Filament drive mechanism for use in additive manufacturing system

Patent metadata

Field	Value
Publication number	US-9321609-B2
Application number	US-201213708116-A
Country	US
Kind code	B2
Filing date	Dec 7, 2012
Priority date	Dec 7, 2012
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

A filament drive mechanism for use with an additive manufacturing system, the filament drive mechanism comprising first and second drive shafts engaged with each other and configured to rotate in opposing rotational directions around substantially parallel and fixed axes, where the first and second drive shafts include engagement surfaces substantially aligned with each other for engaging a filament therebetween.

First claim

The invention claimed is:

1. A filament drive mechanism for use with an additive manufacturing system, the filament drive mechanism comprising:
a first drive shaft having a first rotational axis, and comprising:
first gear teeth extending around the first rotational axis; and
a first engagement surface extending around the first rotational axis, wherein the first engagement surface comprises a first plurality of spaced apart filament engagement surfaces substantially parallel to the first rotational axis; and

a second drive shaft having a second rotational axis that is substantially parallel to and fixed relative to the first rotational axis, wherein the second drive shaft comprises:
second gear teeth extending around the second rotational axis, wherein the second gear teeth are engaged with the first gear teeth; and
a second engagement surface extending around the second rotational axis, wherein the second engagement surface comprises a second plurality of spaced apart filament engagement surfaces substantially parallel to the second rotational axis and is substantially aligned with the first engagement surface of the first drive shaft such that the first and second plurality of spaced apart filament engagement surfaces are configured for engaging a filament therebetween by at least partially compressing a filament surface at one or more locations concurrently.

2. The filament drive mechanism of claim 1 , and further comprising a drive block, wherein the drive block comprises:
a channel configured to receive the filament; and
a pair of lateral openings extending substantially perpendicular to the channel, wherein the first and second engagement surfaces are respectively disposed in the pair of lateral openings.

3. The filament drive mechanism of claim 1 , wherein the first plurality of paced apart filament engagement surfaces comprises a first set of teeth, wherein the second plurality of spaced apart filament engagement surfaces comprises a second set of teeth, and wherein the first set of teeth and the second set of teeth are configured to engage the filament with at least an interlaced engagement.

4. The filament drive mechanism of claim 3 , wherein the first set of teeth are radially aligned with the first gear teeth, and wherein the second set of teeth are radially aligned with the second gear teeth.

5. The filament drive mechanism of claim 1 , wherein the first and second engagement surfaces are offset along an axis by a minimum distance ranging from about 0.975 millimeters to about 1.29 millimeters, the axis being substantially perpendicular to the first and second rotational axes.

6. The filament drive mechanism of claim 1 , wherein the first and second drive shafts have substantially the same cross-sectional dimensions at the first gear teeth and the second gear teeth, and at the first and second engagement surfaces.

7. The filament drive mechanism of claim 1 , and further comprising a capstan gear having perimeter gear teeth, wherein the first drive shaft extends axially from the capstan gear.

8. The filament drive mechanism of claim 1 , wherein the first rotational axis and the second rotational axis are each a substantially fixed axis.

9. A print head for use with an additive manufacturing system, the print head comprising:
a cartridge portion;
a liquefier assembly extending from the cartridge portion; and
a filament drive mechanism disposed in the cartridge portion, the filament drive mechanism comprising:
a first drive shaft extending along a first rotational axis and having a first plurality of spaced apart filament engagement surfaces positioned substantially parallel to the first rotational axis; and
a second drive shaft engaged with the first drive shaft and extending along a second rotational axis that is substantially parallel to and fixed relative to the first rotational axis, the second drive shaft having a second plurality of spaced apart filament engagement surfaces that are positioned substantially parallel to the second rotational axis and substantially aligned with the first plurality of spaced apart filament engagement surfaces of the first drive shaft wherein the first and second drive shafts are configured to engage a filament therebetween by compression of a filament surface at one or more opposing points along a length of the filament corresponding to one or more of the first and second pluralities of spaced apart filament engagement surfaces to feed the filament to the liquefier assembly.

10. The print head of claim 9 , and further comprising a drive block, wherein the drive block comprises:
a first opening;
a second opposing opening from the first opening along a channel axis;
a channel extending along the channel axis between the first and second openings, the channel being configured to receive the filament;
a third opening substantially perpendicular to the channel axis, wherein the third opening intersects the channel and retains the first engagement surface of the first drive shaft; and
a fourth opening substantially perpendicular to the channel axis and substantially parallel to the third opening, wherein the fourth opening intersects the channel adjacent to the third opening and retains the second engagement surface of the second drive shaft.

11. The print head of claim 9 , wherein the second drive shaft is engaged with the first drive shaft in manner such that a rotation of the first drive shaft in a first rotational direction around the first rotational axis forces the second drive shaft to rotate in a second rotational direction around the second rotational axis that is counter to the first rotational direction.

12. The print head of claim 9 , wherein the first engagement surface comprises a first set of teeth, wherein the second engagement surface comprises a second set of teeth, and wherein the first set of teeth and the second set of teeth are configured to engage the filament with an interlaced engagement.

13. The print head of claim 9 , wherein the first plurality of spaced apart filament engagement surfaces comprises first gear teeth extending around the first rotational axis, wherein the second plurality of spaced apart filament engagement surfaces comprises second gear teeth extending around the second rotational axis, and wherein the second drive shaft is engaged with the first drive shaft by an engagement between the first gear teeth and the second gear teeth.

14. The print head of claim 12 , wherein the first engagement surface comprises the same number of teeth as the first gear teeth, and wherein the teeth of the first engagement surface are radially aligned with the first gear teeth.

15. A method for printing a three-dimensional part from a part material with an additive manufacturing system, the method comprising:
providing a first draft shaft and a second drive shaft engaged with each other, and each drive shaft comprising a plurality of spaced apart filament engagement surfaces, the spaced apart filament engagement surfaces positioned parallel to a drive axis of the respective drive shaft and the plurality of spaced apart filament engagement surface are configured to engage a filament by at least partially compressing at least one location on opposing sides of a filament of the part material;
rotating the first drive shaft around a first axis in a first rotational direction;
rotating the second drive shaft by the engagement between the first and second drive shafts, wherein the second drive shaft rotates around a second axis in a second rotational direction that is counter to the first rotational direction, the second axis being substantial

Assignees

• Stratasys Inc

Inventors

• Koop Shawn M
• Schuller Peter D
• Leavitt Paul J

Classifications

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B29C64/118

  using filamentary material being melted, e.g. fused deposition modelling [FDM] · CPC title

• B29C48/02

  Small extruding apparatus, e.g. handheld, toy or laboratory extruders · CPC title

• B29C48/2563

  Mounting or handling of the hopper or feeder · CPC title

• B29C48/2528

  Drive or actuation means for non-plasticising purposes, e.g. dosing unit · CPC title