US3657810A

US3657810A - Razor

Info

Publication number: US3657810A
Application number: US766210A
Authority: US
Inventors: Warren I Nissen
Original assignee: Gillette Co LLC
Current assignee: Gillette Co LLC
Priority date: 1968-10-09
Filing date: 1968-10-09
Publication date: 1972-04-25
Anticipated expiration: 1989-04-25
Also published as: CA937042A; BE740003A

Abstract

A safety razor includes spaced cap and guard support members. A 0.008 inch thick beryllium copper biasing spring has a horizontal blade support strip between the cap and guard support members out of which is bent an upwardly projecting finger and a depending foot. The spring is secured to a bracket which carries an adjusting shaft. The spring urges a blade forwardly into a region of maximum blade edge exposure from which it retracts when increased resistance is encountered during a shaving operation sufficient to overcome the biasing force of the spring.

Description

O United States Patent 51 ,657,810

Nissen [4 1 Apr. 25, 1972 [54] RAZOR 3,177,581 4/1965 Stahl ..30/63 [72] Inventor: Warren 1. Nissen, Topsfield, Mass. Primary Examiner othen M. Simpson [73] Assignee: The Gillette Company, Boston, Mass. A o neyillis M. Ertman [22] Filed: Oct. 9, 1968 57 ABSTRACT PP 766,210 A safety razor includes spaced cap and guard support members. A 0.008 inch thick beryllium copper biasing spring has a {52] U.S. Cl ..30/63 horizontal blade support Strip between the cap and guard 511 lm. Cl ..B26b 2/14 Port members which is hem upwardly Pmiwing 58 Field of Search ..30/42 44 4s 32 62 63 finger and dePhhdhlg The sPihBis sewed a bracket 30/64 which carries an adjusting shaft. The spring urges a blade for wardly into a region of maximum blade edge exposure from [56] Reterences Cited which it retracts when increased resistance is encountered during a shaving operation sufficient to overcome the biasing UNITED STATES PATENTS force of the p 2,038,385 4/1936 Reohr ..30/74 11 Claims, 4 Drawing Figures RAZOR SUMMARY OF INVENTION This invention relates to safety razors and more particularly to arrangements for enhancing the shaving performance of such razors.

Shaving technology involves the movement of a very sharp blade edge in close proximity to the skin to cut hair. Significant advances have been made in this technology through the use of improved blade materials, improved processes for sharpening such blade materials and the provision of shave facilitating coatings applied to the sharpened edges of such blade materials. In addition, adjustable blade holders have been provided which permit the user to vary the exposure of the sharpened blade edge to the particular fixed setting that that user finds most suitable. During a typical shaving operation a range of conditions are involved, however, and it is an object of this invention to provide a novel and improved safety razor that has a dynamic response to conditions encountered during shaving. A change in condition may be due to a change in the pressure of the blade edge and razor against the face, as exerted by the user, for example, or contact by the blade edge with an unusual obstruction on the face, such as an especially dense patch of beard hair.

Another object of the invention is to provide a novel and improved safety razor responsive to a range of different conditions encountered during a shaving operation.

Another object of the invention is to provide a novel and improved safety razor which automatically adjusts its shaving geometry during a shaving operation to provide increased comfort and safety of the shaving operation.

Still another object of the invention is to provide a novel and improved safety razor arrangement which automatically responds to a range of conditions encountered during a single shaving operation.

A further object of the invention is to provide ,a novel and improved safety razor arrangement which includes adjustment capability for selecting a range of conditions to which there will be automatic modification in the shaving geometry of the razor during the shaving operation.

The invention provides in a safety razor the feature of dynamic adjustment of shaving geometry and specifically means for reducing the exposure of the blade edge in response to an increase in resistance encountered during a shaving operation. In a particular embodiment a safety razor includes a blade support structure and a cap structure which cooperates with the support structure to define a zone for receiving a razor blade; and structure which defines a region of zero blade edge exposure. The cap and support structures are coordinated so that movement of the blade edge through the region of zero exposure is permitted. The razor also includes stop structure for limiting the projection of the sharpened edge of the razor blade beyond the region of zero blade edge exposure, and biasing means, which exerts a force of at least grams but less than 100 grams (measured as a force applied perpendicularly to the blade edge at the center thereof), urges the blade against the stop structure into a position of maximum blade edge exposure. This arrangement permits the exposure of the blade edge to be automatically reduced upon contact of the blade edge with an obstruction during a shaving operation.

In such an embodiment the blade movement is limited to two .degrees of freedom, a linear movement in a path normal to the sharpened blade edge and in a plane approximately coincident with the blade body, and a rotary movement about an axis normal to the blade body. In another embodiment the movement may be in a plane parallel to a component of the blade holder. When increased resistance is encountered during a shaving operation sufficient to overcome the force of the biasing means, the blade edge automatically retracts away from the stop structure so that the blade edge moves into a zone of greater safety and comfort and reduced exposure.

It is preferred to include adjustment means for varying the force exerted by the biasing means on the blade so that that force may be adjusted according to the shavers preference. In a particular embodiment it has been found that satisfactory adjustment is provided when the permitted range of adjustment is 20-80 grams. The biasing force should be at least about 15 grams in order to achieve satisfactory shaving and a biasing force not greater than 50 grams provides improved shaving characteristics for many people. Larger biasing forces have been employed by persons with especially tough beards and persons that shave with unusually abrupt strokes.

In a particular embodiment biasing means coupled to the blade support member urges the blade against the cap structure in a blade clamping action. A common spring provides both the clamping force and the edge exposure force.

The invention provides a safety razor which has a dynamic response to different conditions encountered during a shaving operation in an arrangement which increases the safety and comfort of shaving. Further, the dynamic response of the razor may be adjusted by the user to suit his particular shaving sensitivity.

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

FIG. 1 is a side view of a safety razor constructed in accordance with the invention;

FIG. 2 is a top view of the head of the safety razor shown in FIG. 1, with parts broken away;

FIG. 3 is a front view of the safety razor shown in FIG. 1; and

FIG. 4 is an exploded view of components of the safety razor shown in FIG. 1.

DESCRIPTION OF PARTICULAR EMBODIMENT With reference to FIG. 1, there is shown a razor of the injector type that has a handle 10 to which is secured a platform structure 12 and a cap structure 14 that define between them a space or chamber 16 in which a razor blade 18 is disposed. The cap 14 includes at either end of its forward edge a stop projection 20 which is received in a notch 26 in platform 12. Stop structures 20 engage the sharpened blade edge 22 at either end thereof and its forward movement while at the same time providing a protective guard over the sharp corners 24 of the blade 18. The stops 22 thus define a forward limit or boundary of the blade receiving chamber 16. Formed at the forward edge of platform 12 is a depending guard bar 28. Recessed surface 30 on cap 14 defines edge 32 that cooperates with the radiused surface 34 of guide bar 28 to define a plane 36 of zero exposure beyond which the sharpened edge 22 of blade 18 projects when that blade edge is in contact with rear surfaces of stops 20 as indicated in FIG. 1.

Platform 12 has an aperture in it through which an 0.008 inch thick beryllium copper biasing spring member 40 extends. Spring 40, as may be best seen with reference to FIG. 4, includes a horizontal blade support strip 44 out of which is bent an upwardly projecting finger 42. Two

projections

46, 48 are formed in strip 44, one on either side of finger 42 and each end 50 of strip 44 is bent downwardly in a smooth curve. A spring section 52 secures strip 44 to bracket portion 54 which includes two ears 56. Formed beneath bracket portion 54 is a dependent foot 58 in which is formed slot 60. Extending rearwardly and then turning downwardly below strip 44 is an arm This spring member 40 is secured to a bracket structure 64 which is in turn secured to handle 10 by suitable fasteners 66 that cooperate with ears 68 of the bracket 64. Opposed offset wall portions 70 of bracket 64 include apertures 72 which receive pins 74 that engage ears 56 of the spring 40 to define a pivot axis. The depending extension 76 of bracket 64 has a threaded post 78 which carries a rotatably mounted disk 80 and is arranged so that when spring 40 is assembled to bracket 64, the disk 80 engages foot 58 to permit adjustment of the biasing force provided by spring 52.

Fasteners 66, in addition to securing bracket 64 to holder 10, secure the platform structure 12 and a key guide member 84 which guide includes a recess 86 in its rear edge for receiving depending arm 62 of spring 40.

The assembled position of these components as shown in FIGS. l-3. When the projecting key or finger of the blade magazine (not shown) is inserted between guide 84 and the back wall of the holder 10, arm 62 of spring 40 is forced rearwardly, moving projection 42 rearwardly to a median position. The blade 18 is then inserted into this chamber between the platform 12 and guard 14. This insertion action forces spring strip 44 down as the blade engages an end surface 50 and then slides across the strip 44 and

past projections

42, 46, and 48 until the ends of 92, 94 of blade slot 90 are aligned with the

positioning projections

46, 48 so that the blade is in proper lateral position within the blade receiving chamber 16. The key of the magazine is then removed, allowing spring 40 to move forward so that projection 42 engages the front wall 96 of slot 90 and urge the blade 18 forward against stops 20. The spring 40 also flexes upwardly to lightly press the blade 18 against the cap 14 with the force in the order of to 15 grams.

The razor blade 18 thus is held upwardly against cap 14 and urged forwardly by spring 40 against fixed stops 20 so that the sharpened edge of blade 18 is exposed 0.005 inch beyond the tangent plane 36. Rotation of disc 78 adjusts the force urging the blade forward over a range of 20-80 grams. Should a force in excess of the setting be generated during use of the razor in shaving as for example excessive pressure of the blade edge against the face (as exerted by the user) or contact by the blade edge by an unusual obstruction on the skin, such as an especially dense patch of beard hair, or excessive shaving speed the blade edge 22 is automatically retracted along a plane defined by the support platform 12 into a zone of increased safety and comfort. This retraction may occur in a direction perpendicular to the blade edge 22 or if a localized obstruction is encountered at one end of the blade, the blade may be subjected to rotational retraction in which one end of the blade 18 retracts further than the other end.

While the invention has been described with reference to a particular form of injector razor, it will be apparent to those skilled in the art that the invention is applicable to a variety of forms and types of razors. 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 as defined by the claims.

What I claim is:

1. A safety razor having structure for positioning a razor blade in shaving position, said blade positioning structure being arranged to permit the blade edge to move relative to the blade positioning structure thereby reducing the blade edge exposure, and

means responsive to an increase in resistance encountered during a shaving operation to reduce the exposure of the blade edge, thereby increasing the safety and comfort of the shaving operation, said resistance responsive means including biasing means for urging the blade towards a position of normal exposure, said biasing means exerting a force in the range of 15 grams on the blade so that said blade edge automatically retracts when increased resistance is encountered during shaving.

2. In a safety razor having structure for positioning a razor blade in shaving position,

the improvement of means responsive to an increase in resistance encountered during a shaving operation to reduce the exposure of the blade edge, thereby increasing the safety and comfort of the shaving operation, said resistance responsive means including adjustable biasing means for urging the blade towards a position of normal exposure, said biasing means being adjustable to vary the force exerted by said biasing means on the blade so that the force required to reduce the exposure of the blade edge during a shaving operation may be adjusted accordin to the shaver's preference. 3. T e safety razor as claimed in claim 2 wherein said biasing means is adjustable to vary the force required to reduce blade edge exposure over a range within the range of 20-80 grams.

4. A safety razor comprising:

a blade support structure,

cap structure cooperating with said support structure to define a zone for receiving a razor blade, said cap and support structures being coordinated such that movement of the blade in a plane is permitted,

structure defining a region of zero blade edge exposure stop structure for limiting the distance that the sharpened edge of the blade is permitted to project beyond said region of zero blade edge exposure,

and means for urging the blade against said stop structure into a position of maximum blade exposure,

said urging means exerting a force of at least 15 grams and less than 100 grams so that exposure of blade edge will automatically be reduced upon contact of the blade edge with an obstruction during a shaving operation.

5. The razor as claimed in claim 4 and further including means for adjusting the force exerted by said blade urging means.

6. The razor as claimed in claim 4 and further including biasing means coupled to said blade support structure for urging the blade against said cap structure.

7. The razor as claimed in claim 6 wherein said blade urging means and biasing means include a common spring member.

8. The razor as claimed in claim 7 and further including means for adjusting the force exerted by said common spring member.

9. The razor as claimed in claim 8 wherein said common spring member is adjustable to vary the force required to reduce blade edge exposure over a range within the range of 20-80 grams.

10. The razor as claimed in claim 9 wherein said razor is adapted to employ a blade having a single sharpened edge.

11. The razor as claimed in claim 10 wherein said razor is of the type organized to receive a fresh sharp blade from a magazine simultaneously with the discharge of a used blade.

UNITED STATES PATENTOFFICE, CERTIFICATE OF CORRECTION Patent No. 3,657 -,s10 Dated April 2.5, 1972 It Nissen Inventor(s) Warren It is certified that error appears in the above-identified patent and that said Letters-Patentare hereby corrected as shown below:

Column 2 line-43, after "and", insert limit Column 4 line 28 insert comma after "exposure";

Column 4 line 35 after "grams", insert (measured as a force applied perpendicularly to the blade edge at the center thereof) (SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of. Patents FORM PC4050 (10-69) USCOMM-DC 60376-P69 n u.s. GOVERNMENT PRINTING orncz: I969 0-366-334,

Signed and sealed this 26th day of September 1972 g

Claims

1. A safety razor having structure for positioning a razor blade in shaving position, said blade positioning structure being arranged to permit the blade edge to move relative to the blade positioning structure thereby redUcing the blade edge exposure, and means responsive to an increase in resistance encountered during a shaving operation to reduce the exposure of the blade edge, thereby increasing the safety and comfort of the shaving operation, said resistance responsive means including biasing means for urging the blade towards a position of normal exposure, said biasing means exerting a force in the range of 15 - 100 grams on the blade so that said blade edge automatically retracts when increased resistance is encountered during shaving.

2. In a safety razor having structure for positioning a razor blade in shaving position, the improvement of means responsive to an increase in resistance encountered during a shaving operation to reduce the exposure of the blade edge, thereby increasing the safety and comfort of the shaving operation, said resistance responsive means including adjustable biasing means for urging the blade towards a position of normal exposure, said biasing means being adjustable to vary the force exerted by said biasing means on the blade so that the force required to reduce the exposure of the blade edge during a shaving operation may be adjusted according to the shaver''s preference.

3. The safety razor as claimed in claim 2 wherein said biasing means is adjustable to vary the force required to reduce blade edge exposure over a range within the range of 20-80 grams.

4. A safety razor comprising: a blade support structure, cap structure cooperating with said support structure to define a zone for receiving a razor blade, said cap and support structures being coordinated such that movement of the blade in a plane is permitted, structure defining a region of zero blade edge exposure stop structure for limiting the distance that the sharpened edge of the blade is permitted to project beyond said region of zero blade edge exposure, and means for urging the blade against said stop structure into a position of maximum blade exposure, said urging means exerting a force of at least 15 grams and less than 100 grams so that exposure of blade edge will automatically be reduced upon contact of the blade edge with an obstruction during a shaving operation.