US3858315A

US3858315A - Shaving unit for safety razor

Info

Publication number: US3858315A
Application number: US398104A
Authority: US
Inventors: Frank A Ferraro
Original assignee: Warner Lambert Co LLC
Current assignee: Warner Lambert Co LLC
Priority date: 1973-01-23
Filing date: 1973-09-17
Publication date: 1975-01-07
Anticipated expiration: 1992-01-07
Also published as: AU6474574A; GB1426558A; JPS5528218Y2; JPS5057695U; HK60381A

Abstract

The specific disclosure provides a shaving unit having a spacer which includes a pair of spaced forwardly extending projections. A bottom razor blade is connected to the underside of the spacer with its cutting edge positioned beneath the projections, and a top razor blade is connected to the upperside of the spacer with its cutting edge positioned above the projections and rearwardly of the cutting edge of the bottom blade.

Description

United States Patent Ferraro 1 Jan. 7, 1975 [54] SHAVING UNIT FOR SAFETY RAZOR 3,783,510 1/1974 Davitidowicz 30/50 X Inventor: Frank A. Ferraro, Trumbull, Conn. 3,786,563 1/1974 Donon 4. 30/50 [73] Assignee: Warner-Lambert Company, Morris FOREIGN PATENTS B APPLICATIONS Plains NHL 772,532 4/1957 Great Britain 30/50 [22] Filed: Sept 1973 Primary ExaminerAl Lawrence Smith 2 App] 39 104 Assistant ExaminerGary L. Smith Attorney, Agent, or Firm.lames F. Powers, Jr.; Albert 0 H. Graddis [30] Foreign Applicatlon Prlorlty Data Jan. 23, 1973 Great Britain 3365/73 [57] ABSTRACT 52 us. 01. 30/346.58, 30/50 The Specific disclosure PmhdeS a Shaving having 51] Int. Cl B2611 21/54, B26b 21/22 a Spacer which includes a Pair of Spaced forwardly [58] Field of Search 30/50 346.57 346.58 tending Pmiechohs- A bottom razor blade is 36/341659 nected to the underside of the spacer with its cutting edge positioned beneath the projections, and a top [56] References Cited razor blade is connected to the upperside of the spacer with its cutting edge positioned above the pro- UNITED STATES PATENTS jections and rearwardly of the cutting edge of the bot- 2,019,475 11 1935 Baudis 30134 .59 x tom blade 2,713,201 7/1955 Plesch 30/346.57 X 3,262,206 7/1966 Tomek 30/3465) 21 Claims, 13 Drawing Figures Patented Jan. 7, 1975 3,858,315

3 Sheets-Sheet 1 l9 f r w imi in 3Z /5 Patented Jan. 7, 1975 3,858,315

3 Sheets-Sheet 2 Patented Jan. 7, 1975 3 Sheets-Sheet 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 shaving units for safety razors with the shaving units having a plurality of single cutting edge blades bonded together on opposite sides of a spacer such that the cutting edges are tandemly arranged.

2. DESCRIPTION OF THE PRIOR ART Shaving systems which provide for feeding single cutting edge blades to a safety razor from a separable dispenser are well known in the art and are commercially available. For example, dispensers such as described in U.S. Pat. Nos. 2,911,713 and 2,812,576 have an elongated key that is positioned in the head of a safety razor such as disclosed in US. Pat. Nos. 2,911,713, 2,911,714, 3,128,551 and 3,177,581 to wedge a cap in the razor head away from a blade seat. A fingeroperated slide on the dispenser is then used to insert a blade between the cap and blade seat. After the key is removed from the razor head, the cap acts to clamp the blade to the blade seat and to bias the cutting edge of the blade forwardly against a pair of spaced stops on the blade seat or cap.

Tomek US. Pat. No. 3,262,206 describes a shaving unit consisting of a pair of tandemly mounted single cutting edge blades which are vertically separated by a plastic spacer having a forward surface spaced inwardly from both cutting edges. The plastic spacer of Tomek has plastic posts extending through perforations in the two blades to bond the blades thereto. Thus, when the shaving unit of Tomek is clamped and biased against stops in the above-described razors, the portions of the lower blade cutting edge can break down around the stops to cause an unwanted increase in shave angles with regard to a typical guard bar surface located downwardly and outwardly from the cutting edges. Further, the structure of Tomek raises the possibility of planar movement of the spacer and top blade as a result of shear forces resulting from the biasing action in the razor head to seat the unit against stops.

SUMMARY OF THE INVENTION wherein the razor comprises means for locating the shaving unit and means for biasing the shaving unit to said locating means. The shaving unit comprises a razor blade having a cutting edge positioned upwardly and rearwardly of a cutting edge on another razor blade. Means interconnect the two blades for vertically spacing the blades apart, and means extend forwardly from the spacing means to at least the cutting edge of the lower blade for abutting engagement with the locating means. This aspect of the invention avoids or minimizes the possibility of cutting edge breakdown because the abutting engagement means absorbs the forces applied to the forward portion of the unit when the unit is biased to the locating means.

In accordance with another aspect of the invention, the spacing means of the preceding aspect includes rear surface means for abutting engagement with the biasing means whereby the adverse effects of shear forces applied to the blades and spacer are avoided or minimized.

In accordance with still another aspect of the present invention, there is provided a shaving unit comprising a spacer member including a pair of spaced forwardly extending projections. A first razor blade is connected to an underside of the spacer member, and includes a cutting edge positioned beneath the projections. A second razor blade is connected to an upperside of the spacer member, and includes a cutting edge positioned above the projections and rearwardly of the cutting edge of the first razor blade. The projections absorb the forces applied to the forward portion of the unit when the unit is seated in a safety razor.

In accordance with yet another aspect of the present invention, the spacer member of the immediately preceding aspect further includes a surface extending rearwardly to at least the rearmost portions of the first and second razor blades whereby the adverse effects of shear forces applied to the unit are avoided or minimized.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded view of an embodiment of a shaving unit constructed in accordance with the present invention;

FIG. 2 is a top plan view of the shaving unit embodiment of FIG. 1;

FIG. 3 is a cross-sectional view of the shaving unit taken along Lines 3-3 of FIG. 2;

FIG. 4 is a cross-sectional view of another embodiment of a shaving unit constructed in accordance with the present invention;

FIG. 5 is a cross-sectional view of an embodiment of the present invention taken along

Lines

5,5 of FIG. 6;

FIG. 6 is a top plan view of an embodiment of the invention showing blade and spacer orientation means;

FIG. 7 is a cross-sectional view of an embodiment of the invention for bonding the blades and spacer to gether;

FIGS. 8 and 9 are cross-sectional views showing another embodiment for bonding the blades to a plastic spacer;

FIG. 10 is a cross-sectional view of the FIG. 1 embodiment seated in a safety razor;

FIG. 11 is an exploded view of yet another embodiment of a shaving unit constructed in accordance with the present invention;

FIG. 12 is a top plan view of the embodiment of FIG. 11; and

FIG. 13 is a cross-sectional view taken along Lines 13-43 of FIG. 12.

DESCRIPTION OF SPECIFIC EMBODIMENTS With reference to FIGS. 1 3, one embodiment of the present invention provides a shaving unit 10 having a top single edge razor blade 11 and a bottom single edge razor blade 13 connected to opposite surfaces of a spacer member 12. The spacer member 12 has a pair of spaced forwardly extending projections l7, 18 at the outer ends thereof, and a plurality of forwardly extending teeth 16 between the projections l7, 18. The cutting edge l5 of the bottom blade 13 is positioned beneath the

projections

17, 18, and the cutting edge 14 of the top blade 11 is positioned above the

projections

17, 18 and rearwardly of the cutting edge 15 of the bottom blade 13.

As shown in FIG. 3, the forward extension of the teeth 16 is terminated short of the cutting edge 14 of the top blade 11. However, the upper surfaces of the teeth 16 can alternatively be beveled, and the beveled surfaces can then extend forwardly a slight distance from beneath the cutting edge 14 of the top blade 11. Spaces 19 formed between the teeth 16 are in fluid communication with elongated perforations 20 formed in the bottom blade 13. The spaces 19 and the perforations 20 provide shaving residue flow paths from be tween the

cutting edges

14, 15 of the blades 11, 13.

The blades l1, l3 and the spacer member 12 have a pair of spaced elongated slots which may be used as an aid to handling materials and the blades ll, 13 and spacer member 12 during manufacture and assembly of the shaving unit 10. Each one of the blades 11, 13 and the spacer member 12 has a cut-out portion 8 at each end thereof. During assembly of the shaving unit 10, the cut-out portions 8 are aligned as shown in FIG. 2 to orient the blades 11, 13 and the spacer member 12 prior to bonding the blades l1, 13 to the spacer member 12.

In the embodiment shown in FIGS. 1 3, the blades 11, 13 are bonded to the spacer member 12 by a plurality of spot welds 22. Alternatively, the spacer member 12 can have a plurality of upwardly extending and downwardly extending projections having a height of approximately 0.003 inch. In this alternative embodiment, the blades 11, 13 are bonded to the spacer member 12 by a projection welding process such as described in Metals Handbook, Vol. 6 Welding and Brazing, Page 445, American Society for Metals, Metals Park, Ohio 44073, 1971.

FIG. 4. is a modification of the embodiment of FIGS. 1 3 wherein the

projections

17, 18 of FIGS 1 3 are upwardly deformed to provide stops 23 against which the outer ends of the cutting edge 14 of the top blade 11 are seated. The stops 23 may be used as an aid to orient the top blade cutting edge 14 with respect to the spacer member 12 and the bottom blade cutting edge 15. Further, the stops 23 prevent nicks and cuts from the outer corners of the top blade cutting edge 14.

FIGS 5 and 6 show another modification of the embodiment of FIGS 1 3 wherein the spacer member 12 has a pair of upwardly extending

posts

31, 35 which are located in the outer portions of the

top blade slots

30, 33, and a pair of downwardly extending

posts

32, 34 which are located in the innermost portions of the bottom blade slots. The

posts

31, 32, 34, 35 are used to orient the blades 11, 13 with respect to the spacer member 12.

FIG. 7 shows another embodiment of the present invention wherein the top and bottom blades 11, 13' have a plurality of beveled holes 40, 41. The spacer member 12' is upwardly and downwardly deformed 46, 48 by a punch or the like inserted through

holes

45, 47 to form relatively flat-headed rivets 43, 44 in the beveled holes 40, 41.

FIGS. 8 and 9 show another embodiment of the present invention wherein the spacer 50 is formed of plastic and has a plurality of

posts

51, 52 extending upwardly and downwardly through

beveled holes

53, 54 formed in the top and bottom blades 11", 13". The

posts

51, 52 are staked or compressed in any known manner, such as by ultrasonics, heat and/or pressure, to fill out the

beveled holes

53, 54 as shown in FIG. 9.

With reference to FIGS 11 13, the shaving unit 79 has equally dimensioned top and

bottom blades

81, 82. The only difference between the top and bottom blades is that the top blade 81 distance between the rear edge 84 and the cut-out portions 98 is less than the bottom blade 82 distance between its rear edge 85 and its cutout portions 100. The

blades

81, 82 and the spacer have a pair of

elongated slots

95, 96, 97 which may be used for handling the components during manufacture. The unit 79 of FIGS 11 13 is assembled by aligning the cut-out

portions

98, 99, 100 of the

blades

81, 82 and the spacer 80, and the

blades

81, 82 are then bonded to the spacer member 80 by a plurality of spot welds diagrammatically represented as 90, 92, 94 or by projection welding such as described hereinabove with respect to the embodiment of FIGS 1 3.

The cutting edge 89 of the bottom blade 82 is positioned beneath the

projections

86, 87 of the spacer, and the cutting edge 88 of the top blade 81 is positioned above the

projections

86, 87 and rearwardly of the bottom blade cutting edge 89. The rear edge 83 of the spacer 80 extends rearwardly of the

rear edges

84, 85 of the

blades

81, 82.

The

projections

86, 87 can be deformed as shown in FIG. 4 to provide stops for the top blade cutting edge 88. Alternatively, the forwardly extending projections of any one of the foregoing embodiments can have upwardly extending portions spaced from the upper blade cutting edge, but situated with respect to the upper blade cutting edge to preclude nicks and cuts by the corners of the upper blade cutting edge.

The shaving units of the present invention can be dispensed from a modified form of well-known and commercially available single edge blade dispensers. Single edge blade dispensers are described in many patents such as U.S. Pat. Nos. 2.9l1,7l3 and 2,812,576. The dispenser modifications essentially consist of thickening an elongated key of the dispenser such that a cap portion of the razor head is wedged away from a blade seating plate of the razor to permit insertion of the shaving unit between the cap portion and the seating plate. It is also apparent that a blade exit slot of the well-known single edge blade dispenser must be dimensioned to permit removal of shaving units therefrom under the action of a finger-operated pusher.

FIG. 10 is a cross-sectional view of a head 60 of a single edge razor currently manufactured by the Schick Safety Razor Company, Division of Warner-Lambert Company. The razor shown in FIG. 10 functions essentially in the same manner as the razor disclosed in the US. Pat. No. 2,91 1,713, which patent is incorporated herein by reference.

With reference to FIG. 10, the razor head 60 has a frame member 61 having a forwardly extending cap in transverse line contact with the top blade 11 at point 65. From point 65, the underside of the cap is beveled at 66 away from the top blade 11. The head 60 also includes a blade seating plate having a generally flat forwardly projecting flange 69 underlying the cap of the frame 61 to constitute the blade seat for the shaving unit. The seat 69 terminates along its front edge in a downwardly curved serrated guard bar 63. Behind the guard bar 63 is a clearance opening 64 formed in the seat 69. An upwardly extending blade stop 62 is formed on the seat 69 at each end of the guard bar 63. The stops 62 each have a vertical surface 68 against which the forwardly extending

projections

86, 87 are biased.

At least one indent 67 is formed in the frame 61 for abutting engagement with the rear edge of the spacer member 12. As described in US. Pat. No. 2,911,713, an upper part of a spring 71 bears against a flange portion 70 of the blade seating plate to clamp the seat 69 both upwardly and rearwardly such that the shaving unit is firmly clamped between the cap line-contact 65 and the seat 69, and biased forwardly against the vertical surfaces 68 of the spaced stops 62 by the indent 67.

Suitable dimensions for the razor head are shown in FIG. 10. The horizontal distance between the cutting edges of the blades shown in each one of the foregoing embodiments is preferably between about 0.035 to about 0.055 inches, and the vertical distance between the cutting edges of the two blades is preferably between about 0.010 to about 0.026 inches. Suitable dimensions for the embodiment of the shaving unit shown in FIGS 1 3 are provied in FIG. 10.

The shaving unit of FIGS. 11 13 can be suitably constructed of 0.006 inch by 1.50 inch by 0.29

inch razor blades

81, 82, and a spacer member 83 having a thickness or vertical height as viewed in FIG. 13 of0.01 inch. Further, the horizontal distance between the cutting edges 88, 89 can be 0.036 inch, and the spacer rear edge 83 can suitably protrude rearwardly from the top blade rear edge 84 by 0.01 inch. Still further, the upwardly extending portions (not shown) on the

projections

86, 87 discussed hereinabove can suitably extend upwardly 0.005 inch to avoid nicks and cuts from the corners of the top blade cutting edge 88.

As used herein, positioning the bottom blade cutting edge beneath" the spacer projections includes positioning the bottom blade cutting edge in a vertical plane as defined by the forwardmost portions of the projections. It is also contemplated that the spacer projections can extend forwardly of the bottom blade cutting edge. This aspect of the invention requires that the projections come into abutting engagement with the vertical surfaces of blade locating stops which are shown in FIG. as extending upwardly from the blade seat 69, and which are shown in US. Pat. No. 3,177,581 as extending downwardly from a cap portion of a razor head. As discussed above, this aspect of the invention avoids or minimizes the possibility of the bottom blade cutting edge breaking down as a result of abutting engagement with blade stops on a razor.

Similarly, another aspect of the invention contemplates that the rear edges of the blade not extend rearwardly of a vertical plane defined by the rear edge of the spacer. For example, the blade rear edges may lie in a vertical plane defined by the spacer rear edge as shown in FIG. 3, or one or more of the blade rear edges may be forward of the spacer rear edge as shown in FIG. 13. As discussed hereinabove, this aspect of the invention calls for the rear surface of the spacer coming into abutting engagement with biasing means such that in combination with the first abstract the adverse effects of shear forces are avoided or minimized.

The present invention also contemplates more than two single edge blades tandemly arranged such that seating and shear forces are absorbed by at least one spacer member.

What is claimed is:

l. A replaceable shaving unit for a safety razor, wherein said razor comprises a transverse guard surface, spaced stop means for locating said shaving unit with respect to said guard surface, a blade seat member, and means for clamping said shaving unit on said blade seat member and for biasing said shaving unit to said spaced stop means, said shaving unit comprising:

a. a first razor blade having a cutting edge and a blunt rear edge adapted to be positioned upwardly and rearwardly of said guard surface, and an underside for abutting engagement with said blade seat member,

b. a second razor blade having a cutting edge and a blunt rear edge positioned upwardly and rearwardly of said first razor blade,

c. means interconnecting said first and second razor blades for vertically spacing said first and second razor blades apart, said spacing means including rear surface means extending rearwardly to at least the blunt rear edges of said bottom and top razor blades for abutting engagement with said biasing means, and

d. means extending forwardly from said spacing means to at least the cutting edge of said first razor blade for abutting engagement with said spaced stop means.

2. A replaceable shaving unit for a safety razor, wherein said razor comprises a transverse guard surface, spaced stop means for locating said shaving unit with respect to said guard surface, a blade seat member, a frame member including a cap extending forwardly above said blade seat member, and means for biasing said shaving unit in abutting engagement with said stop means and said blade seat member upwardly to clamp said shaving unit between said cap and said blade seat member, said shaving unit comprising;

a. a spacer member including a transversely elongated center portion having a rear surface for abutting engagement with said frame member, a pair of spaced projections extending forwardly from said center portion for abutting engagement with said spaced stop means, an underside, and an upper side;

b. a bottom razor blade connected to said underside, said bottom razor blade including a lower surface for abutting engagement with said blade seat member, an elongated cutting edge positioned beneath said projections, and a blunt rear edge positioned beneath said center portion; and

c. a top razor blade connected to said upper side, said top razor blade including an upper surface for abutting engagement with said cap, an elongated cutting edge positioned above said projections and rearwardly and parallelly with the cutting edge of said bottom razor blade, and a blunt rear edge positioned above said center portion;

(1. said spaced projections extending forwardly to a least a vertical plane defined by the cutting edge of the bottom blade; and

e. said rear surface of said center portion extending rearwardly of the blunt edges of said bottom and top blades.

3. The shaving unit of claim 2, wherein said spacer member further includes a plurality of teeth between said projections, said teeth extending forwardly from said center portion for a distance less than the forward extension of said projections.

4. The shaving unit of claim 3, wherein said bottom razor blade further includes a plurality of perforations between said teeth.

5. The shaving unit of claim 2, wherein each one of said projections includes an upwardly extending surface; and wherein the cutting edge of said top razor blade is seated against the upwardly extending surfaces on said projections.

6. The shaving unit of claim 2, wherein each one of said bottom and top razor blades further includes a transversely elongated slot, the slots being vertically aligned; and wherein said spacer member further includes a pair of transversely spaced posts, one of said posts extending upwardly into one end of the slot in said top razor blade, and the other of said posts extending downwardly into the end of the slot in said bottom razor blade opposite said one end.

7. The shaving unit of claim 6, wherein each one of said bottom and top razor blades further includes another transversely elongated slot, the another slots being vertically aligned; and wherein said spacer member further includes another pair of transversely spaced posts, one of said another posts extending upwardly into one side of the another slot in said top razor blade, and the other of said another posts extending downwardly into the side of the another slot in said bottom razor blade opposite said one side.

8. The shaving unit of claim 2, wherein said bottom and top razor blades each has an equal distance from cutting edge to blunt rear edge.

9. The shaving unit of claim 2, wherein said bottom and top razor blades have identical length, width and height dimensions.

10. The shaving unit of claim 9, wherein each one of said bottom and top razor blades has a height of 0.006 inch, and wherein said spacer member has a height of 0.01 inch.

11. The shaving unit of claim 10, wherein the cutting edge of said top razor blade is in a horizontal plane 0.016 inch above another horizontal plane defined by the cutting edge of said bottom razor blade.

12. The shaving unit of claim 11, wherein a pair of vertical planes defined by the cutting edges of said bottom and top razor blades have a spacing therebetween of about 0.035 inch to about 0.037 inch.

13. The shaving unit of claim 2, wherein said bottom and top razor blades are connected to said spacer member by a plurality of spot welds.

14. The shaving unit of claim 2, wherein said bottom and top razor blades are connected to said spacer member by a plurality of projection welds, the weld projections being initially formed on said spacer member.

15. The shaving unit of claim 2, wherein each of said bottom and top razor blades further includes a plurality of apertures, and wherein said center portion of said spacer member is deformed through said apertures to connect said bottom and top razor blades to said spacer member by integral rivets.

16. the shaving unit of claim 2, wherein each of said bottom and top razor blades further includes a plurality of apertures, and wherein said center portion of said spacer member has a plurality of posts extending through said apertures, said posts being deformed at the outer ends thereof to connect said bottom and top razor blades to said spacer.

17. The shaving unit of claim 2, wherein the cutting edge of said top razor blade is in a horizontal plane from about 0.035 inch to about 0.55 inch above another horizontal plane defined by the cutting edge of said bottom razor blade.

18. The shaving unit of claim 17, wherein a pair of vertical planes defined by the cutting edges of said bottom and top razor blades having a spacing therebetween of from about 0.01 inch to about 0.026 inch.

19. The shaving unit of claim 2, wherein the distance between the cutting edge and the blunt rear edge of said top razor blade is less than the distance between the cutting edge and the blunt rear edge of said bottom blade.

20. The shaving unit of claim 2, wherein the height of one of said top and bottom razor blades is less that the height of the other of said top and bottom razor blades.

21. The shaving unit of claim 2, wherein said projections extend forwardly of the cutting edge of said bottom blade.

Claims

1. A replaceable shaving unit for a safety razor, wherein said razor comprises a transverse guard surface, spaced stop means for locating said shaving unit with respect to said guard surface, a blade seat member, and means for clamping said shaving unit on said blade seat member and for biasing said shaving unit to said spaced stop means, said shaving unit comprising: a. a first razor blade having a cutting edge and a blunt rear edge adapted to be positioned upwardly and rearwardly of said guard surface, and an underside for abutting engagement with said blade seat member, b. a second razor blade having a cutting edge and a blunt rear edge positioned upwardly and rearwardly of said first razor blade, c. means interconnecting said first and second razor blades for vertically spacing said first and second razor blades apart, said spacing means including rear surface means extending rearwardly to at least the blunt rear edges of said bottom and top razor blades for abutting engagement with said biasing means, and d. means extending forwardly from said spacing means to at least the cutting edge of said first razor blade for abutting engagement with said spaced stop means.

2. A replaceable shaving unit for a safety razor, wherein said razor comprises a transverse guard surface, spaced stop means for locating said shaving unit with respect to said guard surface, a blade seat member, a frame member including a cap extending forwardly above said blade seat member, and means for biasing said shaving unit in abutting engagement with said stop means and said blade seat member upwardly to clamp said shaving unit between said cap and said blade seat member, said shaving unit comprising; a. a spacer member including a transversely elongated center portion having a rear surface for abutting engagement with said frame member, a pair of spaced projections extending forwardly from said center portion for abutting engagement with said spaced stop means, an underside, and an upper side; b. a bottom razor blade connected to said underside, said bottom razor blade including a lower surface for abutting engagement with said blade seat member, an elongated cutting edge positioned beneath saId projections, and a blunt rear edge positioned beneath said center portion; and c. a top razor blade connected to said upper side, said top razor blade including an upper surface for abutting engagement with said cap, an elongated cutting edge positioned above said projections and rearwardly and parallelly with the cutting edge of said bottom razor blade, and a blunt rear edge positioned above said center portion; d. said spaced projections extending forwardly to a least a vertical plane defined by the cutting edge of the bottom blade; and e. said rear surface of said center portion extending rearwardly of the blunt edges of said bottom and top blades.