Patents by Inventor Adolf H. Zielinski

Adolf H. Zielinski 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: 4002892
    Abstract: A portable electronic calculator is provided with a housing carrying a first printed circuit board having the operating parts mounted thereon, i.e., keyboard, electronic arithmetic unit, and multi-digit display unit. The housing is of rectangular outline and of shallow height, and is provided at one end with a receptacle communicating with the first printed circuit board and opening at the end of the housing. An electrical supply unit is mounted on a second printed circuit board which slides into said receptacle, said two printed circuit boards having plug-and-socket connection means therebetween for automatically making and breaking connections when said second printed circuit board and electrical supply unit are inserted into or removed from said receptacle.
    Type: Grant
    Filed: September 16, 1974
    Date of Patent: January 11, 1977
    Inventor: Adolf H. Zielinski