Print head assembly and print head for use in fused deposition modeling system

• US 8,647,102 B2
• Filed: 12/21/2011
• Issued: 02/11/2014
• Est. Priority Date: 12/22/2010
• Status: Active Grant

• Current Assignee: Stratasys Incorporated
• Original Assignee: Stratasys Incorporated
• Inventors: Swanson, William J., Batchelder, J. Samuel, Johnson, Kevin C., Hjelsand, Timothy A., Comb, James W.
• Primary Examiner(s): Thrower, Larry
• Assistant Examiner(s): LIU, XUE H
• Application Number:
  US13/332,530
• Publication Number:
  US 20120164256A1
• Time in Patent Office: 783 Days
• Field of Search: 425/162, 425/375
• US Class Current: 425/162
• CPC Class Codes: B29C 41/52 Measuring, controlling or regulating
• CPC Class Codes: B29C 64/106 using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material
• CPC Class Codes: B29C 64/118 using filamentary material being melted, e.g. fused deposition modelling [FDM]
• CPC Class Codes: B29C 64/209 Heads; Nozzles
• CPC Class Codes: B29C 64/25 Housings, e.g. machine housings
• CPC Class Codes: B33Y 30/00 Apparatus for additive manufacturing; Details thereof or accessories therefor

Abstract

A print head assembly that includes a print head carriage and multiple, replaceable print heads that are configured to be removably retained in receptacles of the print head carriage. The print heads each include a cartridge assembly and a liquefier pump assembly retained by the cartridge assembly.

Claims

1. A print head assembly for use in an additive manufacturing system, the print head assembly comprising:

a carriage retained by a gantry mechanism of the additive manufacturing system that is configured to move the carriage substantially in an x-y plane, wherein the carriage is configured to receive a plurality of replaceable print heads and to retain the received print heads at the same time;

at least one suspension mechanism operably connected to the carriage, wherein the carriage and the at least one suspension mechanism are configured to prevent each of the received print heads from moving relative to the carriage in directions parallel to the x-y plane, while also allowing each of the received print heads to be controllably moved in a dimension outside of the x-y plane;

a toggle mechanism for each received print head, which is configured to controllably move the received print head relative to the carriage substantially in the dimension outside the x-y plane; and

a controller configured to independently operate the toggle mechanisms such that the toggle mechanisms controllably move the received print heads independently of each other.

2. The print head assembly of claim 1, wherein the dimension outside of the x-y plane that each of the received print heads is controllably moved is a linear dimension along a z-axis.

3. The print head assembly of claim 1, wherein the dimension outside of the x-y plane that each of the received print heads is controllably moved is a pivoting dimension.

4. The print head assembly of claim 1, wherein the carriage comprises:

a carriage frame; and

a plurality of receptacles, which are the portions of the carriage that are configured to receive the plurality of replaceable print heads.

5. The print head assembly of claim 1, wherein each toggle mechanism comprises a voice coil and a plurality of magnets configured to generate magnetic fields, and wherein the voice coil is disposed at least partially within the generated magnetic fields.

6. The print head assembly of claim 1, and further comprising a plurality of encoder assemblies configured to measure the positions of the received print heads relative to the carriage along the dimensions outside the x-y plane.

7. The print head assembly of claim 1, wherein the controller is further configured to provide electrical power from the additive manufacturing system to each received print head.

8. The print head assembly of claim 1, and further comprising the plurality of replaceable print heads, wherein each of the plurality of replaceable print heads comprises:

a liquefier pump assembly comprising;

a drive block having a first opening and a second opposing opening, the first and second openings being offset by a channel that is configured to receive a filament of a material;

a rotatable shaft having a toothed surface extending at least partially within the channel of the drive block, the toothed surface being configured to engage and drive the filament in the channel; and

a liquefier configured to receive the filament driven by the rotatable shaft; and

a circuit board electrically connected to the liquefier pump assembly.

9. The print head assembly of claim 8, wherein the liquefier pump assembly further comprises:

a motor;

a rotatable gear axially connected to the motor, and having a threaded surface; and

a capstan gear having a rotational axis and perimeter teeth, the perimeter teeth being configured to engage the threaded surface of the rotatable gear, wherein the rotatable shaft extends from the rotational axis of the capstan gear.

10. A print head assembly for use in an additive manufacturing system, the print head assembly comprising:

a plurality of replaceable print heads, each having a cartridge assembly and a liquefier pump assembly;

a carriage retained by a gantry mechanism of the additive manufacturing system that is configured to move the carriage substantially in an x-y plane, wherein the carriage is configured to receive the plurality of replaceable print heads and to retain the received print heads at the same time;

at least one suspension mechanism operably connected to the carriage, wherein the carriage and the at least one suspension mechanism are configured to prevent each of the received print heads from moving relative to the carriage in directions parallel to the x-y plane, while also allowing each of the received print heads to be controllably moved in a dimension outside of the x-y plane;

a toggle mechanism for each received print head, which is configured to controllably and independently move the received print head relative to the carriage substantially in the dimension outside the x-y plane; and

a controller configured to independently operate the toggle mechanisms such that the toggle mechanisms controllably move the received print heads independently of each other.

11. The print head assembly of claim 10, wherein the dimension outside of the x-y plane that each of the received print heads is controllably moved is a linear dimension along a z-axis.

12. The print head assembly of claim 10, wherein the dimension outside of the x-y plane that each of the received print head is controllably moved is a pivoting dimension.

13. The print head assembly of claim 10, wherein the carriage comprises:

a carriage frame; and

a plurality of receptacles, which are the portions of the carriage that are configured to receive the plurality of replaceable print heads.

14. The print head assembly of claim 10, wherein the controller is further configured to provide electrical power from the additive manufacturing system to each received print head.

15. The print head assembly of claim 10, wherein each of the plurality of replaceable print heads comprises:

a liquefier pump assembly comprising;

a drive block having a first opening and a second opposing opening, the first and second openings being offset by a channel that is configured to receive a filament of a material;

a rotatable shaft having a toothed surface extending at least partially within the channel of the drive block, the toothed surface being configured to engage and drive the filament in the channel; and

a liquefier configured to receive the filament driven by the rotatable shaft; and

a circuit board electrically connected to the liquefier pump assembly.

16. A print head assembly for use in an additive manufacturing system, the print head assembly comprising:

a first replaceable print head having a first cartridge assembly and a first liquefier pump assembly;

a second replaceable print head having a second cartridge assembly and a second liquefier pump assembly;

a carriage retained by a gantry mechanism of the additive manufacturing system that is configured to move the carriage substantially in an x-y plane, wherein the carriage is configured to receive the first replaceable print head and the second replaceable print head and to retain the received first and second print heads at the same time;

at least one suspension mechanism operably connected to the carriage, wherein the carriage and the at least one suspension mechanism are configured to prevent the received first and second print heads from moving relative to the carriage in directions parallel to the x-y plane, while also allowing each of the received first and second print heads to be controllably moved in a dimension outside of the x-y plane;

a first toggle mechanism configured to controllably move the received first print head relative to the carriage substantially in the dimension outside the x-y plane;

a second toggle mechanism configured to controllably move the received second print head relative to the carriage substantially in the dimension outside the x-y plane, independently of the controlled movement of the received first print head; and

a controller configured to operate the first and second toggle mechanisms in a manner that controllably moves the received first and second print heads independently of each other.

17. The print head assembly of claim 16, wherein the dimension outside of the x-y plane that the received first and second print heads are each controllably moved is a linear dimension along a z-axis.

18. The print head assembly of claim 16, wherein the dimension outside of the x-y plane that the received first and second print heads are each controllably moved is a pivoting dimension.

19. The print head assembly of claim 16, wherein each toggle mechanism comprises a voice coil and a plurality of magnets configured to generate magnetic fields, and wherein the voice coil is disposed at least partially within the generated magnetic fields.

20. The print head assembly of claim 16, wherein first and second liquefier pump assemblies each comprise:

a drive block having a first opening and a second opposing opening, the first and second openings being offset by a channel that is configured to receive a filament of a material;

a rotatable shaft having a toothed surface extending at least partially within the channel of the drive block, the toothed surface being configured to engage and drive the filament in the channel; and

a liquefier configured to receive the filament driven by the rotatable shaft.