US2363894A

US2363894A - Safety razor and blade

Info

Publication number: US2363894A
Application number: US519899A
Authority: US
Inventors: Muros Joseph
Original assignee: Gillette Safety Razor Co
Current assignee: Gillette Co LLC
Priority date: 1944-01-27
Filing date: 1944-01-27
Publication date: 1944-11-28
Anticipated expiration: 1961-11-28

Description

Nov. 28, 1944. I 2,363,894

SAFETY RAZOR AND BLADE Filed Jan. 27, 1944 v wi h-r MNVgNTOR. BY H %W/ ATTU EY Patented Nov. 28, 1944 ,UNI'TE D STATES, PATENT 1 O FIC 2,363,894 AND Joseph Mums, Cambridge, Mass, assignor to Gil lotto Safety Razor Company, Boston, Mass, a corporation ofDelaware ".fipplieationlamuaryjz'l.1944, sw rm. 519,899 r 10 Claims.

This invention relates tosaie'ty'razors and consistsfin an improved blade of the thin flexible open-end type and "in a novel comination of such blade with the, blade-clamping members ofa safety razor. Open-end razor blades, that to say, blades having a longitudinal slot opening out through one of the transverse end edges of the blade; may i be employed in safety razors in which the cap and guard members are detachably connected, and such blades have the additional advantage that they .may also bepresented by" endwise movement in any safetyrazor wherein t'he cap and guard members are connected to permit only a limited separation. Such razors are preferred by many users because by'obviating the necessity of detaching and separating the parts of the ra zor the danger of misplacihg or losing them is, eliminated.

It has been found thatin safety razo'rs of 'the type wherein the blade is transversely flexed whenit is clamped in shaving position, as the "Gi llette" type safety razors, the cutting edges of an "open-end: blade are frequentlynellected out of their normal parallel relation. Whereas, thetwo sharpenedllongitudinal edges may be dis posed accurately in parallel relation when the outline of the blade is initially determined, the

two edges are often iound'to divergewtoward the l yersecurvature to the blade the desired lateral openeend of the blade when the; blade is flexed and clamped in the razor. fl'ihis is due partly to the fact that the hinge: portion at the closed or solid end of the blade has a restraining eifect on the two side portions. which is entirelyabsent at the open-end of the blade. Going moreuinto d'e-. tail, the side portions are tied together at the.

closed end of the blade by a flexible eomiection which, when curved :by the cooperating: clamping elements of the razor, causes the cutting edges of the blade to draw together. However, inasmuch as the side portions of :the blade ladjacent to its open end :are :free and unconnected the free ends'are not subjected to drawing in action These differences in structure "and behavior, and possibly other causes, often result in a departure from parallelism or Ithetwos'harp- A ened cutting edges in .an open-tend blade when finally clamped in shaving position S1ich variation detracts from the precision of the'ass'embled razor 'and produces irregularities in the edge exposure of the .blade that may evenbecome so excessive as to be-:d'angero1.is in some cases. l

I have improved the structure andiunctioning or open-end razor blades and have solved the (01-1 til-465i I two side portions of the blade to draw together in the clamping operation. until arrested by properly spaced stops or gauging surfaces. Inefiect I impress a drawing-together movement on the free ends of. the blade that compensate for the drawing in of the other ends. of the sharpened edges caused'by the hinge connection between them. This I am able to do by lengthening or flattening a transverse arc in the hinge area or to in the solid endiport'ion of the flexed blade, thereby causing the two side portions of the blade to swing toward each other at their free ends. An

abutment or blade stop is located between the free ends "of the. blade and arranged to present 21-5 opposed outwardly directed stop'origauge faces.

Undersuch circumstances the ends of the blade will continue-to draw in until opposing inwardly directed gauging edges in the two side portions oftheblade' bring up against the outwardly di- 20 rected stop faces of the abutment and so ar-rest the movement of the side portions when each movement l-1as-prog-ressed to the point-wherethe sharpened cutting edges of the blade: are exactlyparallel.

25 The treatment of the open-end blade contemplated by my invention .is effective only when the blade itself is supported or partially clamped-in a. condition. of transverse curvature. I have discovered that having once given such initial transtransverse axis and thus widened, the side portions areiound to swing toward each other about axes located somewhere in the hinge area and near to the closed end or the blade slot.

v' This secondary or longitudinal flexing -of' the hinge area may be efiected in any. desired manher, but as herein shown andin accordance with another feature of my invention, it is effected by providing in the material of the hinge porti-on of the-bladeone or more projections so lo- 45 cate'd as to be engaged and depressed by the into position to be engaged by the inner face of o 1:50 the cap member of the razor when the cap and guard membersare clamped together. The portion oi -the hinge areacontaining the projection is thus flexed longitudinally in the razor and the desired compensating movement isthus imparted pmblem of uneven edge exposure by sensing the o6 totheside portionsoi the-blade; "Preferably-and of the safety razor.

as herein shown the projecting bosses may extend in opposite directions from the hinge area of the blade so that the same flexing of the hinge area will occur no matter which side up the blade is presented. It will be understood, of course, that the cooperating blade-clamping member is shaped to afford proper clearance for the flattening deformation which is impressed tion is within the scope of the present invention. These and other features of the inventionwill practice.

This alternative construcbe (best understood and appreciated from the fOlv In Fig. 1 is shown a portion of the thin flexible steel ribbon used in manufacturing blades. like the blade 10 illustrated individually in Fig. 2.

The steel ribbon is supplied in thicknesses between .003 to .007 and of the width desired in the finished blades. The blades I0 are first outlined in strip by punching the outline of the corner recesses and ofthe longitudinal slot l3. The bosses l6 and H are also produced at the 'proper points in the blade strip as it is advanced from one stationv to the next, either before or after the tempering step. The punched strip is hardened and tempered, annealed in the hinge areas] 2 and ground, honed and stropped to produce the cutting edges II in the blade strip.

1 "Subsequently the individual blades III are sepa-' shown in the accompanying drawing, in which: i

blade in flexed position upon the convex guard member of a safety razor; I

, Fig. 3 is a view of therazor in end elevation showing a blade in cross-section, all on a greatly enlarged scale; and

Fig. 4 is a similar view showing a boss on the cap member Of the razor instead of on the hinge area of the blade. I i f The preferred embodiment of the blade of my invention is best shown in Fig. 2. It is nearly rectangular in outline being sharpened in its opposite longitudinal edges II and provided with reentrant recesses in each of its corners. Two of .these recesses form the elongated unsharpened end [portion [2 at the solid end ofthe blade and in part define the hinge area therein. The blade is also provided with a centrally disposed longitudinal slot l3. This opens out through the outer transverse edge of the elongated unsharpened end portion at the open end of the blade. The slot [3 is designed to receive a blade-locating rib or projections ofthe cap member of a razor and to provide opposed inwardly-directed stop or gauge edges l8'adjacent to the open end of the blade. The slot mergesinto anintermediate circular enlargement I5 provided to receive the threaded stem of the cap. It has also other intermediate enlargements to receiveblade-l'ocating projectionsof the Various. designs found in other safety razors. I

At the solid end of the blade the slot I3 terminates in a narrow transverse enlargement 14 which has the effectof distributing bending stress in the blade and defining the inner boundary of the hinge section. The hinge section is annealed and softened so that it may flex Without breaking, while the remairiderof the blade is hardened and tempered for cutting. At its open end the slot l3 flares somewhat to facilitate engaging the blade-locating projections when the blade is presented endwise and enters between the cap and guard members of the razor. In the material of the hinge area are provided oppositely directed conical bosses l6 and H which may be .003" to .015" in height. As shown in Fig. 2 the boss IT projects upwardly and the. boss 16 downwardly. These bosses are located symmetrically at either side of the longitudinal axis of the blade and substantially centrally between the outer and inner edges of thehinge area, although their location and distance from the and edges of rated from the strip on transverse lines, each line including or coinciding with the right-hand end of one of theblade slots l3 as seen in Fig. 1. Afinal smoothing operation on the transverse the bladesproduces the finished blade.

In Fig. 2 the blade I0 is shown as transversely flexed upon the guard member 20, shown as line being provided with downturned guard bars shoulders 22.

2| atits opposite edges and longitudinal fulcrum tudinal slot 23 and with a central perforation, correspondingto the aperture [5 of the blade,

forthe passage of the stem of the cap. .The

blade is of such length that its open endedge lies flush with or within the adjacent end of the guard. I a j The cap member 24 has a transversely concaved inner face which overhangs the fulcrum shoulders 22 and flexes th blade l0 over them by engaging it along lines within its cutting edges l I. 26 which passes through the guard member 2|] andis engaged by a correspondingly threaded handle 21. The stem 26 is reduced in width immediately. below the face of the cap to accommodate the width of the blade slot 13. The cap is provided with a pair of abutments or short ribs 25 which constitute blade-locating means and which provide outwardly directed stop or gauge surfaces to be engaged by the inwardly directed gauging edges l8of the blade.

The bladeas shown in Fig. 2 is represented as transversely flexed over the fulcrum shoulders 22 of the guard .20, that is to-say, the hinge l2 jected :to a minute secondary flexing by the engagement of the cap 24 with the upstanding boss ll: of the blade. On this account the outer arc B of the hinge I2 is slightly depressed, being flattened and thereby transversely elongated. On the other hand, the. inner are A of the hinge 12 is not subjected to this secondary deflection but remains unchanged in its transverse dimension withthe result that the two side portions of the blade are drawn or thrown inwardly. toward each other at their free ends.

into contact with and stopped against the outwardly'directed gauge faces of the studs or rib 25 and the cutting. edges jll of the blade..are,

It is also provided with a longi- It'is provided with a centrallythreaded stem- The inner Y gauging edges N3 of the blade are thus brought exact parallelism. l

The exact location of the bosses and I1 i of:

secondary importance so long as they serve to receive and transmitto the hinge area the pressure of the cap member 24. They may be located anywhere in the hinge area I2 andmay be separated by substantially thefull width of the hinge I t e 2,363,894 ,therefore, held and maintained in condition of area if desired. It is however, desirable to locate them symmetrically with respect to the major axis of the blade since this permitsthe blades to be conveniently stacked without attention to which face lies uppermost.

In Fig. 4 the invention is shown as embodied in a blade and razor combination wherein the boss 28 is transferred from the blade to the concave face of the cap member 24 of the razor. It is located centrally in the cap and in a position to engage the hinge area of the blade and impart to "it the secondary longitudinal flexing which causes the two side portions of the blade to contract at their free ends or to compensate for any tendency toward spreading. As explained in connection with thexbosses l6 and l! the boss 28 may be located at any convenient spot where itwillv cause the outer arc of the hinge section to flatten when the blade is clamped in shaving position.

The outwardly directed faces of the rib 25 serve as stops for limiting the inward movement of the free ends of the two side portions of the blade l0 caused by the secondary deflection of the solid hinge- 12. It will be understood that this flexing of the hinge causes a progressive compensating movement of the free ends ofRthe blade which is arrested by the faces of the rib 25 only when the dering the cutting edges ll exactly parallel.

Having thus disclosed my invention and described in detail two illustrative embodiments thereof, I claim as new and desire to secure by Letters Patent: 1. A double-edged, .open-endblade for safety razors, having a body divided into similar side portions by a central longitudinal slot, the side portions being spaced apart at one end of the said blade-locating projection. 1

double-edge blade having a longitudinal slot opening through one end and a solid connecting portion at the other, and means for flattening an outer arc of said end portion when the razor members are clamped together'and thereby drawing the side portions of the blade inwardly at their open end untilarrested by engagement with '7. A safety razor havinggcooperating .mem-.

.bers for clamping an interposedflexibleblade in a position of transverse curvature between them, and a blade-locating stop at one end of one of said members, in combination with a double-edged open-end blade having a flexible hinge at one end and side portionsfwhich lie with said blade stop between them, and a contact projection 011 one of said members for flattening a partof the hinge when the bladeis curved by engagement of said clamping members.

8. A safety razor having cooperating bladeclamping members with surfaces shaped for transcontraction has progressed to the point of renblade and having a solid connecting end portion at the other endof the blade, and a projection formed in the material of the said end portion. 2. A double-edged, open-end blade for safety razors, having a flexible body divided into side portionsby a central longitudinal slot, and having i a. solid hinge portion connecting the side portions at one end of the blade, and projections formed in both surfaces of the said hinge portion.

3. A double-edged, open-end blade having a' body of thin flexible steel slottedjfrom onelend and presenting similarside portions havingopposed gauging edges at one end and a solid connecting hinge at the other end of the blade, and a conical bossstruck out of the material of said hinge. l l

4. A double-edged, open-end blade having a body of thin flexible steel slotted inwardly from one end and presenting opposed side portions of equal length, saidsideportions merging into a solid hinge which limits the blade slot at its inner end, and a boss struck out of the steel of the hinge at apoint spaced from its inner edge.-

versely flexing a blade interposed between them, i and an interposed abutment presenting outwardly directed gauging faces, in combination with an open-end blade having a softened hinge portion at one end, and a projection from said hinge portion for impartinga longitudinal deflection to the i already transversely curved hinge portion when the clamping members are drawn together and thereby drawingthe open ends of the blade laterally against the gauging faces of the abut mentl t t 9. A safety razor having blade-clamping members shaped to impart a pronounced transverse curvature to an interposed flexible blade, and a blade stop, in combination with an open-end blade having a soft hingeportion at one end, and means therein wherebyaflattening deformation is imparted to the already transversely flexed hinge by clamping pressure of one of said mem- 'bers. r

10. A safety razor having a guard member with parallel longitudinal fulcrum shoulders and a recessat one end, acooperating cap member, and a stop onone of said members at the end opposite the recessed end of the guard member, in: combination with a double-edged, open-end blade flexed transverselyover said shoulders and embracing said stop at its open end, and means forflexing theclosed end of the blade into the recess of the guard member thereby imparting a compensating contraction of its open end toward said stopq Y JOSEPH Mu os.

5. Asdouble-edged, open-end blade havinga