Hair cutting device with a cutting length adjustment device

The hair cutting device with a lever and sliding sleeve mechanism allows easy switching between stepless and stepped adjustment modes, addressing inefficiencies in existing devices and enhancing salon profitability.

EP4744846A1Pending Publication Date: 2026-05-20WAHL GMBH
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Patent Information

Authority / Receiving Office
EP · EP
Patent Type
Applications
Current Assignee / Owner
WAHL GMBH
Filing Date
2025-11-04
Publication Date
2026-05-20

AI Technical Summary

Technical Problem

Existing hair cutting devices in salons often have either stepless or incremental adjustment modes, leading to inefficiencies and reduced profitability due to the need for multiple types of devices, which are not economically flexible or optimal.

Method used

A hair cutting device with a cutting length adjustment mechanism that allows easy switching between stepless and stepped adjustment modes using a lever with a pre-tensioned detent and a sliding sleeve, located outside the hair clipper, which interacts with the cutting elements to adjust their longitudinal offset.

Benefits of technology

Enables efficient and flexible adjustment of cutting length without complex mechanics, improving machine efficiency and overall profitability in salons by simplifying mode switching.

✦ Generated by Eureka AI based on patent content.

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Abstract

Hair cutting device (100) comprising a blade assembly (102) with a first longitudinally movable cutting element (104) and a second, transversely movable cutting element (106), a drive device that drives the blade assembly (102), and a cutting length adjustment device that interacts with the first cutting element (104) such that a longitudinal offset can be adjusted between the first cutting element (104) and the second cutting element (106), wherein the cutting length adjustment device has a lever (12) with a pre-tensioned detent lug (14) for adjusting the second, movable cutting element and at least one retaining recess such that the detent lug (14) engages in the retaining recess, wherein the lever (12) further comprises a sliding sleeve (24) which, in a first position, holds the detent lug (14) against the pre-tensioning force, and in a second position (14) releases.
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Description

Field of invention

[0001] The invention relates to a hair cutting device with a cutting length adjustment device with a switching function. State of the art

[0002] Hair cutting devices with a cutting length adjustment mechanism are known in the prior art. Typically, a hair cutting device has a blade arrangement with two cutting elements, a first of which is longitudinally displaceable for adjusting the cutting length and is fixed to the rest of the hair cutting device during the cutting process, and a second of which is arranged to oscillate laterally relative to the first and is used to cut the hair during the cutting process. Frequently, cutting elements with comb-like cutting edges are used, in which case the first cutting element is designed as a so-called shearing comb and comes into contact with the skin of the person or animal being treated, or the user. The second cutting element is then designed as a so-called shearing blade.Each cutting element has a series of spaced-apart teeth, which are generally arranged at regular intervals. Such a blade assembly can be designed to allow for different cutting lengths. The cutting length of such an adjustable blade assembly is adjusted by longitudinally offsetting the two cutting elements relative to each other. In removable / replaceable blade assemblies, the second, laterally movable cutting element is usually offset longitudinally, while in blade assemblies permanently attached to the hair clipper, the first cutting element is usually offset longitudinally.

[0003] Solutions for adjusting the cutting length are known from the prior art, allowing for either stepless or incremental adjustment. Both variants occur with roughly equal frequency, although one or the other is usually preferred depending on the user. This leads to a situation, particularly in hair salons with multiple hairdressers, where both stepless and incrementally adjustable hair cutting devices are present, although most of these variants are not in use. As a result, these salons experience low machine efficiency, which in turn reduces overall profitability.

[0004] Solutions known from the state of the art are therefore not very economical, inflexible and often do not offer the optimal adjustment options. Description of the invention

[0005] The object of the present invention is to provide a hair cutting device with a cutting length adjustment device in which it is easy to switch back and forth between a stepless and a stepped adjustment mode. This object is achieved with a hair cutting device according to claim 1.

[0006] A hair cutting device according to the invention comprises a blade arrangement with a first cutting element and a second cutting element, which is designed to be movable at least laterally relative to the first cutting element, a drive device that drives the blade arrangement, and a cutting length adjustment device that interacts with the first cutting element in such a way that a longitudinal offset can be adjusted between the first cutting element and the second cutting element, wherein the cutting length adjustment device has a lever with a pre-tensioned detent for adjusting the first movable cutting element and at least one retaining recess, such that the detent engages in the retaining recess, making it difficult, in particular preventing, the lever from moving out of the retaining recess, wherein the lever further comprises a sliding sleeve that, in a first position, holds the detent against the pre-tension force.and in a second position releases the locking tab. Because the cutting length adjustment device is located outside the hair clipper and a switching function is provided on the cutting length adjustment device, switching between modes is simple. Furthermore, no complicated mechanics are required inside the hair clipper, since the mode switching device, which includes the locking tab and retaining recess, is located on the cutting length adjustment device outside the hair clipper.

[0007] The sliding sleeve preferably surrounds the lever at least partially. This ensures a secure hold of the sliding sleeve on the lever. The sliding sleeve can be completely closed, thus enclosing the lever entirely. Preferably, however, the sliding sleeve completely covers the lever on the side of the locking lug and engages in a groove on the upper and lower sides of the lever. This allows the sliding sleeve to interact securely with the locking lug and simultaneously ensures that the sleeve remains accessible. If the lever has a rectangular or square cross-section, the sleeve extends, in particular, over 2 / 3 of the upper and / or lower sides of the lever.

[0008] The retaining projection is preferably conical in shape and further features a hemispherical end, particularly at its tip. The end may have a flat section. This allows it to slide more easily into the retaining recess, and also enables the sliding sleeve to move the locking lug against the preload force without the need for tools.

[0009] The sliding sleeve preferably has a recess on the side of the locking lug. In particular, the recess tapers from one end of the locking lug to the other end, such that the contact points of the recess with the locking lug approach each other from the first position of the sliding sleeve to the second position. This allows the locking lug to be moved even more easily against the preload force.

[0010] The recess in the sliding sleeve is preferably circular at one end to provide a seat for the locking lug. This prevents accidental switching between the stepless and stepped adjustment modes, particularly if the locking lug has a conical shape. The recess at the entry end is wider than the diameter of the locking lug, so that the locking lug does not contact the sliding sleeve in the second position. Alternatively, the sliding sleeve can be spaced away from the locking lug in the second position, requiring the sleeve to be pushed towards the first position to make contact. Preferably, however, the sliding sleeve acts as a stop for the locking lug, preventing the spring from pushing the locking lug out of the opening. In other words, the sliding sleeve is at least partially positioned over the opening.

[0011] The sliding sleeve preferably projects beyond the surface of the lever on at least one side, or is at least partially protruding. This ensures easier movement of the sliding sleeve, as a user can reliably reach it with, for example, their fingers.

[0012] The lever is at least partially flat on the side facing the hair cutting device, and in particular completely flat. This ensures that the locking lug can securely engage in the retaining recess on the hair cutting device.

[0013] Preferably, the sliding sleeve has a projection that is angled, for example by more than 60° or by 90°. This makes it easier to grip and move the sliding sleeve. Brief description of the characters

[0014] Figure 1 shows a hair cutting device with an adjustment lever in a top view; Figure 2shows an isometric exploded view of a lever of the cutting length adjustment device; Figure 3a shows the lever of the cutting length adjustment device in a side view with a sliding sleeve in a first position; Figure 3b shows the lever of the cutting length adjustment device in a sectional view with a sliding sleeve in a first position; Figure 4a shows the lever of the cutting length adjustment device in a side view with a sliding sleeve in a second position; and Figure 4b shows the lever of the cutting length adjustment device in a sectional view with a sliding sleeve in a second position. Description of preferred embodiments

[0015] In Figure 1Figure 1 shows a hair cutting device 100 with a blade assembly 102 comprising a first cutting element 104 and a second, laterally movable cutting element 106, which is laterally movable relative to the first cutting element 104. The blade assembly 102 is driven by a drive device located in the housing of the hair cutting device 100. The cutting length adjustment device 10 interacts with the first cutting element 104 or the second cutting element 106 such that a longitudinal offset between the cutting elements 104 and 106 can be adjusted. This means that when the lever 12 is moved forward or backward, the first or second cutting element is moved backward or forward (see arrow A), thus shortening or lengthening the cutting length of the hair cutting device 100. Such a mechanism is known in the prior art.The cutting length is adjusted via a lever 10, which is usually provided on the side of the hair cutting device 100.

[0016] In the Figures 2 to 4b The lever of the cutting length adjustment device 10 can be seen in different views. The cross-section of the lever 12 is preferably rectangular or square with rounded edges. In particular, the lever 12 is designed to be as flat as possible on the side facing the hair cutting device 100. The lever 12 has a locking lug 14 and a sliding sleeve 24. The lever 12 also has a step 13, so that the pivot section 22, about which the lever 12 rotates on the hair cutting device 100, is slightly recessed relative to the lever arm in the top view. The pivot section 22 is then preferably connected to the adjustment mechanism inside the hair cutting device 100 via a pin 21, so that a rotation of the lever 12 moves the first or second cutting element 104, 106 in the longitudinal direction A ( Fig. 1 ) moves. In the hair clipper 100, lateral recesses 110 are provided with which the lever 12 interacts, as described later.

[0017] In Figure 2 The lever 10 is shown in an isometric exploded view, with the locking lug 14 arranged on the inside, facing the hair-cutting device. Furthermore, the lever 12 also has a sliding sleeve 24 which interacts with the locking lug 14.

[0018] The sliding sleeve 24 can be formed completely around the lever, but preferably, as shown in the figures, it only covers the inside completely and engages the top and bottom of the

[0019] The lever 12 engages in an upper groove 18 and a lower groove, which guide the sliding sleeve 24 on the lever 12. The sliding sleeve is preferably U-shaped (as shown here), with inwardly inclined projections at the ends that engage in the grooves 18. One or both of these grooves 18 can serve as a stop for the sliding sleeve 24, thus limiting its movement on the lever 10. The sliding sleeve 24 projects beyond the surface of the lever, particularly on its upper and lower surfaces, to facilitate movement by the user's fingers. The edges 26 of the sliding sleeve 24 parallel to the lever are preferably rounded on the outside. However, the edges 28 perpendicular to the lever are formed without rounding, with a clear 90° edge, allowing the user to grip and operate the sleeve more securely. On the inside of the sliding sleeve 24, it rests particularly against the lever 12, e.g. with a small amount of play.On its inner side, the sliding sleeve 24 has a recess 30, which will be described in more detail below. The sliding sleeve 24 may have a rough texture on its surface to provide grip and facilitate its movement.

[0020] The locking lug 14 is pre-tensioned, for example, by a spring element, shown in the figures as a coil spring, or by a repelling magnetic device, each arranged below the locking lug 14, so that the locking lug 14 is pressed out of the lever. The locking lug 14 is preferably at least partially conical and arranged in a circular opening 20 in the lever 12. To prevent the locking lug 14 from falling out of the lever 12, the opening 20 may have an undercut below its surface. In the illustrated embodiment, the sliding sleeve is positioned in the second position with a stop such that the sliding sleeve prevents the locking lug 14 from falling out. A further recess, which has a smaller diameter than the opening 20 and serves to support a spring 17, may be arranged at the bottom of the opening 20. The conical section of the locking lug 14 is preferably the section projecting from the lever 12.The detent lug 14 shown has a circular cross-section, but other basic shapes such as squares, triangles, rectangles, or other polygons are also usable. The detent lug tip 16 is preferably provided with a radius and, for example, is designed as a hemisphere. More preferably, the tip can be flattened. The surface at the tip is, in particular, a flat surface with a radius of 0.5 to 3 mm. A guide projection 15 is preferably formed on the underside of the detent lug, which is received by the spring 17 and ensures that the spring 17 and the detent lug 14 are aligned, in particular concentrically. The detent lug 14 is then pressed by the spring into the recesses 110, so that the user receives tactile feedback about the setting of the lever 12.

[0021] Preferably, no elements are provided on the outside of the lever handle. The end of the lever 12 may be rounded. A through-hole 23 is preferably provided in the rotating section 22, into which a pin of the hair clipper 100 can be inserted, around which the lever 12 can rotate.

[0022] The Figures 3a and 4a show the lever in a top view. Figures 3b and 4b show a longitudinal section of lever 12 from the same direction. In the Figures 3a and 3b The sliding sleeve 24 of the lever is in a first position in which the locking lug 14 is held in a retracted position by the sliding sleeve 24. This can be achieved, for example, by the locking lug 14 having a slot into which the sliding sleeve 24 can be inserted and which holds the locking lug 14.

[0023] Preferably, the sliding sleeve 24 has a recess 30. This recess 30 is designed in particular such that the locking lug 14 can not only be held in the first retracted position, but is also forced from the second position, in which the locking lug 14 protrudes, into the first position, in which the locking lug 14 is retracted. For this purpose, the recess 30 can, for example, be at least partially tapered, i.e., the edges 32 of the recess approach each other. The retaining part in which the locking lug 14 is then held is preferably rectangular or square, such that the end 31 of the recess 30 runs parallel to the edges 28.

[0024] A projection 19 is arranged at the end of the sliding sleeve 24 facing the axis of rotation, extending over the sides of the sliding sleeve 24. In particular, this projection 19 extends upwards, preferably at a 90° angle to the surface of the sliding sleeve. The projection 19 serves to facilitate gripping with a finger or thumb.

[0025] At the end of the recess 30, a circular segment can alternatively be provided that has a wider diameter than the distance between the edges 31 at their narrowest point. The locking lug 14 then engages in the circular segment 34 and is held there in a retracted position, preventing it from sliding back into the tapered section on its own. The circular segment 34 therefore acts as a seat for the locking lug 14. The entrance side of the recess 30 is preferably larger than the largest diameter of the locking lug 14 protruding from the lever. In the second position of the sliding sleeve

[0026] The Figures 4a and 4b The figures show the sliding sleeve 24 of the lever in a second position, in which the sliding sleeve 24 releases the locking lug 14. Figure 4bIt can be seen that the sliding sleeve 24 is not arranged completely away from the locking lug 14, but that the sliding sleeve 24 protrudes beyond the edge of the opening 20 and thus serves as a stop for the locking lug 14.

[0027] When the sliding sleeve 24 is then pushed from the second to the first position, the recess edges 32 contact the side surfaces of the conically shaped locking lug 14. Due to the tapered design, the locking lug 14 is then pressed downwards as the contact points approach the recess 30.

[0028] In the first position of the sliding sleeve 24, the lever 12 is infinitely adjustable. In this position, the locking lug 14 is retracted by the sliding sleeve 24, and the tip 16 of the locking lug 14 is lifted from the hair clipper 100, so that the locking lug 14 cannot engage in the recess 110 for the locking lug 14. In the second position of the sliding sleeve 24, the locking lug 14 protrudes further from the lever 12 due to the spring force of the spring 17 and the absence of a stop on the sliding sleeve 24, so that the tip 16 of the locking lug 14 contacts the hair clipper 100 and engages in the recess 110 for the locking lug 14. This allows the user to feel precisely when the locking lug 14 engages or slides out of the recess 110. Reference symbol list

[0029] 10 Cutting length adjustment device 12 Lever 13 Step 14 Detent lug 15 Guide projection 16 Detent lug tip 17 Spring 18 Upper groove 19 Projection 20 Opening 21 Pin 22 Rotary section 23 Through hole 24 Sliding sleeve 26 Rounded edges 28 Edges 30 Recess 31 End of recess 32 Recess edges 34 Circular recess 100 Hair cutting device 102 Blade assembly 104 First cutting element 106 Second cutting element 110 Recesses for detent lug

Claims

1. Hair cutting device (100) comprising a blade assembly (102) with a first cutting element (104) and a second cutting element (106) which is designed to be movable at least laterally relative to the first cutting element, a drive device which drives the blade assembly (102), and a cutting length adjustment device which interacts with the first cutting element (104) or second cutting element (106) in such a way that a longitudinal offset can be adjusted between the first cutting element (104) and the second cutting element (106), wherein the cutting length adjustment device has a lever (12) with a pre-tensioned detent lug (14) for adjusting the first or second cutting element and at least one retaining recess such that the detent lug (14) engages in the retaining recess, characterized by the fact thatthe lever (12) further comprises a sliding sleeve (24) which in a first position holds the locking lug (14) against the preload force, and in a second position releases the locking lug (14).

2. Hair cutting device (100) according to claim 1, wherein the sliding sleeve (24) at least partially surrounds the lever (12).

3. Hair cutting device (100) according to one of the preceding claims, wherein the sliding sleeve (24) engages in a groove (18) of the lever (12) on the upper and lower sides of the lever.

4. Hair cutting device (100) according to one of the preceding claims, wherein the locking lug (14) is at least partially conical.

5. Hair cutting device (100) according to one of the preceding claims, wherein the sliding sleeve (24) has a recess (30) on the side of the locking lug (14).

6. Hair cutting device (100) according to claim 5, wherein the recess (30) tapers from one inlet end to the other end.

7. Hair cutting device (100) according to claim 5 or 6, wherein the recess at one end is circular in shape to provide a seat (34) for the locking lug (14).

8. Hair cutting device (100) according to one of claims 5 to 7, wherein the recess (30) at the inlet end is larger than the diameter of the locking lug (149) that protrudes from the lever (12).

9. Hair cutting device (100) according to one of claims 5 to 8, wherein the sliding sleeve (24) serves as a stop for the locking lug (14) in the second position, so that the locking lug (14) is held by the sliding sleeve in the opening (20).

10. Hair cutting device (100) according to one of the preceding claims, wherein the sliding sleeve (24) projects beyond the surface of the lever (12) on at least one side of the lever (12).

11. Hair cutting device (100) according to one of the preceding claims, wherein the lever (12) is at least partially flat on the side facing the hair cutting device (100).