US3892036A

US3892036A - Safety razor

Info

Publication number: US3892036A
Application number: US366378A
Authority: US
Inventors: Roger L Perry
Original assignee: Gillette Co LLC
Current assignee: Gillette Co LLC
Priority date: 1973-06-04
Filing date: 1973-06-04
Publication date: 1975-07-01
Anticipated expiration: 1992-07-01
Also published as: JPS5015662A; DE2365516A1; CA984600A; GB1439999A; ES443531A1

Abstract

A safety razor includes a cap portion, a platform portion adapted to support a blade unit against the underside of the cap portion, associated blade aligning structure for locating a blade edge in a predetermined position on the platform portion, and a guard portion of material different than the material of the platform portion positioned forward of the platform portion in spaced relation from the predetermined blade edge position as defined by the blade aligning structure.

Description

United States Patent Perry July 1, 1975 [54] SAFETY RAZOR 3,253,335 5 1966 Kruger 30 62 3,311.975 4 1967 L 3O 62 [75] Invent Perm Lymfield Came 3.374.540 341968 30i62 Mass- 3,657,810 4/1972 Nissen 30/63 [73] Assignee: The Gillette Company, Boston,

M Primary ExaminerAl Lawrence Smith A: 1E. L.S'th Filed: J 973 ssrs an rammer Gary m1 [2H Appl. No.1 366,378 57 ABSTRACT A safety razor includes a cap portion, a platform por- U-S- Cl. t tion adapted to sup ort a blade unit against the under- [51] hit. Cl B26b 21/24 side f the cap portion associated blade aligning [58] Field of Search 30/32, 62-64, structure f locating a blade edge in a predetermined 30/751 1 85, 50 position on the platform portion, and a guard portion of material different than the material of the platform References Cited portion positioned forward of the platform portion in UNITED STATES PATENTS spaced relation from the predetermined blade edge 1.999.060 4/1935 Rydner 30/32 ux Position as defined y the blade aligning strummi- 2,7l3,200 7/1955 Alwood 30/32 3.203.093 8/1965 Kuhn! M 30/63 8 Chum 15 Draw Fgures SAFETY RAZOR SUMMARY OF INVENTION This invention relates to safety razors and more particularly to safety razors of the type that employ replaceable blades or blade units.

The maintenance of the shaving geometry of a shaving system is necessary to provide uniform and high quality shaving. Shaving geometry may be defined in terms of certain parameters which include blade tangent angle (BTA), the angle between the plane bisecting the two facets that define the cutting edge of the blade and a plane through that edge and tangent to the skin engaging surface next forward of that edge; span, the distance of the edge from the next forward skin engaging surface; and exposure, the distance of the edge from a plane defined by the skin engaging surfaces immediately forward of and rearward of the blade edge. The guard structure generally includes the skin engaging surface immediately forward of the blade edge and thus its position relative to the blade edge is critical in determining the geometry of the shaving system. In conventional razors that utilize replaceable blade elements, the guard is formed integral with the platform and is of the same material as the platform. Blade positioning elements, whose locations are precisely determined, engage portions of the blade to position the blade edge in the desired location relative to the guard surface. In razors of the injector type which employ a single edge blade, the blade positioning surfaces conventionally engage the cutting edge of the blade and as such surfaces must be sturdy and not deformed by the repeated engagement of the blade edges, they are conventionally formed of metal.

In particular cases, it may be advantageous to provide a skin engaging surface that has a particular characteristic, for example a low coefficient of friction so that that skin engaging surface will slide freely over the skin, or for other applications, a skin engaging surface with a high coefficient of friction. It is an object of this invention to provide an improved razor which enables greater variety in the nature of the skin engaging surfaces.

lt is another object of this invention to provide a novel and improved razor arrangement which is simple, versatile, economical to manufacture and of sturdy construction.

A more specific object of the invention is to provide a novel and improved razor adapted to receive replacement blade units that are inserted endwise.

A further object of the invention is to provide a simple, sturdy and reliable razor of the injector type which will receive and position for proper shaving a conventional blade having a single edge as well as a blade unit that has two edges offset from one another.

In accordance with a feature of the invention there is provided a safety razor which includes a cap portion, a platform portion which is adapted to support a blade against the underside of the cap portion and has associated blade aligning structure for locating a blade edge in a predetermined position, and a guard portion of material different than the material of the platform portion positioned forward of the platform portion in spaced relation from the predetermined blade edge position as defined by the blade positioning structure. In a particular embodiment, the blade locating structure includes surfaces adapted to be engaged by the cutting edge of a blade element at either end thereof for positioning the blade relative to the guard member, those positioning surfaces are formed of the same metal as the blade support platform and the guard member is of a molded plastic material.

The guard member may be secured to the blade support platform in a variety of ways, such as mechanical fastening or adhesive bonding, in a preferred embodiment the guard includes a body member which includes a reference surface that is positioned against a cooperating reference surface of the support platform; and the support platform includes deformable structure which is placed in firm frictional engagement with the body of the guard member to secure that bodys reference surface firmly in engagement with the reference surface of the blade support platform. In a particular embodi ment, the deformable securing structure includes a plurality of tabs, each of which includes an ofi'set portion that extends under and engages a cooperating surface of the guard body for supporting the guard in position.

It has been found that certain plural edge shaving systems provide superior shaving characteristics. Such a shaving system includes two cutting edges disposed parallel to one another in spaced relation to provide leading and following cutting edges so that both cutting edges are successfully active with respect to the hair elements being cut during a single shaving stroke. The superior shaving characteristics obtained in such a system require careful control of certain parameters including span, exposure, and blade tangent angle. It is a particular object of the invention to provide a novel and improved razor that may provide such a shaving system.

In accordance with another feature of the invention, there is provided a safety razor which includes a main frame member, a relatively movable platform member and a biasing member. The main frame member includes a transversely extending cap portion and a depending handle portion. The platform member is adapted to support the blade against the underside of the cap portion and includes an integral ramp surface inclined at an angle between 45 and to the blade support surface. The biasing member is secured to the handle portion and engages the ramp surface such that it is effective to urge the platform member simultaneously upwardly and rearwardly to secure a blade between the support surface of the platform member and the cap portion in proper shaving position. In a preferred embodiment, the handle portion defines a recess in which the ramp surface is received and the biasing member is a leaf spring, the lower end of which is secured to the two side walls that define the recess such that the upper end of the leaf spring is flexed against the ramp surface. The frame and platform members also include spaced surfaces that cooperate with a dispenser key such that insertion of the dispenser key urges the platform member downwardly and forwardly (sliding the ramp along the spring) to facilitate replacement of a blade unit.

In a particular embodiment, the main frame member includes symmetrically disposed reference surfaces, one on either side of the center of the cap portion and at the rear thereof, for engaging the rear edge of the inserted blade unit, and the platform member carries projecting blade stop surfaces that are adapted to engage the forward edges of the inserted blade unit so that the blade unit is clamped between the reference and stop surfaces to provide the desired positioning of the blade unit relative to the guard surface. A grip portion of plastic material is engaged with the depending handle portion and encloses the latched portions of the spring and frame portion, and also provides greater convenience in handling A particular embodiment of the razor constructed in accordance with the invention accepts a variety of blade units (e.g. both single or plural edge units). The razor is simple in design, economical in construction. sturdy and reliable in use and sturdy tlade positioning structure provides the desired geometry while the correlated skin engaging guard surface may be of different material enabling selection of a variety of characteristics as desired.

Other objects, features and advantages of the invention will be seen as the following description of a particular embodiment progresses, in conjunction with the drawings, in which:

FIGv I is an exploded perspective view of a razor in accordance with the invention;

FIG. 2 is a side view of the frame member of the razor shown in FIG. 1',

FIG. 3 is a plan view of the frame member shown in FIG. 2'.

FIG. 4 is a sectional view taken along the line 4-4 of FIG. 2; FIGS. 5, 6 and 7 are, respectively, a top view, a front view, and an end view of the platform member employed in the razor shown in FIG. 1;

FIGS. 8, 9 and 10 are, respectively, a top view, a front view (partially in section taken along the line 99 of FIG. 8) and an end view of the guard member employed in the razor shown in FIG. 1;

FIG. 11 is an end view of the subassembly of the platform member and the guard member;

FIG. 12 is an end view of the razor assembly;

FIG. 13 is a plan view of a blade unit for use in the assembled razor shown in FIG. 12;

FIG. 14 is a perspective view of the razor shown in FIG. 12 with a cooperating dispenser; and

FIG. 15 is an enlarged view of a portion of the razor showing aspects of the geometry of the shaving system.

DESCRIPTION OF PARTICULAR EMBODIMENT The razor shown in FIG. 1 includes a frame member 10 formed of brass sheet stock that has at its upper end a transversely extending head portion 12 that includes cap portion 14 and rear wall portion 16. At either end of the base of rear wall 16 is an upwardly turned tab 18. The frame member 10 also includes a depending handle portion 20 that includes a rear wall portion 22 and two side wall portions 24 formed to define a channel. Along the inside surface of each side wall portion 24 are a series of projections 26, and at the upper end of each side wall portion is a coupling structure that includes a seat surface 30, a recess 32 and a latch projection 34.

A platform member 40, also formed of brass sheet stock, includes a planar portion which defines a blade support surface 42. Four deformable tab members 44, each of which includes two offset portions 46, a connector portion 48 are connected to planar portion 42. These tabs of T-shaped configuration project in a generally downward direction from the forward edge of portion 42. At either end of surface 42 is a generally horizontal forwardly extending arm 50 with a vertical end portion 52 connected to each arm by a smoothly curved transition. Each arm 50 has a blade stop projection 54 on its upper surface. The platform member also includes a rear wall portion 56 which is configured to define a recess 58 immediately below the rear edge of platform 42. Bent outwardly at an angle of 30 from the center of surface or rear wall 56 is a planar ramp surface 60.

A third member of the razor is a guard member 62 of Noryl" (Polyphenelyne oxide/styrene plastic) that includes a body portion 64 that has a planar upper surface 66, four T-shapecl notches 68 in its forward wall and a notch 70 in its rear wall. Extending forwardly from either end of body 64 are two arms 72 which support transversely extending portion 74 that defines a ribbed skin engaging guard surface 76. At either end of surface 76 is a recess 78. An aligning projection 80 is provided on the upper surface of each arm 72. The rear wall 82 of body 64 is configured to mate with recess 58 in platform member 40 and with the downwardly extending portions 52 of the platform member disposed at either end of the guard surface 76.

A fourth member of the razor assembly is phosphor bronze spring 84. That spring includes a base portion 86 that has a flange 88 on either side, an intermediate portion 90 that is disposed at an angle of about 140 to base portion 86, and an upper portion 92 which is offset at an angle of about 15 from intermediate section 92. A transversely extending ridge 94 defines the transition between

sections

90 and 92 and provides a surface adapted to engage ramp 60.

The fifth component of the razor is a grip member of high impact polystyrene that has a series of gripping ridges 102 along an intermediate portion of its length, a curved upper end 104, and a recess 106 that extends down its rear side for receiving the depending handle portion 20 of frame member 10, projections 26 engaging a ridge in recess 106 to secure the grip 100 to the handle portion 20.

Additional details of frame member 10 may be seen with reference to FIGS. 2-4. As indicated in FIGS. 2 and 4, cap portion 14 at its forward end includes a transverse surface that is inclined upwardly to the front at an angle of 5. Adjacent surface 122 is inclined upwardly to the rear at an angle of 5 so that the junction 124 of

surfaces

120 and 122 defines a blade engaging line. At the rear of cap portion 14 are formed three

projections

126, 128 and 130.

Projections

126 and 130 each have a forward surface 132 and surfaces 132 are disposed in the same plane. Forward surface 134 of projection 128 is recessed about 0.01 inch behind surfaces 132. Surfaces 132 provide two spaced references which are adapted to receive the rear edge of a blade unit for positioning purposes. Projections 126, I28 and 130 also each have a lower surface 136, those three lower surfaces being aligned and providing a guide for the top edge 114 of the key 112 of a cooperating blade dispenser 110 (FIG. 14). At the lower end of rear wall 16 are two tabs 18 which define a lower guide for the dispenser key 112. Neck portion 138 (FIG. 2) is offset rearwardly of rear wall 16 at an angle of about 15 and is joined to handle portion 20 by the curved transition section 140. As indicated in FIG. 2, each latch portion 34 includes a recess 150, and one end of seat surface 30 is defined by shoulder 152 while the transition between seat 30 and recess 32 is defined by intermediate shoulder 154.

Additional details of platform member 40 may be seen with reference to FIGS. 5-7. Formed at each rear corner of blade support surface 42 is a cutout or notch 160, and the side edges 162 of surface 42 are bent downwardly at an angle. Each forwardly extending arm 50 has a blade edge stop projection 54 which includes a vertically disposed blade edge engaging surface 164 (FIGS. 5 and 7). Each T-shaped latch tab 44 is inclined forwardly at an angle of about 20 to the vertical. The recess 58 at the rear of the support platform includes a vertical reference surface, and at either end of the platform member 40 below surface 170 are formed

projection portions

172, 174. The inclined upper surfaces 176 of these projection portions define the lower boundary of recess 58 while the lower edge of projection portion 174 is separated from surface 58 such that a cam surface 178 is provided against which a ridge 116 of the dispenser key 112 acts as that key is inserted into the razor to urge the platform member 40 down. Transition surface 180 (FIG. 5) is also engaged by a key surface and acts to urge the platform member forward. Planar ramp surface 60 is an extension of and is bent out of the plane of the rear wall 56.

Additional details of the guard member 62 may be had with reference to FlGS. 8-10. The body 64 of the guard member has four recesses 68 of T-shaped configuration in its front wall as indicated in FIG. 9. Each recess includes two undercut surfaces 190. Ribs 192, extending between the body 64 and the guard portion 74, provide increased rigidity of the skin engaging surface 76. The top surface of each aligning post 80 is in the same plane as upper surface 66 of body 64. The rear wall 82 of body 64, as best indicated in FIG. 10, includes

inclined surfaces

194, 196 that are connected by reference surface 198.

In assembling the components of the razor, a subassembly of platform member 40 and guard member 62 is first created. As indicated in FlG. 11, platform member 40 is inverted and guard member 62 is inserted so that reference surface 198 of guard 62 is adjacent reference surface 170 of platform member 40 and guard surface 66 is seated on the underside of planar blade support portion 42. The securing portions 44 are then bent from the dotted line position rearwardly to the solid line position indicated in FlG. 11 by moving tapered tools down through the apertures between ribs 192 bending tabs 44 rearwardly so that offset portions 46 engage notch surfaces 190. This action forces reference surface 198 into firm engagement with surface 170 and earns inclined surface 196 against surface 176. Offset surfaces 46 of tabs 44 engage, in interference fitting relation, recess surfaces 190 so that the body of guard member 62 is held firmly in proper position in the platform member 40 while blade positioning surfaces 164 are not deflected. The undersides of arms 50 engage projections 80 and each depending end 52 is disposed in recess 78 on either side of the ribbed guard surface 76. This subassembly provides precise definition of the tangent plane 200 between predetermined blade edge engaging points 202 on projections 54 and a tangent line on the ribbed guard surface, indicated at point 204 in FIG. 11. In this embodiment plane 200 is disposed at an angle of 26 to the blade support surface 42 of platform 40 for a dual edge blade unit.

The guard platform subassembly is then positioned in the razor frame in the position indicated in FIG. 12, and spring 84 is positioned with ridge 94 on ramp 60.

The spring is then slid upwardly as viewed in FIG. 12 until the upper ends of flanges 88 fit into the latch recesses 150, at which point the flange bodies engage seats 30 with the lower ends of the flanges against shoulder 152. In this position, spring 84 is secured to frame member 10 and urges the guard-platform subassembly upwardly and rearwardly against cap 14.

This razor is adapted to accomodate both standard, single edge injector blades and dual edge blade units 210 of the type shown in copending application Ser. No. 287,335, filed Sept. 8, 1972 entitled Plural Edge Blade Unit and assigned to the same assignee as this application. A blade unit of that type is shown in FIG. 13, and includes two identical blade members, each about one .6 inches long, about 0.3 inch wide, and about 0.01 inch thick. A cutting edge 216 is formed along one of the longer sides of each blade element in a position offset with respect to a median plane through the blade, each edge 216 being parallel to the body of the blade but offset about 0.003 inch from the median plane. Seven debris removal slots 220 pierce each blade element, one of the slots 220A being larger and providing a blade orientation indicator. The two

blade elements

212, 214 are secured together in the relation indicated in FIG. 13, as by spot welding at points 224 to form the dual edge blade unit 210, the blade elements being offset such that the edges 216 are spaced a distance of about 0.04 inch apart and define a plane inclined at an angle of about 25 to the median planes of the blade elements.

A blade unit 210 is inserted into the razor as indicated in FIG. 14, by inserting key 112 of the dispenser into the recess 230 defined in part by wall 16, tab 18 and offset projection 174. As the key is inserted, the platform-guard assembly is forced forward as rib 115 slides past transition surface 180. When the projection 116 engages cam surface 178, the guard-platform assembly is urged downwardly against the force of spring 84 so that the entrance end of the guard-platform sub assembly is depressed to increase the entrance opening between cap 14 and platform 40 for a blade unit 210. A blade unit 210 is then fed into the razor by operation of dispenser pusher 118.

The position of the blade unit 210 in the razor is shown in the enlarged view of FIG. 15. The cutting edge 216 of the leading blade element 212 is engaged, at either end, by surfaces 164 of aligning projections 54 and the spring 84, acting against ramp 60, urges the engaged blade rearwardly against reference surfaces 132 of the frame member. Spring 84 also urges the platform-guard subassembly upwardly against cap 14. In the resulting shaving geometry, as indicated in FIG. 15, the span (5,) of the leading blade 212 is 0.06 inch, the tangent angle (BTA) of the leading blade is 26, the span (S of the trailing blade 214 is 0.04 inch, and the ETA of that blade is 25. While FIGS. l2l5 show the razor with a blade unit of 0.02 inch thickness, the razor also accepts blades of other thicknesses, including conventional single edge injector blades of 0.01 inch thickness. It will be seen that the invention provides a versatile razor construction that is simple and economical to manufacture and sturdy and reliable in use.

While a particular embodiment of the invention has been shown and described, various modifications will be apparent to those skilled in the art, and it is not intended that the invention be limited to the disclosed embodiment or to details thereof and departures may be made therefrom within the spirit and scope of the invention.

What is claimed is:

I. An injector type razor comprising a main frame member that includes a transversely extending cap portion and a depending handle portion,

a platform structure mounted for movement relative to said main frame member and adapted to support a blade unit against the underside of said cap portion,

said platform structure including a platform portion adapted to support a blade unit against the underside of said cap portion,

associated blade aligning structure for locating a blade edge in a predetermined position on said platform portion, and

a guard portion of material different than the material of said platform portion positioned forward of said platform portion in spaced relation from the predetermined blade edge position as defined by said blade aligning structure,

said guard and platform portions each including a reference surface and said platform portion including deformable structure which is placed in firm frictional engagement with a surface of said guard portion to secure the two said reference surfaces firmly in engagement with one another,

a ramp surface integral with said platform structure and extending downwardly from said platform portion at a rearwardly inclined angle thereto,

and a biasing member secured to said handle portion and flexed in slidable engagement against said ramp surface, effective to urge said platform structure rearwardly to urge said blade aligning structure rearwardly into engagement with an edge portion of a blade unit on the platform portion and simultaneously to urge said platform structure upwardly to secure the blade unit on said platform portion against the underside of said cap portion in proper shaving position and to permit sliding of said ramp surface along said biasing member to release the blade unit on said platform portion in re sponse to insertion of the key of a blade injector magazine between said main frame member and said platform structure.

2. The razor as claimed in claim 1 wherein said handle portion includes two spaced side walls which define a recess in which said ramp surface is received and said biasing member is a leaf spring, the lower end of which includes two side flanges which are secured to said two side walls such that the upper end of said leaf spring is flexed against said ramp surface to exert said upward and rearward biasing force on said platform structure.

3. The razor as claimed in claim I wherein said blade locating structure, the ramp surface and said platform portion are formed in the same metal member and said guard portion is a member of molded plastic material.

4. The razor as claimed in claim I wherein said main frame member includes two symmetrically disposed reference surfaces, one on either side of the center of said cap portion and at the rear thereof, for engaging rear edge surfaces of an inserted blade unit, and said blade aligning includes projecting blade stop surfaces that are adapted to engage forward edge surfaces of the inserted blade unit so that the blade unit is clamped between said reference and stop surfaces to provide the desired positioning of the blade unit relative to the guard portion.

5. The razor as claimed in claim 1 wherein said deformable structure includes a plurality of tabs, each of which includes an offset portion that extends under and engages a cooperating surface of said guard portion for supporting said guard portion in engagement with said platform portion.

6. The razor as claimed in claim 5 wherein said handle portion includes two spaced side walls which define a recess in which said ramp surface is received and said biasing member is a leaf spring, the lower end of which is secured between said two side walls such that the upper end of said leaf spring is flexed against said ramp surface.

7. The razor as claimed in claim 6 wherein said main frame member includes symmetrically disposed reference surfaces, one on either side of the center of said cap portion and at the rear thereof, for engaging the rear edge of an inserted blade unit, and said blade aligning structure includes projecting blade stop surfaces that are adapted to engage the forward edges of the inserted blade unit so that the blade unit is clamped between said reference and stop surfaces to provide the desired positioning of the blade unit relative to the guard portion.

8. The razor as claimed in claim 7 wherein said blade stop surfaces, said ramp surface and platform portion are formed of the same metal member and said guard member is of molded plastic material.

Claims

1. An injector type razor comprising a main frame member that includes a transversely extending cap portion and a depending handle portion, a platform structure mounted for movement relative to said main frame member and adapted to support a blade unit against the underside of said cap portion, said platform structure including a platform portion adapted to support a blade unit against the underside of said cap portion, associated blade aligning structure for locating a blade edge in a predetermined position on said platform portion, and a guard portion of material different than the material of said platform portion positioned forward of said platform portion in spaced relation from the predetermined blade edge position as defined by said blade aligning structure, said guard and platform portions each including a reference surface and said platform portion including deformable structure which is placed in firm frictional engagement with a surface of said guard portion to secure the two said reference surfaces firmly in engagement with one another, a ramp surface integral with said platform structure and extending downwardly from said platform portion at a rearwardly inclined angle thereto, and a biasing member secured to said handle portion and flexed in slidable engagement against said ramp surface, effective to urge said platform structure rearwardly to urge said blade aligning structure rearwardly into engagement with an edge portion of a blade unit on the platform portion and simultaneously to urge said platform structure upwardly to secure the blade unit on said platform portion against the underside of said cap portion in proper shaving position and to permit sliding of said ramp surface along said biasing member to release the blade unit on said platform portion in response to insertion of the key of a blade injector magazine betweEn said main frame member and said platform structure.

3. The razor as claimed in claim 1 wherein said blade locating structure, the ramp surface and said platform portion are formed in the same metal member and said guard portion is a member of molded plastic material.

4. The razor as claimed in claim 1 wherein said main frame member includes two symmetrically disposed reference surfaces, one on either side of the center of said cap portion and at the rear thereof, for engaging rear edge surfaces of an inserted blade unit, and said blade aligning includes projecting blade stop surfaces that are adapted to engage forward edge surfaces of the inserted blade unit so that the blade unit is clamped between said reference and stop surfaces to provide the desired positioning of the blade unit relative to the guard portion.