U.S. patent number 3,685,150 [Application Number 05/058,539] was granted by the patent office on 1972-08-22 for double edge safety razor embodying flexible blade pressure control.
This patent grant is currently assigned to Philip Morris Incorporated. Invention is credited to Frederick L. Risher.
United States Patent |
3,685,150 |
Risher |
August 22, 1972 |
DOUBLE EDGE SAFETY RAZOR EMBODYING FLEXIBLE BLADE PRESSURE
CONTROL
Abstract
The disclosure introduces a new concept in double edge safety
razor construction; that of the floating head. A floating head is
herein defined as a blade support assembly which is mounted for
movement transverse to the path of movement undergone by the
pressure guard. A double edge safety razor utilizing a floating
head construction of the type herein described for use with double
edge blades is insensitive not only to variations in the
application of handle pressure but also to other skin aberrations
which tend to increase blade pressure. A biased double edge blade
support assembly, comprising the floating head, is mounted for
controlled pivotal movement toward and away from two skin pressure
guards positioned on opposite sides of the razor and integral with
the razor handle whereby the principle of the floating head
maintains with either of the opposed blade edges. This construction
permits a constant blade pressure to be exerted on the skin
irrespective of which blade edge is in use or the pressure which is
exerted on the handle and skin engaging pressure guard.
Inventors: |
Risher; Frederick L. (Laurel,
MS) |
Assignee: |
Philip Morris Incorporated (New
York, NY)
|
Family
ID: |
26216530 |
Appl.
No.: |
05/058,539 |
Filed: |
July 27, 1970 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
29788 |
Apr 20, 1970 |
|
|
|
|
Current U.S.
Class: |
30/74.1; 30/57;
30/527 |
Current CPC
Class: |
B26B
21/18 (20130101) |
Current International
Class: |
B26B
21/08 (20060101); B26B 21/18 (20060101); B26b
021/32 (); B26b 021/52 () |
Field of
Search: |
;30/57,69,70,71,77,87,89,74.1 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Riordon; Robert C.
Assistant Examiner: Smith; Gary L.
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of application Ser. No. 29,788 filed
Apr. 20, 1970, now abandoned.
Claims
I claim:
1. A double edge safety razor, comprising; a handle assembly
including opposed skin pressure guards; a blade support assembly
for mounting the opposed edges of a double edge blade in parallel
juxtaposed relation to the corresponding opposed pressure guards;
and means mounting said blade support assembly on said handle
assembly for floating movement of said blade edges transversely of
the pressure guards.
2. The razor of claim 1 including means for biasing said blade into
a central positionment relative to said pressure guards.
3. The razor of claim 2 wherein said blade support assembly
includes a blade clamping head and manual actuating means for
clamping and unclamping a blade.
4. The razor of claim 3 wherein said handle assembly includes an
elongate hollow handle, said blade support assembly including an
integral elongate extension extending into said hollow handle; and
said first named means including pivot means interconnecting said
handle and elongate extension to define an arcuate path of floating
movement for said blade edges relative to said pressure guards.
5. The razor of claim 4 wherein the means for biasing said blade
includes spring means reacting between the handle assembly and
blade support assembly.
6. The razor of claim 5 including means for adjusting the bias of
said spring means.
7. A double edge safety razor, comprising; a handle assembly
including opposed skin pressure guards adapted to be alternately
drawn along a skin shaving path in contact therewith; double edge
blade support means for supporting one or the other of opposed
blade edges in juxtaposed skin engaging trailing relationship to a
respective pressure guard as the same moves along a skin shaving
path; and means engaging said handle assembly and blade support
means floatingly supporting the latter relative to the former for
transverse movement of both blade edges relative to the shaving
path.
Description
BACKGROUND OF THE INVENTION
The original safety razor development afforded a method of
achieving a close shave without the very real danger of serious
injury that had previously attended the use of straight razors.
Although the safety razor has eliminated the possibility of serious
injury, the very knowledge of this fact on the part of the user has
tended to increase the number of minor abrasions and "nicks"
occasioned by its use since one tends to shave with less care and
precision than would be the case were serious injury possible.
Although the evolution of the safety razor and the concomitant
development of improved blade alloys and honing techniques have
contributed greatly to the ease and comfort of shaving, these prior
developments have been primarily concerned with methods of
achieving a more precise blade angle control relative to the guard,
a faster blade interchange and longer blade life. Present day
safety razors show little improvement over the original models
insofar as the provision of a true "nick-proof" construction is
concerned as is readily apparent to any person who uses such a
razor.
The problem is, perhaps, more pronounced in the case of feminine
use where the areas to be shaven are not always readily visible;
however, even the most experienced shaver is not immune to the skin
"nicks" which are caused by hurried or careless shaving. The most
common cause of these minor injuries is the application of
excessive blade pressure. This may occur, for example, in shaving a
particularly sensitive area, such as the neck or underarms, or in
the failure to vary pressure application as the blade moves across
a varying skin contour.
Although the general proposition of mounting a blade in such a
manner that it may undergo relative movement in relation to its
supporting handle has been previously recognized, as in U.S. Pat.
Nos. 1,479,690; 2,059,172 and 2,125,135; in all of these prior
constructions there has been a direct relationship between the
pressure exerted by a user on the razor handle and the blade
pressure against the skin. Thus in U.S. Pat. No. 2,059,172, the
blade edge may undergo limited relative movement parallel to the
axis of the razor handle and in U.S. Pat. Nos. 1,479,690 and
2,125,135 the blade edge is pivotally supported to follow the
contour of the skin and an excessive pressure application at the
razor handle is reflected in an excessive blade edge pressure.
Stated differently, the prior art has not recognized the advantages
in the provision of a safety razor construction wherein the total
blade pressure is due solely to an independent biasing force and is
totally independent of applied handle pressure.
The foregoing problems were overcome by the advent of that safety
razor construction employing a floating head as described in the
aforesaid pending application which related to a single edge razor
of the injector type. In essence, that application discloses a
pivotally mounted single edge blade support assembly which is
biased in the direction of the single skin pressure guard. Inasmuch
as double edge razors are at least as popular as the single edge
type it is obviously desirable that the floating head, or nick
proof razor, concept be extended to include double edge blades
while yet retaining the general configuration of conventional
double edge razors.
SUMMARY OF THE INVENTION
The invention resides in the provision of a double edge safety
razor having a double edge blade mounting assembly which is mounted
for controlled pivotal movement toward and away from the normal
path of movement undergone by one or the other of the opposed fixed
pressure guards during a shaving operation. The pressure guards may
be rigidly secured to the razor handle and the total pressure
applied to the skin, by the application of handle pressure, is
through one or the other of the pressure guards. An independent
biasing force provides the desired blade edge pressure irrespective
of which of the opposed blade edges is being used and this force
will be the same whether the pressure guard is under a light or
heavy pressure application from the handle.
In a preferred embodiment, the pressure guards are rigidly secured
to the handle and occupy the same positions relative thereto as do
the pressure guards of a conventional double edge safety razor. The
blade support assembly is pivotally mounted on the handle assembly
to support the blade in overlying relationship to the fixed
pressure guards for limited movement of each blade edge toward and
away from its respective underlying pressure guard. The blade
support assembly may be pivotally mounted directly on the handle
structure and, in a preferred form, has a portion thereof including
the pivot structure and biasing means telescopically enclosed
within a hollow handle whereby the conventional appearance of the
razor is maintained. Any desired biasing means such as a coil
spring, leaf spring, mass of rubber or the like may be provided to
effect the desired biasing force.
The blade support assembly is normally biased to a position
centering the double edge blade in relation to the fixed pressure
guards to define a conventional blade angle positionment of either
edge relative to its respective fixed guard. As the razor is moved
along the skin and one or the other of the pressure guards
describes its path of travel along the skin surface, the shaving
blade edge is held into contact with the skin surface solely by the
strength of the biasing force. Any variation in the skin contour
tending to produce excessive blade pressure or any increase in
pressure applied to the handle beyond the strength of the biasing
force is compensated for by movement of the blade edge, against the
biasing force, away from the skin in a direction transverse of the
path of movement undergone by the pressure guard. It will thus be
apparent that irrespective of the varying skin contour or the
applied handle pressure, the blade edge pressure against the skin
will never exceed the strength of the biasing force and will, in
effect, float across the skin as though being towed by the pressure
guard which may be pressed against the skin with any desired
force.
The strength of the biasing force is, desirably, adjustable to take
into account individual variables as regards toughness of beard,
skin sensitivity, etc.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a double edge safety razor
embodying a floating head;
FIG. 2 is an exploded perspective of the same with a portion of the
blade support assembly broken away;
FIG. 3 is a sectional view taken along the line 3--3 of FIG. 1;
FIG. 4 is a sectional view taken along line 4--4 of FIG. 3;
FIG. 5 is a side elevational view illustrating the centralized
position of the floating head in normal shaving position; and
FIG. 6 is a side elevational view illustrating an exaggerated
displaced position of the floating head.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The safety razor 10 comprises a handle assembly 12 including
opposed generally conventional skin pressure guards 14, 16
integrally joined with a handle portion 18 within the hollow
interior of which is pivoted the lower end of a blade support
assembly 20 for limited pivotal movement about pivot pin 22 in
opposition to the bias of tension spring 24 interconnecting the
tail portion 26 of blade support assembly 20 and anchor stud 28
threadedly interconnected with a bias adjusting plug 30 bottomed on
the shoulders of flange 32 within handle 18. As will be apparent
from an inspection of FIG. 2, skin pressure guards 14, 16 are
joined by a web 34 which is rigidly interconnected with handle 18
by yoke structure 36. Blade support assembly 20 includes a
generally conventional blade supporting head 38 having a
conventional blade clamping assembly including a center bar 40,
cross arms 42 and cap members 44 to clamp and release a
conventional double edge blade 46 in the usual manner upon rotation
of the knurled sleeve 48 to advance or retract spider 50 underlying
the clamping assembly. Sleeve 48 is threadedly engaged with an
intermediate portion 52 of the blade support assembly for the usual
axial adjustment relative thereto.
In FIGS. 1, 3 and 4 is illustrated the central positionment of
blade support assembly 20 relative to handle assembly 12. A similar
positionment is shown in FIG. 5 wherein the skin surface being
shaved is schematically illustrated at 54 and the torque applied to
the blade support assembly by the application of handle pressure as
indicated at 56, tending to pivot the same about the axis of pivot
pin 22, does not exceed the bias imposed by spring 24. Thus, under
the aforestated conditions as illustrated in FIG. 5, blade 46 is
centrally positioned above skin pressure guards 14, 16 and assumes
a normal angle of attack with respect to skin surface 54. Under the
shaving conditions illustrated in FIG. 5, razor 10 functions as a
conventional razor since the floating action of head 38 does not
come into play until the blade pressure against skin surface 54,
tending to rotate the blade support assembly clockwise about pivot
22 as viewed in FIG. 5, exceeds the counter-rotating bias applied
thereto by spring 24. The floating head action becomes effective
immediately upon the application of that blade pressure against the
skin which exceeds the maximum safe cutting pressure as determined
by the adjustment of plug 30 to vary the tension of spring 24. This
latter condition is illustrated in FIG. 6 wherein the application
of excessive handle pressure, as schematically indicated by the
heavy arrow 58, imposes a blade pressure on skin surface 54 in
excess of that required for shaving. Thus the clockwise torque
imparted to blade support assembly 20 exceeds the counterclockwise
bias imposed by spring 24 and the head 38 "floats" to assume an
upwardly displaced position, relative to skin pressure guard 16, as
illustrated in FIG. 6. With further reference to FIG. 6, it will be
appreciated that the indicated application of excessive handle
pressure results in an indentation of the skin by skin pressure
guard 16 with the blade and its supporting head merely floating
upwardly to maintain the same blade pressure thereagainst as though
a proper handle pressure were being applied.
The manner in which the razor may be assembled from its component
parts will be apparent from an inspection of FIGS. 2 and 3. The
tail portion 26 of the blade support assembly with its
interconnected spring 24 and stud 28 are inserted through a central
opening 60 in web 34 and into the hollow interior of handle 18.
Stud 28 is generally rectangular in cross section and extends
through a similarly shaped opening 62 circumscribed by the flange
32 formed in handle 18. Pin 22 is then inserted through openings 64
formed in handle 18 and corresponding bore 66 in blade support
assembly 20. Plug 30 is then inserted at the lower end of the
handle and rotated to draw stud 28 into threaded bore 68 until the
desired tension is established in spring 24. The razor is now ready
for use in the manner described and insures that the application of
blade pressure to the skin is a function of pre-established spring
tension rather than applied handle pressure.
Although conventional guards 70, which are a part of the floating
head, are not required for the practice of the invention, they do
contribute to increased shaving comfort and are desirably utilized
to facilitate manufacturing since the floating head itself,
including guards 70, may be purchased separately from conventional
razor manufactures and modified in accordance with the
aforedescribed floating head concept.
* * * * *