System and print head for additive manufacturing system

Abstract

A print head is disclosed for use in an additive manufacturing system. The print head may include a receiving end configured to receive a matrix and a continuous reinforcement, and a discharging end configured to discharge the continuous reinforcement at least partially coated in the matrix. The print head may also include a feeder located between the receiving end and the discharging end. The feeder may be configured to push the continuous reinforcement out of the print head at only select times during discharge of the continuous reinforcement and the matrix.

What is claimed is: 
     
         1 . A print head for an additive manufacturing system, comprising:
 a receiving end configured to receive a matrix and a continuous reinforcement;   a discharging end configured to discharge the continuous reinforcement at least partially coated in the matrix; and   a feeder located between the receiving end and the discharging end, the feeder being configured to push the continuous reinforcement out of the print head at only select times during discharge of the continuous reinforcement and the matrix.   
     
     
         2 . The print head of  claim 1 , wherein the feeder is configured to push the continuous reinforcement and the matrix out of the print head only during a startup sequence. 
     
     
         3 . The print head of  claim 1 , wherein the feeder includes at least one eccentric cam roller. 
     
     
         4 . The print head of  claim 3 , wherein the eccentric cam roller includes:
 a first portion having a first radius and being configured to engage the continuous reinforcement; and   a second portion having a second radius less than the first radius.   
     
     
         5 . The print head of  claim 3 , wherein an arc length of the first portion is equal to a length of the continuous reinforcement pushed out of the print head at the select times. 
     
     
         6 . The print head of  claim 5 , further including:
 a compacting module located downstream of the eccentric cam roller; and   a cutting module located between the eccentric cam roller and the compacting module.   
     
     
         7 . The print head of  claim 6 , wherein the arc length is equal to a distance between the cutting module and the compacting module. 
     
     
         8 . The print head of  claim 1 , wherein:
 the eccentric cam roller is a first eccentric cam roller; and   the print head further includes a second eccentric cam roller oriented in opposition to the first eccentric cam roller.   
     
     
         9 . The print head of  claim 8 , further including an actuator configured to drive rotation of at least the first eccentric cam roller. 
     
     
         10 . The print head of  claim 9 , further including a gear train operatively connecting the first eccentric cam roller to the second eccentric cam roller. 
     
     
         11 . The print head of  claim 8 , wherein the first eccentric cam roller is biased toward the second eccentric cam roller. 
     
     
         12 . A system for additively manufacturing a composite structure, comprising:
 at least one of a gantry and a robotic arm that moves in a plurality of directions during manufacturing of the composite structure; and   a head coupled to the at least one of the gantry and the robotic arm and including:
 a receiving end configured to receive a matrix and a continuous reinforcement; 
 a discharging end configured to discharge the continuous reinforcement at least partially coated in the matrix; 
 eccentric cam rollers located between the receiving end and the discharging end, the eccentric cam rollers being configured to push the continuous reinforcement out of the print head only during a startup sequence. 
   
     
     
         13 . The system of  claim 13 , wherein each of the eccentric cam rollers includes:
 a first portion having a first radius and being configured to engage the continuous reinforcement; and   a second portion having a second radius less than the first radius,   wherein an arc length of the first portion is equal to a length of the continuous reinforcement pushed out of the print head at the select times.   
     
     
         14 . The system of  claim 13 , further including:
 a compacting module located downstream of the eccentric cam rollers; and   a cutting module located between the eccentric cam rollers and the compacting module,   wherein the arc length is equal to a distance between the cutting module and the compacting module.   
     
     
         15 . A method of additively manufacturing a composite structure, comprising:
 receiving a matrix and a continuous reinforcement at a first end of a print head;   discharging the continuous reinforcement at least partially coated in the matrix from a second end of the print head; and   pushing the continuous reinforcement out of the print head at only select times during discharge of the continuous reinforcement and the matrix.   
     
     
         16 . The method of  claim 15 , wherein pushing the continuous reinforcement out of the print head at only select times includes pushing the continuous reinforcement and the matrix out of the print head only during a startup sequence. 
     
     
         17 . The method of  claim 16 , further including moving the print head to cause the continuous reinforcement to be pulled out of the print head during discharging at times other than during the startup sequence. 
     
     
         18 . The method of  claim 16 , wherein pushing the continuous reinforcement out of the print head includes pushing out a length of the continuous reinforcement that is equal to a distance between a cutting module and a compacting module of the print head. 
     
     
         19 . The method of  claim 18 , further including exposing the matrix to a cure energy at a location outside of the print head and downstream of the compacting module. 
     
     
         20 . The method of  claim 15 , further including at least partially coating the continuous reinforcement with the matrix inside of the print head.