US2346235A - Multidirectional electric dry shaver - Google Patents

Description

April 11, 1944. A. ROMAO MULTIDIREGTIONAL ELECTRIC DRY SHAVER Filed July 21. 1941 INVENTOR Patented Apr. 11, 1944 -UNlT'ED STATES PATENT OFFICE MULTIDIRECTIONAL ELECTRIC DRY SHAVER August Romao, San Francisco, Calif.

Application July 21, 1941, Serial No. 403,356

11 Claims.

My invention relates to improvements in a multi-directional electric dry shaver, and it consists of the combinations, constructions and arrangements hereinafter described and claimed.

An object of my invention is to provide a multi-directional electric dry shaver that has a guard with circular hair-receiving openings with cutting edges around their entire circumferences, and a cutter reciprocably and rockably mounted in the guard and having cutting edges extending at different angles to each other so that when the cutter is moved through a double helical motion, its cutting edges will cooperate with the entire circular cutting -edges for severing all of the hair received in the guard openings. The round holes constitute shearing edges that will actually and effectively shear hair on every direction of their circumferences.

' A further object of my invention is to provide a device of the type described in which the guard has two groups of laterally extending slots arranged on opposite sides of the group of circular openings. The slots are for the purpose of receiving longer hairs and comblike members are associated with the slots and are used for the purpose of combing the longer hairs and for guiding them into the slots where they will be severed by the cutter. The comb-like members provide multiple hair-parting combs of novel construction which not only guide the hairs into the slots, but cause the hairs to remain between the shearing edges of the slots until sheared by the cutter. Such a multiple hair-parting comb also reduces skin irritation to a minimum.

A still further object of my invention is to provide a device of the type described in which the circular cutter is yieldingly and constantly kept in contact with the perforated portion of the guard by spring-pressed pins that exert radial forces against the cutter from different angular directions.

Other objects and advantages will appear in the following specification, and the novel features of the device will be particularly pointed-out in the appended claims.

My invention is illustrated in the accompanying drawing forming a part of this application, in which:

Figure 1 is a longitudinal section through the device shown twice normal size;

Figure 2 is an end elevation of the device on the same scale;

Figure 3 is a transverse section of Figure 1. taken along the line III--III of Figure 1 and illustrating the parts at four times normal size;

Figure 4 is a plan view (eight times normal size) of a portion of the cutter and guard; and

Figure 5 is a schematic view illustrating four positions of the cutter with respect to a circular hair-receiving opening.

While I have shown only the preferred form of my invention, it should be understood that various changes or modifications may be made within the scope of the appended claims without departing from the spirit of the invention.

In carrying out my invention, I provide an electric dry shaver casing indicated generally at A in Figures 1, 2 and 3. The casing houses an electric motor, not shown, and the motor shaft I, which is rotated by the motor, has an eccentric portion or stem 2 with a roller 3 that has a pherical periphery. The casing A has a guardreceiving recess A therein and an opening 4 communicating with the recess through which the shaft l extends.

A guard indicated generally at B has a rectangular base that is removably received in the recess A. A set screw 5 or other suitablefastening means is used for securing the guard to the casing. It is best now to describe the guard in detail after which the cutter C will also be set forth in detail. The top of the guard is semicylindrical and it has a cylindrical bore 6 disposed so close to the semi-cylindrical top as to provide a metal thickness at its narrowest point of about three one thousandths of an inch in thickness.

The thin guard portion thus provided has a plurality of circular hair-receiving openings I therein. These openings are preferably twenty live one thousandths of an inch in diameter although I do not wish to be confined to this exact measurement. The openings are arranged in a plurality of rows and I have indicated three rows in Figure 4. The openings in adjacent rows are staggered and they are placed as close to gether as possible. This construction does not weaken the perforated guard portionto too great an extent sincethe diflerences in curvatures between the outer cylindrical surface of the guard and the, inner cylindrical surface of the bore 6 is such as to provide metal adjacent to the sides of the group of circular openings which will rapidly increase in thickness. The guard portion that has the circular openings can be thin because the metal around each opening forms a continuous reinforcement around the opening that serves to support the entire area against external pressure. This external pressure is caused by placing the guard against the skin in the act of shaving. The entire circular edge of each opening 1 constitutes a hair cutting edge as will be hereinafter described more fully;

In addition to the circular openings 1, I provide two groups D and E of transversely extending slots t. The slots in each group have their inner ends preferably extending from points near to the circular openings 1. In actual practice, ten thousandths of an inch separates the openings from the slots. The other ends of the slots terminate at points making angles of 90 with a median line extending longitudinally through the center row of openings 1. The slots are preferably ten thousandths of an inch in width and the distance between adjacent slots is preferably fifteen thousandths of an inch in width. The inner edges is of the slots constitute cuttingedges and also the parallel edges lb of the slots constitute haircutting edges The thickness of the guard metal wall between the circular openings 1 and the inner ends of the slots I is preferably five thousandths of an inch in thickness. As already stated, the thickness of the curved top of the guard wall by traversely extending bars It which are pref-' erably one sixty-fourth of an inch in width.. The

slots Ii extend on opposite sides from the median rapidly increases from an extreme thinness of about three thousandths of an. inch at the top of the guard due to the difference in curvature between the outer guard surface and the bore 6. A wedge-like supporting construction is thus provided for both guard wall portions that extends from the circular openings 1 to the guard base.

The circular openings 1 are designed to receive short hairs while the slots 8 are adapted to receive longer hairs. I provide novel means for guiding the longer hairs into the slots I and this comprises comb-like portions I arranged between ad- Jacent slots. The slots I define bars II and these bars have outwardly extending projections to that form the multiple hair-parting combs 9. The overall height of the projections is preferably not over one thirty second of an inch and the proiections in each comb are placed as close together as possible. The projections taper to their outer irritation to a minimum. The comb teeth are placed close together so as to travel over the skin with less tendency to dig into the skin, thus avoiding this type of discomfort to the user. The inner comb ends start at an angle of approximately twenty two and one half degrees from each side of the median line that extends through the central row of circular openings 1, and the outer comb ends terminate at about an angle of forty five degrees. The multiple combs 9 in bordering the sides of all of the slots 8 will immediately part the longer hairs and guide them into the slots and cause them to remain within the shearing edges of the slots until sheared off by the cutter. The multiple combs prevent the longer hairs from emerging from the slots due to the action of each tooth being followed by a succeeding one to hold the hairs in the slots until sheared.

It is best now to describe the cutter C. The cutter has an outer cylindrical diameter the same as the diameter of the bore t except that the bore l is large enough to permit a slight clearance between the bottom of the cutter and the bottom of the bore. The length of the cutter is less than the length of the guard so that during the reciprocation -of the cutter, its ends will always lie within the ends of -the guard. The cutter has transversely extending slots Ill arranged on opposite sides of a median bar If. The slots are preferably one sixteenth of an inch wide and the median bar I! is preferably about ten thousandths of an inch in width. The slots II are separated bar I! through an arc of substantially 90". The cutter C has a hair-receiving channel or bore it that communicates with the cutter slots. The slots- II are wider than the bars IS in order to allow for a sufilcient time interval for the hairs to enter the slots during each cycle or stroke of the cutter. The bore I4 is ecoentnically arranged with respect to the cutter axis for providing a thin wall about ten thousandths of an inch in thickness adjacent to the median bar If and the inner ends of the slots II. The cutter bars l3 quickly increase in thickness due to the difference in ourvatures between the outer surface of the cutter and the inner surface of the bore H. Th inner edges Ila of the slots I I and the parallel, edges llb constitute hair cutting edges. Although the continuity of the cutting edges Ila is broken by the inter-posing bars l3, these separated edges actually present continuous cutting edges while the cutter is in motion because of the end to end movement of the cutter.

The cutter C has a recess 15 in its base of the exact diameter of the roller and that receives the upper portion of the spherical roller 3. Since the spherical roller is 'eccentrically mounted with respect to the shaft l, a rotation of the shaft will cause the spherical roller to move the cutter through a double helical motion. The advantage of such a motion will be presently set forth. The diameter of the recess i5 is the same as that of the spherical roller periphery.

I provide novel means for yieldingly urging the cutter toward the perforated portion of the guard. Spring-pressed balls l6 are mounted in bores l1 and bear against the cutter base. Screw plugs l8 close the lower ends of the bores and hold the springs l9 against the balls. The bores extend radially from the axis of the cutter receiving bore 6 and two bores are disposed near each end of the guard. Figure3 illustrates the bores as extending inwardly from the base corners. The bores fall short of completely passing into the cutter receiving bore so that the inner ends of the bores will be reduced for preventing the balls Hi from entirely moving into the cutter bore should the cutter be removed and yet the balls are free to ride on the cutter to yieldingly keep the cutter in contact with the guard and to impart an inward and upward pressure to the guard. Any side slap that may have a tendency to develop due to the side thrust of the eccentric drive on the cutter base is prevented.

From the foregoing description of the various Parts of the device, the operation thereof may be readily understood.

In Figure 5, I illustrate what takes place between the cutter and a circular guard opening when the cutter is moved through a complete cycle. Only one opening I is illustrated for purpose of clarity and four positions of the cutter C are illustrated. The eccentric stem 2 and spherical roller are assumed to be moving in a clockwise direction and in the left hand sketch of Figure 5, the cutter is being moved substantially to the left as indicated by the arrow a. Hairs received in the left portion of the opening 1 will be trapped hythe cutting edge ill) and severed. The left hand portion of the cutting edge of the opening I is used.

Through the next of swing of the eccentric, the cutter will be moved substantially laterally in the direction of the arrow b shown in the second sketch of Figure 5. Here the cutting edge Ila of the median bar I! comes into action and cooperates with a portion of the circular opening cutting edge 1 which is removed about 90 from the former cutting edge. Then for .the next 90 of rotation of the eccentric, the cutter is moved substantially to the right as shown'by the arrow in the third sketch in Figure 5. Here the right hand edge portion of the circular opening 'l is used and the edge llb or one of the slots ll disposed on the opposite side of the median bar l2 comes into play. The median bar I 2 has crossed the opening 1.

Finally, the last 90 of eccentric pin movement before the cycle is completed, the cutter will be moving in a substantially transverse direction as shown by the arrow d in the fourth sketch of Figure 5. The opposite side Ila of the median bar cooperates with a portion of the circular opening 1 to sever the hair therein. It will be seen that for each cycle of a double helical movement of the cutter C, four distinct portions of each circular opening I will be used which means that the cutter will sever hair when moving in four different general arc-like directions, each being at an angle of 90 apart from the preceding movement. The four sketches, in Figure 5 give a progressive view of four general phases of one complete cycle. Hairs are sheared off on all portions of each circular opening 1.

While only four phases of the cycle or stroke of the cutter are shown, it will be noted that the peripheries of the openings I are engaged from all angles by the shearing edges I la and llb of the cutter in the course of each cycle of the cutter in its double helical motion, The straight edge of the cutter working against the concave edge of the opening I will create a better hair severing action than where two straight hair-cutting edges cooperate. The cutter is reciprocated from end to end and is rocked from side to side in a compound motion so that all portions of the circular openings will be used for severing hair. The cutter makes a circular out due to its double helical movement.

The longer hairs are combed into the slots 8 by the multiple combs 9 and are kept continually combed into the guard slots by one tooth following another until the hair is severed by the cutter. The rocking of the cutter is preferably through an angle that will carry the median cutter bar l2 past the two side rows of circular openings. The end to end movement of the cutter in effect causes the two rows of spaced cutting edges Ila to become two continuous rows of cutting edges or two continuous cutting edges, One being disposed on each side of the bar l2. The outer surface of the cutter is longitudinally grooved at two places on opposite sides of the bar l2. The grooves are concave in cross section and are for the purpose of reducing friction caused by the lateral stroke of the eccentric drive.

I claim:

1. An electric dry shaver comprising a guard having a plurality of circular openings therein for receiving hair, a cutter movably mounted in the guard and having a plurality of haircutting edges extending at right angles to each other, said cutter being simultaneously reciprocable in a longitudinal and lateral direction for causing its cutting edges to cooperate with the entire circular edges of the guard openings for severing any hair received in the openings.

2. An electric dry shaver comprising a guard having a plurality of circular hair-receiving openings therein, a cutter movably mounted in the guardand having transversely extending 0 slots with transversely extending cutting edges,

the slots being arranged on opposite sides oi a median line to define a bar that has spaced longitudinally extending cutting edges arranged along each side, said cutter being simultaneously reciprocable in a longitudinal and lateral direction for causing successive cutting edges along the bar and the transverse cutting edges of the slots to pass the circular openings and sever any hair received in the openings, the longitudinal l5 movement "of the cutter in effect making continuous cutting edges along the bar sides.

3. In'an electric dry shaver, a guard having a cylindrical cutter-receiving bore therein and hair-receiving openings, a cylindrical cutter slid- 20 ably mounted in the bore, and spring-pressedmeinbers carried by the guard and extending radially from the cutter axis and at different angles for exerting a radial force against the cutter for yieldingly holding it against the cylindrical perforated portion of the guard while permitting -the cutter to move both longitudinally and laterally.

4. In an electric dry shaver, a guard having a plurality of transversely-extending hair-receiving openings separated from each other by trans- 40 and laterally-extending cutting edges, said cutter being movable through a double helical path for causing its cutting edges to cooperate with the entire rims of the circular openings for cutting hair received in the openings in various directions and for causing the cutter edges to cooperate with the slot edges for cutting longer hair received in the slots.

6. In an electric dry shaver, a guard having a plurality of circular hair-receiving openings flanked by two groups of laterally-extending hair-receiving slots, a cutter reciprocably and rockably mounted in the guard and having longitudinal and laterally-extending cutting edges,

said cutter being movable through a double helical path for causing its cutting edges to cooperate with the entire rims of the circular openings for cutting hair received in the openings in various directions and for causing the cutter edges to cooperate with the slot edges for cutting longer hair received in the slots, and comb-like means placed between the slots for combing and guiding long hair into the slots for cutting purposes.

7. In combination, a guard having a plurality of rows of circular hair-receiving openings therein, a cutter movably mounted in the guard and having a median bar with longitudinal and spaced cutting edges, the cutter being rockable for moving the bar transversely across the openings, said cutter also having transverse slots with parallel and transversely extending cutting edges,

said cutter also being movable longitudinally in the guard for causing the parallel cutting edges of the slots to cut hair received in the openings,

whereby the arrangement of the cutting edges in the cutter and the particular movement of the cutter will sever hair around the entire circular edges of the openings in the guard.

8. In combination, a guard having a plurality of rows of circular hair-receiving openings therein, a cutter movably,mounted in the guard and having a median bar with longitudinal and spaced cutting edges, the cutter being rockable for moving the bar transversely across the openings, said cutter also having transverse slots with parallel and transversely extending cutting edges, said cutter also being movable longitudinally in the guard for causing the parallel cutting edges of the slots to cut hair received in the openings, said guard having transverse slots cooperating with the cutter slots ior severing longer hair received in the guard slots.

9. In combination, a guard having a plurality of rows or circular hair-receiving openings there'- in, a cutter movably mounted in the guard and having a median bar with longitudinal and spaced cutting edges,-the cutter being rockable for moving the bar transversely across the openings, said cutter also having transverse slots with parallel and transversely extending cutting edges. said cutter also being movable longitudinally in the guard for causing the parallel cutting edges of the slots to cut hair receivedin the openings, said guard having transverse slots cooperating with the cutter slots for severing longer hair received in the guard slots, and comb-like members carried by the guard for combing longer hair into the guard slots.

10. In an electric dry shaver, a guard having a plurality of circular hair-receiving openings, and a cutter movably mounted in the guard and having cutting edges extending in substantially longitudinal and transverse directions, the cutter being movable longitudinally and transversely so that its cutting edges will be moved totalre a circular path and cooperate with the guard openings for cutting hair around the entire edges 01' the

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