Apparatus and methods for servicing 3D printers

• US 20060061618A1
• Filed: 11/30/2004
• Published: 03/23/2006
• Est. Priority Date: 09/21/2004
• Status: Active Grant

• Current Assignee: 3D Systems, Inc. (3D Systems Corporation)
• Original Assignee: Z CORPORATION (A Holdings Corp.)
• Inventors: Kinsley, Joshua P., Hernandez, Andres Tomas, Zengerle, Walter H. III, Berlin, Andrew A., Russell, David B., Katalichenko, Dmitriy, Korda, Chris, Sweet-Block, Benjamin D.
• Granted Patent: US 7,387,359 B2
• Time in Patent Office: Days
• US Class Current: 347/29
• CPC Class Codes: B29C 64/112 using individual droplets, e.g. from jetting heads
• CPC Class Codes: B33Y 40/00 Auxiliary operations or equipment, e.g. for material handling
• CPC Class Codes: B41J 2/16532 by applying vacuum only
• CPC Class Codes: B41J 2/16538 with brushes or wiper blades perpendicular to the nozzle plate
• CPC Class Codes: B41J 2/16552 using cleaning fluids

Abstract

The invention relates to apparatus and methods for producing three-dimensional objects and auxiliary systems used in conjunction with the aforementioned apparatus and methods. The apparatus and methods involve 3D printing and servicing of the equipment used in the associated 3D printer.

Claims

1. A service station for maintaining a plurality of printheads in a three-dimensional printer, the service station comprising:

a cleaning station;

a discharge station; and

a capping station.

2. The service station of claim 1, wherein the cleaning station comprises:

at least one receptacle for receiving a printhead;

at least one nozzle for spraying a cleaning fluid towards a printhead face of the printhead; and

a wiper disposable in close proximity to the printhead face for removing excess cleaning fluid.

3. The service station of claim 2, wherein the cleaning station further comprises a splash guard for isolating the printhead face and preventing the cleaning fluid from migrating beyond the printhead face.

4. The service station of claim 3, wherein the splash guard comprises an open position and a sealed position, where the splash guard is biased open and is actuated from the open position to the sealed position by contact with a printhead.

5. The service station of claim 4, wherein the splash guard includes a sealing lip that circumscribes the printhead face when in the sealed position.

6. The service station of claim 5, wherein the sealing lip is generally rectangular in shape.

7. The service station of claim 6, wherein the wiper is formed by one side of the sealing lip.

8. The service station of claim 7, wherein the wiper includes a notched portion configured and located to correspond to a location of a jet nozzle array on the printhead face to prevent the wiper from contacting the jet nozzle array.

9. The service station of claim 2, wherein the wiper is capable of movement relative to a printhead.

10. The service station of claim 2, further comprising a fluid source for providing the cleaning fluid to the at least one nozzle under pressure.

11. The service station of claim 2, wherein the cleaning fluid is provided to the at least one nozzle via a manifold.

12. The service station of claim 2, wherein the at least one nozzle comprises an array of nozzles.

13. The service station of claim 2, wherein the at least one nozzle is positionable to spray the cleaning fluid across the printhead face.

14. The service station of claim 1, wherein the printheads are disposable within a carriage capable of moving in at least two directions relative to the service station.

15. The service station of claim 1, wherein the discharge station comprises a receptacle defining an opening that generally corresponds to a printhead face of a printhead.

16. The service station of claim 15, wherein the receptacle defines a plurality of corresponding openings.

17. The service station of claim 15, wherein the receptacle comprises a tray for at least one of capturing and directing discharged fluids.

18. The service station of claim 17, wherein the discharge from the printheads is directed into a standing pool of waste liquid.

19. The service station of claim 1, wherein the capping station comprises:

a printhead cap carrier; and

at least one printhead cap disposed on the carrier for sealing a printhead face of a printhead, wherein the cap is moved between an off position and a capped position by the printhead contacting the carrier.

20. The service station of claim 19, wherein the capping station comprises a plurality of caps disposed on the carrier.

21. The service station of claim 19, wherein the carrier is biased to maintain the at least one cap in an off position.

22. The service station of claim 1, wherein the discharge station and the capping station are combined.

23. The service station of claim 22, wherein the discharge from the printheads is directed into a standing pool of waste liquid.

24. The service station of claim 23, wherein the discharge from the printheads is constrained in a cavity defined by a printhead face, a printhead cap, and the standing pool of waste liquid.

25. An apparatus for cleaning a printhead, the apparatus comprising:

at least one nozzle for spraying a cleaning fluid towards a printhead face of the printhead; and

a wiper disposable in close proximity to the printhead face for removing excess cleaning fluid from the printhead face.

26. The apparatus of claim 25, wherein the cleaning station further comprises a splash guard for isolating a printhead face and preventing cleaning fluid from migrating beyond the printhead face.

27. The apparatus of claim 26, wherein the splash guard comprises an open position and a sealed position, and the splash guard is actuated from the open position to the sealed position by contact with a printhead.

28. The apparatus of claim 27, wherein the splash guard includes a sealing lip that circumscribes the printhead face when in the sealed position.

29. The apparatus of claim 28, wherein the sealing lip is generally rectangular in shape.

30. The apparatus of claim 29, wherein the wiper is formed by one side of the sealing lip, the wiper including a notched portion configured and located to correspond to a location of a jet nozzle array on the printhead face to prevent the wiper from contacting the jet nozzle array.

31. The apparatus of claim 25, wherein the wiper is capable of movement relative to a printhead.

32. The apparatus of claim 25 further comprising a fluid source for providing cleaning fluid to the at least one nozzle under pressure.

33. The apparatus of claim 25, wherein the at least one nozzle comprises an array of nozzles.

34. The apparatus of claim 25, wherein the at least one nozzle is positionable to spray the cleaning fluid across the printhead face.

35. A method of cleaning a printhead, the method comprising the steps of:

positioning a printhead face of the printhead relative to at least one nozzle;

operating the at least one nozzle to spray cleaning fluid towards the printhead face; and

causing relative movement between a wiper and the printhead to pass the wiper in close proximity to the printhead face to remove excess cleaning fluid, wherein the wiper defines a notch configured and located on the wiper to correspond to a location of a jet nozzle array on the printhead face to prevent the wiper from contacting the jet nozzle array.

36. The method of claim 35, wherein the step of positioning the printhead face comprises sealing the printhead face to prevent the cleaning fluid from migrating beyond the printhead face.

37. The method of claim 35, wherein the operating step comprises spraying the cleaning fluid across the printhead face.

38. The method of claim 35 further comprising the step of operating the printhead to discharge cleaning fluid ingested by the printhead during cleaning.

39. The method of claim 35, wherein the at least one nozzle comprises an array of nozzles.

40. An apparatus for cleaning a printhead used in a three-dimensional printer, the apparatus comprising:

a sealing cap defining a cavity and capable of engagement with a printhead face of the printhead;

a cleaning fluid source in communication with the cap for cleaning the printhead face; and

a vacuum source in communication with the cap for removing used cleaning fluid and debris.

41. The apparatus of claim 40, wherein the vacuum source creates a negative pressure within the cavity, the negative pressure serving to at least one of:

draw the cleaning fluid into the cavity from the cleaning fluid source;

prevent the cleaning fluid from entering a jet nozzle; and

drawing at least one of a binder fluid and debris from the jet nozzle.

42. The apparatus of claim 40 further comprising a wiper disposed proximate the cap, the wiper positioned to engage the printhead face as the printhead disengages from the cap.

43. The apparatus of claim 42, wherein the wiper defines a notch configured and located on the wiper to correspond to a location of a jet nozzle array on the printhead face to prevent the wiper from contacting the jet nozzle array.

44. A method of cleaning a printhead used in a three-dimensional printer comprising the steps of:

engaging a printhead face of the printhead with a sealing cap defining a cavity;

drawing a vacuum in the cavity; and

introducing a cleaning fluid into the cavity and into contact with the printhead face.

45. The method of claim 44 further comprising the step of removing the cleaning fluid from the cavity.

46. The method of claim 45 further comprising the steps of:

disengaging the cap from the printhead face; and

removing excess cleaning fluid from the printhead face with a wiper.

47. The method of claim 44, wherein the step of drawing a vacuum creates a negative pressure within the cavity, the negative pressure serving to at least one of:

draw the cleaning fluid into the cavity;

prevent the cleaning fluid from entering a jet nozzle; and

drawing at least one of a binder fluid and debris from the jet nozzle.

48. A method of determining a condition of a printhead in use in a three-dimensional printer, the method comprising the steps of:

acquiring a data value for at least one operational parameter of the printhead; and

comparing the data value to a threshold value, the relationship of the data value to the threshold value indicative of the condition of the printhead.

49. The method of claim 48 further comprising the step of initiating a service routine on the printhead if the data value exceeds the threshold value.

50. The method of claim 48, wherein the operational parameter is selected from the group consisting of time elapsed, number of droplets dispensed by the printhead, number of layers printed, droplets dispensed over previously printed powder, droplets dispensed over previously unprinted powder, and combinations thereof.

51. The method of claim 48, wherein the data value is compensated during acquisition to account for an operational environmental factor of the three-dimensional printer.

52. The method of claim 51, wherein the operational environmental factor is selected from the group consisting of temperature, humidity, binder material, and build material.

53. A method of determining a condition of a printhead in use in a three-dimensional printer, the method comprising the steps of:

counting droplets dispensed by the printhead; and

determining a percentage of the droplets that were dispensed over previously unprinted pixels.

54. The method of claim 53 further comprising the step of initiating a service routine on the printhead if the percentage exceeds a threshold value.