Patent Publication Number: US-2010130928-A1

Title: Combined container-syringe

Description:
TECHNICAL FIELD 
     The present invention relates to a combined container-syringe that is provided with a safety device that is used for covering the injection needle after the completion of injection and the like and ensuring safety. 
     Priority is claimed on Japanese Patent Application No. 2007-114051, filed Apr. 24, 2007, the content of which is incorporated herein by reference. 
     BACKGROUND ART 
     Since a combined container-syringe can be used immediately after being taken out from the packaging without performing troublesome procedures at medical institutions due to the fact that the drug solution has been prefilled, it is very convenient and very useful for lightening the workload of people involved in medical service such as physicians and nurses. For this reason, it is being adopted by many medical facilities. 
     In the past, when people involved in medical service used syringes, they sometimes accidentally stuck themselves with the injection needle after being used for injection, and as a result of doing so faced the risk of a viral infection. For that reason, with the aim of safety treatment of injection needles after injection into patients, a syringe has been proposed that is equipped with a safety device as a cylindrical cover that prevents careless contact with the injection needle by covering the injection needle therewith after injection. For example, according to the syringe that is disclosed in a patent document 1, an inner circumferential wall surface of a rear end of the safety device and an outer peripheral portion of an engagement portion which is provided at a front end side of the syringe are engaged and frictionally fixed each other each other at a position that covers the injection needle.
     [Patent Document 1]: Japanese Unexamined Patent Application, Publication No. 2001-29334   

     DISCLOSURE OF INVENTION 
     [Problems that the Invention is to Solve] 
     However, in the syringe that is equipped with the conventional safety device as described above, since the safety device is merely engaged with the engagement portion by the friction therebetween, the safety device cannot be fixed securely to the engagement portion and stability of the safety device becomes low. Moreover, according to circumstances, there is the problem that the safety device may slip out from the syringe. 
     The present invention has been achieved in view of the above circumstances, and has as its object to provide a combined container-syringe that is equipped with a safety device which is reliably fixed to the syringe and reliably covers an injection needle after injection into a patient so as to prevent careless removal of the safety device. 
     [Means for Solving the Problems] 
     In order to solve the abovementioned problem, this invention proposes the following means. 
     The combined container-syringe according to the present invention has a cylindrical cylinder that is filled with a drug solution and an injection needle is mounted on the front end thereof; an engagement portion that is provided at the front end side of the cylinder; a finger grip that is provided on the rear end side of the cylinder; and a cylindrical-shaped safety device that is mounted in a slidable manner on the outer periphery of the cylinder, and covers all the sphere of the injection needle when it has moved in the front end direction. Furthermore, a return prevention stopper that engages with the engagement portion at the position where the safety device covers all the sphere of the injection needle and prevents the movement of the safety device in the rear end direction, and a slip-out prevention stopper that is formed further to the rear end side than the return prevention stopper and engages with the engagement portion at the position where the safety device covers all the sphere of the injection needle and prevents the movement of the safety device in the front end direction, are provide on an inner circumferential wall of the safety device. 
     When the safety device that is engaged with the outer periphery of the cylinder is moved to the front end direction, the return prevention stopper abuts the engagement portion, the return prevention stopper flexes due to the engagement portion, and the return prevention stopper passes over the engagement portion while expanding the inner diameter thereof. When the safety device moves the position where the safety device covers all the sphere of the injection needle, the slip-out prevention stopper engages with the engagement portion, and the further movement of the safety device in the front end direction is prevented. In this state, even when attempting to move the safety device in the rear end direction, since the return prevention stopper and the engagement portion engage, such movement is prevented. That is, once the safety device covers the injection needle, the safety device is completely fixed to the combined container-syringe because the engagement portion is sandwiched between the slip-out prevention stopper and the return prevention stopper from the front end side and the rear end side. As a result, the safety device does not separate from the combined container-syringe, and neither does it move in the rear end direction and cause the injection needle to be exposed. 
     Furthermore, in the combined container-syringe according to the present invention, it is preferable that the return prevention stopper or the slip-out prevention stopper can deform elastically, a pressing ring is mounted in a slidable manner on the outer periphery of the safety device, and the return prevention stopper or the slip-out prevention stopper which is pressed by the pressing ring projects to the inner side in the radial direction. 
     The return prevention stopper or the slip-out prevention stopper does not project to the inner side in the radial direction under normal conditions, and it projects to the inner side in the radial direction only when it is pressed by the pressing ring from the outer side in the radial direction. Therefore, when mounting the safety device onto a combined container-syringe body from the front side thereof, the return prevention stopper or the slip-out prevention stopper does not abut the engagement portion by providing the stopper in the state that the stopper does not project to the inner side. Accordingly, the safety device can be mounted on the combined container-syringe body easily without preventing its movement. 
     Furthermore, it is preferable that the return prevention stopper has a sloping surface which is formed so as to project from the inner surface of the safety device toward the rear end direction and the slip-out prevention stopper has a sloping surface which is formed so as to project from the inner surface of the safety device toward the front end direction. 
     According to this, when the safety device is moved to the front end direction of the combined container-syringe body, the sloping surface of the return prevention stopper abuts the engagement portion and easily flexes the inner circumference of the safety device. Thereby, the return prevention stopper can readily pass over the engagement portion. 
     On the other hand, when the safety device is mounted onto the combined container-syringe body from the front end direction, the sloping surface of the slip-out prevention stopper abuts the engagement portion and easily flexes the inner circumference of the safety device. Thereby, the slip-out prevention stopper can readily pass over the engagement portion. 
     [Effects of the Invention] 
     According to the combined container-syringe of to the present invention, since the return prevention stopper and the slip-out prevention stopper of the safety device engage with the engagement portion of the combined container-syringe body, and the safety device is reliably fixed to the combined container-syringe, it is possible to reliably cover the injection needle after injection into a patient with the safety device, and so possible to ensure safety. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partial sectional view of the combined container-syringe according to one embodiment of the present invention. 
         FIG. 2  is an enlarged view of the vicinity of the engagement portion, the return prevention stopper, and the slip-out prevention stopper in  FIG. 1 . 
         FIG. 3  is a vertical sectional view of the combined container-syringe body. 
         FIG. 4  is a vertical sectional view of the safety device body. 
         FIG. 5  is a sectional view along a line A-A in  FIG. 4 . 
         FIG. 6  is a sectional view along a line B-B in  FIG. 4 . 
         FIG. 7  is a sectional view along a line C-C in  FIG. 4 . 
         FIG. 8  is a view along arrow D in  FIG. 4  in the vicinity of the return prevention stoppers. 
         FIG. 9A  is a side view of the pressing ring. 
         FIG. 9B  is a plan view of the pressing ring. 
         FIG. 10  is a vertical sectional view of the safety device. 
         FIG. 11A  is a drawing that explains a procedure for mounting the safety device on the combined container-syringe body. 
         FIG. 11B  is a drawing that explains a procedure for mounting the safety device on the combined container-syringe body. 
         FIG. 11C  is a drawing that explains a procedure for mounting the safety device on the combined container-syringe body. 
         FIG. 12  is a drawing that explains a mechanism for fixing the safety device on the combined container-syringe body according to the fourth modification embodiment of the present invention. 
         FIG. 13  is a sectional view in the vicinity of the return prevention stoppers according to the fifth modification embodiment of the present invention. 
     
    
    
     BRIEF DESCRIPTION OF THE REFERENCE SYMBOLS 
       1  . . . combined container-syringe,  2  . . . combined container-syringe body,  3  . . . safety device,  4  . . . safety device body,  5  . . . pressing ring,  7  . . . cylinder,  8  . . . cylindrical tip,  9  . . . finger grip,  10  . . . injection needle,  13  . . . engagement portion,  25  . . . slip-out prevention stopper,  27  . . . return prevention stopper 
     BEST MODE FOR CARRYING OUT THE INVENTION 
     An embodiment of the combined container-syringe according to the invention shall be described hereinbelow with reference to  FIG. 1  to  FIG. 13 . 
     As shown in  FIG. 1 , a combined container-syringe  1  in the present embodiment is constituted by a combined container-syringe body  2 ; a safety device  3  that consists of a safety device body  4  and a pressing ring  5 . Also, hereinbelow, in  FIG. 1  the upper side along an axis O of the combined container-syringe body  2  at which an injection needle  10  is provided shall be called the front end, and the lower side at which a finger grip  9  is provided shall be called the rear end. 
     As shown in  FIG. 3 , the combined container-syringe body  2  is constituted by a cylinder  7 , a cylindrical tip  8  that is fitted on the outer periphery of the front end side of the cylinder  7 , the finger grip  9  made of a synthetic resin that is fitted on the outer periphery of the rear end side of the cylinder  7 , and the injection needle  10  that is mounted on a luer-lock portion  12  that is provided at the front end of the cylindrical tip  8 . 
     The cylinder  7  is made for example of transparent glass, and has a cylindrical shape that extends along the axis O. In the cylinder  7 , a bypass path  7   c  is formed that bulges outward along a predetermined length in the axis direction, and a stopper (not illustrated) is provided at a total of three locations, namely, the front end side and rear end side of the cylinder  7  and directly on the rear end side of the bypass path  7   c.  A drug solution is sealed inside of the cylinder  7 . Also, the front end portion of a plunger rod (not illustrated) that is inserted from the rear end side of the cylinder  7  is connected by being screwed into the stopper on the rear end side. 
     The cylindrical tip  8  is for example made with a transparent synthetic resin. As shown in  FIG. 3 , the cylindrical tip  8  is provided with a cylinder portion  11  in which a bypass chamber  11   a  having an inner diameter that is equal to or slightly larger than the inner diameter of the cylinder  7  and a stopper (not illustrated) is inserted therein, a cylindrical luer-lock portion  12  that is integrally formed at the front end of the cylinder portion  11  and has an inner hole which acts as an attachment portion of the injection needle  10  which communicates with the bypass chamber  11   a,  and a cylindrical engagement portion  13  that is integrally formed at the rear end of the cylinder portion  11  and has a larger diameter than it. By fitting an inner hole  14  of the engagement portion  13  on the outer periphery of the front end portion  7   a  of the cylinder  7 , the cylindrical tip  8  is fitted on the cylinder  7 . Also, the front end side of the engagement portion  13  at the cylindrical tip  8  is fashioned into an engagement step portion  13   a  at which a step portion is formed, and the rear end side is made into an engagement end portion  13   b.    
     The finger grip  9  has a fitting portion  9   a  having a cylindrical shape and a flange  9   b  that is integrally formed on the rear end portion of the fitting portion  9   a  and extends to the outer side in the radial direction. The fitting portion  9   a  is fitted on the outer periphery of the rear end  7   b  of the cylinder  7 . 
     Since the drug solution is filled in advance in the combined container-syringe body  2  having the above constitution, at the time of use it can be used immediately after being taken out from the packaging. Also, the safety device  3  that consists of the safety device body  4  and the pressing ring  5  is mounted on the outer periphery of the combined container-syringe body  2 . 
     The safety device body  4  is made with a material that is transparent and has moderate flexibility such as polypropylene and thinly fabricated in a range that can maintain strength. As shown in  FIG. 1 , the safety device body  4  has an approximately cylindrical shape with the same axis O as the combined container-syringe body  2  serving as the longitudinal direction. 
     As shown in  FIGS. 4 and 5 , on an inner circumferential wall  4   a,  ribs  24  which extending along the axis O and having convex cross-section projecting to the inner side of the radial direction are provided so as to extend predetermined length from its rear end toward the front end side. These ribs  24  are uniformly spaced in the circumferential direction, and the total number of the ribs is twelve, for example. 
     Also, as shown in  FIG. 6 , slip-out prevention stoppers  25  are provided at a total of four locations on the inner circumferential wall  4   a  uniformly spaced in the circumferential direction, and further to the front end side than the ribs  24 . Each slip-out prevention stopper  25  has a sloping surface  25   a  that is formed so as to gradually reduce the diameter of an inner circumferential wall  4   a  toward the front end and an engagement surface  25   b  that is perpendicular to the inner circumferential wall  4   a , extending from the apex of the sloping surface  25   a  to the inner circumferential wall  4   a . Furthermore, a total of four slits  26  are provided at intermediate positions between every two adjacent slip-out prevention stoppers  25  along the circumferential direction of the inner circumferential wall  4   a,  with each slit  26  extending along the axis O and opening so as to make the inner circumferential wall  4   a  communicate with the outer circumferential wall  4   b  of the safety device body  4 . 
     Moreover, as shown in  FIG. 2 , return prevention stoppers  27  are provided on the outer circumferential wall  4   b  of the safety device body  4  further to the front end side than the slip-out prevention stopper  25  and the slits  26 . These return prevention stoppers  27  are provided at two locations so as to be provided at opposing positions as shown in  FIG. 7 . Each return prevention stopper  27  has an outer circumferential surface  27   a  that slopes so as to expand the diameter of the outer circumferential wall  4   b  toward the rear end direction, an engagement surface  27   b  that extends from the outer circumferential surface  27   a  to the inner side in the radial direction, and an inner circumferential surface  27   c  that is positioned on the reverse side of the outer circumferential surface  27   a  so as to be flush with the inner circumferential wall  4   a  of the safety device body  4 . 
     As shown in  FIG. 8  which is a view along arrow D in  FIG. 4  in the vicinity of the return prevention stoppers, each return prevention stopper  27  is surrounded on the rear end side and both sides of the outer circumferential surface  27   a  in the circumferential direction by a U-shaped slit  28  that is cut out so as to make the inner circumferential wall  4   a  communicate with the outer circumferential wall  4   b.  By this U-shaped slit  28 , the return prevention stopper  27  has a structure which is connected with the outer circumferential wall  4   b  of the safety device body  4  only at the front end side of the outer circumferential surface  27   a,  and a recessed groove  29   a  is formed at this connection position  29 . As a result, when a force is applied to the return prevention stopper  27  from the outer side in the radial direction, the return prevention stopper  27  is flexed in the manner of a flat spring toward the inner side of the safety device body  4 , with the recessed groove  29   a  of the connection position  29  serving as a fulcrum point. 
     Ring secondary stop projections  32   a,    32   b  are provided at the rear end side of the U-shaped slit  28  and the front end side of the connection position  29 , respectively, at each return prevention stopper  27  so as to sandwich the return prevention stopper  27  from the front end side and the rear end side. The ring secondary stop projection  32   b  that is positioned at the front end side has a slope that is formed so as to increase the diameter of the outer circumferential wall  4   b  toward the rear end direction. Also, two ring primary stop projections  33  that project to the outer side in the radial direction are provided at opposing positions in the circumferential direction on the outer circumferential wall  4   b  of the safety device body  4 , being positioned further to the front end side than the front end side ring secondary stop projection  32   b.    
     The pressing ring  5 , as shown in  FIGS. 9A and 9B , has a cylindrical shape in which the length in the axis O direction is sufficiently shorter than the safety device body  4 , and similarly to the safety device body  4 , the pressing ring  5  is made with a material that is transparent and has moderate flexibility such as polypropylene and thinly fabricated in a range that can maintain strength. A rear end side of an inner circumferential wall  5   a  of the pressing ring  5  has a sloped shape so as to increase the diameter of its inner circumferential wall. Furthermore, on the inner circumferential wall  5   a,  a plurality of vertical ribs  35  for preventing slippage are formed so as to extend along the axis O and to project toward the outer side in the radial direction. Note that the internal diameter of the pressing ring  5  is approximately the same as or slightly larger than the outer diameter of the safety device body  4 . Also, in order to increase flexibility in the pressing ring  5 , slits may be provided along the axis O. 
     Next, the method of assembling and method of using the combined container-syringe  1  shall be described. 
     First, the inner circumferential wall  5   a  of the pressing ring  5  is fitted and slid on the outer circumferential wall  4   b  of the safety device body  4  from the front end side toward the rear end. The pressing ring  5  passes over the ring primary stop projections  33  due to its flexibility and the rear end of the pressing ring  5  makes contact and stops on the sloped surface of the ring secondary stop projection  32   b.  In this state, as shown in  FIG. 10 , further movement of the rear end side of the pressing ring  5  is prevented by the sloping surface of the ring secondary stop projection  32   b,  and further movement of the front end side is prevented by the ring primary stop projections  33 . Thereby, the pressing ring  5  is supported by the safety device body  4  in a manner of not being moved with a slight force, and thus the safety device  3  is constituted. 
     The safety device  3  is, as shown in  FIG. 11A , mounted on the combined container-syringe body  2  in the state of a protector  36  being mounted on the injection needle  10  with the drug solution having been filled. When the rear end of the safety device  3  is slid from the front end side of the protector  36  of the combined container-syringe body  2  toward the rear end of the combined container-syringe body  2 , the sloping surface  25   a  of the slip-out prevention stopper  25  abuts the engagement step portion  13   a  of the engagement portion  13 . At this time, the sloping surface  25   a  flexes due to the engagement portion  13 , and passes over the engagement portion  13  while expanding the inner diameter of the safety device  3 . Note that since the flexibility is increased by the slits  26  being provided in the periphery of the slip-out prevention stopper  25 , the slip-out prevention stopper  25  can readily pass over the engagement portion  13 . 
     In this state, since there are no other projections on the inner circumferential wall  4   a  of the safety device body  4 , the safety device  3  is readily slid until the rear end of the safety device body  4  abuts the flange  9   b  of the finger grip  9 . As a result, the engagement of the safety device  3  to the combined container-syringe body  2  is completed.  FIG. 11B  shows this state. Furthermore, in this state, the ribs  24  provided on the rear side of the inner circumferential wall  4   a  of the safety device body  4  bite into the outer periphery of the finger grip  9  with appropriate force, and then, the safety device body  4  is fixed to the finger grip  9 . 
     Next, when a force is applied so as to push the pressing ring  5  in the direction of the rear end, the pressing ring  5  passes over the sloping surface of the ring stop projection  32   b  to move in the rear end direction on the outer circumference of the safety device body  4 , and moves further in the rear end direction while abutting the outer circumferential surface  27   a  of the return prevention stopper  27 . The movement of the pressing ring  5  is stopped by contact with the ring secondary stop projection  32   a  from the front side. At this time, the outer circumferential surface  27   a  of the return prevention stopper  27  is pressed inward in the radial direction by the inner circumferential wall  5   a  of the pressing ring  5 , and the return prevention stopper  27  flexes in the manner of a flat spring toward the inner side of the safety device body  4 , with the recessed groove  29   a  of the connection position  29  serving as a fulcrum point. Thereby, as shown in  FIG. 11C , the inner circumferential surface  27   c  of the return prevention stopper  27  slopes so as to cause the inner circumferential wall  4   a  to decrease in diameter toward the rear end direction, and projects from the inner circumferential wall  4   a  of the safety device body  4 . 
     The drug solution is administered to the patient by the combined container-syringe  1  constituted as above. In the state of not mounting the protector  36  on the combined container-syringe  1  after use, when the force along the front direction of the combined container-syringe body  2  to the safety device  3 , the safety device  3  is released from the finger grip  9  and moves toward the front end of the combined container-syringe body  2 . At this time, the inner circumferential surface  27   c  of the return prevention stopper  27  abuts the engagement end portion  13   b  of the engagement portion  13 , but since the safety device  3  itself is constituted with a flexible material, the inner circumferential surface  27   c  of the return prevention stopper  27  passes over the engagement portion  13  by flexing the inner circumferential surface  27   c  by the engagement portion  13  to expand the inner circumference of the safety device  3 . 
     Afterward, as shown in  FIG. 1 , when the safety device  3  moves to a position at which the periphery of the injection needle  10  is completely covered with the safety device  3 , the engagement surface  25   b  of the slip-out prevention stopper  25  and the engagement end portion  13   b  of the engagement portion  13  engage, and further movement of the safety device  3  toward the front end is prevented, as shown in detail in  FIG. 2 . Moreover, in this state, even when attempting to move the safety device  3  in the rear end direction, since the engagement surface  27   b  of the return prevention stopper  27  and the engagement step portion  13   a  of the engagement portion  13  engage, such movement is prevented. That is, once the injection needle  10  is covered with the safety device  3 , since the engagement portion  13  is sandwiched between the slip-out prevention stopper  25  and the return prevention stopper  27  from the front end side and rear end side, the safety device  3  is completely fixed to the combined container-syringe body  2 . As a result, the safety device  3  does not separate from the combined container-syringe body  2  as a result of proceeding too far to the front end side, and neither does it move in the direction of the rear end and cause the injection needle  10  to be exposed. 
     As described above, according to the combined container-syringe  1  of the embodiment, since the safety device  3  is strongly fixed to the combined container-syringe body  2  by engaging the engagement portion  13  of the container-syringe body  2  with the return prevention stopper  27  and the slip-out prevention stopper  25  of the safety device  3 , the safety device  3  does not release from the combined container-syringe body  2 . Therefore, it is possible to reliably cover the injection needle  10  with the safety device  3 , and so possible to treat it safely after injection. 
     Furthermore, since the return prevention stopper does not project to the inner side in the radial direction while the safety device  3  is mounted on the combined container-syringe body  2 , it does not prevent the movement of the safety device  3 . As a result, the safety device  3  can be mounted on the combined container-syringe body  2  easily. 
     In addition, since the safety device  3  is fixed to the combined container-syringe body  2  by the engagement of the ribs  24  and the finger grip  9  while the safety device  3  is mounted on the combined container-syringe body  2 , it does not interfere the treatment of injection to patients using the combined container-syringe  1 . 
     The combined container-syringe  1  of the embodiment of the present invention was described above in detail, but some design modifications are possible without being limited to them as long as not departing from the technical ideas of the present invention. 
     For example, the structure that the cylinder  7  and the cylindrical tip  8  are integrally formed can be employed as the first modification embodiment of the present invention. 
     Furthermore, as the second modification embodiment of the present invention, the safety device  3  may be mounted on the combined container-syringe body  2  from the rear end side of the cylinder  7  together with the finger grip  9 . Alternatively, the safety device  3  may be mounted on the combined container-syringe body  2  from the rear end side of the cylinder  7  in the state that the finger grip  9  is removed therefrom. According to this, even when the safety device  3  having the structure that the return prevention stopper projects to the inner side from the first, the safety device  3  may be mounted on the combined container-syringe body  2  easily without preventing its movement 
     Furthermore, as the third modification embodiment of the present invention, the safety device  3  having the structure that the slip-out prevention stopper  25  can deform elastically and the return prevention stopper  27  projects to the inner side, may be prepared. In this case, after the usage of the syringe, the safety device  3  may cover the injection needle  10  together with the engagement between the engagement potion  13  and the return prevention stopper  27  and the slip-out prevention stopper  25  by engaging the safety device  3  with the combined container-syringe body  2  from the front end side and by passing over the engagement portion  13  according to its elastic deformation. 
     In addition, in the cases of the second and third modification embodiments, the pressing ring  5  may be provided and the pressing ring  5  may push the return prevention stopper  27  and the slip-out prevention stopper  25 . In the second and third modification embodiments, the moving direction of the safety device  3  is unidirectional, and therefore, the safety device  3  can be mounted more easily. 
     Moreover, as the fourth modification embodiment of the present invention, two L-shaped slits  40  may be formed on the rear end of the safety device  3  at opposing positions in the circumferential direction and two projections  41  may be formed on the outer periphery of the fitting portion  9   a  of the finger grip  9  so as to project to the outer side in the radial direction at opposing positions in the circumferential direction as shown in  FIG. 12 . The width of the L-shaped slits  40  are the same as the width of the projections  41 . In this embodiment, when the safety device  3  is mounted on the combined container-syringe body  2 , the safety device  3  is fixed to the combined container-syringe body  2  by engaging two pairs of L-shaped slits  40  and projections  41  each other. Furthermore, one L-shaped slit  40  and projection  41  may be formed on the safety device  3  and the finger grip  9  respectively, and the L-shaped slit  40  and projection  41  may be engaged. 
     In this case, the safety device  3  is slid to the rear end side of the combined container-syringe body  2 , and then the projection  41  is engaged with the portion of the L-shaped slit  40  that extends from the rear end to the front end side. When the projection  41  is abutted to the front end edge of the L-shaped slit  40 , by rotating either of the safety device  3  or the combined container-syringe body  2  in the circumferential direction, engagement of the safety device  3  is performed. In this embodiment, it is needless to provide the ribs  24  to the safety device  3 . According to this embodiment, it is possible to reliably fix the safety device  3  to the combined container-syringe body  2 . 
     In addition, when the safety device is slid to the front end side of the combined container-syringe body  2 , by rotating either of the safety device  3  or the combined container-syringe body  2  in the circumferential direction which is opposed to the direction for fixing them, engagement of the safety device  3  is released. According to this, the safety device  3  can be slid more easily. 
     Furthermore, in order to completely cover the periphery of the injection needle  10  with the safety device  3 , the safety device  3  have to be slid to the front direction along the combined container-syringe body  2 . In this case, for easily slid the safety device  3  toward the combined container-syringe body  2 , a little clearance are provided between the inner circumferential wall  4   a  of the safety device  3  and the outer circumferential wall of the combined container-syringe body  2 . However, due to the size of this clearance, there is the case that the safety device  3  may be shook from side to side when the periphery of the injection needle  10  is covered with the safety device  3 . The fifth modification embodiment of the present invention is achieved to prevent this shake. 
     In the fifth modification embodiment, as shown in  FIG. 13 , a plurality of ribs  51  which extend along the axis O are formed on the inner circumferential wall  4   a  of the safety device body  4  so as to position between the engagement portion  25   b  of the slip-out prevention stopper  25  and the U-shaped slit  28  of the return prevention stopper  27  (that is the position which covers the engagement portion  13  of the combined container-syringe body  2  when the periphery of the injection needle  10  is covered with the safety device  3 ). These ribs  51  project to the inner side of the radial direction and are uniformly spaced in the circumferential direction. Here, the projecting amount of each rib  51  is set approximately the same as or slightly smaller than the clearance between the inner circumferential wall  4   a  of the safety device  3  and the outer circumferential wall of the combined container-syringe body  2 . Furthermore, in  FIG. 13 , each rib  51  is positioned at the front end side of the engagement surface  25   b,  however, it is unnecessary to position the rib  51  at the front end side of the engagement surface  25   b.  That is, the position of the rib  51  may be deviated from the engagement surface  25   b  as far as the rib  51  is provided between the engagement surface  25   b  and the return prevention stopper  27 . In addition a number of the ribs  51  are not limited as far as a plurality of ribs  21  are positioned in the circumferential direction of the inner circumferential wall  4   a  in a well-balanced manner and as the shake of the safety device  3  which is supported by the engagement portion  13  via the ribs  51  is prevented or reduced. That is, the number of the ribs is not less than three. Moreover, it is not necessary to equalize the space between the ribs  51  in the circumferential direction. 
     According to this embodiment, the safety device  3  is supported by the engagement portion  13  via the ribs  51  when the periphery of the injection needle  10  is covered with the safety device  3 , and therefore, the shake of the safety device  3  is prevented or reduced. Furthermore, since the safety device  3  and the outer periphery of the engagement portion  13  are contacted via the back of the ribs  51 , contact area between them is little. 
     In addition, since the ribs  51  are formed so as to extend along the axis O, frictional resistance between the outer periphery of the combined container-syringe body  2  and the back of the ribs  51  is also little when the safety device  3  is slid toward the combined container-syringe body  2 . Therefore, easiness of the sliding performance between the safety device  3  and the combined container-syringe body  2  does not deteriorated by the presence of the ribs  51 . 
     In the combined container-syringe  1  according to the above embodiments, the embodiments that the present invention applies to a double chamber type combined container-syringe are explained, however the present invention is not limited to them, and the present invention can be applied to a single chamber type combined container-syringe. 
     INDUSTRIAL APPLICABILITY 
     According to the present invention, it is possible to reliably cover the injection needle with the safety device, and so possible to treat it safely after injection.