Patent ID: 7993301
Filing Date: 2011-08-09
Classification: A61M,Y10T

Abstract:
1. A drive mechanism for use in a drug delivery device is provided comprising: a housing having a proximal and a distal end; a drive member located within the said housing such that the said drive member is movable longitudinally and is non-rotatable with respect to the said housing; a piston rod that is non-rotatable with respect to the said housing and having at least one set of teeth along an internal surface of the piston rod, the piston rod is adapted to operate through the housing and transfer a force in the longitudinal direction to the distal end of the drug delivery device; a rotating component releasably engaged with said one set of teeth of said piston rod and positioned within said piston rod, wherein a) when the said drive member moves proximally with respect to the said housing the said rotating component moves proximally with respect to the said piston rod; b) when the said drive member moves distally the said rotating component moves distally displacing the said piston rod towards the distal end of the device.