FLUID-DISPENSING HEAD FOR A 3D PRINTER

• US 20140242208A1
• Filed: 02/26/2014
• Published: 08/28/2014
• Est. Priority Date: 02/27/2013
• Status: Active Grant

• Current Assignee: Q5D Technologies Ltd. (Q5Digital)
• Original Assignee: CEL Technology Limited
• Inventors: Elsworthy, Christopher Thomas
• Granted Patent: US 9,314,970 B2
• Time in Patent Office: Days
• US Class Current: 425/375
• CPC Class Codes: B29C 31/042 using dispensing heads, e.g. extruders, placed over or apart from the moulds positioning extruded preforms on conveyors B29C31/085
• 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 64/112 using individual droplets, e.g. from jetting heads
• 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: B33Y 30/00 Apparatus for additive manufacturing; Details thereof or accessories therefor

Abstract

A head assembly for an extrusion-based 3D printer includes: a fluid-dispensing head having a manifold and at least two fluid-dispensing nozzles, of different sizes, which are mounted in communication with a melt chamber in a manifold. Outlets of each nozzle are closed by respective valve members. A rocker serves both to pivot the nozzles to their lowermost nozzle-operating position and to actuate the valve members, for ready switching between the valves, such that the smaller nozzle can be used for high resolution work, and the larger nozzle can be used for bulk infill.

Claims

1. A printer head assembly for a 3D printer, comprising:

a fluid-dispensing head including a manifold;

first and second nozzles mounted to the manifold, each of the first and second nozzles having an outlet and a respective valve member for closing the respective outlet;

a coupling member coupling the fluid-dispensing head to a support for movement of the fluid-dispensing head, thereby moving each of the first and second nozzles to and from respective nozzle-operating positions, wherein, with one of the first and second nozzles in its nozzle-operating position, the outlet of the other of the first and second nozzles is disposed above the outlet of the one of the first and second nozzles that is in its nozzle operating position;

a rocker mounted to oscillate about a rocker axis, the rocker having at least one cam surface engaging a respective fixture for driving the movement of the fluid-dispensing head, the rocker further including first and second abutments engaging respective valve members for opening and closing the nozzle outlet of each of the first and second nozzle when a respective nozzle is in its nozzle-operating position; and

an actuator controlling angular position of the rocker.

2. The printer head assembly of claim 1 wherein

the coupling member comprises a pivot,

the fluid-dispensing head pivots to move the first and second nozzles to their respective nozzle-operating positions, and

the first and second nozzles have of different sizes and are in fluid communication with each other.

3. The printer head assembly of claim 2 wherein the at least one cam surface comprises first and second cam surfaces respectively engaging first and second fixtures, such that engagement of the first cam surface and the first fixture pivots the fluid-dispensing head in a first direction, and engagement of the second cam surface and the second fixture pivots the fluid-dispensing head in a second direction, opposite the first direction direction.

4. The printer head assembly of claim 3 wherein

the rocker is mounted to the fluid-dispensing head, and

the first and second fixtures are disposed on the support.

5. The printer head assembly of claim 4 wherein

first and second cam surfaces are external surfaces of the rocker, and

the first and second abutments include either

a) surfaces disposed at an end of circumferentially elongated slots in the rocker, or

b) surfaces on a periphery of lobes on the rocker.

6. The printer head assembly of claim 2 wherein the pivot includes at least one through-extending passage in communication with the manifold.

7. The printer head assembly of claim 6 wherein the manifold includes a heating element, and the at least one passage passes a consumable filament.

8. The printer head assembly of claim 1 further comprising

a mounting member to which the actuator is mounted, and

a neck in the pivot adjacent the manifold, wherein the neck provides a thermal bridge thermally separating the manifold from the mounting member.

9. The printer head assembly of claim 1 wherein the valve members comprise needles that are retractable from the nozzle outlets.

10. The printer head assembly of claim 9 wherein the first and second abutments engage respective needles for opening the nozzle outlets, and including respective springs cooperating with respective needles for closing the nozzle outlets.

11. The printer head assembly of claim 2 wherein

a pivot axis of the pivot lies in a central plane substantially symmetrically bisecting the manifold, and

the first and second nozzles are respectively disposed on opposing sides of the central plane.

12. The printer head assembly of claim 11 wherein a rocker axis of the rocker is substantially parallel to the pivot axis and lies in the central plane.

13. The printer head assembly of claim 1 wherein the printer head assembly further comprises a fan mounted to the support for directing a cooling air flow adjacent to the first and second nozzles.

14. The printer head assembly of claim 13 wherein the fan and manifold are generally disposed on opposite sides of the printer head assembly.

15. A 3D printer having the printer head assembly of claim 1, wherein one of three orthogonal axes of the 3D printer is defined by a rail, the support includes an aperture, and the rail is received in the aperture such that the printer head is reciprocated linearly along the rail.