U.S. patent number 3,802,072 [Application Number 05/183,937] was granted by the patent office on 1974-04-09 for electric safety razor.
Invention is credited to Andrew F. Wintercorn.
United States Patent |
3,802,072 |
Wintercorn |
April 9, 1974 |
ELECTRIC SAFETY RAZOR
Abstract
The rotary cutters cooperating with the two opposed cutting
edges of the safety razor blade are enclosed by tubular guards in
which longitudinal slots are provided leaving only a predetermined
gap parallel to each of the cutting edges, the width of which can
be varied to suit the closeness of shave a person desires, while
also insuring safety of operation by positively limiting the extent
of bulge of the skin between the adjacent rounded edge of the clamp
that serves as a guard and the far edge of the slot in the tubular
guard, the latter taking over completely the function heretofore
served by the guard on the head of the conventional interchangeable
blade safety razor. The split head of the razor permits easy
assembling of the rotary cutters and their cooperating tubular
metal or plastic guards and the guards can be clamped at their
extreme ends in the two sections of the guard or can be secured by
set screws in adjusted position, the screws being loosenable and
tightenable from behind the guard portion of the razor head where
they are out of the way completely.
Inventors: |
Wintercorn; Andrew F.
(Rockford, IL) |
Family
ID: |
22674919 |
Appl.
No.: |
05/183,937 |
Filed: |
March 13, 1972 |
Current U.S.
Class: |
30/43.4;
30/81 |
Current CPC
Class: |
B26B
21/34 (20130101) |
Current International
Class: |
B26B
21/34 (20060101); B26B 21/08 (20060101); B26b
014/18 (); B26b 021/18 () |
Field of
Search: |
;30/34.1,43.1,43.4,43.5,43.6,74.1,81,82,83,60,60.5,61,50,70-73,346.51 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Simpson; Othell M.
Assistant Examiner: Smith; Gary L.
Claims
I claim:
1. In combination, a safety razor head on which is supported a
straight double edged razor blade, two elongated rotary helically
grooved cutters disposed in parallel relation to said head below
and in hair shearing relationship to the edges of the razor blade,
a single helical drive pinion disposed between and meshed with said
cutters to turn the same in opposite directions toward the blade's
cutting edges, means for driving said pinion, and thin-walled
tubular guard members closely surrounding said cutters, each
rotatably adjustable relative to its associated cutter and having a
longitudinal slot provided therein parallel to the cutting edge of
the blade, the guards being rotatably adjustable so that one
longitudinal edge of the slot spaced outwardly relative to the
adjacent cutting edge of the blade defines with said cutting edge a
cutting gap of a predetermined width in front of each cutting edge
into which the face area to be shaved is adapted to be bulged more
or less depending on the width of the gap, each tubular guard also
having another longitudinal slot provided therein in
circumferentially spaced parallel relation to the first mentioned
slot through which the helical drive pinion projects with ample
working clearance for meshing engagement with the helically grooved
cutters, and means for securing said tubular guards in rotatably
adjusted position.
2. A structure as set forth in claim 1, in which the second slot
for the drive pinion in each guard member is wide enough to give
additional range of rotary adjustment for closeness of shave.
3. A structure as set forth in claim 1, in which one of the tubular
guards is of plastic material having substantially the
characteristics of polyethylene insofar as lubricity is
concerned.
4. A structure as set forth in claim 1, in which one of the tubular
guards is of a cutter lubricating material.
5. In combination, a safety razor head on which is supported a
straight edge razor blade, an elongated rotary cylindrical
longitudinally grooved cutter in parallel relation to said head
below and in hair shearing relationship to the edge of the razor
blade, means for driving said cutter in a direction toward the
cutting edge of said blade, a thin-walled tubular guard member
closely surrounding said cutter and having a longitudinal slot
provided therein parallel to the cutting edge of the blade, the
guard being rotatably adjustable so that one longitudinal edge of
the slot spaced outwardly relative to the adjacent cutting edge of
the blade defines with said cutting edge a cutting gap of a
predetermined width into which the face area to be shaved is
adapted to be bulged more or less depending on the width of the
gap, and means for securing said tubular guard in rotatably
adjusted position.
6. A structure as set forth in claim 5, wherein said tubular guard
member is of plastic material having substantially the
characteristics of polyethylene insofar as lubricity is
concerned.
7. A structure as set forth in claim 5, wherein said tubular guard
member is of a cutter lubricating material.
8. In combination, a safety razor head on which is supported a
straight double edged razor blade, two elongated rotary helically
grooved cutters disposed in parallel relation to said head below
and in hair shearing relationship to the edges of the razor blade,
a single helical drive pinion disposed between and meshed with said
cutters to turn the same in opposite directions toward the blade's
cutting edges, means for driving said pinion, and thin-walled
tubular guard members closely surrounding said cutters, each
rotatably adjustable relative to its associated cutter and having a
longitudinal slot provided therein parallel to the cutting edge of
the blade, the guards being rotatably adjustable so that one
longitudinal edge of the slot spaced outwardly relative to the
adjacent cutting edge of the blade defines with said cutting edge,
a cutting gap of a predetermined width in front of each cutting
edge into which the face area to be shaved is adapted to be bulged
more or less depending on the width of the gap, and means for
securing each of said tubular guards in rotatably adjusted
position.
9. A structure as set forth in claim 8, in which one of the tubular
guards is of a cutter lubricating material.
Description
This invention relates to electric safety razors designed for "wet"
and "dry" shaving.
The principal object is to improve the construction disclosed in
the earlier Wintercorn et al. U.S. Pat. No. 2,229,159, to make it
not only safer, but also improve it from the stand-point that the
user can by proper adjustment vary the closeness of shaving to suit
the needs of his beard, while still retaining the important
advantages of the earlier patented razor construction, namely, its
rotary operation and its unique drive, utilizing a pair of parallel
helically grooved rollers as cutters on the head meshing with a
central helical gear rotatable in a recess provided in the center
of the head substantially concentric with the handle and disposed
in the plane of the head in direct meshing engagement with the
helically grooved rollers to transmit drive thereto in opposite
directions toward the opposed straight cutting edges on the
opposite sides of an interchangeable safety razor blade. Thus,
tubular metal or plastic guards surround these cutters and have
longitudinal slots provided therein in spaced parallel relationship
to the cutting edges of the blade, these guards being easily
adjustable rotatably relative to the cutting edges to vary the
width of gap in which the cutters cooperating with the cutting
edges of the blade to do the shaving operation for as close a shave
as the operator may desire or as the characteristics of the beard
may require.
A square or rectangular plug type space gauge insertable between
the blade edge and the guard slot determines the width of cutting
gap and the closeness of shave.
The invention is illustrated in the accompanying drawing, in
which:
FIG. 1 is a top view of an electric safety razor made in accordance
with my invention;
FIG. 2 is a vertical section on the line 2--2 of FIG. 1;
FIG. 3 is an enlarged sectional detail on the line 3--3 of FIG.
1;
FIG. 4 is a top view of the two-piece head by itself;
FIG. 5 is a greatly enlarged segmentary sectional view illustrating
the operation of the razor;
FIG. 6 illustrates a razor like that of FIGS. 1 to 5, but having a
motor for driving the same forming the handle thereof, and
FIG. 7 is a perspective view of one of the longitudinally slotted
tubular guards.
The same reference numerals are applied to corresponding parts in
the above mentioned views.
Referring to the drawing, the blade 13 is of the conventional
interchangeable blade safety razor type, having two parallel
cutting edges 14 and 15 adapted to cooperate with the rotary roller
type cutters 16 and 17, respectively, the latter being located so
that when the blade 13 is clamped down and is thereby arched
slightly, its edge portions will come directly over the centers of
the cutters and be substantially tangent to the periphery thereof,
as indicated by the fact that the radius lines a-b and c-d, drawn
from the center of the arc of the blade in FIG. 5, pass through the
centers of the cutters 16 and 17 adjacent the cutting edges 14 and
15.
The edges 14 and 15 are double bevel edges and the bottom bevel of
each edge will permit adjusting the blade so that the edges have
the requisite small working clearances with respect to the
peripheries of the cutters for good shearing action. At the same
time, since the cap 18 has its arcuate top surface 19 on the same
arc with the top surfaces 20 and 21, providing for the same, or
substantially the same, clearance with respect to the cutting edges
14 and 15 as in the conventional interchangeable blade safety
razor, it follows that the present razor, although power operated,
will be capable of shaving just as closely as the conventional
hand-operated Gillette safety razor when operated the old way and
with the same degree of safety, as well as the same degree of
handiness and facility of operation, that being due mainly to the
tubular metallic or plastic guards 22 that closely enclose the
cutters 16 and 17 but have longitudinal gap determining slots 23
which, when the guards are properly adjusted rotatably, leave only
a predetermined cutting gap between one edge of the slots parallel
to each of the cutting edges 14 and 15, the width of which can be
varied with the help of a plug type gauge inserted between the
cutting edge and the adjacent edge of the slot, to suit the
closeness of shave a person desires, while also insuring safety of
operation by positively limiting the extent of bulge of skin
between the adjacent round ege 24 of the clamp 18 that serves as a
guard and the far edge of the slot 23 in the tubular guard. The
latter, therefore, takes over completely the function heretofore
served by the guard portions 20 and 21 on the head of the
conventional interchangeable blade safety razor. If plastic guards
are used at 22 I prefer they be of polyethylene because of its
lubricity, helping to reduce drag on the rollers 16 and 17 in the
event of a close fit and also to reduce friction on the person's
face. It is also believed that with plastic guards there is less
likelihood of uncomfortable heating due to friction, while a better
appearance is also obtainable and at lower cost, as the chances are
the plastic guards could be molded to final form, requiring little
or no machining. It should be obvious that the two tubular guards
22 could be set differently, one with the slot 23 opened up
slightly wider than the other to give a closer shave with the wider
gap than the one with the narrower gap, although both tubular
guards are preferably set at the factory so these slots are well
within the range of good safety for all around operation regardless
of how careless the operator might be in shaving on any given
occasion due to being in more of a hurry than usual. I have, in
other words, retained all of the advantages inherent in the
electric safety razor of the earlier Wintercorn et al. Pat. No.
2,229,159, while adding improved safety of operation and a simple
means of varying the closeness of shave obtainable. Once a tubular
guard 22 has been set for the desired width of cutting gap at 23,
the set screw 24 can be tightened to maintain the adjustment.
In operation, with this razor a "once over lightly" should usually
be enough for a clean shave, because all of the hairs coming into
the path of the blade should be shaved off in one pass. There will
usually be no necessity for going over a given area more than once,
any more so than with the ordinary interchangeable blade safety
razor. The fact, that the entire cutting edge of the blade is used
instead of having to work the hair through fine slots to get them
into the path of the cutter makes the shaving action with this
razor so much quicker and more positive than with the razors with
the reciprocating type cutters and is the thing which makes the
razor good for wet or dry shaving. Obviously, with the shearing
action obtained there will be no "pulling" with this razor, even
when the blade may be a trifle dull. The only thing that determines
the closeness of shaving is the adjustment of the tubular guards 22
for a wider or narrower cutting gap between the cutting edge of the
blade and the adjacent edge of the the slot in the guard. The
manufacturer will set these guards for a recommended medium close
shave but leave it up to the user to adjust for a closer shave,
furnishing a properly marked plug type space gauge for that
purpose, and another properly marked space gauge for the opposite
extreme setting. With a rectangular plug both extremes could, of
course, be taken care of in one plug type space gauge.
In passing, it should be obvious that since the helically grooved
roller-type cutters 16 and 17 are driven by meshing engagement with
diametrically opposite sides of an intermediate helical drive
pinion 25, each of the tubular guards 22 requires, in addition to
the longitudinal slot 23 previously described, a wider but shorter
slot 26, as shown in FIG. 7, through which the pinion 25 projects
enough to transmit drive to the roller 16 and 17 operating inside
the guard, enough clearance being left above and below the pinion
25 for ample operating clearance in both extreme settings of the
tubular guard. The required length of the slot is easily
determinable from a study of FIG. 1, while the required width of
the slot is easily determinable from a study of FIG. 2, keeping in
mind the fact that there is only a fairly small range of rotary
adjustment from one extreme position to the other.
The razor shown in FIGS. 1 to 6, except for the two features herein
disclosed is otherwise the same in construction as disclosed in
Wintercorn et al., U.S. Pat. No. 2,229,159. Both have a pinion
drive shaft 34 extending through a slender handle 35 adapted for a
flexible shaft drive similar to those employed in connection with
dental drills, but the invention is not to be construed as limited
to such a drive, inasmuch as the handle may be provided by the
motor for driving the razor, as illustrated at 36 in FIG. 6, and in
that case the razor can be turned on and off by turning a switch
knob 37 on the far end of the motor housing from which the flexible
extension cord 38 extends.
The head 39 shown in FIGS. 1 to 7, is are made of two die-cast
parts that interfit across the middle of the head, as shown at 40,
and have half-round shanks 41, which, when the two halves are
placed together, form a bearing 42 for the drive shaft 34.
Half-round recesses 43 formed in the abutting ends of the two
halves provide a circular chamber in the head for the drive pinion
25 connected to the enlarged fluted end 44 of the shaft 34. The two
halves of the head may, if desired, have the shank portions 41
thereof left blank in the die-casting of these parts so that the
two halves can be identical and then later when the two halves are
suitably held in assembled relation the shank portions can be
threaded, as shown, to thread in the internally threaded enlarged
upper end 45 of the handle 35, or the corresponding parts 35a on
the end of the housing of the motor 36, whereby to secure the two
halves of the head together. At the same time that the shank
portions are threaded, the bearing 42 can, if desired, be reamed to
insure good fit for the shaft 34 therein. The latter, it will be
noted, extends through the hollow handle 35 and in the case of a
flexible shaft drive will be suitably coupled at the outer end of
the handle to the flexible shaft, the casing of which will be
attached to the handle. However, in the case of a direct motor
drive, the shaft 35 can be regarded as the armature shaft of the
motor or the shaft coupled directly to the armature shaft.
The head 39, as seen in FIG. 4, has guards 46 on opposite sides
thereof provided by a series of laterally spaced prongs similar to
what are provided on the conventional interchangeable blade safety
razor. It will be noticed that each half of the head 39 has five of
these prongs on one side and six on the other and that the sixth
prong necessitates the small shoulder 47 on the end of each half,
which, however, is not objectionable, but is really an advantage
from the standpoint of interlocking the two halves of the head more
firmly in assembled relation and securing better alignment between
the halves. As shown in FIG. 4, the recessing for the cutters 16
and 17 at 48' is deep enough radially to provide the additional
space required for the tubular guards 22, and there is in addition
annular recesses 49 as seen in FIG. 3 provided in the opposite ends
of the head 39 to receive the ends of the tubular guard 22. A screw
50, threaded in a radial hole in the head at each end, serves, when
tightened, to clamp the tubular guard 22 in its adjusted position.
The recesses 49 are, of course, in concentric relationship to the
bearings 51 in which the reduced journal portions 52 on the ends of
the rotary cutters 16 and 17 are received for support of the
cutters in accurately spaced relationship to the opposite sides of
the drive pinion 25, and, of course, in true parallel relationship
to the cutting edges 14 and 15 of the razor blade 13.
The fact that the drive is a helical gear drive manifestly makes
for smooth, quiet operation, even though the pinion cannot operate
with lubricant for obvious reasons. Also, the fact that there is
balanced drive with rotary cutters operating on opposite sides of
the handle axis, this arrangement insures reduced vibration. It is
obvious that in the assembling of the razor in either form, the
cutters 16 and 17 can be assembled in the one half of the head in
meshing engagement with the pinion 25 also assembled in that half,
and then the other half of the head can be brought into position,
thus encasing the working parts in the head in proper assembled
relation, whereupon the handle 35 or motor 36, as the case may be,
can be attached to the head, securing the two halves thereof
together. The tubular guards 22 will be assembled in the recesses
49 on the one half before the other half of the razor is assembled
in place.
The cap 18 is generally similar to the blade clamping cap on the
ordinary interchangeable blade safety razor and has a longitudinal
rib 53 extending along the middle of the bottom thereof, which fits
in a longitudinal slot 54 in the middle of the blade and a
registering groove 55 in the head so as to accurately locate the
blade with respect to the head at the same time that it is clamped
in place. There are two studs 56 projecting downwardly from the cap
18 near its opposite ends and these pass through holes in the blade
at opposite ends of the slot 54 and then through holes 57 in the
head to receive knurled nuts 58 arranged to be tightened by hand up
against the flat bottom of the head in the manner clearly shown in
FIG. 2. Realizing the importance of correct clearance between the
edges 14 and 15 of the blade 13 and the cutters 16 and 17 and also
the importance of avoiding having the tightly clamped blade bearing
too heavily on the cutters, or either of them, and acting as a
brake, four adjusting screws 59 are provided in vertical holes 60
in the head in the vicinity of the four corners of the blade 13
arranged to be adjusted up or down in these holes to provide
adjustable seats for the blade at the four corners, so that,
regardless of minor variations in the manufacture of the head or in
the cutters 16 and 17, it will be possible to align both ends of
each cutting edge in the proper relation to the associated cutter
and thereby obtain good shaving action.
It is believed the foregoing description conveys a good
understanding of the objects and advantages of my invention. While
a preferred embodiment of the invention has been illustrated and
described, this is only for the purpose of illustration, and it is
to be understood that various modifications in structure will occur
to a person skilled in this art.
* * * * *