Mounting Assembly

Abstract

According to one aspect, a mounting assembly 10 for a hair-cutting appliance is provided. The mounting assembly includes a head 12 for receiving a cutting unit, a base 14, and a mount. The head is mounted to the base via the mount such that the head is pivotally moveable relative to the base about a first axis 15 and a second axis 30, the first axis and the second axis being non-parallel. The first biasing element 34a and the second biasing element 34b act independently of each other, the first biasing element and the second biasing element being mounted to fixed points and configured to act on the head or mount at respective first and second biasing points to bias pivotal movement of the head relative to the base to a stable position. The first and second bias points are located on the same side of a first plane 50, which plane includes a bias axis 24a parallel to the first axis, about which the first and second bias points are constrained to pivot relative to a fixed point, and a line parallel to a force direction 52 defined by a bias force applied to either the first or second bias points to bias the head in one pivot direction about the first axis to a stable position relative to the base. The first and second bias points are located on opposite sides of a second plane 60, which plane includes a second axis and a line parallel to the force direction to balance the head in a stable position relative to the base about the second axis.

Description

[Technical Field]

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

[0002] Hair-cutting implements typically have a blade head that is pivotable about a first axis to follow the contours of the face. Previously contemplated hair-cutting implements allow for pivotal movement about a second axis to better follow the contours of the face. Summary of the Invention [Problem to be solved by the invention]

[0003] However, ensuring sufficient stiffness in the pivoting movement of the head requires a bulky arrangement of springs and contact parts.

[0004] US2012 / 0060382 discloses a pivot arrangement for a shaving implement having a pivot member and a spring-loaded arrangement for pivoting the pivot member in two pivot directions. [Means for solving the problem]

[0005] According to a first particular aspect, there is provided a mounting assembly for a hair-cutting appliance, the mounting assembly comprising: a head for receiving a cutting unit; a base and a mount, wherein the head is mounted to the base via the mount, the head being pivotally movable relative to the base about a first axis and a second axis, the first axis and the second axis being non-parallel; and a first bias element and a second bias element, the first bias element and the second bias element acting independently of each other, the first bias element and the second bias element being mounted at fixed points and acting on the head or the mount at respective first and second bias points to adjust the pivotal movement of the head relative to the base. to a stable position, the first bias point and the second bias point being located on the same side of a first plane, the plane having a bias axis parallel to the first axis, about which the first bias point and the second bias point are constrained to pivot relative to a fixed point, and a line parallel to a force direction defined by a bias force applied to one of the first bias point or the second bias point to bias the head in one pivot direction relative to the base about the first axis to a stable position, the first bias point and the second bias point being located on opposite sides of a second plane, the plane including the second axis and a line parallel to the force direction to balance the head in a stable position relative to the base about the second axis.

[0006] The first axis and the second axis may be substantially perpendicular.

[0007] The moment arm of the first bias point from the bias axis may be the same length as the moment arm of the second bias point from the bias axis, in other words, the first bias point and the second bias point are equidistant from the bias axis.

[0008] The moment arm of the first bias point from the second axis may be the same length as the moment arm of the second bias point from the second axis, in other words, the first bias point and the second bias point are equidistant from the second axis.

[0009] The mount is disposed between the base and the head and has two arms forming a linkage, each arm coupled at a joint to a respective head coupling on the head and to a respective base coupling on the base. Each joint of each head coupling can be configured to allow pivotal movement about a respective parallel head pivot axis, such that the head is pivotable relative to the base about one of the first axis and the second axis. The joint of the base coupling can be configured to allow pivotal movement of the arm about at least the other of the first axis and the second axis.

[0010] For example, the linkage may be a three-bar linkage in which the head pivot axes of each joint in the head coupling are parallel, and the head pivot axis is either the first axis or the second axis.

[0011] The joint of the base coupling can further allow pivotal movement about a separate base pivot axis parallel to the head pivot axis, with each arm coupled to a different separate head coupling and allowing pivotal movement about a different parallel head pivot axis, thereby forming a four-bar linkage that allows the head to pivotally move relative to the base about a virtual pivot axis, which is either the first axis or the second axis.

[0012] The virtual pivot axis may be the first axis.

[0013] The mounting assembly may include a stroke limiter configured to prevent pivotal movement of the head relative to the base beyond a limit. The stroke limiter is configured to impede pivotal movement of the four-bar linkage, thereby inhibiting pivotal movement of the head relative to the base about the first axis beyond the limit. The bias forces at the first bias point and the second bias point may have the same moment direction with respect to the bias axis. The stable position may be the limit.

[0014] Each biasing element may be a leaf spring. Each biasing element may be disposed in a single integral biasing unit.

[0015] The mounting assembly may include a stop for each biasing element configured to abut the respective biasing element to limit the movement of the biasing element, thereby pretensioning the biasing element. The stops may be integral with the biasing elements.

[0016] According to a second aspect, there is provided a hair-cutting apparatus including a mounting assembly according to the first aspect.

[0017] According to a third aspect, there is provided a biasing unit for a mounting assembly according to the first aspect, the biasing unit having first and second biasing elements acting independently of each other, the first and second biasing elements each being in the form of an integral leaf spring, the biasing unit having a pair of integral stops for each leaf spring, each stop configured to abut a respective leaf spring to limit movement of the leaf spring, thereby pre-tensioning the leaf springs.

[0018] These and other aspects will be apparent from and elucidated with reference to the embodiments described hereinafter. [Brief explanation of the drawings]

[0019] [Figure 1] 1A and 1B are schematic side views of an exemplary mounting assembly for a hair-cutting apparatus; [Figure 2] FIG. 1 is a schematic diagram of an isometric cutaway view of a mounting assembly. [Figure 3] FIG. 10 illustrates the location of bias points on the mounting assembly. DETAILED DESCRIPTION OF THE INVENTION

[0020] Exemplary embodiments will now be described, by way of example only, with reference to the following drawings, in which:

[0021] Figure 1 shows a side view of an exemplary mounting assembly 10 for a hair-cutting tool, and Figure 2 shows an isometric view of the same mounting assembly 10 with parts removed to show the internal mechanical workings of the mounting assembly 10. A hair-cutting tool has a mounting assembly and may also have a handle and a cutting unit.

[0022] The mounting assembly 10 includes a head 12 (shown only in FIG. 1 ; in FIG. 2 , the head 12 is removed) configured to receive a cutting unit, such as a blade or a powered trimming attachment, and a base 14 for connecting to a handle configured to be held by a user. In some examples, the base can be integral with the handle. The head 12 is attached to the base 14 via a mount, which in this example is in the form of a pair of arms 16 (only one arm is shown in FIG. 2 ). 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.

[0023] In this example, each arm 16 has two branching strands in a U-shape, with each arm 16 connected to the base 14 with a single base coupling 22 at the apex of the U, and each arm 16 connected to a separate head coupling 20 at each end of the U. Thus, the base 14 has two base couplings 22 and the head 12 has four head couplings 20. The head 12 is supported relative to the base 14 by the four head couplings 20 that connect to the arms 16.

[0024] In other examples, each arm can have one strand to form an I-shape, with the heads supported by the arms for only two total head couplings, or the arms can have two or more branch strands, with coupler links supported by the arms at two or more coupler joints per arm. Each arm can have a different number of branch strands, for example, to support coupler links at three or five coupler joints. In yet another example, the arms can have two branch strands in a T, V, or Y shape, such that each arm supports coupler links at two coupler joints.

[0025] Each linkage 18 is configured to permit pivotal movement between a respective arm 16, head 12, and base 14 about a parallel 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 two arms 16 provide a mount for attaching the head 12 to the base 14. As a result, the head 12 is pivotably movable relative to the base 14 about a first axis 15 that is parallel to the pivot axis 24. In this example, the first axis 15 is a virtual axis due to the four-bar linkage (i.e., the axis about which the head 12 pivots is not physically connected to the head 12).

[0026] In this example, the couplings 18 of each head coupling 20 connecting the same arm 16 to the head 12 are spaced apart in a direction parallel to the pivot axis 24, such that they share the same pivot axis 24 (i.e., their pivot axes 24 are parallel). The head couplings 20 connecting different arms 16 to the head 12 are spaced apart in a direction perpendicular to the pivot axis 24, such that the couplings 18 of the head couplings 20 for different arms 16 each allow pivotal movement about different, parallel pivot axes 24. The base couplings 22 are also spaced apart along a second axis 30. In this example, the second axis 30 is perpendicular to the first axis 15 (and therefore perpendicular to the pivot axis 24). In other examples, the second axis need not be perpendicular to the first axis, but is not parallel to the first axis.

[0027] In another example, the pivot axes of all joints of the head coupling are parallel, so that the head no longer forms a bar of the linkage, but the arm, head, and base form a three-bar linkage. In such an example, the head can pivot about a head pivot axis that passes through the head coupling. In other words, in this example, the head pivot axis becomes the first axis.

[0028] Each head coupling 20 in this example is a linear bearing, such that the joints 18 of each head coupling only allow pivotal movement about parallel pivot axes 24. 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 joints individually allow pivotal movement about three perpendicular pivot axes. However, due to the four-bar linkage and the spacing of the ball joints along the second axis 30 (i.e., joints 18 of base couplings 22 in this example), the ball joints are constrained to only allow pivotal movement about their individual pivot axes 24 and the second axis 30 that passes through both base couplings 22. Thus, the ball joints allow pivotal movement of the arms 16, and thereby the entire four-bar linkage, together about the second axis 30. As a result, the pivot axis 24 also pivots about the second axis 30.

[0029] It should be appreciated that in other embodiments, the ball bearing can be located in the head and the linear bearing can be located in the base, such that the four-bar linkage cannot move together about the second axis relative to the base, but the head can move relative to the arm and base about the second axis through the ball bearing.

[0030] The mounting assembly 10 includes a stroke limiter 26 configured to prevent pivotal movement of the head 12 relative to the base 14 beyond a limit. In this example, the stroke limiter 26 is configured to impede pivotal movement of the four-bar linkage, inhibiting pivotal movement of the head 12 relative to the base 14 about the first axis 15. In another example, where the linkage is a three-bar linkage, the stroke limiter simply limits pivotal movement of the head about a head pivot axis that passes through the head coupling.

[0031] The stroke limiter 26 in this example has a tab that protrudes from the head 12 in a direction toward the base 14, such that the tab is located between the pair of arms 16. The tab is configured to engage each arm 16 at a respective limit, preventing movement of the four-bar linkage, thereby preventing pivotal movement of the head 12 about the first axis 15. FIG. 1 shows the tab engaging one of the arms 16 at its limit. Thus, the four-bar linkage is constrained to move between the limits imposed by the stroke limiters 26 that engage each arm 16.

[0032] 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 examples, the tab may be located on either the arm, base, or head and configured to engage the head, base, or arm and prevent pivoting movement of the four-bar linkage or pivoting movement of the head about either the first axis or the second axis. The stroke limiter can prevent pivoting movement of the head only in one direction (clockwise or counterclockwise about the first axis or the second axis) or can prevent pivoting movement of the head in both pivoting directions (clockwise and counterclockwise about the first axis or the second axis).

[0033] The mounting assembly 10 further includes a first biasing element 34a and a second biasing element 34b (only the first biasing element 34a is visible in FIG. 1). The first biasing element 34a and the second biasing element 34b act independently of one another to provide independent biasing forces. In this example, the first biasing element 34a and the second biasing element 34b are mounted to the base 14 and configured to engage one of the arms 16 (i.e., the mount) at respective first biasing points 40a and second biasing points 40b. In other examples, the biasing elements may be mounted to the head and act on the mount, or may be mounted to the base and act directly on the head.

[0034] In this embodiment, each biasing element 34 comprises a leaf spring that abuts a respective inner protrusion 36 on one of the arms 16, urging the protrusion 36 upward (i.e., away from the base 14), thereby providing a biasing force to the arm 16 in a force direction 52. In other examples, the biasing elements can have any suitable characteristics capable of providing an appropriate biasing force. The force direction 52 at the first bias point 40a is parallel to and in the same direction as the force direction 52 at the second bias point 40b. In other examples, the force directions need not be parallel and in the same direction.

[0035] The locations of the first biasing element 34a and the second biasing element 34b are shown in Figures 2 and 3. Figure 3 illustrates the locations in an abstract diagram. In this example, the inner protrusions 36 are located on the same arm 16, such that the first biasing element 34a and the second biasing element 34b act on different branch strands of the same arm 16. Thus, the first biasing point 40a and the second biasing point 40b are located on the same side of a first plane 50 (shown as entering the page in Figure 3), which is defined by the plane having the biasing axis 24a and a line parallel to the force direction 52 of the biasing force applied at the first biasing point 40a and the second biasing point 40b (shown as exiting the page in Figure 3). The biasing axis 24a in this example is the pivot axis 24 connecting the arm 16 with the protrusions 36 to the base 14. Thus, the bias force provided by the first biasing element 34a creates a moment about the bias axis 24a in the same direction as the moment about the bias axis 24a provided by the biasing force of the second biasing element 34b. In this example, moment arm d1a of the bias force provided by the first biasing element 34a at the first bias point 40a from the bias axis 24a is the same length as moment arm d1b of the bias force of the second biasing element 34b at the second bias point 40b from the bias axis 24a, such that the first bias point 40a and the second bias point 40b are equidistant from the bias axis 24a. Thus, the moments about the bias axis 24a provided by the first biasing element 34a and the second biasing element 34b combine to bias the four-bar linkage to bias the head 12 about the first axis 15. Head 12 is biased about first axis 15 to a stable position, which in this example is the limit at which arm 16 abuts stroke limiter 26. In other examples, the stable position is when the biasing element abuts a stop (discussed in more detail below), or in examples without a stroke limiter, the stable position is the equilibrium position of the biasing element where it is attached to the mount.

[0036] In other examples where the biasing element is attached to any fixed point, such as on the head, base, or arm, the bias axis may be any axis about which the first and second bias points are constrained to pivot relative to the fixed point. For example, the biasing element can be attached to the base and configured to act directly on the head, in which case the bias axis would be the first axis. In yet another example, if the coupling connecting the head and arm is a ball coupling and the biasing element is attached to the first arm at a fixed point and configured to act on the head, the bias axis would be the pivot axis connecting the first arm and the head.

[0037] The first bias point 40a and the second bias point 40b are located on opposite sides of a second plane 60, which has a line parallel to the second axis 30 and to the direction 52 of the force applied at the first bias point 40a and the second bias point 40b. Thus, the bias force applied at the first bias point 40a creates a moment about the second axis 30 that opposes the moment created about the second axis 30 by the bias force applied at the second bias point 40b. In this example, the moment arm d2a of the first bias point 40a from the second axis 30 is the same length as the moment arm d2b of the second bias point 40b from the second axis 30, such that the first bias point 40a and the second bias point 40b are equidistant from the second axis 30. In this example, the biasing forces from the first biasing element 34a and the second biasing element 34b are equal in magnitude in the stable position, resulting in equal and opposite moments about the second axis 30 to balance the head 12 in a stable position relative to the base 14 about the second axis 30. In other examples, the moment arms of the first and second biasing points may be different lengths from the first and second axes. The moment arms of the biasing elements can be used to fine-tune the stiffness of the pivotal movement of the head 12 about the first and second axes 15, 30.

[0038] As noted above, biasing element 34, in this example, acts on the mount to bias the pivotal movement of head 12 relative to base 14 about first axis 15 and second axis 30. Due to the placement of biasing point 40 relative to first plane 50 and second plane 60, no further biasing element is required to achieve a stable position of head 12 about both first axis 15 and second axis 30.

[0039] Although the force directions 52 applied at the bias points 40 have been described as being parallel, in instances where they are not parallel, the first plane can be defined by a plane having a first axis and a line parallel to either of the force directions. In yet other instances, the force directions can be opposite, such that the moments applied at the first and second bias points are opposite in relation to the first axis and in the same direction in relation to the second axis.

[0040] 2, the first biasing element 34a and the second biasing element 34b each also have a stop 38 configured to abut the respective biasing element 34a, 34b to limit its movement in one direction. Such limiting of movement applies pretension to the biasing elements 34. The pretension can also be adjusted to fine-tune the stiffness of the head's pivoting movement.

[0041] In this example, the leaf spring-shaped first and second biasing elements 34a, 34b are located on a single, integrated biasing unit, with each stop 38 integral with a separate biasing element 34. Having a single unit with the necessary biasing elements to bias the head about two different axes simplifies the construction of the mounting assembly 10 and improves the accuracy of the relative position of the first and second biasing points 40a, 40b. Furthermore, having the stops 38 integral with the leaf springs improves pretension tolerances dictated by part geometry rather than assembly accuracy. Furthermore, having the stops 38 to introduce pretension ensures that a greater force is required to move the head from its stable position, thereby improving head stability in the stable position and minimizing vibration.

[0042] Although the first bias point 40a and the second bias point 40b are described as being on different strands of the same arm 16, in other examples they may be on different arms, on the same side of the second plane, and on opposite sides of the first plane, such that the moments applied at the first bias point and the second bias point are in opposite directions relative to the first axis and in the same direction relative to the second axis.

[0043] Although the mount has been described as having two arms attached by ball bearings and linear bearings, it should be understood that in other examples there may be any suitable mount in which the head is attached to the base such that the head is pivotably moveable relative to the base about first and second axes, where the first and second axes are not parallel.

[0044] Although the application of the biasing element 34 has been described above with reference to a hair-cutting appliance having a mounting assembly 10 with a single head 12, it will be appreciated that the biasing element arrangement can be applied to a hair-cutting appliance having any number of heads arranged together, such as a rotary hair-cutting appliance with two or more heads, and the biasing element arrangement can be applied independently to each head.

[0045] Variations to the disclosed embodiments can be understood and implemented by those skilled in the art practicing the principles and techniques described herein, from a study of the figures, the disclosure, and the appended claims. In the claims, the word "comprise" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in a claim. The mere fact that certain means are recited in mutually different dependent claims does not indicate that a combination of these means cannot be used to advantage. A computer program can be stored or distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but can also be distributed in other forms, such as via the Internet or other wired or wireless communication systems. Any reference signs in the claims should not be construed 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 and a mount, wherein the head is attached to the base via the mount, and the head is pivotally movable relative to the base about a first axis and a second axis, the first axis and the second axis being non-parallel; a first bias element and a second bias element, the first bias element and the second bias element being attached to the base and acting independently of each other on the mount or the head, or on the head and acting independently of each other on the mount; the first bias element and the second bias element are configured to act on the head or the mount at respective first and second bias points to urge the head or the mount toward a stable position in which the head is balanced relative to the base; the first bias point and the second bias point are located on the same side of a first plane, the first plane including a bias axis parallel to the first axis and a line parallel to a force direction defined by a bias force applied to one of the first bias point or the second bias point to urge the head in one pivot direction relative to the base about the first axis to the stable position; the first bias point and the second bias point are located on opposite sides of a second plane, the second plane including the second axis and a line parallel to the force direction to balance the head in the stable position relative to the base about the second axis.

2. 2. The mounting assembly of claim 1, wherein a moment arm of the first bias point from the bias axis is the same length as a moment arm of the second bias point from the bias axis.

3. 2. The mounting assembly of claim 1, wherein a moment arm of the first bias point from the second axis is the same length as a moment arm of the second bias point from the second axis.

4. the mount is disposed between the base and the head and has two arms forming a linkage, each arm being coupled to a respective head coupling on the head at a coupling portion and to a respective base coupling on the base at a coupling portion, each coupling portion of each head coupling being configured to allow pivotal movement about a respective parallel head pivot axis, and the head is pivotable relative to the base about one of the first axis and the second axis; 4. A mounting assembly according to claim 1, wherein the joint of the base coupling is configured to allow pivotal movement of the arm about at least the other of the first axis and the second axis.

5. 5. The mounting assembly of claim 4, wherein the base coupling joint further allows pivotal movement about a respective base pivot axis parallel to the head pivot axis, and each arm is coupled to a different respective head coupling to form a four-bar linkage allowing pivotal movement about a different parallel head pivot axis, the linkage allowing the head to pivotally move relative to the base about a virtual pivot axis that is either the first axis or the second axis.

6. The mounting assembly of claim 5 , wherein the virtual pivot axis is the first axis.

7. 4. A mounting assembly according to claim 1, further comprising a stroke limiter that prevents pivotal movement of the head relative to the base beyond a limit.

8. the stroke limiter impedes pivotal movement of the four-bar linkage, preventing pivotal movement of the head relative to the base about the first axis beyond the limit; 8. The mounting assembly of claim 7 when dependent on claim 6, wherein the biasing forces at the first biasing point and the second biasing point have the same moment direction relative to the biasing axis.

9. The mounting assembly of claim 7 , wherein the stable position is the limit.

10. 4. A mounting assembly according to claim 1, wherein each biasing element is a leaf spring.

11. 4. The mounting assembly of claim 1, wherein each biasing element is disposed in a single integral biasing unit.

12. 4. The mounting assembly of claim 1, further comprising a stop for each biasing element, the stop configured to abut an individual biasing element to limit movement of the biasing element, and the biasing elements are pretensioned.

13. The mounting assembly of claim 12 , wherein the stop is integral with the biasing element.

14. A hair-cutting tool comprising a mounting assembly according to any one of claims 1 to 3.

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