US2003761A - Safety blade - Google Patents

Description

June 4, 1935. N TE I 2,003,761

V SAFETY BLADE Filed Aug. 28, 1934 INVENTOR jvi'clzo avs jsta' fzzw NEY

is moved with a longitudinal component.

Patented June 4, 1935 SAFETY BLADE Nicholas Testi, New York, N. Y., assignor to Gillette Safety Razor Company, Boston, Mass., a corporation of Delaware Application August 28, 1934, Serial No. 741,754

4 Claims.

This invention relates to blades for safety razors and consists in a novel blade having its cutting edge so shaped that in use longitudinal movement of the blade on the face of the user is prevented or limited to a large extent. I have discovered that this desirable object maybe secured by dividing the cutting edge by spaced notches into sections terminated by unsharpened walls incapable of cutting the flesh.

In safety razors as heretofore constructed the degree of edge exposure of the blade has been of the utmost importance and the greatest accuracy has been necessary in manufacturing both the blade and the razor in order to keep the edge exposure within satisfactory limits. If the edge exposure is too little the razor gives an unsatisfactory shave and causes discomfort to the user. If, on the other hand, the edge exposure is too great the razor becomes dangerous and the user is likely to cut himself. On this account it has been found necessary heretofore to limit the edge exposure within tolerances of a few one hundred thousandths of an inch. In shaving with a razor having an edge exposure of the amount heretofore allowed the user has been liable also to cut himself by accidentally moving the razor longitudinally, or approximately so, while in contact with his face. Even skilled users of long experience have been likely to meet with this mishap, perhaps once or twice-during a year and the experience is always extremely startling and unpleasant and causes the user to find fault with his razor or blade although, as a matter of fact, the accident is almost unavoidable if a safety razor of standard construction is moved in the cutting edge into sections and being of sufficient width to admit a substantial ridge of flesh when in use j The side walls defining the cutting edge sections are unsharpened and so shaped as to preclude the possibility of cutting when the blade As herein shown the notches are square and relatively'shallow, and the cutting edge sections are terminated by unsharpened curves. When such a blade is pressed against the face of the user in shaving substantial ridges of flesh enter the notches in the cutting edge of the blade. The re action between these ridges and the walls of the notches in the blade tend strongly to hold the blade against longitudinal movement and at the same time leave it free for movement for the transverse or slightly oblique movement necessary for shaving.

These 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 illustration and shown in the accompanying drawing in which:

Fig. 1 is a plan view on an enlarged scale of a blade embodying the invention.

Fig. 2 is a fragmentary view of the blade on well-known types of safety razors. It is substantially rectangular in form having elongated centrally disposed end portions ll defined by re-entrant recesses in the corners of the blade, which recesses alsoterminate the cutting edges l5.

' The edge supporting portions of the blade are uniformly beveled on both edges from a line 16 to form the cutting edges l5. These are divided into spaced sections by ,a series of uniform notches 13. As herein shown each notch is substantially square at its inner end and is roughly twice the depth of the bevel. It is important that the notches [3 should be of substantial width in order that each may admit a substantial ridge of flesh when pressed against the face of the user.

In this respect a narrow slit would be inadequate and unsatisfactory and I particularly desire to exclude such blade construction from the scope of the present invention. The notches herein shown may be between .040 and .060 in width and it is notches of such order or magnitude that the present invention contemplates.

The'blade is internally slotted for the reception of blade-locating projections in the razor with, which it is to be used. The slot l2 herein shown is substantially as long as the cutting edges of the blade and provided at intermediate points in its length with spaced enlargements, that at the center being substantially circular in outline shaped.

The action of the blade on the face of the user is suggested in Fig. 5, from which it will be noted that the cutting edge Ii of the blade slightly depresses the flesh whlle permitting a substantial ridge thereof to rise and enter the notch l3. Under these conditions it will be apparent that it is important to shape the side walls of the notches so that there will be no danger of cutting in case endwise pressure is imparted to the blade. Accordingly, the walls of each notch II are curved or flared outwardly in an unsharpened curve ll which merges, smoothly into the sharpened cutting edge of the blade. The edge of the blade is thus safeguarded and the general outline of the notch is such as to facilitate its reception of a ridge of flesh which is maintained like a corrugation as the shaving stroke is imparted to the razor. As already pointed out the effect of such a series of spaced corrugations in interlocking engagement with the notches l3 is'to prevent or reduce any tendency toward a dangerous longitudinal movement of the blade. The blade of my invention is, therefore, not only safer and thus more satisfactory for the user but is of value from the manufacturing standpoint in that it permits greater variations in edge exposure without danger to the user and relaxes to some extent the expensive requirementsv of extreme precision heretofore necessary in manufacture.

The cutting edge of the blade herein shown is divided into separate sections by four notches of square bottom contour and uniform width, but it will be understood that the number and dimensions of the notches may be varied so long as they remain capable of serving their intended function, viz.-of retarding longitudinal shifting of the cutting edge on the face of the user. Similarly the bottom of the notches may be curved instead of rectilinear if desired.

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

' 1. An improved safety razor blade having an edge supporting portion which is divided by a series of uniform notches into sections each longer than the width of the notches and sharpened to a cutting edge, the cutting edge being terminated adjacent to each notch by an unsharpened curve of substantially the same radius as the length of the bevel. I

2. An improved safety razor blade having an edge-carrying portion which is divided by spaced square notches into sections of greater length than the width of the notches and beveled to form a cutting edge, the'beveled cutting edge of each section being terminated by a rounded curve incapable of cutting the user.

3. An improved safety razor blade having an edge supporting portion which is divided into spaced sections by notches of sufllcient width each to admit a substantial ridge of flesh, when in use, tending to restrain longitudinal movement of the blade, and each section having a cutting edge terminating in an unsharpened curve tending so to restrain the blade without danger of cutting. 4. An improved safety razor blade having an edge supporting portion divided into beveled edge sections spaced apart by shallow notches extending inwardly for only a short distance within the line of bevel of the edge and each having a flat bottom and flaring unsharpened walls at each side adapted to admit a ridge of flesh, when in use, without danger of cutting.

NICHOLAS TESTI.

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