Multiple chamber automatic injector

An automatic injector comprising :

• a body incorporating at least two chambers containing different ingredients of a medicament, said at least two chambers .›.being.!. including a forward ingredient chamber containing a first ingredient of said medicament and rearward ingredient chamber containing a second ingredient of said medicament, said forward and rearward ingredient chambers being longitudinally disposed adjacent one another within said body and kept in a normally sealed relation from one another, .›.separated by a thin impermeable membrane,.!.
• a needle .›.held.!. normally contained in a sheathed position within .›.said body,.!. said forward ingredient chamber, said needle being movable to an unsheathed position projecting from said body and being capable of dispensing said medicament therethrough,.Iaddend . a releasable drive .›.means.!. assembly within said body which when released drives said needle from said sheathed position into .›.an.!. said unsheathed position projecting from said body, a sealing structure for maintaining said forward and rearward chambers in said normally sealed relation from one another, said sealing structure permitting said chambers to intercommunicate to allow the ingredients to mix within said body in response to a predetermined mixing procedure;
• and
• an expulsion .›.means.!. member disposed within said body for discharging the medicament through said needle.›., and a cutting or piercing means which is movable within said body from a first position in which it is separated from said membrane to a second position where it is forcibly in contact with said membrane so as to cut or pierce said membrane before said drive means is released.!.. .›.2. An automatic injector according to claim 1, wherein said chambers for the different ingredients of the medicament are arranged axially in said body of the
• injector..!.3. An automatic injector according to claim .›.2.!. 1 , wherein .›.a first one of said chambers is arranged to contain said needle in said sheathed position and a second one of said chambers.!. said rearward ingredient chamber is arranged to contain .›.said cutting or piercing means.!. a movable elongated member being manually movable from a first position to a second position and being cooperable with said sealing structure so that said movement from said first position to said second position enables said ingredients to mix within said body before said releasable drive assembly is
• released. 4. An automatic injector according to claim 3, wherein the automatic injector has a substantially cylindrical bore within said body .›.lined by.!. , and further comprising a tubular cartridge .›.which defines.!. disposed within said bore said tubular cartridge defining said longitudinally disposed forward and rearward adjacent .›.axially spaced.!. chambers, and .›.said.!. wherein said sealing structure is in the form of an impermeable membrane separating said forward and rearward chambers .›.extends.!. , said impermeable membrane extending transversely across said cartridge at .›.an.!. a longitudinally intermediate point .›.along the length.!. of said
• cartridge. 5. An automatic injector according to claim 4, wherein said tubular cartridge is formed from a chemically inert, impermeable,
• low-friction plastics material. 6. An automatic injector according to claim 1, .›.wherein said cutting or piercing means comprises a lance.!. further comprising a movable elongated member cooperable with said sealing structure so that movement of said elongated member from a first position to a second position breaks said sealing structure to permit said ingredients to mix, and wherein said expulsion member for discharging the medicament through the needle is in the form of a plunger having a bore extending therethrough, said elongated member being arranged to extend through .›.a.!. said bore in said plunger and .›.be.!. slidable relative to said plunger .›.which constitutes said
• expulsion means for discharging the medicament through the needle.!.. 7. An automatic injector according to claim 6, wherein said releasable drive .›.means.!. assembly comprises a spring-loaded drive member engageable with said plunger , a spring, and a latching .›.means associated with said releasable drive means, said latching means.!. portion serving for holding .›.a.!. said spring in compression, said drive .›.means.!. assembly being urged by said spring to advance said plunger
• when said latching .›.means.!. portion is released. 8. An automatic injector according to claim 7, wherein said needle carries a disc and said .›.lance.!. movable elongated member is engageable with said disc after said .›.lance has cut or pierced said membrane.!. elongated member breaks said sealing structure to permit said ingredients to mix, said .›.lance.!. movable elongated member being subsequently movable with or by said plunger to force said needle out of said body of the injector into said unsheathed position, said plunger being arranged to continue its movement when said needle is in said unsheathed position to expel said medicament from said
• chambers through said needle. 9. An automatic injector according to claim 8, further including .›.means for.!. a drive pin being manually movable for advancing said .›.lance which is.!. elongated member from said first position to said second position to break said sealing structure, said elongated member being movable independently of said drive member of said releasable drive .›.means.!. assembly . 10. An automatic injector according to claim 9, wherein said drive member of said releasable drive .›.means.!. assembly comprises a tubular collet engageable with said plunger, and said .›.means.!. drive pin for advancing said .›.lance.!. elongated member is .›.comprises a drive pin.!.
• movable within said collet. 11. An automatic injector according to claim .›.1.!. 3 , wherein a first removable safety element prevents movement of said .›.cutting or piercing means.!. elongated member and a second removable safety element prevents release of
• said drive .›.means.!. assembly . 12. An automatic injector according to claim 11, wherein an end cap is provided on said body, said end cap being movable relative to said body with said second safety element when said first safety element is removed to advance said .›.cutting or piercing means.!. elongated member and said end cap being subsequently movable relative to said body to effect release of said releasable drive .›.means.!. assembly and advance
• said expulsion .›.means.!. member . 13. An automatic injector according to claim 12, wherein a tamper evident .›.means.!. member is provided for indicating removal of said first
• removable safety element. 14. An automatic injector comprising :
• a body incorporating at least two chambers, each containing different ingredients of a medicament, such chambers being adjacent to one another .›.and separated by a thin impermeable membrane.!., a sealing structure for maintaining said chambers in a normally sealed relation from one another, said sealing structure permitting said chambers to intercommunicate to allow the ingredients to mix within said body in response to a predetermined mixing procedure, a needle normally held in a sheathed position within said body, a releasable drive .›.means.!. assembly within said, body which, when released, drives said needle from said sheathed position into an unsheathed position projecting from said body, said releasable drive assembly including a spring-loaded drive member movable within said body and a latching portion for releasably latching said drive member, a plunger within said body .›.constituting expulsion means.!. for discharging the medicament through said needle,
• .›.cutting or piercing means comprising a lance.!. an elongated member arranged to extend through, and be slidable relative to, said plunger, said .›.releasable drive means comprising a.!. spring-loaded drive member being engageable with said plunger and capable of moving said plunger forwardly within said body upon release of said latching .›.means.!. portion associated with said releasable drive .›.means.!. assembly, a spring .›.held.!. maintained in compression .›.by.!. within said body when said latching .›.means.!. portion is in a latched condition , said drive member being urged by said spring to advance said plunger when said latching .›.means.!. portion is released from said latched condition , and
• .›.means.!. a manually engageable portion for advancing said .›.lance which is.!. elongated member, said elongated member being movable independently of said drive member. 15. An automatic injector according to claim 14, wherein said drive member of said releasable drive .›.means.!. assembly comprises a tubular collet engageable with said plunger, and wherein said .›.means for advancing said lance comprises a.!. manually engageable portion is in the form of a drive pin which is movable within said collet.