Acoustic filter for fuel injection systems: US Pat. No. 7,681,553

U.S. Patent No. 7,681,553, issued on March 23, 2010 to Pulsco, Inc. of Irvine, CA, discloses a multi-chambered acoustic filter for use in the fuel rail of a fuel injection system.

The patent explains that pumping fluids under high pressure (such as in a fuel injection system) creates pulsating vibrations and high intensity noise.  The three-chamber dampener of the patent is disclosed to be able to suppress these effects in a given frequency range, thereby avoiding damage to the fluid system, while also being small and economically produced and implemented.

According to its website, Pulsco has been designing and manufacturing surge arresting and pulsation dampening products for over 80 years.  A page on its website states that “patents are fundamental to Pulsco’s proprietary advantage and success” and it places their patents “on display here for your research and enjoyment.”  The company appears understandably proud of its history of technical innovation, however, reviewing the listed patents for pulsation dampeners shows that they date from 1957 to 1991, so many of them have long since expired.  I’m sure they are gratified by the ’553 patent as proof that their innovating ways are continuing.