Patent US3828987A successfully refreshed from Google Patents.
US3828987A
Expired / Lapsed
US
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Dispensing micropipette apparatus having disposable parts for delivering a preselected quantity of fluid
Assignee: DRUMMOND INSTR CO
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Filing: 1972-06-02
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Granted: 1974-08-13
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Expires: 1992-06-02
Abstract
Abstract This invention is a dispensing micropipette apparatus having disposable parts for delivering a preselected quantity of fluid. The apparatus includes a capillary tube through which a wire plunger extends, the wire plunger being secured at one end to a holder. One end of the capillary tube is reduced in diameter to provide an end wall portion serving as a stop engaged by a stop member mounted on the wire plunger at a predetermined distance from the lower end of the plunger. The engagement of the stop member with the stop means positively and automatically controls the amount of fluid drawn into the capillary tube without visual determination of the amount drawn therein.
Inventors
- 👤 M Drummond
- 👤 J Robinson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:53
CPC Classifications
B; B01; B01L; B01L3/00; B01L3/02; B01L3/021; B01L3/0217; B01L3/022
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
222 words
Apparatus for delivering a preselected quantity of fluid including: a. a tubular member, b. the diameter of said tubular member being reduced at one terminal to provide a wall portion forming a stop, c. a wire plunger slidably movable through said tubular member, d. said wire plunger being in spaced relation to the side wall of said tubular member, e. said wire plunger including piston means at one end thereof of substantially the same diameter as the internal diameter of said tubular member, f. said wire plunger being enlarged at any selected point along its length in predetermined spaced relation to said piston means to form a stop member, g. said stop member engaging said stop to limit the longitudinal travel of said wire plunger and piston means through said tubular member, whereby a maximum precise quantity of fluid is drawn into said tubular member, and h. holder means in gripping engagement with the end of said wire plunger remote from said piston means, i. said holder means including a body portion for receiving a terminal of said wire plunger, j. a spring member mounted on said body portion and in frictional, retaining engagement with said wire plunger, k. said spring member being operable to release said wire plunger, whereby said wire plunger may be moved longitudinally out of said tubular member.
Claim 2
Dependent Claim
222 words
Apparatus for delivering a preselected quantity of fluid including: a. a tubular member, b. the diameter of said tubular member being reduced at one terminal to provide a wall portion forming a stop, c. a wire plunger slidably movable through said tubular member, d. said wire plunger being in spaced relation to the side wall of said tubular member, e. said wire plunger including piston means at one end thereof of substantially the same diameter as the internal diameter of said tubular member, f. said wire plunger being enlarged at any selected point along its length in predetermined spaced relation to said piston means to form a stop member, g. said stop member engaging said stop to limit the longitudinal travel of said wire plunger and piston means through said tubular member, whereby a maximum precise quantity of fluid is drawn into said tubular member, and h. holder means in gripping engagement with the end of said wire plunger remote from said piston means, i. said holder means including a body portion for receiving a terminal of said wire plunger, j. a spring member mounted on said body portion and in frictional, retaining engagement with said wire plunger, k. said spring member being operable to release said wire plunger, whereby said wire plunger may be moved longitudinally out of said tubular member.
Claim 3
Dependent Claim
29 words
The apparatus of claim 1, with the addition of: a. a finger engaging loop affixed to one end of said body portion for facility in operating said holder means.
Claim 4
Dependent Claim
15 words
The apparatus of claim 1, wherein: a. said stop member is of generally cylindrical shape.
Claim 5
Dependent Claim
262 words
Apparatus for delivering a preselected quantity of fluid including: a. a tubular member, b. the diameter of said tubular member being reduced at one terminal to provide a wall portion forming a stop, c. indicia on the side wall of said tubular member a predetermined distance from the terminal of said tubular member opposite said wall portion forming a stop, d. A wire plunger slidably movable through said tubular member, e. said wire plunger being in spaced relation to the side wall of said tubular member, f. said wire plunger including piston means at one end thereof of substantially the same diameter as the internal diameter of said tubular member, g. said wire plunger being enlarged at any selected point between said piston means and said stop and in predetermined spaced relation to said piston means to form a stop member, h. said stop member engaging said stop to limit the longitudinal travel of said wire plunger through said tubular member, i. a terminal of said piston means being uniplanar with said indicia contemporaneously with the engagement of said stop and stop member, and j. a holder unit for gripping the terminal of said wire plunger remote from said piston means, k. said holder unit including a body portion, l. a finger engaging loop at one end of said body portion, m. a spring member secured to said body portion and in frictional engagement with said wire plunger, n. said spring member being operable to release said wire plunger, whereby said wire plunger may be removed longitudinally out of said tubular member.
Claim 6
Dependent Claim
262 words
Apparatus for delivering a preselected quantity of fluid including: a. a tubular member, b. the diameter of said tubular member being reduced at one terminal to provide a wall portion forming a stop, c. indicia on the side wall of said tubular member a predetermined distance from the terminal of said tubular member opposite said wall portion forming a stop, d. A wire plunger slidably movable through said tubular member, e. said wire plunger being in spaced relation to the side wall of said tubular member, f. said wire plunger including piston means at one end thereof of substantially the same diameter as the internal diameter of said tubular member, g. said wire plunger being enlarged at any selected point between said piston means and said stop and in predetermined spaced relation to said piston means to form a stop member, h. said stop member engaging said stop to limit the longitudinal travel of said wire plunger through said tubular member, i. a terminal of said piston means being uniplanar with said indicia contemporaneously with the engagement of said stop and stop member, and j. a holder unit for gripping the terminal of said wire plunger remote from said piston means, k. said holder unit including a body portion, l. a finger engaging loop at one end of said body portion, m. a spring member secured to said body portion and in frictional engagement with said wire plunger, n. said spring member being operable to release said wire plunger, whereby said wire plunger may be removed longitudinally out of said tubular member.
Claim 7
Dependent Claim
14 words
The apparatus of claim 4, wherein: a. said tubular member is a capillary tube.
Claim 8
Dependent Claim
14 words
The apparatus of claim 5, wherein: a. said stop member is of cylindrical shape.
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) | 1977-08-12 | 1978-02-11 | 1978-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-12 | 1982-02-11 | 1982-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-12 | 1986-02-11 | 1986-08-13 | $7700.00 | Window Closed / Lapsed |