System and Method for Moving a Rod of Build Material Using a Pusher in a 3D Printing System

Patent metadata

Field	Value
Publication number	US-2018304532-A1
Application number	US-201815961817-A
Country	US
Kind code	A1
Filing date	Apr 24, 2018
Priority date	Apr 24, 2017
Publication date	Oct 25, 2018
Grant date	—

Abstract

A system and corresponding method to move a rod of build material in a three-dimensional (3D) printing system uses a pusher. The rod of build material has distal and proximal ends relative to an extrusion head. The distal and proximal ends having distal and proximal end surfaces, respectively. The pusher engages with the rod and applies an axial force to at least a portion of the distal end surface of the rod for at least a portion of a path the rod travels toward the extrusion head. The axial force actuates the rod of build material without alteration, such as by shaving, fracturing, or otherwise deforming the rod of build material.

First claim

What is claimed is:

1 . An extrusion assembly for use in a three-dimensional (3D) printing system, the extrusion assembly including:
an extrusion head configured to receive a rod of build material having distal and proximal ends relative to the extrusion head, the distal and proximal ends having distal and proximal end surfaces, respectively; and an actuation assembly including a pusher, the pusher arranged to apply an axial force to at least a portion of the distal end surface of the distal end of the rod, the axial force being applied to the at least a portion of the distal end surface for at least a portion of a path the rod travels toward the extrusion head.

2 . The extrusion assembly of claim 1 , wherein the distal end surface is a normal surface or feature that is normal relative to a longitudinal axis of the rod of build material.

3 . The extrusion assembly of claim 1 , wherein the actuation assembly further includes:
an actuating component coupled to the pusher; and a driving component coupled to the actuating component, the driving component configured to drive the actuating component in a manner that causes bi-directional linear motion of the pusher relative to the extrusion head, the axial force being applied as a function of the pusher being caused to move, linearly, toward the extrusion head.

4 . The extrusion assembly of claim 3 , wherein the actuating component is a lead screw and the driving component is a motor.

5 . The extrusion assembly of claim 1 , wherein: the actuation assembly further includes an actuating component; wherein the pusher includes a traveling component and a pushing component; and wherein the traveling component is arranged to travel, linearly, along a linear actuation path defined by the actuating component, to cause linear motion of the pushing component.

6 . The extrusion assembly of claim 1 , wherein the pusher includes a pusher interface and wherein the pusher interface is arranged to engage with the at least a portion of the distal end surface.

7 . The extrusion assembly of claim 6 , wherein the pusher interface includes complementary features relative to surface features of the at least a portion of the distal end surface.

8 . The extrusion assembly of claim 1 , wherein the pusher includes a traveling component and a pushing component and wherein the pushing component includes at least one cantilevered protrusion of the traveling component.

9 . The extrusion assembly of claim 1 , wherein the pusher includes a traveling component arranged to cause motion of the pusher and wherein the traveling component is a nut.

10 . The extrusion assembly of claim 1 , wherein the pusher includes a traveling component and wherein the actuation assembly further includes:
an actuating component arranged to move the traveling component; and a linear guide coupled to the traveling component via a linear bearing, wherein the linear guide and the linear bearing are arranged to absorb a load otherwise transferred to the actuating component due to application of the axial force.

11 . The extrusion assembly of claim 10 , wherein the linear guide is a linear rail.

12 . The extrusion assembly of claim 1 , further comprising a guide channel, wherein the pusher includes a pushing component, wherein the at least a portion of the path the rod travels toward the extrusion head is defined by the guide channel, and wherein the guide channel defines at least one slot to receive the pushing component.

13 . The extrusion assembly of claim 12 , wherein the guide channel is arranged to contact at least a portion of the rod of build material to provide alignment for the at least a portion of the rod.

14 . The extrusion assembly of claim 1 , wherein the pusher includes a pushing component and wherein the actuation assembly further includes a cam arranged to cause the pushing component to transition between a media load position and a media extrude position as a function of surface contact between the cam and the pushing component.

15 . The extrusion assembly of claim 1 , wherein, in the media load position, the pushing component is arranged to be out of the path the rod travels toward the extrusion head and wherein, in the media extrude position, at least a portion of the pushing component is arranged to be in the path the rod travels toward the extrusion head.

16 . The extrusion assembly of claim 15 , wherein the pushing component and the cam define complementary features and wherein the complementary features are gear teeth.

17 . The extrusion assembly of claim 1 , wherein the extrusion assembly includes a media entrance arranged to load the rod of build material into the extrusion assembly and wherein the path the rod travels toward the extrusion head is from the media entrance to the extrusion head.

18 . A method for moving a rod of build material in a three-dimensional (3D) printing system, the method comprising:
engaging a rod of build material, loaded into an extrusion assembly including an extrusion head, with a pusher, the rod having distal and proximal ends relative to the extrusion head, the distal and proximal ends having distal and proximal end surfaces, respectively; and applying an axial force to at least a portion of the distal end surface of the distal end of the rod, the axial force being applied, by the pusher, to the at least a portion of the distal end surface for at least a portion of a path the rod travels toward the extrusion head in the 3D printing system.

19 . The method of claim 18 , further comprising:
driving an actuating component to cause the pusher to move between a home location and a reset location within the extrusion assembly, the home location and the reset location being distal and proximal pusher locations, respectively, of the pusher relative to the extrusion head; and sensing whether the pusher is located at the home and reset locations.

20 . The method of claim 19 , wherein the sensing is based on feedback from a sensing device.

21 . The method of claim 19 , wherein the sensing is performed in an open-loop manner as a function of a theoretical commanded location.

22 . The method of claim 19 , wherein the rod of build material is a first rod of build material and the method further comprises:
driving the actuating component in a manner that causes the pusher to move from the reset location to the home location in response to the reset location being sensed; and loading a second rod of build material into the extrusion assembly in response to the home location being sensed.

23 . The method of claim 18 , wherein the pusher includes a traveling component and a pushing component and wherein the method further comprises moving the pushing component between a media load position and an extrusion position, the media load position employed for loading the rod of build material and the extrusion position employed for extruding the rod of build material.

24 . The method of claim 18 , wherein the pusher includes a traveling component and a pushing component and wherein the method further comprises driving an actuating component coupled to the traveling component, the driving causing rotation of the actuating component that, in turn, causes linear motion of the pusher.

25 . The method of claim 24 , wherein the linear motion includes a first linear motion toward the extrusion head and a second linear motion away from the extrusion he

Assignees

• Desktop Metal Inc

Inventors

• Burnham Richard
• Laplante John
• Preston Aaron

Classifications

• B29C64/393

  for controlling or regulating additive manufacturing processes · CPC title

• B29C64/321

  Feeding · CPC title

• B29C64/209 Primary

  Heads; Nozzles · CPC title

• B33Y30/00

  Apparatus for additive manufacturing; Details thereof or accessories therefor · CPC title

• B29C64/205

  Means for applying layers · CPC title