Abstract:
A device for selectively protecting a needle includes an adapter holding the needle and a guard engaging the adapter for relative movement therebetween. Further, the device includes a means for guiding movement between the adapter and the guard. Structurally, the guiding means includes a “V” shaped slot in the guard and a radially-extending boss on the adapter. The boss is received in the slot to limit relative movement between the guard and the adapter. Specifically, in a first position of the device, the boss is in a first leg of the slot and the needle partially extends beyond the guard. In a second position, the boss is held at the apex of the slot and the needle fully extends beyond the guard. In a third position, the boss is in the second leg of the slot and the needle is retracted into the guard to protect the needle.

Description:
REFERENCE TO RELATED APPLICATION 
       [0001]    The present application is a continuation of U.S. patent application Ser. No. 11/267,830 filed Nov. 4, 2005, and hereby incorporates the same application herein by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention pertains generally to needle protection devices. More particularly, the present invention pertains to needle protection devices that use a cylindrical guard to extend beyond the needle&#39;s tip to prevent contact with the tip. The present invention is particularly, but not exclusively useful as a needle protection device that uses cooperation between a “V” shaped slot and a radially-extending boss to limit relative movement between the guard and the needle. 
       BACKGROUND OF THE INVENTION 
       [0003]    Needles are very common in medical practices, and are frequently used to deliver medications or to draw blood for diagnosis. As a result of their intensive use, it is estimated that some 600,000 to 800,000 accidental needle stick injuries occur every year. Further, there are roughly 8,000,000 healthcare workers in the United States who are at risk of being stuck with a contaminated needle. As the risks involved in providing medical treatment have risen and individual safety and sanitation are taken into consideration, disposable or single-use type of injection devices have become prevalent. While safer than reusable injection devices, these needles must still be handled carefully and the needle tips must be covered before and after use. 
         [0004]    Although currently there exist various needle protection devices, most require the user to take an affirmative step to cover the needle tip after its use, thereby causing potential risk of contact with the needle. Other devices require specially designed needles, plungers, or medicament chambers. 
         [0005]    In light of the above, it is an object of the present invention to provide a protective device that can be installed on a needle to ensure there is only a single use of the needle. It is another object of the present invention to provide a protective device having a guard that passively covers and protects the needle after an injection. It is another object of the present invention to provide a protective device that controls movement of the guard relative to the needle. Still another object of the present invention is to provide a protective device that requires an affirmative step to uncover the needle, but automatically covers the needle after an injection. Yet another object of the present invention is to provide a protective device for a needle that is relatively easy to manufacture, reliable and easy to use, and is comparatively cost effective. 
       SUMMARY OF THE INVENTION 
       [0006]    In accordance with the present invention, a needle protection device includes an adapter for holding a needle. The device also includes a guard having a cylindrical wall that is dimensioned to engage the adapter for relative axial movement therebetween. Such movement is biased by a spring that urges the guard away from the adapter. Further, the guard includes an orifice for selectively passing the needle therethrough. In order to guide relative movement between the adapter and the guard, the guard is provided with a “V” shaped slot having a first leg and a second leg with an apex therebetween. Correspondingly, the adapter is provided with a radially-extending boss. The boss is received within the slot to limit relative movement between the guard and the adapter. 
         [0007]    As a result of cooperation between the slot and the boss mentioned above, the device is only moveable from a first position to a second position, and from the second position to a third position. In the first position, the boss is in the first leg of the slot and the needle partially extends through the orifice of the guard. In the second position, the needle fully extends through the orifice of the guard and the boss is held at the apex of the slot in response to a force opposing the biasing means. In the third position, the boss is in the second leg of the slot and the needle is retracted into the guard to protect the needle. 
         [0008]    For the purposes of the present invention, the boss is provided with an engagement face that is designed to interact with the slot to ensure that the boss moves to the end of the second leg from the apex during movement of the guard from the second position to the third position. Specifically, the face is inclined toward the second leg, so that contact between the face on the boss and the edge of the slot causes the boss to move toward the end of the second leg. 
         [0009]    In order to protect the needle before use, the device may further include a removable shield. Structurally, the shield includes a hollow portion for receiving the needle. Further, the shield includes a radially extending rib that can be selectively positioned in the orifice of the guard to prevent axial movement of the guard from the first position to the second position. 
         [0010]    For the present invention, the device may further include a locking mechanism that locks the device in the third position, to thereby prevent further relative movement between the guard and the adapter. Specifically, the adapter is provided with a shoulder that extends radially outward, and the guard is provided with an abutment that extends radially inward. When the device moves into the third position, the shoulder and the abutment engage one another to prevent further relative movement between the guard and the adapter. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which: 
           [0012]      FIG. 1A  is a perspective view of a needle protection device of the present invention; 
           [0013]      FIG. 1B  is a perspective view of the guard shown in  FIG. 1A , illustrating the movement of the boss in the “V” shaped slot; 
           [0014]      FIG. 2A  is a cross section view of the needle protection device of  FIG. 1A , as seen along line  2 - 2  in  FIG. 1B ; 
           [0015]      FIG. 2B  is a cross section view of the needle protection device of  FIG. 2A  with the removable shield rotated for removal in accordance with the present invention; 
           [0016]      FIG. 3  is a cross section view of the needle protection device of  FIG. 2B , as seen along line  3 - 3  in  FIG. 1B , with the shield removed and the needle inserted into a subject in accordance with the present invention; 
           [0017]      FIG. 4A  is a cross section view of the needle protection device of  FIG. 3 , as seen along line  4 - 4  in  FIG. 1B , with the needle withdrawn from the subject and the guard advanced to cover the needle tip in accordance with the present invention; 
           [0018]      FIG. 4B  is a cross section view of the needle protection device of  FIG. 4A , as seen from a view taken ninety degrees from the view in  FIG. 4A ; and 
           [0019]      FIG. 5  is a side view of the slot and boss arrangement showing the configuration of the slot and the boss in the first, second and third positions. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0020]    Referring initially to  FIG. 1A , a needle protection device in accordance with the present invention is shown and generally designated  10 . As shown, the device  10  covers a needle  12  (shown in phantom) to prevent inadvertent contact with the needle tip  14 . For discussion of the present invention, the needle  12  defines an axis  16 , a proximal direction  15  and a distal direction  17 . Structurally, the device  10  includes a guard  18  having a cylindrical wall  20  that slidingly engages an adapter  22 . Further, the wall  20  includes a radially extending “V” shaped slot  24  that corresponds with and receives a boss  26  that extends radially outward from the adapter  22 . The slot  24  includes a first leg  28  which meets a longer second leg  30  at an apex  32 . As shown, the boss  26  is positioned in the first leg  28  of the slot  24 . For the purposes of the present invention, the slot  24  and boss  26  cooperate to guide axial movement of the guard  18  relative to the adapter  22 . 
         [0021]    Still referring to  FIG. 1A , the guard  18  is shown as including an axially extending orifice  34  that is formed with a long axis  36  and a short axis  38 . In addition to the guard  18  and the adapter  22 , the device  10  includes a removable shield  40 . In  FIG. 1A , the shield  40  is shown passing through the orifice  34  and including radially extending grips  42  to facilitate rotation of the shield  40  about the axis  16  as discussed below. As shown, the device  10  further includes a spring  44  that biases the guard  18  away from the adapter  22 . 
         [0022]    Referring to  FIG. 1B , the boss  26 ′ is positioned in the first leg  28  of the slot  24  (i.e., the first position of the device  10 ), the boss  26 ″ is positioned at the apex  32  of the slot  24  (i.e., the second position of the device  10 ), and the boss  26 ″ is positioned in the second leg  30  of the slot  24  (i.e., the third position of the device  10 ). As can be understood from cross-referencing  FIG. 1A  with  FIG. 1B , movement of the boss  26  between these positions results in rotational movement of the guard  18  about the axis  16  relative to the adapter  22 , particularly during movement from boss  26 ′ to boss  26 ″. 
         [0023]    Referring now to  FIGS. 2A and 2B , internal components and features of the device  10  can be seen. As shown, the adapter  22  includes an axially-extending and substantially cylindrical base member  46  centered about the axis  16 . Further, the adapter  22  includes a radially-extending cap member  48 . As shown, the adapter  22  has an external surface  50  and an internal surface  52 , with the internal surface  52  defining an internal cavity  54 . As further shown, the needle  12  passes through an aperture  56  formed in the cap member  48 . 
         [0024]    Turning to the guard  18 , it can be seen from  FIGS. 2A and 2B , that the cylindrical wall  20  includes an outer side  58  and an inner side  60 . As shown, the inner side  60  defines a chamber  62  in which the adapter  22  is partially received. The chamber  62  is further bounded by an end member  64  mounted to the cylindrical wall  20  and forming the orifice  34 . For the purposes of the invention, the spring  44  is positioned in the chamber  62  between the cap member  48  of the adapter  22  and the end member  64  of the guard  18  to bias the guard  18  axially away from the adapter  22 . 
         [0025]    As further shown in  FIGS. 2A and 2B , the device  10  includes a removable shield  40  having a hollow portion  66  for receiving the needle  12 . As shown in  FIG. 2A , the shield  40  includes radially extending ribs  68  that are engaged with the guard  18  and the adapter  22 . In the orientation of  FIG. 2A , the ribs  68  prevent axial movement of the guard  18  toward the adapter  22 . Cross-referencing  FIG. 2A  with  FIG. 2B , it can be seen that the ribs  68  may be removed from contact with the guard  18 . Specifically,  FIG. 2B  depicts the shield  40  of  FIG. 2A  after the shield  40  has been rotated ninety degrees about the axis  16 . As a result, the ribs  68  are aligned with the long axis  36  of the orifice  34  (see  FIG. 1A ) and the shield  40  may be removed from the device  10 . 
         [0026]    Typically, the device  10  is stored and transported in the orientation shown in  FIG. 2A . Before the needle  12  is used for an injection, the shield  40  is rotated as in  FIG. 2B  and is removed. Regardless of the position of the shield  40 , each of  FIGS. 1A ,  2 A and  2  B depict the device in a first position  70  in which the boss  26  is received within the first leg  28  of the slot  24 . After the shield  40  is removed, the guard  18  may be moved in the proximal direction  15  toward the adapter  22  if a sufficient force is applied thereto. Specifically, if a force greater than the biasing force of the spring  44  is applied. 
         [0027]    In  FIG. 3 , the result of an application of such a force is shown. As shown, the needle  12  has been injected into a subject  72 . As a result, the force of the subject  72  on the guard  18  has caused the guard  18  to move toward the adapter  22 . Specifically, the device  10  has moved to the second position  74  in which the boss  26  is positioned at the apex  32  of the slot  24 . When the boss  26  reaches the apex  32 , further movement of the guard  18  toward the adapter  22  is prevented by the interaction between the slot  24  and the boss  26 . 
         [0028]    After the needle  12  has injected a fluid  76  into the subject  72 , the needle  12  is withdrawn from the subject  72 . During withdrawal, the spring  44  pushes the guard  18  away from the adapter  22 . At the same time, the boss  26  moves from the apex  32  to the second leg  30  (as shown in  FIG. 4A ). 
         [0029]    To ensure that the boss  26  moves to the end of the second leg  30  rather than back to the first leg  28 , the boss  26  is provided with an engagement face  78 . The face  78  is inclined toward the second leg  30  so that when the boss  26  moves out of the apex  32  it slides to the end of the second leg  30 . 
         [0030]    Referring now to  FIG. 4A , the device  10  is shown in its third position  80  with the boss  26  in the second leg  30 . As shown, the guard  18  is extended and fully covers the needle tip  14 . In order to prevent any further use of the needle  12 , the device  10  is provided with the locking mechanism  82  seen in  FIG. 4B .  FIG. 4B  is a cross section view of the device  10  taken from a view ninety degrees from the view in  FIG. 4A . Approximately ninety degrees from the bosses  26  shown in  FIG. 4A  are two shoulders  84  shown in  FIG. 4B  that extend radially outward from the adapter  22 . As further seen in  FIG. 4B , the device  10  includes two corresponding abutments  86  that extend radially inward from the guard  18 . As shown, the shoulders  84  and abutments  86  are tapered. This construction allows the shoulders  84  to slide in the proximal direction  15  along the inner side  60  of the guard  18  until they pass the abutments  86 . Once the shoulders  84  pass the abutments  86 , the guard  18  can no longer be moved toward the adapter  22 . As a result, the device  10  is locked with the needle  12  protected by the guard  18 . 
         [0031]    Referring now to  FIG. 5 , the interaction between the slot  24  and the boss  26  can be clearly shown. In  FIG. 5 , the boss  26  is shown in the various stations (indicated by  26 ′,  26 ″, and  26 ′″) it passes through during operation of the device  10 . Specifically, the boss  26 ′ is shown in the first leg  28  adjacent the first stop  88  when the device  10  is in the first position  70 . The first stop  88  may serve to prevent axial movement of the guard  18  away from the adapter  22 . As noted above, the shield  40  prevents axial movement of the guard  18  toward the adapter  22  when the ribs  68  are positioned between the guard  18  and adapter  22 . When the ribs  68  are disengaged from the guard  18  and the shield  40  has been removed, the spring  44  retains the boss  26 ′ in the first leg  28 . 
         [0032]    When a force is applied to the guard  18  in the proximal direction  15  to move the guard  18  toward the adapter  22 , i.e., during an injection, the boss  26 ′ moves from the first stop  88  to its position as boss  26 ″ at the apex  32 . Movement of the guard  18  toward the adapter  22  may be stopped by contact between the boss  26 ″ and the apex  32 , or by contact between other components in the device  10 . 
         [0033]    When the force in the proximal direction  15  is removed, i.e., during withdrawal of the needle  12  from the subject  72 , the spring  44  forces the guard  18  away from the adapter  22  in the distal direction  17 . As a result, the boss  26 ″ moves axially away from the apex  32  to its position at boss  26 ′″ in the second leg  30  of the slot  24 . As indicated by  FIG. 5 , during movement from boss  26 ″ to boss  26 ′″, the engagement face  78  may contact the edge  90  of the slot  24 . Due to the inclination of the engagement face  78  toward the second leg  30  and the slope of the edge  90  of the slot  24 , contact between the boss  26  and the edge  90  of the slot  24  causes the boss  26  to move to the second stop  92  of the second leg  30 . Alternatively, the boss  26 ″ may move substantially in the proximal direction  15  directly to the second stop  92  of the second leg  30 . In either case, the spring  44  forces the guard  18  away from the adapter  22  until the boss  26 ′″ contacts the second stop  92  or until further axial movement of the guard  18  away from the adapter  22  is otherwise prevented. As shown in  FIG. 4B , the locking mechanism  82  then prevents any further relative movement between the guard  18  and the adapter  22 . 
         [0034]    While the particular Automatic Needle Guard for Medication Pen as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages herein before stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as described in the appended claims. Further, it is contemplated that the boss and slot cooperating structures may be reversed such that the boss be formed on the guard and the slot be formed in the adapter. Such an embodiment is considered to be an equivalent combination of structure to the specific embodiment disclosed and claimed herein.