US3834590A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microliter fluid delivery apparatus
Assignee: Drummond Scientific Co
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Filing: 1972-10-24
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Granted: 1974-09-10
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Expires: 1992-10-24
Abstract
Abstract This apparatus includes a cylindrical barrel having positioned therein a cylinder in which a piston is slideable longitudinally for drawing fluid into a sample-receiving member connected to the apparatus. A piston assembly engaged with one end of the piston is operable within the barrel to actuate the piston and to simultaneously compress the air within the barrel on the down stroke of the piston assembly. Movement of the first piston through the cylinder discharges the majority of the fluid from the sample-receiving member. Means are provided for sequentially admitting the compressed air to the sample receiving member to blow out any fluid droplets remaining in the member. The discharge of the fluid and blowing out of the sample-receiving member are effected in a single stroke of the piston assembly.
Inventors
- 👤 J Robinson
- 👤 J Kenney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:14
CPC Classifications
B; B01; B01L; B01L3/00; B01L3/02; B01L3/021; B01L3/0217; B01L3/0231; B67; B67D; B67D1/00; B67D1/08; G; G01; G01F; G01F11/00; G01F11/02; G01F11/021; G01F11/025; G01F11/027; G01N; G01N1/00; G01N1/02; G01N1/10; G01N1/14; B01L2300/00; B01L2300/08; B01L2300/0832; B01L2300/0838
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
347 words
Microliter fluid delivery apparatus including: a. a cylinder barrel, b. a sample-receiving member engaged with one end of said barrel, c. a first cylinder coaxially fixedly positioned in said end of the barrel in communication with said sample-receiving member, d. a first piston movable longitudinally in said first cylinder for drawing fluid into and discharging fluid from, said samplereceiving member, e. said first piston being spaced from said first cylinder, f. sealing means between said first piston and first cylinder at the end thereof remote from said said sample receiving member, g. a piston assembly positioned within said barrel in operative engagement with said first piston, h. said piston assembly including a second piston and a piston shaft, i. a portion of said piston assembly being engageable with said first piston for actuating the latter, j. said second piston being slideable longitudinally of said piston shaft and spaced therefrom to provide an air passageway, k. the wall portion of said cylindrical barrel spaced from one end thereof being provided with an air opening in communication with said air passageway, l. sealing means on said second piston engageable with the internal wall of said cylindrical barrel, m. sealing means on said piston shaft and engageable with said second piston upon longitudinal movement of the pIston shaft in one direction, for preventing the flow of air from the air opening through the air passageway, whereby air pressure in advance of said piston assembly is increased upon longitudinal movement thereof through said barrel toward said samplereceiving member, n. means for selectively admitting the air under increased pressure to said first cylinder from said barrel, during the longitudinal movement of said piston assembly thereof, and o. actuating means for moving said piston assembly and first piston longitudinally of said barrel to effect passage of said first piston through said cylinder to discharge fluid from said sample-receiving member, p. said actuating means being sequentially operative to activate said means for selectively admitting air under pressure to said first cylinder to blow out the sample receiving member after fluid has been discharged therefrom.
Claim 2
Dependent Claim
347 words
Microliter fluid delivery apparatus including: a. a cylinder barrel, b. a sample-receiving member engaged with one end of said barrel, c. a first cylinder coaxially fixedly positioned in said end of the barrel in communication with said sample-receiving member, d. a first piston movable longitudinally in said first cylinder for drawing fluid into and discharging fluid from, said samplereceiving member, e. said first piston being spaced from said first cylinder, f. sealing means between said first piston and first cylinder at the end thereof remote from said said sample receiving member, g. a piston assembly positioned within said barrel in operative engagement with said first piston, h. said piston assembly including a second piston and a piston shaft, i. a portion of said piston assembly being engageable with said first piston for actuating the latter, j. said second piston being slideable longitudinally of said piston shaft and spaced therefrom to provide an air passageway, k. the wall portion of said cylindrical barrel spaced from one end thereof being provided with an air opening in communication with said air passageway, l. sealing means on said second piston engageable with the internal wall of said cylindrical barrel, m. sealing means on said piston shaft and engageable with said second piston upon longitudinal movement of the pIston shaft in one direction, for preventing the flow of air from the air opening through the air passageway, whereby air pressure in advance of said piston assembly is increased upon longitudinal movement thereof through said barrel toward said samplereceiving member, n. means for selectively admitting the air under increased pressure to said first cylinder from said barrel, during the longitudinal movement of said piston assembly thereof, and o. actuating means for moving said piston assembly and first piston longitudinally of said barrel to effect passage of said first piston through said cylinder to discharge fluid from said sample-receiving member, p. said actuating means being sequentially operative to activate said means for selectively admitting air under pressure to said first cylinder to blow out the sample receiving member after fluid has been discharged therefrom.
Claim 3
Dependent Claim
77 words
The microliter fluid delivery apparatus of claim 1, with the addition of: a. a member concentrically positioned with respect to said cylinder, and b. a spring engaged with said concentric member for normally urging the latter in a direction opposite the sample-receiving member, c. a part of said piston assembly being movable longitudinally through said cylindrical barrel and engageable with said concentric member for moving the latter longitudinally of said barrel against the tension of said spring.
Claim 4
Dependent Claim
27 words
The microliter fluid delivery apparatus of claim 2, wherein: a. said member comprises a second cylinder in spaced relation to said cylinder fixedly positioned in said barrel.
Claim 5
Dependent Claim
105 words
The microliter fluid delivery apparatus of claim 3, wherein: a. the cylinder fixedly positioned in said barrel includes an air opening in the wall thereof, and b. sealing members carried by the outer periphery of said cylinder on both sides of the air opening, c. said sealing members being normally in contiguous relation with the wall of said second cylinder, d. at least one of said sealing members being spaced from the wall of said second cylinder upon longitudinal movement of said second cylinder by said piston assembly to permit the passage of air from said second cylinder into the cylinder positioned in said barrel.
Claim 6
Dependent Claim
26 words
The microliter fluid delivery apparatus of claim 2, wherein: a. said member comprises a collar in spaced relation to said cylinder fixedly positioned in said barrel.
Claim 7
Dependent Claim
30 words
The microliter fluid delivery apparatus of claim 2, with the addition of: a. a second spring engaged with said first piston for normally urging the same to a retracted position.
Claim 8
Dependent Claim
44 words
The microliter fluid delivery apparatus of claim 6, wherein: a. the spring engaged with said concentric member is stronger than the spring engaged with said first piston, whereby it may be determined by ''''feel'''' when said actuating member initiates movement of said concentric member.
Claim 9
Dependent Claim
48 words
The microliter fluid delivery apparatus of claim 1, wherein: a. said first piston is provided with a flute at a predetermined point along its length for permitting the passage of air between said barrel and cylinder positioned therein during a portion of the stroke of said first piston.
Claim 10
Dependent Claim
60 words
The microliter fluid delivery apparatus of claim 1, with the addition of: a. a groove in the inner wall of said housing at a predetermined point, and b. a ball and spring detent carried by said piston shaft, c. said ball being engaged with said groove to indicate said piston is in position for drawing fluid into said sample-receiving member.
Claim 11
Dependent Claim
17 words
The microliter fluid delivery apparatus of claim 1, wherein: a. said sample-receiving member comprises a volumetric device.
Claim 12
Dependent Claim
18 words
The microliter fluid delivery apparatus of claim 10, wherein: a. said volumetric device is a graduated capillary tube.
Claim 13
Dependent Claim
17 words
The microliter fluid delivery apparatus of claim 10, wherein: a. said volumetric device is a disposable tip.
Claim 14
Dependent Claim
26 words
The microliter fluid delivery apparatUs of claim 1, wherein: a. said actuating means comprises an actuating button connected to the outer end of said piston shaft.
Claim 15
Dependent Claim
26 words
The microliter fluid delivery apparatus of claim 1, wherein: a. said actuating means comprises a finger-engaging loop connected to the outer end of said piston shaft.
Claim 16
Dependent Claim
28 words
The microliter fluid delivery apparatus of claim 1, with the addition of: a. means for controlling the amount of fluid drawn into, and discharged from, said sample-receiving member.
Claim 17
Dependent Claim
91 words
The microliter fluid delivery apparatus of claim 15, wherein: a. said means for controlling the amount of fluid drawn into, and discharged from, said sample-receiving member includes an end cap threadedly engaged with an end of said cylindrical barrel, b. said piston shaft with said actuating means connected to an end thereof extending through said end cap, c. said end cap being threadedly adjustable relative to said cylindrical barrel and said actuating button to vary the distance between said cap and said actuating button to adjust the length of the stroke.
Claim 18
Dependent Claim
164 words
A microliter fluid delivery apparatus including: a. an elongated housing having an opening at one end, b. a sample-receiving member positioned within the opening of said housing, c. a cylinder within said housing adjacent the opening thereof, d. said cylinder having a bore in communication with said housing opening, e. a piston slideable longitudinally of said cylinder for suctioning fluid into, and discharging fluid from, said sample-receiving member, f. a piston assembly connected with the end of said piston remote from said sample-receiving member, g. said piston assembly including means for moving said piston longitudinally of said cylinder, h. said piston assembly further including means for compressing air within said housing on the downstroke of said piston assembly, and i. air passage means selectively admitting the compressed air within said housing to said cylinder after said piston has moved a predetermined distance in its downstroke, whereby the compressed air is directed into said sample-receiving member, for clearing the latter of fluid droplets remaining therein.
Claim 19
Dependent Claim
164 words
A microliter fluid delivery apparatus including: a. an elongated housing having an opening at one end, b. a sample-receiving member positioned within the opening of said housing, c. a cylinder within said housing adjacent the opening thereof, d. said cylinder having a bore in communication with said housing opening, e. a piston slideable longitudinally of said cylinder for suctioning fluid into, and discharging fluid from, said sample-receiving member, f. a piston assembly connected with the end of said piston remote from said sample-receiving member, g. said piston assembly including means for moving said piston longitudinally of said cylinder, h. said piston assembly further including means for compressing air within said housing on the downstroke of said piston assembly, and i. air passage means selectively admitting the compressed air within said housing to said cylinder after said piston has moved a predetermined distance in its downstroke, whereby the compressed air is directed into said sample-receiving member, for clearing the latter of fluid droplets remaining therein.
Claim 20
Dependent Claim
36 words
The microliter fluid delivery apparatus of claim 17, with the addition of: a. means for preventing the passage of air from said sample-receiving member into said housing upon the upstroke of said piston in said cylinder.
Claim 21
Dependent Claim
63 words
The microliter fluid delivery apparatus of claim 17, wherein: a. said piston is spaced from the wall of said cylinder to permit passage of air between the piston and cylinder into said sample-receiving member, and b. sealing means between said piston and cylinder near the end thereof remote from said sample-receiving member, for suctioning fluid into, and discharging fluid from, said sample-receiving member.
Claim 22
Dependent Claim
125 words
The microliter fluid delivery apparatus of claim 17, wherein: a. said piston assembly includes a piston shaft and second piston, b. said second piston being slideable longitudinally on said piston shaft and spaced therefrom to provide an air passageway, c. the wall of said housing being provided with an air opening in communication with said air passageway, d. sealing means on said second piston engageable with the wall of said housing, and e. sealing means on said piston shaft engageable with said second piston upon longitudinal movement of the piston shaft in one direction, for preventing the flow of air from the air opening through the air passageway whereby air pressure in advance of said piston is increased upon longitudinal movement thereof through said housing.
Claim 23
Dependent Claim
148 words
The microliter fluid delivery apparatus of claim 17, wherein: a. said means for admitting the compressed air within said housing to said cylinder comprises an air opening in the wall of said cylinder, b. sealing members carried by the outer periphery of said cylinder on both sides of the air opening, c. a Second cylinder in spaced relation to said cylinder and movable longitudinally of said housing, d. said sealing members being normally in contiguous relation with the wall of said second cylinder to prevent the passage of air from said second cylinder through the air opening, e. at least one of said sealing members being spaced from the wall of said second cylinder upon longitudinal movement of said second cylinder, f. said second cylinder being connected to, and movable with, said piston assembly, to permit the passage of compressed air from said second cylinder into said cylinder.
Claim 24
Dependent Claim
50 words
The microliter fluid delivery apparatus of claim 17, wherein said means for admitting the compressed air to said cylinder comprises: a. a flute on said piston at a predetermined point along its length for permitting the passage of air between said housing and cylinder during the downstroke of the piston.
Claim 25
Dependent Claim
64 words
The microliter fluid delivery apparatus of claim 17, with the addition of: a. a groove in the inner wall of said housing at a predetermined point, along the length thereof, and b. a ball and spring detent carried by said piston assembly, c. said ball being engaged with said groove to indicate said piston is in position for drawing fluid into said sample-receiving member.
Claim 26
Dependent Claim
17 words
The microliter fluid delivery apparatus of claim 17, wherein: a. said sample-receiving member comprises a volumetric device.
Claim 27
Dependent Claim
18 words
The microliter fluid delivery apparatus of claim 24, wherein: a. said volumetric device is a graduated capillary tube.
Claim 28
Dependent Claim
17 words
The microliter fluid delivery apparatus of claim 24, wherein: a. said volumetric device is a disposable tip.
Claim 29
Dependent Claim
24 words
The microliter fluid delivery apparatus of claim 17, with the addition of: a. actuating means engaged with the outer end of said piston assembly.
Claim 30
Dependent Claim
17 words
The microliter fluid delivery apparatus of claim 27, wherein: a. said actuating means comprises an actuating button.
Claim 31
Dependent Claim
17 words
The microliter fluid delivery apparatus of claim 27, wherein: a. said actuating means is a finger-engaging loop.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-09 | 1978-03-11 | 1978-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-09 | 1982-03-11 | 1982-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-09 | 1986-03-11 | 1986-09-10 | $7700.00 | Window Closed / Lapsed |