US 11,774,408 B1
System for determining the density of a sheet of material using a magnetic force feedback actuator positioner
David Bolton, Lena, LA (US)
Assigned to Boise Cascade Company, Boise, ID (US)
Filed by Boise Cascade Company, Boise, ID (US)
Filed on Jan. 28, 2022, as Appl. No. 17/587,114.
This patent is subject to a terminal disclaimer.
Int. Cl. G01N 29/22 (2006.01); G01N 29/04 (2006.01); G01N 29/27 (2006.01); G01N 33/46 (2006.01)
CPC G01N 29/225 (2013.01) [G01N 29/04 (2013.01); G01N 29/27 (2013.01); G01N 33/46 (2013.01); G01N 2291/0238 (2013.01); G01N 2291/02818 (2013.01); G01N 2291/102 (2013.01); G01N 2291/2698 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A system comprising:
a density analysis station, the density analysis station including at least one transmitting transducer element, the transmitting transducer element generating and transmitting ultrasonic signals, the density analysis station including at least one receiving transducer element, the receiving transducer element being positioned a defined distance from the transmitting transducer element for receiving the ultrasonic signals from the transmitting transducer element;
a conveyor system for conveying a sheet of material through the density analysis station such that as the conveyor system conveys the sheet of material through the density analysis station the transmitting transducer element is in contact with a first portion of a surface of the sheet of material and the receiving transducer element is in contact with a second portion of the surface of the sheet of material at the defined distance from the first portion of the surface of the sheet of material such that ultrasonic signals generated and transmitted from the transmitting transducer element enter the sheet of material at the first portion of the surface of the sheet of material and pass through the sheet of material to be received by the receiving transducer element at the second portion of the surface of the sheet of material wherein a time interval between when the ultrasonic signals generated and transmitted from the transmitting transducer element enter the sheet of material at the first portion of the surface of the sheet of material and when the ultrasonic signals are received by the receiving transducer element at the second portion of the surface of the sheet of material is recorded and used to calculate the density of the sheet of material; and
at least one magnetic force feedback actuator positioner operationally coupled to the transmitting transducer element to apply a selected force on the transmitting transducer element to maintain a selected pressure of transmitting transducer element on the first portion of the surface of the sheet of material as the sheet of material is conveyed by the conveyor system through the density analysis station.