Syringe with two-stage sealing pressure
US9669165B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 2013 |
| Grant date | Jun 6, 2017 |
| Priority date | — |
| Expiry date | Jun 30, 2033 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61M2205/8206
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A syringe includes a barrel, a plunger, and a sealing member creating a seal between the plunger and the barrel. The barrel includes a first portion with a first inner diameter and a second portion with a second inner diameter that is larger than the first inner diameter. The sealing member engages the first portion of the barrel to give rise to a first contact pressure when the barrel is filled with product. The first contact pressure is sufficient to maintain a gas-tight seal over the expected temperature ranges −25° C. to 40° C. A first force is applied to the plunger to overcome the first contact pressure and move the plunger out of the first portion and into the second portion to dispense product. The sealing member engages the second portion of the barrel to give rise to a second contact pressure that is lower than the first contact pressure. A second force lower than the first force is sufficient to overcome the second contact pressure and move the plunger in the second portion to continue dispensing product. The syringe may include a restraining element for accommodating expansion of the product during freezing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.