Plunger and drug delivery device

Abstract

The present specification relates to a plunger configured to transmit a force from an energy source to a piston of a primary container, the plunger comprising a plunger rod configured to be subjected to the force from the energy source, the plunger rod having an inner surface forming a cavity, wherein a support element adapted to constrain the energy source within the cavity protrudes radially inwards from the inner surface into the cavity.

1 - 14 . (canceled) 
     
     
         15 . A plunger configured to transmit a force from an energy source to a piston of a medicament container, the plunger comprising:
 a plunger rod configured to be displaced by the force in a distal direction, the plunger rod comprising a body extending along a longitudinal axis, and the body comprising a proximal end and a distal end; and   a projection provided in a proximal end region of the body and extending radially from the body.   
     
     
         16 . The plunger of  claim 15 , wherein the projection comprises two protrusions extending from a surface of the projection in a radially outward direction. 
     
     
         17 . The plunger of  claim 16 , wherein the two protrusions are axially offset with respect to each other along the longitudinal axis. 
     
     
         18 . The plunger of  claim 16 , wherein one protrusion of the two protrusions is arranged at a proximal end of the projection. 
     
     
         19 . The plunger of  claim 16 , wherein one protrusion of the two protrusions is arranged at a distal end of the projection. 
     
     
         20 . The plunger of  claim 16 , wherein a radial end of one protrusion of the two protrusions is shaped differently than a radial end of the other protrusion of the two protrusions. 
     
     
         21 . The plunger of  claim 16 , wherein one protrusion of the two protrusions has a curved portion on a surface section that angularly faces the other protrusion of the two protrusions. 
     
     
         22 . The plunger of  claim 15 , wherein the projection is a first projection, and wherein the plunger further comprises a second projection. 
     
     
         23 . The plunger of  claim 22 , wherein the first and second projections are arranged radially opposite to each other on the body. 
     
     
         24 . The plunger of  claim 15 , further comprising a boss extending radially from the body. 
     
     
         25 . The plunger of  claim 24 , wherein a proximal end surface of the boss lies substantially on a same plane as a proximal end surface of the projection. 
     
     
         26 . The plunger of  claim 25 , wherein the boss comprises an angular surface that is sloped. 
     
     
         27 . The plunger of  claim 15 , wherein the plunger rod comprises a chamfered proximal edge at the proximal end. 
     
     
         28 . The plunger of  claim 15 , further comprising an opening on the body. 
     
     
         29 . The plunger of  claim 28 , wherein the opening extends axially along the longitudinal axis. 
     
     
         30 . The plunger of  claim 28 , wherein the opening is arranged angularly offset with respect to the projection. 
     
     
         31 . The plunger of  claim 28 , wherein a proximal portion of the opening is arranged on a same circumference as a distal portion of the projection. 
     
     
         32 . The plunger of  claim 28 , wherein the opening is a first opening, wherein the plunger further comprises a second opening, and wherein the first and second openings are arranged radially opposite to each other on a distal section of the body. 
     
     
         33 . A drug delivery device comprising a plunger configured to transmit a force from an energy source to a piston of a medicament container, the plunger comprising:
 a plunger rod configured to be displaced by the force in a distal direction, the plunger rod comprising a body extending along a longitudinal axis, and the body comprising a proximal end and a distal end: and   a projection provided in a proximal end region of the body and extending radially from the body.   
     
     
         34 . The drug delivery device of  claim 33 , wherein the medicament container is prefilled with a medicament or a drug.