Piston stem insert for a carpule based piston
US5094148A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 8, 1989 |
| Grant date | Mar 10, 1992 |
| Priority date | — |
| Expiry date | May 8, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T403/7005
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A piston stem insert to be received within a hollow receptacle that is molded at the interior of a carpule based piston, so that a piston stem may be easily attached to and detached from the piston by way of the insert. In a first embodiment of the invention, a set of flexible, anti-displacement wings extend radially from the insert to releasable and frictionally engage the inside walls of a carpule, so as to prevent an inadvertent and premature displacement of the piston through the carpule. In a second embodiment, a set of anti-rotation wings extend radially from the piston stem insert to be received within respective cavities of the receptacle that are shaped so that the wings may be rotated in a single (e.g. clockwise) direction but blocked from rotation in an opposite direction. In a third embodiment, the receptacle of the piston is sized and shaped relative to the anti-rotation wings, such that said wings will be automatically aligned for receipt within the cavities of the receptable during the installation of the insert.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.