Syringe piston with check valve seal
First Claim
1. A syringe piston comprising:
- a piston body having a fluid end and an actuator end opposite the fluid end;
a piston seal coupled to the piston body and located between the fluid end and the actuator end, wherein the piston seal forms an interference fluid seal with an interior wall of a syringe barrel;
a check valve seal coupled to the piston body and positioned such that the piston seal is located between the check valve seal and the actuator end, the check valve seal having a major outer surface that faces a main fluid chamber of the syringe barrel; and
a gas entrapment zone defined between the check valve seal and the piston seal, wherein the check valve seal allows one-way gas flow from the main fluid chamber of the syringe barrel and into the gas entrapment zone, and the piston seal inhibits or prevents gas flow from the gas entrapment zone.
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Accused Products
Abstract
A fluid syringe of the type used with fluid infusion devices is presented here. The fluid syringe generally includes a barrel, a piston, and a check valve seal. The barrel has an interior wall and a sealed main fluid chamber. The piston is slidably coupled within the barrel, and the piston has a piston seal forming an interference fluid seal against the interior wall. The check valve seal is coupled to the piston, and it is located between the piston seal and the main fluid chamber. The check valve seal forms an interference fluid seal against the interior wall when the piston is unloaded, and it disengages the interior wall to allow gas flow from the main fluid chamber toward the piston seal when the piston is loaded.
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Citations
20 Claims
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1. A syringe piston comprising:
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a piston body having a fluid end and an actuator end opposite the fluid end; a piston seal coupled to the piston body and located between the fluid end and the actuator end, wherein the piston seal forms an interference fluid seal with an interior wall of a syringe barrel; a check valve seal coupled to the piston body and positioned such that the piston seal is located between the check valve seal and the actuator end, the check valve seal having a major outer surface that faces a main fluid chamber of the syringe barrel; and a gas entrapment zone defined between the check valve seal and the piston seal, wherein the check valve seal allows one-way gas flow from the main fluid chamber of the syringe barrel and into the gas entrapment zone, and the piston seal inhibits or prevents gas flow from the gas entrapment zone. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A syringe piston comprising:
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a piston body having a fluid end and an actuator end opposite the fluid end; a piston seal coupled to the piston body and located between the fluid end and the actuator end, wherein the piston seal forms an interference fluid seal with an interior wall of a syringe barrel; a check valve seal coupled to the piston body and positioned such that the piston seal is located between the check valve seal and the actuator end, the check valve seal having a major outer surface that faces a main fluid chamber of the syringe barrel, and the check valve seal comprising a flap having asymmetric deflection characteristics such that the flap is easier to deflect in a direction toward the actuator end, relative to deflection in a direction away from the actuator end; and a gas entrapment zone defined between the check valve seal and the piston seal, wherein the check valve seal allows one-way gas flow from the main fluid chamber of the syringe barrel and into the gas entrapment zone, and the piston seal inhibits or prevents gas flow from the gas entrapment zone. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. A syringe piston comprising:
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a piston body having a fluid end and an actuator end opposite the fluid end; a piston seal coupled to the piston body and located between the fluid end and the actuator end, wherein the piston seal forms an interference fluid seal with an interior wall of a syringe barrel; a check valve seal coupled to the piston body and positioned such that the piston seal is located between the check valve seal and the actuator end, the check valve seal having a major outer surface that faces a main fluid chamber of the syringe barrel, and the check valve seal comprising a flap that cooperates with the interior wall of the syringe barrel; and a gas entrapment zone defined between the check valve seal and the piston seal, wherein the check valve seal allows one-way gas flow from the main fluid chamber of the syringe barrel and into the gas entrapment zone, the check valve seal inhibits gas flow from the gas entrapment zone into the syringe barrel, and the piston seal inhibits or prevents gas flow from the gas entrapment zone;
whereinthe flap seals against the interior wall of the syringe barrel when the syringe barrel is closed and the syringe piston is uncompressed; the flap disengages the interior wall of the syringe barrel when the syringe barrel is closed and the syringe piston is compressed; and the flap seals against the interior wall of the syringe barrel when the syringe barrel is open and the syringe piston is compressed for purposes of dispensing fluid. - View Dependent Claims (17, 18, 19, 20)
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Specification