Apparatus and method for detecting liquid penetration by a container used for aspirating and dispensing the liquid

Claim 1

In apparatus for aspirating and dispensing liquid and including a probe for removably mounting a container having an aspirating and dispensing aperture; pressurizing means fluidly connected to said probe for generating an operative pressure differential relative to atmospheric pressure, effective to aspirate or dispense liquid into or from a mounted container; and moving means for advancing said probe and such mounted container toward, and away from a nominal level location; an improved aspiration control system comprising (a) means for controlling the advance of said probe in increments, (b) means for actuating said pressurizing means only when said probe is not advancing, to generate a pressure differential in such container, relative to atmospheric pressure, that is sufficient to indicate whether such container aperture is closed by the liquid, (c) means for detecting and signalling the pressure produced within such container by said pressure differential; and (d) means for comparing the signalled pressure against a reference value determinative of the presence of liquid in such container aperture, said control system further being free of any valve means interposed between said pressurizing means and said detecting means.

Claim 5

A method for detecting that a dispensing container of an aspirating and dispensing apparatus has penetrated into a liquid through an air-liquid interface, said apparatus including a probe for removably mounting a container having an aspirating and dispensing aperture; pressurizing means fluidly connected to said probe for generating an operative pressure differential relative to atmospheric pressure, effective to aspirate or dispense liquid into or from a mounted container; and moving means for advancing said probe and such mounted container toward, and away from, a nominal liquid level location; the method comprising the steps of (a) controlling the advance of said probe in increments, (b) actuating said pressurizing means only when said probe is not advancing, to generate a pressure differential in such container, relative to atmospheric pressure, sufficient to indicate whether such container aperture is closed by the liquid, (c) detecting and signalling the pressure produced within such container by said pressure differential; (d) comparing the signalled pressure against a reference value determinative of the presence of liquid in such container aperture, and (e) after detecting the presence of liquid in said container, aspirating liquid into the container by actuating said pressurizing means, whereby asid method avoids the necessity of switching from one pressurizing means for step (c) to another pressurizing means for step (e).

Claim 6

A method for detecting that a dispensing container of an aspirating and dispensing apparatus has penetrated into a liquid through an air-liquid interface, said apparatus including a probe for removably mounting a container having an aspirating and dispensing aperture; pressurizing means fluidly connected to said probe for generating an operative pressure differential relative to atmospheric pressure, effective to aspirate or dispense liquid into or from a mounted container; and moving means for advancing said probe and such mounted container toward, and away from, a nominal liquid level location; the method comprising the steps of (a) controlling the advance of said probe in increments, (b) actuating said pressurizing means only when said probe is not advancing, to generate a pressure differential in such container, relative to atmospheric pressure, sufficient to indicate whether such container aperture is closed by the liquid, (c) detecting and signalling the pressure produced within such container by said pressure differential; (d) comparing the signalled pressure against a reference value determinative of the presence of liquid in such container aperture, and (e) after detecting the presence of liquid in said container, aspirating liquid into the container by actuating said pressurizing means, whereby asid method avoids the necessity of switching from one pressurizing means for step (c) to another pressurizing means for step (e).

Claim 7

A method for detecting that a dispensing container of an aspirating and dispensing apparatus has penetrated into a liquid through an air-liquid interface, said apparatus including a probe for removably mounting a container having an aspirating and dispensing aperture; pressurizing means fluidly connected to said probe for generating an operative pressure differential relative to atmospheric pressure, effective to aspirate or dispense liquid into or from a mounted container; and moving means for advancing said probe and such mounted container toward, and away from, a nominal liquid level location; the method comprising the steps of (a) controlling the advance of said probe in increments, (b) actuating said pressurizing means only when said probe is not advancing to produce a partial vacuum or a partial pressure within such dispensing container that is sufficient to generate a signal indicative of equilibrium pressure of liquid at a liquid-container interface, if liquid is present, (c) forming said signal characteristic of said partial vacuum or partial pressure produced in step (b), (d) comparing said signal of step (c) against a reference signal characteristic of the pressure in such dispensing container when said container is either at atmospheric pressure or penetrated into the liquid, to determine whether said signal of step (c) is indicative of such dispensing container being at atmposheric pressure or is indicative of such dispensing container having penetrated the liquid, (e) if said signal formed in step (c) is within a threshold value of being indicative of such dispensing container being at atmospheric pressure, then repeating said steps (a) through (d) up to a predetermined limit, or until said signal of step (c) is indicative of such dispensing container being penetrated the liquid, and (f) after detecting the presence of liquid in said container, asperating liquid into the container by actuating said pressurizing means, whereby said method avoids the necessity of switching from one pressurizing means for step (c) to another pressurizing means for step (e).

Claim 8

A method for detecting that a dispensing container of an aspirating and dispensing apparatus has penetrated into a liquid through an air-liquid interface, said apparatus including a probe for removably mounting a container having an aspirating and dispensing aperture; pressurizing means fluidly connected to said probe for generating an operative pressure differential relative to atmospheric pressure, effective to aspirate or dispense liquid into or from a mounted container; and moving means for advancing said probe and such mounted container toward, and away from, a nominal liquid level location; the method comprising the steps of (a) controlling the advance of said probe in increments, (b) actuating said pressurizing means only when said probe is not advancing to produce a partial vacuum or a partial pressure within such dispensing container that is sufficient to generate a signal indicative of equilibrium pressure of liquid at a liquid-container interface, if liquid is present, (c) forming said signal characteristic of said partial vacuum or partial pressure produced in step (b), (d) comparing said signal of step (c) against a reference signal characteristic of the pressure in such dispensing container when said container is either at atmospheric pressure or penetrated into the liquid, to determine whether said signal of step (c) is indicative of such dispensing container being at atmposheric pressure or is indicative of such dispensing container having penetrated the liquid, (e) if said signal formed in step (c) is within a threshold value of being indicative of such dispensing container being at atmospheric pressure, then repeating said steps (a) through (d) up to a predetermined limit, or until said signal of step (c) is indicative of such dispensing container being penetrated the liquid, and (f) after detecting the presence of liquid in said container, asperating liquid into the container by actuating said pressurizing means, whereby said method avoids the necessity of switching from one pressurizing means for step (c) to another pressurizing means for step (e).

Claim 18

A method for detecting that a dispensing container of an aspirating and dispensing apparatus has penetrated into a liquid through an air-liquid interface, said apparatus including a probe for removably mounting a container having an aspirating and dispensing aperture; pressurizing means fluidly connected to said probe for generating an operative pressure differential relative to atmospheric pressure, effective to aspirate or dispense liquid into or from a mounted container; and moving means for advancing said probe and such mounted container toward, and away from, a nominal liquid level location; the method comprising the steps of (a) controlling the advance of said probe in increments, (b) actuating said pressurizing means only when said probe is not advancing to produce a partial vacuum or a partial pressure within such dispensing container that is sufficient to generate a signal indicative of equilibrium pressure of liquid at a liquid-container interface, if liquid is present, (c) forming said signal characteristic of said partial vacuum or partial pressure produced in step (b), (d) comparing said signal of step (c) against a reference signal characteristic of the pressure in such dispensing container when said container is either at atmospheric pressure or penetrated into the liquid, to determine whether said signal of step (c) is indicative of such dispensing container being at atmospheric pressure or is indicative of such dispensing container having penetrated the liquid, (e) if said signal formed in step (c) is within a threshold value of being indicative of such dispensing container being at atmospheric pressure, then repeating said steps (a) through (d) up to a predetermined limit, or until said signal of step (c) is indicative of such dispensing container being penetrated the liquid, said step of repeating steps (a) through (d) including the step of alternating the actuation of said pressurizing means so that, first, a partial vacuum is formed, then, a partial pressure, then, a partial vacuum, each time step (b) is carried out for as many repetitions as are necessary, so that said actuating means need not be specially reset at a starting point after a larger number of failures to detect the container having penetrated the liquid, and (f) after detecting the presence of liquid in said container, aspirating liquid into the container by actuating said pressurizing means, whereby said method avoids the necessity of switching from one pressurizing means for step (c) to another pressurizing means for step (e).

Claim 19

A method for detecting that a dispensing container of an aspirating and dispensing apparatus has penetrated into a liquid through an air-liquid interface, said apparatus including a probe for removably mounting a container having an aspirating and dispensing aperture; pressurizing means fluidly connected to said probe for generating an operative pressure differential relative to atmospheric pressure, effective to aspirate or dispense liquid into or from a mounted container; and moving means for advancing said probe and such mounted container toward, and away from, a nominal liquid level location; the method comprising the steps of (a) controlling the advance of said probe in increments, (b) actuating said pressurizing means only when said probe is not advancing to produce a partial vacuum or a partial pressure within such dispensing container that is sufficient to generate a signal indicative of equilibrium pressure of liquid at a liquid-container interface, if liquid is present, (c) forming said signal characteristic of said partial vacuum or partial pressure produced in step (b), (d) comparing said signal of step (c) against a reference signal characteristic of the pressure in such dispensing container when said container is either at atmospheric pressure or penetrated into the liquid, to determine whether said signal of step (c) is indicative of such dispensing container being at atmospheric pressure or is indicative of such dispensing container having penetrated the liquid, (e) if said signal formed in step (c) is within a threshold value of being indicative of such dispensing container being at atmospheric pressure, then repeating said steps (a) through (d) up to a predetermined limit, or until said signal of step (c) is indicative of such dispensing container being penetrated the liquid, said step of repeating steps (a) through (d) including the step of alternating the actuation of said pressurizing means so that, first, a partial vacuum is formed, then, a partial pressure, then, a partial vacuum, each time step (b) is carried out for as many repetitions as are necessary, so that said actuating means need not be specially reset at a starting point after a larger number of failures to detect the container having penetrated the liquid, and (f) after detecting the presence of liquid in said container, aspirating liquid into the container by actuating said pressurizing means, whereby said method avoids the necessity of switching from one pressurizing means for step (c) to another pressurizing means for step (e).