US3889369A

US3889369A - Shaving unit for safety razor

Info

Publication number: US3889369A
Application number: US532429A
Authority: US
Inventors: Frank A Ferraro
Original assignee: Warner Lambert Co LLC
Current assignee: Warner Lambert Co LLC
Priority date: 1974-12-13
Filing date: 1974-12-13
Publication date: 1975-06-17
Anticipated expiration: 1992-06-17

Abstract

The specific disclosure provides a shaving unit having two flexible double edge razor blades with the cutting edges of the top blade being set back a slight distance from the cutting edges of the bottom blade. The blades are vertically separated by a spacer, and an elongated aperture extends through the blades and the spacer for locating the shaving unit in a double edge safety razor. Means are provided between the aperture and the cutting edges to one side of the aperture for permanently connecting the top blade to the spacer, and means are provided between the aperture and the cutting edges to the other side of the aperture for permanently connecting the bottom blade to the spacer.

Description

United States Patent [1 1 Ferraro June 17, 1975 1 SHAVING UNIT FOR SAFETY RAZOR [75] Inventor:

22 Filed: Dee.,13, 1974 21 App]. No.: 532,429

Frank A. Ferraro, Trumbull, Conn.

[52] US. Cl 30/134658; 30/50 [51] Int. Cl. B26B 21/54; B2613 21/22 [58] Field of Search 30/50, 34657, 346.58,

30/346.59; 76/DIG. 6

[56] References Cited UNITED STATES PATENTS 3,262,206 7/1966 Tomek 30/346.59

FOREIGN PATENTS OR APPLICATIONS 1,103,671 11/1955 France 30/346.58

Primary Examiner-Al Lawrence Smith Assistant Examiner-Gary L. Smith Attorney, Agent, or Firm-James F. Powers, Jr.; Albert H. Graddis [5 7] ABSTRACT The specific disclosure provides a shaving unit having two flexible double edge razor blades with the cutting edges of the top blade being setback a slight distance from the cutting edges of the bottom blade. The blades are vertically separated by a spacer, and an elongated aperture extends through the blades and the spacer for locating the shaving unit in a double edge safety razor. Means are provided between the aperture and the cutting edges to one side of the aperture for permanently connecting the top blade to the spacer, and means are provided between the aperture and the cutting edges to the other side of the aperture for permanently connecting the bottom blade to the spacer.

10 Claims, 3 Drawing Figures 1' SHAVING UNIT FOR SAFETY RAZOR BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to shaving units having. a plurality of cutting edges for use in a safety razor. More particularly, the present invention relates to safety razor shaving units having a plurality of double cutting edge members bonded together.

2. Description of the Prior Art Double edge safety razors are well-known in the art,

I and are in many forms. For example, US. Pat. Nos.

3,293,745, 3,466,746 and 3,708,879 disclose a razor having sectional caps, an adjustable razor and a razor having a hinged cap, respectively. Such razors act to I clamp a thin, flexible couble edge razor blade in the blade are set back a slight distance from the cutting edges of the bottom blade to provide tandemly arranged cutting edges on eachside of the shaving unit. U.K. Pat. No. 772,532 contemplates welding the blades and spacer together, and, at Page 3, lines 98-100, specifically teaches welding the spacer near its elongated ends.

Commercially available flexible steel double edge razor blades having an elongated central slot parallel to the cutting edges are arcuately flexed at tab portions at each end of the slot when firmly seated in double edge razors having manually operatedmechani sms for opening and closing the cap portion. However, as shown in FIG.4 of US. Pat. No. 3,708,879, the portions of the razor blades between the slot and the cutting edges are at least substantially flat.

Weldingrnetal increases grain size of the metal about the weld, and the corrosion rate about the'weld is high. When double edge razor blades are welded together at the tab portions, and the tab portions are thereafter arcuately bent in a razor as specifically taught in U.K. Pat. NO. 772,532, a danger of stress-corrosion cracking is raised; Stress-corrosion cracking is failure by cracking under combined corrosion and applied and /or residual stress.

SUMMARY OF THE INVENTION In accordance with the present invention, there is provided a shaving unit for a double edge safety razor comprising a first flexible member having a pair of opposite cutting edge sides. A second flexible member also having a pair of opposite cutting edge sides is located above the first member with the cutting edges of the second member being set back a slight distance from the cutting edges of the first member. Means are A shaving unit constructed in accordance with the present invention minimizes the stress-corrosion cracking problem by bonding the components of the shaving unit at surfaces which are at least substantially flat when the unit isseated in the razor.

Further, the amount offorce needed to seat theunit in the razor is also minimized by each one of the first and second members being connected to an opposite side of the spacing means. This manner of connecting the components together permits a slight cutting edgesto-cutting edges relative motion between the compo nents as the unit is seated in the razor.

v BRIEF DESCRIPTION OF THE DRAWINGS DESCRIPTION OF SPECIFIC EMBODIMENTS With reference to FIGS. 1 and 2, one representative embodiment of the present invention has first -and'second'members 82, 81 in the form of double cutting'e'dge razor-blades, and means in the form of a spacer element 80 for vertically spacing the second me'mber 81 from the first member 82. The top blade 81 and the spacer element 80 are permanently connected together by two welds 76'diagrammatically represented by dashed circles on one side 79 of transversely

elongated apertures

83, 84 formed in the spacer element 80 and the top blade 81. The bottom blade 82 and the spacer element 80 are permanently connected together by two welds 77 diagrammatically representedbydashed circles on the other side 78 of transversely

elongated apertures

83, 85 formed in the spacer element 80 and the bottom blade 82.

The top blade 8115 but away at 96, 97 above the welds 77, and the bottom blade 82 is similarly cut away at 98, 99 below the welds 76 to permit spot welding of the

blades

81, 82 to opposite sides of 'the spacer element 80. a

As clearly shown in FIG. 2, the cutting edges 88; 89 of the top blade 81 are set back a slight distance from the

cutting edge

90, 91 of the bottom blade 82. The

cutting edges

88, 89 on opposite sides of the top blade are parallel to the

cutting edges

90, 91 on opposite sides of the bottom blade 82. The spacer element 80 has a pair of

blunt surfaces

86, 87 set back a slight distance from the

cutting edges

88, 89 of the top blade 81. The apertures 83-85 extend between

end tab portions

72, 73; 70, 71; 74, of the spacer element and the

blades

81, 82.

FIG. 3 shows the shaving unit seated and clamped in a double edge safety razor having a center-bar and stem assembly 40. The center-bar and stem assembly 40 is fitted through the apertures 83-85 to locate the shaving unit in the razor. A pair of

sectional caps

41, 42 act to bias the shaving unit on a blade seat with the cutting edges of the

blades

81, 82 tandemly arranged with respect to guard bar surfaces 44, 45 formed on the outer ends of the blade seat. FIG. 3 also shows the

shaving unit portions

78, 79 between the tabs 70-75 in a flat state. However, the tab portions 70-75 are arcuately bent (not shown).

The

end tab portions

72, 73; 70, 71; 74, 75 have cut out

portions

30, 31, and the

blades

81, 82 and the composed of thin martensitic stainless steel commonly used for razor blades, or of any other flexible material suitable for double edge razor blades. The thickness of the

blades

81, 82 and of the spacer 80 can be 0.0039 inches. The distance between the cutting edges of the top blade 81 can suitably be 0.832 inches when the'distance between the cutting edges of the bottom blade is 0.870 inches. The distance betweenthe

blunt surfaces

86, 87 of the spacer element 80 can be 0.780 inches.

The shaving unit can be welded anywhere on the flat shaving unit portions, 78, 79 between the

tabs

71, 73, 75; 70, 72, 74, but sufficiently inwardly of the top

blade cutting edges

88, 89 to avoid adversely affecting the'

cutting edges

88, 89. However, as noted above the top blade 81 is preferable perforated above the welds con- I necting the spacer element 80 to the bottom blade 82,

and the bottom blade 82 is perforated below the welds connecting the top blade 81 to the spacer elements. Such perforations permit the

blades

81, 82 and the spacer element 80 to be stacked as shown in FIG. 2,

, and'the welds applied in a single process step.

The components of shaving units can be bonded to- I gether by spot,' -projection, arc, laser or other welding techniques, and more thana two welds can be provided to each side of the aperture. The flat

shaving unit portions

78, 79 alternatively can be bonded to opposite sides of the spacer by adhesives. Further, the spacer can be formed of a plastic material.

The embodiment shown in the figures has symmetrically beveled surfaces-forming the cutting edges of the

blades

81, 82. However, it is contemplated that the beveled cutting edge surfaces of :one or both of the

blades

81, 82 canbe asymmetrically ground to increase the vertical distance between the cutting edges of the l 4 a. a first flexible member including a pair of transversely extending opposite sides, each one of the first member opposite sides having a cutting edge; b. a second flexible member including a pair of transversely extending opposite sides, each one of the second member opposite sides having a cutting edge, said second member being located above said first member with the cutting edges of said second member being positioned upwardly and inwardly of the cutting edges of said first member;

" c. flexible means between said first member and said second member for spacing said second member from said first member;

d. a transversely elongated aperture extending through said first member, said spacing means and said second member between the cutting edges of said first member and said second member for 10- cating said shaving unit in said safety razor;

e. first means between said aperture and the cutting edges to one side only of said aperture for permanently connecting said first member to said spacing means; and a f. second means between said aperture and the cutting edges to the other side only of said aperture for permanently connecting said second member to said spacing means.

2. The shaving unit of claim 1 wherein the cutting edges of said first member and said second member are parallel.

3. The shaving unit of claim 2 wherein said firstand second members are metallic members. I I

4. The shaving unit of claim 3 wherein said spacing means is a metallic component. I I

5. The shaving unit of claim 4 wherein said first and second-connecting means each comprises. a plurality of spot welds. v t

6. The shaving unit of claim 4 wherein said first. and second members are double cuttinge dge safety razor blades.

7. The shaving unit of claim 6 wherein said first and second connecting means each comprises a plurality of spot welds. g

8. The shaving unit of claim 1 wherein said first and second members each further include a pair of spaced end tabs extending outwardly from opposite ends thereof.

9. The shaving unit of claim 1 further comprising a plurality of perforations in said spacing means between said aperture and the cutting edges to each side of said aperture.

10. The shaving unit of claim 9 further comprising a plurality of perforations in said first and second members between said aperture and the cutting edges to each side of said aperture.

Claims

1. A shaving unit for a double edge safety razor, said shaving unit comprising: a. a first flexible member including a pair of transversely extending opposite sides, each one of the first member opposite sides having a cutting edge; b. a second flexible member including a pair of transversely extending opposite sides, each one of the second member opposite sides having a cutting edge, said second member being located above said first member with the cutting edges of said second member being positioned upwardly and inwardly of the cutting edges of said first member; c. flexible means between said first member and said second member for spacing said second member from said first member; d. a transversely elongated aperture extending through said first member, said spacing means and said second member between the cutting edges of said first member and said second member for locating said shaving unit in said safety razor; e. first means between said aperture and the cutting edges to one side only of said aperture for permanently connecting said first member to said spacing means; and f. second means between said aperture and the cutting edges to the other side only of said aperture for permanently connecting said second member to said spacing means.

3. The shaving unit of claim 2 wherein said first and second members are metallic members.

4. The shaving unit of claim 3 wherein said spacing Means is a metallic component.

5. The shaving unit of claim 4 wherein said first and second connecting means each comprises a plurality of spot welds.

6. The shaving unit of claim 4 wherein said first and second members are double cutting edge safety razor blades.

7. The shaving unit of claim 6 wherein said first and second connecting means each comprises a plurality of spot welds.