Patent Publication Number: US-2016220270-A1

Title: Puncture device

Description:
TECHNICAL FIELD 
     The present invention relates to a puncture device, and more particularly to a puncture device for indwelling an outer needle (catheter) in a blood vessel. 
     BACKGROUND ART 
     Conventionally, when a puncture device for indwelling an outer needle (catheter) in a blood vessel is used, there is a possibility of stabbing the used inner needle which is pulled from a blood vessel into the user himself/herself, a patient&#39;s body, or an industrial waste disposal worker and causing hepatitis or communicable disease. Therefore a safety measure for the used inner needle has been desired. 
     As a safety measure, for example, Patent Document 1 discloses a puncture device which includes a needle body providing a sharp needle tip at the end, a hub fixed to a base of the needle body, a protector disposed relatively movable to the needle body and capable of storing the needle tip of the needle body, a shutter operation means which includes a contacting member and a coil spring (a movement means), and a rope (a removal prevent means). The above mentioned puncture device has a structure that when a compressed coil spring is released, a protector body slides and protects the needle tip fixed to the hub. 
     However, in the puncture device disclosed in the Patent Document 1, a user (operator) has to work the compressed coil spring to protect the needle tip. If the user forget to do so, a needle contaminated with blood lead to be exposed. Therefore, there is a problem that safety is not secured. 
     A puncture for solving the above mentioned problem is disclosed in Patent document 2 and Patent Document 3. The puncture disclosed in the Patent Documents 2 and 3 includes an outer needle, an outer needle hub for retaining the outer needle, an inner needle whose tip portion is inserted in the above-mentioned outer needle, and a cylindrical inner needle hub for retaining a base portion of the above-mentioned inner needle at its inside, and the puncture has a structure that after the outer needle is indwelled inside a blood vessel, the inner needle is accommodated in the inner needle hub and the accommodated inner needle is prevented from protruding out of the inner needle hub. 
     Specifically, the puncture further includes a needle block member for blocking an internal passage for the inner needle, which consists of an elastic member. When the inner needle is accommodated in the inner needle hub, restoring force of the needle block member blocks the internal passage for the inner needle thereby the accommodated inner needle is prevented from protruding out of the inner needle hub. 
     As described above, as for the puncture disclosed in the Patent Documents 2 and 3, after the outer needle is indwelled inside a blood vessel, a user (operator) pulls the inner needle out of the outer needle, which accompanies that the inner needle is accommodated in the inner needle hub and the accommodated inner needle is prevented from protruding out of the inner needle hub. Therefore it is possible to prevent a situation that a needle is exposed when the user (operator) forgets to do an operation for protecting the needle tip as disclosed in the Patent Document 1 and it is possible to secure safety. 
     PRIOR ART DOCUMENTS 
     Patent Documents 
     Patent Document 1: Japanese patent laid-open No. 2002-28236
 
Patent Document 2: Japanese patent laid-open No. H11-57002
 
Patent Document 3: Japanese patent laid-open No. 2002-126080
 
     Problems to be Solved by the Invention 
     Incidentally, in the puncture device disclosed in Patent Documents 2 and 3 above, the needle block member is in pressure contact with an outer surface of the inner needle by restoring force (elastic force) of the needle block member in a situation where the inner needle is in the internal passage for the inner needle. When the inner needle passes through a position of the needle block member on a pulling operation, the needle block member expands in the internal passage by restoring force (elastic force) of the needle block member and the internal passage is blocked. 
     There is a problem that when the user (operator) pulls the inner needle from the outer needle, the restoring force (elastic force) of the needle block member becomes sliding resistance since the needle block member is in pressure contact with an outer surface of the inner needle, and the pulling is not easy for the user. 
     If the restoring force (elastic force) of the needle block member is set to be small for reducing the sliding resistance at the pulling operation, the needle block member may fail to expand in the internal passage enough and not completely block the internal passage. Therefore the inner needle may protrude outside. 
     The needle block member is formed of a synthetic resin material such as polyethylene or a metal material such as stainless steel. The needle block member formed of stainless steel is not good because it is too costly. 
     On the other hand, the needle block member formed of a synthetic resin material is preferable in cost but there is a possibility that the internal passage may not be blocked enough when the inner needle is pulled and the inner needle may protrude outside. In a situation that the needle block member is in pressure contact with an outer surface of the inner needle (before the inner needle is pulled out of the outer needle) the needle block member is in a deformed state. Therefore in case the puncture device is not used for a long time because of long storage, plastic deformation may occurs in the needle block member, the needle block member may not expand enough in an inner needle pulling operation and may fail to block the internal passage, and the inner needle may protrude outside. 
     In order to solve the above-mentioned problems, the present inventors have made an effort to provide a present invention that is, a puncture device in which sliding resistance at the inner needle pulling operation is reduced as much as possible, which is produced at a low cost, and in which an inner needle is prevented from protruding outside after the inner needle pulled from an outer needle is accommodated in an inner needle hub even if the puncture device is not used for a long time. 
     The present invention has been made in order to solve the above-mentioned technical problems, and aims to provide a puncture device in which an inner needle is accommodated in an inner needle hub by a pulling operation, a through hole for insertion of the inner needle is blocked without using restoring force of a needle block member and the inner needle is prevented from protruding outside. 
     Means for Solving the Problems 
     The puncture device in accordance with the present invention made in order to solve the above-mentioned technical problems is a puncture device provided with an outer needle, an outer needle hub for retaining a base portion of the above-mentioned outer needle, an inner needle whose tip portion is inserted in the above-mentioned outer needle, and a cylindrical syringe for retaining the base portion of the above-mentioned inner needle; the above-mentioned syringe is provided with an inner needle hub for retaining a base portion of the above-mentioned inner needle and a cylinder body which has gripping means for gripping the above-mentioned outer needle hub and is mounted inside the above-mentioned inner needle hub to move back and forth; the above-mentioned cylinder body is provided with an outer pipe mounted inside the above-mentioned inner needle hub so as to be moveable to and fro, and an inner pipe which is mounted inside the above-mentioned outer pipe so as to be moveable to and fro and is provided with a through hole into which the above-mentioned inner needle is inserted; either the inner pipe or the inner pipe and the outer pipe is provided with through hole block means for blocking communicated condition of the through hole, which makes at least part of the through hole move from a position where the inner needle is inserted to a position where the inner needle is blocked wherein insertion of the inner needle is blocked by moving the through hole of the inner pipe with the through hole block means. 
     As described above, the present invention in which a conventional needle block member is not used but is characterized in that at least part of the through hole of the inner pipe is moved from a position where the inner needle is inserted to a position where the inner needle is blocked whereby a communication state of the through hole is blocked and insertion of the inner needle is blocked. Specifically, the preset invention does not use restoring force for blocking the through hole as opposed to a conventional needle block member. Therefore, in case the puncture device is not used for a long time for reasons of long storage, plastic deformation does not occur and it is possible to block the communication state of the through hole of the inner pipe reliably. In addition, as a needle block member of the present invention is not needed in pressure contact with the inner needle unlike in the case of the conventional needle block member, it is possible to reduce sliding resistance at a pulling operation thereby user pulls the inner needle easily. 
     Here, it is preferable that the through hole block means includes a block body in which a through hole for inserting the inner needle is formed, and a space part which movably accommodates the block body and has a structure that when a tip of the inner needle is pulled out through the block body, the block body moves in the space part by the block body&#39;s own weight and insertion of the inner needle is blocked. 
     When the tip of the inner needle is pulled out through the block body, the block body moves in the space part by the block body&#39;s own weight whereby the through hole of the inner pipe is blocked. Therefore it is possible to prevent the inner needle accommodated in the inner needle hub or, inner needle hub and the cylinder body from protruding outside. 
     In addition, since the restoring force is not used in this invention in contrast to the conventional needle block member, even if the puncture device is not used for a long time for reasons of long storage, plastic deformation does not occur and it is possible to block the communication state of the through hole of the inner pipe reliably. 
     Further, since a size of a through hole of the block body is formed slightly larger than an inner needle diameter, it is possible to reduce the sliding resistance at the pulling operation of the inner needle and the pulling is easy for the user. 
     Further, it is preferable that the inner pipe is provided with a standing piece which rises with being forced out by the inner needle in the through hole and engages with the outer pipe, and when the inner needle pulled out passing through the standing piece, the standing piece is disengaged with the outer pipe, and the disengaged standing piece blocks insertion of the inner needle. 
     According to above, communicated condition of the through hole is blocked more reliably by the disengaged standing piece whereby the inner needle is surely prevented from protruding outside. 
     Here, it is preferable that at least the inner pipe and the block body are made of synthetic resin. 
     It is possible to produce the inner pipe and the block at a low cost by using synthetic resin. 
     It is preferable that the through hole block means includes a groove having at least a spiral portion, which is formed on an inner surface of the outer pipe or an outer surface of the inner pipe and a projecting part movable in the groove, which is formed on an outer surface of the inner pipe or an inner surface of the outer pipe and the through hole in the inner pipe is formed at away from the central axis of the inner pipe, and when the outer pipe moves relative to the inner pipe, the inner pipe and the outer pipe relatively rotate by engagement of the groove and the projecting part, whereby the through hole of the inner pipe moves from a position where the inner needle is inserted to a position where the inner needle is blocked whereby insertion of the inner needle is blocked. 
     As described above, when the outer pipe moves relative to the inner pipe, the inner pipe and the outer pipe relatively rotate, the through hole of the inner needle moves from a position where the inner needle is inserted to a position where the inner needle is blocked and insertion of the inner needle is blocked. Consequently, this motion of the cylinder body can prevent the inner needle accommodated inside the above-mentioned inner needle hub or inside the inner needle hub from protruding outside. 
     In addition, since the restoring force is not used in this invention in contrast to the conventional needle block member, even if the puncture device is not used for a long time for reasons of long storage, plastic deformation does not occur and it is possible to prevent the inner needle from protruding outside. 
     Further, since a size of a through hole of the inner pipe is formed slightly larger than an inner needle diameter, it is possible to reduce the sliding resistance at the pulling operation of the inner needle and the pulling is easy for the user. 
     Further, it is preferable that the inner pipe is provided with a standing piece which rises with being forced out by the inner needle in the through hole and engages with the outer pipe, and when the inner needle pulled out passing through the standing piece, the standing piece is disengaged with the outer pipe, and the disengaged standing piece blocks insertion of the inner needle. 
     Furthermore, it is preferable that the outer pipe and the inner pipe are made of synthetic resin. 
     It is preferable that the through hole block means includes a projection formed on an inner surface of the outer pipe, a block body having a through hole for insertion of the inner needle, a space part formed in the inner pipe, in which the block body movably accommodated, and when the outer pipe moves relative to the inner pipe, the block body is moved in the space part by the projection formed on an inner surface of the outer pipe whereby the insertion of the inner needle is blocked. 
     According to the above mentioned through hole block means, the block body is moved in the space part by the projection formed on an inner surface of the outer pipe in accordance with the outer pipe moving relative to the inner pipe and the insertion of the inner needle is blocked. Therefore, it is possible to prevent the inner needle from protruding outside. 
     In addition, since restoring force is not used as opposed to a conventional needle block member, incase the puncture device is not used for a longtime for reasons of long storage, plastic deformation does not occur and it is possible to block the communication state of the through hole of the inner pipe reliably. 
     Further, since a size of a through hole of the block body is formed slightly larger than an inner needle diameter, it is possible to reduce the sliding resistance at the pulling operation of the inner needle and the pulling is easy for the user. 
     It is preferable that a part to be engaged formed on the block body is engaged to an engaging part formed in the inner pipe so that movement of the block body is prevented and a state that the insertion of the inner needle is blocked is kept. 
     As described above, a block body movement prevention means is formed so that the state that the insertion of the inner needle is blocked is kept and it is possible to block the insertion of the inner needle more reliably. 
     In addition, it is preferable that the outer pipe, the inner pipe, and the block body are made of synthetic resin. If the outer pipe, the inner pipe, and the block body are made of synthetic resin such as polyethylene, it is possible to produce them at a low cost. 
     Effects of the Invention 
     According to the present invention, a puncture device can be obtained in which an inner needle is accommodated in an inner needle hub and the like by pulling operation of an inner needle, and a through hole for inserting the inner needle is blocked without using restoring force, and which prevents the inner needle from protruding outside. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing an appearance of a puncture device in accordance with a first preferred embodiment of the present invention. 
         FIG. 2  is a perspective view showing a situation where a protector of the puncture device in  FIG. 1  is removed. 
         FIG. 3  is an exploded perspective view except the protector of the puncture device in  FIG. 1 . 
         FIG. 4  is a longitudinal sectional view showing the puncture device shown in  FIG. 1 . 
         FIG. 5  is a longitudinal sectional view showing the puncture device of  FIG. 1 , and is a longitudinal sectional view whose section is different from that of the longitudinal sectional view of  FIG. 4  by 90 degrees in a circumferential direction. 
         FIG. 6A  is a perspective view showing an outer pipe. 
         FIG. 6B  is a longitudinal sectional view showing the outer pipe. 
         FIG. 6C  is a longitudinal sectional view showing the outer pipe whose section is different from that of the longitudinal sectional view of  FIG. 6B  by 90 degrees in a circumferential direction. 
         FIG. 7  is the perspective view showing an inner pipe. 
         FIG. 8A  is a plan view showing the inner pipe in an unfolded configuration. 
         FIG. 8B  is a sectional view along the line A-A of  FIG. 8A  showing the inner pipe in the unfolded configuration. 
         FIG. 8C  is a rear view of  FIG. 8A  showing the inner pipe in the unfolded configuration. 
         FIG. 9  is a perspective view showing a block body. 
         FIG. 10A  is a longitudinal sectional view showing a situation where the expansion of the inner needle hub is completed, for explaining the procedure for use of the puncture device shown in  FIG. 1 . 
         FIG. 10B  is a longitudinal sectional view whose section is different from that of the longitudinal sectional view of  FIG. 10A  by 90 degrees in a circumferential direction, showing the situation where the expansion of the inner needle hub is completed, for explaining the procedure for use of the puncture device shown in  FIG. 1 . 
         FIG. 11A  is a longitudinal sectional view showing a situation where the outer needle is released (unlocked), for explaining the procedure for use of the puncture device shown in  FIG. 1 . 
         FIG. 11B  is a longitudinal sectional view whose section is different from that of the longitudinal sectional view of  FIG. 11A  by 90 degrees in a circumferential direction, showing the situation where the outer needle is released (unlocked), for explaining the procedure for use of the puncture device shown in  FIG. 1 . 
         FIG. 12  is a perspective view showing an appearance of a puncture device in accordance with a second preferred embodiment in a situation where a protector is removed. 
         FIG. 13A  is a longitudinal sectional view showing a puncture device in accordance with the second preferred embodiment of the present invention. 
         FIG. 13B  is a longitudinal sectional view whose section is different from that of the longitudinal sectional view of  FIG. 13A  by 90 degrees in a circumferential direction, showing the puncture device in accordance with the second preferred embodiment of the present invention. 
         FIG. 14A  is a perspective view showing the outer pipe in  FIGS. 13A and 13B . 
         FIG. 14B  is a longitudinal sectional view showing the outer pipe in  FIGS. 13A and 13B . 
         FIG. 15A  is a perspective view showing the inner pipe in  FIGS. 13A and 13B . 
         FIG. 15B  is a plan view showing the inner pipe in  FIGS. 13A and 13B . 
         FIG. 15C  is a longitudinal sectional view showing the inner pipe in  FIGS. 13A and 13B . 
         FIG. 16A  is a longitudinal sectional view showing a situation where the expansion of the inner needle hub is completed, for explaining the procedure which uses the puncture device in accordance with the second preferred embodiment of the present invention. 
         FIG. 16B  is a longitudinal sectional view whose section is different from that of the longitudinal sectional view of  FIG. 16A  by 90 degrees in a circumferential direction, showing the situation where the expansion of the inner needle hub is completed, for explaining the procedure which uses the puncture device in accordance with the second preferred embodiment of the present invention. 
         FIG. 17A  is a longitudinal sectional view showing a situation where the expansion of a relay pipe is completed, for explaining the procedure for use of the puncture device in accordance with the second preferred embodiment of the present invention. 
         FIG. 17B  is a longitudinal sectional view whose section is different from that of the longitudinal sectional view of  FIG. 17A  by 90 degrees in a circumferential direction, showing the situation where the expansion of a relay pipe is completed, for explaining the procedure for use of the puncture device in accordance with the second preferred embodiment of the present invention. 
         FIG. 18A  is a longitudinal sectional view showing a situation where the inner pipe is passing through a straight portion of the outer pipe, for explaining the procedure which uses the puncture device in accordance with the second preferred embodiment of the present invention. 
         FIG. 18B  is a longitudinal sectional view whose section is different from that of the longitudinal sectional view of  FIG. 18A  by 90 degrees in a circumferential direction, showing the situation where the inner pipe is passing through a straight portion of the outer pipe, for explaining the procedure which uses the puncture device in accordance with the second preferred embodiment of the present invention. 
         FIG. 19A  is a longitudinal sectional view showing a situation where the inner pipe is passing through a spiral portion of the outer pipe, for explaining the procedure for use of the puncture device in accordance with the second preferred embodiment of the present invention. 
         FIG. 19B  is a longitudinal sectional view whose section is different from that of the longitudinal sectional view of  FIG. 19A  by 90 degrees in a circumferential direction, showing the situation where the inner pipe is passing through the spiral portion of the outer pipe, for explaining the procedure for use of the puncture device in accordance with the second preferred embodiment of the present invention. 
         FIG. 20  is a sectional view showing a situation where the outer needle is released (unlocked), for explaining the procedure for use of the puncture device in accordance with the second preferred embodiment of the present invention. 
         FIG. 21  is an exploded perspective view of the puncture device (except the protector) in accordance with a third preferred embodiment of the present invention. 
         FIG. 22A  is a perspective view showing the outer pipe in  FIG. 21 . 
         FIG. 22B  is a longitudinal sectional view showing the outer pipe in  FIG. 21 . 
         FIG. 22C  is a longitudinal sectional view showing the outer pipe in  FIG. 21  whose section is different from that of the longitudinal sectional view of  FIG. 22B  by 90 degrees in a circumferential direction. 
         FIG. 23A  is a perspective view showing the inner pipe in  FIG. 21 . 
         FIG. 23B  is a perspective view from the bottom side of  FIG. 23A  showing the inner pipe in  FIG. 21 . 
         FIG. 24A  is a plan view showing the inner pipe in  FIG. 21 . 
         FIG. 24B  is a bottom view showing the inner pipe in  FIG. 21 . 
         FIG. 25A  is a sectional view along the line A-A of  FIG. 24A . 
         FIG. 25B  is a sectional view along the line B-B of FIG.  24 A. 
         FIG. 26A  is a perspective view showing the block body in  FIG. 21 . 
         FIG. 26B  is a side view showing the block body in  FIG. 21 . 
         FIG. 26C  is a front view showing the block body in  FIG. 21 . 
         FIG. 27A  is a longitudinal sectional view showing the puncture device in  FIG. 21 . 
         FIG. 27B  is a longitudinal sectional view showing the puncture device in  FIG. 21  whose section is different from that of the longitudinal sectional view of  FIG. 27A  by 90 degrees in a circumferential direction. 
         FIG. 28A  is a longitudinal sectional view showing a situation where the expansion of the inner needle hub is completed, for explaining the procedure for use of the puncture device shown in  FIG. 21 . 
         FIG. 28B  is a longitudinal sectional view whose section is different from that of the longitudinal sectional view of  FIG. 28A  by 90 degrees in a circumferential direction, showing the situation where the expansion of the inner needle hub is completed, for explaining the procedure for use of the puncture device shown in  FIG. 21 . 
         FIG. 29A  is a longitudinal sectional view showing a situation where the outer needle is released (unlocked), for explaining the procedure for use of the puncture device shown in  FIG. 21 . 
         FIG. 29B  is a longitudinal sectional view whose section is different from that of the longitudinal sectional view of  FIG. 29A  by 90 degrees in a circumferential direction, showing the situation where the outer needle is released (unlocked), for explaining the procedure for use of the puncture device shown in  FIG. 21 . 
         FIG. 29C  is a sectional view along the line A-A of  FIG. 29A  showing the situation where the outer needle is released (unlocked), for explaining the procedure for use of the puncture device shown in  FIG. 21 . 
         FIG. 30A  is a perspective view showing an inner pipe of the puncture device in accordance with a fourth preferred embodiment of the present invention. 
         FIG. 30B  is a plan view showing the inner pipe of the puncture device in accordance with a fourth preferred embodiment of the present invention. 
         FIG. 30C  is a longitudinal sectional view showing the inner pipe of the puncture device in accordance with a fourth preferred embodiment of the present invention. 
         FIG. 31A  is a plan view showing the inner pipe in an unfolded configuration. 
         FIG. 31B  is a sectional view along the line A-A of  FIG. 31A  showing the inner pipe in the unfolded configuration. 
         FIG. 31C  is a bottom view of  FIG. 31A  showing the inner pipe in the unfolded configuration. 
         FIG. 32  is a perspective view of a block body of the puncture device in accordance with the fourth preferred embodiment of the present invention. 
         FIG. 33  is a plane view of the block body shown in  FIG. 32 . 
         FIG. 34  is a longitudinal sectional view of the block body shown in  FIG. 32 . 
         FIG. 35A  is a longitudinal sectional view showing the puncture device in accordance with a fourth preferred embodiment of the present invention. 
         FIG. 35B  is a longitudinal sectional view whose section is different from that of the longitudinal sectional view of  FIG. 35A  by 90 degrees in a circumferential direction, showing the puncture device in accordance with a fourth preferred embodiment of the present invention. 
         FIG. 36A  is a longitudinal sectional view showing a situation where the expansion of the inner needle hub is completed, for explaining the procedure which uses the puncture device shown in  FIGS. 35A and 35B . 
         FIG. 36B  is a longitudinal sectional view whose section is different from that of the longitudinal sectional view of  FIG. 36A  by 90 degrees in a circumferential direction, showing the situation where the expansion of the inner needle hub is completed, for explaining the procedure which uses the puncture device shown in  FIGS. 35A and 35B . 
         FIG. 37A  is a longitudinal sectional view showing a situation where the outer needle is released (unlocked), for explaining the procedure which uses the puncture device shown in  FIGS. 35A and 35B . 
         FIG. 37B  is a longitudinal sectional view whose section is different from that of the longitudinal sectional view of  FIG. 37A  by 90 degrees in a circumferential direction, showing a situation where the outer needle is released (unlocked), for explaining the procedure which uses the puncture device shown in  FIGS. 35A and 35B . 
     
    
    
     MODE FOR CARRYING OUT THE INVENTION 
     Hereinafter, a puncture device in accordance with a first preferred embodiment of the present invention will be described with reference to  FIGS. 1 to 11 . 
     As shown in  FIGS. 1 and 2 , a puncture device  1  is provided with an outer needle  21 , an inner needle  3  whose tip portion (left-hand side) is inserted in the above-mentioned outer needle  21 , a cylindrical syringe  4  for retaining an end portion (base portion) of the above-mentioned inner needle  3 , and a protector  5  which covers the above-mentioned outer needle  21  and the above-mentioned inner needle  3 . Further, in the above-mentioned puncture device  1 , all the components except the above-mentioned inner needle  3  are made of resin. It should be noted that the above-mentioned outer needle  21  and the above-mentioned inner needle  3  cannot be seen in  FIG. 1 , since they are covered with the above-mentioned protector  5 . 
     Further, as shown in  FIGS. 2 and 3 , the above-mentioned catheter  2  has the outer needle  21  formed of a flexible hollow pipe and the outer needle hub  22  for retaining the base portion of the outer needle  21 . 
     As shown in  FIGS. 2 to 5 , the above-mentioned syringe  4  is provided with a cylindrical inner needle hub  41  and a plug  42  which is press fitted into and attached to a base portion (right-hand side) of the above-mentioned inner needle hub  41  and has a substantially cylindrical needle retaining part  42   a  by which the base portion of the above-mentioned inner needle  3  is retained. 
     Further, the above-mentioned syringe  4  is provided with an outer pipe  6  fitted inside the above-mentioned inner needle hub  41  so as to be freely moveable, and an inner pipe  7  having four arms  71 A for gripping the above-mentioned outer needle hub  22  and fitted inside the above-mentioned outer pipe  6  so as to be freely moveable. 
     It should be noted that although this preferred embodiment shows a situation where the above-mentioned four arms  71 A are formed at the above-mentioned inner pipe  7 , the outer needle hub  22  may be retained by two or more arms. 
     As shown in  FIGS. 6A, 6B, and 6C , the above-mentioned outer pipe  6  is provided with a groove  61  formed along an axis of a shaft  64  of the above-mentioned outer pipe  6  (formed along a direction of back and forth movement of the inner pipe  7 ) and an arm opening/closing part  62  which accommodates the above-mentioned four arms  71 A, and cylindrically formed as a whole. 
     It should be noted that the above-mentioned four arms  71 A are arranged to be moveable guided by four guide grooves  62 A formed at upper and lower sides, and both lateral sides on the inner surface of the above-mentioned arm opening/closing part  62 . 
     As shown in  FIG. 4  and  FIG. 6C , the above-mentioned grooves  61  are axisymmetrically formed at two places, an upper part and a lower part in the periphery of the above-mentioned outer pipe  6 . 
     Further, as shown in  FIGS. 4 and 5 , when the above-mentioned inner pipe  7  is accommodated in the above-mentioned outer pipe  6 , the above-mentioned four arms  71 A are folded, and the above-mentioned arm opening/closing part  62  grasps the above-mentioned outer needle hub  22 . 
     On the other hand, when the above-mentioned inner pipe  7  is pulled (advanced) from the above-mentioned outer pipe  6 , the restriction by the guide grooves  62 A (arm opening/closing part  62 ) is released as shown in  FIGS. 11A and 11B  so that the above-mentioned four arms  71 A are unfolded by elasticity of the arm  71 A itself to release the above-mentioned outer needle hub  22 . 
     As described above, gripping means for gripping the above-mentioned outer needle hub  22  is constituted by the above-mentioned four arms  71 A and the above-mentioned arm opening/closing part  62 . In a situation where the above-mentioned four arms  71 A are retracted into the arm opening/closing part  62 , the outer needle hub  22  is grasped as shown in  FIGS. 4 and 5 . In a situation where the above-mentioned four arms  71 A are advanced from the arm opening/closing part  62 , the outer needle hub  22  is released as shown in  FIGS. 11A and 11B . 
     In particular, the above-mentioned four arms  71 A are formed to have an unfolded shape with respect to the periphery of the inner pipe  7  in advance as shown in  FIG. 3 . 
     Further, in the case where the arms  71 A of the above-mentioned inner pipe  7  are inserted (accommodated) in the guide grooves  62 A (see  FIG. 6A ) of the above-mentioned outer pipe  6 , the above-mentioned four arms  71 A are folded by the above-mentioned arm opening/closing part  62 . That is to say, the above-mentioned arm opening/closing part  62  folds the above-mentioned four arms  71 A so as to cause the above-mentioned four arms  71 A to grasp the above-mentioned outer needle hub  22 . 
     Furthermore, as the above-mentioned inner pipe  7  is pulled (advanced) from the above-mentioned outer pipe  6 , the above-mentioned four arms  71 A are pulled out of the above-mentioned arm opening/closing part  62  and return to the originally unfolded state as shown in  FIGS. 11A and 11B . That is to say, the above-mentioned arm opening/closing part  62  causes the above-mentioned four arms  71 A to be in the open state, and the above-mentioned four arms  71 A allows the above-mentioned catheter  2  to be released. 
     As shown in  FIG. 7 , the above-mentioned inner pipe  7  has a head part  71  provided with the above-mentioned four arms  71 A, a shaft  72  having a diameter smaller than that of the above-mentioned head part  71 , and a through hole  73  which penetrates the centers of the above-mentioned head part  71  and the above-mentioned shaft  72 , and through which the above-mentioned inner needle  3  is inserted, thus being cylindrically formed as a whole. 
     The above-mentioned shaft  72  is provided with a projection  72 A which is moveably accommodated in the above-mentioned groove  61  of the above-mentioned outer pipe  6 , and a standing piece  72 B which is pushed out to stand by the inner needle  3  in the above-mentioned through hole  73  and engaged with the above-mentioned groove  61 . 
     In addition, a diameter of a through hole  73  is formed slightly larger than a diameter of the inner needle  3  so that sliding resistance at pulling operation of the inner needle  3  is reduced. 
     The above-mentioned projections  72 A are formed axisymmetrically at two places, an upper surface and an under surface of the above-mentioned shaft  72 , so as to respectively correspond to the above-mentioned grooves  61  (see  FIG. 4 ). Further, the above-mentioned groove  61  and the above-mentioned projection  72 A restrict the back and forth movement of the above-mentioned inner pipe  7  with respect to the above-mentioned outer pipe  6  (back and forth movement of the above-mentioned outer pipe  6  with respect to the inner pipe  7 ). 
     It should be noted that when the above-mentioned inner pipe  7  is advanced relatively to the above-mentioned outer pipe  6 , the above-mentioned projection  72 A is arranged to be engaged by an end portion  61   a  of the groove  61 , so as not to separate the above-mentioned outer pipe  6  from the inner pipe  7 . 
     Here, as shown in  FIGS. 8A, 8B and 8C , the above-mentioned inner pipe  7  is a component in which the lower part  7 A (left-hand side) provided with the above-mentioned standing piece  72 B and the upper part  7 B (right-hand side) which are on opposite sides of a central line  1  are integrally formed. It is formed by folding the above-mentioned lower part  7 A and the above-mentioned upper part  7 B along a fold line (central line  1 ). 
     Further, grooves  73 A and  73 B whose cross sections are in the shape of a semicircle are formed along the axial direction of the above-mentioned inner pipe  7  in the centers of the above-mentioned lower part  7 A and the above-mentioned upper part  7 B, respectively. When the above-mentioned lower part  7 A and the above-mentioned upper part  7 B are folded, these grooves  73 A and  73 B form one through hole  73 . 
     Furthermore, as shown in  FIG. 4 , as the above-mentioned inner needle  3  is inserted (accommodated) in the above-mentioned through hole  73 , the above-mentioned standing piece is pushed out to stand up by the periphery of the above-mentioned inner needle  3  and engages with an end portion of the above-mentioned groove  61 . 
     Here, the above-mentioned standing piece  72 B engages with the end portion on the above-mentioned catheter  2  side of the above-mentioned groove  61 , and therefore sandwiches the above-mentioned outer pipe  6  in conjunction with the above-mentioned head part  71  of the above-mentioned inner pipe  7 , thus being engaged by the above-mentioned outer pipe  6 . 
     In other words, in the case where the inner needle  3  is in the above-mentioned through hole  73 , the above-mentioned inner needle  3  allows the above-mentioned standing piece  72 B to stand up, the outer pipe  6  and the inner pipe  7  are unified, and the above-mentioned outer pipe  6  is inhibited from being pulled out of the above-mentioned inner pipe  7 . 
     Further, when the above-mentioned inner needle  3  is pulled from the inside of the above-mentioned through hole  73  and the above-mentioned standing piece  72 B is not pushed out by the inner needle  3 , the standing piece  72 B pivots in a direction of blocking the above-mentioned through hole  73  so as to be accommodated within (returns to) the above-mentioned inner pipe  7  and is disengaged from the above-mentioned groove  61 . 
     In other words, in the case where the inner needle  3  is not in the above-mentioned through hole  73 , the above-mentioned standing piece  72 B is not engaged by the above-mentioned outer pipe  6 , so that the outer pipe  6  and the inner pipe  7  may be separable and the above-mentioned inner pipe  7  can be pulled from the above-mentioned outer pipe  6 . 
     In case the standing piece  72 B has restoring force (elastic force), the standing piece  72 B pivots in a direction of blocking the above-mentioned through hole  73  by the restoring force (elastic force) and blocks the above-mentioned through hole  73 . 
     On the other hand, even if the standing piece  72 B does not have restoring force (elastic force) or restoring force (elastic force) of the standing piece  72 B is weak whereby the standing piece  72 B does not pivot in a direction of blocking the above-mentioned through hole  73  by the restoring force (elastic force), when the inner pipe  7  is separated from the outer pipe  6 , the standing piece  72 B is raised by the end portion  61   a  of the groove  61 , pivots in a direction of blocking the above-mentioned through hole  73 , and blocks the above-mentioned through hole  73 . 
     As described above, the standing piece  72 B is raised by the end portion  61   a  of the groove  61 , pivots in a direction of blocking the above-mentioned through hole  73  (the direction of the arrow shown in  FIGS. 4 and 10A and 10B ), and blocks the above-mentioned through hole  73 . Therefore in case the puncture device is not used for a long time because of long storage for example, and the standing piece  72 B have lost restoring force (elastic force), it is possible to block the above-mentioned through hole  73  reliably. 
     In addition, when a contact pressure between the standing piece  72 B and the inner needle  3  is set weak (restoring force (elastic force) of the standing piece  72 B is set weak), the standing piece  72 B is raised by the end portion  61   a  of the groove  61 , pivots in a direction of blocking the above-mentioned through hole  73 , and blocks the above-mentioned through hole  73  as described above. Therefore it is possible to reduce sliding resistance at the pulling operation of the inner needle. 
     Further, as shown in  FIGS. 4, 5, and 8A, 8B and 8C , a cylindrical space  74  which leads to the through hole  73  for insertion of the inner needle  3  is formed in a head part  71  of the inner pipe  7 . 
     In addition, as shown in  FIG. 9 , a cylindrical block body  75  which is provided with a through hole  75   a  (the through hole  75   a  constitutes at least a part of the through hole  73 ) for insertion of the inner needle  3  is accommodated in the space  74 . The space  74  is formed larger than an outer diameter of the block body  75  so that the block body can move in the space  74 . 
     The space  74  and the block body  75  constitute a through hole block means for blocking communicated condition of the through hole  73 , which makes at least part of the through hole  73  move from a position where the inner needle  3  is inserted to a position where the inner needle  3  is blocked. 
     As described above, since the block body  75  is placed in the space  74  in the head part  71  of the inner pipe  7 , once a tip of the inner needle  3  is pulled out through the through hole  75   a  of the block body  75 , the block body  75  falls in the space  74  by the block body&#39;s own weight. This will cause the through hole  75   a  to be placed elsewhere than on the line that extends from the through hole  73  and a communication state of the through hole  73  to be blocked. 
     In addition, since a diameter of the through hole  75   a  is formed slightly larger than that of the inner needle, it is possible to reduce the sliding resistance at the pulling operation of the inner needle  3 . 
     Further, as shown in  FIGS. 4 and 5 , it is arranged that the relay pipe  8  which extends the outer pipe  6  is provided between the above-mentioned inner needle hub  41  and the outer pipe  6 . The relay pipe  8  is not necessary, and as shown in  FIG. 3 , the relay pipe  8  may not be used. 
     For example, flexibility is given to the relay pipe  8  by a soft synthetic resin material for forming the relay pipe  8 , even if a direction to pull the inner needle hub  41  is an inclined direction (which is not on an extension of the inner needle  3 ) and bending force is applied to the relay pipe  8 , it is possible to prevent the relay pipe  8  from being damaged by buckling etc. 
     This relay pipe  8 , formed in the shape of a cylinder, has an outer diameter allowing itself to be accommodated inside the above-mentioned inner needle hub  41 , and has an inner diameter allowing the outer pipe  6  to be accommodated in itself. It is arranged that an engaging portion  8   a  is formed at one end of this relay pipe  8  and engages with a projection formed at the end portion  63  of the outer pipe  6 . Further, it is arranged that a projection  8   b  is formed at the other end of the relay pipe  8  and engaged with an engaging portion formed at the end portion  41   a  of the inner needle hub  41 . 
     In the case where the relay pipe  8  is not used, it is arranged that an engaging portion formed at end portions  41   a  of the above-mentioned inner needle hub  41  fits an engaging portion formed at end portions  63  of the above-mentioned outer pipe  6  so as not to be separated (spaced apart) from each other. 
     Next, a case where such a puncture device  1  is used will be described. It should be noted that below explanation has been described with reference to the case where restoring force (elastic force) of a standing piece  72 B is weak and the standing piece  72 B is not in pressure contact with an inner needle. 
     Firstly, the protector  5  is removed from the puncture device  1  shown in  FIG. 1 , and the catheter  2  and the inner needle  3  are exposed as shown in  FIGS. 4 and 5 . Further, the above-mentioned outer needle  21  and the above-mentioned inner needle  3  are punctured to a blood vessel (patient&#39;s body  110 ). 
     Then, in order to indwell the above-mentioned outer needle  21 , the above-mentioned inner needle hub  41  is moved along the axial direction shown by the arrows in  FIGS. 4 and 5  in a direction away from the above-mentioned outer needle  21  (pull-out operation is performed). The above-mentioned syringe  4  is expanded by pulling out this inner needle hub  41 . In particular, in a situation where the above-mentioned outer needle  21  is indwelled, when the above-mentioned inner needle hub  41  is moved along the axial direction away from the above-mentioned outer needle  21 , the above-mentioned inner needle hub  41  moves along the axial direction, and the above-mentioned syringe  4  is expanded as a whole. At this time, the outer needle hub  22  is retained by the inner pipe  7 , and the standing piece  72 B unifies the inner pipe  7  with the outer pipe  6 . 
     Therefore, as the inner needle hub  41  for retaining the rear end portion (base portion) of the inner needle  3  is moved along the axial direction, the inner needle  3  similarly moves along the axial direction. Further, the inner needle  3  is pulled from the outer needle  21 , and the thus pulled inner needle  3  is covered with the inner pipe  7 , the outer pipe  6 , and the inner needle hub  41  (see  FIGS. 10A and 10B ). 
     In the pull-out operation of the inner needle hub, once a tip portion of the inner needle  3  passes through a through hole  75   a  of a block body  75  and the inner needle is pulled out from the block body  75 , the block body moves down in the space  74  by the block body&#39;s own weight. This will cause the through hole  75   a  to be placed elsewhere than on the line that extends from the through hole  73  and a communication state of the through hole  73  to be blocked (see  FIGS. 10A and 10B ). 
     Therefore, after the through hole  73  is blocked by the block body  75 , even if the force of moving the inner needle hub  41  to the catheter  2  side is applied, the block body  75  inhibits the movement of the inner needle  3  and the inner needle  3  does not return into the outer needle  21  gain. 
     Further, the above-mentioned inner needle hub  41  is moved along the axial direction away from the above-mentioned outer needle  21 . As shown in  FIGS. 10A and 10B , after the tip of the inner needle  3  passes over the standing piece  72 B, the standing piece  72 B is free from a force by a side surface of the inner needle  3 . At this time, the standing piece  72 B does not pivot in a direction of blocking the above-mentioned through hole  73  because of weak restoring force (elastic force) of the standing piece  72 B so, a locking state between the standing piece  72 B and the outer pipe  6  is maintained. 
     Then, the relay pipe  8  is pulled out of the inner needle hub  41 , and a fitting portion  8   b  of the relay pipe  8  fits a fitting portion formed at the end portion  41   a  of the inner needle hub to be full extension. Then, the standing piece  72 B is raised up by an end portion  61   a  of a groove  61  of the outer pipe  6 . The raised standing piece  72 B pivots in a direction of blocking the above-mentioned through hole  73  (the direction of the arrow shown in  FIGS. 10A and 10B ) and blocks the through hole  73  with disengaging the above-mentioned outer pipe  6 . 
     As a result, the outer pipe  6  and the inner pipe  7  become separable, and it follows that as the above-mentioned inner needle hub  41  moves, the above-mentioned outer pipe  6  moves along the axial direction. 
     Since the above-mentioned groove  61  is guided by the above-mentioned projection  72 A, the above-mentioned inner pipe  7  is pulled from the above-mentioned outer pipe  6 , whilst being guided by the projection  72 A of the above-mentioned inner pipe  7 . 
     In addition, after the standing piece  72 B is raised up, even if the force of moving the inner needle hub  41  to the catheter  2  side is applied, the above-mentioned standing piece  72 B inhibits the movement of the inner needle  3 , which does not return into the outer needle  21  again. 
     As described above, after the standing piece  72 B is raised up, the above-mentioned standing piece  72 B inhibits the movement of the inner needle  3 , and moreover, the block body  75  inhibits the movement of the inner needle  3 . Therefore, it is possible to inhibit surely the inner needle return into the outer needle  21  again. 
     Further, when the above-mentioned inner needle hub  41  is moved away from the above-mentioned outer needle  21  along the axial direction, the above-mentioned outer pipe  6  is moved, and the above-mentioned inner pipe  7  is pulled from the above-mentioned outer pipe  6 , then the above-mentioned four arms  71 A are opened as shown in  FIGS. 11A and 11B , and the retention of the outer needle hub  22  by the above-mentioned four arms  71 A is released. 
     That is to say, by separating the above-mentioned inner needle hub  41  from the above-mentioned outer needle  21  along the axial direction and expanding the above-mentioned syringe  4 , the above-mentioned inner needle  3  pulled from the above-mentioned catheter  2  is accommodated inside the above-mentioned outer pipe  6 , and the inner needle hub  41 , then the outer needle hub  22  is released from the state where the outer needle hub  22  is retained by the above-mentioned four arms  71 A and arm opening/closing parts  62 . 
     Accordingly, whilst the above-mentioned catheter  2  (outer needle  21 ) indwelling in a blood vessel, the above-mentioned inner needle  3  is pulled from the above-mentioned outer needle  21  and accommodated inside the above-mentioned inner needle hub  4 , and the above-mentioned outer needle hub  22  is removed from the above-mentioned syringe  4 . 
     Thus, only by pulling the above-mentioned inner needle  3  from the above-mentioned outer needle  21 , the above-mentioned puncture device  1  can accommodate the above-mentioned inner needle  3  in the above-mentioned inner needle hub  41 , and the above-mentioned outer needle hub  22  can be removed from the above-mentioned inner needle hub  4 . 
     In addition, although the above mentioned use of the puncture device has been described with reference to the case where the restoring force (elastic force) of the standing piece  72 B is weak and the standing piece  72 B is not in pressure contact with an inner needle, the restoring force (elastic force) may be applied to the standing piece  72 B without increasing a slide resistance at the pulling operation of the inner needle  3  too far. 
     It should be noted that although the first preferred embodiment has been described with reference to the case where the block body  75  and the space  74  are described as a cylindrical shape, the present invention is not particularly limited to this structure. For example, the block body  75  may be formed in a globe shape and the space  74  may be formed in a rectangular shape. It is only needed that the block body  75  is formed in a movable state in the space  74 . 
     Next, a second preferred embodiment will be described with reference to  FIGS. 12 to 20 . A through hole block means in this embodiment is arranged that the inner pipe and the outer pipe relatively rotate when the outer pipe moves relative to the inner pipe, and has a characteristic feature that the through hole of the inner needle moves from a position where the inner needle is inserted to a position where the inner needle is blocked and insertion of the inner needle is blocked. 
     As shown in  FIGS. 12 and 13A and 13B , a puncture device  100  is provided with an outer needle  102 , an inner needle  103  whose tip portion (left-hand side) is inserted in the above-mentioned outer needle  102 , a cylindrical syringe  104  for retaining an end portion (base portion) of the above-mentioned inner needle  103 , and a protector (not shown in the figures) which covers the above-mentioned outer needle  102  and the above-mentioned inner needle  103 . Further, in the above-mentioned puncture device  100 , all the components except the above-mentioned inner needle  103  are made of resin. 
     Further, as shown in  FIGS. 12 and 13A and 13B , the above-mentioned catheter  101  has the outer needle  102  formed of a flexible hollow pipe and the outer needle hub  102   a  for retaining the base portion of the outer needle  102 . 
     A position of the outer needle  102  that is arranged in the outer needle hub  102   a  is placed at a position deviated from the center position O of the outer needle hub  102   a  as shown in  FIGS. 12 and 13B . 
     As shown in  FIG. 13B , the above-mentioned syringe  104  is provided with a cylindrical inner needle hub  105  and a plug  106  which is press fitted into and attached to a base portion (right-hand side) of the above-mentioned inner needle hub  105  and has a substantially cylindrical needle retaining part  106   a  by which the base portion of the above-mentioned inner needle  103  is retained. 
     Further, the above-mentioned syringe  104  is provided with an outer pipe  107  fitted inside the above-mentioned inner needle hub  105  so as to be moveable to and fro, and an inner pipe  108  having two arms  108 A for gripping the above-mentioned outer needle hub and fitted inside the above-mentioned outer pipe  106  so as to be freely moveable. 
     As shown in  FIGS. 14A and 14B , the above-mentioned outer pipe  107  is provided with a groove  107   b  formed along an axis of a shaft  107   a  of the above-mentioned outer pipe  107  (formed along a direction of back and forth movement of the inner pipe  7 ) and an arm opening/closing part  107   c  which accommodates the above-mentioned two arms  108 A, and cylindrically formed as a whole. 
     The center position of the shaft  107   a  is arranged at a position L deviated from the center line of the arm opening/closing part  107   c  as shown in  FIG. 14B . That is to say, the shaft  107   a  is arranged at a downward position in the arm opening/closing part  107   c  and the center line of the arm opening/closing part  107   c  does not coincide with an axis of a shaft  107   a.    
     As shown in  FIG. 14B , the above-mentioned grooves  107   b  are axisymmetrically formed at two places, an upper part and a lower part in the periphery of the above-mentioned outer pipe  107 . 
     Further, as shown in  FIG. 13A , when the above-mentioned inner pipe  108  is accommodated in the above-mentioned outer pipe  107 , the above-mentioned two arms  107 A are folded, and the above-mentioned arm opening/closing part  107   c  grasps the above-mentioned outer needle hub  102   a.    
     On the other hand, when the above-mentioned inner pipe  108  is pulled (advanced) from the above-mentioned outer pipe  107 , the restriction by the arm opening/closing part  107   c  is released as shown in  FIG. 20  so that the arms  108 A are unfolded by elasticity of the arm  108 A itself to release the above-mentioned outer needle hub  102   a.    
     Grooves  107   d  for movably attaching projecting parts  108 F formed on an outer surface of the inner pipe  108  are formed on an inner periphery of the arm opening/closing part  107   c.    
     The grooves  107   d  are formed by arranging right and left sides in a pair. A linear portion  107   d   1  in which the groove is formed linearly is formed at a side of the shaft  107   a  and next to the linear portion  107   d   1 , a spiral portion  107   d   2  in which the groove is formed spirally is formed. 
     As shown in  FIGS. 15A, 15B, and 15C , the above-mentioned inner pipe  108  has a head part  108 B provided with the above-mentioned two arms  108 A, a shaft  108 C having a diameter smaller than that of the above-mentioned head part  108 B, and a through hole  108 D which penetrates the above-mentioned head part  108 B and the above-mentioned shaft  108 C, and through which the above-mentioned inner needle  3  is inserted. 
     As shown in  FIG. 15C , the shaft  108 C is arranged at a position deviated from the center line of the head part  108 B and the center line of the head part  108 B does not coincide with an axis of a shaft  108 C. 
     According to the above, the through hole  108 D formed on the inner pipe  108  is arranged at a position L which is away from (deviated from) the central axis of the inner pipe  108 . 
     It is arranged that, when the head part  108 B of the inner pipe  108  is accommodated in the arm opening/closing part  107   c  of the outer pipe  107 , the above-mentioned shaft  108 C is accommodated in the shaft  107   a  of the outer pipe  107 . 
     The above-mentioned shaft  108 C is provided with a standing piece  108 E which is pushed out to stand by the inner needle  103  in the above-mentioned through hole  108 D and engaged with the above-mentioned slit  107   b.    
     The standing piece  108 E is same with the standing piece  72 B in the first preferred embodiment, and will not be described further in detail. In addition, a diameter of the through hole  108 D is formed slightly larger than a diameter of the inner needle  3  so that sliding resistance at pulling operation of the inner needle  3  is reduced. 
     A pair of projecting part  108 F is formed on an outer surface of an edge portion at a shaft  108 C side of the head part  108 B. As described above, the pair of projecting part  108 F is formed axisymmetrically each other so that the projecting parts  108 F respectively corresponds to the above-mentioned grooves  107   d  (See  FIGS. 14A and 14B ). 
     The inner pipe  108  and the outer pipe  107  relatively rotate since the pair of projecting part  108 F moves along the grooves  107   d  when the inner pipe  108  moves relative to the outer pipe  107 . 
     According to the above, since the through hole  108 D formed on the inner pipe  108  is arranged at a position L which is away from the central axis of the inner pipe  108  and the through hole block means includes the grooves  107   d  which contain the spiral portion formed on the inner surface of the outer pipe  107  and projecting parts  108 F formed on the outer surface of the inner pipe  108 , which is movable in the grooves  107   d , the inner pipe  108  and the outer pipe  107  relatively rotate whereby it is possible to move the through hole  108 D formed on the inner pipe  108  from a position where the inner needle is inserted to a position where the inner needle is blocked. 
     In addition, after the pair of projecting part  108 F moves along the grooves  107   d  and the arms  108 A are unfolded, since the pair of projecting part  108 F is locked at end portion of the spiral portion  107   d   2  in the groove  107   d  on the outer pipe  107 , relative movement between the outer pipe  107  and the inner pipe  108  is regulated. That is to say, the outer pipe  107  and inner pipe  108  are configured so as not to separate from each other. 
     Further, as shown in  FIGS. 13A and 13B , it is arranged that the relay pipe  109  which extends the outer pipe  107  is provided between the above-mentioned inner needle hub  105  and the outer pipe  107 . Since the relay pipe  109  is used in the same way as the first embodiment, the relay pipe  109  will not be described further in detail. 
     Next, a case where such a puncture device  100  is used will be described. It should be noted that below explanation has been described with reference to the case where restoring force (elastic force) of a standing piece  102 E is weak and the standing piece  102 E is not in pressure contact with an inner needle  103  in the same way as the first embodiment. 
     Firstly, the protector is removed from the puncture device  100 , and the catheter  101  and the inner needle  103  are exposed as shown in  FIGS. 13A and 13B . Further, the above-mentioned outer needle  102  and the above-mentioned inner needle  103  are punctured to a blood vessel (patient&#39;s body). 
     Then, in order to indwell the above-mentioned outer needle  102 , the above-mentioned inner needle hub  105  is moved along the axial direction and in a direction shown by the arrows in  FIGS. 13A and 13B  away from the above-mentioned outer needle  102  (pull-out operation is performed). The above-mentioned syringe  104  is expanded by pulling out this inner needle hub  105 . 
     In particular, in a situation where the above-mentioned outer needle  102  is indwelled, when the above-mentioned inner needle hub  105  is moved along the axial direction away from the above-mentioned outer needle  102 , the above-mentioned inner needle hub  105  moves along the axial direction, and the above-mentioned syringe  4  is expanded as a whole. At this time, the outer needle hub  105  is retained by the inner pipe  108 , and the standing piece  108 E unifies the inner pipe  108  with the outer pipe  107 . 
     Therefore, as the inner needle hub  105  for retaining the rear end portion (base portion) of the inner needle  103  is moved along the axial direction, the inner needle  103  similarly moves along the axial direction. Further, the inner needle  103  is pulled from the outer needle  102 , and the thus pulled inner needle  3  is covered with the outer pipe  107 , and the inner needle hub  105  (see  FIGS. 16A and 16B ). 
     The above-mentioned inner needle hub  105  is further moved away from the above-mentioned outer needle  102  along the axial direction. Then, when the tip of the inner needle  103  passes by the standing piece  108 E as shown in  FIGS. 16A and 16B , the force is not applied to the standing piece  108 E from the side of the above-mentioned inner needle  103 . At this time, the standing piece  108 E does not pivot in a direction of blocking the above-mentioned through hole  108 D because of weak restoring force (elastic force) of the standing piece  108 E so, a locking state between the standing piece  108 E and the outer pipe  107  is maintained. 
     Then, as shown in  FIGS. 17A and 17B  the relay pipe  109  is pulled out of the inner needle hub  105 , and a fitting portion  109   a  of the relay pipe  109  fits a fitting portion formed at the end portion  105   a  of the inner needle hub to be full extension. Then, the standing piece  108 E is raised up by an end portion  107   b   1  of a groove  107   b  of the outer pipe  107 . The raised standing piece  108 E pivots in a direction of blocking the above-mentioned through hole  108 D and blocks the through hole  108 D with disengaging the above-mentioned outer pipe  107 . 
     As a result, the outer pipe  107  and the inner pipe  108  become separable, and it follows that as the above-mentioned inner needle hub  105  moves, the above-mentioned outer pipe  107  moves along the axial direction. 
     In addition, after the standing piece  108 E is raised up, as shown in  FIG. 18B , even if the force of moving the inner needle hub  105  to the catheter  101  side is applied, the above-mentioned standing piece  108 E inhibits the movement of the inner needle  103 , which does not return into the outer needle  102  again. 
     Once the locking state between the outer pipe  107  and the inner pipe is released, as shown in  FIGS. 18A and 18B , projections  108 F of the inner pipe  108  are guided by the linear portion  107   d   1  of the grooves  107   d  and move. 
     Subsequently, while projections  108 F of the inner pipe  108  are, as shown in  FIGS. 19A and 19B , guided by the spiral portion  107   d   2  of the grooves  107   d  and move, the outer pipe  107  rotates relative to the inner pipe. In actuality, the outer pipe  107  moves and rotates relative to the inner pipe  108  which grasps a fixed catheter  101 . 
     As a result, the through hole  108 D of the inner pipe is moved from a position where the inner needle is inserted to a position where the inner needle is blocked whereby a communication state of the through hole  108 D is blocked. 
     Furthermore, the outer pipe  107  is moved as the outer pipe  107  rotates relative to the inner pipe, and when the inner pipe  108  is moved away from the outer pipe  107 , as shown in  FIG. 20 , the above mentioned two arms  108 A are opened and the retention of the outer needle hub  102   a  by the above-mentioned arms  108 A is released. That is to say, by separating the above-mentioned inner needle hub  105  from the above-mentioned outer needle  102  along the axial direction and expanding the above-mentioned syringe  104 , the above-mentioned inner needle  103  pulled from the above-mentioned catheter  101  is accommodated inside the above-mentioned outer pipe  107 , and the inner needle hub  105  (sometimes the relay pipe  109 ), then the outer needle hub  102   a  is released from the state where the outer needle hub  102   a  is retained by the above-mentioned four arms  108 A and arm opening/closing parts  107   c.    
     Accordingly, whilst the above-mentioned catheter  101  (outer needle  102 ) indwelling in a blood vessel, the above-mentioned inner needle  103  is pulled from the above-mentioned outer needle  102  and accommodated inside the above-mentioned inner needle hub  105 , and the above-mentioned outer needle hub  102   a  is removed from the above-mentioned syringe  104 . 
     Thus, only by pulling the above-mentioned inner needle  103  from the above-mentioned outer needle  102 , the above-mentioned puncture device  100  can accommodate the above-mentioned inner needle  103  in the above-mentioned inner needle hub  105 , and the above-mentioned outer needle hub  102   a  can be removed from the above-mentioned inner needle hub  105 . 
     As described above, after the standing piece  108 E is raised up, even if the force of moving the inner needle hub  105  to the catheter  101  side is applied, the above-mentioned standing piece  108 E inhibits the movement of the inner needle  103 , which does not return into the outer needle  102  again. 
     Further, since the inner pipe  108  and the outer pipe  107  relatively rotate and the through hole  108 D formed on the inner pipe  108  moves from a position where the inner needle  103  is inserted to a position where the inner needle  103  is blocked, the through hole  108 D is blocked and the inner needle does not return into the outer needle  102  again. 
     Therefore, it is possible to surely prevent the inner needle returning into the outer needle  102  again because of a movement of the standing piece  108 E and the through hole  108 D of the inner pipe  108 . 
     In addition, although the above mentioned second embodiment has been described with reference to the case where the grooves  107   d  are formed on the inner surface of the outer pipe  107  and the projecting parts  108 F formed on the inner pipe  108 , grooves may be formed on the inner pipe and projecting parts may be formed on the outer pipe to the contrary. 
     Next, a third preferred embodiment will be described with reference to  FIGS. 21 to 29 . A through hole block means in this embodiment includes a block body on which a through hole for inserting the inner needle is formed, a space, formed in the inner pipe, in which the block body is movably accommodated, and is arranged that when a tip of a inner needle is pulled out through the block body and an inner pipe moves with respect to an outer pipe, the block body is moved in the space by a projection formed on an inner surface of the outer pipe and an insertion of the inner needle (a through hole for insertion of the inner needle) is blocked. It should be noted that the same parts or corresponding parts are designated by the same reference signs as in the first preferred embodiment, and will not be described further in detail. 
     A puncture device  200  of the third embodiment differs in an outer pipe  201 , an inner pipe  210 , and a block body  220  from the outer pipe, the inner pipe and the block body  7  of the first embodiment. 
     That is to say, as shown in  FIGS. 21 and 22A, 22B and 22C , a tongue-like part  202  surrounded by a U-shaped through hole  203  in planar view is formed at an arm opening/closing part  204  of the outer pipe  201 , which accommodates two arms  71 A. A projection  205  is formed at a tip portion of the tongue-like part  202 . In addition, the tongue-like part  202  is arranged that a base end portion of the tongue-like part  202  is located on a tip portion side of the outer pipe  201 . 
     The projection  205  formed at the tip portion of the tongue-like part  202  contacts to the block body and moves the block body upward when the inner pipe  210  moves in the outer pipe  201 . 
     Next, the inner pipe  210  is explained below. 
     As shown in  FIGS. 21, 23A, 23B, 24A, 24B, 25A and 25B , the inner pipe  210  has a rectangular head part  211  provided with the above-mentioned two arms  71 A, a shaft  72  having a diameter smaller than that of the above-mentioned head part  211 , and a through hole  73  which penetrates the centers of the above-mentioned head part  211  and the above-mentioned shaft  72 , and through which the above-mentioned inner needle  3  is inserted. 
     A concave space  212  which has a one open surface for connecting to a through hole  73  through which the above-mentioned inner needle  3  is inserted is formed on the head part  212  of the inner pipe  210 . 
     In addition, cutout portions  215 ,  216  which are open on an open surface side of the concave space  212  are formed on a front wall  213  and a back wall  214  of the above mentioned head part  211 . 
     Further, a planar portion  72 C is formed on a cutout portion  215  side on the shaft  72  which is formed at a tip portion side of the head part  211 . 
     In addition, the space  212  is for housing the block body  220 . The space  212  is formed larger than an outside diameter of the block body  220  so that the block body can move in the space  212 . 
     Further, projections  219   a ,  219   b  protruding into a space  212  side are formed inside of a sidewall  217  and a side wall  218  of the head part  211 . As shown in  FIGS. 25A and 25B , the projections  219   a ,  219   b  are arranged at a back side than the through hole  73  as seen from the open surface side of the concave space  212  and in parallel with an axis of the through hole  73 . 
     The projections  219   a ,  219   b  are for engaging with the block body after movement of the block body. 
     Next, the block body  220  is explained below. 
     As shown in  FIGS. 26A, 26B and 26C , regarding the block body  220 , a semicylindrial concave portion  221   b  is formed on a top face of a main body  221 , and hook portions  222   a ,  222   b  which extend upward from the top face  221   a  are formed. 
     The concave portion  221   b  is formed on the main body  221  in a front-rear direction. When the block body  220  is accommodated in the space  212 , it is arranged that the inner needle  3  contacts with the block body  220  and slides inside the concave portion  221   b.    
     In addition, when the block body  220  moves in the space  212 , the hook portions  222   a ,  222   b  are engaged on the projections  219   a ,  219   b  so that the block body  220  is maintained in the space  212 , and the hook portions  222   a ,  222   b  limit the movement of the block body  220 . 
     An inclined plane  221   e  which is inclined so as to become downward as it goes from a front face  221   c  side to a rear face  221   d  side is formed on the front face  221   c  of the main body  221 . 
     The inclined plane  221   e  of the main body  221  is, as shown in  FIG. 27A , is accommodated in the space  212  so as to contact with a projection  205  at the tip portion of the tongue-like part  202 . That is to say, the projection  205  enters the space  212  from the cutout portion  215  and comes in contact with the inclined plane  221   e.    
     The through hole block means includes the space  212 , the block body  220 , and the outer pipe  201 . When the outer pipe  201  moves relative to the inner pipe  210 , the block body  220  is pushed up (moved) in the space  212  by the projection  205  whereby a state where the inner needle  3  is inserted is changed to a state where the inner needle  3  is blocked and a communication state of the through hole  73  is blocked. 
     Work and operation of the puncture device  200  in accordance with the above structured third preferred embodiment will be described with reference to  FIGS. 27 to 29 . 
     Firstly, the protector  5  is removed from the puncture device  200 , and the catheter  2  and the inner needle  3  are exposed as shown in  FIGS. 27A and 27B . Further, the above-mentioned outer needle  21  and the above-mentioned inner needle  3  are punctured to a blood vessel (patient&#39;s body). 
     Then, in order to indwell the above-mentioned outer needle  21 , the above-mentioned inner needle hub  41  is moved along the axial direction shown by the arrows in  FIGS. 27A and 27B  and in a direction away from the above-mentioned outer needle  21  (pull-out operation is performed). As the inner needle hub  41  for retaining the rear end portion (base portion) of the inner needle  3  is moved along the axial direction, the inner needle  3  similarly moves along the axial direction. Further, the inner needle  3  is pulled from the outer needle  21 , and the thus pulled inner needle  3  is covered with the inner pipe  210 , the outer pipe  201 , and the inner needle hub  41 . 
     Further, as shown in  FIGS. 28A and 28B , when the above-mentioned inner needle hub  41  is moved in a direction away from the above-mentioned outer needle  21  along with the axial direction, the outer pipe  201  moves relative to the inner pipe  210 , the projection  205  slides on the front face  221   c , and the block body  220  is pushed up (moved) by the projection  205 . 
     According to the above, the concave portion  221   b  is arranged to be placed elsewhere than on the line that extends from the through hole  73  and a communication state of the through hole  73  to be blocked by the main body  221  of the block body. 
     Further, when the above-mentioned inner needle hub  41  is moved in a direction away from the above-mentioned outer needle  21  along with the axial direction, as shown in  FIG. 29C , the hook portions  222   a ,  222   b  of the pushed up block body  220  are engaged on the projections  219   a ,  219   b  whereby the block body is fixed and a blocked state is sustained. 
     Therefore, after the hook portions  222   a ,  222   b  are engaged on the projections  219   a ,  219   b  and the through hole  73  is blocked by the block body  220 , even if the force of moving the inner needle hub  41  to the catheter  2  side is applied, the block body  220  inhibits the movement of the inner needle  3  and the inner needle  3  does not return into the outer needle  21  gain. 
     In the third embodiment, as in the first embodiment, when the above-mentioned inner pipe  210  is pulled from the above-mentioned outer pipe  201 , the above-mentioned two arms  71 A are opened as shown in  FIG. 29B , and the retention of the outer needle hub  22  by the above-mentioned two arms  71 A is released. That is to say, by separating the above-mentioned inner needle hub  41  from the above-mentioned outer needle  21  along the axial direction and expanding the above-mentioned syringe  4 , the above-mentioned inner needle  3  pulled from the above-mentioned catheter  2  is accommodated inside the above-mentioned outer pipe  201  and the inner needle hub  41 , then the outer needle hub  22  is released from the state where the outer needle hub  22  is retained by the above-mentioned four arms  71 A and arm opening/closing parts  62 . 
     Accordingly, whilst indwelling the above-mentioned catheter  2  (outer needle  21 ) in a blood vessel, the above-mentioned inner needle  3  is pulled from the above-mentioned outer needle  21  and accommodated inside the above-mentioned inner needle hub  41 , and the above-mentioned outer needle hub  22  is removed from the above-mentioned syringe  4 . 
     Thus, only by pulling the above-mentioned inner needle  3  from the above-mentioned outer needle  21 , the above-mentioned puncture device  200  can accommodate the above-mentioned inner needle  3  in the above-mentioned inner needle hub  41 , and the above-mentioned outer needle hub  22  can be removed from the above-mentioned inner needle hub  41 . 
     Next, a fourth preferred embodiment will be described with reference to  FIGS. 30 to 36 . 
     A through hole block means in this embodiment includes a block body in which a through hole for inserting the inner needle is formed, a space formed in the inner pipe, in which the block body is turnably accommodated. When an outer pipe moves with respect to an inner pipe, the block body turns inside the space by a projection formed on an inner surface of the outer pipe and an insertion of the inner needle is blocked. 
     In addition, while the block body is arranged to be movable in an upper/lower direction in the third embodiment, on the other hand the fourth embodiment differs in that the block body is arranged to be turnable. It should be noted that the same parts or corresponding parts are designated by the same reference signs as in the first or the third preferred embodiment, and will not be described further in detail. 
     Next, the inner pipe  301  is explained below. 
     A puncture device  300  of the fourth preferred embodiment differs in the inner pipe  301  and the block body  310  from the inner pipe  210  and the block body  220  of the third preferred embodiment. The outer pipe has the same construction with the third preferred embodiment. 
     As shown in  FIGS. 30A, 30B, 30C, 31A, 31B and 31C , the inner pipe  301  has a rectangular head part  302  provided with the above-mentioned two arms  71 A, a shaft  72  having a diameter smaller than that of the above-mentioned head part  302  and a through hole  73  which penetrates the centers of the above-mentioned head part  302  and the above-mentioned shaft  72 , and through which the above-mentioned inner needle  3  is inserted. 
     As shown in  FIGS. 30A, 30B, 30C, 31A, 31B and 31C , a space  303  which connect to the through hole  73  in which inner needle  3  is inserted is formed inside the head part  302 . 
     In addition, as shown in  FIG. 32 , the space  303  is for accommodating the block body  310  having the through hole  73  in which inner needle  3  is inserted. The space  303  is formed in cylindrical shape with a larger diameter than an outside diameter of the block body  310  so that the block body  310  can move in the space  303 . 
     The space  303  is provided with a first cylindrical space part  303   a  which accommodates the block body  310 , and a second cylindrical space part  303   b  which is formed on the right and the left of the first cylindrical space part  303   a . The second cylindrical space part  303   b  is for a space which accommodates a rotary axis of the block body  310 . 
     A concave portion  302   b  is formed on an upper wall  302   a  of the head part  302  in a front-rear direction (in an axial direction of the through hole  73 ). An opening  303   c  of the space  303  is formed on a bottom of the concave portion  302   b.    
     Further, a projection  304  is formed on an inner wall surface of the head part  302 , which forms the space part  303   a . The projection  304  is for engaging with the block body  310  and extends toward the direction orthogonal to the axial direction of the through hole  73 . 
     As shown in  FIGS. 31A, 31B and 31C , the inner pipe  301  is a component in which an upper part  301 A (left-hand side) and a lower part  301 B (right-hand side) which are on opposite sides of a central line  1  are integrally formed. It is formed by folding the above-mentioned upper part  301 A and the above-mentioned lower part  301 B along a folding line (central line  1 ). 
     Further, grooves  73 A and  73 B whose cross sections are in the shape of a semicircle are formed along the axial direction of the above-mentioned inner pipe  301  in the centers of the above-mentioned upper part  301 A and the above-mentioned lower part  301 B, respectively. When the above-mentioned lower part  301 A and the above-mentioned upper part  301 B are folded, these grooves  73 A and  73 B form one through hole  73 . 
     The head part  302 A and the head part  302 B are formed on end portions of the upper part  301 A and the lower part  301 B respectively. Concave portions  303 A and  303 B whose cross sections are in the shape of a semicircle are formed on the head part  302 A and the head part  302 B respectively. When the above-mentioned upper part  301 A and the above-mentioned lower part  301 B are folded, one space  303  is formed. 
     Arms  71 A 1 ,  71 A 2  are formed at the head part  302 A and the head part  302 B, respectively. When the above-mentioned upper part  301 A and the above-mentioned lower part  301 B are folded, two arms  71 A are formed at the head part  302 . 
     Next, the block body  310  is explained below. 
     As shown in  FIGS. 31 to 33 , the block body  310  is provided with a cylindrical main body  311 , and shafts  312  formed on both end faces of the main body  311 . 
     In addition, a through hole  75   a  for insertion of the inner needle  3  is formed in the block body  311  in the direction orthogonal to the axial direction of the main body  311 . 
     A projection  313  projecting to the concave portion  302   b  from the opening  303   c  of the space  303  is formed on a peripheral surface of the cylindrical main body  311 . 
     Since a tip portion of the projection  313  projects in the concave portion  302   b , when an inner pipe  301  moves with respect to an outer pipe, the projection  205  (See.  FIGS. 22B and 22C ) contact to the projection  313 , which rotates the block body  310 . 
     A hook portion  314  is formed on the peripheral surface of the cylindrical main body  311 , which is engaged with the projection  304 . When the block body  310  rotates in the space  313 , the hook portion  314  is engaged with the projection  304  whereby the block body  310  is fixed in the space  313  and a rotation of the block body  310  is inhibited. 
     As described above, a projection  205  of the outer pipe  201  rotates the block body  310  from a position where the inner needle  3  is inserted to a position where the inner needle  3  is not inserted and the communication state of the through hole  73  is blocked. 
     Next, work and operation of the puncture device  300  in accordance with the above structured fourth preferred embodiment will be described. 
     Firstly, the protector  5  is removed from the puncture device  300 , and the catheter  2  and the inner needle  3  are exposed as shown in  FIGS. 35A and 35B . Further, the above-mentioned outer needle  21  and the above-mentioned inner needle  3  are punctured to a blood vessel (patient&#39;s body). 
     Then, in order to indwell the above-mentioned outer needle  21 , the above-mentioned inner needle hub  41  is moved along the axial direction shown by the arrows in  FIGS. 35A and 35B  and in a direction away from the above-mentioned outer needle  21  (pull-out operation is performed). As the inner needle hub  41  for retaining the rear end portion (base portion) of the inner needle  3  is moved along the axial direction, the inner needle  3  similarly moves along the axial direction. Further, the inner needle  3  is pulled from the outer needle  21 , and the thus pulled inner needle  3  is covered with the inner pipe  301 , the outer pipe  210 , and the inner needle hub  41 . 
     Further, when the above-mentioned inner needle hub  41  is moved in a direction away from the above-mentioned outer needle  21  along with the axial direction, the inner pipe  301  moves inside the outer pipe  210  (the outer pipe  201  moves relative to the inner pipe  301 ), the projection  205  abuts on the projection  313  of the block body  310  and the block body  310  is rotated (see.  FIGS. 36A and 36B ). 
     In accordance with the rotation of the block body  310 , the through hole  75   a  of the block body  310  is also rotated, and the through hole  75   a  is placed elsewhere than on the line that extends from the through hole  73  which causes a communication state of the through hole  73  to be blocked (see.  FIG. 36B ). 
     Therefore, even if the force of moving the inner needle hub  41  to the catheter  2  side is applied, the block body  310  inhibits the movement of the inner needle  3  and the inner needle  3  does not return into the outer needle  21  gain. 
     Further, when the inner needle hub  41  is moved along the axial direction away from the outer needle  21 , as shown in  FIGS. 37A and 37B , the hook portion  314  of the block body  310  is engaged with the projection  304  whereby the block body  310  is fixed, a blocked state is sustained, and a rotation of the block body  310  is inhibited. 
     After the hook portion  314  of the block body  310  is engaged with the projection  304 , since the block body  310  is not rotated and the through hole  73  is surely blocked, even if the force of moving the inner needle hub  41  to the catheter  2  side is applied, the block body  310  inhibits the movement of the inner needle  3  and the inner needle  3  does not return into the outer needle  21  gain. 
     In the fourth embodiment as shown in  FIGS. 37A and 37B , when the above-mentioned inner pipe  301  is pulled from the above-mentioned outer pipe  201 , the above-mentioned two arms  71 A are opened, and the retention of the outer needle hub  22  by the above-mentioned two arms  71 A is released. 
     Accordingly, whilst the above-mentioned catheter  2  (outer needle  21 ) indwelling in a blood vessel, the above-mentioned inner needle  3  is pulled from the above-mentioned outer needle  21  and accommodated inside the above-mentioned inner needle hub  41 , and the above-mentioned outer needle hub  22  is removed from the above-mentioned syringe  4 . 
     Thus, only by pulling the above-mentioned inner needle  3  from the above-mentioned outer needle  21 , the above-mentioned puncture device  1  can accommodate the above-mentioned inner needle  3  in the above-mentioned inner needle hub  41 , and the above-mentioned outer needle hub  22  can be removed from the above-mentioned inner needle hub  41 . 
     DESCRIPTION OF THE REFERENCE NUMERALS 
     
         
           1 ,  100  puncture device 
           2 ,  101  catheter 
           21 ,  102  outer needle 
           22 ,  102   a  outer needle hub 
           3 ,  103  inner needle 
           4 ,  104  syringe 
           5  protector 
           6 ,  107  outer pipe (cylinder body) 
           7 ,  108  inner pipe (cylinder body) 
           7 A upper part 
           7 B lower part 
           41 ,  105  inner needle hub 
           42 ,  106  plug 
           42   a ,  106   a  needle retaining part 
           61 ,  107   b  groove 
           62 ,  107   c  arm opening/closing part (gripping means) 
           107   d  groove 
           107   d   1  linear portion 
           107   d   2  spiral portion 
           71 ,  108 B head part 
           71 A,  108 A arm (gripping means) 
           72 ,  108 C shaft 
           72 A projection 
           72 B,  108 E standing piece 
           73 ,  108 D through hole 
           108 F projecting part 
           200  puncture device 
           201  outer pipe 
           205  projection 
           210  inner pipe 
           212  concave space 
           219   a ,  219   b  projection 
           220  block body 
           222   a ,  222   b  hook portion 
           300  puncture device 
           301  inner pipe 
           303  space 
           304  projection (engaging part) 
           310  block body 
           313  projection 
           314  hook portion (part to be engaged)