Shroud deployment in automatic injection devices

An automatic injection device, comprising:

• a housing having an internal bore extending between a proximal end and a distal end;
• a shroud disposed within the internal bore at the proximal end of the housing of the automatic injection device, the shroud movable between a retracted position and an extended position relative to the housing, the shroud comprising:
• a tubular member extending between a proximal end and a distal end, and
• one or more arms extending from the distal end of the tubular member;
• and
• a syringe carrier disposed partly within the tubular member of the shroud, the syringe carrier comprising a tubular member having a slot forming a trench in an outer surface thereof extending along a length of the syringe carrier;
• wherein, as the shroud is deployed from the retracted position to the extended position, the one or more arms of the shroud move forwardly within a constrained space formed between an inner surface of the housing of the automatic injection device and an outer surface of the tubular member of the syringe carrier to engage with the trench;
• and
• wherein the trench is configured to facilitate movement of the one or more arms of the shroud within the constrained space during deployment of the shroud.

A method for forming an automatic injection device, the method comprising:

• providing a housing having an internal bore extending between a proximal end and a distal end;
• disposing a shroud within the internal bore at the proximal end of the housing of the automatic injection device, the shroud movable between a retracted position and an extended position relative to the housing, the shroud comprising:
• a tubular member extending between a proximal end and a distal end, and
• one or more arms extending from the distal end of the tubular member;
• disposing a syringe carrier partly within the tubular member of the shroud, the syringe carrier comprising a tubular member having a slot forming a trench in an outer surface thereof extending along a length of the syringe carrier to configure a constrained space formed between the housing of the automatic injection device and the tubular member of the syringe carrier to minimize a pinching effect of the one or more arms of the shroud during its movement in the constrained space when moving from the retracted position to the extended position.

A method for using an automatic injection device to deliver an injection, the method comprising:

• providing a shroud having one or more arms within a housing of the automatic injection device, the shroud being in a retracted position relative to the housing to expose a needle through an open proximal end of the shroud;
• delivering an injection using the automatic injection device through the needle;
• and
• deploying the shroud from the retracted position to an extended position relative to the housing of the automatic injection device to protectively sheath the needle after the injection, the one or more arms of the shroud moving forwardly within a constrained space formed between an inner portion of the housing of the automatic injection device and an outer portion of a tubular member of a syringe carrier
• wherein the constrained space and/or the one or more arms of the shroud are configured to minimize a pinching effect of the one or more arms during its movement in the constrained space;
• and
• wherein the outer portion of the tubular member of the syringe carrier comprises a slot forming a trench in an outer surface thereof extending along a length of the syringe carrier that increases the constrained space.