FR2606995A1 - INJECTION DEVICE FOR INJECTING A PRODUCT, IN PARTICULAR FOR THE ARTIFICIAL INSEMINATION OR THE TRANSMISSION OF EMBRYOS, PARTICULARLY FOR ANIMALS - Google Patents

Abstract

A) INJECTION DEVICE FOR INJECTING A PRODUCT ESPECIALLY FOR ARTIFICIAL INSEMINATION OR EMBRYO TRANSMISSION, ESPECIALLY INTENDED FOR ANIMALS. B) CHARACTERIZED IN THAT THE LONGITUDINAL CANAL OF THE FORMING BODY RECEIVES THE SHEATH WHICH IS SURROUNDED BY THE FORMING BODY AND THE WALL OF ITS LONGITUDINAL CANAL TAPES INTO A CONICAL WAY IN THE SAME DIRECTION AS THE OUTER WALL OF THE SHEATH.

Description

Injection device for injecting a product, in particular

  for artificial insemination or transmission of

  embryos, especially for animals. "

The invention relates to a device

  to inject a product, the device consists of

  a hollow cylindrical cannula, open at both ends, and in which can be engaged from the proximal end or the distal end, a tubular straw containing the product to be injected and from the proximal end a mandrel to expel

  the straw and an interchangeable tubular sheath

  ble that is fitted on the cannula and whose proximal end is removably attached to the proximal end of the cannula, its distal end having an opening to let out the product to be injected,

  by being narrowed conically at the level of the

  distal vertex, by having a body of symmetrical shape

  in rotation, and having a longitudinal channel.

  Such injection devices are used in particular but not exclusively

  in the veterinary field for artificial insemination

  or transmission of embryos. In this device, firstly the outer sheath is generally wrapped in synthetic material, disposable after use, and whose distal end is tapered conically; then from the proximal end, first introduced the straw with the product to

  inject into the cannula; then after introduction of the

  positive injection for example in the vagina of a cow, is expelled to the front with the aid of a mandrel. The straw can also be introduced from the front before the introduction of the sheath. The injection device is also suitable for injecting drugs in the liquid or pasty state. As separate glitter, we have no

  only light bulbs as well as small tubes

  synthetic material closed at both ends and having

  dimensions corresponding to at least two diameters

  very common trade. Depending on the case, more or less thin cannulas are used and at the distal end conical tips having a greater or lesser opening are required; we also have more diameter sheaths

or less big.

The attachment of such sheaths

  for one use presents difficulties.

  For fixing at the end

  tale, it is known to use a structure according to the pre-

  ambule of claim 1, recalled above (DE-OS 31 06 306, Figure 3); in this case, the form piece is glued to the front in the sheath and is fitted with it on the cannula. During the injection, it is possible that the piston which presses the straw abutting against the cone inside the shaped part and towards the front makes

  that the piece of shape emerges from the sheath and does not

  che and stay in the organ. Such pistons are generally

  consist of small balls (that is to say, as beads for closing the flake or in the case of a spherical end mandrel) of a diameter for example

  3 mm which are slipped into the straw and eject

  this. When the ball finally arrives on the conical surface,

  she exerts her thrust on it.

  To attach the sheath to the proximal end of the cannula, it is known (DE 27 29 428)

  to use a conical extension at the level of this ex-

  tremity of the cannula; this conical extension is committed

  on the proximal end, split for this purpose about 3 to 4 cm from the sheath; the sheath is then pinched on the

  cone with a fixing ring fitted by the former

  TER AL. According to another embodiment, there is a file

  step with a large step at the proximal end of the cannula, thread on which the sheath is screwed. In this case, it does not

  the sheath must not be split at the level of its

proximal mite.

  The diversity of straws in parti-

  sparks of semen and the different diameters

  cannula requires that the veterinarian has

  different injection devices or only different

  sleeves which are fitted on the cannula; Unfortunately, the veterinarian sometimes finds on the spot that he has the wrong type of sheath or bad

  injection device. This is very possible in particular

  bind when as it happens frequently for sperm

  that he has different glitter.

  The present invention aims to

  overcome the disadvantages of known solutions and

  for this purpose, an injection device of the type

  characterized in that the longitudinal channel of the shaped body receives the sheath which is surrounded by the shaped body and the wall of its longitudinal channel tapers conically in the same direction as the outer wall of the sheath. Thus by fixing the sheath at the distal end as indicated above, because of the cone, there is a certain centering for thin flakes or thicker flakes without risking that the shaped body is torn off by the pressure exerted by the piston on the straw, and without risk that this body of form remains in the organ. Because the shaped body is located outside the sheath, the piston for example in the form of a ball that slides in the cone and which itself pushes on the conical portion of the sheath can not tear this body of shape of the sheath. Moreover, this embodiment of the shaped body makes it possible to

  create a rounded distal end that facilitates the introduction

  safe injection of the injection device.

  According to another characteristic of

  the invention, the form body is a body of ex-form

  shell which, in addition to the sheath, receives a body of internal shape having a conical outer surface whose conicity is equal to that of the conical wall of the channel

  longitudinal shape of the outer body and between

  ci and the wall of this longitudinal channel is pinched the conical portion of the sheath, and an inner surface

  taper which narrows towards the end

  tale. Thus, the distal end of the sheath is pinched in the gap between the outer-shaped body and the inner-shaped body; this is particularly easy to achieve compared to a collage. The shaped bodies may be extended towards the distal end by non-conical portions; it is thus easy to achieve a rounded outer shape while creating a connection between the two shaped parts especially in the non-conical area. Indeed, the outer form body and the inner shape body can

be coupled to each other.

  According to another characteristic of the invention, the outer-shaped body and the inner-shaped body comprise a coupling mechanism

  by snapping. This means of coupling is a mechanism

  snap coupling which securely secures

  the combined form body on the end of the sheath.

  Thus, this combined form body is used only one

  only once as the sheath. A variant consists of using

  a screw connection or a balcon-

  you. According to another feature of the invention, the outer-shaped body and the inner-shaped body have distal end surfaces which pass into each other without recess. This means can be

  easily made by a rigid connection in the direc-

  axially giving a smooth front surface for the whole

ble of the two bodies of form.

  According to another characteristic of

  the invention, the conical narrowing of the end

  the sheath is formed between the corresponding walls

  body shape and body shape.

  compression inside during the establishment of the body of form. The material of the sheath can be initially

  cylindrical and not tapered in a conical

  calf of its extremity only by pinching in the conical interval. The material of the sheath can then be supplied

not cut to length.

  According to another characteristic, the wall thickness of the inner-shaped body between its conical outer surface and its inner surface

  taper decreases towards the opposite end to the ex-

  distal tremity. It is thus possible to have a small recess at the beginning of the inner-shaped body, so that the straw enters the longitudinal channel

  conical shape of the inner body and does not remain

end surfaces.

  The embodiment comprising an outer and inner shaped body ensures a very strong attachment of this combined shaped body to the sheath, which virtually excludes any stalling of the sheath as for the exclusive use of the shaped body

outside.

  According to another characteristic of the invention, the injection device is characterized

  by an eccentric pinching device at the end

  proximal mute of the cannula, which device presses at least a part of the periphery of the end zone

  proximal of the sheath against the wall of the cannula.

  According to another characteristic of the invention, the eccentric pinch device is a jaw-type chuck. Thus, at the proximal end of the cannula, it is possible to have an eccentric nip pinching nip, for example a jaw-type chuck, which pushes the rear edge of the sheath against the outer side of the nipple. cannula and so it does not matter whether the end of the sheath is split or not. The choice of a suitable small diameter of the cannula allows

  to receive any sheath dimension. The man

  Drin can be an eccentric pinch device that by easy pivoting ensures local pressure against the wall of the cannula by holding the sheath to

this place.

  Thus, according to one characteristic of the invention, the eccentric pinching device is composed of a rotation locking member slightly eccentric with respect to the cannula also of revolution, when the axes are parallel and which can be rotatively engaged by an unhooked area at the outer diameter of the cannula and an eccentrically offset zone, which locking member comprises a two-part bore, the first portion being on the eccentric recess zone of the corresponding cannula

  the diameter of the latter increased by a sliding interval

  and the second portion of which has a diameter corresponding to the outer diameter of the remaining wall of the cannula increased by an interval equal to at least 7 to the thickness of the wall of the sheath, being shifted eccentrically relative to in the first part, the axes being parallel, and connecting to the first

  part towards the distal end.

  According to another characteristic of the invention, the eccentric offset zone of the cannula

  consists of a cylindrical tubular piece fitted

  the cannula and having a wall of regular thickness

  die. The piece of tube that can generally serve

  The handle element is advantageously of synthetic material

  or metal glued to the cannula, welded or screwed and fixed by bending avoiding that the pinch lining of the sheath is detached during the extraction

  of the injection device. Thus following another characteristic

  the cannula consists of a metal tube

  that and the cylindrical tubular element is provided to the ex-

  the end of the metal tube, the latter being further fixed

  by folding at the end of the tube.

  According to another characteristic, the tubular piece of synthetic material comprises a flange in which is formed a sliding path and the locking member has the shape of a rotation handle and comprises an axial projection which engages in the sliding path of the flange and whose ends in the pivoting direction limit the angle

  pivoting of the locking member. The swivel range-

  the eccentric is limited, which gives a positive

  determined opening and in the direction of

  ture, maximum pressure can not be exceeded on the

cannula.

  According to another characteristic, the flange comprises a guide bore with two open ends, of parallel axis, and the locking member comprises a knife which, when the locking member is pivoted,

  passes over one of the openings of the guide bore.

  According to another feature, the knife is associated with the end plane of the locking member facing the flange and is under the knife with a cavity in the extension corresponding to the area swept by the guide bore when rotated the locking member, cavity whose bottom is a radial abutment plane. The structure of the eccentric pinch device is further used to cut the front of

  straw without the need for additional instruments

  res. This cut must be precisely

  eyelike to the axis of the straw, that is to say that it must

  be done in a radial plane so that the straw becomes

  then plique tightly against the device. The movement

  rotation of the locking member offers for this an advantageous possibility in the case of a knife which

  moves in a radial plane and is placed by the

  guiding hole at the end of the straw. The radial abutment plane defines a cutting zone and exerts no annoying longitudinal thrust on the flake

during the pivoting movement.

According to another characteristic

  of the invention, the cannula provided with the sheath is covered by

  free from a shirt made up of a thin sheet of paper

  the protection whose distal end is closed but

  which, by pulling on the shirt towards the end

  The proximal mite is torn and has a means of

  grasping at its proximal end.

  According to another characteristic of

  the invention, the shirt has at its end

  proximal mite a side pennant with one or more finger holes. This facilitates the manipulations

  avoiding the introduction of defilements

  from the area of the vaginal entry of the treated animal.

  The present invention will be described in more detail with the aid of the accompanying drawings, in which: - Figure 1 is a longitudinal section of an injection device according to the invention for the introduction of a

equipment in an animal body.

  - Figure 2 is a section in a plane with. view according to II-II of Figure 1. - Figure 3 is a section in the same plane with a view along the direction III-III of Figure 1, - Figure 4 is a longitudinal section of a variant of the device. injection not showing the sheath and

the distal end of it.

  FIG. 5 is a front view of the device of FIG.

  Figure 1, the mandrel having been removed.

  - Figure 6 is a rear view of a locking member

  used in the embodiment of Figure 4.

  FIG. 7 is a longitudinal section of the distal end of the sheath receiving a body of form in two.

  parts according to an alternative embodiment.

  FIG. 8 is a section according to FIG.

  The injection device shown in FIG. 1 consists of a cannula (1) formed of a long, thin-walled metal tube which receives for the injection a straw (2) of a product with inject a small tube of semen containing seed

  animal, as well as a mandrel (3) with which the

  lette (2) is first slid to the distal end of the cannula (1), then an organ constituting a

  means of closure and a piston, being in the pail-

  lette (2), ball-shaped member (3) is pushed forward under the application of the straw (2). For this, the mandrel (3) has at its distal end also a button-shaped head (5) whose diameter is adapted to that of the liner used. To can

  also push a fine straw which has in general

  neral a piston constituted by a wick in cotton, one 1.0

  advantageously has two mandrels of different thicknesses.

  ferent. At the proximal end of the mandrel, it is

  saw a plate for the thumb. The injection device further comprises a sheath (6) which envelops the cannula (1); this sheath is made of flexible synthetic material and

  is removed after each use of the injection device

  to be replaced by a new, clean sheath or sheath. At its distal end, the tubular material of the sheath (6) tapers conically to its orifice (7) and a piece

  annular form (8) is glued on this conical part.

  than; this piece (8) has a conical inner bore

  whose conicity corresponds to that of the tube forming

  the sheath (6), the outer shape being rounded.

  Thanks to the conical inner volume of the end piece of the sheath (6), whose conicity is such that even tubular sequins of diameter

  relatively weak can still rely on it, the

  (2) implementation is properly centered independently

  its diameter and can be emptied through the hole (7).

  When the ball (4) is pushed by the mandrel (3) or

  a cotton wick, by the head (5), the wall of the pail-

  lette (2), then the ball (4) or the head (5) push themselves inwardly against the cone without exerting significant effort in the axial direction on the annular piece (8). As this force acts first on the material of the tubular wall of the sheath (6) and acts only through this wall on the annular piece (8), there is no risk that this piece of form itself

  separates from the tubular wall of the sheath (6).

  As the support, ie the application

  of the counter-force to the ejection force exerted

  the mandrel is transmitted by the sheath (6), it is necessary that this sheath is strongly attached to the cannula (1) or to the handle of this cannula. This attachment is made at the proximal end (12) of the sheath (6). The proximal end (13) of the cannula (1) is slightly flared and this end carries a tubular piece of synthetic material (14), glued, provided with a

  annular flange (15) directly at its end.

  proximal mite. The tubular part made of synthetic material

  (14) is mounted eccentrically on the cylindrical cannula

  circular drique (1); thus at a place on its periphery

  it has a greater wall thickness

  than in an opposite point. A locking member (18) is provided

  seen on this tubular piece of synthetic material (14);

  this member (18) has a shape facilitating the prehening

  that is to say close to a rhombus as well as two

  longitudinal bores (19, 20), eccentric with respect to

  port to the other and whose reciprocal eccentricity corresponds

  preferably lies at the eccentricity of the tubular piece

  plastic material (14) relative to the cannula (1).

  The bore (19) has a diameter that is only slightly greater than the outer diameter of the tubular plastic part (14), that is to say that the locking member can be pivoted thereon. The bore (20) has a diameter slightly greater than that of the cannula (1) sufficiently that the wall of the tube forming the sheath (6) can be inserted between the outer surface

  the cannula (1) and the inner surface of the bore (20).

  Turning the locking member (18) onto the tubular

  plastic material (14) because of the eccentricity

  cited, the inner wall of the bore (20) presses along a semicircle against the outer wall of the cannula (1), if necessary by pinching the sheath (6). For this, it does not matter whether the proximal end (12) of the sheath (6) is split or not. As indicated, it is necessary that the difference in diameter between the cannula (1) and the bore (20) is sufficient so that can be fitted sleeves (6) of diameter adapted to that of the cannula (1)

  or larger sheaths (6) possibly forming

  a fold. It can be seen that the importance of the eccentricity and the ratio of the diameter of the cannula (1) and the bore (20) must be chosen in relation to each other

  to achieve a strong pinch effect, necessary.

  For example, we have the following advantageous dimensions:

  : for an outer diameter of the cannula equal to 3.75 mm, the tubular part made of synthetic material (14)

  has a diameter of 8 mm and an eccentricity of 1 mm. The thick-

  the sheath (6) is 0,2 mm and the

  The diameter of the bore (20) is 4.8 mm.

  A rod which, in the example described, is a screw (21) provided with a head, protrudes from the locking member (18) towards the flange (15) and passes through a guide slot (22). ) made in the flange (15); this slot provides complementary guidance and limits the pivoting movement of the locking member (18); in addition, the locking member (18) is maintained

  in the axial direction so that it can not separate

  from the proximal end of the injection device.

  In the embodiment described, the injection device also comprises a jacket (25) formed of a thin protective sheet surrounding and wrapping the sheath (6) from its distal end to just before its proximal end. At the beginning, the opening (7) is first closed by the jacket (25). As, it is easy to tear the material of the liner at the distal end, if necessary thanks

  a set breaking zone (26) provided therein

  right, pulling the shirt (25) back, tears its closed front end and thus releases the opening (7). The shirt (25) has at its proximal end

  a flag (27) with two holes (28) for the fingers.

  This flag (27) makes it possible to pull the sleeve (27) backwards by exerting an antagonistic force on the flange (15) in order to

  thus tearing the front end. We avoid any

  lure of the sheath (6) in particular at its opening (7) during the introduction of the injection device by tearing the front of the liner only when the injection device has been sufficiently introduced so that its distal end has already passed the area in which there is a risk of contamination. Advantageously, the sheaths (6) are already provided with the jacket (25) by

  example being packaged in a single package.

  In the embodiment of Figures 4 to 6, the device comprises a cutting device for cutting the tip of the straw. The straw from which the front end has been cut must apply

  narrowly by its distal end against the

  the inner surface of the sheath and for this the cutting surface must be precisely located in a radial plane of the circular cylindrical flake. When using scissors, possibly with poor lighting,

  we often encounter difficulties.

  As shown in FIG. 4, the flange (15) which in this embodiment is bowl-shaped, has at its edge

  a reinforced portion (31) directed towards the interior

  and has a guide bore (32). The

  guide bore has a diameter such that it can receive

  see the usual glitter; both ends of this hole are open. At the junction plane of the flange (15) and the locking member (18), in the region which, when the locking member (18) is rotated, passes under the guide bore (32), there is a cut-out cavity (33) and on the side of the locking member (18) facing the flange (15) there is a knife (34) whose cutting edge (35) has a component

  radial. The knife (34) is integrally connected in rotation

  to the locking member (18) and turning the or-

  With the lock (18) between the limits determined by the guide slot (22), the cutting edge (35) scans the entire section of the opening of the guide bore (32).

  turned towards the locking member (18).

  The cavity (33) has a bottom (36) facing the hole of the guide bore (32). This bottom (36) is in a radial plane relative to the axis of rotation of the locking member (18) and thus has no axial component, so that the sequin placed does not leave its stop position against the bottom (36) during cutting, nor

undergoes a push.

  The cuts made by the neck

  water (34) in the straw are thus always located at a predetermined location in a precise radial plane without

  require for this a particular instrument.

  FIG. 7 shows the distal tip of the sheath (6) equipped with its shaped body and this according to an embodiment comprising a shaped body

  exterior (38) and an inner-shaped body (39). In-

  be a conical inner wall (40) of the outer-shaped body (38) and a conical outer wall (41) of the inner-form body (39), both having the same conicity, there is a narrow gap (32) in

  which is clamped the distal end of the sheath (6).

  The inner-shaped body (39) is generally in the form of a conical tube whose front end, that is to say the distal end

  is a cylindrical tubular piece (43) with a shoulder-

  latching member (44) facing outwards; this shoulder (44) is continued by a conical tubular piece (45) whose internal conical angle increases towards the end (46) of the inner fiber piece (39), so that its thickness is not more than very weak at the end (46). When 1-5 the sleeve (6) is connected to the cannula (1), the end (46) rests against the distal end surface of the cannula and the engaged straw does not remain in any way hooked to the end (46) but centers itself automatically in the conical inner wall of the tubular piece (45).

  The outer form body (38)

  carries at its distal end a non-conical longitudinal canal-shaped piece with a rib

  an inwardly directed peripheral (50)

* port towards its distal end a radial limit corresponding to the snap-on shoulder (44) and the opposite side a conical limitation (51). In the assembled state,

  the rib (50) is applied against the clipping shoulder

  (44) and because of the sizing of the two

  i5 of shape, the distal end surface (52) which is

  laying surfaces of both pieces of form is smooth and

without steps.

  The two shaped pieces (38) and (39) are made of elastic synthetic material with a smooth outer surface. The elasticity provides some radial extensibility of the outer-form body (38) and some

  radial compressibility of the inner-form body (39).

  During assembly, the sheath (6) is first connected to the inner-shaped body (39), which, in the case of a conical point sheath (6), has a slight conical extension and is it is a simply cylindrical sheath (6) by a simple fitting of the shaped body (39). The assembly composed of the sheath (6) and the

  inner-form body (39) is then engaged in the

  wide width of the outer form body (38) and in

  the case of a cylindrical sheath (6), the latter takes from itself

  even a conical shape forming a slot (42). Lors-

  when the distal end surface of the shaped body (39) reaches the conical limit (51) of the rib (50), this expands the outer-shaped body (38) and compresses the inner-shaped body ( 39) Up

  the snap-on shoulder (44) has passed

  vure (5), then the form bodies take up their

  and the sheath tip is fixed without being able to move. It is avoided that the inner-shaped body (39) can not advance further by the contact of the walls (40, 41) with the interposition of the sheath (6). The sheath (6) is clamped sufficiently securely between these conical walls to prevent it from being released in the measurement

  o the application of a thrust on the inferior shaped body

  (39) towards the end surface (52)

  distal leads to a pinching of stronger and stronger.

  The tip mounted on the sheath (6) formed of two shaped parts (38) and (39) made in the form of plastic parts, simple and

  cheap, throws itself with the sheath (6) after use.

  For centering flakes of different diameters in the conical longitudinal channel

  body shape, it is possible in addition to the use of

  As previously mentioned, a corresponding mandrel can be used to use a single mandrel which is suitable for small-diameter flakes, that is to say for 0.25 ml fine flakes according to French practice and for flakes of larger diameter. that is to say, flakes of 0.5 ml according to French practice (medium flakes)

  centering with a peripheral shoulder

  that not shown provided in the tube of the cannula by exerting a force on the cannula and expel with the thin mandrel mentioned. While the thin mandrel is sufficient to expel the straw, it would not be appropriate to center the straw at the outlet end, because when

  is pushed, he does not see any resistance from rubbing

  enough. 0.25 ml flakes (thin flakes) of half length and double diameter (minitube)

  comprise as closing means and as a general piston

  normally a ball against which the thin mandrel is applied and which under the effect of a sufficient directed force

  forward on the wall of the straw pushes the pail-

  lette. FIG. 8 shows an alternative embodiment of the clamping device according to FIGS. 1 to 3, namely a three-jaw mandrel (55) which, by rotation of a spiral thread (56), deviates or becomes

  brings together and pushes at the proximal end

  male, the sheath (6) against the cannula (1). Just one

  chuck with two jaws or a jaw to hold the sheath.

  The injection device as described allows the doctor or the veterinarian to use the sheaths described, which are introduced cleanly and

  suitable for a large number of different flakes

  products to be injected or for other sheaths.

  Other sheaths may have split or smooth sheaths; the size of the sheath is not either

  critical. So, in summary, we have an injection device

universal use.

1.8

RE V E N D I C A T I 0 N S

  1) Injection device for injecting

  a product, a device consisting of a cylindrical cannula

  that hollow (1), open at both ends, and in which we can engage from the proximal end

  male or distal end (13), a tubular straw

  tubular (2) containing the product to be injected and from the proximal end a mandrel (3) for expelling the straw, and an interchangeable tubular sheath

  which is fitted on the cannula and whose end pro-

  proximal end (12) is removably attached to the proximal end of the cannula, the distal end thereof being

  an opening (7) to let out the injection product

  conically narrowed at the distal opening (7) by being provided with a rotationally symmetrical shaped body (8) and having a longitudinal channel, characterized in that the longitudinal channel of the shaped body receives the sheath (6) which is surrounded by the form body and the wall of its

  longitudinal channel is narrowing in a confined

  only in the same direction as the outer wall of the sheath.

  2) Device for injection according to the

  claim 1, characterized in that the shaped body is an outer-shaped body (38) which in addition to the sheath (6) receives an inner-shaped body (39) having a conical outer surface (41) whose conicity is

  equal to that of the conical wall (40) of the longitudinal canal

  dinal of the outer-shaped body and between it and the wall of this longitudinal channel is pinched the conical portion of the sheath, and a conical inner surface,

  which is narrowing towards the distal end (52).

  3) Injection device according to the

  claim 2, characterized in that the outer-shaped body (38) and the inner-shaped body (39) have non-conical, mainly cylindrical inner or inner and outer (43) surfaces between the distal end (52) and conical wall surfaces

(40, 41).

  4) Injection device according to the claim

  2 or 3, characterized in that the outer-shaped body (38) and the inner-shaped body (39) can

to be couples to each other.

   ) Injection device according to the

  4, characterized in that the externally shaped body

  (38) and the inner-form body (39) comprise

  a snap coupling mechanism (44, 50).

  6) Injection device according to one-

  any of claims 2 to 5, characterized in that

  the outer shaped body (38) and the inner shaped body (39) have end surfaces (52)

  distal which pass into each other without detachment.

  ) Injection device according to one

  any of claims 2 to 6, characterized in that

  that the conical narrowing of the distal end of the sheath (6) is formed between the corresponding walls (40, 41) of the outer-shaped body (38) and the inner-form body (39) by compression upon

place of the body of form.

  8) Injection device according to one

  any of claims 2 to 7, characterized in that

  that the wall thickness of the inner form body

  (39) between its conical outer surface (41) and its

  conical inner face is decreasing towards the end

  (46) opposite the distal end (52).

  9) Injection device according to one

  any of claims 1 to 8, characterized in that

  that the cannula (1) provided with the sheath (6) is freely covered with a jacket (25) constituted by a thin

  protective sheet whose distal end is

  but which, by pulling on the shirt towards 2.0, the proximal end tears and which

  grasping device (27) at its proximal end.

   ) Injection device according to the

  9, characterized in that the sleeve (25) comprises

  door at its proximal end a

  lateral (27) with one or more holes (28) for the fingers.