Note: Descriptions are shown in the official language in which they were submitted.
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'~ SHAVING INSTRU~NT
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The invention relates to a shaving instrument havingat least one razor blade which is firmly clamped between a
base part made of plastics material and a cover part pro-
vided with a glide surface which faces the skin to be sha-
ven and ends at a predetermined distance from the cutting
edge of the blade, and having a guard bar arranged in front
of the blade cutting edge, the guard bar having a surface
area which come~ into contact with -the skin and is equipped
with elements for stretching the skin and is aligned at a
predetermined distance parallel to the blade cut~ing edge.
~ he quality ol a ~having in~trument not only depend0
on the exact po~ition ol the blade cutting edge relative
to the guard barf but al80 on the effectivene~s of the ele-
ments on the guard bar which stretch the ~kin~ ~he~e ele-
ments not only have the purpose of pre~enting skin crea~e~
from forming when the shaving instrument is gu~ded in an un-
accustomed direction which may cause unexpected injuries,
but al~v of lifting up the hair~ of the beard in front o~
the blade cutting edge 80 -that they can be cut clo9e to the
root~ In the kno~ln instruments of the above-described
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type, the base part and -the guard bar consist of one piece and,
for cost reasons, of plastics material. In these instruments,
it is not possible to pro~ide the stretching elements wlth edges
which are sufficiently sharp but not irritating to the skin, in
. order thereby to achieve a satisfactory stretching effect, even
.. if these stretching elements have a saw-tooth shaped cross-sec-tion,
as -this has become known from West German Patent 1,110,047.
One aspect of the present invention is based on the novel
finding that such stretching elements can be manufactured with
sharp edges by plastic deformation with the displacement of por-
`; tions of the surface area of the guard bar, when the material of
the guard bar is metal. Therefore, the basic concept of this
aspect of the invention is to manufacture the guard bar of metal
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and to combine it with one of the two parts clamping the razor
blade~ As a result, it is possible to select not only the most
suitable material for the parts clamping the blade and for the
guard bar, but also the mo,st Eavorable manufacturing me-thod.
Broadly stated, there:Eo:re, according to this Eirst as~pect
of the presen-t :invention, there is pro~ided a sha~iny instrument
comprisiny a holding part o~ plastics rna.terial haviny a g].ide
. surface facing the skin to be shaven and a guard bar of metal
cominy into contact with the skin, said guard bar connected to
` said holding part, said guard bar provided with a plurality of
- elements with sharp edges for stretching the skin,
Another aspect of the present invention is the manner
in which the correct spacing between the blade cuttiny edge and
the guard is achieved.
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Accoxding to this other aspect~ the~e is provided a
shaving instrument eomprising a base part of plaskics material,
at least one razor blade having a cutting edge placed on said
base part, a cover part a-ttaehed to said base part so that said
razor blade is clamped between said base part and said cover part,
said cover part having a glide surface facing the skin to be
shaven and away from said base part and endiny at a distance from
said cutting edge of said razor blade, a guard bar for contacting
the skin ahead o~ said razor blade, the guard ~ar having a main
portion and legs at each end ar~anged at an angle to said main
portion and connected without play to one of said base part and
said cover part, at least two lugs connected to one of said base
part and said cover part near said legs of said guard bar, said
lugs engaging the main portion of said guard bar and thereby
maintaining the main portion of said guard bar positioned at a
predetermined distance from and parallel to said cuttlng edge of
said razor blade.
Because the luys ]~eeping the guarcl bar spaced away are
located outside of the efeective rancle o~ the eutting edge, unim~
paired passaye oE cut hairs and soap throucJh the opening between
the guard bar and -the blade is achieved.
Other features of -the invention will become clear ~rom
the following detailed diseussion of the invention with reference
to the aceompanyîng drawings, in whieh:
Figure 1 is a side view of a shaving instrument aeeording
to the invention;
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Figure 2 is a top view of the instrument of Fiyure 1;
Figure 3 is a section along the line III~ of Figure 2;
.: Figures 4 to 7 show stages of the manuEacture of the
. teeth on the guard bar in sectional and top view, the sections
of Figures 4 and 6 being taken along the lines IV-IV of Figure 5
and VI-VI of Figure 7, respectively;
Figure 8 is a bottom view of the instrument; and
. Figure 9 shows a detail on a larger scale.
.~ The instrument in accordance with the invention has a
blade holder which in its totality is denoted by reference
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numeral 4 and i9 compoeed of a ba~e part 1 with a handle
mDlded to the base pa~ 1 in one plece a~d a cDver 3, The
ra~r blade 5 iB firmly clamped between ~ase p~rt 1 and co-
ver ~ and cannot be exchanged, ~or protection~ B guard bar
6 is provided which i B ~upported by the base part ~, ~he
front sidesof the base part 1 and the cover 3 form a front
face 7 which, together with a glide surface 8 of the cover
3, forms a fron~ edge 9.
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~ he blade 5 protrudes beyond the front face 7. ~he
guard bar 6 has at its end~ leg6 10 which form an angle with
the guard bar 6 and are inserted into recesses of the base
part and are maintained in fixed position ~n these recesses
without play. ~or exactly maintaining the distance of the
guard bar 6 from the front face 7, lug~ 1a are provi~e~ at
the base part 1 in close proximity to the legs. The guard
bar iB inserted into the ~lade holder 4 in 6uch a way that
its leg~ e~tend parallel to the center plane 28 of the blade
5, and it~ ~urface area coming ~nto contact with the skin
e~tends parallel to the cutting edge 26 o~ the blade,
In the illustrated example, the guard bar 6 has four
rows of teeth provided on stretching elements arranged sym-
metrically to -the center plane 11 of the guard bar and the
legs 10, However, the rows of teeth 12,13,14,15 do not al-
, ways have to be arranged symmetrically, and, further~ the
number of
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row~ of teeth may deviate ~rom the n~mber four, Although
the rows oI teeth 14 and 15 are of les~ importance for the
~ha~ing action of the inetrument, it is u~eful to arrange
the~e row8 of teeth because they ma~e it pos6ible that the
guard bar 6 can be inserted in the base part 1 without ha~ing
to checX whe~her the rows of teeth are in fact located on the
~ide facing the blade 5~ ~he teeth are formed by coining and
have eharp edges 169 17, 18, 19 which e~tend parallel to the
a~is of the guard bar.
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The positions of the rows of teeth are selected in ~uch
: a way that at least one of them is located on that ~urface
portion o~ the guard bar 6 which faces the blade. Thi~ por-
tion i~ defined by a line 25a with which a tangential plane
24a e~tending through the blade cutting edge 26 contacts the
surface of the ~uard bar 6. An improved embodiment re~ult~
in that another row of teeth iB arranged in front o~ thi~
line of contact at the guard bar 6.
~he manu~acture o~ the teeth iB illu~trated in ~ig~. 4
to 7~ The guard bar 6 iB placed on a ~upport ~0 in ~uch a
way that the center plane 1 include~ an angle of approxima-
tely 30 ~ith the direction of movement of the toDl 21, The
tool 21 includes punches 22 which are arranged in two row~
. an~ coin a pluralit~ of ~ymmetrically arranged teeth 13, 15
on the guard bar 6~ Subsequentl~a the guard bar 6 i~ turned,
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~o that its center plane 11 again includes an a~gle of 30
with the direction ~f movement of the tool, howevery the
incli~ation be~ng oppDsite as compared to the ~irs~ coining
prDcedure. Simultaneously, the guard bar 6 has been moved
a~ially, ~o that the teeth 12, 14 produced by the tool are
off~et relative to the teeth 1~, 15 of the previously formed
row of teeth,
~ he punches 22 do not have to be pri~matic and they do
not have to have the end face 23 perpendicular to the moving
direction of the tool 21. The tool as illustrated forms
teeth whose sharp edges extend parallel to the rows of teeth.
Each tooth projeets over its entire length uniformly above
the ~urface of the guard bar 6, A tangential plane of the
guard bar 6 extending through the front edge 9 eontacts the
guard bar along the line of contact 25. ~he cutting edge 26
of the blade 5 is to have a certai~ position relative to the
tangential plane 24. ~he cutting edge ma~ pro~ect by up to
0,12 mm over the tangential pl~ne 24 or recede by up -to OaO~
mm Iro~ it. The glide ~urface 8 i8 pre~erably loca~ed ~n the
.tangential plane 24. ~he sharp edges 16 7 17 of the rows of
teeth arranged in front of and behind the line of contact 25
should preferably be located in the tangential plane ~4.
~inally, for achieving the object of the invention9 the di~-
tance of the guard bar 6 from the cutting edge 26 and from
the front face 7 also ~ys a role. Useful re~ult~ are ob-
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tained w~en the dis~ance between the ~l~e of c~ntact 25
from the blade cutt~ng ed~e i~ between 1~0 and ~ or
example~ 1.2 to 1,6 mm,
Go~d sh2ving re~ults could be achieved ~ith instru-
ments ~hich are described in further detail bel~w.
The guard bar 6 had a circular cross-section with a
diameter of 1r2 to 272 mmO ~he guard baT wa~ provided
with .~our rcws of teeth arra~ged ~ymmetrically to the cen-
ter plane 11~ ~he sharp edges of the teeth e~tended paral-
lel to the row~ of teeth and the la~ter extended parallel
to the longitudinal a~is of the guard bar and9 thus, also
to the cutting edge 26 of the blade. ~he lengths of the
sharp edges of the teeth ~aried between 0,3 and 1.0 mm.
They each pro~ected.b~ their entire lengths above the sur-
face of the guard bar, thi.s dis~ance measuring between 0.~
and 0~12 m~0 ~he ~ooth cpaces within o~e row were of a ~lze
of a~out 1.0 mm, The teeth of adjacent r~w~ were of~eet.
The distance between the r~Js i~ ~elected between 0.5 and
1.5 mm. ~specially favorable ~e~ults were obtained with
distances which measured between 0.7 an~ 1.0 mm~ The cen-
ter plane 28 defined by the sides 27 which form the cutting
edge 26 of the razor blade 5 and the tangential plane 24 in-
cluded an angle of between 14 and 28~
~ xcellent shaving results were obtained with the ~ol~
lowing instrument~ The guard bar 6 had a diameter of
1.59 + 0.01 mm and was provided with rows of teeth which
had lengths of 36 mm and were composed of twenty-two teeth~
The length of the blade cutting edge was 37 mmO The length
of the individual sharp edges of the teeth was 0.5 mm, The
teeth had within each row a spacing of 1.0 mm, Pits in
the surface of the guard bar, constituting tooth roots 6a
have a spacing of about 1 mm between the rows of the teeth
12 and 14 as well as between -the rows 13 and 15~ lhe four
rows of teeth provided were staggered approximately 30 on
the circumference of the guard bar and were arranged sym-
metrically to the center plane 11 of the latter. The sharp
edges of the teeth protruded uniformly about 0.07 mm from
the surface of the guard bar. The center plane 28 of the
blade cutting edge 26 and the tangential plane 24 included
an angle of 20, ~y the selection of the adequate manu~
facturing tolerancea, it was achieved that -the blade cut-
ting edge 26 projected above the tangential plane 24 by only
0.05 to OJ 09 mm~ The sharp edges 16 of the teeth 12 were
located in the tangential plane 24~ ~he distance of the
line of contact 25 a from the cutting edge 26 was 1,4 mm~
~ he arrangement and the dimensions were selected in
such a way that the loads occurring during the normal use
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an~ life span Or ^the lnstr~nent di~ ~t cau~e any di~place-
ment or permanent deformation ~f the lndi~i~ual part~
~providi~g an approprla~ely ~tlff constructi~n~ i~ was po~-
sible to ensure that9 prior to, ~uring and after the use of
~he in6trument, the front edge 9, the cutting edge 26 ana
the lines of contact 25, 25a were locate~ between two ima-
inary parallel planes having a distance from one another
of at most 0,05 mm~ preferably 0~0~ mm,
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~ ig. 9 shows an embodiment of the shaving in~trumerlt by
way of example on a larger scale~ The base part 1 has a lug
1a near each en~ of the cutting edge 26 for the guard bar 6
and alBo 8 lug 1b for the cutting edge 26 of the blade 5.
~he blade 5 has holes 29 which are in al-lgnment with bores
in the base part when the ~lade ie in the correct position,
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The bores are ~maller than the holes 29 and po~ltioned in
exact distance f~om the lug~ 1a~ The cover part '3 hae ri-
vet plne which extend without corltact through the holes 29
of the blade and flt snugl~ in the bore~ of the ba~e part 1.
Af ter the blade ha~ been moved ~orwardly by means of a mag-
net and the cutting edge 26 rests against the lugs 1b, riveting
is performed and the blade 5 is thereby permanently clamped be-
t~een the base part and the cover ~lith the cutting edge at the
exact distance from the guard bar 6 andl due to the expan-
sion of the rivet pins in the bores of the base part, the
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cover iB e~actly po~itioned a~ well, Due tD the fact th
the lug~ ~a ~nd 1b are prDYided on the same part ~f the
bla~e holder, this distance between the guard bar and the
bla~e cutting ed~e can be hel~ within very ~mall tolerances.
Another ~ay of en~uring this distance between the cut-
ting eage a~d the guard bar 6 without using the lug~ 1b ~e-
~ides in manufacturing the holes 29 of the blade e~actl~ ln
relation to its cutting edge ~6, In this case, the riYet
pin~ 30 are utilized for the e~act positloning ~f the cut-
ting e~ge 26. ~he diame~er of the ri~et pins i8 smaller
than that of the holes 29 in the blade, however, the pins
are provided with two oppositely loczted ribs ~1 which are
arranged in the direction perpendicular to the cutting edge
26 ~he cylindrical generated surIace circumscribing these
rib~ 31 ~as a diame*er w~ich læ approximately 0.01 mm smal-
ler than that of the blade hole 29~ ~he diameter~ ~ the
bore~ ln the base part 1 can be equal ~o or be omaller b~
up to 0,02 mm than the d~ameter~ of the hole~ 29, Instead
of the two ribs as illustrated, it i5 also possible, e~g, t
to provide three ribs distri.buted uniformly over the circum-
ference, A centering procedure results from a minute expan-
sion of the pins during the riveting operation, so that the
holes in the blade are in e~act alignment with the bores in
the base part 1 Of course9 the lugs 1b are omitted in these
cases~
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It i~ essential that the alignment of the guard bar
6 relative to the cutting edge 26 is effec-ted by means
which are provided together on one of the two part~ of
the blade holder, either on the base part 1 or the cover
part ~,
In order to ensure that the lugs 1a are not deformed
by excessive resistance when the legs of the guard bar
are in~erted into the blade holder, the legs of the guard
bar 6 are calibrated in order to reduce the tolerance. This
permits to fit the legs into the recesses provided in the
base part 1 for their reception and to maintain them there
without play in fixed position. These recesses which are
- not illustrated in the drawing are arranged in the blade
holder and are provided with two spacedly arranged wall
surfaces extending parallel to the plane 11 of the guard
bar~ The legs 10 of the guard bar 6 are calibrated paral-
lel -to the same plane to a dimension which i~ appro~imately
0002 mm smal]er tharl the ~mallest dimension oi' the lege
permissible wlth respect to tolerance prlor to calibrationu
~ he invention is not limited to the embodiment illu~-
trated in the drawing.
In the embodiment, a wire of s-tainless steel was used
for the guard bar 6, however, other metallic materials c~
be used. The shape of the teeth and the rows of the teeth
may vary. The cross-section of the guard bar 6 may deviate
from the circle shape. However, it is useful to construct
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co~ve~l~ the ~urface area coming into contact wi~h the ~kin,
~ he handle of the ~nstrument i8 formed in one piece
with the blade holder or i~ connected to the lat-ter, ~ow-
ever, a construction may al~o be selected whereln a loo~ely
in~ertable blade i~ clamped in the blade holder in the
~nown manner,
~ . However, the instrument can also be use~ withcut a blade
.! either for massaging the facial skin or for adjusting the
.~ hair~ of the beard prior to ~ha~ingO
In order to ensure the e~act position of the lugs 1a,
1b or of the lug~ 1a and the bores in the base part for the
rivet pin~ during the production, it i8 advantageous to u~e
an in~ection molding tool for the manu~acture of a blade ~ol-
. der which includes the negativee of all lug8 or bores i~ a
part of the tool which i~ con~-tructed in one piece or i~ GOm-
posed of a plurallty of element~ which remain fixedly con-
nected to one another even when the tool iB opened,
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