1. A drive assembly (32, 32B) for a device for use with a medicament container (22)
having a container body (24) and a slidable piston (26) therein, comprising: a drive
ribbon (40, 40B) movable between an axially retracted configuration and an axially
extended configuration to advance said piston axially within the container body,
wherein during movement of the drive ribbon a retracted portion of the drive ribbon
defines a spiral about a drive axis , and an extended portion (52) of the drive ribbon
defines a helical column about said drive axis in which a proximal edge section of the
drive ribbon is in engaged with a distal edge section that is adjacent to the proximal
edge section , wherein the extended portion defines a distal end of the drive ribbon
that is disposed within the container body to advance said piston .
2. The drive assembly of claim 1, wherein the drive ribbon includes a radially inward
facing surface and a plurality of gear teeth disposed along the radially inward facing
surface.
3. The drive assembly of claim 1, wherein the drive ribbon includes a radially
exterior surface and a plurality of gear teeth disposed along the radially exterior
surface.
4. The drive assembly of claim 1, wherein in the spiral the proximal edge section and
the distal edge section lie in a common plane.
5. The drive assembly of any one of the preceding claims, wherein the distal edge
section of the drive ribbon in the axially retracted configuration lies in a first plane,
and the proximal edge section of the drive ribbon in the axially retracted configuration
lies in a second plane, wherein the distance between the first and second planes is
equivalent to a width of the drive ribbon.
6. The drive assembly of any one of the preceding claims, further comprising a thrust
member engaged with one of the proximal or distal edge sections, wherein relative
rotation between the thrust member and the drive ribbon transitions the retracted
portion to the extended portion.
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7. The drive assembly of any one of the preceding claims, further comprising a
bearing member coupled to the distal end of the drive ribbon.
8. The drive assembly of any one of the preceding claims, wherein the proximal edge
section of the drive ribbon is interlocked with the distal edge section in the extended
portion of the drive ribbon.
9. The drive assembly of any one of the preceding claims, wherein one of the
proximal and distal edge sections defines a radially extending lip to directly engage
the other one of the proximal and distal edge sections.
10. The drive assembly of any one of the preceding claims, wherein one of the
proximal and distal edge sections defines a plurality of projections and the other one
of the proximal and distal edge sections defines a plurality of cooperating recesses
receiving said projections to form said helical column as an interlocked rigid
cylindrical column with axial and torsional strength sufficient to advance the piston.