FR2469987A1 - SHAVER - Google Patents

Abstract

BY SLIGHTLY CHANGING THE SHAPE OF THE PREPARING KNIVES WITH WHICH THIS RAZOR IS EQUIPPED, THE LARGEST LENGTH OF HAIR LIFT OBTAINED FOR THIS RAZOR WAS PRESERVED AS EACH KNIFE OF THE KNOWN RAZOR WAS PROVIDED WITH A PROTUBERANCE. KNIVES PREPARATORS THEIR LOW MASS AND GREAT FLEXIBILITY ARE ESSENTIAL. APPLICATION: DRY RAZORS WITH FLOATING HEADS.

Description

"Razor" The invention relates to a razor having a comb with openings

  bristles, and a cutting unit movable with respect to said comb and formed by a cutter with knives, the end of each knife, located on the side of the comb,

  having a cutting edge and being provided with a prepa-

  which is movable along a guide wall of the knife, while the end of each knife preparer

  is in the vicinity of the cutting edge of the knife corres-

  laying and penetrating, by its edge located on the side of the hair, in this one, each preparer knife being provided with a

  protuberance of the preparatory knife on the side of the hair

  cut, protuberance that extends the end of the knife

  preparer and defines the maximum depth of penetration

  the, while the appearance of the face of the preparer knife, located on the side of the hair is, compared to that of the knife face which is movable along the comb adapted as best as possible to the average entry angle of the hair in

the hair entrance opening.

  The razor described above is described in the

  French vat N079 30104 filed on 7/12/79 in the name of the Applicant.

  In French Patent No. 2 266 578, reference is made to a dry razor which comprises a comb with openings for entering the bristles-and in which the knives that cut the bristles are preceded by preparation knives. The role of these preparation knives is to exert some traction on the hairs before cutting so that, to a certain extent, the hairs

  are pulled out of the epidermis; we thus obtain as re-

  final result that the hairs are cut closer to the epi-

  dermis, because in fact, the hairs having been cut closer to their roots, the section of hair remaining in the epidermis withdraws farther into the epidermis than in the case of a normal cut made without exerting the said

traction on the hairs.

  However, it has been found that the depth of penetration

  the edge of the preparer knife located on the side of the pile is not always the same and depends for example on the

  hardness of the hairs. This hardness differs from person to person

  born. Now, in turn, the depth of penetration of the preparatory knife into the hair defines the extent to which, during cutting, the hairs are lifted by the preparation knives. The greater the depth of penetration of the preparer knife into the pile, the less the distance remaining available to exert a certain traction on the pile, particularly since the depth of penetration into the pile and the length of movement of the dressing knife along the knife

  corresponding directly depend on each other.

  Another parameter for the extent to which the preparer knife lifts the hair is the angle between, on the one hand,

  the guiding face of the knife along which moves

  this the preparer knife, and secondly, the knife face that moves along the comb. This angle is

for example equal to about 500.

  According to the main patent, the height of

  hair removal increases due to a protuberance located on the side of the hair to be cut, this protuberance extending

  the end of the preparatory knife and defining the

  melter of maximum penetration. In this case, penetration

  tion of the preparatory knife into the hair is possible only up to the foot of said protrusion, the penetration depth being dimensioned so that the hair

  certainly be seized by the protuberance. In the case-

  of a penetration depth limited in this way, the

  length of movement of the preparer knife on the neck

  corresponding water can be increased in a certain

  because, for that depth of penetration,

  tion and the said length of displacement does not exist,

  on the basis of the dimensions defined in advance, that a long

  maximum total value determined. The limitation of the depth of penetration is ensured very well when 246998i the pace of the face of the preparer knife, located on the side of the hair is, compared to that of the knife face

  which is movable along the comb, adapted as best as possible

  the average entry angle of the hair into the opening of the

  hairy. This look of the knife face prepares

  side of the pile makes the hair come into contact with the preparer knife and can

  to be grasped very precisely by the protuberance.

  By the use of the face of the preparer knife brought into contact with the hair, the thickness of the preparer knife inevitably becomes larger, so

  that the mass and stiffness of the preparatory knives

  lie. Now, in order for the preparation knife to fulfill its function properly, the mass and the stiffness of the preparatory knife must be as small as possible.

  The object of the invention is to guarantee the greatest

  height of uplift obtained by the protuberance which is provided with the preparer knife in the presence of a minus

  large mass and greater flexibility of the knife pre-

  parateur. For the razor corresponding to the main patent, the object specified above is achieved because the face of the preparer knife, located on the side of the pile and coming into contact therewith, is formed by a reinforced portion of the knife blade preparation in the neighborhood of

  front edge and in the direction of the hair to be cut.

  In this way, the thickness of the knife

  The operator is able to meet the requirements resulting in as small a mass as possible and adequate flexibility of this preparer knife. The end of the preparation knife which is necessary for the lifting of the hair and which is in contact with it, however,

  protuberance as well as the face that comes into con-

  tact with the hair, these face and protuberance defining

  together the depth of penetration into the hair.

  According to another embodiment of the invention

2469987.

  vention, the length of the face coming into contact with the hair is, in the direction of the hair, at least equal

  double the height of the protuberance.

  The following description, next to the drawings

  annexed, all given by way of example, will make it

  how can the invention be realized.

  Figure 1 is an elevational view of a razor

having three combs.

  FIG. 2 is a profile view of the razor according to FIG. 1, some constituents of this razor being

  shown in section along the plane II-II in FIG.

  Figure 3 is a perspective view that shows

  separately the cutting element and the knives

  tors. Figure 4 is a plan view of the elements shown separately in Figure 3 but now assembled. Figure 5 is a section along the V-V plane

in figure 4. -

  Figure 6 explains how it works

  the preparation knife according to the invention.

  The shaver according to FIGS. 1 and 2 comprises a housing 1 which partly serves as support 2 for three

  combs 3 provided with openings for entry of hair 4.

  As shown in FIG. 2, a cutting unit 5 is located near the inner face of the comb 3. This cutting unit, which is only shown diagrammatically in FIG. 2, is formed by a cutting member and by preparer knives, and is represented to larger

scale in Figures 3, 4 and 5.

  With the aid of the hollow shaft 6 (FIG. 2), gears 7 and 8 and the shaft 9, the cutting unit 5 is

  coupled to the electric motor 10 so that it is possible

  The gear 7 is rotatably mounted to a pin 11 secured in a mounting plate 12. The gear 7 is rotatably mounted to the cutting unit 5 relative to the associated comb 3. The gear 7 is rotatably mounted on a pin 11 secured in a mounting plate 12. The gear 7 has a recess 13, covered by a cover plate 14. Said recess contains a cheek 15 of the hollow shaft 6. Because the cheek 15 is not circular but for example square, and

  that the hollow 13 is shaped in correspondence, it is

  06 bli a coupling to transmit to the hollow shaft 6 the movement

  The spring 16, the majority of which is in the hollow shaft 6 and which is stretched between this shaft and the gear 7, exerts on the latter a force in the direction of the spindle. cutting unit 5. Because the cylindrical portion 17 of the shaft

  6 rests against the cutting unit 5, said force is exerted

  on this unit and through it also on the comb which thereby, by its edge 18, is applied against its support 2. Due to external forces that can occur for example during the use of the razor, the comb 3 with the cutting unit 5 and the shaft 6 can be tilted inwards against the action

spring 16.

  The coupling for transmitting the rotational movement between the hollow shaft 6 and the cutting unit 5 is obtained because said hollow shaft 6 has an end 19 of rectangular cross section. This

  end 19 is in a recess coupling hole

  corresponding tangular 20 of the cutting unit 5.

  The coupling established with the electric motor and described above is identical for the three razor cutting units according to FIGS. 1 and 2, the three

  gears 7 used in this way meshing a pinion cen-

  tral 8 placed on the motor shaft 9.

  The cutting unit 5 (FIGS. 3 to 5) comprises a cutting member 21 and a member 22 for exerting a

  some traction on the hairs to cut.

  The cutting member 21 is formed by a central body 23 which at its periphery is provided with knives 24 and

  which also has the coupling opening 20.

  On its side the organ 22 for exerting a certain traction on the hairs to be cut is made of a material

2469987;

  plate-shaped elastic and comprises a central part

  the 25 at which the preparation knives 26 are linked

  by elastic connecting arms 27. That central part

  Trale 25 has a central opening 28. The way in which the two members 21 and 22 are united to form the cutting unit 5 is such that the guide wall 29

  each knife 24 comes into contact with a prepa-

  The central portion 25 of the traction member 22 is in this case in contact with the central body 23 of the cutting member 21, and said portion 25 and the body 23 can be made integral with one another. other in known manner, for example using an adhesive, a weld or a screw connection. As a result of the elasticity of the connecting arms 27, the preparation knives 26 can slide relative to the knives 24. These knives 24 as well as the preparation knives 26 are made

  as plate-like flat parts.

  In order not to complicate Figure 5,

  This shows only three knives with the knives

  correspondents. The preparer knife 26 between

  in contact with its knife 24 along its front wall

  re and can slip on this knife. The prepared knife

  The rater itself is provided with a protrusion 35 which, on the side of the hair to be cut, extends the end 32 of the knife.

  preparer, end 32 which is in contact with the comb.

  The preparation knife 26 is in contact with the guide wall 38 of the knife, and can slide along this

  wall. To allow this, the thinness of the prepared knife

  26 is such to allow this knife to move elastically along the arc 51 and in particular on the wall

guide 38 of the knife 24.

  In known manner, under the action of the prepa-

  26, a hair 34 which has penetrated into a hair entry opening 4 must, before being cut, be removed slightly from its hair follicle. Consequently, as shown in FIG. 6, the dressing knife 26 penetrates its protuberance 35 into the pile 34 as soon as 24699Bi this knife 26 stops against the pile 34. The knife 24

  which follows the preparatory knife then slides laterally

  In an elastic manner, the preparer knife 26 which in FIG. 6 deviates on this occasion upwards and drives the pile 34 over a certain length, namely a length such that the knife tip 30 abuts against the pile and - cut afterwards. Looking more closely at the movement ratios, we can see that the distances traveled and the movements take place in a coordinated way, namely according to well-defined movement parameters. Inside the hair entry opening 4, the hair 34 is cut when its tip 30 the knife 24 abuts against the hair which by its dorsal portion rests against the opening. Given

  that the knife 24 now precedes the knife prepared

  26 and that the latter keeps the hair in place, the distance over which it is now possible to exercise

  some traction on the hair in a certain direction

  undermines the value yr given by the former

  pressure: Yr = (drx - Xrs) tgo In this expression: Yr is the length over which the hair is removed between points A and B by the preparer knife drx is the width of the preparer knife 26, including protrusion 35, xrs is the depth of penetration of the preparer knife 26 in the pile 34, and tgé characterizes the angle between on the one hand, the knife face 37 in contact with the comb 3 and

  on the other hand, the guide wall 38.

  The expression in question shows that the length Yr on which the hair is removed from its hair follicle becomes maximum when the depth of penetration

  of the preparer knife 26 in the pile 34 is equal to zero.

  This situation is obviously not feasible, since

2469987;

  given that in this case the system is not able to function

  OPERATE. However, it must be ensured that

  penetrator of knife preparer 26 be limited

  value necessary to ensure a traceability effect.

  impeccable. The above expression also makes it possible to observe that the thickness of the preparer knife 26 is preferably chosen to be large, which is also

the case of the angle.

  Another parameter that exerts influence on the exit of the hair from its hair follicle is the friction between the hair 34 and the wall 36 of the hair entry opening 4. In the most favorable case, this

  coefficient of friction Phl is an order of magnitude lower than

less than 0.5.

  Figure 6 illustrates an achievement of the

  characteristics which emerge from the expression given above.

  In the direction of the pile 34, the edge 39 of the end 32 of the preparer knife 26, edge 39 which is oriented towards the pile 36, belongs to an extension of this end 32. When the preparer knife 26 stops against the hair

  34, it is only the protuberance 35 which is able to penetrate

  in the hair, since already the

  re 40 of the preparer knife 26 comes into contact with the hair. As a result, the preparer knife 26 is not

  able to penetrate deeper into the hair 34.

  The angle f3 is between 550 and 750. When the angle A becomes too large, the friction between the guide wall 38 and the wall 53 of the preparation knife 26, which wall slips on the wall 38, risks becoming

too high.

  The drx diameter of the preparer knife is now

  kept as large as possible, -but we must

  to set boundaries that are defined by properties

elasticity and mass.

  The elasticity of the preparer knife 26 must be such that it allows the easy return of the knife

  preparator on the guide wall 38 of the knife 24. This

  This means that, in view of the low mass and high elasticity, the thickness of the preparatory knife should be kept as small as possible. Preferred thicknesses are those between 50 μm and 100 μm. However, in order to respect the requirement for as large a diameter as possible and the presence of a well-defined protuberance 35, the preparer knife 26 is reinforced in the vicinity of the protuberance 35. This reinforcement consists in that the values drx and xrs are chosen in the desired order of magnitude. At the dorsal end of the protrusion 35, the anterior wall 40 of the preparer knife is bent in the area 55 at an angle y in the direction of entry of the pile 34. The shape of the

  zone 55 is in this case chosen essentially perpendicular

  The angle and the angle together form

  an angle of 900. The length of the anterior wall zone

  55 of the preparer knife 26 is selected in accordance with

  EIux requirements in rigor. From the end

  greater than 57 of said anterior wall zone 55, the thick

  material of the preparer knife material has again, the

  along a face 59, the normal thickness has a prepa-

  The appearance of face 59 can be defined in

  Correspondence to manufacturing requirements.

  By this reinforcement 54 of the preparer knife 26, the preparer knife remains elastic, has a mass as small as possible and is still able to remove the length yr hair 34 from point A to point B before the cutting edge 30 of

  knife 24 does not come to the pile 34. to cut it then.

24699B7 ..

Claims (2)

  A razor having a comb with bristle entry openings, and a cutting unit movable with respect to said comb and formed by a cutter with knives, the end of each knife located on the comb, having a cutting edge and being provided with a preparer knife which is movable   along a guide wall of the knife, while the former   The end of each preparation knife is in the vicinity of the cutting edge of the corresponding knife and penetrates, by its edge located on the side of the pile, into the latter, each preparation knife being provided with a protuberance of the preparation knife on the side of the hair to be cut. protrusion which extends the end of the preparer knife and defines the maximum depth of penetration, while the appearance of the face of the preparer knife, located on the side of the hair is, compared to that of the knife face which is movable along the comb adapted as best as possible to the average entrance angle of the hair in the entrance opening   of hair, characterized in that the face of the knife   of the pile side and coming into contact therewith is formed by a reinforced portion of the pick knife blade in the vicinity of the front edge.   and in the direction of the hair to be cut.   2. Razor according to claim 1, characterized in that in the direction of the hair, the length of the face coming into contact with the hair is at least equal to   double the height of the protuberance.