US2543145A

US2543145A - Electric shaving device

Info

Publication number: US2543145A
Application number: US735400A
Authority: US
Inventors: Wussow William
Original assignee: LEONARD M MAUNU
Current assignee: LEONARD M MAUNU
Priority date: 1947-03-18
Filing date: 1947-03-18
Publication date: 1951-02-27
Anticipated expiration: 1968-02-27

Description

Feb. 27, 1951 w. wussow 2,543,145

ELECTRIC SHAVING DEVICE Filed March 18, 1947 INVENTOR Patented Feb. 27, 1951 ELECTRIC SHAVING DEVICE William Wussow, Wauwatosa, Wis., assignor of one-half to Leonard M. Maunu, Milwaukee,

Wis.

Application March 18, 1947, Serial No. 735,400

1 7 Claims.

My invention relates to improvements in motor driven hair cutting and shaving devices.

A primary object of my invention is to provide a hollow handle of a so-called dry-shaver with an electric motor having a rotary cutter mounted directly on the motor shaft for centrifugal projection against a cylindrical portion of the handle wall, which includes an arcuate set of shear bars applicable to the skin of the user.

More specifically, my object is to provide a hair cutting device of the dry-shaver type with a hollow handle having a cylindrical peripheral portion, including a set of shear bars adapted to be applied to the skin, said handle containing an electric motor having one or more cutter blades resiliently supported from the motor shaft in a position for travel along the inner surface of said cylindrical portion, with the cutting edge of each obliquely disposed with reference to the shear bars, whereby the motor may be started without material frictional resistance, and the cutter blade or blades projected with increasing frictional pressure across the shear bars and along the other surfaces of the inner face of said cylindrical portion.

In the drawings:

Figure l is a perspective view of a shaving device embodying my invention.

Figure 2 is a sectional View drawn to line 2-2 of Figure 1.

Figure 3 is a sectional view drawn to line 3-3 of Figure 2.

Figure l is a fragmentary sectional view drawn generally to line l4 of Figure 3.

Figure 5 is a detail view of one of the cutter blades and the means for supporting it from the motor shaft.

Figure 6 is an enlarged sectional view of the shear bar carrying portion of the casing, with one of the cutter blades in contact with the illustrated shear bar.

Figure 7 is a similar view showing a modified form of shear bar construction.

Figure 8 is a view similar to Figure 6, showing a further shear bar modification.

Lil-2e parts are identified by the same reference characters throughout the several views.

The handle of my improved hair cutting and having device comprises a cup-shaped body It, preferably of a generally concavo-convex form, with a cylindrical rim portion H including an arcuate row of shear bars i2, preferably formed by cross slotting the peripheral wall, as clearly shown in Figure 1. This portion of the peripheral wall is made very thin and is adapted to be applied to the skin of the user from which hair is to be cut.

A cover I3, also preferably of concavo-convex form, has snap-on engagement with the body it along the circular line 'at It and form with the body a handle-shaped enclosure for an electric motor it secured by screws ii to interior studs $8 on the interior surface of the body wall. At a point remote from the shear bars !2 an electric cord 29 is plugged into the body, as indicated at 2! in Figure 2, whereby electric power can be supplied to the motor through the interior electrical connections 22. The motor has its shaft 24 transversely disposed within the handle and provided with radially extending arms 25, the end portions of which are curved at 2'! toward the cylindrical rim portion E i and provided with arcuate end portions 36 with which the rim portion ii is concentric. The ends of the arm portions 39 are outwardly turned at 3|, and provided with cutter blades 32 for travel along the inner surfaces of the rim ii and of the shear bars 62. The arm portions 39 are biased to either urge the cutter blade 32 against the shear bars under light pressure or to normally hold them slightly out of contact with the shear bars and also out of contact with the cylindrical wall ll, whereby the cutter blades will offer no material frictional resistance to the rotation of the motor armature. However, as soon as the motor acquires operating speed, the cutters 35 will be swung outwardly by centrifugal force to develop the necessary shearing pressure against the shear bars. It will be observed in Figure i that the cutting edge 32 extends obliquely across the inner surfaces of the shear bars l2, whereby shearing contact with each bar occurs at only one point at any given time.

If desired, the arms 25 may comprise a cross bar centrally connected with the motor shaft at 25, and the

portions

25, 3i and 32 may or not be integrally formed. But it is important that the portions 36 be resilient and that the cutting edge 32 have the requisite hardness. Therefore the arm 30 will preferably be formed of spring steel, and the portion 3!, or at least the cutting edge portion 32, is preferably formed of tool steel and welded to the free end of the arm is. The arm portion 30 preferably extends from the portion 21 in the direction of rotation in order that the severed hair may be pushed away from the blade instead of being drawn between it and the shear bars.

The radially extending member 25 is relatively thick and rigid, and it is not essential to the invention herein claimed whether it extends in a plurality of directions radial to the shaft or whether it consists of a member extending in,

only one direction and supporting only one resilient arm 30 and cutter blade 3|. Therefore, in the appended claims, I refer to the part 25 as a radially extending blade supporting member, and to the part 30 as a resilient blade carrying arm. Inasmuch as this arm extends in the direction of rotation along a circular line with which the rim I I is concentric, the blade may be normally held either in slight frictional contact with the inner surface of the rim It or slightly out of contact with such surface until the motor attains sufiicient speed to move the blade into contact with the shear bars by centrifugal force. Therefore, when the motor is electrically connected it will either start automatically or it may be caused to start by a slight jar, and a miniature motor of very light power can quickly acquire the necessary speed.

The outer surface of the slotted portion of the rim II is ground away and thereby slightly flattened, as indicated in Figure 1, and as the blade is nowhere exposed, the device has the characteristic of a safety razor in this regard.

The cutter blade or blades 32 have cutting edges not only obliquely disposed with reference to the shear bars but also beveled for fiat contact of the beveled surface with the inner face of the rim portion l l, including the inner surfaces of the shear bars. Therefore the blade or blades are continuously sharpened by their frictional contact with the portion H, and as the bearing surface is a true cylinder, the blade operates without vibration, whereas all other dry shavers of which I am aware operate with considerable vibration.

In the form of construction shown in Figure 1 to Figure 6, inclusive, the body wall I!) extends radially outward at 33 for integral connection with the cylindrical portion H and the respective shear bars !2. In the modified form shown in Figure 7, the body wall Illa is obliquely connected at 34 with both margins of the cylindrical portion and its shear bars IZa, and the slots in the wall II which form the shear bars are extended into the wall portion 34 as indicated at 35.

In Figure 8 the body wall lilb is connected with a transversely arcuate peripheral wall llb, one portion of which is slotted to provide a set of arcuate shear bars I217.

The modifications shown in Figures 7 and 8 are illustrated to indicate that my invention is adaptable to the various well-known types of shear bar applicators used in connection with dry shavers.

I claim:

1. Shaving apparatus, comprising the combination with a hollow handle, having one of its walls provided with an arcuate row of shear bars, a resiliently supported cutter blade mounted for travel along a circular path with which the shear bars are closely concentric, and a motor in the handle in substantially the plane of the shear and having an armature shaft normal to said plane and disposed within the handle and an arm attached to the shaft and overhanging the motor and operatively connected to drive said cutter blade along said circular path in resilient pressure contact with the shear bars.

2. Shaving apparatus comprising the combination with a hollow handle, of an electric motor mounted therein and having a shaft, a radially extending member mounted on the shaft and provided with a resilient arm extending from said member arcuately in the direction of shaft rotation, said arm having a free end portion positioned to revolve directly around the motor, an arcuate set of shear bars supported by the handle substantially in the plane of the motor and in a circle concentric to the path of said resilient arm and in close proximity there to, and a cutter blade carried by the free end of said arm in a position to be urged by centrifugal force into pressure contact with the shear bars.

3. Shaving apparatus, comprising the combination with a hollow handle comprising a shell of generally circular form in one elevation and generally ellipsoidal form in transverse section, said shell having a cylindrical wall provided with a thin slotted portion constituting a set of shear bars, an electric motor within the handle shell, and a cutter operatively connected with the motor for actuation along a circular path immediately within said cylindrical wall for pressure contact with the inner surfaces of said shear bars.

4. Shaving apparatus, comprising the combination with a hollow handle, having a cylindrical wall provided with a thin slotted portion constituting a set of shear bars, an electric motor within the handle and centered within said portion, and a cutter operatively connected with the motor for actuation along a circular path immediately within said cylindrical wall for pressure contact with the inner surfaces of said shear bars, said motor having its shaft provided with a radially extending cutter support overchanging the motor and including a resilient arm extending arcuately about the motor in the direction of cutter rotation and adapted to hold the cutter in contact with the shear bars with a pressure dependent upon the speed of the motor and the centrifugal force generated thereby in the cutter.

5. Shaving apparatus, comprising a handle having a hollow body provided with a generally cylindrical rim having one portion provided with transverse slots defining a series of shear bars for contact with a skin from which hair is to be cut, a cover detachably connected with the body, an electric motor mounted within the body and intersected by the plane of said bars and including a shaft having an exposed end provided with a radially extending member also projecting axially from the shaft end and overhanging the motor, an arcuate resilient arm carried by said member and with which said rim is concentric, said arm projecting from said member in the direction of rim rotation and having its free end provided with a cutter blade in a position for pressure contact with the inner surface of a rim at least while the motor is bein operated at suificient speed to project the blade centrifugally.

6. Shaving apparatus as set forth in claim 5, in which the rim slots extend into the body beyond the rim on each side thereof.

7. Shaving apparatus, comprising a generally concave-convex body provided with a rim and a detachable cover, an electric motor mounted in the body and having a shaft with an exposed end extending along a line with which the rim of the body is concentric, said rim being of an arcuate cross section in a plane parallel to the shaft axis and having one portion provided with spaced slots in its exterior surface, the rim portions between slots constituting a series of thin shear bars for contact with a skin from which REFERENCES CITED hair is to be 0 1;, said eries of b lying i a The following references are of record in the plane intersecting the motor and normal to the file O s pat nt shaft, said shaft having at least one radially 5 UNITED STATES PATENTS extendmg member pro ectmg axially from said end to overhang the motor and provided with an Number Name Date arcuate resilient .arm extending along the rim 2,370,331 susunaga 27, 1945 in the direction of rotation, and a cutter mount- FOREIGN PATENTS ed on the free end of said resilient arm and provided with a shearing edge conforming to the curvature of the inner surfaces of the shear bars in substantial contact therewith and adapted for increasing pressure contact with the shear bars under centrifugal force dependent upon the 15 speed of the motor.

10 Number Country Date 516,242 Great Britain Dec. 28, 1939 867,155 France July 7, 1941 WILLIAM WUSSOW.