MXPA99006115A - Safety razors - Google Patents

Abstract

A novel cutting element in or for a safety razor comprises an elongate member with a series of slots (5), each slot (5) tapering from an open forward end to a substantially closed trailing end, and each slot (5) being confined between a pair of shaped edges (6) for slicing hairs as they move through the slot as the cutting element is moved across the skin. One or more of the cutting elements may be used in a safety razor blade unit, either alone or in combination with a blade having a conventional straight sharpened edge.

Description

POCKET KNIVES OR SHAVING MACHINES Field of Invention The present invention relates to shaving machines, ie razors with cutting elements having sharp edges that cut through the hairs due to the displacement of the cutting element on the skin during shaving, and without the Cutting element and another member is actuated one in relation to the other producing an action of zallamien to. The invention particularly relates to a novel form of cutting element for a blade unit for the razor, and to a razor blade unit incorporating said cutting element.

Background of the Invention Razors generally comprise a razor blade unit with one or more cutting elements that move through the skin during shaving by means of a handle to which the razor blade unit is attached. It can Re: 030594 firmly mounting the blade unit to a handle with the intention of replacing the entire razor when the cutting edges become dull, or the cutting element (s) is replaced in the blade unit. As an alternative, the blade unit can be mounted separately on a handle for replacement when required. The replaceable blade units are generally known as cartridges.

Most shaving machines in use today have cutting members in the form of blades with sharp straight edges that extend perpendicular to the direction in which the blades, when in use, should be moved across the skin. There is a tendency for hair to break with a leaf edge before the blade cuts through the hair, but effective hair cutting is obtained, however, as a result of having the hair root firmly in the skin. and by locating the edge of the sheet closely adjacent to the surface of the skin. It was suggested to incline the edge of the sheet in the direction of displacement on the skin in order to preferably produce a cutting action perpendicular to the hair, but such proposals have not been accepted due to the increased risk of injuries as a result of the blade cutting the skin.

Description of the invention.

The present invention is based on a new form of cutting element that ostensibly departs from the prior art practices. According to the invention there is provided a cutting element for a shaving machine comprising grooves that taper from open front ends to essentially closed rear ends; each slot is contained between a pair of edges, at least one of which is sharp to cut the hairs entering the slot and moving therethrough to the rear end as the cutting element travels through the slot. of the skin during shaving.

With a cutting element according to the invention, the sharp ends extend essentially in alignment with the direction of movement of the cutting element through the skin such that the hairs are effectively shaved, but the grooves may be narrow enough as to prevent the skin from entering the slots, so that the risk of cutting the skin is not greater with conventional razor blades, and may even decrease. Another advantage of the cutting element of the invention is that the sharp edges do not need to scrape the surface of the skin in the same way as conventional razor blades do, and consequently less tissue is removed from the skin during the shaved Furthermore, because the hairs are cut with a cutting action perpendicular to the hair, a better feeling of comfort is produced after shaving because the extreme cutting faces of the hairs are more perpendicular to the length of the hairs and parallel to the hair. skin that in the case of the hairs cut with conventional leaves that usually hit and cut them along planes, at an almost flat angle with respect to the length of the hair, with which ends are pointed on the cut hairs.

In preferred embodiments of a cutting element according to the invention, both edges of each groove are sharpened to achieve a better perpendicular haircut. The taper angle, ie, the angle between the opposite groove edges is appropriately not greater than 10 ° and a taper angle in the range of 3 ° to 7 ° is suitable. The length of the cutting edges measured along the slots does not need to be large and the effective cutting of the hairs perpendicularly can be achieved with a length in the range of 1 to 2.5 mm. The thickness of the grooves at the leading end of the sharp edges is in the range of 50 to 500 μm.

More conveniently, the cutting element is elongated with a series of parallel grooves distributed along the element with which it extends essentially perpendicular to the length of the element; the slots are preferably positioned to a degree in the range of 0.5 to 2.0 mm.

The invention includes within its scope a razor equipped with a cutting element according to the invention, and a blade unit for a razor with a cutting element according to the invention. Two or more of said cutting elements are included in a cutting unit that moves through the skin in turn; with the grooves of all the cutting elements oriented in the same direction forwards.

In addition, the cutting element according to the invention can be used in a blade unit in combination with a conventional blade having a rectilinear sharp edge, and the cutting element is located in front of or behind the edge of the conventional blade with its grooves essentially in place. e perpendicular to the length of the edge of the sheet.

Another embodiment of the blade unit includes two cutting elements according to the invention arranged against one another, whereby the blade unit shaves in both directions. In addition, several cutting elements can be used in a shaver of the coated class with their grooves oriented in different directions so that the hairs are shaved when the head of the shaver, which includes the cutting elements, is rubbed on the surface of the skin moving in several directions.

For a clear understanding of the invention, a more detailed description of an embodiment is provided below, and reference is made to the accompanying drawings, in which: Figure 1 is a schematic illustration showing the cutting action of a conventional razor blade; Figure 2 in a corresponding schematic illustration showing the cutting action perpendicular to the hair obtained with a cutting element embodying the invention.

Figure 3 is an isometric view of a cutting element according to the invention; Figure 4 is an isometric view illustrating another embodiment of a cutting element according to the invention; and Figures 5 to 8 are partial isoelectric views illustrating the respective razor blade units incorporating the cutting elements as shown in Figure 3.

With reference to Figure 1, there is shown a conventional razor blade 1 with a rectilinear sharp edge 2 approaching a hair H in the direction of the arrow A, which is perpendicular to the edge 2. The blade cuts through the hair of the best described as the chopping action. There is a tendency for the hair to move and strike against the movable edge of the blade, but it is cut off because the hair root remains firmly on the skin. The cutting element according to the present invention involves a very different cutting action, whose principles are presented in Figure 2. A tapered groove 5 is defined with a pair of sharp cutting edges, opposite 5; the edges are at an angle of approximately 5o in yes. The front end of the groove is open and has a thickness slightly larger than the diameter of the hairs to be cut, for example a thickness of approximately 250 μ. The rear end of the slot may be completely closed, or it may have a very narrow opening. The cutting element moves across the skin in the direction of the arrow A. When the hair H enters the front end of the groove 5 and moves in relation to the sharp edges 6 towards the rear end of the groove, the hair enters in contact with the edges that cut the hair perpendicularly; the depth of the cut increases gradually until the hair is completely cut. An opening of a few microns in thickness is left between the rear ends of the sharp edges, but the section of uncut hair is so thin that it breaks immediately.

A specific embodiment of the cutting element of the invention is shown in Figure 3, it comprises an integral metal strip that initially is in a flat position. A series of essentially identical parallel grooves 5 are formed in the strip to a uniform degree, for example, in the range of 0.5 to 2.0 mm, along the strip. The grooves are tapered from the open ends at a leading edge of the strip towards the closed rear ends. The grooves are conveniently made in such a way that the sharp edges 6 are formed simultaneously along the sides of the grooves. For example, a V-shaped grinding wheel can be used to form the grooves; the depth of the grinding gradually decreases so that initially the grinding wheel breaks through the metal of the strip, but after the closed ends of the groove, the strip. The strip is then flexed to form an essentially flat surface 9 which connects to the skin, on the surface of which are located the tapered grooves 5, a rounded front edge section where the grooves are not shaped with sharp edges or removed therefrom, and a rear wall portion 10 which serves to give rigidity to the cutting element. Each of the slots 5 has a length of about 1.8 mm and serves to cut two hairs into a cutting action by sections when the cutting element travels through the skin. The rounded front portions of the teeth between the grooves serve to guide the skin towards the contact surface with the skin and away from the front ends of the sharp edges of the grooves. The sharp edges, due to the shape of the abrasive wheel, are located on the contact surface with the skin 9 in such a way that the hairs are cut as close to the skin as possible.

The edges do not need to be sharpened entirely to the front ends of the slots. The thickness of the slots at the position where the sharp edges begin is in the range of 50 to 500 μm, while the thickness of the slots at the most forward ends where the edges may not be sharp and whose purpose is not to cut them. hair, is in the range of 50 to 1500μm.

A slightly modified cutting element is shown in Figure 4. The metal strip has a side wall 11 below the rounded sections at the front ends of the teeth between the slots 5 which offers greater rigidity and provides greater support to resist any tendency of the teeth deviate laterally when the hairs are cut in the grooves.

In Figure 5 there is shown an end portion of a razor blade unit or cartridge comprising a frame 20 providing the protective and lid surfaces 21, 22 respectively, and two cutting elements mounted in tandem in an opening defined by the frame between the protective and lid surfaces; the front cutting element 23 is according to what has been described above with reference to Figure 3 and therefore according to the invention, while the second cutting element or rear cutting element 24 in a conventional sheet with a rectilinear cutting edge .

Figure 6 partially shows a razor blade unit similar to that of Figure 5, although it differs in that the positions of the cutting elements are reversed, so that the conventional blade 24 constitutes the element of The front cut and the cutting element 23 according to the invention is positioned behind the leaf 24.

In Figure 7 there is presented a razor blade unit with two tandem cutting elements between the surfaces between the protective and lid surfaces, and both cutting elements 23 are in accordance with that described with reference to Figure 3 The grooves of the respective cutting elements align with each other or move relative to one another longitudinally with respect to the blade unit.

The razor blade unit shown in Figure 8 also has two cutting elements 23 in accordance with that described with reference to Figure 3, but in this embodiment they are mounted against each other between the protective surfaces / cover 26 provided. in the frame, such that the blade unit can be used by gently rubbing the blade unit from one side to the other while in contact with the surface of the skin to be shaved.

The specifically described embodiments constitute a non-limiting example and other specific forms of cutting element are possible within the scope of the invention, as defined in the following claims.

It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it relates.

Having described the invention as above, the content of the following is claimed as property.

Claims (15)

Claims

1. A cutting element for a razor characterized in that it comprises grooves, the grooves have an open face facing end facing the shaving and having a removable rear end of the entry end along the shaving direction, and the openings having confronted side edges spaced apart by a distance much longer than the diameter of the hair to be shaved at the inlet end, at least one of the facing edges being sharpened to cut the hairs entirely into the openings and moving them along the As the cutting end moves through the skin during shaving, the length of the opening between the entrance and the rear ends is several times greater than the distance between the edges confronted at the entry end.

2. The cutting element of claim 1, characterized in that both edges of each groove are sharp to cut the hairs in perpendicular form.

3. The cutting element of claims 1 or 2, characterized in that the angle of taper between the edges of the groove is not greater than 10 °.

4. The cutting element of claim 3, characterized in that the taper angle between the edges of the groove is from 3 ° to 7 °.

5. The cutting element of any of claims 1 to 4, characterized in that the sharp edges have a length along the slots in the range of 1 to 2.5 mm.

6. The cutting element of any of the rei indications 1 to 5, characterized in that the thickness of the grooves at the leading end of the sharp edges is in the range of 50 to 500 μm.

7. The cutting element of any of claims 1 to 6, characterized in that the element is elongate with a series of slots distributed therein extending substantially perpendicular to the length of the element.

8. The cutting element of claim 1, characterized in that the slots are positioned along the element to a degree in the range of 0.5 to 2.0 mm.

9. The cutting element according to any of the preceding claims, characterized in that the grooves are formed in an essentially flat cutting element portion defining a contact surface with the skin, and the ends of the sharp edges are on the surface.

10. The cutting element according to any of the preceding claims, characterized in that on any of the sides of the front end of each slot, the cutting element is shaped to move the skin away from the sharp edges.

11. The cutting element according to claim 10, characterized in that the element has radiated surface portions on each side of the leading end of each slot.

12. A razor blade unit characterized in that it includes at least one cutting element as defined in any of the preceding claims.

13. A razor characterized in that it comprises a cutting element as defined in any of the preceding claims.

14. The blade unit for a razor according to claim 12, or the razor according to claim 13, characterized in that the two cutting elements are arranged against each other.

15. The razor blade unit of claim 12, or the razor of claim 13, characterized in that several cutting elements are provided and positioned with their grooves extending in different directions.