WO2017016585A1

WO2017016585A1 - Method of riveting of a shaving head and a shaving head obtained thereby

Info

Publication number: WO2017016585A1
Application number: PCT/EP2015/067114
Authority: WO
Inventors: Ioannis Bozikis
Original assignee: Bic-Violex Sa
Priority date: 2015-07-27
Filing date: 2015-07-27
Publication date: 2017-02-02

Abstract

A shaving head (3) for a wet shaving razor (1) comprises a base (4) comprising two or more holes (10), said base (4) having parallel upper and lower surfaces; at least a first blade (5a) superposed on the upper surface of the base (4), said first blade (5a) having open areas (12a) in correspondence with said n holes (10); a cap portion (7) including a plurality of pins (11), such that each pin (11) corresponds to one hole (10), said cap portion (7) being superposed on said first blade (5a), said pins (11) going through said open areas (12a) of the first blade (5a) and trough the holes (10) of the base (4), said pins being riveted against the lower surface of the base (4) so as to hold the base (4), the first blade (5a) and the cap portion (7) together; and the upper surface of the base (4) further comprises a recess (14) around each hole (10), so that the base (4) has an elastic area (15) of reduced thickness (TR) around each hole (10).

Description

Method of riveting of a shaving head and a shaving head obtained thereby

FIELD OF THE INVENTION

The present invention relates to methods of riveting shaving heads, shaving heads manufactured by such methods and razors comprising such shaving heads.

BACKGROUND OF THE INVENTION

In particular, the present invention is related to a shaving head having a base including two or more holes, at least one blade superposed on the base, and a cap portion including a plurality of pins and being superposed on the at least one blade. The pins go through the open areas of the first blade and trough the holes of the base, so that the pins are riveted against the lower surface of the base so as to hold the base, the first blade, and the cap together.

IN0015/CAL/2002A already describes such a shaving head. More particularly, it concerns a razor having a blade support portion integral with a handle, the blade support portion comprising a platform, a guard portion and a plurality of slots allowing for passing of hair debris. The shaving head comprises a top cap member with projected pins, two blades and a spacer positioned between the blades. The components are positioned on a machine and the projected pins are riveted, so that the handle with blades cannot be detached.

As the pins are riveted, the tips of the pins are deformed against the lower part of the platform, so that each deformed portion forms a structure which prevents the corresponding pip to be pulled out of the hole it originally went through.

The inventors of the present invention have remarked that, in this kind of a shaver head, the deformed portion of the rivet does not fit closely to the surface it has been deformed against. At least a small gap is present between the above mentioned surface and the deformed portion which could allow for a loose assembly between the deformed portion and the surface. In long term, or after extreme impacts on the shaving head structure, as for example after dropping of the shaver on a floor, this looseness could lead to an increasing movement between the riveted parts, for example between the support portion and the blades. Such movement in the blade assembly thus reduces the user's control over the shaving head and the process of shaving might become less convenient and less precise .

The objective of the present invention aims to mitigate these drawbacks.

SUMMARY OF THE INVENTION

To this aim, according to the invention, a shaving head for a wet shaving razor comprises a base comprising two or more holes, said base having parallel upper and lower surfaces; at least a first blade superposed on the upper surface of the base, said first blade having open areas in correspondence with said holes; a cap portion including a plurality of pins, such that each pin corresponds to one hole, said cap portion being superposed on said first blade, said pins going through said open areas of the first blade and through the holes of the base, said pins being riveted against the lower surface of the base so as to hold the base, the first blade and the cap together .

The shaving head is characterized in that the upper surface of the base further comprises a recess around each hole, so that the base has an elastic area of reduced thickness around each hole.

Such elastic area is substantially rigid as the rest of the base, but due to its reduced thickness, it can be elastically deformed by the crimping of free ends of the pins. In other words, during riveting the free ends of the pins are plastically deformed, so that they form enlarged mushroom-like shaped portions, which bear on the elastic areas around the holes. Due to the reduced thickness of the elastic areas, the forces needed to perform said deformation on the pin ends allow the elastic areas to flex .

With these features, when the pins of the cap portion are riveted to the lower surface of the base, the looseness between the deformed portion and the lower surface of the base is either considerably reduced or almost eliminated. This is because the elastic area is elastically deformed (flexed) toward the upper surface of the base by the deformed portion during the riveting process and thus has a tendency to return back to its original position after riveting. Consequently, the elastic area of the lower surface of the base is spontaneously pressured against the deformed portion, so that during the relaxation of the elastic area the gap between the deformed portion and the elastic area is gradually diminished. The resulting gap is much smaller when compared to the manufacturing of heads with no recesses around the holes as are generally used in the prior art.

The shaving head of the present invention thus offers a tight assembly of all its key components and increases reliability of the shaver, while increasing the precision of the shaving as well as it reduces the risk of dislocation of one or more of the riveted parts. This is particularly important as such accidental dislocation may affect the shaving properties of the shaving head.

In some embodiments, one might also use one or more of the following features:

said pins have a deformed portion bearing against the lower surface of the base at the elastic area, and said elastic area bears elastically on said deformed portion. Thus, the pressure of the elastic area against the deformed portion is maintained during use of the product. The riveted parts of the shaving head are thus held together in a more effective way and the probability of moving of one part with respect to another is decreased. This applies for both short-term and long term use of the shaving head. Another advantage of maintaining a constant tension between the elastic area and the deformed portion is that when an accident happens, and the shaving head according to the present invention is dropped to the floor for example, the riveted parts experience a sudden shock of an impact and might even move to some degree relative to each other. However, the continuing force pressing the elastic area towards its original unflexed position and against the deformed portion of the tip of the pin still generates a constant tension, which tends to compensate for any small variations between relative positions of the riveted parts that may have occurred during the impact.

the base includes at least a front wall, a back wall, a pair of side walls extending between the front wall and the back wall and at least a support plate extending near the back wall, said at least one support plate including said holes and being separated from said front wall by an open wash-through area, said holes being formed near said wash-through area,

and wherein said support plate has a least one protruding area which protrudes in the wash-through area toward the front wall, and at least some of said holes are formed respectively in said protruding areas (the protruding areas are further beneficial in strengthening the base structure, particularly the areas around the holes, and even more importantly the areas of reduced thickness corresponding to the elastic areas of the base; the risk of breaking these areas is thus further reduced and may help maintain the tight assembly of the shaving head) ; said base has a first thickness around each recess, said each elastic area having a reduced thickness comprised between 50% and 80% of said first thickness (the thickness of the elastic area should preferably be at most 80% of the first thickness of the base, since the effect of generating the constant elastic return force of the elastic area after its deformation may not be strong enough to keep all the riveted parts in place and to reduce the gap between the lower part of the base and the deformed portion to the required degree; on the other hand, the thickness of the elastic area should preferably be at least 50% of the first thickness of the base, in order to ensure that the material of the base sustains the pressure of the riveting process and is not deformed permanently) ;

- each hole has a diameter and the elastic area around said hole has a radial width lying between 30-60% of the diameter of the hole (the radial width of each elastic area should preferably not exceed 60% of the diameter of the hole in order to maintain constant tension throughout the entire radial width of the elastic area; bigger radial widths may cause uneven tension properties of the elastic areas and may introduce a certain amount of looseness between the elastic area and the deformed portion; similarly, the radial width of each elastic area should preferably not be lower than 30% of the diameter of the hole, as it may cause an improper distribution of tension between the deformed portion and the base) ;

the shaving head further comprises a second blade and a first spacer interposed between the first blade and the second blade, said second blade and said first spacer having open areas in correspondence with said holes, said pins going through said open areas of the second blade and through the open areas of first spacer;

the shaving head further comprises a third blade and a second spacer interposed between the second blade and the third blade, said third blade and said second spacer having open areas in correspondence with said holes, said pins going through said open areas of the third blade and through the open areas of second spacer;

- the base and the cap portion are made of plastic .

The invention also concerns a wet shaving razor comprising the above described shaving head held on a handle .

Furthermore, it concerns a method of manufacturing a shaving head comprising the steps of:

- providing a base comprising two or more holes, said base having parallel upper and lower surfaces;

at least a first blade superposed on the upper surface of the base, said first blade having open areas in correspondence with said n holes;

a cap portion including a plurality of pins, such that each pin corresponds to one hole; and

a recess around each hole on the upper surface of the base so that the base has a elastic area of reduced thickness around each hole;

- inserting said cap portion into said open areas of the first blade and the holes of the base, such that said cap portion is superposed on said first blade;

- riveting said pins against the lower surface of the base so as to hold the base, the first blade and the cap together, and such that said elastic area is elastically deformed during the riveting process;

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages of the invention will readily appear from the following description of one of its embodiments, provided as a non- limitative example, and of the accompanying drawings.

On the drawings :

- Fig. 1 is a razor with a shaving head according to the present invention,

Fig. 2 shows an exploded view of the shaving head,

Fig. 3 is a side cross-sectional view of the shaving head taken along the line III of Fig. 2,

Fig. 4 is an enlarged view of the cross-section of Fig. 3, focusing on penetration of the pin through the hole, during assembly of the shaver head, before riveting,

Fig. 5 illustrates the crimping of the tip of the pin against the elastic area of the base; the continuous lines show the final position after crimping, the dashed lines show the elastic area before crimping and the dash-dotted lines show the maximum elastic deformation of the elastic area during crimping (the extent of deformation has been voluntarily exaggerated to better illustrate the invention) ,

Fig. 6 and Fig. 7 are similar views to Fig. 3 and 4, taken along the line VI of Fig.2.

On the different Figures, the same reference signs designate the same or similar elements.

DETAILED DESCRIPTION

On Fig. 1 a wet shaving razor 1 including a handle 2 and shaving head 3 is illustrated. The handle 2 is not limited to any particular shape. The handle 2 could be made from any suitable material, e.g. metal, plastic, or any combination of materials. It can also have elastomeric portions disposed thereon.

The whole shaving head 3 is shown on Fig. 2. Generally, it comprises a base 4, one or more blades 5a, 5b, 5c and a cap portion 7. When viewed from top the base 4 may have a substantially rectangular shape, and having a front wall, a back wall and two side walls extending between the front wall and the back wall. The side walls may be slanted in a direction from the upper back towards the lower front. The front wall of the base 4 may have a guard 21. The guard 21 could be an integral part of the front wall or it could be attached to the front wall separately .

The base 4 has parallel upper and lower surfaces. It may further include at least one support plate 9 near the back wall. In that case, the upper and lower surfaces of the base 4 may be formed by the support plate 9. The support plate 9 preferably extends through an entire longitudinal length of the base 4 from one side wall of the base 4 to the other. The support plate 9 may be connected to the front wall via at least one rib 23. The ribs 23 are preferably substantially parallel with the side walls of the base 4. The ribs 23 may be provided in plurality and evenly distributed between the side walls of the base 4. The support plate 9 is thus separated from the front wall by an open wash-through area 18, which is formed by the open areas between the ribs 23. The base 4 further comprises two openings 19 near each of the two side walls. Furthermore, the base 4 comprises two or more holes. Each hole 10 extends between the upper and the lower surface of the base 4. More particularly, each hole 10 may go through an entire support plate 9 from top to bottom. The holes are preferably formed near the wash-through area 9.

Referring to Fig. 2, the one or more blades 5a, 5b, 5c are in form of metal sheets, each having a cutting edge 22a, 22b, 22c on its front side and each including at least one open area 12a, 12b, 12c. The blades 5a, 5b, 5c may have for example a generally rectangular shape. The open areas 12a, 12b, 12c of the blades 5a, 5b, 5c may have different shapes or patterns and may be provided in one or in plurality in each of the blades 5a, 5b, 5c. The open areas 12a, 12b, 12c of the blades 5a, 5b, 5c are aligned with the holes 10. Similarly, the open areas 12a, 12b, 12c are aligned with the side openings 19. The first blade 5a of the shaving head 3 is superposed on the upper surface of the base 4. An embodiment of the invention may comprise two or more blades. In that case, any two neighbouring blades are spaced apart from each other with a spacer 6a, 6b.

The cap portion 7 may be provided with a lubricating strip 8 including any moisturizing composition known in the art, for example soap. The lubricating strip 8 may be located atop of the cap portion 7. The cap portion 7 has an elongated structure with a pair of side members 20 positioned generally perpendicular to the elongated structure of the cap portion 7 and at each side of the cap portion 7. The side members 20 may be sloped and may partly serve as leading surfaces for the user's skin during shaving. The side members 20 may be superposed on the side walls of the base 4. From the bottom of each side member 20 protrudes a block 20A, each fitting into one opening 19 on each side of the base 4.

The cap portion 7 further includes a plurality of pins 11 and may be superposed on the first blade 5a. The pins 11 penetrate through the open areas 12a of the first blade 5a and through the holes 10 of the base 4. Preferably, the number of the pins 11 is the same as the number of the holes 10 in the base 4. In an alternative embodiment, the shaving head 3 further comprises a second blade 5b and a first spacer 6a. The first spacer 6a is interposed between the first blade 5a and the second blade 5b. The first spacer 6a has at least one open area 13a in correspondence with the holes 10. There may be a single open area 13a, or a plurality of open areas 13a having various suitable shapes or patterns. When the head 3 is assembled, the pins 10 penetrate both the open areas 12b of the second blade 5b, and the open areas 13a of the first spacer 6a. The first spacer 6a may have substantially rectangular shape. In yet another embodiment, the shaving head 3 further comprises a third blade 5c and a second spacer 6b. The second spacer 6b is interposed between the second blade 5b and the third blade 5c. The second spacer 6b has at least one open area 13b in correspondence with the holes 10. There may be a single open area 13b, or a plurality of open areas 13b having various suitable shapes or patterns. When the head 3 is assembled, the pins 10 penetrate both the open areas 12c of the third blade 5c, and the open areas 13b of the second spacer 6b. The second spacer 6b may have substantially rectangular shape. The embodiment with the shaving head 3 having three blades is illustrated on the accompanying drawings.

During the manufacture of the shaving head 3, the pins 11 of the cap portion 7 are inserted into the corresponding open areas 12a, 12b, 12c of the at least one blade 5a, 5b, 5c and if applicable into the corresponding open areas 13a, 13b, 13c of the at least one spacer 6a, 6b, and into the corresponding holes 10. In an assembled position as shown on Fig. 3, the cap portion 7 is superposed on the at least one blade. A tip of each pin 11 is then riveted to the lower surface of the base 4. Each pin 11 is thus deformed against the lower surface of the base 4, so that the cap portion 7, the base 4, the one or more blades 5a, 5b, 5c, and alternatively the one or more spacers 6a, 6b are all held together. A typical deformed portion 16 of pin 11 can be seen on Fig. 5. The tip of each pin 11 is plastically deformed into the deformed portion 16, which then remains in the deformed shape for the entire life of the head 3. The deformed portion 16 may have approximately a mushroom-like shape.

It is desirable, that the deformed portion 16 fits as closely to the lower surface of the base 4 as possible. In contrast to the current state of the art, it is intended to provide the upper and lower surfaces of the base 4, which are not completely flat, and to ensure that the deformed portion 16 created from the riveting process does fit tightly enough to the base's lower surface. When a gap is present between the deformed portion 16 and the lower surface of the base 4, the riveted parts such as the blades 5a, 5b, 5c and the cap portion 7 may not be completely fixed in their positions. The stacking of the riveted part may not be as tight as needed, as a certain amount of looseness exists between the deformed portion 16 and the base 4. Such a gap can be present either immediately after the riveting or may appear later during use of the product. Both short-term and long-term characteristic of the result of the riveting process thus has to be addressed in order to come to an objective improvement of the state of the art. The need thus arises for obtaining a riveting process, at the end of which there is a close permanent stacking of all the riveted components. One objective of the present invention is thus to considerably reduce or even completely eliminate the appearance of any potential gap between the deformed portion 16 and the lower surface of the base 4. Another objective is to maintain a minimum gap or no gap at all during the entire life of the shaving head 3, especially during long-term use of the head 3, or after accidental situations such dropping a shaver on a floor, etc. With at least these objectives, the precision of shaving can be improved, and the reliability of the shaving head 3 could be increased.

In order to increase tightness of the assembly of the riveted parts and to avoid any potential looseness between them, the upper surface of the base 4 further comprises a recess 14 around each hole 10. Such recess can be seen on a cross-sectional view of the head 3 on Fig. 3 and on an enlarged view on Fig. 4. The base 4 thus has an elastic area 15 around each hole 10. The position of the elastic areas 15 before riveting is showed with the dashed lines on Fig. 5. When the pins 11 are being riveted to the lower surface of the base 4, a force is applied to the lower surface of the base 4. Therefore, the tips of the pins 11 are deformed against the lower surface of the base 4, creating the deformed portion 16. During the riveting the deformed portion 16 is pushed onto the elastic areas 15. The elastic areas 15 around the holes 10 are elastically deformed in an upward direction, such that the ends of the elastic areas 15 move toward the upper surface of the base 4. The extreme flexed position of the elastic areas 15 is illustrated with dash-dotted lines on Fig. 5 (this corresponds to maximum elastic deformation of the elastic areas 15 that result from applied forces responsible for the deformation of the pin ends 11) . On Fig. 5 the elastic areas 15 in the extreme flexed position are showed as spaced apart from the deformed portion 16 in the upward direction. The flexing of the elastic areas 15 is intentionally exaggerated on Fig. 5, thus showing more clearly the stages that the elastic areas 15 go through. The actual maximum vertical displacement of the elastic areas 15 that occurs during the riveting process lies between 5-20% of thickness of the elastic areas 15 (will be discussed in more detail in the following paragraphs) . Also, the spacing between the elastic areas 15 and the deformed portion 16 is merely illustrative and may be different to that shown on Fig. 5. Alternatively, there may be almost no space between the elastic areas 15 and the deformed portion 16 during riveting.

When the riveting is completed, the elastic areas 15 are flexed in extreme position showed by the dash-dotted lines on Fig. 5. The elastic areas 15 then generate a return force that applies on the deformed portion 16 in a direction towards the lower surface of the base 4. The return force makes the elastic areas 15 flex back toward the lower surface of the base 4 and the contact between the elastic areas 15 and the deformed portion 16 is tightened. The shaving head 3 obtained with the above described riveting process ensures that a constant tension is present between the deformed portion 16 and the lower surface of the base 4, and more particularly between the deformed portion 16 and the elastic areas 15. As the tension is present, any potential gap between the deformed portion 16 and the elastic areas 15 is reduced to minimum or eliminated completely. Such tension keeps the cap portion 7, the one or more blades 5a, 5b, 5c, the base 4 and where applicable the spacers 6a, 6b stacked together in a very tight manner. By providing the recesses 14 and the corresponding elastic areas 15 around the holes 10, the looseness between the riveted components is considerably lower .

The tight stacking of the riveted components is not only maintained immediately after the riveting, but also in the long-term horizon, as the constant tension between the elastic areas 15 and the deformed portion 16 keeps existing even when using the shaving head 3. Moreover, when there is a sudden and/or strong impact to the shaving head 3, such as when dropping the shaver on the floor, the riveted components, such as blade 5a, 5b, 5c or the cap portion 3 may experience slight variations in their absolute and/or relative positions. An advantage of the recesses 14 and the elastic areas 15 generating the constantly present return force between the deformed portion 16 and the elastic areas 15 is that the return force compensates for these variations in position and keeps the riveted parts firmly held and close together in a continuing compact fashion. Thus, there is no noticeable movement of the riveted components, especially of the blades 5a, 5b, 5c, which in prior art may for example affect the head assembly final dimensions. The present invention thus aims to improve both short-term and long term reliability of the shaving head 3, as well as to improve its convenience.

Another aspect of the present invention is that it takes into account any potential reverse structural changes of the deformed portion 16. The deformed portion 16 may slightly change its shape towards its original position, which is another reason why the shaving assembly might loosen and thus loose its ideal properties. Even in this case, any such changes of the deformed portion 16 are compensated by the elasticity of the elastic areas 15, which are continuously forced to maintain the required tightness between themselves and the deformed portion 16 of the pins 11.

The tightness of the riveted parts of the shaving assembly could depend on various factors. One of them is the materials selected to form the base 4 and/or the elastic areas 15, as well as the cap portion 7 and/or the pins 11. Good results can be achieved with the base 4 and the cap portion 7 being manufactured from a plastic material, such as ABS, but any other material with suitable elastic properties would be appropriate as well. Another factor affecting the tightness of the shaving assembly may be for example radial width W of the elastic areas 15, as discussed in the following paragraphs.

The base 4 has a first thickness Tl between its upper and lower surfaces, which may be substantially constant on the entire area of the base 4, or at least in the area around each recess 14 of each hole 10. The first thickness Tl may correspond to the thickness of the support plate 9 forming the upper and lower surfaces of the base 4. Each recess 14 is thus surrounded with a material having the first thickness Tl. Each recess 14 reduces a thickness of the area directly around the corresponding hole 10. Therefore, an elastic area 15 corresponding to a hole 10 with such recess 14 has a reduced thickness TR.

The reduced thickness TR of the elastic area 15 should preferably be at most 80% of the first thickness Tl of the base 4. This ensures that the return force generated by the elastic area 15 after riveting is sufficiently strong to maintain all the riveted pieces together and to reduce or eliminate the gap between the elastic area 15 and the deformed portion 16 as desired. When the reduced thickness TR is higher than 80% of the first thickness Tl, the flexibility and the elastic properties of the elastic area 15 might be partially lost, thus the effect of generating the constant elastic return force of the elastic area 15 after its deformation may not be high enough. At the same time, the reduced thickness TR should preferably be at least 50% of the first thickness Tl of the base 4, in order to ensure that the material of the base 4 sustains the pressure of the riveting process and is not permanently deformed. Additionally, when the reduced thickness TR is too low, the return force generated by the elastic area 15 might again decrease.

Advantageously, the radial width W of each elastic area 15 is selected so as not to be higher than 60% of the diameter D of the hole 10. With this provision, the tension is kept evenly distributed throughout the entire radial width W of the elastic area 15. Bigger radial widths may cause uneven tension properties of the elastic areas 15 and may introduce a partial looseness between the elastic area 15 and the deformed portion 16. Similarly, the radial width W of each elastic area 15 should preferably not be lower than 30% of the diameter D of the hole 10, as it may cause an improper distribution of tension between the deformed portion 16 and the base 4.

With the above specified ratios, one can obtain an ideal flexing properties of the elastic areas 15. The preferable vertical displacement of the elastic areas 15 during the riveting process lies between 5-20% of the thickness of the elastic areas 15. As one specific example, the diameter of the hole 10 may be chosen to be 1.8mm, while the thickness TR of the elastic area is 0.65mm, the first thickness Tl being 1.0mm, and the radial width W of the elastic area being set to 0.7mm. The maximum vertical displacement of the elastic area 15 during riveting was 0.094mm. The material of the base 4 in this example was selected to be ABS (Acrylonitrile butadiene styrene) .

The holes 10 may be included in the support plate 9 of the base 4. The holes 10 are preferably positioned near the wash-through area 18. Each hole 10 has a recess 14 radially extending around it. Thus, it may be further beneficial to provide the support plate 9 with at least one protruding area 17, which protrudes in the wash through area 18 toward the front wall of the base 4. At least one hole 10 may then be formed in the protruding area 17. Alternatively, the recess 14 of the at least one hole 10 may be formed in the protruding area 17. The protruding area may have any suitable shape, for example rounded, or rectangular. The protruding area 17 strengthens a plate structure around the hole 10 and thus provides an additional support for the hole 10. The process of riveting may then be more effective and the elastic properties of the elastic areas 15 may be even further improved.

Due to an applied manufacturing method or even to constraints related to an overall design of the shaving head 3, the areas available for creating the holes 10 and consequently the elastic area 15 around some of the holes 10 could be limited, so that this elastic area 15 is not symmetrical around the hole 10. However, it is preferable that at least one elastic area 15 of a corresponding hole 10 is formed in symmetric fashion, so that it could be used to its full potential. A limited arrangement of the elastic area 15 can be seen of Figures 6-7. A limited elastic area 15A is formed on the front side of the support plate 9 closer to the wash-through area 18. The limited elastic area 15A in this case forms approximately a half-circle. It could be seen that the limited elastic area 15A has a decreased radial width W when compared to the elastic area 15, which is formed closer to the back of the base 4. The elastic area 15 in this example forms the other half of the round around the hole 10.

Providing the protruding area 17 may allow to have a full elastic area 15 at least around some of the holes 10, while consuming only minimum amount of additional space in the construction of the shaving head 3. Advantageously, the wash-through area 18 may be maintained large enough to ensure effective washing of the shaving debris.

The base 4 may be moulded from any suitable material known in shaver industry, particularly plastic and similar, for example ABS ( acrylonitrile butadiene styrene) . The plastic material is preferred as it provides suitable properties to the base 4, especially the elastic properties of the elastic areas 15 could be achieved conveniently. Similarly, the cap portion 7 may be manufactured from any material, particularly plastic, as long as the required properties of the material are achieved, especially with regard to deforming the tip of the pins 11 into the deformed portion 16.

Claims

1. A shaving head (3) for a wet shaving razor (1) comprising :

- a base (4) comprising two or more holes (10), said base (4) having parallel upper and lower surfaces;

- at least a first blade (5a) superposed on the upper surface of the base (4), said first blade (5a) having open areas (12a) in correspondence with said holes (10);

- a cap portion (7) including plurality of pins

(11), such that each pin (11) corresponds to one hole (10), said cap portion (7) being superposed on said first blade (5a), said pins (11) going through said open areas (12a) of the first blade (5a) and through the holes (10) of the base (4), said pins (11) being riveted against the lower surface of the base (4) so as to hold the base (4), the first blade (5a) and the cap portion (7) together;

characterized in that the upper surface of the base (4) further comprises a recess (14) around each hole (10), so that the base (4) has an elastic area (15) of reduced thickness (TR) around each hole (10) .

2. The shaving head (3) according to claim 1, wherein said pins (11) have a deformed portion bearing against the lower surface of the base (4) at the elastic area (15), and said elastic area (15) bears elastically on a deformed portion (16) .

3. The shaving head (3) according to any of the preceding claims, wherein the base (4) includes at least a front wall, a back wall, a pair of side walls extending between the front wall and the back wall, and at least a support plate (9) extending near the back wall, said at least one support plate (9) including said holes (10) and being separated from said front wall by an open wash- through area (18), said holes (10) being formed near said wash-through area (18), and wherein said support plate (9) has at least one protruding area (17) which protrudes in the wash-through area (18) toward the front wall, and at least some of said holes (10) are formed respectively in said protruding areas (17).

4. The shaving head (3) according to any of the preceding claims, wherein said base (4) has a first thickness (Tl) around each recess (14), said flexing area (15) having a reduced thickness (TR) comprised between 50% and 80% of said first thickness (Tl) .

5. The shaving head according to any of the preceding claims, wherein each hole (10) has a diameter (D) and the elastic area (15) around said hole (10) has a radial width (W) lying between 30-60% of the diameter (D) of the hole (10) .

6. The shaving head (3) according to any of the preceding claims, further comprising a second blade (5b) and a first spacer (6a) interposed between the first blade (5a) and the second blade (5b), said second blade (5b) and said first spacer (6a) having open areas (12b, 13a) in correspondence with said holes (10), said pins (11) going through said open areas (12b) of the second blade (5b) and through the open areas (13a) of the first spacer (6a) .

7. The shaving head (3) according to any of the preceding claims further comprising a third blade (5c) and a second spacer (6b) interposed between the second blade (5b) and the third blade (5c), said third blade (5c) and said second spacer (6b) having open areas (12c, 13b) in correspondence with said holes (10), said pins (11) going through said open areas (12c) of the third blade (5c) and through the open areas (13b) of the second spacer (6b) .

8. The shaving head (3) according to any of the preceding claims, wherein the base (4) and the cap portion (7) are made of plastic.

9. A wet shaving razor (1) comprising: a handle ( 2 ) , and

a shaving head (3) according to any of the preceding claims, held on the handle (2) .

10. A method of manufacturing a shaving head (3) comprising the steps of:

- providing a base (4) comprising n holes (10), n being an integer equal to 2 or more, said base (4) having parallel upper and lower surfaces;

at least a first blade (5a) superposed on the upper surface of the base (4), said first blade (5a) having open areas (12a) in correspondence with said holes (10);

a cap portion (7) including n pins (11), such that each pin (11) corresponds to one hole (10); and

a recess (14) around each hole (10) on the upper surface of the base (4) so that the base (4) has a elastic area (15) of reduced thickness (TR) around each hole (10);

- inserting said cap portion (7) into said open areas (12a) of the first blade (5a) and the holes (10) of the base (4), such that said cap portion (7) is superposed on said first blade (5a);

- riveting said pins (11) against the lower surface of the base (4) so as to hold the base (4), the first blade (5a) and the cap portion (7) together, and such that said elastic area (15) is elastically deformed during riveting.