US1772432A - Safety-razor blade - Google Patents

Description

Aug. 5, 1930. R. E. THOMPSON SAFETY RAZOR BLADE Original Filed March 19, 1930 Invenitn" 3 W gag.

, broken off in dispose of only obviated but Patented Aq s, 1930 f UNITED STATES PATENT QFFlCE RALPH E. THOMPSON, 0E BROOKLINE, MASSACHUSETTS, ASSIGNOR TO GILLETTE SAFETY RAZOR COMPANY, OF BOSTON, MASSACHUSETTS, AEORPORATION 0F. DELA- WARE SAFETY-RAZOR BLADE Original application filed March 19, 1930, SerialjNo. 437,224. Divided and this application filed July 7,

1930. Serial No. 465,880. r

This invention relates to safety razors constructed and arranged so to treat a replaceable blade when clamped in the holder as ,to indicate unmistakably that the blade has been used. In one aspect my invention consists in a blade adapted to be altered, marked or modified in its shape by being swagedor molded in the holder so as to indicate the fact of its use.

It is'important from themanufacturers standpoint to discourage the practice of resharpening standard blades and their sale by unscrupulous dealers as original blades. By this practice the purchaser is misled, exposed to danger of possible infection andlthe annoyance of blades with inferior and unsatisfactory cutting edges. My invention contemplates a novel blade for use in a safety razor of such construction that it will be impossible to clamp the blade in it for shaving purposes without permanently swaging or striking up from the material of the blade a characteristic upstanding configuration permanently incorporated in the blade structure and conspicuously indicating the history of the blade in respect to its prior use.

The attempt has been made heretofore to accomplish these results by providing the blade with a superfluous part which may be use, but this expedient not only introduces difficult problems into the manufacture of the tion of small jagged pieces of steel when the blade is used and these are troublesome to safely. In accordance with the present invention, these objections are not certain advantages are imparted to the used blade; for example, the swaged configuration imparted to it serves to insure the accurate location of the blade in the holder for every successive use, so that'the 'user may exactly re-establish the original conditions of location and edge exposure for each individual blade. Further, where the upstanding configuration takes the form of a blade but results in the forma- V 'guard. The blade projecting rim or tit, it serves to hold a part of the blade away from a' flat surface so that it may be easily picked up by the user. As herein shown, an upstanding rim or tit is swaged upon each face of the blade so that regardless of which face is down, one end of the blade will be lifted from the supporting surface and its handling thus facilitated.

ese and other features'of the invention will be best understood and appreciated from the following description of a preferred embodiment thereof, selected for purposes of lllustration and shown in the accompanying draw1ngs,-in which Fig. 1 is a view in perspective, on an enlarged scale, of an unused blade;

Fig. 2 is a view in perspective of the holder parts of the safety razor;

Fig 3 is a view similar to Fig. 1 of a used blade; and

Fig. 4 is a fragmentary view in section through the holder illustrating" the swaging 1 operation.

' guard members having cooperating blade shaping faces between which a thin flexible blade is clamped and positioned and its edge exposure determined.

The cap member 10 has a concave bladeshaplng face and parallel longitudinal edges adapted to engage the blade near its cutting edges and bend it over the surface of the 10 is provided with a central longitudinal rib 12 for locating the blade thereon and with a central threaded stud 14 with which the handle 32 cooperates in claniping the parts of the holder together. The cap 10 is herein shown as provided with reinforced corner lugs 16 and while this is a desirablecharacteristic, it is not essential to the present invention.

The guard member 22 is convex blade-shaping face either longitudinal edge in guard teeth 23 'ity 20 and the guard member is -ner recesses 44 definin concentrated in the end portions of the It is provided with a central aperture 26 through which the threaded stud 14 may freely pass and with a central longitudinal groove 24 to receive the rib 12 of the cap.

I-provide the cap and guard members with cooperating die elements and these may be arranged in any desired location and may be of any suitable shape. As herein shown, the cap 10 is provided at a point approximately midway between the end of the rib 12 and one of the corner lugs 16 with a four-sided pyramidal projection 18 which constitutes the male member of cooperating swaging dies. The guard member 22 is provided, in a corresponding location, with a square-sided opening 30, constituting the die cavity or female member of the pair of swaging dies. The cap 10 is further provided, at a diametrically opposite point, with a die cavrovided at the same location with a pyrami a1 swaging projection 28. It will be understood that the two pair of swaging dies described act in opposite directions upon a blade positioned between the cap and guard, the member 18 cooperating with the die 30 to swage an upwardly-extending configuration in the interposed blade and the projection 28 corresponding with the die cavity 20 in swaging a downwardly-extending configuration in the blade. The blade 40 herein shown as adapted for use with the holder above described is of the general type described in my copending application Serial No. 410,220, filed November 27, 1929. It is of thin flexible steel having oppositely-disposed cutting edges and cora central elongated unsharpened portion 0 the blade. It is provided with a centrally disposed slot 42 of substantially the same length as the cuttinged e which serves to locate or position the bla e in the holder and also to eliminate bending stress from the blade material adjacent to the cutting edges. The bending stresses aria) 1thus a e, which are softened in fan-shaped areas, indicated approximately by dotted lines in Figs. 1 and 3. The slot 42 intersects two diamondshaped apertures which may be used for positionin studs 0 similar shape. The blade is rovided with a small hole 46 located in eac of the softened areas, substantially half way between the slot 42 and the reentrant angle of a corner recess 44, where it will register with the die elements of the guard and cap. The holes 46 are preferably pf such size as to receive the ointed end of the yramidal projections 1 and 28 but are sma ler in diameter than the dimensions of the base of these ro- "ections. The result is that when the b ade 1S firmly clamped between the cap and ard the die rojections 18 and 28 are orced against t e edge of the holes 46 which, as already explained are located within softened the blade in holders provided with areas and are, consequently, of a flexible or ductile nature. The material of the blade is thus swaged or drawn upwardly, forming a more or less irregular upstanding rim or a tit 48, as shown in Figs. 3 and 4. As the metal of the blade is expanded in this operation, it will be impossible to restore it to original condition or to bend it down again without noticeably distorting the original outline of the hole. The blade is thus unmistakably and indelibly marked as a used blade. It is, moreover, accurately and perfectly fitted to the individual holder in which it is to be used and, as already pointed out, 3

it will no longer lie flat upon or adhere to a supporting surface but will rest in a spaced condition wherein it may be easily picked up. The tits, moreover, tend to prevent displacement of the blade. in the holder in case the clampin engagement of the cap and guard is released y the user, as is sometimes done in order to secure an increased edge exposure of the blade. Further, the tits tend to hold the blade slightly away from the blade engaging faces of the holder when the clam ing pressure is releasedand thus facilitate ush-.

ing the razor.

While I have shown the holes 46 in the blade as circular in outline, it will be understood thatthese may be of any ,desired shape which will facilitate the swaging operation and may be located in the softened areas of the blade wherever desired. Furthermore,

while it is desirable to form one or more swaged configurations in each end of the blade, it would be within the scope of the lnventlon to treat the blade at a single point only.

The present'application is a division of my copending application Serial No. 437 ,224, filed March 19, 1930, in which I have disclosedand claimed one form of safety razor adapted for use with the blade herein shown.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

' 1. A thin flexible blade for a safety razor having positioning a ertures, a ductile area,

and a hole distinct rom said apertures, lo-

cated in the ductile area and ada ted. to re-' ce1ve a swaging projection in a holder, whereby the margins of the hole are swaged out of the plane of the blade.

2. A thin flexible blade fora safety razor havmg a positioning aperture and a ductile area ad acent one end of the blade in which 15 formed a small hole adapted to receive a ta ermg swaging projection in a holder, w ereby the edge of the hole is drawn into an upstanding rim when the blade is clamped in the holder.

3. A thin flexible blade for a safety razor having a positioning aperture and duetile areas adjacent to. both ends of the blade in 'which are formed holes adapted to receiveoppositely directed swa ro'ections in aholder, whereby op osit l fixgenlling tits are formed in the bla e when-it is clamped in the holder. v

4. A safety razor blade having cutting edges terminating in reentrant corner recesses which define an elongated unsharpened portion of the blade, an elongated slot centrally disposed in the blade, ductile areas extending from the ends of the slot to the ends of the blade, and a hole located in one of said ductile areas and adapted to have its margin swaged into an upstanding tit.

Signed at Boston, Massachusetts, this 3rd day of July, 1930.

RALPH E; THOMPSON.

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