Patents by Inventor Eric J. Schaffer

Eric J. Schaffer has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5971714
    Abstract: The construction and operation of the control of this invention is designed to minimize pressure changes at pump changeover by sampling pump pressure characteristics for each pump cycle, calculating a compensating motion profile and applying the profile to the motor which drives the pump. This control can be used with any pump which has the following characteristics: positive displacement, repeating cycle characteristics, rotary motor drive and an output pressure cycle curve which never falls to zero.
    Type: Grant
    Filed: May 27, 1997
    Date of Patent: October 26, 1999
    Assignee: Graco Inc
    Inventors: Eric J. Schaffer, Neal A. Werner, James J. Handzel
  • Patent number: 5070995
    Abstract: A feeder conveyor system for transferring randomly spaced products received from an input conveyor to precise locations within flites of a wrapper conveyor. A plurality of conveyors, prior to the wrapper conveyor, are independently driven by product positioning drive subsystems. Each product positioning drive subsystem associates products on its respective conveyor with target flites on the wrapper conveyor, and characterizes positional errors of the products on the conveyor relative to their associated target flites as being in one of a plurality of discrete positional error states representing a range of errors. The velocity of the conveyors controlled by the positioning drive subsystem as a function of the positional error state and the fill state of the associated target flite and flite previous to the target flite. A plurality of spacing conveyors are positioned upstream from the positioning conveyors and are independently driven by products spacing drive subsystems.
    Type: Grant
    Filed: July 19, 1990
    Date of Patent: December 10, 1991
    Assignee: MTS Systems Corporation
    Inventors: Eric J. Schaffer, David J. Hanson