Abstract:
Method, system and device involving a needle device with a needle safety element with improved stable structure. A frame can surround the needle safety element to provide added stiffening of the needle safety element. The frame can include stays extending laterally of the needle safety element. The needle safety element with the frame can be slidably located on a needle and in a catheter hub in a ready to use position and be removable from the catheter hub in a protective position.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a Continuation application of Ser. No. 13/257,572, filed Sep. 19, 2011, which is a national phase application under 35 U.S.C. §371 of PCT Application No. PCT/EP2010/002757, filed May 5, 2010, which claims the benefit of German application No. 10 2009 020 061.4 filed May 6, 2009, the contents of which are expressly incorporated herein by reference. 
     
    
     FIELD OF ART 
       [0002]    The present disclosure relates to a needle safety device. 
       BACKGROUND 
       [0003]    A needle safety device of this kind is known from WO 99/08742 and EP 1 363 690, wherein a clip made of sheet metal is provided as a needle safety element in which two resilient arms extend from the proximal rear wall in a distal direction and intersect. In the ready position, bent distal ends of the arms, which are opposite each other, abut on the needle shaft, and in the protective position they cover the needle tip. Such a needle safety element can be used in connection with a catheter, as known from WO 99/08742, wherein the needle safety element is held in the catheter hub until the needle is displaced so far out of the catheter that a radial projection on the needle shaft engages with the proximal rear wall of the needle safety element, whereupon the needle safety element is withdrawn from the catheter hub with the needle. Likewise, this known needle safety element can also be used without a catheter device, as shown for example in EP 1 363 690. Additionally, from EP 1 363 690, the combination of the needle safety element with a sleeve is known. In the protective position, the proximal rear wall engages the radial projection of the needle shaft via the sleeve. 
         [0004]    As the needle shaft extends between the intersecting arms of the needle safety element, the arms are formed relatively narrow in the middle portion. In the protective position, in which the needle safety element is positioned freely at the needle tip and the arms are no longer guided through the needle shaft, a lateral displacement of the arms of the needle safety element can occur during handling. 
       SUMMARY 
       [0005]    It is an object of the present method, system and device to provide a needle safety element of the type described above such that its protective function is improved and it has a more stable structure. 
         [0006]    According to the present method, system and device, stays extend laterally from the two arms of the needle safety element approximately parallel to the needle shaft, wherein the stays are joined at the proximal end to the proximal rear wall and to each other at the distal ends by a bracket extending transversely to the needle axis. In this way, a stiffening of the needle safety element results in which the arms of the needle safety element are prevented by the lateral stays from moving away laterally from the needle. 
         [0007]    Preferably, the bracket can be provided at the distal ends of the stays at least on one side with a shoulder for forming a cap shape, for achieving further stiffening in the distal end area. 
         [0008]    Additionally, the edge of the shoulder can have an extension in the proximal direction at least on one side, for limiting radial displacement of one of the arms, wherein this extension further contributes to stiffening of the structure. 
         [0009]    For stiffening a lateral stay, at least one of the stays can be provided on at least one side with an enlargement. 
         [0010]    Hereby, a lug extending in the peripheral direction can be formed at least on one side of at least one of the stays in the middle portion of the stay, for stiffening the stay. 
         [0011]    When a safety element is provided that has radially protruding portions at the proximal and distal ends, the lugs expediently extend in the peripheral direction into the free region between the radially protruding portions of the needle safety element, so as not to enlarge the contours of the needle safety element in a front view of the safety element. 
         [0012]    For joining the lateral stays to the proximal rear wall of the needle safety element, lugs can be provided at the lateral stays or at the proximal rear wall. It is also possible to provide at least one stay integral with the proximal rear wall. 
         [0013]    Expediently, the frame formed by the lateral stays, the bracket at the distal end and the proximal rear wall, which frame is located around the movable arms of the safety element, is formed from a thin metal sheet by punching and bending; however, it is also possible to assemble a plurality of parts to obtain such a configuration. 
         [0014]    Advantageously, a needle safety element having intersecting arms is used; however, a needle safety element can also be surrounded by a frame whose two arms do not intersect and extend on opposite sides of the needle shaft along the same. 
         [0015]    A contribution to the stiffening of the stays is for these to have a bent cross-section or edges bent inwards. Additionally or alternatively, the stays can be provided with stiffening ribs extending longitudinally. 
         [0016]    For engagement of the needle shaft with the proximal rear wall, crimping of the needle shaft with at least one resulting radially protruding bulge or another radial protrusion attached to the needle shaft, for example a bead, can be provided, wherein a sleeve can also be provided at the needle shaft between proximal rear wall and radial protrusion. Here, the sleeve can either be fixedly connected to the needle safety element and thus formed as part of the needle safety element, or alternatively it is not fixedly connected to the needle safety element and is merely arranged loosely on the needle at the needle shaft between needle safety element and radial protrusion. Here, in the protective position, the edge of the opening in the proximal rear wall of the needle safety element engages the radial protrusion at the needle shaft via the sleeve. 
         [0017]    In the case of a needle shaft without a radial projection, the opening in the proximal rear wall of the needle safety element or the sleeve fixed thereto can engage with the needle shaft in the protective position by clamping when the safety element is canted or tilted in relation to the needle shaft. The needle safety element is then preferably formed with further suitable clamping areas, which engage with the needle shaft to provide additional clamping in the protective position. Even when the needle shaft has a radial protrusion, the needle safety element can also have corresponding clamping areas. For increasing the secure grip in the protective position, in a clamping embodiment an additional tether can be provided between needle safety element and needle hub. 
         [0018]    Expediently, the bracket of the frame is provided with a bore for receiving the needle in the ready position; however, the bracket can also be formed such that it has only an approximately semicircular recess along an edge, in which recess the needle is guided. 
         [0019]    An aspect of the present disclosure refers to a needle safety assembly comprising:
       a needle safety element slidably mounted on a needle shaft having a needle tip; the needle safety element comprising a proximal wall having an opening and a movable distal wall;   a frame surrounding, at least in part, the needle safety element comprising a first stay and a second stay connected to a bracket and to the needle safety element.       
 
         [0022]    In such an embodiment the needle safety assembly can comprise further:
       a first lug connected to the first stay along a first axial position on the first stay and extends radially relative to the needle shaft.       
 
         [0024]    Further the needle safety assembly can comprise:
       a second lug connected to the second stay along a first axial position on the second stay and extends radially relative to the needle shaft.       
 
         [0026]    In such an embodiment the first axial position on the first stay can be located, relative to the needle shaft, at a different position than the first axial position on the second stay. 
         [0027]    Preferably the first lug extends radially so that an end edge of the first lug is closer to the second stay than the first stay. 
         [0028]    Further the bracket and the two stays are unitarily formed preferably. 
         [0029]    It is of advantage that safety element comprises a first arm and a second arm. 
         [0030]    The present method, system and device also comprise combinations of the features described. 
         [0031]    Further aims, advantages, features and application options of the present method, system and device follow from the following description of the embodiments with reference to the drawing. Hereby, all the features described and/or represented by the drawing form the subject matter of the present method, system and device in themselves or in any meaningful combination, independently of their summary in the claims and the back-references thereof. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0032]    The present method, system and device are explained in more detail below with reference to the drawing, in which: 
           [0033]      FIG. 1  shows a side view of a needle safety element having two intersecting arms in the protective position without lateral stays, 
           [0034]      FIG. 2  shows a view of the needle safety element from below in  FIG. 1 , 
           [0035]      FIG. 3  shows a longitudinal section through the needle safety element in the protective position with a lateral stay, 
           [0036]      FIG. 4  shows in the same view as  FIG. 3  an embodiment with a cap-shaped bracket, 
           [0037]      FIG. 5  shows an embodiment with a cap extended on one side, 
           [0038]      FIG. 6  shows an embodiment with a lug on one side of each stay, wherein the arms are in the ready position, 
           [0039]      FIG. 7  shows a plan view from above in  FIG. 6 , 
           [0040]      FIG. 8  shows a perspective view of the bracket shape in  FIGS. 6 and 7  without the needle safety element, 
           [0041]      FIG. 9  shows a plan view of the embodiment according to  FIG. 8 , 
           [0042]      FIG. 10  shows a perspective view of a further embodiment in the protective position, 
           [0043]      FIG. 11  shows a view of the embodiment in  FIG. 10  from below, and 
           [0044]      FIG. 12  shows a perspective view of the needle safety device inside a protective needle cap. 
       
    
    
     DETAILED DESCRIPTION 
       [0045]      FIG. 1  shows a hollow medical needle  1 . The medical needle  1  comprises a shaft  1 . 1  having a portion  1 . 3  near the needle tip  1 . 2  having an enlarged diameter in relation to the diameter of needle shaft  1 . 1 , for forming a radial projection. In the embodiment according to  FIG. 1 , this portion  1 . 3  has the form of a crimp of the needle shaft, which is indented on two sides and broadened in the transverse direction. According to another embodiment, the portion  1 . 3  can also only have the form of a bead on the needle shaft, having a predetermined distance from the needle tip in accordance with the length of the arms of the safety element  2 . A further embodiment of the portion  1 . 3  can also be only a bulge or a crimp on only one side of the needle shaft  1 . 1 , or be formed by a metallic coating on the needle shaft. 
         [0046]    On the needle shaft  1 . 1 , there is arranged a needle safety element  2  formed from thin sheet metal, which has a proximal rear wall  2 . 1  having a bore  2 . 2 , through which the needle shaft  1 . 1  extends displaceably. The diameter of the bore  2 . 2  is smaller than the outer diameter of the portion  1 . 3  on the needle shaft, so the needle safety element  2  cannot be displaced beyond the needle tip in the distal direction, because the edge of the bore  2 . 2  in the rear wall of the needle safety element retains the portion  1 . 3  with an enlarged diameter. Thus the bore  2 . 2  in the rear wall  2 . 1  of the needle safety element forms an engagement means with the needle shaft. Instead of a bore, a sleeve can also be provided at or in front of the proximal rear wall  2 . 1  of the needle safety element  2 , through which sleeve the needle shaft  1 . 1  extends and whose inner diameter is smaller than the outer diameter of portion  1 . 3  having the enlarged diameter, so that by means of the sleeve, the place of engagement of needle  1  and safety element  2  in  FIG. 1  is displaced to the left or in the distal direction. 
         [0047]    In the embodiment of the needle safety element  2  in  FIG. 1 , two resilient arms  2 . 3  and  2 . 4  extend from the proximal rear wall in a distal direction, wherein the arms are preferably of different length and intersect in the middle portion. Bent wall portions  2 . 5  and  2 . 6  are provided at the distal ends and are formed onto the straight portions of the arms  2 . 3  and  2 . 4  by means of an elbow-shaped portion  2 . 7  which is bent outward. These elbow-shaped portions  2 . 7  serve for engagement with a catheter hub when the needle safety device is used in connection with a catheter device. At the free ends, the two arms  2 . 3  and  2 . 4  each have a bent end portion  2 . 8 , which abuts resiliently on the needle shaft  1 . 1  in the ready position, and contributes to a reduction in friction by means of the bend. 
         [0048]    Although the needle safety element  2  is shown formed from a single sheet of spring steel, it is also possible to assemble different parts of the needle safety element to give a needle safety element by welding, brazing or beading. Here, different materials can also be used for individual parts, for example plastic and metal. 
         [0049]      FIG. 1  shows the protective position of the needle safety element  2  wherein the portion  1 . 3  having an enlarged diameter which can be formed as a radial projection, abuts on the edge of the bore  2 . 2  in the proximal rear wall  2 . 1 . The longer arm  2 . 3  overlaps the needle tip  1 . 2  by means of the wall portion  2 . 6 . The distance between needle tip  1 . 2  and portion  1 . 3  can also be configured smaller, so that the shorter arm  2 . 4  also overlaps the needle tip. 
         [0050]    As  FIG. 2  shows at  2 . 41 , the arms  2 . 3  and  2 . 4  adjacent to the proximal rear wall  2 . 1  have a widened portion which merges into a narrow portion along which a stiffening rib  2 . 3   a  or  2 . 4   a  is formed. The needle  1  extends between these two narrower, intersecting, laterally distanced portions. In the distal end portion, the arms  2 . 3  and  2 . 4  again have widened portions, as  FIG. 2  shows at  2 . 32 , wherein the distal wall portions  2 . 5  and  2 . 6  have a lesser width dimension than the arms  2 . 3  and  2 . 4  in the proximal area adjacent to the rear wall  2 . 1 . 
         [0051]    As shown in  FIGS. 1 and 3 , the bent end portion  2 . 8  of the arm  2 . 4  abuts laterally on the needle tip  1 . 2 , so that the safety element  2  cannot be tilted in the counter-clockwise direction relative to the needle shaft in  FIGS. 1 and 3 . To prevent tilting of the safety element  2  in the clockwise direction relative to the needle shaft in the protective position, the transversely-extending edge  2 . 32   a  ( FIGS. 2 and 3 ) of the widened portion  2 . 32  adjacent to the elbow-shaped portion  2 . 7  is positioned in such a way that this edge  2 . 32   a  abuts on the needle in the protective position of  FIGS. 1 to 3 . If the distal end of the arm  2 . 4  also covers the needle tip  1 . 2  in the protective position, then the corresponding edge  2 . 42   a  ( FIG. 3 ) of the widened portion adjacent to the elbow-shaped portion  2 . 7  can also be used for preventing tilting of the safety element  2  in relation to the needle shaft. 
         [0052]    In the proximal area of the needle safety element  2 , lateral stays  3   a  and  3   b  ( FIG. 8 ) are fixed, which extend along both sides of the arms  2 . 3  and  2 . 4 . In the embodiments shown, bent and protruding lugs  2 . 9  ( FIGS. 1 and 2 ) are formed at the proximal rear wall  2 . 1  in the distal direction, wherein the proximal ends of the stays  3   a  and  3   b  are fixed onto these lugs  2 . 9  by adhesion, laser welding or resistance welding such that they form a unit with the safety element  2 . Instead of the lugs  2 . 9 , corresponding lugs can also be formed on the proximal ends of the stays which can be joined to the proximal rear wall  2 . 1  of the needle safety element after bending. 
         [0053]    Thus the present method, system and device comprise a needle safety element having preferably two intersecting arms having two stays which are spaced apart from each other and are fixedly joined to the proximal end of the needle safety element. In one embodiment, the fixing location is distal of the proximal wall by means of lugs extending from the proximal wall in a distal direction. In another embodiment, the fixing at the proximal wall takes place by bending over the two proximal ends of the two stays and fixing the bent ends directly at the proximal wall. 
         [0054]    According to another embodiment, at least one of the stays  3   a  and  3   b  can be formed by means of punching of a sheet metal integral with the proximal rear wall of the safety element  2 . 
         [0055]    The stays  3   a ,  3   b  likewise preferably consist of sheet metal, and they are joined to each other at the distal ends by a bracket  3   c , which extends transverse to the needle  1  and is preferably provided with a throughbore  3   c   1  for receiving the needle  1 . The stays  3   a  and  3   b  each have upper and lower edges  3 . 8   a  and  3 . 8   b  ( FIG. 3 ), so the two intersecting arms  2 . 3  and  2 . 4  are more visible with respect to their function. 
         [0056]    The bracket  3   c  with the two lateral stays  3   a  and  3   b , which can be denoted as a protective band or frame  3 . 9  in  FIG. 3 , prevents lateral displacement of the needle safety element  2  relative to the needle shaft  1 . As can be seen in  FIG. 1 , the safety element  2  can become displaced on the needle section  1 . 3 , so the distal wall areas  2 . 5  and  2 . 6  can move out of the protective position somewhat, i.e. somewhat out of the plane of  FIG. 1 . By means of the two spaced-apart lateral stays  3   a  and  3   b , a relative movement between needle tip  1 . 2  and distal wall portions  2 . 5  and  2 . 6  is prevented—if such a relative movement occurs at all—because the needle  1  is fenced in the space defined by the two stays and the two arms. Because the longer arm  2 . 3  cannot be displaced laterally or downward, the possibility of the needle tip becoming exposed by a lateral movement is prevented, as the protective element  2  is moved into the protective position. Thus the present method, system and device comprise a protective element having two intersecting arms and a protective band or frame which has two spaced-apart stays joined to the protective element in the proximal area and joined to the bracket in the distal area, for preventing deflection of the two stays against each other or away from each other. The joining of the two stays also limits the displacement of the safety element by limiting the movement of the needle tip to an area which is defined by the two stays and the two arms, called a needle containment space. In certain embodiments, the arms can be generally parallel or intersect as shown. 
         [0057]    To stiffen the stays  3   a ,  3   b  formed from a metal strip, stiffening ribs  3   a   1  and  3   b   1  are formed along these in the wall areas. Alternatively or additionally to this, the metal strip of the stays can be formed from a thicker sheet material. In a cross-sectional view, the stays  3   a ,  3   b  themselves can be slightly bent or have edges bent inward so that the stiffness of these stays is improved. In the cross-sectional view, the flat extension of the stays  3   a ,  3   b  extends transverse to the flat extension of the arms  2 . 3  and  2 . 4 , as shown in  FIG. 3 . 
         [0058]    In a plan view of the embodiment in  FIG. 3 , the bracket  3   c  forms an approximately rectangular frame with the proximal rear wall  2 . 1  of the needle safety element and the two stays  3   a  and  3   b , wherein the two arms  2 . 3  and  2 . 4  of the needle safety element are able to move inside this frame. Thus according to an aspect of the present method, system and device a frame is provided comprising a distal wall (bracket), two stays and a proximal wall within which the two intersecting arms can move. The safety element is also to be understood as such, having two arms which can lie in a position radially outside the space or region delimited by the frame, and moving into the region delimited by the frame. According to one embodiment, the safety element can have two arms which start from a position outside the region delimited by the frame and intersect in a position inside the region delimited by the frame. 
         [0059]      FIG. 4  shows an embodiment in which the distal bracket  3   c   1  is formed on the upper and lower side by a rounded boss  3 . 1  in the form of a cap. The rounded cap is preferably provided for avoiding sharp edges. This rounded boss  3 . 1  can also be formed on only one side of the bracket  3   c   1 . As shown, the two rounded bosses are arranged above and below the two edges  3 . 8   a  and  3 . 8   b  of the two band-shaped stays. If only one rounded boss is provided, then a device is understood thereby which has a single boss either above or below the two edges and a straight edge on the other side of the bracket. 
         [0060]    In the embodiment according to  FIG. 5 , the boss  3 . 1  is provided with an extension  3 . 2  in the proximal direction on the side opposite the distal end of the longer arm  2 . 3 , and by means of this extension a displacing movement of the distal end  2 . 6  of the longer arm is further prevented. For example, when the distal end  2 . 6  moves upwards in  FIG. 5 , it will come to abut on the elongation  3 . 2  and thus it will be prevented by this elongation from moving out too far radially from the space or region defined by the frame. On the other hand, this elongation  3 . 2 , corresponding in cross-section to the rounded boss  3 . 1 , is configured with regard to its length such that the short arm in  FIG. 5  can move out upwardly over this elongation  3 . 2 . 
         [0061]      FIGS. 6 and 7  show an embodiment in which the stays made from a metal sheet by punching and/or stamping have an enlargement  3 . 3  on at least one side in the distal end portion. The enlargement is preferably formed on the side of the distal end of the shorter arm  2 . 4  and ensures improved protection from lateral displacement especially of the distal end of the shorter arm, wherein the proximal elongation  3 . 2  of the boss  3 . 1  at the side edges abuts on this enlargement  3 . 3  as shown in  FIG. 6 . 
         [0062]    Depending on the type of cutting die, during production of the guard band or stiffening bracket forming a frame with the rear wall  2 . 1 , the distal end portion of the enlargement  3 . 3  can extend into the proximal elongation  3 . 2  at the cap-shaped bracket. For example, the extension  3 . 2  can extend somewhat upwards such that at least a part of this extension  3 . 2  is covered by the enlargement  3 . 3  in a perspective view of  FIG. 6 . This proximal elongation  3 . 2  can have in the middle portion thereof a gap or a parting line in the axial direction of the needle, which parting line is determined by the metal blank which is used for deformation after punching by stamping and bending. 
         [0063]    Approximately in the area of the point of intersection of the two arms  2 . 3  and  2 . 4  of the needle safety element, on one side of each stay a lug  3 . 4   a  and  3 . 4   b  is formed extending in the peripheral direction, bent somewhat inwardly toward the needle and adapted to the curve of the elongation  3 . 2  in the cap portion. The lug  3 . 4   b  is formed on the side of the stay  3   b  on which the shorter arm  2 . 4  extends, as shown in the plan view in  FIG. 7 , so that this lug  3 . 4   b  ensures further protection from upward displacement of the arm  2 . 4  in  FIGS. 6 and 7 . In a corresponding way, the lug  3 . 4   a  is formed at the lower side of the stay  3   a  in  FIGS. 6 and 7 , to prevent the arm  2 . 3  extending along the stay  3   a  from downward displacement. 
         [0064]    Thus an aspect of the present method, system and device is a protective element having two arms, wherein each arm comprises a portion extending along an associated side of the needle shaft. A band or a stay also extends on each side of the needle shaft and of the two arms. In one embodiment, a lug extending in the peripheral direction extends from each stay over an associated arm. According to a further aspect of the present method, system and device, a protective band or frame is provided which surrounds a safety element, wherein two spaced-apart lugs are provided which each extend from a stay, and wherein the two lugs extend in the clockwise direction in the view from the proximal to the distal end. 
         [0065]    While  FIG. 5  shows the arms  2 . 3  and  2 . 4  in the protective position, the arms in  FIG. 6  are shown in the ready position, in which the bent end portions  2 . 8  of the arms abut on the needle shaft which is not shown in  FIG. 6 . In this position, the elbow-shaped portions  2 . 7  project further upwardly and downwardly over the lateral stays  3   a  and  3   b , so that the lugs  3 . 4   a  and  3 . 4   b  offer additional protection from displacement of the arms.  FIGS. 8 and 9  show the arrangement of the lugs  3 . 4   a  and  3 . 4   b  at the stays without a safety element. In other words,  FIGS. 8 and 9  show a band-shaped guard  3 . 9  provided according to an aspect of the present method, system and device, wherein the safety element  2  is not shown in  FIGS. 8 and 9 . 
         [0066]      FIG. 10  is a perspective view of an embodiment in which lugs  3 . 4   a ′ and  3 . 4   b ′ are formed enlarged in the longitudinal direction of the stays, by means of which the protection from deformation of the needle safety element  2  is further improved. Here, a contribution to the stiffness of the device is also made by a lug being formed on each side of each stay  3   a  and  3   b , as shown in  FIGS. 10 and 11 , wherein  FIG. 11  represents a view of the needle safety device from below in  FIG. 10 . In other words, each stay comprises two lugs extending from each longitudinal edge of the stay. As can be seen from  FIG. 10 , due to the enlargement of the lug, in the proximal direction a shorter distance results between the proximal edge of the lug  3 . 4   b ′ and the widened portion  2 . 31  of the arm  2 . 3 , while on the opposite side, the distal edge of the enlarged lug  3 . 4   b ′ lies in the distal direction a shorter distance from the arm  2 . 4  and overlaps the same, so that the two arms  2 . 3  and  2 . 4  can be displaced upwardly and downwardly to a slighter degree than in the embodiment of  FIGS. 6 and 7 . 
         [0067]    Thus the present method, system and device comprise an elongation or extension of the lug in a distal and/or proximal direction at the associated stay, to limit upward and downward displacement of the arm. In other words, the lugs can be configured in the axial direction such that they determine the displacement of the arms in the radial direction. 
         [0068]    To achieve this effect, the lugs formed at the opposite stays  3   a  and  3   b  can also be offset to each other in the longitudinal direction, so that for example in  FIG. 10  the lug  3 . 4   b ′ is offset further in the distal direction relative to the opposite lug  3 . 4   a ′.  FIG. 11  shows lugs  3 . 4   a ′ and  3 . 4   b ′ offset relative to each other in the longitudinal direction. 
         [0069]    The lugs have rounded corners to avoid sharp edges. Preferably, an arc-shaped transition is formed between the enlargement  3 . 3  and the shoulder of the lug  3 . 4   b ′, as  FIG. 10  clearly shows. 
         [0070]    Thus a further aspect of the present method, system and device is a safety means having a band-shaped guard having two lugs along a first side which are offset in the axial direction, and along a second side, which are also offset in the axial direction. 
         [0071]    The stiffening frame made from thin sheet metal by punching and bending and having the stays  3   a ,  3   b , has an approximately U-shaped basic form with flattened shoulders corresponding to the stays, as can be seen from  FIGS. 8 and 9 . The stays  3   a  and  3   b  provided with lugs, extending transverse to the arms  2 . 3  and  2 . 4 , extend continuously from the proximal end over the distal end of the needle safety element  2  and provide a stiff frame for the needle safety device. 
         [0072]    According to another embodiment, the lugs  3 . 4   a ′ and  3 . 4   b ′ in  FIGS. 10 and 11  can be formed lengthened in the peripheral direction, so that the edges of the lugs, which lie opposite each other, form a narrow gap on the upper and lower side of the needle safety device, which gap is formed relatively wide in  FIGS. 10 and 11  by the distance of the opposite edges of the lugs  3 . 4   a ′ and  3 . 4   b ′. In other words, the edge of each lug extending in the longitudinal direction can extend further in the direction towards the needle shaft or in the peripheral direction, so a narrower gap is present between the two opposite edges of the two lugs  3 . 4   a ′ and  3 . 4   b ′ extending in the longitudinal direction in  FIG. 11 . 
         [0073]    According to a further embodiment, the opposite lugs  3 . 4   a ′ and  3 . 4   b ′ can also be lengthened in the peripheral direction so far that their edges abut at each other on the upper and lower side or only on one side and thus overlap or cover the middle portion of the intersecting arms  2 . 3  and  2 . 4 . In such an embodiment, the lugs  3 . 4   a  and  3 . 4   b  provide a closed or approximately closed cross section together with the stays  3   a  and  3   b  in a sectional view of the needle safety device. Hereby, the lugs surrounding the needle safety element  2  extend into the free space O ( FIG. 1 ) between the proximal and the distal ends of the needle safety element such that they lie inside the elbow-shaped portions  2 . 7  of the arms of the safety element in a front view of the needle safety element, at least when the arms are in the ready position, in which they are pre-stressed in a radially outward direction by the needle shaft, as shown in  FIG. 6 . The peripheral line of the elongation  3 . 2  is also formed together with the cap-shaped bracket such that it lies radially inside the elbow-shaped portions  2 . 7  of the arms in the ready position, as shown in  FIG. 6 . In this way, the radial outer dimensions in the area of the cap and of the lugs correspond approximately to the outer dimension of the proximal rear wall  2 . 1 . Preferably, the cap and the lugs have a smaller profile than the proximal rear wall  2 . 1  in the front view from the left in  FIG. 6 . 
         [0074]    In the embodiment of  FIG. 6 , each lug  3 . 4   a  and  3 . 4   b  can also extend along approximately half of the periphery up to the opposite stay  3   a  or  3   b , so that in this way too, a closed cross section is provided in the middle portion of the needle safety element  2 . 
         [0075]    According to a further modification, the needle safety element can also be formed with arms  2 . 3  and  2 . 4  extending approximately parallel to each other, wherein the two arms can be bent in the middle portion preferably somewhat inwardly toward the needle, so that in this area the lugs  3 . 4   a  and  3 . 4   b  can overlap the arms of the safety element further inwardly, while the elbow-shaped portions  2 . 7  provided for engagement with a catheter hub are exposed. In the embodiments shown, in the view according to  FIG. 1 , by means of the intersecting arms  2 . 3  and  2 . 4  a free space O is provided in their middle area between the articulation portion of the arms at the proximal rear wall  2 . 1  and elbow-shaped portions  2 . 7 , into which the lugs  3 . 4   a  and  3 . 4   b  can extend. This free space O can also be formed by deflection of non-intersecting but opposite arms. 
         [0076]    The needle safety element  2  described is preferably formed by punching and bending of a thin metal strip so that altogether the smallest possible overall dimensions are achieved. In practice, the safety element  2  has for example a longitudinal dimension of approximately 8 mm and a radial dimension of approximately 3 mm. In a corresponding way, the frame around the two arms is formed by punching and bending of the sheet metal such that the overall dimensions of the needle safety device are not increased by a remarkable amount. It is clear that the same configuration can be achieved using a plurality of components or parts which are assembled to obtain a safety element having a band-shaped guard for improving stability. The plurality of single parts can be formed from different metals or materials or from a plastic-metal compound. 
         [0077]    According to a modification, the cap-shaped bracket  3   c  can also be joined to the stays  3   a  and  3   b  by adhesion or welding. The bracket can also be formed such that it extends under or over the needle shaft, wherein for example an approximately semicircular recess can be formed in the bracket for guiding the needle shaft in the ready position. A bracket having a bore for the passage of the needle as shown is preferred. 
         [0078]    When the elbow-shaped portions  2 . 7  have another function than engaging with a catheter hub, these arc-shaped portions  2 . 7  can also have another shape. For example, they can be bent sharply, to form an edge acting outwardly. It is also possible to form this arc-shaped portion  2 . 7  flattened, so that it does not protrude or hardly protrudes over the periphery of the cap-shaped bracket  3   c.    
         [0079]    Instead of sheet metal, another material can also be used, which when having small dimensions is correspondingly formable to form a needle safety device having small dimensions in this way. 
         [0080]    The small dimensions of the needle safety device made of sheet metal also allow the needle safety device arranged in the ready position on a hollow medical needle in the proximal area of the needle shaft to be covered by a conventional needle safety cap  5 , which cap is placed on a needle hub  1 . 4 , as  FIG. 12  shows, without the risk of the needle safety device being moved on the needle shaft during removal of the needle safety cap  5 . 
         [0081]    Preferably, grooves extending lengthwise are formed onto the needle safety cap  5  and distributed over its inner periphery, and by means of these grooves the needle safety cap is held on the needle hub  1 . 4  on which corresponding radially projecting ribs  1 . 5  are formed distributed over the periphery. Due to the small radial dimensions of the needle safety element  2  having the stiffening frame  3   a  to  3   c , there is no risk that the needle safety cap  5  could contact the needle safety element  2 , so the inner and/or outer surfaces of the needle safety cap  5  can also be formed corrugated. 
         [0082]    If the described needle safety device is made of plastic, it has larger dimensions, wherein a frame formed as described is provided in the same way around the resilient arms of the needle safety element. 
         [0083]    Instead of two bent distal end walls of the safety element  2 , a safety element can also be provided wherein only one arm has a bent distal end wall, which overlaps the needle tip in the protective position.