Additive manufacturing system having shutter mechanism

1. An additive manufacturing system, comprising:

a head configured to discharge a composite material including a matrix and a continuous reinforcement;

a first shutter mechanism mounted to the head, configured to receive the composite material, and moveable only from an open position at which the composite material is free to pass through the first shutter mechanism to a completely closed position at which the composite material is severed from the head; and

a second shutter mechanism at least partially enclosed inside of the first shutter mechanism, and configured to move only between a fully open position at which the composite material is free to pass through the second shutter mechanism and a partially open position at which the second shutter mechanism grasps the continuous reinforcement after discharge from the head at a location upstream of where severing occurs.

2. The additive manufacturing system of claim 1 , further including a controller having a memory with operational instructions stored therein for causing the second shutter mechanism to grasp and hold the continuous reinforcement during coordinated movement of the head against an anchor point as the matrix cures at a start of a manufacturing process.

3. The additive manufacturing system of claim 1 , further including at least one cure enhancer, wherein the second shutter mechanism is configured to selectively block energy generated by the at least one cure enhancer from reaching the matrix.

4. The additive manufacturing system of claim 3 , wherein the first shutter mechanism includes:

an annular frame connected to the head at a nozzle tip; and

a plurality of leaves configured to pivot open and closed during rotation of the annular frame.

5. The additive manufacturing system of claim 4 , wherein the at least one cure enhancer is located inside of the annular frame.

6. The additive manufacturing system of claim 4 , further including:

an actuator configured to rotate the annular frame; and

a controller configured to selectively energize the actuator.

7. The additive manufacturing system of claim 6 , wherein the controller is configured to:

receive information regarding a structure to be manufactured with the composite material; and

coordinate operation of the first and second shutter mechanisms with movement of the head based on the information.

8. The additive manufacturing system of claim 1 , wherein:

the print head is configured to gravity feed matrix through the nozzle with the continuous reinforcement; and

the second shutter mechanism is further configured to close around the continuous reinforcement without severing and inhibit matrix leakage from the head when the second shutter mechanism is in the closed position.

9. An additive manufacturing system, comprising:

a head having a nozzle configured to discharge a composite material including a matrix and a continuous reinforcement;

at least one light source located adjacent the nozzle and configured to enhance curing of the matrix; and

a shutter mechanism mounted to the head and configured to completely enclose the nozzle and the at least one light source and selectively block energy generated by the at least one light source from reaching the matrix.

10. The additive manufacturing system of claim 9 , wherein the shutter mechanism includes:

an annular frame connected to the head at a nozzle; and

a plurality of leaves configured to pivot open and closed during rotation of the annular frame.

11. The additive manufacturing system of claim 10 , wherein the at least one light source is located inside of the annular frame.

12. The additive manufacturing system of claim 11 , further including:

an actuator configured to rotate the annular frame; and

a controller configured to selectively energize the actuator.

13. The additive manufacturing system of claim 12 , wherein the controller is configured to:

receive information regarding a structure to be manufactured with the composite material; and

coordinate operation of the shutter mechanism with movement of the head based on the information.

14. The additive manufacturing system of claim 9 , wherein the shutter mechanism is configured to move from an open position at which energy from the at least one light source is unrestricted by the shutter mechanism, to a partially open position at which energy from the at least one light source is at least partially restricted.

15. The additive manufacturing system of claim 14 , wherein the shutter mechanism is further configured to move to a closed position at which energy from the at least one light source is completely restricted by the shutter mechanism.

16. An additive manufacturing system, comprising:

a head configured to discharge a composite material including a matrix and a continuous reinforcement;

a support connected to the head and configured to move the head in multiple dimensions during discharging;

a cure enhancer mounted on the head and configured to expose the matrix to cure energy at discharge;

a shutter mechanism mounted to the head and configured to:

selectively grasp and sever the continuous reinforcement; and

selectively block energy generated by the at least one cure enhancer from reaching the matrix; and

a controller having a memory with operational instructions stored therein for:

receiving information regarding a structure to be manufactured with the composite material; and

selectively coordinating operation of the shutter mechanism, the cure enhancer, and the support to grasp the composite material with the shutter mechanism during anchoring, to move the head away from an anchor with the support to initiate discharging, to cure the composite material with the cure enhancer during discharging, and to sever the composite material with the shutter mechanism after discharging, based on the information.