Patent Publication Number: US-10307572-B2

Title: Needle safety device

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 14/237,657 filed on Feb. 7, 2014, which is the national phase of International Application No. PCT/IB2012/054034 filed on Aug. 8, 2012, which claims priority from Indian Provisional Patent Application No. 2330/DEL/2011 dated Aug. 9, 2011, the entire disclosures of which are incorporated herein by reference. 
    
    
     The present invention relates to a needle safety device for a medical device such as, for example, an intravenous catheter apparatus, a base portion having a bore extending along a longitudinal center axis therethrough for receiving a needle; and two opposing jaws extending from the base portion generally in the axial direction and each having a head portion in the region of its free end, wherein the needle safety device includes a locking projection for securing the needle safety device to the medical device. 
     A needle safety device of this kind is generally known and operative as a guard for the tip of a needle of the medical device by automatically covering the needle tip during withdrawal of the needle from a patient. The needle safety device thereby serves to prevent accidental pricking of for example, a medical professional by the needle after removal of the needle from the medical device. 
     In the prior art document EP 2 016 963 B1 a corresponding needle safety device is disclosed. This corresponding safety device has an annular resilient member surrounding the two jaws in a ring-like fashion. Although this needle safety device has a reliable functioning, it can be improved and simplified in regard to its structure. 
     It is an object of the invention to provide a needle safety device which provides a reliable protection against accidental pricking by the needle and which has a simple structure. 
     This object is satisfied by a needle safety device having the features of claim  1 . 
     The needle safety device of the invention is characterized by at least one elastic element mounted to the jaws in a non-surrounding manner lateral to the center axis in a region between the base portion and the head portions, wherein the at least one elastic element and the jaws are configured such that the jaws can be spread apart against a restoring force of the at least one elastic element in order to allow the needle received in the bore to extend all the way through the needle safety device. 
     Due to the at least one elastic element exerting its restoring force on the jaws in the spread apart state of the jaws, which is the state in which the medical device, for example, an intravenous catheter apparatus, is typically shelved prior to use, the at least one elastic element ensures that the spread apart jaws will snap together and guard the needle tip upon withdrawal of the needle from the medical device even after a longer shelf time, thereby continuously ensuring a correct functioning of the needle safety device. In addition, the at least one elastic element prevents the jaws from becoming loose when the needle safety device slides along the needle, thereby further aiding a correct functioning of the needle safety device. 
     As a result of the at least one elastic element being arranged in a region between the base portion and the head portions of the jaws, the at least one elastic element also helps prevent the needle tip from protruding sideways out of the needle safety device, thereby further increasing the protecting function of the needle safety device. 
     Furthermore, due to the arrangement of the at least one elastic element between the base portion and the head portions of the jaws, a locking recess for receiving a locking protrusion formed inside the housing of the medical device is formed between the elastic element and the locking shoulder of the at least one head portion. When the locking protrusion engages with the recess formed by the shoulder of the at least one head portion and the at least one elastic element, the needle safety device is safely secured inside the housing of the medical device and is, in particular, prevented from in the axial direction relative to the housing. 
     In contrast to the above-mentioned prior art, the at least one elastic element does not surround the needle safety device. Instead, the at least one elastic element is mounted to the jaws such that it biases the jaws to one another by means of the restoration force. Preferably the at least one elastic element is integrally fixed to the jaws such that it cannot be moved or lost or inappropriately positioned on the needle safety device in use or during manufacturing. 
     According to one embodiment, the at least one elastic element provides said restoring force substantially in axial direction. In other words, the at least one elastic element is drawn or tensioned substantially along the direction of the longitudinal center axis of the needle safety device, i.e. along the needle shaft when the needle shaft extends through the space between the two jaws and spreads the jaws under the restoration force of the at least one elastic element. 
     According to an alternative embodiment, the at least one elastic element provides said restoring force transverse to said axial direction. In this alternative embodiment, the at least one elastic element is drawn or tensioned substantially transverse to the direction of the longitudinal center axis of the needle safety device, i.e. in the direction transverse to the needle shaft when the needle shaft extends through the space between the two jaws and spreads the jaws apart against the restoration force of the at least one elastic element. 
     In a further embodiment, the two different kinds of elastic elements can be combined, e.g. by using one elastic element providing its restoration force transverse to said axial direction on one side of the needle shaft and providing its restoration force substantially along the axial direction on the other side of the needle shaft. 
     The at least one elastic element can be adapted to form a partial sidewall such that together with the jaws it defines a chamber inside the needle safety device, in which the needle tip is held after complete withdrawal of the needle from the medical device, thereby further increasing the guarding function of the needle safety device. 
     The axial dimension of the at least one elastic element may range from about one fifth of the length of the jaws to about two thirds or three fourths of the length of the jaws, and preferably is in the range of about one third of the length of the jaws. 
     Preferably, the at least one elastic element is made from a material having elastic properties, for example, an elastic material such as rubber, silicone or the like. Due to its elastic properties, the elastic element creates a restoring force on the jaws, when the needle fully extends through the needle safety device thereby spreading the jaws apart and expanding the elastic element. As soon as the needle tip passes the free ends of the jaws upon pulling the needle through the needle safety device, the jaws are positively collapsed by the elastic element due to its restoring force. As described below, it can also be formed by a metal spring. For example, the at least one elastic element comprises a tension ring or tension strip or tension spring mounted to the jaws, respectively. 
     In accordance with a further embodiment, the jaws are connected to each other by at least one link in a region between the base portion and the head portions. Preferably, the link is arranged in the region of the elastic element. The link may be provided on only one side of the jaws. Alternatively, first and second links may be provided on opposite sides of the jaws. 
     Preferably, the at least one link is formed to have spring-like properties such that the jaws can be spread apart against a restoring force of the link. For example, the link may have a curved shape, such as an S- or Z-like shape. Alternatively, the link may have a substantially straight shape. 
     The at least one link prevents the two jaws from spreading apart too far, thus preventing over-stretching of the elastic element which could result in a loss of elastic properties. Furthermore, the link supports the elastic element in exerting a force on the jaws in the collapsing direction, thereby aiding the elastic element in preventing the jaws from becoming loose when the needle safety device slides along the needle. In addition, the link causes the jaws to collapse even if the elastic element should fail in its function. The link is designed such that it retains its spring-like properties over the period of shelf live. 
     To allow for a simplified and cost-effective production of the needle safety device, the base portion, the jaws, the elastic element and preferably also the at least one link may be integrally formed and preferably made from a plastic material, for example, by injection molding. Alternatively, the base portion, the jaws, and preferably also the at least one link may be made from a metal material. According to a further embodiment, the base portion, the jaws and/or the link each comprise a different material or combination of materials, such as a different plastic material, a different metal material or a different combination of plastic and/or metal materials. For example, the base may be made from a metal material and the jaws may be made from a plastic material, or vice versa. It is also considered that the inner part of the jaws, which contacts the needle, is made from a thermoplastic material such as TPE, whereas the outer part of the jaws may be made from a different material, for example, a plastic, metal, composite or elastomer material, so that the needle safety device causes less friction when sliding along the needle thereby facilitating the withdrawal of the needle. The elastic element can be formed of any kind of rubber material. 
     In regard to the further structure of the needle safety device according to the present invention, it is possible according to one embodiment that the tension ring is mounted to mounting features provided on each of the jaws. In particular, in this embodiment of the invention it can be provided that the mounting features comprise mounting projections, mounting hooks, mounting recesses or the like. This means that the tension ring is hooked onto the particular mounting features and biased therebetween. 
     As an alternative, it is possible that the tension strip is integrally fixed with its ends to the jaws, in particular by using an adhesive or by co-molding. In other words, the tension strip is fixedly connected with it ends to each of the jaws and connects the jaws such that the tension strip is biased as soon as the jaws are spread by the needle shaft. 
     According to a still further embodiment, it can be provided that tension spring is formed by a coil spring fixed with its ends to each of the jaws, respectively. The coil spring is extended against its restoration force when the jaws are spread by the needle shaft. 
     Generally, it is possible that only one elastic element is provided on only one side of the jaws. As long as the elastic element is strong enough to provide sufficient restoration force to the jaws, only one elastic element is sufficient. Preferably in order to increase the reliability of the needle safety device according to the present invention first and second elastic elements are provided on opposite sides of the jaws. 
     In order to prevent the needle tip guarded by the needle safety device from protruding beyond the free ends of the jaws, at least one of the jaws has an angled end section at its free end, which extends towards the other one of the jaws in a direction generally perpendicular to the axial direction. 
     Preferably, the length of the at least one angled end section is selected such that the angled end section is supported on the needle when the needle extends all the way through the needle safety device, thereby spreading the jaws apart far enough for the shoulder of the head portion of the jaw having the angled end section to be able to engage behind the locking protrusion provided in the housing of the medical device. 
     The needle safety device according to the present invention as mentioned above has a locking projection for securing the needle safety device to the medical device. This locking projection can be formed by a projection which interacts with a corresponding recess or projection in the interior of the medical device, e.g. a catheter hub, which receives the needle safety device. On the other hand, according to an alternative embodiment of the present invention, the locking projection may be formed on an additional arm provided at the needle safety device which interacts with the outside surface of the medical device, e.g. the catheter hub. 
     Further subject matter of the invention is a needle for a medical device such as, for example, an intravenous catheter apparatus, which has an inner profile, i.e. cross-section area defined by the inner periphery or circumference of the needle, a principal outer profile, i.e. principal cross-section area defined by the outer periphery or circumference of the needle, and a needle tip, the needle further comprising at least one enlargement in the region of the needle tip, wherein the enlargement is formed from an increase of the outer profile, whereas the inner profile remains substantially unchanged. 
     Still further subject matter of the invention is a medical device, in particular an intravenous catheter apparatus, comprising a needle of the aforementioned type and a needle safety device, in particular of the above described kind, which is slidably arranged on the needle for protecting the needle tip, wherein the needle safety device includes a base portion having a bore extending therethrough for receiving the needle, the bore being adapted to the principal outer profile of the needle. 
     The enlargement and thus increase in effective diameter in the region of the needle tip prevents the needle tip from being pulled through the base portion of the needle safety device during withdrawal of the needle from the medical device. In other words the enlargement prevents the needle safety device from sliding beyond the needle tip and thus ensures that the needle tip is continuously and reliably guarded by the needle safety device after removal of the needle from the medical device. 
     By forming the enlargement such that only the outer profile of the needle is increased, whereas the inner profile remains unchanged, in other words by maintaining a substantially constant inner cross-section area throughout the entire length of the needle, blood from a patient entering the needle can freely flow along the inside of the needle. In other words a flashback of blood, which occurs when the needle penetrates a vein, is not adversely affected by the enlargement. 
     The enlargement may be formed by subjecting the needle to concentrated heat at a localized area using, for example, a welding process such as a laser welding process, with or without addition of additional material. 
     Alternatively, the enlargement may be formed from additional material dispensed onto the outer surface of the needle. In order to locate the dispensed material in a defined position, a recess or groove may be formed in the outer surface or circumference of the needle. 
     The additional material may, for example, be selected from at least one of a plastic material, an adhesive, a resin and a metal material. 
     In the case of the additional material being a metal material, the enlargement may, for example, be formed by build-up welding of the additional material onto the needle. 
     Preferred embodiments of the invention are described in the following description and in the accompanying drawings, wherein: 
    
    
     
         FIG. 1  shows a view partly in cross-section of a wing housing of an intravenous catheter apparatus, including a needle safety device according to a first embodiment of the invention inserted therein and a needle extending therethrough; 
         FIG. 2  shows a view partly in cross-section of the wing housing of  FIG. 1 , including the needle safety device, but not the needle; 
         FIG. 3  shows a side view of a second embodiment of the needle safety device including a tension strip biased in a direction transverse to the longitudinal direction; 
         FIG. 4  shows a side view of a third embodiment of the needle safety device including a tension strip biased substantially in longitudinal direction; 
         FIG. 5  shows a side view of a fourth embodiment of the needle safety device including a tension ring biased substantially in longitudinal direction; 
         FIG. 6  shows a side view of a fifth embodiment of the needle safety device including a tension spring biased substantially in longitudinal direction; 
         FIG. 7  shows a plan view of the wing housing of  FIG. 1 ; 
         FIG. 8A  shows a cross-sectional view of a section of the wing housing of  FIG. 7  detailing an annular locking protrusion; 
         FIG. 8B  shows a cross-sectional view of a section of the wing housing of  FIG. 7  detailing an alternative embodiment of the annular locking protrusion; 
         FIG. 9A  shows a side view of the needle tip region of the needle of  FIG. 1  showing the details of an enlargement formed on the outer surface of the needle; 
         FIG. 9B  shows a plan view of the needle tip region of  FIG. 9A ; 
         FIG. 10  shows a cross-sectional view of the needle of  FIG. 9  in the region of the enlargement which has been formed by welding; and 
         FIG. 11  shows cross-sectional views of the needle of  FIG. 9  in the region of the enlargement, illustrating the formation of the enlargement by a deposition process. 
     
    
    
     Referring to  FIG. 1 , a catheter hub or wing housing  10  of an intravenous catheter apparatus is shown. The wing housing  10  comprises a main body  12  of generally tubular form and extending in an axial direction. The main body has a distal end  14  and a proximal end  16 . A catheter  17  ( FIG. 7 ) is attached to the main body  12  at the distal end  14  of the main body  12 . A port  18  extends from the main body  12  in a direction generally perpendicular to the axial direction. Wings  20  ( FIG. 7 ) are provided at the main body  12  opposite from the port  18 . The main body  12  defines a chamber  22  extending from the proximal end  16  towards the distal end  14 . 
     Prior to use of the intravenous catheter apparatus, a needle  24  extends through the wing housing  10  in the axial direction. The needle  24  has an inner profile, i.e. cross-section area defined by the inner periphery or circumference of the needle  24 , which is substantially constant across the length of the needle  24 . A principal outer profile, i.e. principal cross section area defined by the outer periphery or circumference of the needle  24 , is also substantially constant across the length of the needle  24  except for an enlargement  26  of the needle  24  provided in the region of the needle tip at the distal end of the needle  24 , which will be described in more detail below with reference to  FIGS. 9 to 11 . 
     Still referring to  FIG. 1 , a needle safety device  28  is slideably arranged on the needle  24 . Prior to use of the intravenous catheter apparatus, the needle safety device  28  is inserted into the chamber  22  from the proximal end  16  of the main body  12 . 
     As can be seen from  FIGS. 1 and 2 , the needle safety device  28  comprises a base portion  30  which has a bore extending in the axial direction therethrough for receiving the needle  24 . The bore is matched in shape and size to the principal outer profile of the needle  24 . The bore can be reinforced with an additional member, like a metal washer, a sleeve or the like. There can also be provided a sleeve on the needle shaft having a larger outer diameter than the bore in the base portion  30 . 
     First and second jaws  34 ,  36  extend from the base portion  30  generally in the axial direction. The first jaw  34  has a first head portion  38  in the region of its free end, and the second jaw  36  has a second head portion  40  in the region of its free end. The first head portion  38  extends beyond the second head portion  40  and has an angled end section  42  at its free end, which extends towards the second jaw  36  in a direction generally perpendicular to the axial direction. 
     The length of the angled end section  42  is selected such that the angled end section  42  protrudes over at least a part of the second head portion  40 , when the jaws  34 ,  36  are in a relaxed position as is shown in  FIGS. 2 to 6 . When the needle  24  extends all the way through the needle safety device  28 , such as prior to use of the intravenous catheter device as shown in  FIG. 1 , the angled end section  42  is supported on the needle  24 , whereby the first jaw  34  is forced away from the second jaw  36  from its relaxed position into a spread apart position. 
     In the embodiment according to  FIGS. 1 and 2  the jaws  34 ,  36  are connected by two tension strips  44  (only one shown) in a region between the base portion  30  and the head portions  38 ,  40 . The tension strips  44  are made from an elastic material, such as rubber, silicone or the like. The tension strips  44  are fixed with their end portions  45 ,  47  to two opposite sides of the jaws  34 ,  36 , i.e. by using an adhesive or by molding these tensions strips integrally onto the jaws  34 ,  36 . The tension strips  44  exert a restoring force on the jaws  34 ,  36 , when the jaws are spread apart by the needle  24 , as shown in  FIG. 1 . There is no additional elastic member surrounding the needle safety device  28 , like a rubber ring or the like. 
     As is illustrated in  FIGS. 1, 2 and 3 , the tension strips  44  cover a substantial part of the jaws  34 ,  36  seen in the axial direction. Specifically, the axial dimension of the tension ring may range from about one fifth of the length of the jaws to about two thirds or three fourth of the length of the jaws, and preferably is in the range of about one third of the length of the jaws. 
     As can be seen from  FIGS. 1 and 2 , the jaws  34 ,  36  are slightly angled towards each other in the region of the tension strips  44 , resulting in the outer profile of the needle safety device  28  being tapered towards the head portions  38 ,  40 . 
     Two part annular protrusions  48  are formed on the outer surface of the jaws  34 ,  36 , as shown in  FIGS. 1 and 2 . It is to be noted that the part annular protrusions  48  are optional, i.e. the needle safety device  28  can also be made without any part annular protrusions. 
     As can be seen from  FIGS. 1 and 2 , a locking shoulder  50  is formed at the side of each head portion  38 ,  40  facing the tension ring  44 . The locking shoulder  50  and the tension ring  44  together form a recess or groove  52 . 
     Referring again to  FIG. 1 , an annular locking protrusion  54  is formed on the inner surface of the main body  12  of the wing housing  10  and protrudes into the chamber  22 . 
     Prior to use of the intravenous catheter apparatus, i.e. when the needle safety device  28  is inserted into the chamber  22  and the needle  24  extends all the way through the needle safety device  28  and the wing housing  10 , the annular locking protrusion  54  is received in the recess  52  defined by the tension ring  44  and the head portion  38  of the first jaw  34 , which is forced away from the second jaw  36  due to the angled end section  42  supported on the needle  24 . 
     Because of the annular locking protrusion  54  engaging into the recess  52  of the needle safety device  28  in the spread apart state of the jaws  34 ,  36 , the needle safety device  28  is secured against movement relative to the main body  12  in the axial direction. Specifically, the needle safety device  28  cannot be pulled out of the wing housing  10 , since the locking shoulder  50  of the head portion  38  of the first jaw  34  engages behind the annular locking protrusion  54 . 
     As is illustrated in  FIG. 7 , the annular locking protrusion  54  is a distance away from the proximal end  16  of the main body  12 , this distance being in the range of 5 mm to 6 mm or more. 
     The annular locking protrusion  54  may have a substantially rectangular profile with rounded edges ( FIG. 8A ), a rounded profile similar to a Gaussian curve or a semi-sinusoidal curve ( FIG. 8B ) or any other profile suitable for locking of the needle safety device  28  in the wing housing  10 . 
     Preferably, the locking protrusion  54  is of continuous annular shape. However, it is generally also possible to consider an annular locking protrusion  54  having one or more interruptions. 
     When the needle  24  is being withdrawn from a patient and, thus, from the intravenous catheter apparatus, the needle  24  is simultaneously pulled through the needle safety device  28 . As has been mentioned above, as long as the jaws  34 ,  36  are in their spread apart position, the needle safety device  28  is secured against axial movement relative to the main body  12 , i.e. the needle safety device  28  remains in the wing housing  10 . 
     However, as soon as the tip  56  of the needle  24  moves into the needle safety device  28 , i.e. passes beyond the angled end section  42  of the first jaw  34 , the first jaw  34  snaps back or collapses into its relaxed position, as shown in  FIG. 2 , due to the restoring force exerted by the tension strip  44 . 
     When the first jaw  34  adopts its relaxed position, the locking protrusion  54  is released from the recess  52  and the locking shoulder  50  of the first head portion  38  is disengaged from the locking protrusion  54 . As a result, the safety device  28  is free to move relative to the main body  12  in the axial direction. Specifically, the needle safety device  2 S can now be pulled out of the wing housing  10 , as is indicated in  FIG. 2 . 
     As is illustrated in  FIG. 9 , the position of the enlargement  26  formed on the outer surface of the needle  24  is selected such that the enlargement  26  abuts the base portion  30  of the needle safety device  28  as soon as the needle tip  56  has passed the free end of the second jaw  36 . 
     Since the maximum outer dimension of the needle  24  in the region of the enlargement  26  is larger than the dimension of the bore in the base portion  30 , which is adapted to the principal outer profile or circumference of the needle  24 , the needle  24  cannot be further pulled out of the needle safety device  28 . In other words, because of the enlargement  26 , the needle safety device  28  cannot slide off the needle  24  during normal use of the needle  24  and needle safety device  28 , i.e. unless an excessive external force is applied to the needle  24  and/or the needle safety device  28 . 
     With the needle tip  56  captured inside the needle safety device  28 , the needle tip  56  is covered by the angled end section  42  of the first jaw  34 . At the same time, the tension strips  44  prevent the needle tip  56  from coming sideways out of the needle safety device  28 . Hence, the needle tip  56  is safely guarded by the needle safety device  28 . 
     Referring to  FIGS. 10 and 11 , the enlargement  26  of the needle  24  is formed such that the inner profile of the needle  24  is not affected by the formation of the enlargement  26 , i.e. remains substantially unchanged. Thereby, when the needle  24  penetrates a vein, the flow of blood through the needle  24  will not be adversely affected by the enlargement  26 . 
     The enlargement  26  may be formed as a bump by subjecting the needle  24  to concentrated heat at a localized area, for example, using a welding process, such as a build-up welding process or a laser welding process, with or without addition of additional material ( FIG. 10 ). 
     Alternatively, the enlargement  26  may be formed by dispensing additional material  58  onto the outer surface of the needle  24 , such as an adhesive, a resin or a metal material. The additional material  58  may be placed in a recess  60  which has been formed in the outer surface of the needle  24  prior to dispensing the additional material  58 . However, formation of the recess  60  is optional. 
     Although only one enlargement  26  is shown in  FIGS. 9 to 11 , it is to be noted that more than one enlargement may be present on the outer surface of the needle  24 . 
     Referring to  FIG. 3  a second embodiment is shown, wherein the needle safety device  28  is depicted in a relaxed state without the needle) and with a different kind of base portion  30 . The base portion includes two arms and  29 ,  31 , wherein the first arm  29  has a shorter extent in axial direction entering the second arm  31  has a larger extent in axial direction. At the free end of the second arm  31  a locking protrusion  33  is integrally formed with the second arm  31  which is provided to interact with a corresponding recess or projection at the outside surface of the wing housing (not shown). Thereby, the needle safety device can be held in position in regard to the wing housing when the needle is been retracted as described above. As soon as the enlargement  26  of the needle comes into contact with the base portion  30 , the needle safety device can be retracted from the wing housing by overcoming the resistance and dissolving the interaction between the locking protrusion  33  and the corresponding feature on the outside surface of the wing housing. 
     The embodiment according to  FIG. 3  also has two tension strips  44  fixed  36  by co-molding with their end portions  45 ,  47  to the two jaws  34 , for biasing the jaws  34 ,  36  as described above. 
       FIG. 4  shows a further embodiment including two tension strips  44 . The shape and structure of the needle safety device  28  is similar to the embodiment according to  FIG. 3 . However, the tension strips  44  of this embodiment are fixed by co-molding with their end portions  45 ,  47  to the head portions  38 ,  40  of the two jaws  34 ,  36  such that the tension strips  44  are biased substantially in longitudinal direction. In other words, as shown in  FIG. 4  the tension strips  44  run in longitudinal direction in the relaxed state, i.e. along the longitudinal center axis of the needle safety device  28 . When the jaws  34 ,  36  are spread apart due to the needle shaft extending therebetween (not shown), of the tension strips  44  are stretched and run inclined to the longitudinal center axis. 
       FIG. 5  shows a further embodiment including two tension rings  44 . The tension rings  44  are annular elements, e.g. 0-rings, formed from elastic material such as rubber or the like. On each head portion  38 ,  40  of the two jaws  34 ,  36  hook-like projections  51 ,  53  are integrally formed, which protrude from the needle safety device  28  in lateral opposite directions. The tension rings  44  are hooked on these projections  51 ,  53  and biased there between. The functioning is similar to that of the tension strips  44  shown in  FIG. 4 . 
       FIG. 6  shows a further embodiment including at least one tension spring  44 . The tension spring  44  is fixed with its end portions  45 ,  47  to opposite sides  37 ,  39  of the two head portions  36 ,  38  of the two jaws  34 ,  36 . The tension spring  44  is formed as the coil spring which is stretched and expanded against a restoration force when the two jaws  34 ,  36  are spread by the needle shaft extending therebetween (not shown). The fixation of the end portions  45 ,  46  of the tension spring  44  on the opposite surfaces  37 ,  39  can be achieved by press-fitting the end portions  45 ,  47  into corresponding recesses in these surfaces  37 ,  39 , by hook-like connections, by using an adhesive the end portions or by combinations thereof. 
     REFERENCE NUMERAL LIST 
     
         
           10 : wing housing 
           12 : main body 
           14 : distal end 
           16 : proximal end 
           17 : catheter 
           18 : port 
           20 : wing 
           22 : chamber 
           24 : needle 
           26 : enlargement 
           28 : needle safety device 
           29 : side arm 
           30 : base portion 
           31 : side arm 
           32 : locking projection 
           34 : first jaw 
           36 : second jaw 
           37 : surface 
           38 : head portion 
           39 : surface 
           40 : head portion 
           42 : angled end section 
           44 : tension strip, tension ring, tension spring 
           45 : end portion 
           46 : link 
           47 : end portion 
           48 : annular protrusion 
           50 : locking shoulder 
           51 : hook-like protrusion 
           52 : recess 
           53 : hook-like protrusion 
           54 : locking protrusion 
           56 : needle tip 
           58 : additional material 
           60 : recess