Compact build tank for an additive manufacturing apparatus

Abstract

Described is an additive manufacturing apparatus that includes a telescopic build tank operatively connected at opposing ends to a powder table and a build table. The telescopic build tank includes at least two segments telescopically coupled to one another, each of the at least two segments comprising a set of engagement grooves located on an interior surface of the at least two segments and a set of engagement pins located on an exterior surface of the at least two segments. The set of engagement pins is configured to engage with and travel along a corresponding set of engagement grooves of another of the at least two segments, and each engagement groove comprises a first axially extending channel positioned along a single axis and having at least one closed end, the at least one closed end being configured to impede separation of the at least two segments relative to one another.

1 . An additive manufacturing apparatus for forming a three-dimensional article layer by layer from a powder, the additive manufacturing apparatus comprising:
 a powder table;   a build table; and   a telescopic build tank operatively connected at one end to the powder table and at an opposing other end a portion of the build table, the telescopic build tank comprising at least two segments telescopically coupled relative to one another, each of the at least two segments comprising a set of engagement grooves located on an interior surface of the at least two segments and a set of engagement pins located on an exterior surface of the at least two segments,   wherein:
 the set of engagement pins of one of the at least two segments is configured to engage with and travel along a corresponding set of engagement grooves of another of the at least two segments, and 
 each engagement groove of the set of engagement grooves comprises a first axially extending channel positioned along a single axis and having at least one closed end, the at least one closed end being configured to impede further translation of a corresponding engagement pin and separation of the at least two segments relative to one another. 
   
     
     
         2 . The additive manufacturing apparatus according to  claim 1 , wherein the set of engagement pins are each circumferentially offset relative to the set of engagement grooves on each of the at least two segments. 
     
     
         3 . The additive manufacturing apparatus according to  claim 1 , wherein the set of engagement pins on each of the at least two segments includes three engagement pins and the set of engagement grooves on each of the at least two segments includes three engagement grooves. 
     
     
         4 . The additive manufacturing apparatus according to  claim 3 , wherein the three engagement pins and the set of engagement grooves are equally spaced apart relative to one another around a circumference of each of the at least two segments. 
     
     
         5 . The additive manufacturing apparatus according to  claim 3 , wherein the three engagement pins are each offset circumferentially a distance from a corresponding one of the three engagement grooves, so as to define three distinct groove and pin pairings on each of the at least two segments. 
     
     
         6 . The additive manufacturing apparatus according to  claim 1 , wherein the set of engagement pins are positioned adjacent a lower edge of each of the at least two segments. 
     
     
         7 . The additive manufacturing apparatus according to  claim 1 , wherein:
 the first axially extending channel of each engagement groove has an open end adjacent to and intersecting a lower edge of each of the at least two segments, and   the first axially extending channel of each engagement groove has a closed end opposite the open end, adjacent to but non-intersecting an upper edge of each of the at least two segments.   
     
     
         8 . The additive manufacturing apparatus according to  claim 7 , wherein:
 each engagement groove further comprises a second channel;   the second channel comprises a first portion parallel with and spaced apart a spacing distance from the first axially extending channel; and   the second channel comprises a second portion perpendicular to both the first portion and the first axially extending channel, the second portion interconnecting the first portion and the first axially extending channel at a point intermediate the open end and the closed end of the first axially extending channel.   
     
     
         9 . The additive manufacturing apparatus according to  claim 8 , wherein the engagement groove is substantially Y-shaped and the second channel is substantially L-shaped. 
     
     
         10 . The additive manufacturing apparatus according to  claim 8 , wherein the first portion of the second channel has an open end adjacent to and intersecting with the upper edge of the segment. 
     
     
         11 . The additive manufacturing apparatus according to  claim 1 , wherein:
 the first axially extending channel of each engagement groove has a closed end adjacent to but non-intersecting an upper edge of each of the at least two segments; and   each engagement groove further comprises a second channel that intersects with the first axially extending channel intermediate the closed end and a lower edge of each of the at least two segments.   
     
     
         12 . The additive manufacturing apparatus according to  claim 11 , wherein:
 the second channel has an open end opposite an end of the second channel that intersects with the first axially extending channel;   the first axially extending channel has an open end opposite the closed end of the first axially extending channel; and   the open end of the first axially extending channel and the open end of the second channel are circumferentially offset relative to one another on the segment, such that an engagement pin travelling in the first axially extending channel can only exit the open end of the second channel following a combination of axial translation and axial rotation.   
     
     
         13 . The additive manufacturing apparatus according to  claim 1 , wherein:
 the telescopic build tank is disposed in a build chamber of the additive manufacturing apparatus; and   the additive manufacturing apparatus further comprises at least one bellows assembly having a first portion operatively connected to a portion of the build table and a second portion operatively connected to an environment outside the build chamber.   
     
     
         14 . The additive manufacturing apparatus according to  claim 13 , wherein:
 the portion of the build table to which the at least one bellows assembly is attached is an extension of the build table; and   a longitudinal axis of the at least one bellows assembly is offset from a longitudinal axis of the telescopic build tank.   
     
     
         15 . The additive manufacturing apparatus according to  claim 1 , wherein said at least two segments comprises a plurality of segments, and the set of engagement grooves define at least a minimum overlap between said each adjacent segment. 
     
     
         16 . The additive manufacturing apparatus according to  claim 15 , wherein the set of engagement grooves on each of the plurality of segments comprises a first axially-only extending channel having a closed end substantially adjacent to but non-intersecting with a top edge of the plurality of segments, the closed end limiting travel of the set of engagement pins to provide the minimum overlap. 
     
     
         17 . The additive manufacturing apparatus according to  claim 15 , wherein said minimum overlap is no more than 25 mm in fully extracted position. 
     
     
         18 . The additive manufacturing apparatus of  claim 1 , further comprising energy beam source arranged for creating an energy beam. 
     
     
         19 . A telescopic build tank for an additive manufacturing apparatus for forming a three-dimensional article layer by layer from a powder, the telescopic build tank comprising:
 at least two segments telescopically coupled relative to one another, each of the at least two segments comprising a set of engagement grooves located on an interior surface of the at least two segments and a set of engagement pins located on an exterior surface of the at least two segments, wherein:
 the set of engagement pins of one of the at least two segments is configured to engage with and travel along a corresponding set of engagement grooves of another of the at least two segments, and 
 each engagement groove of the set of engagement grooves comprises a first axially extending channel positioned along a single axis and having at least one closed end, the at least one closed end being configured to impede further translation of a corresponding engagement pin and separation of the at least two segments relative to one another. 
   
     
     
         20 . The telescopic build tank of  claim 19 , wherein one end of the telescopic build tank is coupled to a powder table of the additive manufacturing apparatus and an opposing other end of the telescopic build tank is coupled to a portion of a build table of the additive manufacturing apparatus.