Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS3514856 A
Publication typeGrant
Publication dateJun 2, 1970
Filing dateOct 30, 1967
Priority dateOct 30, 1967
Publication numberUS 3514856 A, US 3514856A, US-A-3514856, US3514856 A, US3514856A
InventorsCamp Harold E, Evans James W
Original AssigneeCorning Glass Works
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Razor blade configuration
US 3514856 A
Abstract  available in
Images(1)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

June 2, 1970 H. E. CAMP ETAL 3,514,856

RAZOR BLADE CONFIGURATION Filed 001:. so. 1967 INVEN'R )RS. HAROLD E. CAMP JAMES w. EVANS AT TORNE Y 3,514,856 RAZOR BLADE CONFIGURATION Harold E. Camp and James W. Evans, Corning, N.Y., assignors to Corning Glass Works, Corning, N.Y., a corporation of New York Filed Oct. 30, 1967, Ser. No. 678,846 Int. Cl. B26b 21/54 U.S. Cl. 30-34653 4 Claims ABSTRACT OF THE DISCLOSURE Razor blade construction having defined angular and dimensional limits of the converging surfaces forming the cutting edge and an effective recessed portion immediately adjacent thereto for improved cutting ease and shaving comfort.

BACKGROUND OF THE INVENTION The invention resides in the field of razor blade construction and particularly to the cutting edge configuration required to provide improved shaving comfort.

The prior art contains various chemical and mechanical procedures for preparing the cutting edge of razor blades; however, as a Whole, the art lacks any criteria as to what is necessary to actually provide the ultimate in frictionless shaving. US. Pat. No. 2,262,588 to Mailman discloses a conventional V-shaped blade and a method of providing a double-edged hollow-ground blade which facilitates the formation of a keen cutting edge without excessive heat. However, the patent does not suggest any parameters or criteria necessary in order to produce a blade which provides a minimum amount of friction and discomfort during the shaving operation.

US. Pat. No. 3,071,858 to Alter sets forth the prior art concept of forming razor blades with multiple tapered facets. Although dimensions and angles are given with respect to the final converging facets which form the cutting edge, there is no indication as tothe limits or parameters which provide improved shaving comfort, and in fact the patent leads one to believe that the only way to accomplish such result is to apply a coating to the blade.

The instant invention overcomes this void in the prior art by actually setting forth specific criteria for razor blade configurations to provide optimum shaving comfort based upon scientific investigations and experimental data.

SUMMARY OF THE INVENTION The present invention, in its simplest form, sets forth an optimum razor blade configuration for shaving comfort which not only includes a minimum and maximum included angle between the converging surfaces forming the cutting edge, but also the maximum length of such converging surfaces and the minimum length of an effective relief portion immediately adjacent such converging surfaces.

It thus has been an object of the present invention to provide an improved razor blade configuration having defined parameters which produce minimum whisker drag during shaving and accordingly afford the utmost in shaving comfort.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmental cross-sectional view of the cutting edge configuration of a preferred embodiment of the present invention.

FIG. 2 is a fragmental cross-sectional view in elevation of a further embodiment of the blade configuration shown in FIG. 1 but with one side extended for strength.

United States Patent DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1, a greatly enlarged blade portion 10 of a razor blade 12 is shown having a pair of converging surfaces or facets 14 forming a cutting edge 16. Immediately behind the converging surfaces 14 and communicating therewith are a pair of substantially parallel surfaces 18 of a shank portion 20 forming an effective relief area. The surfaces 18 are not only substantially parallel to each other, but also are substantially parallel to a cross-sectional axis of the blade which bisects the included angle between facets 14. A pair of tapered surfaces 22 extend rearwardly of the parallel surfaces 18 and join the shank portion 20 with the full body width of the razor blade 12.

The included angle a formed by and between the converging surfaces 14, which produce the cutting edge 16, must be between 10 and 35. Should the included angle a between the surfaces 14 exceed 35, the resulting tip or cutting edge 16 exhibited to the skin whiskers, is so blunt that virtually no cutting action is achieved. If, on the other hand, the included angle a is less than 10, the resulting razor blade tip is extremely weak and subject to failure. Further, the length of the converging surfaces of facets 14, which form a nose portion, should be maintained as short as economically and/or structurally possible, to reduce shaving friction by presenting a minimal surface area to the skin and whiskers. In order to obtain a comfortable shave the maximum length b of the facets 14 should not exceed .002 inch, or otherwise an excessive frictional area is presented to the beard hairs resulting in undesirable irritation.

The length of the substantially parallel surfaces 18- along shank portion 20, providing an effective relief area for the beard hairs, taken in conjunction with the length of the nose portion or point formed by facets 14 is critical for obtaining optimum shaving comfort. That is, shaving comfort is maximized by reducing the amount of drag or friction between the razor blade and the beard hairs during the actual cutting of the individual hairs. It has been found that the average thickness or diameter of a beard hair is between .004 and .006 inch, with about .005 being a median. Since our main criteria in devising a razor blade configuration for ultimate shaving comfort is to reduce the amount of razor blade surface area in contact with the beard hair as it is being cut, the blade length 0 as represented by the combined nose portion and shank between the cutting edge 16 and rear portion of the shank 20, must not be less than the thickness of an average beard hair, or about .005 inch, so that the blade will pass entirely through the beard hair before the hair engages tapered surface 22 of the blade. That is, as the blade passes through a beard hair, facet 14 of minimal length is the only surface which engages the hair, since the parallel surfaced shank portion 20, in effect, provides a relief area for the hair being cut, so that there is virtually no razor surface drag or friction created on the hair in the relief area.

Although the minimum blade length 0 between the cutting edge 16 and rear portion of shank 20 is about .005 inch, as determined by the size of the average beard hair, the maximum blade length 0 is determined by the thickness 'of the shank and the rigidity of the material utilized. We have found that when utilizing a glass blade with a shank thickness between parallel surfaces 18 of about .001 inch to about .0006 inch, the maximum blade length should preferably not exceed .01 inch in order to avoid an undesirable tendency of the blade length to flex and thus bow one of the relief surfaces 18 into a friction surface. However, the maximum length which can be utilized without obtaining a flexing or bowing 3 of the relief area will, of course, vary with the thickness of the shank and the material utilized.

The maximum thickness of the shank is limited by the fact that the facets 14 must not exceed .002 inch and must define an included angle between and 35. Accordingly, the maximum thickness of the shank is about .001 inch, since if made thicker, it would undesirably increase the length of the facets 14. Although very small minimum shank thicknesses are theoretically possible, in the case of glass, we have found that a practical minimum from a strength standpoint is about .0006 inch, since the blade becomes fairly weak below this thickness. Again, it is conceivable that lesser thicknesses would be feasible with other materials.

The particular angle formed by tapered surfaces 22 is not critical to shaving comfort, since it begins at a point where the beard hair has already been severed by the cutting edge, and accordingly such surfaces may be formed with virtually any desired angular configuration.

Referring now to FIG. 2, a further embodiment of a razor blade construction is shown which is similar in many respects to that illustrated in FIG. 1. That is, a blade portion 10 of a razor blade 12 is shown having a sloped facet 14, cutting edge 16', a flat relief surface 18', and a tapered surface 22'. Opposite facet 14 is an extended facet 24, which not only converges with facet 14' to form cutting edge 16', but which also extends rearwardly at a substantially constant angle to join the body portion of the blade 12.

Blade portion 10' is, in effect, one-half of blade portion 10, with the parameters of angle a and distances [1' and c bein the same as those specified for angle a and distances b and 0, respectively. The main difference between blade portion 10' and blade portion 10 is the fact that either side of blade portion 10 may be presented to the skin for shaving since it has effective relief portions 18 on both sides thereof, whereas blade portion 10 may only have one surface thereof presented to the skin for shaving since it only has one relief area surface 18. The main advantage derived from the configuration of blade portion 10 is the fact that added rigidity and strength is obtained by increasing the thickness dimensions of the shank portion 20'. Since the thickness of the shank portion 20 is increased, the relief surface area 18 may be slightly concave, if desired.

It should be appreciated that the invention disclosed herein is equally applicable to both single-ended and double-ended glass or metal razor blades. Although we have set forth the now preferred embodiments of our invention, it will be apparent to those skilled in the art that various changes and modifications may be made thereto without departing from the spirit and scope thereof as defined in the appended claims.

We claim:

1. An improved razor blade configuration comprising, a main body portion, a pair of converging facets forming a cutting edge, said facets forming an included angle of between about 10 and said facets having a maximum length rearwardly of said cutting edge of .002 inch, a short relief area having a thickness substantially less than said main body portion and having a pair of surfaces communicating with said facets and extending rearwardly thereof at an angle to a cross-sectional axis of said blade bisecting the included angle formed by said facets which is less than the angle to such axis formed by said facets, tapered surfaces communicating between said relief surfaces and said main body portion at an angle to said axis which is greater than that formed thereto by said relief surfaces, an effective blade length comprises a shank portion and a nose portion, said nose portion being formed by said converging facets, said shank portion providing said relief area and said combined shank and nose portions having a maximum length along said cross-sectional axis of .01 inch.

2. An improved razor blade configuration comprising, a main body portion, a pair of converging facets forming a cutting edge, said facets forming an included angle of between about 10 and 35, at least one of said facets having a maximum length rearwardly of said cutting edge of .002 inch, a short relief area having a thickness substantially less than said main body portion and having a surface communicating with said facet and extending rearwardly thereof at an angle to a cross-sectional axis of said blade bisecting the included angle formed by said facets which is less than the angle to such axis formed by said facets, a tapered surface communicating between said relief surface and said main body portion at an angle to said axis which is greater than that formed thereto by said relief surface, said converging facets communicating with a shank portion having a pair of substantially parallel relief surfaces, and said shank portion having a maximum thickness of .001 inch.

3. An improved razor blade configuration as defined in claim 2 wherein said converging facets form a nose portion, said nose portion and said facet portion are formed of glass, and the combined length of said nose portion and shank portion is less than .01 inch with said shank portion having a minimum cross-sectional thickness of .0006 inch.

4. An improved razor blade configuration as defined in claim 1 wherein said razor blade is formed of glass.

References Cited UNITED STATES PATENTS 2,244,053 6/1941 Comstock 30346.54 2,555,214 5/1951 Wallach et al. 30346.55 X 2,705,834 4/1955 Lundy 30346.55 X 3,349,488 1 0/1967 Craig 30-346.6 2,262,588 11/1941 Mailman 30'346.55

FOREIGN PATENTS 557,482 5/ 1923 France.

364,927 1/ 1932 Great Britain.

428,172 5/1935 Great Britain.

429,029 5/ 1935 Great Britain.

623,839 8/1961 Italy.

ROBERT C. RIORDON, Primary Examiner J. C. PETERS, Assistant Examiner US. Cl. X.R.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2244053 *Feb 22, 1938Jun 3, 1941Gregory J ComstockHard cemented carbide composite
US2262588 *May 9, 1940Nov 11, 1941Mailman Joseph LHollow ground double edge flexible razor blade
US2555214 *Feb 4, 1948May 29, 1951Associated Dev & Res CorpMethod of producing glass razor blades and product thereof
US2705834 *Feb 3, 1951Apr 12, 1955Lundy Robert RSafety razor blade
US3349488 *Aug 9, 1966Oct 31, 1967Craig Burnie JRazor blades
FR557482A * Title not available
GB364927A * Title not available
GB428172A * Title not available
GB429029A * Title not available
IT623839B * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3805387 *May 22, 1972Apr 23, 1974American Optical CorpFiber razor blade
US3831466 *Feb 8, 1972Aug 27, 1974J HicksGlass blade and glass blade blank
US3842499 *Sep 8, 1972Oct 22, 1974Gillette CoRazor blade assembly
US3861040 *Sep 8, 1972Jan 21, 1975Gillette CoPlural edge blade unit
US3863340 *Sep 8, 1972Feb 4, 1975Gillette CoPlural edge shaving system
US4184429 *Jan 29, 1976Jan 22, 1980Max Datwyler & Co.Constant bevel doctor blade and method and apparatus using same
US4209017 *Mar 14, 1975Jun 24, 1980Shaw Robert FSurgical instrument having self-regulating radiant heating of its cutting edge and method of using the same
US5048191 *Oct 16, 1990Sep 17, 1991The Gillette CompanyRazor blade technology
US5056227 *Mar 19, 1990Oct 15, 1991The Gillette CompanyRazor blade technology
US5077901 *May 18, 1990Jan 7, 1992Warner Joseph ACeramic blades and production methodology therefor
US5121660 *Oct 9, 1991Jun 16, 1992The Gillette CompanyRazor blade technology
US6327784 *Dec 22, 1999Dec 11, 2001U.S. Philips CorporationMethod of manufacturing a cutting member having an auxiliary layer
US6743128 *Apr 16, 2001Jun 1, 2004Liechty, Ii Victor JayCutting blade
US6804886 *Feb 28, 2003Oct 19, 2004The Gillette CompanySafety razors
US7140113Apr 17, 2002Nov 28, 2006Lazorblades, Inc.Ceramic blade and production method therefor
US7204180 *Sep 11, 2002Apr 17, 2007Technoplast Kunststofftechnik GmbhApparatus for cutting plastic profiles
US7587829Nov 28, 2006Sep 15, 2009Lazorblades, Inc.Ceramic blade and production method therefor
US9339289 *Jun 18, 2015May 17, 2016Ehticon Endo-Surgery, LLCUltrasonic surgical instrument blades
US9414853Mar 25, 2013Aug 16, 2016Ethicon Endo-Surgery, LlcUltrasonic end effectors with increased active length
US9504855Mar 20, 2015Nov 29, 2016Ethicon Surgery, LLCDevices and techniques for cutting and coagulating tissue
US9510850Nov 11, 2013Dec 6, 2016Ethicon Endo-Surgery, LlcUltrasonic surgical instruments
US9623237Sep 28, 2015Apr 18, 2017Ethicon Endo-Surgery, LlcSurgical generator for ultrasonic and electrosurgical devices
US9642644Mar 12, 2015May 9, 2017Ethicon Endo-Surgery, LlcSurgical instruments
US9649126Jan 6, 2015May 16, 2017Ethicon Endo-Surgery, LlcSeal arrangements for ultrasonically powered surgical instruments
US9700339May 20, 2009Jul 11, 2017Ethicon Endo-Surgery, Inc.Coupling arrangements and methods for attaching tools to ultrasonic surgical instruments
US9700343Nov 2, 2015Jul 11, 2017Ethicon Endo-Surgery, LlcDevices and techniques for cutting and coagulating tissue
US9707004Mar 12, 2015Jul 18, 2017Ethicon LlcSurgical instruments
US9713507Jan 4, 2016Jul 25, 2017Ethicon Endo-Surgery, LlcClosed feedback control for electrosurgical device
US9724118Mar 15, 2013Aug 8, 2017Ethicon Endo-Surgery, LlcTechniques for cutting and coagulating tissue for ultrasonic surgical instruments
US9737326Oct 23, 2015Aug 22, 2017Ethicon Endo-Surgery, LlcHaptic feedback devices for surgical robot
US9743947Dec 9, 2015Aug 29, 2017Ethicon Endo-Surgery, LlcEnd effector with a clamp arm assembly and blade
US9764164Dec 20, 2013Sep 19, 2017Ethicon LlcUltrasonic surgical instruments
US9795405Feb 18, 2015Oct 24, 2017Ethicon LlcSurgical instrument
US9795808Mar 13, 2015Oct 24, 2017Ethicon LlcDevices and techniques for cutting and coagulating tissue
US9848901Aug 17, 2015Dec 26, 2017Ethicon LlcDual purpose surgical instrument for cutting and coagulating tissue
US9848902Feb 4, 2014Dec 26, 2017Ethicon LlcErgonomic surgical instruments
US20030047055 *Sep 11, 2002Mar 13, 2003Meinhard SchwaigerApparatus for cutting plastic profiles
US20040163262 *Apr 17, 2002Aug 26, 2004King Rodney L.Ceramic blade and production method therefor
US20070157475 *Nov 28, 2006Jul 12, 2007King Rodney LCeramic blade and production method therefor
US20110147018 *Dec 23, 2009Jun 23, 2011Bruce Douglas GTillage blade configured to stay sharp longer
US20150282834 *Jun 18, 2015Oct 8, 2015Ethicon Endo-Surgery, Inc.Ultrasonic surgical instrument blades
WO1999037437A1 *Jan 27, 1999Jul 29, 1999Peter GlucheDiamond cutting tool
Classifications
U.S. Classification30/346.53, 30/346.55, 65/61
International ClassificationB26B21/56, B26B21/00
Cooperative ClassificationB26B21/56
European ClassificationB26B21/56