Torsion-spring based wind-up auto injector pen with dial-up/dial-down mechanism
US9533106B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 2012 |
| Grant date | Jan 3, 2017 |
| Priority date | — |
| Expiry date | Mar 23, 2033 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61M2205/42
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
The present invention relates to an automatic torsion spring based injection device having a dial-up/dial-down mechanism by which a dose can be set by rotating a dose setting member in a first direction and which dose size can be reduced by rotating the same dose setting member in a second and opposite direction. The dial-up/dial-down mechanism operates a torsion spring which is strained when setting a dose and unstained when rotating the dose setting element in the second direction. In order to secure the torsion spring when strained, a ratchet arm (21) following the rotation of the dose setting element in the first direction, engages a toothed element (10) such that engagement of the at least one ratchet arm (21) with teeth (12) of the toothed element (10) prevents unwinding of the torsion spring, and wherein the rotation of the dose setting member in the first direction moves the ratchet arm (21) from one tooth (12) to the subsequent tooth (12) of the toothed element (10), and rotation of the dose setting member in the second direction lowering the set dose activates the ratchet arm (21) to disengage the teeth (12) of the toothed element (10) and thereby allow the torsion spring…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.