US3722090A

US3722090A - Guard bar for safety razors

Info

Publication number: US3722090A
Application number: US00171075A
Authority: US
Inventors: J Dawidowicz
Original assignee: Warner Lambert Co LLC
Current assignee: Warner Lambert Co LLC
Priority date: 1971-08-12
Filing date: 1971-08-12
Publication date: 1973-03-27
Anticipated expiration: 1990-03-27

Abstract

The disclosure is directed to a safety razor guard bar having a continuous guard bar surface positioned outwardly and below the cutting edge of a razor blade. The continuous guard bar surface is provided to fix the cutting angle of the blade, and to smooth and stretch the skin prior to its engagement with the cutting edge of the blade. The guard bar includes a plurality of ridges spaced along the upper surface thereof. Each of the ridges has an outer arcuate surface extending from the continuous guard bar surface upwardly and inwardly to beneath the blade such that the upper portion of each of the ridges is in close proximity to the cutting edge of the blade.

Description

United States Patent [1 1 Dawidowicz Mar. 27, 1973 [73] Assignee: Warner Lambert Company, Morris Plaines, NJ.

[22] Filed: Aug. 12, 1971 [21] Appl.No.: 171,075

[56] References Cited UNITED STATES PATENTS 2/1937 Samuel ..30/77 11/1959 Kuhnl ..30/62 FOREIGN PATENTS OR APPLICATIONS 380,958 9/1932 Great Britain ..30/77 Primary Examiner-Othell M. Simpson Assistant ExaminerGary L. Smith Att0mey-James F. Powers, Jr. et a1.

[57] ABSTRACT The disclosure is directed to a safety razor guard bar having a continuous guard bar surface positioned outwardly and below the cutting edge of a razor blade. The continuous guard bar surface is provided to fix the cutting angle of the blade, and to smooth and stretch the skin prior to its engagement with the cutting edge of the blade. The guard bar includes a plurality of ridges spaced along the upper surface thereof. Each of the ridges has an outer arcuate surface extending from the continuous guard bar surface upwardly and inwardly to beneath the blade such that the upper portion of each of the ridges is in close proximity to the cutting edge of the blade.

1 1 Claims, 5 Drawing Figures GUARD BAR FOR SAFETY RAZORS BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to safety razors of the type having a guard bar surface below and outwardly from the cutting edge of a blade. More particularly, the present invention relates to a guard bar structure for limiting the amount of skin entering between the guard bar surface and the cutting edge of the blade to thereby minimize the possibility of nicks and cuts.

2. Description of the Prior Art It is known to provide a continuous guard bar surface extending parallel to the cutting edge of a blade and positioned below and outwardly from the cutting edge. Guard bars of this type are shown at least in U.S. Pat. Nos. 2,911,713 and 3,171,198. Such guard bar surfaces act to stretch and smooth the skin prior to the skin coming in contact with the cutting edge of the blade. Further, guard bars of this sort provide a predetermined cutting angle for the blade, and also limit the amount of skin which may enter between the guard bar and the cutting edge of the blade. However, even with a continuous guard bar individuals having skin imperfections such as acne may be susceptible to nicks and cuts.

It is also known to provide guard means comprising a plurality of spaced teeth extending downwardly and outwardly from the cutting edge of a blade. Such guard means are shown in at least U.S. Pat. Nos. 2,143,276 and 2,893,l 19. In each of these patents, the blade rests on the teeth such that portions of the cutting edge of the blade serve little or no function. For example, U.S. Pat. No. 2,893,1 19 provides for longitudinal movement of the blade such that the portions of the cutting edges that were positioned on the teeth can be used as cutting surfaces. U.S. Pat. No. 3,378,922 discloses guard means of a plurality of teeth which are not in contact with the cutting edge of a blade. However, guard means consisting of a plurality of spaced teeth do not provide a continuous surface for smoothing and stretching the skin prior to its engagement with the cutting edge of the razor. Rather, such guard means acts to pinch the skin to provide a plurality of raised skin surfaces which are then shaved by the cutting edges of the blade.

It is also known to provide razor blades having selfcontained guards. For example, U.S. -Pat. No. 1,846,622 provides for dividing a cutting edge of a blade into sharpened and dull portions by spaced deposits of material secured to the cutting edge. U.S. Pat. No. 3,505,734 also provides for dulling portions of the cutting edge of a blade by having a plurality of spiral windings of a thread firmly-attached to the blade, and spaced along and extending around the cutting edge of the blade. Thus, blades having self-contained guards such as described in U.S. Pat. Nos. 1,846,622, and 3,505,734 act to reduce the effective cutting surface of the blade.

SUMMARY OF THE INVENTION In accordance with an aspect of the present inven tion that is provided a guard bar structure for a safety razor wherein an elongated guard bar has a longitudinal axis extending parallel to the cutting edge of a blade, and wherein the guard bar has an outer surface portion positioned outwardly and downwardly from the cutting edge of the blade. The invention provides for a plurality of spaced ridges formed along the outer surface portion of the guard bar, and for each of the ridges to extend upwardly and inwardly from the outer surface portion of the guard bar to beneath and in close proximity to the cutting edge of the blade. In accordance with a specific aspect of the invention, each of the ridges has an arcuate outer surface extending from an arcuately formed outer surface portion of the guard bar.

The guard bar as structured according to the present invention provides for a continuous guard bar surface for smoothing and stretching the skin, and ridge surfaces which continue the smoothing and stretching action such that a minimum amount of skin enters between the guard bar and the cutting edge of the blade to minimize the possibility of nicks and cuts particularly for an individual who has skin imperfections such as acne.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a safety razor having a guard bar embodiment of the present invention;

FIG. 2 is a side view of the razor;

FIG. 3 is an enlarged sectional view of the guard bar portion of the razor taken along the line 3-3 of FIG. 1;

FIG. 4 is a plan view of the blade-seating plate of the razor; and

FIG. 5 is a front view of the blade-seating plate of the razor.

DESCRIPTION OF SPECIFIC EMBODIMENTS The guard bar structure according to the present in vention is suitable for use in any type of safety razor. By way of example, the guard bar structure is shown in asafety razor of the type in which new blades are adapted to be fed into the head of the razor from a separate blade-filled magazine. The embodiment described with reference to the Figures modifies the guard bar of the safety razor of Kuhnl U.S. Pat. No. 2,911,713, issued Nov. 10, 1959. U.S. Pat. No. 2,91 1,713 is incorporated herein by reference.

With reference to the figures, the safety razor includes a substantially rigid handle 10 of plastic or other material, and a head 11 in which a blade 12 is adapted to be inserted edgewise from one side of the head 1 1.

The head 1 1 includes a substantially rigid main frame 13 of sheet metal construction. The lower portion of the frame 13 extends downwardly into and is fixedly secured in the upper part of the handle 10. The upper portion of the frame 13 is curved forwardly at 15 and terminates at its upper end in a narrow forwardly and downwardly inclined flange or cap 16. The blade 12 is adapted to be clamped against the underside of the cap 16. The cap 16 overlies only the rear portion of the blade 12 in order to leave the cutting edge 17 of the blade 12 exposed.

The frame 13 is provided with a flat downwardly extending section 18 immediately beneath and behind the cap 16. the section 18 forms the rear stationary wall of an expansible channel 19 in which a positioning key (not shown) of a typical blade dispensing magazine (not shown) is adapted to be inserted.

The head 11 of the razor is provided with a forwardly and downwardly movable blade-seating plate 26 of generally L-shaped cross section. The upper portion of the seating plate 26 consists of a flat forwardly projecting flange 27 which underlies the cap 16 and constitutes the seat for the blade 12. The blade seat 27 is connected, at its front edge, to a downwardly curved, longitudinally serrated guard bar 28. A clearance opening 29 (FIG. 4) is provided in the seat 27 behind the guard bar 28.

The blade-seating plate 26 is provided with a flat downwardly extending flange 30 (FIG. 5) immediately beneath and behind the seat 27. The downwardly extending flange 30 is disposed in a forwardly spaced relation to the flat section 18 of the frame 13 and forms the front forwardly shiftable wall of the expansible channel 19 for a positioning key (not shown) of a blade dispensing magazine (now shown). The seating-plate 26 terminates in two laterally spaced downwardly tapering end portions 31 (FIG. 5) below the flange 30. The end portions 31 are nested in the main frame 13.

With reference to FIG. 5, the two laterally spaced downwardly tapering end portions 31 of the blade seating-plate 26 form a centrally arranged downwardly opening rectangular recess 35 of substantial width and depth. The recess 35 has a straight horizontally disposed upper edge 36 and parallel side edges 37. The upper edge 36 of the recess 35 islocated a substantial distance below the seat 27 and also a substantial distance above the lower ends of the downwardly tapering end portions 31. The upper edge 36 of the recess 35 constitutes a line-contact fulcrum for self-adjusting coaction with a seat clamping spring (FIG. 1

The seat clamping spring 25 is of substantially flat heavy leaf construction. The lower portion 38 of the spring 25 is of downwardly tapered form and is clamped solidly against the front face of the frame 13. The upper portion 41 of the spring is reduced abruptly and is of generally rectangular form. The lower part of the upper portion 41 of the spring 25 is nested snugly but freely within the downwardly opening rectangular recess 35 of the seating plate 26, and the upper forwardly bent portion of the Spring 25 bears rearwardly and upwardly with a substantial pressure against the upper edge 36 of the recess in line contact with the front of such edge.

The front cutting edge 17 of the blade 12 is engaged at its ends by small, upstanding lug 47 on the bladeseating plate 26 at the ends of the guard bar 28. Thus, the cutting edge 17 lies in a vertical plane as defined by rear vertical walls 50 of the lugs 47 (FIG. 3).

In accordance with the present invention, a plurality of spaced ridges 51-55 are provided on the upper surface of the guard bar 28. The ridges 51-55 eachhas an upper arcuate surface 56 (FIG. 3) which arcuately blends into the outer arcuate surface portion 57 of the guard bar at 28. As shown in FIG. 3, the outer surface portion 57 of the guard bar 26 and the ridge upper surface 56 has a common radius of curvature from approximately C to D. As also shown in FIG. 3, the arcuate upper surfaces of the guard bar intermediate the ridges 51-55 have a smaller radius of curvature than that of the ridges such that the guard bar upper surfaces are below that of the upper surfaces of the ridges and extend in an are from E to F. The guard bar 26 and the ridges 5155 can have longitudinally extending serrations 58 formed along their outer surfaces to aid in smoothing and stretching the skin prior to engagement with the cutting edge 17 of the blade 12.

The guard bar 28 provides for smoothing and stretching of the skin along the continuous outer surface 57 of the guard bar 28, and such smoothing and stretching is continued by the upper surface 56 of each of the ridges 51-55 prior to the skin coming into cutting engagement with the cutting edge 17 of the blade 12. The skin intermediate the spaced ridges 51-55 will bow slightly in a taut state as a result of the smoothing and stretching action of the guard bar 28 and the upper surfaces 56 of the ridges 51-55. This action smooths and stretches skin imperfections such that a minimum amount of skin enters between the guard bar and the cutting edge, to thus minimize a possibility of nicks and cuts. Further, the above described guard bar structure provides for use of the whole cutting edge 17 of the blade. I

A preferred embodiment provides that the guard bar 28 spacing intermediate the ridges 51-55 is 2.8 times the longitudinal width of the upper surface 56 of each of the ridges 51-55. As shown in FIG. 5, the preferred embodiment provides that the longitudinal width of each of the ridges 51-55, as defined by parallel side walls perpendicularly extending upwardly from the guard bar, is 0.55 inch, and that the spacing between each of the ridges 51-55 is 0.154 inch. Further, the preferred embodiment provides arcuate upper ridge surfaces 56 which are contiguous with the arcuate outer surface portion 57 of the giard bar 28 such that the arcuate surface C D (FIG. 3) has a radius of curvature of 0.090 inch from a point A. The upper guard bar surface 59 intermediate the spaced ridges 51-55 is also arcuately contiguous with the outer surface 57 of the guard bar 28. As shown in FIG. 3, the upper guard bar surface 59 has a radius of curvature between at least points E and F of 0.055 inch from a point B.

As shown in FIG. 3, each of the ridges 51-55 arcuately extends from the guard bar outer surface 57 upwardly and inwardly to at least a plane defined by the vertical rear walls 50 of the lugs 47 and beneath the cutting edge 17 of the blade 12 which rests against the vertical rear walls 50. In the embodiment shown, the ridge upper surface 56 extends rearwardly beneath the cutting edge 17 of the blade 12 to a point D which is 0.007 inch from the plane defined by the rear wall of the lugs 50.

As shown in FIG. 3, the uppermost portion of each of the ridges is preferably between about 0.002 inch and about 0.007 inch beneath the seat 27. A typical blade has a thickness of about 0.010 inch, and the cutting edge is formed by two beveled surfaces. Thus, the cutting edge 17 is about 0.005 inch above the seat 27, and the uppermost portion of each of the ridges is preferably between about 0.007 inch and 0.012 inch beneath the cutting edge 17.

As used herein, arcuate describes the curved or bowed general contour of the outer surface portion 57 of the guard bar, of the upper guard bar surfaces 59, and of the upper ridge surfaces 56. Arcuate is meant to include a surface having serrations therein such as the longitudinal serrations 58, and when used in this context, the arcuate surface will be defined by the peaks of the surfaces formed by the serrations. For example, the are between points C and D includes the peaks formed by serrations in the guard bar 28 and in the ridge 53. It is also possible to form vertical serrations in the guard bar 28 and the ridges 51-55, and in this instance, the

arcuate surface is also defined by peaks formed intermediate the serrations.

Although the embodiment of the invention is described in combination with the razor of U.S. Pat. No. 2,91 1,713, it is obvious that the invention can take other shapes or forms in combination with other types of razors by modifications made by those skilled in the art without deviating from the scope and spirit of invention. For example, guard bar structure in accordance with the present invention can be used in combination with a ribbon-type razor such as shown in Kuhnl U.S. Pat. No. 3,555,681, or in a cap-type double edge safety razor such as shown in Dawidowicz et al U.S. Pat. No. 3,466,746, or in safety razors having an adjustable guard bar such as Ferraro U.S. Pat. No. 3,552,008 and Kuhnl U.S. Pat. No. 3,203,093. Further, guard bar structure according to the present invention can be used in a rigid plastic member which permanently secures a razor blade such as described in Hanson U.S. Pat. No. 3,388,831, and generally known as a bonded blade or bonded razor.

What is claimed is:

1. A safety razor comprising means for exposing at least one blade cutting edge, and at least one elongated guard; said guard including a continuous skin engaging outer surface portion positioned outwardly and downwardly from said cutting edge for smoothing and stretching a skin surface during shaving, and a plurality of spaced ridges, each one of said ridges extending upwardly and inwardly from said continuous outer surface portion of said guard to beneath and in close proximity to said cutting edge.

2. The razor of claim 1 wherein each one of said ridges has an arcuate upper surface extending from said continuous outer surface portion of said guard.

3. The razor of claim 1 wherein said arcuate upper surface of each of said ridges extends to between about 0.007 inch and about 0.012 inch beneath said cutting edge.

4. The razor of claim 1 wherein said continuous outer surface portion of said guard is arcuately formed, and wherein said arcuate upper surface of each of said ridges is a contiguous continuation of said continuous arcuate outer surface portion of said guard.

5. The razor of claim 4, wherein said guard has upper arcuate surfaces intermediate said ridges, said guard bar upper arcuate surfaces having a radius of curvature less than that of said ridges.

6. The razor of claim 5, wherein each of said ridges has a pair of parallel sides perpendicularly extending upwardly from said guard.

7. The razor of claim 6 wherein each of said guard upper arcuate surfaces is about 2.8 times greater in length, taken along the longitudinal axis of said guard, than the distance between said pair of parallel sides.

8. The razor of 6 wherein each of said guard upper arcuatesurfaces is about 0.154 inch in length takes along the longitudinal axis of said guard, and wherein the distance between said pair of parallel sides in about 0.055 inch.

9. The razor of claim 8 wherein at least five ridges are formed along said outer surface portion of said guard.

10. The razor of claim 5 wherein said arcuate upper surface of each of said'ridges extends to between about 0.007 inch and about 0.0 2 1nch beneath sald cutting edge.

11. The razor of claim 1 wherein said continuous outer surface portion of said guard and said ridges each have serrations for contacting the skin surface during shaving.

Claims

8. The razor of 6 wherein each of said guard upper arcuate surfaces is about 0.154 inch in length takes along the longitudinal axis of said guard, and wherein the distance between said pair of parallel sides in about 0.055 inch.

10. The razor of claim 5 wherein said arcuate upper surface of each of said ridges extends to between about 0.007 inch and about 0.012 inch beneath said cutting edge.