WO2018167663A1

WO2018167663A1 - Hair trimmer

Info

Publication number: WO2018167663A1
Application number: PCT/IB2018/051659
Authority: WO
Inventors: Kwok Yung Anthony Law; Man Hin Raymond WONG; Man Lok YEUNG
Original assignee: Rjw Technology Ltd.
Priority date: 2017-03-13
Filing date: 2018-03-13
Publication date: 2018-09-20

Abstract

A hair trimmer (20) includes a housing (22), an outer cutter (34) coupled to the housing (22), defining a reciprocating axis (42), and including a plurality of outer cutter ribs (44). An inner cutter (36) is disposed within the housing (22) and configured for sliding along the reciprocating axis (42). The inner cutter (36) includes a plurality of inner cutter ribs (56), a biasing surface (70) opposite the inner cutter ribs (56), and an arm (76) integral with the biasing surface (70) and the plurality of cutter ribs (44,56), the arm (76) including a connection end (82). A rocker (85) is coupled to the connection end (82) of the arm (76) and configured to pivot relative to the housing (22) at a rocker axis (86), a motor (83) is operably coupled to the rocker (85) to pivot the rocker (85) about the rocker axis (86), and a support guide is coupled to the housing (22) and positioned to engage the biasing surface (70) of the inner cutter (36), thereby to bias the inner cutter ribs (56) toward the outer cutter ribs (44).

Description

HAIR TRIMMER

TECHNICAL FIELD

[0001] The present disclosure generally relates to hair trimmers and, more particularly, to hair trimmers insertable into nose or ear cavities and methods of forming components for such hair trimmers.

BACKGROUND

[0002] Hair trimmers that use linear reciprocating cutting systems typically include a linearly reciprocating inner cutter disposed inside a stationary outer cutter. The inner and outer cutters have blade edges that cut through hairs trapped therebetween. While it is generally desirable to simply construction of such devices by reducing the overall number of components, it has proven difficult to achieve this goal while maintaining the functionality of the hair trimmer. Additionally, size constraints associated with smaller hair trimmers intended for use in tight spaces, such as nose or ear cavities, complicate the manufacture of certain components, such as the inner cutter. Still further, conventional hair trimmers are often prone to jamming.

SUMMARY

[0003] In accordance with an aspect of the disclosure, a hair trimmer includes a housing defining a cutter opening, an outer cutter coupled to the housing, disposed within the cutter opening, and defining a reciprocating axis, the outer cutter including a plurality of outer cutter ribs, and an inner cutter disposed within the housing and configured for sliding along the reciprocating axis. The inner cutter includes a plurality of inner cutter ribs, a biasing surface opposite the inner cutter ribs, and an arm integral with the biasing surface and the plurality of cutter ribs, the arm including a connection end. The hair trimmer also includes a rocker coupled to the connection end of the arm and configured to pivot relative to the housing at a rocker axis, a motor operably coupled to the rocker to pivot the rocker about the rocker axis, and a support guide coupled to the housing and positioned to engage the biasing surface of the inner cutter, thereby to bias the inner cutter ribs toward the outer cutter ribs. [0004] According to an additional aspect of the disclosure, an inner cutter is provided for a hair trimmer having a support guide, the inner cutter including an inner cutter head portion including a plurality of inner cutter ribs and a biasing surface opposite the inner cutter ribs, the biasing portion configured to engage the support guide of the hair trimmer, and an arm provided integrally with the biasing surface and the plurality of cutter ribs, the arm extending along an arm axis and including a head end adjacent the inner cutter head portion and a connection end, the arm being configured to deflect in a flex direction substantially normal to the arm axis.

[0005] According to a further aspect of the disclosure, a method of forming an inner cutter for a hair trimmer is provided, the method including etching a single, planar piece of metal to form an initial inner cutter piece having a first arm half joined to a second arm half by a cutter portion, the cutter portion including a plurality of inner cutter ribs. The method further includes folding the initial inner cutter piece over a fold axis so that the first arm half overlies the second arm half and each of the plurality of inner cutter ribs includes an arcuate portion.

[0006] Other aspects and features of the disclosed systems and methods will be appreciated from reading the attached detailed description in conjunction with the included drawing figures. Moreover, selected aspects and features of one example embodiment may be combined with various selected aspects and features of other example embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] For further understanding of the disclosed concepts and embodiments, reference may be made to the following detailed description, read in connection with the drawings, wherein like elements are numbered alike, and in which:

[0008] FIG. 1 is a perspective view of a top portion of a hair trimmer constructed according to the present disclosure.

[0009] FIG. 2 is a front view of the top portion of the hair trimmer of FIG. 1.

[0010] FIG. 3 is a side elevation view of the top portion of the hair trimmer of FIG. 1, with a cover removed to show internal components of the hair trimmer. [0011] FIG. 4 is a perspective view of the top portion of the hair trimmer of FIG. 1, with a cover removed to show internal components of the hair trimmer.

[0012] FIG. 5 is an enlarged side elevation view, in cross-section, of the hair trimmer of FIG. 1.

[0013] FIG. 6 is an exploded perspective view of the hop portion of the hair trimmer of FIG. 1.

[0014] FIG. 7 is a side elevation view of a top portion of an alternative embodiment of a hair trimmer, with a cover removed to show internal components of the hair trimmer.

[0015] FIG. 8 is a perspective view of the top portion of the hair trimmer of FIG. 7, with a cover removed to chow internal components of the hair trimmer.

[0016] FIG. 9 is an enlarged side elevation view, in cross-section, of the hair trimmer of FIG. 7.

[0017] FIG. 10 is a block diagram schematically illustrating a method of forming an inner cutter.

[0018] FIG. 11 is an enlarged plan view of an initial inner cutter piece used to form an inner cutter.

[0019] FIG. 12 is an enlarged plan view of an initial outer cutter piece used to form an outer cutter.

[0020] It is to be noted that the appended drawings illustrate only typical embodiments and are therefore not to be considered limiting with respect to the scope of the disclosure or claims. Rather, the concepts of the present disclosure may apply within other equally effective embodiments. Moreover, the drawings are not necessarily to scale, emphasis generally being placed upon illustrating the principles of certain embodiments.

DETAILED DESCRIPTION

[0021] Referring now to FIGS. 1-6, a first embodiment of a hair trimmer constructed in accordance with the present disclosure is generally referred to by reference numeral 20. The hair trimmer 20 may be particularly suited for use in constricted spaces. Accordingly, the hair trimmer 20 may have a housing 22 with a relatively large grip portion (not shown), a trimming end 24 that is relatively small, and a transition portion 26 extending between the grip portion and the trimming end 24. The trimming end 24 may be sized for insertion into areas with limited access, such as the nose or ear cavity of a user. The housing 22 defines a cutter opening 28 that leads to an interior housing chamber 30.

[0022] The trimming end 24 of the housing 22 carries a cutter assembly 32 operable to engage and cut hairs. The cutter assembly 32 generally includes an outer cutter 34 and an inner cutter 36. The outer cutter 34 is stationary. Accordingly, the outer cutter 34 may be coupled to the housing 22, such as by posts 38 formed integrally with the housing 22, and projects through the cutter opening 28. The inner cutter 36 includes a head portion 40 disposed within the outer cutter 34 that is supported for reciprocal movement within the outer cutter 34. For example, the outer cutter 34 may define a reciprocating axis 42 along which the inner cutter 36 travels.

[0023] In greater detail, the outer cutter 34 includes a plurality of outer cutter ribs 44 extending between slots 46, as best shown in FIGS. 3-6. Referring specifically to FIG. 6, each of the plurality of outer cutter ribs 44 may include spaced first and second lateral sides 48, 50 joined by an arcuate portion 52. Accordingly, the outer cutter 34 may have a generally U-shaped profile projecting from the cutter opening 28 of the housing 22. An interior surface 53 of each outer cutter rib 44 may be formed with sharp cutting edges 54.

[0024] The inner cutter 36 includes a head portion 40 having a plurality of inner cutter ribs 56, extending between slots 58, which cooperate with the outer cutter ribs 44 to engage and cut hairs. As best shown in FIGS. 5 and 6, each of the inner cutter ribs 56 includes first and second lateral sides 60, 62 joined by an arcuate portion 64. Accordingly, the inner cutter 36 may also have a generally U-shaped profile. An exterior surface 66 of each inner cutter rib 56 is formed with sharp cutting edges 68. As the inner cutter 36 reciprocates within the outer cutter 34 and along the reciprocating axis 42, hairs projecting through the slots 46, 58 may be engaged and cut by the sharp cutting edges 54, 68 of the outer and inner cutters 34, 36, respectively.

[0025] In some embodiments, the inner cutter 36 includes additional integral features to improve performance and/or simplify construction and assembly. For example, as best shown in FIGS. 5 and 6, the head portion 55 of the inner cutter 36 may further include a biasing surface 70 for biasing the inner cutter 36 into close surface contact with the outer cutter 34. In the illustrated embodiment, the biasing surface 70 faces directly opposite the inner cutter ribs 56. When engaged by a support guide, such as a rod 72 coupled to the housing 22, the biasing surface 70 directs the inner cutter ribs 56 toward the outer cutter ribs 44.

[0026] Still further, the inner cutter 36 may have an integral arm 76 configured both to transmit reciprocating movement to the inner cutter ribs 56 and to spring load the inner cutter ribs 56 against the outer cutter ribs 44. As best shown in FIGS. 3-5, the arm 76 extends along an arm axis 78 and includes a head end 80 adjacent the inner cutter head portion 40 and a connection end 82. The arm 76 is configured to deflect in a flex direction (indicated by arrow 84) substantially normal to the arm axis 78, which in the illustrated embodiment is also substantially normal to the reciprocating axis 42. As used herein, the term "substantially normal" is intended to cover angles within approximately 30 degrees normal to a given reference axis. Deflection in the flex direction 84 may be achieved through material selection, geometry of the arm 76, and other factors or combinations thereof. For example, the arm 76 may have a length "L" between the head end 80 and the connection end 82 that is sufficiently long, and a width "W" that is sufficiently narrow, to permit deflection in the flex direction 84. The particular dimensions of the length L and width W that permit deflection in the flex direction 84 may be affected by the material used for the arm 76. Deflection of the arm 76, in combination with the biasing surface 70 engaging the rod 72, ensures that the inner cutter ribs 56 maintain close surface contact with the outer cutter ribs 44 during the entire range of reciprocal travel of the inner cutter 36.

[0027] The hair trimmer 20 may further include a drive system 81 for reciprocating the inner cutter 36. For example, as best shown in FIGS. 3, 4, and 6, the drive system 81 includes a motor 83 operably coupled to a rocker 85. The motor 83 may include an output shaft, such as rotating eccentric shaft 89. The rocker 85 is pivotably coupled to the housing 22 at rocker axis 86 and includes an eccentric receptacle 88 configured to receive the eccentric shaft 89. The rocker 85 is also pivotably coupled to the arm 76, such as by rocker pin 90 coupled to the rocker 85 and extending through a connection aperture 92 formed through the connection end 82 of the arm 76. In operation, rotation of the eccentric shaft 89 pivots the rocker 85. Movement of the rocker 85 causes the arm 76 to move, such that the arm 76 also acts as a push rod to drive the inner cutter 36 in a linear, reciprocating manner. [0028] In some embodiments, the outer cutter ribs 44 and inner cutter ribs 56 are configured to reduce jamming and promote air flow through the cutter assembly 32. For example, the outer cutter ribs 44 may be spaced by an outer cutter rib pitch distance 94, while the inner cutter ribs 56 are spaced by an inner cutter rib pitch distance 96, as best shown at FIG. 5. The outer cutter rib pitch distance 94 is different than the inner cutter rib pitch distance 96, so that adjacent pairs of outer and inner cutter ribs 44, 56 engage hairs sequentially, instead of simultaneously. Not only does this reduce the peak cutting load encountered by the inner cutter 36, but also ensures an open air flow through at least one adjacent pair of outer and inner cutter ribs 44, 56, such as at locations 97, 98 in FIG. 3.

[0029] An alternative embodiment of a hair trimmer 100 is illustrated in FIGS. 7-9. The hair trimmer 100 is substantially identical to the hair trimmer 20 described above in connection with FIGS. 1-6, except for the support guide. In this embodiment, the support guide is provided as a step 102 coupled to the housing 22. The step 102 may include a body portion 104 and a shoulder 106 sized to receive the biasing surface 70 of the inner cutter 36. During reciprocal movement of the inner cutter 36, the biasing surface 70 slides along the shoulder 106 of the step 102.

[0030] A method 120 of forming an inner cutter 36 for a hair trimmer is schematically illustrated at FIG. 10. At block 122, the method includes etching a single, planar piece of metal to form an initial inner cutter piece 140. As best shown at FIG. 11, the initial inner cutter piece 140 may have a first arm half 142 joined to a second arm half 144 by a cutter portion 146. The cutter portion 146 may include a plurality of inner cutter ribs 56 extending between slots 58. In some embodiments, the etching includes forming sharp cutting edges 68 in the exterior surface 66 of each inner cutter rib 56. Additionally, the etching may further include forming a first connection hole 148 in the first arm half 142 and a second connection hole 150 in the second arm half 144.

[0031] The method 120 may continue at block 124 by folding the initial inner cutter piece 140 over a fold axis 152, as best shown in FIG. 12. The fold axis 152 may be located along a line of symmetry of the initial inner cutter piece 140, so that the first arm half 142 closely overlies the second arm half 144. After folding, each of the plurality of inner cutter ribs 56 includes an arcuate portion 64. In embodiments where etching included forming the first and second connection holes 148, 150, the first and second connection holes 148, 150 may be located so that they are aligned with each other after folding, thereby to form a connection aperture 92.

[0032] The outer cutter 34 may be formed in a similar fashion to the inner cutter 36. That is, a single, planar piece of metal may be etched to form an initial outer cutter piece 160. As best shown in FIG. 12, the initial outer cutter piece 160 may include an outer cutter first lateral side 162 and an outer cutter second lateral side 164 joined by a cutter portion 166. The cutter portion 166 may include a plurality of outer cutter ribs 44 extended between slots 46. In some embodiments, etching the initial outer cutter piece 160 includes forming sharp cutting edges 68 in the interior surface 53 of each outer cutter rib 44. Additionally, the outer cutter first lateral side 162 may include a base 168, while the outer cutter second lateral side 164 includes anchors 170. The initial outer cutter piece 160 may be folded about the outer cutter fold axis 174 to form arcuate portions 52 in the outer cutter ribs 44. Additionally, the anchors 170 may be folded so that they engage, or are in close proximity to, the base 168 of the cutter first lateral side 162. The anchors 170 may then be welded, such as by laser welding, to the base 168, thereby increasing rigidity of the outer cutter 34 and more securely retaining the inner cutter 36 during operation.

[0029] While the present disclosure has shown and described details of exemplary embodiments, it will be understood by one skilled in the art that various changes in detail may be effected therein without departing from the spirit and scope of the disclosure as defined by claims supported by the written description and drawings. Further, where these exemplary embodiments (and other related derivations) are described with reference to a certain number of elements it will be understood that other exemplary embodiments may be practiced utilizing either less than or more than the certain number of elements.

Claims

What is claimed is:

1. A hair trimmer comprising:

a housing defining a cutter opening;

an outer cutter coupled to the housing, disposed within the cutter opening, and defining a reciprocating axis, the outer cutter including a plurality of outer cutter ribs;

an inner cutter disposed within the housing and configured for sliding along the reciprocating axis, the inner cutter including:

a plurality of inner cutter ribs;

a biasing surface opposite the inner cutter ribs; and

an arm integral with the biasing surface and the plurality of cutter ribs, the arm including a connection end;

a rocker coupled to the connection end of the arm and configured to pivot relative to the housing at a rocker axis;

a motor operably coupled to the rocker to pivot the rocker about the rocker axis; and a support guide coupled to the housing and positioned to engage the biasing surface of the inner cutter, thereby to bias the inner cutter ribs toward the outer cutter ribs.

2. The hair trimmer of claim 1, in which the support guide comprises a rod.

3. The hair trimmer of claim 1, in which the support guide comprises a step.

4. The hair trimmer of claim 1 , in which the arm is configured to deflect in a flex direction normal to the reciprocating axis.

5. The hair trimmer of claim 1, in which the motor includes a rotating eccentric shaft, and in which the rocker includes an eccentric receptacle configured to receive the eccentric shaft.

6. The hair trimmer of claim 1, in which the plurality of outer cutter ribs are spaced by an outer cutter rib pitch distance, the plurality of inner cutter ribs are spaced by an inner cutter rib pitch distance, and the outer cutter rib pitch distance is different than the inner cutter rib pitch distance.

7. The hair trimmer of claim 1, in which each of the plurality of outer cutter ribs includes an arcuate portion, and in which each of the plurality of inner cutter ribs includes an arcuate portion.

8. The hair trimmer of claim 7, in which the outer cutter is formed of a single piece of etched metal folded about an outer cutter rib axis to define an outer cutter first lateral side and an outer cutter second lateral side spaced from the outer cutter first lateral side and joined by the arcuate portions of the plurality of outer cutter ribs.

9. The hair trimmer of claim 8, in which the outer cutter includes a base extending from the outer cutter first lateral side configured for attachment to the housing, and at least one anchor extending from the outer cutter second lateral side and coupled to the base.

10. The hair trimmer of claim 7, in which the inner cutter is formed of a single piece of etched metal folded over an inner cutter rib axis to define an inner cutter first lateral side and an inner cutter second lateral side, wherein the inner cutter first lateral side is joined to the inner cutter second lateral side by the arcuate portions of the plurality of inner cutter ribs.

11. An inner cutter of a hair trimmer having a support guide, the inner cutter comprising:

an inner cutter head portion including a plurality of inner cutter ribs and a biasing surface opposite the inner cutter ribs, the biasing portion configured to engage the support guide of the hair trimmer; and

an arm provided integrally with the biasing surface and the plurality of cutter ribs, the arm extending along an arm axis and including a head end adjacent the inner cutter head portion and a connection end, the arm being configured to deflect in a flex direction substantially normal to the arm axis.

12. The inner cutter of claim 11 , in which in which each of the plurality of inner cutter ribs includes an arcuate portion.

13. The inner cutter of claim 12, in which the inner cutter is formed of a single piece of etched metal folded over an inner cutter rib axis to define an inner cutter first lateral side and an inner cutter second lateral side, wherein the inner cutter first lateral side is joined to the inner cutter second lateral side by the arcuate portions of the plurality of inner cutter ribs.

14. A method of forming an inner cutter for a hair trimmer, the method comprising:

etching a single, planar piece of metal to form an initial inner cutter piece having a first arm half joined to a second arm half by a cutter portion, the cutter portion including a plurality of inner cutter ribs; and

folding the initial inner cutter piece over a fold axis so that the first arm half overlies the second arm half and each of the plurality of inner cutter ribs includes an arcuate portion.

15. The method of claim 14, in which, prior to folding, etching further comprises forming a sharp cutting edge on an outer surface of each of the plurality of inner cutter ribs.

16. The method of claim 14, in which etching comprises forming a first connection hole in the first arm half and a second connection hole in the second arm half, wherein the first connection hole and second connection hole are located such that the first connection hole is aligned with the second connection hole after folding.