Patents Assigned to Design Research & Development Corp.
  • Patent number: 7367547
    Abstract: Provided is a lifting device comprising: a hook or clip; secured to the hook or clip, one or more first pulleys; a second hook or clip; secured to the second hook or clip, (i) a release mechanism comprising a second pulley and a releasable lock for an engaged flexible serpentine article and, optionally, (ii) one or more third pulleys, the second and third pulleys collectively the beta pulleys; and the flexible serpentine article engaged, at a first end, to one or the other hook or clip, and serially engaged through the first pulleys and beta pulleys, to provide a nominal two-fold or greater mechanical advantage, wherein the other end of the serpentine article is last engaged, among above recited elements, by one of the first pulleys.
    Type: Grant
    Filed: December 18, 2006
    Date of Patent: May 6, 2008
    Assignee: Design Research & Development Corp.
    Inventor: Stephen J. Plzak
  • Patent number: D541190
    Type: Grant
    Filed: January 20, 2005
    Date of Patent: April 24, 2007
    Assignee: Design Research & Development Corp.
    Inventor: Stephen J. Plzak
  • Patent number: D543440
    Type: Grant
    Filed: January 20, 2005
    Date of Patent: May 29, 2007
    Assignee: Design Research & Development Corp.
    Inventor: Stephen J. Plzak