Note: Descriptions are shown in the official language in which they were submitted.
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RAZOR ASSEMBLY
The present invention relates to a razor blade structure and more particularly
to a guard to be employ
in combination with a blade or blades in a razor or razor cartridge. This
application is a division of commonly
owned Canadian Patent Application No. 2,288,101 of April 27, 1998.
In U.S. Patent Number. 3,724,070, issued Apr. 3, 19739 in the name of Francis
VV. Dorion, Jr., there
is disclosed a blade assembly in which blade means are held between the blade
assembly surfaces adapted to
engage the surface being shaved in front of and behind, respectively, cutting
portions ofthe blade means. Such
surfaces axe generally referred to in the prior art as "guard" and "cap"
surfaces.
Various combinations of guard, cap and blade means have been disclosed in the
prior art. Typical
combinations are disclosed in U. S. Patent Number. 4,168, 571, issued
September 25, 1979, in the name of John
F. Francis, in which the guaxd, cap and blade means are each movable
independently of each other; and U.S.
Patent Number. 4,270,268, issued June 2, 1981, in the name of Chester F.
Jacobson. Further disclosures of
such combinations may be found in U.S. Patent Numbers 4,270,268; 4,488,357;
4,492,024; 4,492,025;
4,498,235; 4,551,916; 4,573,266; 4,586,255; 4,378,634; 4,587,729; and
4,621,424, all issued in the name of
Chester F. Jacobson and assigned to the assignee of the present invention.
In U.S. PatentNumber 5,249,361, issued Oct. 5, 1993, to Domenic V. Apprille,
Jr. et al., and
assigned to the assignee of the present invention, there is disclosed a razor
blade body in the form of a cartridge
structure which includes a guard member assembled forward of, and extending
parallel to, the blade or blades
of a razor cartridge. The guard is of a two-part molded structure having an
upper portion of elastomeric
material with a plurality of upwardly projecting protrusions, and a lower base
portion of rigid plastic material,
preferably polypropylene. The lower base portion of rigid plastic material has
a downwardly projecting
V-shaped crosssectional portion and a pair of projecting elements disposed in
spaced relation in the blade
cartridge and separated so as to form a recess in which the V-shaped base
portion is received. The two-part
guard comprising the upper portion of elastomeric material and the base
portion of rigid plastic material has
been marketed by the assignee of the present application under the trade
designation "Sensor Excel" and has
met with customer acceptance and has proven to be commercially successful.
As disclosed in the above-cited U.S. Patent Number 5,249,361, the guard member
is manufactured
of two distinct components which are formed together prior to assembly in the
razor blade structure requiring
a separate manufacturing step to produce the guard member, prior to its
installation into the razor blade
assembly. Additionally, the final combination of the portion of elastomeric
material and the base portion of
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rigid plastic material are of necessity larger in the fore to aft width
dimension than would be a single
elastomeric material unit installed directly into the razor blade structure.
The configuration of the upwardly
projecting protrusions, and their location relative to the blades, and to one
another, is therefore more restricted
than would be the situation should the guard member be provided as a unitary
element, supported within the
razor blade assembly structure.
The invention as set forth in the parent applicatnion defines a safety razor
blade unit which comprises
at least one blade, a razor blade body structure supporting the at least on
blade and having a front wall
extending parallel with a blade edge and disposed forward of the at least one
blade, and an elongated guard
member disposed in the razor blade body structure for contacting and
stretching a skin surface being shaved
in from of the at least one blade during shaving. The guard member comprises a
unitary molded member of
elastomeric material. The unitary molded member comprises a molded bottom base
portion extending
downwardly for juxtaposition adjacent the front wall of the body structure
along the length of the guard
member, and a molded upper portion having a plurality of protrusions
projecting upwardly therefrom for
contacting the skin surface onto shich the at least one blade is applied, the
protrusions comprising at least three
fins extending along an upper surface ofthe guard upper portion parallel to
the blade edge and spaced one from
the other, each spaced apart fin having a fin proximal base and a fin distal
edge above the fin base, the fin distal
edges being disposed on a substantially arcuate convex surface and successive
fins being inclined more towards
the at least one blade than forwardly disposed adjacent fins. The guard member
will engage the skin being
shaved at a series of separate contact areas spanning an area greater than the
sum of contact areas of individual
fin distal edges.
The invention of the parent application also contemplates a razor blade
assembly which comprises an
elongate platform comprising a first plastic material, at least one blade
member disposed on the platform and
having a cutting edge generally oriented in a forward direction defining a
cutting path, and an elongated guard
member comprising a second plastic material and being disposed adjacent the
forward edge ofthe platform and
spaced forwardly of the blade member cutting edge. The guard member has a base
portion with a plurality of
fins disposed thereon. Each of the fins extends upwardly from the base portion
and generally perpendicular
to the cutting path. The fins are spaced one from the other and each ftn has
its uppermost surface disposed
below that of a rearwardly disposed fin, the uppermost surface collectively
intersecting an outwardly convex
arcuate surface. A smoothly continuous traction force is exerted on skin of a
user as the razor blade assembly
changes orientation relative tv the skin during shaving.
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The present invention, on the other hand, provides a razor blade assembly
comprising an elongate
platform provided with a plurality of apertures in spaced relation to a
plurality of webs therebetween, at least
one blade member disposed on said platform, and an elongated guard member
molded in situ omo said platform
through the apertures to surround the webs to maintain the guard member in
interlocking engagement with the
platform.
The present invention also contemplates a method of manufacturing a razor
blade assembly comprising
the steps of providing an elongate platform for supporting at least one blade
therein, the platform defining a
plurality of apertures extending therethrough, and molding an elongate guard
member through the apertures
in situ onto the platform in spaced relation with the blade, whereby first
portions of the elongate guard member
extend through the apertures and second portions of the elongate guard member
are disposed on opposite
surfaces of the elongate platform.
Reference is made to the accompanying drawings in which there is shown an
illustrative embodiment
of the invention from which its novel features and advantages will be
apparent, wherein:
Figure I is a front elevational perspective view showing a razor blade
assembly for use in a shaving
1 S instrument and constructed in accordance with the teachings of the present
invention;
Figure 2 is a front elevational exploded view showing the various elements of
the stnacture of Figure
1.
Figure 3 is a front elevational perspective view similar to Figure 1, having
selected elements of the
structure of Figure 1 removed;
Figure 4 is a top plan view showing details of the structure of Figure 3;
Figure 5 is a front elevational view showing further details ofthe structure
of Figures. 3 and 4;
Figure 6 is a top plan view showing the platform element of the structure of
Figures 1 through 5;
Figure 7 is a front elevational sectional view taken along the line VII -VII
of Figure 6;
Figure 8 is an enlarged side elevational sectional view taken along the line
VIII--VIII of Figure 4;
Figure 9 is a cross-sectional view of a portion of he structure of Figure 8,
taken on an enlarged scale
for clarity; and
Figure I0 is an enlarged side elevational sectional view taken along the line
X--X of Figure 4.
Referring now to the drawing and in particular to Figures I and 2 there is
shown a razor blade
assembly 10 comprising an elongated platform 12 for supporting a pair of
blades 13 and 14, having a spacer
16 disposed between the blades and separating the blades one from the other. A
cap member 18 is provided
with four cylindrical rivets 20, 21, 22 and 23 which when assembled to the
platform 12 extend through a
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plurality of circular openings 24 in the blades 13 and 14 and the spacer 16,
and are received in the circular
bores 26, 27, 28 and 29 formed in the platform 12.
A guard member 30 having upwardly projecting fins 3 l, 32 and 33 is disposed
at the forward edge of
the platform 12. The guard member 30 is forrn~l in situ onto the platform 12
and has portions 34, 35 and 36
which are disposed on the opposite surface, or undersurface of the platform,
and a portion 37 formed in a
groove 44 provided on the platform I2. It should be understood that the guard
member 30 being molded
directly onto the platform I2 will not appear separately as depicted in Figure
2, as the portions 34, 35 and 36
are molded through apertures in the platform and would be severed from the
guard member, if the guard
member were removed from the platform. The element 30 of Figure 2 is therefore
presented as a separate unit
to show details of the various components of the razor blade assembly 10.
Further, while the guard member 30 is depicted herein to be farmed on a
portion of a razor structure
having a pair of stationary blades 13 and 14, it should be understood that the
guard member herein to be
described may be employed in either a razor structure, or a cartridge, and may
be employed with a single blade,
multiple blades or in combination with movable blades as shown in the
aforementioned 1,3.5. Patent 5,249,361,
issued to Apprille et al.
Referring now to Figures 3 through 10, the platform 12, which is combined in
the razor blade structure
10 shown in Figures 1 and 2, is manufactured of a polypropylene material to
provide the necessary rigidity for
supporting the blades 13 and 14. The platform is provided with a plurality of
rectangular webs 38 which
extend upwardly from a surface 39 adjacent the forward edge of the platform,
and a plurality of apertures 40
are formed between the webs 38 to extend through the surface 39 and are open
at the underside ofthe platform
12. Portions of the elastomeric material of guard member 30 surround webs 38.
The platform 12 of the present embodiment further comprises a pair of
attachment members 42 and
43 which are provided to assemble the razor blade structure onto a handle (not
shown). The assembly of the
razor blade structure 10 onto a suitable handle will not be discussed or
described herein as such handles and
methods of attachment are well known in the art, may take many forms, and
constitute no part of the present
invention.
Prior to the assembly of the platform 12 into the razor blade assembly 10, the
elongate guard member
is injection molded onto the platform by providing a suitable mold and
injection molding machinery (not
shown) which may be o~ any type well known in the art to achieve the
configuration as described herein.
30 The elongate guard member 30 is generally manufactured of a thermoplastic
elastorneric material
which is chosen to provide a flexibility in the upstanding ribs 31, 32 and 33
to provide the preferred tactile
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sensation to the skin during the shaving process. In order to produce this
flexibility, the chosen materials
generally have a hardness value in the range of 27 to 7~ on the Shore A scale,
and materials which may be
selected are Kraton'~ 62705 having a hardness of 55 on the Shore A scale which
is manufactured by the Shell
Corporation, Evoprene~ #966 having a Shore A hardness value of 27 and
distributed by Gary Chemical
S Corporation of Leominster, Mass., Santoprene~ 271-55 having a Shore A
hardness value of 55 and
Santoprene~ 271-73 having a Shore A hardness value of 73, both manufactured by
Advanced Elastomerics
Corporation.
While the elongate guard member 30 may be injected in any manner to produce
the desired
configuration, in the present embodiment the injection takes place at the rear
of the platform 12 through a
groove 44 provided for that purpose. As the material flows through the groove
44 the portion 37 is formed in
the groove and the material is restrained within the mold to produce the fins
31, 32, and 33, and extends
downwardly through the apertures 40 and around the rectangular webs 38 forming
the elongate portions 34,
3S and 36 on the underside of the platform I2 as shown in Figure 2. This
provides a locking ofthe flexible
material onto the more rigid platform 12 retaining the guard member 30 in a
fixes position under the platform.
Furthermore, chemical affinity between the two plastics assists the bond. This
arrangement advantageously
provides the ease of manufacturing the second stage molding within the same
mold cavity, and then removing
the entire finished subassembly formed of platform 12 and guard member 30.
In the present embodiment, the razor blade sta~s~cture 10 when connected to a
suitable handle (not
shown) is intended to be rotatable about the handle. However, even without
this feature, it is considered that
during the shaving process the razor blade assembly will be rotated slightly.
It is therefore highly desirable that
the fms 31, 32 and 33 conform to the radial surfaces at the forward edge of
the platform I2 so as to increase
the smoothness of flow of the razor structure over the skin during the shaving
operation. As the guard member
is now a single unitary element, a great deal of latitude exists in molding
the guard member onto the
structure of the platform I2.
25 As best shown in Figure 9, the elongate guard member 30 in the present
structure is molded to provide
a base portion 48 having a radial surface 49 from which the fins 31, 32 and 33
extend upwardly. The fins 31,
32, 33 extend generally perpendicular to the cutting path of cutting edges of
blades 13, 14. 'The fins 31, 32 and
33 are each spaced one from the other, and each has its uppermost surface
below that of a rearwardly disposed
fin. In order to give a proper flexibility and strength to each ofthe fins 31,
32 and 33, each fin has a maximum
30 thickness at its base portion and tapers to a minimum thickness at its
uppermost surface.
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As best shown in Figures 9 and 10, the fins 31, 32, and 33 have distal ends
located away from base
portion 48 arranged along a convex arcuate surface. Together the fin distal
ends define a guard surface
spanning an area greater than the sum of the contact areas defined by the
individual distal ends (l. e., the surface
defin~i by the fin distal ends and the spacing between the distal ends is
greater than the surface area of the fin
distal ends themselves), but due to the comparatively claw spacing of the fms
31, 32, 33, the fzel to the skin
is generally that of a continuous surface. The resiliency of the fins and the
higher coefficient of friction of the
elastomeric material of the fins than that of the platform material
contributes to a pleasant traction force on
the skin. Due to the arrangement of fins extending generally perpendicular to
the directian of a shaving
movement over the skin surface, i.e., the shaving path being generally
parallel to the blade edges, a traction
force advantageous for shaving is exerted on the skin.
Again referring to Figure 9, each fin 31, 32, 33 disposed successively more
rearward, i.e., in the
direction towards the blades 13, 14, is inclined away from the vertical (i.e.,
towards the blades) more than its
forwardly-disposed neighboring fin. As shown in Figure 9, the leading edge
flank 33a of fin 33 is
approximately vertical at an angle A of about 1° rearward inclination;
leading edge flank 32a of fin 32 is
inclined at angle B of about 5° rearward; and leading edge flank 31a of
fin 31 is inclined at angle C of about
15° rearward. This disposition of fins 31, 32, 33 is referred to as a
splayed or raked back condition, and
advantageously provides more skin contact surface within the same base portion
48 spatial envelope than if
the fins were only vertical, and without the need to add a greater number of
fins closer to primary blade 14,
which might otherwise interfere with the exposure of primary blade 14, thus
providing good traction force with
less material and without impairing blade exposure. The splayed condition also
assists parting ofthe injection
mold tool to release the in situ molded cartridge and guard. As shown in
Figure 9, the trailing edge fin flanks
31b, 32b, 33b opposite respective leading edge flanks 31a, 32a, 33a can be
inclined towards a median plane
bisecting each fin at an angle of inclination away from an upwardly directed
vertical axis that is different from
the angle of inclination of the respective leading edge flanks to influence
the flexibility of each fin.
Advantageously, as shown in Figures 8 and 10, and in contrast to the assembly
shown in the
above-cited U.S. Patent5,249,361 at Figure 6 therein, the front wall portion
ofguard member 30 and leading
fin 33 do not overhang or extend mare forward than the platform 12, thus
contributing to resisting peeling or
separation of the fin from the platform in the high-friction forward fin axes
and reducing the user's perception
of too "flat" a feeling of orientation to the skin, e.g. face, being shaved.
The arrangement of distal ends of fins
31, 32, 33 along a generally convex or arcuate surface formed by the splayed
back fins allows a natural fit to
curved skin surfaces of the body, such as the face, without pushing the
cartridge flat against the skin surface
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as could result if all the fins terminated in a broad flat surface, while
still providing sufficient registration to
the skin surface to serve as a message to tlae user to properly orient the
cartridge shaving attitude. Elastorneric
fins 31, 32, 33 in this progressively splayed condition provide the advantage
of a high friction traction force
within a small actual working envelope and helps the user orient the cartridge
on the surface being shaved more
comfortably than a broad flat fin tip area.
With the elongate guard member 30 molded onto the platform 12 as shown in
Figures 3, 4 and 5, the
blades 13 and 14, spacers 16 and cap member 18 are assembled to produce a
razor blade assembly 10 as
shown in Figure 2. A razor blade assembly 10 is, therefore, provided having a
guard member 30 of
substantially flexible thermoplastic material and a platform 12 of
substantially rigid plastic material, the
platform being capable of supporting the blades 13 and 14, and of rigid
attachment to a handle to complete the
razor construction.
