Razor Blade Assembly

Abstract

A razor blade assembly having one or more groups of multiple cutting edge, tandem acting shaving elements assembled on a generally rectangular supporting structure or frame. Each group of cutting elements comprises two or more blades, the cutting edges of which are located in spaced, parallel, tandem acting relationship. One or more of the cutting edges of each group is essentially chisel shaped. The dimensions of the frame and the disposition and orientation of the cutting edges are such as to cooperatively provide, in a conventional razor, favorable geometry for tandem blade shaving operations.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention is applicable in the field of replaceable, so-called, double edge and single edge razor blades. The invention resides particularly in the provision of a blade assembly of one or more groups of tandem acting, spaced, parallel cutting edges located along one side, in the case of single edge blades, or, in the case of double edge blades, oppositely facing sides of a generally rectangular blade structure.

2. Description of the Prior Art

It has long been desirable to provide a shaving instrument or system which affords a very close shave as well as a safe shave. There has recently been developed a multiple, tandem acting, cutting edge shaving system, in which certain edge characteristics and geometrical relationships are observed, that provides the desired closeness with safety. The shaving system includes two cutting edges disposed parallel to one another, and in spaced relation, to provide leading and following cutting edges, so that both cutting edges are successively active with respect to the hair elements being cut during a single shaving stroke.

The shaving system employs a cartridge wherein two cutting edges, each formed on a separate blade, are supported in spaced, tandem, parallel, relationship to one another by structure which extends along substantially the entire lengths of the blades. As part of the same cartridge, a guard structure is disposed proximate to the leading cutting edge and cooperates with the other elements to define, in part, the desirable geometrical relationships. Significant components of that geometrical relationship include "blade tangent angle," "exposure," and "span."

"Blade tangent angle" is defined as the angle between the bisector of the included angle of a cutting edge and a line from the cutting edge to the point of tangency of the skin engaging surface immediately forward of that cutting edge. For example, in a two bladed tandem acting system, the guard is the "skin engaging surface immediately forward" of the first acting cutting edge and the first cutting edge is the "skin engaging surface immediately forward" of the second cutting edge.

"Exposure" is defined as the distance from a cutting edge to a reference plane or a line connecting the points of tangency of the skin engaging surfaces immediately in front of and behind the cutting edge, the distance being measured perpendicularly to the reference plane or line. The exposure is considered positive when the cutting edge is located on the outer or skin side of the reference plane and is considered negative when the cutting edge is further from the skin than that plane.

"Span" is defined as the distance between a cutting edge and the point of tangency of the skin engaging surface forward of that cutting edge.

In the prior art system referred to, particularly as disclosed in U.S. Pat. application Ser. No. 176,547, filed Aug. 31, 1971, now U.S. Pat. No. 3,786,563, in the names of Francis W. Dorion, Jr., et al., the blades each have tangent angles in the range of 20.degree.-32.degree., an exposure in the range of -0.002 to +0.004 inch and a span in the approximate range of 0.03-0.08 inch. Both blades are planar and are disposed parallel to one another. In such multiple blade cartridges, cooperating guard and cap structures are of molded plastic material and the cap, base and spacer members and blades are secured together in fixed geometrical relationship to define a blade unit which is easily attached to and released from a handle.

The desirability of providing a replaceable tandem acting multiple cutting edge "razor blade," as distinguished from a cartridge as taught by Dorion, Jr., et al., for use with conventional double edge and injector type razors has long been recognized. Providing a commercially acceptable blade, however, has until now presented insurmountable problems. This is due primarily to the fact that since the guard and cap structures of conventional razors, together with the blades between them, define the geometry of a shaving system and since the guard and cap cannot be changed, except for certain spacing adjustments, the blade geometry is the only variable of the system. This is distinguished from the tandem blade cartridge in which the cap and guard elements were designed de novo. Given the fixed relationships between cap and guard portions of existing double edge razors, the disposition of a tandem multiple cutting edge blade assembly between those elements has proven to be incompatible within optimum geometrical relationships so long as presently available cutting edges are employed.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a tandem acting, multiple cutting edge blade assembly for use with conventional razors.

A further object of the invention is to provide such a blade assembly in which the cutting edges cooperate with the razor guard and cap portions to define critical geometric relationships within desirable ranges.

With the above and other objects in view, as will hereinafter appear, a feature of the present invention is the provision of a tandem acting, multiple cutting edge razor blade assembly adapted to be replaceably clamped between the cap and support means of a conventional razor. Such razors generally have a guard portion integral with the support means or separate therefrom but proximate thereto. The blade assembly comprises a frame, first blade means permanently joined to said frame and adapted to be engaged by said razor support means. Second blade means are also permanently joined to said frame and adapted to be engaged by said cap member. The cutting edges are substantially parallel, at least one being substantially of a chisel configuration. The cutting edges and frame are so configured and arranged relative to the razor's cap and guard as to define desirable geometric shaving relationships. In a double-edge embodiment the frame is contoured to be readily held in any conventional double edge razor.

The above and other features of the invention, including various novel details of construction and combinations of parts, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular razor blade assembly embodying the invention is shown by way of illustration only and not as a limitation of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference is made to the accompanying drawings in which is shown an illustrative embodiment of the invention from which its novel features and advantages will be apparent.

FIG. 1 is a diagrammatic representation of certain prior art, illustrating the geometric relationships above described;

FIG. 2 is a plan view of one form of frame member for use in an illustrative embodiment of the invention;

FIG. 3 is an end elevational view of the frame member shown in FIG. 2;

FIG. 4 is an enlarged end elevational view of a portion of the frame member shown in FIG. 3;

FIG. 5 is a plan view of a blade element for assembly with the frame member shown in FIGS. 2-4;

FIG. 6 is an enlarged end elevational view of the blade element shown in FIG. 5;

FIG. 7 is a further enlarged end elevational view of the cutting edge portion of the blade shown in FIGS. 5 and 6;

FIG. 8 is an enlarged schematic elevational view of an illustrative chisel edge blade of the present invention compared with a prior art blade edge shown in phantom;

FIG. 9 is a plan view similar to FIG. 2, of a blade assembly including the frame and the blades;

FIG. 10 is an enlarged end elevational view of the blade assembly of FIG. 9;

FIG. 11 is an elevational sectional view of the illustrative blade assembly of FIGS. 9 and 10, shown disposed in a conventional, non-adjustable double edge razor;

FIG. 12 is an enlarged elevational sectional view of a portion of the blade assembly and razor shown in FIG. 11;

FIG. 13 is an elevational sectional view similar to FIG. 11, but with the illustrative blade assembly of FIGS. 9 and 10 shown disposed in a conventional adjustable double edge razor;

FIG. 14 is an enlarged section view similar to FIG. 2, of a portion of the blade assembly and adjustable razor of FIG. 13; and

FIGS. 15 and 16 are similar to FIG. 14, but show the adjustable razor at alternative selective settings.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In FIG. 1, the above mentioned geometrical relationships of blade tangent angle, span and exposure are defined with reference to two tandem acting blades in combination with a cap and guard of a conventional razor. The blade tangent angle for the leading blade, as herein defined, is the angle L between the bisector a of the included angle of the cutting edge E' and a line b from the cutting edge E' to the point of tangency PT.sup.1 of the skin engaging surface immediately forward of that cutting edge, in this instance the guard. In like manner, the blade tangent angle for the trailing blade is the angle M between the bisector c of the included angle of the cutting edge E.sup.2 and a line d from the cutting edge E.sup.2 to the point of tangency PT.sup.2 of the skin engaging surface immediately forward of that cutting edge. In this instance the point of tangency PT.sup.2 is the leading blade cutting edge E'.

The exposure of the leading blade is the distance N from the cutting edge E' to the reference plane e connecting points of tangency of the skin engaging surfaces immediately in front of (guard) and behind (trailing blade) the cutting edge E', the distance being measured perpendicularly to the reference plane e. In like manner, the exposure of the trailing blade is the distance P.

The span for the leading blade is the distance R between the cutting edge E' and the point of tangency PT.sup.1 of the skin engaging surface (guard) forward of that cutting edge. In like manner the span for the trailing blade is the distance S.

A conventional double edge razor (without a blade), includes on both sides, a guard member and a cap member, as diagrammatically illustrated in FIG. 1. The spacing of these members is predetermined, though in some instances adjustable, and successful tandem blade arrangements must be such as to cooperatively define acceptable geometrical relationships with the pre-existing guard and cap members. The usual razor blade technology has not proven up to the task.

For example, in FIG. 1 there is illustrated a blade assembly of two blades and a frame member. If the blades are arranged so that the exposures N, P, are acceptable, and if acceptable first and second blade spans R, S, are utilized, and resultant blade tangent angles L, M, of the leading and trailing blades are of a magnitude such as to provide a close but less comfortable shave than blade tangent angles of a lesser magnitude. Accordingly, it is preferable to decrease the blade tangent angles L, M, by several degrees. The position of the guard is preset and cannot be moved (except in adjustable razors where some movement of the guard is permitted) to reduce the blade tangent angle of the leading blade. A lesser exposure would reduce the blade tangent angle, but a pronounced negative exposure generally is not preferred. A thinner frame member would reduce the blade tangent angle of the second blade only. Further, as will be discussed herein below, the frame thickness preferably should not be diminished to a dimension shorter than the diameter of a hair element. Thus, the problem that has blocked the development of an acceptable arrangement has been the inability of such a blade assembly to fit into the given conventional razor environment and in cooperation with that environment define suitable geometric relationships. More specifically, when the various parameters are placed within acceptable limits, the blade tangent angles of the two blades are too high to provide a comfortable and safe shave. The problem is further aggravated in adjustable razors, of either the double edge or injector type, where the guard and blade edge may be moved relative to each other to increase the blade tangent angle of the leading blade, as well as the leading blade span, to even higher values. The problem then, is to reduce the blade tangent angle to an acceptable value while not greatly disturbing the other critical parameters.

Referring again to the drawings, and particularly FIGS. 2-4, it will be seen that the present invention includes a frame or spacer member 2, preferably, but not necessarily, of metal. A preferred embodiment of the frame member 2 has an elongated central base or plateau portion 4 flanked on either side by an integral ramp or depending skirt portion 6. The ramp portions 6 are inclined relative to the base portion 4 by about 13.degree.-16.degree., and preferably at an angle A of approximately 15.degree.. As will be further described below, the frame preferably is preformed or contoured to its ultimate desired configuration, obviating any need for flexing or bending of the frame when placed in a razor. Thus, the geometry of the frame member is predetermined and not dependent upon flexing or bending.

The preferred embodiment of frame member shown in FIGS. 2-4 has an overall axial length Fl of 1.68 inch and an overall width Fw of 0.867 inch; has a thickness Ft of 0.01 inch and is preferably of stainless steel or other suitable metal. The length Fl and width Fw are determined by the necessity that the blade assembly be accepted by a conventional double edge razor. The thickness Ft of the frame member 2 should be no more than 0.02 inch and greater than 0.006 inch, the latter being the diameter of larger hair elements. A thickness of less than 0.006 inch might present clogging problems during use. A thickness of more than 0.02 inch cannot be reconciled with other desired geometrical relationships, particularly the blade tangent angle of the second cutting edge E.sup.2. Accordingly a thickness of 0.006-0.02 is preferred and 0.01 inch, or thereabouts, appears to be most suitable. As will be discussed in more detail below, the frame member could be made somewhat wider but bendable in a razor to assume a width of 0.867 inch, or thereabouts.

Referring to FIGS. 5 and 6, there will be seen an illustrative blade element 10 that becomes secured to the frame member 2. The blade element 10 includes an elongated planar portion 12 having a sharpened cutting edge portion 14 extending lengthwise along one edge thereof. In a preferred embodiment, the blade element 10 is 1.42 inch in length B1, 0.189 inch in width Bw, 0.004 inch in thickness Bt and preferably of stainless steel or other suitable metal. As shown in FIG. 6, the cutting edge portion 14 of the blade element 10 is substantially a chisel-edge, having a first side 16 which is substantially a continuation of a first flat bottom side 22 of the planar portion 12 of the blade element, and a second side 18 which is inclined substantially from a second side 24 of the planar portion 12 to the first side 16 of the cutting edge portion.

FIG. 7 shows the chisel shaped cutting edge portion 14 of the blade element, enlarged several times. In the embodiment shown, the second side 18 of the cutting edge portion 14 includes a first portion, the surface 18a of which is disposed at an angle B of about 12.degree. from a plane representing a continuation of the second side 24 of the planar portion 12 of the blade element. A second portion includes a surface 18b disposed at an angle C of about 14.degree. to the above mentioned reference plane. A third surface portion 18c is still further inclined. It will be seen that the first side 16 of the cutting edge portion has a slight taper 16a near its outer extremity. This results from a burr removing lapping operation. The taper surface 16a is inclined at an angle D of about 6.degree. to an imaginary extension of the first side 16 of the cutting edge portion 14, resulting in a fine edge 26 defined by the surfaces 18c, 16a which include an angle E of about 25.degree..

Although under certain circumstances a conventional symmetrically shaped cutting edge may be utilized, the advantages to be obtained by the chisel configuration are critical to the invention, as will be explained in detail below, and at least one cutting edge of a tandem arrangement must be of a substantially chisel or non-symmetrical geometry.

The significance of the chisel edge blade readily may be appreciated upon reference to FIG. 8, which shows an enlarged view of the leading blade 10a cutting edge and, for comparison purposes, shows in phanton a prior art blade cutting edge 60. It will be seen that in a given environment, the chisel edge blade tangent angle L is substantially less than the blade tangent angle T of a corresponding symmetrical blade. Thus, whereas the use of a symmetrical blade might result in blade tangent angle too high to be acceptable, the use instead of a chisel edge blade reduces the blade tangent angle to a value well within a proven acceptable range. In like manner, use of the chisel shaped edge on the trailing blade element permits a blade tangent angle for the trailing blade substantially less than would be the case with a conventional symmetrically shaped blade edge. In FIG. 8 an angle W is defined between the bisectors of the cutting edge angles and illustrates the substantial impact substitution of a chisel shaped blade for a symmetrically shaped blade has upon the blade tangent angle in a given razor environment. Assuming the chisel edge structure is substantially as shown and described above with reference to FIG. 7, the angle W will be equal to about 6.degree.-7.degree..

Referring to FIGS. 9 and 10, it will be seen that a razor blade assembly 30 comprises the frame member 2 having attached thereto a plurality of the blade elements 10. The blade elements 10 may be spot welded to the frame member 2. The corners of the frame member 2 are provided with integral lugs 32 (FIG. 4) which facilitate positioning of the trailing blades (upper blades as viewed in FIG. 10) on the frame member prior to welding. The trailing blades may be placed on the frame member 2 and moved outwardly until their cutting edges engage the lugs 32. They are then in position for welding or other attachment procedure. The base portion 4 of the frame member 2 is provided with a suitable opening 34 for receiving the spider mechanism of a conventional double edge razor, as will be described below. The preferred embodiment of blade assembly is substantially of the same length and width dimensions as the frame member, 1.68 inch and 0.867 inch, respectively.

In FIG. 11, there is shown a blade assembly 30, as described above, disposed in a conventional double edge razor 40, of the type shown and described in U.S. Pat. No. 2,900,721, issued Aug. 25, 1959 upon application of Warren I. Nissen, wherein the construction and operation of the razor is explained in detail. Suffice at this point to say that the razor 40 includes platform portions 42 (including guard portions 42') and cap portions 44. Extending upwardly from a handle portion 46 is a reciprocable spider portion 48. As is described in the above referred to patent, the cap portions 44 open outwardly from the spider portion 48, the cap portions being pivotally mounted upon bridge portions 50 (one bridge portion 50 shown in FIG. 11) which in turn are connected to the spider portion 48. In the open condition, the razor may receive a blade assembly 30, the spider 48 passing through the opening 34 in the blade assembly. The blade assembly 30 rests upon the platform portion 42, the leading blade elements 10a, or lower blade elements as viewed in FIG. 11, abutting upper surfaces 42" of the platform portion, which surfaces 42" are disposed at an angle F of approximately 15.degree. to a plane f--f tangent to the uppermost points of the platform portions. Upon closure of the cap portions 44, to the positions shown in FIG. 11, the cap portions engage the uppermost, or trailing blade elements 10b. The contour of the blade assembly is such that no flexing or bending of the blade assembly ordinarily occurs.

The geometric relationships between the blade assembly 30 and the guard portion 42' and cap portion 44 are shown in FIG. 12. The leading blade element 10a has a span R of about 0.062 inch, a blade tangent angle L of about 26.degree. and an exposure N of about 0.001 inch. The trailing blade element 10b has a span S of about 0.035 inch, a blade tangent angle M of about 23.5.degree. and an exposure P of about 0.001 inch. Thus, the blade assembly 30 cooperates with the given razor structure to define geometrical relationships within ranges affording desirable shaving characteristics. The thickness of the spacer member may be less than the 0.01 inch shown for illustrative purposes with a consequent lessening of the span between the two blades. In various combinations of geometrical relationships, the span R may be about 0.02 inch -0.08 inch and the span S about 0.02-0.055 inch and still provide acceptable performance in shaving operations.

In FIG. 13 there is shown the blade assembly 30 disposed between the platform portions 42 and cap portions 44 of a conventional double edge adjustable razor 70 of the general type shown and described in U.S. Pat. No. 2,848,806, issued Aug. 26, 1958 upon application of Meyer J. Shnitzler et al. The structure and operation of this type of razor is fully described in the above referred to patent. For the purposes of explaining the present invention, it is necessary to note only that by rotation of a cylindrical member 72 an operator causes movement of the platform portions 42, blade assembly 30, and cap portions 44, which in this type razor is movable as a unit toward or away from the guard portion 74. Such movement causes pronounced changes in the leading blade span and blade tangent angle. For example, in FIG. 14 typical values of critical parameters are shown for the blade assembly 30 in an adjustable double edge razor at setting "1," or the setting at which the guard 74 is closest to the blade assembly. It will be noted that the blade tangent angle for the leading blade is about 15.5.degree., for the trailing blade about 23.5.degree., and the leading blade span is about 0.0235 inch. FIG. 15 is illustrative of the adjustable razor of FIG. 13 having been set at a setting of "4," or a moderate setting, and FIG. 16 is illustrative of a "9" setting, or that setting at which the guard is furthest removed from the blade assembly. As will be observed in FIGS. 14-16, an increase in setting value increases the respective blade tangent angles and first blade spans, but that in each instance the various geometrical relationships remain generally within or close to acceptable ranges. The adjustability of the razor does not affect the blade tangent angle of the trailing blade which remains at about 23.5.degree.. The upper edges 43 of the platform portions 42 receive the leading blades 10a and are conventionally disposed at an angle G of approximately 15.degree. to a plane g--g tangent to uppermost portions of the platform portions 42 (FIG. 13).

It is to be understood that the present invention is by no means limited to the particular construction herein disclosed and/or shown in the drawings, but also comprises any modifications or equivalents within the scope of the disclosure. For example, various modifications of the structure of the chisel edge blades may be used to obtain desired bisectors of the cutting edge included angle. As used herein, the term "chisel shaped" or "chisel edge" refers to cutting edges in which a bisector of a cutting edge included angle, or the angle defined by the two major surfaces of the cutting edge (surfaces 18c and 16a in FIG. 7, for example) is disposed at an angle to the plane of the blade. While the chisel edge blade shown results in a cutting edge included angle bisector forming an angle of about 7.degree. with the plane of the blade, other configurations of blade edges may be utilized to obtain different angles, as desired.

A further modification within the scope of the disclosure relates to the overall dimensions of the frame member and the blade assembly. While it is preferred that the ramp portions 6 be disposed at approximately 15.degree. to the base portion 4 and that the overall width of the assembly be 0.867 inch, it is apparent that an assembly could be arranged having a greater width but bendable in a razor in such a manner as to arrive at a width of, or close to 0.867 inch. In describing and claiming the width of the assembly, it is intended that such variations be within the purview of such dimensional qualifications or limitations. Thus, in referring to a blade assembly width of 0.867 inch, while it is preferred that the assembly be non-flexing and have such width permanently, it is intended also to encompass an alternative arrangement in which the assembly is manufactured having a larger width dimension but is bendable to 0.867, or thereabouts, for use in a razor.

It is further to be understood that while double edge razors have been shown for illustrative purposes, the invention herein is equally applicable to single edge razors, including those of the injector type. Of course, a tandem blade assembly for use in an injector razor will necessarily have blades and frame of configuration and dimensions commensurate with injector razors.

Claims

Having thus described our invention, what we claim as new and desire to secure by Letters Patent of the United States is:

1. A razor blade assembly comprising:

a. a frame in the form of a spacer member, said spacer member having an elongated central base portion and a ramp portion on each side thereof, said ramp portions having a pair of surfaces thereon and being permanently inclined at an angle of 13.degree.-16.degree. relative to said base portion,

b. a planar first blade disposed on one surface of each of said ramp portions and having a first cutting edge extending beyond an edge of said frame,

c. a planar second blade disposed on the other surface of each of said ramp portions and having a second cutting edge extending a second distance beyond said edge of said frame,

d. said surfaces having a maximum separation of 0.006-0.02 inch,

e. at least one said blades having a cutting edge such that a bisector of an angle defined by surfaces of the cutting edge is disposed at an angle to the plane of such blade.

2. The razor blade assembly as defined by claim 1 in which each of said ramp portions is inclined at an angle of about 15.degree. to the plane of said base portion.

3. The razor blade assembly as defined by claim 1 in which said spacer member is of metal.

4. The razor blade assembly as defined by claim 3 in which said blade elements are welded to said spacer member.

5. The razor blade assembly as defined by claim 4 in which said blade elements and said spacer are of stainless steel.

6. The razor blade assembly as defined by claim 1 in which the thickness of said spacer member between said blade portions is about 0.01 inch.

7. The razor blade assembly as defined by claim 1 in which said spacer member is of metal and is about 1.68 inch in length, about 0.867 inch in width, and is about 0.010 inch in thickness, said ramp portions being inclined to said base portion at an angle of about 15.degree..

8. The razor blade assembly as defined by claim 1 in which said first distance exceeds said second distance.

9. The razor blade assembly as defined by claim 1 in which each of said blade elements is of metal, is about 1.42 inch in length, about 0.189 inch in width, and about 0.004 inch in thickness.

10. Razor blade assembly comprising a relatively thin spacer member having an elongated central planar base portion flanked on each longitudinal side edge by an integral depending skirt portion, said skirt portions being permanently inclined at a predetermined substantially constant angle relative to said central base portion, first and second separate, distinct, planar blades disposed on the first of said integral depending skirt portions and separated thereby, said first and second blades having respectively first and second cutting edges facing outwardly from said assembly, and third and fourth separate, distinct, planar blades disposed on the second of said integral depending skirt portions and separated thereby, said third and fourth blades having respectively third and fourth cutting edges facing outwardly from said assembly and in a direction generally opposite to the direction in which said first and second edges face.

11. The invention according to claim 10 in which said spacer member is metal.

12. The invention according to claim 10 in which said depending skirt portions are permanently inclined relative to the base portion by about 13.degree.-16.degree..

13. The invention according to claim 10 in which said second blade cutting edge is recessed relative to said first blade cutting edge and in cutting operation trails said first blade cutting edge and said fourth blade cutting edge is recessed relative to said third blade cutting edge and in cutting operation trails said third blade cutting edge.

14. The invention according to claim 13 in which the span of said second blade and said fourth blade is about 0.02-0.055 inch.

15. The invention according to claim 13 in which the blade tangent angle for said second and fourth blade is less than 30.degree..

16. The invention according to claim 10 in which said spacer member and said blade are fixed together with said blades contiguous to said spacer member.

17. The invention according to claim 15 in which said blade tangent angle is in the range of 22.degree.-26.degree..

18. The invention according to claim 15 in which said blade tangent angle is about 23.5.degree..

19. A razor blade assembly as defined in claim 10 wherein said spacer is substantially rigid.

20. Razor blade assembly comprising a frame portion, two groups of blades, each group comprising a planar first blade having a first cutting edge extending beyond an edge of said frame portion, a planar second blade having a second cutting edge extending in the same direction as said first blade, said frame portion having a thickness of about 0.006-0.02 inch, said first and second cutting edges having a span therebetween of 0.02-0.055 inch, and said second cutting edge having a blade tangent angle of less than 30.degree., said first and second blades being assembled on said frame portion such that said first and second cutting edges are located in spaced, parallel tandem acting relationship with said frame portion disposed therebetween, one of said cutting edges being such that a bisector of an angle defined by surfaces of the cutting edge is disposed at an angle to the plane of such blade.

21. The razor blade assembly as defined by claim 20 in which said second-mentioned angle is about 7.degree..