Patent Application
20080216320
The present invention relates to a shaving system in which more than one shaving action is performed during a shaving operation, to methods of shaving, and to blade unit sub-assemblies and cassettes for use in such apparatus and methods.
A shaving system having one stationary razor blade and one linearly reciprocating razor blade is known from Swiss patent CH199 850 (Metzler et al.). This arrangement has two double-edged sided razor blades (38, 39) of the “Gillette type” (see page 3, left column, line 21) and reciprocates one razor blade (39) while the other razor blade (38) of the two is stationary. The moving razor blade is actuated by pins 31 on a linearly reciprocating pusher 30, the pins 31 engaging in the short slots 40 of the moving blade 39, whereas the stationary blade 38 has longer clearance slots 41 so that the pins 31 move without moving the stationary blade 38 (page 3, left column, lines 4 to 18). The razor blades are positioned so that either the top razor blade moves and the bottom blade is stationary, or the bottom razor blade moves and the top blade is stationary (page 3, right column, lines 3 to 9). Guard (24, 25) is positioned in front of the forward blade.
Systems are known in which a rotating guard member is positioned in front of a sharp safety razor, e.g. U.S. Pat. No. 5,022,154 (Johnson). A shaving system having a plurality of pairs of rotating sieve-like guard elements positioned in front of and feeding hairs to razor blades positioned behind the rotating guards is known from German patent DE 1 182 554 (Brand). The roller-guard and razor blade pairs are positioned around the semi-circular periphery of the shaver housing (FIG. 2). The cylindrical roller guard 1 is rotated by having its friction roller end 13 driven by a friction driver wheel 4. Each razor blade 2 is mounted on a bridge 3, and are either static or driven in linear reciprocation shown by arrow 24 in FIG. 6, see column 3, lines 49 to 52. When the razor blades are linearly oscillated as in FIG. 6, they are driven by contours 19 in cam wheel 20 against restoring springs 2a (FIG. 3), and the blade edge can have serrations 22. As described at column 4, lines 27 to 39, and FIG. 6, the roller guards have rectangular openings 26 formed by the framework of the roller guard, and in operation beard hair enters the openings 26 and by rotation of roller guard 1 is pushed against the razor blade 2 for cutting.
A shaving system having both a static guard and a rotating, profiled feeder positioned in front of a sharp razor blade is known from German patent application DE 25 03 175 (Hansom). This document shows two types of embodiments, the first that of FIGS. 1-5, and the second that of FIGS. 6-8. In each, the static guard 5 or 36 is positioned in front of a single wet safety-razor type blade edge 4 or 33, which defines with the sharp edge a skin plane 7 or 44, and a beard hair is shown as 13 or 45 (FIG. 1, 8). Between the static guard and the blade edge is a rotating feeder. The rotating feeder of FIG. 1 is a cylindrical sleeve 8 defining three longitudinal slits which define continuous edges 11. In operation described at page 5, rotation of the edges 11 effects that hairs 13 are brought into contact with sharp cutting edge 4 to be cut. Alternative versions of the rotating feeder are described at pages 5 to 6 that it is a rotating strip having two edges, and that the strip can be straight or spiral; or can be cross-shaped (FIG. 3); or toothed (FIG. 4); or a perforated sleeve 20 with openings 22 (FIG. 5), and the embodiments of FIGS. 1 to 5 do not disclose that the edges of the rotating feeder are sharp. In the alternative embodiment of FIG. 6 the rotating feeder is formed by a conventional drill bit shaft 23 having two spiral edges 25 which are sharp (page 7, lines 1-5), and shown in cross-section in FIG. 8. The DE 25 03 175 states that since the skin is flexible the drill bit shaft 23 is spaced from skin plane 44 so as to not contact the skin since otherwise the user will experience an undesirable burning irritation feeling.
Shaving systems comprising multiple foil-type units are known, e.g. from U.S. Pat. No. 6,098,289 (Wetzel et al.) which also discloses combinations of short hair cutters with a long hair cutter, or also U.S. Pat. No. 6,223,438 (Parsonage et al.) or U.S. Pat. No. 3,967,372 (Beck et al.).
Shaving systems comprising multiple razor-sharp blades are also known, e.g. from GB-A-1,460,732 which describes shaving cartridges comprising two parallel razor-sharp blades, and U.S. Pat. No. 5,661,907 (Apprille, Jr.) which discloses a shaving cartridge comprising three parallel razor-sharp blades.
It is also known to provide a long hair trimming unit comprising a pair of interacting blades at the upper side of the shaver alongside a foil-type reciprocating shaving unit, e.g. JP-A-2000-288267 (Hitachi Maxell).
It is further known to have non-cutting, hair-erecting scraper edges positioned adjacent or radially outward of the rotary cutter units on known rotary-type electric shavers such as sold by Philips Corporation. See WO 00/13859 (Barish), which discloses a rib-like, thin, blunt scraper member (232) surrounding each cutter (FIG. 20) and a common scraper member (242) (see FIG. 22) surrounding the several cutters. Allegedly, the scraper member tautens the skin and erects the hairs, but does not cut the hair, just before hairs are received within the slits of the electric razor cutter, for producing a closer shave when the electric shaver is used with a lubricating liquid for effecting a wet shave, as described at pages 13-15 therein. However, if such a construction is used without a lather when operated in a dry shaver mode, it will disadvantageously increase skin irritation. It is also known from United States published patent applications US 2001/0027608 A1 (Barish) and US 2001/0042308 A1 (Barish) that such scraper edges can be relatively sharp and formed as either a square edge (15a, see FIG. 5) or an outwardly extending edge (25d, see FIG. 6), but in both cases this edge does not cut hairs. Nonetheless, it causes such significant skin irritation that during normal use of the electric shaver, it is not meant to contact the skin surface being shaved; rather, these documents teach that the electric shaver must first be tilted obliquely (compare shaving position LA where the hair-erecting edge is not engaged, with the tilted position LA′ where the hair-erecting edge is engaged to erect hairs) to selectively engage the hair-erecting scraper where the user feels the electric cutter unit has missed a hair, which has the simultaneous disadvantage that the cutter unit is no longer at the intended orientation for efficient hair cutting. Indeed, other embodiments therein (FIGS. 7-8) teach that during a normal shaving action the scraper edges are completely out of contact with the skin. In other words, with these described devices, the user would be subject to skin irritation if he attempted to use the scraper edge constantly during normal operation of the electric hair cutter disc, and thus must forego the alleged benefit of a closer shave except in sporadic use where he determines that the electric hair cutter disc missed a spot, and he repeats the shave with the product tilted so as to engage the scraper edge into the skin and tolerate some irritation. This is also cumbersome and inefficient.
Another device is known from DE-A-34 28 631 A1 (Ebner) which discloses an electric shaver having a single foil-type reciprocating shaving unit together with an auxiliary blade element (4) disposed laterally of the main shaving unit in a recess of the shaving head and which, subsequent to completing the electric shaving operation, can be pivoted from a rest position (FIG. 5) into an outwardly extending operating position (FIG. 6) for removing stray long hairs which may have been missed during operation of the foil-type cutter unit. The documents explains at page 8, at the last paragraph of the disclosure, that the auxiliary cutting device (4) is deployed as an “emergency razor” when the battery has discharged There is however no suggestion that the foil-type cutter should be used in tandem with the blade unit and the geometry of the shaver would not make this feasible.
Combinations of hair manipulators and cutting members are also known, e.g. from WO-A-01/07212 and WO-A-01/07213 (Pragt).
Other types of shaving system are also known. For example, GB-A-1,444,960 (de Raemy) discloses a dry shaver having a cylindrically arcuate cutting surface defined by a plurality of cutting edges and means for rotationally reciprocating the cutter head about its longitudinal axis. In a preferred embodiment, the reciprocating cutter head is positioned beneath a cylindrically curved outer cutting foil. Further arrangements of this type are disclosed in GB-A-1,469,556 (Ascoli) and in GB-A-1,533,679 (Buchholz).
Another rotary appliance for removing hair is disclosed in WO-A-98/07551 (Garenfeld et al.), which comprises a rotary clamping device for clamping hair and subsequently extracting it at least partially from the skin, whereupon the hair is severed adjacent the skin by a separate shaver or hair trimmer arrangement (13, 29), consisting of a static shaver blade (33) adjacent the skin and a shearing blade (31) which reciprocate in shearing relationship. The appliance can be selectively set to a mode in which the oscillating shearing trimmer (13, 29) is decoupled from the drive, so that the appliance functions like a conventional epilator.
It has also been proposed in various published documents to provide in a shaving system a blade structure comprising a plate defining a plurality of apertures having annular sharpened shaving edges on the plate or formed in separate discs mounted to the plate. Systems of this type are disclosed in U.S. Pat. No. 5,604,983 (Simms et al.), U.S. Pat. No. 5,490,329 (Chylinski et al.), U.S. Pat. No. 3,702,026, U.S. Pat. No. 4,483,068, U.S. Pat. No. 4,807,360 and U.S. Pat. No. 5,153,992.
It has also been proposed to have a twin-blade assembly comprising two blade members secured for replacement, as a unit, in a plastics razor head of the wet shaving type, in order to have the ecological advantage of discarding the dulled blades and re-using the cartridge frame components, as disclosed in U.S. Pat. No. 5,551,153 (Simms).
As is well-known, the dry shaving system has advantages which are not shared by the wet shaving system, and vice versa. For example, the dry shaving system is exceptionally convenient for the user, does not require the application of liquid to the face and is comfortable. The wet shaving system, on the other hand, normally requires the application of a lubricant, such as soap, and for some users tends to produce more discomfort than the dry shaving system. It does however on the whole produce a closer shave, for most users, than a dry shaving system.
In spite of these known advantages and disadvantages, it has never previously been proposed to provide a hybrid shaving system combining the advantages of the dry shaving and the wet shaving systems without the attendant disadvantages.
According to one aspect of the invention, there is provided a shaving apparatus comprising a drivable shaving unit having a skin-engaging cutter for performing a first shaving action on a user's skin; a motor adapted to drive the shaving unit to perform the first shaving action; and a razor blade having a guarded sharp cutting edge positioned for hair-cutting shaving engagement with the user's skin, whereby the blade performs a second shaving action during use of the shaving unit to perform the first shaving action, the drivable shaving unit being devoid of an exposed sharpened razor blade edge and comprising two cooperating cutter elements which cooperate to cut hair. The razor-sharp cutting edge is of the type commonly referred to as a “wet” shaving blade, whereas the drivable shaving unit is of the type referred to as a “dry” shaver, whether of the “short hair cutting unit” or “long hair cutting unit” construction.
It has been observed that non-humid conditions, such as prevailing in a dry winter climate, favor a conventional dry shaver, but that higher temperature and humidity leads to more hydration and more missed hairs. Thus, as hydration increases, that favors using instead a conventional “wet” shaving sharp blade. However, the arrangement of the present invention permits, even under disadvantageous temperature/humidity conditions, the efficiency of the overall system to approximate that of a non-humid day.
It is particularly preferred for the blade to be floatably mounted (i.e., spring mounted or biased on a resilient support). Moreover, it may be preferable to provide a second drivable shaving unit coupled to the motor and having a skin engaging cutter for performing a third shaving action on the user's skin, the blade being mounted between the first and second shaving units. In this construction, the first of the shaving units may be constructed as a short hair cutting unit and the second shaving unit may be constructed as a long hair cutting unit. In such a construction, the blade is expediently mounted on the long hair cutting unit. Alternatively, both the first and second shaving units may be of the same type, for example both short hair cutting units.
In a particularly preferred embodiment, a third drivable shaving unit may be coupled to the motor and constructed as a short hair cutter to perform a fourth shaving action, the second shaving unit being disposed between the first and third shaving units. In this construction, a second guarded razor-sharp blade may also be positioned for shaving engagement with the user's skin, so that the second blade can perform a fifth shaving action during use of the drivable shaving units to perform their own shaving actions. The blades may preferably be mounted on respective opposite sides of the long hair cutter unit.
The, or each, blade may be guarded by a portion of the adjacent shaving unit, e.g. the side region of a foil-type cutter. However, for improved safety and comfort, the or each blade may be mounted on a respective guard member. The guard member may be constructed as a bar of plastic or metal generally parallel to the extent of the sharp blade, as is known from the “wet” shaving art. Alternatively, the guard member may be provided by a plurality of fingers extending forwardly of the blade edge. For additional security, a guard wire may be provided along the distal ends of the fingers.
In one variant, the or each shaving unit may comprise an inner cutter mounted for hair shearing engagement with the skin engaging outer cutter thereof and coupled to the motor to be driven thereby. The or each inner cutter may be mounted for linear reciprocation. In this case, the or each razor-sharp blade preferably has a straight edge mounted parallel to the direction of linear reciprocation.
According to another aspect of the invention, there is provided shaving apparatus comprising a drivable shaving unit having an outer cutter for contact with the user's skin and an inner cutter mounted in hair shearing engagement with the outer cutter to provide a first shaving action; a motor adapted to drive the inner cutter to perform the first shaving action; and a razor-sharp blade having a cutting edge positioned for hair-cutting shaving engagement with the user's skin, whereby the blade performs a second shaving action during use of the drivable shaving unit to perform the first shaving action. The blade is preferably floatably mounted.
In one embodiment, a second drivable shaving unit is coupled to the motor and has an outer cutter for contact with a user's skin and an inner cutter mounted in hair shearing engagement with the outer cutter to provide a third shaving action, the blade being mounted between the first and second shaving units. In this embodiment, the first of the shaving units is preferably constructed as a short hair cutting unit and the second shaving unit is preferably constructed as a long hair cutting unit; alternatively, the first and second shaving units could be constructed to be the same. The blade may be mounted on the long hair cutting unit.
In another embodiment, there is further provided a third drivable shaving unit coupled to the motor and constructed as a short hair cutter to perform a fourth shaving action, the second shaving unit being disposed between the first and third shaving units.
In this further embodiment, a second guarded razor-sharp blade may be positioned for engagement with the user's skin whereby the second blade can perform a fifth shaving action during use of the drivable shaving units to perform their respective shaving actions.
In a further modification, the blades are mounted on respective opposite sides of the long hair cutter unit. In the illustrated embodiments, the first and second razor-sharp blades face in opposite directions so that naturally the second and fifth shaving actions will not occur simultaneously.
For improved comfort and safety, the or each blade may be mounted on a guard member providing a plurality of fingers extending forwardly of the blade edge. For extra security, a guard wire may be mounted along the distal ends of the fingers.
Preferably the or each inner cutter is mounted for linear reciprocation.
According to a further embodiment of the invention, there is provided shaving apparatus comprising: a shaver unit having a drivable skin-engaging cutter for performing a first shaving action on a user's skin; a motor adapted to drive the cutter to perform the first shaving action; and a guarded razor blade having a sharpened cutting edge positioned for hair-cutting engagement with the user's skin, whereby the blade performs a second shaving action during use of the shaving unit to perform the first shaving action, and the drivable skin-engaging cutter being mounted about an axis to be driven for pivotal motion, and the guard surface being disposed between the drivable skin-engaging cutter and the razor blade sharpened edge.
The blade is preferably floatably mounted and may expediently be mounted on the cutting unit.
In one embodiment, a second shaving unit is coupled to the motor and has a drivable skin-engaging cutter for performing a third shaving action on the user's skin, the blade being mounted between the first and second shaving units. In a further variation, a third drivable shaving unit is coupled to the motor and disposed between the first and third shaving units to perform a fourth shaving action during use of the apparatus.
In a further variation, a second guarded razor-sharp blade is positioned to perform a fifth shaving action similar to the second shaving action during use of the shaving unit.
Preferably, the blades are mounted on respective opposite sides of the third shaving unit.
For improved comfort and safety, the or each blade may be mounted on a guard member providing a plurality of fingers extending forwardly of the blade edge. For further security, a guard wire may be mounted along the distal ends of the fingers.
According to another aspect of the invention, there is provided a method of shaving comprising the steps of engaging the skin with the cutter of a drivable shaving unit; driving the shaving unit to perform a first, hair-shearing shaving action; and performing a second, hair-cutting shaving action with a razor blade having a sharpened cutting edge during the hair-shearing first shaving action, where the drivable shaving unit is devoid of an outwardly protruding sharpened razor edge and is comprised of two cooperating cutting elements which cooperate to cut hair.
The drivable shaving unit may comprise an outer cutter for contact with the user's skin and an inner cutter mounted in hair shearing engagement with the outer cutter in which case the motor will drive the inner cutter to perform the first shaving action.
In another embodiment, the shaving unit will comprise a drivable skin-engaging cutter for performing the first shaving action on the user's skin, in which case the motor will drive the cutter to perform the first shaving action.
According to a further embodiment of the invention, there is provided a blade unit sub-assembly that carries the razor-sharp blade edge or edges and that is mountable into a frame of a powered shaving head. This provides a replacement part so that the razor-sharp edges can be exchanged if they become dulled. In some embodiments the sub-assembly has twin blade supports and twin sharp blade edges that face in opposite directions and can be mounted between dry-type shaving units, and in preferred embodiments is mounted for biased displacement. In another embodiment the sub-assembly carries a spring-biased blade, and is preferably attached to an external surface of the shaving head.
For a better understanding of the invention and to show how the same can be carried into effect, reference will now be made, by way of example, to the accompanying drawings.
a shows region A of
In the various Figures, corresponding components are provided with corresponding reference numerals.
During operation of the shaving apparatus, the user shaves in the conventional manner by drawing the dry shaving unit 3 across the skin surface. During this operation, hairs are also engaged by the razor-sharp edge of the blade 11 so that a dual or hybrid shaving action results, the first action being of the dry shave type and the second action of the wet shave type, being performed together. The blade unit 4 can perform either or both of two functions; firstly it performs a second cut on hairs already cut by the dry shaving unit 3 so that an even closer shave is produced; secondly it also acts to capture and cut any longer hairs which may be missed by the foil-type cutter. The user receives this benefit without having to wet or lather the beard or skin, or to make multiple passes, or to hold the appliance at different orientations, or to selectively engage different ones from among the “dry” and “wet” types of hair-removing units. However, a conditioning step may be included if desired; conditioning can include hydrating, lubricating or any other means of preparing the skin and/or hair to be shaved, and may or may not include the use of water. Lathering helps hydrate the hairs, and may also include agents such as soaps, gels, oils or emollients to reduce friction with the skin.
The dry shaving unit can be of the type disclosed in U.S. Pat. No. 6,098,289 (Wetzel), in particular having an outer apertured shaving foil and a reciprocating undercutter, which is hereby incorporated by reference. The shaving unit could also be constructed as is known from U.S. Pat. No. 5,745,995 (Yamashita et al.) having one or more rotary cutters of the type marketed under the name Hitachi, which is likewise incorporated by reference. As a consequence of the close proximity between the foil-type cutter unit 3 and the blade unit 4, the blade 11 is guarded, at least to some extent, by a portion of the surface of the foil 5 which thus assumes the function of what is commonly referred to—in the parlance of wet shaving—as the guard surface. An imaginary plane P can be constructed tangential to the blade 11 and guard surface of foil 5 which generally lies along the skin surface being shaved by the both units. The dimensions and geometry are chosen so that this arrangement is sufficiently safe.
However, in order to provide further safety and comfort, various techniques may be adopted.
In the embodiment of
The embodiment of
In this embodiment, two separate blade units 4a and 4b are provided on opposite sides of the long hair cutting unit 3c. As illustrated, each blade unit is provided with safety skis and a guard wire and thus corresponds substantially to the construction shown in FIGS. 4,12 and 13.
In the embodiment of
In either of the embodiments shown in
In any of the above-described embodiments, a lubricant or other conditioner dispenser or lubricant strip may be provided to reduce friction between the razor-sharp blade or blades and the user's skin, and consequently improve shaving comfort. A suitable strip can be mounted rearward of the sharp blade and includes polyethylene oxide (“polyox”).
As for the blade or blades, in the embodiments shown in
The sharpness of such blades is conventionally defined by the tip radius in a manner known to those skilled in the art. Measured in a conventional way, the tip radius, may typically be less than 0.5 microns, which would be a relatively blunt blade, and may lie in the range 0.5 microns to 50 nm (nanometers)(i.e., 0.05 microns), which would be relatively sharp. In the embodiments of the present invention, the blade sharpness may lie anywhere between these extremes, depending on the cutting effect desired, as is well-known to those skilled in the art. It can even be advantageous to have a tip radius smaller than 0.05 microns, in some circumstances.
It has been observed that conventional Sensor, Sensor Excel or Mach3 blades give a short lifetime before becoming dulled when used dry in the embodiments disclosed herein. Thus it is preferred to use a blade that has a similar geometry to such blades but is thicker in the tip region than such standard “wet” blades, for example having the geometry shown in TABLE 1 below.
A particularly preferred blade is a Cr/Pt coated stainless steel blade with the tip profile defined by TABLE 1 below:
In any of the above-described embodiments, the sub-assembly comprising the frame or housing which supports both the razor-sharp blade or blades (and where applicable its or their blade mounting supports) together with at least an outer cutter of one of the dry-type shaving units (such as an outer foil, as shown in
The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.”
Every document cited herein, including any cross referenced or related patent or application, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 02022316.0 | Oct 2002 | EP | regional |
This is a continuation of U.S. application Ser. No. 11/784,897, filed Apr. 7, 2007, which is a divisional of U.S. application Ser. No. 11/11,305, filed Apr. 7, 2005, now abandoned, which is a continuation of PCT Application No. PCT/US2003/031676, filed on Oct. 6, 2003, which claims priority to Europe Patent Application No. 02022316.0, filed on Oct. 8, 2002, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11784897 | Apr 2007 | US |
| Child | 12150279 | US |
