US2747113A - Armature arm for electric hair clipper - Google Patents

Description

May 22, 1956 L. J. WAHL ARMATURE ARM FOR ELECTRIC HAIR CLIPPER Filed Sept. 29, 1952 13' v 2a 1? JZ 2,747,113 Ice Patented May 22, 19

ARMATURE ARM FOR ELECTRIC HAIR CLIPPER Leo J. Wahl, Sterling, 111., assignor to Wahl Clipper Corporation, Sterling, [1]., a corporation of Illinois Application September 29, 1952, Serial No. 311,994

3 Claims. (Cl. 310-29) My invention pertains to an electric hair clipper, and in particular it relates to an improved arm for carrying the armature element of such a clipper.

The armature arm of this invention is an improvement on the arm illustrated in my prior U. S. Patent No. 2,265,880.

Electric hair clippers of one kind or another have been manufactured and sold for many years, and, within limits, an ecceptable size of such a clipper has become more or less standardized. Therefore, as a practical matter, improvements in clipper design must be made without appreciably varying the accepted overall size of the clipper.

One object of the invention is to provide an armature arm which produces significant improvement in clipper operation. The arm is so constructed and arranged that the movable clipper blade, driven at its center by the armature, oscillates on an are having substantially the maximum radius which can be provided within the available size limit of the clipper. By maximizing the radius of this arc, the path traveled by the blade is, of course, as close to a straight line as possible. Thus, the respective straight cutting edges of the movable and stationary blades may be aligned closely with one another without danger that the trailing end of the former will protrude beyond the latter as the former reaches each end of its travel path. It will be understood that if the edge end of the movable blade protrudes forwardly of the edge of the stationary blade, cutting of skin is likely to result. Therefore, the pivot or flexing point of my improved armature arm is at the extreme rear end of the arm, and this arm end is located at the extreme rear of the clipper.

Another object of the invention is to provide an armature arm which pivots or flexes from a centrally located point with respect to the width dimension of the clipper. Since the center of the travel path of the movable blade likewise coincides with the center of the width dimension of the clipper, it will be seen that the forward displacement of the movable blade with respect to the stationary blade, due to the arcuate travel path, is a minimum. This, of course, again enables a closer setting of the cutting edges of the two blades without the aforesaid danger of the trailing end of the movable blade swinging forwardly of the stationary blade.

Other objects and advantages of the invention will be apparent as the description proceeds, reference being had to the accompanying drawing which illustrates one structural form of the invention. It is to be understood, of course, that in commercial applications of the invention various details might well vary somewhat from those here shown and described.

In the drawing:

Fig. 1 is a plan view, partly in section, of an electric clipper embodying my invention, the casing cover being removed to expose the interior of the clipper;

Fig. 2 is a side elevational view, partly in section, of the clipper shown in Fig. l, the sectional plane being taken along the interior of the casing side wall;

Fig. 3 is a plan view, partly in section, of an armature arm of my invention illustrated in combination with an associated armature, and

Fig. 4 is a side elevational view of the armature arm and associated armature of Fig. 3.

Referring now to Figs. 1 and 2 of the drawing, my invention is shown embodied in an electric clipper which includes a casing 5. An electromagnet 6 is mounted in the forward portion 7 of the casing, while an armature 8 is disposed in effective relation with core 9 of the electromagnet. A finger element 10 extends forwardly from armature 8, and it centrally engages and drives the movable clipper blade (not shown).

Armature 8 is carried by an arm 12, shown in detail in Figs. 3 and 4. Arm 12 comprises a strip of spring stock which is rigidly connected at one end to armature 8, as clearly shown in the drawing. The desired position of arm 12, depending on local voltage conditions, is established by a pair of like compression springs 13-13 coaxially extending respectively between opposing casing walls and arm 12. A power screw 13a in one of the walls is adjustable to vary the axial position of the springs and thus the position of arm 12.

The spring strip includes a portion 14 which extends rearwardly from armature 8 substantially to the rear i wall 15 (Fig. 1) of easing 5. The strip has a generally circular loop 16 at its rear terminus, and an end portion 17 extending from the loop in substantial parallelism with rearwardly extending portion 14, as best shown in Figs. 1 and 3.

End portion 17 is provided with at least a pair of threaded openings 18 which receive screws 19 (Fig. 1) serving to secure arm 12 to the interior surface of casing side wall 20. It will be noted that casing side wall 20 is substantially thicker than the opposite casing side wall 21, a feature which, in addition to providing needed rigidity, cooperates to position rearwardly extending portion 14 substantially on the longitudinal center line of the clipper, as best shown in Fig. 1. A switch 21a is mounted in the casing adjacent portion 14.

Rearwardly extending portion 14 of the arm is provided with stiffening means which make this portion of the arm substantially non-flexible throughout its entire length. In the form of the invention illustrated, the stiifening means takes the form of lateral flanges 22 and 23 which extend in length continuously from armature 8 to loop 16, the flanges being relatively wide adjacent armature 8 and narrower adjacent loop 16. It is to be understood that other and equivalent stiffening means are within the scope of my invention, the flanges 22 and 23 merely being exemplary. Such stiffening means insures that the portion 14 will be substantially rigid, that is, it will not be subject to appreciable flexing during clipper operation.

When lateral flanges 22 and 23 are used, they may be enlarged at their forward ends as respectively shown at 24 and 2S, and these enlargements are secured to armature 8 to provide the aforesaid rigid connection.

An armature arm constructed and mounted in the clipper as described is non-flexible except in the region of loop 16. In other words, all significant flexing action of the arm is confined to loop 16. As loop 16 is positioned as far rearwardly in casing 5 as possible, it will be seen that the forward end of armature 8, particularly finger element 10, moves on the greatest possible radius. Thus the arcuate travel path of the movable clipper blade is as near to a straight line as possible.

In prior arms constructed without stifiening means such as flanges 22 and 23, arm flexing occurs substantially for wardly of the region corresponding with the position of loop 16, with the result that the effective radius of the arc is materially shorter. In this case the forward displacement of the movable blade with respect to the stationary blade is correspondingly greater, and close alignment of the blades cannot be employed safely.

As will be seen in Fig. 1, loop 16, in addition to its rearward location in casing 5, is located centrally with respect to the width dimension of the clipper. Since the two clipper blades also are located centrally with respect to the width dimension, as is the point of drive of the movable blade, the forward displacement tendency of the trailing edge end of the movable blade again is minimized.

Thus, my invention has provided correction for two conditions which heretofore have resulted in dangerous forward displacement of the movable clipper blade. Accordingly, desirably close alignment of the cutting edges of the two clipper blades is now possible.

From the above description it is thought that the con struction and advantages of my invention will be readily apparent to those skilled in the art. Various changes in detail may be made without departing from the spirit or losing the advantages of the invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a hair clipper having a casing of predetermined length, an electromagnet mounted in the forward portion thereof and an armature cooperating with said electromagnet: an arm for carrying said armature comprising a strip of spring stock rigidly connected at one end to said armature, said strip including a portion extending rearwardly from said armature substantially to the rear wall of said casing, a generally circular loop at its rear terminus, an end portion extending from said loop in substantial parallelism with said rearwardly extending portion and rigidly secured to the interior surface of the adjacent side wall of said casing, said surface being offset slightly from the center of said casing, whereby said rearwardly extending portion is substantially centrally located in said casing, and continuous lateral stilfening flanges on said rearwardly extending portion between said armature and said loop whereby all significant flexing action of the arm is confined to said loop.

2. The combination of claim 1 wherein said lateral stiffening flanges are enlarged at their forward ends and rigidly secured to said armature.

3. An armature for an electric hair clipper comprising a strip of spring stock, said strip including an elongated portion, a generally circular loop at one terminus, a mounting end portion extending from said loop in substantial parallelism with said elongated portion, and lateral stiffening flanges extending the entire length of said elongated portion whereby the significant flexing capabilities of the arm are confined to said loop.

References Cited in the file of this patent UNITED STATES PATENTS 376,158 Northrup Jan. 10, 1888 1,504,595 Andis Aug. 12, 1924 1,670,584 Lockstein May 22, 1928 1,891,486 Wahl Dec. 20, 1932 1,981,041 Hartzell Nov. 20, 1934 2,202,301 Probst May 28, 1940 2,228,663 Knapp Jan. 14, 1941

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