Pen-shaped torsion spring driven injection device
US10137252B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 23, 2015 |
| Grant date | Nov 27, 2018 |
| Priority date | — |
| Expiry date | Jan 18, 2036 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61M2205/585
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
The invention relates to a pen-shaped torsion spring driven injection device for apportioning set dose of a liquid drug. A piston rod having an external thread is driven forward by a rotatable piston rod guide engaging the piston rod. The piston rod guide is rotated by a torsion spring encompassed between the housing and the piston rod guide. A scale drum having a thread engaging the external thread of the piston rod is provided, and the scale drum is rotated up and down the piston rod by a proximal located rotatable dose setting member cooperating with the scale drum. The scale drum thus move helically when rotated as the piston rod is held inrotatable during dose setting.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.