Patent Application
20230226708
The disclosure relates to shaver handles, shavers including such handles and methods of manufacturing the same.
Shaver handles are usually compact plastic molded parts, molded as a single part or sometimes molded as several parts which are later assembled.
WO2006081842 shows an example of a known shaver handle.
One of the purposes of the present disclosure is to improve the shaver handles of the prior art, in particular with regard to material consumption and economy.
Thus, the present disclosure proposes a handle for a wet shaver, having:
Thanks to these features, the mechanical structure of the handle body can be highly efficient and may save a lot of material compared to compact handles full of solid material, for the same or similar mechanical properties.
Embodiments of such a shaver handle may incorporate one or more of the following features:
Rbe=(F/d)/Vm, wherein:
A further object of the disclosure is a shaver comprising a handle with any of the above described features and a shaver head mounted on the head supporting portion of said handle.
Still another object of the disclosure is a method for reducing the amount of raw material used in manufacturing a handle for wet shaver comprising defining a cell containing structure by using a space partionioning algorithm, wherein the material volume used to manufacture said handle is at least 33% inferior compared to a handle having a similar bending efficiency ratio. Said space partinioning algorithm may define a cell containing structure formed as a Voronoi diagram
The above and other objects and advantages will become apparent from the detailed description of one embodiment of the disclosure, considered in conjunction with the accompanying drawings.
In the drawings:
In the drawings, the same reference numbers denote identical or similar elements.
The shaver head 3 may have a guard 4, one or several blades 5 and possibly a cover 6 or similar.
The handle 2 may be formed in one piece. In that case, the handle 2 may be formed by a digital fabrication technology such as three dimensional (3D) printing, also called additive manufacturing. Said 3D printing may be chosen in particular among additive manufacturing methods such as material extrusion (e.g. fused deposition modelling etc.), material jetting, VAT photopolymerization (e.g. digital light processing and electron beam melting, stereolithography etc.), sheet lamination, direct energy deposition, powder bed fusion (e.g. laser sintering etc.) and binder jetting. Additionally a second step may follow, having the part shaped using conventional techniques (e.g. milling).
Alternatively, the handle may be formed in two or more parts which are later assembled together. In that case, the handle may be manufactured by injection molding or by any known manufacturing method including additive manufacturing.
The handle 2 may be formed in one or several materials. For instance, the handle 2 may be formed in one or several of the following materials: plastic materials, metals, mixtures of synthetic and natural materials including wood and paper, etc.
The handle 2 may comprise an elongated handle body 7 and a head supporting portion 8 supporting the shaver head 3. The shaver head 3 may be removably or non-removably attached to the head supporting portion 8.
The handle body 7 is adapted to be held in hand by a user. The handle body 7 extends between a distal end 9 (opposite the head supporting portion 8) and a proximal end 10 (close to the head portion 8), along a central line C. The central line C may be curved. The central line C may be included in a sagittal plane P0.
The shaver head 3 may be connected to the head supporting portion 8 by any known way, for instance pivotally around a pivot axis perpendicular to the sagittal plane P0, or otherwise.
In the example shown in the drawings, as can be seen in particular in
As shown in
The hollow cells 16 may have more than one shape and form, for instance 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14 or 15 or 16 or 17 or 18 or 19 or 20 or more different shapes and forms.
The hollow cells 16 may have may have only curved (not angled) extremities/edges. The hollow cells 16 may have ovoidal extremities.
The envelope volume Vt encompasses a certain empty volume Ve.
The ratio Ve/Vt of said empty volume on said envelope volume being between 33% and 90%, preferably more than 65%.
The solid walls 15 may form a network of solid threads or arms which are connected together.
The cell structure 15, 16 may be formed as any structure. The cell structure 15, 16 may be formed by using a space partitioning algorithm. Space partitioning is the process of dividing a space into non-overlapping regions, using mathematical diagrams or algorithms. Voronoi diagrams are among the most popular ways of dividing a space into partitions. The cell structure may be formed as for example a Voronoi diagram.
In a particularly advantageous embodiment, as shown in
In the example shown in the drawings, the inner volume 14 is empty and free of solid walls. In other embodiments, not shown, the inner volume 14 may include solid walls belonging to the cell structure and defining empty cells, for instance according to a 3D Voronoi diagram, in which case said cell structure 15, 16 may be formed along the whole volume of the handle. In other embodiments, the handle body may be produced around any object (e.g. an insert made of any known material) entrapping it and/or enabling it to move freely in the handle body 7.
The grid shell structure 15, 16 may extend continuously around the central line C. The grid shell structure 15, 16 may define a top portion 17, a bottom portion 18 and two side portions 19 all extending along the central line from the distal end to the proximal end, and said grid shell structure forms an apex 20 at the distal end 9 of the handle body (
The grid shell structure 15, 16 may be such that said empty cells 16 represent between 30% and 60% of said outside surface.
The grid shell structure 15, 16 may be such that said empty cells 16 have an average surface density (parallel to the envelope surface S) comprised between 0.3 and 3 cells/cm2.
The grid shell structure 15, 16 may be such that a plane perpendicular to said central line C and intersecting the handle body 7 (for instance the planes P1, P2 shown in
The grid shell structure 15, 16 may be such that a plane including said distal end 9 and said proximal end 10 (for instance the sagittal plane P0), intersects an average number of empty cells 16 comprised between 3 and 20.
Typically, the thickness e of the grid shell structure 15, 16 may be a few millimeters, for instance between 0.3 and 5 mm; the transverse dimension D of the grid shell structure 15, 16, perpendicular to the central line C, may be for instance between about 8 and 25 mm.
The length of grid shell structure 15, 16 may be for instance of about 90 to 120 mm and the total length of the shaver handle 2 may be for instance between about 110 to 140 mm. These dimensions may be typical for a normal handle and are not deemed to be limitative. The handle can also be smaller, for instance with a length in the range of about 30-80 mm, in which case the length of the grid shell structure 15, 16 would be consequently reduced. Additionally the handle may have the grid shell structure 15, 16 only in a portion of its length and not in the whole volume.
Thanks to the above features, the shaver handle 2 according to the disclosure saves a lot of material compared to existing shaver handles, thus also saving weight and energy. Some comparative examples are shown in Table 1 below.
The method used to calculate the values in Table 1 is as follows:
A variety of commercially available shaver handles were gathered.
The volume of solid material (Vm) was measured by inserting each handle at a time in a volume measuring tube full of deionized water and measuring the water volume coming out of the tube.
After this first measurement, each handle was covered with a plastic film, simulating that the handle has a compact (full of material) shape and similarly the handle was inserted in the volume measuring tube, again full of deionized water. The water volume coming out of the tube was measured, corresponding to the envelope volume (Vt).
Then the empty volume (Ve) was calculated by using the formula: Ve=Vt−Vm.
Finally the ratio Ve/Vt was calculated.
In addition to saving material and minimizing energy footprint of the product, the invention also enables to improve the mechanical efficiency of the material used.
This mechanical efficiency, for a shaver handle, can be measured by a bending efficiency ratio Rbe, which is defined as:
Rbe=(F/d)/Vm,
wherein:
This bending efficiency ratio Rbe may be possibly obtained from a theoretical analysis, in particular from a finite element analysis which uses a 3d digital model to calculate the bending efficiency ratio by taking as input the force F applied to a distal end 9 of the handle and calculating the displacement d of the distal end 9 of the handle and the volume Vm of solid material of the handle.
The following table 2 shows the comparison of the calculation of the bending efficiency ratio Rbe in the case of the shaver handle of
Table 2 shows that the mechanical efficiency, measured by the ratio Rbe, is higher in the case of the invention compared to a compact handle of the same external shape.
More generally, the bending efficiency ratio of a handle according to the invention is preferably more than 1.20 10−4 N·mm−4, even more preferably larger than 1.30 10−4 N·mm−4.
In addition to the above advantages, the invention also provides better gripping for the user, increasing the comfort and the feeling of safety while shaving.
In the second and third embodiments, described below, the general structure of the handle body and the above advantages are kept, so that these second and third embodiments will not be described again in detail. Mainly the differences over the first embodiment will be explained below.
In the second embodiment, shown in
The handle body 7 may include a central empty channel 21, obtained by using a slider in the mold if the handle body is manufactured by injection molding. The central channel 21 may be axially open at the proximal end 10 of the central body. The central channel 21 may extend along the central line C of the handle, which is curved in the example of
In the second embodiment, the grid shell structure 15, 16 may have a larger and/or variable thickness compared to the first embodiment, the maximum width of channel 21 being defined by the neck of the handle body 7.
In the third embodiment, shown in
The insert 22 may advantageoulsy be hollow, defining the empty inner volume 14. For instance, the insert 22 may be blow molded. The thickness of the insert 22 may typically range from a few tens of millimeters to a few millimeters.
In one specific example, the material of the insert may be PCTG (Glycol-modified Poly-Cyclohexylenedimethylene Terephthalate), for instance a PCTG with high optical transparency.
In a particular example, the grid shell structure 15, 16 may be injection molded from thermoplastic elastomer (TPE) on the insert 22.
| Number | Date | Country | Kind |
|---|---|---|---|
| 17160416.8 | Mar 2017 | EP | regional |
| 17160417.6 | Mar 2017 | EP | regional |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16492357 | Sep 2019 | US |
| Child | 18175428 | US |
