DEVICE FOR ADJUSTING A BLADE OF A HAIR TRIMMER

An adjusting device for adjusting a blade of a hair trimmer where the blade of the hair trimmer has a dynamic cutter blade and a static comb blade. The adjusting device comprises a base, an adjuster pivotably connected to the base, a locator for locating the blade and a biasing means for biasing the blade against the adjuster. The adjuster has a comb-contacting face at a first radial distance from its rotation axis while a cutter-adjusting face is at a second radial distance from the rotation axis, the second radial distance being larger than the first radial distance. By rotating the adjuster, a clearance is created between the cutter blade and the comb blade.

FIELD OF THE INVENTION

The present invention generally relates to the field of hair trimmers. More specifically, the invention relates to an adjusting device allowing to adjust a clearance between a reciprocating cutter blade and a static comb blade of the blade of a hair trimmer.

BACKGROUND OF THE INVENTION

Users and barbers use hair trimmers of different sizes and shapes. The hair trimmer has a dynamic cutter blade which slides in a reciprocating movement on top of a static comb blade that is in contact with the skin of a user. In order to prevent cutting through skin, the extremity of the dynamic cutter blade must be adjusted at a very small distance behind that of the static comb blade. This distance, known as clearance, is makes much of a difference on the quality of shaving and is therefore very important to barbers to ensure fine, smooth and safe shaving.

Properly adjusting the clearance is not easy however, let alone adjusting it for different models of blades from different manufacturers. Some manufacturers provide an adjuster specific to their blade models, but that nevertheless forces barbers to purchase different adjusters for their different trimmers. There is therefore a need for a trimmer adjuster which can accommodate different blade models.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an adjusting device for adjusting a blade of an electric trimmer that overcomes or mitigates one or more disadvantages of known blade adjusting devices, or at least provides a useful alternative.

The invention provides the advantages of being adapted to adjust a variety of blades for electric trimmers from different manufacturers.

In accordance with an embodiment of the present invention, there is provided an adjusting device for adjusting a blade of an electric hair trimmer where the blade of the electric trimmer has a dynamic cutter blade and a static comb blade. The adjusting device comprises a base, an adjuster, a locator and a biasing means. The base has a transversal axis, a longitudinal axis and a receiving surface for receiving the comb blade. The adjuster has a comb-contacting face, a cutter-adjusting face and a rotation axis. The adjuster is pivotably connected to the base so that the rotation axis is parallel with the transversal axis of the base. The comb-contacting face is at a first radial distance from the rotation axis while the cutter-adjusting face is at a second radial distance from the rotation axis. The second radial distance is larger than the first radial distance. The locator is connected to the base and is movable along the longitudinal axis of the base. The locator has a receiving portion configured to receive and to locate a non-cutting extremity of the static comb. The biasing means is operable to bias the static comb against the comb-contacting face of the adjuster via the locator. The cutter-adjusting face is operable to displace the cutter blade with respect to the comb blade by pivoting the adjuster around the rotation axis.

The receiving surface of the base may be flat.

Optionally, the adjusting device may further comprise a locking mechanism operable to selectively prevent the locator from moving with respect to the base. The locking mechanism may be connected to the biasing means and to the base.

Optionally, the rotation axis of the adjuster may be substantially co-planar with the receiving surface of the base.

Optionally, the cutter-adjusting face of the adjuster may be located above the rotation axis and above the receiving surface of the base. The cutter-adjusting face may have a curved profile in a cross-sectional plane normal to the rotation axis. This curved profile may have increasing second radial distances.

Optionally, the receiving portion of the locator may comprise a ramp and a lip. The lip is positioned proximate an upper portion of the ramp so that the non-cutting extremity of the blade is displaced along the ramp up to the lip under a bias of the biasing means.

Optionally, the biasing means may be connected between the locator and the base in order to bias the locator substantially along the longitudinal axis of the base. The biasing means may be a spring.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to an adjusting device for adjusting the blades of a hair trimmer that is suited for accepting different models of blades from different manufacturers.

FIG.1is referred to. An adjusting device100for adjusting a blade102of an electric trimmer is depicted. The blade102of the electric trimmer has a reciprocating cutter blade104and a static comb blade106. The adjusting device100comprises a base108, an adjuster110, a locator112and a biasing means114, best shown inFIGS.2,3and4, now concurrently referred to. The base108has a transversal axis116, a longitudinal axis118and a receiving surface120for receiving the comb blade106. The receiving surface120of the base102is typically flat, or at least provides a flat supporting surface. The adjusting device100may be made of plastic or of metal.

The adjuster110comprises two portions for contacting the blade102: a comb-contacting face122and a cutter-adjusting face124, best shown inFIG.2. A lever127is also connected to, or part of, the adjuster110to provide leverage so the user can more easily rotate the adjuster110. The comb-contacting face122serves as a stopper against which the comb blade106rests. In certain models of blade102, it is also possible that the cutter blade104also contacts the comb-contacting face122when the comb-contacting face122is in a substantially vertical orientation. The comb-contacting face122may be flat or curved. If curved, the comb-contacting face122adopts a semi-cylindrical surface, at least locally where it is intended to contact the comb blade106. This semi-cylindrical shape is of a circular cross-section with a constant radius centered on a rotation axis126, the axis around which the adjuster110rotates. The rotation axis126is typically placed substantially co-planar or in a parallel plane slightly above the receiving surface120by a few millimeters (typically between 0 to 2 mm, corresponding to 0 to 0.078 in), and parallel with the transversal axis116. The cutter-adjusting face124is adapted to contact the cutter blade104, above the rotation axis126and above the receiving surface120. The cutter-adjusting face124may adopt a straight or curved profile146. Such a curved profile146is shown in a plane of the cross-sectional view ofFIG.3, which is normal to the rotation axis126. Being located above the comb-contacting face122, that is closer to the cutter blade104itself resting above the comb blade106, the cutter-adjusting face124is positioned to contact the cutter blade104first without contacting the comb blade106. Each point along the profile146which may potentially contact the cutter blade104is located at a gradually increasing radial distance from the rotation axis126, thereby allowing gradually pushing the cutter blade104along the comb blade106. As can be seen, any first radial distance128, which is the radial distance of any point along the profile146to the rotation axis126is larger than any second radial distance130, which is the radial distance of any point along the comb-contacting face122to the same rotation axis126.

Adjustment of the cutter blade104with respect to the comb blade106is achieved by rotating the adjuster110around its rotation axis126. This is shown inFIG.4. Further rotating the adjuster110pushes further the cutter blade104with respect to the comb blade106and thereby further increase the gap, also known as clearance, between the respective tips of the cutter blade104and the comb blade106. The exact geometry of the adjuster110and of the blade102influence how the cutter blade104moves with respect to the comb blade106. Consequently, the clearance between the cutter blade104and the comb blade106may not increase proportionally with the rotation angle of the adjuster110.

Although the cutter-adjusting face124is intended to only contact the cutter blade104when adjusting, it is possible that the comb-contacting face122also marginally displaces the comb blade106. The important point is that the cutter-adjusting face124displaces more the cutter blade104than the comb-contacting face122displaces the comb blade106. Hence, the objective is to create a relative displacement of the cutter blade104with respect to the comb blade106.

Conveniently, the adjuster110is provided with an opening129so the user can see through and witness the effect of rotating the adjuster110on the position of the cutter blade104, and visually assess the clearance. As such clearance is very small, the opening129allows the user to use a magnifying glass or a camera of a mobile phone for zooming.

The locator112is movable along the longitudinal axis118of the base108, guided by a channel131. The locator112has a receiving portion132configured to receive and to locate a rear portion of the blade102, and particularly its non-cutting extremity134. Although it depends on the design of a particular blade model, the rear portion of one blade102is often constituted of the rear portion, or non-cutting extremity134, of the comb blade106. The receiving portion132of the locator112comprises a ramp136ending with a retaining lip138. The lip138is positioned proximate an upper portion of the ramp136so that, when positioned, the non-cutting extremity134of the blade102is guided along the ramp136up to the lip138under a force exerted by the biasing means114. The intersection of the ramp136with the lip138creates an interior corner139designed to hold the non-cutting extremity134in place. The location of this corner139above the receiving surface120determines a height at which rests the non-cutting extremity134of the blade102. This height is determined so that a bottom140of the comb blade106rests substantially flat on the receiving surface120of the base108. It has been found that a distance H between the corner139and the receiving surface120of approximately 5 mm (0.197 in) suits most brands of blades. If this distance H of 5 mm (0.197 in) does not suit a specific model of blade102, it is possible to increase the height of the corner139by inserting shims under the locator112. Alternatively, it is possible to use thinner or thicker locators112to best suit different blade models.

The biasing means114is typically connected between the locator112and the base108, and more particularly between the locator112and a back wall142of the base108. So positioning the biasing means114allows pushing, or biasing, the locator112towards the adjuster110substantially along the longitudinal axis118of the base108. Different types of biasing means114may be used, typically a spring which can be a coil spring, a leaf spring, in fact basically any type of suitable spring known in the art made of a metal or plastic. A spring made of a resilient material such as rubber may also be suitable.

In order to prevent the locator112from being pushed back when rotating the adjuster110, the adjusting device may be provided with a locking mechanism144. The locking mechanism144prevents the locator112from moving with respect to the base108. The locking mechanism144is typically connected between the locator112and the base108. In the present example, the locking mechanism144is a screw passing in a slot150of the locator112and engaging threads in the base108. The screw can be tightened, thereby preventing the locator112from moving.

A dial154may be shown on a face of the base108and in proximity to the adjuster110to indicate the displacement of the adjuster110, which in turn is an indication of the relative displacement of the cutter blade104with respect to the comb blade106. This dial154may be a set of corresponding marks on the adjuster110and the base108as shown inFIG.2. The corresponding marks may simply be unitless reference marks, may be sequentially-marked marks, may indicate an angular value of the angle of the adjuster110with respect to the base106, or may indicate the actual displacement value (according to the metric system or to the imperial system) of the cutter blade104with respect to the comb blade106, for example in tenth of millimeter increments. An alternative way of displaying this information provided by the dial is through the use of a sensor155capable of reading or interpreting the movement of the cutter blade104and connected to a digital readout156as shown inFIGS.3and4. The sensor155can be a displacement sensor (linear or rotation displacement) or an optical sensor. The sensor may read the movement of the cutter blade104directly, that is by being in direct contact or aiming directly at the cutter blade104when in place in the adjusting device100, or indirectly, that is by monitoring, being in contact or aiming at the adjuster110and interpreting the movement of the cutter blade104through the movement of the adjuster110.

In use, the user places the non-cutting extremity134of the blade102along the ramp136of the locator112until the non-cutting extremity134reaches the corner139. While still holding the blade102, the user pushes the locator112towards a back of the adjusting device100, thereby compressing the biasing means114. A cutting extremity152of the blade102is then lowered so that the bottom140of the comb blade106lays substantially flat against the receiving surface120of the base108. The biasing means114then pushes the blade102against the adjuster110. If the blade102already had a clearance between the cutter blade104and the comb blade106and if the adjuster110is in its raised or starting position such as inFIG.3, only the comb blade106should contact the adjuster110, and more particularly the comb-contacting face122. The locator112is then locked into place with the locking mechanism144. The cutter blade104is loosened from the comb blade106so that it can be adjusted. If not already in contact, the cutter blade is brought forward in contact with the cutter-adjusting face124. The adjuster110is then rotated to an adjusting position as depicted inFIG.4, so that the cutter-adjusting face124pushes the cutter blade104towards the non-cutting extremity134of the blade102. This creates the clearance gap between the cutter blade104and the comb blade106. Once the desired clearance between the cutting extremities of both the comb blade106and the cutter blade104is achieved, the cutter blade104is tightened against the comb blade106. The locator112is pulled back by loosening the locking mechanism144, thereby allowing the removal of the blade102from the adjusting device100.

The present invention has been described with regard to preferred embodiments. The description as much as the drawings were intended to help the understanding of the invention, rather than to limit its scope. It will be apparent to one skilled in the art that various modifications may be made to the invention without departing from the scope of the invention as described herein, and such modifications are intended to be covered by the present description. The invention is defined by the claims that follow.