Abstract:
A medical injection device has an injection unit and an anti-rotation device. Said anti-rotation device is non-rotationally connected to a port and connection portion of the injection device so as to surround the outside thereof in the manner of a sleeve. As a result, an intuitively usable and operationally safe injection device is obtained. When a protective cap for an injection cannula of the injection unit is being removed from the port and connection portion, an unwanted rotation of the port and connection portion relative to the container about components of a plug-in connection arranged therebetween is safely prevented.

Description:
[0001]    The content of German Patent Application DE 10 2013 214 442.3 is incorporated by reference. 
       FIELD OF THE INVENTION 
       [0002]    The invention relates to a medical injection device comprising an injection unit. 
       BACKGROUND OF THE INVENTION 
       [0003]    Medical injection devices are known from EP 460 914 B1, from EP 707 860 B1, from U.S. Pat. No. 4,838,871, from EP 692 271 B1, from U.S. Pat. No. 4,944,397, from U.S. Pat. No. 4,982,842, from U.S. Pat. No. 5,232,455, from U.S. Pat. No. 5,139,489, from U.S. Pat. No. 5,154,285, from U.S. Pat. No. 5,277,311, from U.S. Pat. No. 5,232,454, from U.S. Pat. No. 5,312,367, from U.S. Pat. No. 5,342,322, from U.S. Pat. No. 5,423,765, from U.S. Pat. No. 5,643,219, from WO 1991/009639 A2, from EP 862 920 B1, from EP 885 621 B1, from EP 1 525 016 B1, from EP 1 568 321 A1, from EP 1 587 419 B1, from EP 1 592 346 B1, from U.S. Pat. No. 5,584,816 and from U.S. Pat. No. 5,632,732. An injection syringe comprising a needle sheath is known from DE 600 32 171 T2. 
       SUMMARY OF THE INVENTION 
       [0004]    It is an object of the present invention to further develop an injection device of the type named at the outset in such a way that an intuitively usable and operationally safe injection device is obtained. 
         [0005]    According to the invention, this object is achieved by a medical injection device comprising an anti-rotation device which is non-rotationally connected to the port and connection portion, and which surrounds the outside of the port and connection portion in the manner of a sleeve. 
         [0006]    In order to remove the protective cap from the injection cannula, a user may either grasp the anti-rotation device or the protective cap. When the protective cap is being screwed off in order to remove the protective cap from the port and connection portion, an unwanted rotation of the container relative to the port and connection portion in the region of the plug-in connection is then not possible. This prevents an unwanted release of the plug-in connection when the protective cap is being screwed off, thus ensuring that an interior of the container remains sterile. The plug-in connection may be a tapered connection. The plug-in connection may be a Luer-Lock connection. The plug-in connection may be configured in a rotationally-symmetric manner in such a way as to allow for a rotation of the port and connection portion relative to the near-cannula end of the container about a cannula axis. The plug-in connection may be provided with at least one snap-in portion such that the connection is secured by means of a positive fit. 
         [0007]    An axial covering of the plug-in connection by the anti-rotation protection prevents access to the plug-in connection from outside, which also helps to prevent an unwanted release of the plug-in connection. 
         [0008]    A positive-fit adapter between the anti-rotation device and the injection unit ensures a rotation-proof connection of the anti-rotation device and the injection unit. The positive-fit adapter is also connected to the remaining anti-rotation device in a rotation-proof manner. The positive-fit adapter may be a component of the anti-rotation device. 
         [0009]    This applies in particular to a positive-fit adapter that is non-rotationally connected to the port and connection portion via a positive-fit connection. 
         [0010]    A configuration of the anti-rotation device comprising at least one positive-fit latch that is received between two adjacent, axially extending peripheral ribs of the port and connection portion, wherein the positive-fit latches are held between the peripheral ribs by means of at least one hold-down means provides for a particularly secure anti-rotation protection of the positive-fit adapter relative to the port and connection portion. The hold-down means may be formed by a hold-down sleeve, for example a telescopic sleeve, which is push-fitted over the positive-fit adapter during an assembly of the anti-rotation device. The hold-down means ensures that the at least one positive-fit latch is non-rotationally connected to the port and connection portion. The remaining anti-rotation device may be rigidly connected to the at least one positive-fit latch. There may be provided a plurality of positive-fit latches which surround an axial longitudinal axis of the port and connection portion and therefore the entire injection unit. A number of the positive-fit latches may be adapted to a width and a number of peripheral ribs of the port and connection portion. 
         [0011]    A carrier ring configuration of the positive-fit adapter formed in one piece with the at least one positive-fit latch, wherein the carrier ring is push-fittable onto the port and connection portion and is snap-locked therewith, results in a particularly stable design and an effective anti-rotation protection. Alternatively, the positive-fit adapter may be configured in the shape of a letter C such that it is push-fittable over the port and connection portion from the side and is in particular snap-lockable therewith. This facilitates an assembly of the positive-fit adapter. 
         [0012]    An embodiment for holding down the at least one positive-fit latch by means of at least one inner axial rib which interacts with a counter hold-down means at the positive-fit adapter results in a particularly secure anti-rotation protection of the positive-fit adapter relative to the port and connection portion. The hold-down counter means may be formed by an outer axial rib of the positive-fit adapter. 
         [0013]    A multi-component injection-molding design of the at least one component of the anti-rotation protection increases the possibilities of manufacturing the components of the anti-puncture device. The multi-component injection-molded part may be configured as a two-component injection-molded part or as an injection-molded part comprising more than two components, for instance three components, four components, five components or even more components. Softer plastic materials may be combined with harder plastic materials. Softer plastic materials may for instance be used for a grip portion of the anti-puncture device or for formed parts abutting against counter components in order to compensate for a play therebetween and/or in order to produce or increase a frictional fit between the respective formed part and the respective counter component. 
         [0014]    A soft component of the multi-component injection-molded part may for instance be produced from one or more than one thermoplastic elastomers (TPE), from polyurethane or from silicone. A hard component of the multi-component injection-molded part may be produced from polypropylene, from polyethylene, from ABS (acrylonitrile butadiene styrene), from a thermoplastic material on the basis of methyl metacrylate, acrylonitrile, butadiene and styrene (MABS), from polyoxymethylene, from polybutylene terephthalate (PBT) or in the form of a blended system, in other words a mixture, on the basis of polyolefins as well as polyamide. 
         [0015]    The embodiment in which the at least one multi-component injection-molded part of the anti-rotation device is configured as an outer sleeve which has at least one grip portion and at least one carrier body, wherein the carrier body on the one hand and the at least one grip portion on the other are configured as different injection-molded components of the multi-component injection-molded part is an advantageous embodiment for the use of multi-component injection-molded parts. 
         [0016]    A multi-component injection-molding design of the positive-fit member and the positive-fit member carrier body allows the at least one positive-fit member, which may be configured as an axial rib, to be made of a material that is softer than that of the positive-fit member carrier body, with the result that a frictional fit between the positive-fit members and the inner port and connection portion is improved. This results in an improved anti-rotation protection of the positive-fit adapter relative to the port and convection portion. 
         [0017]    Exemplary embodiments of the invention will hereinafter be explained in more detail with reference to the drawing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0018]      FIG. 1  shows a medical injection device, assembled and ready for delivery, comprising an injection unit and a telescopic anti-puncture device; 
           [0019]      FIG. 2  shows the injection device according to  FIG. 1  in a ready-to-use condition in which an original protective cap has been removed from an injection cannula; 
           [0020]      FIG. 3  shows the injection device according to  FIG. 2  during a displacement of the telescopic anti-puncture device between an injection position according to  FIGS. 1 and 2  in which the injection cannula is exposable ( FIG. 1 ) or exposed ( FIG. 2 ) for injection of a medium, and a protection position in which a cannula tip of the injection cannula is retracted into a protective component of the telescopic anti-puncture device; 
           [0021]      FIG. 4  shows the injection device comprising the telescopic anti-puncture device in the protection position; 
           [0022]      FIG. 5  shows a partial longitudinal section through the injection device with the original protective cap fitted thereto, wherein the telescopic anti-puncture device is shown in a position between the injection position and the protection position; 
           [0023]      FIG. 6  shows an enlarged sectional view of detail VI in  FIG. 5 ; 
           [0024]      FIG. 7  shows an enlarged view of a section of the injection device in the protection position; 
           [0025]      FIGS. 8 to 11  show instantaneous positions during assembly of the injection device; 
           [0026]      FIG. 12  shows an exploded view of another embodiment of a medical injection device comprising a telescopic anti-puncture device; 
           [0027]      FIG. 13  shows the injection device according to  FIG. 12  with its anti-puncture device in the injection position; 
           [0028]      FIG. 14  shows the injection device according to  FIG. 12  with its anti-puncture device in the protection position; 
           [0029]      FIG. 15  shows a positive-fit adapter for forming a positive fit between the anti-puncture device according to  FIGS. 12 to 14  and the injection unit, wherein the positive-fit adapter is configured as a C-shaped adapter that is radially snap-lockable thereto; 
           [0030]      FIG. 16  shows a telescopic sleeve of the anti-puncture device according to  FIGS. 12 to 14  which is arranged between the positive-fit adapter according to  FIG. 15  and a telescopic protection sleeve of the anti-puncture device; 
           [0031]      FIG. 17  shows the telescopic protection sleeve of the anti-puncture device according to  FIGS. 12 to 14 ; 
           [0032]      FIG. 18  shows an exploded view of another embodiment of a telescopic anti-puncture device for a medical injection device; 
           [0033]      FIG. 19  shows an injection device comprising the anti-puncture device according to  FIG. 18  in the injection position; 
           [0034]      FIG. 20  shows the injection device according to  FIG. 18  with its anti-puncture device in the protection position; 
           [0035]      FIG. 21  shows a positive-fit adapter for forming a positive connection between the anti-puncture device according to  FIGS. 18 to 20  and the injection unit; 
           [0036]      FIG. 22  shows a telescopic connection sleeve of the anti-puncture device according to  FIGS. 18 to 20  which is arranged between the positive-fit adapter according to  FIG. 12  and a central telescopic sleeve of the anti-puncture device; 
           [0037]      FIG. 23  shows a central telescopic sleeve of the anti-puncture device according to  FIGS. 18 to 20  which is arranged between the telescopic connection sleeve according to  FIG. 22  and a telescopic protection sleeve of the anti-puncture device; 
           [0038]      FIG. 24  shows the telescopic protection sleeve of the anti-puncture device according to  FIGS. 18 to 20 ; 
           [0039]      FIG. 25  shows an annular lid for the telescopic protection sleeve according to  FIG. 24 ; 
           [0040]      FIG. 26  shows an axial longitudinal section through the anti-puncture device according to  FIGS. 18 to 20  shown in the protection position; 
           [0041]      FIGS. 27 to 35  show illustrations, similar to  FIGS. 18 to 26 , of components of another embodiment of an anti-puncture device for an injection unit; 
           [0042]      FIGS. 36 to 42  show illustrations, similar to  FIGS. 18 to 24 , of components of another embodiment of an anti-puncture device for an injection unit; and 
           [0043]      FIG. 43  shows an axial longitudinal section through the anti-puncture device according to  FIGS. 36 to 38  shown in the protection position. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0044]      FIGS. 1 to 11  show an embodiment of a medical injection device  1 . The injection device  1  has an injection unit  2 . This injection unit  2  includes a container  3  for the medium to be injected. The container  3  may be configured as a syringe container for receiving a syringe plunger which is not shown in the drawing. The injection unit  2  further includes an injection cannula  4  which is visible in  FIG. 2  and which is covered in  FIG. 1  by an original protective cap  5 . Upon delivery of the injection device  1  according to  FIG. 1 , the original protective cap  5  is fitted onto the injection cannula  4  and axially snap-locked with a near-cannula end of the container  3 . For injection of the medium, the injection cannula  4  communicates with the container  3  via a near-cannula port and connection portion  6  of the container  3  which is visible in the sectional view according to  FIG. 5 . The port and connection portion  6  is also referred to as opening and connection portion  6 . The opening and connection portion  6  is push-fitted onto a conically tapering opening end of a glass body of the container  3  and may additionally be connected therewith by means of a positive-fit connection, in particular a snap-in locking connection. The injection cannula  4 , which is a cannula made of metal, is connected to the opening portion  6  via a plug-in connection, in other words a tapered connection  7 . In an embodiment of the injection device  1  not shown, the tapered connection  7  is configured as a Luer-Lock connection. In the region of the plug-in connection, in other words the tapered connection  7 , an inner wall of the opening portion  6  may be snap-locked with an outer wall of a cannula projection or may be positively connected therewith in any other way. 
         [0045]    Apart from the injection cannula  4 , all components of the injection device  1  are made of plastics. It is however conceivable for the injection cannula  4  to be made of plastics as well. 
         [0046]    The injection device  1  is further provided with an anti-puncture device  8 . Said anti-puncture device  8  is displaceable between an injection position shown in  FIG. 2  in which the injection cannula  4  is exposable for instance for subcutaneous or intravenous injection of the medium, and a protection position shown in  FIG. 4  in which a cannula tip  9  of the injection cannula  4  is retracted into a protective component  10  of the anti-puncture device  8 . 
         [0047]    The anti-puncture device  8  surrounds the opening portion  6  in the form of a sleeve and has at least two telescopic sleeves. In the embodiment according to  FIGS. 1 to 11 , the anti-puncture device  8  has a total of three telescopic sleeves  10 ,  11  and  12 , wherein one of these three telescopic sleeves, the telescopic protection sleeve  10 , acts as the protective component of the anti-puncture device  8 . At the same time, the telescopic protection sleeve  10  is the outermost of the three telescopic sleeves  10  to  12  of the anti-puncture device  8 . An innermost of the three telescopic sleeves, the telescopic connection sleeve  12 , is connected to the injection unit  2  via a positive-fit adapter  13 . The telescopic sleeve  11  is arranged between the innermost telescopic sleeve  12  and the outermost telescopic sleeve  10  of the anti-puncture device  8  and forms another telescopic sleeve of the anti-puncture device  8 . 
         [0048]    In the injection position, the telescopic sleeves  10  to  12  are disposed one above the other in such a way as to be in perfect alignment. In the injection position, the anti-puncture device  8  axially covers the tapered connection  7 , thus preventing access thereto from outside. In the protection position, the telescopic sleeves  10  to  12  are extended relative to each other. 
         [0049]      FIGS. 5 and 6  show details of the injection device  1  and in particular details of the anti-puncture device  8 . 
         [0050]    A protective unit in the form of a protective snap-in locking arrangement  14  is provided to ensure that the protective component, in other words the outermost telescopic protective cap  10 , is securely fastened in the protection position. Said protective snap-in locking arrangement  14  has rows  15  of snap-in locking teeth comprising snap-in locking teeth  16  that are arranged one behind the other along the central telescopic sleeve  11  and the inner telescopic connection sleeve  12 . Each of the telescopic sleeves  11 ,  12  has two outer rows  15  of snap-in locking teeth which are arranged opposite to each other when seen in the peripheral direction about the longitudinal axis of the injection device. The two rows  15  of snap-in locking teeth of the central telescopic sleeve  11  are staggered by 90° relative to the two rows  15  of teeth of the inner telescopic connection sleeve  12  when seen in the peripheral direction about the longitudinal axis of the injection device  1 . Each of the snap-in locking teeth  16  is engaged by a counter snap-in locking body  17  of the outer telescopic protection sleeve  10  or by a counter snap-in locking body  18  (cf.  FIG. 7 ) of the central telescopic sleeve  11 . In the axial longitudinal sectional view of the injection device, the snap-in locking teeth  16  have a saw-tooth profile with a preferred direction which allows the telescopic sleeves  10 ,  11  to be moved from the injection position into the extended protection position in one direction only. One snap-in locking tooth  16 ′ (cf.  FIG. 6 ), which corresponds to a maximum extended relative position of the associated telescopic sleeves  10 ,  11 , has a preferred direction which is exactly opposite thereto when seen in the axial sectional view in order to define the maximum extended position, in other words the protection position of the anti-puncture device  8 . 
         [0051]    The snap-in locking teeth  16  are formed in one piece with the respective telescopic sleeve  11 ,  12 . 
         [0052]    The anti-puncture device  8  is provided with groove/tongue guide devices  19  which ensure a telescopic guidance and at the same time an anti-rotation protection between two adjacent ones of the three telescopic sleeves  10  to  12 , in other words between the telescopic sleeves  10 ,  11  on the one hand and the telescopic sleeves  11 ,  12  on the other. 
         [0053]      FIG. 7  shows a groove  20  of one of the groove/tongue guide devices  19  which is formed in an outer jacket wall of the inner telescopic connection sleeve  12  in the form of an axial longitudinal groove. This groove  20  is engaged by a complementary tongue  21  which projects inwardly from an inner wall of the central telescopic sleeve  11 . The tongue  21  of the central telescopic sleeve  11 , which interacts with the groove  20  of the inner telescopic sleeve  12  in a guiding manner, is formed by the inner ends of the snap-in locking teeth  16  of the central telescopic sleeve  11 . 
         [0054]    Another tongue/groove guide device  19  is formed by axial longitudinal grooves  22  in the inner jacket wall of the outer telescopic protection sleeve  10  and tongues  23  complementary thereto which are formed in the outer jacket wall of the central telescopic sleeve  11  in such a way as to radially protrude in the outward direction. Two identical groove/tongue guide devices  19  are in each case arranged opposite to each other relative to the longitudinal axis of the injection device  1 . Relative to one of the telescopic sleeves  10 ,  12 , the snap-in locking components of the snap-in locking arrangement  14  are alternately arranged with the components of the groove/tongue guide device  19  such that one snap-in locking component of the snap-in locking protective arrangement  14  is in each case followed by a component of the groove/tongue guide device  19  which is staggered thereto by 90° when seen in the peripheral direction about the longitudinal axis of the injection device  1 . 
         [0055]      FIGS. 8 to 11  show instantaneous positions during assembly of the injection device  1 . The positive-fit adapter  13  is locked with the container  3  of the injection unit  2  by means of snap-in locking hooks  24 . To this end, the snap-in locking hooks  24  engage a snap-in locking collar  25  of the container  3  which is arranged at the transition to the opening portion  6 . The inner telescopic connection sleeve  12  is axially connected to the positive-fit adapter  13  by means of a plurality of snap-in locking bodies  26  which are formed at free ends of snap-in latches  27  of the positive-fit adapter  13 . The snap-in latches  27  extend in the axial direction and are formed at a common carrier ring  28  of the positive-fit adapter  13 . The positive-fit adapter  13  therefore has the shape of an axially fittable adapter sleeve. A distance between two snap-in latches  27  which are adjacent to each other when seen in the peripheral direction about the longitudinal axis of the injection device  1 , and the number of the snap-in latches  27  is adapted to a width and a number of axially extending peripheral ribs  29  which are formed on an outside of the opening portion  6  of the container  3 . When the positive-fit adapter  13  is mounted, a respective one of the snap-in latches  27  fits between two adjacent ones of the peripheral ribs  29 , thus ensuring an anti-rotation protection of the positive-fit adapter  13  relative to the container  3 , strictly speaking relative to the opening and connection portion  6  of the container  3 . An inner wall of the inner telescopic connection sleeve  12  is provided with axial structures which are not shown in more detail in the drawing and which ensure an anti-rotation protection between the inner telescopic connection sleeve  12  and the positive-fit adapter  13  when the inner telescopic connection sleeve  12  is snap-locked with the positive-fit adapter  13 . The inner axial structures of the telescopic connection sleeve  12  engage into the space between in each case two adjacent snap-in latches  27  of the positive-fit adapter  13 . 
         [0056]    When the inner telescopic connection sleeve  12  is mounted, the snap-in locking bodies  26  engage a complementary snap-in locking collar of the telescopic connection sleeve  12 , which is not shown in more detail in the drawing. 
         [0057]    An injection connection arrangement configured as an injection snap-in locking arrangement allows the telescopic protection sleeve  10 , in other words the protective component of the anti-puncture device  8 , to be positively and securely fastened to the injection unit  2  in the injection position. Snap-in locking components of said injection snap-in locking arrangement are on the one hand the outer edges of the free ends of the snap-in locking hooks  24  of the positive-fit adapter  13 , and the counter snap-in locking bodies  17  of the telescopic protection sleeve  10  on the other which engage therewith in the injection position. Said injection snap-in locking arrangement  17 ,  24  can be released from engagement with the snap-in latches  24  by disengaging the counter snap-in locking bodies  17 . This is done by applying a defined amount of pressure to the anti-puncture device  8 . 
         [0058]    The injection device  1  is assembled as follows: At first, the injection unit  2  is in a commercially available supply condition which is shown in  FIG. 8 . The anti-puncture device  8  comprising the sleeves  10  to  12  is preassembled in the injection position in which the telescopic sleeves are disposed one above the other in such a way as to be in perfect alignment. The positive-fit adapter  13  is then push-fitted onto the injection unit  2  from the cannula end of the injection unit  2  with its snap-in locking hooks  24  ahead until the snap-in locking hooks  24  engage the snap-in locking collar  25  of the container  3  (cf.  FIG. 9 ). Afterwards, the prefabricated anti-puncture device  8  comprising the three telescopic sleeves  10  to  12 , which are fitted one inside the other and snap-locked with each other, is push-fitted onto the injection unit  2  from the cannula end of the injection unit  2  as well until the inner telescopic connection sleeve  12  snap-locks with the positive-fit adapter  13 , causing the snap-in latches  27  to be radially pressed between the peripheral ribs  29  to achieve an anti-rotation protection, and the injection snap-in locking arrangement  17 ,  24  comes into locking engagement. The inner telescopic connection sleeve  12  is oriented in the peripheral direction in such a way that when it is push-fitted onto the positive-fit adapter  13 , the inner axial structures of the telescopic connection sleeve  12  engage into the space between the snap-in latches  27  of the positive-fit adapter  13 . When the inner telescopic connection sleeve  12  has been fully push-fitted onto the positive-fit adapter  13 , a leading stop collar of the telescopic connection sleeve  12  abuts against a front wall of the carrier ring  28  of the positive-fit adapter  13  facing the stop collar. 
         [0059]    At the same time, inner structures of the telescopic connection sleeve  12  act as hold-down means for holding the snap-in latches  27  between the peripheral ribs  29  of the opening portion  6  of the injection unit  2 . 
         [0060]    Upon assembly, the injection device  1  comprising the anti-puncture device  8  is in the injection position, and the protective cap  5 , which had already been mounted, covers the injection needle  4  as shown in  FIGS. 1 and 11 . The various anti-rotation components ensure that the four components  10  to  13  of the anti-puncture device  8  are secured against rotation relative to each other and that the entire anti-puncture device  8  is secured against rotation relative to the injection device  2 . 
         [0061]    The injection device  1  is used as follows: In a first step, the protective cap  5  is removed from, in other words screwed off the injection cannula  4  (cf arrow  30  in  FIG. 1 ). When the protective cap  5  is being screwed off, the cross-sectional design of the telescopic protection sleeve  10 , which protrudes beyond the outer periphery of the container  3 , ensures that in order to remove the protective cap  5 , the user must grasp the injection device  1  by its telescopic protection sleeve  10 . To this end, the telescopic protection sleeve  10  is provided with axially extending longitudinal ribs which prevent an unwanted movement of the telescopic protection sleeve  10  between the fingers of the user when removing the protective cap  5 . Since all components of the anti-puncture device  8  are secured against rotation relative to each other, and the positive-fit adapter  13  is secured against rotation relative to the opening portion  6 , it is ensured that when the protective cap  5  is rotated relative to the anti-puncture device  8  in the direction of the arrow  30  (or in a counter-direction thereto), the protective cap  5  is actually screwed off the opening portion  6  as required. When the protective cap  5  has been screwed off, it can be removed from the injection cannula  4 . 
         [0062]    The injection device  1  is now ready to use, which is shown in  FIG. 2 . In order to move the anti-puncture device  8  into the protection position (cf.  FIGS. 3 to 7 ), a defined amount of pressure is applied to the telescopic protection sleeve  10  from both sides in a pressure region  31  marked on the outer telescopic protection sleeve  10 . This causes the counter snap-in locking bodies  17  to disengage from the snap-in locking hooks  24 , thus allowing the outer telescopic protection sleeve  10  to be axially extended relative to the telescopic sleeve  11  in the direction of the arrow  32  applied to the outer telescopic protection sleeve  10  (cf. arrow  33   a  in  FIG. 3 ). In doing so, the counter snap-in locking body  17  clicks over the snap-in locking teeth  16  of the protective snap-in locking arrangement  14  until the end position of the counter snap-in locking body  17  in front of the near-end snap-in locking tooth  16 ′ of the central telescopic sleeve  11  is reached. Afterwards, the central telescopic sleeve  11  is extended relative to the inner telescopic connection sleeve  12 , causing the counter snap-in locking bodies  18  of the central telescopic sleeve  11  to click over the snap-in locking teeth  16  of the inner telescopic connection sleeve  12  until the end position of the counter snap-in locking body  18  is reached in which it abuts against the near-end snap-in locking tooth of the inner telescopic connection sleeve  12 . The anti-puncture device  8  is now in the fully extended protection position according to  FIG. 4 . In this position, the cannula tip  9  of the injection cannula  4  is fully retracted into the telescopic protection sleeve  10 , thus ensuring a secure anti-puncture protection. It shall be noted that due to the one-way design of the associated snap-in locking arrangements  14 , it is not possible for a user to move the anti-puncture device  8  from the protection position according to  FIG. 4  back to the state in which the cannula tip  9  is exposed without destroying it. 
         [0063]    Another embodiment of an injection device  33  will hereinafter be explained with reference to  FIGS. 12 to 17 . Components and functions which correspond to those described above with reference to  FIGS. 1 to 11  are designated by the same reference numerals and are not discussed in detail again. 
         [0064]    The anti-puncture device  8  of the injection device  33  according to  FIGS. 12 to 17  has three telescopic sleeves as well, namely an outer telescopic protection sleeve  34  the function of which corresponds to that of the telescopic protection sleeve  10  of the embodiment according to  FIGS. 1 to 11 , a central telescopic sleeve  35  the function of which corresponds to that of the telescopic sleeve  11  of the embodiment according to  FIGS. 1 to 11 , and an inner telescopic connection component  36  which is at the same time a positive-fit adapter for forming a positive fit between the anti-puncture device  8  and the injection device  2 . In other words, the functions of the inner telescopic sleeve  12  and those of the positive-fit adapter  13  of the embodiment according to  FIGS. 1 to 11  are combined in the telescopic connection component  36 . 
         [0065]    The telescopic connection component  36  is configured as a radially snap-lockable C-shaped adapter. The telescopic connection component  36  is radially snap-locked with the opening portion  6  of the container  3 , causing the telescopic connection component  36  to engage a peripheral region of the snap-in locking collar  25  of the opening portion  6  in order to axially secure the telescopic connection component  36 . 
         [0066]    In order to increase the frictional fit between the telescopic connection component  36  and the opening portion  6  of the container  3  of the injection unit  2 , and therefore in particular to ensure an anti-rotation protection, inner ribs  37  of the telescopic connection component  36 , which—in the assembled state—abut against the opening portion  6  between the peripheral ribs  29  thereof, are made of a softer plastic material than the rest of the base body of the telescopic connection component  36 . The ribs  37  may for example be formed on the base body of the telescopic connection component  36  by multi-component technology, in particular by 2C technology.  FIG. 15  shows only one rib  37  of the inner ribs  37 . The base body is however provided with more than one, for instance five, ribs  37  which are arranged at equal distances from each other when seen in the peripheral direction, wherein this distance is adapted to the peripheral distance of the peripheral ribs  29 . 
         [0067]    The central telescopic sleeve  35  (cf.  FIG. 16 ) is connected to the telescopic connection component  36  via a radially acting snap-in locking connection. To this end, the central telescopic sleeve  35  is provided with a flexible tongue  38  which engages into a corresponding snap-in locking recess of the telescopic connection component  36 . 
         [0068]    The outer telescopic protection sleeve  34  is provided with a flexible tongue  39  as well which engages with a rear side of a corresponding snap-in locking receptacle in the central telescopic sleeve  35  or in the telescopic connection arrangement  36  so as to form a locking connection. The flexible tongue  39  and the snap-in locking receptacle associated therewith in the injection position thus combine to form the injection connection arrangement for positively securing the telescopic protection sleeve  34  to the injection unit  2  in the injection position. 
         [0069]    In the protection position of the anti-puncture device  8  in the embodiment according to  FIGS. 12 to 17 , the snap-in latch  39  engages with a rear side of a snap-in receptacle  40  which is formed in the central telescopic sleeve  35 . As a result, a protective snap-in locking arrangement is obtained which, together with a corresponding snap-in locking connection between the central telescopic sleeve  35  and the telescopic connection component  36 , ensures that the telescopic protection sleeve  34  is securely held in place in the protection position. 
         [0070]    Apart from the differences explained above, assembly and usage of the injection device  33  correspond to the above description of the injection device  1 . 
         [0071]    Another embodiment of an injection device  41  will be explained below with reference to  FIGS. 18 to 26 . Components and functions which correspond to those that have already been described above with reference to the injection devices  1  and  33  are designated by the same reference numerals and are not discussed in detail again. 
         [0072]    The injection device  41  is provided with a telescopic anti-puncture device  8  as well which comprises a telescopic connection sleeve  12 , a positive-fit adapter  13 , a central telescopic sleeve  11  and a telescopic protection sleeve  10  and therefore has basically the same structure as the protective device  8  of the injection device  1 . There are however differences in the structures of the snap-in locking connections and of the guide systems. In the injection device  41 , the snap-in locking connections are configured as axial snap-in locking connections. 
         [0073]    In the anti-puncture device  8  of the injection device  41 , the telescopic protection sleeve  10  is composed of two parts, thus consisting of the actual telescopic sleeve and an additional ring-shaped lid  42 . An outer periphery of the lid  42  is snap-locked with an inner peripheral groove  34  in an outer end region of the telescopic protection sleeve  10 . An outer periphery of the lid  42  combines with the inner peripheral groove  43  to form an annular snap fit between the lid  42  and the telescopic protection sleeve  10 . The lid  42  is provided in order to reduce an externally accessible opening width of the telescopic protection sleeve  10  to such an extent that a through-opening  44  is obtained which has a diameter that is smaller than the internal diameter of the remaining telescopic protection sleeve  10 . 
         [0074]    During assembly of the anti-puncture device  8  according to  FIGS. 18 to 26 , the central telescopic sleeve  11  is at first inserted into the telescopic protection sleeve  10  from the side; at this point, the telescopic protection sleeve  10  is not yet provided with a lid  10 . Afterwards, the telescopic connection sleeve  12  is inserted into the central telescopic sleeve  11  from the same side. Then the lid  42  is snap-locked with the inner peripheral groove  43 . Finally, the positive-fit adapter  13  is inserted into the telescopic connection sleeve  12  from the opposite side. 
         [0075]    The anti-puncture device preassembled in this manner is then ready to be push-fitted onto the injection unit  2 . This is done until a stop collar  45  of the positive-fit adapter  13  abuts against the snap-in locking collar  25  of the injection unit  2  (cf. for instance  FIG. 8 ). 
         [0076]    When the anti-puncture device  8  according to  FIGS. 18 to 26  is moved further along the injection unit  2  in the direction of the container  3 , the telescopic connection sleeve  12  is axially displaced in the direction of the positive-fit adapter  13 , which is then axially secured to the snap-in locking collar  25 , until snap-in locking hooks  46  formed on the telescopic connection sleeve  12  engage the snap-in locking collar  25  of the opening portion  6  of the injection unit  2 . In the injection device  41 , the positive connection in the injection position between the telescopic protection sleeve  10  in its function as protective component of the anti-puncture device  8  as well as other components thereof and the injection unit  2  is not achieved by means of snap-in locking hooks provided at the positive-fit adapter  13  but by means of the snap-in locking hooks  46  provided at the telescopic connection sleeve instead. 
         [0077]    In the injection device  41 , an anti-rotation protection is provided between the anti-puncture device  8 , which is at the same time an anti-rotation device, and the opening portion  6  of the injection unit  2  as well. To this end, the positive-fit adapter  13  of the injection device  41  is again provided with anti-rotation latches  47  which correspond to the snap-in latches  27  of the embodiment according to  FIGS. 1 to 11 . The anti-rotation latches  47  extend axially and are interconnected via the carrier ring  28  of the positive-fit adapter  13  of the injection device  41 . In the assembled state, the anti-rotation latches  27  are in each case received between two adjacent, axially extending peripheral ribs  29  of the opening portion  6  of the injection unit  2 . 
         [0078]    The anti-rotation latches  27  are held between the peripheral ribs  29  by means of a hold-down means formed on the telescopic connection sleeve  12 . Said hold-down means is formed by a total of four inner axial ribs two of which are visible in the axial sectional view according to  FIG. 26 . Seen in the peripheral direction, the axial ribs  48  are formed on an inner wall of the telescopic connection sleeve  12  in such a way as to be staggered relative to each other by in each case 90°. Each of the axial ribs  48  interacts with a counter hold-down means at the positive-fit adapter  13  in order to hold down in each case one anti-rotation latch  47 . The counter hold-down means are formed by outer axial ribs  49  at the positive-fit adapter  13 . (cf.  FIG. 21 ). 
         [0079]    The positive-fit adapter  13  is secured to the telescopic connection sleeve  12  while in each case two telescopic sleeves  12 ,  11 ,  10  abutting against each other are secured relative to each other by means of anti-rotation devices so as to prevent a relative rotation thereof about the longitudinal axis of the anti-puncture device  8 . Said anti-rotation device is again formed by outer tongues  50  at in each case one of the components  13 ,  12 ,  11  which interact with complementary inner axial grooves  51  in the respective adjacent telescopic sleeves  12 ,  11 ,  10  in such a way as to prevent rotation. 
         [0080]    At the same time, the tongues  50  act as stops which interact, via the snap-in locking hooks  46  of the telescopic connection sleeve  12 , with axially extending recesses  51   a  acting as stops defining an axial end position of the telescopic connection sleeve  12  relative to the positive-fit adapter  13  when the anti-puncture device  8  is snap-locked with the snap-in locking collar  25  of the opening portion  6 . 
         [0081]    The central telescopic sleeve  11  and the telescopic protection sleeve  10  are also provided with radially acting snap-in locking hooks  52  which are comparable to the snap-in locking hooks  46  of the telescopic connection sleeve  12 . Just like the snap-in locking hooks  46 , the snap-in locking hooks  52  are also arranged in such a way as to be staggered relative to each other by 90° when seen in the peripheral direction. In the injection position, for instance according to  FIG. 19 , the snap-in locking hooks  46 ,  52  of adjacent telescopic sleeves  12 ,  11 ,  10  are arranged one above the other in such a way as to be in perfect alignment. The snap-in locking hooks  52  of the central telescopic sleeve  11  engage complementary recesses  53  in the outside of the snap-in locking hooks  46 . The snap-in locking hooks  52  of the telescopic protection sleeve  10  engage corresponding recesses  53  in the outside of the snap-in locking hooks  52  of the central telescopic sleeve  11 . 
         [0082]    In the protection position of the anti-puncture device  8  (cf for instance  FIGS. 20 and 26 ), the snap-in locking hooks  52  of the central telescopic sleeve  11  on the one hand and of the telescopic protection sleeve  10  on the other interact with outer peripheral grooves  53   a  formed in the telescopic connection sleeve  12  on the one hand and in the central telescopic sleeve  11  on the other. 
         [0083]    When the telescopic sleeves  11 ,  10  are moved from the retracted injection position to the extended protection position, the snap-in locking hooks  52  slide between the respective counter recesses  53  and the peripheral grooves  53   a . In order to ensure that an even force is applied to the snap-in locking hooks  52  when the telescopic sleeves  11 ,  10  are being moved to the protective position, the telescopic sleeves  12 ,  11  widen conically between the respective counter recesses  53  and the respective peripheral grooves  53   a.    
         [0084]    The telescopic protection sleeve  10  is configured as a 2C (two component) injection-molded part. The telescopic protection sleeve  10  includes a carrier body  54  as well as a grip portion  55 . The carrier body  54  on the one hand and the grip portion  55  on the other are configured as different injection-molded components of the 2C component. Suitable 2C plastic materials include for example ABS (acrylonitrile budadiene styrene) for a hard component such as the carrier body  54 , and TPE (thermoplastic elastomer) for a soft component such as the grip portion  55 . It is conceivable as well to use a different number of components for a multi-component injection-molded part of this type, for instance three or more components made of different plastic materials of an in particular different hardness. 
         [0085]    Being configured as a 2C (two component) injection-molded part, the telescopic protection sleeve  10  ensures a more secure grip in the region of the grip portion  55  of the telescopic protection sleeve  10 . 
         [0086]    The axial ribs  48  of the telescopic connection sleeve  12  may also be formed of a plastic material which is different from that of the remaining telescopic connection sleeve  12 , and the axial ribs  48  may be secured to a carrier body of the telescopic connection sleeve  12  by means of 2C injection molding technology. 
         [0087]    Another embodiment of the injection device  56  will be explained below with reference to  FIGS. 27 to 35 . Components and functions which correspond to those described above with reference to the injection devices  1 ,  33  and  41  and in particular with reference to the injection device  41  are designated by the same reference numerals and are not discussed in detail again. 
         [0088]    The telescopic connection sleeve  12  and the central telescopic sleeve  11  are in each case provided with three intermediate notches  57  between the counter recesses  53  and the peripheral grooves  53   a . When the telescopic protection sleeve  10  and the central telescopic sleeve  11  are displaced from the injection position into the protection position, the respective snap-in locking hooks  52  of the telescopic protection sleeve  10  and those of the central telescopic sleeve  11  click over the intermediate notches  57  along their displacement path between the respective counter recesses  53  and the respective peripheral grooves  53   a . As a result, a haptic feedback is delivered to the user informing him about the distance already covered by the two telescopic sleeves  10 ,  11  on their way between the injection position and the protection position. 
         [0089]    Another embodiment of an injection device  58  will be explained below with reference to  FIGS. 36 to 43 . Components and functions which correspond to those described above with reference to the injection devices  1 ,  33 ,  41  and  56  are designated by the same reference numerals and are not discussed in detail again. 
         [0090]    Similar to the injection device  1 , the injection device  58  is composed of four parts as well, thus comprising an inner positive-fit adapter  13 , a telescopic connection sleeve  12 , a central telescopic sleeve  11  and an outer telescopic protection sleeve  10 . 
         [0091]    The function of snap-in locking hooks  46  and  52  of the telescopic sleeves  12 ,  11  and  10  of the injection device  58  is similar to that of the injection device  41 . The telescopic sleeves  11  and  10  are in each case provided with two snap-in locking hooks  52  which are arranged opposite to each other, in other words they are staggered relative to each other by 180° when seen in the peripheral direction. Similar to the concept of the counter snap-in locking bodies and the snap-in locking teeth in the injection device  1 , the snap-in locking hooks  52  of the central telescopic sleeve  11  are staggered relative to the snap-in locking hooks  52  of the telescopic protection sleeve  10  by 90° in the peripheral direction when the injection device  8  is mounted. During assembly, the central telescopic sleeve  11  is at first inserted into the outer telescopic protection sleeve  10  in the direction of the arrow  32  until the snap-in locking hooks  52  of the outer telescopic protection sleeve  10  engage counter recesses  59  of the central telescopic sleeve  11  which are formed at the end of axial guideways  60  in an outer wall of the central telescopic sleeve  11 . 
         [0092]    Afterwards the telescopic connection sleeve  12  is inserted into the central telescopic sleeve  11  in the direction of the arrow  32  as well. This is done until the snap-in locking hooks  52  of the central telescopic sleeve  11  engage recesses  61  of the telescopic connection sleeve  12  which are in turn formed at the end of axial guideways  60  in an outer wall of the telescopic connection sleeve  12 . 
         [0093]    In the next step, the positive-fit adapter  13  is inserted into the telescopic connection sleeve  12  in the direction of the arrow  32  as well until the snap-in locking hooks  46  of the telescopic connection sleeve  12  engage recesses  62  of the positive-fit adapter  13  from outside. The recesses  62  are again formed in axial guideways  60  of the positive-fit adapter  13 . In the position preassembled in this manner, the sleeves  11  and  12  are virtually completely arranged in the outer telescopic protection sleeve  10 . The largest part of an axial extension of the positive-fit adapter  13  between the recesses  62  and the stop collar  45  protrudes beyond the telescopic sleeves  10  to  12  inserted into each other. 
         [0094]    When the preassembled anti-puncture device  8  is to be mounted to the injection device  2 , the anti-puncture device  8  is push-fitted onto the opening portion  6  of the injection unit  2  with the positive-fit adapter  13  going in first until the stop collar  45  abuts against the snap-in locking collar  25  of the opening portion  6 . Afterwards the three telescopic sleeves  10  to  12  inserted into each other are moved axially in the direction of the container  3 , causing the snap-in locking hooks  46  of the telescopic connection sleeve  12  to disengage from the recesses  62  of the positive-fit adapter  13  so as to slide along the guideways  60  before engaging the snap-in locking collar  25  in order to secure the anti-puncture device  8  to the injection unit  2 . At the same time, another set of hold-down means ensure that the anti-rotation latches  47  of the positive-fit adapter  13  between adjacent peripheral ribs  29  of the opening portion  6  are held down in order to prevent a rotation of the anti-puncture device  8  relative to the injection unit  2 . 
         [0095]    The interaction of the guideways  60  with the associated snap-in locking hooks  46 ,  52  prevents rotation of the components of the anti-puncture device  8  relative to each other. Axial guideways, which are arranged at an angle of 90° relative to the structure of snap-in locking hooks and guideways, provide an additional amount of anti-rotation protection. 
         [0096]    The anti-puncture device  8  is now ready to use in the injection position. 
         [0097]    When the anti-puncture device  8  is moved from the injection position into the protection position, the snap-in locking hooks  52  of the central telescopic sleeve  11  disengage from the recesses  61  of the telescopic connection sleeve  12  while the snap-in locking hooks  52  of the outer telescopic protection sleeve  10  disengage from the counter recesses  59  of the central telescopic sleeve  11 . The snap-in locking hooks of the telescopic sleeves  10 ,  11  move axially along the respective guideways  60  of the telescopic sleeves  11  and  12  until the snap-in locking hooks  52  of the outer telescopic protection sleeve  10  engage recesses  63  which are formed at ends of the guideways  60  that are opposite to the counter recesses  59 . In the protection position, the snap-in locking hooks  52  of the central telescopic sleeve  11  further engage recesses  63  which are formed at ends in the guideways  60  of the telescopic connection sleeve  12  that are opposite to the recesses  61 . The anti-puncture device  8  is now in the extended protection position according to  FIG. 38  or  43 .