US3661152A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Syringe with self-returnable plunger
Assignee: American Hospital Supply Corp
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Filing: 1970-05-08
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Granted: 1972-05-09
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Expires: 1990-05-08
Abstract
Abstract A plunger-type syringe is provided in which the plunger returns after it is depressed. The syringe includes an elastic membrane which is received by the tubular barrel and interposed between the barrel and the plunger. A portion of the membrane is secured to the end of the barrel and is thereby restrained against longitudinal movement, and another portion is engagable with the plunger for longitudinal movement therewith within the barrel. As the plunger is depressed, the membrane is stretched and provides a force tending to return the plunger to its original position. When the plunger is released, the elastic membrane returns the plunger.
Inventors
- 👤 Frank R Beich
- 👤 Glenn L Beall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:48
CPC Classifications
A; A61; A61M; A61M3/00
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
181 words
A syringe comprising an elongated barrel having a tubular wall, a plunger longitudinally slidably received by the barrel, and a membrane interposed between the barrel and plunger and sealingly engaging the wall of the barrel, the membrane including a first portion restrained against longitudinal movement by the barrel, a second portion engageable with the plunger for longitudinal movement therewith within the barrel, and a third stretchable elastic portion joining the first and second portions for providing a return force to the second portion and the plunger upon longitudinal movement thereof away from the first portion, the barrel being generally cylindrical and having a plunger end which receives the plunger and an ejector end, the second portion of the membrane providing an elastic sealing portion having a generally circular transverse cross section, the barrel being provided with a diametrically enlarged portion adjacent the plunger end, the sealing portion being sized to be compressed as it moves longitudinally from the diAmetrically enlarged portion of the barrel toward the ejector end whereby a substantially fluid-tight seal is obtained between the barrel and the plunger.
Claim 2
Dependent Claim
181 words
A syringe comprising an elongated barrel having a tubular wall, a plunger longitudinally slidably received by the barrel, and a membrane interposed between the barrel and plunger and sealingly engaging the wall of the barrel, the membrane including a first portion restrained against longitudinal movement by the barrel, a second portion engageable with the plunger for longitudinal movement therewith within the barrel, and a third stretchable elastic portion joining the first and second portions for providing a return force to the second portion and the plunger upon longitudinal movement thereof away from the first portion, the barrel being generally cylindrical and having a plunger end which receives the plunger and an ejector end, the second portion of the membrane providing an elastic sealing portion having a generally circular transverse cross section, the barrel being provided with a diametrically enlarged portion adjacent the plunger end, the sealing portion being sized to be compressed as it moves longitudinally from the diAmetrically enlarged portion of the barrel toward the ejector end whereby a substantially fluid-tight seal is obtained between the barrel and the plunger.
Claim 3
Dependent Claim
122 words
A syringe comprising an elongated barrel having a tubular wall, a plunger longitudinally slidably received by the barrel, and a membrane interposed between the barrel and plunger and sealingly engaging the wall of the barrel, the membrane including a first portion restrained against longitudinal movement by the barrel, a second portion engageable with the plunger for longitudinal movement therewith within the barrel, and a third stretchable elastic portion joining the first and second portions for providing a return force to the second portion and the plunger upon longitudinal movement thereof away from the first portion, the third portion of the membrane comprising a plurality of bands extending longitudinally between the first and second membrane portions at spaced locations around the peripheries thereof.
Claim 4
Dependent Claim
122 words
A syringe comprising an elongated barrel having a tubular wall, a plunger longitudinally slidably received by the barrel, and a membrane interposed between the barrel and plunger and sealingly engaging the wall of the barrel, the membrane including a first portion restrained against longitudinal movement by the barrel, a second portion engageable with the plunger for longitudinal movement therewith within the barrel, and a third stretchable elastic portion joining the first and second portions for providing a return force to the second portion and the plunger upon longitudinal movement thereof away from the first portion, the third portion of the membrane comprising a plurality of bands extending longitudinally between the first and second membrane portions at spaced locations around the peripheries thereof.
Claim 5
Dependent Claim
154 words
A syringe comprising an elongated barrel having a tubular wall, a plunger longitudinally slidably received by the barrel, and a membrane interposed between the barrel and plunger and sealingly engaging the wall of the barrel, the membrane including a first portion restrained against longitudinal movement by the barrel, a generally cup-shaped second portion receiving an end of the plunger for longitudinal movement therewith within the barrel, and a third stretchable elastic portion joining the first and second portions for providing a return force to the second portion and the plunger upon longitudinal movement thereof away from the first portion, the plunger including a generally cylindrical portion provided with an annular groove adjacent the end thereof received by the cup-shaped second portion of the membrane, the cup-shaped second portion of the membrane including a radially inwardly extending flange received by the annular groove in the plunger whereby the membrane is removably attached to the plunger.
Claim 6
Dependent Claim
154 words
A syringe comprising an elongated barrel having a tubular wall, a plunger longitudinally slidably received by the barrel, and a membrane interposed between the barrel and plunger and sealingly engaging the wall of the barrel, the membrane including a first portion restrained against longitudinal movement by the barrel, a generally cup-shaped second portion receiving an end of the plunger for longitudinal movement therewith within the barrel, and a third stretchable elastic portion joining the first and second portions for providing a return force to the second portion and the plunger upon longitudinal movement thereof away from the first portion, the plunger including a generally cylindrical portion provided with an annular groove adjacent the end thereof received by the cup-shaped second portion of the membrane, the cup-shaped second portion of the membrane including a radially inwardly extending flange received by the annular groove in the plunger whereby the membrane is removably attached to the plunger.
Claim 7
Dependent Claim
137 words
A syringe comprising an elongated barrel having a tubular wall, a plunger longitudinally slidably received by the barrel, and a membrane interposed between the barrel and plunger and sealingly engaging the wall of the barrel, the membrane including a first portion restrained against longitudinal movement by the barrel, a second portion engageable with the plunger for longitudinal movement therewith within the barrel, and a third stretchable elastic portion joining the first and second portions for providing a return force to the second portion and the plunger upon longitudinal movement thereof away from the first portion, the second portion of the membrane being generally cup-shaped and receiving an end of the plunger, the cup-shaped membrane portion including a generally cylindrical wall interposed between the plunger and the barrel and having a circumferentially extending sealing rib engaging the barrel.
Claim 8
Dependent Claim
137 words
A syringe comprising an elongated barrel having a tubular wall, a plunger longitudinally slidably received by the barrel, and a membrane interposed between the barrel and plunger and sealingly engaging the wall of the barrel, the membrane including a first portion restrained against longitudinal movement by the barrel, a second portion engageable with the plunger for longitudinal movement therewith within the barrel, and a third stretchable elastic portion joining the first and second portions for providing a return force to the second portion and the plunger upon longitudinal movement thereof away from the first portion, the second portion of the membrane being generally cup-shaped and receiving an end of the plunger, the cup-shaped membrane portion including a generally cylindrical wall interposed between the plunger and the barrel and having a circumferentially extending sealing rib engaging the barrel.
Claim 9
Dependent Claim
58 words
The syringe of claim 4 in which the plunger includes a generally cylindrical portion provided with an annular groove adjacent the end of the plunger received by the cup-shaped membrane portion, the cup-shaped membrane portion including a radially inwardly extending flange received by the annular groove in the plunger whereby the membrane is removably attached to the plunger.
Claim 10
Dependent Claim
99 words
An elastic membrane adapted for use in sealingly connecting the barrel and plunger of a syringe comprising an annular barrel-attaching portion having an upper radially extending annular wall and an axially extending outer wall adapted to be positioned along the outside surface of the wall of the barrel, a generally cup-shaped plunger portion adapted to receive an end of the plunger and to be interposed between the plunger and the barrel to provide a substantially fluid-tight seal therebetween, and a plurality of elastic stretchable bands extending between the upper wall of the barrel-attaching portion and the cup-shaped plunger portion.
Claim 11
Dependent Claim
99 words
An elastic membrane adapted for use in sealingly connecting the barrel and plunger of a syringe comprising an annular barrel-attaching portion having an upper radially extending annular wall and an axially extending outer wall adapted to be positioned along the outside surface of the wall of the barrel, a generally cup-shaped plunger portion adapted to receive an end of the plunger and to be interposed between the plunger and the barrel to provide a substantially fluid-tight seal therebetween, and a plurality of elastic stretchable bands extending between the upper wall of the barrel-attaching portion and the cup-shaped plunger portion.
Claim 12
Dependent Claim
28 words
The membrane of claim 6 in which the cup-shaped plunger portion includes a radially inwardly extending attaching flange whereby the membrane may be removably attached to the plunger.
Claim 13
Dependent Claim
36 words
The membrane of claim 6 in which the cup-shaped plunger portion includes a radially inwardly extending attaching flange removably attaching the membrane to the plunger and a radially outwardly extending sealing rib for engaging the barrel.
Claim 14
Dependent Claim
22 words
The membrane of claim 6 in which the cup-shaped plunger portion includes a radially outwardly extending sealing rib for engaging the barrel.
Claim 15
Dependent Claim
25 words
The membrane of claim 6 in which the cup-shaped plunger portion includes a pair of spaced-apart radially outwardly extending sealing ribs for engaging the barrel.
Claim 16
Dependent Claim
134 words
A syringe having a tubular barrel with an open rear end and an orifice at its front end, and a plunger slidably disposed in said barrel and projecting from the open rear end thereof, the improvement wherein a member of stretchable elastic material extends between said barrel and said plunger, said member having a first portion fixed to said barrel adjacent the open rear end thereof, a second portion engaged by the plunger and sealingly engaging the barrel, a third portion comprising a plurality of bands extending longitudinally between the first and second portions of the member, each band having an untensioned length constituting a minor part of the total length of the interior of said barrel and exerting a return force on said plunger when said plunger is urged towards the barrel''s orifice.
Claim 17
Dependent Claim
134 words
A syringe having a tubular barrel with an open rear end and an orifice at its front end, and a plunger slidably disposed in said barrel and projecting from the open rear end thereof, the improvement wherein a member of stretchable elastic material extends between said barrel and said plunger, said member having a first portion fixed to said barrel adjacent the open rear end thereof, a second portion engaged by the plunger and sealingly engaging the barrel, a third portion comprising a plurality of bands extending longitudinally between the first and second portions of the member, each band having an untensioned length constituting a minor part of the total length of the interior of said barrel and exerting a return force on said plunger when said plunger is urged towards the barrel''s orifice.
Claim 18
Dependent Claim
80 words
The structure of claim 11 in which said barrel has a major portion of its length with internal cross-sectional dimensions slightly less than the maximum cross-sectional dimension of said third portion of said membrane in an uncompressed state, said barrel also having adjacent its open end a circumferential internal enlargement with internal cross-sectional dimensions larger than those of the barrel''s major portion to receive said third portion of said membrane and relieve compressive forces thereon when said plunger is retracted.
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) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |