Blade assembly for a vibrator motor

Information

  • Patent Grant
  • 6658740
  • Patent Number
    6,658,740
  • Date Filed
    Friday, March 16, 2001
    23 years ago
  • Date Issued
    Tuesday, December 9, 2003
    20 years ago
Abstract
A blade assembly for an electric hair cutter that includes a stationary blade and a cutting blade, where the cutting blade is configured for reciprocating arcuate motion relative to the stationary blade. The stationary blade includes a plurality of stationary cutting teeth, with each of the stationary cutting teeth having a tip at a distal end thereof, and wherein the tips of the stationary cutting teeth define a first imaginary line. The cutting blade includes a plurality of reciprocating cutting teeth, with each of the reciprocating cutting teeth having a tip at a distal end thereof, and wherein the tips of the reciprocating cutting teeth define a second imaginary line. The distance between the first imaginary line and the second imaginary line is greater near both end portions thereof than a corresponding distance at a center portion between the end portions.
Description




This invention relates to blade assemblies for vibrator motors, and more particularly to blade assemblies for hair clippers, and the like, that are configured to reduce the likelihood of nicking or cutting a subject's skin.




BACKGROUND OF THE INVENTION




Vibrator motors have been used in electric hair clippers for many years, as in U.S. Pat. Nos. 2,877,364, 2,986,662 and 3,026,430, which are hereby incorporated by reference in their entirety. One example of a conventional vibrator motor in a hair clipper is shown in FIG.


5


. Of course, there are other types and models of hair clippers other than that shown in

FIG. 5

that also include vibrator motors. Referring back to

FIG. 5

, this figure shows a hair clipper


10


that includes a case


12


, a stationary hair cutting blade


14


, and a reciprocating hair cutting blade


16


. The blade


16


is driven by a vibrator motor


18


, which includes a stationary coil


20


, coil laminations


22


and moving laminations


24


. It should be noted that in some models, a moving steel arm is utilized in place of the moving laminations


24


.




The coil laminations


22


are stationary within the case


12


. The moving laminations


24


are part of a vibrating arm


26


. The vibrating arm


26


also includes a tail bracket


28


. The arm


26


is operatively connected to the moving blade


16


through a resilient finger


32


. A mechanical spring system


34


includes the tail bracket


28


, which is fixed at one end to the case


12


, and coil springs


36


located on each side of the tail bracket


28


and between adjacent walls of the case


12


. The mechanical spring system


34


is designed so that the vibrating arm


26


has an appropriate resonant frequency.




In operation, the arm laminations


24


tend to reciprocate in a slight arc because the vibrating arm


26


is fixed at one end. As a result, the moving blade


16


tends to reciprocate along an elliptical path A. As will be explained below, the elliptical path of the moving blade


16


contributes to the problem addressed by the present invention.




While the conventional hair clippers just described have been useful and commercially successful, cutting or nicking a subject's skin can be a problem. Specifically, hair clippers are sometimes used to cut close to the scalp, with the tips of the blade teeth being placed directly against the scalp. However, due to the elliptical path of the cutting blade, there is a tendency for the cutting blade to extend beyond the stationary blade towards the end of the blade's stroke, resulting in cutting or nicking of a subject's skin. By manner of illustration,

FIG. 6A

is a front view of a conventional cutting assembly, and

FIG. 6B

is an enlarged fragmentary view of

FIG. 6A

showing the cutting blade


16


extending beyond the stationary blade


14


towards the end of the cutting stroke.




To address the above-described problem, in some conventional hair clippers, the length of the stationary blade


14


is increased with respect to the length of the moving blade in order to increase the size of an overlap, X


Gap


(shown toward the left of FIG.


6


A), which is measured between the end of the cutting blade


16


and end of the stationary blade


14


. Notably, if the overlap X


Gap


is sufficiently great, then the cutting blade


16


will not extend beyond the stationary blade


14


at the end of the cutting stroke. Unfortunately, in order to provide an extremely close cut, it is desirable to reduce X


Gap


to approximately zero.




Alternatively, some conventional hair clippers incorporate a blade guide into the device in order to ensure that the cutting blade travels in a straight line, without extending beyond the stationary blade. This approach provides satisfactory results, but results in higher manufacturing costs, making this approach unsuitable for low cost hair clippers. Moreover, the blade guide imposes a side load on the reciprocating blade, which undesirably reduces the cutting power in a vibrator type clipper.




Yet another approach to the above-described problem involves reducing the stroke of the cutting blade. As described above, the cutting blade is most likely to extend beyond the stationary blade at the extreme end of the stroke. Thus, the likelihood of the stationary blade extending beyond the stationary blade may be reduced by, for example, reducing the ampere-turns of the motor. However, reducing the stroke of the blade in this manner can also reduce cutting performance to an unacceptable level.




Thus, there is a need for a blade assembly for hair clippers which provides an extremely close cut while avoiding pinching or nicking of the skin. There is also a need for blade assemblies which are inexpensive to manufacture, and which avoid the use of rigid guide paths. Another need is for an improved blade assembly for vibrator hair clippers, where the improved blade assembly can be easily incorporated in existing product designs.




Accordingly, one object of this invention is to provide new and improved blade assemblies for vibratory hair clippers.




Another object is to provide new and improved blade assemblies which provide a close cut without the use of a rigid blade guide.




Yet another object is to provide new and improved blade assemblies which provide a close cut without sacrificing cutting power.




Still another object is to provide new and improved blade assemblies which are simple to make and assemble, and which can be easily adapted for use in conventional vibrator hair clippers.




SUMMARY OF THE INVENTION




Briefly, the present invention relates, in part, to a blade assembly for an electric hair cutter, where the blade assembly includes a stationary blade and a cutting blade. The stationary blade includes a plurality of stationary cutting teeth, with each of the stationary cutting teeth having a tip at a distal end thereof, and wherein the tips of the stationary cutting teeth define a first imaginary line. The cutting blade is configured for reciprocating arcuate motion relative to the stationary blade, and has a plurality of reciprocating cutting teeth, with each of the reciprocating cutting teeth having a tip at a distal end thereof. The tips of the reciprocating cutting teeth define a second imaginary line. One important feature of the present invention is that the distance between the first imaginary line and the second imaginary line is greater near both end portions thereof than a corresponding distance at a center portion between the end portions.




The increased distance near the end portions may be realized in any of several different ways. For example, the tip heights of the reciprocating cutting teeth may gradually increase from each of the first and second ends toward the midpoint, whereby the tooth tips define the second imaginary line in the form of an arc. Alternatively, the tip heights of the reciprocating cutting teeth near both the first and second ends only may be shorter than the tip heights of the reciprocating cutting teeth near the midpoint, such that a group of the reciprocating cutting teeth near the midpoint are all of a uniform tip height.




According to another embodiment of the present invention, the cutting teeth height configurations of the stationary blade and the cutting blade are transposed. Specifically, tip heights of the stationary cutting teeth proximate one of the first and second ends are longer than the tip heights of the cutting teeth proximate a midpoint between the first and second ends. In this embodiment, the first imaginary line is thus preferably in the form of a generally concave arc, either with or without a straight center portion.




As a further alternative, both the first and the second imaginary lines may be configured so that neither line is a generally straight line. Preferably, the first imaginary line is generally concave and the second imaginary line is generally convex. Optionally, either one of, or both, the first imaginary line and the second imaginary line may also include a straight portion near the center thereof.




Each of the above described embodiments provides a closer cut than possible with traditional hair clipper blades, without sacrificing cutting power or increasing the cost of manufacture.











BRIEF DESCRIPTION OF THE DRAWINGS




The above-mentioned 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 description of several embodiments of the invention taken in conjunction with the accompanying drawings in which:





FIG. 1A

is a first embodiment of a clipper blade assembly of the present invention in an initial state;





FIG. 1B

is an enlarged fragmentary view of

FIG. 1A

in an initial state;





FIG. 1C

is an overhead plan view of the clipper blade assembly of

FIG. 1A

;




FIG.


1


C′ is a variation on the embodiment shown in

FIG. 1C

;





FIG. 1D

shows the clipper blade assembly of

FIG. 1A

towards the end of a cutting stroke;





FIG. 1E

is a drawing of partial sectional views of a tooth of the stationary blade and a tooth of the reciprocating blade;





FIG. 2A

is a second embodiment of a clipper blade assembly of the present invention in an initial state;





FIG. 2B

is an enlarged fragmentary view of

FIG. 2A

;





FIG. 2C

is an overhead plan view of the clipper blade assembly of

FIG. 2A

;




FIG.


2


C′ is a variation on the embodiment shown in

FIG. 2C

;





FIG. 2D

shows the clipper blade assembly of

FIG. 2A

towards the end of a cutting stroke;





FIG. 3A

is a third embodiment of a clipper blade assembly of the present invention in an initial state;





FIG. 3B

is an enlarged fragmentary view of

FIG. 3A

;





FIG. 3C

is an overhead plan view of the clipper blade assembly of

FIG. 3A

;




FIG.


3


C′ is a variation on the embodiment shown in

FIG. 3C

;





FIG. 3D

shows the clipper blade assembly of

FIG. 3A

towards the end of a cutting stroke;





FIG. 4A

is an overhead plan view of another embodiment of the present clipper blade assembly;





FIG. 4B

is a variation on the embodiment shown in

FIG. 4A

;





FIG. 5

is a sectional view of a conventional hair cutter assembly;





FIG. 6A

is front view of a conventional cutting assembly; and





FIG. 6B

is an enlarged fragmentary view of

FIG. 6A

showing the cutting blade extending beyond the stationary blade at the end of the cutting stroke.











DETAILED DESCRIPTION OF THE EMBODIMENTS




The inventor of the present invention has discovered that it is possible to provide a closer cut than possible with a conventional cutting blade assembly, while still maintaining a low likelihood of undesirably nicking the subject's skin, by selectively increasing the gap between the reciprocating teeth and the stationary teeth.




A blade assembly


100


(

FIGS. 1A-3D

) of the present invention is configured for use with a conventional hair clipper. For illustrative purposes, the present blade assembly


100


will be described for use with the conventional hair clipper


10


shown in FIG.


5


. However, it should be understood that the present invention is not limited to being used with hair clippers of the type depicted in

FIG. 5

, but instead may be adapted for use with many different types of hair clippers.




The blade assembly


100


includes a reciprocating blade


102


and a stationary blade


104


. More particularly, the blade assembly


100


of the present invention is specifically configured for use with a hair clipper which drives the cutting blade along a slightly elliptical path.




The blades


102


and


104


have rows of teeth


106


and


108


, respectively, which are arranged so that hair which enters between adjacent teeth


106


is cut as the teeth


106


move back and forth across the teeth


108


. As best seen in

FIG. 1E

, teeth


106


and


108


are generally composed of a root portion


106




root


,


108




root


and a cutting face portion


106




face


,


108




face


. As known to those of ordinary skill in the art, the majority of the cutting action takes place where the face portion of the reciprocating blade crosses the face portion of the stationary blade.




As described in the background of the invention, achieving an extremely close cut requires a reduction in the overlap X


Gap


between the cutting blade and the stationary blade. However, once the overlap is reduced below a threshold level, there is an increased likelihood of cutting or nicking a subject's skin.





FIG. 1A

illustrates a first embodiment of the clipper blade assembly


100


of the present invention in an initial state in which a midpoint


102


C of the reciprocating cutting blade


102


is aligned with a midpoint


104


C of the stationary cutting blade


104


.





FIG. 1B

is an enlarged fragmentary view of a rightmost portion of

FIG. 1A

, showing that selected reciprocating cutting teeth


106


S, located at the proximate end


102


R of the reciprocating cutting blade


102


, are formed with tips that are shorter than cutting teeth


106


C, which are located proximate the midpoint


102


C. In contrast, the teeth


108


of the stationary blade


104


each have a uniform tip height. This aspect of the invention is further illustrated in

FIG. 1C

, which shows the overall shape of the reciprocating cutting blade


102


and the overall shape of the stationary cutting blade


104


.




Reducing the tip heights of the outer teeth may be accomplished in a variety of different ways. For example,

FIG. 1C

shows an embodiment where the tip heights of the outer teeth have been shortened, and an imaginary tip line


106




Tip


(created by drawing a line connecting together the tips of the reciprocating blade


102


) is defined. As can be seen in

FIG. 1C

, line


106




Tip


includes curved portions at the right and left ends thereof, and a straight portion connecting the two curved portions. Thus, the tip heights gradually increase from the short tip heights at the right and left ends until reaching the center portion, at which point all of the tip heights are the same. As a slight variation on the

FIG. 1C

embodiment, it is contemplated that two straight inclined lines (not shown) may be substituted for the two curved portions on the right and left ends.




While the tip height is varied as discussed above, one of ordinary skill in the art will also appreciate that there are several approaches of varying the tooth height of a tooth, which is defined as the distance between the tip and the root of the tooth. One approach is to lower the position of the tip, such as depicted by the far left and right edges of


106




tip


of

FIG. 1C

, while maintaining the roots of each tooth along a straight line, such as shown by


106




root


. In the

FIG. 1C

embodiment, the tooth heights of the leftmost and the rightmost teeth are shorter than the tooth heights of the center teeth, which each have tips that are aligned along an imaginary straight line.




FIG.


1


C′ shows an example of an embodiment in which the tooth heights are constant, and only the tip heights of the outer right and left teeth are shortened. In this figure, both the tips (


106




Tip


) and the roots (


106




root


) are varied in the same manner, and accordingly the imaginary tip line and the imaginary root line are parallel. However, it should be noted that the relative tip heights of the leftmost and the rightmost teeth are shorter than the tip heights of the center teeth. Yet another approach is to vary the positions of both the imaginary root line and the imaginary tip line (not illustrated in the drawings).




Referring back to

FIG. 1B

, this figure shows that the stationary cutting teeth


108


cooperatively define a first overlap X


1


with the relatively shorter reciprocating cutting teeth


106


S. The overlap X


1


is measured from a tip end portion


110


of tooth


108


to a tip end portion


112


of the tooth


106


S. Similarly, the stationary cutting teeth


108


C cooperatively define a second overlap X


2


with the tooth


106


C. The overlap X


2


is measured from a tip end portion


114


of tooth


108


to an end


116


of the tooth


106


C. Notably, the overlap X


1


is greater than the overlap X


2


, and preferably X


2


is approximately zero.




In one preferred embodiment, the overlap X


1


is approximately between 10 and 15 thousandths of an inch, although other dimensions are also contemplated as being within the scope of the invention. Moreover, depending on the pivot point of the reciprocating blade


102


, the maximum overlap at the rightmost stroke position (

FIG. 1B

) of the reciprocating blade


102


may be different from the maximum overlap at a leftmost stroke position of the reciprocating blade


102


(not illustrated).





FIG. 1D

shows the cutting assembly


100


towards the end of a cutting stroke in which end


102


R of the reciprocating cutting blade


102


is at a leftmost position. It should be noted that even in this extreme leftmost position, the tips of the reciprocating teeth on blade


102


are not higher than the tips of the teeth on the stationary blade


104


.




One of ordinary skill in the art will readily appreciate that the cutting assembly of this embodiment provides an extremely close cut, as the majority of the teeth


106


have the minimal overlap X


2


with the teeth


108


, since very few of the teeth


106


S have the larger overlap X


1


(where X


1


and X


2


are shown in FIG.


1


B).





FIG. 2A

illustrates a second embodiment of clipper blade assembly


100


in an initial state in which a midpoint


102


C of the reciprocating cutting blade


102


is substantially aligned with the midpoint


104


C of the stationary cutting blade


104


.





FIG. 2B

is an enlarged fragmentary view of the

FIG. 2A

, showing that a tip height of the reciprocating cutting teeth


106


gradually increases from a shortest height proximate end


102


R (and end


102


L) of the reciprocating cutting blade


102


, reaching a maximum tip height proximate the midpoint


102


C. Again, in this embodiment also, the teeth


108


of the stationary blade


104


have a uniform tip height. This aspect of the invention is further illustrated in

FIG. 2C

which shows the overall shape of the reciprocating cutting blade


102


and the overall shape of the stationary cutting blade


104


.




As described above, the graduated tip heights of the teeth may be achieved by varying the tip positions while either maintaining the root positions along a straight line or by varying the root positions. Thus, for example,

FIG. 2C

illustrates that the graduated height of the teeth is achieved by varying the tip positions


106




Tip


, while maintaining a uniform root position


106




Root


, and FIG.


2


C′ shows an alternate method for varying the tip heights of the teeth (similar to FIG.


1


C′). In FIG.


2


C′, the tips


106




Tip


of the teeth are aligned along an imaginary curved line, as in

FIG. 2C

, but the roots


106




Root


are different from those of FIG.


2


C. In the FIG.


2


C′ embodiment, the imaginary root line


106




Root


is curved in the same manner as the imaginary tip line


106




Tip


, while in

FIG. 2C

, the imaginary root line


106




Root


is a straight line. Thus, in the FIG.


2


C′ embodiment, although the tip heights are shorter near the right and left ends, the tooth heights are all equal because line


106




Tip


is approximately parallel with line


106




Root


. It should be noted that the tip lines (


106




Tip


) of FIGS.


2


C and


2


C′ are essentially both the same, and the tip lines of FIGS.


1


C and


1


C′ are essentially both the same, but the tip lines of FIGS.


2


C and


2


C′ differ from those of FIGS.


1


C and


1


C′. Specifically, the tip lines in FIGS.


2


C and


2


C′ are curved along their entire lengths while the tip lines in FIGS.


1


C and


1


C′ each include a straight line portion in the center.




Referring back to

FIG. 2B

, the stationary cutting teeth


108




1


,


108




2


,


108




3


. . .


108




C


cooperatively define a continuously varying overlap X


1


, X


2


, X


3


. . . X


C


with the reciprocating cutting teeth


106




1


,


106




2


,


106




3


. . .


106




C


. Notably, the maximum overlap, X


1


, is defined by cutting teeth


106




1


, which are located at proximate ends


102


L and


102


R, and the overlap gradually decreases until reaching the minimum overlap X


C


, defined by cutting teeth


106




C


, which are proximate the midpoint


102


C.





FIG. 2D

shows the cutting assembly


100


towards the end of a cutting stroke, i.e., with reciprocating blade


102


in its leftmost position. In particular,

FIG. 2D

shows that the teeth of the reciprocating blade


102


do not extend beyond the teeth on the stationary blade


104


at the end of the cutting stroke.





FIG. 3A

illustrates a third embodiment of clipper blade assembly


100


in an initial state in which a midpoint


102


C of the reciprocating cutting blade


102


is aligned with the midpoint


104


C of the stationary cutting blade


104


.





FIG. 3B

is an enlarged fragmentary view of the FIG.


3


A.

FIGS. 3A and 3B

together show that the height of the stationary cutting teeth


108


gradually increases from a shortest height proximate the midpoint


104


C of the stationary cutting blade


104


to a maximum height at proximate ends


104


L and


104


R. In contrast, the teeth


106


of the reciprocating cutting blade


102


have a uniform tip height. This aspect of the invention is further illustrated in

FIG. 3C

, which shows the overall shape of the reciprocating cutting blade


102


and the overall shape of the stationary cutting blade


104


. FIG.


3


C′ shows a variation of FIG.


3


C. In FIG.


3


C′, the stationary blade


104


includes a center portion where the tips are all of a uniform height (defining a straight line), whereas in

FIG. 3C

, the tips at the center portion are of varying heights to define a concave curve along the entire length of an imaginary line created by the tip heights.




Referring back to

FIG. 3B

, one can see that the stationary cutting teeth


108




1


,


108




2


,


108




3


. . .


108




C


cooperatively define a continuously varying overlap X


1


, X


2


, X


3


. . . X


C


with the reciprocating cutting teeth


106


, which are of a uniform height. Notably, the maximum overlap, X


1


, is defined by cutting teeth


108




1


, which are located at proximate ends


104


L and


104


R (FIG.


3


A), and the overlap gradually decreases until reaching the minimum overlap X


C


defined by cutting teeth


108




C


proximate the midpoint


104


C (FIG.


3


A).





FIG. 3D

shows the cutting assembly


100


towards the end of a cutting stroke. In particular,

FIG. 3D

shows that the teeth


102


do not extend beyond the teeth


108


at the end of the cutting stroke.





FIGS. 4A and 4B

show the overall shapes of the reciprocating cutting blade


102


and the stationary cutting blade


104


of two other embodiments of the present invention.

FIG. 4A

shows an embodiment in which the tips of the stationary blade


104


form an imaginary line that defines a concave curve, and the tips of the reciprocating blade


102


define an imaginary line that has straight angled portions on the ends and a straight line portion in the middle.





FIG. 4B

shows an embodiment in which the tips of the stationary blade


104


define an imaginary tip line that is curved on the ends and straight in the middle. The reciprocating blade


102


in this embodiment defines and imaginary tip line with a convex curve along its entire length. It should be noted that the present invention is not limited to the embodiments depicted, but also includes combinations of the disclosed embodiments, such as the stationary blade defining an imaginary tip line created by a concave curved line and the reciprocating blade defining an imaginary tip line created by a convex line; the stationary blade defining an imaginary tip line created by straight angled line segments and the reciprocating blade defining an imaginary tip line created by convex line segments on the ends and a straight line portion in the center; etc. One important consideration to remember when determining the blade shapes of the present invention is that the distance between the tips of the reciprocating blade and the tips of the stationary blade should be increased near the ends thereof. As discussed above, such increased distances at the ends may be achieved by reducing the tip heights of the end sections of teeth of the reciprocating blade, by increasing the tip heights of the end sections of teeth of the stationary blade, or by a combination of these tip reductions of the reciprocating blade and these tip elongations of the stationary blade. In this manner, the tips of the reciprocating blade will not overlap the tips of the stationary blade, even as the reciprocating blade moves in its designated arcuate motion.




The advantages of this invention should now be apparent. Specifically, the various embodiments incorporate a unique design which enables a decrease in the overlap between the reciprocating cutting teeth and the stationary cutting teeth, thereby facilitating a closer cut than that possible with conventional cutting blade assemblies, without increasing the likelihood of cutting or nicking.




While the principles of the invention have been described above in connection with a specific apparatus and specific applications, it is to be understood that this description is made only by way of example and not as a limitation on the scope of the invention.



Claims
  • 1. A blade assembly for an electric hair cutter with a vibrator motor, said blade assembly comprising:a stationary blade including a plurality of stationary cutting teeth, with each of said stationary cutting teeth having a tip at a distal end thereof, and wherein said tips of said stationary cutting teeth define a first imaginary line; a cutting blade configured for vibratory reciprocating elliptical arcuate motion relative to said stationary blade and having a plurality of reciprocating cutting teeth, with each of said reciprocating cutting teeth having a tip at a distal end thereof, and wherein said tips of said reciprocating cutting teeth define a second imaginary line; and wherein the distance between said first imaginary line and said second imaginary line is greater near both end portions thereof than a corresponding distance at a center portion between said end portions, and wherein the distance at one of said end portions is different from the distance at the other of said end portions, and further wherein said first imaginary line is a generally straight line and said second imaginary line is a line that is not generally straight along the entire length thereof.
  • 2. The blade assembly according to claim 1, wherein said second imaginary line is a generally convexly curved line.
  • 3. The blade assembly according to claim 2, wherein said second imaginary line includes a generally straight portion near a center thereof.
  • 4. The blade assembly according to claim 1, wherein at least one of said first imaginary line and said second imaginary line is completely defined by three relatively straight line segments extending in different directions.
  • 5. A blade assembly for an electric hair cutter, said blade assembly comprising:a stationary blade including a plurality of stationary cutting teeth, with each of said stationary cutting teeth having a tip at a distal end thereof, and wherein said tips of said stationary cutting teeth define a first imaginary line; a cutting blade configured for reciprocating arcuate motion relative to said stationary blade and having a plurality of reciprocating cutting teeth, with each of said reciprocating cutting teeth having a tip at a distal end thereof, and wherein said tips of said reciprocating cutting teeth define a second imaginary line; wherein the distance between said first imaginary line and said second imaginary line is greater near both end portions thereof than a corresponding distance at a center portion between said end portions; and further wherein said second imaginary line is a generally straight line and said first imaginary line is a line that is generally not straight along the entire length thereof.
  • 6. A blade assembly for an electric hair cutter, said blade assembly comprising:a stationary blade including a plurality of stationary cutting teeth, with each of said stationary cutting teeth having a tip at a distal end thereof, and wherein said tips of said stationary cutting teeth define a first imaginary line; and a cutting blade configured for reciprocating arcuate motion relative to said stationary blade and having a plurality of reciprocating cutting teeth, with each of said reciprocating cutting teeth having a tip at a distal end thereof, and wherein said tips of said reciprocating cutting teeth define a second imaginary line; wherein the distance between said first imaginary line and said second imaginary line is greater near both end portions thereof than a corresponding distance at a center portion between said end portions; and further wherein said first imaginary line is a generally concavely curved line.
  • 7. The blade assembly according to claim 6, wherein said first imaginary line includes a generally straight portion near the center thereof.
  • 8. A blade assembly for an electric hair cutter, said blade assembly comprising:a stationary blade including a plurality of stationary cutting teeth, with each of said stationary cutting teeth having a tip at a distal end thereof, and wherein said tips of said stationary cutting teeth define a first imaginary line; and a cutting blade configured for reciprocating arcuate motion relative to said stationary blade and having a plurality of reciprocating cutting teeth, with each of said reciprocating cutting teeth having a tip at a distal end thereof, and wherein said tips of said reciprocating cutting teeth define a second imaginary line; wherein the distance between said first imaginary line and said second imaginary line is greater near both end portions thereof than a corresponding distance at a center portion between said end portions; and further wherein said first imaginary line is a generally concavely curved line and said second imaginary line is a generally convexly curved line.
  • 9. The blade assembly according to claim 8, wherein said first imaginary line includes a generally straight portion near a center thereof.
  • 10. The blade assembly according to claim 8, wherein said second imaginary line includes a generally straight portion near a center thereof.
  • 11. The blade assembly according to claim 8, wherein both said first imaginary line and said second imaginary line include generally straight portions near respective center portions thereof.
  • 12. An electric hair clipper comprising:a housing; a vibrator motor provided in said housing; a stationary blade including a plurality of stationary cutting teeth, with each of said stationary cutting teeth having a tip at a distal end thereof, and wherein said tips of said stationary cutting teeth define a first imaginary line; a cutting blade configured to be driven by said vibrator motor with vibratory reciprocating arcuate elliptical motion relative to said stationary blade and having a plurality of reciprocating cutting teeth, with each of said reciprocating cutting teeth having a tip at a distal end thereof, and wherein said tips of said reciprocating cutting teeth define a second imaginary line; and a vibrating arm for transferring vibratory motion from said vibrator motor to said cutting blade, said vibrating arm being connected to said housing near a rear portion thereof, while said stationary blade and said cutting blade are located near a front portion of said housing, wherein the distance between said first imaginary line and said second imaginary line is greater near both end portions thereof than a corresponding distance at a center portion between said end portions, and where the distance at one of said end portions is different from the distance at the other of said end portions, and further wherein said first imaginary line is a generally straight line and said second imaginary line is a line that is not generally straight along the entire length thereof.
  • 13. The electric hair clipper according to claim 12, wherein said second imaginary line includes a relatively straight portion near a center thereof.
  • 14. The electric hair clipper according to claim 12, wherein said vibrator motor is located between the connection point of said vibrating arm with said housing and a blade assembly defined by said stationary blade and said cutting blade.
  • 15. An electric hair clipper comprising:a housing; a motor provided in said housing; a stationary blade including a plurality of stationary cutting teeth, with each of said stationary cutting teeth having a tip at a distal end thereof, and wherein said tips of said stationary cutting teeth define a first imaginary line; a cutting blade configured for reciprocating arcuate motion relative to said stationary blade and having a plurality of reciprocating cutting teeth, with each of said reciprocating cutting teeth having a tip at a distal end thereof, and wherein said tips of said reciprocating cutting teeth define a second imaginary line; and wherein the distance between said first imaginary line and said second imaginary line is greater near both end portions thereof than a corresponding distance at a center portion between said end portions; and further wherein said first imaginary line is completely defined by three relatively straight line segments extending in different directions.
  • 16. An electric hair clipper comprising:a housing; a motor provided in said housing; a stationary blade including a plurality of stationary cutting teeth, with each of said stationary cutting teeth having a tip at a distal end thereof, and wherein said tips of said stationary cutting teeth define a first imaginary line; and a cutting blade configured for reciprocating arcuate motion relative to said stationary blade and having a plurality of reciprocating cutting teeth, with each of said reciprocating cutting teeth having a tip at a distal end thereof, and wherein said tips of said reciprocating cutting teeth define a second imaginary line; wherein the distance between said first imaginary line and said second imaginary line is greater near both end portions thereof than a corresponding distance at a center portion between said end portions; and further wherein said second imaginary line is completely defined by three relatively straight line segments extending in different directions.
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Number Name Date Kind
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1746989 Bristow Feb 1930 A
2174130 Looper Sep 1939 A
2713718 Hudson Jul 1955 A
2877364 Wahl et al. Mar 1959 A
2986662 Wahl May 1961 A
3026430 Wahl Mar 1962 A
5819415 Bruggers et al. Oct 1998 A