Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~5~37
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The present in~ell~ion relatcs generally to cutt:ing
units Eor clry shavers ancllnoLe particularly to a dry shavcr of
the typc wllere;n Ihe c~ t;llc3 unit is rcciurocally located
S wltl~ a per;Eorated oil of the shaver. More specifically,
tile invellt;on reldtes to a rnethod and appara~us for forminy the
cutter strip of tlle cutting unit into a helical confic3uration.
Tlle cutting strip is of the type which is formed with undulations
e~tending along the lengths of the strip and after formation '
into its helical pattern the strip is mounted upon a central
longitudinal support member.
In the type of dry shaver to which the present invention
relates, the perforated foil of the shaver is placed in contact
with the skin and hair protruding through the perforations
of the foil is cut by a shearing action which occurs between
the cutting edge of the reciprocating cutter unit and the edges
of the perforations.
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An important consideration in such shavers requires
that the cutter unit be arranged to operate in an efficient
~`20 manner. It has been found that a cutter unit formed from a
plurality of parallel blades mounted in a rigid support will
operate efficiently. However, although such a cutter unit
exhibits adequate efficiency, it involves an arrangement which
has been found difficult and costly to manufacture. ~;
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105~3 ~
In one method of cons-truction o~fering some manufacturin
advantagesl a wire is wound on a mandrel having a circular
cross section with subsequent grinding operation beiny performed
to provide a cutting edge for the cutter unit. Cutters made
in accordance with this prior art method have not, however, been
found satisfac-tory primarily due to the fact that it is difficult
to grind or otherwise provide a cutting edge in the unit.
Furthermore, it has been found that the blades themselves
develop inherent weaknesses.
Accordingly, there has been proposed a cutter unit
for a dry shaver which involves utilization of an elongated
strip which is wound edgewise into a helical configuration. ~The
strip has undulations extending along the length thereof and
the helically wound strip is mounted or embedded in a central
longitudinal support member in order to form the cutter unit
for the shaver.
The present invention relates to an improved method
and apparatus for forming the undulated cutter strip of such
a unit into a helix. The invention is directed to the provision
of a cutter unit of this type which will exhibit superior
operating characterists but which will not create adverse
manui turing problems.
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SUMMARY OF T~E INVENTION
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srie~ly~ the apparatus of -the present invention may
be described as comprising a triad of rollers which includes
a main roller or ma~drel and a pair of auxiliary rollers arranged
to engage the periphery of the main roller or mandrel in such
a manner that when an elongated undulated cutter strip is
passed between the circumferences of the rollers, a helical
form is imparted to the strip. I'he cutter strip comprises a
generally elongated configuration and before the strip is passed
through the roller triad undulations are formed in the strip
which extend along the length thereof. The main roller or
mandrel of the apparatus is formed with a diameter which is
larger than the diameter of the auxiliary rollers. Each of the
rollers of the roller triad are arranged for rotation about
parallel axes. Both of the auxiliary rollers are shaped with
circumferential slots thereabout with the slots having a width
` dimension which is sufficiently large to accommodate therein theundulations of the cNtter strip. The slots are offset relative
to each other axially of the rollers and in the performance of
the method of the invention the strip is passed in an edgewise
position through the slots of the auxiliary rollers in order to
thereby press an edge of the strip against the circumference of
the main roller or mandrel. As a result of the axial spacing of
` the slots and of the overall arrangement of the roller triad, the
strip will have a helical forma-tion imparted thereto by passage
throug the apparatus o~ the invention.
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10540~7
The various features of novelty which characterize the
inven-tion are pointed out with par-ticularity in -the claims
annexed to and forming a part of this disclosure. For a better
understanding of the invention, its operating advantages and
specific objects attained by its use, references should be had
to the accompanying drawings and descriptive matters in which
there lS illustrated and described a preferred embodiment of the
invention.
DESCRIPTION OF THE DP~WINGS
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In the drawings:
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Fig. 1 is a perspective view depicting a portion of
a cutter strip of the type utilized in connection with the
present invention;
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Fig. 2 is a perspective view showing the shape of a
portion of the cutter strip after it has been wound in a helical
configuration by the apparatus of the present invention;
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Fig. 3 is a perspective view of the overall cutter
strip wound in the form of a helix by the method and apparatus
of the invention;
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Fig. 4 is a perspective view showing a portion of a
cutter unit which utilizes the cutter strip wound in helical ;
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form b he present invention~
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Fig. 5 is an end view of the apparatus of the present
invention showing the cutter strip as it is passed therethrough;
Fig. 6 is a side view of the apparatus oE Fiy. 5; and
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Fig. 7 is a perspective view of the apparatus of the
invention showing the cutter strip during its formation.
DETAILfED DESCRIPTION OF THE PREFERREfD EMBODIMENT
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Referring now to the drawings, wherein like reference
numerals refer to similar parts throughout the various figures
thereof, there is shown in Fig. 1 a portion of a strip 1 of
cutter material which is to be formed by the method and apparatus ~;
of the present invention. The strip 1 may be made of any
suitable cutter material and it is formed with undulations or
waves which extend longitudinally of the strip throughout its
length. The strip 1 comprises a pair of longitudinal edges 2
and 3 and~ in Fig. 1, the strip is shown before it is wound ; ;
, in a~helical configuration in the practice of the present
invention. In the formation of the cutter unit with which the -
strip is utilized, the strip 1 must first be wound edgewise
into a helical configuration identified by the numeral 4 and
shown in Fig. 3. With the strip wound in the form shown generally
in Fig~ 3, the strip may then be mounted or embedded in a
longitudinal support member 5 in order to form the overall cutter
unit. ~he cutter unit, including the helically wound strip 4
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1054037
and the longitudinal support member 5 is depicted in Fig. 4.
Figs. 5, 6 and 7 depict the apparatus of the presen-t invention
utilized for winding strip ~ into its helical shape. ~s depicted
in Figs. 5-7, the apparatus of the invention involves a triad
oE rollers which comprises the rollers A, B and C.
The roller A is a main roller or mandrel having a
diameter which is larger than the diameter of either of the
rollers B or C. The rollers B and C may be considered auxiliary
; rollers and, as seen in the drawings, they are arranyed with
their circumferences generally coincident with or adjacent to
the circumference of the main roller or mandrel A.
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The rollers A, B and C are mounted for rotation upon
shafts 12, 14 and 16, respectively, with the axis of rotation
; of each of the rollers being parallel to the axis of rotation
of each of the other rollers.
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The rollers B and C are each formed with a circumferentic 1 - ~;
slot lOB and lOC, respectively, which extend about the periphery ;~
of each of the auxiliary rollers. The main roller or mandrel A
is formed on its circumference with serrations or corrugations 18
` 20 extending generally axially along the roller circumference.
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In the performance of the method of the present inventio
the strip 1 having undulations formed therein is first introduced
into t roller trlad A-B-C by insertion of the strip 1 in an ;~
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edgewise position into the slot lOB. Rotation of the rollers
will cause the strip 1 to be drawn about the circumference of
the mandrel A through the slot lOB and into the slot lOC of
. the second auxiliary roller C.
As the rollers A, H and C are rotated, the strip 1 will
pass through the slots lOB, lOC and be pressed about the
circumference of the roller A against the serrations 18. As
a result, the strip will pass out of the slot lOC and because
.: of its engagement within the roller triad A-B-C, the strip will
be formed into the helical shape 4 shown in the drawings and
best seen in Fig. 7.
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The slots lOB and lOC are formed with a width dimension
: which is sufficiently large to accommodate therein the undulation
of the strip 1. That is, the widths of the slots lO.B, lOC must
be at least as large as the amplitude of the wave pattern of :.
the undulations which extend lengthwise of the strip 1. -
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Furthermore, the depth of the slots lOB, lOC must be
formed with an appropriate dimension in order to enable the ..
edge of the strip 1 to be pressed against the circumferential
surface of the roller A to a degree appropriate for forming the
helica conEiguration 4 of th- ~trip.
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105~037
As shown in the drawings and as best seen in Figs. 6
and 7, the slots lOB and lOC are offset laterally in a direction
axlally of the rollers. That is, as seen in Fig, 6, the roller C
may be placed at a position somewhat to the right of the roller B
so that the slot lOC will be to the right of the slot lOB when
the apparatus is viewed from the direction indicated in Fig. 6.
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As a result of the offset arrangement of the slo-ts lOB,
lOC, when the strip 1 is introduced into the slot lOB it will
pass in a rightward direction, as viewed in Fig. 6, into -the
slot lOC and, as a result, it will exit from the point of contact
between the roller A and the roller C in its helical pattern.
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The degree to which the slots lOB and lOC are offset will -~
determine the final pitch of the helix ~ which is formed.
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; Of course, other considerations are involved in the
; 15 formation of the helix regarding the size and diameter of the
helix which is formed. A primary consideration is the fact that
` the roller A is of larger diameter than the rollers B and C.
Furthermore, the points of contact between the roller A and each
of the rollers B and C respectively has an effect upon the shape
of the helix which is formed. For example, the various diameters
I of the rollers could be varied within limits and the general
positioning of the rollers B and C relative to each other and
relative to the roller A could also be varied within limits, as
will be apparent to those skilled in the art, in order to adjust
the parameters of the helical con~iguration to be formed.
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lOS4037
As a result of the overall arrangement of the invention,
the diameter of the helix which is formed is not dependent upon
the geometry of the roller arrangement and is not dependent
upon the diameter of any one of the rollers. Thus, it will be
seen tha-t varlations of the overall arrangement depicted and
described herein may be effected by those having ordinary skill
in the art to vary the specific dimensions of the arrangement
and of the helix which is formed without departing ~rom the
spirit and scope of the invention. ~ ;
While a specific embodiment of the invention has been
shown and described in detail to illustrate the application of
the inventive principles, it will be understood that the
invention may be embodied otherwise without departing from
such principles.
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