CARTRIDGE BASED FLUID DISPENSING APPARATUS

• US 20090250491A1
• Filed: 09/07/2007
• Published: 10/08/2009
• Est. Priority Date: 09/08/2006
• Status: Active Grant

• Current Assignee: A.C. Dispensing Equipment Incorporated
• Original Assignee: A.C. Dispensing Equipment Incorporated
• Inventors: Marshall, Chris, MacLean, Ian, Ricker, David, Stoneman, Kevin, Erman, P. Gregory, McDougall, Michael, Wilson, Avery
• Granted Patent: US 8,561,841 B2
• Time in Patent Office: Days
• US Class Current: 222/135
• CPC Class Codes: A47J 31/402 Liquid dosing devices
• CPC Class Codes: F04B 13/00 Pumps specially modified to deliver fixed or variable measured quantities
• CPC Class Codes: F04B 9/02 the means being mechanical

Abstract

A concentrated flavour dispensing machine having displacement pumps for delivering between a fraction of a millilitre and a few ounces of fluids having a viscosity value between 1 to 4000 centepoise is described. The dispensing machine includes a cabinet for containing a multitude of displacement pumps, where each displacement pump is realisably connected to a disposable pre-filled fluid cartridge. Each displacement pump includes a stepper motor in engagement with a threaded drive rod that is advanced or retracted by any one of several predetermined distances. The drive rod impels a plunger positioned within the disposable cartridge to dispense a volume of fluid. Flexible capillary tubes connected to the output of each disposable cartridge direct the fluid to a central dispensing area. The disposable cartridge includes an expandable plunger which draws fluid back into the cartridge when the drive rod is withdrawn after a dispense operation for drip prevention.

Claims

1. A pump unit for dispensing a predetermined volume of fluid comprising:

a stepper motor in threaded engagement with a threaded drive rod, the stepper motor rotatable in one direction by a number of steps to advance the threaded drive rod;

a cartridge mount coupled to a stepper motor, the cartridge mount having a locking means with an aperture sized to pass the threaded drive rod;

a disposable cartridge having a first end adapted to engage the locking means for securing the disposable cartridge to the cartridge mount, the disposable cartridge having a chamber sealed with a plunger slidable in the chamber, the disposable cartridge having an outlet nozzle at a second end for dispensing contents of the chamber when the plunger is pushed by the threaded drive rod.

2. The pump unit of claim 1, wherein the plunger includes an expandable plunger top of resilient material deformable to an expanded state when the plunger is pushed by a piston connected to the threaded drive rod, the expandable plunger top returning to a relaxed state when the piston is withdrawn from the plunger by a predetermined distance.

3. The pump unit of claim 1, wherein the locking means includes a bayonet style twist lock, and the first end of the disposable cartridge is adapted for engaging the bayonet style twist lock.

4. The pump unit of claim 1, further including a capillary tube releasably connected to the outlet nozzle.

5. The pump unit of claim 1, further including a driver card in electrical communication with the stepper motor, the driver card including a microcontroller for controlling the stepper motor in response to pump control data.

6. The pump unit of claim 5, wherein the driver card includes a connector for receiving the pump control data.

7. The pump unit of claim 1, wherein the cartridge mount includes a mounting means for securing the cartridge mount to a chassis.

8. A dispensing machine for providing a predetermined volume of fluid corresponding to a user selection, comprising:

a pump unit having a stepper motor for advancing a threaded drive rod in response to pump control data;

a disposable cartridge releasably connected to the pump unit, and having a plunger for engaging the threaded drive rod;

a user interface for providing electrical selection signals in response to the user selection; and

a microprocessor for receiving the electrical selection signals and for providing the pump control data corresponding to the pump unit, the pump control data including stepper motor direction data and number of steps data.

9. The dispensing machine of claim 8, wherein the disposable cartridge includes a chamber sealed with the plunger, the plunger having an expandable plunger top of resilient material deformable to an expanded state when the plunger is pushed by the threaded drive rod for dispensing the predetermined volume of fluid, the expandable plunger top returning to a relaxed state when the threaded drive rod is withdrawn from the plunger by a predetermined distance.

10. The dispensing machine of claim 9, further including a capillary tube releasably connected to the outlet nozzle for directing the contents of the chamber to a dispensing area.

11. The dispensing machine of claim 8, wherein the pump unit includes a cartridge mount coupled to the stepper motor, the cartridge mount having a locking means with an aperture sized to pass the threaded drive rod and the disposable cartridge being adapted for engaging the locking means.

12. The dispensing machine of claim 11, wherein the pump unit includes a driver card in electrical communication with the stepper motor, the driver card including a controller for controlling the stepper motor in response to pump control data.

13. The dispensing machine of claim 12, wherein the pump unit includes an electromotive force detector for detecting a predetermined position of the threaded drive rod.

14. The dispensing machine of claim 12, wherein the pump mount includes an interface card adapted for electrically engaging the driver card for passing the pump control data when the pump unit is secured to the pump mount.

15. A method for dispensing a volume of fluid from a disposable cartridge, comprising:

a) receiving a selection signal from a user interface for dispensing the volume of fluid;

b) providing an alert and locking the disposable cartridge if the volume of fluid is greater than a remaining amount of fluid in the disposable cartridge; and

,

c) dispensing the volume of fluid from the disposable cartridge when the remaining amount of fluid in the disposable cartridge is at least the volume of fluid.

16. The method of claim 15, wherein the step of dispensing includes advancing a threaded drive rod for pushing a plunger in the disposable cartridge, in response to the selection signal.

17. The method of claim 16, wherein pushing the plunger includes deforming an expandable plunger top of the plunger.

18. The method of claim 17, wherein pushing the plunger includes deforming the expandable plunger top before the plunger is moved by the threaded drive rod.

19. The method of claim 17, wherein the step of dispensing includes withdrawing the threaded drive rod away from the plunger by a predetermined distance after the volume of fluid is dispensed for returning the expandable plunger top to a relaxed state to draw fluid back into the disposable cartridge.

20. The method of claim 16, wherein the step of providing an alert includes homing the threaded drive rod.

21. The method of claim 16, further including detecting an end position of the threaded drive rod.

22. The method of claim 21, wherein the step of detecting an end position of the threaded drive rod includes providing the alert, locking the disposable cartridge and homing the threaded drive rod.

23. A cartridge plunger for receiving a piston, comprising:

a hollow body having an open end for receiving the piston; and

,

an expandable plunger top at a closed end of the hollow body deformable to an expanded state by the piston, the expandable plunger top returning to a relaxed state when the piston is withdrawn from the plunger by a predetermined distance.

24. The cartridge plunger of claim 23, wherein the hollow body includes,

a first circular side-wall with a first diameter for defining a primary plunger chamber, the primary plunger chamber having the open end for receiving the piston and having an internal shoulder at a second end for abutment with an edge of the piston,

a secondary plunger chamber extending from the shoulder, the secondary plunger chamber having the closed end with the expandable plunger top.

25. The cartridge plunger of claim 23, wherein the expandable plunger top includes folds of resilient material.