Note: Descriptions are shown in the official language in which they were submitted.
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~ Shaving apparatus.
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The invention relates to a shaving
- apparatus having a shear plate with a wall in which hair~ .`
entrance aper-tures are formed and a cutting unit wliich is
drlvable rela.tive to the shear plate, whlch CUttillg unit
. comprises a CUtti..llg member with cutters, ~hich cutters are
~ provided wi-th lead cutters ~hi`ch are movable relative to
~ -. the cutters, which lead cutters are positioned with a
J sliding surface against the shear-plate wall with hair-
3 . 10 entrance apertures.
s ~ Such a shaving apparatus is for example
; B: known from British Patent 1 467 557_ ~ In this
known construction the lead cutter all over en~ages with
the cutter and both the lead cutter and the cutter are pro-
vided wi$h a s~idingg surface at the end, which surface
: engages ~th the inner side of the shear plate in the
assembled condit.ion. Starting from this initial situation
-the lead cutter can only move relative to the cutter in
2 an inward direction away from the shear plate.
. However, if in deviation from the ~lo~n
~ construction a construction is used wllere the lead cutte.r
: does not or only partl~ engages with the cutter~ it i5
` possible that starting from -the initial situation the lead
cutter can also move in an ou-tward direction relative to the
cutter. This poss:ibility also occurs with the ~lol~n construc- :
tion if one or more :Lead cutters do not completel~r engP~go
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; with the associa-ted cutter as a result of manufacturing
tolerances. However, in tha-t case there is a risk that the
lead cutter, which generally has a substantially smaller
thickness than the cutter, gets into a hair-entrance aper-
ture with great risk of damage to the apparatus.
` The construction in accordance with
the inventi-on, whose object it is to eliminate this dis-
advantage, is characterized in that the lead cutter has a
I sliding surface of such a shape and dimensions -that in each
¦ 10 pOSi-tiOIl relative -to a hair-entrance aperture the sliding
surface is in contact with a part of the shear-plate wall
which adjoins the hair-entrance aperture.
A special embodiment i~ characterized
in -that thc lead cutter :is prov:Lded ~aith a bent-over tab
~ which is also positioned with a sliding surface against the
shear-plate wall with hair-entrance apertures.
The invention is also embodied by a
cutting unit as employed in a shaving apparatus as defined
in the ~oregoing.
The invention will now be explained by
means of a description of some embodiments shownin the
Figures.
Fig. 1 is an elevation of a shaving appa-
ratus having three shear plates.
Fig. 2 shows the shaving apparatus of
Fig. 1 in side view and partly in a cross-section -taken on
the line II-II in Fig. 1.
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Fig. 3 is a perspective view of the
cutting member wi-th lead cu-tters and a part of the shear
~ plate.
~, FLgs. 4 t,hrough 9 show elevations of the `
~!1 5 , sliding surfaees of cutter and lead cut-ter in different
embodiments.
,~ , Figs. 10 and 11 illustrate the operation
~`! ` of the lead cutter. `
The shaving apparatus in accordance wi-th
Fi~ures 1 alld 2 eomprises a hous~ng 1, o~ which a part ta'k,er
the form of a shear-plate holder 2 for three shear plates 3.
The shear plates 3 have hn:ir-entrallce apertures 4.
As i9 shown in the partial cross-
section of Fig.2 a cutting unit 5 is disposecl on the inner
side o~ a shear plate 3. This cutting unit 5, which for
the sake of clarity is only shown schematically in Fig. 2,
, ~ : -comprises a cutting member and lead cutters and is shown
in detail on an enlarged scale in fig. 3.
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l~ . The cutting unit 5 is eoupled to~the
~ 20 elec-tric motor 10 by means of the hollow spindle 6(Fig. 2),
~- the gear wheels 7 and 8 and the spindle 9, so that the
cutting unit is rotatable relati~e to the assoeiated shear
` ` plate 3. The gear wheel 7 is rotatably journalled on a pin
11 which is mounted in a moun~lg plate 12. The gear wheel
25` 7 has a recess 13 which is closed by a co~rer plate 1L~.
This recess accommodates the flange 15 at the end of the
hollow spindle ~. By gi~ing the flange 15 a non-round, for
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example square,.shape and by shaping the recess 13
accordingly, a coupling is obtained for the trans~
mission of -the rotary movement of the gear wheel 7 to the
spindle 6. The spring 16, which for the greater part is
disposed in the hollow spindle 6 and which i6 -tensioned
between the hollow spindle 6 and the gear wheel 7,-exerts
a force on the spindle 6 in the dlrection of the cutting
unit 5. As the cylindrical por-tion 17 of the spindle 6 bears
- against the cutting Ullit 5 this force is exertod on the cut-
ting uni-t and via the outting unit on the shear plate 3, so
thatjthe shear plate is pressed ~ainst -the shear plate holder
2 with thee~ge18. As a result of external forces, as for
example may occur during use o:~ the shaving apparatus, the
shear plate 3 together with t:he cutting unit 5 and the
I . 15 spindle 6 can be pressed inwards against the action o~ the
'~ spring 16.
i . The coupling for the transmission of the
rotary movement between the spindle 6 and the cutting uni-t 5
is obtained in that the spindle 6 has an end 19 of substan-
tially rectangular cross-section. This end 19 is disposed in
. a corresponding coupling opening 20 of $he cutting unit 5.
The coupling to the electric motor 10
as described in the ~regoing is identical for the. three cutting
units of the apparatus of Figures 1 and 2, the three gear-
. 25 wheels 7 being in engagement with a single centrally disposed
gearwheel 8 on the motor spindle 9.
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` As is shown in Fig. 3 the CUttillg unit
5 comprises a cutting member 21 which is constituted by a
central body 22 with -the cutters 23 at the circumference.
In the central body 22 the coupling opening 20 is formed.
The cutters 23 are provided with lead
~' cutters 2~ which are manufactured from a resilient sheet
! material. The lead cutters 24 are integral with an annular
1 portion 25 which is for example secured to the central body
;, 22 of the cutting member by spot-welding or g:Lueing. The
' 10 cutters 23 and the lead cutters 24 engage with the inner
I wall 28 with hair-entrance apertures 1~ of the shear
plate 3 by ~leans of sliding surfaces 26 and 27 respectively
~ (also see Flgs~ 4 through 9).
ii 'l'he part 29 o~ the :Lead cutters 24
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1 15 ~ which adjoi~is the annular portion 25 and the part 30 of the
cutters 23 which adjoins the central--bod~ are spaced from
each other. Owing to the elastic properties of the
material from which the lead cutters are manufactured,
these lead cutters are movable relative to the associated
cutters and can move both in an inward direction, away
from the shear plate, and in the opposite outward direc-
tion. In order to prevent the lead cutters 24 from being
pressed into the hair-entrance apertures 4 by the forces
acting on it, the lead cutters in the construction of Figuxe
3 and Figure 4, which relates to this construction are pro-
vided with a bent-over tab ~1 which also eng~ages with the
inner wall 2~ o~ the sh~r pla-te 3 b~ a sliding surface 32
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The cons-tructioIl is such that always a part of the
sliding surface 27, 32 is in contact with the part
of the wall 28 of the shear plate 3 which adjoins the
, hair entrance aperture 4.
~ 5 Figures 5 through 9 show some variants
!~ . of the construction in accordance with Figures 3 and 4,
which in a similar way as ln Fig. 4 only show an
eleva-tion of the sliding surfaces of lead cutter 24 and
cu-tter 23, a hair-entrance ape~ture 4 being represented by
dashed llnes. In the construction of Figures 4, 5 and 7 the
~i tabs 31, and 33, 34 respectively provide a correct guidance
? during the movement of the lead cutter 24 relative to the
~i cutteI~s 23.
-~ . Figures 10 and 11 schematically show a
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, 15 side view of a part of a cutter 23 and a lead cutter 24 and
of a part of the shear plate 3 and serve -to illustrate the
operation of a lead cutter. If a hair 35 is trapped in a hair
entrance aperture 4, this hair will soon come into contact
` - with the shard edge 36 of lead cutter 24 a-t location A owing
to the rotary movement of cutter 23 and lead cutter 24. 'rhe
sharp edge is such that it will slightly penetrate the hair
35, without cutti.ng off the hair. The reaction force which
is exerted on the lead cutter 24 by the hair 35 will be
directed oppositely to the direction of movement P. This
force should be compensated fQr by the component N1 of the
normal force N which is e.~erted on the lead cutter 24 by
the guide wall 37 of the cutter 23 (Fig. 10). For the sake
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of simplicit~ the slight frictional forces between the
` lead cutter 24 and the cutter 23 have been neglected.
', The componen-t N2 of the normal ~orce N will cause the lead
cutter to slide along the guide wall 37. The angle ~ between
the guide wall 37 and the wall 26 of the cutter 23 which
, engages with t~ wall 28 of the shear plate 3 should be
smaller than 90.
Owing to _ ~ alia the natural
j elasticit~ o~ the skin the hair 35 will be moved along
J . 10 by the lead cutter 2ll unti:L the cutting edge 3~ o~ the cutter
~' 23 has reached thc hair at the location B (~ig. 11). Subse-
quently, the hair will be out by the cooperation of the shear
plate 3 and thc cutter 23. l'hus, a length of the hair 35 is
cut which is ,'Longer than the length which would be cut with-
out lead cutter by an amount equal'to- the distance between
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, ~ and B, so that a better shaving result is obtained.
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