Patent US2405597A successfully refreshed from Google Patents.
US4144761A
Expired / Lapsed
US
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Handpipette
Assignee: Pfizer Health AB
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Filing: 1978-02-24
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Granted: 1979-03-20
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Expires: 1998-02-24
Abstract
Abstract A pipette having an axially displaceable piston is provided with a transversely displaceable stopping device for limiting the displacement of the piston in accordance with a volumetric scale marked on the stopping device. Operation of the piston and stopping device can be done with one hand.
Inventors
- 👤 Heinz Dzaack
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:08
CPC Classifications
B; B01; B01L; B01L3/00; B01L3/02; B01L3/021; B01L3/0217; B01L3/0224
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
160 words
A measuring handpipette suitable for one-hand operation comprising a piston axially displaceable in a cylinder into which liquid is sucked, the displacement of the piston being controlled by a measuring means having at least two relatively displaceable elements, one of said two elements being movable with said piston, the other of said two elements being movable with respect to the cylinder between a plurality of predetermined positions by a finger of the hand holding the cylinder, one of said two elements having a stop means, the other of the two elements also having a sloping surface which engages with said stop means at selected locations to adjustably limit movement of the piston in one direction by an amount corresponding to one of the predetermined positions of the first mentioned other element, said piston including a pushbutton projecting outwardly of the cylinder for movement of the piston in said one direction also by a finger of the hand holding the cylinder.
Claim 2
Dependent Claim
160 words
A measuring handpipette suitable for one-hand operation comprising a piston axially displaceable in a cylinder into which liquid is sucked, the displacement of the piston being controlled by a measuring means having at least two relatively displaceable elements, one of said two elements being movable with said piston, the other of said two elements being movable with respect to the cylinder between a plurality of predetermined positions by a finger of the hand holding the cylinder, one of said two elements having a stop means, the other of the two elements also having a sloping surface which engages with said stop means at selected locations to adjustably limit movement of the piston in one direction by an amount corresponding to one of the predetermined positions of the first mentioned other element, said piston including a pushbutton projecting outwardly of the cylinder for movement of the piston in said one direction also by a finger of the hand holding the cylinder.
Claim 3
Dependent Claim
19 words
A measuring handpipette according to claim 1, wherein said sloping surface is stepped to provide incremental limits of movement.
Claim 4
Dependent Claim
60 words
A measuring handpipette according to claim 1, wherein the second mentioned other of said two elements is mounted in the cylinder for reciprocatory movement transverse to the direction of movement of the piston, said second mentioned other element having portions projecting outwardly on opposite sides of the cylinder for respective engagement by a finger of the hand holding the cylinder.
Claim 5
Dependent Claim
38 words
A measuring handpipette according to claim 1, wherein a fixed stop is provided to limit movement of the piston in the opposite direction for sucking in a liquid, said liquid being dispensed during movement in said one direction.
Claim 6
Dependent Claim
40 words
A measuring handpipette according to claim 1, wherein liquid is sucked in during movement of the piston in said one direction, and a fixed stop is provided to limit movement of the piston in the opposite direction while dispensing liquid.
Claim 7
Dependent Claim
58 words
A measuring handpipette according to claim 1, wherein an elongated inlet and discharge tube is provided at one end of said cylinder to removably receive a detachable pipette tip, and a tip remover mounted on said tube is connected to said piston to remove a tip when the piston is fully displaced in a direction to dispense liquid.
Claim 8
Dependent Claim
54 words
A measuring handpipette according to claim 1, wherein a second pushbutton is reciprocatorily mounted on said cylinder for operation by a finger of the hand holding the cylinder, said second pushbutton being connected to the piston by motion transmitting means to move the piston in the opposite direction when the second pushbutton is depressed.
Claim 9
Dependent Claim
49 words
A measuring handpipette according to claim 7, wherein said pushbuttons are located at one end of the cylinder and said motion transmitting means comprises gear means rotatably mounted in the cylinder to move a respective one of the pushbuttons in the opposite directions when the other pushbutton is depressed.
References Cited (Backward Citations)
US2670881A
Cited
DE1276369B
Cited
US3248950A
Cited
US3517668A
Cited
US3494201A
Cited
US3881360A
Cited
US3933048A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-03-19 | 1982-09-18 | 1983-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-19 | 1986-09-18 | 1987-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-19 | 1990-09-18 | 1991-03-20 | $7700.00 | Window Closed / Lapsed |