US 12,382,213 B2
Flextensional low frequency sound projector
Yub Je, Daejeon (KR); Soo-Hyun Lim, Daejeon (KR); Yo-Han Cho, Daejeon (KR); Jeong-Min Lee, Daejeon (KR); and Hee-Seon Seo, Daejeon (KR)
Assigned to AGENCY FOR DEFENSE DEVELOPMENT, Daejeon (KR)
Filed by AGENCY FOR DEFENSE DEVELOPMENT, Daejeon (KR)
Filed on Jun. 22, 2023, as Appl. No. 18/212,917.
Claims priority of application No. 10- 2022-0101371 (KR), filed on Aug. 12, 2022.
Prior Publication US 2024/0056726 A1, Feb. 15, 2024
Int. Cl. H04R 17/00 (2006.01); H04R 1/28 (2006.01); H04R 17/10 (2006.01)
CPC H04R 1/2811 (2013.01) [H04R 17/10 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A flextensional low-frequency sound projector comprising:
a piezoelectric actuator including a piezoelectric stack formed by stacking piezoelectric element and generating vibration in a lengthwise direction in response to an electrical signal that is input, and a pair of weighted objects that are brought into surface contact with both ends, respectively, of the piezoelectric stack; and
a stave mounted on the piezoelectric actuator in such a manner as to encompass an outer surface of the piezoelectric actuator and generating the vibration in the lengthwise direction, which is generated by the piezoelectric actuator, as vibration in a lateral direction perpendicular to the outer surface of the piezoelectric actuator,
wherein the stave activates two vibration modes that use different resonant frequencies.