Patents by Inventor Joseph J. Pramberger

Joseph J. Pramberger 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: 3942403
    Abstract: For use in the pivotal connections of wooden members in a piano action, a bushing formed of a suitable plastic or elastomeric material, such as Teflon, is inserted in bushing holes in each arm of a forked action member for supporting a bearing pin secured to the tongue portion of a mating action member. The bushing has an internal bore of substantially uniform diameter throughout its length, and an outer diameter at the end portions of that portion received in the bushing hole smaller than the outer diameter over the portion thereof mediate the end portions, whereby the bushing can rotate along its axis relative to the bushing hole so as to be self-aligning with the bearing pin received in the internal bore. Because of the "barrel shape" of the bushing, variations in the tolerance on the size of the bushing holes are taken up by compression, causing a slight reduction in the diameter of the internal bore and thereby providing a low-friction essentially line contact between the bushing and the bearing pin.
    Type: Grant
    Filed: February 18, 1975
    Date of Patent: March 9, 1976
    Assignee: Steinway & Sons
    Inventor: Joseph J. Pramberger