US2545533A - Safety razor with concave upper cap face - Google Patents

Description

ATTORNEYS Filed 001;. 22, 1949 E A STEWART SAFETY RAZOR WITH CONCAVE UPPER CAP FACE March 20, 1951 Patented Mar; 20, 1951 I iii g- FEICE This invention relatesto a safety razor and is intended, in particular, to provide a razor which --lends itself to favorable angle of applistructural characteristics, the present invention achieves a razor which blends the separate effects intoa result which is more efficient than th re'sults obtained separately in the prior art,

, and in which the optimum angle of presentation of the blade edge to the face of a user is at all times automatic by the mere expedient of applying the upper surface of the blade housing fully on, the face of the user. The razor, furthermore, is adapted for secure locking of a blade, yet easy removal thereof without com pletely detaching the blade clamp.

It is therefore an'object of the invention to provide a safety razor having an appreciable extent of upper surface adapted to fit the face of a user at all times during shaving strokes and to thus provide a constant attitude of the blade edge in use. Other objects are to provide a razor and blade combination in which the blade is easily insertable and removable without complete separation of the razor parts, and to provide an arrangement wherein debris and lather are easily and continuously removed without undue penetrationlfinto th razor assembly.

Other objects and advantages will be appar out to t hoseskilled in the art from the description tofollow and the drawings, in which:

Fig. l is a front elevational view of the assembled razor,

Fig. 2 is a side view of Fig. 1,

Fig. 3 is an exploded view, in perspective, of the three parts of the razor,

Fig. 11 is a bottom view of Fig. l, and

Fig. is a top view of Fig. 1 with the top bladeclamping element removed.

Referring to the drawings by characters of reference, there is shown a razor having a handle I with a tapering portion 2 peened or otherwise secured for rotation in an opening 3 in a lower blade holder or clamp element 4, in a manner so 'as not to protrude thereabove, and the SAFETY RAZOR WITH CONCAVE UPPER "CAP FACE Elmer Stewart, Los Angeles, Calif.

, I Application October 22,1949, Serial No. 122,985

, .6 Claims. (01. 30 19) 2 portion 2 being internally threaded as at 6. The clamp element 4 has an upper, concave surface 1 and a lower, convex surface 8 which are mu:-

tually parallel and which are arcuate in form,

" or nearly so, being, preferably, cylindrical surfaces of right, circular form, with elements'perpendicular to the axis of cylindrical handle I. The front portion of the upper part of element 4 is rabbeted to provide a surface 9 at lower level than the surface 1 serving as a clearance for the underside of the blade edgewhereby debris is collected in a limited zone and passes out through an elongate slot l l. The "front corners of the surface 1 are provided with upright'lugs or posts l2 and I3 of a height not greater than the thick-' ness of blade employed, which posts serve to retain the blade in place, in coaction with the clamping elements.

The upper clamp element, indicated generally by the numeral [4 is generally wedge-shaped and has a lower, convex, cylindrical surface It complementary in form to surface i of the lower clamp element. The upper surface I! of the upper clamp element I4 is concavely cylindrical and the element as a whole may t be described as a segment of a toroid of wedge-shaped, cross-section, defined by a generating radius with origin on the axis of curvature of cylindrical surface I when the razor is in assembled condition. However, for the wedge angle and the radius considered, and the permissible tolerances, the member [4 may be roughly defined as bounded by two intersecting cylindrical surfaces, having their axes ina common plane but inclined one to the other.

It has been found thata radius of curvature of about seven inches is suitable for the cylindrical surfaces but, of course, this may be varied within limits without. sacrifice'to the efiiciency of performance of the razor. The preferred wedge angle is about 20,"but this also may be varied somewhat.

The clamp element 14 has fixed to its underside a screw 2| engageable in the threaded opening 6 of the handle. Element I4 also has a de-. pendent rear flange 22 which engages behind the rear edge of clamp element 4 and has a depth throughout equal to the thickness of the element 4, underside 23 of the flange and its line of intersection 24 having a curvature similar to that of surfaces 1 and I6. However, it is not essential that surface 8 and the underside of flange 22 be curved, and these may be plane if desired.

The blade 26 has asemicircular slot 21 in its rear edge to clear the screw 2| and permit the 3 blade edge to abut flange 22, and the slot 21 is flared at 28 for ready positioning on the screw. The front corners of the blade are cut away as at 29, 3| for engagement behind lugs l2, l3, respectively.

The clamp elements 4, M are joined by inserting screw 2| into opening 6 and turning handle I. When approach of the parts is such that flange 22 engages behindiel'emenlr 4; relative: rotation ofthe: clamp elements is'prevented. The blade 26 may be slipped into position abutting flange 22 and with corner slots 29, 3i engaged behind posts [2-,

I3. approach of the clamp elements 4', I4 deforms blade 26 into full contact with surfaces 1 and I6 and the assembly is ready for use: Removal of the blade may be effected by. merely unscrewing the parts until the blade may be slipped over posts 12, I3 and so withdrawn.

In use, the wedge form of the upper element lzfl 'provid'es aready guide:- fcn a. favorable attitudes of;the-bladeedge-when the upper: surface [1-- of: element; I4: i's retained? contact with the skin; Due: to. the; cylindrical form of surface I1 to'-- gather: the wedge shape;, the contact with. the skin: at. all times. is spread: over. area ficientlthat-theefull extent-,. or at least a substantialextent,, of the-blade edge is in: cuttingyengage ment at all times; Withwed'ge-shap err-but; plane tops razors; on with: razors: transversely" curved: inv substantially'a single; cylindrical surface; thati without? the? wedge fol-m2 defined? by twcr distinct, cylindrical; surfaces; this result is; not; attained. the blade is; general; effective only' throughout arelativeiy small extentyof its length, and" dean; uniform; shaving: is accomplished. only after unduly repetitious'stmkingg; or else the constant optimum cutting angle is not-:automat:i'- cally maintained;

0bviously, the particular manner of effecting: closure of. the biade-holdingmembers is notzmae terial to' the invention: and'cam partake: of various.- fcrms in: theart In: generalg. while: a meferred embodiment on the: invention has been. shown, the invention: not: limited theretm. since changes, in the: size; shape; and arrangementi of; thervarious parts may beresorted to, without, however, departing from: the spirit" or'scope: ofithe: appended claims...

What is"- claimed is:

A safetyrazcn'ofi the type having a: pain: of blade-clamping members and. a; handle. one of said; blade-damping members: having" an: upper; concave surface ofi cylindrical form: cylina drical elements generally transverse to=the razor: handle and the other of said bladerclamping members: having? an. under; conm. surface of cylindrical. form, cnmplementary ta the first- Upon further rotation of; the handler L the said blade-clamping members having an upper, concave surface of cylindrical form with cylindrical elements generally transverse to the razor handle, and the other of said blade-clamping members having an under, convex surface of cylindrical form, complementary to the firstmentioned cylindrical surface, and having an upper, concave, cylindrical surface with its axis of; curvature substantially car-planar. with, but inclined at an angle of about 20 with respect to, the axis of curvature of its said under surface.

3. A safety razor of the type having a pair of blade-clamping. members and a handle, one of said. blade-clamping members having an upper,

concave surface of cylindrical form with cylindrical elements generally transverse to the razor handle, ,an1l the, other of said blade-clamping members havingan under, convex surface of cylindrical form, complementary to the firstmentioned cylindrical surface, and having an upper concave, cylindrical surface its axis of, curvature. substantially co.-planar. With-,1.,hl112 inclined with respectto, the. axis. of curvature of itssaid under surface,, said other of said bladeclamping; memb ersghaying; a. dependent flange on its rearward face engageable behind the rear-'- ward. face of said, one ofv said. bladerclamping members.

4:. In, a. razor as in: claim, 3, a; stepped. portiom on the forward part. of. said one of; said, bladeclamping members, to, provide a. concave, cylirrsurface.- lower than its saidL upper. concave surface, and. a1 throughslott extending, lengthwise of. said. lower surfaces A safety, razor of the type having; alowfln, blade-clamping. member; amu-pper blade: clamp,- ing. member;- and-aihandle generally transyerse to; said blade-clamping members. saidlower. member. having an. upper, concave-surface oficyl-indricalform, and said.- upper member having am under,' convex. surface: of. cylindrical form com-.- plementary tovthempper. surfaceof theesaidlomeir member, and. an upper, concavesurfaca of cyl'm.- drical form. intersecting: its lower surface; the: upper andlower surfaces of. said upper member being so related.- that the cross-sectional format; the said. upper member is: substantially constant along: its; general pathv of. curvature.

6, A. safetyrazor. of. the type. having a lower;

. blade-clamping member, an. upper, bladerclamping member, and: a; handle generally transverse: to said blade-clamping, members, said lower member having. an. upper, concave surface of. cylindrical form,. and. saidupper. member;- com-.- prising, substantially, a toroidal segment. at" wedge-shaped, CTQSSr-SeCtiQn. defined by a, 581162-9- ating radius, with center substantiallyomthe. of curvature of the; upper surface. ofsaid, lower. member,, when the. members are in nested; assembly; A... STEWART;

No references cited.

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