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US5496285A Expired / Lapsed US ⏱️ 0.0 years remaining

Disposable syringe

Assignee: Carl Freudenberg KG
•
Filing: 1994-11-18
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Granted: 1996-03-05
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Expires: 2014-11-18
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Abstract

Abstract A disposable syringe for administering liquid medicinal agents to live animal or human subjects is disclosed. The syringe comprises a hollow cylinder, filled with a medicinal agent, with which an injection needle is attached. The cylinder surrounds a piston that can be moved by means of a piston rod towards the injection needle. The piston is produced from a thermoplastically processable rubber mixture and is delimited in the direction of the medicinal agent by a peripheral sealing lip that contacts the hollow cylinder and that can be deflected in the radial direction.

Inventors

  • 👤 Herbert Schumacher
  • 👤 Norbert Messner
  • 👤 Ernst Osen
  • 👤 Dirk Ecknig

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 21:09
CPC Classifications
A; A61; A61M; A61M5/00; A61M5/178; A61M5/31; A61M5/315; A61M5/31511; A61M5/31513; A61M2005/31516; A61M2005/31521; A61M5/31515

Claims Analysis

Total Claims: 15
Claim 1
Independent Claim 168 words
A disposable syringe for administering liquid medicinal agents; comprising: a hollow cylinder having proximal and distal ends, said hollow cylinder being configured to receive a liquid; an injection needle located at the proximal end of the hollow cylinder; a piston made from a thermoplastically processable rubber mixture and being delimited in the proximal direction by a radially deflectable peripheral sealing lip, said piston being provided with a recess radially inside the sealing lip; and a piston rod, said piston being located at one end of the piston rod, said piston rod and said piston being configured to be slidable within the hollow cylinder so that the piston can be displaced by the piston rod within the hollow cylinder towards the injection needle at the proximal end of the cylinder; wherein the peripheral sealing lip on the piston contacts the hollow cylinder and is configured to be radially deformed so as to reduce the recess when driven by the piston rod towards the proximal end of the hollow cylinder.
Claim 2
Dependent Claim 168 words
A disposable syringe for administering liquid medicinal agents; comprising: a hollow cylinder having proximal and distal ends, said hollow cylinder being configured to receive a liquid; an injection needle located at the proximal end of the hollow cylinder; a piston made from a thermoplastically processable rubber mixture and being delimited in the proximal direction by a radially deflectable peripheral sealing lip, said piston being provided with a recess radially inside the sealing lip; and a piston rod, said piston being located at one end of the piston rod, said piston rod and said piston being configured to be slidable within the hollow cylinder so that the piston can be displaced by the piston rod within the hollow cylinder towards the injection needle at the proximal end of the cylinder; wherein the peripheral sealing lip on the piston contacts the hollow cylinder and is configured to be radially deformed so as to reduce the recess when driven by the piston rod towards the proximal end of the hollow cylinder.
Claim 3
Dependent Claim 38 words
A disposable syringe according to claim 1, wherein the piston is fastened by means of internal threads to external threads on the piston rod, said internal threads being axially shorter than the external threads of the piston rod.
Claim 4
Dependent Claim 37 words
A disposable syringe according to claim 1, wherein the piston is fastened by means of external threads to internal threads on the piston rod, said internal threads being axially shorter than the external threads of the piston.
Claim 5
Dependent Claim 17 words
A disposable syringe according to claim 1, wherein the rubber mixture consists predominantly of a block polymer.
Claim 6
Dependent Claim 17 words
A disposable syringe according to claim 4, wherein the rubber mixture contains a quantity of a polyolefin.
Claim 7
Dependent Claim 28 words
A disposable syringe according to claim 5, wherein polypropylene is used as the polyolefin; and the quantity in which it is provided is 1 to 30 wt %.
Claim 8
Dependent Claim 24 words
A disposable syringe according to claim 4, wherein the rubber mixture contains a quantity of 0.1 to 2 wt % of a silicone rubber.
Claim 9
Dependent Claim 31 words
A disposable syringe according to claim 1, wherein the sealing lip has at least one sealing edge that is delimited on the outside by two conical surfaces that intersect one another.
Claim 10
Dependent Claim 22 words
A disposable syringe according to claim 1, wherein the recess comprises a peripheral groove penetrating into the end surface of the piston.
Claim 11
Dependent Claim 40 words
A disposable syringe according to claim 9, wherein the hollow cylinder has an end wall, and wherein radially inside the groove the piston has an end surface that has a shape conforming to said end wall of the hollow cylinder.
Claim 12
Dependent Claim 30 words
A disposable syringe according to claim 1, wherein the end surface of the piston delimits a projection that extends beyond the sealing lip in the direction of the end wall.
Claim 13
Dependent Claim 48 words
A disposable syringe according to claim 11, wherein the piston comprises an excess length at its proximal side and this excess length is dimensioned so that the radial displacement of the sealing lip that results when the piston is pressed against the end wall substantially fills the groove.
Claim 14
Dependent Claim 32 words
A disposable syringe according to claim 10, wherein the end surface is interrupted by at least one recess, running radially, that extends from the outer circumference to the center of the piston.
Claim 15
Dependent Claim 22 words
A disposable syringe according to claim 8, wherein the recess comprises a peripheral groove penetrating into the end surface of the piston.

References Cited (Backward Citations)

US4057052A Cited
US4266557A Cited
US4354507A Cited
US4303070A Cited
US4704105A Cited
US5061252A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1999-03-05 1999-09-04 2000-03-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2003-03-05 2003-09-04 2004-03-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2007-03-05 2007-09-04 2008-03-05 $7700.00 Window Closed / Lapsed

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