Pen-type injector

摘要

The present invention relates to injectors, such as pen-type injectors, that provide for administration of medicinal products from a multidose-cartridge and permit a user to set the delivery dose. The injector may include a housing, a piston rod adapted to operate through the housing, a dose dial sleeve located between the housing and the piston rod, and a drive sleeve located between the dose dial sleeve and the piston rod. The dose dial sleeve may have a helical thread of first lead and the drive sleeve may have a helical groove of second lead. The first lead of the helical thread and the second lead of the helical groove may be the same.

主权项

1. A drive mechanism for use in a drug delivery device comprising:
a housing having a longitudinal axis and comprising an inner surface with an insert that is rotationally and axially fixed relative to the housing; a piston rod positioned and aligned with the longitudinal axis having a first thread on a first end that is engaged with the insert; and a drive sleeve that extends about the piston rod and has internal and outer surfaces, where the internal surface is engaged with the piston rod; wherein longitudinal axial movement of the drive sleeve causes the piston rod to rotate through the insert relative to the housing.