US3028668A - Dry shaver with rocking cutter - Google Patents

Description

April 10, 1962 c. DECHAUX 3,028,668

DRY SHAVER WITH ROCKING CUTTER Filed Aug. 16, 1960 2 Sheets-Sheet 1 u n u u a u a n nu ii ihllml TIE-.4;

l9 VENTOR Chaw'es DEC/I'AUX April 10, 1962 c. DECHAUX DRY SHAVER WITH ROCKING CUTTER 2 Sheets-Sheet 2 Ill Filed Aug. 16. 1960 //VVE'/VTO/? C'bar/es OFCHAUX United States Patent Ofitice 3,028,668 DRY SHAVER WITH ROCKING CUTTER. Charles Dchanx, Ave. Francis de Pressense 11, Chatenay-Malabry, France Filed Aug. 16, 1960, Ser. No. 49,953

3 Claims. (Cl. 30-43) This application is a continuation in part of applica tion No. 709,586, filed Jan, 17, 1958, which has now become abandoned.

This invention generally relates to electric shaving apparatus of the type used for dry shaving.

Such shavers, comprise a drive mechanism operating a cutter over a protective grating or comb which is applied against the skin. The cutter assembly may be arranged to perform various motions depending on the particular type of shaver.

Thus, it is known to drive the cutter system of the shaver in an oscillatory movement about an axis which may be regarded as the longitudinal axis of the shaver, thereby eilecting a transverse sweep motion across the comb. in order to obtain a uniform movement of suitable amplitude, without having to resort to casings of unacceptable shape and size, it is usual to provide a relatively complex drive mechanism including an electric motor and gearing.

In other razors, the cutter system of an electric shaver is operated by means of an electromagnetic system constituting a vibrator. In conventional shavers such electromagnetic systems drive a cutter in an axial translational path adjacent to the comb, said cutter sliding in a support and being operated by a finger or similar element driver by the electromagnetic system, which is then arranged with its axis perpendicular to the longitudinal axis of the shaver casing.

lt'is an object of this invention to provide an electric shaver which will combine the advantages of conventional systems while overcoming the drawbacks thereof resulting from the complexity of the drive mechanisms used.

The invention is embodied in an electric dry shaver having an oscillating shaft and a perforated comb parallel thereto and spaced therefrom, the combination comprising; cutter-carrier means rigidly fixed to said shaft so as to follow its oscillations; a cutter having divergent blades extending parallel to said shaft; said cutter being resiliently held against the undersurface of said perforated comb; means freely mounting said cutter into said carrier so as to permit limited rocking movement of the cutter relative to the carrier and allow only one blade to remain in contact with the combs in each direction of the oscillations.

The accompanying drawings illustrate, by way of example, one form of embodiment of the shaver of the invention.

FIG. 1 is a side view, with parts broken away, of the internal mechanism of the shaver of the invention;

FIG. 2 is a corresponding View, in vertical cross section, along line ll-II of FIG. 1;

FIG. 3 is a larger-scale sectional view illustrating the manner in which the cutters are mounted.

FIG. 4 is a transverse sectional view on an enlarged scale on line IVlV of FIG. 3.

FIG. 5 is a large-scale vertical sectional view through the comb of the shaver on the line IX-IX of FIG. 6.

FIG. 6 is a partial plan view of the comb on an enlarged scale and in developed form.

FIG. 7 shows a modified form of comb member, in developed form, and

FIG. 8 illustrates, in enlarged view, a cross section of the comb member.

The shaver of the invention comprises a mechanism housed in a two-part casing I of conventional type, made e.g. of moulded plastic. The casing receives, therein, a cage 2 of metal or moulded material which is generally U-shaped. The bottom or middle leg of the cage 2 carries a U-shaped core or armature 3 having two Windings 4 wound thereon. The free ends of the U-shaped core 3 provide pole piecesS having an end contour as apparent from FIG. 2, which contour includes an arcuate portion 5a and a straight portion 5b.

The pole pieces 5 cooperate with two stacks of laminated magnetic strips 6 having arcuate lower edges 6a secured on a tube 7 of magnetic material. The assembly comprising core 3, windings 4, pole pieces 5, stacks 6 and tube 7 constitutes the magnetic drive circuit of the shaver.

Tube 7, which forms part of the rocking or oscillating assembly described later, is pivotally mounted through.

self-lubricating rings 3 (FIG. 3) on a fixed spindle 9 extending through the side legs of cage 2, in which it is retained by nuts it? or other suitable means. The movable assembly of the shaver is rockable about said fixed spindle 9 which forms the longitudinal axis of the shaver.

As better seen in FIGS. 3 and 4, tubular guides 11 are fixed to, and radially project from horizontal tube 7. There are, preferably, two such guides 11 mounted on tube 7, each adapted to slidably receive two shanks or rods 12 in telescopic engagement. These rods 12 are interconnected at their upper ends by a cutter-carrier spindle 13 which extends parallel to the spindle 9 about which the oscillating assembly is rockable. The spindle l3 receives thereon a cutter having a sleeve 14 which car- 1 r'ies two cutter blades 15, 15 more clearlyvisible on FIG. 4. Cutter blades l5, l6 diverge outwardly from sleeve 14 and are formed with cutting edges 17, 18 at their outer ends the said ends being disposed in a common plane. Sleeve 14 is rockable about spindle 13, as will be later described in connection with the operation of the shaver.

Sleeve 14 is formed with lugs 19 extending tangentially downwardly on either side of each shank 12. There is, between each lug ll and shank 12, a clearance 10 which permits an angular displacement of the cutter-carrier sleeve 14.

Helical compression springs 20 are interposed between tube 7 and sleeve 14. Each helical spring surrounds tubular guide 11, shank 12 and lug portions 19, urging the cutter assembly resiliently upwards so as to apply it against a comb or grating screen 21, to be described in more details hereafter.

it will be noted from the drawings that the fixed spindle 9, the spindle i3 and the cutting edges 17 and 18 of the cutters are parallel, so that no additional angular gearing need be provided in the transmission of the drive to the cutters, as is the case in conventional shavers of the electromagnetically operated type. This type of mounting is made possible by the particular arrangement of the electromagnetic system.

It will be appreciated by inspection of FIG. 4 that, when the oscillating movement is along arrow A, cutting edge 17, by the light frictional resistance which it creates with the undersurface of comb member 21, will produce rocking of the cutter about spindle 13 in opposite direction until the leftward lug 19 abuts the coils of spring 29. In this position, only cutter edge 17 is in use. Of course, when the oscillating movement reverses, then only cutter edge 18 is used. This is the rocking movement aforesaid.

Both stacks of magnetic strips are interconnected under the tube 7, by a rod 22 (see FIGS. 1 and 2) the ends of which are secured through suitable means to the stacks. The pin or red 22 carries in its intermediate part a ball member 23 against which are seated tapered Patented Apr. 10, 1962' coil springs 24, 25 the smaller-diameter ends of which, engaging the ball 23, are guided in a sleeve 26 while the larger-diameter ends thereof are seated in sockets 27 formed in flanges 28 carried by the center leg of the U-shapecl cage 2. The said springs participate in controlling the operation of the rocker assembly driving the cutters.

The grating or comb member 21 of the shaver has an upper face having an arcuate contour with a large radius of curvature. The said contour comprises a circumfercntial arc concentric with axis parallel to the longitudinal axis of the shaver. The comb grating member is formed from a comparatively thick-gauge metal sheet trimmed and stamped to shape with transverse reinforcing ribs 29 (FIG. and perforated to provide cutouts 39 more apparent from FIG. 6. In the instant case the cutouts are inclined to the transverse axis of the comb member 21, and two sets of cutouts 30 are provided between two adjacent ribs 29, which sets of cutouts define between them a solid strip 31. The upper edges of the cutters 15, 16 are notched as shown at 32 (FIG. 5), so that the cutters are furthermore guided by the comb member 21 during their rocking motion about the axis 9 of the assembly. The depth of the notches 32 is originally equal to the height of the ribs 29. However, after some time of use the bottom walls of the notches will bear against the tops of the ribs, while the edges 17 and 18 of the cutters will be less strongly applied against the lower face of the comb member. Wear is thus transferred to the ribs 29.

The comb member 21 is secured to the cage 2 by means of two side rods 33 which are parallel to the axis 9 and are fitted into said cage 2 at their ends. As shown in FIGS. 1 and 3, the comb member 21 does not extend fully to the ends of the shaver but provides a clearance towards its ends for bent-over flanges 34 of the cage, cut out to provide combs. The end combs 34 cooperate with cutter blades 35 secured to the tube 7 and driven therewith in an oscillatory movement for severing the longer hairs.

It will be understood from the above description of the shaver components that in operation the cutter blades 15, 16 are driven in an oscillatory motion about the spindle 9 adjacent to the comb or grating member 21. The oscillatory motion is produced by the assembly which includes elements of the electromagnetic system. As previously indicated the electromagnetic rocker here used comprises the dual electromagnet 3, 4, the pole pieces 5, stacks of laminations 6 and magnetic tube 7.

The two cutting edges 17 and 18 of the cutter blades 15, 16 act in succession during the rocking movements of the assembly and are alternately applied against the comb member 21 so that the edge of the leading cutter (in the sense of displacement of the assembly) will at every time be applied against the comb member, while the other edge is slightly displaced therefrom as shown in exaggerated form in FIG. 4, to prevent reverse cutting effects.

As the cutting assembly reaches an extreme position and as the motion reverses, for a very short period of time there occurs a simultaneous application of both cutter blades 15, 16 against the comb member 31, then the sleeve 14 rocks about the spindle 13 at the start of the reverse displacement, partly through the effect of friction of leading cutter edge against the comb member, and partly by the effect of the resistance opposed to cutting the rirst hairs encountered by the cutter. This results in an alternating action which provides a particularly satisfactorily cutting effect.

FIGS. 7 and 8 show a modified form of comb member 21, wherein the longitudinal parallel ribs are spaced by a single row of transversely extending inclined cutouts 30', instead of two sets of cutouts 30 separated by a solid strip 31, as in FIG. 6.

Experiments have demonstrated that the removal of 4 strips 31, as well as all plain surfaces between the cutouts and ribs 2?, appreciably improved the shavers performance.

Effectively, since ribs 29' are obtained by stamping, it follows that notches 29a will be formed on the opposite face of comb member 21'.

When the shaver is moved along the skin, it cannot be applied directly thereagainst if there are plain flat surface portions on the external area of the comb. Hairs will gather on solid strips (such as 31, FIGURE 6) so that those that extend through the comb will not be cut at the base thereof but, rather, at a short distance from the skin.

With the embodiment of FIG. 7, the hairs of the face will be located either in the cutouts 36 or in a notch 29a so that the skin D will stand quite close to the comb surface.

it is, therefore, preferred to locate a rib, and therefore a notch, right next to the cutouts so as to avoid any solid strips.

1 claim:

1. In an electric dry shaver having an oscillating shaft and a perforated comb parallel thereto and spaced therefrom, the combination comprising: cutter-carrier means rigidly fixed to said shaft so as to follow its oscillations; a cutter having divergent blades extending parallel to said shaft; resilient means engaging said cutter and pressing it against the undersurface of said comb; means slidably mounted on said cutter-carrier means and freely mounting said cutter for rocking movement relative to said cutter-carrier means; and means on said cutter to limit said rocking movement of said cutter so as to allow only one blade to remain in contact with the comb in each direction of the oscillation.

2. In an electric dry shaver having an oscillating shaft and a perforated comb parallel thereto and spaced therefrom, the combination comprising: tubular cutter-carriers rigidly fixed to said shaft so as to follow its oscillations;

a cutter having divergent blades extending parallel to said shaft; resilient means encircling said tubular cuttercarricrs and pressing said cutter against the undersurface of said comb; said cutter being freely mounted on a U- bent rod, the legs of which are telescopically received in said tubular cutter-carriers; and means on said cutter to limit rocking movement of said cutter relative to said tubular carrier so as to allow only one blade to remain in contact with the comb in each direction of the oscillatron.

3. In an electric dry shaver having an oscillating shaft and. a uniformly curved perforated comb parallel thereto and spaced therefrom, the combination comprising: tubu- 131' cutter-carriers rigidly fixed to, and radially projecting from said shaft so as to follow its oscillations; a U-bent rod having legs telescopically received into said carriers and an intermediate section joining said legs and being parallel to said shaft; a cutter having a sleeve into which said intermediate section is freely located; blades proectmg and diverging from said sleeve in the direction of said comb; springs concentric with said carriers and legs pressing said cutter against the undersurface of said comb; means on said sleeve to limit rocking movement of said cutter in relation to said carriers and shaft so as to allow only one blade to remain in contact with the comb in each direction of oscillation.

References Cited in the file of this patent UNITED STATES PATENTS 2,266,884 Martin Dec. 23, 1941 2,298,872 Dalkowitz Oct. 13, 1942 2,331,500 Rand Oct. 12, 1943 2,341,833 Volz Feb. 15, 1944 2,520,487 Arey Aug. 29, 1950 2,591,403 Carissimi Apr. 1, 1952 2,701,414- Knapp -a Feb. 8, 1955

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