초록 ▼

A positive displacement liquid drawing and dispensing apparatus (21) having a tubular member (22) with an axially extending lumen (24) and a plunger (31) mounted for axial displacement in the lumen (24). The plunger (31) has a first seal (33) positioned proximate an end (34) of the plunger and a sec

A positive displacement liquid drawing and dispensing apparatus (21) having a tubular member (22) with an axially extending lumen (24) and a plunger (31) mounted for axial displacement in the lumen (24). The plunger (31) has a first seal (33) positioned proximate an end (34) of the plunger and a second seal (37) axially spaced from the first seal (33). The first and second seal each slidably and sealingly engage an interior surface (23) defining the lumen (24) as the plunger (31) is displaced in the lumen. The plunger further includes a recess (38) intermediate the first and second seals for receipt of trapped gas (40,41) which can be drawn in through an intake end (27) of the lumen during drawing of the liquid (36) into the tubular member (22). The plunger is formed for positioning of the first seal (33) beyond the intake opening (27) so that air will automatically be isolated between the first and second seals (33,37) as the plunger is withdrawn into a lumen. A substantially gas-free draw of liquid will result between the first seal (33) and the intake opening (27). A method of drawing the liquid in the apparatus which includes automatically isolating an uppermost portion of the liquid (36) and gas (41) from a lower portion of the volume drawn into the apparatus (21).

대표청구항 ▼

[ What is claimed is:] [1.] A liquid drawing and dispensing apparatus comprising:a tubular member having an interior surface defining an axially extending lumen having a length dimension and terminating in a draw opening enabling drawing of a liquid into said lumen and dispensing of liquid therefrom

[ What is claimed is:] [1.] A liquid drawing and dispensing apparatus comprising:a tubular member having an interior surface defining an axially extending lumen having a length dimension and terminating in a draw opening enabling drawing of a liquid into said lumen and dispensing of liquid therefrom; anda plunger mounted for axially displacement in said lumen in a first direction to draw liquid into said lumen and a second opposite direction to dispense liquid from said lumen, said plunger having a length dimension extending over substantially the entire length dimension of said lumen, said plunger having a first seal positioned proximate a draw end of said plunger closest to said draw opening and a second seal positioned axially spaced from said first seal in a direction away from said draw end, said first seal and said second seal each slidably and sealingly engaging said interior surface as said plunger is displaced axially in said lumen, and said plunger being recessed intermediate said first seal and said second seal for receipt of gas trapped during drawing in of said liquid, and said plunger having a length dimension sufficient for displacement of said first seal to a position outwardly of said draw opening while said plunger is coupled to a pipetter, and said first seal is dimensioned to be drawn back into said lumen through said draw opening during drawing of liquid.