Mounting assembly

Abstract

According to one aspect, there is provided an attachment assembly 20 for a hair-cutting appliance 10, the attachment assembly comprising: a head 24 configured to receive a cutting unit 14; a base 22 connected to the head; a pivot mechanism 30 connecting the base to the head, the pivot mechanism configured to allow pivoting of the head relative to the base about a head pivot axis 50; and a rotatable locking element 40, the rotatable locking element configured to be rotated between an engaged position, where the rotatable locking element prevents pivoting of the head, thereby locking the head in a locked position about the head pivot axis, and a disengaged position, where the rotatable locking element does not prevent pivoting of the head, such that the head is freely pivotable relative to the base about the head pivot axis, and wherein by rotating the rotatable locking element to the engaged position, the rotatable locking element is configured to drive the head into the locked position.

Description

Technical Field

[0001] The present invention relates to a mounting assembly for a hair cutting device and a hair cutting device.

Background Art

[0002] Hair cutting devices such as beard trimmers and shavers typically have a contour following function that allows the blade to follow the contour of an object such as the face. However, these hair cutting devices also often require a function that enables particularly close shaving, and this close shaving is considered to be best achieved when the blade is at an angle of approximately 20 to 30 degrees with respect to the surface of the skin, especially when the hair grows in random directions, and this has been experimentally derived. Therefore, in some applications, having contour following may reduce the effectiveness of the trimmer for close shaving.

[0003] U.S. Patent Application No. 2010175260 discloses an electric shaver including a gripping portion held by a user's hand and a head portion configured to hold a razor unit and supported to be swingable in a predetermined direction with respect to the gripping portion. The head portion includes a shaving unit configured to be switched between a ready-to-use state and a stored state by an operating element, and an engaging portion for fixing the head portion, and the engaging portion is configured to engage with the operating element when the shaving unit is switched to the ready state.

Summary of the Invention

[0004] According to a first particular aspect, there is provided a mounting assembly for a hair cutting device, the mounting assembly comprising a head configured to receive a cutting unit, a base connected to the head, a pivoting mechanism connecting the base to the head and configured to allow pivoting of the head about a head pivot axis relative to the base, and a rotary locking element configured to rotate between an engaged position and a disengaged position, wherein (i) in the engaged position, the rotary locking element prevents pivoting of the head, thereby locking the head in a locked position about the head pivot axis, and (ii) in the disengaged position, the rotary locking element does not prevent pivoting of the head, such that the head is pivotable freely about the head pivot axis relative to the base, and the rotary locking element is configured to drive the head to the locked position by rotating the rotary locking element to the engaged position.

[0005] The rotary locking element is configured to rotate about a locking axis that is perpendicular to the head pivot axis.

[0006] The mounting assembly comprises a paddle fixed to the head and extending from the head towards the base. The rotary locking element is configured to interact with the paddle when in the engaged position to lock the head in the locked position. The paddle extends between arms of the pivoting mechanism disposed between a node and the head and is configured to engage each arm at respective limits to prevent pivoting of the head beyond the limits.

[0007] The rotary locking element comprises a locking tab configured to prevent pivoting of the head when the rotary locking element is in the engaged position. The rotary locking element may comprise two locking tabs configured to prevent pivoting of the head in opposite directions when the rotary locking element is in the engaged position, thereby locking the head in the locked position.

[0008] The locking tabs are arranged on opposite sides of the locking elements and prevent pivoting, for example, by engaging with a head, a paddle fixed to the head, or a pivoting mechanism. The two locking tabs each engage with different parts of the mounting assembly to apply moments in opposite directions to the head or the pivoting mechanism, thereby locking the head in the locked position. The tabs are arranged 180 degrees apart on the base of the locking element. Thus, during rotation of the locking element, the tabs approach and engage with different parts of the mounting assembly, applying moments in opposite directions to each other.

[0009] The mounting assembly may include two paddles spaced apart in a direction parallel to the head pivot. Each rotary locking element is configured to interact with a respective paddle to apply pivoting moments in opposite directions to the head about the head pivot.

[0010] The rotary locking elements may include a third locking tab and an optional fourth locking tab so that the head can be locked in two different locked positions by rotating the rotary locking elements in opposite directions relative to each other.

[0011] The locking tabs have a stiffness defined by an increase in moment per degree of rotation of the pivoting mechanism when in the locked position. The stiffness may be greater than approximately 7.5 Nmm / degree. The stiffness may be between approximately 0.5 Nmm / degree and 7.5 Nmm / degree.

[0012] The pivoting mechanism includes a four-bar linkage extending between the head and the base and including a pair of arms connected to the head and the base at respective head joints and base joints, each of the head joint and the base joint allowing pivoting about respective parallel pivots, the head being one link of the four-bar linkage, the base being one link of the four-bar linkage, and each arm being one link of the four-bar linkage. The rotary locking element is configured to interact with the pivoting mechanism in the engaged position to lock the head in the locked position.

[0013] The pivotal mechanism may include two four-bar link mechanisms spaced in a direction parallel to the head pivot, the head being one joint of the two four-bar link mechanisms and the base being one joint of the two four-bar link mechanisms. There may be two arms extending between the head and the base for each four-bar link mechanism so as to result in a total of four arms, or there may be two arms, each arm having two branch strands, each branch strand forming one joint of a different four-bar link mechanism.

[0014] Each paddle is configured to extend from the head to the base between the arms of different four-bar link mechanisms.

[0015] According to a second aspect, there is provided a haircut device comprising the attachment assembly described in any of the preceding paragraphs.

[0016] These and other aspects will become apparent and be elucidated with reference to the embodiments described below.

[0017] For purposes of illustration only, exemplary embodiments will be described with reference to the following drawings.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0019] FIG. 1 shows a haircutting device 10 comprising a handle 12, a mounting assembly 20 fixed to the handle 12, and a cutting unit 14 received on the mounting assembly 20. The mounting assembly 20 is configured to enable pivoting of the cutting unit 14 about a head pivot 50 relative to the handle 12. In some examples, the mounting assembly may further enable pivoting about a secondary axis perpendicular to the head pivot such that the cutting unit is pivotable relative to the handle about two perpendicular axes.

[0020] FIG. 2 shows the mounting assembly 20 in more detail, FIG. 3 shows an exploded view of the mounting assembly 20, and FIG. 4 shows a cross-sectional view of the mounting assembly 20 taken along line A-A. Each of these figures omits a drive unit for driving the cutting unit that is attached to the mounting assembly, but it should be understood that the mounting assembly may further comprise such a drive unit for reciprocally driving the cutting unit.

[0021] The mounting assembly 20 comprises a base 22 and a head 24 (only the head 24 is shown in FIG. 4). The base 22 is configured to be fixed to the handle 12. The head 24 is configured to receive the cutting unit 14. The base 22 is connected to the head 24 such that the head 24 is pivotable relative to the base 22. In some examples, the base may be integral with the handle.

[0022] The attachment assembly 20 includes a base 22 connected to a head 24 and a pivoting mechanism 30 configured to enable pivoting of the head 24 relative to the base 22 about a head pivot 50. In this example, the pivoting mechanism 30 includes two four-bar link mechanisms that are spaced apart in a direction parallel to the head pivot 50, and each four-bar link mechanism includes a pair of arms 26 extending between the head 24 and the base 22. Each arm 26 is connected to the head 24 at a respective head joint 28 and to the base at a respective base joint 32, such that the head 24 forms one link of both four-bar link mechanisms, the base 22 forms one link of both four-bar link mechanisms, and each arm 26 forms one link of each of these four-bar link mechanisms. Thus, in this example, there are a total of four arms 26.

[0023] The head joints 28 (a total of four head joints 28 in this example) enable pivoting between each arm 26 and the head 24, and the head joints 28 interconnect each arm 26 and the head 24 about respective pivots parallel to the head pivot 50. The base joints 32 enable pivoting between each arm 26 and the base 22, and the base joints 32 also interconnect each arm 26 and the base 22 about respective pivots parallel to the head pivot 50. Thus, the pivots of the head joints 28 are parallel to the pivots of the base joints 32, enabling both four-bar link mechanisms to move in harmony with each other. The two four-bar link mechanisms have the same dimensions, the head joints 28 of one four-bar link mechanism share the same pivot as the head joints 28 of the other four-bar link mechanism, and the base joints 32 of one four-bar link mechanism share the same pivot as the base joints 32 of the other four-bar link mechanism.

[0024] The pivotal mechanism 30 with a four-bar link mechanism ensures that the head pivot 50 around which the head 24 can pivot becomes a virtual pivot located directly above the head 24 on the side of the head facing the base 22. By making the head pivot 50 a virtual pivot directly above the head 24, it enables a better fit of the head to the object to which the haircut device 10 with this mounting assembly 20 is applied.

[0025] In other examples, the pivotal mechanism may comprise only a single four-bar link mechanism, or two four-bar link mechanisms may comprise an arm with two branched strands, and each branched strand of a single arm may form one link of a different four-bar link mechanism. In still other examples, the pivotal mechanism may comprise any suitable mechanism that enables pivoting of the head relative to the base around a head pivot, such as a head connected to the base by a simple pivot.

[0026] In this example, the mounting assembly 20 is fixed to the head 24 and comprises a pair of paddles 48 extending from the head 24 towards the base 22. The paddles 48 are spaced along a direction parallel to the head pivot 50, and each paddle 48 extends between the arms 26 in a different four-bar link mechanism. Thus, each paddle 48 functions as a stroke limiter for each four-bar link mechanism that prevents pivoting of the four-bar link mechanism beyond the limits in both pivoting directions. In other examples, the paddles may not extend between the four-bar link mechanisms, or there may be only a single paddle or no paddles.

[0027] The mounting assembly 20 further comprises a rotary locking element 40 configured to selectively lock the head 24 in a locked position by selectively preventing pivoting of the head 24 relative to the base 22. The locking element 40 is fixed to the base 22 and is rotatable in this example around a rotation axis 52 perpendicular to the head pivot 50. In other examples, the rotation axis may be any suitable axis, such as one parallel to the head pivot.

[0028] In this example, the locking element 40 projects from a support 44 having a hollow and shallow cylindrical profile, and includes a pair of locking tabs 42 disposed on opposite sides of the support 44 about a rotation axis 52. The locking tabs project in a direction from the support 44 toward the head 24. In this example, the locking tabs 42 are disposed 180 degrees apart about the rotation axis 52 on the support 44 of the locking element 40. In other examples, the locking tabs may project in any suitable direction and may be disposed at any suitable location about the support.

[0029] The locking tab 40 seats around a central post 46 that projects from the base 22 toward the head 24 and is configured to rotate relative to the central post 46. The locking element 40 is configured to rotate between an engaged position (shown in FIG. 2) and a disengaged position (not shown). The central post includes a central opening for receiving components of a drive unit for reciprocally driving a cutting unit on the mounting assembly. In other examples, the drive unit may be located at any suitable location.

[0030] In this example, in the engaged position, the locking tabs 42 of the locking element 40 interact with paddles 48 fixed to the head 24 to prevent pivoting of the head 24 and are configured to lock the head 24 in a locked position. For example, it may be advantageous to enable locking of the head 24 in the locked position when the user desires to be able to use the hair trimmer at a predetermined angle without moving the trimmer or for travel.

[0031] When the locking element 40 is rotated between the engaged position and the disengaged position, the locking tabs 42 on opposite sides of the locking element each approach and engage a different paddle 48, such that each locking tab 42 applies a pivoting moment in opposite directions to the head 24 via the paddle 48 about the head pivot 50, thereby being configured to lock the head 24 in the locked position.

[0032] When the locking element 40 is rotated to the disengaged position, the locking tab 42 does not prevent the pivoting of the head 24 relative to the base 22 about the head pivot 50. As a result, the head 24 is pivotable freely relative to the base 22 about the head pivot 50.

[0033] The locking element 40 is configured to engage with the head 24 or the pivoting mechanism during its rotation towards the engaged position, whereby the head 24 is driven to the locked position. As a result, the head does not need to be manually positioned in the locked position in order to be locked there.

[0034] The locking element 40 is held in the engaged position by the interaction between the support 44 of the locking element 40 and the central post 46 (best seen in FIG. 4). The support 44 includes a pair of snap tabs 54 protruding from the inner surface of a hollow cylindrical shape, and these snap tabs 54 are configured to cooperate with respective corresponding pairs of snap grooves 56 protruding from the outer surface of the central post 46 in a snap fit arrangement. In other examples, a friction fit for holding the locking element in the engaged position may be used, or any other means for holding the locking element relative to the central post, or other portions of the base with which the locking element interacts, may be used.

[0035] The support 44 also includes a block 60 protruding from the inner surface of the support 44. The block 60 is configured to cooperate with a stop 62 on the outer surface of the central post 46 to prevent rotation of the locking element 40 relative to the central post 46 beyond the disengaged position. The outer diameter of the central post 46 also increases up to the stop 62, such that when the block 60 abuts against the stop 62, the block 60 frictionally cooperates with the central post 46 to hold the locking element 40 in the disengaged position.

[0036] The locking tab 42 has a stiffness defined by an increase in the moment on the head 24 per degree of rotation of the head 24 about the head pivot 50 when the locking tab 42 is in an engaged state with the paddle 48. The stiffness in this example is approximately 7.5 Nmm / degree to ensure that the locking tab 42 securely continues to lock the head 24 in the locked position. In other examples, the locking tab may be flexible to have a stiffness of approximately 0.5 Nmm / degree. This allows the head to move slightly in the locked position, effectively increasing the stiffness of the pivoting mechanism. Having a more flexible locking tab that allows some movement of the head can be beneficial for users with less sensitive skin, as it enables such users to apply a higher load to the mounting assembly to achieve a closer shave.

[0037] The locking element 40 has been described as comprising two locking tabs 42 that interact with respective paddles 48 to lock the head 24 in the locked position. However, in some examples, the locking element may comprise only a single locking tab, which engages with the paddle, head, or pivoting mechanism and prevents pivoting of the head by pressing the head, paddle, or pivoting mechanism to the locked position, which is the limit at which the paddle engages with one of the arms of the four-bar linkage. In other examples, the locking element may comprise three or four locking tabs such that the locking element can be rotated to two different engagement positions in two different directions to provide two different locked positions for the head.

[0038] In a further example, in the absence of a paddle, when the locking element is in the engaged position, the locking tab may be configured to engage with the arm of the four-bar linkage to prevent pivoting of the head and thereby lock the head in the locked position.

[0039] In another example, there is no locking tab on the locking element. Instead, other parts of the locking element may be configured to prevent the pivoting of the head relative to the base and lock the head in a locking position about the head pivot. For example, the locking element is disposed between two arms of the same four-bar linkage mechanism having an irregular shape of rotation about the axis of rotation, such as an elliptical cross-sectional shape. When the major axis of the ellipse is parallel to the head pivot, the locking element is in a disengaged position so as not to interfere with the pivoting of the head. When rotated so that the major axis is perpendicular to the head pivot, the locking element engages with the arm of the pivoting mechanism and prevents the arm from pivoting relative to the base, and thus prevents the head from pivoting about the head pivot.

[0040] The locking element has been described as having an engaged position and a disengaged position. However, the locking element may have additional intermediate positions between the engaged position and the disengaged position. The locking element can be rotated and held to these intermediate positions, for example, by the frictional interaction between the central post and the support. In these intermediate positions, the locking tab allows the head to move freely around the head pivot, but may limit the pivoting of the head up to a new limit before the paddle engages with the arm. This allows the user to select a more limited range of pivoting of the head.

[0041] Modifications to the disclosed embodiments can be understood and effected by those skilled in the art in light of the drawings, disclosure, and appended claims, practicing the principles and techniques described herein. In the claims, the terms "comprising", "having", "including" do not exclude other elements or steps, and the singular does not exclude the plural. Merely the fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. An attachment assembly for a hair cutting device, the attachment assembly comprising: a head for receiving a cutting unit; a base connected to the head; a pivoting mechanism for connecting the base to the head, the pivoting mechanism enabling pivoting of the head about a head pivot axis relative to the base; a rotary locking element rotatable between an engaged position and a disengaged position; (i) in the engaged position, the rotary locking element prevents pivoting of the head, thereby locking the head in a locked position about the head pivot axis; (ii) in the disengaged position, the rotary locking element does not prevent pivoting of the head, such that the head is pivotable freely about the head pivot axis relative to the base; The rotary locking element is configured to drive the head to the locked position by rotating the rotary locking element to the engaged position. An attachment assembly.

2. The attachment assembly according to claim 1, wherein the rotary locking element rotates about a locking axis, and the locking axis is perpendicular to the head pivot axis.

3. The attachment assembly according to claim 1 or 2, further comprising a paddle fixed to the head, the paddle extending from the head towards the base, and the rotary locking element interacting with the paddle when in the engaged position to lock the head in the locked position.

4. The attachment assembly according to claim 3, wherein the paddle extends between arms of the pivoting mechanism disposed between a node and the head and engages each arm at respective limits to prevent pivoting of the head beyond the limits.

5. The attachment assembly according to claim 1 or 2, wherein the rotary locking element comprises a locking tab, and the locking tab prevents pivoting of the head when the rotary locking element is in the engaged position.

6. The attachment assembly according to claim 5, wherein the rotary locking element comprises two locking tabs that prevent pivoting of the head in opposite directions when the rotary locking element is in the engaged position, thereby locking the head in the locked position.

7. The mounting assembly according to claim 6, comprising two paddles spaced apart in a direction parallel to the head pivot, each rotary locking element interacting with a respective paddle to impart pivot moments in opposite directions to the head about the head pivot.

8. The mounting assembly according to claim 7, wherein the rotary locking elements are provided with a third locking tab and an optional fourth locking tab so that the head can be locked in two different locking positions by rotating the rotary locking elements in opposite directions to each other.

9. The mounting assembly according to claim 5, wherein the locking tab has a stiffness defined by an increase in moment per degree of rotation of the pivoting mechanism when in the locking position, and the stiffness is greater than approximately 7.5 Nmm / degree.

10. The mounting assembly according to claim 5, wherein the locking tab has a stiffness defined by an increase in moment of the pivoting mechanism per degree of rotation, and the stiffness is between approximately 0.5 Nmm / degree and 7.5 Nmm / degree.

11. The mounting assembly according to claim 1 or 2, wherein the pivoting mechanism comprises a four-bar linkage including a pair of arms extending between the head and the base and connected to the head and the base at respective head joints and base joints, each of the head joint and the base joint allowing pivoting about respective parallel pivots, the head being one link of the four-bar linkage, the base being one link of the four-bar linkage, each arm being one link of the four-bar linkage, and the rotary locking element interacting with the pivoting mechanism in the engaged position to lock the head in the locking position.

12. The mounting assembly according to claim 11, wherein the pivoting mechanism comprises two four-bar linkages spaced apart in a direction parallel to the head pivot, the head being one link of the two four-bar linkages, and the base being one link of the two four-bar linkages.

13. The mounting assembly according to claim 12, dependent on claim 7, wherein each paddle extends from the head to the base between the arms of different four-bar linkages.

14. A haircutting device comprising the mounting assembly according to claim 1 or 2.

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