FR2581340A1 - CERAMIC SCISSORS - Google Patents

Abstract

THE INVENTION RELATES TO CERAMIC SCISSORS. IT RELATES TO CERAMIC SCISSORS WHICH INCLUDE TWO BRANCHES 1 CONNECTED TO ONE ANOTHER BY A PIN 9. ACCORDING TO THE INVENTION, EACH BRANCH IS SHAPED OF MOLDED PLASTIC MATERIAL BEARING A CUTTING EDGE 2 SHAPED OF A CERAMIC AND HAVING A CLOSED INTERNAL CAVITY 11 SUCH THAT THE APPARENT DENSITY OF THE SCISSORS IS LESS THAN 1.0. IN THIS WAY, THE SCISSORS MAY FLOAT ON THE WATER, WITHOUT RUST. APPLICATION TO THE MANUFACTURE OF DOMESTIC SCISSORS.

Description

The present invention relates to ceramic scissors having a

  excellent cutting quality, not risky

  no rust and able to float on the water.

  The most conventional scissors of metal such as carbon steel or stainless steel have been made. These scissors, initially having a good quality of cut, can not keep this quality for a long time given the low hardness of the edge. Carbon steel scissors, having a better cutting quality than steel scissors

  stainless, are more susceptible to rust than these.

  Stainless steel scissors are less likely to rust but have a lower cutting quality than

carbon steel scissors.

  Metal scissors of different types therefore have respective advantages and disadvantages. As a result, scissors made entirely of ceramic, for example alumina or zirconia, have been developed for solving the aforementioned problems. Ceramic scissors have a good cutting quality and do not rust but, as these scissors are totally formed of ceramic, they can break or crack when they fall by accident or when a major shock is

applied to scissors.

  Japanese Utility Model 58-106,073 describes

  ceramic scissors to remedy the

  previous accounts. Ceramic scissors are described

  in the following with reference to the drawings.

  As indicated in FIG. 1, the known ceramic scissors comprise two branches 1 of shape

  identical dimensions and a connecting device

  two branches 1 so that they can be opened and closed. Each of the two branches 1 has a blade 4 having an edge 2 and a back 3, and a handle 6 having an annular portion 5 for the passage of the fingers at its rear end. Each of the two branches 1 has a connecting hole 7 for the passage of an axis described below, between the blade 4 and the handle 6. The blade 4 and the handle 6 of each of the branches 1 are formed in one piece by a plastic material such as "nylon" or polycarbonate, and the edge 2 of the blade 4 is formed of ceramic such as alumina or zirconia. As shown in Figure 2 which is a section of Figure 1 along the line A-A, the edge 2 of the blade 4 is housed in a groove 8 formed on the back of the blade 4 and is fixed

  on the back 3 of the blade 4 by an adhesive agent.

  The aforementioned connection device comprises an axis 9 and a head 10. The connecting device associates the two branches 1 so that they can

  be opened and closed around axis 9, with

  the two limbs 1 so that the edges of the blades 4 are turned towards each other, the axis 9 being placed in holes 7 connecting the two branches 1, the latter being clamped one towards the other by axis

9 and the head 10.

  The aforementioned ceramic scissors which are known have a good quality of cut and breakage or cracking scissors does not occur even after a significant shock applied to scissors because only the

  edge 2 of the blade 4 is formed of ceramic.

  However, known ceramic scissors, as they have a density greater than 1.0, do not float on water. As a result, when you want to cut

  a fishing line during a sea fishing and when

  let the ceramic scissors fall into the sea by

  they can not be recovered.

  Under these conditions, it is desirable to have ceramic scissors having a good cutting quality, not rusting and floating on the water, such ceramic scissors having never before

been made.

  The invention thus relates to ceramic scissors

  with good cutting quality, not rusting

not and floating on the water.

  More specifically, the invention relates to ceramic scissors which comprise two branches each having a handle and a blade which has an edge and a back, the edge of the blade at least being formed of ceramic, and a connecting device of the two branches. to

  that they can be opened and closed; according to the invention

  ceramic scissors have a lower density

at 1.0.

  Other features and advantages of the

  will be better understood by reading the description

  examples of embodiments and with reference to the accompanying drawings in which:

  FIG. 1 is an exploded perspective represented

  sensing ceramic scissors of known type; Figure 2 is a section along the line A-A of Figure 1; Figure 3 is a plan view of ceramic scissors according to a first embodiment of the invention; Figure 4 is a side elevation of the ceramic scissors of the first embodiment of the invention; Figure 5 is a section of Figure 3 along the line A-A; Figure 6 is another section of Figure 3 along the line B-B; Figure 7 is a section showing the handle of the ceramic scissors of a second embodiment of the invention; Figure 8 is a plan view of ceramic scissors according to a third embodiment of the invention; Figure 9 is a section of Figure 8 along the line A-A; Figure 10 is a plan view of ceramic scissors according to a fourth embodiment of the invention; Figure 11 is a side elevation of the ceramic scissors of the fourth embodiment of the invention; Fig. 12 is a plan view showing the blade of the ceramic scissors of the fourth embodiment of the invention; Figure 13 is a section along the line A-A of Figure 10; Fig. 14 is a sectional view showing the handle of the ceramic scissors of a fifth embodiment of the invention; Figure 15 is a plan view of ceramic scissors according to a sixth embodiment of the invention; Fig. 16 is a side elevation of the ceramic scissors of the sixth embodiment of the invention; Figure 17 is a plan view of the ceramic scissors according to a seventh embodiment of the invention; Fig. 18 is a side elevation of the ceramic scissors of the seventh embodiment; Fig. 19 is a plan view of the blade of the ceramic scissors of the seventh embodiment of the invention; Figure 20 is a side elevation of the blade of the ceramic scissors of the seventh embodiment of the invention; Fig. 21 is a plan view showing the handle of the ceramic scissors of the seventh embodiment of the invention; Figure 22 is a section along the line A-A of Figure 21; Figure 23 is a section of the ceramic scissors grip according to an eighth embodiment of the invention; Fig. 24 is a plan view showing

  ceramic scissors according to a ninth mode of

  invention; and FIG. 25 is a section along the line

A-A of Figure 24.

  Important studies have been carried out within the scope of the invention for the development of ceramic scissors having a good cutting quality, not rusting and floating on the water. This research has shown that it is possible to make scissors

  ceramic having a density of less than 1.0 per

  a closed cavity in the ceramic scissors or by gluing a piece of cork on the scissors

ceramic.

  The present invention is based on this discovery.

green.

  Fig. 3 is a plan view showing

  ceramic scissors according to a first embodiment

  invention, and Figure 4 is a side elevation of these scissors. As shown in Figures 3

  and 4, the ceramic scissors of the first embodiment

  of the invention comprise two branches 1 of form

  identical dimensions and a connecting device

  two branches 1 so that they can be opened and closed. Each of the two branches 1 has a blade 4 which has an edge 2 and a back 3, and a handle 6 which has an annular portion 5 for the passage of the fingers at its rear end. Each of the branches 1 has a connecting hole 7 for the passage of an axis described below, in the part between the

blade 4 and the handle 6.

  As shown in FIG. 5 which represents a section along the line AA of FIG. 3, each of the branches 1 has a closed cavity 11 sufficient for the density of the ceramic scissors to be less than 1.0. Several small closed cavities, sufficient for the scissors density to be less than 1.0, can

  be arranged in each of the two branches 1.

  The blade 4 and the handle 6 of each branch 1 are formed in a single piece of plastic such as "nylon" or polycarbonate, and the edge 2 of the blade 4 is formed of a ceramic such as alumina or zirconia. As shown in Figure 6 which is a section along the line BB of Figure 3, the edge 2 of the blade 4 is housed in a groove 8 formed on the back 3 of the blade 4 and is fixed to the back 3 of the blade 4 by an adhesive agent. The aforementioned connection device comprises an axis 9 and a head 10. The connecting device associates the two branches 1 so that they can be opened and closed, the axis 9 constituting a pivot, the two branches 1 overlapping that the edges 2 of the blades 4 are turned towards each other, the axis 9 being introduced into the holes 7 connecting the two branches 1, these being brought together by

  tightening the axle 9 and the head 10.

  The aforementioned ceramic scissors of the first embodiment of the invention still float on the water because each branch 1 has at least one closed cavity

  It is sufficient for the density of the scissors to be

greater than 1.0.

  We now consider ceramic scissors

  of the second embodiment of the invention.

  Figure 7 is a sectional view of the chisel 6 of the second embodiment. These scissors are substantially identical to those of the first embodiment of the invention described above, but the back 3 of the blade 4 and the handle 6 of each of the branches 1 are formed of a piece of cork 12 coated with plastic, in sufficient quantity for

  the density of the ceramic scissors is less than 1.0.

  The aforementioned ceramic scissors of the second embodiment of the invention still float on the water since the back 3 of the blade 4 and the handle 6 of each branch 1 are formed of the piece of cork 12 coated with plastic in sufficient quantity for

  the density of the scissors is less than 1.0.

  We now consider the third mode of

embodiment of the invention.

  Fig. 8 is a plan view of the ceramic scissors according to the third embodiment of the invention, and Fig. 9 is a section along line AA of Fig. 8. As shown in Figs. The ceramic scissors of the third embodiment are substantially identical to those of the first embodiment, but each of the branches 1 has, on a part of its surface, a piece of cork 13 which is glued therein, in an amount sufficient for the density scissors is less than 1.0. The piece of cork 13 can be glued on the entire surface of each of the

two branches 1.

  The ceramic scissors of the third embodiment still float on the water-because the piece of cork 13 which is sufficient for the scissors density to be less than 1.0 is glued on at least one part

  the surface of each of the two branches 1.

  We now consider the fourth mode of

embodiment of the invention.

  Figure 10 is a plan view of the scissors

  of the fourth embodiment of the invention.

  Figure 11 is a side elevation of the

  Figure 12 is a plan view showing the blade of these scissors. As indicated in FIGS. 11 and 12, the ceramic scissors of the fourth embodiment comprise two branches 1 of identical shape and dimension and a device for elastic connection of the two branches 1 so that they can be opened and closed. . Each of the branches 1 has a

  handle 6 and a blade 4 having an edge 2 and a back 3.

  The handle 6 and the blade 4 of each branch 1 are made of a single piece of plastic such as "nylon" or polycarbonate and the edge 2 of the blade 4 is formed of a ceramic such as alumina or zirconia . The edge 2 of the blade 4 is housed in a groove 14 formed on the back 3 of the blade 4 and the edge 2 of the blade 4 is fixed

  on the back 3 of the blade 4 by an adhesive agent.

  Each of the branches 1 has a closed cavity 15 sufficient for the density of the scissors to be less than 1.0 as shown in FIG. 13 which is a section along the line AA of FIG. 10. Several fine closed cavities sufficient for the scissors density is less than 1.0, can be dispersed

in the whole pair of branches 1.

  The aforementioned connection device comprises a connector 17. It connects the two branches elastically so that they can be opened and closed, the spring 17 constituting the pivot, by covering the branches 1 on one another so that the edges 2 of the blades 4 are turned towards each other, the spring

  17 being hooked to the rear ends of the two branches 1.

  The above-mentioned ceramic scissors of the fourth embodiment of the invention always float on water because each of the branches 1 has at least one closed cavity 15 which is sufficient for the density of the scissors

less than 1.0.

  We now consider ceramic scissors

  of the fifth embodiment of the invention.

  Figure 14 is a section showing the handle 6 of the scissors of the fifth embodiment of the invention. The scissors of this embodiment are substantially identical to those of the fourth embodiment described above, but the blade 4 and the handle 6 of each branch 1 are formed of a piece of cork 16 coated with a plastic material, in quantity sufficient for the density of scissors to be lower

at 1.0.

  The aforementioned ceramic scissors of the fifth embodiment of the invention still float on the water since the blade 4 and the handle 6 of each branch 1 are formed of a piece of cork 16 coated with a plastic material in an amount sufficient to that density

  scissors is less than 1.0.

  Ceramic scissors are now considered according to the sixth embodiment of the invention. Fig. 15 is a plan view showing the ceramic scissors of the sixth embodiment of the invention and Fig. 16 is a side elevation showing these scissors. As shown in Figures 15 and 16, the ceramic scissors of the sixth mode of

  are virtually identical to those of the fourth

  third embodiment of the invention described above

  However, each of the branches 1 has, on a part of its surface, a piece of cork 18 which is stuck therein, in an amount sufficient so that the density of the scissors is less than 1.0. The piece of cork 16 can be

  stuck on the entire surface of each branch 1.

  The aforementioned ceramic scissors of the sixth embodiment of the invention still float on water since the piece of cork 18 is sufficient for the density of the scissors to be less than 1.0 and is adhered to at least a portion of the surface of each

both branches 1.

  We now consider ceramic scissors

  of the seventh embodiment of the invention.

  Figure 17 is a plan view of the scissors

  of the seventh embodiment of the invention.

  and Figure 18 is a side elevation of these scissors. As indicated in FIGS. 17 and 18, the ceramic scissors of the seventh embodiment comprise two branches 1 of identical shape and dimensions and a connecting device of the two

  branches 1 so that they can be opened and closed.

  Each of the branches 1, as shown in FIGS. 19 and 21, is divided into a handle 6 and

  a blade 4 having an edge 2 and a back 3.

  The edge 2 and the back 3 of the blade 4 of each of the branches 1 are made of a single piece of ceramic material such as alumina or zirconia. The blade 4 of each of the branches 1 has a connection hole 19 for the passage of an axis described hereinafter, as shown in FIGS. 19 and 20. The handle 6 of each of the two branches 1 is formed of plastic material such as "nylon" or polycarbonate. As indicated in part 21, the handle 6 has, at its upper end, a concave seat 20 for housing the rear end of the blade 4 and a connecting hole 21 for the passage

  of an axis described hereinafter. The extré-

  rear mite of the aforementioned blade4 fits in the seat

  concave 20 of the handle 6 so that the connecting hole 19

  deement of the blade 4 is opposite the hole 21 for connecting the handle 6, and the blade 4 is fixed on the handle 6 by an adhesive agent. The handle 6 has, at its rear end, an annular portion 5 for the passage of the fingers. The handle 6 of each of the two branches 1 has a closed cavity 22 which is sufficient so that the density of the ceramic scissors is less than 1.0 as shown in Figure 22 and which is a section along the line AA of Figure 21. Several fine closed cavities, sufficient for the density of the ceramic scissors to be less than 1.0, can be

  dispersed in the handle 6 of each of the two branches 1.

  The aforementioned connection device comprises an axis 9 and a head 10. This device connects the two branches 1 so that they can be opened and closed around the axis 9 which constitutes a pivot, by covering the two branches 1 one on the other so that the edges 2 of the blades 4 are turned towards each other

  the other, the axis 9 being placed in the connecting hole 19

  the blade 4 and into the connection hole 21

  of the handle 6, these holes being placed opposite each other

  the axis 9 and the head 10 are then tightened so

  that the two branches 1 are drawn towards each other.

  The above-mentioned ceramic scissors of the seventh embodiment of the invention still float on the water because the handle 6 of each of the branches 1 has at least one closed cavity 22 which is sufficient for the density of the scissors to be less than 1.0. . We now consider ceramic scissors

  of the eighth embodiment of the present invention.

  FIG. 23 is a section showing the handle 6 of the eighth mode ceramic scissors

  embodiment of the invention. These scissors are practically

  identical to those of the seventh embodiment described above but the handle 6 of each of the branches 1 comprises a piece of cork 23 coated with plastic material, in an amount sufficient for the

  density of the ceramic scissors is less than 1.0.

  The aforementioned ceramic scissors of the eighth embodiment of the invention still float on the water because the handle 6 of each of the two branches 1 is formed of a piece of cork 23 coated with plastic material, in an amount sufficient for the density

  ceramic scissors is less than 1.0.

  Finally, the scissors of

  ceramic of the ninth embodiment of the invention.

  Fig. 24 is a plan view showing the ceramic scissors of the ninth embodiment of the invention, and Fig. 25 is a sectional view of Fig. 24 taken along the line A-A. As shown in Figures 24 and 25, the ceramic scissors of the ninth embodiment are substantially identical to the ceramic scissors of the eighth embodiment of the invention described above, but a piece of cork 24 sufficient for the density of the ceramic scissors less than 1.0 is glued on a portion of the surface of the handle 6 of each of the two branches 1. The piece of cork 24 can be glued on the entire surface of the handle 6 of each of

two branches 1.

  v 12 We now consider examples of scissors

ceramic according to the invention.

EXAMPLE 1

  The edges 2 each having the shape shown in Figure 12 are prepared using various ceramics having the properties shown in Table I, and four pairs of ceramic scissors each having the structure shown in Figures 10, 11 and 13.

  are made using the edges 2 thus prepared.

  In each pair of ceramic scissors, the blade 4 and the handle 6 are formed of "nylon" in one piece, and the closed cavity 15 is formed in each

pairs of branches 1.

TABLE I

  lumen Zirconia Nitride Silicon silicon carbide _I _ Hardness (Hmr) 1800 1700 1900 1900 Flexural strength 30 50 60 60 107 Pa Resistance to corrosion 0.2 0.3 0.4 0.4 sion (pg / cm3 ) Density 3.9 5.8 3.2 3.1 In Table I, the corrosion resistance represents the weight loss of test pieces of all ceramic materials after immersion in 95% sulfuric acid for 24 hours. . The density is calculated for each pair of scissors thus manufactured. The results are in Table II. In it, (1) represents alumina scissors, (2) zirconia scissors, (3) silicon nitride scissors and (4) silicon carbide scissors (these same designations apply

following tables also).

TABLE II

(1) (2) (3) (4)

0.80 0.92 0.76 0.75

  The density of each pair of ceramic scissors

  was calculated under the following conditions:

  (1) volume of each pair of ceramic scissors

  15.8 cm3 (2) weight of each pair of ceramic scissors

  as shown in Table 3.

TABLE III

  j (1) (2) (3) (4) 12.7 (g) 14.5 (g) 12.0 (g) 11.9 (g) As Table II clearly indicates, all pairs of ceramic scissors have a density

  less than 1.0 and so float on the water.

EXAMPLE 2

  Edges 2 each having the shape shown in Fig. 12 are prepared using the various ceramics having the properties shown in Table I, and four pairs of ceramic scissors all having the structure of Figs. 15 and 16 are manufactured at the same time. 2 edges thus prepared. In each pair of scissors, the blade 4 and the handle 6 of each branch 1 are formed of "nylon" in one piece, and the piece of cork 18 of density 0.52 is glued to the surface of the handle 6

of each branch 1.

  The density is calculated for each pair of ceramic scissors thus manufactured. The results

are shown in Table IV.

TABLE IV

(1) (2) (3) (4)

0.77 0.89 0.73 0.73

  The density of each pair of ceramic scissors

  is calculated under the following conditions: (1) volume of each pair of scissors: 15.8 cm3 (2) weight of each pair of ceramic scissors shown in Table V.

TABLE V

(1) (2) (3) (4)

  | 12.2 (g) 14.1 (g) 11.6 (g) 11.5 (g) As Table V clearly indicates, all

  pairs of ceramic scissors have an inferior density

  than 1.0 and therefore float on the water.

EXAMPLE 3

  Blades 4 each having the shape shown in Figures 19 and 20 are prepared using various ceramics having the properties shown in Table I, and handles 6 each having the shape shown in Figures 21 and 22 are manufactured, and four pairs of scissors each having the structure indicated in Figures 17 and 18 are then made using these blades 4 and handles 6. In each pair of scissors, the handle 6 of each of the branches 1 is formed of a fiber reinforced plastic material, and the closed cavity 22 is formed in the handle 6

of each branch 1.

  The density is calculated for each pair of scissors thus manufactured. The results appear in

Table VI.

TABLE VI

(1) (2) (3) (4)

0.75 0.89 0.70 0.69

  The density of each pair of scissors is calculated under the following conditions:

  (1) volume of each pair of ceramic scissors

  10.9 cm3, (2) weight of each pair of ceramic scissors

as shown in Table VII.

TABLE VII

(1) (2) 1 (3) (4)

  8.17 (g) 9.69 (g) 7.61 (g) 7.53 (g) As Table VI clearly indicates, all pairs of scissors have a density of less than 1.0 and

so float on the water.

EXAMPLE 4

  Blades 4 each having the shape shown in Figures 19 and 20 are prepared using various ceramics having the properties shown in Table I, and handles 6 each having the shape shown in Figure 21 are made, four pairs scissors each having the structure of FIGS.

  18 being then made using the blades 4 and the pins

  6 thus prepared. In each pair of scissors, the handle 6 of each branch 1 is formed of "nylon", and the closed fine cavities are formed in the handle 6

of each branch 1.

  The density is calculated for each pair of scissors thus produced. The results appear in

Table VIII.

TABLE VIII

(1) (2) (3) (4)

0.84 0.98 0.79 0.78

  The density of each pair of scissors is calculated under the following conditions: (1) volume of each pair of scissors: 10.9 cm3 (2) weight of each pair of scissors, as

indicated in Table IX.

TABLE IX

  j (1) j (2) (3) (4) 9.18 (g) 10.7 (g) 8.62 (g) 8.54 (g) As Table VIII clearly indicates, all pairs scissors have a lower density

to 1.0 and so float on the water.

  The invention as described above allows the manufacture of ceramic scissors having a good quality of cut, not rusting and floating

on the water.

  Of course, various modifications may be made by those skilled in the art to the devices which have just been described as examples only.

  non-limiting without departing from the scope of the invention.

Claims (10)

  Ceramic scissors, of the type comprising: two branches each comprising a handle (6) and a blade (4) having an edge (2) and a back (3), the edge of the blade at least being formed of a ceramic, and a device (9, 10) for connecting the two branches (1) so that the scissors can be opened and closed, characterized in that: the ceramic scissors have a lower density at 1.0.   2. Ceramic scissors according to claim 1, characterized in that: the handle (6) and the blade (4) of each of i15 branches (1) are formed of plastic material in one piece, the edge (2) of the blade (4) being fixed in a groove (8) formed on the back (3) of the blade (4), each of the branches (1) having a connecting hole (7) in a portion between the handle (6) and the blade (4), the connecting device comprising an axis (9) and a head (10), the connection device connecting the two branches (1) while allowing their opening and closing, the axis (9). acting as a pivot, by covering the branches (1) so that the edges (2) of the blades (4) are rotated towards each other, the axis (9) being introduced into the connection holes (7) of the two branches (1), the latter being brought closer to each other by clamping by the axis (9) and the head (10), and each of the branches (1) has at least one cavity closed (11) sufficient for the density of scissors   ceramic is less than 1.0.   3. Scissors according to claim 1, characterized in that: the handle (6) and the blade (4) of each of the branches (1) form a one-piece body, the edge (2) of the blade ( 4) being fixed in a groove (8) formed on the back (3) of the blade (4), each of the legs (1) having a connecting hole (7) in a portion between the handle (6) and the blade (4), the connecting device comprising an axis (9) and a head (10), this device connecting the two branches (1) so that it allows their opening and closing, the axis (9) playing the role a pivot, by overlapping the legs (1) one on the other so that the edges (2) of the blades (4) are rotated towards each other, the axis (9) being introduced into the connecting holes (7) of the two branches (1), the branches (1) being clamped towards each other by the axis (9) and the head (10), and each of the branches (1) comprises a piece of cork (12) coated with a plastic material, in quantity enough for the density of ceramic scissors less than 1.0.   4. Scissors according to claim 1, characterized   in that: the handle (6) and the blade (4) of each of the branches (1) are formed of plastic in one piece, the edge (2) of the blade (4) being fixed in a groove ( 8) formed on the back (3) of the blade (4), each of the branches (1) having a connecting hole (7) in a portion between the handle (6) and the blade (4), the connecting device comprises an axis (9) and a head (10), this device connecting the two branches (1) so that it allows the opening and closing of the scissors, the axis (9) constituting a pivot, with overlap of the two branches (1) one by the other so that the edges (2) of the blades (4) are rotated towards each other, the axis (9) being introduced into the connecting holes (7) of the two branches (1), these being brought closer to each other by the axis (9) and the head (10), and each of the two branches (1) has at least a part of its surface which is provided with a piece of cork (13) which is adhered to, in sufficient quantity te for that   the density of the ceramic scissors is less than 1.0.   5. Scissors according to claim 1, characterized in that: the handle (6) and the blade (4) of each of the branches (1) are made in one piece by a plastic material, the edge (2) of the blade (4) being fixed in a groove (14) formed on the back (3) of the blade (4), the connecting device comprises a spring (17), this device elastically connecting the two branches (1) while allowing their opening and closing, the spring (17) constituting a pivot, with overlapping limbs (1) one by the other so that the edges (2) of the blades (4) are rotated towards each other , the spring (17) being hooked to the rear ends of the two branches (1), and each of the two branches (1) has at least one closed cavity (15) which is sufficient for the density of the   ceramic scissors is less than 1.0.   6. Scissors according to claim 1, characterized   in that: the handle (6) and the blade (4) of each of the branches (1) are formed in one piece, the edge (2) of the blade (4) being fixed in a groove (14) formed on the back (3) of the blade (4), the connecting device comprising a spring (17) and elastically connecting the two branches (1) so that it allows the opening and closing of the scissors, the spring (17) constituting the pivot, with overlapping of the two limbs (1) one by the other in such a way that the edges (2) of the blades (4) are rotated towards each other, the spring (17) being hooked to the rear ends of the two branches (1), and each of the branches is composed of a piece of cork (16) coated with a plastic material, in an amount sufficient for the density of the ceramic scissors less than 1.0. -   7. Scissors according to claim 1, characterized in that: the handle (6) and the blade (4) of each of the branches (1) are formed of plastic material in one piece, the edge (2) of the blade ( 4) being fixed in a groove (14) formed on the back (3) of the blade (4), the connecting device comprises a spring (17) elastically connecting the two branches (1) so that it allows the opening and the closure, the spring (17) playing the role of the pivot, with overlapping of the two branches (1) one on the other in such a way that the edges (2) of the blades (4) are turned one towards the other, the spring (17) being hooked to the rear ends of the two branches (1) which each have, on at least a part of its surface, a piece of cork (18) which is glued therein, in an amount sufficient to that the density of scissors   ceramic is less than 1.0.   8. Scissors according to claim 1, characterized in that: each of the branches (1) is divided into a handle (6) and a blade (4), the edge (2) and the back (3) of the blade being formed a one-piece ceramic, the rear end of the blade (4) being fixed in a concave seat (20) formed at the upper end of the handle (6), each of the branches (1) having a hole connection piece (21, 19) in a part between the handle (6) and the blade (4), the connecting device comprises an axis (9) and a head (10), this device connecting the   two branches (1) allowing opening and closing   scissors, the axis (9) forming the pivot, with recou-   the two limbs (1) to one another so that the edges (2) of the blades (4) face each other, the axis (9) being introduced into the connection holes. (21, 19) of the two branches (1), the latter being clamped towards each other by the axis (9) and the head (10), and the handle (6) of each branch (1) is formed of plastic material, and the handle (6) of each of the branches (1) has at least one closed cavity (22) sufficient   for the density of ceramic scissors to be greater than 1.0.   9. Scissors according to claim 1, characterized   in that: each of the two branches (1) is divided into a handle (6) and a blade (4), the edge (2) and the back (3) of the blade (4) being formed of ceramic in one single piece, the rear end of the blade (4) being fixed in a concave seat (20) formed at the upper end of the handle (6), each of the legs (1) having a connecting hole (21, 19 ) in a part between the handle (6) and the blade (4), the connecting device comprises an axis (9) and a head (10), this device connecting the two branches (1) so that the scissors can be open or closed around the axis (9) constituting the pivot, with overlapping of the two branches (1) one on the other so that the edges (2) of the blades (4) are rotated one towards the other, the axis (9) being introduced into the connection holes (21, 19) of the two branches (1), the latter being clamped towards each other by the axis (9) and the head ( 10), and the handle (6) of each branch s (1) is composed of a piece of cork (23) coated with plastic material, in a quantity sufficient for the density   ceramic scissors is less than 1.0.   10. Scissors according to claim 1, characterized   in that: each of the two branches (1) is divided into a handle (6) and a blade (4), the edge (2) and the back (3) of the blade (4) being formed of ceramic in one single piece, the back end of the blade (4) 258134S   being secured in a concave seat (20) formed at the upper end of the handle (6) each of the two legs (1) having a connecting hole (21, 19) in a portion between the handle (6) and the blade (4), the connecting device comprises an axis (9) and a head (10) connecting the two branches (1) allowing their opening and closing, the axis (9) constituting the pivot, with overlap of the two branches (1) on each other so that the edges (2) of the blades (4) are rotated towards each other, the axis (9) being introduced into the connection holes (21, 19 ) of the two branches (1), the latter being clamped towards each other by means of the axis (9) and the head (10), and the handle (6) of each of the two branches (1) is made of plastic, the handle (6) of each of the two branches (1) having, on at least part of its surface, a piece of cork (24) which is glued therein, in a sufficient quantity for the density   ceramic scissors is less than 1.0.