Abstract: A volume adjustable pipette, comprising a plunger mounted for movement in a housing to and from a stop to aspirate a fluid into and dispense the fluid from a tip extending from the housing. An axially moveable volume setting member in the housing defines the stop and a volume setting for the pipette and is axially moveable by a user turnable volume setting member. Turning of the volume adjusting member also controls a coarse volume setting means and a fine volume setting means, the course volume setting means being responsive to a relatively small turning of the volume adjusting member for moving the volume setting member a relatively large axial distance and the fine volume setting means being responsive to a relatively large turning of the volume adjusting member for moving the volume setting member a relatively small axial distance.

Abstract: A pipette tip and mounting shaft combination in an air displacement pipette, the combination comprising a pipette tip mounting shaft having a radially stepped exterior comprising adjacent substantially cylindrical portions of different diameter and an annular sealing zone including an annular edge seal at an outermost edge of a radially extending shaft transition, a pipette tip including an annular sealing region having an inner sealing surface on a sidewall of the tip which in the sealing region is sufficiently thin as to expand slightly and form an interference fit and air tight seal between the sealing surface and the sealing zone when the sealing zone penetrates the sealing region, and axial penetration limiting means for limiting penetration of the shaft into the tip to limit axial contact between the sealing region and the sealing zone to a narrow annular band comprising the annular edge seal.

Abstract: A volume adjustable pipette, comprising a plunger mounted for movement in a housing to and from a stop to aspirate a fluid into and dispense the fluid from a tip extending from the housing. An axially moveable volume setting member in the housing defines the stop and a volume setting for the pipette and is axially moveable by a user turnable volume setting member. Turning of the volume adjusting member also controls a coarse volume setting means and a fine volume setting means, the course volume setting means being responsive to a relatively small turning of the volume adjusting member for moving the volume setting member a relatively large axial distance and the fine volume setting means being responsive to a relatively large turning of the volume adjusting member for moving the volume setting member a relatively small axial distance.

Abstract: An air displacement pipette having axially spaced annular sealing and lateral support zones and regions on the pipette's mounting shaft and tip, respectively, the annular sealing zone comprising an annular sealing surface outward of an outer surface of the mounting shaft at a lower end thereof and a sidewall of the pipette tip in the sealing region being sufficiently thin as to expand slightly and form an interference fit and air tight seal between the sealing surface and the sealing region when the sealing zone penetrates the sealing region and an outer diameter of the mounting shaft in the lateral support zone being equal to or slightly greater than an inner diameter of the pipette tip in the lateral support region to produce an secondary interference fit or air tight seal between the mounting shaft and pipette tip.

Abstract: An air displacement pipette having axially spaced annular sealing and substantially cylindrical lateral support zones on the outer surface of the pipette's mounting shaft for mating with axially spaced annular sealing and substantially cylindrical lateral support regions on the inner surface of a pipette tip, whereby the pipette tip is easily and firmly mountable on and easily ejectable from the pipette tip mounting shaft by the application of minimal axial mounting and ejection forces.

Abstract: An ergonomic, manually precisely controllable return springless air displacement pipette relying upon the friction of a piston seal to maintain a plunger unit of the pipette in any axial location established by a user of the pipette.

Abstract: An air displacement pipette having axially spaced annular sealing and lateral support zones and regions on the pipette's mounting shaft and tip, respectively, the annular sealing zone comprising an annular sealing surface outward of an outer surface of the mounting shaft at a lower end thereof and a sidewall of the pipette tip in the sealing region being sufficiently thin as to expand slightly and form an interference fit and air tight seal between the sealing surface and the sealing region when the sealing zone penetrates the sealing region and an outer diameter of the mounting shaft in the lateral support zone being equal to or slightly greater than an outer diameter of the pipette tip in the lateral support region to produce an secondary interference fit or air tight seal between the mounting shaft and pipette tip.

Abstract: An air displacement pipette having axially spaced annular sealing and substantially cylindrical lateral support zones and regions on the pipette's mounting shaft and tip, respectively, in combination with means for insuring uniform depth of mounting shaft penetration into the pipette tip to maintain uniform tip interference with the mounting shaft as successive tips are mounted on and ejected from the mounting shaft whereby the pipette tip is easily and firmly mountable on and easily ejectable from the pipette tip mounting shaft by the application of axial mounting and ejection forces of about two pounds and one pound, respectively.

Abstract: A pipette tip and mounting shaft combination in an air displacement pipette, the combination comprising a pipette tip mounting shaft having a radially stepped exterior comprising adjacent substantially cylindrical portions of different diameter and an annular sealing zone including an annular edge seal at an outermost edge of a radially extending shaft transition, a pipette tip including an annular sealing region having an inner sealing surface on a sidewall of the tip which in the sealing region is sufficiently thin as to expand slightly and form an interference fit and air tight seal between the sealing surface and the sealing zone when the sealing zone penetrates the sealing region, and axial penetration limiting means for limiting penetration of the shaft into the tip to limit axial contact between the sealing region and the sealing zone to a narrow annular band comprising the annular edge seal.

Abstract: An air displacement pipette having axially spaced annular sealing and substantially cylindrical lateral support zones and regions on the pipette's mounting shaft and tip, respectively, in combination with means for insuring uniform depth of mounting shaft penetration into the pipette tip to maintain uniform tip interference with the mounting shaft as successive tips are mounted on and ejected from the mounting shaft whereby the pipette tip is easily and firmly mountable on and easily ejectable from the pipette tip mounting shaft by the application of axial mounting and ejection forces of about two pounds and one pound, respectively.

Abstract: A volume adjustable manual pipette having a hand-holdable housing supporting (i) an electronic digital display and associated position sensing and control circuitry, (ii) a plunger unit and (iii) a quick set volume adjustment mechanism for simultaneously controlling the volume setting of the pipette and the electronic display, the quick set volume adjustment mechanism comprising a pipette volume setting member for limiting upward movement of the plunger unit within the housing to define the volume setting for the pipette and the volume setting member being supported for axial movement on the plunger unit and releasably secured relative to the housing by a pipette user operable locking mechanism. When released from the housing, the volume setting member is axially moveable on and with the plunger unit to quickly set the volume for the pipette.

Abstract: An ergonomic, manually precisely controllable return springless air displacement pipette relying upon the friction of a piston seal to maintain a plunger unit of the pipette in any axial location established by a user of the pipette.

Abstract: A blowout springless manual air displacement pipette including a mechanical assist for generating a mechanical force opposing a return spring force on a plunger unit to aid a pipette user in locating and maintaining the plunger unit at a “home” position within a pipette body and ready for immersion of a pipette tip in a liquid to be drawn into the tip.

Abstract: An ergonomic, manually precisely controllable return springless air displacement pipette relying on the friction of a piston seal to maintain a plunger unit of the pipette in any axial location established by a user of the pipette.

Abstract: A bilaterally symmetrical lightweight hand holdable battery powered microprocessor controlled electronic pipette including an axially elongated hollow housing having a vertically extending longitudinal axis. An upper portion of the housing includes a forward compartment containing a forwardly facing electronic display, a plurality of forwardly facing control keys and at least one forwardly facing trigger switch arranged in a vertically spaced pattern such that a pipette user in gripping a lower handle portion of the housing in either his or her right or left hand can easily reach with his thumb the control keys, trigger switch(es) as well as a push button of a pipette tip ejector.

Abstract: A bilaterally symmetrical lightweight hand holdable battery powered microprocessor controlled electronic pipette including an axially elongated hollow housing having a vertically extending longitudinal axis. An upper portion of the housing includes a forward compartment containing a forwardly facing alpha-numeric display, a plurality of columns of forwardly facing control keys and plurality of forwardly facing trigger switches arranged in a vertically spaced pattern such that a user in gripping a lower handle portion of the housing in either his or her right or left hand can easily reach with his thumb the control keys, trigger switches as well as a push button of a pipette tip ejector.

Abstract: A battery powered, microprocessor controlled portable electronic pipette, comprising a hand holdable housing supporting a battery, a linear actuator for driving a plunger lengthwise in a cylinder to aspirate and dispense fluid into and from a pipette tip extending from the housing and a control circuit for the linear actuator. The linear actuator is powered by the battery and comprises a stepper motor with current receiving windings for electromagnetically driving a rotor to impart the lengthwise movement to the plunger.