Plunger/ram assembly adapted for a fluid injector
US5800388A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 29, 1996 |
| Grant date | Sep 1, 1998 |
| Priority date | — |
| Expiry date | Feb 29, 2016 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61M2005/5073
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A plunger/ram assembly adapted for a hypodermic fluid injector having a nozzle body defining a fluid chamber and an orifice communicating with the chamber. The plunger/ram assembly comprises a plunger adapted to be movably positioned in the chamber and a ram assembly. The ram assembly is operatively connected to the plunger for drawing fluid into and expelling fluid out the chamber through the orifice. The ram assembly includes first and second driving members spaced apart by a preselected free travel distance and a resilient biasing member having a preselected preload. The resilient biasing member is operatively disposed for maintaining the free travel distance when the preload is greater than a force applied to the first driving member. The maximum fluid pressure generated by the plunger/ram assembly is controlled by a free travel distance or gap existing between first and second driving members before the injector is fired. Prior to firing, the gap is accurately maintained during movement of the plunger/ram assembly by a resilient spring member. This arrangement ensures that the injected fluid will be delivered to the patient's body at a desired pressure sufficient to properly p…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.