Patents by Inventor David R. Hassel

David R. Hassel 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: 6080939
    Abstract: A mass determination device includes a combination of an elastic element connected with a mass holder. The combination has a normalized temperature coefficient of frequency substantially equal to zero over a temperature range of intended use for the mass determination device, whereby mass determination accuracy of the device during temperature change in the range is enhanced. The elastic element has a first normalized temperature coefficient of frequency over the temperature range. A second normalized temperature coefficient of frequency over the temperature range attributable to the mass holder is determined. The first normalized temperature coefficient and the second normalized temperature coefficient are substantially counterbalanced over the temperature range, for example, through material selection and/or heat treatment of the elastic element and/or material or geometry variation of the mass holder.
    Type: Grant
    Filed: June 12, 1998
    Date of Patent: June 27, 2000
    Assignee: Rupprecht & Pataschnick Company, Inc.
    Inventor: David R. Hassel
  • Patent number: 5488203
    Abstract: In an inertial mass measurement instrument, an active force compensator compensates for inertial forces transmitted by an oscillating elastic element to a primary support of the instrument. The compensator applies equal and opposite compensating forces to the primary support along an effective line of action of the oscillating element. Application of the compensating forces result in a substantially zero net acceleration of the primary support and avoids measurement inaccuracies attributable to changes in properties of secondary support elements.
    Type: Grant
    Filed: November 5, 1993
    Date of Patent: January 30, 1996
    Assignee: Rupprecht & Patashnick Company, Inc.
    Inventors: David R. Hassel, Lauren R. Basch
  • Patent number: 4696181
    Abstract: A suspension system (11) for effectively decoupling an oscillating element microbalance (10) from its environment employs longitudinally extending suspension members axially aligned with an instantaneous center of rotation (S) of the microbalance. In a preferred embodiment, the microbalance includes a tapered elongate elastic element (12) having an elliptical cross section and the suspending members comprise a torsion bar arrangement (20, 22) oriented parallel to the major axis (HD) of the elliptical cross section. The suspension system minimizes vibrational losses from the microbalance while at the same time rendering environmental noise ineffectual.
    Type: Grant
    Filed: April 10, 1986
    Date of Patent: September 29, 1987
    Assignee: Rupprecht & Patashnick Co., Inc.
    Inventors: Georg Rupprecht, David R. Hassel