US2289447A - Shaving device - Google Patents

Description

July 14, 1942. x A. P. MILLER 2,289,447

SHAVING DEVICE Filed Aug. 5, 1958 Patented July 14, 1942 UNITED o STATES PATENT GFFICE -sHAvmG DEVICE Anthony r. Miner, Atlantic City, N. J. Application August s', 193s, serial No. 223,152

3 Claims.

This invention relates to a shaving device, and more particularly to a so-called electric shaver in which a driving motor for a cutterris located within a housing adapted to be grasped in the hand of the user.

Shaving devices of the general character just indicated have been provided with reciprocating cutters which must of necessity be driven from a rotary motor through some means capable of transforming the rotary motion of the motor shaft into the reciprocatory m'otion of the cutter. inasmuch as a shaving device of this type must of necessity be small and have a motor incapable of supplying any large amount of driving power, and inasmuch as such a device is subject to considerable abuse through nonfoiling and the accumulation of dirt, primarily the clippings o f hair, it is obvious that any additional elements in the mechanism only serve `to increase the tendency toward failure of operation. A considerable load is, furthermore, imposed in reciprocatory devices due to several causes. First; the

vrelatively movable and stationary-blades must y be in contact to provide proper cutting and, in

general, the arrangements have been such that all of the pairs of cutting elements produce their cuts simultaneously. Thus in operation sudden loadsare placed on the reciprocating mechanism which, in conjunction with friction, tend to-pre .vent its proper operation. In reciprocatingv devices, furthermore, dirt entering between the relatively moving cutting elements tends to remain there since there is no cleaning sweep serving to dislodge it, with the result that it may not be dislodged for considerable periods during which friction is greatly increased. It is difiicult, furthermore, to provide relatively reciproeating surfaces which remain in sufficiently close lcontact to provide an effective shearing action.

' In accordance with the present invention, there is provided a shaving device in which the moving Accumulation of dirt is effectively avoided by reason ofthe continuous rotation of the cutter whereby it tends to clean thevcooperating cutter surfaces. The rotary action further facilitates shaving when perspiration isoccurring since the 'apidly rotating screw tends to keep the face dry aidcool.

I have discovered, furthermore, that greatly improved operation may be provided if the cutting surfaces, which arenecessarily of hardened steel, do not in themselvesprovide the bearing for a cutter. In accordance with the preferred embodiment of the present invention, the rotary cutter is provided with bearing elements of suitable bearing metal which, under the urging of a spring, serve to maintain the cutting surfaces in proper contact without producing any binding.' The above and other objects of the invention, primarily relating to details of construction, will be apparent from the following description, read in conjunction with the accompanying drawing, in which:

Figure 1 is a plan view partially broken away illustrating a preferred embodiment-of the inventidn;

Figure l2 is a lengthwise section through the cutting elements thereof;

' Figure 3 is an end view of the cutting elements;

Figure 4 is a transverse section taken on the plane the trace of which is indicated at d-ll in plane the trace of which is indicated at t-- in Figure 2; and

Figure 6 is a perspective sectional view showing a modified arrangement of cutter.

Referring first to Figures i to 5, inclusive, the improved shaving device comprises a housing 2 which may be of plastic material and whichis exteriorly shaped to be gripped by the hand of a user of the device. A driving electric motor 4,

preferably of the universal type commonly used in shaving devices of this nature is enclosedwithin the housing 2 with its shaft 6 extending lengthwise of the housing. Alternatively, a a spring motor may be used, or the cutter may be driven from a remote motor through a flexible shaft. Secured to one end of the housing, and preferably covered by portions thereof,

broken away in Figure l, is a supporting frame 5 thin wall adjacent the slotsl is cylindrically formed, as indicated at 24, to closely embrace al which Amay be brazed or otherwise secured in A place and which leaves openings 30 fo'r the exit of cuttings accumulating within the member I4..

Within the slots I8 and IB-there is located a transverse bearing member 32, preferably formed of some material such as bronze or the like, which will provide with a hardened` steel shaft a proper bearing. A similar bearing 34 extends through the slots 29 inwardly of the closure element 28. Mounted in thosebearing members -32 and 34 Ais a hardened screw II, the shaft 38 of which extends inwardly to engage the shaft B of the motor. The screw cutter 36 thus provided is urged into engagement with the cylindrical portion 24 of the thin wall carrying lthe slots vby means of a spring 40 held to the tubular member I4 by screws 42 and yieldingly urging the bearing members 32 and 34 in a .direction to cause the screw to bear upon the thin wall adjacent thel slots. The screw 38 is provided with one or more threads providing cutting edges designed to cooperate with lthe edges of the slots 22 for shearing purposes and also providing conveying means for moving cuttings lengthwise of the barrel to the discharge. The thread or threads of the screw 36 may be square in cross-section or slightly. hollow ground at their edges to provide for a better cutting action. The outside diameter of the threads is made such as to provide a good fit with a cylindrical surface 24. The slots may extend directly across the axis of the screw,

but preferably the slots are so arranged as to` extend in the direction of the helix angle of th screw' at itsA periphery. Under such circumstances there is a greater opportunity for the entra'nce kQf hair into the slots, particularly if the screw. has alarge pitch, and consequently more rapid cutting action. This is in contrast to-the little opportunity afforded for entrance of hairsv in the usual reciprooatory cutter. vThe slots 22 are preferably as narrow as they may be consistent with the.proper entrance of hair, and

should be sufficiently long to receive long hairs as well as short stubble.

While it is possible to have a cutter screw of l ment being such that thecutting edge of said the type described located within the cutter cylinder fitting it relatively tightly'and provided with the cutting slots, and therefore hardened, I have found that such an arrangement is more likely to produce overheating and cause the accumulation of dirt and impede action than an arrangement such as that described in which the contact of the hardened steel parts is limited to the portions necessary for cutting purposes. This willl be evident from Figure 4, in which it will be noted that the contact occurs substantially only over that area which is slotted. With such an arrangement, the bearing for the rotating screw -may be made of proper bearing material such as bronze and, furthermore, the dirt is swept from between the cutting surfaces into the open portion 2i of the tubular member wherein it may accumulate and ultimately fall out through the openings 30. A spring such as 40 may be readily adjusted to secure the proper bearing tension between the cutting surfaces.

v'Ihe operation of the device just described is substantially superior to that of reciprocating devices heretofore known. Though the cutter is 4 cutter.

nght m weight. its weight is to some extnt com. parable with the weight of the rotating parts of the motor, and consequently it contributes to maintaining the speed of the motor substantially constant' so as to overcome the irregular loads imposed by the cutting. Without a rotary action there can, of course be no such effect, and the tendency of reciprocating devices is to stop under conditions of maximum load. A self-cleaning actionalso results from the use of the rotary drical walls may be adiusted so as to properly maintain the running clearances in such condition as to provide proper cutting. The bore 40 permits the escapeof cuttings. The device of this figure may .be used either withoutonwith separate bearings of the type described in connection with the previous modification. Instead of having a bore 46, the block may be open on the upper slide of the bore 4`I, i. e., of U-shaped form.

.What I claim and desire to protect by Letters Patent is:

1. A shaving device comprising a member having a thin wall provided with slots for the entrance of hairs, a screw engaging said thin Wall with its axis extending transversely of said slots, said screw having a thread provided with a cutting edge forming a shearing arrangementin conjunction with edges of the slots, each slot having at least one edge arranged for shearingl cooperation with said cutting edge of the screw and extending in the direction of the threads at an' angle to the direction/of the screw axis substantially corresponding to the helix angle of the screw, and each slot extending through a substantial circumferential extent of said thin wall, and means for rotating said screw, said arrangethread meets vall parts of the cooperating edge of a slot substantially simultaneously during rotation of the screw.

2. A shaving device comprising a member having a thin wall provided with slots for the entrance of hairs, a screw engaging said thin wall with its axis extending transversely of said slots,

said screw having a thread provided with va cuthave extended engagement with, said screw, y

means for yieldingly urging said screw into continuous engagement with the cylindrical surface of said thinwall, and means for rotating said screw, said arrangement being such that the cutting edge of said thread meets all parts of the assaut' cooperating edge of a slot substantially simultaneously during rotation of the screw.

3. A'shaving device comprising a memberhav'- ing a thin wall provided with slots for the entrance of hairs, a screw engaging said-thin wall with its axis extending transversely of said slots,

s'aid screw having a thread provided with a cutting edge forming a shearing arrangement in conjunction with edges oi the slots, each slot having at least one edge arranged tor shearing cooperation with said cutting edge oi the screw and extending inthe direction of the threads at an angle to the direction ot the screw axis suby 3 stantialiy corresponding to the helix angle of the screw, 'and each slot extending .through a substantiai circumferential extent of said thin wall,

ousiy during rotation bearings for said screw movable independently of each other relatively t'osaid thin wall, resilient means acting upon said bearings to urge said screw yieldingly into continuous engagement with said thin wall,l and means for rotating said screw, said arrangement being such that the cutting edge of said thread meets-all parts of the coa operating edge of a slot substantially simultaneof the screw.

ANTHONY P. MILLER.

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