Patents by Inventor Wolfgang Zirk

Wolfgang Zirk 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: 5667234
    Abstract: A telescoping front fork of a bicycle which has a spring system which acts between an upper cylindrical housing and a lower cylindrical housing and includes at least one suspension spring, a supplemental spring and a spring in the rebound direction, each of which is made of a compressible elastic foamed, or expanded cellular elastomer. The spring constant of the supplemental spring is lower than that of the suspension spring. This arrangement has the advantage that acceleration peaks are reduced during the transition from a situation in which the two cylindrical houses are at rest and one in which the two cylindrical houses slide in relation to one another. The breakaway force is oriented to the weaker supplemental spring in connection with the rebound direction spring and as the support force increases, the suspension spring is compressed on a delayed basis, without any measurable additional breakaway force.
    Type: Grant
    Filed: December 22, 1995
    Date of Patent: September 16, 1997
    Assignee: Fichtel & Sachs AG
    Inventors: Wolfgang Zirk, Gerald Bischof
  • Patent number: 5372224
    Abstract: An oscillation damper is provided with a by-pass that includes a by-pass valve. The by-pass valve is switchable between an open position and a closed position. When the by-pass valve is moved between the open and closed positions, the rate of change of the cross-sectional area of the by-pass valve during the time when the by-pass valve is adjacent the closed position is considerably less than the average rate of change of the cross-sectional area during the entire time that it takes for the by-pass valve to switch between the open and closed positions.
    Type: Grant
    Filed: February 5, 1993
    Date of Patent: December 13, 1994
    Assignee: Fichtel & Sachs AG
    Inventors: Otto Samonil, Wolfgang Zirk
  • Patent number: 4643407
    Abstract: A pneumatic spring for motor vehicles comprises a bellows. Adjacent portions of the bellows overlap each other. These adjacent portions are normally maintained at a distance from each other. Under certain conditions the faces touch each other. In such a case, considerable friction and wear occur between adjacent faces. In order to reduce such wear, a lubricant is provided. In order to prohibit undesirable effects of the presence of the lubricant, particularly with respect to the fixation of the bellows to adjacent parts of the pneumatic spring, the lubricant is enclosed and fixed by at least one membrane. This membrane is destroyed only when the faces are pressed against each other.
    Type: Grant
    Filed: July 6, 1984
    Date of Patent: February 17, 1987
    Assignee: Fichtel & Sachs AG
    Inventor: Wolfgang Zirk