Laboratory dispensing apparatus

Claim 2

Dispensing apparatus comprising a base section, liquid reservoir means on said base section for containing a liquid to be dispensed, agitator means associated with said reservoir means pick up the liquid therein, carrier means mounted on said base section for horizontal movement between a first non-dispensing position at one side of said liquid reservoir means and a second dispensing position in which said carrier means overlies a portion of said liquid reservoir means, liquid receptacle means supported on said carrier means, pick up and dispensing means mounted on said base section in operative alignment above said portion of said reservoir means, means for moving said pick up and dispensing means vertically relative to said base section, whereby, when said carrier means is in said first position, said pick up and dispensing means may be lowered to a first position to withdraw liquid from said portion of said reservoir means, then raised to permit said carrier means to be placed in said second position, and then lowered to a second position to dispense the withdrawn liquid into said receptacle means.

Claim 3

Dispensing apparatus as in claim 1, said liquid reservoir means comprising a trough positioned underneath said pick up and dispensing means, a liquid supply well remote from said trough and communicating therewith through connecting channel means, and said agitator means causing agitation of the liquid in said trough.

Claim 4

Dispensing apparatus as in claim 2, wherein said channel means comprises a pair of channels connecting said supply well with said trough, and said agitator means causes recirculation of the liquid between said supply well and said trough via said channels.

Claim 5

Dispensing apparatus as in claim 3, said agitator means comprising a permanent magnet rotatably mounted in said supply well for stirring said liquid, a drive assembly for said magnet including motor means mounted on said base section, a drive magnet rotated by said motor means, said drive magnet being operatively associated with said stirring magnet to rotate the same upon actuation of said motor means.

Claim 6

Dispensing apparatus as in claim 4, wherein said pair of channels extends substantially tangentially from the outer periphery of said supply well to the outer portions of said trough, and another channel intersects and extends from the inlet one of said pair of channels toward the central section of said Trough to ensure that all of the liquid in said trough is agitated.

Claim 7

Dispensing apparatus as in claim 1, wherein said agitator means comprises a permanent magnet rotatably mounted in said liquid reservoir means for stirring said liquid, a drive assembly for said stirring magnet including motor means mounted on said base section, a drive magnet rotated by said motor means, said drive magnet being operatively associated with said stirring magnet to rotate the same upon actuation of said motor means.

Claim 8

Dispensing apparatus as in claim 1, wherein said base section includes a lower base plate and an upper mounting bed-plate supported above said base plate, said liquid reservoir means, said carrier means, and said pick up and dispensing means being mounted on said upper mounting bed-plate, said mounting bed-plate having an elongated slot at least part of which extends underneath said reservoir means, said agitator means comprising a permanent magnet rotatably mounted in said reservoir means for stirring the liquid therein, motor means mounted on said lower base plate, a drive magnet rotated by said motor means and positioned within said slot of said reservoir means, said drive magnet being operatively associated with said stirrer magnet to rotate the same upon actuation of said motor means.

Claim 9

Dispensing apparatus as in claim 7, comprising an electrical control system for said agitator motor means, a pneumatic control system for operating said pick up and dispensing means, and at least some of the components of said electrical and pneumatic control systems being mounted on said base plate, thereby providing a compact, self-contained dispensing apparatus.

Claim 10

Dispensing apparatus as in claim 1, said pick up and dispensing means comprising manifold means, a pipette head unit including a plurality of dispensing pipettes normally retained in assembled relationship in said head unit, means for removably connecting said pipette head unit to said manifold means, flexible diaphragm means operatively positioned between said manifold means and said pipette unit, said manifold means having air passage means leading to one side of said diaphragm means, and a pneumatic supply system connected to said air passage means for creating a differential pressure on opposite sides of said diaphragm means to simultaneously pick up predetermined quantities of liquid from said reservoir means into said pipettes and thereafter simultaneously dispense said quantities from said pipettes.

Claim 11

Dispensing apparatus as in claim 9, said manifold means comprising a manifold having an air passageway, an actuating guide plate connected to said manifold and having a plurality of apertures communicating at one end with said manifold air passageway and terminating at their other ends at said one side of said diaphragm means, piston means mounted in each of said apertures and normally biased into engagement with said one side of said diaphragm means, said pipette head unit being removably connected to said manifold and piston guide plate, with each pipette being operatively aligned on the other side of said diaphragm means with a corresponding piston.

Claim 12

Dispensing apparatus as in claim 10, said pipette head unit comprising a dropper plate having a plurality of openings which operatively align with said piston guide plate apertures, a retainer plate connected to said dropper plate and having openings aligning with said dropper plate openings, each of said pipettes having an enlarged diameter section at one end slidably received within one of said dropper plate openings and a smaller diameter section extending outwardly through the aligned retainer plate opening, and spring means biasing said enlarged diameter section into engagement with the other side of said diaphragm means in operative alignment with one of said pistons.

Claim 13

Dispensing apparatus as in claim 10, said means for removably connecting said pipette head unit to said manifold means comprising clamp means for supporting said head unit, shaft means slidably extending through said manifold and piston guide plate and fixed at one end to said clamp means, locking means connected to the other end of said shaft means and movable between locked and unlocked positions, whereby when said locking means is in said locked position said head unit is operatively clamped to said manifold and said piston guide plate, and when said locking means is in said unlocked position said head unit is unclamped and may be readily removed from said pick up and dispensing means.

Claim 14

Dispensing apparatus as in claim 12, wherein said shaft means is adjustable screw means adjustably connected to said clamp means so that the effective actuating pressure acting on said diaphragm means may be varied by adjustment of said screw means.

Claim 15

Dispensing apparatus as in claim 9, wherein said pneumatic supply system includes a vacuum source.

Claim 16

Dispensing apparatus comprising a base section including a lower base plate and an upper mounting bed-plate supported above said base plate; liquid reservoir means on said mounting bed-plate for containing a liquid to be dispensed, said reservoir means including a trough and a liquid supply well remote from said trough and connected therewith through connecting channel means; liquid agitator means comprising a permanent stirring magnet rotatably mounted in said reservoir means, motor means mounted on said lower base plate, a drive magnet rotated by said motor means and operatively associated with said stirring magnet to rotate the same upon actuation of said motor means; carrier means mounted on said mounting bed-plate for movement between a first non-dispensing position at one side of said trough and a second dispensing position in which said carrier means overlies said trough; liquid receptacle means supported on said carrier means; pick up and dispensing means mounted for vertical movement on said bed-plate in operative alignment above said trough, said pick up and dispensing means comprising manifold means, a pipette head unit including a plurality of dispensing pipettes normally retained in assembled relationship in said head unit, means for removably connecting said pipette head unit to said manifold means, flexible diaphragm means operatively positioned between said manifold means and pipette head unit, said manifold means having air passage means leading to one side of said diaphragm means; a pneumatic control system connected to said air passage means for creating a differential pressure on opposite sides of said diaphragm means to permit simultaneous pick up of predetermined quantities of liquid from said trough when said carrier means is in said first non-dispensing position and then dispensing of said predetermined quantities of liquid from said pipettes into said liquid receptacle means when said carrier means is in said second dispensing position; an electrical control system for said agitator motor means; and at least some of the components of said pneumatic control system and said electrical control system being mounted on said lower base plate to provide a compact, self-contained dispensing apparatus.

Claim 17

Dispensing apparatus comprising a base section including a lower base plate and an upper mounting bed-plate supported above said base plate; liquid reservoir means on said mounting bed-plate for containing a liquid to be dispensed, said reservoir means including a trough and a liquid supply well remote from said trough and connected therewith through connecting channel means; liquid agitator means comprising a permanent stirring magnet rotatably mounted in said reservoir means, motor means mounted on said lower base plate, a drive magnet rotated by said motor means and operatively associated with said stirring magnet to rotate the same upon actuation of said motor means; carrier means mounted on said mounting bed-plate for movement between a first non-dispensing position at one side of said trough and a second dispensing position in which said carrier means overlies said trough; liquid receptacle means supported on said carrier means; pick up and dispensing means mounted for vertical movement on said bed-plate in operative alignment above said trough, said pick up and dispensing means comprising manifold means, a pipette head unit including a plurality of dispensing pipettes normally retained in assembled relationship in said head unit, means for removably connecting said pipette head unit to said manifold means, flexible diaphragm means operatively positioned between said manifold means and pipette head unit, said manifold means having air passage means leading to one side of said diaphragm means; a pneumatic control system connected to said air passage means for creating a differential pressure on opposite sides of said diaphragm means to permit simultaneous pick up of predetermined quantities of liquid from said trough when said carrier means is in said first non-dispensing position and then dispensing of said predetermined quantities of liquid from said pipettes into said liquid receptacle means when said carrier means is in said second dispensing position; an electrical control system for said agitator motor means; and at least some of the components of said pneumatic control system and said electrical control system being mounted on said lower base plate to provide a compact, self-contained dispensing apparatus.

Claim 18

Dispensing apparatus as in claim 15, said pneumatic control system comprising an air supply source, a solenoid-operated air valve mounted on said lower base plate and connected between said supply source and said air passage means in said manifold means, manually operated electrical switch means connected to said air solenoid valve means for operating said valve means, said switch means being accessible to an operator, and a pressure indicator means mounted on said base plate and extending through said mounting bed-plate so as to be readily visible by an operator.

Claim 19

Dispensing apparatus as in claim 16, said electrical control system comprising an electrical supply source, a transformer mounted on said base plate, second switch means connecting the primary side of said transformer to said electrical supply source, said second switch means being mounted above said bed-plaTe for ready access by an operator, first circuit means connecting the secondary side of said transformer to said agitator motor means and including a variable resistance mounted on said lower base plate for varying the speed of said motor means, and second circuit means including an indicator lamp mounted above said bed plate and readily visible to an operator to indicate operation of the apparatus when said second switch means has been placed in an on position.

Claim 20

Dispensing apparatus as in claim 16, wherein said air supply source is a vacuum source and said indicator means is a vacuum gauge.