US3052022A

US3052022A - Mounting structure for shaver blade

Info

Publication number: US3052022A
Application number: US857180A
Authority: US
Inventors: John F Wahl
Original assignee: Wahl Clipper Corp
Current assignee: Wahl Clipper Corp
Priority date: 1959-12-03
Filing date: 1959-12-03
Publication date: 1962-09-04
Anticipated expiration: 1979-09-04

Description

Sept. 4, 1962 J. F. WAHL 3,052,022

MOUNTING STRUCTURE FOR sHAvER BLADE Filed DeC. 3, 1959 INVENToR. mi2/w? F' Wahl aegwM/m www Horner/s UnitedStates Patent O 3,052,022 MGUNTING STRUCTURE FOR SHAVER BLADE John F. Wahl, Sterling, Ill., assigner to Wahl Clipper Corporation, Sterling, Ill., a corporation of Illinois Filed Dec. 3, 1959, Ser. No. 857,180 2 Claims. (Cl. 30-43) This invention relates to mounting structure for a shaver blade, and more particularly to a fixed outer shaver blade for an electric shaverand means for mounting this shaver blade on the casing of the electric shaver.

This application is a continuation-impart application based on my prior, copending application for Electric Shaver Apparatus, Serial No. 753,773, filed August 7, 1958, now abandoned.

' In order for an electric shaver to function properly, the fixed or outer shaver bl-ade must have proper bearing contact with the inner or movable blade over their entire cutting region. Since the outerblade is formed from thin sheet material, it is subject to permanent deformation by accidental blows, and such deformation could destroy this bearing contact between the blades, thus adversely affecting operation of the shaver. Heretofore, many of the outer shaver blades either were permanently mounted in a blade guard or they were attached thereto by a complicated mounting structure. This ,arrangement was undesirable because the shaver operation could not be examined or tested properly after installation of the blade guard. In addition, the added difficulty involved in mounting the fragile outer blade on the blade guard resulted in an objectionable increase in the cost of production.

Furthermore, during production, and when in consumer use, it occasionally happened that the outer blade was accidentally deformed after it had been connected to the blade guard. This often required both the blade and the blade guard to be discarded. It is apparent that such losses could be minimized if the outer blade and the blade guard were completely independent of each other.

Therefore one of the objects of this invention is to provide a shaver in which the fixed outer blade and the blade guard are independent of each other and are separately mounted on the casing of the electric shaver.

Another disadvantage with the outer blades of prior Shavers was that the outer blade could be mounted on the shaver casing with either surface in position to Contact the skin. This is undesirablebecause the fixed outer blades are designed to work only when a particular surface is in contact with the skin. Since the opposed surfaces of the fixed outer blade are similar in appearance, it was possible for the lblade to be mounted on the shaver casing with the wrong surface out so that the manufacturer or the user had togo to the trouble and expense of removing the blade and then reinstalling it correctly. What is needed, therefore, and comprises another object of this invent-ion is a fixed outer blade for an electric shaver which can be mounted on the shaver in only Oneway. Y

Besides these considerations, the casings of man Shavers are formed from a plastic material which may vary dimensionally due to molding conditions. In the past this has caused the fragile fixed outer blade to buckle or tear. What is needed, therefore, and comprises another object of this invention, is a fixed outer blade which when mounted on the shaver casing or housing can accommodate Variations in the size of the shaver housing without becoming deformed or torn.

j 3,052,022 Patented Sept. 4, 1962 Since the fixed outer blade is fragile, it may have to be replaced after `a period of time. For that reason the blade must be removably mounted on the shaver casing. At the same time, because the blade is bent arcuately and is under tension when it is mounted on the casing there is a danger that during the mounting operation the blade can spring off the casing and cause injury or else become damaged. What is needed therefore and comprises still another object of this invention is a self locking resilient blade for an electric shaver Iwhich is removably mounted on the shaver casing. Y

' Safety is another important consideration in the manufacture of electric Shavers. This is particularly important because the fixed outer blade is generally formed from thin sheet metal which contacts the skin during use. This arrangement raises the possibility of electric shock unless precautions are taken. Therefore, another object of this invention is to provide a mounting which in addition to holding the fixed outer 4blade on the casing provides electrical insulation between the fixed outer blade and the motor parts of the shaver.

These and other objects of this invention will become more apparent when read in the light of the accompanying drawing and specification wherein:

FIG. 1 is a side elevational View of the front end portion of an electric shaver showing a fixed outer blade and blade guard;

FIG. 2 is an end elevational View of the blade guard installed on an electric shaver;

FIG. 3 is a perspective view ofthe shaver head showing the fixed outer blade in dotted lines;

FIG. 4 is a plan view of the xed outer blade before it is installed on the shaver, and

FIG. 5 is an enlarged side View partially in section showing details of the way the fixed outer blade is mounted on the shaver casing;

FIG. 6 is an enlarged plan view of the fixed outer blade showing self-locking tangs in greater detail.

Referring now to the drawing, an electric shaver indicated generally by the reference numeral 10 includes a casing 12 formed from a moldable insulating material such as nylon. Casing 12 is formed in two

sections

14 and 16, see FIG. 3, and a fixed outer blade 18 is mounted on the ends of these sections as best shown in FIG. 5. A portion of this blade rconstituting cutting region 32 is in slidable engagement with a portion of an inner movable cut- -ting blade 19 (FIG. 5). The casing sections may be held together Iby means of a blade guard 20 which also cooperates to secure the fixed outer blade to the front of the casing as shown in FIG. 1 and described more fully below.

As seen in FIGS. 3 and 5,

casing sections

14 and 16` have spaced tapered or converging

surfaces

22 and 24 at the top end portion 11 of the shaver. Three cylindricai projecting members or pins 26 and one non-j cylindrical pin 27 are integrally formed and molded with the casing 12 and extend outwardly from the end portions of

surfaces

22 and 24. As seen in FIG. 5, these pins are transverse to the plane defined by junction 28 of the sides of the casing sections and are substantialy opposite to each other on the opposite sides of the casing. This arrangement defines an acute rearwardly facing angle 30' (FIG. 5) at the junction between each projecting member 26Y and 27 and the tangent to the converging surfaces at that point.

Fixed outer blade l'18, as seen in FIG. 4, is normally 3 planar and rectangular in shape before it is mounted on the casing. This blade is formed from thin resilient sheet metal and is provided with a perforate portion constituting a cutting region 32. Four projecting

member receiving openings

34, 36, 38 and 40 are formed in the sheet metal and as illustrated, are disposed on the corners of the periphery of a rectangle which is deiined by imaginary lines connecting the openings.

Projecting member 27 is irregular, e.g. semi-circular in cross section, see FIG. 3, and this member is adapted to extend through a correspondingly shaped opening 34 in fixed outer blade 18 to orient the blade on the casing so the proper surface invariably will be on the outside and thus in position to contact the skin.

Openings

36 and 38 are elongated to provide compensation for variations in the spacings between the openings and between the projecting members which are received within the openings. Thus, buckling of blade 18 is avoided despite such variations. In other words, the elongated holes permit a relaxation of production standards since a larger variation between the spacings of the projecting members on the casing and the openings in the fixed outer blade can be tolerated.

As shown in FIG. 6, tangs 35, l37 and 39 are formed in

openings

34, 36 and 38, and these tangs cooperate, as

will be seen, to establish a self-locking relationship between blade 18 and the projecting members.

To mount blade 18 onto the casing 12, the blade is iiexed as shown in FIG. 5 so that central or perforate cutting region 32 is arcuate in cross section. The ends of the blade are pressed against the substantially

opposed converging surfaces

22 and 24 so that all four projecting

members

26 and 27 can pass through the

openings

34, 36, 38 and 40. In order for this to happen, the blade 18 must be oriented so that projecting member 27, which is irregular or semi-circular in cross section, can pass through the correspondingly shaped opening 34. If the blade 18 is not properly oriented, a cylindrical projecting member 26 will be aligned with the opening 34, but it will be too large to pass through it.

As stated above, projecting

members

26 and 27 form a rearwardly facing acute angle 30 with a tangent to the

converging surfaces

22 and 24 at the junction of the projecting

members

26 and 27 and the converging surfaces. The magnitude of the acute angle 30 and the length of the projecting members and the converging surfaces are selected so that as the arcuately exed resilient blade 18 tends to move back toward its planar unstressed form,

tangs

35, 37 and 39 in

openings

34, 36 and 38 bite into the associated

projecting members

26 and 27 to removably hold the blade onto the casing, see FIG. 5.

It is noted that this mounting avoids any metal to metal contact between the fixed outer blade and any part of the shaving mechanism (other than movable blade 19 which likewise is insulated) thus greatly reducing shock hazard.

After outer blade 18 is mounted on the casing, it is additionally locked thereon by blade guard 20. This blade guard is formed from an insulating and preferably moldable slightly resilent material. As seen in FIGS. 1 and 3, blade guard 20 comprises spaced parallel

upstanding ears

21 and 23 which are connected together by converging connecting portions 25.

Each

ear

21 and 23 of the blade guard may be provided with an opening 29, see FIG. 2, to receive a locking abutment 31 which is integrally formed and molded with casing 12.

'Ihe inner surfaces of converging portions 25 of the blade guard are provided with grooves (not shown) and when blade guard 20 is forced over end 111 of the casing, the grooves on the inner surfaces of the blade guard pass over and embrace the outer ends of the projecting

members

26 and 27. This positively locks outer blade 18 onto the casing, and the inner surfaces of portions 25

overlie covering surfaces

22 and 24 on the casing with portions of blade 1 8 therebetween.

In addition, the blade guard 20 is positioned so openings 29 in ears 21 and 23' are aligned with the locking abutments 31 whereby the blade guard may be snapped into place on the casing and held there. This arrangement also locks the

casing sections

14 and 16 together, thus giving the blade guard an added function.

This invention may be embodied in other forms without departing from the spirit or essential characteristics thereof as set forth inthe claims, and the present embodiment is therefore to be considered as illustrative and not restrictive and it is intended to include all changes which come within the scope and range of the claims.

I claim:

l. In a dry shaver:

a casing having opposed wall portions converging toward each other toward one casing end, said wall portions formed of insulating material;

spaced projecting members attached to and extending outwardly from said wall portions and deiining therebetween acute angles on the sides of the members away from said casing end;

at least one of said projecting members having cross sectional shape different than the other members;

a xed outer blade formed of initially flat perforate resilient sheet material having projecting member receiving openings therein, said outer blade iiexed to an arcuate cross section and mounted on said casing with said projecting members extending through said projecting mem-ber receiving openings whereby said `blade tends to be locked to said casing by virtue of said acute angles between said projecting members and said wall portions;

corresponding openings adjacent opposite edges of said blade elongated to compensate for dimensional variations in the spacing of said spaced projecting members;

the opening for said differently shaped projecting member having corresponding shape to insure proper orientation of said blade;

an opening adjacent each edge of said blade having a marginal irregularity providing a deformable tang gripping the projecting member extending through said opening whereby said blade additionally is locked in position on said casing; and

a blade guard detachably secured to said casing end and effective to prevent disengagement between said blade and said projecting members, said blade guard covering the edges of said blade and having a central opening exposing a perforate portion of said blade.

2. In a dry shaver:

a casing having opposed wall portions formed of insulating material;

spaced projecting members attached to and extending outwardly from said wall portions;

a fixed outer blade formed of initially flat perforate resilient sheet material having projecting member receiving openings therein, said outer blade iiexed to an arcuate cross section and mounted on said casing with said projecting members extending through said projecting member receiving openings;

an opening adjacent each edge of said blade having a marginal irregularity providing a deformable tang gripping the projecting member extending through said opening whereby said blade is locked in position on said casing; and

a blade guard detachably secured to said casing end and 5 eective to prevent disengagement between said blade and said projecting members, said blade guard covering the edges of said blade and having a central opening exposing a perforate portion of said blade.

References Cited in the le of this patent UNITED STATES PATENTS 387,260 Rush Aug. 7, 1888 6 Lipe July 2, 1889 Unbany Mar. 22, 1938 Picard Nov. 20, 1945 Jepson Nov. 14, 1950 Streng July 17, 1951 Palson Nov. 6, 1951 Tuchel Oct. 2, 1956 Braun et al. Oct. 20, 1959