초록 ▼

A medication dispensing apparatus having a manually operable plunger axially shiftable relative to the apparatus housing. The plunger is pullable relative to the housing in a proximal direction to cock the apparatus, and when the plunger is then manually pushed back toward the housing, a piston with

A medication dispensing apparatus having a manually operable plunger axially shiftable relative to the apparatus housing. The plunger is pullable relative to the housing in a proximal direction to cock the apparatus, and when the plunger is then manually pushed back toward the housing, a piston within a medicine container of the apparatus is shifted to force medication from a needle assembly at the distal end of the apparatus. The medication dispensing apparatus also includes a priming mechanism which is operated by rotating an externally accessible driver portion to prime the apparatus for use, which priming can be performed whether or not the apparatus is in a cocked state.

대표청구항 ▼

We claim: 1. A medication dispensing apparatus comprising: a housing; a fluid container mounted to said housing, said container defining a medicine-filled reservoir with a movable piston at one end and an outlet at the other end; a drive screw with external threading, said drive screw axially exten

We claim: 1. A medication dispensing apparatus comprising: a housing; a fluid container mounted to said housing, said container defining a medicine-filled reservoir with a movable piston at one end and an outlet at the other end; a drive screw with external threading, said drive screw axially extending within said housing and movable distally to advance said movable piston toward said outlet; at least one anti-rotation member operably engaging said drive screw to prevent rotation of said drive screw within said housing; a priming driver axially retained relative to said housing and having a first portion and a second portion, said first portion internal to said housing and in threaded engagement with said drive screw, said second portion external to said housing to be manually rotatable, whereby rotation of said second portion rotates said first portion to force said drive screw to translate distally; a follower axially movable relative to said priming driver and rotatably fixed thereto, said follower including a portion internal to said housing and in threaded engagement with said drive screw; a plunger axially movable relative to said housing between a distal position and a proximal position, said plunger including a manually graspable grip portion which is pullable proximally to move said plunger from said distal position to said proximal position, said plunger connected to said follower to allow relative rotation therebetween and to shift said follower axially when said plunger moves back and forth between said distal and proximal positions; and wherein each of said follower portion and said priming driver first portion comprises a resilient construction, whereby when said plunger is pulled from said distal position to said proximal position to shift said follower proximally, said follower portion slides over said threading of said drive screw that is being axially retained by engagement with said priming driver first portion, and whereby when said plunger is pushed from said proximal position to said distal position to shift said follower distally, said priming driver first portion slides over said threading of said drive screw that is being axially advanced by engagement with said follower portion; and wherein said priming driver first portion comprises a plurality of axially extending fingers angularly spaced around a circumference of said drive screw. 2. The medication dispensing apparatus of claim 1 wherein said follower portion comprises a plurality of angularly spaced, axially extending fingers that interfit with said plurality of fingers of said priming driver first portion to rotationally key said follower with said priming driver. 3. The medication dispensing apparatus of claim 2 wherein at least one of said plurality of fingers of said priming driver first portion comprises a projecting stop that abuts at least one of said plurality of fingers of said follower portion to limit distal travel of said follower during use. 4. The medication dispensing apparatus of claim 1 wherein said priming driver comprises a radially inwardly extending ledge that abuts a radially outwardly projecting shoulder of said follower to limit proximal travel of said follower during use. 5. The medication dispensing apparatus of claim 1 wherein said priming driver comprises one of a ratchet pawl and ratchet teeth, and said housing comprises the other of the ratchet pawl and ratchet teeth, said ratchet pawl and ratchet teeth interfitting to prevent rotation of said priming driver within said housing in a direction that would force said drive screw to translate proximally. 6. The medication dispensing apparatus of claim 1 wherein said at least one anti-rotation member comprises a pair of diametrically opposed prongs that radially inwardly project from an interior wall of said housing, said prongs fitting within a pair of longitudinally extending slots formed in said threading of said drive screw. 7. The medication dispensing apparatus of claim 1 wherein said fluid container comprises a disposable cartridge removable from the apparatus for replacement, and further comprising means for resetting said drive screw to reuse the medication dispensing apparatus with a replacement cartridge. 8. The medication dispensing apparatus of claim 7 wherein said resetting means comprises a camming element movable within said housing between a ready position and a camming position, wherein movement of said camming element from said ready position to said camming position forces said follower portion and said priming driver first portion to bend radially outward to disengage said follower portion and said priming driver first portion from threaded engagement with said drive screw. 9. A medication dispensing apparatus comprising: a housing; a fluid container mounted to said housing, said container defining a medicine-filled reservoir with a movable piston at one end and an outlet at the other end; a drive screw with external threading, said drive screw axially extending within said housing and movable distally to advance said movable piston toward said outlet; at least one anti-rotation member operably engaging said drive screw to prevent rotation of said drive screw within said housing; a priming driver axially retained relative to said housing and having a first portion and a second portion, said first portion internal to said housing and in threaded engagement with said drive screw, said second portion external to said housing to be manually rotatable, whereby rotation of said second portion rotates said first portion to force said drive screw to translate distally; a follower axially movable relative to said priming driver and rotatably fixed thereto, said follower including a portion internal to said housing and in threaded engagement with said drive screw; a plunger axially movable relative to said housing between a distal position and a proximal position, said plunger including a manually graspable grip portion which is pullable proximally to move said plunger from said distal position to said proximal position, said plunger connected to said follower to allow relative rotation therebetween and to shift said follower axially when said plunger moves back and forth between said distal and proximal positions; and wherein each of said follower portion and said priming driver first portion comprises a resilient construction, whereby when said plunger is pulled from said distal position to said proximal position to shift said follower proximally, said follower portion slides over said threading of said drive screw that is being axially retained by engagement with said priming driver first portion, and whereby when said plunger is pushed from said proximal position to said distal position to shift said follower distally, said priming driver first portion slides over said threading of said drive screw that is being axially advanced by engagement with said follower portion; wherein said fluid container comprises a disposable cartridge removable from the apparatus for replacement, and further comprising means for resetting said drive screw to reuse the medication dispensing apparatus with a replacement cartridge; wherein said resetting means comprises a camming element movable within said housing between a ready position and a camming position, wherein movement of said camming element from said ready position to said camming position forces said follower portion and said priming driver first portion to bend radially outward to disengage said follower portion and said priming driver first portion from threaded engagement with said drive screw; and wherein said camming element comprises an inner ring, an outer ring and a plurality of arms connecting said inner ring and said outer ring, said inner ring positioned radially between said drive screw and both said follower portion and said priming driver first portion, said outer ring positioned within said housing radially outward of said follower portion and said priming driver first portion, and said connecting arms extending through angular gaps between said follower portion and said priming driver first portion. 10. The medication dispensing apparatus of claim 9 wherein said outer ring is located distally of said inner ring. 11. A medication dispensing apparatus comprising: a housing; a fluid container mounted to said housing, said container defining a medicine-filled reservoir with a movable piston at one end and an outlet at the other end; a drive screw with external threading, said drive screw axially extending within said housing and movable distally to advance said movable piston toward said outlet; at least one anti-rotation member operably engaging said drive screw to prevent rotation of said drive screw within said housing; a priming driver axially retained relative to said housing and having a first portion and a second portion, said first portion internal to said housing and in threaded engagement with said drive screw, said second portion external to said housing to be manually rotatable, whereby rotation of said second portion rotates said first portion to force said drive screw to translate distally; a follower axially movable relative to said priming driver and rotatably fixed thereto, said follower including a portion internal to said housing and in threaded engagement with said drive screw; a plunger axially movable relative to said housing between a distal position and a proximal position, said plunger including a manually graspable grip portion which is pullable proximally to move said plunger from said distal position to said proximal position, said plunger connected to said follower to allow relative rotation therebetween and to shift said follower axially when said plunger moves back and forth between said distal and proximal positions; and wherein each of said follower portion and said priming driver first portion comprises a resilient construction, whereby when said plunger is pulled from said distal position to said proximal position to shift said follower proximally, said follower portion slides over said threading of said drive screw that is being axially retained by engagement with said priming driver first portion, and whereby when said plunger is pushed from said proximal position to said distal position to shift said follower distally, said priming driver first portion slides over said threading of said drive screw that is being axially advanced by engagement with said follower portion; wherein said fluid container comprises a disposable cartridge removable from the apparatus for replacement, and further comprising means for resetting said drive screw to reuse the medication dispensing apparatus with a replacement cartridge; wherein said resetting means comprises a camming element movable within said housing between a ready position and a camming position, wherein movement of said camming element from said ready position to said camming position forces said follower portion and said priming driver first portion to bend radially outward to disengage said follower portion and said priming driver first portion from threaded engagement with said drive screw; and a biasing member urging said camming element from said ready position to said camming position, and wherein said camming element is operably connectable to said fluid container such that mounting of said fluid container to said housing automatically shifts said camming element from said camming position to said ready position against the urging of said biasing member, and such that dismounting said fluid container from said housing allows said biasing member to automatically shift said camming element from said ready position to said camming position. 12. The medication dispensing apparatus of claim 11 wherein said camming element is operably connectable to said fluid container by a separate interface member disposed within said housing distally of said camming element, said interface member comprising a cartridge abutting surface and a camming element abutting surface. 13. A medication dispensing apparatus comprising: a housing; a fluid container mounted to said housing, said container defining a medicine-filled reservoir with a movable piston at one end and an outlet at the other end; a drive screw with external threading, said drive screw axially extending within said housing and movable distally to advance said movable piston toward said outlet; at least one anti-rotation member operably engaging said drive screw to prevent rotation of said drive screw within said housing; a priming driver axially retained relative to said housing and having a first portion and a second portion, said first portion internal to said housing and in threaded engagement with said drive screw, said second portion external to said housing to be manually rotatable, whereby rotation of said second portion rotates said first portion to force said drive screw to translate distally; a follower axially movable relative to said priming driver and rotatably fixed thereto, said follower including a portion internal to said housing and in threaded engagement with said drive screw; a plunger axially movable relative to said housing between a distal position and a proximal position, said plunger including a manually graspable grip portion which is pullable proximally to move said plunger from said distal position to said proximal position, said plunger connected to said follower to allow relative rotation therebetween and to shift said follower axially when said plunger moves back and forth between said distal and proximal positions; and wherein each of said follower portion and said priming driver first portion comprises a resilient construction, whereby when said plunger is pulled from said distal position to said proximal position to shift said follower proximally, said follower portion slides over said threading of said drive screw that is being axially retained by engagement with said priming driver first portion, and whereby when said plunger is pushed from said proximal position to said distal position to shift said follower distally, said priming driver first portion slides over said threading of said drive screw that is being axially advanced by engagement with said follower portion; wherein said fluid container comprises a disposable cartridge removable from the apparatus for replacement, and further comprising means for resetting said drive screw to reuse the medication dispensing apparatus with a replacement cartridge; wherein said resetting means comprises a camming element movable within said housing between a ready position and a camming position, wherein movement of said camming element from said ready position to said camming position forces said follower portion and said priming driver first portion to bend radially outward to disengage said follower portion and said priming driver first portion from threaded engagement with said drive screw; and wherein said camming element comprises a grip portion and a camming portion, said grip portion external to said housing and connected to said camming portion internal to said housing. 14. The medication dispensing apparatus of claim 13 wherein said camming element translates axially when shifted from said ready position to said camming position. 15. The medication dispensing apparatus of claim 7 further comprising means for ensuring a complete resetting of said drive screw. 16. A medication dispensing apparatus comprising: a housing; a fluid container mounted to said housing, said container defining a medicine-filled reservoir with a movable piston at one end and an outlet at the other end; a drive screw with external threading, said drive screw axially extending within said housing and movable distally to advance said movable piston toward said outlet; at least one anti-rotation member operably engaging said drive screw to prevent rotation of said drive screw within said housing; a priming driver axially retained relative to said housing and having a first portion and a second portion, said first portion internal to said housing and in threaded engagement with said drive screw, said second portion external to said housing to be manually rotatable, whereby rotation of said second portion rotates said first portion to force said drive screw to translate distally; a follower axially movable relative to said priming driver and rotatably fixed thereto, said follower including a portion internal to said housing and in threaded engagement with said drive screw; a plunger axially movable relative to said housing between a distal position and a proximal position, said plunger including a manually graspable grip portion which is pullable proximally to move said plunger from said distal position to said proximal position, said plunger connected to said follower to allow relative rotation therebetween and to shift said follower axially when said plunger moves back and forth between said distal and proximal positions; wherein each of said follower portion and said priming driver first portion comprises a resilient construction, whereby when said plunger is pulled from said distal position to said proximal position to shift said follower proximally, said follower portion slides over said threading of said drive screw that is being axially retained by engagement with said priming driver first portion, and whereby when said plunger is pushed from said proximal position to said distal position to shift said follower distally, said priming driver first portion slides over said threading of said drive screw that is being axially advanced by engagement with said follower portion; wherein said fluid container comprises a disposable cartridge removable from the apparatus for replacement, and further comprising means for resetting said drive screw to reuse the medication dispensing apparatus with a replacement cartridge; and means for ensuring a complete resetting of said drive screw, wherein said resetting ensuring means comprises at least one over-center spring mechanism engagable with said drive screw. 17. The medication dispensing apparatus of claim 16 wherein said at least one over-center spring mechanism comprises at least one spring loaded pivotable member including a tip portion that slides within a longitudinally extending slot formed in said threading of said drive screw, and wherein said pivotable member automatically pivots from a first position to a second position when said tip portion inserts within a recess formed in said slot and acts against a ledge surface of said drive screw which defines said recess. 18. The medication dispensing apparatus of claim 17 wherein said ledge surface comprises a surface defining a throughbore through said drive screw. 19. The medication dispensing apparatus of claim 17 wherein said at least one spring loaded pivotable member comprises first and second pivotable members each including a tip portion that slides within a different longitudinally extending slot formed in said threading of said drive screw.