Patents Examined by Steven P. Marques
  • Magnetically controllable couplings containing ferrofluids
    Patent number: 4957644
    Abstract: This invention discloses a new ferrofluid and the use of ferrofluids in magnetically controllable couplings such as electromagnetic clutches and brakes. The new ferrofluid is comprised of a stable suspension of magnetizable particles having a size of at least one micron, a fluid carrier and a complexing agent. The complexing agent maintains the magnetizable particles in suspension within the carrier fluid.
    Type: Grant
    Filed: June 27, 1989
    Date of Patent: September 18, 1990
    Inventors: John T. Price, Jurgen M. Kruse