The following PDF below shows patents that are based on our original designs. Cool Sound Industries MAIN PATENT which Herbert F. Wighard is given credit to for all patents below. Which are related to the "Double Acting Pulse Tube Electroacoustic System" the original patent number is US 5813234 and is used for thermoacoustic air conditioning.
** In January 2020 the company has 24 new advanced design patents to the original patents that are patent pending at this time.
All Patents based on Original Patent