US2259001A - Hair clipper - Google Patents

Description

l06f. 14, R; KNAPP HAIR CLIPPER Filed March 12, 1958 Patented Oct. 14, 1941 UNITED srr HAIR CLIPPER Raymond Knapp, Long Island City, N. Y., as-

signor to Knapp-Monarch Company, St. Louis, Mo., a corporation of Missouri Application March 12, 1938, Serial No. 195,521

2 Claims.

This invention relates to hair clippers and particularly to a type of hair clipper designed to cut extremely close to the skin and for this reason ordinarily known as a dry shaver.

Among the objects of my invention is the provision of a dry shaver for shearing close to the skin which is adapted to cut both long and short hair equally well and having a convenient shape which will permit its being used on relatively inaccessible portions of the body.

Another object of my invention is the provision of a new and improved all purpose dry shaver having a simple and rugged construction and which is relatively inexpensive to manufacture.

Still another object is the provision -of a hair clipper especially suitable for cutting long fine hair in which is incorporated av construction of such design that the cutter blades 4cannot become readily clogged with the cut hair.

A further object is the provision of a hair clipper for cutting close to the skin, having anarrow rounded cutting face which glides easily over the skin producing no unpleasant eHect and which is especially adapted to cutting hair in hollows of the body such as the arm pits. l

Still another object is the provision of a hair clipper suitable for shaving hair from the' surface of the body wherein the cutting edge isV made in the shape of an arch to permit provision of an outer shear plate having a thickness Varying progressively from normal to an absolute minimum which is prevented from collapsing when pressure is applied by reason of its curved shape functioning as an arch. Y

With these and other objects in View, my invention consists in the construction, arrangement and combination of the various parts of my device, whereby the objects contemplated 'are attained, as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawing, in which:

Figure 1 is a fragmentary longitudinal section of a mounting showing a cutter head positioned therein.

Figure 2 is a longitudinal section of the head.

Figure 3 is a fragmentary perspective Yview showing the cutting portion of the head with the inner shear plate partly withdrawn; and

Figure 4 is a side view of the cutter head partly in section.

In the design of hair clippers and particularly those of a type adapted to cut hair extremely close to the surface of the skin for shaving withcutter not present in the hair clippers heretofore designed. In these close cutting hair clippers which are commonly termed dry shavers because of their being suitable for use Without a lather, there must be incorporated ruggedness of design in order `to withstand the almost ceaseless wear of a rapidly reciprocated cutting element. Combined with these qualities there must be incorporated in the cutting element, shearing plates havingsuch an extreme thinness that `there will be but the shortest possible stub ofv hair remaining after the cutting operation is complete, thus necessitating an unusual combination of rugged ness and delicacy in design which draws greatly upon the ingenuity of the designer.

In providing a hair clipper which is adapted to all dry shaving conditions, other factors must be taken into consideration as well. One of these is the frequent necessity of cutting long hair, very much longer than the stubby growth ordinarily comprising the average mans beard, and it has been found that in the cutters heretofore devised it has been extremely inconvenient and often impossible to cut such hair without completely clogging the cutting head of the so-called dry shaver. It has therefore become necessary to construct a cutting head which will expel long ends of hair as faSt as they are cut. Moreover, hair which is extremely thin and silk-like is especially likely to clog a cutting head of the ordinary sort. There are hollow spots on the body where long hair appears and a cutting head is requiredkto not only clip extremely close to the skin but also one which by, tapering to rounded edges is especially desirable since it can be worked into the hollows and will at the same time not scratch or irritate the surface of the skin. The particular cutting head forming the subject matter of this invention is one capable of performing in the face` of the diftlculties outlined and one which is at the same time capable of being used in =a machine of the customary design.

In the drawing there is shown the end of a machine. or mounting designated by the character A in whichis mounted a cutting head B. The working parts of the motor are not shown except for the end of an actuating arm Ill which is shown extending into the cutting head in operative position and a clip l2 for holdingthe cutting head in place in the mounting.

The cutting head is composed generally of an elongated casing I4 having a pair of slots I6 one at each side adapted to be engaged by the clip I2 when the cutting head is inserted in the mounting out the use of lather, problems present themselves in either direct or reversed position. A hollow shell I8 made from a stamping is held between opposite portions of the casing by means of rivets 2B, the sides of said casing being prevented from collapsing by a spreader 22 in which are provided a pair of deep recesses 23.

This shell is bent upon itself roughly into the form of a narrow elongated wedge having a point 26 bent around in a smooth continuous curve. The rounded point 24 of the wedge has formed therein a great number of similarly rounded teeth V26 separated by slots 28 of substantially the same width extending from side to side clear through the point of the wedge. At each end the shell is turned backwards upon itself in order to form reinforcing flanges 32 which .extend slightly be.- yond the surface of the teeth 26. In cross section it will be noted that teeth 26 are substantially arch-shaped having a maximum thickness at the base of the arch and a minimum thickness at the crown, a construction which can be seen readily in h cthligures 1 and :2. Although the crown .of the teeth is extremely thin, .the minimum section is comparatively small and is thin at a point .where pressure against the teeth is likely -to be least .eiective At the same ,time the crown is well .supported lby the adjacent thicker `portions ,of -the arch supported by .an inherent stiffness ofthe sides of the shell.

Within :the shell and particularly the lower end as viewed in Figure 2 devoted to cutting .thereis provided an inner shear plate 34 shown s olidin this embodiment. The inner shear plate .fits snugly within the point of the wedge-shaped shell and is itself substantially wedge-shaped in design. Teeth are formed on the inner -lshear plate by making wide slots .36 across thepointof the wedge thus forming afplurality of solid teeth 38.

The teeth of the inner shear plate Vare h eld snugly in cutting relation to .the teeth of the outer shear plate by means of .pressure applied to the inner surface of the inner shear plate 34. Pressure is exerted by 4means .of :a plunger .4,0 having a ball shaped end 42 and a peenedover top 44 which is yurged .into vposition against the shear plate by meansof `ac oiled spring 46. The plunger and its parts are .held in .place .in the cutter head by means of a threaded sleeve .4 8 positioned in a correspondingly threaded holed!! in the spreader 22.

It will be noted that .the depth of the slots in the 4outer shear plate is only slightly less than the effective `depthof the slots between .the teeth 3,8 of the inner .shear plate. Attention is further called .to lthe fact that the .slots 36 Lbetween the teeth of the innershear plate .are whatrnight :be termed asclosedor dead end slots. .By reason of this structure any hair which .is cut by the blades is not permitted to enter within the cutting -head and because of the extreme narrowness of lthe cutting portions of the head, hair is immediately ejected after having .been cut. There are no pockets within which it maycollect This narrow or atwise structure of thecutting .head is equallyieiective when used `both to cut long h air and hair which is extremely silky and fine,` either of which is quiteapt to clog .cutters of adifferent and less well constructeddesign. ,Also byreason of the fact 4that the slots .in theouter-shear plate extend around both sides and the. end of-.the plate it ispcssible to cut hair at both thesides andthe end, a factor which is extremely important in cutting long hair.

There has moreover been provided a cutter head for a hair clipper extending essentially in a flatwise direction much like a true razor blade but which is provided with a rounded edge adapted to be used against the skin wherever it may be encountered upon the body without scratching it while at the same time producing an extremely close clip or shave.

Some changes may be made in the construction and arrangement of the parts of my device without departing from the real spirit and purpose of my invention, and it is my intention to cover by umy claims., any modified forms of structure or use of mechanical equivalents, which may be reasonably included within their scope.

`I clairnas my invention:

1. I n a cutting head assembly for a hair clipper the combination of a relatively thin outer shear plate having opposite hat sides disposed at ,an oblique zangle to each other wherein the cutting portion extends in Y,thelorm Vof a rounded edge tangent at each en d to said sides, said cutting por-tion having fslots .extending through the rounded edge providing correspondingly rounded teeth having a thickness varying between a minimum thick-ness at the crown thereof and a maximum thickness at .the hase. an inner shear 491.091? having a rear face A.making .equal angles at the edges with the hat .sides 0f the :Shearplate and itself having flat :sides disposed at v an oblique angle to veaolji ptheregual to the angle of sides of Said outer shear plate fitting within the Outer nlatefahd adaptedto A,more relative thereto in a longitudinal .reciprocal .direction only., said ,inner .shear block havheislots yextending therethrough from one oblique Iside to the other with the bottoms of said slots parallel to the rear face of s aid inner plate and forming teeth adapted to p royide both -ilat and curved shearing planes at the cutting portion of the plate, and spring pressed means -for urging the inner shear ,block into close cutting relation xwith portions of the teeth at the sides and end of the outer `plate so that a resultant portion of the force exerted by the spring acts .against the obliquely positioned lateral faces.

2. In a ,Cutting ihead assembly for a hair clipperfthefoombinationof a relatively thin outer shear plate :comprising a stamping wherein the cutting portion extends flatwise terminating in a rounded Awedge shaped element, said cutting portion having slots extending through `the rounded point'of the wedge providing .teeth having a rounded arch `shape of varying thickness with the thinnest .portion at the crown thereof, and an inner wedge shaped shearing block of solid material yfitting within the wedge shaped element, said inner 'block :having slots extending therethrough from YOneoblique side `to the .other and isolid teeth :of uniform A thickness therebetween completelyseparating said slots so that clipped hair entering the slots on one side .between the teeth'may pass outward at the other side and cannot enter the interior of the cutting head, said inner block lbeing adapted to lmove `in a reciprocal direction only relative to Athe outer shear plate.

"RAYMOND KNAPP.

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