US2908970A

US2908970A - Shearing head for dry shaver employing flexible shear plate and reciprocating cutter

Info

Publication number: US2908970A
Application number: US403348A
Authority: US
Inventors: Braun Artur; Futterer Bodo
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-01-12
Filing date: 1954-01-11
Publication date: 1959-10-20
Anticipated expiration: 1976-10-20

Description

Oct. 20, 1959 A. BRAUN ETAL 4 2,908,970

SHEARING HEAD EoR DRY sHAvER EMPLOYING FLEXIBLE SHEAR PLATE AND RECIPROCATING CUTTER Filed Jan. 11. 1954 'all l Fig. 5

:NVMTORS l ARTUR BRAUN BODO FUTTERER ATTORNEYS frame.

United States Patent SHEARING HEAD FOR DRY SHAVER EMPLOY- ING FLEXIBLE SHEAR PLATE AND RECIPRO- CATING CUTTER Artur Braun, Frankfurt am Main, and Bodo Ftterer,

Langen, Hessen, Germany, assignors to Max Braun, Frankfurt am Main, Germany, a partnership The present invention relates to the construction of shearing heads of dry Shavers, and provides a construction whereby the outer shear plate may be conveniently removed from the shaver and separated from 4the inner cutter to facilitate cleaing of the shaver or replacement of the shear plate.

Dry Shavers to which this invention relates consist in general, of a Ibody member containing a driving unit terminating in and operating an oscillating drive pin. The shaving mechanism includes an outer stationary shear plate slotted or perforated to provide a plurality of shear surfaces together with an inner cutter generally toothed to provide cooperating shear surfaces and driven by Ithe oscillating drive pin. The shaving operation is performed by passing the shear plate over the surface of the skin in such a manner that the hair to be shaved passes through the slots or perforations in the shear plate and is severed by the cutter at the inner edge of the perforations. inasmuch as cutting occurs at the inner surface of the shear plate, that member is advantageously made as thin las practical so that the hair may be cut oif `as close as possible. The shear plate accordingly is generally qui-te fragile and flexible.

The present invention provides a shearing head construction in which the shear plate may be easily and safely removed from'the body of the shaver and from the inner cutter wi-th little or no danger of causing damage to it and by an entirely manual operation. struction thereby provides a shaving head which may be thoroughly cleaned with little effort, and -in which the shear plate may be easily replaced when that becomes necessary.

In the construction provided by this invention, the

thin flexible shear plate is mounted in a frame which is detachably secured to the shaver body, while the cutter is independently connected with the oscillating drive pin and independently spring-biased into close contact with the inner surface of the shear plate. In this manner, the shear plate is reinforced'and held in proper shape by the frame and may :be removed from the shaver body and separated from the inner cutter to provide access to the cutting surfaces with little danger of causing it damage.

The shear plate is preferably a normally flat thin sheet of a resilient-ly ilexible metal bowed to provide a rounded shaving surface and ysecured at opposite edges to the Conveniently, opposite inner surfaces of the frame are formed with lugs engaging corresponding openings in the edges of the shear plate, the resiliency of the bowed shear plate urging and assuring engagement of the openings with the lugs in the frame, while permitting easy removal of the shear plate simply by forcing its opposed edges inwardly to disengage the lugs. If desired, fhowever, the shear plate may Kbe secured to the frame by other means such a-s screws or rivets.

The Vinner cutter,` it will be understood, is completely independent of the shear plate and frame but cooperates This con- I `with the shear plate against which it is urged -by one or more springs situated between Vthe shaver bodyV and the cutter. In preferred embodiments, the cutter is mounted von the oscillating drive pin to prevent dislodgment of the cutter when the shear plate and frame are removed. Conveniently, the `dr-ive pin is provided with an enlarged end engaged within a recess in the underside of the cutter which is retained on 'the `drive pin by its enlarged head.

This invention will be better understood from the following ydetailed description of preferred embodiments thereof selected for purposes of illustration and from the accompanying drawings in which:

Fig. l is a perspective view of the `shaving head of a dry shaver embodying the present invention;

Fig. 2 shows a cross-section end elevation of the shearing head construction of this invention;

Fig. 3 shows a cross-sectional lateral elevation of the embodiment shown in Fig. 2;

Fig, 4 is a longitudinal elevation in cross-section showing a further modification of the construction of this invention, and

Fig. 5 is a plan view of the shear plate normally eX- tended.

In the illustrated embodiments, the shaver body 1 containing the driving mechanism, generally an electric motor, is provided with a shearing head 10 consisting of a shear plate 12 secured to the body 1 by means of a frame 14, and an inner cutter 16 pressed against the inner ysurface of the shear plate 12 and driven across the lshear plate by an oscillating drive pin 18. The shear plate and cutter `are suitably of conventional construction, the shear plate 12 being provided with a plurality of closely spaced narrow slots 2 0, the edges of which define cutting surfaces, and the cutter 16 being provided with a plurality of closely spaced blades 21 conforming to the inner surface of the shear plate and cooperating with the slots v20 to effect shear cutting at the inner edges of the slots.

The frame 14 is generally in the form of a cowling mounted to the body member 1 at its upper end, which is preferably recessed so that the frame can be accommodated within the general contour of the body member. In the illustrated embodiments, the frame 14 is formed of opposite side segments 15 joined by outwardly bowed end segments 17, the latter having rounded top edges extending above the side segments to provide an opening entirely surrounding the edges of the shear plate 12. To secure the frame 14 in place, the lower edge of each side segment 15 is provided with a lip 22 which engages a bead 24 provided near the lower edge of the recessed top region of the body member 1. The frame thus snaps `in place, its inherent resiliency permitting the lip 22 to pass the bead 24 upon the application of a force tending to spread the side segments 15, which may lconveniently be applied by pressing the end segments 17 together.

The cooperating lip and bead engagement of the frame to the body member 1 suggested above, provides a particularly convenient means of securing the frame to the body, but other well known engaging and securing mechanisms for instance, set screws threaded to the frame and engaging an appropriate abutting surface provided in the base member could, if desired, be used, or a spring latch in the body engaging a lip in the frame would be satisfactory.

The shear plate 12 consists of a normally at thin resilient sheet of suitable hard stock having openings 28 at its opposite side edge portions, and is held within the frame in bowed relation with the openings 28 engaging corresponding lugs 26 provided at the inner surfaces of the side segments 15. The bowed shear plate 12 thus provides a rounded cutting head surface which may be easily removed by further bowing the plate to permit the perforations 28 to disengage the lugs 26.

The cutter 16 is shown as comprising a plurality of parallel spaced cutting blades 2.1 shaped to correspond generally to the curvature of the shear plate 12 and formed on an arched base plate 19.

`In the embodiment shown in Figs. 2 and 3, the base plate 19 is provided on its underside with a pair of wells 30, accommodating springs 32 supported at their other ends in corresponding seats 34 provided in the end of the body member 1. 4In this embodiment the drive pin 18 is in the form of a blade enlarged at its outer end. A pair of resilient pins 36 extending across the bottom of the base plate 19 engage opposite sides of the drive pin 18 whereby its oscillation causes the cutter to reciprocate. The enlarged head of the drive pin 18, it will be seen, is of width greater than the spacing of the pins 36 and prevents detachment of the cutter from the body of the shaver.

In the embodiments shown in Fig. 4, the bottom of the cutter is provided with a recessed region 40 and a drive plate 42 bored to accommodate the oscillating drive pin 18 is secured to and seated about the edges of the recess 40 as by a screw 43. To press the cutter against the shear plate, a spring 44 is situated around the drive pin 18 between an abutment 45 provided at the base of the drive pin, and the drive plate 42. The spring 44 thus urges the cutter outward from the drive pin and against the shear plate. lIn this embodiment, to prevent accidental dislocation of the cutter, the end of the drive pin y18 is grooved to receive a split retaining washer 46 which forms an enlarged head preventing withdrawal of the drive pin from the drive plate 42. `In this embodiment, the drive pin and corresponding opening in the drive plate may be circular in cross-section to permit rotation of the cutter and access to its underside as well as access to the top end of the base member 1.

In the preferred embodiment of this invention, the shear plate is of extreme thinness, e.g. about .002 inch, and is accordingly quite exible. This feature has been found valuable since it obviates the necessity of preforming the cutter to correspond precisely in curvature with the inner surface of the shear plate. The flexibility of the shear plate in conjunction with the force urging the cutter against the' shear plate causes the curvature of the shear plate to conform to the curvature of the edges of the cutter blades, particularly in those areas where the outer surface of the shear plate engages the skin and is pressed by the skin into close engagement with the edges of the inner cutting blades against the spring pressure applied to the cutter. Because of the flexible nature of the shear plate and the deformation it may thus be subjected to in the areas where it is pressed against the skin, areas of the plate not in contact with the skin may not closely engage the cutting blades, but the closeness and effectiveness of cutis not thereby impaired.

It will further be seen that by mounting the shear plate in an easily detached frame, while securing the cutter independently to the drive pin provides extreme facility of cleaning while minimizing the danger of dropping or damaging the shearing members. Removal of the frame and shear plate exposes the blades of the cutter so that the cuttings dropping into the spaces between adjacent blades may be readily brushed out. Also when the frame and shear plate are removed, the cutter remains in driven relation to the drive pin 18 so that by turning on the power to shake the cutter back and forth after removal of the frame and shear plate, cuttings deposited in the spaces between the cutting blades may be largely shaken out. Such a power cleaning operation is exceedingly simple and facile.

Inasmuch as the driving mechanism actuating the drive pin forms no pant of the present invention, and may be of conventional construction well known to the art for imparting an oscillatory motion, a detailed description there;

'4 of is deemed unnecessary for a full understanding of this invention. The embodiments described above, it will also be understood, are given by way of illustration, it being contemplated that obvious modifications will occur to those skilled in the art, and may be made without departing from the scope of this invention.

Having thus disclosed our invention and described in detail preferred embodiments thereof, we claim and desire to secure by Letters Patent:

1. In a dry shaver having a body member, a drive pin, and driving means for oscillating the drive pin: a shearing head comprising a frame detachably secured to the body member about the drive pin, a shear plate mounted to said frame, an inner cutter cooperating with the shear plate, spring means urging the inner cutter against the shear plate, linking means on the under side of the inner cutter engaging opposite sides of the drive pin comprising a plate positioned under a recess in the inner cutter and provided with an opening through which the drive pin projects and an enlarged means on the end portion on said drive pin securing the inner cutter against detachment from the drive pin when said plate is in its aforesaid position.

2. A shearing head for a shaving implement having a body and drive means for reciprocating a cutter, comprising an inner cutter driven by said drive means and having a plurality of blades having edges convexly curved in a plane transverse to the direction of reciprocation, an open frame surrounding said cutter detachably mounted at a fixed operable location on said body, a thin flexible resilient shear plate having hair receiving openings and bowed into curved condition around the edges of the blades of said cutter and secured by its unbowed margins to oppose sides of said frame with supporting means engaging the bowed portion of the shear plate entirely constituted by the edges of the blades of said cutter, and means mounting said cutter in operable position including resilient yielding means urging said cutter outwardly of the body and into contact with the shear plate whereby when the bowed portion of the shear plate is held against the skin, the skin contacting area of the shear plate is conformed to the contour of the edges of the blades by the pressure of the cutter.

3. A shearing head for a shaving implement having a body and an outwardly extending drive pin for reciprocating an inner cutter, comprising an inner cutter driven by said drive pin and pivotally mounted thereto to swing in a plane transverse to the axis of said drive pin and having a plurality of blades having edges convexly curved in a plane transverse to the direction of reprocation, an open frame surrounding said cutter detachably mounted at a xed operable location on said body, a thin flexible resilient shear plate having hair receiving openings and bowed into curved condition around the edges of the blades of said cutter and secured by its unbowed margins to oppose sides of said frame with supporting means engaging the bowed portion of the shear plate entirely constituted by the edges of the blades of said cutter, and means mounting said cutter in operable position including resilient yielding means urging said cutter outwardly of the body and into contact with the shear plate whereby when the bowed portion of the shear plate is held against the skin, the skin contacting area of the shear plate is conformed to the contour of the edges of the blades by the pressure of the cutter.

4. A shearing head structure for a shaving implement comprising a body provided with a head portion, a drive member mounted in said head portion for reciprocating a cutter, an inner overlying said drive member, said cutter having a series of transversely directed cutting blades spaced therealong and provided with cutting edges at the upper portions thereof, a head frame largely enclosing said cutter but having an opening there- .r 4 m1-ln.pn

through adjacent said cutting edges, a shear plate secured to said head frame and having hair receiving openings disposed adjacent said first mentioned opening, means detachably mounting said head frame in cutter enclosing position on the head portion of said body, spring means urging the cutting edges of said blades into engagement with the portion of said shear plate which is provided with said hair receiving openings, means engaging said cutter with said drive member to afford upward and downward movement of said cutter while maintaining the cutter in driven relation to the drive member, and means affording power cleaning of cuttings from the spaces between the blades including means holding said inner cutter against detachment from said drive member when said head frame and shear plate are detached from said body, whereby said cutter remains in driven relation to said drive member when said head frame and shear plate are detached.

5. A shearing head structure for a shaving implement comprising a body provided with a head portion, a drive member mounted in said head portion for reciprocating a cutter, an inner cutter overlying said drive member, said cutter having a series of transversely directed cutting blades spaced therealong and provided with curved cutting edges at the upper portions thereof, an open frame largely enclosing said cutter but having an opening therethrough adjacent said cutting edges, a thin flexible resilient shear plate carried by said frame 'and having opposite side edgeportions secured respectively to opposite side segments of said frame, said shear plate having an intermediate portion between said side edge portions which is vprovided wtih hair receiving openings, said intermediate portion having a bowed shape and disposed adjacent said lirst mentioned opening with supporting means engaging the bowed portion of the shear plate entirely constituted by the edges of Ythe blades of said cutter, means detachably mounting said frame in cutter enclosing position on the head portion of said body, spring means urging the cutting edges of the blades into engagement with said bowed'portion of the shear plate, with the aforesaid frame and shear plate positioned with said inner cutter to afford conformance in curvature between the portions of said shear plate and cutting blades which are urged into engagement one with the othere by said spring means, and means affording power cleaning of cuttings from the spaces between the cutting blades including means holding said inner cutter against detachment fromsaid drive member when said frame and said shear plate carried Vthereby are detached from said body, whereby said cutter remains in driven relation to said drive member when said frame and shear plate are detached.

6. A shearing head structure for a shaving implement comprising a body provided with a head portion, a drive member mounted in said head portion for reciprocating a cutter, an inner cutter overlying said drive member, said cutter having a series of transversely directed cutting detachably mounting said head frame in cutter enclosing position on the head portion of said body, spring means urginzr the cutting edges of said blades into engagement with said bowed portion of the shear plate, means engaging said cutter with said drive member to afford upward and downward movement of said cutter while maintaining the cutter in driven relation to the drive member, and means holding said inner cutter against detachment from said drive member when said head frame and said shear plate carried thereby are detached from said body, whereby said cutter' remains in driven relation to said drive member when said head frame and shear plate are detached.

7. Dry shaving apparatus comprising, in combination, a casing a shear plate carrier affixed to said casing, a iiexible shear plate having a concave lower surface and two longitudinal edges and affixed to said carrier only at said longitudinal edges to be deformable in respect of the curvature of said lower surface, a lower blade having a cylindrical cutting surface and mounted with freedom of lateral translation and reciprocation in respect of the axial direction of its coating surface, a drive mechanism contained in said casing and operatively connected to said lower blade for reciprocating the same in the axial direction of its cutting surface, and at least one compression-elastic and omnidirectionally fleXure-elastic member extending transversely to said cutting surface and having one end undisplaceably held relative to the casing and another end undisplaceably held relative to the lower blade, whereby said lower blade is urged against said lower surface of said shear plate and held with freedom of lateral translation, and said shear plate is caused to adapt to the form of the lower blade and at the same time forms, a yielding guide for the lower blade.

References Cited in the tile of this patent UNITED STATES PATENTS 2,174,039 Muros Sept. 26, 1939 2,196,098 Bruecker Apr. 2, 1940 2,200,186 Muros May 7, 1940 2,234,893 Bruecker Mar. 11, 1941 2,296,093 Dalkowitz Sept. 15, 1942 2,526,153 Page Oct. 17, 1950 2,688,184 Jepson Sept. 7, 1954 2,691,216 Ross Oct. 12, 1954 UNITED STATES PATENT OFFICE CERTIFICATE OE CORRECTTON l 1Patent No.l 2,908,970 October 20., 1959 Artt@ Braun iet 'aL VW printed specification It is herebj'y certified that error appears in the that the said Letters of the above numbered patent requiring correction and Patent should read as corrected below.

Signed and sealed this 10th day of May 1%@o (SEAL) Attest:

ROBERT C. WATSON KARL lH. .XlIlW-l Attesting4 Ofcer Commissioner of Patents