Plunger/ram assembly adapted for a fluid injector
First Claim
1. A plunger/ram assembly adapted for a fluid injector having a nozzle body defining a fluid chamber, an orifice communicating with the chamber, and a ram for communicating a force to the plunger/ram assembly, said plunger/ram assembly comprising:
- a plunger adapted to be movably positioned in said chamber; and
a ram assembly operatively connected to the plunger for drawing fluid into and expelling fluid out the chamber through the orifice, said ram assembly including first and second driving members spaced apart by a preselected free travel distance and a resilient biasing member having a preselected preload, said plunger connected to the second driving member, said resilient biasing member operatively disposed for maintaining said free travel distance when said preload is greater the force applied to the plunger/ram assembly.
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0 Petitions
Accused Products
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 pierce the patient'"'"'s skin or the like.
187 Citations
17 Claims
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1. A plunger/ram assembly adapted for a fluid injector having a nozzle body defining a fluid chamber, an orifice communicating with the chamber, and a ram for communicating a force to the plunger/ram assembly, said plunger/ram assembly comprising:
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a plunger adapted to be movably positioned in said chamber; and a ram assembly operatively connected to the plunger for drawing fluid into and expelling fluid out the chamber through the orifice, said ram assembly including first and second driving members spaced apart by a preselected free travel distance and a resilient biasing member having a preselected preload, said plunger connected to the second driving member, said resilient biasing member operatively disposed for maintaining said free travel distance when said preload is greater the force applied to the plunger/ram assembly. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A fluid injector, comprising:
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a nozzle body defining a fluid chamber and an orifice communicating with the chamber; and a plunger/ram assembly having a ram for communicating a force to the plunger/ram assembly, said plunger/ram assembly comprising; a plunger movably positioned in said chamber; and a ram assembly operatively connected to the plunger for drawing fluid into and expelling fluid out the chamber through the orifice, said ram assembly including first and second driving members spaced apart by a preselected free travel distance and a resilient biasing member having a preselected preload, said plunger connected to the second driving member, said resilient biasing member operatively disposed for maintaining said free travel distance when said preload is greater than the force applied to the plunger/ram assembly and for collapsing said free travel distance when said preload is smaller than the force applied to the plunger/ram assembly and when resistance of the plunger to movement is greater than the force applied to the plunger/ram assembly.
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Specification