor 39 to be subjected to an operation in which bristles 20 are sheared by machining device 40, applying portion 8 may be formed into a prescribed shape.

As shown in FIG. 7, machining device 40 of the present embodiment includes a rotary blade 48 that includes cutting blades 46 extending in a longitudinal direction of a columnar body portion 44, and a receiving blade 42 having the same width as that of the cutting blades. The receiving blade 42 and the cutting blades 46 are disposed so as to be parallel to each other across a very small gap therebetween when the rotary blade 48 rotates at a high speed about a center shaft Y. In the present embodiment, four cutting blades 46 are for example secured at evenly spaced intervals in a circumferential direction about body portion 44 in such fashion as to be inclined slightly in the direction of rotation (i.e., where the direction of rotation is counterclockwise as viewed at (a) in FIG. 7, cutting blades 46 do not extend exactly radially from the rotational axis of body portion 44 but are angled slightly relative to the radial direction so that the tips of cutting blades 46 lead the base of cutting blades 46 as body portion 44 is made to rotate in counterclockwise fashion). In the present embodiment, all cutting blades 46 have the same blade length and the same height. The machining device 40 shears the bristles 20 entering the gap between the cutting blade 46 and the receiving blade 42. Hereinafter, the gap between the rotating cutting blade 46 and the receiving blade 42, i.e., the line along which shearing of bristles 20 takes place, is referred to as shear line Z. In the present embodiment, the machining device 40 is capable of being moved in a forward direction DR which is orthogonal to body portion 44 while the rotary blades 48 are made to rotate at high speed.

Next, at position adjusting step S3, the positions of the cosmetic brush precursor 39 and the machining device 40 are adjusted. The cosmetic brush precursor 39 is disposed in front of the machining device 40 in such fashion that the central axis X of the core wire portion 18 is orthogonal to the shear line Z as seen in top view, and the central axis X is parallel to the forward direction DR as seen in a side view. Position adjustments in the vertical direction and the circumferential direction might, for example, be performed using surface 34 and the shear line Z as datums.

As shown in FIG. 12, to form surface 22 at applying portion 8, an adjustment might first be performed so as to cause distance D in the vertical direction from center point X′ to shear line Z to be equal to distance 22h from center point X′ to line segment 22a (see the cell at column (a) in the row corresponding to Machining Operation No. 1 in FIG. 12). As described below, while position in the circumferential direction may be arbitrarily chosen at Machining Operation No. 1, at Machining Operation No. 2 and thereafter the appropriate position is determined by the shape which is desired to be obtained.

Next, at main machining step S4, the machining device 40 is moved in the forward direction DR toward the cosmetic brush precursor 39 while rotating the rotary blade 48 at a high speed so that the shear line Z passes from a rear end to a tip end of the applying portion 8, and accordingly, the bristle tip end portions 22c are sheared. By rotating the cosmetic brush precursor 39 by 180° about the central axis X while the shear line Z passes from the rear end to the tip end of the applying portion 8, the helicoidal surface 22 is formed about the central axis X on the applying portion 8 (see the cell at column (b) in the row corresponding to Machining Operation No. 1 in FIG. 12).

In order to form the surface 24 at step S5, position adjusting step S3 is carried out in iterative fashion. The machining device 40 is moved rearward, and the cosmetic brush precursor 39 is returned by an amount corresponding to the amount of rotation)(180° in the circumferential direction to the original disposed position before the main machining step. Then, the cosmetic brush precursor 39 is disposed at a position rotated an angle α1 from the returned position in the circumferential direction in such fashion as to cause distance D in the vertical direction to be equal to distance 24h between line segment 24a and center point X′ (length of perpendicular 24d) (see the cell at column (a) in the row corresponding to Machining Operation No. 2 in FIG. 12). Angle α1 is the angle between perpendicular 22d and perpendicular 24d.

Next, main machining step S4 is carried out in iterative fashion. In the same manner as described above, the machining device 40 is moved toward the cosmetic brush precursor 39 positioned ahead while rotating the rotary blade 48, and accordingly, the bristle tip end portions 24c are sheared. By rotating the cosmetic brush precursor 39 at a fixed speed in the circumferential direction by the same angle of 180° in the same direction as those of the first iteration of the main machining step while the shear line Z is moved from the rear end to the tip end of the applying portion 8, the helicoidal surface 24 about the central axis X can be formed on the applying portion 8.

The remaining surfaces 26, 28, 30 are also formed by carrying out position adjusting step(s) and main machining step(s) in iterative fashion in the same manner (see FIG. 12), as a result of which the applying portion 8 having five side surfaces 22, 24, 26, 28, and 30 formed in helicoidal fashion about the central axis X is formed.

As described above, one position adjusting step S3 and one main machining step S4 causes one helicoidal surface to be formed on applying portion 8, position adjusting step(s) and main machining step(s) being carried out in iterative fashion until no surface to be machined remains.

By the manufacturing method described above, helicoidal surfaces extending along the central axis X while rotating about the central axis X can be formed on the applying portion 8. When forming the plurality of surfaces, position adjustments are performed, and by rotation by the same prescribed angle (e.g.,) 180° each time, the applying portion 8 having a complicated shape in which base end surface 34 continues along the central axis X to tip end surface 36 while rotating, e.g., by 180°, in the circumferential direction about the central axis X of the core wire portion 18, and which has the same pentagonal shape in cross-section as that of end surface 34 at any cut position, and is different only in orientation from end surface 34, can be formed.

Manufacturing Method of Cosmetic Brush 119

Next, a manufacturing method of a cosmetic brush 119 according to a second embodiment is described.

As was the case at the first embodiment, at preparation step S1, bristles 120 are first cut to the same length and sandwiched between a pair of core wires 118a, and the core wires 118a are twisted to secure the bristles 120 therebetween to form applying portion 108.

Thereafter, at trimming step S2, tip ends of the bristles 120 are uniformly cut, and at this time, the applying portion 108 is formed into a bullet shape (see the cell at column (b) in the row corresponding to Machining Operation No. 0 in FIG. 13) that is reduced in diameter toward the tip end, and accordingly, a cosmetic brush precursor 139 is formed.

Next, at position adjusting step S3, the cosmetic brush precursor 139 is disposed in front of machining device 40 in such fashion as to cause central axis X of the core wire portion to be orthogonal to shear line Z as seen in top view, and cause central axis X to be parallel to forward direction DR as seen in side view. Adjustment is performed to cause distance D in the vertical direction to be equal to distance 52h from center point X′ to line segment 52a (i.e., the length of perpendicular 52d) (see the cell at column (a) in the row corresponding to Machining Operation No. 1 in FIG. 13).

Next, at main machining step S4, the machining device 40 is moved in the forward direction DR while rotating the rotary blade 48 at a high speed, and accordingly, bristle tip end portions 52c are sheared. While the machining device 40 passes from a rear end to a tip end of the applying portion 108, the cosmetic brush precursor 139 is rotated by 180° about the central axis X. The rotary blade 48 shears the bristles 120 to a middle point of the main portion 102 and the reduced-diameter portion 104, and the surface 52 about the central axis X is formed on the applying portion 108 (see the cell at column (b) in the row corresponding to Machining Operation No. 1 in FIG. 12).

Next, in order to form the surface 54 at step S5, position adjusting step S3 is carried out in iterative fashion. The machining device 40 is moved rearward, and the cosmetic brush precursor 139 is also returned an amount corresponding to the amount of rotation)(180° in the circumferential direction to the original disposed position before the main machining step. In the circumferential direction, the cosmetic brush precursor 139 is disposed at a position rotated an angle α5 from the returned position. Angle α5 is the angle between perpendicular 52d and perpendicular 54d. It is not necessary to readjust the distance D in the vertical direction since the lengths of perpendiculars 52d, 54d, 56d, 58d, 60d of all of the machining surfaces 52, 54, 56, 58, 60 to center point X′ are the same (all 52h) (see the cell at column (a) in the row corresponding to Machining Operation No. 2 in FIG. 13).

Next, main machining step S4 is carried out in iterative fashion. In the same manner as described above, the machining device 40 is moved toward the cosmetic brush precursor 139 positioned ahead while rotating the rotary blade 48, and accordingly, bristle tip end portions 54c are sheared. By rotating the cosmetic brush precursor 139 in the circumferential direction at a fixed speed by the same angle of 180° in the same direction as those of the first iteration of the main machining step while the shear line Z is moved from the rear end to the tip end of the applying portion 108, the helicoidal surface 54 about the central axis X is formed on the applying portion 108.

The remaining surfaces 56, 58, 60 are formed in the same manner. Position adjusting step(s) and main machining step(s) are carried out in iterative fashion until no surface needing to be machined remains (step S5). A portion left without being sheared of the main portion 102 is the surface 62.

By the manufacturing method described above, the cosmetic brush 119 having a complicated shape including the reduced-diameter portion 104 can be manufactured. In the present embodiment, distance D in the vertical direction is the same on all machined surfaces, so that after one position adjustment, position readjustment in the vertical direction is unnecessary. Therefore, following positioning of the cosmetic brush precursor 139, it is required to control only the rotation of the cosmetic brush precursor 139 and the movement of the machining device 40 in the front-rear direction, so that the control is simple and machining is easy.

Variations

While the present invention has been described above in terms of specific embodiments, the present invention is not limited thereto, it being possible to carry out various modifications and variations.

For example, the present invention is not limited to embodiments in which the applying portion 8 has sectional shape as described above, it being possible to achieve similar effect through employment of an applying portion 8 having a sectional shape as shown, for example, at any of (a) through (i) in FIG. 10.

Furthermore, while there is no limitation with respect to the direction in which helicoidal side surfaces of the applying portion 8 are made to rotate as one proceeds along the central axis thereof, it is preferred that the helicoidal side surfaces of a single cosmetic applicator are all made to rotate in the same direction, i.e., either clockwise or counterclockwise.

At the trimming step, note that it is also possible in some embodiments for the applying portion 108 to be formed into a spheroidal shape. In such case, it is preferred that the helicoidal surfaces are formed on a central portion of the applying portion. Note that the reduced-diameter portion 104 in some embodiments may have a columnar shape with a radius smaller than that of the main portion 102.

At the position adjusting step, note that it is also possible to cause the orientation of the cosmetic brush precursor 39 to be reversed so that the tip end thereof is directed toward the machining device 40, and the applying portion 108 is sheared from the tip end side to the base end side.

At the main machining step, whereas it was described above that the cosmetic brush precursor 30 is rotated by 180°, it is also possible in some embodiments for this rotation angle to be any other suitable angles; e.g., 90°, 135°, 270°, 360°, 540°, 720°, 900°, etc. Furthermore, whereas it was described above that the bristles 20 are sheared by moving the machining device 40 toward the cosmetic brush precursor 39, it is also possible in some embodiments for the cosmetic brush precursor 39 to be moved toward the machining device 40 while rotating.

As shown in FIG. 11, at cosmetic brush 119, the applying portion 8 may be deformed after being formed in order to improve usability. In an embodiment in which cosmetic brush 119a is curved with respect to the centerline of the cosmetic applicator 2, this may permit it to better follow the shape of eyelashes and more easily touch the eyelashes. Or in an embodiment in which cosmetic brush 119b is inclined with respect to the centerline of the cosmetic applicator 2, this may make it possible to maintain a constant angle with respect to eyelashes and may make it possible to more easily apply mascara thereto.

While embodiments of the present invention have been described above, modes of carrying out the present invention are not limited to the foregoing embodiments, a great many further variations being possible without departing from the gist of the present invention. For any of the various function(s) described with reference to the attached drawings, so long as it would not interfere with ability to carry out the function(s) in question, the order of steps may be different from that described herein.

EXPLANATION OF REFERENCE NUMERALS

1 Mascara cosmetic product

2 Cosmetic applicator

4 Cap

6 Base shaft

6a Base end portion (of base shaft)

6b Hole (of base shaft)

8, 108 Applying portion

10 Mascara container

12 Reduced-diameter portion

14 Wiper

16 Mascara

18, 118 Core wire portion

18a, 118a Core wire

18b Base shaft portion (of core wire portion)

19, 119, 119a, 119b Cosmetic brush

20, 120 Bristle

22, 24, 26, 28, 30, 34, 36 Surface

22a, 24a, 26a, 28a, 30a Line segments (constituting surface 34)

22b, 24b, 26b, 28b, 30b Line segments (constituting cut surface of applying portion 8)

22c, 24c, 26c, 28c, 30c Bristle tip end portion

22d, 24d, 26d, 28d, 30d Perpendicular (to center point X′)

22h, 24h, 26h, 28h, 30h Distance (to center point X′)

38a Vertex

39, 139 Cosmetic brush precursor

40 Machining device

42 Receiving blade

44 Body portion

46 Cutting blade

48 Rotary blade

52, 54, 56, 58, 60, 62, 64, 66 Surface

52a, 54a, 56a, 58a, 60a Line segments (constituting surface 64)

62a Arc

52b, 54b, 56b, 58b, 60b Line segments (constituting cut surface of applying portion 108)

62b Arc

52c, 54c, 56c, 58c, 60c Bristle tip end portion

52d, 54d, 56d, 58d, 60d Perpendicular (to center point X′)

52h Distance (to center point X′)

102 Main portion (of applying portion 108)

104 Reduced-diameter portion (of applying portion 108)

D Distance (in vertical direction)

X Central axis (of core wire portion)

X′ Center point

Y Center shaft (of rotary blades 48)

Claims

1. A cosmetic applicator comprising

an applying portion having a linear core wire portion formed of at least two metal core wires helically twisted together; and a multiplicity of bristles pinched by a twisted portion of the core wires and continuing in helicoidal fashion in an axial direction of the core wire portion while being distributed in radial fashion thereabout;

wherein the applying portion has a three-dimensional external shape which is a locus formed by causing a third shape that is substantially polygonal with interior angles that are each not greater than 180° as seen in sectional view at any position along the axial direction of the core wire portion to be rotated in continuous fashion in a circumferential direction about an axis of the core wire portion as it is made to advance in the axial direction of the core wire portion;

the third shape is a bilaterally symmetrical shape formed by superposing a first shape and a second shape, the first shape being a bilaterally symmetrical polygonal shape, an uppermost side of the first shape being the longest side of the first shape, the second shape being an isosceles triangle, the bottommost side of the second shape being the uppermost side of the first shape, the bottommost side of the second shape being straddled in isogonal fashion by two sides of the second shape that are each longer than any of the sides making up the first shape except for the uppermost side of the first shape; and

the core wire portion is eccentrically located, being disposed in the direction of the first shape, from a midpoint along a line of bilateral symmetry of the third shape.

2. The cosmetic applicator according to claim 1 wherein

the third shape is a bilaterally symmetrical substantially pentagonal shape;

the first shape is an isosceles trapezoid obtained by bisecting a regular hexagon at two vertices thereof; and

the second shape is an isosceles triangle, the bottommost side of which is the longest side of the first shape, the second shape having two sides that are each longer than any one side of the regular hexagon.

3. The cosmetic applicator according to claim 1 wherein

the third shape is a substantially hexagonal shape;

the first shape is a bilaterally symmetrical trapezoid; and

the second shape is a substantially quadrilateral shape in which what would otherwise be an angle formed by the two sides of the second shape that are each longer than any of the sides making up the first shape except for the uppermost side of the first shape is instead made to be an arc centered on the core wire portion.

4. A manufacturing method of the cosmetic applicator according to claim 1 comprising:

a preparation step of forming a cosmetic brush precursor that includes an applying portion consisting of a linear core wire portion formed of at least two core wires and bristles distributed in radial fashion from a twisted portion of the core wires that continues in helicoidal fashion and is formed by causing a multiplicity of bristles with prescribed lengths that are arranged in parallel band-like fashion to be pinched between the at least two core wires and twisted thereabout in helical fashion;

a trimming step of forming an external shape of the applying portion into a substantially columnar shape by uniformly cutting tip ends of the bristles constituting the applying portion;

a position adjusting step of adjusting a positional relationship between the cosmetic brush precursor and a machining device including a cutting blade and a receiving blade which are of prescribed width and are flat blades to shear the bristles constituting the applying portion; and

a main machining step of forming a shear surface extending in helicoidal fashion on the external shape of the applying portion by shearing tip ends of the bristles of the applying portion by relatively moving the machining device parallel to the axial direction of the core wire portion while rotating the cosmetic brush precursor around the core wire portion.

5. The manufacturing method of the cosmetic applicator according to claim 4 wherein

in the main machining step, the cosmetic brush precursor is rotated a prescribed angle about the core wire portion, and

by carrying out the position adjusting step and the main machining step in iterative fashion a prescribed number of times, an applying portion with a desired shape is formed.

6. The manufacturing method of the cosmetic applicator according to claim 5 wherein

the prescribed number of times is equal to the number of straight sides constituting the third shape.