US3571928A

US3571928A - Automatically compensating hair blending device

Info

Publication number: US3571928A
Application number: US791655*A
Authority: US
Inventors: Glenn R Willey; William B Fuller; Vernon W Biesecker
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-01-16
Filing date: 1969-01-16
Publication date: 1971-03-23
Anticipated expiration: 1988-03-23

Abstract

Method and apparatus for blending hair which includes a plurality of cutting reliefs for capturing the hair to be blended wherein the reliefs are of arcuate configuration and disposed in the stationary cutting teeth. The configuration of the reliefs are such in respect to the stroke of the moving cutting teeth that a predetermined area of the relief is not traversed by the moving cutting teeth. A percentage of the hair in the relief will pass to the back of the relief and not be cut against shearing edges disposed within the relief. The area of the relief which is untraversed by the moving cutting teeth is constant resulting in the cutting of a percentage of thicker hair passing into the relief than thinner hair thus automatically compensating the blending effect according to the thickness of the hair being cut.

Description

United States Patent [72] Inventors Glenn R. Willey 1181 BellemeadDr-ive, Warminster, Pa. 18974; 1

William B. Fuller, Upperstate Road, Chalfont, Pa. .18914; Vernon W. Biesecker, 1171 Bellemea drive, Warminster, Pa.

1 1 18740 [2]] Appl. No. 791,655 [22] Filed Jan. 16, 1969 [45] Patented Mar. 23, 1971 [54] AUTOMATICALLY COWENSATING HAIR {5 4 l BLENDING DEVICE 2,001,206 5 1935 Matthes 2,008,631 7/1-935 Udkovich 30/195 2,035,632 3/1936 Andis 30/195 FOREIGN PATENTS 1,010,722 11/1965 GreatBritain 30/195 be blended wherein the reliefs are of arcuate configuration and disposed in the stationary cutting teeth. The configuration of the reliefs are such in respect to the stroke of the moving cutting teeth that a predetermined area of the relief is not traversed by the moving cutting teeth. A percentage of the hair in the relief will pass to the back of the relief and not be out against shearing edges disposed within the relief. The area of the relief which is untraversed by the moving cutting teeth is constant resulting in the cutting of a percentage of thicker hair passing into the relief than thinner hair thus automatically compensating the blending effect according to the thickness of the hair being cut.

AUTOMATICALLY COMPENSA'I'ING HAIR BLENDING DEVICE BACKGROUND OF INVENTION The present invention concerns hair cutting devices and, more particularly, hair cutting devices of the type which blend the hair being cut.

In the process of cutting hair, the bulk of the hair is first removed and the hair generally brought into the form desired. Following this, the hair is trimmed and finally blended to give the final appearance of the hair style.

The blending operation is a very important step in the hair cutting process and is the final step in which the ends of the hair are cut to irregular lengths so as to lay one over the other to avoid the appearance of a step cut. This process is not to be confused with thinning of hair in which a percentage of the hair is cut close to the scalp rather than the ends.

In any blending operation, the volume of the hair must be considered. In the case of thicker hair, a greater degree of blending is required for proper appearance than thinner hair.

The blending operation may be accomplished either by hand in which a comb and blending scissors are used by power operated shears. Blending by hand is a time consuming and tiring job and, as well, requiresv a great deal of skill to be done properly. Mechanically operated shears for blending are less time consuming and tiring but those presently available today suffer from a serious drawback in not being able to compensate for the relative volume and thickness of hair .being blended.

OBJECTS AND SUMMARY OF INVENTION The principle object of the present invention is to improve mechanically powered hair cutting blending shears by providing cutters which will automatically vary the blending effectin proportion to the volume of the hair being cut.

It is a further object of the present invention to provide blending cutters according to the principle object in which the degree of automatic compensation can be varied slightly, by the speed at which the cutters are passed through the hair in one embodiment and by the angle at which used in another embodiment.

Thepresent invention carries out the foregoing objects by utilizing a plurality of reliefs in a pair of oscillating cutting blades. The reliefs may be in either or both cutting blades and both blades may oscillate, although in a preferred embodiment, one of the blades is stationary and the reliefs are in the stationary cutting blade.

The reliefs include shearing edges therein and the hair being blended is adapted to pass into the reliefs. The cross'sectional area of the reliefs is proportioned in respect to the extent to which the moving cutter blade passes over the relief such that there will always be a predetermined percentage of the crosssectional area of the relief which is untraversed by the oscillating cutting blade. This predetermined area is so adjusted that, in the case of very thin hair, all of the hair which passes into the relief will be forced to the back part of the relief which is untraversed by the cutting blade thus resulting in shearing of very little of the thinner hair. In the case of hair of increasing volume, the predetermined area will remain constant and thereof a greater percentage of the hair must be sheared against the shearing edges of the blade in each oscillation of the cutting blade. The result is an automatic compensation in the extent of blending of the hair depending upon the volume of the hair being cut.

In another embodiment of the invention, forwardly extending cutting edges one disposed between the reliefs-to make the blending effect of the cutting attachment sensitive to the rate at which the attachment is passed through the hair.

. In a third embodiment, the untraversed area of each relief is increasingly diminished toward the rear of the cutting teeth to make the blending effect greater for hair passing toward the rear of the attachment. In this manner, the automatic blending effect can be slightly varied depending upon the angle at which the cutting attachment passes through the hair.

DESCRIPTION OF DRAWINGS FIG. 1 is a perspective view of the blending attachment of the present invention in place on a motor driven shears;

FIG. 2 is an enlarged view showing in detail a portion of the cutting blades of the attachment of FIG. 1;

FIG. 3 is a view of the cutting blades of FIG. 2 in full stroke left position;

FIG. 4 is an enlarged detailed view of a second embodiment of cutting blades of the present invention providing for adjustrrient of the automatic blending effect depending upon the rate of movement through the hair; and

FIG. 5 is an enlarged detailed view of a third embodiment of the cutting blades of the present invention which also adjust the blending etfect depending upon the angle of use.

DETAILED DESCRIPTION OF INVENTION A preferred embodiment of the present invention is shown in FIG. 1 of the drawings. The cutting attachment 10 is designed to be used with a motor driven clipper handle I I and is interchangeable with other I conventional cutting attachments normally used with the handle II. The attachment 10 includes an oscillating upper cutting blade 12 and a stationary lower cutting blade 13. The

blades

12 and 13 are suitably supported and joumaled one to the other to permit a relative oscillating motion between the blades I2 and I3. The cutting attachment is also retained in the handle II by a spring clip (not shown) and the cutting blades are driven through a conventional fork arrangement. To this point, the cutting attachment and handle II are like convention cutting shears well known to those skilled in the art and for that reason the details thereof have not been illustrated.

The improved design which constitutes the present invention resides in the configuration and relative cooperation of the cutting teeth associated with the oscillating and stationary cutting blades. In the embodiment of invention shown in FIG. I, the oscillating cutting blade 12 includes a plurality of elongate cutting teeth 14. The cutting teeth I4 are rounded at their ends 15 and include a sharp lower edge I6 thereon against which the hair to be cut is sheared.

The lower stationary cutting blade I3 includes a plurality of cutting teeth I7. These teeth 17 are, likewise, rounded at their ends I8 to provide for smooth passage of the cutting teeth through the hair. Each of the cutting-teeth includes a plurality of reliefs I9 which are ground into the cutting blades. Each relief is undercut so as to provide a shearing edge 20 along the perimeter of the relief.

In operation, the oscillating cutting teeth 14 move back and forth across the reliefs 19 disposed on either side of the cutting teeth. In accordance with the invention, the stroke of the cutting teeth is adjusted so as to pass only partially across the relief.

As the cutting attachment passes through the hair to be blended, the hair will pass between the oscillating cutting teeth' and into the reliefs as the oscillating cutting teeth pass through their intermediate position as shown in FIG. 2. Further, as the oscillating cutting teeth I4 move to the limit of their left and right stroke, the hair captured in the reliefs I9 will be forced toward the back of the reliefs.

In the case of verythick hair, the volume of hair in the relie will result in some of the hair being sheared between the shearing edge I6'and the flanks-of the shearing edge 20 as a result of the volume and resistance of the hair in being moved to the rear of the relief. As the cutting tooth I4 continues to move to the limit of its stroke, the area of the relief in which the hair is captured continues to decrease and additional hair will be sheared against the shearing edges I6 and 20 until the cutting tooth has reached the limit of its stroke as shown in FIG. 3. At this point, the hair left uncut will be that which may occupy the untraversed area of the relief 19.

In the case of thinner hair, there is less overall resistance by the hair in moving into the rear of the relief 19 and consequently less shearing action occurs as the cutting, blade moves across the relief. Likewise, in the case of thinner hair,

there is overall less hair to occupy the relief and at the end of the cutting stroke, that hair which will remain uncut in the untraversed area of the relief will represent a greater proportion of the hair initially passing into the relief. This occurs inasmuch as the cross-sectional area of the relief, which is untraversed, remains constant irrespective of the volume of the hair being blended.

From the foregoing, it will be appreciated that the percentage of hair which will be cut is, for all practical purposes, dependent upon the relative volume of the hair passing into the reliefs thus resulting in an automatic variation of the blending effect depending upon the thickness of the hair.

The above described operation of the cutting attachment of the present invention is dependent upon certain relationships being maintained between the length of the stroke of the cutting teeth 14, the width between the cutting teeth 17 and the configuration of the reliefs 19. This may be understood by first considering that, for any given spacing between the cutting teeth 17, there will be exposed to the cutting reliefs 19 a given strip or width of hair. This given strip of hair will be evenly divided by the cutting tooth I and captured in the various reliefs 19 on either side of the tooth 15. Thus initially, the total area of each relief 19 must be large enough to accommodate all of the hair presented to the relief in the case of the thickest hair. Secondly, the untraversed area at the end of the cutting stroke must be so proportioned to effect the minimum percentage of blending desirable for the thinnest hair. Lastly, the degree of blending will remain constant for the same volume of hair regardless of the configuration of the relief if the relief is so constructed that the total cross-sectional area of the relief is reduced to a predetermined percentage of that initial cross-sectional area at the end of the cutting stroke.

Turning specifically to the embodiment of FIGS. 2 and 3, it is to be noted that the cutting blades do not employ any cutting edge on the forward edge of the cutting teeth 17. Accordingly, once the hair has been blended to that percentage controlled by the relative volume of the hair, which occurs within a relatively few strokes of the cutting blade, the continued presence of the cutting attachment in the hair does not result in any significant further cutting of the hair. Thus, in the embodiment of FIGS. 2 and 3, the relative speed of the cutting blades and the speed at which the cutting attachment moves through the hair does not produce any significant difference in the extent of blending which occurs.

In some applications, it is desirable to vary the percentage of blending for any given volume of hair to suit the hair of the particular individual. The cutting attachment of FIGS. 2 and 3 may be modified as shown in FIG. 4 to provide such a variation to a limited degree. In the embodiments of FIG. 4, the reliefs 19 are spaced by forwardly projecting cutting edges 23 having shearing edges 24 at the leading edge thereof. In this arrangement, all of the hair will not pass into the relief 19 but, instead, a percentage thereof will be sheared across the projecting cutting edge 23 as the cutting teeth pass across the shearing edge 24.

Due to the presence of the shearing edge 24, the speed of the cutting teeth 14 and the speed at which the cutting attachment is passed through the hair now does become a factor in the percentage of hair which is cut for any given volume of hair. The relative porportions between the width of the cutting edge 24 and the configuration of the relief I9 will determine the sensitivity of the cutting attachment to the speed of the cutting blades and the rate at which the attachment is passed through the hair. The optimum attachment has been found to proportion to the relative cutting on the forward edge 24 to l030 percent of the cutting occurring within the reliefs.

In the embodiment of FIG. 4, the best performance of the cutting attachment has been found wherein the reliefs 19 are arcuate and the relief is traversed by the cutting blade 14 to one-half the depth of the arc. The best sensitivity in respect to speed of the attachment is found wherein the width of the forwardly projecting edges 24 is within the range of 30 to 60 percent of the diameter of the arcuate reliefs.

The automatic variation of the blending effect found in the embodiment of FIG. I may also be varied slightly by modifying the attachment of FIG. I as shown in FIG. 5. In this embodiment, the reliefs 25 are of decreasing depth toward the rear of the cutting tooth 17. The effect is to decrease the percentage of initial cross-sectional area of the relief which is untraversed as the hair passes toward the rear of the cutting tooth. Thus an increasingly greater blending effect will occur for the same volume of hair dependent upon the extent to which the hair passes to the rear of the tooth 17. In turn. the angle at which the cutting attachment is passed through the hair will control the amount of hair passing into the rear position of the attachment. Accordingly. the blending effect can be varied in the attachment of FIG. 5 depending upon the angle at which it is used.

The same effect can be accomplished as that of FIG. 5 where the width of the cutting tooth I4 is increased toward the rear and the depth of the cutting relief held constant.

The configuration of the relief 19 has been shown in FIGS. 25 as arcuate and is the preferred form. However, so long as the basic relationships are maintained between the stroke. teeth width and relief configuration as discussed above. other forms of relief may be used and may include such configurations as V-shaped reliefs. Whatever form of relief is used, it is preferable that the relief have a shearing edge therein which converges inwardly of the relief. A converging shearing edge provides a better cutting or scissors action on the hair during the cutting stroke. Nevertheless, the present invention can be applied to a relief having straight parallel sides.

The foregoing invention has been described in respect to particular embodiment thereof shown in the drawings. It will be apparent that various modifications of the above described embodiments of the invention will be apparent to those skilled in the art, it is thereof to be understood that such modifications can be made without departing from the spirit and scope of the invention as set out in the appended claims.

We claim:

1. A hair blending device which automatically controls the percentage of hair cut as a functionof the relative volume of the hair being blended comprising;

a first cutting blade having a plurality of cutting teeth;

a second cutting blade having a plurality of cutting teeth and supported in respect to said first cutting blade for relative oscillating shearing movement therebetween;

a plurality of reliefs in selected ones of said cutting teeth into which at least a portion of the hair to be blended passes, said reliefs being of a given cross-sectional area and including shearing edges therein against which a portion of the hair within said relief is cut; and

means limiting the relative movement of said first and second cutting blades one to the other such that a predetermined percentage of the given cross-sectional area of said reliefs are untraversed during the oscillating shearing movement of the first and second cutting blades, said predetermined percentage being equal to the area capable of being occupied by that quantity of hair represented by the minimum percentage of blending for the thinnest hair, whereby a greater percentage of thicker hair will be cut within each relief during the blending action than thinner hair.

2. The hair blending device of claim I in which one of said cutting blades is a stationary cutting blade.

3. The hair blending device of claim 2 wherein all of said reliefs are disposed within the stationary cutting blade.

4. The hair blending device of claim I wherein each of said reliefs within said cutting teeth are separated one from another by forwardly projecting cutting edges.

5. The hair blending device of claim I wherein each of said cutting reliefs are of decreasing cross-sectional area inwardly of said cutting blade to provide a scissors action between the cutting blades.

6. The hair blending device of claim 5 wherein said reliefs are of arcuate configuration,

7. The hair blending device of claim 6 wherein each of said the arc. reliefs within said cutting teeth are spaced one from the other 10, Th h i ble ding device of claim 1 wherein the by forwardly projecting cutting edges.

8. The hair blending device of claim 7 wherein the width of the forwardly projecting cutting edges is within the range of 30 to 60 percent of the diameter of thearcuate reliefs.

- 9. The hair blending device of claim 6 in which the cutting blades traverses the arcuate reliefs to one-half of the depth of predetermined area of each of said reliefs remaining untraversed at the end of the shearing movement of said cutting blades increasingly diminishes toward the rear of said cutting blades.

LII

Claims

1. A hair blending device which automatically controls the percentage of hair cut as a function of the relative volume of the hair being blended comprising; a first cutting blade having a plurality of cutting teeth; a second cutting blade having a plurality of cutting teeth and supported in respect to said first cutting blade for relative oscillating shearing movement therebetween; a plurality of reliefs in selected ones of said cutting teeth into which at least a portion of the hair to be blended passes, said reliefs being of a given cross-sectional area and including shearing edges therein against which a portion of the hair within said relief is cut; and means limiting the relative movement of said first and second cutting blades one to the other such that a predetermined percentage of the given cross-sectional area of said reliefs are untraversed during the oscillating shearing movement of the first and second cutting blades, said predetermined percentage being equal to the area capable of being occupied by that quantity of hair represented by the minimum percentage of blending for the thinnest hair, whereby a greater percentage of thicker hair will be cut within each relief during the blending action than thinner hair.

2. The hair blending device of claim 1 in which one of said cutting blades is a stationary cutting blade.

4. The hair blending device of claim 1 wherein each of said reliefs within said cutting teeth are separated one from another by forwardly projecting cutting edges.

5. The hair blending device of claim 1 wherein each of said cutting reliefs are of decreasing cross-sectional area inwardly of said cutting blade to provide a scissors action between the cutting blades.

6. The hair blending device of claim 5 wherein said reliefs are of arcuate configuration.

7. The hair blending device of claim 6 wherein each of said reliefs within said cutting teeth are spaced one from the other by forwardly projecting cutting edges.

8. The hair blending device of claim 7 wherein the width of the forwardly projecting cutting edges is within the range of 30 to 60 percent of the diameter of the arcuate reliefs.

9. The hair blending device of claim 6 in which the cutting blades traverses the arcuate reliefs to one-half of the depth of the arc.

10. The hair blending device of claim 1 wherein the predetermined area of each of said reliefs remaining untraversed at the end of the shearing movement of said cutting blades increasingly diminishes toward the rear of said cutting blades.