US3760639A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pipette assembly
Assignee: Bio Data Corp
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Filing: 1972-10-20
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Granted: 1973-09-25
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Expires: 1992-10-20
Abstract
Abstract A pipette assembly for accurate aspiration and discharge of fixed amounts from a pipette tip is disclosed. A spring-biased cylinder is mounted for rotation about its longitudinal axis for selecting the desired volume of liquid to be discharged. A variable volume control chamber is defined between the ID of the cylinder and the OD of a stationary piston rod. Reciprocation of the cylinder varies the volume of the control chamber.
Inventors
- 👤 M Sokol
- 👤 F Kent
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:30
CPC Classifications
B; B01; B01L; B01L3/00; B01L3/02; B01L3/021; B01L3/0217; B01L3/0231
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
148 words
A pipette assembly comprising a housing having first and second ends, a pipette tip support coupled to said first end of said housing, said support having a bore therethrough, a stationary hollow rod in said housing and communicating with said bore, a cylinder in said housing surrounding said rod and spaced therefrom to define a chamber of variable volume, the volume of said chamber increasing when said cylinder moves toward said pipette tip support, sealing means between said rod and cylinder for sealing the ends of said chamber, spring means biasing said cylinder away from said pipette tip support to effect a decrease in the volume of said chamber, said rod having a passage communicating with said chamber, and limit stop means for limiting the extent of movement of said cylinder in a direction away from said pipette tip support due to the bias of said spring means.
Claim 2
Dependent Claim
148 words
A pipette assembly comprising a housing having first and second ends, a pipette tip support coupled to said first end of said housing, said support having a bore therethrough, a stationary hollow rod in said housing and communicating with said bore, a cylinder in said housing surrounding said rod and spaced therefrom to define a chamber of variable volume, the volume of said chamber increasing when said cylinder moves toward said pipette tip support, sealing means between said rod and cylinder for sealing the ends of said chamber, spring means biasing said cylinder away from said pipette tip support to effect a decrease in the volume of said chamber, said rod having a passage communicating with said chamber, and limit stop means for limiting the extent of movement of said cylinder in a direction away from said pipette tip support due to the bias of said spring means.
Claim 3
Dependent Claim
36 words
A pipette assembly in accordance with claim 1 wherein said limit stop means is selectively operable to limit the extent of movement of the cylinder in a direction away from the pipette support to predetermined distances.
Claim 4
Dependent Claim
41 words
A pipette assembly in accordance with claim 2 wherein said limit stop means includes an adapter supported by said housing, said adapter having a plurality of recesses of different depths, each adapted to receive the limit stop member on said cylinder.
Claim 5
Dependent Claim
43 words
A pipette assembly in accordance with claim 1 wherein said cylinder is rotatably supported by the housing for rotation about the axis of the cylinder, and means connected to the cylinder for selectively rotating the cylinder about its axis relative to the housing.
Claim 6
Dependent Claim
39 words
A pipette assembly in accordance with claim 1 wherein said spring means controls discharge at a rate defined by the rate of expansion of the spring means and greater than the rate of discharge under the effect of gravity.
Claim 7
Dependent Claim
70 words
A pipette assembly in accordance with claim 1 wherein said limit stop means includes an adapter supported by said housing, said adapter having a plurality of circumferentially spaced recesses on an end thereof, said adapter surrounding said cylinder, said cylinder having a limit stop pin adapted to enter each of said recesses, and means for selectively rotating one of said adapter and cylinder about the longitudinal axis of the cylinder.
Claim 8
Dependent Claim
59 words
A pipette assembly in accordance with claim 1 wherein said chamber surrounds said rod, a head closing said rod at the end of the rod remote from said pipette tip support, said sealing means for sealing the ends of said chamber including a piston connected to said hollow rod and a seal supported by said cylinder for movement therewith.
Claim 9
Dependent Claim
140 words
A pipette assembly comprising a support housing, a pipette tip support coupled to said housing, said support having a bore therethrough, a hollow rod in said housing and communicating with said bore, a cylinder in said housing surrounding said rod and spaced therefrom to define a chamber of variable volume, sealing means between said rod and cylinder for sealing the ends of said chamber, means defining a passage communicating said chamber with the interior of said rod, spring means biasing said cylinder away from said pipette tip support whereby discharge from said pipette tip is at the rate of expansion of the spring means, and means for selectiveLy limiting the extent of movement of said cylinder to a plurality of predetermined distances in a direction along the longitudinal axis of said cylinder due to the bias of said spring means.
Claim 10
Dependent Claim
140 words
A pipette assembly comprising a support housing, a pipette tip support coupled to said housing, said support having a bore therethrough, a hollow rod in said housing and communicating with said bore, a cylinder in said housing surrounding said rod and spaced therefrom to define a chamber of variable volume, sealing means between said rod and cylinder for sealing the ends of said chamber, means defining a passage communicating said chamber with the interior of said rod, spring means biasing said cylinder away from said pipette tip support whereby discharge from said pipette tip is at the rate of expansion of the spring means, and means for selectiveLy limiting the extent of movement of said cylinder to a plurality of predetermined distances in a direction along the longitudinal axis of said cylinder due to the bias of said spring means.
Claim 11
Dependent Claim
56 words
A pipette assembly in accordance with claim 8 wherein said last-mentioned means includes an adapter supported by said housing and having a plurality of circumferentially spaced recesses of different depths, and means for rotating said cylinder about its longitudinal axis, a limit stop member secured to said cylinder and adapted to be received in said recesses.
Claim 12
Dependent Claim
51 words
A pipette assembly in accordance with claim 8 including a pipette tip removably mounted on said pipette tip support, said sealing means including a piston connected to said rod and a seal supported by said cylinder for movement with the cylinder, said spring means including a coil spring surrounding said rod.
References Cited (Backward Citations)
US3244099A
Cited
US3494201A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-24 | 1977-03-26 | 1977-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-24 | 1981-03-26 | 1981-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-24 | 1985-03-26 | 1985-09-25 | $7700.00 | Window Closed / Lapsed |