US4004718A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Syringes
Assignee: Nestec SA
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Filing: 1974-05-23
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Granted: 1977-01-25
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Expires: 1994-05-23
Abstract
Abstract A syringe, especially for measuring microliter amounts, which comprises a barrel having over at least a part of its length an inner liner composed of a resilient plastics material surrounding a bore and a piston slidable within the liner bore, the maximum cross-sectional area of the piston being slightly greater than the cross-sectional area of the undeformed bore. The liner is preferably made of a polytetrafluoroethylene and the piston comprises a wire with a bead at one end. A method of attaching a needle to the syringe is also disclosed.
Inventors
- 👤 Frank Wesley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 02:28
CPC Classifications
F; F04; F04B; F04B53/00; F04B53/16; F04B53/162; A; A61; A61M; A61M5/00; A61M5/178; A61M5/31; A61M5/315; A61M5/31525; A61M5/31531; A61M5/32; A61M5/34; A61M5/344; B; B01; B01L; B01L3/00; B01L3/02; B01L3/021; B01L3/0217; B01L3/022; F04B53/008; F04B53/14; A61M5/347
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
173 words
A syringe which comprises an elongated transparent barrel, an elongated plunger disposed in said barrel and slidable along a first length thereof, an inner liner in said barrel disposed along the remaining length of said barrel, said liner being comprised of a resilient plastics material and extending in an encircling course enclosing a space defining a bore of normally substantially constant cross-sectional dimension, said bore providing a reservoir for holding a fluid, and a piston connected to said plunger extending coaxially therewith and within the liner bore for sliding travel in said bore when said plunger is slid in said barrel first section, said first length of said barrel being graduated to indicate the volume of fluid in the syringe, the cross-sectional area of at least a tip end portion of said piston being greater than the cross-sectional area of said liner bore, said liner bore enlargingly deforming when said piston tip end slides in said liner to maintain a substantially gas tight seal between said piston tip end portion and said liner.
Claim 2
Dependent Claim
173 words
A syringe which comprises an elongated transparent barrel, an elongated plunger disposed in said barrel and slidable along a first length thereof, an inner liner in said barrel disposed along the remaining length of said barrel, said liner being comprised of a resilient plastics material and extending in an encircling course enclosing a space defining a bore of normally substantially constant cross-sectional dimension, said bore providing a reservoir for holding a fluid, and a piston connected to said plunger extending coaxially therewith and within the liner bore for sliding travel in said bore when said plunger is slid in said barrel first section, said first length of said barrel being graduated to indicate the volume of fluid in the syringe, the cross-sectional area of at least a tip end portion of said piston being greater than the cross-sectional area of said liner bore, said liner bore enlargingly deforming when said piston tip end slides in said liner to maintain a substantially gas tight seal between said piston tip end portion and said liner.
Claim 3
Dependent Claim
34 words
A syringe according to claim 1 in which the piston comprises a wire having a bead at one end thereof, the end of the wire remote from said bead being connected to said plunger.
Claim 4
Dependent Claim
14 words
A syringe according to claim 1 in which the plastics material is a polytetrafluoroethylene.
Claim 5
Dependent Claim
31 words
A syringe according to claim 1 in which the maximum cross-sectional area of the piston is not more than 0.05 mm 2 greater than the cross-sectional area of the undeformed liner.
Claim 6
Dependent Claim
22 words
A syringe according to claim 4 in which the cross-sectional area of the bore is not greater than 0.3 mm 2 .
Claim 7
Dependent Claim
78 words
In combination with a syringe according to claim 1, a needle coaxial with the barrel with the inner end of the needle inserted within the liner and adjacent to but spaced from the tip end portion of said piston when said plunger is slid to its maximum travel position in the direction of said needle, the end of the liner protruding from the barrel and being surrounded by a plug of resilient material which is retained under compression.
Claim 8
Dependent Claim
63 words
The combination of claim 6 in which the plug is retained under compression by a threaded cap which engages a threaded collar mounted on the end of the barrel, the collar being retained on the end of the barrel by engagement with an annular protrusion around the barrel and a cushioning washer of flexible material is positioned between the protrusion and the collar.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-01-25 | 1980-07-26 | 1981-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-25 | 1984-07-26 | 1985-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-25 | 1988-07-26 | 1989-01-25 | $7700.00 | Window Closed / Lapsed |