Pen needle magazine

Abstract

An attachable needle assembly (2) for use on a medication delivery pen (4), the needle assembly (2) comprising a spike housing (8) that is configured to engage the medication delivery pen (4) and pierce a reservoir septum (6) of the medication delivery pen (4), a needle assembly housing (22) secured to the spike housing (8), the needle assembly housing (22) enclosing a septum (40) with a cavity (42) that is in continuous fluid communication with the spike housing (8), and a plurality of needles (44) configured to pierce the needle assembly septum (40), wherein when the needle assembly housing (22) is in a first position, the plurality of needles (44) are disengaged from the needle assembly septum (40), and when the needle assembly housing (22) is in a second position, one of the plurality of needles (46) enters into fluid communication with the septum cavity (42) and is exposed for medicament delivery.

1 . An attachable needle assembly for use on a medication delivery pen, the needle assembly comprising:
 a plurality of needles;   a main housing having a first curvilinear path;   a needle assembly housing having a second curvilinear path; and   a rotating ratchet including a follower comprising an angled surface, wherein   when the needle assembly housing is in a first position, the follower travels along the first curvilinear path, and when the needle assembly housing is in a second position, the follower travels along the second curvilinear path.   
     
     
         2 . The attachable needle assembly of  claim 1 , wherein
 when the needle assembly housing is in the first position, the plurality of needles are not exposed, and when the needle assembly housing is in the second position, a selected needle of the plurality of needles is exposed for medicament delivery.   
     
     
         3 . The attachable needle assembly of  claim 1 , wherein the rotating ratchet rotates when the needle assembly housing moves from the first position to the second position. 
     
     
         4 . The attachable needle assembly of  claim 1 , wherein the first and second curvilinear paths are partially offset with respect to each other. 
     
     
         5 . The attachable needle assembly of  claim 1 , wherein the second curvilinear path cooperates with the first curvilinear path and guides the follower of the rotating ratchet to rotate. 
     
     
         6 . The attachable needle assembly of  claim 1 , wherein the second curvilinear path aligns the rotating ratchet to a selected needle of the plurality of needles to expose the selected needle for medicament delivery. 
     
     
         7 . The attachable needle assembly of  claim 6 , wherein the selected needle is disposed in the rotating ratchet. 
     
     
         8 . The attachable needle assembly of  claim 6 , wherein when the needle assembly housing moves from the first position to the second position, the rotating ratchet moves the selected needle downward to exposure for medicament delivery. 
     
     
         9 . The attachable needle assembly of  claim 1 , wherein when the needle assembly housing moves from the first position to the second position, the rotating ratchet moves downward. 
     
     
         10 . The attachable needle assembly of  claim 1 , wherein when the needle assembly housing moves from the second position to the first position, the rotating ratchet moves upward. 
     
     
         11 . The attachable needle assembly of  claim 1 , wherein when the needle assembly housing moves from the second position to the first position, the rotating ratchet rotates as the follower transitions from the second curvilinear path to the first curvilinear path. 
     
     
         12 . The attachable needle assembly of  claim 1 , further comprising a spring to move the needle assembly housing from the second position to the first position. 
     
     
         13 . The attachable needle assembly of  claim 1 , wherein the spring ensures that the follower of the rotating ratchet contacts at least one of the first and second curvilinear paths. 
     
     
         14 . The attachable needle assembly of  claim 1 , wherein the main housing is disposed in the needle assembly housing. 
     
     
         15 . The attachable needle assembly of  claim 1 , wherein the needle assembly housing moves axially relative to the main housing. 
     
     
         16 . A method of operating an attachable needle assembly on a medication delivery pen, the method comprising:
 moving a needle assembly housing from a first position to a second position;   rotating a rotating ratchet while moving downward;   aligning the rotating ratchet to a selected needle of a plurality of needles; amd moving the selected needle downward to expose the selected needle for medicament delivery.   
     
     
         17 . The method of  claim 16 , further comprising applying a spring force to move the needle assembly housing from the second position to the first position. 
     
     
         18 . The method of  claim 16 , further comprising rotating the rotating ratchet while moving upward when the needle assembly housing moves from the second position to the first position. 
     
     
         19 . The method of  claim 16 , wherein the rotating ratchet moves the selected needle downward.