Plunger for retracting needle syringe
US7713245B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 28, 2005 |
| Grant date | May 11, 2010 |
| Priority date | — |
| Expiry date | Dec 9, 2028 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61M2005/31516
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A plunger for a retracting needle syringe includes a hollow elongate body portion having a proximal end, a distal end, and a side wall therebetween defining a cavity. The distal end includes a distal wall having an inside surface and an outside surface. A stopper, at the distal end of the body portion, includes a peripheral portion performing a seal with the inside surface of a syringe barrel and at least one radial element extending from about a center of the outside surface of the distal wall to the peripheral portion. The distal end of the body portion includes at least one primary chamfer in the cavity at an intersection of the inside surface of the distal wall and the side wall. The chamfer is positioned under the at least one radial element for supporting the distal wall and the radial element when a hollow sleeve in the syringe barrel cuts through the end wall plunger. A secondary, smaller chamfer on each side of the primary chamfer is also provided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.