US2384051A - Safety razor blade - Google Patents

Description

P 1945. s. c. STAMPLEMAN SAFETY RAZOR BLADE Filed Nov. 9, 1944 WVE/VTU/Fl Patented Sept. 4, 1945 2,384,051 SAFETY RAZOR BLADE Samuel C. Stampleman, Cohasset, Mass., asslgnor to Gillette Safety Razor Company, Boston, Mass., a corporation of Delaware Application November 9, 1944, Serial No. 562,605

1 Claim.

This invention relates to blades for safety razors and more particularly to improvements in blades of the thin, flexible type.

Heretofore, the cutting edges of razor blades have been formed with the oppositely disposed bevels, which produce the edges, commencing directly and immediately from the opposed surfaces of the body portion of the blade and from lines quite close to the edges to be formed. Such construction makes for rigidity of th cutting edge when the blade is clamped between the ca and guard of the razor.

It has been found that the shaving qualities of a blade are considerably improved if its cutting edge is flexibly supported so that as it approaches the beard to make its severing contact therewith a slight yielding action occurs; that is, if the cutting edge is arranged so that it will flex minutely, a smooth, cleaner severing action takes place upon the follow-through of the stroke. This is mechanical compensation for the skilled wristfiex action of practiced barbers. While the support for the cutting edge must be sufficiently pliant to permit of the slight flexing beforementioned it still must have sufiicient body to prevent the edge from chattering.

Accordingly, it is the object of the present invention to provide a razor blade having cutting edges, the cross-sectional outline of which are,

in miniature, substantially that of the old-fashioned barbers razor, and which cutting edges are partially oriented from the blade proper by oppositely disposed grooves extending longitudinally in the opposite surfaces of the blade, adjacent the edges, to form slightly resilient connecting webs between the cutting edge portions and the blade proper.

These and other features of the invention will be best understood and appreciated from the following description of two preferred embodiments thereof, selected for purposes of illustration and shown in the accompanying drawing in which:

Fig. 1 is a perspective view of the blade on an enlarged scale;

Fig, 2 is a cross-sectional View, taken on the line IIII of Fig. 1;

Fig. 3 is a fragmentary sectional elevation showing the blade as flexed between guard and cap members of a safety razor; and

Fig, 4 is a similar view but showing a modification of the longitudinal edge-orienting grooves, the grooves herein being wider and extending under the cap member of the razor.

The invention as herein shown is embodied in is not restricted in its application to that or to any particular type of blade and with suitable modifications may be incorporated in any blade having a fairly substantial thickness, say in the order of .006 of an inch or more.

The blade herein shown is generally rectangular in outline, having reentrant corner recesses which define elongated unsharpened end portions I0 and I I, between which extend two similar side portions 12 and I3 that are separated throughout their length by a medial slot I4. The blade is of uniform thickness throughout its body portion and is flexible transversely of its medial longitudinal center. The slot It is of the usual configuration found in Gillette blades, being substantially co-extensive in length with the cutting edges ii of the blade, and having a centrally disposed circular enlargement and other intermediate enlargements that cooperate with corresponding projections (not shown) on either the cap or the guard of the razor for securely and accurately locating the blade thereon.

The outer longitudinal edges I5 of sid portions l2 and I3 are ground, honed and stropped to present keen, parallel shaving edges.

Preferably just prior to the edge-grinding operations, oppositely disposed rectangular shaped grooves [6 having sharply defined base corners are ground throughout the entire length of the side portions l2 and I 3, adjacent the edges IS. The depth to which the grooves are cut is governed conformably to the thickness of the blade but in any event sufiicient stock is removed from both surfaces to form a thin, fiexible web I! of uniform thickness throughout its entire length and width. The thickness of the web ll approximates per cent but not greater than 60 per cent of the thickness of the-blade stock. Specifically, in a blade of .006" thickness, the grooves are formed to a depth in the order of .0015" in opposite surfaces of the blade adjacent each edge IS. The width of the grooves is preferably sub stantially greater than their depth, say, at a minimum in the order of .012", although, as shown in Fig. 4, the width may be substantially increased and thereby corresponding increased flexibility of the rib I! obtained.

These grooves, by virtue of the sharply defined corners, partially but substantially orient the cuta blade of the well-known Gillette type but it ting edges from the blade proper. Finally, upon bevels at that point where they are intersected and the perpendicular wall of the groove that is farthest away from the cutting edge, and thus a flexible support for a relatively inflexible cutting edge is provided.

An alternative method of providing the groove II in the blade is by swaging the stock from opposite sides with suitably formed swaging toolsf In practicing this method, the grooving operation is performed concurrently with the blade-outlining or blanking operation and before the tempering process has taken place. In using this method any over-extension of the width of the blade between its parallel cutting edges is corrected by removal of the excess stock during the edgegrinding operations.

The location of grooves IS on the blade is such that when the narrower form of groove is provided (see Fig. 3) it lies completely beyond the outer edge of the cap l8 of the razor when the blade is clamped between the cap and the fulcrum shoulder l9 0! the guard. When the wider groove, shown in Fig. 4, is provided, a portion thereof lies under the cap for approximately three-fourths or thereaboutsof the groove width. In this latter form, wherein the degree of flexibility of the cutting edge is materially increased by the wider web [1, the extreme outer edge of the cap acts as a limiting stop for the outward flex of the cutting edge by the base of the upper groove l6 contacting the lower comer of the cap when the outward flex oi the cutting edge has exceeded a proper amount of yield and would, it not prevented, increase the exposure of the cutting edge beyond safe limits.

Having thus disclosed my invention and described in detail, illustrative embodiments thereof, I claim as new and desire to secure by Letters Patent: 1

An improved safety razor blade having a flexible body of uniform thickness throughout, arelatively inflexible beveled cutting edge portion, and a thin flexible web co-extensive in length with the cutting edge, connecting the cutting edge portion and the body of the blade and being of substantially less thickness than the body of the blade, the back of the cutting edge portion being the full thickness of the body of the blade and the blade being constructed and arranged to be clamped in shaving position with the said connecting web free to flex and to support the relatively inflexible cutting edge portion in a yielding in shaving position.

resilient manner SAMUEL C. STAMPLEMAN.

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