Safety devce for a pre-filled syringe and an injection device

Abstract

According to the invention, a safety device for a pre-filled syringe with an injection needle comprises of a support body adapted to mount the pre-filled syringe, a needle shield slidably arranged with respect to the support body, a retention and locking means (M) for retaining and locking the needle shield with respect to the support body in a first and a second advanced position (PA1, PA2) and in a retracted position (PR). The needle shield comprises an annular flange adapted to rest on the skin of the patient receiving an injection. The retention and locking means (M) are arranged at a distal end of the safety device.

1 . A safety device ( 1 ) for a pre-filled syringe ( 2 ) with an injection needle ( 2 . 1 ) comprising
 a support body ( 1 . 2 ) adapted to mount the pre-filled syringe ( 2 ),   a needle shield ( 1 . 1 ) slidably arranged with respect to the support body ( 1 . 2 ),   a retention and locking means (M) for retaining and locking the needle shield ( 1 . 1 ) with respect to the support body ( 1 . 2 ) in a first and a second advanced position (PA 1 , PA 2 ) and in a retracted position (PR),   wherein the needle shield ( 1 . 1 ) comprises an annular flange ( 1 . 1 . 1 ) adapted to rest on the skin of the patient receiving an injection and wherein the retention and locking means (M) are arranged at a distal end of the safety device ( 1 ).   
     
     
         2 . A safety device ( 1 ) according to  claim 1 ,
 characterized in that the support body ( 1 . 2 ), the needle shield ( 1 . 1 ) and/or the outer body ( 1 . 3 ) is at least partially made from a transparent plastics material.   
     
     
         3 . A safety device ( 1 ) according to  claim 1  or  2 ,
 characterized in that the needle shield ( 1 . 1 ) is movable from the first advanced position (PA 1 ) to the retracted position (PR) and further to the second advanced position (PA 2 ), wherein the needle shield ( 1 . 1 ) in the first advanced position (PA 1 ) protrudes the support body ( 1 . 2 ) in the distal direction by a first distance (D 1 ) and the needle shield ( 1 . 1 ) in the second advanced position (PA 2 ) protrudes the support body ( 1 . 2 ) in the distal direction by a second distance (D 2 ), wherein the first distance (D 1 ) is smaller than the second distance (D 2 ). 
 
     
     
         4 . A safety device ( 1 ) according to one of the previous claims,
 characterized in that the retaining and locking means (M) are arranged to releasably retain the needle shield ( 1 . 1 ) in the first advanced position (PA 1 ) in a manner that is releasable by a linear translatory movement of the needle shield ( 1 . 1 ) with respect to the support body ( 1 . 2 ) parallel to a central axis (A) of the safety device ( 1 ).   
     
     
         5 . A safety device ( 1 ) according to one of the previous claims,
 characterized in that the retention and locking means (M) comprise at least one deflectable resilient arm ( 1 . 1 . 2 ).   
     
     
         6 . A safety device ( 1 ) according to one of the previous claims,
 characterized in that the resilient arm ( 1 . 1 . 2 ) is arranged with the needle shield ( 1 . 1 ) as one piece and is arranged within the needle shield ( 1 . 1 . 1 ) so as to shield the resilient arms ( 1 . 1 . 2 ) from being influenced from the exterior.   
     
     
         7 . A safety device ( 1 ) according to one of the previous claims,
 characterized in that the resilient arm ( 1 . 1 . 2 ) latches to a catching recess ( 1 . 2 . 3 ) formed to a distal end of the support body ( 1 . 2 ) to releasably retain the needle shield ( 1 . 1 ) in the first advanced position (PA 1 ).   
     
     
         8 . A safety device ( 1 ) according to one of the previous claims,
 characterized in that resilient arm ( 1 . 1 . 2 ) is pre-tensioned and deflected in the radial outward direction when latching to the catching recess ( 1 . 2 . 3 ) to releasably retain the needle shield ( 1 . 1 ) in the first advanced position (PA 1 ).   
     
     
         9 . A safety device ( 1 ) according to  claim 8 ,
 characterized in that the pre-tensioned resilient arm ( 1 . 1 . 2 ) unbends due to a material memory effect when the needle shield ( 1 . 1 ) is released from being retained in the first advanced position (PA 1 ).   
     
     
         10 . A safety device ( 1 ) according to  claim 7 ,
 characterized in that the resilient arm ( 1 . 1 . 2 ) is stressed and inwardly deflected when the needle shield ( 1 . 1 ) is in the retracted and in the second advanced position (PA 2 ).   
     
     
         11 . A safety device ( 1 ) according to  claim 10 ,
 characterized in that at least two of the stressed and inwardly deflected resilient arms ( 1 . 1 . 2 ) are locked to each other by interlocking elements ( 1 . 1 . 4 ) of the retaining and locking means (M).   
     
     
         12 . A safety device ( 1 ) according to  claim 11 ,
 characterized in that two inwardly deflected resilient arms ( 1 . 1 . 2 ) that are arranged opposite to each other are locked to each other by two interjacent interlocking elements ( 1 . 1 . 4 ) arranged opposite to each other in manner that the two inwardly deflected resilient arms ( 1 . 1 . 2 ) and the two interlocking elements ( 1 . 1 . 4 ) form an interlocked structure (S) that comprises an essentially ring-shaped cross-section.   
     
     
         13 . A safety device ( 1 ) according to one of the previous claims,
 characterized in that the needle shield ( 1 . 1 ) is biased with respect to the support body ( 1 . 2 ) in the distal direction by a spring means ( 1 . 4 ).   
     
     
         14 . A safety device ( 1 ) according to one of the previous claims,
 characterized in that the spring means ( 1 . 4 ) comprises a spring arm ( 1 . 4 . 1 ) made from a plastics material, wherein the spring arm ( 1 . 4 . 1 ) is attached to the needle shield ( 1 . 1 ) and engages a first ramp ( 1 . 2 . 6 ) formed to an outer surface of the support body ( 1 . 2 ).   
     
     
         15 . An injection device (D) comprising a safety device ( 1 ) according to one of the previous claims and a pre-filled syringe ( 2 ), wherein the safety device ( 1 ) comprises
 a support body ( 1 . 2 ) adapted to mount the pre-filled syringe ( 2 ),   a needle shield ( 1 . 1 ) slidably arranged with respect to the support body ( 1 . 2 ),   a retention and locking means (M) for retaining and locking the needle shield ( 1 . 1 ) with respect to the support body ( 1 . 2 ) in a first and a second advanced position (PA 1 , PA 2 ) and in a retracted position (PR),   wherein the retention and locking means (M) are arranged at a distal end of the safety device ( 1 ).