BACKGROUND OF THE INVENTION
[0001] The present invention relates to wet shaving systems of the blade type and more particularly
to a shaving system having a movable blade positioned within a blade cartridge or
the like.
[0002] During the shaving process, shavers have long sought a wet shaving system which provides
a smooth and comfortable shave without having annoying cuts and abrasions. In order
to accomplish this objective, it has been known in the art to utilize multiple blade
shaving systems which provide independent movement of the blades relative to the blade
cartridge. (
See, U.S. Patent No. 4,168,571).
[0003] Typically, such shaving systems include two blades disposed parallel to one another
so as to provide first and second cutting edges which successively engage the shaving
surface in a predetermined spaced relationship. The use of multiple blades operates
to provide a close, more efficient shave. Further, the independent movable blades
permit the shaving geometry of each blade to adapt to the various conditions encountered
during the shaving process in an effort to reduce nicks and cuts.
[0004] The terms utilized to define the various geometric relationships between the blades,
the various elements of the blade cartridge and the shaving surface include "shaving
plane", "blade exposure" and "shaving angle". The term "shaving plane" means the plane
tangent to skin engaging surfaces, for example a guard and a cap, which are disposed
on both sides of the blade so as to engage the shaving surface before and after engagement
by the blade. The term "blade exposure" means the distance by which the blade edge
projects forwardly of the shaving plane. Finally, the term "shaving angle" means the
acute angle between the plane tangent to the cutting edge of the blade and the shaving
plane.
[0005] Various approaches have been used to enable the shaving blade to move relative to
the blade cartridge or razor body in response to shaving forces encountered during
the shaving process in an effort to present the correct blade exposure and shaving
angle.
[0006] One approach disclosed in prior art patents illustrates a blade cartridge comprising
two blades separated by a spacer with the blades and the spacer attached to a cap
to form a unitary assembly. The blade assembly is movable between various blade exposures
and shaving angles within various degrees of control and direction in response to
forces encountered during shaving. For example,
Ciaffone et al., U.S. Patent No. 4,461,079, discloses a razor cartridge comprising a body portion
10 which includes a guard bar 12 (Figs. 1-5). The guard bar 12 defines a leading skin-engaging
surface fixed to the body portion. A rear beam 17 spans end walls 14 and 16 of the
body portion 10 and a medial support member 13 to join the front of the cartridge
12 to the end thereof. A plurality of generally flat coplanar segments 18,19,21,22,
each having an opening 23, are hinged to the rear beam 17 by mating webs 24,26,27,28
(col. 2, lines 50-52). Collectively, the segments 18,19,21,22 define a blade seat
which is operable to pivot about the beam 17, thereby changing the attitude of blade
edge relative to guard bar 12 (col. 2, lines 53-57). A cap 33 is apparently placed
above an assembly of two skin-engaging blades 34,36, straddling a spacer 37 (Fig.
3). The two blades and the spacer are secured to one coplanar segment 21 of the blade
support or blade seat by a conventional rivet 38 to form a rigid unit. A hinge 27
connects the coplanar segment 21 to the rear-beam 17 (col. 3, lines 1-8). As compared
to the position of the blade edges relative to the guard bar at the normal or free
position set in accordance with a predetermined blade geometry (Fig. 3), a change
in blade geometry occurs during the course of shaving when a shaving force F causes
the blade package to rotate or pivot about rear-beam 17 in the direction of arrow
R where the blade edges are rendered less "aggressive" (Fig. 4, col. 3, lines 13-23).
Upon relaxation of shaving forces, the elastic memory of hinges 24,26,27,28 forces
the blade seat, and therefore the blade edges, to return to their normal position
(Fig. 3., col. 3, lines 24-26).
[0007] In an alternative embodiment,
Ciaffone et al. shows the blade seat is hinged to a front beam 175 by webs 240,260,270,280 (Figs.
6-10, col. 3, lines 46-48). Upon exertion of a shaving force F' (Fig. 9) onto the
cap 330, the coplanar segments 180,190,210 and 220, move in the direction of the arrow
R (Fig. 9) to provide a more aggressive edge exposure (col. 4, lines 1-9). As in the
embodiment of Figs. 1-5, the elastic memory of the hinges 240,260,270,280 forces the
blade edges to return to the free position when shaving forces are released (col.
4, lines 11-13).
[0008] Oldroyd et al., U.S. Patent No. 4,063,354, discloses a shaving unit wherein a blade unit comprises
two blades separated by a spacer 5 (Figs. 13-16). A resiliently flexible metallic
or plastic guard 3 is secured to the blade unit by spot welding or other means (col.
3, lines 26-28). The blade unit, which is illustrated in its normal forward position
of maximum blade exposure in Fig. 13, can bow rearwardly under pressure applied during
shaving to carry the blade unit along a plane to the rear, relative to the platform
1 and cap 4. This reduces blade exposure but increases the shaving angle, as indicated
by dotted lines 3' in Figs. 13 and 15 (col. 3, lines 26-37).
[0009] Althauset et al., U.S. Patent No. 5,074,042, discloses a shaver head comprising two staggered blades
7 embedded in a blade block 6 (Fig. 3). A cover cap portion 9 covers the top side
of the blade block 6 (col. 3, lines 12-15). A spring 14 is placed between the blade
block 6 and a body 2. The blade block 6, together with the two staggered blades 7,
can swivel about an axis A (col. 3, lines 17-43). During shaving, pressure is applied
to the razor blade unit, thereby causing the blade block 6 to swivel and alter shaving
geometry of the blades (col. 3, lines 46-60).
[0010] Jacobson U.S. Patent Nos. 4,442,598, 4,378,634 and 4,270,268 disclose a razor blade assembly
including a body member 2 having blade means 36,36' being independently movable in
response to spring finger biasing means 18,18' integral with the body member. In the
Jacobson patents, the spring fingers 18,18' move the blade means 36,36' along planes defined
by slots 16 in end portions 4,6 of the body member 2.
[0011] In all of the aforementioned patents, the blade members either engage movable spring
fingers formed integral with the blade cartridge, or are mounted permanently to a
platform which is movably connected to the blade cartridge. These methods of providing
a movable blade necessitate an elaborate and expensive molding procedure to create
a blade cartridge having either integral spring fingers or a movable blade platform.
While it has been noted that blades movable relative to the shaving surface during
the shaving process are advantageous, it is desirable to eliminate the need for the
elaborate molding process required by the movable blade assemblies of the prior art.
[0012] Additionally, prior art shaving systems have attempted to reduce the uncomfortableness
in shaving caused by the frictional drag of the razor across the skin in conjunction
with the force necessary to sever the hair protein structure or whisker. One known
method of reducing the frictional drag is shown in U.S. Patent 4,170,821 issued to
Booth. As described in
Booth, a lubricating agent commonly referred to as a "lube strip" is cemented to the cap
portion of the blade cartridge to reduce the frictional forces between the razor and
the skin.
[0013] However, such systems suffer from various drawbacks. First, a significant portion
of the blade cartridge not containing any friction reducing agent remains in contact
with the skin. For example, the ends of the blade cartridge extending perpendicular
to the cutting edge remain in contact with the skin. As such, the frictional drag
encountered during shaving remains significant. Second, the requirement of producing
and cementing an additional "lube strip" to the blade cartridge increases manufacturing
costs.
[0014] US 4,574, 476 on which the preamble of claim 1 is based, and which is regarded as
the closest prior art discloses a razor blade assembly having two blades spaced apart
by spacer segments.
SUMMARY OF THE INVENTION
[0015] The present invention provides a flexible blade cartridge as set out in claim 1.
According to an embodiment, a plurality of blade members are permanently fixed relative
to the blade cartridge. Unlike the movable blade assemblies of the prior art, there
are no movable support members in the blade cartridge. Each blade is mounted such
that a substantial portion of the blade is free from contact with support members.
The free end of each blade functions as a single cantilever forming a "flexing zone"
about which the cutting edge of the blade bends in response to an applied force. Each
blade is flexible about the longitudinal axis of the blade. Thus, the present invention
can provide for individually movable blades without requiring an elaborate molding
procedure to create movable spring fingers or movable blade platforms.
[0016] In addition, the present invention can optimizes the geometric relationship between
the blade means and the other elements of the blade cartridge so as to maximize the
comfort and closeness of the shave without the associated nicks and cuts normally
associated with twin blade shaving cartridges designed to shave close.
[0017] Furthermore, the present invention may provide a novel means of applying a friction
reduction agent to a substantial portion of the blade cartridge so as to improve shaving
comfort, while minimizing manufacturing costs associated with incorporating the friction
reducing agent in the blade cartridge.
[0018] Accordingly, an embodiment of the present invention relates to a blade cartridge
comprising a platform member having a blade seat and a guard member. The guard member
is located forward of and parallel to the blade seat so as to form a longitudinal
slot between the blade seat and the guard member. The blade cartridge also comprises
a primary blade which is disposed on the blade seat such that the cutting edge of
the blade is located rearwardly of the guard member. A substantial portion of the
primary blade extends into the slot formed between the guard member and the blade
seat such that the blade is flexible about the longitudinal axis of the blade into
the slot. Preferably, the cutting edge of the primary blade is parallel to the guard
member.
[0019] The blade cartridge also comprises a spacer which is located on the upper surface
of the primary blade. The spacer comprises a rear portion which functions to separate
the primary blade and a secondary blade. The spacer also comprises a forward portion
which extends from the rear portion and functions to prevent upward movement of the
primary blade, and to create an opening beneath the forward portion of the lower surface
of the secondary blade.
[0020] The blade cartridge also comprises a cap member disposed on the secondary blade.
The cap member comprises fastening means to secure the members forming the blade cartridge
together, and a member which prevents upward movement of the secondary blade.
[0021] The corners or outer edges of the primary and secondary blades are covered by "C"
shaped end clips which are coated with a friction reduction agent so as to minimize
the drag forces associated with the shaving process. The end clips also function to
provide additional stability to the ends of the primary and secondary blades (i.e.
prevents the ends or corners of the blades from moving in the upward direction).
[0022] As described hereinafter, each blade is independently movable in response to shaving
forces applied to the blade. Specifically, each blade is flexible about the longitudinal
axis of the blade within a flexing zone defined by the ratio between the portion of
the blade overlying a physical structure and the portion of the blade overlying the
opening formed beneath the forward portion of each blade, in combination with the
physical characteristics of the blade. If a force exceeding the resilient force of
the blade is exerted on the blade, the blade flexes about the longitudinal axis so
as to bend in the downward direction against the resilient force of the blade. The
bending movement of the blade results in the simultaneously decrease of blade exposure
and shaving angle.
[0023] Preferably, the blade cartridge is connected to a handle, and can be pivotally connected
so as to allow the blade cartridge to further respond to shaving forces encountered
during the shaving process.
[0024] The invention itself, together with further objects and advantages, will best be
understood by reference to the following detailed description taken in conjunction
with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025]
Figure 1 is a cross-sectional view of the blade cartridge of an embodiment of the
present invention through a rivet on the cap member illustrating the assembly with
both the primary and secondary blade at rest.
Figure 2 illustrates a top plan view of the platform member of an embodiment of the
present invention showing the blade seat, the guard member and a plurality of support
members integrally molded to the blade seat and guard member.
Figure 3 illustrates a top plan view of a first embodiment of the spacer of the present
invention.
Figure 4 illustrates an end view of the spacer shown in Fig. 3.
Figure 5 illustrates a top plan view of the primary and secondary blade, and the spacer
in the assembled position.
Figure 6 illustrates a front view of a first embodiment of the cap member of the present
invention.
Figure 7 illustrates an end view of the cap member shown in Fig. 6.
Figure 8 illustrates a blade used for the primary blade structure.
Figure 9 illustrates a blade used for the secondary blade structure.
Figure 10 illustrates one embodiment of the platform member adapted to receive a razor
handle so as to pivotally connect the blade cartridge to the razor handle.
Figure 11 is the same cross-sectional view of the blade cartridge as shown in Fig.
1 illustrating the optimum geometric relationships of the various components with
the blades at rest.
Figure 12 is the same cross-sectional view of the blade cartridge as shown in Fig.
1 illustrating the blades fully flexed.
Figure 13 illustrates a side view of an end clip.
Figure 14 is a perspective view of the blade cartridge of an embodiment of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] Turning now to the drawings, Figs. 1-14 illustrate a movable blade shaving cartridge
("MBSC" or blade cartridge) or razor head 10 which comprises a platform member 2,
flexible blade means 32, 34, a spacer 6 and a cap member 8.
[0027] As shown in Figure 2, the platform member 2 comprises a blade seat 24 having a front
and rear wall 12,14, and ends 16,18. The ends 16,18 extend beyond the front wall 12
so as to allow a guard member 20 to be interconnected between the ends 16,18 at a
position forward of the front wall 12. The guard member 20 extends parallel to the
front wall 12 forming a slot 26 between the guard member 20 and the front wall 12.
The guard member 20 also is connected to the front wall 12 by a plurality of support
members 22, which extend substantially perpendicular to the longitudinal axis of the
both the guard member 20 and the front wall 12.
[0028] The blade seat 24 further comprises an upper surface 28, as well as a plurality of
securing apertures 30. The securing apertures operate in conjunction with fastening
means 80 located on the cap member 8, such as rivets, to permanently secure the platform
member 2, the flexible blade means, the spacer 6 and the cap member 8 together.
[0029] The flexible blade means comprises a primary and secondary blade 32,34, each having
substantially parallel front and rear edges with the front edge of each blade defining
a cutting edge 36,38. Each blade 32,34 defines a longitudinal axis which is parallel
to the cutting edge of the blade 32,34, and a lateral axis which is perpendicular
to the cutting edge of the blade 32,34. Each blade 32,34 is flexible about its longitudinal
axis. As shown in Fig. 8, the primary blade 32 comprises securing apertures 40 which
align with the securing apertures 30 of the blade seat 24 so as to allow the fastening
means 80 to pass through the securing apertures 40 of the primary blade 32, thereby
securing the primary blade 32 to the blade cartridge 10.
[0030] The secondary blade 34 is illustrated in Fig. 9. Similar to the primary blade 32,
the secondary blade 34 comprises securing apertures 43 which align with the securing
apertures 30 of the blade seat 24 so as to allow the fastening means 80 to pass through
the securing apertures 43 of the secondary blade 34, thereby securing the blade to
the blade cartridge 10. However, the securing apertures 43 of the secondary blade
34 preferably are oval in shape and perform a dual function. The first function, which
has already been stated, is to secure the secondary blade 34 to the blade cartridge
10. The second function of the apertures 43 is to contribute to the flexibility of
the secondary blade 34. The secondary blade 34 is positioned such that the fastening
means 80 passes through the rear portion of each securing aperture 43 (i.e. the portion
farthest away from the cutting edge 38). As a result, the portion of the aperture
43 free from contact with the fastening means 80 contributes to the flexibility of
the secondary blade 34.
[0031] Furthermore, both the primary and secondary blades 32,34 comprise a plurality of
holes 42 located proximate the cutting edge 36,38 of the respective blade 32,34. The
holes 42 provide a passage to facilitate the removal of shaving debris and contribute
to the flexibility of the blades 32,34. Specifically, the diameter of the holes 42
in combination with the thickness of the blades 32,34 partially determines the degree
of flexibility of the blades 32,34. Preferably, the sum of the longitudinal dimensions
of the holes 42 on the primary blade 32 should be between 35 to 75 percent of the
length of the blade. Similarly, the sum of the longitudinal dimensions of the apertures
43 and holes 42 on the secondary blade 34 should be between 35 to 75 percent of the
length of the blade.
[0032] As shown in Figures 1 and 2, the support members 22 extend downwardly away from the
upper surface 28 of the blade seat 24 so as to create a gap 46 between the lower surface
48 of the primary blade 32 and the upper surface of each support member 22. Preferably,
each support member 22 also comprises a lip 60 which operates as a stop to prevent
further downward movement of the primary blade 32.
[0033] The spacer or "soap bar" 6, which is placed between the primary and secondary blades
32,34, functions to separate the blades 32,34. As shown in Figures 1 and 4, the spacer
6 comprises an upper and lower surface 58,56 and is divided into a forward portion
62 and a rear portion 64. The rear portion 64 of the spacer 6 exhibits a uniform height
(i.e. the distance between the blades 32,34 measured perpendicularly to the longitudinal
axis of the blades), so that when the blades 32,34 are secured to the upper and lower
surface 58,56 of the spacer 6, respectively, the blades 32,34 are parallel to one
another.
[0034] Preferably, as shown in Fig. 1, the primary blade 32 and the secondary blade 34 are
separated from each other by a distance of about 0.0508 cm (0.020 inches) to about
0.127 cm (0.050 inches) by the spacer 6. The height of the rear portion 64 of spacer
6 defines the separation between the two blades 32,34.
[0035] The forward portion 62 of the spacer 6 comprises portions having a reduced height
relative to the rear portion 64 so as create areas where the blades 32,34 do not contact
the spacer 6. Specifically, as shown in Figures 1 and 4, the upper surface 58 of the
forward portion 62 exhibits an arcuate downward slope proximate the rear portion 64
and thereafter extends in the direction parallel to the plane of the blade 34. Furthermore,
a plurality of ribs 66 are disposed on the upper surface 58 of the forward portion
62 of the spacer 6. The ribs 66 extend perpendicularly to the longitudinal axis of
the blades 32,34 and exhibit a height such that the top of ribs 66 are below the plane
of the upper surface 58 of the rear portion 64 of the spacer 6.
[0036] The lower surface 56 of the forward portion 62 of the spacer 6 forms a cavity 68,
which extends in a direction parallel to the cutting edge 36,38 of the blades 32,34.
The lower surface 56 of the forward portion 62 of the spacer 6 further comprises a
plurality of downwardly extending pads 70 on the outer edge of the forward portion
62 of the spacer 6. As shown in Fig. 3, the pads 70 are separated from one another
so as to allow water to flow through the front of the spacer 6 into the cavity 68.
Referring to Fig. 1, it is apparent that the primary blade 32 extends beyond the downwardly
extending pads 70 of the spacer 6. As a result, the pads 70 operate as a stop limiting
the upward movement of the primary blade 32.
[0037] Furthermore, similar to both blades 32,34, the spacer 6 comprises four securing apertures
44 which are located on the rear portion 64 of the spacer 6. The securing apertures
44 operate in conjunction with the fastening means 80 to secure the spacer 6 to the
blade cartridge 10. The spacer 6 also comprises a plurality of holes 41 located on
the forward portion 62 of the spacer 6, which align with the holes 42 of both the
primary and secondary blades 32,34. The alignment of the spacer holes 41 and blade
holes 42 allows water to be directed to the edges of both blades 32,34 so as to facilitate
the removal of shaving debris.
[0038] Figure 5 illustrates the alignment of the primary and secondary blades 32,34 and
the spacer 6. As shown the cutting edge 36 of the primary blade 32 is located forward
of the cutting edge 38 of the secondary blade 34. The holes 42 in the blades 32,34
and the holes 41 in the spacer 6 align such that the water can flow from the lower
surface 48 of the primary blade 32 to the upper surface 54 of the secondary blade
34. The water passage facilities the removal of shaving debris from the cutting edges
36,38 of the blades 32,34.
[0039] The cap member 8 is disposed on the upper surface 54 of the secondary blade 34. As
shown in Figure 1 and 6, similar to the spacer 6, the lower surface 72 of the cap
member 8 forms a cavity 76 which extends parallel to the cutting edge 36,38 of the
blades 32,34. Also, the lower surface 72 of the cap member 8 comprises a plurality
of downwardly extending pads 78 on the forward portion of the cap member 8. Again,
similar to the spacer 6, the pads 78 are separated from one another so as to allow
water to flow through the front of the cap member 8 into the cavity 76. As shown in
Fig. 1, the secondary blade 34 extends beyond the downwardly extending pads 78 of
the cap member 8, and therefore the pads 78 operate as a stop limiting the upward
movement of the secondary blade 34.
[0040] In addition, the cap member 8 comprises a plurality of fastening means 80, such as
rivets. The fastening means 80 extend downwardly from the lower surface 72 of the
cap member 8 and pass through the securing apertures 44 of the spacer 6 and the securing
apertures 40,43 of the blades 32,34 and into the securing apertures 30 of the blade
seat 24. The ends of the fastening means 80 extend beyond the blade seat 24 and are
upset thereby permanently affixing the blade seat 24, blades 32,34, spacer 6 and cap
member 8 together.
[0041] Figure 1 illustrates in detail the novel structure of the blade cartridge 10 of the
present embodiment. As is apparent, the primary blade 32 is disposed on the upper
surface 28 of the blade seat 24 with the cutting edge 36 extending over the slot 26
between the guard member 20 and the front wall 12 of the blade seat 24. The width
of the blade seat 24 (i.e distance between the front and rear wall 12,14) and the
width of the primary blade 32 is such that a substantial portion of the primary blade
32 extends over the slot 26.
[0042] The spacer 6 is disposed on the upper surface 50 of the primary blade 32. As shown
in Figure 1, one edge of the cavity 68 generally aligns with the front wall 12 of
the blade seat 24 so as to form a vertical plane, thereby partially defining a flexing
zone for the primary blade 32. The application of force upon the primary blade 32
causes the primary blade 32 to flex about the longitudinal axis in a downwardly direction.
The downward movement of the primary blade 32 stops when the blade 32 engages the
lips 60 formed on the support members 22. Thus, the distance the blade 32 is allowed
to flex is defined by the height of the lip 60 relative to the upper surface 28 of
the blade seat 24. The resiliency of the primary blade 32 returns the blade to the
normal, horizontal position (as shown in Fig. 1) upon removal of the applied shaving
force.
[0043] The secondary blade 34 is disposed on the upper surface 58 of the spacer 6 with the
cutting edge extending over the opening 47 created between the forward portion 62
of the spacer 6 and the lower surface 52 of the secondary blade 34. Similar to the
primary blade 32, the width of the rear portion 64 of the spacer 6 is such that a
substantial portion of the secondary blade 34 extends over the opening 47.
[0044] The cap member 8 is disposed on the upper surface 54 of the secondary blade 34 such
that one edge of the cavity 76 formed on the lower surface 72 of the cap member 8
generally aligns with beginning of the forward portion 62 of the spacer 6 so as to
form a vertical plane. As shown in Figure 1, the edge of the cavity 76 in conjunction
with the sloping surface of the forward portion 62 of the spacer 6 partially defines
the flexing zone for the secondary blade 34. As with the primary blade 32, the application
of a force on the secondary blade 34 causes the blade 34 to flex about the longitudinal
axis in the downwardly direction. The downward movement of the secondary blade 34
stops when the blade engages the ribs 66 formed on the upper surface 58 of the spacer
6. The resiliency of the secondary blade 34 returns the blade to the normal, horizontal
position upon removal of the applied force.
[0045] As previously stated, the downwardly extending pads 70,78 of the spacer 6 and the
cap member 8 prevent movement of the primary and secondary blades 32,34, respectively,
in the upward direction beyond the horizontal position. It will be appreciated that
as the portion of the primary and secondary blade 32,34 extending over the slot and
opening 26,47, respectively, is reduced (i.e. as the flexing zone moves closer to
the cutting edge), the flexibility of the blade will also be reduced. The flexibility
of each blade depends upon factors including (1) the location of the flexing zone,
(2) the thickness of the blade, and (3) the dimensions of the holes 42 in the blades
(apertures 43 also contribute to the flexibility of the secondary blade). These factors
can be adjusted so that the blades 32,34 flex when the applied force exceeds a predetermined
level.
[0046] In order to maximize shaving comfort and closeness, and minimize the potential for
nicks and cuts, the blade exposure and shaving angle of the primary and secondary
blades 32,34 are preset to the "at-rest" positions shown in Fig. 11.
[0047] More specifically, referring to Fig. 11, the shaving plane of the primary blade 32,
denoted by reference line 100, is defined by the plane tangent to the upper portion
21 of the guard 20 and the skin engaging portion 88 of the spacer 6. The shaving plane
of the secondary blade 34, denoted by reference line 102, is defined by the plane
tangent to the skin engaging portion 88 of the spacer 6 and the upper portion 9 of
the cap 8. Thus, the skin engaging portion 88 of the spacer 6 functions to maintain
the geometry of the primary blade 32 relative to the shaving surface by establishing
a safe contact and control surface behind the primary blade 32. The skin engaging
portion 88 of the spacer 6 also maintains the geometry of the secondary blade 34 relative
to the shaving surface.
[0048] The blade exposure of the primary blade "eP" in the "at-rest" position ranges between
about - 0.0025 to 0.0051 cm (-0.001 to 0.002 inches), with the preferred range being
between about 0.002 to 0.003 cm (0.0008 to 0.0012 inches). The blade exposure of the
secondary blade "eS" ranges between about -0.0025 to 0.0076 cm (-0.001 to 0.003 inches),
with the preferred range being between about 0.003 to 0.0048 cm (0.0012 to 0.0019
inches).
[0049] The shaving angle of the primary blade, which is the acute angle between the plane
tangent to the cutting edge 36 of the primary blade 32 and the shaving plane denoted
by reference line 100, ranges from 22 to 28 degrees, with the preferred range being
between 25.8 to 26.6 degrees. The shaving angle of the secondary blade, which is the
acute angle between the plane tangent to the cutting edge 38 of the secondary blade
34 and the shaving plane denoted by reference line 102, ranges from 18 to 24 degrees,
with the preferred range being between 21.0 to 22.4 degrees.
[0050] As stated previously, the separation between the primary and secondary blades 32,34
in the "at-rest" position is governed by the thickness of the spacer 6, which ranges
from 0.0508 to 0.127 cm (0.020 and 0.050 inches). The preferred thickness of the spacer
6 is 0.0762 cm (0.030 inches).
[0051] Fig. 11 also illustrates the aperture ranges and edge separation for both the primary
and secondary blades 32,34. First, the primary aperture is the distance from the upper
portion 21 of the guard 20 to the cutting edge 36 of the primary blade 32 measured
along the shaving plane 100. Referring to the figure, the primary aperture is denoted
Pa and ranges from 0.0635 to 0.1143 cm (0.025 to 0.045 inches), with the preferred
aperture being about 0.0914 cm 0.036 inches.
[0052] Similarly, the secondary aperture, which is denoted by Sa is the distance from the
skin engaging portion 88 of the spacer 6 to the cutting edge 38 of the secondary blade
34 measured along shaving plane 102. The range of the secondary aperture is also 0.0635
to 0.1143 cm (0.025 to 0.045 inches), with the preferred aperture being about 0.0914
cm (0.036 inches).
[0053] Finally, the edge separation of the primary blade 32 is the distance from the cutting
edge 36 of the primary blade 32 to the skin engaging portion 88 of the spacer 6 measured
along the shaving plane 100. Referring to the Fig. 11, the edge separation of the
primary blade 32 is denoted Pe and ranges from about 0.1219 to 0.3124 cm (0.048 to
0.123 inches), with the preferred aperture being about 0.2134 cm (0.084 inches).
[0054] Similarly, the edge separation of the secondary blade 34, which is denoted by Se
is the distance from the cutting edge 38 of the secondary blade 34 to the upper portion
9 of the cap 8 measured along shaving plane 102. The range of the secondary aperture
is also about 0.1219 to 0.3124 cm (0.048 to 0.123 inches), with the preferred aperture
being about 0.1219 cm (0.048 inches).
[0055] The foregoing geometric dimensions concerning blade position operate to maximize
both shaving comfort and the closeness of the shave, while at the same time minimizing
the potential for nicks and cuts. This results, in part, from the skin engaging portion
88 of the spacer 6 which allows for an aggressive exposure of both the primary and
secondary blades 32, 34, while at the same time contributing to the prevention of
nicks and cuts.
[0056] Fig. 12 illustrates both the primary blade 32 and the secondary blade 34 in the fully
flexed position. As shown in Fig. 12, the downward movement of the primary and secondary
blades 32,34 are limited by the lip 60 of the support member 22 and the ribs 66 on
the spacer 6, respectively.
[0057] In order to prevent the corners of the blades 32,34 from engaging the skin of the
user, end clips 82 cover the outer edges of the primary and secondary blades 32,34.
As shown in Figure 13, each end clip 82 comprises a thin strip of material having
a leg 31,33 on each end and is generally in a "C" shape. Each end clip wraps around
the blade cartridge 10, whereby the legs 31,33 of each end clip are secured to the
bottom of blade cartridge 10. Referring to Fig. 2, one end clip 82 is disposed in
a slot 84 adjacent end 16. A second end clip 82 is disposed in a slot 86 adjacent
end 18. Each end clip 18 runs perpendicular to the longitudinal axis of the blades
32,34 and covers the outer edges of the blades 32,34.
[0058] Furthermore, the end clips 82 which represent a significant portion of the skin engaging
surface of the blade cartridge 10, are coated with a friction reduction agent so as
reduce the drag forces associated with the blade cartridge 10 engaging the skin, thereby
improving shaving comfort.
[0059] The friction reduction agent is applied to the end clips 82 prior to the end clips
82 being secured to the blade cartridge 10. Specifically, the friction reduction agent
is applied in liquid form to the end clip, which can comprise, for example, an aluminum
wire. The friction reduction agent is applied such that a thin film of the agent completely
covers each end clip 82. The end clip 82 is then exposed to heat, or other appropriate
means, so that molecules of the friction reduction agent crosslink with the molecules
of the material of the end clip 82 to form a solid, thereby bonding the friction reduction
agent to the end clip 82. The preferred range of the thickness of the friction reduction
agent is between about 0.0008 to 0.0013 (0.0003 to 0.0005 inches). Multiple applications
of the friction reduction agent are employed, if necessary.
[0060] While other friction reduction agents can be utilized, the preferred agent is polyvinyl
acetyl (PVA). Some other acceptable agents include: nylon 515, polyimide, polyester
imide, polyamide, polyester and teflon.
[0061] As a result of mounting the blades 32,34 in accordance with the present embodiment,
there is no longitudinal movement of either the primary or secondary blade 32,34 relative
to the remainder of the blade cartridge 10. Only rotational movement about the flexing
zone associated with the each blade 32,34 is possible. More specifically, each blade
32,34 can only bend about the longitudinal axis of the blade within the flexing zone
in a direction which reduces the blade exposure and shaving angle of the blade relative
to a shaving surface. Furthermore, the primary and secondary blades 32,34 flex independently
of one another.
[0062] For example, if the pressure encountered by the primary blade 32 exceeds the resilient
force of the primary blade 32, the primary blade 32 bends in response to that force.
Specifically, the primary blade 32 bends about the flexing zone, thereby causing the
cutting edge 36 to move in a downward manner. Upon removal of the force, the primary
blade 32 would return to the horizontal position as shown in Figure 1. If an equivalent
force were applied to the secondary blade 34, it would respond in a similar manner.
Thus, the cutting edges 36,38 of the blades 32,34 move downwardly away from the shaving
plane and adjust to a lower, safer shaving angle and blade exposure.
[0063] As illustrated in Figs. 1 and 2, the guard member 20 placed in front of the primary
blade 32 is integral with the ends 16,18 of the platform member 2 and is therefore
stationary relative to the blade cartridge 10. Similar to the guard 20 being positioned
in front of the primary blade 32, as shown in Fig. 5, the spacer 6 has a raised oval
or round skin engaging portion 88, which provides an engaging surface to control exposure
of the secondary blade 34 to the shaver's skin.
[0064] Finally, Fig. 14 is a perspective view of the blade cartridge of the present embodiment,
which is useful in understanding the structure as well as the position of the components
identified in Figs. 1-13 relative to one another. The components identified in Figs.
1-13 are identified by the same numeral in Fig. 14. It is noted that the arrows 95
shown in Fig. 14 represent possible water flow paths for the removal of shaving debris
from the blade cartridge. It is also noted that end clips 82 are not shown in Fig.
14.
[0065] Variations on the embodiments described above are possible. In a first variation,
the height of the lips 60 formed of the support members 22 may be varied so as to
effect different bending patterns. For example, if the lips 60 on the support members
22 in the center of the platform member 2 are lower relative to the lips 60 on the
support members located proximate the ends of the platform member 2, the primary blade
32 exhibit increases movement in the center of the blade. With regard to the secondary
blade, the same changes can be effected by varying the height of the ribs 66 located
on the upper surface 58 of the spacer 6.
[0066] Furthermore, numerous variations of the flexible blades 32,34 are possible. For example,
each blade 32,34 may be tapered such that the thickness of the blade decreases in
the direction of the forward portion of the blade. Also, each blade 32,34 can comprise
a U-shaped channel in the forward portion of the blades, which functions to define
the flexing zone for the blade 32,34. Finally, the additional holes can be added to
the blades of the preferred embodiment to vary the flexibility of the blades 32,34.
[0067] In another variation, the blade means comprises a single blade positioned between
the platform member 2 and the cap member 8. The operation and movement of the single
blade is the same as either blade in the two blade embodiment. However, the forward
portion of the cap member would be extended relative to the cap member of the two
blade embodiment such that the single blade razor exhibits the correct shaving geometry.
[0068] In another variation, as shown in Fig. 6 and 7, the cap member 8 further comprises
a downwardly extending guide member 99 which functions to locate the secondary blade
34 in the desired position prior to permanently securing the cap member 8 to the platform
member 2.
[0069] In another variation, the guard member 20 may include means to allow independent
movement of the guard member 20 in the direction away from the direction of shaving
forces acting upon the guard member 20.
Jacobson U.S. Patent Nos. 4,442,598, 4,378,634 and 4,270,268 disclose a blade cartridge having
movable guard means.
[0070] Similarly, the cap member 8 may include means to allow independent movement in a
direction away from the direction of shaving forces acting upon said cap member 8.
Oldroyd et al., U.S. Patent No. 4,063,354, discloses a shaving unit having a movable cap member
8 suitable for use with this invention.
[0071] In yet another variation, an additional shaving aid may be affixed or included with
the blade cartridge 10. Typically, as shown in Figure 1, the shaving aid comprises
a polystyrene-polyethylene oxide blend in the form of lubricating strip 92, which
may affixed to the upper surface 74 of the cap member 8 behind the secondary blade
34. During shaving, the polyethylene oxide leaches out of the styrene matrix. Other
suitable shaving aids for use with the invention are also described in U.S. Patent
No. 4,170,821 issued to
Booth entitled "Razor Cartridges." Preferably, the shaving aid comprises a matrix of polystyrene,
polyethylene oxide and aloe and/or vitamin E. Also, the shaving aid 90 may define
a lubrication strip 94, shown by dotted lines in Fig. 1, positioned near the guard
member 20, either separately or in combination with the lubrication strip 92 located
on the cap member 8.
[0072] In yet a further variation, the blade cartridge 10 may be permanently or detachably
connected to a handle by suitable structures formed on the bottom surface of the blade
cartridge 10. For example, the bottom surface of the blade cartridge 10 can be formed
so as to attach to a handle in the manner described in U.S. Patent No. 4,883,779 entitled
PLATFORM, HANDLE AND SHIELD FOR SAFETY RAZOR, which issued to C. Iten.
[0073] Alternatively, the blade cartridge 10 can be mounted on a handle in such a manner
that it pivots or is stationary while it is used to shave a surface. For example,
as illustrated in Fig. 10, the bottom surface of the platform member 2 comprises mounting
members 98 which allow the blade cartridge 10 to be pivotally mounted to a handle.
[0074] Still further, it is within the scope of this invention, which is defined by claim
1, to detachably connect the blade cartridge 10 to a handle, such as in U.S. Patent
No. 4,026,016 entitled RAZOR BLADE ASSEMBLY, issued to Warren I. Nissen.
[0075] In another variation, the upper and lower surfaces 58,56 of the rear portion 64 of
the spacer 6 comprises a plurality of channels so as to allow shaving debris to be
led out the back of the blade cartridge 10. Conversely, water can be directed into
the back of the blade cartridge 10 to be channeled out through the front of the blade
cartridge 10 and the edges 36,38 of the blades 32,34.
[0076] In another variation, the downwardly extending pads 70,78 located on the spacer 6
and the cap member 8 are replaced by a single downwardly extending pad which is parallel
to the cutting edges of the blades and has a length at least equal to the length of
the blades.
[0077] The embodiments described above provide a number of significant advantages. The use
of a blade which is flexible about the longitudinal axis of the blade within a body
portion of a blade cartridge or the like precisely controls blade geometry in response
to shaving forces. Any flexing of the blade results in the simultaneous reduction
of both critical safety dimensions, blade exposure and shaving angle.
[0078] Furthermore, the optimized geometric relationships between the various components
of the blade cartridge as disclosed provide for maximum comfort and closeness, while
simultaneously minimizing the potential for nicks and cuts.
[0079] As yet another advantage, the blade cartridge of the present invention can simplify
the manufacturing process for creating blade cartridges. The present invention can
eliminate the need for creating an injection mold comprising a plurality of thin,
individual spring fingers or leaf springs or the like.
[0080] In addition, the use of end clips coated with a friction reduction agent provide
for a significant reduction in the drag forces associated with the shaving process
so as to provide a more comfortable shave.
[0081] Of course, it should be understood that a wide range of changes and modifications
can be made to the preferred embodiment described above within the scope of the claims.
1. A flexible blade cartridge which comprises:
a platform (2) having a guard member (20), a cap (8), a spacer (6), and
blade means, said blade means having first and second blades (32, 34) which each have
a forward portion, a rearward portion and a cutting edge (36, 38), each of the rearward
portions of the blades (32, 34) being secured between the guard member (20) and the
cap (8) so as to be immovable relative to the platform (2), the forward portions of
one or both the first and second blades (32,34) being flexible about a longitudinal
axis of the respective blade (32, 34) downward and away from the cap (8) to a less
aggressive shaving angle in response to forces applied during shaving, said blade
means comprising a continuous blade edge extending substantially the length of said
guard member, said spacer (6) being disposed between the first and second blades (32,
34) to define a predetermined distance between the reaward portion of said first and
second blades and provided with a first surface (66) which limits the degree to which
the second blade (34) can be flexed to a less aggressive shaving angle,
characterized in that said spacer (6) has a skin engaging surface (88) which engages, in use, a skin surface
being shaved to define, in combination with the guard member (20), a first shaving
angle of the first blade (32), and to define, in combination with the cap member (8),
a second shaving angle of the second blade (34).
2. A flexible blade cartridge as set forth in claim 1, characterized in that the spacer (6) projects forward to a position which is intermediate of the cutting
edges (36, 38) of the first and second blades (32, 34) so as to locate the skin engaging
surface (88) between the cutting edges (36,38).
3. A flexible blade cartridge as set forth in claims 1 or 2, characterized in that the first shaving angle is greater than the second shaving angle when the first and
second blades (32,34) are not flexed away from their respective rest positions.
4. A flexible blade cartridge as set forth in claim 3, characterized in that the first shaving angle is in the range of 25.8 to 26.6 degrees, and in that the second shaving angle is in the range of 21.0 to 22.4 degrees.
5. A flexible blade cartridge as set forth in any of the preceding claims, characterized in that the blades (32, 34) are permanently and immovably fixed in position between said
cap (8) and the guard member (20) by a plurality of rivets (80) which extend down
from the cap (8) through the rearward portion of the blades (32, 34), the spacer (6)
and the platform (2).
6. A flexible blade cartridge as set forth in any of the preceding claims characterized by a plurality of end clips (82) which cover the corners of the forward portions of
the first and second blades (32, 34) and which prevent the comers from moving upward.
7. A flexible blade cartridge as set forth in claim 6, characterized in that the plurality of end clips (82), which cover the outer edges of the forward portions
of the first and second blades (32, 34), are coated with a friction reducing agent
which reduces clip-skin drag forces encountered when shaving.
8. A flexible blade cartridge as set forth in claim 7, characterized in that the friction reducing agent is bonded to a surface or surfaces of the end clips (82)
at a molecular level and in that the agent is polyvinyl acetate (PVA), nylon 515, polyimide, polyester imide, polyamide,
polyester or Teflon.
9. A flexible blade cartridge as set forth any of the preceding claims, characterized in that the platform is formed with a lip or lips (60) which engage the first blade (32)
after a predetermined amount of downward flexure to limit the amount of aggressive
shaving angle.
10. A flexible blade cartridge as set forth any of the preceding claims, characterized in that the spacer (6) has downwardly extending pads (70) which engage the upper surface
of the first blade (32) when the first blade (32) is in an un-flexed, rest position
and prevents upward flexure of the first blade in a direction which increases its
aggressive shaving angle.
11. A flexible blade cartridge as set forth any of the preceding claims, characterised in that the cap (8) has downwardly extending pads (78) which engage the upper surface of
the second blade (34) when the second blade (34) is in an un-flexed, rest position
and prevents upward flexure of the second blade in a direction which increases its
aggressive shaving angle.
12. A flexible blade cartridge as set forth in any of the preceding claims, characterized in that the first and second blades (32, 34) are formed with holes/apertures (42, 43) which
permit water to pass therethrough to flush away shaving debris, and in that the holes/apertures (42, 43) contribute to the flexibility of the first and second
blades (32, 34) which permits the blades to be flexed downwardly to their respective
less aggressive shaving angles.
1. Flexible Klingeneinheit mit:
einer Plattform (2) mit einem Schutzelement (20), einer Kappe (8), einem Abstandshalter
(6) und
einer Klingeneinrichtung mit einer ersten und einer zweiten Klinge (32, 34), die jeweils
einen Vorderbereich, einen Hinterbereich und eine Schnittkante (36, 38) aufweisen,
wobei die Hinterbereiche der Klingen (32, 34) so zwischen dem Schutzelement (20) und
der Kappe (8) befestigt sind, daß sie relativ zur Plattform (2) unbeweglich sind,
die Vorderbereiche der ersten und/oder der zweiten Klinge (32, 34) um eine Längsachse
der jeweiligen Klinge (32, 34) nach unten und weg von der Kappe (8) zu einem weniger
aggressiven Rasierwinkel in Reaktion auf während der Rasur angewandte Kräfte flexibel
sind, die Klingeneinrichtung eine zusammenhängende Klingenkante aufweist, die sich
im wesentlichen über die Länge des Schutzelements erstreckt, und der Abstandshalter
(6) zwischen der ersten und der zweiten Klinge (32, 34) angeordnet ist, um einen vorbestimmten
Abstand zwischen den Hinterbereichen der ersten und der zweiten Klinge zu definieren,
und mit einer ersten Fläche (66) versehen ist, die den Grad begrenzt, bis zu dem die
zweite Klinge (34) zu einem weniger aggressiven Rasierwinkel gebogen werden kann,
dadurch gekennzeichnet, daß der Abstandshalter (6) eine Hauteingriffsfläche (88) aufweist, die in Benutzung in
Eingriff mit einer zu rasierenden Hautfläche ist, um in Kombination mit dem Schutzelement
(20) einen ersten Rasierwinkel der ersten Klinge (32) und in Kombination mit dem Kappenelement
(8) einen zweiten Rasierwinkel der zweiten Klinge (34) zu definieren.
2. Flexible Klingeneinheit nach Anspruch 1, dadurch gekennzeichnet, daß der Abstandshalter (6) sich nach vorne zu einer Position erstreckt, die zwischen
den Schneidekanten (36, 38) der ersten und der zweiten Klinge (32, 34) liegt, so daß
sich die Hauteingriffsfläche (88) zwischen den Schneidekanten (36, 38) befindet.
3. Flexible Klingeneinheit nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß der erste Rasierwinkel größer ist als der zweite Rasierwinkel, wenn die erste und
die zweite Klinge (32, 34) nicht aus ihren jeweiligen Ruhepositionen weggebogen werden.
4. Flexible Klingeneinheit nach Anspruch 3, dadurch gekennzeichnet, daß der erste Rasierwinkel zwischen 25,8 und 26,6 Grad und der zweite Rasierwinkel zwischen
21,0 und 22,4 Grad liegt.
5. Flexible Klingeneinheit nach einem der vorstehenden Ansprüche, dadurch gekennzeichnet, daß die Klingen (32, 34) durch mehrere Nieten (80) die abwärts von der Kappe (8) durch
den Hinterbereich der Klingen (32, 34), den Abstandshalter (6) und die Plattform (2)
verlaufen, in ihrer Position permanent und unbeweglich zwischen der Kappe (8) und
dem Schutzelement (20) fixiert sind.
6. Flexible Klingeneinheit nach einem der vorstehenden Ansprüche, gekennzeichnet durch mehrere Seitenclips (82), die die Ecken der Vorderbereiche der ersten und der zweiten
Klinge (32, 34) abdecken und die Ecken an der Aufwärtsbewegung hindern.
7. Flexible Klingeneinheit nach Anspruch 6, dadurch gekennzeichnet, daß die mehreren Seitenclips (82), die die Außenkanten der Vorderbereiche der ersten
und der zweiten Klinge (32, 34) abdecken, mit einem Reibungsreduktionsmittel überzogen
sind, das die beim Rasieren auftretenden Clip/Haut-Widerstandskräfte reduziert.
8. Flexible Klingeneinheit nach Anspruch 7, dadurch gekennzeichnet, daß das Reibungsreduktionsmittel an einer oder mehreren Flächen der Seitenclips (82)
auf Molekularniveau angebracht ist, und das Mittel in Polyvinylacetat (PVA), Nylon
515, Polyimide, Polyester Imid, Polyamid, Polyester oder Teflon besteht.
9. Flexible Klingeneinheit nach einem der vorstehenden Ansprüche, dadurch gekennzeichnet, daß die Plattform mit einer oder mehreren Lippen (60) ausgebildet ist, die nach einem
vorbestimmten Betrag an Herunterbiegung in die erste Klinge (32) eingreifen, um den
Betrag des aggressiven Rasierwinkels zu begrenzen.
10. Flexible Klingeneinheit nach einem der vorstehenden Ansprüche, dadurch gekennzeichnet, daß der Abstandshalter (6) nach unten verlaufende Polster (70) aufweist, die in Eingriff
mit der oberen Fläche der ersten Klinge (32) sind, wenn die erste Klinge (32) in einer
ungebogenen Ruheposition ist, und ein Heraufbiegen der ersten Klinge in eine ihren
aggressiven Rasierwinkel vergrößernde Richtung verhindert.
11. Flexible Klingeneinheit nach einem der vorstehenden Ansprüche, dadurch gekennzeichnet, daß die Kappe (8) nach unten verlaufende Polster (78) aufweist, die in Eingriff mit der
oberen Fläche der zweiten Klinge (34) sind, wenn die zweite Klinge (34) in einer ungebogenen
Ruheposition ist, und ein Heraufbiegen der zweiten Klinge in eine ihren aggressiven
Rasierwinkel vergrößernde Richtung verhindert.
12. Flexible Klingeneinheit nach einem der vorstehenden Ansprüche, dadurch gekennzeichnet, daß die erste und die zweite Klinge (32, 34) mit Löchern/Öffnungen (42, 43) ausgebildet
sind, die Wasserdurchtritt zum Wegspülen von Rasierabfall erlauben, und daß die Löcher/Öffnungen
(42, 43) zur Flexibilität der ersten und der zweiten Klinge (32, 34) beitragen, was
ein Herunterbiegen der Klingen zu ihren jeweiligen weniger aggressiven Rasierwinkeln
erlaubt.
1. Tête à lames flexibles comprenant :
un plateau (2) muni d'un organe de protection (20), un chapeau (8), un élément intercalaire
(6) et des moyens formant lames, lesdits moyens formant lames comportant des première
et seconde lames (32, 34) qui possèdent chacune une partie avant, une partie arrière
et un bord de coupe (36, 38), chacune des parties arrière des lames (32, 34) étant
assujettie entre l'organe de protection (20) et le chapeau (8) de manière à être immobile
par rapport au plateau (2), tandis que la partie avant de l'une ou de chacune des
deux première et seconde lames (32, 34) est flexible autour d'un axe longitudinal
de la lame (32, 34) correspondante vers le bas et à distance du chapeau (8) pour adopter
un angle de rasage moins agressif en réponse à des forces appliquées au cours du rasage,
lesdits moyens formant lames comprenant un bord de lame continu qui s'étend sensiblement
sur toute la longueur dudit organe de protection, et ledit élément intercalaire (6)
étant disposé entre les première et seconde lames (32, 34) pour définir une distance
prédéterminée entre la partie arrière desdites première et seconde lames et étant
muni d'une première surface (66) qui limite le degré de flexion possible de la seconde
lame (34) pour adopter un angle de rasage moins agressif,
caractérisée en ce que ledit élément intercalaire (6) comporte une surface (88) de contact avec la peau,
qui, en service, vient en contact avec une surface cutanée en cours de rasage pour
définir, en combinaison avec l'organe de protection (20), un premier angle de rasage
de la première lame (32), et, en combinaison avec le chapeau (8), un second angle
de rasage de la seconde lame (34).
2. Tête à lames flexibles telle que définie dans la revendication 1, caractérisée en ce que l'élément intercalaire (6) fait saillie vers l'avant jusqu'à une position intermédiaire
entre les bords de coupe (36, 38) des première et seconde lames (32, 34) afin de positionner
la surface (88) de contact avec la peau entre les bords de coupe (36, 38).
3. Tête à lames flexibles telle que définie dans la revendication 1 ou 2, caractérisée en ce que le premier angle de rasage est supérieur au second angle de rasage lorsque les première
et seconde lames (32, 34) ne sont pas fléchies à distance de leurs positions de repos
respectives.
4. Tête à lames flexibles telle que définie dans la revendication 3, caractérisée en ce que le premier angle de rasage se situe dans la plage de 25,8 à 26,6 degrés, et en ce que le second angle de rasage se situe dans la plage de 21,0 à 22,4 degrés.
5. Tête à lames flexibles telle que définie dans l'une quelconque des revendications
précédentes, caractérisée en ce que les lames (32, 34) sont fixées en place de manière permanente et immobile entre ledit
chapeau (8) et l'organe de protection (20) par plusieurs rivets (80) qui s'étendent
vers le bas depuis le chapeau (8) en passant à travers la partie arrière des lames
(32, 34), l'élément intercalaire (6) et le plateau (2).
6. Tête à lames flexibles telle que définie dans l'une quelconque des revendications
précédentes, caractérisée par de multiples colliers d'extrémité (82) qui couvrent les coins des parties avant des
première et seconde lames (32, 34) et qui empêchent un mouvement vers le haut desdits
coins.
7. Tête à lames flexibles telle que définie dans la revendication 6, caractérisée en ce que les multiples colliers d'extrémité (82) qui couvrent les bords extérieurs des parties
avant des première et seconde lames (32, 34) sont revêtus d'un agent réducteur de
friction qui réduit des forces de frottement des colliers sur la peau occasionnées
lors du rasage.
8. Tête à lames flexibles telle que définie dans la revendication 7, caractérisée en ce que l'agent réducteur de friction est lié à une ou des surfaces des colliers d'extrémité
(82) à un niveau moléculaire, et en ce que l'agent est un poly(acétate de vinyle) (PVA), du Nylon 515, un polyimide, un polyester
imide, un polyamide, un polyester ou du Téflon.
9. Tête à lames flexibles telle que définie dans l'une quelconque des revendications
précédentes, caractérisée en ce que le plateau comporte une ou des lèvres (60) qui viennent en contact avec la première
lame (32) après un degré prédéterminé de flexion vers le bas, afin de limiter l'importance
de l'angle de rasage agressif.
10. Tête à lames flexibles telle que définie dans l'une quelconque des revendications
précédentes, caractérisée en ce que l'élément intercalaire (6) comporte des patins (7) s'étendant vers le bas qui viennent
en contact avec la surface supérieure de la première lame (32) lorsque la première
lame (32) est dans une position de repos non fléchie, et empêche une flexion vers
le haut de la première lame dans une direction augmentant l'angle de rasage agressif
de celle-ci.
11. Tête à lames flexibles telle que définie dans l'une quelconque des revendications
précédentes, caractérisée en ce que le chapeau (8) comporte des patins (78) s'étendant vers le bas qui viennent en contact
avec la surface supérieure de la seconde lame (34) lorsque la seconde lame (34) est
dans une position de repos non fléchie, et empêche une flexion vers le haut de la
seconde lame dans une direction augmentant l'angle de rasage agressif de celle-ci.
12. Tête à lames flexibles telle que définie dans l'une quelconque des revendications
précédentes, caractérisée en ce que les première et seconde lames (32, 34) comportent des trous/ouvertures (42, 43) qui
permettent le passage de l'eau pour chasser des débris de rasage, et en ce que les trous/ouvertures (42, 43) contribuent à la flexibilité des première et seconde
lames (32, 34) qui permet une flexion vers le bas des lames pour qu'elles adoptent
leurs angles de rasage moins agressif respectifs.