Патент USA US2809485

OGL 15, 1957
D. E. KEEcH
2,809,477
RAZOR BLADE STROP AND MÉTHOD OF USING THE SAME
Filed June 25, 1956
1&6. c?.
Maf.
„z2/16.6'.
.lâ/o. 4.
IN VEN TOR.
United States atent
rice
2,899,477
Patented Get. i5, i957
2
l.
a razor strop including a pair of opposed stropping ele
ments in which the whole strop including said stropping
elements and the means for connecting the same and
2,809,477
Ul
RAZÜR BLADE STROP ANl) Íl/IÍETHSD ÜF
USING THE SAR/IE
holding these resiliently in spaced relation ready to have
the fingers applied thereto is comprised entirely in a
single molded article.
ln razor blade strops in the kprior art of the type being
discussed the stropping elements were presented so as to
Application
Dana E.
.lune
Keech,
25, 1956,
Los Angeles,
Serial No. 593,744
cause occasional accidental collision of the razor blade
edge with one of the stropping elements while the razor
11 Claims. (Cl. :3l-1%)
blade was being inserted edge ñrst between these ele
ments. Such collisions, of course, damage both the strop
This invention relates to the stropping of razor blades
and has particular utility in stropping the edges of safety
razor blades of wafer-like thinness.
it has long been known that the edge of a safety razor
blade may be stropped by the simultaneous application to
opposite faces of the blade of stropping elements made of ~
leather or rubber and then, while the blade is placed
under pressure from said elements, withdrawing the
blade from between said elements in a direction at right
angles to said edge. in spite of this knowledge, how-
and the razor blade edge and seriously impair the utility
of the strop.
It is another object of the present invention to provide
a razor blade strop of the general type mentioned which
will render such accidental collision of the razor blade
edge with the strop, while said blade is being inserted
between the stropping elements, relatively easy to avoid.
The manner of accomplishing the foregoing objects
as well as further objects and advantages will be made
manifest in the following description taken in connection
with the accompanying drawings in which:
Fig. 1 is a perspective view of a preferred embodiment
ever, an inexpensive and satisfactory razor blade strop 25 of the invention.
Fig. 2 is an end elevational View of Vthe strop shown
operating on this general principle has not heretofore
in Fig. l with the strop held between the thumb and
een provided.
forefinger of one hand and showing how a single-edged
lt is an object of this invention to provide a simple,
razor blade may be inserted, edge first, between the
inexpensive razor blade strop which can be manipulated
manually in the manner above indicated to strop a razor 30 stropping pads without likelihood of the cutting edge
colliding with the strop while the blade is being so in
blade and which will have a relatively high degree of
etiiciency in producing a keen shavinLT edge on said blade.
serted.
Fig. 3 is a View similar to Fig. 2 and shows the next
The razor blade strops of the general type mentioned
step in applying the strop to the blade in which the strop
and heretofore >developed have been based on tie prin
ci le of applying pressure to the blade throughout its 35 ping pads are pinched together until the extremities come
in contact with the blade. This View also shows the
length simultaneously. l have discovered that while
steep convergence of the stropping pads as they are thus
theoretically an advantage, this feature has two distinct
brought into contact with the blade which feature also
disadvantages. lt causes the device to be unnecessarily
operates to prevent collision between the blade edge and
large and by spreading the pressure applied thereto uni
formly over the entire blade edge, it robs the device of 40 the strop.
Fig. 4 is a View similar to Fig. 3 and illustrates the
the capacity to apply a carefully adjusted and relatively
next successive step in applying the strop to the razor
high degree of pressure to successive areas of the blade
blade. In this step the stropping pads are pinched to`
edge. î have also discovered that the application of such
gether on the blade so as to enfold the blade edge be
high opposing pressures to local areas of the blade edge
is the secret of attaining uniformly good stropping by 45 tween the opposed stropping pads and apply substantial
pressure from the thumb and forelinger through certain
this method.
it is therefore-another object ofthe present invention
to provide a finger manipulated razor strop and method
of using the same in which the blade is compressed be
tween- two stropping elements pressed thereagainst by
the fingers to strop the blade edge, in which a relatively
high Vpressure may be applied in opposite directions to
a small area ofthe blade- edge while withdrawing the
localized areas of said pads to the blade edge.
This view
also illustrates in broken lines, the step of withdrawing
the razor blade from between the stropping pads when
50 the latter are thus pinched against the blade edge.
Fig. 5 is a face View of a single-edged razor blade and
showing the strop of the invention applied as in Fig. 4
to press the stropping pads thereof against opposite sides
of a specific local area of the edge portion of said blade
blade from between the stropping elements.
Another feature-common to strops of thisV general type 55 at one end of the latter. This view also shows in dotted
lines how the entire edge of said blade may be stropped ~
produced in the past has been the backing of the strop
byapplication of the strop successively to similar like
ping element with metal plates which-greatly inhibits the
areas consecutively >located along the edge portion of
dow of a rubber stropping element about the microscopic
the blade.
metal particles of the blade edge when the blade is being
60
Fig. 6 is a face view of a double-edged razor blade
withdrawn-from between the stropping elements.
showing a pair of said strops applied »thereto with cor
it is an Vobject' of the present invention to provide a
responding local areas of the respective cutting edge
finger manipulated razor blade strop and method of
portions of said blade gripped by the application of said
using the same in which the stropping elements are free
strops thereto in similar manner to that'shown in Fig. 4.
to respond to the fleshy tips of the iingers and thumb,
by which they are applied, so as to closely conform to 65 This view also illustrates how similar consecutively re
lated areas of the blade edge portions may be strapped
the beveled faces of the razor blade adjacent the edge
by successive applications of the two strops to said blade.
particles to beV stropped whereby the material of the
Fig. 7 illustrates the manner of using the invention to
stropping elements will flow over these bevelled faces,
strop a double-edged bla-de and shows an end view of such
while said elements are pressed thereagainst with a rela
tively high local pressurepand the blade is being simul
a blade with a certain area of one edge portion of said
taneously withdrawn from between said elements.
blade gripped by one of said strops and with the blade
ì
lt is a _still further object of t .e invention to provide
manipulated, through the grip with which it isthus held,
2,809,477
3
.
4
to insert the opposite vedge portion of the blade between
embraces a limited section of the edge portion 19 of the
the stropping pads of the second strop.
'blade 16 located near one end of the edge 21 as shown in
Y
Fig. 8 is a view simila-r to Fig. 7 showing the comple
tion of the lapplication of two strops in gripping relation
with opposite localareas of the two edge portions of a
double-edged blade.
'
Fig. 5.
'
A stropping action is now produced on that portion of ,
the blade edge 21 lying within area 25 'by withdrawing the
blade 16 from between the strop pads 11 in the direction
of arrow 26 at a right angle with the blade edge 21 while
maintaining a substantial pressure on said blade edge
Y
Fig. 9 illustrates the next step inV stropping a double
Vedged blade. This View shows how excessive pressure is
applied in gripping one edge portion of said blade withV
portion in area 25 thereof through said pads. Following
one of said strops and a somewhat less pressure applied
this stropping of that part of the Yrazor 'blade edge 21 ern
to the opposite edge portion of the blade by the other
braced by area 25, the same stropping operation just de
strop, and the two strops then pulled ‘apart so as to slip
scribed for this area is repeated for similar areas 28 and
29 which areas consecutively overlap each other and,
the second strop away from its gripping relation with the
razor blade, thus stropping'that area of the edge portion
taken together, embrace the entire. cutting edge 21 of
of said blade which was gripped between the pads of the
the blade 16.
second strop.
A fairly good stropping of the cutting edge 21 of the
blade 16 may be accomplished by covering the entire
'
'
Y
Referring specifically to the drawings and particularly
to Fig. l, the embodiment ofthe invention disclosed
therein comprises an approximately U-shaped integrally
molded soft rubber strop 10, including opposite side ele
ments 11 which comprise soft rubber stropping pads
this, of course is optional.
ín flat sheet form, and an arcuate middle connecting ele
ment 12 lwhich is preferably of the same thickness as the
Reference is now made to Figs. 6, 7, 8 and 9 which
illustrates the use of the stropV 10 for stropping the two
pads 11.
cutting edges 35 and 36 of a double edged blade 17. The ' '
blade edge only once with a series of stropping operations
as above described. A better stropping is sometimes ac
complished Iby going over the edge two or three times, but
`
'
Y
The inner faces 15 of the padsV 11 of the strop 10 are 25 stropping of a double-edged blade 17 may be performed
smooth land the strop is preferably made of black car
with a single strop 10 in Vexactly the same man-ner as
bon impregnated butyl rubberY with ya hardness of 50
above described for stropping la single edged ‘blade 16 in
which case one edge portion 37 of the blade 17 must be
The strop 10 of the invention may have any preferred
held in one hand while the other edge portion 38 of the
durometers.
-
'
i
external surface characteristics but it isV highly preferable 30 blade is being stropped. The blade is t‘hen reversed and
thatthe inner stropping pad faces 15 be smooth. The
the stropped edge portion held in one hand while the un
strop 10 is adapted for stropping a sharpened edge of a
stropped edge portion of the Iblade is stropped. This
safety razor 'blade including the well known single-edged
mode of operation, however, involves a danger of getting
blade 16 (Figs. 2-5) or the well known double-edged . cut by gripping one'ed-ge of the blade with the hand.
blade 17 (Figs. 6-9).
`
Likewise, gripping an edge portion -between the fingers in
_
Reference will now be m-ade to Figs. 2 to 5 inclusive,
which illustrate the various steps of the method of the
this manner, after it'h'as been stropped, may impair the
beneficial results -produced by stropping it.
f
present invention as this is performed by applying strop
To avoid these difficulties in stropping a double-edged
10 thereof in sharpening a single-edged blade 16.
blade, the method of the present invention preferably em
Y The first step in performing this method is illustrated
ploys two of the strops 10 in this operation. Fig. 6 shows
in Fig. 2 where one of the strops 10V is shown as held
two strops 10 applied to areas 39 and 40 of opposite edge
lightly between the thumb and forefinger of one hand
portions 37 and 38 respectively of the blade 17 toward
while a blade 16 is held by the metal shod4 edge Y18 there
one end of `said ‘blade so as to snugly grip Vsaid blade edge
of in the other h-and and the sharpened edge portion' 19
45 portions in said areas as shown in Fig. 8.
of the blade, with cutting edge21 thereof in the lead, is
With the blade 17 gripped by said two strops, the
inserted into the relatively wide U-shaped mouth of the
pressure applied by one of the latter is increased above
strop 10. This view shows the latitude allowable in in
the pressure applied by the other of said strops and the
troducing the blade edge 21 b'etween the stropping pads
11 of the strop 10 of the inventionrwithoutany colli
sion being inadvertently produced between theA 'blade edge
50
and the rubber of the strop. Obviously, any such colli
sion would be injurious to »both the strop and the blader
edge and must be avoided for the advantages of using the `
strop to ‘be fully realized.
While holding the blade 16 with the sharpened edge
portion 19 thereof inserted between the strop pads 11, the
strops are then pulled apart as shown in Fig. 9, inthe
directions of arrowsl 41 and Y42 thus; causing the blade
to remain gripped by the strop through which the greater
pressure is applied and permitting the strop> through
which the lesser pressure is applied to slip from its clamp
ing relation withv blade 17 at iight angles to edges 35
55 and 36 thereof, thereby erñecting a stropping action on
that edge portion of the blade lying. within the area which
has been compressed between the stropping pads 11 ofV
latter are pinched together between the thumb `and fore
that strop.
p
ñnger, which results in these pads assuming an increas
This operation is followed by allowing the strop 10,
ingly steep convergence toward eachother ‘and toward 60 which was slipped from clamping relation with the blade,
the razor blade, culminating in the free edges of the pads
to expand as shown in Fig. '7 and then reapplying thispto
engaging the yblade as shown in Fig, 3. This manner in
grip another area 43 of the same edge portion of the
blade. An excessive pressure is now applied through
which the pads approach and recede fromthe blade pro
Vvides an additional circumstance, tending to` prevent the Y
that strop to area 43 while a lesser pressure is applied
likelihood of a collision between the razor. blade edge 21 65 to the area 39 by the strop on the other side of the blade,
and the material of the strop.
Y
and the two strops are pulled apart. This will leave the
The step shownV in Fig.'3 is followed immediately by ’ blade gripped by pressure applied in area 43 while the
added pressure being applied to the strop pads 11 from
blade edge embraced by the area 39 is stropped by the
the thumb and foreiinger holding the strop which results
strop gripping this being pulled from clamping relation
in bringingthe pads 11 into parallel-clamping relation 70 with the blade.V
with the edge portion 19 of theîblade 16 `as shown in_Fig.
This second stropping operation on double-edged bladev
4. This application of the strop 10 to the edgeportion
17, just described, is followed by the reapplication of
19 of the blade 16 is preferably selected so that'th‘e- area
the left strop10 into gripping relation with the left bladeY
25 in which the pressure fromthe thumb and foreiinger` is;Y edge portion to apply pressure thereto in the area 44.
transmitted through the stropping pagdsll to the blade 16 V7_ 5 A -third stropping operationris now performed by an ex
2,809,477
cessive pressure being applied in the area 44 and a lesser
pressure in the area 43 and the two strops pulled apart to
perform a stroppiug operation in the area 43. Follow
ing this operation the right hand strop 10 is reapplied to
the right edge portion of the blade 17 to clamp the latter
in the area 45. The blade is then gripped with an ex
cessive pressure in the latter area and with a lesser pres
sure in area 44 and the two strops pulled apart stripping
the left hand strop from the area 44 and effecting a
stropping action in this area on the left blade edge 35.
The left hand strop 10 is now reapplied to the left
blade edge portion to clamp the same in the area 46 with
an excessive pressure and the right blade edge is clamped
6
Use of the strop 10 of the present invention as above
described has been found to reduce the skin cuts other
wise suffered in safety razor shaving approximately 90%.
Such use also makes the razor cut the beard smoothly,
closely and with practically no pulling, Its use further
more doubles the number of shaves to be had from each
blade as well as making all shaves uniformly excellent.
The claims are:
l. A method of strapping an edge of a safety razor
blade which comprises the steps of interposing between
the thumb and the foreñnger of one hand, a pair of soft
sheet rubber pads, held in spaced relation and with said
pads free to resiliently adapt themselves to the shape of
The right hand strop 10 is now reapplied to grip the right
said thumb and foreñnger when said pads are forced to
gether and compressed between said thumb and fore
ñnger, inserting an edge portion of said safety razor blade
edge of the blade 17 with an excessive pressure in the
area 45, and a lesser pressure is applied through the
other strop in the area 46 while the strops are pulled
apart to effect a stropping operation in the area 46.
in the area thereof corresponding to the opposed areas in
in area 45 with a lesser pressure while the strops are
pulled apart to effect a stropping operation in area 45.
Both cutting edges 35 and 36 of double-edged blade
17 are now stropped and the blade ready for use in
shaving.
between said spaced pads, pinching said pads and blade
edge portion between said thumb and foreñnger to apply
substantial compression to said blade edge portion only
which said pads are pressurally engaged respectively by
the tips of said thumb and 'forefingen withdrawing said
blade from between said pads while so compressed, in a.
in full size scale.
direction at a right angle with said edge, and repeating
said operation with successive fractions of said blade
edge portion disposed within the compression area afore
said, whereby the entire blade edge is stropped.
sidered to be the distance which the blade 16 would ex
fractional area stropping operations performed on one of
The drawings illustrate the invention at a scale so that
when the drawings are reduced in size in printing the
patent, the patent will illustrate the invention correctly
2. A method as in claim l in which a double-edged
It may be noted by observing the shape of the strop
safety razor blade is stropped and in which the aforesaid
1i) in Fig. 2, that this strop, when unconstrained, pro
vides a mouth for receiving the cutting edge 21 of the 30 method is applied concurrently by the respective thumbs
and foreíingers of two hands to the two edge portions of
razor blade 16 which is wide enough to permit consider
said razor blade and in which said blade is held tightly by
able latitude in inserting said edge into said mouth with
the gripping of one edge portion thereof between one
out accidentally contacting the strop 10 with said cutting
pair of said pads and thumb and forelinger of one hand,
edge. Dotted line representations of the blade 16 in
each time said stropping operation is performed on a
Fig. 2 illustrate this latitude. The “width” of said mouth
fractional area of the other edge portion of said razor
is considered to be the distance which the surfaces 15
blade by the other hand.
of the stropping pads 11 are separated at the free ends of
3. A method as in claim 2 in which the successive
said pads. The “depth” of said mouth may be con
tend into said mouth past the plane of the free ends of
pads 11 if said blade were extended horizontally from
the position in which it is shown in Fig. 2 until its edge
21 contacted the innermost point in said mouth. The
“length” of said mouth may be considered as the outside
dimension of the strop 19 measured along the axis of
curvature of the middle element 12.
By reference to Figs. 2 or 7 it may be observed that, in
the preferred embodiment of the invention here illus
trated, the width of the U-shaped mouth formed by
strop 1Q when the strop is free of constraint is almost
as much as the depth of said mouth.
Such a ratio be
tween the width and depth of the mouth of the strop 10
is highly desirable, although the invention may be prac
tically operated with a somewhat smaller ratio between
the width and depth of said mouth. It is preferable,
however, that the front opening of the mouth of the
strop 19 have a width which is in excess of one-half the
the edges of said double-edged blade are interspersed
alternately between the corresponding successive frac
tional area stropping operations performed on the other
of said edges.
4. A safety razor blade strop comprising a pair of
soft rubber stropping pads in iiat sheet form and means
for uniting said pads along one side of said strop in wide
ly spaced relation to form a relatively wide U-shaped
mouth between said pads, the length of said mouth be
ing substantially shorter than said safety razor blade,
said pads being free to be pressed together between a
thumb and a forelinger, while a razor blade extends be
tween said pads, and to yieldably conform to the opposed
tips of said thumb and foreñnger and transmit pressure
to said razor blade confined substantially to the areas
on said pads engaged by said tips of said thumb and 'fore
finger, a stropping operation taking place when a Arazor
blade, thus compressed, is withdrawn from between said
pads in a direction at a right angle with the razor edge,
depth of said mouth, in order to prevent accidental col
a repetition of said operation on successive fractions of
lision between the cutting edge 21 and one of the pads
60 said edge being requisite to strop the entire edge.
11 when inserting said edge between said pads.
5. A safety razor blade strop comprising an approxi
lt is also to be noted in Fig. 2, that the inside radius of
curvature of the middle element 12 is approximately one
third the depth of said mouth.
This ratio is preferable
and this radius should be in excess of at least one-fourth
the depth of said mouth. 1t is also preferable that the
pads 11 diverge from their points of union with said
middle element when the strop 16 is not under constraint.
Attention is also called to the fact that the preferred
embodiment of the invention shown in the drawings has
an over-all width in the piane of the mouth opening
thereof which is approximately equal to the over-all
depth of the unit. While the strop of the invention is
described as preferably made of soft rubber, the claims
mately U-shaped integrally molded soft rubber unit in
which the opposite side elements of the U comprise
stropping pads in flat sheet form and the middle connect
ing element of the U comprises a torque-providing inte
grating base which unites the stropping pads, and, when
unconstrained, holds said pads in opposed spaced rela
tion to provide a relatively wide mouth into which a
razor blade may be inserted, edge first, with relatively
small likelihood of a frontal collision between said edge
and said strop, said base yielding when said pads are
pinched between a thumb and foreiinger to cause said
pads to swing inwardly and converge at a steep angle in
their initial contact with said razor blade, said pads then
employing this term are understood to also embrace
equivalent materials.
l75 yielding to further pressure 'from said thumb and fore
f.
,
2,809,477
7
_
,_
_
_Y
iinger to ñattenagainst opposite faces of said razor blade
comprises an approximately U-shaped unit including a
resilient sheet-form hinge element, opposite extremities of
and transmit pressure to said lblade only in'the area
thereof corresponding to the areas in which said thumb
which are integrally united with said stropping pads, .the
and finger pressurally engage said pads.
wide mouth between said pads, being substantially shorter
6. A safety razor blade strop comprising a pair of
soft rubber stropping pads in ñat sheet form and means
_ for uniting said pads along one side of said strop whereby
the resiliency of the material in said pads normally holds
than said razor edge, the inside radius of said hinge ele-.
mentrbeing` in excess of one-quarter the depth of said
mouth, saidY stropping pads diverging from their union
said pads, when unconstrained, in widely spaced relation
with said hinge element, when not under constraint, to
facilitate said introduction of said blade edge therebe
defining a wide mouth between said pads into which the
sharpened edge of a razor blade may be readily inserted
tween.
in Ya direction at right angles with said edge and Without
10. A combination as in claim 7 in which said strop
comprises an approximately U-shaped unit including a
colliding'with said pads, said pads being free to be di
resilient sheet-form hinge element, opposite extremities.
Y rectly engaged respectively by the thumb and forelinger of
a hand and to be liexed inwardly by said engagement
of which are integrally united with said stroppingvpads',
the Vwide mouth between said pads being substantially>
into compressing relation with said blade, said pads being
immediately returned by said resiliency to said spaced
shorter than said razor edge, the width of said unit in
relation upon the relaxing of pressure on said pads by said
equal to the depth of said unit.
thumb and foreiinger.
_
the plane of said mouth opening being approximately
11. A strop as defined in claim 7 which, when com
7. A safety razor blade strop comprising a pair of
soft rubber stropping'pads in ñat sheet form which are
molded integrally with each other so as to be thus united
along one side of said strop and normally held by said
pressed between tips of a thumb and foreiinger, with any
portion of an edge of a double-edged safety razor blade
integral relation, when unconstrained, in widely spaced
one-third of said blade edge whereby, the withdrawal
of said edge from between said pads in a direction at
right angles to said edge, while said portion of said edge
is thus compressed permits the stropping `of said one-third
of said edge with the full compressive capacity of said
thumb and foreíinger applied solely to said one-third of
30 said edge, said pads when released »from pressure, im
relation defining a wide mouth between said pads into
which the sharpened edge of a razor blade may be readily
inserted in a direction at right angles with said edge and
without colliding with said pads, said pads being free
to be directly engaged respectively by the thumb and
fore?inger of a hand and to be ñexed by said engagement
into compressed relation with said blade, said pads being
immediately returned, by the resiliency of the material
of which they are molded and by their integral connec
tion, to said normal spaced relation upon the relaxing of
pressure upon said pads by said thumb and foreiinger.
8. A combination as in claim 7 in which said strop
comprises an approximately U-shaped unit including a
resilient sheet-form hinge element, opposite extremities
of which are integrally united with said stropping pads,
the wide mouth between said pads being substantially
shorter
n ing, the
of said
9. A
than said razor edge, and having a front open
width of which is in excess of one-half the depth
mouth.
combination as in claim 7 in which said strop
held therebetween, transmits said compression from said
thumb and foreiinger to a maximum of approximately
mediately regaining their widely spaced relation whereby
a different and unstropped portion ‘of said blade edge
may be inserted rapidly in the opposite direction between
said pads, for continuing the operation of progressively
stropping said edge, a fractional portion at atime.
References Citedlin the lile of this patent
UNITED STATES PATENTS
609,516
Mack _______________ __ Aug. 23, 1898
932,536
Conrad ______________ __ Aug.'31, 1909
1,179,459
1,723,124
2,629,211
Kennedy _____________ __ Apr. 11, 1916
Bencze _______________ __ Aug. 6, 1929
Tierney ______________ _.. Feb. 24, 1953