US2702938A - Electric dry shaver - Google Patents

Description

March l, 1955 JEPSON 2,702,938

ELECTRIC DRY SHAVER Filed Deo. 6, 1950 2 Sheets-Sheet l l /2 P' (j /3 23 24. 2.223 24 23 |4 40 NvEN'roR NAR JEPsoN Wm fMuA ATTYs.

March l, 1955 l. .JEPsoN 2,702,938

` ELECTRIC DRY SHAVER Filed Dec, e, 195o 2 snee'ts-sneet 2 fie/' f a 2 so 404 l; 3 24- ATTY'S.

United States Patent() 2,702,938 y ELiicrnic par sHAvER Ivar Jepson, OakiPark, Ill., assignor to Sunbeam Corpo-` 3 Claims. (Cl. 30-43) This invenion relates to electric dry shavers, that is, apparatus for use in removing beards or face hair as well as effecting depilation of hair on the arms, legs and other portions of the human body.

The electric dry shaver is coming more and more into general use and today a substantial percentage of people who shave use electric dry shavers exclusively for this purpose. It has been desirable for .some time to reduce the shaving time required when using such dry shavers while still obtaining a satisfactory shave. In prior copending Jepson application, Serial No. 71,927, filedJanuary 2l, 1949, there is disclosed and claimed an electric dry shaver which has gone into extensive commercial use and has been very satisfactory. The electric dry shaver disclosed in the aforementioned Jepson application is a very fine instrument which is capable of giving long years of excellent service and consequently is a relatively expensive device embodying the very satisfactory effectively arcuate cutter and powerful brush type universal motor. There is, however, a market for a somewhat less expeiisive, less satisfactory shaver which has a lower manufacturing cost and hence can be sold at a lower price. Although not giving quite as satisfactory a service, it will excellently serve those who cannot afford the more satisfactory device as shown in the above-entitled application. Such an electric dry shaver should be designed so that it may be held comfortably and conveniently in. the hand of the operator without the requirement of tightly gripping the same as has been the case prior to the advent of the dry shaver shown in the above-entitledJepson application. Accordingly,l it is an object of the present invention to provide a new and improved electric dry shaver.

It is another object of the present invention to provide a relatively inexpensive` dry shaver having a greatly increased cutting area so as to reduce the shaving time substantially. i k

Further objects and advantages of the present invention will become apparent as the following description proceeds and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of the present invention, reference may be had to the accompanying drawings in which:

Fig. l is an elevational View with certain portions cut away illustrating one embodiment of an electric dry shaver incorporating thepresent invention;

Fig. 2 is an end view looking in the direction of the arrows 2 2 of Fig. l;

Fig. 3 is a sectional view taken on line 3--3 of Fig. 2;

Fig. 4 is a sectional view taken on line 4-4 of Fig. 3, assuming that Fig. 3 shows the complete structure;

Fig. 5 is a fragmentary View of a portion of Fig. 3 in order to illustrate the motor starting means of the present invention;

Fig. 6 is a fragmentary end sectional view of the same portion of the shaver shown in Fig. 5 of the drawings;

Fig. 7 is a schematic circuit diagram illustrating the electric circuit of the dry shaver of the present invention;

Fig. S is a sectional view similar to Fig. 3 illustrating a modification of the present invention; and

Fig. 9 is a sectional view similar to Fig. 8 illustrating still another modification of the present invention.

The electric dry shaver of the present invention generally designated by the reference `numeral 10 in Figs. 1 to 7 of the drawings is of the type used in shaving beards and for removing hair from other parts of the body.

Essentially, theshaver 10 comprises a casing 11 having attached thereto one or more shaver heads 12 extending completely across the longest dimension of the housing or casing 11. The heads 12, two of which are shown in Fig. 4 of the drawings, are provided with the conventional reciprocating inner cutters 13 which are reciprocated at a relatively high speed by means of a motor generally designated at 14 disposed within the casing 11.

The electric dry Shavers available on the market prior to the invention disclosed in the above-entitled Jepson application, generally comprised an elongated casing around which the operators lingers were usually clasped in a fairly tight grip to manipulate the shaver. The invention disclosed in the above-entitled Jepson application has resulted in the production of an electric shaver having a configuration that may readily be cupped in the hand of the user in a natural manner with the fingers loosely engaging the same. The casing in the aboveentitled Jepson application was of rectangular configuration with the two walls of major area substantially square. In the instant application, the same general configuration is involved except that instead of the two walls being substantially square, the outing surface is preferably on the side or edge of the casing having the longest dimension so as to provide the maximum possible cutting surface. With this configuration, the casing 11 may be comfortably cupped in the hand with the fingers usually loosely engaging the same as contrasted with the tight grip required of most users when holding the elongated casings of prior art Shavers where the fingers of necessity had to encircle the longitudinal axis of the casing.

As illustrated, the casing 11 of the dry shaver 10 essentially comprises two cooperating cup-shaped complementary portions 11a and 11b which are adapted to fit t0- gether to provide a somewhat rectangular-shaped casing having side walls which approach a square in configuration and define a casing having a thickness substantially less than either dimension of the side walls. The casing portions 11a and 11b are preferably molded from a suitable moldable material, many moldable plastic molding materials being readily available on the market for this purpose providing a smooth and satisfactory appearing surface of any desired color. If desired, the central portion of the casing 11 which is likely to be engaged by the operators fingers may be provided with slightly raised rib portions or similar deformations in the form of ribs or indentationsvto make it easier to manipulate the dry shaver and for the additional purpose of providing a more pleasing appearance. The complementary casing sections 11a and 11b are provided with suitable integral formed portions for accommodating fastening means. As illustrated, the casing section 11b is proivded with suitable openings 16 for receiving fastening screws such as 17 which threadedly engage tapped rib portions i8 defined in complementary casing section 11a. If desired, the tapped rib portions 18 may include threaded metal inserts molded therein, although with certain plastics available on the market, it may be possible to tap the plastic material directly or mold the threads directly therein. The casing section 11b is suitably recessed to accommodate the heads of the fastening means 17 so that they in no way interfere with the operators use of the dry shaver 10.

For the purpose of producing the desired cutting action, there are provided the shaver heads 12, two of which are shown in the drawings, although it should be understood that a single head or more than two may be employed, depending upon the particular application involved. A suitable thumb screw 15 is mounted on casing section 11a permitting ready attachment and detachment of the heads 12 relative to the casing 11. The complementary casing sections 11a and 11b are provided with portions 19 defining an integral ledge or shelf adjacent the head end of the dry shaver 10 for supporting thereon a thin somewhat resilient plate 20 effectively dividing the dry shaver into a motor chamber and a cutter chamber. This plate 20 is provided with hook-shaped ends 20a for engaging with enclosure members 21 so as to provide a sort of hinged closure through which access to the cutter com- 3 partment for the removal of hairs lodged therein during the shaving operation is afforded. Disposed within the cutter chamber upon the plate is a cutter support 22 for supporting in a reciprocal manner the one or more inner cutters 13. Suitable means specifically illustrated as balls 23 biased by springs 24 push the reciprocating cutters 13 into shearing engagement with the shaver heads 12. The cutters and shaver heads are each, provided with suitable openings into which the hairs being cut extend so as to be sheared by the relative reciprocal motion thereof. The particular construction of the reciprocating inner cutters and the shaver heads forms no part of the present invention and any satisfactory elements for this purpose may be employed. However, an important aspect of the present invention is the fact that these cutters and shaver heads extend along substantially one entire side of the casing and, moreover, along the longest dimension of the casing so as to give the maximum cutting area.

In order to reciprocate the one or more cutters 13 associated with the shaver 10, the motor 14 is provided which may be any suitable type of motor, but which preferably is of the type disclosed in Jepson and Cerveny application Serial No. 142,752, filed February 7, 1950. As illustrated, the motor 14 is of the so-called impulse type coinprising a field structure made up preferably of a stack of U-shaped laminations thereby to define a U-shaped field structure. Encircling the base or bight of the field structure 25 is a field coil 26 preferably comprising an insulating spool 27 having two sections for receiving thereon two lield winding sections 26a and 26b clearly shown in the schematic diagram of Fig. 7 of the drawings and making up the eld coil 26. Preferably, the spool 27 is formed of two parts of suitable insulating material capable of being interrelated when placed around the base or bight of the U-shaped field structure 25.

Secured to the field structure 25 are a pair of bearing plates 29 and 30 which extend beyond the open end of the U-shaped field structure. Preferably, the bearing plates 29 and 30 are rigidly related to the field structure 25 in the manner shown in the drawings by suitable screws or fastening means 31 extending through aligned openings in these members. It will be understood that these fastening means are suitably insulated from the laminations through which they extend. To hold the impulse motor 14 in position within the casing 11, the latter is preferably provided with tapped openings to receive fastening means such, for example, as the screws 32 rigidly to relate the motor 14 with the casing 11. The insulating plates 29 and 30 may be formed of any suitable material such, for example, as a molded plastic such as nylon. These insulating bearing plates, moreover, define suitable bearings within which is journalled a crank shaft 35. To the crank shaft 35 is suitably fastened as by set screws or the like an armature 37 formed of a stack of laminations riveted or otherwise secured together. The armature 37 has such a configuration as to provide a two-pole armature capable of rotating between the ends'of the U-shaped field structure 25. The longitudinal axis of the crank shaft 35 is disposed parallel to the short dimension of the casing 10 and perpendicular to each of the long dimensions of the casing 10. The end of the crank shaft 35 extending beyond the bearing plate 30 has an elliptical cross section designated by the reference numeral 35a for controlling the contacts of the impulse motor to be described hereinafter. The other end of the crank shaft 35 extending beyond the bearing plate 29 terminates in a crank comprising the eccentric pin 39.

For the purpose of drivingly relating the motor 14 and the reciprocating cutters 13, there is provided a driving lever 40 attached to a pivot pin 41 pivotally mounted in suitable integral ears or projections 29a and 30a of the bearing plates 29 and 30, respectively. The driving lever 40 is illustrated as effectively comprising a bell crank pivotal about the bearings for pivot pin 41 and the end thereof adjacent the crank shaft 35 is provided with an elongated opening 43 for receiving therein the crank pin 39 whereby rotary movement of the crank shaft 35 causes oscillating movement of bell crank 40 about the bearings for pivot 41. The other arm 40a of bell crank 40 extends through aligned openings 42, 43 and 44, respectively, defined in the ledge 19, the plate 20 and the cutter support 22, respectively and an enlarged end thereof is disposed within a recess 46 defined adjacent one end of the Gti cutter 13. Where a plurality of cutters such as are shown in Fig. 4 are employed, a plurality of arms such as 4th: are rigidly attached to the pivot pin 41 so as to be oscillated in response to oscillation of the main arm of the bell crank 40 with a resultant reciprocation of the cutters 13.

It will be understood that an impulse motor requires control means for periodically making and breaking the energization circuit of the field Winding sections 26a and 26b. To this end, the bearing plate 30 preferably comprises integral projections 49, 50, 51 and 52 for maintaining in position a pair of resilient contact arms 53 and 54, one disposed on either side of the elliptical portion 35a of the crank shaft 35. As illustrated, each of the contact arms 53 and 54 is provided With a central portion of somewhat circular configuration so as substantially to encircle the associated projections 50 and 51, respectively. The ends of these resilient contact arms 53 and 54 remote from the elliptical portion 35a are provided with a reverse bend to receive therein the projections 49 and 53, respectively, thereby not only maintaining the contact arms 53 and 54 in position, but inherently biasing them so that suitable contacts 56 and 57 supported from the other ends of the contact arms 53 and 54, respectively, are biased into contacting engagement. Relative separation of the contacts 56 and 57 is caused in response to rotation of the elliptical cross section portion 35a which engages suitable blocks 58 and 59, respectively, of insulating material attached to the resilient contact arms thereby insulating the latter from the motor shaft 35. When the ends of maximum diameter of the elliptical portion 35a engage the insulating contact blocks 58 and 59 which, incidentally, may be formed of nylon or other suitable material, the circuit through contacts 56 and 57 is broken or interrupted. On the other hand, when the elliptical portion 35a of the crank shaft 35 is disposed so that the ends of its minimum diameter are suitably engaged by the insulating blocks 58 and 59, the contacts 56 and 57 complete an electrical circuit in the manner clearly apparent from Iig. l of the drawings. It will be understood that rotation of the crank shaft 35 will canse alternate making and breaking of the circuit at the contacts 56 and 57.

The electrical circuit of the impulse motor of the present invention can now be considered with reference to Fig. of the drawings where the circuit elements are schematically illustrated. There are illustrated, contact prongs 60 which effectively comprise the terminals of the electrical circuit within the motor casing 11 to which may be connected a conventional power cord or the like for connecting the motor circuit to a source of electrical energy such as a conventional wall outlet. These contact prongs 60 are clearly shown in Figs. 2 and 3 of the drawings and as illustrated the complementary casing sections 11a and 11b are so designed as to define a plug recess 61 within which the prongs are disposed so as to facilitate the connection between the prongs 60 and a power cord not shown. Referring again to Fig. 7, it will be observed that the prongs 60 are electrically connected by conductors 62 and 63 with the terminals of winding sections 26a and 26b, respectively. The other terminals of winding sections 26a and 26h are connected to the contacts 56 and 57, respectively. It will be apparent that the circuit through the windings 26a and 26b is alternately made and broken as the contacts 56 and 57 are engaged and disengaged. It should be understood that the impulse motor per se is old and the operation thereof 1s well understood by those skilled in the art. The contacts 56 and 57 close the eld circuit when the armature poles approach the field or stator poles of the field structure 25 and the contacts 56 and 57 are separated when the armature poles are about to recede from the stator poles. In other words, the armature is so shaped and positioned with respect to the field structure 25 that the torque produced by the action of the field magnet upon the armature would be alternately clockwise and counterclockwise if the armature were mechanically rotated and the field structure were constantly excited without any interruption of its excitation. It is for this reason that the contacts 56 and 57 are provided which are so interrelated by means of the elliptical portion 35a of the crank shaft 35 that the energization circuit for the field structure is opened at those times when the torque tends to be negative with respect to the direction of rotation. An impulse motor operates at a speed of the order of 8,000 revolutions per minute and by virtue of the periodically operated contacts 56 and 57 operates equally well whether connected to a source of direct or a source of alternating current. i

For the purpose of preventing excessive arcing at the 4contacts 56 and 57 and thereby to increase the contact life, there is included in the electrical circuit as best :shown in Fig. 7 of the drawings a capacitor 65 connected 'across the contacts 56 and 57, preferably through two `serially arranged identical resistors 66. The resistors 66 tend to limit the magnitude of the discharge current of the capacitors 65 so as to reduce arcing when the charged capacitor 65 is suddenly short-circuited by closure of the contacts 56 and 57. Preferably, the capacitor 65 and the resistors 66 are supported in the casing 11 in the manner disclosed in the above-mentioned copending Jepson and Cerveny application.

It will be understood that an impulse motor may have stopped in a position such that no starting torque will be applied to the armature to cause rotation thereof and to this end such impulse motors are usually provided with some manually actuable starting means. As illustrated in the drawings, the casing 11 is provided with a suitable aperture 68 through which may extend the manually engageable portion 69a of a starting lever 69 pivotally mounted as indicated at 70 to the bearing plates 29 and 30. The starting lever 69 is provided with a projection 69b at the end thereof disposed within the casing 11 which tends to stress a torsion spring 71 wrapped around the pivot 70. This torsion spring has one end 71a anchored to a pin 72 projecting from the bearing plate 29. The other end of the torsion spring 71 designated as 71b extends in a direction toward the crank shaft 35 to which is attached as by suitable fastening means 7S a ratchet wheel 76. The torsion spring 71 includes a lateral projection 71C which is adapted to engage the teeth of the ratchet wheel 76 to rotate the same in a clockwise direction as viewed in Fig. of the drawings upon release of the starting lever 69, thereby giving the impulse motor an initial rotation suficient to start rotation.

From the above description, it will be apparent that there has been provided a simple and compact electric shaver with a greatly increased cutting surface and cornprising relatively inexpensive parts which can be assembled in a rapid and expeditious manner. The operation of the shaver embodying the invention can readily be understood in view of the above description.

In Fig. 8 of the drawings there is illustrated a slight modification of the present invention in which the corresponding parts are designated by the same reference numerals as in the preceding figures of the drawings. The difference between the arrangement disclosed in Fig. 8 and that of the preceding figures resides primarily in the means for transmitting the driving force between the motor designated as f4 in Fig. 8 of the drawings and the reciprocating cutters designated as 13 in Fig. 8 of the drawings. In the preceding arrangements, the oscillating arms were disposed so as to engage the cutters adjacent one end thereof whereas in Fig. 8 the cutters 13 are provided with recesses 80 at the center thereof for receiving therein the ends of the arms 40a of the lever 40. With this arrangement the motor is substantially reversed with the armature adjacent the center of the casing and the winding 26 adjacent one end of the casing. If desired, instead of the starting lever shown in the preceding embodiments of the drawing, a suitable starting wheel may be attached directly to an extension of the crank shaft 35 which may protrude at least partially through a suitable opening in the casing 11.

It will be understood that a relatively powerful motor is required in order to reciprocate the cutters with the extensive cutting area provided therefor. Under these circumstances, a considerable amount of heat produced in the field winding 26 must be dissipated. In Fig. 9 of the drawings, there is illustrated a modification of Fig. 8 in which a substantially greater cutting area is provided by having the cutting surface along the longest dimension of the casing. Instead of having the two winding sections concentrated at one place, a more or less double field winding structure 81a and Sib is employed with windings 82 and 83 disposed at the bight portions of the field structure and the armature disposed at the adjacent ends of the field structure remote from windings 82 and 83. With this arrangement, the windings 82 and 83 are distributed with the consequent disabbassa *i skilled in the art.

1. 2, .j. y i I: tribution of heat produced therebyfsimplifyingthe motor cooling problem. The operation -of the 'arrangement disclosed 1n Fig. 9 will readily be understood by those While there has been shown anddescribed particular embodiments of the present invention, it will be understood that other changes and modifications may obviously be made by those skilled in the art without departing from the invention in its broader aspects, and it is desired in the appended claims to cover all such changes and modifications as fall within the true spirit and scopel cf the present invention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. An electric dry shaving device comprising a casing having a pair of substantially parallel walls each of generally rectangular configuration, spaced from each other by a distance considerably less than the smallest dimension of said Walls, the dimensions of said casing being such to permit the device comfortably to be cupped in the hand of the operator and readily manipulated by such operator during a hair removal operation, a cutting head extending substantially entirely along one of the longest dimensions of said casing, a cutter movable in shearing engagement with the inside of said cutting head, a rotary motor disposed within said casing, means including a lever oscillatable about a fixed pivot interconnecting said motor and said cutter, and a manually actuable starting mechanism pivotally mounted in said casing including a portion engageable with said motor to impart rotation thereto, and energy storage means included in said starting mechanism.

2. An electric dry shaving device comprising a casing having a pair of substantially parallel walls each of generally rectangular configuration, spaced from each other by a distance considerably less than the smallest dimension of said Walls, the dimensions of said casing being such to permit the device comfortably to be cupped in the hand of the operator and readily manipulated by such operator during a hair removal operation, a cutting head extending substantially entirely along one edge of said casing, a cutter movable in shearing engagement with the inside of said cutting head, a relatively at rotary motor disposed within said casing with the axis of rotation of said motor extending in the direction of the minimum dimension of said casing and perpendicular with the longitudinal axis of said cutter, a bellcrank pivotally mounted within said casing drvingly interconnecting said motor and said cutter, a pivotal element mounted in said casing having a manually actuable portion thereof extending outside the casing, spring means supported in said casing and engageable following stressing and release thereof with the rotatable portion of said motor to impart a slight rotary motion to said rotatable portion, and means on said pivotal element for stressing said spring means.

3. An electric dry shaving device comprising a at rotary electric motor of the type having a U-shaped field structure with an armature rotatable between the ends of the arms of said U-shaped field structure and a coil surrounding the bight portion of said structure, a casing for said motor including a pair of side walls each of generally rectangular configuration and spaced from each other by a distance considerably less than the shortest edge dimension of said wall, means for supporting said motor within said casing with the motor shaft extending between said side walls and generally perpendicular thereto and with the arms of said field structure extending generally parallel with the longest dimension of said walls whereby said casing for said motor has dimensions such as to permit the device comfortably to be cupped in the hand of the operator and readily manipulated by such operator during a hair removing operation, a cutting head extending substantially entirely along one of the long edges of said walls and generally parallel with said arms, a cutter in shearing engagement with said cutting head and mounted for reciprocating movement longitudinally of said long edges of said walls, and means including a lever pivotally mounted to a xed pivot within said casing and oscillatable by said motor shaft and reciprocating said cutter.

(References on following page) References Cited in the le of this patent UNITED STATES PATENTS Jepson Apr. 10, 1951 Florman Nov. 23, 1937 5 Murphy Feb. 7, 1939 8 Hanley Oct. 17, 1939 Johnson et al Nov. 12, 1940 Holsclaw July 6, 1943 Mehl July 6, 1943 Rand Mar. 7, 1944

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