This invention relates to a razor blade for use in a shaving razor, and in particular a razor blade having multiple apertures containing cutting edges; and which has an increased usage compared to known blades.

In the past, conventional razors have consisted of a metal foil blade which is sharpened to form cutting edges along the elongate sides of the foil. Thus, both elongate sides can be used in the shaving operation. One disadvantage of this type of razor is that, in order to ensure safety from exposed blades, it is necessary to provide guards between the skin and cutting edges of the blade, so that the blade can remove hair without cutting the skin.

A safer type of razor is also known in which the skin engaging surface is a metal foil having a plurality of sharp-edged apertures over the surface to provide the cutting edges. In this way, an additional safety guard is not necessary, because the cutting edges are within the apertures. For example, EP 2165809 discloses a razor blade comprising a metal foil sheet with a plurality of apertures, the perimeter of each aperture forming a cutting edge. Such a razor is safe under normal usage conditions, without any additional guard. Similar blades which comprise thin foils with apertures are also described in EP 0527770, EP 0755318, EP 0436693 and EP 0541723.

The prior art patent documents described above have cutting edges on one surface of the metal foil sheet. When the cutting edges within the apertures become blunt, the blade, and sometimes the razor, is discarded. There is a need to retain the safety features of the aperture type of blade, but with the ability to achieve greater usage associated with the conventional type of double edged foil blade. The present invention solves this problem by providing cutting edges within the apertures adjacent both surfaces of the metal foil sheet. In that way the total length of the cutting edges of the present razor is double that of prior aperture type blades; and, in a preferred embodiment, also greater than the combined two edges of a conventional double edged foil blade.

It is suggested in EP0523170 that a ceramic blade containing apertures can be subject to a grinding and polishing process at both surfaces, and the blade reversed. However, that patent is concerned with non-metallic razor blades, so there is no suggestion that such a process could be applied to a metal foil. In fact, a ceramic blade must be bulky, because a thin ceramic blade would be too brittle.

Accordingly, the present invention provides a razor blade for use in a razor, the razor blade comprising a metal foil sheet having a first planar surface and a second planar surface, the metal foil sheet having a plurality of apertures therein, wherein the razor blade is adapted to be removably attached to the razor with either the first planar surface or the second planar surface providing a skin-engaging surface, characterized in that each aperture has a cutting edge adjacent both the first planar surface and the second planar surface of the metal foil sheet.

The metal foil sheet of the present razor blade may be formed from any metal material that retains strength, flexibility and blade sharpness. Suitable metal materials include metal alloys such as steel, preferably stainless steel.

The length and width of the metal foil sheet of this invention may be about the same size as the head of a conventional razor, typically from 30 to 35mm long and from 11 to 18mm wide. The thickness of the metal foil sheet is about 100 microns, for example from 50 microns to 200 microns.

The cutting edges are formed within each aperture adjacent both planar surfaces of the metal foil sheet. There is at least one cutting edge adjacent each planar surface. Preferably, the cutting edge adjacent each planar surface is on only one lateral side of the aperture. Preferably also, within one aperture, the cutting edge adjacent the first planar surface is on the opposite lateral side of the aperture to the cutting edge adjacent the second planar surface. In this way, the cutting edge adjacent one planar surface will not hinder the action of the cutting edge adjacent the other planar surface.

Thus, as the protruding facial or bodily hairs enters the aperture, it is cut by the cutting edges adjacent the skin-engaging surface of the blade and is unhindered by the cutting edges adjacent the other planar surface of the blade.

The apertures may be any shape, provided they allow entry of a hair follicle. For example, the shape of each aperture may be circular, hexagonal, triangular, rectangular, or square. Preferably the apertures are rectangular.

The apertures are of sufficient size to readily accommodate one or more human hair follicles, each follicle being typically approximately 0.02mm to 0.2mm in diameter. For example, the distance from the cutting edge to the opposite lateral side of the aperture is suitably from 0.5mm to 3mm, for example from 1mm to 2mm, preferably from 1.4mm to 1.8mm.

The length of each cutting edge is suitably from 1mm to 2.5mm, for example from 1.2mm to 2mm, preferably from 1.4mm to 1.6mm. The spacing between each aperture on the metal foil sheet should be sufficient to retain the rigidity thereof, that is to prevent the metal foil sheet from being easily bent or distorted. Suitable spacings between each aperture at the skin-engaging surface are from 0.75mm to 3mm, preferably from 0.5mm to 1.5mm, for example about 1mm.

The apertures are generally spaced equidistantly from each other. It is preferred that alternate rows of apertures in the metal foil sheet are offset from each other to allow the maximum efficiency to capture every hair follicle, as the razor is pulled across the surface of the skin.

With the dimensions of the metal foil sheet and the apertures described above, the numbers of apertures in the metal foil sheet may suitably be from 30 to 150, for example from 40 to 100, preferably from 50 to 60.

The apertures in the metal foil sheet are formed by any suitable method, such as stamping, laser cutting such as using a femtosecond laser.

Cutting edges are then formed by sharpening edges of the apertures adjacent both planar surfaces of the metal foil sheet. Because of the small and complex geometry of such an arrangement, conventional grinding processes for sharpening are less effective. A preferred sharpening process is the use of a laser beam, in particular a femtosecond laser, using a cold ablation recipe. Precise sharpening can be achieved with a laser using ultrashort pulses, of less than 10 picosecond (1 picosecond = 10 ¹² seconds), in particular a femtosecond laser. It is also advantageous to employ a laser positioning system, in order to enable a precise sharpening process in three dimensions. Laser positioning systems are known in the art, for example a multi-axis galvanometer scanner. A femtosecond laser can also be used to hone and polish the cutting edges. A key feature of the razor blade of the present invention is that it is removably attached to the head portion of a razor, so that either planar surface can provide a skin-engaging surface. In that way, when the cutting edges adjacent one planar surface become blunt after numerous uses, the blade can simply be reversed to expose a second set of sharp cutting edges.

Furthermore, when both sets of cutting edges have become blunt, the razor blade of this invention can be simply removed from the razor and the cutting edges re-sharpened using the methods described above, for example a femtosecond laser. Thus, instead of discarding the blade after use, it can be re-sharpened and re-used, providing an important ecological advantage.

The removable attachment of the razor blade to the razor may be provided by a releasable retaining means on the head portion of the razor, hereinafter referred to as the razor head. For example the razor head may have a frame into which the razor blade fits. The releasable retaining means may also comprise protrusions on the razor head, which cooperate with slots or apertures in the metal foil sheet to maintain the razor blade in a fixed position for use.

In a preferred embodiment of the invention, the releasable retaining means comprises a spring mechanism on the razor head. The spring mechanism provides a tension to push apart two movable parts of the razor head. That tension acts on the metal foil sheet to retain its position in the frame and over the protrusions on the razor head. In that way, a user can squeeze the razor head against the tension of the spring. That action causes the metal foil sheet to bend, enabling it to be removed by the user. The operation is reversed to replace the metal foil sheet on the razor head.

The perimeter of the metal foil sheet is preferably rounded, in order to avoid any sharp edges, so that the edges can be gripped in the removal and replacement operations

The razor head of the razor of this invention is suitably attached to a handle. To assist in this attachment, the razor head may be provided with a recess to cooperate with a complementary structure on the handle. For example, the underside of the razor head may comprise sockets and/or slots, which cooperate with protrusions on the handle. Such an attachment may allow a fixed positioning of the razor head onto the handle, or may allow a tilting or rocking mechanism.

The razor of this invention provides a smooth and efficient shaving process. It is suitable for use by men or women and may be used to shave hair from the surface of any part of the body including the face, legs and under the arms.

An embodiment of the present invention will now be described with reference to the accompanying drawings in which:

Fig. 1A and Fig. IB show the two planar surfaces of the metal foil sheet of one embodiment of a razor of the present invention;

Fig. 2A and Fig. 2B are partial perspective representations of the cutting edges within one aperture;

Fig. 3 shows the attachment means to attach the metal foil sheet to the head portion of the razor;

Fig. 4 is a perspective view showing the metal foil sheet retained on the head portion of the razor; Fig. 5 is a detail view of the spring mechanism to release the razor blade from the head portion of the razor;

Fig. 6 is a perspective view of the reverse side of the head portion of the razor;

Fig. 7 shows the fitting of a handle to the head portion of razor.

Referring to Figs. 1A and IB, razor blade 1, in the form of a metal foil sheet, 100 micron thickness, has a rectangular shape, with a first planar surface 1A and a second planar surface IB. Either surface can be used as a skin-engaging surface. The razor blade 1 is constructed from stainless steel and measures approximately 32mm in length and approximately 18mm in width. It has a rounded perimeter 2, so that the edges can be easily gripped to reverse the orientation of the razor blade. The razor blade 1 contains apertures 3, situated in five rows. Each aperture 3 has a rectangular cross-section. Each alternate row of apertures is offset so that one row contains 11 apertures, and the next row contains 10 apertures, making a total of 53 apertures.

Each aperture 3 has two sharpened cutting edges 4A and 4B, formed on opposite lateral sides of each aperture 3. One cutting edge 4A is adjacent the first planar surface 1A and the second cutting edge 4B is adjacent the second planar surface IB. The razor blade also has circular slots 5 at each lateral periphery, to fit onto the head portion of the razor.

The cutting edges can be seen in more detail in Figs. 2A and 2B. In Fig.2A, the first planar surface 1A is uppermost and becomes the skin- engaging surface. In this position, the operational cutting edge is 4A. As the razer is moved across the skin, hairs enter the aperture and are sliced off by the operational cutting edge 4A, adjacent surface 1A, unhindered by the non-operational cutting edge 4B. Similarly, as shown in Fig 2B, when the razor blade 1 is reversed, the surface IB becomes the skin-engaging surface and the cutting edge 4B is the operational cutting edge.

The razor blade 1 is removably attached to the head of a razor.

Fig. 3 shows the construction of the head portion of the razor, which enables the razor blade 1 to be removably attached thereto. The razor head 6 is in two parts, namely a body member 7 and an end member 8. The two parts are movably connected to each other via cylindrical spring pins 9 and 10. The pins 9 and 10 fit into sockets (not shown) in the end member 8. Once in place, the spring pins 9 and 10 retain an outward tension to keep the members 7 and 8 slightly apart. An internal rim (not shown) prevents further separation of the members 7 and 8.

The razor head 6 contains a peripheral frame 11, into which the razor blade 1 fits. The razor head also contains eight projections 12, which cooperate with the slots 5 in the metal foil sheet 1. The side portions of each projection 12 have a 5° inward draft, i.e. the side portions are 5° from the vertical position so that the base of the projection is narrower than the top of the projection. That shape allows the razor blade 1 to be retained in position over the projections.

Fig. 4 shows the razor blade 1 in place on the razor head 6. The edges of the razor blade 1 fit into the frame 11; and the holes 5 fit over the projections to maintain the position of the razor blade 1. There is a small gap 13 between the two parts 7 and 8 of the razor head 6. The gap 13 can be seen in more detail in Fig. 5, which also shows the spring pin 9, between parts 7 and 8 of the razor head 6. In operation, a user can place a razor blade of this invention onto the head portion of the razor, by first squeezing together the lateral edges of the razor head 6. That action closes the gap 13, so that the body member 7 and the end member 8 of the razor head 6 are fully abutted. With the razor head in that position, the razor blade can be placed into the frame 11; and the slots 5 placed over the projections 12. The manual pressure on the razor head is then released, so that the spring pins 9 and 10 move the members 7 and 8 slightly apart, causing a tension which holds the slots 5 at the narrower base of the projections 12 and thereby secures the razor blade 1 onto the razor head 6.

To remove the razor blade, the above process is reversed. The user applies manual pressure to the lateral ends of the razor head 6. That action contacts the razor head, closing the gap 13. The razor blade 1 flexes upwards and is released from the projections 12 and the frame 11, so that it can be removed manually from the razor head. The razor blade can then be reversed and replaced on the razor head 6 with the second planar surface uppermost, to form the skin-engaging surface. Alternatively, when both surfaces have been used, the razor blade can be replaced and the used blade sent for re-sharpening.

The razor head 6 is attached to a handle.

Fig. 6 shows the reverse side of the razor head 6 having lateral sockets 14 to allow the razor head 6 to be attached to a handle.

Fig. 7 shows a handle attached to the razor head to form the razor of this invention. The handle 15 has a connector portion 16 which is provided with two resilient clips 17. Each clip 17 is provided with a cylindrical protrusion 18 which fit into lateral sockets 14 in the razor head 6, shown in Fig. 6. To fit the razor head onto the handle, the clips 17 are manually squeezed inwardly, so that the protrusions 18 clip into the sockets 14.

The connector portion 16 allows some rotation, so that the razor head can pivot with respect to the handle 15 during use. In operation, the razor is moved across the skin and hairs enter an aperture in the razor blade 1, to be sliced off by either of the cutting edges 4A or 4B, depending on which planar surface of the razor blade is in use. If hairs are missed by one row of cutting edges, the offset rows of apertures ensure that they will be captured by the next row. The open apertures allow the cut hair to be rinsed away between the razor head and the handle of the razor. Thus, a smooth and efficient shaving process is ensured.