Note: Descriptions are shown in the official language in which they were submitted.
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IMPROVLD METE~ODS AND
APPARATUS FOR CLIPPING HAIR
Back~round of the Invention
This invention relates to methods and apparatus
for clipping hair, and more particularly, to methods and
apparatus for trimming~ thinning and layering hair with
electric hair clippers.
Most electric hair clippers include two
bladesO One blade is ~tationary, and the other blade
lQ oscillates with respect to the stationary blade. Each
blade has a row of pointed hair eutting teeth 9 and the
two rows of teeth are arranged parallel to and in contact
with each other. The tips of the teeth on the stationary
blade form a generally straight blade edge.
The teeth are arranged to ~orm generally V-
shaped cavities between adjacent teeth. Hair strands
which enter the cavities between the teeth on the
stationary blade are cut by the oscillating motion o~ the
teeth on the reciprocating blade.
Such hair clippers cut hair easily and
efficiently across the entire blade edge of the hair
clipper. Mistakes can be made easily, however, because
the clippers cut many hair strands at one time. In
addition, it is difficult to merely trim the hair lightly
without leaving visible signs of where the hair was
trimmed.
Some hair styling is done with shearing
scissors. Such scissors have notched blades so that hair
is only cut along selected portions of the blades, and is
not cut along the notched portions. As a result, only a
predetermined percentage of the hair strands between the
blades is cut at any one time.
Shearing scissors may be used to layer hair or
thin it, but are generally not used for trimming.
Layering or thinning hair with shearing scissors is
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tedious and time-consuming, and requires a high level of
skill. Also 9 the resulting layers of hair are often
distinct and differentiated because all of the hair
strands in the hair cutting portions of the blades are
cut essentially the same length. Such distinct layers
are often visible even when the desire is to merely thin
the hair without layering it.
Hair can be thinned or layered with specially
adapted electric clippers in which only the hair strands
between selected teeth of the stationary blade are cut by
the motion of the reciprocating blade. As suggested in
U.S. Patent No. 2,470,287, this may be accomplished by
making the cavities between the selected stationary teeth
deeper than the cavities between unselected stationary
teeth, and moving the reciprocating blade and the blade
edge away from each other so that the reciprocating blade
only cuts hair in cavities between selected teeth, and
not in cavities between unselected teeth. A great number
of hair strands which are not intended to be cut pass
through the cavities between the unselected teeth,
however, and can be torn or otherwise damaged. Such torn
or damaged hair strands may eventually break off or split
at the ends. The likelihood of such damage occurring is
increased if the clipper moves through the hair quickly.
Another concern with such specially adapted
hair clippers is that in order to only cut hair which is
in cavities between selected stationary teeth, the
selected cavities are made deeper than the cavities which
are not selected so that the reciprocating blade may be
drawn back to only pass across the selected teeth. As a
result, the hair must enter a substantially deeper cavity
to be cut, which is undesirable because the operator must
move the clipper closer to the head in some
circumstances. Since the tips of the blade teeth are
hard and relatively sharp9 the deep cavities increase the
risk of injury in the event that the teeth strike or
scrape the skin.
Thus, there is a need for electric hair
clippers which are adapted for use in trimming, thinning
and layering hair quickly, without creating distinct
layers when distinct layers are not desired. There is
als~ a need ~or electric hair clippers which do not
damage strands of hair which are not intended to be cut,
and do not have excessively deep cavities and relatively
sharp teeth.
Shaping hair is somewhat difficult with
conventional scissors and conventional electric clippers
because they are designed to remove a substantial number
of hair strands at a time. As a result, it is easy to
cut hair too short without realizing it. Consequently,
there is also a need for apparatus and methods for
shaping hair gradually, to permit inspection of the style
and shape Or the hair throughout the process.
The texture or feeling of cut hair is very
important to most people. Known methods and apparatus
for cutting hair cut so many strands of hair the same
length that the texture of the hair is often coarse and
unnatural, and unlike the natural texture of the hair
after it grows for a period of time following a
haircut. Thus, there is a need for methods and apparatus
for cutting hair which create a natural, relatively
fluffy, filigreed texture.
The proper use of both shearing scissors and
electric hair clippers requires skill, and a person's
appearance can easily be ruined if the scissors or
clippers are not used properly. One reason for many of
the commonly occurring mistakes is that a significant
number of strands of hair may be cut at a time, as
previously described. Thus, there is a need for methods
and apparatus for cutting hair which do not easily ruin a
person's appearance if not used properly.
Spiking or notching hair is a popular technique
used to create certain hair styles. The technique is
difficult to use with scissors and is relatively time-
?^~ 3 ~3
consuming. Therefore, there is a need for me-thods and
apparatus for spiking or notching hair which are easy to use
and are relatively fast.
ummary of the Invention
In keeping -~ith one aspect of this invention, an
electric hair clipper is disclosed which has a stationary blade
and a reciproca-ting blade. The stationary blade has a
plurality of stationary teeth which are arranged in a row.
The stationary teeth have relatively blunt tips whi~h ~orm a
line called a blade edge, and each sta-tionary tooth has at
least one cutting edge which forms an angle with the blade
edge. The stationary teeth are arranged in a plurality of
groups of one or more teeth, and each group of teeth is spaced
apart from each other group. Each group is separated from each
other group by a smooth and unobstructed space which has a
width at the blade edge which is greater than the distance
between the tips of adjacent stationary teeth.
The reciprocating blade has a plurality of reciprocatiny
teeth arranged in a row. The reciprocating teeth are generally
complementary to the stationary teeth, and each reciprocating
tooth has at least one cutting edge which reciprocates past at
least one cutting edge of a stationary tooth which the
reciprocating blade tooth complementsO The reciprocating blade
teeth ars arranged in clusters of one or more teeth, and
preferably one tooth, and have gaps between clusters which are
arranged so that the spaces between the groups of teeth on the
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stationary blade are substantlally unobstructed by the teeth
on the reciproca-ting blade.
Hair strands may be cut by passing the hair clipper o~er
the hair in a series of swift, flo~ing strokes. The clipper
may be passed over the hair at the outer periphery of the hair,
or it may be passed over the hair within the periphery -to
change the hair style. The hair style may be changed gradually
using the swift stroke method just described, without
drastically changing the style with any single pass. In this
manner, the hair may be slowly sculpted into a desired hair
style, and the hair style may be inspected easily as it is
created. The hair clipper just described may also be used to
thin or layer hair.
In summary, therefore, the present invention may be
considered as providing apparatus ~or clipping hair comprising:
a handle and a cutting head secured to the handle, the handle
having a source of electrical power, an electric motor and
drive means operatively connecting the motor to the cutting
head; the head comprising a stationary blade and a
reciprocating blade operatively connected to the drive means
to reciprocate with respect to the stationary blade during
operation; the stationary blade having a set of stationary
teeth arranged in a row, the stationary teeth each having at
least one cutting edge and a tip, the tips defining a blade
edge; each of the stationary teeth being separated from
adjacent the stationary teeth by a substantially unobstructed
space; the reciprocating blade having a plurality of
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~Y~
reciprocating teeth complementing the sta-tionary teeth so that
one of the reciprocating teeth passes one of the cutting edges
of the stationary blade teeth; the reciprocating teeth being
separated from each other by substantially unobstructed yaps,
the gaps being arranged so that a substantial portion of each
of the spaces is substantially unobstructed by the
reciprocating teeth; the stationary blade defining a total
distance "b" over which hair strands could encounter the
blades, and the reciprocating teeth defining a plurality of
spaced linear distances "c" over which hair strands are likely
to be cut, the ratio of the sum of the distances "ci' to the
distance "b" being less than about 0.29.
srief Description of the Drawin~s
The above mentioned objects and other features of this
invention and the manner of obtaining them will become more
apparent, and the invention itself will be best understood by
reference to the following detailed description, taken in
conjunction with the accompanying drawings, in which:
FIG. 1 is a side elevation view of a portion of an
electric hair clipper made in accordance with the principles
of this invention;
FIG. 2 is a top plan view of the cutting head of the
hair clipper of FIG. 1, showing the reciprocating blade in the
center of the head;
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,,; ~
FIG. 3 is another top plan view of the cutting
head of the hair clipper of FIG. 1, showing the
reciprocating blade on the left side of the head;
FIGo 4 is a cross section view of a portion of
the cutting head shown in FIG. 3~ taken along lines 4-4;
FI~. 5 is a bottom plan view o~ the cutting
head of the hair clipper of FIG~ 1;
FIG. 6 is a side elevation view of the cutting
head of the hair clipper of FIG. 1;
,lO FIG. 7 is a top plan view of the stationary
blade of the cutting head of FIG. 2, with the
recîprocating blade removed;
FIG~ 8 is a partial view of an alternate
embodiment of the stationary blade of FIG. 7;
FIG. 9 is a top plan view of the reciprocating
blade of the cutting head of FIG. 2 J with the
reciprocating blade removed from the stationary blade7
FIG. 10 is an illustration of a portion of a
person's head and hair showing the hair after it has been
cut with shearing scissors;
FIG. 11 is an illustration of a person' 9 head
and hair;
FIG. 12 is an illustration of a portion of the
person's head and hair shown in FIG. 11 showing the hair
after it has been cut with the hair clipper of FIG. 1;
FIG. 13 is an illustration of a person's hair
being cut according to one method of the present
invention;
FIG. 14 is another illustration of a person's
hair being cut according to the method shown in FIG. 13;
FIG. 15 is still another illustration of a
person's hair being cut according to the method shown in
FIG. 13; and
FIG. 16 is an illustration of a person's hair
being cut according to another method of the present
invention.
5 ~
~etailed Description
As seen in FIG. 1, a hair clipper 20 includes a
handle 22 (partially shown) and a cutting head 24. The
handle 22 includes an internal ~ower source, such as
batteries, or a line cord or the like for c~nnection to
an external power source. The handle 22 also incl~des an
electric motor and drive means (not shown) operatively
connected to the cutting head 24. The cutting head 24
includes a stationary blade 26 which is secured to the
`lO handle 22 by any suitable means, such as screws or the
like (not shown), and a reciprocating blade 28 which
oscillates with respect to the stationary blade 2~ during
operation.
The cutting head 24 is shown in greater detail
in FI~S. 2-5. The stationary blade 26 has a set o~
stationary teeth 30 (FIG. 5) arranged in a row, and the
stationary teeth 30 have stationary tips 31 which define
a line 32, referred to herein as the blade edge. The
blade edge 32 is preferably ~ubstantially straight. The
stationary tips 31 are preferably relatively blunt to
reduce the likelihood of in~ury in the event that the
teeth come in contact with skin. The stationary tips 31
may have a rounded or flattened end, or any other
unpointed shape. The stationary teeth 30 also include at
least one cutting edge 33 (FIGS. 2 and 8) which forms an
angle "a" with the blade edge 32. The angle "a" may be
90, but is preferably less than 90.
The reciprocating blade 28 (FI5. 2) has a set
of reciprocating teeth 34 having reciprocating tips 35.
The reciprocatine tips 35 define a line 37 which is
preferably slightly recessed from the stationary tips 31
(FIG. 5~, so that if the stationary tips 31 come in
direct contact with skin, the oscillating teeth 34 do not
contact the skin and pos~ibly irritate it or cut it. The
distance be~ween the blade edge 32 and the line 37 is not
great, however, so that hair s~rands do not have to enter
deep cavities in order to be cut, and so that the
g-5a;~
operator can clip the hair close to the skin, i~
desired~ A preferre~ re~ess o~ the line 37 from ~he
blade edge 32 is between about .015 inches an~ o020
inches.
The reciprocating teeth 34 (FIG. ~) are
generally complementary to the stationary teeth 30, and
have cutting edges 39 which reciprocate past at least one
edge 33 on the stationary blade 26. The reciprocating
teeth 34, in combination with the stationary teeth 30,
cut hair whi.ch enters a plurality of cavities 36 (FIGo 3)
between adjacent stationary teeth 30. The cavities 36
are generally V-shaped or U-shaped, and end at a vertex
38 (FIG. 5). The vertexes 38 of the various cavities 36
de~ine a line 40 which is spaced from and generally
parallel to the blade edge 32. The distance between the
blade edge 32 and the line 40 is preferably relatively
small, on the order of ~1 inches or less. A preferred
distance between the blade edge 32 and the line 40 is
about .090 inches or less.
The stationary teeth 30 are segregated into a
plurality of groups 42, as shown in FIG. 7~ Each group
42 may include one or more stationary teeth 30, but two
teeth per group, as in FIG. 7, or three teeth per group,
as in FIG. 8, are preferred. The groups 42 are each
separated by a space 44. The spaces 44 have bottoms 45
which are smooth and unobstructed, and may be
substantially straight, as in F`IG. 7, or curved as
desired.
The teeth 34 are arranged in a plurality of
clusters 46 (FIG. 9), so that one reciprocating tooth 34
crosses each cavity 36 as the blade 28 reciprocates. If
each group of stationary teeth 30 forms only one cavity
36, as in FIG. 7, then only one tooth 34 is needed for
each cluster 46, as in FIG. 9.
The clusters 46 are separated from each other
by gaps 48. The gaps 48 are arranged so that the spaces
44 are substantially unobstructed by the reciprocating
r-~3
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teeth 34. The gaps 48 include gap bottoms 47 which
pre~erably correspond to the bottoms 45, as in FIGS. 2, 3
and 5.
FIG. 4 shows certain aspects of the
relationship between the stationary blade 26 and the
reciproeating blade 28 in greater detail. The distance
between the blade edge 32 and the line 37, and the
relatively blunt stationary blade tip 31 are easily
seen. As shown in FIG. 4, the gap bottom 47 is slightly
closer to the blade edge 32 than the bottom 45, and the
gap bottom 47 is a relatively smooth, blunt surface.
This structure is desirable so that hair strands which
enter the spaces 44 will confront the relatively smooth,
blunt surfaces of the gap bottoms 47, and are not damaged
by a sharp surface~ This could be accomplished in other
ways, however. For example, the bottom 45 could be made
closer to the blade edge 32 than the gap bottom 47, and
the bottom 45 could have a relatively smooth, blunt
surface, or the bottoms 45t 47 could be coextensive and
both have relatively smooth, blunt surfaces.
FIG. 8 shows a portion of an alternate
embodiment of the stationary blade 26, in which there are
three stationary teeth 30 in each group 42. FIG. 8 also
shows an alternate configuration of the stationary teeth
30. The blunt stationary tips 31 can be easily seen.
The stationary teeth 30 include a generally rectangular
portion 49 adjacent the stationary tips 31. The
rectangular portions 49 improve the manner in which hair
strands are fed into the cavities 36, and reduce the
likelihood that some strands will be pushed away from the
teeth 30 when the reciprocating blade teeth 34 (not shown
in FIG. 8) pass across the cavities 36. For this reason,
it is preferable to provide such rectangular portions on
the reciprocating teeth 34, as well.
Each space 44 should have a width along the
blade edge 32 which is greater than the distance betwaen
adjacent stationary tips 31. The preferred relationship
between the groups 42 and the spaces 44 may be described
in a general ~anner by comparing the total linear
distance "b" (FIG. 7) along the blade edge 32, which is
the distance over which hair strands could encounter and
be cut by the blades 26, 28~ with the total of the linear
distances "c" over which hair strands are likely to enter
one of the cavities 36 and be cut. Experiments have
shown that good results can be achieved when the ratio of
the total of the linear distances "c" to the distance "b"
is about .35 or less, and that the preferred ratio is
about .29. Experimentation h~s also shown that while
each of the groups 42 may be made up of a single tooth,
two teeth in each group are preferable.
In operation, the oscillating blade 28 travels
back and forth in the two directions indicated by an
arrow 50 in FIG. 3. The reciprocating teeth 34 each
travel across one cavity 36, and preferably do no~ travel
much beyond the stationary teeth 30 which form the cavity
36 associated with each reciprocating tooth 34.
The reciprocating blade 28 is shown in FIG. 3
in a position which is about as far to the left as the
blade 28 might be expected to travel. ~s the blade 28
travels to the right, hair strands in the cavities 36
will be cut by the interaction of the cutting edges 39
(FIG. 3) with the cutting edges 33. As the blade 28
travels back to the left, cutting edges 39 on the left
sides of the reciprocating teeth 34 will cut hair strands
which are in the cavities 36 by interaction with the
cutting edges 33 on the left side of the cavities 36.
The configuration of teeth on the blades 26,
28, in combination with the relatively fast speed and
ease of hair cutting which is made possible by electric
hair clippers, has led to the development of several new
and unique processes for trimming, thinning and layering
hair. The processes work especially well on curly and
wavy hair, but also work on relatively straight hair.
- 12 -
While the clipp~r 20 and the processes to be
described have many applications, such as grooming
animals and the like, the processes will be d~scribed
with reference to human hair. As seen in FIGS. 11 and
12, hair 51 includes a number of hair strands 52 which
grow out of a scalp 5L~. The hair strands 52 define an
outer periphery 56 which is a predetermined distance from
the scalp ~4. The lay of the hair strands 52, which is
their natural tendency to grow in a particular direction,
~lO is downwards.
The hair clipper 20 may be used to quickly and
neatly trim the hair, if desired. This may be
accomplished by stroking the periphery 56 several times
in a fairly rapid motion, following the general shape of
the hair 50, and gradually moving the clipper 20 so that
the clipper is passed over a selected portion of hair
being trimmed. The strokes may be up, down, or both up
and down. A rate of about one to three strokes per
second is expected to produce good, thorough trimming in
less time than such trimming might take using known
methods. This method is particularly useful when it is
desired to maintain a particular hairstyle trimmed closer
to the head.
Hair may also be trimmed to a different shape
using the rapid motion technique just described. When
styling the hair, the technique may be used to gradually
change the shape of the hair, without abruptly changing
it drastically. This allows the operator to sculpt the
hair slowly, and critique the style as it evolves. This
process is particularly useful for developing new hair
styles, and for students studying hair styling.
In addition to trimming hair, the hair clipper
20 may be used to thin or layer hair. Hand-operated
shearing scissors tend to produce distinct layers, even
when distinct layers are not desired, as seen in FIG. 10,
in part because such scissors cut substantial clusters of
hair strands the same length 9 and also in part because
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the scissors are held in a substantially fixed position
when the hair is cut so that the hair is not pulled.
Distinct layers are most Yisible when the hair is
straight~ but they may also be visible when the hair is
curly or wavy.
With the hair clipper of this invention, the
hair may be thinned by moving the clipper 20 through the
hair 50 with the relatively quick, fluid motion
previously describedO If desired, however, instead of
.lO following the shape of the hair, the clipper may be moved
in towards the scalp 54, and away from the scalp 54 at
the same or a di~erent angle, cutting hair strands 52 in
the manner shown in FIG. 12. The resultant texture of
the hair 50 is natural and soft, in contrast to the
relatively unnatural, coarse texture often obtained using
shearing scissors.
FIGS. 13, 14 and 15 illustrate another method
of clipping hair using the electric clipper 20 of FIG.
1. As seen in FIG. 13, the operator holds the clipper 20
in one hand, and a comb 58 in the other hand. The comb
58 is passed through a portion of the hair 50 with a
brisk, continuous motion, preferably upward, against the
natural lie of the hair. The comb 58 displaces hair
strands as it passes through the hair 50, and creates a
wave-like trough 60 which travels behind the comb 58.
The clipper 20 follows the comb 58, as in FIGS. 13 and
14, and catches and clips hair strands as they return to
their natural position. The clipper may be passed
through the hair following the contour of the scalp 54,
or it may be passed through the hair at an angle to the
scalp 54, cutting the hair as in FIG. 12.
As the comb 58 leaves the hair 50, the comb may
be returned to the lower part of the head, for another
pass through the hair 50, if desired. The comb 58 may
begin a new pass as the clipper 20 finishes the previous
pass (FIG. 15), if desired, so that a fairly continuous
motion may be used to cut the hair. About one to three
~ f ~;t~
- 14 ~-
passes per second are contemplated as a typical pace~ In
this manner~ the hair may be thinned or layered
relatively quickly. Since the clipper 20 cuts a
relatively low number of hair strands per cycle, there is
little chance that a grave error will occur on any
particular pass.
Another process which may be used with the hair
clipper 20 is known as spiking or notching. As seen in
FIG. 16, a tuft of hair 62 is held relatively firmly in
~lO place with one hand 64, while the other hand &6 moves the
hair clipper 20 into the tuft 62 generally perpendicular
to the tu~t 62. The hair clipper 20 cuts a plurality ~f
fairly distinct notches 68 in the hair. The hair clipper
20 may be pushed into the tuft 62 any desired number of
times and in any desired manner, to create randomly
different hair lengths, resulting in a variety of hair
styles. The repetition rate can be between about one to
three cuts per second.
The many advantages of this invention are now
apparent. The hair clipper may be used to trim, thin or
layer hair with or without producing distinct,
differentiated layers of hair, as desired9 and without
tearing or otherwise damaging hair strands which are not
intended to be cut. The hair clipper may a~so be used to
notch the hair in a variety of ways relatively easily and
quickly. The reduced number of teeth cut a relatively low
number of hair strands at a time, giving the operator
added freedom of movement with less risk of irreparable
error. The relatively blunt ends of the teeth provide an
added degree of safety.
The processes taught for trimming hair are not
excessively tedious and time-consuming, and generally do
not require a high level of skill. Hair can be removed
easily, without changing the general shape of the hair,
or the shape of the hair can be changed gradually, and
sculpted into a new style. The thinning and layering
processes disclosed result in a natural, fluffy,
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filigreed texture. The notching processes result in a
variety of unique hair styles.
Whi]e in the f`oregoing specification this
invention has been described in relation to certain
preferred embodiments thereof, and many details have been
set forth for purpose of illustration, it will be
apparent to those skilled in the art that the invention
is susceptible to additional embodiments and that certain
of the details described herein can be varied
~10 considerably without departing from the basic principles
of the invention.
