Syringe device having a vented piston
First Claim
1. A syringe device for dispensing a material, comprising:
- a hollow syringe barrel having an open first end and an open second end;
a piston assembly positionable within said hollow syringe barrel, said piston assembly being capable of reciprocal movement within said hollow syringe barrel between a fully advanced position and a fully retracted position, said piston assembly including a first O-ring having an air pervious gap disposed therein, wherein said piston assembly contacts said hollow syringe barrel and forms a seal against said hollow syringe barrel that is substantially impervious to the material but is not impervious to the flow of air.
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Accused Products
Abstract
A syringe assembly specifically designed to dispense high viscosity material. The syringe assembly includes a syringe barrel into which the high viscosity material is placed. A piston assembly is introduced into the syringe barrel. The piston assembly creates a seal against the interior of the syringe barrel that is impervious to the high viscosity material but is not impervious to the passage of air. Consequently, as the piston assembly is advanced into the syringe barrel, any trapped air is permitted to exit the syringe barrel without passing through the high viscosity material. The piston assembly also contains a shaped piston head that stresses the high viscosity material as it is displaced through the syringe barrel. By stressing the high viscosity material in the syringe barrel before it is dispensed, air bubbles and gaps contained within the material can be greatly reduced. Consequently, as the high viscosity material is dispensed from the syringe assembly, a homogenous mix is produced that contains very few air bubbles and gaps.
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Citations
14 Claims
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1. A syringe device for dispensing a material, comprising:
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a hollow syringe barrel having an open first end and an open second end; a piston assembly positionable within said hollow syringe barrel, said piston assembly being capable of reciprocal movement within said hollow syringe barrel between a fully advanced position and a fully retracted position, said piston assembly including a first O-ring having an air pervious gap disposed therein, wherein said piston assembly contacts said hollow syringe barrel and forms a seal against said hollow syringe barrel that is substantially impervious to the material but is not impervious to the flow of air. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A syringe device for dispensing a material, comprising:
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a syringe barrel having a first open end and an opposite second open end; a ramrod sized to fit within said syringe barrel; a piston head coupled to said ramrod within said syringe barrel, said piston head including a cut O-ring that defines a gap, wherein said gap is sized to inhibit the flow of the material but not of air and said piston head forms a seal against said syringe barrel that is substantially impervious to the material but is not substantially impervious to the flow of air. - View Dependent Claims (10, 11, 12, 13, 14)
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Specification