US3874382A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sealing piston cap for hypodermic injection syringe
Assignee: Individual
•
Filing: 1973-04-02
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Granted: 1975-04-01
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Expires: 1993-04-02
Abstract
Abstract The invention relates to a sealing piston cap made of rubber for a hypodermic injection syringe, the piston cap making it possible to obtain automatic sealing during suction and compression. It comprises, around its cylindrical skirt and outwardly thereof, a single circular sealing ring and, inwardly thereof, a bead for mounting it at the end of the piston, the bead being forwardly of an annular groove located in line with the outer sealing ring to reduce the thickness of the joint skirt. The forward bottom wall of the piston cap, in contact with the liquid to be injected, is completely convex and smooth.
Inventors
- 👤 Louis Nogier
- 👤 Paul Nogier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:43
CPC Classifications
A; A61; A61M; A61M5/00; A61M5/178; A61M5/31; A61M5/315; A61M5/31511; A61M5/31513; F; F16; F16J; F16J1/00; F16J1/005; F16J1/006; F16J15/00; F16J15/16; F16J15/32; F16J15/3204
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
125 words
In a syringe having a cylinder, a piston slidable therein and a resilient sealing cap on said piston, the improvements comprising: said sealing cap being of generally cup shape, having an end wall extending across the end of said piston and a single skirt portion extending loosely between said piston and cylinder; an integral annular sealing ring extending circumferentially around said skirt in sliding engagement with said cylinder, said sealing ring being in the form of a thin-walled rib and defining and annular groove at the inner side of said skirt; and a solid annular rib, integral with said skirt on the inner surface of said skirt between said sealing ring and said end wall, said rib extending into an annular groove in said piston.
Claim 2
Dependent Claim
125 words
In a syringe having a cylinder, a piston slidable therein and a resilient sealing cap on said piston, the improvements comprising: said sealing cap being of generally cup shape, having an end wall extending across the end of said piston and a single skirt portion extending loosely between said piston and cylinder; an integral annular sealing ring extending circumferentially around said skirt in sliding engagement with said cylinder, said sealing ring being in the form of a thin-walled rib and defining and annular groove at the inner side of said skirt; and a solid annular rib, integral with said skirt on the inner surface of said skirt between said sealing ring and said end wall, said rib extending into an annular groove in said piston.
Claim 3
Dependent Claim
33 words
A syringe as defined in claim 1 wherein the end of said piston is spaced from said end wall whereby said piston transmits sliding movement to said cap only through said annular rib.
Claim 4
Dependent Claim
69 words
a syringe as defined in claim 1 wherein said piston is provided with an annular shoulder adjacent and facing the end of said skirt, said shoulder being inclined outwardly and away from said end of said skirt to engage and bias said skirt and sealing ring outwardly when said piston slides toward said end wall, said rib being of lesser axial dimension than said annular groove in said piston.
Claim 5
Dependent Claim
20 words
A syringe as defined in claim 3 wherein said shoulder is inclined at an angle of from 10* to 15*.
Claim 6
Dependent Claim
44 words
A syringe as defined in claim 2 wherein said end wall is spaced from the end of said piston and is sufficiently thick and rigid to resist flexure into contact with the end of said piston as a result of pressure in said syringe.
References Cited (Backward Citations)
US2895773A
Cited
US3147753A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |