Rapid prototyping and manufacturing system and method

• US 20070077323A1
• Filed: 09/30/2005
• Published: 04/05/2007
• Est. Priority Date: 09/30/2005
• Status: Abandoned Application

• Current Assignee: AT&T Properties, LLC (AT&T, Inc.)
• Original Assignee: 3D Systems, Inc. (3D Systems Corporation)
• Inventors: Wahlstrom, Ben, Reynolds, Gary, Hunter, Don, Stonesmith, Matthew, Stout, Lansing
• Application Number:
  US11/240,822
• Publication Number:
  US 20070077323A1
• Time in Patent Office: Days
• US Class Current: 425/174.400
• CPC Class Codes: B29C 64/135 the energy source being concentrated, e.g. scanning lasers or focused light sources
• CPC Class Codes: B29C 64/182 in parallel batches
• CPC Class Codes: B33Y 30/00 Apparatus for additive manufacturing; Details thereof or accessories therefor

Abstract

A stereolithography apparatus having a resin vat with resupply containers in one-way flow communication and a leveling container in two-way flow communication, an automatic offload cart to remove and replace build support platforms, an elevator assembly for supporting and releasably retaining a build platform removably attached to the stereolithography apparatus frame such that elevator forks supporting the build platform can be released into the vat and removed from the stereolithography apparatus with the vat, and a recoater assembly and recoater blade for mapping the resin surface in the vat and applying a fresh coating of resin to a cross-section being built in the vat.

Claims

1. Stereolithography apparatus comprising:

a) a housing having at least one interior frame defining a stereolithography chamber;

b) a vat for liquid resin adapted to be received within said chamber and releasably fixed axially in alignment with said chamber;

c) a laser operatively connected to said housing for supplying energy within said chamber for solidifying the resin layer-by-layer in response to a predetermined object representation;

d) first and second build platforms for supporting layers of solidified resin, said platforms being adapted to fit within said vat beneath the surface of the resin;

e) an elevator translatably fixed to said frame and extending horizontally into said chamber to releasably secure said build platforms thereon and to raise and lower said platforms within said vat to expose the resin to the laser one layer thickness at a time;

f) a cart for automated removal of said first platform and replacement with said second platform;

g) a recoater carrier translatably secured to said frame for movement vertically and horizontally across the surface of the resin;

h) a recoater releasably secured to said carrier;

i) a first sensor translatably secured to said carrier for transport along the length of said recoater blade to determine the distance of the bottom of said recoater blade from the surface of the building medium at a plurality of points in the direction of travel of said blade;

j) a second sensor fixed to said frame for determining the level of the surface of the building medium within said container; and

k) a controller operatively connected to said laser, elevator, cart, recoater carrier, and first and second sensors, thereby to control operation of said stereolithography apparatus.

2. Stereolithography apparatus according to claim 1 wherein said housing further comprises at least two separate stereolithography chamber associated therewith, and wherein said laser is a single laser and said apparatus further comprises galvanometer driven mirrors operatively connected to said laser for deflecting the laser beam seriatim to each chamber for each layer.

3. An elevator for elevating a build platform in a stereolithography chamber, whereby a build platform is lowered into and raised out of a vat of liquid resin, said elevator comprising first and second elevator subassemblies, said first subassembly operatively associated with a vat for installation into a chamber with the vat, and said second subassembly fixed within a stereolithography chamber for releasably engaging said first subassembly, and wherein said first subassembly comprises:

a) an elevator attachment bracket;

b) an elevator frame to which said attachment bracket is fixed, said frame having

i) a vertically extending portion for being lowered into and raised out of the resin vat,

ii) a generally horizontally extending portion for supporting a build platform,

iii) releasably engaging latch members located on said horizontal portion for releasably engaging the build platform, and

iv) a latch linkage operable to secure and release the platform; and

wherein said second subassembly comprises;

c) an elevator drive plate for releasably engaging said elevator attachment bracket of said first subassembly, said elevator drive plate operatively connected to a drive screw along which said elevator drive plate is translated for vertical movement of said first subassembly, and

d) a frame element having a ramped surface for engaging and actuating said latch linkage to release a build platform from secure engagement.

4. The stereolithography chamber elevator according to claim 3 wherein said elevator drive plate further comprises a support rod extending parallel to said first subassembly attachment bracket for supporting said first elevator subassembly, and a pin extending outwardly for engaging said first subassembly attachment bracket and locating said first elevator subassembly in a vertical alignment plane, and wherein said first elevator subassembly comprises hooks for releasable gravity engagement of said support rod and a receiver for releasable engagement of said pin.

5. An elevator for elevating a build platform in a stereolithography chamber, whereby a build platform is lowered into and raised out of a vat of liquid resin, said elevator comprising first and second elevator subassemblies, said first subassembly operatively associated with a vat for installation into a chamber with the vat, and said second subassembly fixed within a stereolithography chamber for receiving said first subassembly, and wherein said first subassembly comprises an elevator attachment bracket having hooks and a receiver thereon for releasably engaging said second elevator subassembly, said first subassembly further comprising an elevator frame to which said attachment bracket is fixed, said frame having a vertically extending portion for being lowered into and raised out of the resin vat, a generally horizontally extending portion for supporting a build platform, releasably engaging latch members located on said horizontal portion distally of said vertically extending portion for releasably engaging the build platform, and a spring-biased latch linkage operable to secure and release the platform, and wherein said second subassembly comprises an elevator drive plate having a horizontally extending support rod parallel to said attachment bracket for receiving said attachment bracket hooks, a pin extending perpendicularly outwardly therefrom for engaging said receiver on said attachment bracket, thereby to locate said first elevator subassembly in a vertical plane, and wherein said drive plate is operatively connected to a drive screw along which said elevator drive plate is translated for vertical movement of said first subassembly and build platform, said second elevator subassembly further comprising a frame element having a ramped surface for engaging and actuating said latch linkage to release said build platform from secure engagement.

6. Stereolithography apparatus comprising:

a) a housing having at least one interior frame defining a stereolithography chamber;

b) a vat for liquid resin adapted to be received within said chamber and releasably fixed axially in alignment with said chamber, said vat comprising a receptacle for the resin and at least one supplemental resin container containing resin and in flow communication with said receptacle for adding resin to or removing resin from said vat, thereby to maintain a predetermined resin level in said receptacle;

c) a laser operatively connected to said housing for supplying energy within said chamber for solidifying the resin layer-by-layer in response to a predetermined object representation;

d) first and second build platforms for supporting layers of solidified resin, said platforms being adapted to fit within said vat beneath the surface of the resin;

e) an elevator comprising first and second elevator subassemblies, said first subassembly operatively associated with said vat for installation into said chamber with said vat, and said second subassembly fixed within said stereolithography chamber for receiving said first subassembly, and wherein said first subassembly comprises an elevator attachment bracket having hooks and a receiver thereon for releasably engaging said second elevator subassembly, said first subassembly further comprising an elevator frame to which said attachment bracket is fixed, said frame having a vertically extending portion for being lowered into and raised out of the resin vat, a generally horizontally extending portion for supporting a build platform, releasably engaging latch members located on said horizontal portion distally of said vertically extending portion for releasably engaging said build platforms, and a spring-biased latch linkage operable to secure and release said platforms, and wherein said second subassembly comprises an elevator drive plate having a horizontally extending support rod parallel to said attachment bracket for receiving said attachment bracket hooks, a pin extending perpendicularly outwardly therefrom for engaging said receiver on said attachment bracket, thereby to locate said first elevator subassembly in a vertical plane, and wherein said drive plate is operatively connected to a drive screw along which said elevator drive plate is translated for vertical movement of said first subassembly and build platform, said second elevator subassembly further comprising a frame element having a ramped surface for engaging and actuating said latch linkage to release said build platform from secure engagement;

f) a cart for automated removal of said first platform and replacement with said second platform, said cart comprising a base, a vertically extending support member, and telescoping arms supporting a drip tray and extending from said support member into said stereolithography chamber for receiving said first build platform on said drip tray, and telescoping arms supporting said second build platform thereon for extending into said stereolithography chamber for introducing said second build platform onto said elevator;

g) a recoater carrier translatably secured to said frame for movement vertically and horizontally across the surface of the resin;

h) a recoater releasably secured to said carrier and comprising a longitudinally extending blade body having front and back surfaces and top and bottom surfaces, a foot for sensing blade gap at each end of said blade body extending laterally outward from said front surface thereof and having a flat bottom surface level with the bottom surface of said blade body and a top surface tapering distally from said blade to a thinned-down blade gap sensing portion of said top surface of said foot, whereby a sensor in sensing communication with said sensing portion of said foot can sense the distance of the top of said foot from a liquid resin surface;

i) a first sensor translatably secured to said carrier for transport along the length of said recoater blade to determine the distance of said blade gap sensing feet from the surface of the resin at a plurality of points in the direction of travel of said recoater;

j) a second sensor fixed to said frame for determining the level of the surface of the building medium within said container; and

k) a controller operatively connected to said laser, elevator, cart, recoater carrier, and first and second sensors, thereby to control operation of said stereolithography apparatus.

7. Apparatus according to claim 6 wherein said first and second sensors are laser diode sensors.

8. An elevator for elevating a build platform in a stereolithography chamber, whereby a build platform is lowered into and raised out of a vat of liquid resin, said elevator comprising first and second elevator subassemblies, said first subassembly operatively associated with a vat for installation into a chamber with the vat, and said second subassembly fixed within a stereolithography chamber for releasably engaging said first subassembly, and wherein said second subassembly includes locating means for aligning the vat within the stereolithography chamber.

9. The stereolithography chamber elevator according to claim 8 further comprising the locating means being a locating pin cooperative with a receptacle on the vat to center the vat in the stereolithography chamber.

10. The stereolithography chamber elevator according to claim 9 further comprising the vat containing liquid resin with a working surface and the locating pin locates the vat in a horizontal plane parallel with the working surface of the resin.