US3494031A

US3494031A - Electric shaver

Info

Publication number: US3494031A
Application number: US702462A
Authority: US
Inventors: Wenceslas F Sklenar
Original assignee: WENCESLAS F SKLENAR
Current assignee: WENCESLAS F SKLENAR
Priority date: 1968-02-01
Filing date: 1968-02-01
Publication date: 1970-02-10
Anticipated expiration: 1987-02-10

Description

Feb. 10,- 1970 w. E. SKLENAR ELECTRIC SHAVER med Feb. 1. 1968 INVENTOR. WE/VL'ESLAS F SKLEWAR a) W KMQMW United States Patent O 3,494,031 ELECTRIC SHAVER Wenceslas F. Sklenar, 537 McKellar Circle, Las Vegas, Nev. 89109 Filed Feb. 1, 1968, Ser. No. 702,462 Int. Cl. B26b 19/14 US. Cl. 30-43.6 8 Claims ABSTRACT OF THE DISCLOSURE The disclosure describes an electric shaver having radially mounted T-shaped double-edged shaving blades resiliently held against the inside of a cylindrical hardened steel screen having transversely oriented perforations and driven from a rotor through a reversible subfractional or miniature electric motor. In one embodiment the direction of rotation of the rotor is controlled by automatic switch means which reverses at predetermined intervals, i.e., after each 500 revolutions. The shaving blades are so shaped and mounted as to be essentially self-cleaning and selfsharpening and the device is readily manufactured from modern materials of construction at low cost. The shaving action is cycled to pass the blades both with and against the beard growth to obtain a close shave for the toughest ingrown beard. In one embodiment the screen is formed in semi-circular halves with one-half encompassing the inner path of the blades and the outer half encompassing the outer path of the blades, both with an automatic sharpening action.

BACKGROUND OF THE INVENTION One of the principal disadvantages of electric shavers is their inherent inability to produce a good smooth close shave. In several known designs of electric shavers cutter bars with square ends are used which chop the heard instead of giving a true shaving action. Because of the high speeds of rotation and the shape of the cutter bars and screen there is a tendency to out each hair of the beard at an angle to its longitudinal axis regardless of how the shaver head is manipulated against the skin. The cut-off ends of the beard stubble are readily felt with the finger tips after shaving because their sharp edges turn upward under pressure and frictional forces. Furthermore, the prior art cutter bars do not present a razor sharp cutting edge to the beard and there is a tendency to crush the beard rather than out it transversely, which action becomes more intensified as the cutter bars become dull through use. Also, the shape and resilience of the screens used in the prior art devices are not conducive to a close shaving action.

SUMMARY OF THE INVENTION The instant invention overcomes these and other shortcomings of the prior art shavers by providing rotating shaving blades with razor sharp cutting edges, operating againsta hard thin circular screen having transverse perforations, i.e., their longest dimension or axis is essentially perpendicular to the direction of travel of the shaving blades or parallel to the cutting edge of the blades, with means to allow the outer surface of the blade heads to be held against the inside of the screen by centrifugal force and means for reversing the direction of travel of the blades at will or in timed cycles.

The instant invention is further characterized by providing a screen constructed of hard alloyed steel, chromium plated only on its outer surface, which provides an inner blade-sharpening surface. The screen is formed in two semi-circular halves, the topmost of which is readily removed for cleaning the shaver. The shaving blades provide leading razor sharp Patented Feb. 10, 1970 edges in either direction of rotation which blades have outer faces of radial configuration conforming with the inside circumferential surface of the Screen. The heads of the shaving blades are elongated transverse the direction of rotation and are T-shaped with the under edge surfaces straight or hollow ground to meet the radial configuration of the outer faces at an acute angle of 45 or less such that a relatively thin, substantially constant, taper-shaped profile of the cutting edge is maintained as the blade faces are worn against the inside of the hard steel screen. In addition, the shaving blades are resiliently mounted on a high carbon steel rotor operating upon selflubricating bronze bearings so that vibration-free rotation is accomplished and the life of the blades is prolonged. Upon cyclic reversal of the direction of rotation of the rotor and blades a true criss-cross shaving action is obtained without tiring manipulation of the shaver across the face of the user. These and other embodiments of this invention will become apparent or be described as the specification proceeds.

DESCRIPTION OF THE DRAWINGS One illustrative embodiment of this invention is shown in the drawings wherein:

FIG. 1 is a side elevational view of the shaver of this invention to illustrate the compact design and arrangement of certain of the parts shown in dotted lines or diagrammatically;

FIG. 2 is a cross-sectional view taken along the lines 22 of FIG. 1;

FIG. 2A is a partial view in cross-section to show one form of attachment of the shaving head screen to the housing;

FIG. 2B is a partial view in cross-section to show another form of attachment of the shaving head screen to the housing;

FIG. 2C is a partial view in cross-section to show still another form of attachment of the shaving head screen to the housing;

FIG. 3 is a perspective view of the rotor and shaving blade assembly; and

FIG. 4 is a cross-sectional view taken along the lines 44 of FIG. 2.

THE PREFERRED EMBODIMENT Referring to the drawings, particularly FIGS. 1 and 2, the shaver of this invention is shown to comprise a plastic, electrically insulated case 10 having a flattened handle section 12, the outer surface of which can be knurled or otherwise made slip resistant for ease of handling. The upper body of the case 10 has a pair of spaced

shoulders

14 and 16 molded integral therewith and formed with a thickened supporting wall defining therebetween opposed

recesses

18 and 20 which house self-lubricating bronze bearings 22 and 24, which in turn support the driven shaft 26 carrying the rotor 30.

The shaft 26 and the rotor 30 are formed of high carbon power transmission steel and are driven by means of the driven pulley or sprocket 32, within the recess 20 (see FIG. 4) carrying drive belt or drive chain 34 con nected to the drive pulley or drive sprocket 36. The drive sprocket 36 is carried on the shaft 38 fromthe drive motor 40 within the space 42 of the handle section 12.

The DC motor 40 is contained within the space 42 of the housing through the base 42 which is affixed to the inner wall 44 by means of the screws 46. The electrical lead from an AC source is illustrated at 48 and a connector 50 (transistorized DC power supply) is provided to supply DC current to the motor 40 through an automatic reversing switch and timer 52 by means of the manual switch 54 having ON-OFF button 56. If desired, the manual switch means may include an ON clockwise button 58 and an ON counter-clockwise button 60, to be used alternatively with, or substituted for, the timer 52. Also, if desired, an AC motor can be used and the converter eliminated.

The head portion of the housing has a semicircular transverse opening 62 against which is permanently fixed the lower semi-circular screen-half 64. A matching upper screen-half 66 fits over the top of the shaver between the two

shoulders

14 and 16 and a space 68 is provided at each end of the rotor 30 for the purpose of collecting hair cuttings. The screen halves are made from very hard alloyed steel and the outer surface only of the upper half is chromium plated.

The screen half 66 is detachably affixed to the housing by any desired means such as by providing the screen half 66 with a transverse clip 70 (FIG. 2A) having a boss 72 adapted to receive the screw 74 to hold the clip end within a matching recess 76 within the plastic housing 10. This arrangement can be used on both sides of the shaver head.

In FIG. 2B there is shown an alternate construction wherein the clip 70 has a spring steel edge 78 offset to engage the boss of the housing 10. The boss 80 has a top shoulder 82 which engages a recess 84 in the spring clip 7 0' and a lower head 86 to engage the offset 78. I111 FIG. 20 another form of construction is shown wherein the spring clip 70" has a lower inner rounded head 90' which is wedged into the U-groove 92 formed in the top edge of the boss 80. In each of these embodiments the top screen half 66 abuts against a shoulder, such as the shoulder 94 in FIG. 2A, the shoulder 96 in FIG. 2B and the shoulder 98 in FIG. 2C, so that its edge 100 is precisely aligned with the top edge of the lower screen half 64 and these parts are maintained concentric and flush to each other to provide a smooth inner surface against which the shaving blades will ride without interference.

The top screen half 66 has a plurality of closely spaced elongated apertures 102 Which have their longest axes parallel to each other and transverse the direction of rotation of the rotor 30. The apertures 102 can be oriented in a circumferential line or a series of rows around the circumference of the screen 66 or be in a staggered relationship therearound. The entire surface of the screen 66 can be perforated or a section, such as A-B (FIG. 2) can bear the perforations, which area represents about one-third to one-half the circumferential length of the screen 66. The steel screen 66 also can have marginal reinforcing ribs, such as indicated at 104 in FIG. 1, which ribs extend over the semicircular length of the screen half 66. The very thin, face engaging area of the screen 66 may also be reinforced by imperforated band-areas 105, as shown.

Referring more particularly to FIGS. 3 and 4, the rotor 30 is shown to have a series of radial spokes 106 which extend along the length of the rotor and have slots 108 therein to receive the T-shaped shaving blades 110 by means of their transverse trunks or bases 112. The trunks, or stems, of the T-shaped shaving blades fit closely within the corresponding slots 108 so that there is little or no circumferential movement. The blades, however, are adapted to move radially in the slots 108.

Each blade 110 has a smooth radial outer surface 114 which rides against the smooth and uniformly curved (circular) surfaces 116 and 118 of the

screen elements

64 and 66. The leading and trailing

edges

120 and 122 of each blade are tapered razor edges formed by the angular or hollow ground under surfaces 124 which meet the

surfaces

116 and 118 at an angle preferably of about 45 or less. The stem 112 of each blade rests upon or presses against an elongated leaf spring 130 located in and along the space 132 between the end of the stem 112 and the bottom of the slots 108. The springs 130 are narrower than the slots and have at least one arched portion 134 which is normally under compression with the blades in their assembled condition on the rotor 30 and within the cylindrical body formed by the

screen elements

64 and 66. The springs 130 normally bias the shaving blades so that their surfaces 114, which have the same curvature as the

surfaces

116 and 118 of the

screen members

64 and 66, are frictionally engaged by the screen members as the rotor is turning. In this way the edges and 122 are constantly maintained in a razor sharp condition by the honing action of the

surfaces

116 and 118. The angular spacing between the shaving blades is subject to variation and any number of blades other than the six shown can be used. The rotor and blade combination should, of course, be statically and dynamically balanced and held at the center of the cylinder comprising the screen halves 64 and 66, by the shaft 26.

The operation of the shaver of this invention is conducted as follows: With the conduit or cord 48 connected to a suitable source of power, e.g., AC power, and with the automatic reversing switch and timer 52 set for fifteen second intervals of motor operation in each direction, and with the motor driving the shaving blade rotor at 2,000 rpm, for example, the blade rotor will make about 500 revolutions in each direction during each interval. With the motor operating in this manner, the shaving head is placed against the face of the user and the beard passes through the apertures 102 to be cut first in one direction and then in the other direction by the then leading

edges

120 or 122 of the shaving blades. The razor screen is then passed over the face of the user until the shaving process is completed.

The improved razor may also be made for manual switching to accomplish periodic reversal of the motor 40, in which case the manual switch means buttons 58 and 60 would be connected to the bypass automatic timer and switch means 52, so that the user could reverse the motor operation as he may desire. It will be understood that reversal of motor operation may be accomplished by other means, if desired, such as by a gear box arranged for mechanical operation of a reversing gear through mechanical connection with the buttons 58 and 60.

For automatic or electrical reversing operation, any type of fractional or sub-fractional (miniature) horsepower electrical motor 40, capable of reversing itself while operating at full speed, can be used. The motor should 'be at least of the general-purpose type, e.g., built to withstand all normal conditions and also may be built to withstand dust, dirt, moisture, steam, abnormal shock or vibration, prolonged operation at overloads, high altitudes and the proximity of objects which block normal ventilation, such as hair, soap and the like.

In general, standard -DC miniature motors can be used and arranged to start from rest in either direction of rotation. Shaded pole motors must be specially designed for this type of service. Small DC and universal motors with the brushes set on neutral can operate in both directions. Standard polyphase induction and miniature DC motors can be reversed while running and may be used in the shaver of this invention. Preferably, the motor is a two-pole complete reversing 'DC motor having a horsepower output of about to A and preferably about horsepower, at about 2,000 rpm. Chokes, resistors, governors, armatures and the like may be used to control the motor speed. Such motors are lightweight for a given output and highly suitable for this purpose.

It will also be understood that suitable means, not shown, may be incorporated with the herein described electric razor whereby the motor circuit is automatically interrupted whenever the razor head or upper screen half is loosened for removal, thus assuring that the individual showing blades will not be thrown from the razor when the screen is removed.

Although the invention has been described in relation to specific embodiments, it is apparent that various modifications can be made in the device of this invention without departing from the spirit of the appended claims. The belt or chain 34 can be a double or multiple link type. The housing can be made of any type of plastic having good impact resistance and electrical insulating properties. A knurled, indented hand grip area on each side can be formed in the housing. The screen half 66 can be mounted in a rigid frame to hold its precisely curved configuration, or be formed in a flat resilient sheet which is bent over suitably recessed shoulders at the housing end to form the shaving head. A shoulder 69 is provided within each of the spaces 68 on the inside of the spaced

shoulders

14 and 16 to support the outer edges of the screen 66. Also other means than removal of the outer screen half 66 may be employed for removal of the cuttings collected within the razor head during its use.

What is claimed is:

1. An electric shaver comprising (a) a housing member having an opening in one end defined between spaced side shoulder members;

(b) a cylindrical screen mounted within said opening and between said shoulders;

(c) said cylindrical screen having a uniformly cylindrical inner surface and a thin perforated wall encompassing said open end to define a circular shaving head;

((1) a rotor mounted longitudinally between said shoulder members;

(e) said rotor having at least a pair of angularly spaced spoke members with longitudinally slotted ends uniformly spaced from said cylindrical inner surface and extending parallel to the axis of said rotor;

(f) elongated shaving blade members slidably supported in the slotted ends of each of said spoke members;

(g) said blade members being T-shaped in cross-section with their stems engaged within said slotted ends and having outer double-edged curved faces conforming with the curvature of said inner cylindrical surface of said screen and in sliding contact therewith;

(h) said blade members having razor edges along the longitudinal margins of said curved faces; and

(i) means to rotate said rotor in each direction alternatively with said curved faces of said blades being urged into sliding engagement with said inner surface of said screen.

2. An electric shaver in accordance with claim 1 in which (a) said shaving head is semi-circular and is a separable portion of said cylindrical screen; and

(b) means are provided for detachably mounting said shaving head to said housing member.

3. An electric shaver in accordance with claim 1 in which the perforations in said perforated wall are elongated with their longest axis substantially perpendicular to the direction of rotation of said rotor.

4. An electric shaver in accordance with claim 1 in which said edges of said curved faces of the said blades are inwardly beveled at an angle no greater than about 45 to form said razor edges.

5. An electric shaver in accordance with claim 1 in which (a) said means to rotate said rotor comprises a reversible motor; and

(b) drive means are connected between said motor and said rotor.

6. An electric shaver in accordance with claim 1 in which a space is provided within said open end of said housing member at each end of said rotor to receive the cuttings from said blades.

7. An electric shaver in accordance with claim 2 in which said means for detachably mounting said shaving head includes means for aligning the edges of said shaving head with the edges of the adjoining portion of the cylindrical screen whereby said edges abut squarely to form a smooth continuous inner surface at the juncture.

8. An electric shaver in accordance with claim 7 in which (a) said means for detachably mounting said shaving head comprises a pair of spring clips afiixed to the edges of said shaving head;

(b) said spring clips having an ofiT-sct shoulder; and

(c) a recess is provided in the side of said housing to engage said shoulder.

References Cited UNITED STATES PATENTS 2,220,800 11/1940 Jepson 3043.5 2,331,500 10/1943 Rand 30--43.9

ROBERT C. RIORDON, Primary Examiner GARY F. GRAFEL, Assistant Examiner