Mounting assembly for hair cutting device

Abstract

According to one aspect, a mounting assembly 10 for a hair-cutting appliance is provided, the mounting assembly having a head 12 configured to receive a cutting unit; and a base 14, the head being attached to the base via a pair of arms 16 to form a linkage. Each arm is connected to a head coupling 20 on the head at a connection 18 and to a respective base coupling 22 on the base at a connection. The base couplings are spaced apart along the line of travel, each connection configured to allow pivotal movement about parallel pivot axes. The stroke limiter 26 is configured to prevent pivotal movement of the head relative to the base beyond a limit. At least one of the base couplings is a flexible base coupling that is resiliently mounted to the body 38 of the base, such that each flexible base coupling is movable relative to the body in a direction that is parallel to the line of travel and has a component away from the other base coupling to allow pivotal movement of the head relative to the base beyond a limit imposed by the stroke limiter.

Description

[Technical Field]

[0001] The present invention relates to a mounting assembly for a hair-cutting appliance, and to a hair-cutting appliance including such a mounting assembly. [Background technology]

[0002] Hair-cutting appliances such as manual or electric razors typically have a blade head attached to a handle, which may be pivotally mounted to the handle so as to rotate relative to the body about an axis, as in WO2015 / 074882. Summary of the Invention [Problem to be solved by the invention]

[0003] However, such pivoting can result in a hard stop that provides an abrupt limit to the pivoting movement of the head, which can be uncomfortable for the user and can result in poor cutting performance on complex shapes such as the face. [Means for solving the problem]

[0004] According to a first particular aspect, there is provided a mounting assembly for a hair-cutting appliance, the mounting assembly comprising: a head configured to receive a cutting unit; a base, wherein the head is attached to the base via a pair of arms to form a linkage, each arm being coupled to a head coupling on the head at a coupling portion and to a respective base coupling on the base at a coupling portion, the base couplings being spaced apart along a line of movement, each coupling being configured to allow pivotal movement about parallel pivot axes; and a stroke limiter configured to prevent pivotal movement of the head relative to the base beyond a limit; wherein at least one of the base couplings is a flexible base coupling resiliently attached to a body of the base, such that each flexible base coupling is movable relative to the body in a direction parallel to the line of movement and having a component away from the other base couplings, allowing pivotal movement of the head relative to the base beyond the limit imposed by the stroke limiter.

[0005] Pivoting of the head relative to the base can include the head pivoting about an imaginary axis parallel to the pivot axis.

[0006] Each arm is coupled to a different respective head coupling to enable pivotal movement about a different parallel head pivot axis, thereby forming a four-bar linkage, such that the head is pivotally movable relative to the base. The stroke limiter is configured to impede pivotal movement of the four-bar linkage, thereby preventing pivotal movement of the head relative to the base beyond the limit.

[0007] The stroke limiter can have a tab protruding from the head, the tab configured to engage at least one of the arms to prevent movement of the four-bar linkage in the plane of movement.

[0008] The mounting assembly may include a first spring configured to engage the arm and bias the four-bar linkage to a limit.

[0009] Both of the handle base couplings may be flexible base couplings.

[0010] Each flexible base coupling may be attached to the body of the base on a cantilevered resilient beam that allows movement relative to the body of the base coupling in a direction parallel to the line of movement and having a component away from the other base coupling.

[0011] The body can have a stop for each flexible base coupling, where the stop can be configured to abut the resilient beam to limit movement of the resilient beam in a direction toward the other base coupling.

[0012] The base may further include a pretensioning spring configured to bias the resilient beam of each flexible base coupling toward the stop.

[0013] The pretension spring can be configured to bias the flexible base coupling against the stop.

[0014] The stiffness of the pretension spring may be greater than the stiffness of the elastic beam in the plane of movement.

[0015] Each base coupling may be a ball bearing configured to cooperate with a corresponding ball socket on a respective arm.

[0016] The base couplings can be aligned at intervals in the plane of movement.

[0017] Each flexible base coupling may be movable relative to the body such that the base coupling moves only in a single plane - in other words, the resilient beam to which the flexible base coupling is attached may not allow movement in a direction parallel to the pivot axis.

[0018] According to a second aspect, there is provided a hair-cutting apparatus including a mounting assembly according to the first aspect.

[0019] These and other aspects will be apparent from and elucidated with reference to the embodiments described hereinafter. [Brief explanation of the drawings]

[0020] [Figure 1] 1A and 1B are schematic cross-sectional views of an exemplary mounting assembly for a hair-cutting apparatus; [Figure 2] FIG. 2 illustrates an exploded isometric view of the exemplary mounting assembly of FIG. 1. [Figure 3] FIG. 10 is a schematic cross-sectional view of the mounting assembly extended beyond its stroke limit. DETAILED DESCRIPTION OF THE INVENTION

[0021] Exemplary embodiments will now be described, by way of example only, with reference to the following drawings, in which:

[0022] Figure 1 shows a cross-sectional view of an exemplary mounting assembly 10 for a hair-cutting appliance in a first position, and Figure 2 shows an exploded isometric view of the same mounting assembly 10.

[0023] The mounting assembly 10 includes a head 12 configured to receive a cutting unit, such as a blade or a powered trimming attachment, and a base 14 for connection to a handle configured to be held by a user. In some examples, the base can be integral with the handle.

[0024] The head 12 is attached to a base 14 via a pair of arms 16. Each arm 16 is connected to a respective head coupling 20 at a joint 18 and to a respective base coupling 22 at a joint 18.

[0025] In this example, the arms 16 each have two branching strands in a U-shape, such that each arm 16 is connected to the base 14 at a single base coupling 22 at the apex of the U, and each arm 16 is connected to a separate head coupling 20 at each end of the U. Thus, there are two base couplings 22 in the base 14 and four head couplings 20 in the head 12. The head 12 is supported relative to the base 14 by the four head couplings 20 that connect to the arms 16.

[0026] In another example, each arm can have one strand to form an I-shape, so that the heads are supported by the arms at only two head couplings total, or the arms can have two or more branch strands, so that coupler links are supported by the arms at two or more coupler joins per arm. Each arm can have a different number of branch strands, for example, to support coupler links at three or five coupler joins. In yet another example, the arms can have two branch strands in a T, V, or Y shape, so that each arm supports coupler links at two coupler joins.

[0027] Each linkage 18 is configured to permit pivotal movement between a respective arm 16, head 12, and base 14 about a parallel first pivot axis 24 (shown entering the page in FIG. 1 ), forming a four-bar linkage, where each arm 16 is one bar of the four-bar linkage, the head 12 is one bar, and the base 14 is one bar. Thus, the four-bar linkage is permitted to move in a plane of movement perpendicular to the first pivot axis 24.

[0028] In this example, two head couplings 20 connecting the same arm 16 to the head 12 are spaced apart only in a direction parallel to the first pivot axis 24, such that they share the same first pivot axis 24 (i.e., their pivot axes 24 are parallel). Head couplings 20 connecting different arms 16 to the head 12 are spaced apart in a plane of motion (i.e., a direction perpendicular to the first pivot axis 24), such that the couplings 18 of the head couplings 20 for the different arms 16 each allow pivotal movement about different, parallel first pivot axes 24. The base couplings 22 are also spaced apart in the plane of motion along a line of motion, which in this example is the second pivot axis 30. Thus, the four-bar linkage allows pivotal movement of the head 12 relative to the base 14 about a virtual pivot axis, where the virtual pivot axis is parallel to the first pivot axis 24 of the couplings 18.

[0029] In other examples, the pivot axes of all joints in the head coupling are parallel, so that the head no longer forms a bar of the linkage, and the arm, head, and base form a three-bar linkage. In such examples, the head is pivotable about a first pivot axis that passes through the head coupling.

[0030] Each head coupling 20 in this example is a linear bearing, allowing pivotal movement only about a parallel first pivot axis 24 in a plane of motion. Each base coupling 22 in this example is a ball bearing, configured to cooperate with a corresponding ball socket 32 ​​on an individual arm 16 to form a ball joint (best shown in FIG. 2 ). The ball joint allows pivotal movement about three perpendicular pivot axes. However, because of the four-bar linkage, the ball joints (i.e., joints 18 on base couplings 22 in this example) are constrained to allow pivotal movement only about the individual first pivot axis 24 and a second pivot axis 30 in a plane of motion that passes through both base couplings 22. The second pivot axis 30 allows for unitary movement of the entire four-bar linkage, such that the first pivot axis 24 also pivots about the second pivot axis 30, thereby causing the plane of motion to also pivot about the second pivot axis 30.

[0031] In some examples, the ball bearing may be a linear bearing such that there is no pivotal movement about the second pivot axis. It should be understood that in other embodiments, the ball bearing may be located in the head and the linear bearing may be located in the base.

[0032] The mounting assembly 10 includes a stroke limiter 26 configured to prevent pivotal movement of the head relative to the base beyond a limit. In this example, the stroke limiter 26 is configured to prevent pivotal movement of the four-bar linkage and inhibit pivotal movement of the head 12. In another example, if the linkage is a three-bar linkage, the stroke limiter may simply limit pivotal movement of the head about a first pivot axis that passes through the head coupling.

[0033] The stroke limiter 26 in this example has a tab that protrudes from the head 12 in a direction toward the base 14 so that the tab is located between the pair of arms 16. The tab is configured to engage each arm 16 at a respective limit to impede movement of the four-bar linkage in a plane of movement. FIG. 1 shows the tab engaging one of the arms 16 at its limit. Thus, the four-bar linkage is constrained to move in a plane of movement between the limits imposed by the stroke limiter 26 engaging each arm 16.

[0034] It should be appreciated that the tab may be located on the head on the outside of the arms or may be configured to engage the outside of one of the arms and prevent movement beyond the limits of the four-bar linkage. In other embodiments, the tab may be located on one of the arms or the base and configured to engage the head or base and prevent pivoting movement of the four-bar linkage or pivoting movement of the head. The stroke limiter may prevent pivoting movement of the head in only one direction, or may prevent pivoting movement of the head in both pivot directions.

[0035] The mounting assembly 10 also includes a pair of first springs 34, which in this example are attached to the base 14 and each are configured to engage one of the arms 16 to bias the four-bar linkage to one of its limits (i.e., the first position shown in FIG. 1 ). In this example, each first spring 34 includes a leaf spring that abuts an inner protrusion 36 on one of the arms 16 and urges the protrusion 36 upward. Both protrusions 36 are on the same arm 16, and therefore the first springs 34 act together to pivot the arm 16 until the stroke limiter 26, in this example, engages the same arm 16 and prevents further pivotal movement at the limit of the first position.

[0036] The first springs 34 are spaced apart along a direction parallel to the first pivot axis 24 (i.e., they are positioned on either side of the plane of movement). It should be understood that only one first spring is required to provide the biasing force biasing the head to the first position, as shown in Figure 1, and that there may be no first springs biasing the head to the first position. It should also be understood that the first springs may be located elsewhere, such as in the arms or head, to bias the four-bar linkage to its limits.

[0037] In this example, the base coupling 22 is a flexible base coupling 22 that is attached to the body 38 of the base 14 on a cantilevered resilient beam 40 and is movable to a second position.

[0038] Figure 3 shows the mounting assembly 10 of Figure 1 in a second position. A resilient beam 40 is attached to the body 38 at one end, and a base coupling 22 (i.e., a ball bearing) is attached to the other end of the resilient beam 40 to form the flexible base coupling 22. Thus, when an external force is applied, the resilient beam 40 allows the flexible base coupling 22 to move relative to the base body 38 in a direction having a component parallel to the line of movement (i.e., the second pivot axis 30 in this example) to the second position. In the second position, the first pivot axis 24 of the joint 18 moves with the flexible base coupling 22. It should be understood that in some embodiments, only one flexible base coupling is required.

[0039] In this example, the resilient beam 40 permits movement only in a single plane. In other words, the stiffness of the resilient beam 40 prevents movement of the flexible base coupling 22 in directions out of the single plane. In some examples, the resilient mount of the base coupling to the base can permit movement of the flexible base only in a plane of movement, such as movement along the second pivot axis, for example, if the resilient mount is in the form of a simple linear spring such as a coil spring.

[0040] When the head 12 is biased to a limit by the first spring 34 or moved to a limit by an external force, the stroke limiter 26 prevents movement of the head 12 relative to the base 14 beyond the limit (as shown in FIG. 1 ). Further application of the external force forces one of the flexible base couplings 22 to move in a single plane from the first position to the second position, away from the other base coupling 22, in a direction with a component parallel to the line of movement. This lengthens the bars of the four-bar linkage defined by the base 14, thereby changing the layout of the four-bar linkage and allowing pivotal movement of the head 12 relative to the base 14 beyond the limit imposed by the stroke limiter 26. This arrangement provides a soft stop to pivotal movement of the head 12 relative to the base 14 when an external force is applied to the head 12, such as when the head 12 is applied to skin for shaving. Furthermore, having both base couplings 22 be flexible base couplings 22 can act as a suspension unit, so that when excessive force is applied to the head 12 in the direction of the base 14, both flexible base couplings 22 can move to provide a degree of suspension, which can improve user comfort.

[0041] 1-3, in this example, the body 38 of the base 14 has a stop 42 for each flexible base coupling 22. Thus, the base 14 has two stops 42 on opposite sides of the body 38. Each stop 42 is configured to abut the resilient beam 40 to which the respective base coupling 22 is attached (or interfere with other flexible attachments), and limit movement of the resilient beam 40 in a direction toward the other base coupling 22.

[0042] In this embodiment, the base 14 further includes a pretensioning spring 44 configured to bias the resilient beam 40, and thus the flexible base coupling 22, towards and against the stops 42. In this example, the pretensioning spring is in the form of a clip disposed around the stops 42 and acting on both stops 42 from opposite sides. In other embodiments, each stop can have its own pretensioning spring that limits movement of the flexible mount.

[0043] In this example, the pretension spring 44 has a higher stiffness than the elastic beam 40 in the single plane in which the flexible base coupling 22 is configured to move, and as a result, it provides smooth movement of the head 12 beyond the limits imposed by the stroke limiter 26.

[0044] It should be appreciated that in some examples, the base coupling may be attached to a beam that is pivotally attached to the body of the base, and a pretension spring may provide resilient movement of the base coupling.

[0045] Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the principles and techniques described herein, from a study of the figures, the disclosure, and the appended claims. In the claims, the word "comprises" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude a plurality. The mere 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 interpreted as limiting the scope of the invention.

Claims

1. 1. A mounting assembly for a hair-cutting appliance, comprising: a head for receiving the cutting unit; a base, the head being attached to the base via a pair of arms forming a linkage, each arm being coupled to a head coupling on the head at a coupling portion and to a respective base coupling on the base at a coupling portion, the base couplings being spaced apart along a line of motion, each coupling allowing pivotal movement about a parallel pivot axis, the line of motion being perpendicular to the pivot axis; a stroke limiter disposed on the head and engaging with the arm, or on the arm or the base and engaging with the head or the base at a limit, thereby preventing pivotal movement of the head relative to the base beyond the limit; a mounting assembly wherein at least one of the base couplings is a flexible base coupling that is resiliently mounted to a body of the base, and wherein each flexible base coupling is movable relative to the body in a direction that is parallel to the line of movement and has a component away from the other base coupling.

2. each arm is coupled to a different respective head coupling to form a four-bar linkage, allowing pivotal movement about different parallel head pivot axes, the head being pivotally movable relative to the base; The mounting assembly of claim 1 , wherein the stroke limiter impedes pivotal movement of the four-bar linkage to inhibit pivotal movement of the head relative to the base beyond the limit.

3. 3. The mounting assembly of claim 2, wherein the stroke limiter has a tab projecting from the head, the tab engaging at least one of the arms to prevent movement of the four-bar linkage in a plane of movement.

4. 3. The mounting assembly of claim 2, further comprising a first spring engaging said arm to bias said four-bar linkage to said limit.

5. 5. A mounting assembly according to any preceding claim, wherein both base couplings are flexible base couplings.

6. 5. A mounting assembly according to claim 1, wherein each flexible base coupling is attached to the body of the base on a cantilevered elastic beam that allows movement of the base coupling relative to the body in a direction parallel to the line of movement and having a component away from the other base coupling.

7. 7. The mounting assembly of claim 6, wherein the body has a stop for each flexible base coupling, the stop abutting the resilient beam to limit movement of the resilient beam in a direction toward the other base coupling.

8. The mounting assembly of claim 7 , wherein the base further comprises a pretensioning spring biasing the resilient beam for each flexible base coupling toward the stop.

9. The mounting assembly of claim 8 , wherein the pretensioning spring biases the flexible base coupling against the stop.

10. The mounting assembly of claim 8 , wherein the pretensioning spring has a stiffness greater than the stiffness of the resilient beam in the plane of movement.

11. 5. A mounting assembly according to any preceding claim, wherein each base coupling is a ball bearing which cooperates with a corresponding ball socket on a respective arm.

12. 5. A mounting assembly according to claim 1, wherein each flexible base coupling is movable relative to the body such that the base coupling moves only in a single plane.

13. A hair-cutting tool comprising a mounting assembly according to any one of claims 1 to 4.

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