Oxford Laboratories Inc.

Ronald Leo Sturm

James C Smith

Stanley J Withers

Pipette

A hand-held pipette with a liquid dispensing knob at one end operably connected therewithin to a piston and piston cylinder assembly at the opposite end that is detachable from the pipette body for cleaning or replacement. An internal pawl and rack mechanism causes the piston to advance a small amount each time the knob is pressed, thereby repetitively dispensing small volumes of liquid therefrom. A second knob cooperatively engages an internal mechanism for both urging the piston to an overshoot position within the piston chamber and to disengage the piston from the internal mechanism in the pipette housing.

Hand-held pipette for repetitively dispensing precise volumes of liquid

A micropipettor having an adjustable stop threadedly engaged with an internal reciprocal plunger assembly for defining the stroke length of the plunger and thus of a fluid displacing piston that is attached to the plunger assembly. The adjustable stop is manipulated by operable connection with a volume adjustment knob provided on the outside of the micropipettor body. The plunger carries a coarse volume indicating scale and the volume adjustment knob is provided with a fine volume setting scale. Accidental changes in volume adjustments are avoided by two types of automatic locks: a frictional engagement of the internal volume adjustment mechanism unless the plunger is deliberately placed in a certain position by the operator, and a detent lock of the volume adjustment knob unless the operator deliberately depresses it.

Hand-held micropipettor with fluid transfer volume adjustment mechanism

A hand-held liquid dispenser of the type using a piston and piston cylinder for precise dispensing of desired volumes of liquid, including an improvement that automatically eliminates any air from the piston cylinder when an operator normally fills the piston cylinder with the desired liquid. A second piston of larger diameter than the first is disposed to draw fluid through the piston chamber at a much faster rate during a first short segment of an intake stroke than would the first piston, thereby to exhaust all dead air from the cylinder and fill it entirely with liquid.

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San Carlos, CA, United States of America

Ronald Leo Sturm