MXPA96004960A - Safety razors - Google Patents

Abstract

A shaving unit includes a skin engagement surface member for contact with the skin in advance of a blade edge and defined by a series of resiliently mounted elements (9) defining between themáslots (10) through which hairs can pass while being subjected to a light pulling force to increase the length of hair projecting from the skin prior to cutting. The skin engagement surface member may be a guard of the shaving unit or it can be mounted between two blades.

Description

SAFETY SHAVERS DESCRIPTION OF THE INVENTION The invention relates to safety razors 5 and in particular the invention relates to a shaving unit having one or more elongated cutting blades and a coupling member with the skin for contacting the skin in advance with the edge of the cutting blade. The shaving unit can be the head of a disposable razor Jv sue has a grip in which the head is permanently attached, the entire shaver being unloaded when the cutting blade (s) have been worn, or the shaving unit may be a cartridge to be replaced mounted on a reusable shaver grip. In general, a shaving unit has a stop to contact the advancing skin of the cutting blade (s) as the cutting blades are moved across the skin. "During shaving, and a cover for contacting the skin behind the edge (s) of the cutting blade (s), 0 different configurations and different materials for the surface stop have been proposed, thus the surface stops have been designed for Stretching the skin in front of the blade, or to introduce pleasing tactile sensations to the beam as the stop slides on its surface.The shaving units are generally solidly rigid, by which the edges of the blade are cut. It has been proposed, however, a REF: 23245 flexible shaving cartridge adapted to bend in a plane essentially perpendicular to the plane of the cutting blade.In order to achieve the desired flexibility of the stop is defined by diver Separate segments mounted individually on cutting blade supports. A cartridge like the one mentioned is described in "PCT / US92 / 05467", according to the mentioned the segments are formed and mounted to avoid the entrance of the skin inside the spaces that are 'A. find between the segments. The stop segments are not adapted to prepare the hairs for cutting. The present invention has for its object to provide a shaving unit with improved shaving operation by preparing the hair to be cut in advance of a cutting blade edge. According to the invention there is provided a cutting unit comprising a skin engaging surface elongated to contact the skin in advance with a cutting blade edge that moves through the skin during shaving, said surface defined by elements with spaces therebetween for the hairs to pass through them, the adjacent elements being laterally formed and separated to elastically couple the hairs passing through the spaces therebetween to apply a small force of traction to the hairs as it slides on the skin from which the hairs of the surface are projected. A preferred embodiment of the shaving unit according to the invention comprises a surface of engagement with the elongated skin defined by a multiplicity of elements arranged on the length of the surface and delimiting between the same through grooves extending from the edge forward towards the trailing edge of said surface, the width of each wedge-shaped slot being backward from the mouth thereof at the leading edge and having a minimum value less than the diameter of a hair, and the surface elements being elastically movable relative to one another substantially in the plane of said surface. By using said cutting unit, most of the hair protruding from the skin passes through the mating surface with the skin and enters the grooves and because the elements of A- surface should be deflected by means of the hairs to make them pass through the narrower portions of the grooves, whereby the hairs are subjected to a pulling force. This tensile force increases the projection length of the hair from the skin and, as there is a delay before the hair re-retracts after being tracciopated, the proximity of the obtained shave can be improved because the cutting edge of the hair Leaf that slides through the hairs while they are still extended. In order to increase the length of the exposed hair only a small tensile force is necessary. For example, a traction of only 1 gram can extend a hair as much as 100μ. If, at the opposite end, a great pulling force is exerted on the hair, it can cause unpleasant sensations, if not discomfort. It is preferable that the surface elements are arranged to exert a tensile strength within the range of about 0.5 to 20 grams, to ensure a significant extension without causing discomfort, and more preferably the pulling force exerted on a hair is not greater than 10 grams, for example substantially equal to 5 grams. This ensures that the uncut hairs do not remain enclosed between the surface elements, and therefore are not so clustered that it produces annoying results, because the surface elements release the hairs allowing »_. they pass out of the grooves in the trailing edge of the mating surface with the skin. This release of the hairs is reliably achieved because the adjacent elements are able to move away, due to their elastic assemblies, to widen the grooves sufficiently to allow the hairs to easily pass through them. It is preferable for most hairs to pass through the grooves and it is preferable that the width of the grooves in the mouths of the grooves is not less than the width of the surface elements at the leading edge of the groove surface. coupling with the skin. In a particular embodiment, the width of the mouth of the groove is within the range of 1 to 2 times, for example about 1.5 times the width of the elements at the leading edge. A groove mouth width in the order of 0.50mm is adequate, ie several times larger than the typical hair diameter of 0.10mm. The minimum groove width is preferably at the trailing edge of the skin engaging surface, i.e. the one closest to the cutting edge of the next cut sheet.

A minimum slot width in the order of 0.05 mm has been found suitable. In order for most of the hairs to pass through the slots, it is preferable to provide a large number of slots. Preferably the slots are uniformly spaced apart and in a pitch of no more than 1.2 mm, preferably within the range of 0.7 to 1.0 mm. The skin engaging surface is conveniently formed by a member, for example made of metal, having the general shape of a comb, the tip portion of which forms a front wall which is substantially perpendicular to the engagement surface with the skin. defined by the teeth of the comb constituting the surface elements. The elasticity of the elements surface is provided by the bending of the torsion springs formed by the root pats that connect the 5 teeth to the tip part. In this embodiment, the surface elements are mounted as a cantilever effect by means of the torsion springs and some movement substantially perpendicular with respect to the coupling surface with the skin at their free rear ends can be allowed, which can be useful to dislodge remnants of hair cut from the slots.

Therefore, there is a strong tendency of the hairs to enter the mouths of the grooves, which causes the hairs to be flattened against the skin by the surface of engagement with the skin, therefore it is preferable that there is a transition relatively abrupt from the surface of engagement with the skin to the front wall. A radio , > curvature in the order of 0.16 mm has been found suitable for this edge. In a modified form of said embodiment, the teeth are transported by respective springs integrally connected to the rear ends of the tooth. The springs can be L-shaped and extend rearwardly from the upper edge of a front wall and then up towards the tooth. The movement of the tooth to widen the grooves is enabled by the torsional bending of the spring portions that extend backwards. The springs can also act as strip springs providing an elastic mount for the tooth to enable some elastic displacement generally perpendicular to the plane of the engagement surface with the skin. According to an alternative construction, the skin engaging surface is formed by a molded plastic member that includes surface elements conveyed on respective parallel band springs that enable elastic lateral deflection of the surface elements. The grooves defined between the surface elements are preferably formed and sized as described above. The surface of engagement with the skin may be the top surface of the shaving unit, ie, positioned to contact the skin immediately opposite the cutting blade of a single-blade shaver, or the front blade in the case of a shaver having two or more blades arranged in succession. Alternatively, the skin engaging surface may be arranged to contact the skin behind the front cutting blade of a multi-blade shaving unit, eg, in advance of the second blade in a shaving unit. double leaf. A more complete understanding of the invention will be obtained - ß - "from the following description directed with reference to the accompanying drawings, in which: Figure 1 illustrates a perspective view and an end part of a shaving unit according to the invention; Figure 2 illustrates in scale enlarged a part of the stop member of the shaving unit illustrated in the Figure 1? Figure 3 is a view similar to that of Figure 1 illustrating a modified shaving unit embodying the invention; and Figure 4 is a view similar to that of Figure 1 5 illustrating another embodiment of the invention; Figures 5 and 6 illustrate in perspective cutouts of respective modified shapes of the surface engaging members with the skin of Figures 1 and 2; /? Fig. 7 is a front perspective view illustrating a section of another modified form of a surface engaging member with the skin; Figure 3 is a rear perspective view of a surface engaging member with the skin of Figure 7; Figures 9A to 90 are views illustrating different shapes of slot edge for the embodiments of Figures 1 to 3; and Figures 10 to 11 illustrate alternative forms of skin engaging members for the shaving units embodying the invention. The shaving unit illustrated in Figure 1 can be a removable mounting cartridge on a reusable grip, or it can be fixed to the grip of a disposable razor. It can comprise two cutting blades 1, 2 mounted in tandem in a mounting frame 3 which can be defined by the lid 4 of the shaving unit, or can have a removable lid member mounted thereon.

The shaving unit also includes a stop member 6 which defines a mating surface with the skin for contacting the skin being shaved directly in front with the cutting edge of the front cut sheet 1.

The stop member is supported by a longitudinal bar ? integral with or otherwise affixed to the frame 3. The stop member is in the form of a solid comb with a tip defining a front wall 3 attached to the support bar and a plurality of substantially identical teeth 9 substantially curved 90 ° towards the front wall and define the superiro face of the mating surface with the skin. The trailing edge of the skin engaging surface may end short of the front edge of the cutting edge of the front cut sheet 1 or may be positioned to be below the cutting edge on the side of the skin sheet. cut that is away from the skin during shaving As can be better seen in Figure 2, the teeth delimit the grooves 10 which, at the front end of the abutment surface, have U-shaped notches 11 that extend downwards into the front wall. The width of each of the slots is a maximum of 0.50 mm, at the mouth of the slot in the. front end of the mating surface with the skin.

The slot narrows inward at a relatively sharp angle over a first portion of the slot, and then continues to narrow at a very small angle to define a minimum slot width of 0.05 mm at the trailing edge of the mating surface with the skin. The tooth width at its rear ends is 0.3 mm, producing a groove pitch of 0.85 mm, and the width of the tooth roots is 0.35 mm. The length of the teeth between the front and rear edges of the mating surface with the skin is 1.6 mm. The sheet of metal or other material with which the stop member is made is made with a thickness of 0.08 mm. In order to manufacture the mole member, it can initially be formed flat and then bent into a small radius of curvature, for example 0.16 mm, such that the teeth are substantially perpendicular to the front face. When using the shaving unit, the abutment surface It slides on the skin in front of the edge of the cutting blade. Most of the hairs protruding from the skin enter into the slots 10 and are guided along the slots. As a hair, having a typical diameter of 0.10 mm, approaches the narrowest part of the groove, it is gripped slightly between the two teeth or each side of the groove. As the hair continues its course through the groove, it pushes the teeth away, this elastic movement being made possible by the bending of the roots of the teeth that serve as torsion springs.

The teeth exert an action of traction on the hair, with a force of or, 5 to 20 grams, for example 5 grams, tending to lift the hair from the skin. The hair is released in the rear brocade of the stop member and meets the cutting edge of the next cutting blade before it has time to retract into the skin. The hardnesses exerted on the hairs are not large enough to cause displeasure. If the stop surface does not end at the front of the cutting blade and the trailing edge of its surface, defined by the free ends of the tooth, lying below the cutting edge of the blade, the hairs will continue to be located in the grooves, and therefore they will be subjected to traction causing them to be extended from the skin when they come into contact and are cut by the sheet.

The embodiment illustrated in Figure 3 is basically the same as that of Figures 1 and 2, except that the teeth defining the mating surface are shorter in length, and the sides of the grooves have a constant narrowing. The slot widths at the leading and trailing edges of the abutment surface, and the other dimensions may be the same as those specified for the first embodiment. Modifications are possible without departing from the concept of the invention. For example, it is not necessary for the stop member to be made in one piece, and it can be assembled in two parts fastened together and each providing alternating teeth in the length of the stop surface. Furthermore, it is not essential for the front wall 3 of the comb that it be perpendicular to the coupling surface with the The skin, for example, can be arranged to extend at an acute angle towards the plane of the tooth 9, and / or to be displaced backwards from the front edge of the skin engaging surface, for example by bending the front wall so that extend back and then down.

In the embodiments described above, the coupling surface with the grooved skin is the abutment surface. Alternatively, or in addition, in a shaving unit having two or more cutting blades such as a grooved surface that contacts the skin that may be located immediately forward of the second blade or a rear blade. In Figure 4 an embodiment of said shaving unit is illustrated. This shaving unit has two cutting blades and a comb-like member 6, essentially the same shape as the top of the shaving unit illustrated in Figure 3, is arranged between the cutting blade to define the coupling surface with the grooved skin behind the front cutting blade 1 and facing the cutting edge of the second cutting blade 2. The member 6 may be the same as that described above in relation to the embodiments of Figures 1 to 3. Although the shaving unit is illustrated having a conventional stop 15, a slotted stop can be provided such that these grooved surfaces that engage the skin are defined before each edge of the cutting blade. With a contact member with the skin between blades as illustrated in Figure 4, it is preferable that the distance between the leading and trailing edges of the grooved surface, and therefore the length of the surface defining the elements should not be greater than about 1.0 mm. The skin engaging surface member of Figure 5 is basically the same as in Figures 1 and 2, and the same reference numerals have been used to designate corresponding parts in the drawings. The differences main are that the teeth 9 extend rearwardly by the tail portions bent downwards 19, the slot sections being defined between the adjacent tooth tail portions of substantially constant width, and the teeth bifurcated. When the member is mounted on a shaving unit, the tail portions 19 can be extended approaching the next cutting blade edge without < ? adverse effect on the hair cutting behavior on that edge. The bifurcated shape of the teeth gives them a Y shape as can be seen in the drawing. The diverging forks 20 may be rigid such that the deflection caused by the hairs passing through the grooves 10 are due to the torsion springs formed by the leg portions 21 that transport the tooth as in the embodiments described above, or the forks 20 may be elastic in such a way that at least some of their deflection Lateral is due to the elastic or bending of the forks. The pitch and dimensions of the grooves may be the same as that described above with reference to Figures 1 and 2. The skin engaging surface member illustrated in Figure 6 is similar to 1 in Figure 5, but 5 a hairpins 20 of each tooth are formed to form an additional rear convergent groove 30 and a diamond-shaped section 31 at the front end of this groove.Hairs that can not enter the grooves 10 between the teeth can enter these additional grooves. 30 and being subjected to a slight pulling force because these hairs are slightly gripped between the forks 20. The narrower front end portions 33 of the forks can provide the necessary resilience to allow the forks to be separated from each other a little. to cause the hairs to pass through the additional slots 30. Figures 7 and 3 illustrate another modified embodiment of the coupling member. With the skin of the general shape described with reference to Figures 1 and 2. In this embodiment, the tooth 9, between which the trapezoidal groove 10 is defined, is carried by respective L-shaped springs 35 solidly connected to each other. the back ends of the tooth. The springs extend backward from the upper edge of a front wall 3 and then up towards the tooth. The front ends of the tooth have narrow tips, to facilitate the entry of the hairs into the mouths of the slots 10, and the upper surfaces of the tips are curved to increase comfort during shaving. The slots 10 can be formed and dimmanded accordingly. described in relation to Figures 1 / 2. In use, when the skin engaging surface member is mounted on a shaving unit, for example as in Figure 4, the hairs will enter the slots. they will be gripped slightly between the teeth and therefore will experience a controlled pulling force. The di can move laterally to increase the width of the ra because the rearwardly extending portions of springs 35 act as torsion springs. With embodiment, the springs 35 can serve as spring springs to allow a degree of elastic displacement of the teeth substantially perpendicular to the engagement surface with the skin, which can be advantageous, especially if the cutting blade of The shaved together are mounted on springs. All of the skin engaging surface members of Figures 1 to 8 can be formed initially substantially flat and then formed to be medially curved. Different manufacturing techniques are possible for the production of the grooves, for example, cutting the stamping and punching, electrophoresis, and erosion by chi and the opposition of the lateral edges of the adjacent die may differ in orientation according to the method used. Figure 9A illustrates a hair H between the edges of the tooth substantially perpendicular to the engagement surface with the skin S. Alternatively, the edge surfaces may be conveyed toward the engagement surface with the skin S as illustrated in Fig. 9B. , or the tooth edges can be rounded as illustrated in Figure 9C. As shown in Fig. 9D, the teeth have rounded edges that are cut downwardly so that the ridges 35 extend over the skin and the engaging surface S over the length of the grooves. The members of skin engaging surface of a construction different from that described above are illustrated in Figures 10 and 11. These members can be molded with plastic and in each case the member comprises a beam carrier 40 with a series of strapping springs 5 uniformly spaced parallel 41 extending upwardly from the bundle. Mounted on the upper end of each strap spring is a surface element Solidary or pallet 42. The vanes are formed to define slots 10 with relatively sharp convergent entry portions and followed by gradually tapering portions having a minimum width smaller than the diameter of a hair. The entrance parts lead the hairs into the slots in such a way that they are gripped between them and are pulled lightly by the adjacent vanes which, due to their assemblies on strapping springs, can be moved laterally to widen the slot for allow the hair to pass through it. As illustrated the faces of opposite sides of adjacent vanes 42 are inclined to converge towards the mating surface with the skin but this is not essential. The dimensions of the groove can be the same as those described above in relation to other embodiments, but it should be understood that in all embodiments the dimensions of the groove and the spring ratio of the springs will be selected to obtain the order of desired amount of pulling force to be exerted on the hairs passing through the grooves.

The surface members engaging with the skin of the Figs 10 and 11 differ only in the shape and size of the blades 42. Any of the above-described skin-engaging surface members may be elastically mounted on the frame of a shaving unit. For example, the limb may be driven adjacent to its ends by means of leaf springs that urge the limb to a position higher and allow the limb to move downwardly under the forces exerted against the engagement surface with the skin. as it is experienced during shaving. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects or products to which it refers. Having described the invention as above, property is claimed as contained in the following:

Claims (2)

1. - ^ CLAIMS 1. A shaving unit comprising an engagement surface with the skin elongated to contact the skin in advance to an edge of a cutting blade moved through the skin during shaving, said surface being defined by elements with spaces between them, characterized by therein the spaces are arranged so that the hairs pass through the spaces, and laterally adjacent elements that are formed and separated to elastically couple with the hairs that pass through the spaces between them. same for the application of a small pulling force to the hairs as the skin from which the hairs are projected slides on the surface. A shaving unit according to claim 1, or 3, characterized in that the pulling force exerted on the hairs is within the range of 0.5 to 20 grams. 3. A shaving unit according to claim 2, characterized in that the pulling force exerted on the hairs is 5 grams. 4. A shaving unit according to claims 1, 2 or 3, characterized in that it has a series of elements separated in the length of the surface and defining between the same through grooves extending from the front end towards the end rear of said surface, narrowing in the width of each slot backward from the mouth thereof at the leading edge and having a minimum value less than the diameter of a hair, and the adjacent elements are elastically movable relative to each other in shape substantially parallel to the plane of said surface. 5. A shaving unit according to claim 4, characterized in that the slots have a minimum width at the rear edge of the surface. 6. A shaving unit according to any of claims 4 to 5, characterized in that the grooves have a minimum width substantially equal to 0.05 mm. 7. A shaving unit according to any of claims 4 to 6, characterized in that the slots are positioned in a uniform pitch of no more than 1.20 mm. 8. A shaving unit according to claim 7, characterized in that the step is within the range of 0.70 to 1.00 ram. 9:. A shaving unit according to any of claims 4 to 8, characterized in that the width of the groove in the mouth thereof is not less than the width of the surface elements at the front edge of the body. claim 15, face bristled by the fact that the surface elements are supported by respective torsion springs connected to the elements at the leading edge of said surface. 17. A shaving unit according to claim 16, characterized in that the engagement surface with the skin approaches a front wall at the leading edge, said front wall having indentations in register with the slots and separating connecting strips. which are said torsion springs. A shaving unit according to any of claims 4 to 17, characterized in that the leading edge of the engagement surface with the skin approaches a front surface extending substantially perpendicular to the engagement surface with the skin, presenting there a sharp edge transition between said surfaces. 19. A shaving unit according to any of claims 15 to 18, characterized in that the elements have portions of inclined tail moving away from the coupling surface with the skin.
2. 2 . A shaving unit according to any of claims 15 to 19, characterized in that the elements are bifurcated with forks that extend backwards. r '21. A shaving unit according to claim 20, characterized in that the forks of each 5 elements define an additional slot through which the hairs can pass and be elastically coupled by means of the forks to be subjected to small tensile forces. 22. A shaving unit according to claim 12, characterized in that the surface elements are supported by respective springs connected to the elements at the rear edge of said surface. 23. A shaving unit according to claim 22, characterized in that the springs are 15 extend backwards and then upwards towards the surface elements. 24. A shaving unit according to claim 23, characterized in that the rearwardly extending portions of said springs act as torsion springs 0 allowing a relative lateral movement between adjacent elements. 25. A shaving unit according to claim 22, 23 or 24, characterized in that the surface elements have sharp points at their rear ends. 26. A shaving unit according to any of claims 1 to 11, characterized in that the surface elements are driven on respective parallel strip springs. 27. A shaving unit according to claim 26, characterized in that the surface elements and the band springs are integrally molded with an elongate support member. 28. A shaving unit according to any one of the preceding claims, characterized in that it includes a frame in which a member defining the surface of engagement with the skin is supported by means of springs enabling an elastic displacement of the member. generally perpendicular to said surface. 29. A shaving unit according to any of the preceding claims, characterized in that i coupling surface is the abutment surface of the shaving unit. A shaving unit according to any one of claims 1 to 29, characterized in that the engagement surface with the skin is located behind a front cutting edge and in front of a cutting edge of an additional cutting blade. of the shaving unit. 5