US1815745A - Safety razor - Google Patents

Description

July 21, 1931. THOMPSON I 1,815,745

SAFETY RAZOR Original Filed April 25. 1929 Patented July 21, 1931 UNITED STATES PATENT OFFECE RALPH E. THOMPSON, OF BROOKLINE, MASSACHUSETTS, ASSIGNOR TO GILLETTE SAFETY RAZOR COMPANY, OF BOSTON, MASSACHUSETTS, A. CORPORATION 01 DELA- WARE SAFETY nAzon Original application filed April 25, 1929, Serial No. 358,114. Divided and this application flled December 3, 1930. Serial No. 499,744.

My invention relates to safety razors in which a-thin, flexible and elastic blade, of oblong contour with unsharpened ends and internally apertured to receive positlonmg 5 and clamping means, is removably secured in a holder comprising a guard member adapted to support the blade adjacent to its longitudinal cutting edges and a cap member provided on oppositesides with parallel straight edges which engage the blade adjacent to the longitudinal edges of the latter and flex it transversely on the guard member as a fulcrum during the process of clamping the blade in the holder, so that, when the razor is ready for use, the blade is maintained in -a transversely curved condition and subjected to a pronounced stress, particularly at its longitudinal edge portions.

The Gillette razor exemplifies the type of razor which is described above. For convenience that type of razor will be referred to in this specification and in the appended claims as the Gillette type, which term will imply the entire description contained in the preceding paragraph.

In-the use of such a razor, satisfactory operation requires very accurate positioning of the blade edge with respect to the guard, and consequently it is extremely desirable so that the parts which engage and flex the blade should retain, permanently, the precise shapes and dimensions imparted to them when manufactured. This is particularly true of the longitudinal straight edges of the blade-clamping cap, on which the alignment and amount of exposure of the blade edges depend, but inasmuch as these cap edges are necessarily made thin, in order to enable the cutting edge of the blade to reach the skin when the razor is held at the proper shaving angle, they are very easily deformed, particularly at the cap corners, to such an extent as seriously to impair the eificiency of the razor.

For example, the mere dropping of the razor, or of the cap alone has frequently resulted in bending over a corner of the cap to an extent suflicicnt, when the clamping pressure is applied to the blade, to produce an uneven edge exposure or even to crack or break off a portion of the blade itse1f., Such a result may occur even though the bending of the cap corner is so slight that it is not likely to be noticed by the user, this being due to the fact thatthe pressure thereby ap plied to the blade tends to flex it locally in a different direction from that in which it has already been flexed by the cap as a Whole, and accor ing to a familiar eometrical rinciple the blade cannot be so exed even slightly, without sub'ecting it to a greatly increased stress. n sucha case the user invariably considers the unsatisfactory operation of is razor to be due to a defective blade, and either continues to use the defective holder and to find fault with the blades, or else discards the razor in favor of one of another make.

To meet the difficulty above explained I have devised an improvement which is applicable to any razor of the construction hereinbefore described, and which consists in reinforcing the cap corners and giving the blade such a contour as to accommodate the reinforced corners.

The blade is described and claimed per se and also in combination with a safety'razor of well known construction in my copending application Serial No. 358,114 filed April 25, 1929 of which the present application is so a division.

Generally speaking, the present invention consist in a safety razor having a ca with reinforced corners, a construction w ich is made possible by the novel contour of my 85 blade and serves to minimize the liability of deformation of the cap, thus insuring the preservation of the straightness of its longitudinal edge where it acts upon the blade to flex and position it. The novel safety razor 00 thus characterized and the novel combination of such a razor with the blade of my invention is claimed herein.

My invention may be embodied to good advantage, if desired, in a safety razor havin 05 a' guard member provided with a channe un erlying the cutting edge of the blade as the channel provides a spacefor the reception of lugs which may be employed for reinforcing the cap corners, thus insuring that 100 the ln shall not contact with the guard for in sue a case the blade flexing or clamping action of the cap mightbe objectionably limited.- 1 These and other features of my 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 drawings, in which,'

Fig. 1 is a view in perspective'of one form of my improved razor. Fig. 2 is a view in perspective of the blade. Fig. 3 is a view in perspective on an enlarged scale showing a portion of the cap with the blade positionedthereon;

A Fig. 4 is a view in perspective of'one end of the assembled razor seen from beneath.

The blade-holding parts of the razor shown 1n the drawing are in general of stand- 7 operates. with the /guard 12 and is provided with a threaded center stem 19 projecting from its inner face and adapted .to' pass through a corresponding perforation in the guard member 12. The cap is also provided with a pair of blade-locating pins 16 herein.

shown as being circular in cross section, but which may be of any desired contour. The threaded center stem 19 extends into a hollow handle 18 which is secured at one end to the guard in the center of the latter and a nut 19 adapted to turn freely in the handle 18 and having its inner end internally threaded to engage the stem 19, whereby the parts are clamped together. I

The longitudinal edges 10 of the cap 15 overhang and are parallel to the fulcrum shoulders 14 of the guard and are located above the channels in position to overlie the cutting edges of the blade, so that when the blade is clamped in the holder the cutting edges are adjustably positioned and held over the channels as described in U. S. Let- I theremoval of the blade from the cap but also to provide enough material between the end perforation 23 and the ends of the blade to prevent cracking of the latter along its center line. In contrast to the standard blade heretofore employed in this type of razor,

however, my blade 22 is cut away at each. of

itsfour corners in such fashion as to provide a reentrant recess which bounds the corresponding end of the adjacent cutting edge and is so proportioned that when the blade is clamped in the holder these recesses span the, respective corners of the cap and provide clearance spaces of sufficient size to receive the corners and their reinforcing lugs which will be presently described. Consequently while my blade is being flexed transversely by the cap 15 and is engaged only by those portions of the straight edges 10 of the cap which lie between the corresponding recesses 25 of the blade, it cannot be broken or cracked by engagement with a cap corner either by being flexed or when clamped in final position in the holder.

It is noted that the reentrant recesses 25 are each bounded internally by a filet or inwardly curved portion, the effect of which is to prevent excesses of concentration of stress at these points when the blade is stressed, and thereby avoid breakage on account 'of such stresses.

The cap, which is of a distinctive construction made possible by the novel contour of the blade, is provided at each corner with a projection or reinforcing lug. 17. These as herein shown are located on the inner or concaved face of the cap and constitute reinforcements which supply additional strength to the cap at the points where it is most likely to be bent or distorted. The lugs 17 are integral with the cap and'so shaped that they taper inwardly from a maximum thickness at substantially the outer edge ofthe cap and are flush with its ends. The lugs therefore protect and safeguard the straight blade defleeting edges 10 of the cap, thus aflording additional assurance that the portion of the cap blade shall be undistorted and accurate in shape. The lugs are preferably so disposed and proportioned that when theparts of the razor are clamped together they pass into or through the recesses 25 in the corners vof the blades and into the channels of the'guard member 12 but without engaging the latter and without interfering with the cooperative blade-clamping action of the 'cap' and guard. The reinforcing lugs 17 may thus be made thicker and stronger than would otherwise be practical, but if these projections are not thicker than the blade itself or which is critical in its action upon the are differently disposed, the preference or absence of the channels is unimportant so far as the lugs are concerned.

In Fig. 3 the blade 22 is shown as resting upon the cap 15 in which condition the relative transverse position of the cap and blade. is determined by the action of the bladelocating studs 16 in the apertures of the blade. Thereentrant recesses in the corners of the blade receive the upwardly projecting lugs 17 affording clearance spaces for them, the blade thereby being entirely out of contact with the lugs and uninfluenced in any way by them. In assembling the guard member 12 upon the blade and cap it will be noted that the fulcrum shoulders 14 are located Within the blade flexing edges 10 of the 'no distortion of the reinforced cap corners is to be anticipated it will be apparent that, even should these become bent. the clearance spaces afforded by the reentrant recesses 25 of the blade will save the blade from being distorted or objcctionably affected in respect to its edge exposure.

Having thus described my invention what I claim as new and desire to secure by Let ters Patent of the United States is:

1. A safety razor comprising a flexible and elastic blade of substantially oblong contour and internally apertured to receive positioning and clamping means, a guard member adapted to support the blade adjacent. to the cutting edges of the latter, a blade clamping cap provided with parallel longitudinal edges and with reinforced corners, means for positioning the blade between the cap and the guard member, and means for clamping said parts together and simultaneously causing the longitudinal edges of the cap to flex the blade transversely on the guard member as a fulcrum the blade being provided with unsharpened ends and being cut away at each of its corners to such an extent as to span the corresponding reinforced cap corner and provide a clearance space of suflicient area to receive said cap corner if bent toward the guard member, each cap corner being located within the area of a cut away clearance space in the blade and also within the area of the guard and opposite the corners thereof, whereby a cap corner is prevented from exerting pressure on the blade while the latter is being flexed or when clamped and thereby breaking the blade or distorting its cutting edges.

2. A safety razor comprising a flexible and elastic blade of substantially oblong contour and internally apertured to receive positioning and clamping means, a guard member adapted to support the blade. adjacent to the cutting edges of the latter, a blade clamping cap provided with parallel longitudinal edges and reinforcing lugs at its corners, blade positioning projections, and means for clamping the cap and guard membertogether and for causing the longitudinal edges of the cap to flex the blade transversely on the guard member as a fulcrum, the blade being providedwith unsharpened ends and with reentrant recesses located at its corner portions respectively and each extending both longitudinally and transversely of the blade and cap to such an extent as to span the corresponding reinforced cap corner and provide a clearance. space freely to receive said cap corner each reinforcing corner lug being located within the area of one of said recntrant recesses and also within the area of the guard member and opposite to one corner thereof whereby the cap corner is prevented from exerting pressure on the blade while the latter is being flexed or when clamped and thereby breaking the blade or distorting its cutting edge.

3. A safety razor according to claim 2, in which the guard member is provided with a channel underlying the cutting edge of the blade and the corresponding cap corners and thereby providing space for the reception of the reinforcing lugs on the cap corners without limiting the blade flexing and clamping action of the cap.

4. A safety razor comprising a transversely flexible blade having a longitudinal cutting edge tcrminating at each end in a recess, which recesses constitute clearance spaces to eliminate clamping pressure at such recessed ends, a blade supporting member extending lengthwise beyond the cutting edge of the blade, and a blade-clamping cap having a straight edge engaging that portion of the blade between said recesses to bend substantially the whole blade transversely upon said supporting member and having its corners provided with reinforcing lugs extending in opposed relation to and toward the blade supporting member in the clearance spaces provided by said pressure preventing recesses and terminating in close proximity to said member.

5. A safety razor comprising a flexible blade with longitudinal cutting edges, cap and guard members shaped to maintain the blade in a transversely curved condition between thom, and means for clamping the parts together, said blade having recntrant open areas at the ends of its cutting edge, which open end areas constitute clearance spaces to prevent clamping pressure at the ends of the cutting edges, and the cap member having reinforcing lugsthat project above its bladeshaping surface and which pass into theopen areas of the blade toward the guard member within the area or outline of saidguard member and terminate in close proximity thereto.

(3. A safety razor comprising a flexible blade, with longitudinal cutting edges, cap and guard members shaped to maintain the blade in a transversely curved condition beterminate in close proximity thereto.

7. A safety razor comprising a flexible and elastic blade modified to receivepositioning and clamping means, a guard member adapted to support the blade adjacent to a cutting edge of the latter, a blade clamping cap provided with an outer clamping edge and with reinforcing lugs at its corners, means for positioning the blade between .the cap and guard members, and means to clamp said members together and simultaneously causing an outer edge of the cap to flex the blade transversely on the guard member as a fulcrum, the blade being cut awayat each of its corners at a cutting edge thereof to such an extent as to span the corresponding reinforcing lug and provide a clearance space of suflicient a'rea to receive said reinforcing cap lu each lug being. located within the area 0 the cut away clearance space in'the blade and also Within the area of the guard and opposite the corners thereof whereby a cap corner is prevented from exerting pressure on the blade while the latter is being flexed or when clamped and thereby breaking'the blade or distorting its cutting edge.

8. A safety razor comprising a cap memher, a guard member and a flexible blade, said blade having a shaving edge, said members and blade having positioning means for said blade and cooperating surface portions on said members to flex said blade trans- I versely and maintain said blade and the edge thereof in shaving position, in combination with means to draw said members together and maintain said blade i'n transversely fllexed of said members, said reinforcing means ex-- tending transversely of said blade at the ends of its cutting edge portion.

Signed at Boston, Massachusetts, this twenty-ninth day of November, 1930.

RALPH E. THOMPSON.

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