US3756105A

US3756105A - Ultrasonic electric shaver

Info

Publication number: US3756105A
Application number: US00193246A
Authority: US
Inventors: L Balamuth; M Karatjas
Original assignee: Ultrasonic Systems Inc
Current assignee: Ultrasonic Systems Inc
Priority date: 1971-10-28
Filing date: 1971-10-28
Publication date: 1973-09-04
Anticipated expiration: 1990-09-04
Also published as: DE2252918A1; GB1384422A; FR2159032A5

Abstract

An electric razor having a guard member with a plurality of apertures for hairs to extend therethrough and a cutter member oscillated relative to the guard member for severing the hairs. The guard member and/or the cutter member are vibrated at an ultrasonic rate to improve the entry of hairs into the operative range of the cutter member, to reduce the force required to oscillate the cutter member relative to the guard member, and to utilize the high accelerations of the ultrasonically vibrated cutter member in shearing the hairs, and the method of shaving accordingly.

Description

United States Patent Balamuth et al.

ULTRASONIC ELECTRIC SHAVER Inventors: Lewis Balamuth, New York; Manuel Karatjas, Glen Oaks, both of N.Y.

Ultrasonic Systems, lnc., Farmingdale, N.Y.

Filed: Oct. 28, 1971 Appl. No.: 193,246

Assignee:

US. Cl 83/14, 30/34.2, 30/45,

83/701 Int. Cl B26b 19/28 Field of Search 83/13, 14, 701' References Cited UNITED STATES PATENTS 3/1969 Thuillier 30/45 [451 Sept. 4, 1973 3,610,080 10/1971 Kuris ..s3/13 3,509,626 5/l970 Mead /45 Primary ExaminerFrank T. Yost Attorney-Leonard W. Suroff [57] ABSTRACT An electric razor having a guard member with a plurality of apertures for hairs to extend therethrough and a cutter member oscillated relative to the guard member for severing the hairs. The guard member and/or the cutter member are vibrated at an ultrasonic rate to improve the entry of hairs into the operative range of the cutter member, to reduce the force required to oscillate the cutter member relative to the guard member, and to utilize the high accelerations of the ultrasonically vibrated cutter member in shearing the hairs, and the method of shaving accordingly.

88 Claims, 15 Drawing Figures Patented Sept. 4, 1973 6 ShectsSheet l WI Ill w\ u II k\ (I U r ill|lla hm NR -l Q R Q\ I- .Q n. 1 wm m u NV mm E i R J NQFm Patented Sept. 4, 1973 3,755,105

6 Sheets-Sheet 2 54 FIG. 4

mmmmmilflmhlildmm Patented Sept. 4, 1973 6 Sheets-Sheet 5 Patented Sept. 4, 1973 6 Sheets-Sheet 5 Patented Sept. 4, 1973 6 Sheets-Sheet 6 I QFm BACKGROUND OF THE INVENTION This invention relates to methods and apparatus for electric shaving, and more particularly to methods and apparatus for personal shaving employing ultrasonic energy suitable for regular use in the home.

The use of ultrasonic energy has been proposed for shaving in which a razor blade is ultrasonically vibrated for engagement with and cutting the hairs in a wet type shaving instrument as exemplified in US. Pat. Nos. 3,509,626 and 3,610,080, the latter patent assigned to the assignee of the present invention.

The inventors of the present invention have now discovered that ultrasonic energy may be utilized in an electric dry" type shaver to enhance its effectiveness in various ways as hereinafter explained in detail.

The present art of dry shaving instruments take various forms, but all consist basically of an electric motor powered by battery or from a standard electric current source, and a blade or cutting member which is driven by the motor. The motion imparted to the blade member may be rotary, longitudinal, or oscillatory. In all of the devices of this type known to date, the movement of the blade member is effected at a rate of speed related to commercial power frequencies, i.e., 60 cycles per second, and the blade member may move in the order of from generally 60 to 120 times a second.

Such motor driven instruments provide certain advantages over conventional manual shaving. Since a great many more cutting edges per second are provided by the powered device, substantially more cutting is performed by the user in a given amount of time. Also, since the motor provides the power necessary to move the cutting head in the prescribed manner it is only necessary for the user to guide the guard member over the skin surfaces being shaved to achieve proper results. These devices then are appealing in that they are relatively simple to use and also serve to provide what amounts to an increased coverage to an area per unit time, as compared to conventional manual shaving.

However, the use of these conventional motor driven and manual shaving instruments does not overcome many objectionable aspects of shaving. Essentially, to obtain an optimum shave there are two factors that are important. The first is that we have a minimal amount of frictional resistance between the shaving instrument and the skin as it is moved relative thereto, and the second is that the cutting edge of the blade be maintained as sharp as possible to facilitate the cutting of the hairs as the shaving instrument moves across the surface of the skin.

OBJECTS OF THE INVENTION It is the general object of the present invention to avoid and overcome the objections to prior art practices by the provisions of methods and apparatus employing ultrasonic energy for shaving which enables significantly better shaving of skin and which is completely safe for use in the home.

Another object of this invention is to provide novel and improved shaving techniques and apparatus for dry shaving giving clean shaves for various kinds of hair growths.

Another object of this invention is to provide novel forms of shaving apparatus and improved shaving techniques employing ultrasonic energy in which the frictional resistance to movement. of the shaving instrument over the skin is substantially reduced.

Another object of this invention is to provide a novel and improved shaving technique and apparatus employing ultrasonic energy which may be employed for dry shaving.

Another object of the present invention is to provide a novel form of shaving apparatus employing ultrasonic energy in which the rate of uptake of hairs through the guard member is increased. Other objects and advantages of the present invention will be obvious as the disclosure proceeds.

SUMMARY OF THE INVENTION The aforesaid objects of the present invention, and other objects which will become apparent as the description proceeds, are achieved by providing a series of features, steps and elements assembled and working together in interrelated combination to provide the shaving effects of the present invention. The present inventors have discovered that, when ultrasonic energy is applied to a cutting member that an improved shave may be obtained without any damage to the skin.

Briefly, in accordance with the present invention the electric razor is designed to overcome certain limitations or disadvantageous of present day dry shavers.

In the field of electric shaving the current standard approach involves the use of a very thin metal sheet guard behind which an oscillatory or rotatory shear acting cutting head operates. In this way, hair is cut by the shearing action as close to the surface of the skin as the thickness of the guard. The trend in this direction has been to make thinner guards so as to improve closeness of shaving. It is found with such common electric shaving practice that various disadvantages accure, such as the cutting through of the hair in an uneven manner due to to the very low compliance of same, and an irritability to the skin adjacent the hair due to a combination of factors such as the shear cutting force needed to cut the hair producing a drag on the skin together with a rubbing action as well as possible irritation arising from the jagged cut hair itself. For example, in cutting through a hair, the hair starts to bend and so although it may be cut very close to the skin at the beginning of the out, due to said bending the hair tapers off to a sharp point. This point diminishes the feel of smoothness during the day as the hair grows out preparatory to a new shave. In the case of very delicate skin, the sharp pointed hairs actually curl about and the point, by penetrating the skin, begins to develop an ingrown hair which serves not only for irritation but also for minor skin infections.

The inventors have discovered that by vibrating the guard member at an ultrasonic rate the uptake of the hairs or their ability to enter the guard apertures is substantially enhanced. As is known each guard member contains a plurality of apertures in spaced relation to each other and that the initial step in the shaving process is their entering through the apertures.

Now a basic fact of the invention rests on the unexpected discovery that, as the guard member of small openings is placed lightly against the bearded skin to be shaved, when the ultrasonic vibrations are present, the hairs feed automatically into the openings in a remarkable fashion; an effect wholly absent when the ultrasonic vibrations are absent. Of course, as the hairs feed through the openings, the shear cutter head immediately cuts them off completely as long as the cutter head has a gross transverse motion greater than the diameter of the hair. If this gross motion is 0.5 mm, which is easily attainable and larger than the coarsest hair one would be likely to encounter the cutting will take place. The total result of the unique combination of motions disclosed is, that hairs may be removed from the face with a lighter pressure, and a closeness and comfort not hitherto possible for electric shavers in regular use. In addition, the design makes possible the use of a light weight shaver of dimensions smaller than those currently on the market. Tightness and compactness are obvious advantages when combined with the superior shaving qualities indicated.

Just how the ultrasonic energy produces the unique effect of facilitating beard hair feed through in the guard or stator elements is not completely understood, but the presence of the effect is readily demonstrable. It might be theorized that, in general a high frequency mechanical vibration field facilitates feed through of small elements in a sieve, by producing a substantial friction reduction. it is, in fact, well known in the ultrasonic art that the feed-through of powders and viscous masses may be enormously accelerated by vibrating the sieve. There is a sufficient similarity hence to warrent the supposition that some aspect of this accelerated feed through effect is in fact present in the disclosed shaver.

The shaver guard member (as well as the cutters) may be designed to accomodate a plane surface output in contact with the skin, or a curved surface contour such as is exemplified by a cylindrical or a spherical surface.

The present invention utilizes an ultrasonic motor, which is essentially an electric motor, and has an output that oscillates or reciprocates back and forth at a very high number of reciprocations per second, which we call the frequency of the motor. For example, above 16,000 reciprocations per second, we are in a range which for sound waves is above the level of human hearing, hence the term ultrasonic. Now, if we consider a vibrating or reciprocating element which is moving back and forth over a space of about 0.001 of an inch in the ultrasonic range of frequency, this element will reach the incredibly high acceleration of more than 20,000 times the acceleration of gravity. This unique property of ultrasonic motors cannot be realized by any other known means where such small motions are involved. For the sake of completeness and for clear understanding, it should be mentioned that although the number of reciprocal strokes per second is very high, the top speed realized by the vibrating element during each stroke is a quite low speed actually in the horse and buggy range of to miles per hour. Therefore. with the ultrasonic motor in the range being described, we are dealing with a very high reciprocal rate and a very high acceleration combined with a relatively low peak speed. This is very important in order to appreciate that with ultrasonic cutting devices we are dealing with an extremely safe kind of tool, which has been amply demonstrated in the dental and industrial fields over a period of years. Now, of course, the question naturally arises what is the relevance of these technical facts to the performance of an ultrasonic electric shaver.

If a cutting edge be allowed to reciprocate at an ultrasonic frequency, it will approach and recede from a surface to which it is applied many thousands of times every second. Let us follow the blade edge during one complete cycle of reciprocation. Let us say we start at the point where it is in contact with the surface and instantly it recedes from that surface due to the oscillation and it continues to recede for a half cycle during the next half cycle it again approaches the surface coming in contact once again at the completion at the second half of the cycle. Now this whole operation has taken no more than l/30,000 of a second as our ultrasonic motors frequency is 30,000 vibrations per second. in this incredibly short period of time the acceleration of the output edge of the motor is so high that the surface being pressed against remains out of contact with the edge during most of the cycle. From this it follows that a cutter or blade member being used in this manner will be out of contact with the guard member practically all the time with the result that there is set up what is called a relatively impenetrable zone of motion. The consequence is that the high frequency oscillating blade automatically runs most of the time on an air film and the surface friction is greatly reduced. This produces an electric razor in which a smaller force is required to obtain the necessary gross movement of the cutter member.

This is one outstanding property realizable in an ultrasonic razor. in addition, it is well known that the dynamic net force operating in a mechanical system is equal to mass times acceleration, this is called Newtons second law of motion. A consequence of this simple relationship is that when the acceleration is extremely high (as in an ultrasonic motor) then the dynamic force capability of such a motor is greatly magnified. This means that a blade edge of the cutter member due to its reciprocation is able to penetrate hair with a high dynamic force. Hence, in shaving terms such a shaver greatly reduces the drag ordinarily incurred in actual cutting of hair at the same time once the blade has entered a given hair the high frequency or reciprocation reduces the friction that the blade encounters in passing through the hair. These two factors add up to the potential that the hair extending through the guard member is cut clean through without the sharp points referred to above in connection with standard methods of electric shaving due to the extreme case with which the hair is bent. Accordingly as we endow the blade edge of the cutter member with the right kind of reciprocating motion, whatever good qualities the blade edge had prior to reciprocation it will continue to have with the addition of the greater enhanced improvements described above.

Accordingly, the ultrasonic energy when transmitted to the cutter member effects a reduction of friction between the inner surface of the guard member and the output edges of the cutter member. In a conventional electric razor a considerable amount of force is now required to overcome the static friction between the guard member and cutter member. By ultrasonically vibrating the cutter member this force is substantially reduced. in addition, by inducing ultrasonic vibrations within the cutting member the shearing action is enhanced due to the high accelerations generated therein.

Although the discussion of the invention has been limited to basic mechanical considerations of shaving and the consequent comfort realized by theuser, the ultrasonic razor of the present invention has additional important virtues. As is well known, ointments, skin creams, skin conditioners, etc. have become an important adjunct to the mens skin care market. Now, in the presence of ultrasonic energy, medicaments in the form of conditioners will be more effective in performing their functions. This arises because of a variety of effects whereby ultrasonic energy introduces the possibility of superior cleansing action and enhanced diffusion or penetration of the skin and in many cases an increased chemical activity for the given conditioner. The present invention permits the use of chemical products for skin use which will have an enhanced useful effect automatically occurring during the previous processes disclosed herein.

In conclusion, it is therefore believed that as stated at the outset, the ultrasonic motor introduces unique possibilities where through a combination of new effects a completely new concept in shaving is made possible. This includes smothness in shaving, reduction in drag and skin irritation, better hair cutting dynamics, and improved skin conditioning.

BRIEF DESCRIPTION OF THE DRAWINGS Although the characteristic features of this invention will be particularly pointed out in the claims, the invention itself, and the manner in which it may be made and used, may be better understood by referring to the following description taken in connection with the accompanying drawings forming a part hereof wherein like reference numerals refer to like parts throughout the several views and in which:

FIG. 1 is a side elevational view, partly in section, of an assembled electric shaver incorporating ultrasonic energizing means associated therewith;

FIG. 2 is a front elevational view, partly in section, of the shaver illustrated in FIG. 1;

FIGS. 3-6 are enlarged schematic representations of the vibration pattern of the guardmember and hair, to help illustrate the present invention;

FIG. 7 is a side elevational view, partly in section, of an assembled electric shaver incorporating ultrasonic energy means coupled to the cutter member, in accordance with the present invention;

FIG. 8 is a front elevational view, partly in section, of the shaver illustrated in FIG. 7;

FIGS. 9 and 10 are enlarged schematic representations of the interrelationship of the various elements to help illustrate the present invention;

FIG. 10A is a greatly magnified view in schematic form of a portion of the elements illustrated in FIG. 10, to aid in explaining the principles of the present invention;

FIG. 11 is a side elevational view, partly in section, of an assembled electric shaver incorporating ultrasonic energizing means coupled to the cutter members and guard member;

FIG. 12 is a front elevational view, partly in section, of the shaver illustrated in FIG. 11;

FIG. 13 is a side elevational view, partly in section, of an assembled electric shaver incorporating essentially a single motor to produce both the low frequency gross motion and high frequency mechanical vibrations; and

FIG. 14 is a front elevational view, in section, of the shaver illustrated in FIG. 13.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing now the drawings in detail it will be seen that components not necessary for an understanding of the invention have either been omitted or shown diagrammatically.

Referring to the drawings, there is shown in FIGS. 1 and 2 an electric dry shaver designated generally by reference numeral 10. The shaver includes a boxlike housing 12 on which is superimposed a shaving head assembly 15. The housing 12 is formed of a housing member with an outwardly facing opening 16. The shaving head assembly 15 is received within the opening 16 and cooperates with the housing 12 to form an enclosure 17 within which a conventional electric motor 18 is mounted.

As is well known in the art, the batteries may be provided in the housing that are of the rechargeable variety, and suitable means provided for connecting the batteris to an external power source for recharging purposes. A switch 20 controls the energization of the motor 18.

The shaving head assembly 15 further includes an outer frame 24 which comprises an outer shearing or guard 25 in the form of a perforated comb capable of supporting vibrations in the ultrasonic range and an inner cutter assembly 30. The guard member 25 in the form of a perforated comb is a thin flexible member having an outer surface 26 adapted for engagement with the skin of the user and a spaced apart inner surface 28 with a plurality of apertures 32 extending therebetween with each aperture 32 having an inclined wall 34 merging with the respective inner and outer surfaces at an edge 36 and which is secured to a supporting frame 26 whereby the comb 25 assumes an inverted U- shape, as is best shown in FIG. 1. In order to shear hair which extends through the perforations 32 in the guard member 25, there are a plurality of cutters or cutting blades 40 which are carried by base 42 and having a front edge 44 for shearing engagement with the underside surface 28 of the comb 25. The structure of the guard member 25 and the inner cutter assembly 30 made up of the cutting blades 40, base 42 and supporting shaft 46 coupled to the motor 18, and extending from the bottom face 43 with a spring 48 biasing the front end 44 of the blades 40 against the inner surface 28 of the guard member 25 is well known in the art, and their action need not be described in detail herein.

The cutter member 25 having a plurality of individual cutters 40 is already well known inthe art and cooperates with the guard member or shear foil 25 that overlies the cutters 40 which latter can be constructed in a known manner of a plurality of cutter blades mounted on or integral with a frame 42 or the like. The guard member 25 is a very thin foilwhich is provided with a great number of apertures or perforations 32 through which the hair or beard stubble can come into contact with the cutters 40 respectively. In the illustrated embodiment the shear foil 25 may be connected with the outer frame 24 in any conventional manner and may be of the removable type well known in the art. However, it would also be possible to utilize a double shear foil overlying two cutters in which case the shear foil would of course have to be provided in the middle with suitable support.

At their outer ends, that is those which are connected with the outer wall of the housing, the guard member 25 is so mounted in known manner as to have a certain freedom of movement so that it can conform itself to the contours and movements of the cutters 40 which are pressed against the guard member 25 from below under the biasing action of spring 48, which is associated with the cutters 40.

The utilization of ultrasonic mechanical vibrations is illustrated with respect to FIGS. 3 6, and particularly the relative movement of the guard member 25 and its apertures 32 extending in spaced relation to each other between the outer surface 26 and the inner surface 28, with each aperture 32 having a side wall 34 terminating in a wall edge 36 defining the cross-sectional area which may be circular, rectangular, or any desired shape.

To produce the friction reduction effect to obtain the uptake in rate for the hairs 50 extending from the skin 52, and having a front end or edge 55, to enter the apertures 32 of the guard member 25, ultrasonic vibration generating means 60 is utilized and is coupled to the guard member 25 so as to apply ultrasonic energy to the outer surface to produce mechanical vibrations having a component substantially normal and/or parallel to the outer surface 26 and skin 52. In this manner the resistance or friction of the inner wall 34 of the aperture 32 to the hair 50 is substantially reduced to permit a ready entrance of the hair 50 within respective apertures 32. In this manner there is an increase in the rate of entry of the hairs 50 through the apertures 32.

Accordingly, the vibration generating means 60 includes a vibration generator 62, which may be of an adjustable type to vary frequency, power, and amplitude, and one or more ultrasonic motors or transducers 65 coupled to the underside surface 28 of the guard member 25 so as to generate ultrasonic mechanical vibrations. The transducer 65 may be of a commercial type as of a piezoelectric element coupled to the guard member 25 in energy transmission relation thereto as by a bonding material or epoxy material.

The ultrasonic motor 65 may also be coupled to the guard member 25 on an exterior surface thereof. The ultrasonic motor may be of a variety of configurations such as, electrodynamic, piezoelectric or magnetostrictive, however, for the operating range of frequencies and space available most desirable for an ultrasonic shaver, the transducer 65 includes an element 66 which is preferably of the piezoelectric type. The transducer 65 produces ultrasonic .vibration which effects elastic vibration of the guard member 25 at a high frequency of at least 5,000 cycles per second with peak accelerations of the order of at least l,Og whereby the frictional resistance to the hair 50 or skin 52 is quantitatively reduced so that the force to permit relative movement may be of a relatively small magnitude. As defined herein the term ultrasonic is intended to include vibrations in the range of 5,000 to 1,000,000 cycles per second and preferably in the range of 15,000 to 100,000 cycles per second.

The vibration may be continuous to vibrate the entire guard in phase, or due to the thinness of the guard member 25 zones of vibratory motion may be produced either in a predetermined spacing or by random vibration. Accordingly the generator means 62 may be of the type adapted to continuously vary the frequency of vibration of the transducer or ultrasonic motor 65 so as to vary the position of the zones of vibration therealong so as to prevent substantial concentration or heat buildup along the surface 26 at any location thereon. Preferably the guard member 25 is vibrated in phase but due to the thinness of the guard member it may vibrate having loops in certain areas and nodes (dead spots) in other areas. If a substantial portion of the guard member 25 is actively vibrated the beneficial effects will still be obtained except that by sweeping the frequency of vibration the nodal and loop areas are continuously changed at an ultrasonic rate such that for all intentional purposes each portion of the guard member 25 is actively vibrated.

Due to the thickness of the guard member 25 the vibratory energy produces motion having generally a component that is both normal to and parallel with the outer surface 26 such that the motion at each aperture 32 is such that the wall 34 moves from the phantom line to the solid line of the wall at a rate say at 50,000 cycles per second. In this manner the wall edge 36 likewise shifts in position such as that seen in FIG. 3. The end 58 of certain hairs may be at the edge 36 or beyond and by a normal pass of the razor the hairs 50 would not enter any aperture 32. But, when the guard member 25 is made to vibrate as seen with respect to FIG. 4 those hairs in the vicinity of the aperture tend to glide into a respective aperture.

Although the complete theory is not understood at this time it is possible that the tips 55 of the hairs 50 may also be induced to flexurally vibrate so that it might wiggle its way into a respective aperture. In any event as seen in FIG. 5 those hairs 50 that would not have entered an aperture 32 are respectively positioned therein. It is appreciated that the vibration pattern may have components of vibration substantially parallel to the surface, norm'al thereto as seen in FIG. 6, as well as elliptical, torsional, orbital etc.

By coupling one or more transducers 65 to the inner surface 28 of the guard member 25 a plurality of zones of vibratory motion may be obtained due to the thinness of the guard member 25, with the spacing of the zones being such that each hair 50 is substantially always exposed to zones of vibratory motion. It is possible to vibrate the entire support surface 26 in a certain phase relationship, but with respect to the utility it is deemed desirable that as long as there are sufficient number of zones of motion, having a component in the plane normal and/or parallel to the direction of movement of the skin 52, that the friction reduction effect will be sufficient to permit the hairs 50 to extend into the apertures 32 at a rapid speed. The magnitude of vibration as seen in FIG. 6, in that the outer surface 26 is moving from between the solid line, at the end of a vibratory cycle, to the phantom surface line at the other end of the vibratory cycle, approximately 50,000 cycles per second, at say an amplitude of vibration of 0.0002 inch, which essentially means that it is continuously falling away from the skin surface 54 of the skin 50 at a quicker rate than the gravitational force of gravity such that in a sense only upon the outer surface 26 reaching its peak height is it momentarily in contact with the skin 54. This phenomenon is a unique property of ultrasonic vibratory mechanical energy which can be utilized in a razor so as to permit it to move relative to the skin with a minimum of resistance. Controlling the coefficient of friction between the skin 52 and guard member 25 is obtained by varying the amplitude and/or frequency of vibration which makes it possible to control the degree of friction reduction, which may be controllable by the individual user of the shaver if provision is made therefore.

It has been found that, by reason of the vibrations in a plane perpendicular to the direction of the static force againsst the face, the frictional resistance of the guard member 25 to movement on the skin 52 is very substantially reduced. A possible explanation of this observed phenomenon is that the extremely high acceleration of the upper surface 26 of the guard member 25 resulting from the vibrations causes only a relatively small sliding friction to be present between the engaged skin 54 and the guard surface 26. Thus, even though the skin 54 is stationary the guard member 25 nevertheless is easily displaceeble with respect thereto.

As illustrated in FIG. 6, the frequency of the vibrations between the solid and phantom line at the free end portion of the guard member 25 may be in the range from to 1,000 kilocycles per second,'while the amplitude of the vibrations is selected within the range from approximately 0.00001 to 0.010 inch so as to insure the introduction of vibratory energy sufficient to substantially minimize the frictional resistance of the skin surface 54 to the advancement of the guard member 25. Accordingly by manually moving the ultrasonically vibrating guard member 25 relative to the hairs 50 a substantial area may be shaved.

The converter 62 is illustrated to be of a size that can be plugged within a wall outlet by means of its prongs 66 and connected by cable 68 to the housing 12 and inturn connected in a conventional manner to the electric motor 18 used to oscillate the cutter member 30 in the direction of double headed arrow 70 to obtain the cross movement for cutting the hairs extending therethrough. The converter 62 may also be of the battery powered type and adapted for incorporation within the housing 12, and may be of the type disclosed in a copending patent application Ser. .No. 1 19,298, filed Feb. 26, 1971 and assigned to the assignee of the present invention. The converter 62 is connected to the ultrasonic motor 65 by

leads

72 and 74 which are connected, as by soldering, to both sides. of the crystal element, in a conventional manner. The dimensional relationship of crystals 65 and associated guard member 25 are designed to be of a certain frequency. The switch 20 is wired to both motor 18 and the converter 62, and inturn motor 65 such that when placed in its on position we have simultaneous gross movement of the cutter member 30 in the direction of arrow 70 and guard member 25 at an ultrasonic rate.

FIGS. 7 and 8 illustrate another embodiment of the invention in which the electric razor 10a has the cutter member 30a ultrasonically energized by the transducer means 65a. Mounted on the cutter member 30a are piezoelectric elements 66a and secured by a bonding agent or other means to the bottom surface 43a of the base 42a of the cutter member 30a. A back element 80a may be secured to the rear surface of the transducer element 66a by a bonding agent 82a with power leads 72a and 74a secured to the transducer element 66a and rear block 80a or opposite sides of the transducer element 66a. The

wires

72a and 74a are in turn connected to the converter 62a which in this embodiment is contained within the housing 12a. As hereinafter explained since the static force required to move the cutter member 30a relative to the guard member 25a is substantially reduced then the electric motor 18a used to oscillate the cutter member 300 relative to the guard member 25a may be reduced in power and in turn size. Obviously the cutter member may be the rotary type or other type generally used and the inventors have merely utilized the oscillating type for purpose of illustrating the present invention. Furthermore the transducer means 65a may be of various shapes and sizes and coupled to the cutter member on various locations thereon. It is appreciated that there exists the possibility of forming all or substantially all of the cutter member from a transducer material itself. Although wires are shown as coupling the electrical energy to the transducers it is appreciated that contacting electrical arms may also be used as described in the above referenced co-pending patent application all of which subject matter is incorpoated herein by reference.

The electrical current is obtained by the plug 84a coupled to a wall outlet by prongs 85a and connected to a power cable 68a. When the switch 20a is placed in its on position the cutter member 30a will vibrate or oscillate in the direction of arrow a and at the same time at an ultrasonic rate as hereinafter discussed with respect to FIGS. 9 and 10.

The shaving head assembly 15a includes the outer frame 24a which comprises the outer shearing guard 25a in the form of a perforated comb and an inner cutter assembly 30a. The guard member 25a in this embodiment is also in the form of a perforated comb of a thin flexible member having an outer surface 260 and spaced apart inner surface 280 with a plurality of apertures 32a extending therebetween with each aperture 32a having an inclined wall 340 merging with the respective inner and outer surfaces at an edge 36a and which is secured to a supporting frame whereby the comb 25a assumes an inverted U-shape. In order to shear hair which extends through the perforations 32a the guard member 25a includes a plurality of cutters or cutting blades 40a which are carried by the base 42a and having a front edge 44a for shearing engagement with the underside surface 280 of the comb 25a. The structure of the guard member 25a and the inner cutter assembly 25a made up of the cutting blades 40a base 42a and supporting shaft 460 coupled to the motor 18a, and extending from the bottom face 43a with a spring 48a biasing the front end 44a of the blades 400 against the inner surface 28a of the guard member 25a is well known in the art, and their action need not be described in detail herein.

The cutter member 25a having a plurality of individual cutters 40a is already well known in the art and cooperates with the guard member or shear foil 25a that overlies the cutters 40a which latter can be constructed in a known manner of a plurality of cutter blades mounted on or integral with a frame 42a or the like. The guard member 25a is a very thin foil which is provided with a great number of apertures 32a through which the hair or beard stubble 50a can come into contact with the cutters 40a respectively. In the illustrated embodiment the shear foil 250 may be connected with the outer frame 24a in any conventional manner and may be of the removable type well known in the art.

At their outer ends, that is, those which are connected with the outer wall of the housing, the guard member 25a is so mounted in known manner as to have a certain freedom of movement so that it can conform itself to the contours and movements of the cutters 40a which are pressed against the guard member 25a from below under the biasing action of spring 48a, which is associated with the cutters 40a.

One aspect of the invention is the obtainment of the effects illustrated in FIGS. 3 6 by introducing the vibratory motion at an ultrasonic rate but doing so through the intermittant contact of the output edge 44a of the blades 40a when the cutter member is ultrasonically vibrated in this manner we also produce the friction reduction effect to obtain the uptake in rate for the hairs 50a extending from the skin 52a and having a front edge 55a, to enter the apertures 32a of the guard member 25a. In this manner the resistance or friction of the inner wall 34a of the aperture 32a to the hair 50a is substantially reduced to permit a ready entrance of the hair 50a within respective apertures 320. In this manner there is an increase in the rate of uptake of the hairs 5011 through the apertures 320.

Accordingly, the vibration generating means 600 of this embodiment also includes a vibration generator 620 which may be of an adjustable type to vary frequency, power, and amplitude, and one or more ultrasonic motors or transducers 65a coupled to the underside surface 43a of the cutter member 30a so as to generate ultrasonic mechanical vibrations. The transducer 65a may be of a commercial type as of a piezoelectric element coupled in energy transmission relation.

The transducers 65a produce ultrasonic vibration which effect elastic vibration of the cutter member 30a at a high frequency of at least 5,000 cycles per second with peak accelerations of the order of at least 1,000g whereby the frictional resistance to the movement of the blades 400 relative to the surface 28a is quantitatively reduced so that the force to permit relative movement may be ofa relatively small magnitude. This permits the use of a less powerfull motor 18a than is normally required.

By coupling one or more transducers 65a to the lower surface 43a of the cutter member 30a each blade 42a is vibrated over a given amplitude and stroke such that the output edge of each blade 40a is out of contact with the surface 2811 a substantial portion of the time as illustrated in FIGS. 9 and 10. The magnitude of friction reduction is in part related to the actual amplitude of vibration as seen in FIG. 10A, in that the outer surface 44a is moving from between a normal rest position indicated by the solid line to the phantom surface line at each end of the vibratory cycle, approximately 50,000 cycles per second, at say an amplitude of vibration of 0.0002 inch, which essentially means that it is continuously falling away from the guard surface 43a of the guard member 25a at a quicker rate than the force of gravity would produce such that in a sense only the outer edge 44a reaching its peak height is it momentarily in contact with the surface 28a. This phenomenon is a unique property of ultrasonic vibratory mechanical energy which can be utilized in a razor so as to permit it to move relative to the guard member 25a with a minimum of resistance. Controlling the coefficient of friction between the cutter member 30a and guard member 25a is obtained by varying the amplitude and/or frequency of vibration which makes it possible to control the degree of friction reduction, which may be controllable by the individual user of the shaver if provision is made therefore.

It has been found that, by reason of the vibrations in a plane perpendicular to the direction of the static force against the guard member 25a by the skin 52a the frictional resistance of the cutter member 30a to movement of the guard member 25a is very substantially reduced. A possible explanation of this observed phenomenon is that the extremely high acceleration of the upper surface 44a of the cutter member 30a resulting from the vibrations causes only a relatively small sliding friction to be present between the engaged cutter edges 44a and the guard surface 28a. Thus, even though the guard member 26a is stationary the cutter member 30a nevertheless is easily displaceable with respect thereto.

As illustrated in FIG. 10, the frequency of the vibrations between the solid and phantom line at the free end portion of the cutter member 25a may be in the range from 5 to 1,000 kilocycles per second, while the amplitude of the vibrations is selected within the range from approximately 0.00001 to 0.005 inch so as to insure the introduction of vibratory energy sufficient to substantially minimize the frictional resistance to the reciprocation of the cutter member 30a. A general guide to design is, that the higher the frequency the smaller is the vibration amplitude needed to produce the desired friction reduction.

Accordingly, in the embodiment of FIGS. 7 and 8 the cutting edges 440 are allowed to reciprocate at an ultrasonic frequency, and will approach and recede from the surface 28a to which it is applied many thousands of times every second. Let us follow the blade edge 44a during one complete cycle of reciprocation. Let us say we start at the point where it is in contact with the surface 28a and instantly it recedes from that surface due to the oscillation and it continues to recede for a half cycle a total distance defined by the strokes, with the amplitude A, defining one half of the stroke, of the motor as seen in FIG. 10, during the next half cycle it again approaches the surface 28a coming in contact once again at the completion at the second half of the cycle. Now this whole operation has taken no more than l/50,000 ofa second as our ultrasonic motors frequency is 50,000 vibrations per second. In this incredibly short period of time the acceleration of the output edge of the motor is so high that the surface being pressed against remains out of contact with the edge during most of the cycle. From this it follows that that a blade member 30a being used in this manner will be out of contact with the guard member 25a practically all the time with the result that there is set up what is called a relatively impenetrable zone of motion. The consequence is that the high frequency oscillating blade 40a automatically runs most of the time on an air film and the surface friction is greatly reduced. This produces an electric razor in which a smaller force is required to obtain the necessary gross movement as illustrated by arrow a of the cutter member 30a.

This is one outstanding property realizable in an ultrasonic razor. In addition, it is well known that the dynamic net force operating in a mechanical system is equal to mass times acceleration, this is called Newtons second law of motion. A consequence of this simple relationship is that when the acceleration is extremely high (as in an ultrasonic motor) then the dynamic force capability of such a motor is greatly magnitied. This means that a blade edge 44a of the cutter member 300 due to its reciprocation is able to penetrate hair with a high dynamic force. Hence, in shaving terms such a shaver greatly reduces the drag ordinarily incurred in actual cutting of hair at the same time.

Once the blade has entered a given hair the high frequency or reciprocation reduces the friction that the blade encounters in passing through the hair. These two factors add up to the potential that the hair extending through the guard member is cut clean through without the sharp points referred to above in connection with standard methods of electric shaving due to the extreme ease with which the hair is bent. Accordingly, as we endow the blade edge 44a of the cutter member 30a with the right kind of reciprocating motion, whatever good qualities the blade edge had prior to reciprocation it will continue to have with the addition of the greater enhanced improvements described above. Further the force, F, required to oscillate the cutter as indicated by the arrow will be substantially reduced.

FIG. A is an enlarged view in schematic form to illustrate how the combined actions of friction reduction and vibratory energy are combined in one process.

First, the friction reduction effect might be explained by referring to the working surface 44a of the vibrating blade 40a when said vibrator is at rest, i.e., when the transducer is not energized. When blade 40a is vibrated in the plane normal to the surface 280 of the guard a while moving in the direction as indicated by arrow 70a, it will have a direction or component of vibratory motion normal to the plane of said moving edge 44a. In accordance with the present invention, it has been found that a frequency range about 5,000 to 100,000 cycles per second and an amplitude of vibration from 0.0001 inch to 0.010 inch permits the known beneficial effects of friction reduction to play a role in the shaving process.

The vibrating blade a will vibrate with a stroke, S, in the direction of motion of the double-headed arrow 90a. This stroke creates the zone of motion as indicated by the shading produced by the spaced parallel solid and dash lines in FIG. 10A. The lines emanating on either side of the working surface 44a which is also the plane of maximum velocity, V in a given cycle of vibration, are initially spaced farthest apart, and as they approach the maximum excursion that the cutter member traverses in one cycle, they diminish in spacing to indicate that the vibratory velocity has diminished. Thus, the shading is the closest at points D where the acceleration is the highest, A and where the velocity is the lowest. Actually, a point, P, on the cutter surface 44a obeys a simple equation as follows:

Displacement of P X A sin 2 ft Speed of P 21rfA cos 217 ft Acceleration of P a 41r f" A sin 21rft 411' f F Frequency of vibration S Stroke of vibration A S/2 amplitude of vibration Thus we have Peak displacement A $65 Peak speed 21rfA 'rrfS V,,,,,,,

Peak acceleration 41r f A 21rfV,,,,,, We can comput a table of peak values for Equations I and II and we get the following approximate peak accelerations:

Frequency (kilocycles per second) 50 kc. 20 kc. 10 kc. 5 kc. Peak displacement A (in.) 0.002 0.002 0.002 0.002 Peak speed V... (feet per second) 5O 20 I0 5 Peak acceleration Am. (No. ofg's) 107,000 75,000 18.750 4.690

Thus is seen that we have a high reciprocal rate process of relatively low peak speed, but with very large peak accelerations.

In order for the separation of the guard member and cutter member to occur during vibration, we must know the acceleration which the static force against the guard the spring 480 tends to produce in the urging together of the two members if the cutter member against the guard has a weight W, then the static force, F,,, will produce in the weight, W, an acceleration given by For example, if we have a 0.10 lb guard member and there is a static force of 5 lbs., then and the accelerations shown above are sufficiently high to guarantee separation of the guard member and cutter member during compression. However, even in cases where complete separation does not occur, there is still a substantial beneficial friction reduction effect arising from the presence of the vibrations.

FIGS. 11 and 12 illustrate another embodiment of the invention in which the electric razor 10b has the cutter member 30b and the guard member 25b ultrasonically energized by the vibration generating means 60b. Mounted on the cutter member 30b are piezoelectric elements 66b and secured by a bonding agent or other means to the bottom surface 43b of the base 42b of the cutter member 30b. A back element b may be secured to the rear surface of the transducer element 66b by a bonding agent 82b with power leads 72b and 74b secured to the transducer element 66b and rear block 80b or opposite sides of the transducer element 66b. The wires 72b and 74b are in turn connected to the converter 62b which in this embodiment is contained within the housing 12b. As explained herein since the static force required to move the cutter member 30b relative to the guard member 25 b is substantially reduced then the electric motor 18b used to oscillate the cutter member 30b relative to the guard member 25b may be reduced in power and in turn size. It is appreciated that there exists the possibility of forming all or substantially all of the cutter member from a transducer material itself. Although wires are shown as coupling the electrical energy to the transducers it is appreciated that contacting electrical arms may also be used as described in the above referenced co-pending patent application all of which subject matter is incorporated herein by reference.

The electrical current is obtained by the plug 84b coupled to a wall outlet by prongs 85b and connected to a power cable 68b. When the switch 20b is placed in its on position the cutter member 30b will vibrate or oscillate in the direction of arrow 70b and at the same time at an ultrasonic rate.

The shaving head assembly 15b includes the outer frame 24b which comprises the outer shearing guard 25b in the form of a perforated comb and an inner cutter assembly 30b. The guard member 25b in this embodiment is also in the form of a perforated comb of a thin flexible member having an outer surface 26b and spaced apart inner surface 28b with a plurality of apertures 32b extending therebetween with each aperture 32b having an inclined wall merging with the respective inner and outer surfaces and which is secured to a supporting frame whereby the comb 25b assumes an inverted U-shape. In order to shear hair which extends through the perforations 32b the guard member 25b includes a plurality of cutters or cutting blades 40b which are carried by the base 42b and. having a front edge for shearing engagement with the underside surface 28b of the comb 25b. The structure of the guard member 25b and the inner cutter assembly 25b made up of the cutting blades 40b base 42b and supporting shaft 46b coupled to the motor 18b and extending from the bottom face of 43b with a spring 48b biasing the front end of the blades 40b against the inner surface 28b of the guard member 25b is well known in the art, and their action need not be described in detail herein.

To produce the friction reduction effect to obtain the uptake in rate for the hairs extending from the skin to enter the apertures 32b of the guard member 25b, ultrasonic vibration generating means 60b is utilized and is coupled to the guard member 25b so as to apply ultrasonic energy to the outer surface to produce mechanical vibrations having a component substantially normal and/or parallel to the outer surface 26b. In this manner the resistance or friction of the inner wall of the apertures 32b to the hairs is substantially reduced to permit a ready entrance of the hair within respective apertures 32b. In this manner there is an increase in the rate of entry of the hairs through the apertures 32b.

Accordingly, the vibration generating means 60b includes one or more ultrasonic motors or transducers 65b coupled to the underside surface 28b of the guard member 25b so as to generate ultrasonic mechanical vibrations, wires 72b and 74b connect the transducer element 66b to the converter 62b. The transducer 65b may be of a piezoelectric element coupled to the guard member 25b in energy transmission relation thereto as by a bonding material or epoxy material.

FIGS. 13 and 14 illustrate another embodiment of an electric razor 100 of the invention in which the vibration generating means 60c includes a vibration generator 62c contained in the housing 12c and an ultrasonic motor 65c which is designed to vibrate the guard member 300 to produce both gross motion as indicated by the arrow 70c and ultrasonic motion as indicated by the arrow 92c in a direction substantially parallel to the outer surface 26c and another component as indicated by arrow 90c having a component substantially normal thereto.

The ultrasonic motor 65c may in part be generally of the type as described in a co-pending patent application Ser. No. 38,149, filed May 18, 1970, assigned to the assignee of the present application, and the inventor thereof is one of the inventors of the present invention. The entire subject matter of said above copending application being incorporated herein by reference.

The electrical current is obtained by the plug 840 coupled to a wall outlet by prongs 85c and connected to a power cable 68c. When the switch c is placed in its on position the cutter member 300 will vibrate or oscillate in the direction of arrow 70c and at the same time at an ultrasonic rate as hereinafter discussed.

The shaving head assembly 15c includes the outer frame 24c which comprises the outer shearing or guard member 250 in the form of a perforated comb and an inner cutter assembly 300. The guard member 25c in this embodiment is also in the form of a perforated comb ofa thin flexible member having an outer surface 26c and spaced apart inner surface 280 with a plurality of apertures 32c extending therebetween with each aperture 320 having an inclined wall merging with the respective inner and outer surfaces and which is secured to a supporting frame whereby the comb 25c assumes an inverted U-shape. In order to shear hair which ex tends through the perforations 320 the guard member 25c includes a plurality of cutters or cutting blades 40c which are carried by the base 420 and having a front edge 446 for shearing engagement with the underside surface 28c of the comb 250. The inner cutter assembly 30 is made up of the cutting blades 40c base 42c and supporting shaft or transmission member 460 coupled to the motor 65c, and extending with the blades 400 against the inner surface 280 of the guard member 250. In th illustrated embodiment the shear foil 250 may be connected with the outer frame 24c in any conventional manner and may be of the removable type well known in the art.

Accordingly, the vibration generating means 60c of this embodiment also includes a vibration generator 62c which may be of an adjustable type to vary frequency, power, and amplitude, and the ultrasonic motor 65c coupled to the underside surface 430 of the cutter member 30c so as to generate ultrasonic mechanical vibrations.

The transducers 65c produce ultrasonic vibration which effect elastic vibration of the cutter member 30c at a high frequency of at least 5,000 cycles per second with peak accelerations of the order of at least 1,000g whereby the frictional resistance to the movement of the blades 400 relative to the surface 38c is quantitatively reduced so that the force to permit relative movement may be of a relatively small magnitude.

The motor 650 contained within the housing 12c has the transmission member or vertical shaft 46c extending therefrom and coupled to the base 420 at the surface 43c. The casing 12c has a horizontal wall portion 92c with an opening 940 and a similar wall 96c associated therewith and extending from the outer frame 240. A flexible closure is provided having a neck portion 98c in surrounding relation to the transmission member 460 to accept the gross motion and prevent cut hair from entering the inner casing and having an extending flat body portion 100a a secured to the wall 960.

The motor 650 at its lower end is comprised ofa pair of spaced apart elongated sections 102C and Me with coupling means in the form of a support member 1050 maintaining the sections in a relatively fixed position. The front end of section l04c has a contoured neck portion 1086 that merges with the transmission member 46c. Supporting means in the form of elastic members l10c are provided in contact with the casing wall 1 12c which may have a complimentary seat therefor. In this manner, if the elastic members 1100 are designed as springs of a stiffness such that the 60 cycle A.C. force at the low frequency motor 18c will vibrate the entire ultrasonic motor 65c, rather than relying on the simultaneous bending of the transmission member 460 with the high frequency and the low frequency alternating current source.

The motor 650 further includes transducer means extending between the sections 102C and 104c in the form of spaced apart crystal elements 1120 and 114C with a spaced metallic block 116a positioned therebetween with respective end members 1186 and 1200 with a threaded fastener 1120 in the form of a blot having a head 1240 extending therethrough. A lug 1250 is contained below the head 124C with electrical lead 72c connected to spacer block 1160 and ground lead 74c to the lug 1250, which leads are inturn connected to the converter in a convertional manner.

Accordingly the motor 65c inparts to the cutters 40c the ultrasonic mechanical vibrations and the motor 180 as seen in FIG. 14 imparts the gross low frequency vibratory motion to the blades 400 which movement is at least equal to the diameter of the aperture 32c to sever the hairs extended through surface 260 and beyond surface 28c. Although various means are available of obtaining the gross motion, one such form is illustrated herein, and as seen in FIG. 14 consists of magnets 126C and 128C secured to the shaft 640 on opposite sides thereof and polarized in opposite directions. Motor supports 130s and 132a extend outwardly from the casing 120 in horizontal alignment with the magnets 126C and 1280. An iron core or members 1340 and 1360 are secured at the front of motor supports l30c and 132C in spaced relation to the magnets 126c and 128C to permit gross motion as the alternating low frequency current, i.e., 60 cycle per second, flows through the coil 138a in surrounding relation to the supports 130C and 123c. A choke 140a is connected between the coil 138C and the wire 72c to keep the high frequency current out of this circuit. It is appreciated tha the motor 180 has been illustrated in a schematic form. The motor will induce oscillation in the arm 46c and inturn the necessary gross motion to the cutter member 300. Depending upon the motor mounting and thickness of the shaft 460 either the complete motor will oscillate or just the shaft 466.

CONCLUSION From the foregoing, it will be evident that the application of ultrasonic energy to an electric dry shaver is effective to provide a significantly improved shaving action. In accordance with the present invention, relatively small amplitude vibrations are employed in the guard and/or cutter for inducing various novel results. The instrument is perfectly safe, whereby it may be regularly employed by men and women throughout the world without any special training or skill.

The reduction of the coefficient of friction between the hairs and guard apertures provides for an increase of the rate of entrance of the hairs therein to obtain a quicker shave which is most important for many individuals. In addition, a superior shaving action is provided by the high accelerations present at the cutter blades.

It will be seen therefore, that in accordance with the invention a method of utilizing ultrasonic energy for improved shaving is provided, together with a novel form of apparatus by means of which the process may be carried out. Although only a few general forms of the latter has been illustrated, it will be recognized that many modifications thereof may be made without departing from the spirit of the invention. For example,

the shape and configuration of the ultrasonic motor may be changed radically from that shown and different forms of coupling of the energy to the guard or cutter may be provided. Moreover, the casing as illustrated accommodates a transistorized oscillatory power supply instead of merely including a connection to an external source. In addition the guard and cutter element may take various configurations, such that both are purchased together and thereafter replaced as a unit. In addition the blade may be mounted in a shaving instrument in which the cutter is rotated as is presently the case in electric shaving instruments, but at the same time ultrasonically vibrated in accordance with the present invention. Also, in addition, although only electric means have been described to produce the low frequency reciprocal motion of the cutter blades, it will be evident tha mechanical type of reciprocator might be just as well employed, such, for example, as a handwound spring type motion, or a simple kinematical linkage assembly whereby the power of the shavers hand, when moving the shaver over the face, will cause relative gross movement of the cutter elements and the flexible guard screen.

We claim:

1. A method of shaving hair comprising the steps of A. positioning adjacent the hairs to be shaved a guard member capable of supporting vibrations in the ultrasonic range and having a plurality of apertures extending from an outer surface adapted for engagement with the skin of the user to an inner surface,

B. moving a cutter member relative to the inner surface of said guard member to sever the hairs extending through said apertures, and

C. inducing vibrations in said guard member at a frequency in the ultrasonic range to increase the rate of uptake of the hairs through said apertures.

2. The method of shaving as defined in claim 1, and further including the step of moving said ultrasonically vibrating guard member relative to the hairs to shave a substantial area thereof.

3. The method of shaving as defined in claim 1, wherein said guard member is vibrated at a frequency between about 5,000 and 1,000,000 cycles per second.

4. The method of shaving as defined in claim I, wherein said guard member is vibrated at a frequency between about 15,000 and 100,000 cycles per second.

5. The method of shaving as defined in claim 1, wherein said guard member is manually moved relative to the skin surface.

6. The method of shaving as defined in claim 1, wherein the amplitude of vibration of said guard member is sufficient to obtain a reduction of friction between the relative movement of the guard member and the hairs.

7. The method of shaving as defined in claim 1, wherein the amplitude of vibration of said guard member is sufficient to obtain a reduction of friction between the relative movement of the guard member and said cutter member.

8. The method of shaving as defined in claim I, wherein said ultrasonic vibrations in said guard member have a component of motion substantially normal to said outer surface.

9. The method of shaving as defined in claim 1, wherein said ultrasonic vibrations produce peak accelerations of the order of at least l,000g in said guard member.

It). The method of shaving as defined in claim 1, and further including the step of varying the frequency of vibration so as to vary the zones of motion along said guard member to continuously have the hairs received through said apertures.

11. A method of guard hair comprising the steps of A. positioning adjacent the hairs to be shaved a guard member capable of supporting vibrations in the ultrasonic range and having a plurality of apertures extending from an outer surface adapted for engagement with the skin of the user to an inner surface,

B. moving a cutter member relative to the inner surface of said guard member to sever the hairs extending through said apertures,

C. inducing vibrations in said shaving member at a frequency in the ultrasonic range between about ,000 and 1,000,000 cycles per second tp produce peak accelerations of the order of at least 1,000g in said guard member, wherein the amplitude of vibration of said guard member is transmitted to said cutter member to reduce the force required to obtain relative movement therebetween and to increase the rate of uptake of the hairs through said apertures, and

D. moving said ultrasonically vibrating guard member relative to the hairs to shave a substantial area thereof.

12. The method of shaving as defined in claim 11, wherein the amplitude of vibration of said guard member is sufficient to obtain a reduction of friction between the relative movement of the guard member and the hairs.

13. The method of shaving as defined in claim 11, wherein said ultrasonic vibrations in said guard member have a component of motion substantially parallel to said outer surface.

14. The method of shaving as defined in claim 11, wherein said ultrasonic vibrations in said guard member have a component of motion substantially normal to said outer surface.

15. A method of shaving hair comprising the steps of A. positioning adjacent the hairs to be shaved a guard member capable of supporting vibrations in the ultrasonic range and having a plurality of apertures extending from an outer surface adapted for engagement with the skin of the user to an inner surface,

C. simultaneously inducing vibrations in said cutter member at a frequency in the ultrasonic range to enhance the cutting effectiveness of said cutter member.

16. The method of shaving as defined in claim 15, and further including the step of moving said guard member relative to the hairs to shave a substantial area thereof.

17. The method of shaving as defined in claim 15, wherein said cutter member is vibrated at a frequency between about 5,000 and l,000,000 cycles per second.

18. The method of shaving as defined in claim 15, wherein said cutter member is vibrated at a frequency between about 15,000 and 100,000 cycles per second.

19. The method of shaving as defined in claim 15, wherein said guard member is manually moved relative to the skin surface.

20. The method of shaving as defined in claim 15,

5 wherein the amplitude of vibration of said cutter member is transmitted to said guard member to increase the rate of uptake of the hairs through the apertures.

21. The method of shaving as defined in claim 15, wherein the amplitude of vibration of said cutter member is sufficient to obtain a reduction of friction between the relative movement of the guard member and the cutter member.

22. The method of shaving as defined in claim 15, wherein said ultrasonic vibrations in said cutter member have a component of motion substantially normal to said inner surface.

23. the method of shaving as defined in claim 15, wherein said ultrasonic vibrations produce peak accelerations of the order of at least 1,000g in said cutter member.

24. A method of shaving hair comprising the steps of A. positioning adjacent the hairs to be shaved a guard member capable of supporting vibrations in the ultrasonic range and having a plurality of apertures extending from an outer surface adapted for engagement with the skin of the user to an inner surface,

B. moving a cutter member relative to the inner surface of said guard member to sever the hair extending through said apertures,

C. simultaneously inducing vibrations in said cutter member at a frequency in the ultrasonic range at a frequency between about 5,000 and 1,000,000 cycles per second to produce peak accelerations of the order of at least 1,000g in said cutter member to enhance the cutting effectiveness of said cutter member, and

D. moving said guard member relative to the hairs to shave a substantial area thereof.

25. The method of shaving as defined in claim 24, wherein said ultrasonic vibrations in said cutter member have a component of motion substantially normal to said inner surface.

26. The method of shaving as defined in claim 24, wherein said guard member is manually moved relative to the skin surface.

27. The method of shaving as defined in claim 24, wherein the amplitude of vibration of said cutter member is sufficient to obtain a reduction of friction between the relative movement of the guard member and the hairs.

28. The method of shaving as defined in claim 24, wherein the amplitude of vibration of said cutter member is sufficient to obtain a reduction of friction between the relative movement of the guard member and said cutter member.

29. The method of shaving as defined in claim 24, wherein said cutter member has a plurality of blades each vibrating at said ultrasonic rate.

30. A method of shaving hair comprising the steps of A. positioning adjacent the hairs to be shaved a guard member capable of supporting vibrations in the ultrasonic range and having a plurality of apertures extending from an outer surface adapted for engagement with the skin of the user to an inner surface,

B. inducing vibrations in said guard member at a frequency in the ultrasonic range to increase the rate of uptake of the hairs through said apertures,

C. moving a cutter member relative to the inner surface of said guard member to sever the hairs extending through said apertures, and

D. simultaneously inducing vibrations in said cutter member at a frequency in the ultrasonic range to enhance the cutting effectiveness of said cutter member.

31. The method of shaving as defined in claim 30, and further including the step of moving said ultrasonically vibrating guard member relative to the hairs to shave a substantial area thereof.

32. The method of shaving as defined in claim 30, wherein said members are vibrated at a frequency between about 5,000 and 1,000,000 cycles per second.

33. The method of shaving as defined in claim 30, wherein said members are vibrated at a frequency between about 15,000 and 100,000 cycles per second.

34. The method of shaving as defined in claim 30, wherein said guard member is manually moved reative to the skin surface.

35. The method of shaving as defined in claim 30, wherein the amplitude of vibration of said guard member is sufficient to obtain a reduction of friction between the relative movement of said guard member and the hairs.

36. The method of shaving as defined in claim 30, wherein the amplitude of vibration of said guard member is sufficient to obtain a reduction of friction between the relative movement of said guard member and said cutter member.

37. The method of shaving as defined in claim 30, wherein said ultrasonic vibrations in said guard member have a component of motion substantially normal to said outer surface.

38. The method of shaving as defined in claim 30, wherein said ultrasonic vibrations produce peak accelerations of the order of at least 1,000g in said guard member.

39. The method of shaving as defined in claim 30, and further including the step of varying the frequency of vibration so as to vary the zones of motion along said guard member to continuously have the hairs received through said apertures.

40. An electric razor comprising,

A. a guard member having a plurality of apertures extending therethrough,

B. a cutter member positioned on one side of said guard member substantially adjacent thereto,

C. means for moving said cutter member to obtain gross movement across said apertures, and

D. means for simultaneously vibrating said guard member at an ultrasonic rate to increase the rate of uptake of the hairs through said apertures.

41. An electric razor as defined in claim 40, wherein said guard member is vibrated at a frequency between about 5,000 and 1,000,000 cycles per second.

42. An electric razor as defined in claim 40, wherein said guard member is vibrated at a frequency between about 15,000 and 1,000,000 cycles per second.

43. An electric razor as defined in claim40, wherein the amplitude of vibration of said guard member is sufficient to obtain a reduction of friction between the relative movement of said guard member and the hair.

44. An electric razor as defined in claim 40, wherein the amplitude of vibration of said guard member is sufficient to obtain a reduction of friction between the relative movement of said guard member and said cutter member.

45. An electric razor as defined in claim 40, wherein said ultrasonic vibrations in said guard member have a component of motion substantially normal to its outer surface.

46. An electric razor as defined in claim 40, wherein said ultrasonic vibrations produce peak accelerations of the order of at least 1,000g in said guard member.

47. An electric razor as defined in claim 40, wherein said means for vibrating said guard member is adapted to continuously vary the frequency of vibration so as to vary the position of the zones of motion along the guard member so as to continuously have the hairs received through said apertures.

48. An electric razor as defined in claim 40, wherein said means for vibrating said guard member at an ultrasonic rate includes transducer means coupled thereto.

49. An electric razor as defined in claim 48, wherein said transducer means includes a piezoelectric element coupled to said guard member in energy transferring relation thereto.

50. An electric razor as defined in claim 48, wherein said means for vibrating said guard member at an ultrasonic rate includes converter means for transferring electric current to an ultrasonic rate.

51. An electric razor as defined in claim 50, wherein said converter is contained in a housing adapted to be plugged into an electric outlet.

52. An electric razor as defined in claim 50, wherein .said converter is contained within the housing provided for containing the electric razor.

53. An electric razor as defined in claim 40, wherein said guard member is vibrated with peak accelerations of the order of at least 1,000g, whereby the frictional resistance to the motion between said guard member and cutter member is quantitatively reduced so that the force to obtain relative movement between said guard member and cutter member is ofa relatively small magnitude.

54. An electric razor as defined in claim 40, wherein said ultrasonic vibrations are transmitted to said cutter member to induce vibrations therein.

55. An electric razor as defined in claim 40 wherein said ultrasonic vibrations in said guard member have a component of motion substantially parallel to its outer surface.

56. An electric razor comprising,

A. razor housing means,

B. a guard member having an outer surface and an inner surface with a plurality of apertures extending therethrough and mounted in substantially fixed relationship to said housing means,

C. a cutter member having cutting elements .positioned adjacent the inner surface of said guard member within said housing means for substantial engagement of said cutting elements with said guard member,

D. means for moving said cutter member to obtain gross movement across said apertures for severing any hairs extending therethrough, and

E. means for simultaneously vibrating said guard member at an ultrasonic frequency rate between about 5,000 and 1,000,000 cycles per second to produce peak accelerations of the order of at least 1,000g in said guard member, wherein the rate of uptake of the hairs through the apertures is increased, said means including transducer means coupled to said guard member in energy transferring relation thereto and a converter for energizing said transducer means.

57. An electric razor as defined in claim 56, wherein said converter is contained in a housing adapted to be plugged into an electric outlet.

58. An electric razor as defined in claim 56, wherein said converter is contained within the housing provided for containing the electric razor.

59. An electric razor as defined in claim 56, wherein said cutter member has cutting elements extending therefrom for engagement with the guard member, and said ultrasonic vibrations are transmitted to said cutting elements to substantially reduce the coefficient of sliding friction between said guard member and said cutter member.

60. An electric razor comprising,

A. a guard member having a plurality of apertures extending therethrough,

C. means for moving said cutter to obtain gross movement across said apertures, and

D. means for simultaneously vibrating said cutter member at an ultrasonic rate.

61. An electric razor as defined in claim 60, wherein said means for vibrating said cutter member at an ultrasonic rate includes transducer means coupled thereto.

62. An electric razor as defined in claim 61, wherein said transducer means includes a piezoelectric element coupled to said cutter member in energy transfering relation thereto.

63. An electric razor as defined in claim 60, wherein said means for vibrating said cutter member at an ultrasonic rate includes converter means for transforming electric current to an ultrasonic rate.

64. An electric razor as defined in claim 63, wherein said ultrasonic rate is at a frequency between about 5,000 and 1,000,000 cycles per second.

65. An electric razor as defined in claim 63, wherein said ultrasonic rate is at a frequency between about 15,000 and 100,000 cycles per second.

66. An electric razor as defined in claim 63, wherein said converter is contained in a housing adapted to be plugged into an electrical outlet.

67. An electric razor as defined in claim 63, wherein said converter is contained within the housing provided for containing the electric razor.

68. An electric razor as defined in claim 60, wherein said cutter member has cutting elements extending therefrom for engagement with the guard member, and said ultrasonic vibrations are transmitted to said cutting elements to substantially reduce the coefficient of friction between said guard member and said cutter member.

69. An electric razor as defined in claim 60, wherein said cutter member is vibrated with peak accelerations of the order of at least 1000g, whereby the frictional resistance to the motion between said guard member and cutter member is quantitatively reduced to that the force to obtain relative movement between said guard member and said cutter member is of a relatively small magnitude.

70. An electric razor as defined in claim 60, wherein said ultrasonic vibrations are transmitted to the guard member to induce vibrations therein to increase the uptake of the hairs through said apertures.

71. An electric razor comprising,

A. razor housing means,

C. a cutter member having cutting elements positioned adjacent the inner surface of said guard member within said housing means for substantial engagement of said cutting elements with said guard member,

E. means for simultaneously vibrating said cutter member at an ultrasonic frequency rate between about 5,000 and 1,000,000 cycles per second to produce peak accelerations of the order of at least 1,000g in said cutter member and wherein the amplitude of vibration in said cutter member enhances the cutting effectiveness thereof and the coefficient of sliding friction between said guard member and said cutter member is substantially reduced, said means including transducer means coupled to said cutter member in energy transferring relation thereto and a converter for energizing said transducer.

72. An electric razor as defined in claim 70, wherein said transducer means for vibrating said cutter member at an ultrasonic rate includes:

a. a pair of sections,

b. transmission member one end coupled to said cutter member, and its other end coupled to one of said sections,

c. coupling means for maintaining said sections in a relatively fixed position relative to each other,

d. said transducer means extending between said sections for inducing high frequency vibrations in said transmission member in spaced relation to said ends, wherein vibrations are transmitted therethrough to induce vibrations at said end coupled to said cutter member, and

e. said means for moving said cutter member to obtain gross movement is coupled to said transmission member.

73. An electric razor as defined in claim 72, wherein said transducer means is of piezoelectric material.

74. An electric razor as defined in claim 72 wherein said transducer means includes a pair of piezoelectric disks with an electrode therebetween and spaced apart end members at least one of which is in engagement with said transmission member for transmitting vibrations thereto.

75. An electric razor as defined in claim 72, wherein said transducer means includes a central bolt which serves to compress said transducer means between said end members.

76. An electric razor as defined in claim 72, further including means for mounting said ultrasonic motor within said casing.

77. An electric razor as defined in claim 76, wherein said mounting means is resilient to permit gross motion of said entire motor while ultrasonically vibrating.

78. An electric razor comprising,

A. a guard member having a plurality of apertures extending therethrough,

C. means for moving said cutter member relative to said cutter member to obtain gross movement across said apertures,

D. means for simultaneously vibrating said guard member at an ultrasonic rate wherein entrance of the hair within said apertures is enhanced, and

E. means for simultaneously vibrating said cutter member at an ultrasonic rate to enhance the cutting effectiveness of said cutter member.

79. An electric razor as defined in claim 78, wherein said means for vibrating said cutter member at an ultrasonic rate includes transducer means coupled thereto.

80. An electric razor as defined in claim 79, wherein said transducer means includes a piezoelectric element coupled to said cutter member in energy transferring relation thereto.

81. An electric razor as defined in claim 78, wherein said means for vibrating said cutter member at an ultrasonic rate includes converter means for transforming electric current to an ultrasonic rate.

82. An electric razor as defined in claim 78, wherein said ultrasonic rate is at a frequency between about 5,000 and 1,000,000 cycles per second.

83. An electric razor as defined in claim 78, wherein said ultrasonic rate is at a frequency between about 5,000 and 1,000,000 cycles per second.

84. An electric razor as defined in claim 81, wherein said converter is contained in a housing adapted to be plugged into an electric outlet.

85. An electric razor as defined in claim 81, wherein said converter is contained within the housing provided for containing the electrical razor.

86. An electric razor as defined in claim 72, wherein said cutter member has cutting elements extending therefrom for engagement with the guard member, and said ultrasonic vibrations are transmitted to said individual cutting elements.

87. An electric razor as defined in claim 78, wherein said cutter member is vibrated with peak accelerations of the order of at least 1,000g, whereby the frictional resistance to the motion between said guard member and said cutter member is quantitatively reduced so that the force to obtain relative movement between said guard member and said cutter member is ofa relatively small magnitude.

88. An electric razor as defined in claim 78, wherein said ultrasonic vibrations of said cutter member is transmitted to the guard member to induce said vibrations therein.

Claims

1. A method of shaving hair comprising the steps of A. positioning adjacent the hairs to be shaved a guard member capable of supporting vibrations in the ultrasonic range and having a plurality of apertures extending from an outer surface adapted for engagement with the skin of the user to an inner surface, B. moving a cutter member relative to the inner surface of said guard member to sever the hairs extending through said apertures, and C. inducing vibrations in said guard member at a frequency in the ultrasonic range to increase the rate of uptake of the hairs through said apertures.

4. The method of shaving as defined in claim 1, wherein said guard member is vibrated at a frequency between about 15,000 and 100,000 cycles per second.

8. The method of shaving as defined in claim 1, wherein said ultrasonic vibrations in said guard member have a component of motion substantially normal to said outer surface.

9. The method of shaving as defined in claim 1, wherein said ultrasonic vibrations produce peak accelerations of the order of at least 1,000g in said guard member.

10. The method of shaving as defined in claim 1, and further including the step of varying the frequency of vibration so as to vary the zones of motion along said guard member to continuously have the hairs received through said apertures.

11. A method of guard hair comprising the steps of A. positioning adjacent the hairs to be shaved a guard member capable of supporting vibrations in the ultrasonic range and having a plurality of apertures extending from an outer surface adapted for engagement with the skin of the user to an inner surface, B. moving a cutter member relative to the inner surface of said guard member to sever the hairs extending through said apertures, C. inducing vibrations in said shaving member at a frequency in the ultrasonic range between about 5,000 and 1,000,000 cycles per second tp produce peak accelerations of the order of at least 1,000g in said guard member, wherein the amplitude of vibration of said guard member is transmitted to said cutter member to reduce the force required to obtain relative movement therebetween and to increase the rate of uptake of the hairs through said apertures, and D. moving said ultrasonically vibrating guard member relative to the hairs to shave a substantial area thereof.

15. A method of shaving hair comprising the steps of A. positioning adjacent the hairs to be shaved a guard member capable of supporting vibrations in the ultrasonic range and having a plurality of apertures extending from an outer surface adapted for engagement with the skin of the user to an inner surface, B. moving a cutter member relative to the inner surface of said guard member to sever the hairs extending through said apertures, and C. simultaneously inducing vibrations in said cutter member at a frequency in the ultrasonic range to enhance the cutting effectiveness of said cutter member.

17. The method of shaving as defined in claim 15, wherein said cutter member is vibrated at a frequency betWeen about 5,000 and 1,000,000 cycles per second.

20. The method of shaving as defined in claim 15, wherein the amplitude of vibration of said cutter member is transmitted to said guard member to increase the rate of uptake of the hairs through the apertures.

24. A method of shaving hair comprising the steps of A. positioning adjacent the hairs to be shaved a guard member capable of supporting vibrations in the ultrasonic range and having a plurality of apertures extending from an outer surface adapted for engagement with the skin of the user to an inner surface, B. moving a cutter member relative to the inner surface of said guard member to sever the hair extending through said apertures, C. simultaneously inducing vibrations in said cutter member at a frequency in the ultrasonic range at a frequency between about 5,000 and 1,000,000 cycles per second to produce peak accelerations of the order of at least 1,000g in said cutter member to enhance the cutting effectiveness of said cutter member, and D. moving said guard member relative to the hairs to shave a substantial area thereof.

30. A method of shaving hair comprising the steps of A. positioning adjacent the hairs to be shaved a guard member capable of supporting vibrations in the ultrasonic range and having a plurality of apertures extending from an outer surface adapted for engagement with the skin of the user to an inner surface, B. inducing vibrations in said guard member at a frequency in the ultrasonic range to increase the rate of uptake of the hairs through said apertures, C. moving a cutter member relative to the inner surface of said guard member to sever the hairs extending through said apertures, and D. simultaneously inducing vibrations in said cutter member at a frequency in the ultrasonic range to enhance the cutting effectiveness of said cutter member.

32. The method of shaving as defined in claim 30, wherein said members are vibrated at a frequency beTween about 5,000 and 1, 000,000 cycles per second.

33. The method of shaving as defined in claim 30, wherein said members are vibrated at a frequency between about 15,000 and 100, 000 cycles per second.

40. An electric razor comprising, A. a guard member having a plurality of apertures extending therethrough, B. a cutter member positioned on one side of said guard member substantially adjacent thereto, C. means for moving said cutter member to obtain gross movement across said apertures, and D. means for simultaneously vibrating said guard member at an ultrasonic rate to increase the rate of uptake of the hairs through said apertures.

42. An electric razor as defined in claim 40, wherein said guard member is vibrated at a frequency between about 15,000 and 1,000, 000 cycles per second.

43. An electric razor as defined in claim 40, wherein the amplitude of vibration of said guard member is sufficient to obtain a reduction of friction between the relative movement of said guard member and the hair.

52. An electric razor as defined in cLaim 50, wherein said converter is contained within the housing provided for containing the electric razor.

53. An electric razor as defined in claim 40, wherein said guard member is vibrated with peak accelerations of the order of at least 1,000g, whereby the frictional resistance to the motion between said guard member and cutter member is quantitatively reduced so that the force to obtain relative movement between said guard member and cutter member is of a relatively small magnitude.

56. An electric razor comprising, A. razor housing means, B. a guard member having an outer surface and an inner surface with a plurality of apertures extending therethrough and mounted in substantially fixed relationship to said housing means, C. a cutter member having cutting elements positioned adjacent the inner surface of said guard member within said housing means for substantial engagement of said cutting elements with said guard member, D. means for moving said cutter member to obtain gross movement across said apertures for severing any hairs extending therethrough, and E. means for simultaneously vibrating said guard member at an ultrasonic frequency rate between about 5,000 and 1,000,000 cycles per second to produce peak accelerations of the order of at least 1,000g in said guard member, wherein the rate of uptake of the hairs through the apertures is increased, said means including transducer means coupled to said guard member in energy transferring relation thereto and a converter for energizing said transducer means.

60. An electric razor comprising, A. a guard member having a plurality of apertures extending therethrough, B. a cutter member positioned on one side of said guard member substantially adjacent thereto, C. means for moving said cutter to obtain gross movement across said apertures, and D. means for simultaneously vibrating said cutter member at an ultrasonic rate.

64. An electric razor as defined in claim 63, wherein said ultrasonic rate is at a frequency between about 5,000 and 1,000, 000 cycles per second.

65. An electric razor as defined in claim 63, wherein said ultrasonic rate is at a frequency between about 15,000 and 100, 000 cycles per second.

71. An electric razor comprising, A. razor housing means, B. a guard member having an outer surface and an inner surface with a plurality of apertures extending therethrough and mounted in substantially fixed relationship to said housing means, C. a cutter member having cutting elements positioned adjacent the inner surface of said guard member within said housing means for substantial engagement of said cutting elements with said guard member, D. means for moving said cutter member to obtain gross movement across said apertures for severing any hairs extending therethrough, and E. means for simultaneously vibrating said cutter member at an ultrasonic frequency rate between about 5,000 and 1,000,000 cycles per second to produce peak accelerations of the order of at least 1,000g in said cutter member and wherein the amplitude of vibration in said cutter member enhances the cutting effectiveness thereof and the coefficient of sliding friction between said guard member and said cutter member is substantially reduced, said means including transducer means coupled to said cutter member in energy transferring relation thereto and a converter for energizing said transducer.

72. An electric razor as defined in claim 70, wherein said transducer means for vibrating said cutter member at an ultrasonic rate includes: a. a pair of sections, b. transmission member one end coupled to said cutter member, and its other end coupled to one of said sections, c. coupling means for maintaining said sections in a relatively fixed position relative to each other, d. said transducer means extending between said sections for inducing high frequency vibrations in said transmission member in spaced relation to said ends, wherein vibrations are transmitted therethrough to induce vibrations at said end coupled to said cutter member, and e. said means for moving said cutter member to obtain gross movement is coupled to said transmission member.

78. An electric razor comprising, A. a guard member having a plurality of apertures extending therethrough, B. a cutter member positioned on one side of said guard member substantially adjacent thereto, C. means for moving said cutter member relative to said cutter member to obtain gross movement across said apertures, D. means for simultaneously vibrating said guard member at an ultrasonic rate wherein entrance of the hair within said apertures is enhanced, and E. means for simultaneously vibrating said cutter member at an ultrasonic rate to enhance the cutting effectiveness of said cutter member.

82. An electric razor as defined in claim 78, wherein said ultrasonic rate is at a frequency between about 5,000 and 1,000, 000 cycles per second.

83. An electric razor as defined in claim 78, wherein said ultrasonic rate is at a frequency between about 5,000 and 1,000, 000 cycles per second.

87. An electric razor as defined in claim 78, wherein said cutter member is vibrated with peak accelerations of the order of at least 1,000g, whereby the frictional resistance to the motion between said guard member and said cutter member is quantitatively reduced so that the force to obtain relative movement between said guard member and said cutter member is of a relatively small magnitude.