US3581956A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Syringe plunger head
Assignee: Hamilton Co Inc
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Filing: 1968-09-26
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Granted: 1971-06-01
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Expires: 1988-09-26
Abstract
Abstract Syringe apparatus having a plunger head with a peripherally grooved flange urged against the interior wall of the syringe by a resilient O-ring wedged in an annular groove in the head.
Inventors
- 👤 John D Reid
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:17
CPC Classifications
A; A61; A61M; A61M5/00; A61M5/178; A61M5/31; A61M5/315; A61M5/31511; A61M5/31513
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
188 words
A plunger head for a syringe comprising: A. A cylindrical body; B. a cylindrical reduced diameter part extending forwardly from the forward end of said body; C. an annular flange on said reduced diameter part, said flange being spaced forwardly of the forward end of said body, there being an annular outwardly opening groove defined by the adjacent end walls of said body and said flange, said groove being narrower at its base where it joins the reduced diameter part than at the open top part and narrower longitudinally at its base than at the outer free end; D. a resilient O-ring wedged in the groove exerting forward springlike pressure against and for urging the flange pivotally forwardly and flexing said flange in an annular pivotal base area in the region of the junction of the flange with the reduced diameter part of the plunger head and pressing the outer annular surface of said flange against the interior syringe wall, the outside diameter of said O-ring being no greater than the diameter of the flange; E. and an anchoring and support part projecting rearwardly of the cylindrical body.
Claim 2
Dependent Claim
188 words
A plunger head for a syringe comprising: A. A cylindrical body; B. a cylindrical reduced diameter part extending forwardly from the forward end of said body; C. an annular flange on said reduced diameter part, said flange being spaced forwardly of the forward end of said body, there being an annular outwardly opening groove defined by the adjacent end walls of said body and said flange, said groove being narrower at its base where it joins the reduced diameter part than at the open top part and narrower longitudinally at its base than at the outer free end; D. a resilient O-ring wedged in the groove exerting forward springlike pressure against and for urging the flange pivotally forwardly and flexing said flange in an annular pivotal base area in the region of the junction of the flange with the reduced diameter part of the plunger head and pressing the outer annular surface of said flange against the interior syringe wall, the outside diameter of said O-ring being no greater than the diameter of the flange; E. and an anchoring and support part projecting rearwardly of the cylindrical body.
Claim 3
Dependent Claim
26 words
The invention defined by claim 1, wherein the outside diameter of the O-ring, when disposed in said groove, is smaller than the diameter of the flange.
Claim 4
Dependent Claim
21 words
The invention defined by claim 2, wherein the flange has a plurality of peripheral, cylindrical lands separated longitudinally by peripheral grooves.
Claim 5
Dependent Claim
28 words
The invention defined by claim 3, including plunger rod, the anchoring and support part of the plunger head being secured to the front end of said plunger rod.
Claim 6
Dependent Claim
24 words
The invention defined by claim 1 wherein the flange has a plurality of peripheral grooves, and peripheral lands at the sides of said grooves.
Claim 7
Dependent Claim
63 words
The invention defined by claim 4, including a tubular syringe barrel in which the syringe head and plunger are operably disposed, said flange being in peripheral engagement with the inner wall of the barrel, said barrel having a forward end wall from which a tip extends forwardly, there being a fluid passage through the tip and into the hollow interior of the barrel.
Claim 8
Dependent Claim
34 words
The invention defined by claim 4, wherein the plunger rod is hollow and said anchoring and support part of the plunger head is disposed and secured within a forward portion of said plunger rod.
Claim 9
Dependent Claim
75 words
The invention defined by claim 1, wherein the forward end of the plunger body has an annular wall adjacent the periphery of the body which is inclined forwardly and inwardly, and the adjacent side of the flange has at least an inner annular wall portion inclined forwardly and inwardly at a greater angle relative to the cylindrical surface of the reduced diameter part than the angle of the adjacent inclined annular wall of the body.
Claim 10
Dependent Claim
32 words
The invention defined by claim 8, wherein the forward end of the flange has at least an inner annular wall part that flares from the base of said flange forwardly and outwardly.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-31 | 1974-11-30 | 1975-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-31 | 1978-11-30 | 1979-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-31 | 1982-11-30 | 1983-06-01 | $7700.00 | Window Closed / Lapsed |