U.S. patent number 3,722,090 [Application Number 05/171,075] was granted by the patent office on 1973-03-27 for guard bar for safety razors.
This patent grant is currently assigned to Warner Lambert Company. Invention is credited to Jan Dawidowicz.
United States Patent |
3,722,090 |
Dawidowicz |
March 27, 1973 |
GUARD BAR FOR SAFETY RAZORS
Abstract
The disclosure is directed to a safety razor guard bar having a
continuous guard bar surface positioned outwardly and below the
cutting edge of a razor blade. The continuous guard bar surface is
provided to fix the cutting angle of the blade, and to smooth and
stretch the skin prior to its engagement with the cutting edge of
the blade. The guard bar includes a plurality of ridges spaced
along the upper surface thereof. Each of the ridges has an outer
arcuate surface extending from the continuous guard bar surface
upwardly and inwardly to beneath the blade such that the upper
portion of each of the ridges is in close proximity to the cutting
edge of the blade.
Inventors: |
Dawidowicz; Jan (Fairfield,
CT) |
Assignee: |
Warner Lambert Company (Morris
Plaines, NJ)
|
Family
ID: |
22622411 |
Appl.
No.: |
05/171,075 |
Filed: |
August 12, 1971 |
Current U.S.
Class: |
30/34.2; D28/46;
30/81 |
Current CPC
Class: |
B26B
21/40 (20130101); B26B 21/16 (20130101) |
Current International
Class: |
B26B
21/16 (20060101); B26B 21/40 (20060101); B26B
21/08 (20060101); B26B 21/00 (20060101); B26b
021/00 (); B26b 021/14 () |
Field of
Search: |
;30/32,74.1,77,81 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Simpson; Othell M.
Assistant Examiner: Smith; Gary L.
Claims
What is claimed is:
1. A safety razor comprising means for exposing at least one blade
cutting edge, and at least one elongated guard; said guard
including a continuous skin engaging outer surface portion
positioned outwardly and downwardly from said cutting edge for
smoothing and stretching a skin surface during shaving, and a
plurality of spaced ridges, each one of said ridges extending
upwardly and inwardly from said continuous outer surface portion of
said guard to beneath and in close proximity to said cutting
edge.
2. The razor of claim 1 wherein each one of said ridges has an
arcuate upper surface extending from said continuous outer surface
portion of said guard.
3. The razor of claim 1 wherein said arcuate upper surface of each
of said ridges extends to between about 0.007 inch and about 0.012
inch beneath said cutting edge.
4. The razor of claim 1 wherein said continuous outer surface
portion of said guard is arcuately formed, and wherein said arcuate
upper surface of each of said ridges is a contiguous continuation
of said continuous arcuate outer surface portion of said guard.
5. The razor of claim 4, wherein said guard has upper arcuate
surfaces intermediate said ridges, said guard bar upper arcuate
surfaces having a radius of curvature less than that of said
ridges.
6. The razor of claim 5, wherein each of said ridges has a pair of
parallel sides perpendicularly extending upwardly from said
guard.
7. The razor of claim 6 wherein each of said guard upper arcuate
surfaces is about 2.8 times greater in length, taken along the
longitudinal axis of said guard, than the distance between said
pair of parallel sides.
8. The razor of 6 wherein each of said guard upper arcuate surfaces
is about 0.154 inch in length takes along the longitudinal axis of
said guard, and wherein the distance between said pair of parallel
sides in about 0.055 inch.
9. The razor of claim 8 wherein at least five ridges are formed
along said outer surface portion of said guard.
10. The razor of claim 5 wherein said arcuate upper surface of each
of said ridges extends to between about 0.007 inch and about 0.012
inch beneath said cutting edge.
11. The razor of claim 1 wherein said continuous outer surface
portion of said guard and said ridges each have serrations for
contacting the skin surface during shaving.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to safety razors of the type having a
guard bar surface below and outwardly from the cutting edge of a
blade. More particularly, the present invention relates to a guard
bar structure for limiting the amount of skin entering between the
guard bar surface and the cutting edge of the blade to thereby
minimize the possibility of nicks and cuts.
2. Description of the Prior Art
It is known to provide a continuous guard bar surface extending
parallel to the cutting edge of a blade and positioned below and
outwardly from the cutting edge. Guard bars of this type are shown
at least in U.S. Pat. Nos. 2,911,713 and 3,171,198. Such guard bar
surfaces act to stretch and smooth the skin prior to the skin
coming in contact with the cutting edge of the blade. Further,
guard bars of this sort provide a predetermined cutting angle for
the blade, and also limit the amount of skin which may enter
between the guard bar and the cutting edge of the blade. However,
even with a continuous guard bar individuals having skin
imperfections such as acne may be susceptible to nicks and
cuts.
It is also known to provide guard means comprising a plurality of
spaced teeth extending downwardly and outwardly from the cutting
edge of a blade. Such guard means are shown in at least U.S. Pat.
Nos. 2,143,276 and 2,893,119. In each of these patents, the blade
rests on the teeth such that portions of the cutting edge of the
blade serve little or no function. For example, U.S. Pat. No.
2,893,119 provides for longitudinal movement of the blade such that
the portions of the cutting edges that were positioned on the teeth
can be used as cutting surfaces. U.S. Pat. No. 3,378,922 discloses
guard means of a plurality of teeth which are not in contact with
the cutting edge of a blade. However, guard means consisting of a
plurality of spaced teeth do not provide a continuous surface for
smoothing and stretching the skin prior to its engagement with the
cutting edge of the razor. Rather, such guard means acts to pinch
the skin to provide a plurality of raised skin surfaces which are
then shaved by the cutting edges of the blade.
It is also known to provide razor blades having self-contained
guards. For example, U.S. Pat. No. 1,846,622 provides for dividing
a cutting edge of a blade into sharpened and dull portions by
spaced deposits of material secured to the cutting edge. U.S. Pat.
No. 3,505,734 also provides for dulling portions of the cutting
edge of a blade by having a plurality of spiral windings of a
thread firmly attached to the blade, and spaced along and extending
around the cutting edge of the blade. Thus, blades having
self-contained guards such as described in U.S. Pat. Nos.
1,846,622, and 3,505,734 act to reduce the effective cutting
surface of the blade.
SUMMARY OF THE INVENTION
In accordance with an aspect of the present invention that is
provided a guard bar structure for a safety razor wherein an
elongated guard bar has a longitudinal axis extending parallel to
the cutting edge of a blade, and wherein the guard bar has an outer
surface portion positioned outwardly and downwardly from the
cutting edge of the blade. The invention provides for a plurality
of spaced ridges formed along the outer surface portion of the
guard bar, and for each of the ridges to extend upwardly and
inwardly from the outer surface portion of the guard bar to beneath
and in close proximity to the cutting edge of the blade. In
accordance with a specific aspect of the invention, each of the
ridges has an arcuate outer surface extending from an arcuately
formed outer surface portion of the guard bar.
The guard bar as structured according to the present invention
provides for a continuous guard bar surface for smoothing and
stretching the skin, and ridge surfaces which continue the
smoothing and stretching action such that a minimum amount of skin
enters between the guard bar and the cutting edge of the blade to
minimize the possibility of nicks and cuts particularly for an
individual who has skin imperfections such as acne.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of a safety razor having a guard bar
embodiment of the present invention;
FIG. 2 is a side view of the razor;
FIG. 3 is an enlarged sectional view of the guard bar portion of
the razor taken along the line 3--3 of FIG. 1;
FIG. 4 is a plan view of the blade-seating plate of the razor;
and
FIG. 5 is a front view of the blade-seating plate of the razor.
DESCRIPTION OF SPECIFIC EMBODIMENTS
The guard bar structure according to the present invention is
suitable for use in any type of safety razor. By way of example,
the guard bar structure is shown in a safety razor of the type in
which new blades are adapted to be fed into the head of the razor
from a separate blade-filled magazine. The embodiment described
with reference to the Figures modifies the guard bar of the safety
razor of Kuhnl U.S. Pat. No. 2,911,713, issued Nov. 10, 1959. U.S.
Pat. No. 2,911,713 is incorporated herein by reference.
With reference to the figures, the safety razor includes a
substantially rigid handle 10 of plastic or other material, and a
head 11 in which a blade 12 is adapted to be inserted edgewise from
one side of the head 11.
The head 11 includes a substantially rigid main frame 13 of sheet
metal construction. The lower portion of the frame 13 extends
downwardly into and is fixedly secured in the upper part of the
handle 10. The upper portion of the frame 13 is curved forwardly at
15 and terminates at its upper end in a narrow forwardly and
downwardly inclined flange or cap 16. The blade 12 is adapted to be
clamped against the underside of the cap 16. The cap 16 overlies
only the rear portion of the blade 12 in order to leave the cutting
edge 17 of the blade 12 exposed.
The frame 13 is provided with a flat downwardly extending section
18 immediately beneath and behind the cap 16. the section 18 forms
the rear stationary wall of an expansible channel 19 in which a
positioning key (not shown) of a typical blade dispensing magazine
(not shown) is adapted to be inserted.
The head 11 of the razor is provided with a forwardly and
downwardly movable blade-seating plate 26 of generally L-shaped
cross section. The upper portion of the seating plate 26 consists
of a flat forwardly projecting flange 27 which underlies the cap 16
and constitutes the seat for the blade 12. The blade seat 27 is
connected, at its front edge, to a downwardly curved,
longitudinally serrated guard bar 28. A clearance opening 29 (FIG.
4) is provided in the seat 27 behind the guard bar 28.
The blade-seating plate 26 is provided with a flat downwardly
extending flange 30 (FIG. 5) immediately beneath and behind the
seat 27. The downwardly extending flange 30 is disposed in a
forwardly spaced relation to the flat section 18 of the frame 13
and forms the front forwardly shiftable wall of the expansible
channel 19 for a positioning key (not shown) of a blade dispensing
magazine (now shown). The seating-plate 26 terminates in two
laterally spaced downwardly tapering end portions 31 (FIG. 5) below
the flange 30. The end portions 31 are nested in the main frame
13.
With reference to FIG. 5, the two laterally spaced downwardly
tapering end portions 31 of the blade seating-plate 26 form a
centrally arranged downwardly opening rectangular recess 35 of
substantial width and depth. The recess 35 has a straight
horizontally disposed upper edge 36 and parallel side edges 37. The
upper edge 36 of the recess 35 is located a substantial distance
below the seat 27 and also a substantial distance above the lower
ends of the downwardly tapering end portions 31. The upper edge 36
of the recess 35 constitutes a line-contact fulcrum for
self-adjusting coaction with a seat clamping spring 25 (FIG.
1).
The seat clamping spring 25 is of substantially flat heavy leaf
construction. The lower portion 38 of the spring 25 is of
downwardly tapered form and is clamped solidly against the front
face of the frame 13. The upper portion 41 of the spring is reduced
abruptly and is of generally rectangular form. The lower part of
the upper portion 41 of the spring 25 is nested snugly but freely
within the downwardly opening rectangular recess 35 of the seating
plate 26, and the upper forwardly bent portion of the spring 25
bears rearwardly and upwardly with a substantial pressure against
the upper edge 36 of the recess in line contact with the front of
such edge.
The front cutting edge 17 of the blade 12 is engaged at its ends by
small, upstanding lug 47 on the blade-seating plate 26 at the ends
of the guard bar 28. Thus, the cutting edge 17 lies in a vertical
plane as defined by rear vertical walls 50 of the lugs 47 (FIG.
3).
In accordance with the present invention, a plurality of spaced
ridges 51-55 are provided on the upper surface of the guard bar 28.
The ridges 51-55 each has an upper arcuate surface 56 (FIG. 3)
which arcuately blends into the outer arcuate surface portion 57 of
the guard bar at 28. As shown in FIG. 3, the outer surface portion
57 of the guard bar 26 and the ridge upper surface 56 has a common
radius of curvature from approximately C to D. As also shown in
FIG. 3, the arcuate upper surfaces of the guard bar intermediate
the ridges 51-55 have a smaller radius of curvature than that of
the ridges such that the guard bar upper surfaces are below that of
the upper surfaces of the ridges and extend in an arc from E to F.
The guard bar 26 and the ridges 51-55 can have longitudinally
extending serrations 58 formed along their outer surfaces to aid in
smoothing and stretching the skin prior to engagement with the
cutting edge 17 of the blade 12.
The guard bar 28 provides for smoothing and stretching of the skin
along the continuous outer surface 57 of the guard bar 28, and such
smoothing and stretching is continued by the upper surface 56 of
each of the ridges 51-55 prior to the skin coming into cutting
engagement with the cutting edge 17 of the blade 12. The skin
intermediate the spaced ridges 51-55 will bow slightly in a taut
state as a result of the smoothing and stretching action of the
guard bar 28 and the upper surfaces 56 of the ridges 51-55. This
action smooths and stretches skin imperfections such that a minimum
amount of skin enters between the guard bar and the cutting edge,
to thus minimize a possibility of nicks and cuts. Further, the
above described guard bar structure provides for use of the whole
cutting edge 17 of the blade.
A preferred embodiment provides that the guard bar 28 spacing
intermediate the ridges 51-55 is 2.8 times the longitudinal width
of the upper surface 56 of each of the ridges 51-55. As shown in
FIG. 5, the preferred embodiment provides that the longitudinal
width of each of the ridges 51-55, as defined by parallel side
walls perpendicularly extending upwardly from the guard bar, is
0.55 inch, and that the spacing between each of the ridges 51-55 is
0.154 inch. Further, the preferred embodiment provides arcuate
upper ridge surfaces 56 which are contiguous with the arcuate outer
surface portion 57 of the guard bar 28 such that the arcuate
surface C - D (FIG. 3) has a radius of curvature of 0.090 inch from
a point A. The upper guard bar surface 59 intermediate the spaced
ridges 51-55 is also arcuately contiguous with the outer surface 57
of the guard bar 28. As shown in FIG. 3, the upper guard bar
surface 59 has a radius of curvature between at least points E and
F of 0.055 inch from a point B.
As shown in FIG. 3, each of the ridges 51-55 arcuately extends from
the guard bar outer surface 57 upwardly and inwardly to at least a
plane defined by the vertical rear walls 50 of the lugs 47 and
beneath the cutting edge 17 of the blade 12 which rests against the
vertical rear walls 50. In the embodiment shown, the ridge upper
surface 56 extends rearwardly beneath the cutting edge 17 of the
blade 12 to a point D which is 0.007 inch from the plane defined by
the rear wall of the lugs 50.
As shown in FIG. 3, the uppermost portion of each of the ridges is
preferably between about 0.002 inch and about 0.007 inch beneath
the seat 27. A typical blade has a thickness of about 0.010 inch,
and the cutting edge is formed by two beveled surfaces. Thus, the
cutting edge 17 is about 0.005 inch above the seat 27, and the
uppermost portion of each of the ridges is preferably between about
0.007 inch and 0.012 inch beneath the cutting edge 17.
As used herein, arcuate describes the curved or bowed general
contour of the outer surface portion 57 of the guard bar, of the
upper guard bar surfaces 59, and of the upper ridge surfaces 56.
Arcuate is meant to include a surface having serrations therein
such as the longitudinal serrations 58, and when used in this
context, the arcuate surface will be defined by the peaks of the
surfaces formed by the serrations. For example, the arc between
points C and D includes the peaks formed by serrations in the guard
bar 28 and in the ridge 53. It is also possible to form vertical
serrations in the guard bar 28 and the ridges 51-55, and in this
instance, the arcuate surface is also defined by peaks formed
intermediate the serrations.
Although the embodiment of the invention is described in
combination with the razor of U.S. Pat. No. 2,911,713, it is
obvious that the invention can take other shapes or forms in
combination with other types of razors by modifications made by
those skilled in the art without deviating from the scope and
spirit of invention. For example, guard bar structure in accordance
with the present invention can be used in combination with a
ribbon-type razor such as shown in Kuhnl U.S. Pat. No. 3,555,681,
or in a cap-type double edge safety razor such as shown in
Dawidowicz et al U.S. Pat. No. 3,466,746, or in safety razors
having an adjustable guard bar such as Ferraro U.S. Pat. No.
3,552,008 and Kuhnl U.S. Pat. No. 3,203,093. Further, guard bar
structure according to the present invention can be used in a rigid
plastic member which permanently secures a razor blade such as
described in Hanson U.S. Pat. No. 3,388,831, and generally known as
a "bonded" blade or "bonded" razor.
* * * * *