Precision bead forming 3D print head for cementitious materials

Patent metadata

Field	Value
Publication number	US-11752663-B2
Application number	US-202017039292-A
Country	US
Kind code	B2
Filing date	Sep 30, 2020
Priority date	Sep 30, 2020
Publication date	Sep 12, 2023
Grant date	Sep 12, 2023

Abstract

A print head for additive manufacturing with a material includes an accumulator comprising an elongated body with an open interior and an inside diameter. A slide tube is slidably mounted within the open interior of the elongated body. The slide tube has a sealing piston head hermetically sealing the open end within the elongated body to define a variable gas containment space. A pressurized gas is supplied to the gas containment space. A rotatable shaping nozzle with an opening for discharging material is provided. A positive displacement extruder delivers material from the accumulator to the nozzle assembly. The nozzle assembly can include a nozzle rotation drive for rotating the shaping nozzle about an axis of rotation. The nozzle opening can be aligned with the axis of rotation, and defines a discharge axis that can be perpendicular to the axis of rotation. A method of additive manufacturing is also disclosed.

First claim

We claim:

1. A print head for additive manufacturing with a material, comprising:
an accumulator comprising an elongated body with an open interior and an inside diameter; a slide tube slidably mounted within the open interior of the elongated body, the elongated body having a distal material outlet, the slide tube comprising a conduit for directing the material from a slide tube material inlet to a slide tube material outlet at an open end of the slide tube, the slide tube comprising a sealing piston head having an axial passageway defining the open end, the piston head forming a sliding hermetic seal between the sliding tube and the elongated body, the slide tube having an outside diameter that is less than the inside diameter of the elongated body, the slide tube, elongated body and sealing piston head defining a gas containment space and the sealing piston head and elongated body distally defining an accumulator space between the piston head and the distal material outlet of the elongated body, a gas conduit system for receiving pressurized gas and directing the pressurized gas to the gas containment space, and for exhausting pressurized gas from the gas containment space;
wherein the gas conduit system is configured such that pressurized gas in the gas containment space will apply pressure to the piston head, the piston head will apply pressure to the material in the accumulator space, and wherein the hermetic seal and the gas conduit system are configured to prevent the pressurized gas from entering the accumulator space and thereby the material, and the pressure applied by the piston head to the material will drive the material through the distal material outlet of the elongated body and material will flow through the axial passageway of the piston head;
a nozzle assembly comprising a rotatable shaping nozzle with a nozzle opening for discharging the material; and,
an extruder for moving the material from the accumulator to the nozzle assembly.

2. The print head assembly of claim 1 , wherein the nozzle assembly further comprises a nozzle rotation drive for rotating the shaping nozzle about an axis of rotation.

3. The print head assembly of claim 2 , wherein the nozzle opening is aligned with the axis of rotation.

4. The print head assembly of claim 2 , wherein the nozzle opening defines a discharge axis, and wherein the discharge axis is perpendicular to the axis of rotation.

5. The print head assembly of claim 2 , wherein the nozzle assembly further comprises a registration system for registering the initial position of the nozzle.

6. The print head assembly of claim 1 , wherein the accumulator further comprises a proximal end with an end cap for closing the gas containment space, the end cap having an opening for slidably receiving a proximal end of the sliding tube, the end cap further comprising a seal for hermetically sealing the sliding tube within the end cap opening.

7. The print head assembly of claim 1 , wherein the gas containment space is annular.

8. The print head assembly of claim 1 , wherein the extruder is a positive displacement twin screw extruder.

9. The print head assembly of claim 1 , wherein the extruder is a screw extruder with a screw, the screw comprising an elastomeric outer covering.

10. The print head assembly of claim 1 , further comprising a pressure relief fitting comprising a magnetic attachment to the assembly.

11. The print head assembly of claim 1 , wherein the material is a cementitious material.

12. An additive manufacturing assembly for manufacturing with a material, comprising:
a motion device for holding a print head assembly and for moving the print head assembly in three dimensional space during an additive manufacturing process;
the print head assembly comprising an accumulator comprising an elongated body with an open interior and an inside diameter; a slide tube slidably mounted within the open interior of the elongated body, the elongated body having a distal material outlet, the slide tube comprising a conduit for directing the material from a slide tube material inlet to a slide tube material outlet at an open end of the slide tube, the slide tube comprising a sealing piston head having an axial passageway defining the open end, the piston head forming a sliding hermetic seal between the sliding tube and the elongated body, the slide tube having an outside diameter that is less than the inside diameter of the elongated body, the slide tube, elongated body and sealing piston head defining a gas containment space and the sealing piston head and elongated body distally defining an accumulator space between the piston head and the distal material outlet of the elongated body, a gas conduit system for receiving pressurized gas and directing the pressurized gas to the gas containment space, and for exhausting pressurized gas from the gas containment space;
wherein the gas conduit system is configured such that pressurized gas in the gas containment space will apply pressure to the piston head, the piston head will apply pressure to the material in the accumulator space, and wherein the hermetic seal and the gas conduit system are configured to prevent the pressurized gas from entering the accumulator space and thereby the material, and the pressure applied by the piston head to the material will drive the material through the distal material outlet of the elongated body and material will flow through the axial passageway of the piston head;
a nozzle assembly comprising a rotatable shaping nozzle with a nozzle opening for discharging the material; and
an extruder for moving the material from the accumulator to the nozzle assembly;
a source of the material for delivering the material to the print head assembly;
a source of pressurized gas connected to the gas conduit system; and,

a processor for controlling at least one selected from the group consisting of the movement of the motion device, the delivery of the material to the print head assembly, the delivery and removal of pressurized gas to the gas containment space, the operation of the extruder, and the rotation of the nozzle assembly.

13. The additive manufacturing assembly of claim 12 , wherein the material is a cementitious material.

14. A method of additive manufacturing, comprising the steps of:
providing a motion device for holding a print head assembly and for moving the print head assembly in three dimensional space during an additive manufacturing process;
providing a print head assembly comprising an accumulator comprising an elongated body with an open interior and an inside diameter; a slide tube slidably mounted within the open interior of the elongated body, the elongated body having a distal material outlet, the slide tube comprising a conduit for directing the material from a slide tube material inlet to a slide tube material outlet at an open end of the slide tube, the slide tube comprising a sealing piston head having an axial passageway defining the open end, the piston head forming a sliding hermetic seal between the sliding tube and the elongated body, the slide tube having an outside diameter that is less than the inside diameter of the elongated body, the slide tube, elongated body and sealing piston head defining a gas containment space and the sealing piston head and elongated body distally defining an accumulator space between the piston head and the distal material outlet of the elongated body,
providing a gas conduit system for receiving pressurized gas and directing the pressurized gas to the gas containment space, and for exhausting pressurized gas from the gas containment space;
wherein the gas cond

Assignees

• Ut Battelle Llc

Inventors

• Lind Randall F
• Post Brian K
• Chesser Phillip
• Atkins Celeste

Classifications

• B28B1/001 Primary

  Rapid manufacturing of 3D objects by additive depositing, agglomerating or laminating of material (selective deposition modelling of metallic powder B22F10/00; rapid manufacturing of 3D objects in general and in particular of plastics B29C64/00) · CPC title

• B28B3/224

  Twin screw extruders, e.g. double shaft extruders · CPC title

• B29C64/209

  Heads; Nozzles · CPC title

• B29C64/241

  for rotary motion · CPC title

• B29C64/393

  for controlling or regulating additive manufacturing processes · CPC title