US2591403A - Shaver head - Google Patents

Description

April 1, 1952 L. c. CARISSIMI 03 SHAVER HEAD Filed June 26, 1947 INVENTOR C. C'arzaazmz Patented Apr. 1, 1952 SHAVER HEAD Louis C. Carissimi, Fairfield, Conn., assignor to Remington Rand Inc., New York, N. Y., a corporation of Delaware Application June 26, 1947, Serial No. 757,278

(Cl. m -43) 2 Claims. 1

This invention relates to improvements in the construction of heads for dry shavers.

It is characteristic of the operation of dry shaver that the bristles over which the shaver head is traversed in normal operation are not all shaved off at one sweep. In practice it is necessary to move the shaver back and forth several times in contact with each area of skin to be shaved before it can be shaved smooth. In fact, not all the hairs and/or bristles which enter through the slots of the outer cutter are severed, many of them being rejected or forced out again by the inner cutter bars. With many types of head, some bristles, especially if they are more than ordinarily long, and hair, for example, such as the hair at the edges of a mustache and the bottom edges of the side burns, instead of being severed, can be gripped between noncutting regions of the cooperating cutter bars and the result is an unpleasant and somewhat painful dragging action.

It is an object of the present invention to pro vide a dry shaver head in which those disadvantages are minimized. To that end a dry shaver head, according to the present invention, comprises a stationary outer cutter and a cooperating reciprocating inner cutter, both of which have fiat cutter bars extending transversely, the inner cutter being narrower than the interior of the outer cutter and being located therein so that a space is left in the outer cutter at each side of the inner cutter into which space the ends of the longer bristles and hair can project free of contact with the inner cutter, and, in addition, the edges of the inner cutter are beveled so that the ends of hair and/or bristle in the spaces can be caught between the cutter bars of the inner cutter before, with normal traversal of the shaver head across the skin, the entrapped bristles and/ or hair pass to the cutting zone, where the inner cutter is reciprocating with its outer face in engagement with the back of the cutter bars of the outer cutter.

In the drawing:

Fig. 1 is an enlarged side elevation of a portion of one end of an electric shaver showing a cutter head, constructed according to the invention, in side elevation with portions broken away and shown in section to illustrate details of construction.

Fig. 2 is a transverse section taken substantially centrally through the head structure shown in Fig- 1.

Fig. 3 is a fragmentary plan view on the enlarged scale of Fig. 2 showing one end of the inner and outer cutter in assembled relation illustrating details of construction.

Fig. 4 is an enlarged fragmentary longitudinal cross-section taken on line 44 of Fig. 3.

Fig. 5 is a bottom plan View of the inner cutter on a reduced scale from that shown in the pre-v vious figures.

Shearing head I according to the present invention is formed of a stationary outer cutter 2 and an inner cutter 3 mounted in outer cutter 2 for reciprocating movement. Fig. I shows the shearing head mounted on a handle 4 in a manner well-kown in the art.

Stationary outer cutter 2 has a base 5 extending longitudinally and the sides of a sheet metal shear plate of inverted substantially channel formation secured to opposite sides thereof, in the manner shown in Fig. 2. The shear plate is formed on the outer end opposite base 5 with a plurality of spaced parallel, straight, flat cutter bars 5 separated in the central portion by groove 7 formed by an inwardly projecting guide rib 8.

The shear plate is formed with upwardly offset ends 9 at opposite ends to provide a rigid cutter structure. Side walls H! of outer cutter 2 are offset at H in longitudinally extending relation below the ends of cutter bars 6 for cooperation with onset ends 3 and rib 8 to further increase the rigidity of the outer cutter structure. It will be noted that the outer cutter in being slotted to form spaced parallel cutter bars 6 is constructed so that the cutter bar and slot structure extends down side walls Ill leaving openings 12 so that long hair can move into the shaver head between cutter bars 6. Rib structure 8 is also slotted below the ends of cutter bars 5, as shown in Fig. 2 at l3, to facilitate the entry of hair between the cutter bars. Cutter bars 6 have the central portions joined by lands 6'.

The outer cutter has the inner sides of cutter bars 6 and the outer sides of rib 8 as indicated at M and I5, respectively, accurately ground and lapped to provide a desired thickness of cutter bars and the desired dimension between opposite outer side faces of rib B. This grinding and lapping provides a substantially flat inner surface on the cutter bars and flat guide faces on rib 8.

Inner cutter 3 is formed of sheet metal bent into a substantially rectangular shape in crosssection, as shown in Fig. 2. The meeting edges of the strip forming inner cutter It are at the bottom on one side, as illustrated at IS in Fig. 5. Inner cutter 3 is formed with a pair of spaced rows of cutter bars I! in spaced parallel relation to provide slots between said bars. These spaced rows of cutter bars H are separated by inwardly extending rib l 8 having the inner side facesspaced apart a distance slightly greater than the distance between the ground outer sides l5 of guide rib 8, so that rib [8 will cooperate with rib 8 to provide a guide for the inner cutter in its reciprocating movement in the outer cutter with just sufficient clearance between the ribs to provide free movement of the inner cutter.

Side walls IQ of inner cutter 3 are spaced apart a distance substantially less than the distance between the upper ends of side walls It of outer cutter 2, as shown in Fig. 2, to provide open hairreceiving chambers 20 between the inner faces of side walls I and the outer faces of side walls l9 of outer and inner cutters 2 and 3 respectively. This provides for the combing action of the outer cutter receiving long as well as short hair between cutter bars 6 so the hair may be freely combed into the open slots between cutter bars 6 and into hair-receiving chambers 20 before reaching the cutting zone of the shearing head.

Cutter bars ll of inner cutter 3 have a pitch equal to twice the pitch of cutter bars 6 so that they are, therefore, spaced apart a distance equal to two cutter bar 6 and, therefore, engage every other cutter bar in normal operation of the shaver head as clearly shown in Figs. 3 and 4. Cutter bars 6 on one side of groove 1 and the corresponding cutter bars ll of inner cutter 3 are arranged in staggered relation to the cutter bars on the opposite side of groove 1. This is clearly shown in Fig. 3. The ofiset of cutter bars IT on inner cutter 3 at opposite sides of the inner cutter is equal to and the same as the offset of cutter bars 6 on opposite sides of groove i. Cutter bars 6 on opposite sides of groove 1 are arranged in alternate relation and staggered so that the cutting edge of the cutter bars on one side of groove I are staggered to an extent equal to one-half of the pitch of the cutter bars on the other side. Cutter bars I! on inner cutter 3 are also wider than cutter bars 6, as shown in Figs. 3 and l, in order that a portion of each of the cutterbars always has bearing engagement with the under facesof one or more cutter bars 6 of the outer cutter.

In order to increase the cutting efficiencyof thecutter heads, the inner cutter has the outer faces of cutter bars I! ground and lapped to produce flat outer surfaces for accurate registry and cutting cooperation with the inner flat lapped surfaces on cutter bars 6 to obtain efiicient cutting cooperation between the cutterbars of the inner-and outer cutters. To further increase the cutting efliciency of the shearing head, inner cutter3 has the ends of cutter bars ll where they join sides I 9, beveled on' a substantially 30 angle, as indicated at 2|, and the inner ends of these cutter bars joined with rib l8 beveled on a substantially 45 angle, as indicated at 22. These beveled ends on cutter bars H are formed by a grinding operation foraccurately grinding the ends of the bars to provide sharp cutting corners on cutter bars I! for cooperation with cutter bars 6 in providing an efficient cutting cooperation at points spaced inwardly from the ends of cutter" bars 6, as shown in Fig. 2.

The usual spring-pressed balls 23, or other equivalent means may be provided in shearing head base for resiliently projecting inner cutter 3 so that cutter bars I! have bearing engagement for cutting cooperation with cutter bars 6 of the outer cutter. An oscillating arm 24 operated by an electric motor, not shown, is utilized in a manner well-known in the art to reciprocate inner 2,591,403 l i .f.

cutter 3 in the operation of the shaver head. Balls 23 are larger than those usually used and have the upper ends of pockets 24 formed in base 5 receiving them, of a sufficiently larger size, to provide for oscillating movement of balls 23 back and forth with inner cutter 3 to reduce wear on the under side of the inner cutter.

With a shearing head constructed ashereinabove described, guide rib 8 interrupting the central portion of straight cutter bars 6, the ground inner faces of the cutter bars and the outer faces of rib 8, provide for accurate cooperation of inner.

cutter 3 therewith, so that it is accurately guided in the outer cutter. The ground guide faces l5 on rib 8 provide for this accurate guiding of the inner cutter and maintain it in position so hair receiving chambers 28 will receive hair combed by the ends of cutter bars 6 for the eflicient cutting of both long and short. hair as soon as it engages between the sharp corners at the outer ends of cutter bars ii of inner cutter 3 formed by ground beveled ends 2!. The beveled ends 22 on cutter bars ll at the inner end thereof, will also provide sharp cutting corners for cooperation with cutter bars 6 to out both short and long hairs entering between cutter bars H from central slots 1 at points spaced inwardly from the ends of cutter bars 6, as clearly shown in the'enlarged disclosure in Fig. 2. Lands 6 also cooperate to pick up short hair and straighten it for close cutting. Lands 6' aid in obtaining transverse close cutting of hair and to avoid cutting on a bias.

The invention claimed is:

1. In a dry shaver head including a stationary outer cutter of inverted substantially channel form having plural transverse laterally offset cut; ting bars, the outer ends of which define the upper terminals of downwardly extending vertical open slots, an inner cutter of inverted substantially channel form, slidable longitudinally in said outer cutter having an operative face defined by't'ransversely extending spaced cutter bars for cutting engagement with the cutter bars of said outer cutter, the outer ends of said inner cutter bars being bevelled to provide cutter bar portions extending outwardly beyond the cutting portions thereof and defining the upper terminals of downwardly extending vertical open slots, means for resiliently urging the outer face of said inner cutter into sliding cutting engagement with the backs of said cutter bars of said outer cutter, said outer bevelled ends of the inner cutter bars being spaced inwardly from the inner side walls of said outer cutter a distance greater than the thickness of said outer cutter and greater than the size of hair to be cut, and said vertical slots of said inner cutter being parallel to and spaced from the respective outer cutter vertical slots whereby hair and bristle may enter said outer cutter slots to freely project into the spaces between outer cutter bars and into the space between the outer ends of said inner cutter bars and the inner sides of said outer cutter before engagement with said inner cutter, with subsequententry of said hair and bristle between the bevelled outer ends of said'inner cutter bars for being firmly gripped therebetween before reaching the portions of said inner cutter bar engaged with said outer cutter bars for cutting of said hair and bristle.

2. A dry shaver head as set forth in claim' 1. wherein the outer cutter is formed of sheet metal having a flat top portion formed with depending side walls at opposite edges of said top portion, said top portion and side Walls having said cutter 2,691,403 5 7 bars formed with intervening slots therein, and REFERENCES CITED an P cutter formed of sbeet metal ha'Vmg The following references are of record in the plurality of cutter bars with transverse slots file of this patent: formed in a flat top portion, side walls depending from opposite sides of said inner cutter top por- 5 UNITED STATES PATENTS tion having continuations of said slots therein, Number Name Date said inner cutter top portions and side walls hav- 2,215,0 9 Going Sept. 17, 1940 ing a spaced relation to the inner surfaces of said 2, 23,156 Benner Nov. 26, 1940 outer cutter side Walls greater than the thickness 2,266,884 Martin Dec. 23, 1941 of said walls and greater by several times the 10 ,1 Carissimi A1312 194:3 thickness of human hair. 2,325,267 Murphy July 27, 1943 LOUIS C. CARISSIMI.

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