HOT GLASS 3D PRINTING HEAD AND METHOD

Abstract

An apparatus for dispensing hot glass during 3D printing includes a crucible with a cylindrical barrel open at a proximal end and an aperture at a distal end, a holder-actuator to hold a glass rod feedstock and move the feedstock into and within the barrel, a first heater on or adjacent the outer surface of the barrel, and a second heater on or adjacent the outer surface of the barrel energized independently, and positioned proximally, of the first heater. A method of dispensing glass during 3D printing includes feeding a glass rod feedstock into the proximal, open end of a crucible having an aperture at its distal end while maintaining the crucible at a first position within a first temperature range and maintaining the crucible at second position, proximal of the first position, within a second temperature range lower than the first temperature range.

Claims

1. An apparatus for dispensing hot glass during 3D printing, the apparatus comprising: a crucible comprising a cylindrical barrel open at a proximal end of the crucible and having a barrel axis and a barrel cross section and an inner barrel surface and outer barrel surface, and an aperture at a distal end of the crucible in fluid communication with the barrel and having an aperture cross section, the barrel cross section being larger than the aperture cross section; a holder-actuator positioned proximally of the barrel and structured to hold a glass rod feedstock, when present, and to move the feedstock within the barrel along a direction generally parallel to the axis of the barrel; a first heater positioned on or adjacent to the outer surface of the barrel; and a second heater energized independently of the first heater and positioned on or adjacent to the outer surface of the barrel proximally of the first heater.

2. The apparatus of claim 1, wherein the second heater is mounted in an adjustable mount such that a distance between the first and second heaters is adjustable.

3. The apparatus of claim 2, wherein the adjustable mount is manually repositionable.

4. The apparatus of claim 2, wherein the adjustable mount is automatically repositionable.

5. The apparatus of claim 1, further comprising a third heater positioned on or adjacent to the outer surface of the barrel proximally of the second heater and energized independently of the first heater and the second heater.

6. The apparatus of claim 5, wherein the third heater is mounted in a second adjustable mount such that a distance between the second and third heaters is adjustable.

7. The apparatus of claim 6, wherein the second adjustable mount is manually repositionable.

8. The apparatus of claim 6, wherein the second adjustable mount is automatically repositionable.

9. A method of dispensing glass during 3D printing the method comprising: feeding a glass rod feedstock into the proximal and open end of a cylindrical barrel of a crucible, the crucible having an aperture at a distal end of the crucible, the aperture in fluid communication with the barrel and having an aperture cross section, the barrel cross section being larger than the aperture cross section; maintaining the crucible at a first position within a first temperature range; and maintaining the crucible at second position proximal of the first position within a second temperature range lower than the first temperature range.

10. The method according to claim 9, wherein the second temperature range is selected to correspond to a feedstock viscosity of between 10.sup.8-10.sup.11 poise.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 is a combined diagrammatic and cross sectional representation of an apparatus according to an embodiment of apparatuses the present disclosure;

[0014] FIG. 2 is a combined diagrammatic and cross sectional representation of an apparatus according to certain alternative embodiments of apparatuses the present disclosure; and

[0015] FIG. 3 is a cross sectional view of a (prior art) crucible usable with the methods and apparatuses of the present disclosure.

DETAILED DESCRIPTION

[0016] Reference will now be made in detail to various embodiments.

[0017] As shown in FIG. 1, an embodiment of apparatus 10 for dispensing hot glass during 3D printing, according to the present disclosure includes a crucible 20, supported in this embodiment in and opening in a retainer 12, with the retainer 12 mounted on a support frame 14.

[0018] The crucible 20 comprises a cylindrical barrel 30 open at a proximal end of the crucible 20 and having a barrel axis and a barrel cross section and an inner barrel surface 32 and outer barrel surface 34 (shown in FIG. 3), and an aperture 24 at a distal end of the crucible in fluid communication with the barrel. The aperture 24 as an aperture cross section, with the barrel cross section being larger than the aperture cross section.

[0019] The apparatus 10 further comprises a holder-actuator 40 positioned proximally of the barrel 30 and structured to hold a glass rod feedstock 50, when present, and to move the feedstock 50 within the barrel 30 along a direction generally parallel to the axis of the barrel 30. In the embodiment shown in FIG. 1, the holder-actuator 40 comprises a gripping mechanism 42 mounted on a piston 44 in a piston actuator 46. The holder-actuator 40 can be supported on the support frame 14.

[0020] The apparatus 10 further comprises a first heater 60a positioned on or adjacent to the outer surface 32 of the barrel 30 and a second heater 60b positioned on or adjacent to the outer surface 32 of the barrel 30, proximally of the first heater 60a. The second heater 60b is energized independently of the first heater 60a, such as by respective heater drivers 70a and 70b as shown in FIG. 1. Heaters 60a and 60b are represented as inductive heaters but can take other forms, such as resistive heaters, thermoelectric heaters, and others. A an electronic controller 90 of some form, such as a programmable electronic controller, can be used to control the heater drives 70a and 70b (and thereby the heaters 760a and 60b). Feedback of sensed temperatures at the crucible 20 can also be used to for the controller 90.

[0021] The apparatus 10 can have the second heater 60b mounted on an adjustable mount 80 such that a distance between the first and second heaters 60a, 60b is adjustable. The adjustable mount 80 can be manually repositionable and/or automatically repositionable, optionally under control of the controller 90. The holder-actuator 40, or as in the embodiment of FIG. 1, the piston actuator 46, can also operate under control of the controller 90.

[0022] In other embodiments according to the present disclosure illustrated in FIG. 2, the apparatus 10 can further comprise a third heater 60c positioned on or adjacent to the outer surface 32 of the barrel 30, proximally of the second heater 60b, and energized independently of the first heater 60a and the second heater 60b, such as by third heater drive 70c as shown. A fourth heater 60d with a fourth heater driver 70d can optionally be added also, and potentially more if needed. These additional heaters can also be mounted in adjustable mounts, to be manually and/or automatically repositionable. As further shown in FIG. 2, in other embodiments according to the present disclosure, the holder-actuator 40 may take the form of cooperating wheels 47, 48, with one or both of the cooperating wheels being rotatably actuated to move the feedstock 50 as desired.

[0023] Further according to other embodiments of the present disclosure, a method of dispensing glass during 3D printing is provided, the method comprising: (1) feeding a glass rod feedstock 50 into the proximal and open end of a cylindrical barrel 30 of a crucible 20, the crucible having an aperture 24 at a distal end of the crucible 20, the aperture 24 being in fluid communication with the interior of the barrel 30—the aperture 24 also has an aperture cross section with the barrel cross section being larger than the aperture cross section; (2) maintaining the crucible 20 at a first position (corresponding to the location of the first heater 60a) within a first temperature range; and (3) maintaining the crucible 20 at second position proximal of the first position (the second position corresponding to the location of the second heater 60b) within a second temperature range lower than the first temperature range. In this method, the second temperature range is desirably selected to correspond to a feedstock viscosity of between 10.sup.8-10.sup.11 poise, more desirably of between 10.sup.9-10.sup.10 poise.

[0024] FIG. 3 shows some additional preferred features of the crucible 20 from the prior art, including a flared rim 22 at the proximal end of the crucible 20 for assisting in supporting the crucible 20 in the retainer 12 of FIGS. 1 and 2, and a narrowing portion or “knuckle” 26 which narrows gradually from the barrel 30 to the aperture 24. The inner surface 34 of the barrel 30 (and of the crucible 20 as a whole) may include a coating 28.

[0025] It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit or scope of the disclosure. For example, the directions shown within the figures herein are not to be taken as limiting and the embodiments of the apparatuses disclosed may be operated in various orientations. “Proximal” and “distal” are in this sense relative indications of position within the immediately described structure only, and have no connection to any larger frame of reference.