US 11,872,737 B2
System and apparatus for injection molding
Scot Stodart, Pinckney, MI (US); Andrew H. Joseph, Milford, MI (US); and Glenn W. Nausley, Jr., Howell, MI (US)
Assigned to Promess, Inc., Brighton, MI (US)
Filed by Promess, Inc., Brighton, MI (US)
Filed on Jul. 28, 2021, as Appl. No. 17/387,103.
Claims priority of provisional application 63/058,702, filed on Jul. 30, 2020.
Prior Publication US 2022/0032521 A1, Feb. 3, 2022
Int. Cl. B29C 45/76 (2006.01); G05D 17/00 (2006.01); G05D 7/00 (2006.01)
CPC B29C 45/762 (2013.01) [B29C 45/76 (2013.01); B29C 2945/7602 (2013.01); B29C 2945/762 (2013.01); B29C 2945/76013 (2013.01); B29C 2945/76531 (2013.01); B29C 2945/76658 (2013.01); G05D 7/00 (2013.01); G05D 17/00 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A system for controlling an injection unit that is arranged to transfer a material to a mold cavity, the system comprising:
a first actuator, a second actuator, a torque transducer, and a controller;
wherein the controller is operatively connected to the first actuator and the second actuator, and in communication with the torque transducer;
wherein the first and second actuators are coupled to a ram of the injection unit that is disposed within a barrel of the injection unit;
including the first actuator being a rotary actuator, and the second actuator being a linear actuator;
wherein the torque transducer is arranged to monitor a torque that is being exerted by the first actuator to rotate the ram; and
wherein the controller includes an instruction set, the instruction set being executable to:
execute an injection molding cycle that includes an advance shot stage, a pack stage, a hold stage, and a material fill stage;
deactivate, during the advance shot stage, the pack stage, and the hold stage, the first actuator such that the ram is not rotated within the barrel;
control the first and second actuators to inject the material into the mold cavity during execution of the pack stage; and
during the material fill stage:
control the first actuator to rotate the ram within the barrel to maintain a constant torque based upon feedback from the torque transducer,
control the second actuator to translate the ram within the barrel, and
control the second actuator to retract the ram away from a nozzle of the injection unit that fluidly couples to the mold cavity and to exert a compression force on the ram towards the nozzle of the injection unit.
 
15. The system of claim 1, further comprising the material being introduced in a solid state into the injection unit during the material fill stage.