| 摘要 |
<p>1,271,683. Pipette with disposable tip. OXFORD LABORATORIES. 17 April, 1969 [16 Aug., 1968], No. 19757/69. Heading B1X. [Also in Division Fl] In a pipetting apparatus having disposable tips 10 a plunger 28 has a reduced section 36 and is actuated by depression of knob 27 to deliver liquid in two stages. A first predetermined part of the liquid is delivered on depressing the knob 27 against the action of a weak spring 38 to a position defined by abutment of a collar 29 on the plunger 28 with the shoulder of a cup-shaped member 30. The plunger is further depressed against the action of. a strong spring 31 to deliver the remainder of theliquid contained within the lower tapered portion 19 of the pipette until the knob 27 abuts the top of pipette body 16. The length of the first part of the stroke may be varied by varying the thickness of collar 29, the size of member 30 and the diameter of piston extension 36. The tips may have ribs 14 which engage with a recess 26 in a tray 21 whereby the tips may be removed from the pipette without manual contact with the tips.</p> |
