Automatic self-injection device

An automatic injection device comprising:

• a housing having a longitudinal axis;
• a cartridge mounted within said housing;
• a piston slidably mounted within said cartridge;
• a needle assembly mounted to said cartridge;
• a rod;
• a driver releasably coupled to said rod;
• a constant force spring having one end secured to said housing and a second end variably wound with respect to a portion of said rod for urging said rod along the longitudinal axis of said housing such that said driver urges said cartridge and said rod urges said piston along the longitudinal axis, and
• means for automatically decoupling said driver and said rod as said rod moves along the longitudinal axis such that said rod moves said piston with respect to said cartridge upon said driver being decoupled from said rod.

An assembly for providing automatic injections, comprising:

• a syringe assembly including a cartridge, a piston slidably mounted within said cartridge, a first end portion including a needle assembly mounted to said cartridge, and a second end portion including an abutment member;
• a drive assembly including a housing having an open end, a rod slidably mounted within said housing, a spring having one end secured to the housing and a second end engaged with said rod for resiliently urging said rod towards the open end of said housing, and retaining means for releasably retaining said rod in a storage position against the force of said spring, and
• means for releasably connecting said syringe assembly and said drive assembly,
• said abutment member being engageable with said rod when said syringe assembly is moved into the open end of said housing of said drive assembly, thereby urging said rod away from said open end against the force of said spring.

A drive assembly for an automatic injection device comprising:

• a housing having a longitudinal axis, a first end, and a second end;
• a drive rod positioned within said housing, said drive rod including a first engagement member;
• a driver including a body having an opening, and a second engagement member, said drive rod extending through said opening such that said second engagement member is engageable with said first engagement member;
• spring means having one end secured to said housing and a second end secured with said drive rod for resiliently urging said drive rod towards said first end of said housing, and
• means for automatically disengaging said second engagement member from said first engagement member as said drive rod moves axially within said housing such that said drive rod moves independently of said driver.

An automatic injection device comprising:

• a drive assembly including a housing and a drive rod slidably mounted within said housing;
• a syringe assembly including a cartridge, a piston slidably mounted within said cartridge, and a needle assembly mounted to said cartridge;
• constant force spring means having one end secured to said housing and a second end variably wound with said drive rod for resiliently urging said drive rod towards said syringe assembly;
• means fix releasably retaining said drive rod in a storage position, said means for releasably retaining including a pushbutton slidably mounted to said housing, and
• means for drawing said pushbutton within said housing as said drive rod moves from said storage position to a deployed position.

An automatic injection device comprising:

• a syringe assembly including a cartridge, a piston slidably mounted within said cartridge, and a needle assembly mounted to said cartridge;
• a sleeve, said syringe assembly being positioned at least partially within said sleeve;
• a drive assembly coupled to said syringe assembly and including a housing, a first drive member within said housing for driving said syringe assembly, a second drive member within said housing for driving said piston with respect to said cartridge, and constant force spring means having one end secured to said housing and a second end variably wound with said second drive member for resiliently urging said first and second drive members towards said syringe assembly;
• a pushbutton movably mounted to said housing, said pushbutton including a projection extending outside said housing, a first engagement member releasably retaining said first and second drive members in a storage position, and a second engagement member,
• means for slidably mounting said sleeve with respect to said syringe assembly such said sleeve is slidable between first and second axial positions, said second engagement member of said pushbutton being in opposing relation to a portion of said sleeve when said sleeve is in said first axial position such that said portion of said sleeve limits the movability of said pushbutton with respect to said housing, said portion of said sleeve being displaced from said second engagement member when said sleeve is in said second axial position such that said pushbutton can be moved a sufficient distance with respect to said housing to release said first and second drive members from said first engagement member.

An automatic injection device comprising:

• a syringe assembly including a cartridge, a piston slidably mounted within said cartridge, and a needle assembly mounted to said cartridge;
• a drive assembly coupled to said syringe assembly, said drive assembly including a housing, a drive apparatus within said housing, and first means comprising a constant force spring having one end secured to said housing and a second end variably wound with said drive apparatus for resiliently urging said drive apparatus towards said syringe assembly such that said piston is displaced with respect to said cartridge and said syringe assembly is displaced with respect to said housing from a storage to a deployed position;
• an elongate sleeve mounted to said cartridge, and
• second means for resiliently urging said sleeve over said needle assembly, said elongate sleeve being movable by said second means for resiliently urging to a position covering said needle assembly when said syringe assembly is in said deployed position.